uu.seUppsala University Publications
1 - 60 of 60
rss atomLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
  • Spagopoulou, Foteini
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Condition-dependence in life history evolution2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Ageing is the progressive physiological deterioration that appears with increasing age and eventually leads to a decline in survival and reproduction. This physiological process is omnipresent across the tree of life, but the expected trajectory can widely vary between and within species. Classic theories predict that the evolution of senescence is strongly influenced by the level of extrinsic mortality. Furthermore, variation in early-life developmental environments can shape individual condition and thus lead to alternative life-history strategies. The interplay between early-life environment and individual condition might therefore predict the trajectory of ageing and is of importance when studying life history evolution. In this thesis, I focus on condition dependent life-history strategies and how this can translate in differential ageing patterns. Moreover, I specifically investigate the influence of early-life environment on key life history traits (i.e. survival and reproduction) and how this might eventually carry-over to future generations via nongenetic inheritance. First, I used an experimental approach involving lab populations of the nematode Caenorhabditis remanei to show that males, but not females, pay the cost for the evolution of increased lifespan (Paper I). Second, I used an empirical dataset based on 25 years of observations, to investigate the long-term effects of early-life environment on reproduction and survival (Paper II). Reproductive success of low-condition females in natural populations of collared flycatchers (Ficedula albicollis) peaks later in life, when high-condition females are already in steep reproductive decline and suffer from high mortality rates. Third, I used the neriid fly Telostylinus angusticollis in an experimental environment, to test whether condition-dependent investment in secondary sexual traits affects the life-history strategies of males (Paper III). High-condition males developed and aged faster than low-condition males, but interaction with rival males did not affect male reproductive ageing. Finally, continuing the T. angusticollis experiment, I also found that parental diet interacts with parental sex and offspring sex, ultimately affecting offspring life-histories. Parental effects can thus play an important role in shaping between-individual variation in reproductive and actuarial senescence (Paper IV). Overall, in this thesis I have explored the interaction between environment, condition and ageing in both experimental and natural settings.

    List of papers
    1. Evolution of male age-specific reproduction under differential risks and causes of death: males pay the cost of high female fitness
    Open this publication in new window or tab >>Evolution of male age-specific reproduction under differential risks and causes of death: males pay the cost of high female fitness
    2016 (English)In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 29, no 4, p. 848-856Article in journal (Refereed) Published
    Abstract [en]

    Classic theories of ageing evolution predict that increased extrinsic mortality due to an environmental hazard selects for increased early reproduction, rapid ageing and short intrinsic lifespan. Conversely, emerging theory maintains that when ageing increases susceptibility to an environmental hazard, increased mortality due to this hazard can select against ageing in physiological condition and prolong intrinsic lifespan. However, evolution of slow ageing under high-condition-dependent mortality is expected to result from reallocation of resources to different traits and such reallocation may be hampered by sex-specific trade-offs. Because same life-history trait values often have different fitness consequences in males and females, sexually antagonistic selection can preserve genetic variance for lifespan and ageing. We previously showed that increased condition-dependent mortality caused by heat shock leads to evolution of long-life, decelerated late-life mortality in both sexes and increased female fecundity in the nematode, Caenorhabditis remanei. Here, we used these cryopreserved lines to show that males evolving under heat shock suffered from reduced early-life and net reproduction, while mortality rate had no effect. Our results suggest that heat-shock resistance and associated long-life trade-off with male, but not female, reproduction and therefore sexually antagonistic selection contributes to maintenance of genetic variation for lifespan and fitness in this population.

    Keyword
    heat shock, intralocus sexual conflict, life-history trade-off, senescence, sex-specific pleiotropy
    National Category
    Evolutionary Biology
    Identifiers
    urn:nbn:se:uu:diva-295550 (URN)10.1111/jeb.12833 (DOI)000373929000015 ()26801472 (PubMedID)
    Available from: 2016-06-08 Created: 2016-06-08 Last updated: 2018-04-09Bibliographically approved
    2. “Silver-spoon” natal conditions increase early-life fitness but accelerate reproductive ageing in a wild bird
    Open this publication in new window or tab >>“Silver-spoon” natal conditions increase early-life fitness but accelerate reproductive ageing in a wild bird
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Early-life conditions can have long-lasting effects and organisms that experience a poor start in life are often expected to age at a faster rate. Alternatively, individuals raised in high-quality environments can overinvest in early-reproduction resulting in rapid ageing. Here we use long-term experimental manipulation of early-life conditions in a natural population of collared flycatchers (Ficedula albicollis), to show that females raised in a low-competition environment have higher early-life reproduction but lower late-life reproduction than females raised in high-competition environment. We experimentally created either artificially increased (high-competition) or reduced (low-competition) broods. Reproductive success of high-competition females peaked in late-life, when low-competition females were already in steep reproductive decline and suffered from higher mortality rate. Our results demonstrate that “silver spoon” effects can increase female early-life performance at the cost of faster reproductive ageing and increased late-life mortality. These findings support the evolutionary theory of ageing and show that early-life environmental conditions shape reproductive and demographic ageing in nature.

    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Animal Ecology
    Identifiers
    urn:nbn:se:uu:diva-347831 (URN)
    Available from: 2018-04-08 Created: 2018-04-08 Last updated: 2018-04-09
    3. Ontogenetic timing as a condition-dependent life history trait: High-condition males develop quickly, peak early, and age fast
    Open this publication in new window or tab >>Ontogenetic timing as a condition-dependent life history trait: High-condition males develop quickly, peak early, and age fast
    Show others...
    2017 (English)In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 71, no 3, p. 671-685Article in journal (Refereed) Published
    Abstract [en]

    Within-population variation in ageing remains poorly understood. In males, condition-dependent investment in secondary sexual traits may incur costs that limit ability to invest in somatic maintenance. Moreover, males often express morphological and behavioral secondary sexual traits simultaneously, but the relative effects on ageing of investment in these traits remain unclear. We investigated the condition dependence of male life history in the neriid fly Telostylinus angusticollis. Using a fully factorial design, we manipulated male early-life condition by varying nutrient content of the larval diet and, subsequently, manipulated opportunity for adult males to interact with rival males. We found that high-condition males developed more quickly and reached their reproductive peak earlier in life, but also experienced faster reproductive ageing and died sooner than low-condition males. By contrast, interactions with rival males reduced male lifespan but did not affect male reproductive ageing. High-condition in early life is therefore associated with rapid ageing in T. angusticollis males, even in the absence of damaging male-male interactions. Our results show that abundant resources during the juvenile phase are used to expedite growth and development and enhance early-life reproductive performance at the expense of late-life performance and survival, demonstrating a clear link between male condition and ageing.

    Place, publisher, year, edition, pages
    WILEY, 2017
    Keyword
    Condition dependence, costs of secondary sexual traits, life history, reproductive ageing, senescence, sexual selection
    National Category
    Evolutionary Biology
    Identifiers
    urn:nbn:se:uu:diva-320842 (URN)10.1111/evo.13172 (DOI)000396039000012 ()28067402 (PubMedID)
    Funder
    Australian Research CouncilEU, European Research CouncilSwedish Research Council
    Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2018-04-09Bibliographically approved
    4. Early-life parental diet effects on ageing depend on the sex of parents and their offspring
    Open this publication in new window or tab >>Early-life parental diet effects on ageing depend on the sex of parents and their offspring
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Animal Ecology
    Identifiers
    urn:nbn:se:uu:diva-347832 (URN)
    Available from: 2018-04-09 Created: 2018-04-09 Last updated: 2018-04-09
  • Public defence: 2018-05-25 10:15 Nya Brusewitzsalen, Uppsala
    Hellborg, Sabina
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Law, Department of Law.
    Diskrimineringsansvar: En civilrättslig undersökning av förutsättningarna för ansvar och ersättning vid diskriminering2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This doctoral thesis examines liability for discrimination under Swedish private law. According to chapter 5, section 1 of the Swedish Discrimination Act (diskrimineringslagen) compensation shall be paid by natural or legal persons who violate the prohibitions of discrimination that are established in the act. The purpose of the compensation is not only to compensate the person discriminated against for the violation of the right to equal treatment, but also to prevent further discrimination.

    The thesis examines two main questions: (i) what preconditions need to be fulfilled in order to establish liability for discrimination? and (ii) what circumstances affect the amount of compensation? An overarching aim of the thesis is to create an understanding of the characteristic problems and questions that occur when handling discrimination-related questions in a private law context. Consideration is taken to the EU law background and the aim, articulated in EU directives, to achieve effective, proportionate and dissuasive remedies for breaches of the principle of equal treatment.

    The research focuses on the prohibitions applicable in the working life and regarding goods, services and housing. It includes detailed analyses of the prohibitions against direct discrimination, indirect discrimination, inadequate accessibility, harassment and sexual harassment. The analyses deal with questions concerning the subjective motives of the discriminating party, problematic aspects considering the burden of proof as well as the exceptions from the prohibitions. Circumstances affecting the amount of compensation are analysed considering the character of the discriminating behaviour and its effects. Certain aspects attributable to the preventive function of the damages are examined, as well as how they have been decisive in the court judgements.

  • Public defence: 2018-05-25 10:15 ITC 2446, Uppsala
    Sticko, Simon
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    High Order Cut Finite Element Methods for Wave Equations2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis considers wave propagation problems solved using finite element methods where a boundary or interface of the domain is not aligned with the computational mesh. Such methods are usually referred to as cut or immersed methods. The motivation for using immersed methods for wave propagation comes largely from scattering problems when the geometry of the domain is not known a priori. For wave propagation problems, the amount of computational work per dispersion error is generally lower when using a high order method. For this reason, this thesis aims at studying high order immersed methods.

    Nitsche's method is a common way to assign boundary or interface conditions in immersed finite element methods. Here, penalty terms that are consistent with the boundary/interface conditions are added to the weak form. This requires that special quadrature rules are constructed on the intersected elements, which take the location of the immersed boundary/interface into account. A common problem for all immersed methods is small cuts occurring between the elements in the mesh and the computational domain. A suggested way to remedy this is to add terms penalizing jumps in normal derivatives over the faces of the intersected elements.

    Paper I and Paper II consider the acoustic wave equation, using first order elements in Paper I, and using higher order elements in Paper II. High order elements are then used for the elastic wave equation in Paper III. Papers I to III all use continuous Galerkin, Nitsche's method, and jump-stabilization. Paper IV compares the errors of this type of cut finite element method with two other numerical methods. One result from Paper II is that the added jump-stabilization results in a mass matrix with a high condition number. This motivates the investigation of alternatives. Paper V considers a hybridizable discontinuous Galerkin method. This paper investigates to what extent local time stepping in combination with cell-merging can be used to overcome the problem of small cuts.

    List of papers
    1. A stabilized Nitsche cut element method for the wave equation
    Open this publication in new window or tab >>A stabilized Nitsche cut element method for the wave equation
    2016 (English)In: Computer Methods in Applied Mechanics and Engineering, ISSN 0045-7825, E-ISSN 1879-2138, Vol. 309, p. 364-387Article in journal (Refereed) Published
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-298112 (URN)10.1016/j.cma.2016.06.001 (DOI)000383828400015 ()
    Projects
    eSSENCE
    Available from: 2016-06-21 Created: 2016-06-29 Last updated: 2018-04-10Bibliographically approved
    2. Higher order cut finite elements for the wave equation
    Open this publication in new window or tab >>Higher order cut finite elements for the wave equation
    2016 (English)In: Computing Research Repository, no 1608.03107Article in journal (Other academic) Submitted
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-301820 (URN)
    Projects
    eSSENCE
    Available from: 2016-08-10 Created: 2016-08-25 Last updated: 2018-04-10Bibliographically approved
    3. High order cut finite elements for the elastic wave equation
    Open this publication in new window or tab >>High order cut finite elements for the elastic wave equation
    2018 (English)In: Computing Research Repository, no 1804.00332Article in journal (Other academic) Submitted
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-347421 (URN)
    Projects
    eSSENCE
    Available from: 2018-04-01 Created: 2018-04-01 Last updated: 2018-04-10Bibliographically approved
    4. High-order numerical methods for 2D parabolic problems in single and composite domains
    Open this publication in new window or tab >>High-order numerical methods for 2D parabolic problems in single and composite domains
    Show others...
    2018 (English)In: Journal of Scientific Computing, ISSN 0885-7474, E-ISSN 1573-7691Article in journal (Refereed) Epub ahead of print
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-339130 (URN)10.1007/s10915-017-0637-y (DOI)
    Available from: 2018-01-10 Created: 2018-01-16 Last updated: 2018-04-10Bibliographically approved
    5. High order cut discontinuous Galerkin methods with local time stepping for acoustics
    Open this publication in new window or tab >>High order cut discontinuous Galerkin methods with local time stepping for acoustics
    2018 (English)In: Article in journal (Other academic) Submitted
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-347423 (URN)
    Projects
    eSSENCE
    Available from: 2018-04-01 Created: 2018-04-01 Last updated: 2018-04-10Bibliographically approved
  • Public defence: 2018-05-25 10:15 Sal X, Uppsala
    Drakman, Annelie
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Department of History of Science and Ideas.
    När kroppen slöt sig och blev fast: Varför åderlåtning, miasmateori och klimatmedicin övergavs vid 1800-talets mitt2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    For 2500 years, bloodletting, purging, climate medicine and the miasmatic theory were the fundaments of Western medicine. But then, over the course of just a few decades during the middle of the nineteenth century, they disappeared. Silently, without having been disproven or even disputed, before the breakthrough of bacteriology.

    In this study I investigate the reasons behind this abandonment, which has been described as ”a precondition for scientific medicine”, using 8800 yearly reports written by 2500 Swedish provincial doctors between 1820 and 1900. These were state funded doctors, based in mostly rural districts throughout all of Sweden. Their tasks included overseeing midwives and vaccinators, inspecting pharmacies, managing epidemics, establishing their own practice and reporting back to the National Board of Health. Their digitised reports constitute a unique source of materials giving direct insight into their conceptions of health and disease.

    The reports provide evidence that the collapse of ”traditional” medicine should be understood as the result of a decisive break between two different ways of understanding the interaction between body and environment: ”flow-managing” and ”boundary-protecting” medicine. Until the 1860s, the provincial doctors aimed to manage the volume and pace of flows of body fluids. However, between 1865 and 1900, they instead focused on upholding the boundaries between the body and its environment. Doctors stopped understanding bodies as open, fluid, and constantly interacting with the world around them, and rather began perceiving them as closed off, autonomous from and independent of their environment. This shift in what it meant to practice medicine explains the covert but momentous demise of ”traditional” theories and therapies.

  • Public defence: 2018-05-25 13:00 A1:107a, BMC, Uppsala
    Bergman, Hilde-Marléne
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Applications of nanospray desorption electrospray ionization mass spectrometry: In situ lipid and metabolite analysis from cells to tissue2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Ambient mass spectrometry (MS) has proved to be an important addition to the bioanalytical toolbox. These methods perform analyte sampling and ionization under atmospheric pressure, and require very little sample preparation other than the sampling process in front of the machine. Nanospray desorption electrospray ionization (nano-DESI) is an ambient MS technique developed in 2010 that utilizes localized liquid extraction for surface sampling. The aim of this thesis was to explore the possibilities of this technique, and identify areas in which nano-DESI MS could further contribute to the community of MS-based surface analysis.

    One such area was found to be mass spectrometry imaging (MSI) of small-molecule neurotransmitters. By the use of deuterated standards of acetylcholine, γ-aminobutyric acid and glutamate, the respective endogenous compounds were successfully imaged in coronal sections of rat brain. The use of internal standards was shown to be essential to compensatee for matrix effects in different regions of the brain. In a second imaging study, nano-DESI MSI was used to compare the chemical profiles of diabetic rat kidney tissue and control. Analysis was performed on kidney two weeks after diabetic onset, before any pathohistological changes relating to diabetic nephropathy can be seen in a microscope. In our study, it was shown that a large number of chemical species related to energy metabolism were detected with altered signal intensity in diabetic kidney tissue.

    To push the limits of nano-DESI analysis, its use for single-cell analysis was evaluated. By placing buccal epithelial cells in contact with the nano-DESI probe, it was possible to identify 46 endogenous compounds and detect differences between cells from three human donors. In addition, it was shown that molecules from single cells on a surface could be detected by scanning the surface with the nano-DESI probe, which opens up for development of an automated analysis with higher throughput.

    The last study in this thesis was concerned with method development rather than application, as it presented a setup for pneumatically assisted nano-DESI. Evaluation showed that the setup provided improved sensitivity in the analysis of small metabolites, and provided the possibility of using pure water as nano-DESI solvent.

    List of papers
    1. Quantitative mass spectrometry imaging of small-molecule neurotransmitters in rat brain tissue sections using nanospray desorption electrospray ionization
    Open this publication in new window or tab >>Quantitative mass spectrometry imaging of small-molecule neurotransmitters in rat brain tissue sections using nanospray desorption electrospray ionization
    2016 (English)In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 141, no 12, p. 3686-3695Article in journal (Refereed) Published
    Abstract [en]

    Small molecule neurotransmitters are essential for the function of the nervous system, and neurotransmitter imbalances are often connected to neurological disorders. The ability to quantify such imbalances is important to provide insights into the biochemical mechanisms underlying the disorder. This proof-of-principle study presents online quantification of small molecule neurotransmitters, specifically acetylcholine, γ-aminobutyric acid (GABA) and glutamate, in rat brain tissue sections using nanospray desorption electrospray ionization (nano-DESI) mass spectrometry imaging. By incorporating deuterated internal standards in the nano-DESI solvent we show identification, accurate mapping, and quantification of these small neurotransmitters in rat brain tissue without introducing any additional sample preparation steps. We find that GABA is about twice as abundant in the medial septum-diagonal band complex (MSDB) as in the cortex, while glutamate is about twice as abundant in the cortex as compared to the MSDB. The study shows that nano-DESI is well suited for imaging of small molecule neurotransmitters in health and disease.

    National Category
    Analytical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-281314 (URN)10.1039/c5an02620b (DOI)000378942900021 ()26859000 (PubMedID)
    Funder
    Swedish Research Council, VR 621-2013-4231Swedish Foundation for Strategic Research , SSF ICA-6
    Available from: 2016-03-22 Created: 2016-03-22 Last updated: 2018-04-05Bibliographically approved
    2. Metabolite aberrations at early onset of diabetes detected in rat kidney using mass spectrometry imaging
    Open this publication in new window or tab >>Metabolite aberrations at early onset of diabetes detected in rat kidney using mass spectrometry imaging
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Chemical Sciences
    Research subject
    Chemistry with specialization in Analytical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-347672 (URN)
    Available from: 2018-04-05 Created: 2018-04-05 Last updated: 2018-04-05
    3. Profiling and quantifying endogenous molecules in single cells using nano-DESI MS
    Open this publication in new window or tab >>Profiling and quantifying endogenous molecules in single cells using nano-DESI MS
    2017 (English)In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 142, no 19, p. 3639-3647Article in journal (Refereed) Published
    Abstract [en]

    Molecular profiling of single cells has the potential to significantly advance our understanding of cell function and cellular processes of importance to health and disease. In particular, small molecules with rapid turn-over rates can reveal activated metabolic pathways resulting from an altered chemical environment or cellular events such as differentiation. Consequently, techniques for quantitative metabolite detection acquired in a higher throughput manner are needed to characterize the biological variability between seemingly homogenous cells. Here, we show that nanospray desorption electrospray ionization (nano-DESI) mass spectrometry ( MS) enables sensitive molecular profiling and quantification of endogenous species in single cells in a higher throughput manner. Specifically, we show a large number of detected amino acids and phospholipids, including plasmalogens, readily detected from single cheek cells. Further, by incorporating a phosphatidylcholine ( PC) internal standard into the nano-DESI solvent, we determined the total amount of PC in one cell to be 1.2 pmoles. Finally, we describe a higher throughput approach where molecules in single cells are automatically profiled. These developments in single cell analysis provide a basis for future studies to understand cellular processes related to drug effects, cell differentiation and altered chemical microenvironments.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2017
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-336430 (URN)10.1039/c7an00885f (DOI)000411703800013 ()28835951 (PubMedID)
    Funder
    Swedish Research Council, VR 621-2013-4231Swedish Foundation for Strategic Research , SSF ICA-6
    Available from: 2017-12-15 Created: 2017-12-15 Last updated: 2018-04-05Bibliographically approved
    4. A pneumatically assisted nanospray desorption electrospray ionization source for increased solvent versatility and enhanced metabolite detection from tissue
    Open this publication in new window or tab >>A pneumatically assisted nanospray desorption electrospray ionization source for increased solvent versatility and enhanced metabolite detection from tissue
    2017 (English)In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 142, no 18, p. 3424-3431Article in journal (Refereed) Published
    Abstract [en]

    Nanospray desorption electrospray ionization (nano-DESI) has been established as a powerful technique for mass spectrometry imaging (MSI) of biomolecules from tissue samples. The direct liquid extraction of analytes from a surface at ambient pressure negates the need for significant sample preparation or matrix application. Although many recent studies have applied nano-DESI to new and exciting applications, there has not been much work in the development and improvement of the nano-DESI source. Here, we incorporate a nebulizer to replace the self-aspirating secondary capillary in the conventional nano-DESI setup, and characterize the device by use of rat kidney tissue sections. We find that the pneumatically assisted nano-DESI device offers improved sensitivity for metabolite species by 1-3 orders of magnitude through more complete desolvation and reduced ionization suppression. Further, the pneumatically assisted nano-DESI device reduces the dependence on probe-to-surface distance and enables sampling and imaging using pure water as the nano-DESI solvent. This provides exclusive detection and imaging of many highly polar endogenous species. Overall, the developed pneumatically assisted nano-DESI device provides more versatile solvent selection and an increased sensitivity for metabolites, which generates ion images of higher contrast - allowing for more intricate studies of metabolite distribution.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2017
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-334756 (URN)10.1039/c7an00901a (DOI)000409919200016 ()28828451 (PubMedID)
    Funder
    Swedish Foundation for Strategic Research , SSF ICA-6Swedish Research Council, VR 621-2013-4231
    Available from: 2017-11-27 Created: 2017-11-27 Last updated: 2018-04-05Bibliographically approved
  • Public defence: 2018-05-25 13:15 Gustavianum, Uppsala
    Svefors, Pernilla
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, International Maternal and Child Health (IMCH).
    Stunted growth in children from fetal life to adolescence: Risk factors, consequences and entry points for prevention - Cohort studies in rural Bangladesh2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Stunted growth affects one in four children under the age of five years and comes with great costs for the child and society. With an increased understanding of the long-term consequences of chronic undernutrition the reduction of stunted growth has become an important priority on the global health agenda. WHO has adopted a resolution to reduce stunting by 40% by the year 2025 and to reduce stunting is one of the targets under the Sustainable Development Goals.

    The aim of this thesis was to study linear growth trajectories, risk factors and consequences of stunting and recovery of stunting from fetal life to adolescence in a rural Bangladeshi setting and to assess the cost-effectiveness of a prenatal nutrition intervention for under-five survival and stunting.

    A birth cohort of children of women participating in the Maternal and Infant Nutrition Interventions trial (MINIMat), a randomized prenatal food and multiple micronutrient (MMS) trial, was followed from birth to adolescence. Information about socioeconomic and nutritional characteristics of the mother and father was collected, and frequent anthropometry assessments of the child were done at birth, in infancy, and during childhood and adolescence. At puberty, pubertal stages according to Tanner, age at menarche and start of the pubertal growth spurt in boys were assessed. Calculations were made regarding the cost-effectiveness of prenatal food and micronutrient intervention related to the disability adjusted life years (DALYs) lost by death and stunting.

    At birth, the children were on average short compared the WHO growth reference and more than half of the children were Small-for-Gestational-Age. Linear growth faltered dramatically up to 2 years, after which height-for-age Z-score increased up to adolescence. The prevalence of stunting was highest at 2 years (50%) and thereafter decreasing to 25% in adolescence. Birth size, maternal anthropometry and parental education were the most influential factors for linear growth up to and stunting at 2 years. Conditions after birth, such as feeding practices and morbidity, were less important. At 10 years, children born to short mothers (<147.5 cm), mothers with no education, or those conceived in the pre-monsoon season had an increased probability to be stunted. The median age at menarche was 13.0 years. Children that were stunted in infancy and childhood had later pubertal development as compared to non-stunted children. Children that recovered from stunting had a similar timing of puberty as their peers who had never been stunted. Supplementation with combined early prenatal food and multiple micronutrients was highly cost-effective in averting DALYs from under-five deaths and stunting.

    The results from this thesis support the conclusion that a lifecycle approach is needed for the prevention of stunting. The gaps between current knowledge, policy and practice needs to be closed, with more emphasis given to prenatal interventions.

    List of papers
    1. Stunted at 10 Years. Linear Growth Trajectories and Stunting from Birth to Pre-Adolescence in a Rural Bangladeshi Cohort.
    Open this publication in new window or tab >>Stunted at 10 Years. Linear Growth Trajectories and Stunting from Birth to Pre-Adolescence in a Rural Bangladeshi Cohort.
    Show others...
    2016 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 3, article id e0149700Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND: Few studies in low-income settings analyse linear growth trajectories from foetal life to pre-adolescence. The aim of this study is to describe linear growth and stunting from birth to 10 years in rural Bangladesh and to analyse whether maternal and environmental determinants at conception are associated with linear growth throughout childhood and stunting at 10 years.

    METHODS AND FINDINGS: Pregnant women participating in the MINIMat trial were identified in early pregnancy and a birth cohort (n = 1054) was followed with 19 growth measurements from birth to 10 years. Analyses of baseline predictors and mean height-for-age Z-scores (HAZ) over time were modelled using GLMM. Logistic regression analysis was used to investigate the associations between baseline predictors and stunting (HAZ<-2) at 10 years. HAZ decreased to 2 years, followed by an increase up to 10 years, while the average height-for-age difference in cm (HAD) to the WHO reference median continued to increase up to 10 years. Prevalence of stunting was highest at 2 years (50%) decreasing to 29% at 10 years. Maternal height, maternal educational level and season of conception were all independent predictors of HAZ from birth to pre-adolescence (p<0.001) and stunting at 10 years. The highest probability to be stunted at 10 years was for children born by short mothers (<147.5 cm) (ORadj 2.93, 95% CI: 2.06-4.20), mothers with no education (ORadj 1.74, 95% CI 1.17-2.81) or those conceived in the pre-monsoon season (ORadj 1.94, 95% CI 1.37-2.77).

    CONCLUSIONS: Height growth trajectories and prevalence of stunting in pre-adolescence showed strong intergenerational associations, social differentials, and environmental influence from foetal life. Targeting women before and during pregnancy is needed for the prevention of impaired child growth.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-280082 (URN)10.1371/journal.pone.0149700 (DOI)000371724200047 ()26934484 (PubMedID)
    Funder
    Sida - Swedish International Development Cooperation AgencySwedish Research Council
    Available from: 2016-03-08 Created: 2016-03-08 Last updated: 2018-04-04Bibliographically approved
    2. The relative importance of pre- and postnatal determinants of stunting.: Data mining approaches to the Maternal and Infant Nutrition Interventions in Matlab (MINIMat) cohort, Bangladesh
    Open this publication in new window or tab >>The relative importance of pre- and postnatal determinants of stunting.: Data mining approaches to the Maternal and Infant Nutrition Interventions in Matlab (MINIMat) cohort, Bangladesh
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Background The WHO has set a goal to reduce the prevalence of stunted child growth by 40% by the year 2025. To reach this goal, it is imperative to establish the relative importance of risk factors for stunting to deliver the appropriate interventions. Currently, most interventions take place in late infancy and early childhood. This study aimed to identify the most critical pre- and postnatal determinants of linear growth 0–24 months and the risk factors for stunting at two years, and to identify subgroups with different growth trajectories and levels of stunting at two years.

    Method and Findings Conditional inference-tree-based methods were applied to the extensive Maternal and Infant Nutrition Interventions in Matlab (MINIMat) trial database with 309 variables of 2,723 children: their parents and living conditions, including socioeconomic, nutritional and other biological characteristics of the parents; maternal exposure to violence; household food security; breast- and complementary-feeding; and measurement of morbidity of the mothers during pregnancy and repeatedly of their children up to 24 months of age. Child anthropometry was measured monthly from birth to 12 months, thereafter quarterly to 24 months. Birth length and weight were the most critical factors for linear growth 0–24 months and stunting at two years, followed by maternal anthropometry and parental education. Conditions after birth, such as feeding practices and morbidity, were less strongly associated with linear growth trajectories and stunting at two years.

    Interpretation The results of this study, together with findings from recent reviews, motivate a change in policy and practice, emphasizing the benefit of interventions before conception and during pregnancy to reach a substantial reduction in stunting.

    Keyword
    Stunting, nutrition, undernutrition, pre and postnatal interventions, data mining, decision tree, risk factors
    National Category
    Public Health, Global Health, Social Medicine and Epidemiology
    Research subject
    Medical Science
    Identifiers
    urn:nbn:se:uu:diva-347522 (URN)
    Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-04-04
    3. Stunting, recovery from stunting and puberty timing in the MINIMat cohort, Bangladesh
    Open this publication in new window or tab >>Stunting, recovery from stunting and puberty timing in the MINIMat cohort, Bangladesh
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Introduction: Nutritional status is a well-known determinant of pubertal development and age at menarche. In low-resource settings, puberty onset usually takes place at an older age. Epidemiological and adoption studies have indicated that early life undernutrition that is followed by catch-up growth may result in early puberty and younger age at menarche. Early puberty might, in turn, be associated with an increased risk of adult chronic diseases. This paper aims to analyze the association between intrauterine growth restriction, infancy and childhood stunting, recovery from stunting, and the outcome timing of puberty in a rural Bangladeshi cohort.

    Methods: The participants in the present study were children to mothers participating in the Maternal and Infant Nutrition Interventions in Matlab (MINIMat) trial. Pregnant women were identified in early pregnancy, and a birth cohort was followed from birth to puberty. The analyzed sample included 994 girls and 987 boys aged from 12 to 15 years. Puberty assessment was done by evaluating the breast, testicle, and hair developments according to Tanner. The age at menarche was recorded and in boys data from pre-pubertal and two consecutive pubertal height measurements, six months apart were used to determine whether the pubertal growth spurt had started or not. Intrauterine growth restriction, infancy and childhood stunting, and recovery from stunting were modeled with age at menarche by Cox proportional hazards analyses, and with pubertal onset in boys by logistic regression.

    Results: The median age at menarche was 13.0 years (95% CI 13.0-13.1). Adolescents, who had reached a later stage of puberty and had a younger age at menarche, had mothers who were heavier, more educated, and belonged to a higher socioeconomic group. There was no difference in age at menarche between girls that were small or appropriate for gestational age at birth. Boys born small for gestational age entered their pubertal growth spurt later than those with appropriate weight. Children who were stunted had later pubertal development, age at menarche and timing of growth spurt than non-stunted children. Children who recovered from stunting had similar pubertal development, age at menarche, and timing of growth spurt in boys as non-stunted children.

    Conclusion: Infant and childhood stunting was associated with a later pubertal development. Infant or young child recovery from stunting was not associated with earlier puberty in comparison with non-stunted children.

    Keyword
    Stunting, Undernutrition, Puberty, Recovery, Menarche, Tanner, Bangladesh, Adolescence
    National Category
    Public Health, Global Health, Social Medicine and Epidemiology
    Research subject
    Medical Science
    Identifiers
    urn:nbn:se:uu:diva-347523 (URN)
    Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-04-04
    4. Cost-effectiveness of prenatal food and micronutrient interventions on under-five mortality and stunting: Analysis of data from the MINIMat randomized trial, Bangladesh.
    Open this publication in new window or tab >>Cost-effectiveness of prenatal food and micronutrient interventions on under-five mortality and stunting: Analysis of data from the MINIMat randomized trial, Bangladesh.
    Show others...
    2018 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 2, article id e0191260Article in journal (Refereed) Published
    Abstract [en]

    INTRODUCTION: Nutrition interventions may have favourable as well as unfavourable effects. The Maternal and Infant Nutrition Interventions in Matlab (MINIMat), with early prenatal food and micronutrient supplementation, reduced infant mortality and were reported to be very cost-effective. However, the multiple micronutrients (MMS) supplement was associated with an increased risk of stunted growth in infancy and early childhood. This unfavourable outcome was not included in the previous cost-effectiveness analysis. The aim of this study is to evaluate whether the MINIMat interventions remain cost-effective in view of both favourable (decreased under-five-years mortality) and unfavourable (increased stunting) outcomes.

    METHOD: Pregnant women in rural Bangladesh, where food insecurity still is prevalent, were randomized to early (E) or usual (U) invitation to be given food supplementation and daily doses of 30 mg, or 60 mg iron with 400 μg of folic acid, or MMS with 15 micronutrients including 30 mg iron and 400 μg of folic acid. E reduced stunting at 4.5 years compared with U, MMS increased stunting at 4.5 years compared with Fe60, while the combination EMMS reduced infant mortality compared with UFe60. The outcome measure used was disability adjusted life years (DALYs), a measure of overall disease burden that combines years of life lost due to premature mortality (under five-year mortality) and years lived with disability (stunting). Incremental cost effectiveness ratios were calculated using cost data from already published studies.

    RESULTS: By incrementing UFe60 (standard practice) to EMMS, one DALY could be averted at a cost of US$24.

    CONCLUSION: When both favourable and unfavourable outcomes were included in the analysis, early prenatal food and multiple micronutrient interventions remained highly cost effective and seem to be meaningful from a public health perspective.

    Keyword
    cost-effectiveness, stunting, nutrition intervention, DALY, child mortality, nutrition, Bangladesh
    National Category
    Public Health, Global Health, Social Medicine and Epidemiology
    Research subject
    Medical Science
    Identifiers
    urn:nbn:se:uu:diva-347520 (URN)10.1371/journal.pone.0191260 (DOI)29447176 (PubMedID)
    Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-04-26Bibliographically approved
  • Public defence: 2018-05-25 13:15 ITC 2446 (Polacksbacken), Uppsala
    Cubo, Rubén
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Automatic control. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Systems and Control.
    Model-based optimization for individualized deep brain stimulation2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Deep Brain Stimulation (DBS) is an established therapy that is predominantly  utilized in treating the symptoms of neurodegenerative diseases such as Parkinson's Disease and Essential Tremor, crippling diseases like Chronic Pain and Epilepsy, and psychiatric diseases such as Schizophrenia and Depression. Due to its invasive nature, DBS is considered as a last resort therapy.DBS is performed by transmitting electric pulses through an electrode implanted in the brain of the patient.

    The stimulation is driven by a battery-powered Implanted Pulse Generator. The brain is a very delicate and complex organ and, therefore, accurate positioning the electrode is vital. To achieve a satisfactory therapeutical result, the stimulation targets a certain predefined brain structure that depends on the disease.

    The effect of DBS depends on the individual, the chosen stimulating contact(s), and the pulse parameters, i.e. amplitude, frequency, width, and shape. Tuning these parameters to the best effect is currently done by a lengthy trial-and-error process. Insufficient stimulation does not properly alleviate the symptoms of the disease, while overstimulation or stimulation off target is prone to side effects.

    This work envisions assisting physicians in DBS therapy by utilizing model-based estimation and optimization, maximizing stimulation of the target and minimizing stimulation in potentially problematic areas of the brain. This work focuses on amplitude and contact selection. Because of inter-patient differences, individualized models based on clinical imaging have to be created. Alternatively, semi-individualized models can be designed using atlases that save time but potentially introduce inaccuracies. Other optimization  applications to DBS are proposed in the thesis, e.g. fault alleviation and electrode design.

    Electrical properties of the brain can change over time and alter the stimulation spread. A system identification approach has been proposed to quantify these changes.

    The main aim of DBS is to alleviate the symptoms of the disease and quantifying symptoms is important. The ultimate vision of this work is to design a closed-loop system that can deliver optimal stimulation to the brain while automatically adapting to changes in the brain and the severity of symptoms.

    List of papers
    1. Accuracy of the Finite Element Method in Deep Brain Stimulation Modelling
    Open this publication in new window or tab >>Accuracy of the Finite Element Method in Deep Brain Stimulation Modelling
    2014 (English)In: Proc. International Conference on Control Applications: CCA 2014, Piscataway, NJ: IEEE , 2014, p. 1479-1484Conference paper, Published paper (Refereed)
    Place, publisher, year, edition, pages
    Piscataway, NJ: IEEE, 2014
    National Category
    Control Engineering Medical Equipment Engineering
    Identifiers
    urn:nbn:se:uu:diva-238211 (URN)10.1109/CCA.2014.6981533 (DOI)000366055800214 ()978-1-4799-7409-2 (ISBN)
    Conference
    CCA 2014, October 8–10, Antibes, France
    Funder
    EU, European Research Council, 247035
    Available from: 2014-10-10 Created: 2014-12-10 Last updated: 2018-03-29Bibliographically approved
    2. Optimization of lead design and electrode configuration in Deep Brain Stimulation
    Open this publication in new window or tab >>Optimization of lead design and electrode configuration in Deep Brain Stimulation
    2016 (English)In: International Journal On Advances in Life Sciences, ISSN 1942-2660, E-ISSN 1942-2660, Vol. 8, p. 76-86Article in journal (Refereed) Published
    National Category
    Control Engineering
    Identifiers
    urn:nbn:se:uu:diva-305224 (URN)
    Available from: 2016-06-30 Created: 2016-10-13 Last updated: 2018-03-29Bibliographically approved
    3. Electric field modeling and spatial control in Deep Brain Stimulation
    Open this publication in new window or tab >>Electric field modeling and spatial control in Deep Brain Stimulation
    2015 (English)In: Proc. 54th Conference on Decision and Control, Piscataway, NJ: IEEE , 2015, p. 3846-3851Conference paper, Published paper (Refereed)
    Abstract [en]

    Deep Brain Stimulation (DBS) is an established treatment, in e.g. Parkinson's Disease, whose underlying biological mechanisms are unknown. In DBS, electrical stimulation is delivered through electrodes surgically implanted into certain regions of the brain of the patient. Mathematical models aiming at a better understanding of DBS and optimization of its therapeutical effect through the simulation of the electrical field propagating in the brain tissue have been developed in the past decade. The contribution of the present study is twofold: First, an analytical approximation of the electric field produced by an emitting contact is suggested and compared to the numerical solution given by a Finite Element Method (FEM) solver. Second, the optimal stimulation settings are evaluated by fitting the field distribution to a target one to control the spread of the stimulation. Optimization results are compared to those of a geometric approach, maximizing the intersection between the target and the activated volume in the brain tissue and reducing the stimulated area beyond said target. Both methods exhibit similar performance with respect to the optimal stimuli, with the electric field control approach being faster and more versatile.

    Place, publisher, year, edition, pages
    Piscataway, NJ: IEEE, 2015
    National Category
    Control Engineering Medical Equipment Engineering
    Identifiers
    urn:nbn:se:uu:diva-284317 (URN)10.1109/CDC.2015.7402817 (DOI)000381554504006 ()9781479978847 (ISBN)
    Conference
    CDC 2015, December 15–18, Osaka, Japan
    Funder
    EU, European Research Council, 247035
    Available from: 2015-12-18 Created: 2016-04-16 Last updated: 2018-03-29Bibliographically approved
    4. Optimization-based contact fault alleviation in deep brain stimulation leads
    Open this publication in new window or tab >>Optimization-based contact fault alleviation in deep brain stimulation leads
    2018 (English)In: IEEE transactions on neural systems and rehabilitation engineering, ISSN 1534-4320, E-ISSN 1558-0210, Vol. 26, no 1, p. 69-76Article in journal (Refereed) Published
    National Category
    Medical Engineering
    Identifiers
    urn:nbn:se:uu:diva-342456 (URN)10.1109/TNSRE.2017.2769707 (DOI)000422939000008 ()29324404 (PubMedID)
    Available from: 2017-11-03 Created: 2018-02-26 Last updated: 2018-03-29Bibliographically approved
    5. Semi-Individualized electrical models in deep brain stimulation: A variability analysis
    Open this publication in new window or tab >>Semi-Individualized electrical models in deep brain stimulation: A variability analysis
    Show others...
    2017 (English)In: 2017 IEEE Conference on Control Technology and Applications (CCTA), 2017Conference paper, Published paper (Refereed)
    Abstract [en]

    Deep Brain Stimulation (DBS) is a well-established treatment in neurodegenerative diseases, e.g. Parkinson’s Disease. It consists of delivering electrical stimuli to a target in the brain via a chronically implanted lead. To expedite the tuning of DBS stimuli to best therapeutical effect, mathematical models have been developed during recent years. The electric field produced by the stimuli in the brain for a given lead position is evaluated by numerically solving a Partial Differential Equation with the medium conductivity as a parameter. The latter is patient- and target-specific but difficult to measure in vivo. Estimating brain tissue conductivity through medical imaging is feasible but time consuming due to registration, segmentation and post-processing. On the other hand, brain atlases are readily available and processed. This study analyzes how alternations in the conductivity due to inter-patient variability or lead position uncertainties affect both the stimulation shape and the activation of a given target. Results suggest that stimulation shapes are similar, with a Dice’s Coefficient between 93.2 and 98.8%, with a higher similarity at lower depths. On the other hand, activation shows a significant variation of 17 percentage points, with most of it being at deeper positions as well. It is concluded that, as long as the lead is not too deep, atlases can be used for conductivity maps with acceptable accuracy instead of fully individualized though medical imaging models.

    Keyword
    bioelectric phenomena;biological tissues;biomedical electrodes;brain;diseases;neurophysiology;partial differential equations;patient treatment;DBS stimuli;Parkinson disease;Partial Differential Equation;brain atlases;brain tissue conductivity;chronically implanted lead;deep brain stimulation;electric field;electrical stimuli;interpatient variability;medical imaging models;neurodegenerative diseases;semiIndividualized electrical models;variability analysis;Brain modeling;Computational modeling;Conductivity;Lead;Mathematical model;Satellite broadcasting
    National Category
    Control Engineering
    Identifiers
    urn:nbn:se:uu:diva-347344 (URN)10.1109/CCTA.2017.8062514 (DOI)
    Conference
    2017 IEEE Conference on Control Technology and Applications (CCTA)
    Available from: 2018-03-29 Created: 2018-03-29 Last updated: 2018-03-29
    6. Calculating Directional Deep Brain Stimulation Settings by Constrained Optimization
    Open this publication in new window or tab >>Calculating Directional Deep Brain Stimulation Settings by Constrained Optimization
    Show others...
    (English)Article in journal (Refereed) Submitted
    Abstract [en]

    Objective: Deep Brain Stimulation (DBS) consists of delivering electrical stimuli to a brain target via an implanted lead to treat neurodegenerative conditions. Individualized stimulation is vital to ensure therapeutic results, since DBS may otherwise become ineffective or cause undesirable side effects. Since the DBS pulse generator is battery-driven, power consumption incurred by the stimulation is important. In this study, target coverage and power consumption are compared over a patient population for clinical and model-based patient-specific settings calculated by constrained optimization. Methods: Brain models for five patients undergoing bilateral DBS were built. Mathematical optimization of activated tissue volume was utilized to calculate stimuli amplitudes, with and without specifying the volumes, where stimulation was not allowed to avoid side effects. Power consumption was estimated using measured impedance values and battery life under both clinical and optimized settings. Results: It was observed that clinical settings are generally less aggressive than the ones suggested by unconstrained model-based optimization, especially under asymmetrical stimulation. The DBS settings satisfying the constraints were close to the clinical values. Conclusion: The use of mathematical models to suggest optimal patient-specific DBS settings that observe technological and safety constraints can save time in clinical practice. It appears though that the considered anatomy-related safety constraints depend on the patient and further research is needed in this regard. Power consumption is important to consider since it increases with the square of the stimuli amplitude and critically affects battery life. Significance: This work highlights the need of specifying the brain volumes to be avoided by stimulation while optimizing the DBS amplitude, in contrast to minimizing general stimuli overspill, and applies the technique to a cohort of patients. It also stresses the importance of taking power consumption into account.

    Keyword
    Neuromodulation, Deep Brain Stimulation, inverse problems
    National Category
    Control Engineering
    Identifiers
    urn:nbn:se:uu:diva-347345 (URN)
    Available from: 2018-03-29 Created: 2018-03-29 Last updated: 2018-03-29
    7. Online tissue conductivity estimation in Deep Brain Stimulation
    Open this publication in new window or tab >>Online tissue conductivity estimation in Deep Brain Stimulation
    (English)In: Article in journal (Refereed) Submitted
    Abstract [en]

    Deep Brain Stimulation (DBS) is an established therapy that consists of sending electrical pulses to the brain via a chronically implanted electrode. DBS is used to alleviate symptoms of neurological medical conditions such as Parkinson’s Disease and Essential Tremor. However, the stimulation effect is patient-specific and hard to predict. In addition, the brain tissue around the lead changes its electrical properties over time thus influencing the therapeutical effect. This paper proposes an approach to online conductivity estimation by sending a specially designed electrical probing signal into the brain from one contact of the electrode and measuring the response on another one. A conductivity estimate is then obtained from the parameters of an estimated linear time-invariant model. Both voltage-controlled and current-controlled DBS systems are treated. Continuous Least Squares and Laguerre domain identification are employed to estimate the involved models. Results suggest that a smooth Gaussian-shaped signal is sufficient to identify the model in a noise-free situation, but the resulting excitation might be not enough for accurate estimation in the face of disturbances, e.g. local field potential due to neuron firings. Better excitation is produced by input signals with designed Laguerre spectra. Due to the infeasibility of assigning electrical properties to the surroundings of the lead in vivo, synthetic data from an individualized high-fidelity mathematical model of DBS are used instead. The latter model is validated against clinically measured impedance values.

    National Category
    Control Engineering
    Identifiers
    urn:nbn:se:uu:diva-347346 (URN)
    Available from: 2018-03-29 Created: 2018-03-29 Last updated: 2018-03-29
  • Public defence: 2018-05-25 13:15 Hörsal 2, Uppsala
    Leite, Emilene
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Business Studies.
    Complexity in the 'Extended' Business Network: A Study of Business, Social, and Political Relationships in Smart City Solutions2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis an 'extended' business network is investigated. The ‘extended’ view refers to the inclusion of socio-political actors in the firm’s business network. Building on a business network perspective, the thesis’ purpose is to understand how interactions between business, social, and political actors influence the development of smart city solutions. Based on the findings from the four articles included in the thesis, a complexity lens for further understanding of interaction with socio-political actors is presented. It argues that reaching success in the relationship entails finding a balance between economic and social needs.

    Through the analysis of two smart city projects developed in Brazil, this study investigates the influence of socio-political actors on firms’ cooperative and competitive behavior as well as their decisions relating to resource allocation. The findings illustrate that decisions to cooperate or compete are associated with centrality. The firm’s willingness to be a central actor, i.e., a project leader, places traditional buyer-supplier partners in competition. In addition to this, resource allocation is closely linked to customization. In cities demanding a high level of customization of the smart city solution, companies will be encouraged to allocate resources to exploitation, while in cities requiring a low level of customization, exploration will be chosen instead. But knowledge about how to allocate resources is closely linked to the centrality issue, since a central actor may enjoy better access to a large pool of resources and information. Consequently, the final outcome in relational terms can lead to win-lose rather than a win-win situation if rivalry for centrality between business partners intensifies over time.

    The study of such complex interaction contributes to the industrial marketing and business network literature by providing a practical perspective and showing how socio-political actors can be a source of competitive advantages for companies. In addition, this thesis suggests that managers need to cope with the complexity inherent in such type of relationships, primarily due the fact that interaction with socio-political actors has important competitive implications for firms. Ultimately, the thesis offers a framework for investigating complexity in actors’ interactions and resource heterogeneity that complements our understanding of intraorganizational relationships, opening opportunities for a new perspective and better comprehension of the influence of socio-political actors in firms’ business networks.

    List of papers
    1. A business network view on value creation and capture in public-private cooperation
    Open this publication in new window or tab >>A business network view on value creation and capture in public-private cooperation
    2018 (English)In: Industrial Marketing ManagementArticle in journal (Refereed) In press
    Abstract [en]

    Intersecting the boundaries between public and private economic activity, this study contributes to the research on public-private cooperation. It comprehends how these hybrids organizational arrangements influence value creation and capturing mechanisms in infrastructural city projects. A case study based on the development of a public transportation solution in Brazil is undertaken. Using a business network approach, we propose a theoretical framework of value creation and capturing through public-private cooperation and argue that the value is constructed through the complementarity of resources and the cohesiveness of motives of the involved actors. Our findings suggest that the success of the cooperation goes beyond the benefits from simply generating revenues, thereby expanding the value capturing concept.

    Place, publisher, year, edition, pages
    Elsevier, 2018
    Keyword
    public-private cooperation, business network theory, value creation, value capturing
    National Category
    Business Administration
    Research subject
    Business Studies
    Identifiers
    urn:nbn:se:uu:diva-347349 (URN)
    Available from: 2018-03-29 Created: 2018-03-29 Last updated: 2018-04-11
    2. "The Cooperation-Competition Interplay in the ICT Industry"
    Open this publication in new window or tab >>"The Cooperation-Competition Interplay in the ICT Industry"
    (English)In: Article in journal (Refereed) Accepted
    National Category
    Social Sciences
    Research subject
    Business Studies
    Identifiers
    urn:nbn:se:uu:diva-338349 (URN)
    Available from: 2018-01-08 Created: 2018-01-08 Last updated: 2018-04-06
    3. Business and Socio-Political Interaction in International Service Projects
    Open this publication in new window or tab >>Business and Socio-Political Interaction in International Service Projects
    (English)In: Article in journal (Refereed) Submitted
    Abstract [en]

    The paper discusses multinational enterprises (MNEs) socio-political behavior in a foreign market. In specific, the aim is to increase the understanding of how service MNEs from the ICT (information communication technology) industry, through projects oriented to improve public service in cities, deal with society and public officials in Brazil. A conceptual framework containing the four concepts cooperation, legitimacy, commitment and knowledge is applied for the analysis. Based on two case studies the paper illustrates cross border activities where MNEs from Sweden, Spain and China join effort with local actors to strengthen their competitive market position. Our results reveal that an important strategy used by service MNEs is to get involved in cooperative service project involving business and socio-political actors. Successful cooperation is partially explained by the managements’ ability to incorporate the business resources with the needs of the socio-political actors. The key implication is that extensive public-private networking is needed even when MNEs enjoy an established position in a foreign market.

    Keyword
    socio-political actors, cooperation, competitive market position, legitimacy, knowledge, commitment
    National Category
    Business Administration
    Identifiers
    urn:nbn:se:uu:diva-347352 (URN)
    Available from: 2018-03-29 Created: 2018-03-29 Last updated: 2018-04-06
    4. Cooperative Innovation Networks – Why do they emerge and how are they configured?
    Open this publication in new window or tab >>Cooperative Innovation Networks – Why do they emerge and how are they configured?
    2018 (English)Other (Other academic)
    Abstract [en]

    The paper aims to examine why innovation network emerges and how it gets configured. To address that, we examine two cases of IoT (internet of things) technologies applied on public service in Brazil. By using the conceptual framework proposed by Ritala et al., (2016), we demonstrate that innovation network emerges because MNEs are under constant need for innovation and second they have limitation to pursuit and integrate complex knowledge on their own and for that reason cooperation becomes crucial. Such process is characterized by a dynamic complex process which the MNEs’ searching-acting-convincing on an opportunity require business and nonbusiness actors participation. The novelty, however, is that, the findings shows that the locus of innovation is not limited to the traditional business to business relationships but it can also arise from non-business actors such as NGOs and local government.

    Keyword
    Innovation networks, MNEs, government and NGOs, IoT (internet of things).
    National Category
    Social Sciences
    Identifiers
    urn:nbn:se:uu:diva-347688 (URN)
    Available from: 2018-04-06 Created: 2018-04-06 Last updated: 2018-04-06
  • Public defence: 2018-05-25 13:15 Sal IX, Universitetshuset, Uppsala
    Dalberg, Tobias
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Mot lärdomens topp: Svenska humanisters och samhällsvetares ursprung, utbildning och yrkesbana under 1900-talets första hälft2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This dissertation employs Pierre Bourdieu’s concepts of capital and field alongside Robert K. Merton’s notion of accumulation of advantage to study how different types of assets affect career trajectories in the humanities and social sciences. Assets may be inherited from the parental home, or acquired, such as through academic qualifications and professional experience. Career trajectories includes occupying both incumbencies, such as professorships, and positions based on possessing substantial amounts of assets that are valuable in the field of humanities and social sciences.

    A prosopography of Swedish humanists and social scientists entering the academic profession ca 1915–1955 comprises the main empirical data, used in combination with library catalogues, secondary data and documents. The bulk of the data is analysed by quantitative methods, foremost geometric data analysis and sequence analysis.

    The institutionalisation of the social sciences in the first half of the 20th century brought about both new incumbencies at the universities and a polarisation of the mode of accumulating assets. In a normally austere academic labour market, new professorships were vital to sustain a university career, especially so in the rising social sciences where there were, unlike many of the humanities disciplines, no established alternative career paths – like schoolteacher – to fall back on. The polarisation of the field separated social scientists more oriented towards political and administrative spheres of society from humanists more endowed with honorary titles, academy memberships and international recognition. However, this evolution did not change the basic division of the academic field, as this was still most clearly marked by the opposition between those with more and those with less academic and scientific power. This fundamental division had less to do with humanities and social science than with seniority in the field. Despite the expansion of the field during this period, the recruitment of academics from more modest social origins did not increase. This ought to be attributed to the fact that the school system efficiently eliminated children from the lower classes at an early stage.

    In this sense, the structure of the field, together with the supply of incumbencies, shaped a set of assured possibilities of success, while the field structure itself was shaped by the assets accumulated by its agents.

  • Public defence: 2018-05-25 13:30 Häggsalen, Uppsala
    Adlmann, Franz Alois
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Opportunities and challenges of surface scattering at next generation neutron sources2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Complex fluids and soft matter are ubiquitously found in the world and all contacts in life are made over surfaces. To describe the mechanical behavior of such substances, rheological methods are used. Flow instabilities are a big challenge in rheology since they will be reflected in the macroscopic variables probed, like e. g. the viscosity. Many such discontinuities may actually originate at the surface. Investigating the properties of liquids in contact with the surface under mechanical load is the main course of the thesis. Neutron reflectometry and GISANS are perfect tools in this context to access the solid liquid interfaces, since they can penetrate many engineering materials and show a comparably large scattering potential at deuterated samples. In this thesis shear was applied on a model solution and neutron scattering techniques were used to investigate the structure under load. The focus was set on the development of the measurement methods themselves to enable new scientific insights in the future. First, by stroboscopic measurements the flux limitations are overcome for oscillatory rheology. By reintegration in the post processing it is shown that kinetic measurements with neutrons are possible with a time resolution below one millisecond. Second, the transformation of grazing incidence data from the laboratory system into q-space is strongly non-linear resulting in a need for re-binning. In this thesis a universal tool has been developed for this purpose. Finally, there is an ongoing discussion on depth sensitive neutron scattering experiments from solid-liquid boundaries. By using emission densities we show that such experiments face severe limitations due to the low absorption cross section of the neutron.

    List of papers
    1. Depth-resolved grazing-incidence time-of-flight neutron scattering from a solid-liquid interface
    Open this publication in new window or tab >>Depth-resolved grazing-incidence time-of-flight neutron scattering from a solid-liquid interface
    Show others...
    2014 (English)In: Journal of applied crystallography, ISSN 0021-8898, E-ISSN 1600-5767, Vol. 47, p. 130-135Article in journal (Refereed) Published
    Abstract [en]

    Small-angle scattering in grazing-incidence beam geometry has been applied on a time-of-flight neutron instrument to investigate a solid-liquid boundary. Owing to the broad wavelength distribution provided for a specific incident beam angle, the penetration depth of the neutron beam is varied over a wide range in a single measurement. The near surface structures of block copolymer micelles close to silicon substrates with distinct surface energies are resolved. It is observed that the very near surface structure strongly depends on the surface coating, whereas further away from the surface, bulk-like ordering is found.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-219976 (URN)10.1107/S1600576713028665 (DOI)000330485100018 ()
    Available from: 2014-03-12 Created: 2014-03-09 Last updated: 2018-04-11Bibliographically approved
    2. Polymer Brush Collapse under Shear Flow
    Open this publication in new window or tab >>Polymer Brush Collapse under Shear Flow
    Show others...
    2017 (English)In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 50, no 3, p. 1215-1224Article in journal (Refereed) Published
    Abstract [en]

    Shear responsive surfaces offer potential advances in a number of applications. Surface functionalization using polymer brushes is one route to such properties, particularly in the case of entangled polymers. We report on neutron reflectometry measurements of polymer brushes in entangled polymer solutions performed under controlled shear as well as coarse-grained computer simulations corresponding to these interfaces. Here we show a reversible and reproducible collapse of the brushes, increasing with the shear rate. Using two brushes of greatly different chain lengths and grafting densities, we demonstrate that the dynamics responsible for the structural change of the brush are governed by the free chains in solution rather than the brush itself, within the range of parameters examined. The phenomenon of the brush collapse could find applications in the tailoring of nanosensors and as a way to dynamically control surface friction and adhesion.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2017
    National Category
    Materials Engineering
    Identifiers
    urn:nbn:se:uu:diva-320464 (URN)10.1021/acs.macromol.6b02525 (DOI)000394410200053 ()
    Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2018-04-11Bibliographically approved
    3. Probing the dynamics of high-viscosity entangled polymers under shear using Neutron Spin Echo spectroscopy
    Open this publication in new window or tab >>Probing the dynamics of high-viscosity entangled polymers under shear using Neutron Spin Echo spectroscopy
    Show others...
    2016 (English)In: VI European Conference On Neutron Scattering (ECNS2015), 2016, article id UNSP 012014Conference paper, Published paper (Refereed)
    Abstract [en]

    Neutron Spin Echo spectroscopy provides unique insight into molecular and submolecular dynamics as well as intra-and inter-molecular interactions in soft matter. These dynamics may change drastically under shear flow. In particular in polymer physics a stress plateau is observed, which might be explained by an entanglement-disentanglement transition. However, such a transition is difficult to identify directly by experiments. Neutron Spin Echo has been proven to provide information about entanglement length and degree by probing the local dynamics of the polymer chains. Combining shear experiments and neutron spin echo is challenging since, first the beam polarisation has to be preserved during scattering and second, Doppler scattered neutrons may cause inelastic scattering. In this paper we present a new shear device adapted for these needs. We demonstrate that a high beam polarisation can be preserved and present first data on an entangled polymer solution under shear. To complement the experiments on the dynamics we present novel SANS data revealing shear-induced conformational changes in highly entangled polymers.

    Series
    Journal of Physics Conference Series, ISSN 1742-6588 ; 746
    National Category
    Accelerator Physics and Instrumentation
    Identifiers
    urn:nbn:se:uu:diva-346197 (URN)10.1088/1742-6596/746/1/012014 (DOI)000409470900014 ()
    Conference
    6th European Conference on Neutron Scattering (ECNS), AUG 30-SEP 04, 2015, Univ Zaragoza, CSIC, Mat Sci Inst Aragon, Zaragoza, SPAIN
    Available from: 2018-03-15 Created: 2018-03-15 Last updated: 2018-04-11Bibliographically approved
    4. Depth resolved grazing incidence neutron scattering experiments from semi-infinite interfaces: a statistical analysis of the scattering contributions
    Open this publication in new window or tab >>Depth resolved grazing incidence neutron scattering experiments from semi-infinite interfaces: a statistical analysis of the scattering contributions
    Show others...
    2018 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 30, article id 165901Article in journal, Letter (Refereed) Published
    Abstract [en]

    Grazing incidence neutron scattering experiments offer surface sensitivity by reflecting from an interface at momentum transfers close to total external reflection. Under these conditions the penetration depth is strongly non-linear and may change by many orders of magnitude. This fact imposes severe challenges for depth resolved experiments, since the brilliance of neutron beams is relatively low in comparison to e.g. synchrotron radiation. In this article we use probability density functions to calculate the contribution of scattering at different distances from an interface to the intensities registered on the detector. Our method has the particular advantage that the depth sensitivity is directly extracted from the scattering pattern itself. Hence for perfectly known samples exact resolution functions can be calculated and visa versa. We show that any tails in the resolution function, e.g. Gaussian shaped, hinders depth resolved experiments. More importantly we provide means for a descriptive statistical analysis of detector images with respect to the scattering contributions and show that even for perfect resolution near surface scattering is hardly accessible.

    Place, publisher, year, edition, pages
    UK: Institute of Physics Publishing (IOPP), 2018
    Keyword
    GISANS, neutrons, interfaces, depth profiling, resolution
    National Category
    Condensed Matter Physics
    Research subject
    Physics with spec. in Atomic, Molecular and Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-348219 (URN)10.1088/1361-648X/aab573 (DOI)
    Available from: 2018-04-11 Created: 2018-04-11 Last updated: 2018-04-11Bibliographically approved
    5. Normalization of stroboscopic neutron scattering experiments
    Open this publication in new window or tab >>Normalization of stroboscopic neutron scattering experiments
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Neutron scattering studies of kinetic processes are often ux limited. For processes,which can be repeated many times, this can be mitigated by the so-called strobo-scopic reintegration. The recorded scattering signals are assigned to dierent timeslices of the process and corresponding slices from all repetitions are summed up. Thenormalisation of such data with respect to the incident beam spectrum can be chal-lenging since the incident neutron ux may not necessarily be evenly distributed overall time slices. In this paper we discuss how this can result in misleading informationand a technique to amend for these issues is presented.

    National Category
    Condensed Matter Physics
    Research subject
    Physics with spec. in Atomic, Molecular and Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-348265 (URN)
    Available from: 2018-04-11 Created: 2018-04-11 Last updated: 2018-04-13Bibliographically approved
    6. Överlåtaren: a fast way to transfer and orthogonalize two-dimensional off-specular reflectivity data
    Open this publication in new window or tab >>Överlåtaren: a fast way to transfer and orthogonalize two-dimensional off-specular reflectivity data
    Show others...
    2016 (English)In: Journal of applied crystallography, ISSN 0021-8898, E-ISSN 1600-5767, Vol. 49, p. 2091-2099Article in journal (Refereed) Published
    Abstract [en]

    Reflectivity measurements offer unique opportunities for the study of surfaces and interfaces, and specular reflectometry has become a standard tool in materials science to resolve structures normal to the surface of a thin film. Off-specular scattering, which probes lateral structures, is more difficult to analyse, because the Fourier space being probed is highly anisotropic and the scattering pattern is truncated by the interface. As a result, scattering patterns collected with (especially time-of-flight) neutron reflectometers are difficult to transform into reciprocal space for comparison with model calculations. A program package is presented for a generic two-dimensional transformation of reflectometry data into q space and back. The data are represented on an orthogonal grid, allowing cuts along directions relevant for theoretical modelling. This treatment includes background subtraction as well as a full characterization of the resolution function. The method is optimized for computational performance using repeatable operations and standardized instrument settings.

    Keyword
    off-specular scattering, neutron reflectometry, interfaces, surfaces
    National Category
    Atom and Molecular Physics and Optics Other Physics Topics Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-315086 (URN)10.1107/S1600576716014382 (DOI)000391195900025 ()
    Funder
    Swedish Research Council, C0511501The Swedish Foundation for International Cooperation in Research and Higher Education (STINT), IG-2011-2067
    Available from: 2017-02-09 Created: 2017-02-09 Last updated: 2018-04-11Bibliographically approved
    7. Towards neutron scattering experiments with sub-millisecond time resolution
    Open this publication in new window or tab >>Towards neutron scattering experiments with sub-millisecond time resolution
    Show others...
    2015 (English)In: Journal of applied crystallography, ISSN 0021-8898, E-ISSN 1600-5767, Vol. 48, p. 220-226Article in journal (Refereed) Published
    Abstract [en]

    Neutron scattering techniques offer several unique opportunities in materials research. However, most neutron scattering experiments suffer from the limited flux available at current facilities. This limitation becomes even more severe if time-resolved or kinetic experiments are performed. A new method has been developed which overcomes these limitations when a reversible process is studied, without any compromise on resolution or beam intensity. It is demonstrated that, by recording in absolute time the neutron detector events linked to an excitation, information can be resolved on sub-millisecond timescales. Specifically, the concept of the method is demonstrated by neutron reflectivity measurements in time-of-flight mode at the Liquids Reflectometer located at the Spallation Neutron Source, Oak Ridge National Laboratory, Tennessee, USA, combined with in situ rheometry. The opportunities and limitations of this new technique are evaluated by investigations of a micellar polymer solution offering excellent scattering contrast combined with high sensitivity to shear.

    Keyword
    neutron scattering, in situ rheology, block copolymers, time-resolved studies, surface kinetics, large amplitude oscillatory shear (LAOS), time-of-flight reflectometry
    National Category
    Other Physics Topics
    Identifiers
    urn:nbn:se:uu:diva-246826 (URN)10.1107/S1600576714027848 (DOI)000349210700028 ()
    Available from: 2015-03-10 Created: 2015-03-10 Last updated: 2018-04-11Bibliographically approved
  • Public defence: 2018-05-26 13:15 Ihresalen, Uppsala
    Cöllen, Sebastian
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Languages, Department of Modern Languages.
    Gefiolierte blüte kunst: Eine kognitionslinguistisch orientierte Untersuchung zur Metaphorik in Frauenlobs Marienleich2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Heinrich of Meißen, also known as Frauenlob († 1318), is a central figure in Middle High German literature. As is evident from its early reception, his work was highly admired in the middle ages. In research literature, however, his ‘obscure’ poetry initially was faced with a lack of understanding.

    The main challenge for comprehending Frauenlob lies in his rich metaphorics. However, despite the importance of the metaphors in Frauenlob’s work, the question about their role in the construction of meaning was not seriously raised until the last decades and has not yet been thoroughly investigated. This problem is all the more serious as Frauenlob’s poetry, which has often been attributed with a seemingly ‘modern’ ambivalence, is at the centre of the recent debate of the historicity of metaphor. His poetry offers a fruitful empirical entry to the important issues whether metaphors are interpreted today in the same way as in the middle ages, and whether modern theories of metaphor are adequate for the historical analysis of medieval metaphorics.

    The present study aims to describe and explain how the metaphors in Frauenlob’s Marienleich functions. It is shown that the traditional substitution account of metaphor leads to a reductionist view of the construction of meaning in this text. The modern interaction account also contains aspects whose suitability with regard to the medieval expectations on the production of meaning can be questioned. As an alternative, the present investigation proposes a context sensitive analytic model based on cognitive linguistics that tries to preserve the hermeneutic difference to Frauenlob’s Marienleich. This cognitive perspective, which is here applied to Frauenlob’s work for the first time, enables a more precise description and explanation of how the metaphorical meaning is constructed than was hitherto possible. The result shows that, whereas Frauenlob’s poetry may not be as modern as is sometimes believed, the metaphors in his Marienleich are much more than an artistic show-off; rather, they represent an efficient means of actualising a complex religious meaning.

  • Public defence: 2018-05-28 13:00 Hambergsalen, Geocentrum, Uppsala
    Fälth, Billy
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics. Clay Technology AB.
    Simulating Earthquake Rupture and Near-Fault Fracture Response2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Sweden is presently a low seismicity area where most earthquakes are small and pose no serious threat to constructions. For the long-term perspectives of safety assessments of geological repositories for spent nuclear fuel, however, the effects of large earthquakes have to be considered. For the Swedish nuclear waste storage concept, seismically induced secondary fracture shear displacements across waste canister positions could pose a long-term seismic risk to the repository.

    In this thesis, I present earthquake simulations with which I study the potential for near-fault secondary fracture shear displacements. As a measure I use the Coulomb Failure Stress (CFS), but also calculate explicit fracture displacements. I account for both the dynamic and quasi-static stress perturbations generated during the earthquake. As numerical tool I use the 3DEC code, whose performance I validate using Stokes closed-form solution and the Compsyn code as benchmarks. In a model of a Mw 6.4 earthquake, I investigate how fault roughness, the fault rupture propagation model and rupture velocity may impact the near-fault CFS evolution. I find that fault roughness can reduce the amount of fault slip by tens of percent, but also increase the near-fault CFS with similar amounts locally. Furthermore, different fault rupture models generate similar CFS levels. I also find that the secondary stresses scale with rupture velocity.

    In a model based on data from the Forsmark nuclear waste repository site, and assuming stress conditions prevailing at the end of a glaciation, I simulate several high stress drop ~Mw 5.6 earthquake scenarios on the gently dipping fault zone ZFMA2 and calculate secondary fracture displacements on 300 m diameter planar fractures. Less than 1% of the fractures at the shortest distance from ZFMA2 generate displacements exceeding the 50 mm criterion established by the Swedish Nuclear Fuel and Waste Management Co. Given the high stress drops and the assumption of fracture planarity, I consider the calculated displacements to represent upper bound estimates of possible secondary displacements at Forsmark. Hence, the results should strengthen the confidence in the safety assessment of the nuclear waste repository at the Forsmark site.

    List of papers
    1. Simulating earthquake rupture and off-fault fracture response: Application to the safety assessment of the Swedish nuclear waste repository
    Open this publication in new window or tab >>Simulating earthquake rupture and off-fault fracture response: Application to the safety assessment of the Swedish nuclear waste repository
    Show others...
    2015 (English)In: Bulletin of The Seismological Society of America (BSSA), ISSN 0037-1106, E-ISSN 1943-3573, Vol. 105, no 1, p. 134-151Article in journal (Refereed) Published
    Abstract [en]

    To assess the long‐term safety of a deep repository of spent nuclear fuel, upper bound estimates of seismically induced secondary fracture shear displacements are needed. For this purpose, we analyze a model including an earthquake fault, which is surrounded by a number of smaller discontinuities representing fractures on which secondary displacements may be induced. Initial stresses are applied and a rupture is initiated at a predefined hypocenter and propagated at a specified rupture speed. During rupture we monitor shear displacements taking place on the nearby fracture planes in response to static as well as dynamic effects. As a numerical tool, we use the 3Dimensional Distinct Element Code (3DEC) because it has the capability to handle numerous discontinuities with different orientations and at different locations simultaneously. In tests performed to benchmark the capability of our method to generate and propagate seismic waves, 3DEC generates results in good agreement with results from both Stokes solution and the Compsyn code package. In a preliminary application of our method to the nuclear waste repository site at Forsmark, southern Sweden, we assume end‐glacial stress conditions and rupture on a shallow, gently dipping, highly prestressed fault with low residual strength. The rupture generates nearly complete stress drop and an Mw 5.6 event on the 12  km2 rupture area. Of the 1584 secondary fractures (150 m radius), with a wide range of orientations and locations relative to the fault, a majority move less than 5 mm. The maximum shear displacement is some tens of millimeters at 200 m fault‐fracture distance.

    Keyword
    earthquake rupture modelling fracure
    National Category
    Geophysics
    Research subject
    Geophysics with specialization in Seismology
    Identifiers
    urn:nbn:se:uu:diva-237807 (URN)10.1785/0120140090 (DOI)000348898700008 ()
    Available from: 2014-12-05 Created: 2014-12-05 Last updated: 2018-04-04Bibliographically approved
    2. Simulation of co-seismic secondary fracture displacements for different earthquake rupture scenarios at the proposed nuclear waste repository site in Forsmark
    Open this publication in new window or tab >>Simulation of co-seismic secondary fracture displacements for different earthquake rupture scenarios at the proposed nuclear waste repository site in Forsmark
    2016 (English)In: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 84, p. 142-158Article in journal (Refereed) Published
    Keyword
    Secondary displacement; Forsmark; Nuclear waste disposal; Stress drop; Seismic efficiency
    National Category
    Geophysics
    Research subject
    Geophysics with specialization in Seismology
    Identifiers
    urn:nbn:se:uu:diva-283128 (URN)10.1016/j.ijrmms.2016.02.009 (DOI)000371895200015 ()
    Available from: 2016-04-11 Created: 2016-04-11 Last updated: 2018-04-10
    3. Influence of Fault Roughness on Co-Seismic Near-Fault Stress Evolution
    Open this publication in new window or tab >>Influence of Fault Roughness on Co-Seismic Near-Fault Stress Evolution
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Co-seismic displacements on fractures and faults close to large earthquakes may not contribute significantly to the shaking hazard for surface infrastructures. However, for deep geological nuclear waste repositories, such secondary displacements could, if large enough, damage intersected waste containers and constitute a significant long-term safety concern. To study how the potential for such displacements may depend on the earthquake rupture evolution, we simulate dynamic earthquake ruptures, and calculate the co-seismic evolution of Coulomb Failure Stress (CFS) on hypothetical fracture planes in the near-fault continuum. Poroelastic coupling is accounted for via Skempton’s coefficient B. We study three cases: (1) A planar fault with homogeneous properties. (2) A planar fault where the dynamic friction increases gradually along the fault edge to obtain a gentler rupture arrest. (3) An undulated fault with fractal properties. For Case 3, we consider ten different fault surface realizations. Since the undulations reduce fault slip, we also run models with adjusted dynamic friction coefficients, such that they generate seismic moments on par with that of Case 1. We observe the following: (i) The initial stress field, rather than the co-seismic stress effects, is the dominating influence on the fracture orientations that obtain the highest CFS values. (ii) Lower slip gradients and less fault slip in Case 2 reduce the maximum CFS by 10-15% relative to the reference case. (iii) Fault roughness may increase CFS locally by tens of percent. (iv) Given our reference value of B=0.5, B-value variations of ±0.5 would give CFS variations of ±20%, at most.

    National Category
    Geophysics
    Identifiers
    urn:nbn:se:uu:diva-346811 (URN)
    Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-04-04
    4. How does the Fault Rupture Model affect Simulated Co-Seismic Near-Fault Stress Evolution?
    Open this publication in new window or tab >>How does the Fault Rupture Model affect Simulated Co-Seismic Near-Fault Stress Evolution?
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The dynamic and static stress perturbations generated in an earthquake affect the stability of faults and fractures in the vicinity of the rupture. Estimates of co-seismic near-fault stress effects can be made using numerical simulations. Here, we study the co-seismic stress evolution close to an earthquake using two different models to simulate the rupture. One model is the linear slip-weakening (SW) model, where a spontaneous earthquake rupture is simulated. We compare this to a constant rupture velocity time-weakening (TW) model, which we implement in four different instances of rupture velocity Vr and strength reduction time interval Δtred. We evaluate the near-fault stress effects using the Coulomb Failure Stress (CFS), which we calculate from the stress evolution at various positions relative to the rupture plane. The results show that the TW method is capable of generating similar secondary effects as those generated by the SW model. However, the assumption of constant values of Δtred and Vr implies that there will always be locations on the rupture plane where these values are incompatible. We also see that variationsin Δtred and Vr have a significant impact on the results. Particularly, Vr is important for how the stresses around the rupture front are superimposed, and is thus important for the temporal evolution and spatial distribution of CFS around the fault. Lower Vr tends to generate a gentler near-fault stress evolution and lower peak CFS values. The results also indicate that not only the momentary value of Vr is important for the secondary stress effects at a near-fault position passed by the rupture, but also the integrated Vr-history up to that position.

    National Category
    Geophysics
    Research subject
    Geophysics with specialization in Seismology
    Identifiers
    urn:nbn:se:uu:diva-347597 (URN)
    Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-04-04
  • Public defence: 2018-05-28 13:15 Polhemssalen, Ångströmlaboratoriet, Uppsala
    Paulsson Do, Ulrica
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences.
    Psychosocial Vulnerability Underlying Unhealthy Behaviours in Swedish Adolescents2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The overall aim was to examine the relationship between Swedish school adolescents´ health-related behaviours and psychosocial and socio-demographic factors, with the purpose of identifying vulnerability factors for unhealthy behaviours and exploring adolescents’ own experiences and thoughts about this.

    Three studies were quantitative cross-sectional studies and used data from two different questionnaires. The fourth study was a qualitative study based on focus group interviews. The sample in study I consisted of 13–18-year-old adolescents (n= 10,590) and 15–16-year-old adolescents in studies II (n=492), III (n=492) and IV (n=36). The quantitative data were analysed using a number of different statistical methods. Foremost, structural equation modelling was used in studies I and II and Poisson regression analysis in study III. Study IV used qualitative content analysis by Graneheim and Lundman.

    The results indicated that nearly 60 per cent of 15–16-year-old adolescents have at least two unhealthy behaviours. Interrelated psychosocial and socio-demographic factors constituted vulnerability for unhealthy behaviours in general in adolescents. Good psychosocial relationships were strongly related with high well-being, whereas poor social relationships and low well-being were associated with unhealthy behaviours in general. Low socio-economic group was associated with unhealthy behaviours in general but the strength of this association varied between the adolescent age groups. Encouragement from parents to adopt healthy behaviours was associated with less unhealthy behaviours. Having adolescents who cared about what their parents said regarding health-related behaviours was also associated with a lower number of unhealthy behaviours. The school and family were important social environments for adolescents´ health-related behaviours. Similarly, friends and social media were important social contexts. Fellowship, and close social relationships, in particular, was important to healthy behaviours. Fellowship with others was also stated to influence high well-being. The experience of feeling pressure was stated to be associated with low well-being and unhealthy behaviours in adolescents.

    The thesis brings new knowledge to the field of psycho-social and socio-demographic factors associated with unhealthy behaviours in Swedish adolescents. Findings may be useful in supporting adolescents to reach positive health-related behaviours.

    List of papers
    1. Vulnerability to unhealthy behaviours across different age groups in Swedish Adolescents: A cross-sectional study
    Open this publication in new window or tab >>Vulnerability to unhealthy behaviours across different age groups in Swedish Adolescents: A cross-sectional study
    2014 (English)In: Health Psychology and Behavioral Medicine, ISSN 2164-2850, Vol. 2, no 1, p. 296-313Article in journal (Refereed) Published
    Abstract [en]

    Purpose:

    There is lack of evidence on the effects of health-promoting programmes among adolescents. Health behaviour models and studies seldom compare the underlying factors of unhealthy behaviours between different adolescent age groups. The main objective of this study was to investigate factors including sociodemographic parameters that were associated with vulnerability to health-damaging behaviours and non-adoption of health-enhancing behaviours in different adolescent age groups.

    Methods:

    A survey was conducted among 10,590 pupils in the age groups of 13–14, 15–16 and 17–18 years. Structural equation modelling was performed to determine whether health-damaging behaviours (smoking and alcohol consumption) and non-adoption of health-enhancing behaviours (regular meal habits and physical activity) shared an underlying vulnerability. This method was also used to determine whether gender and socio-economic status were associated with an underlying vulnerability to unhealthy behaviours.

    Results:

    The findings gave rise to three models, which may reflect the underlying vulnerability to health-damaging behaviours and non-adoption of health-enhancing behaviours at different ages during adolescence. The four behaviours shared what was interpreted as an underlying vulnerability in the 15–16-year-old age group. In the youngest group, all behaviours except for non-participation in physical activity shared an underlying vulnerability. Similarly, alcohol consumption did not form part of the underlying vulnerability in the oldest group. Lower socio-economic status was associated with an underlying vulnerability in all the age groups; female gender was associated with vulnerability in the youngest adolescents and male gender among the oldest adolescents.

    Conclusions:

    These results suggest that intervention studies should investigate the benefits of health-promoting programmes designed to prevent health-damaging behaviours and promote health-enhancing behaviours in adolescents of different ages. Future studies should examine other factors that may contribute to the underlying vulnerability in different age groups.

    National Category
    Public Health, Global Health, Social Medicine and Epidemiology Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-226085 (URN)10.1080/21642850.2014.892429 (DOI)
    Available from: 2014-06-11 Created: 2014-06-11 Last updated: 2018-04-09Bibliographically approved
    2. Psychosocial vulnerability underlying four common unhealthy behaviours in 15–16-year-old Swedish adolescents: a cross-sectional study
    Open this publication in new window or tab >>Psychosocial vulnerability underlying four common unhealthy behaviours in 15–16-year-old Swedish adolescents: a cross-sectional study
    2017 (English)In: BMC Psychology, E-ISSN 2050-7283, Vol. 5, article id 39Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND: Factors that influence unhealthy behaviours in adolescents may have different impacts in different sociocultural settings. There is lack of research on the association between psychosocial vulnerability and unhealthy behaviours in adolescents, particularly outside the United States. The aim was to investigate both direct and indirect relationships between psychosocial conditions (subjective well-being, social relationships and self-esteem) and four health-related behaviours (smoking, alcohol consumption, meal frequency and physical activity) in Swedish adolescents aged 15-16 years. Socio-demographic variables (socio-economic status, gender and age) were also investigated.

    METHODS: To study these associations, a hypothesised model was tested using structural equation modelling. In the hypothesised model, interrelated psychosocial conditions (low well-being, poor social relationships and low self-esteem) and socio-demographic factors (low self-perceived socio-economic status, being female and higher age) together represented a vulnerability underlying smoking, alcohol consumption, irregular meal frequency and low level of physical activity. In this cross-sectional study, self-report questionnaires were used to collect data from 492 adolescents.

    RESULTS: Hypothesised pathways between psychosocial conditions, socio-demographic factors and the four unhealthy behaviours were confirmed. Low well-being was strongly associated with unhealthy behaviours, and poor social relationships showed a strong indirect association with the unhealthy behaviours. Low self-esteem, low self-perceived socio-economic status and female gender were also vulnerability factors for the unhealthy behaviours.

    CONCLUSIONS: Vulnerability for four common unhealthy behaviours was found in Swedish adolescents. This study presents the interrelationships of psychosocial and socio-demographic factors and how they were related with unhealthy behaviours. The results bring new insight into how psychosocial factors are related to unhealthy behaviours in adolescents living in northern Europe.

    National Category
    Public Health, Global Health, Social Medicine and Epidemiology
    Identifiers
    urn:nbn:se:uu:diva-336735 (URN)10.1186/s40359-017-0209-9 (DOI)29246175 (PubMedID)
    Available from: 2017-12-15 Created: 2017-12-15 Last updated: 2018-04-08Bibliographically approved
    3. Health communication with parents and teachers and unhealthy behaviours in 15- to 16-year-old Swedes
    Open this publication in new window or tab >>Health communication with parents and teachers and unhealthy behaviours in 15- to 16-year-old Swedes
    2017 (English)In: Health Psychology and Behavioral Medicine, E-ISSN 2164-2850, Vol. 5, no 1, p. 229-257Article in journal (Refereed) Published
    Abstract [en]

    Background: Unhealthy behaviours during adolescence constitute a major risk for numerous diseases in adulthood.

    Aim: To explore the associations between multiple unhealthy behaviours in adolescents and health behaviour information communicated by their parents and teachers, how much the adolescents cared about this information and whether adolescents went to schools with an annual health-themed week or not.

    Methods: In this cross-sectional study, a self-reported questionnaire was delivered to pupils aged 15 and 16 (n = 492). The results were analysed using Poisson regression.

    Results: The number of unhealthy behaviours was lower in adolescents whose parents encouraged them to adopt healthy behaviours. Adolescents at schools with an annual health-themed week reported more unhealthy behaviours than other adolescents. In addition, attendance at such schools did not compensate for a lack of health behaviour information communicated by parents. Caring about health behaviour information communicated by parents was associated with fewer unhealthy behaviours. In contrast, the opposite was found when adolescents cared about health information communicated by teachers.

    Conclusion: It is important for parents to encourage their adolescent children to adopt healthy behaviours because this is particularly effective at lowering the number of unhealthy behaviours in adolescents. It also appears to be important for parents and teachers to develop credibility among adolescents regarding information communicated about health issues. The results also indicate the importance of involving parents in the school health work to influence them to encourage their adolescent children to adopt healthy behaviours.

    National Category
    Public Health, Global Health, Social Medicine and Epidemiology
    Identifiers
    urn:nbn:se:uu:diva-324318 (URN)10.1080/21642850.2017.1316666 (DOI)000424575500016 ()
    Funder
    Lars Hierta Memorial Foundation
    Available from: 2017-06-14 Created: 2017-06-14 Last updated: 2018-04-08Bibliographically approved
    4. How 15–16-year-old Swedish adolescents experience associations of social relationships with health-related behaviours: A qualitative study
    Open this publication in new window or tab >>How 15–16-year-old Swedish adolescents experience associations of social relationships with health-related behaviours: A qualitative study
    (English)In: Article in journal (Refereed) Submitted
    National Category
    Public Health, Global Health, Social Medicine and Epidemiology
    Identifiers
    urn:nbn:se:uu:diva-347826 (URN)
    Available from: 2018-04-08 Created: 2018-04-08 Last updated: 2018-04-08
  • Public defence: 2018-05-29 10:00 Seminar Room, Belém
    Cardias Alves de Almeida, Ramon
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Electronic structure and exchange interactions from ab initio theory: New perspectives and implementations2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, the magnetic properties of several materials were investigated using first principle calculations. The ab initio method named real space linear muffin-tin orbitals atomic sphere approximation (RS-LMTO-ASA) was used to calculate the electronic structure and magnetic properties of bulk systems, surface and nanostructures adsorbed on surfaces.

    We have implemented new features in the RS-LMTO-ASA method, such as the calculation of (a) Bloch Spectral Function (BSF), (b) orbital resolved Jij and (c) Dzyaloshinskii-Moriya interaction (DMI). Using (a), we have shown that one can calculate the dispersion relation for bulk systems using a real space method. Furthermore, the dispersion relation was revealed to be existent even for finite one-dimensional structures, such as the Mn chain on Au(111) and Ag(111) surfaces. With (b), we have investigated the orbital resolved exchange coupling parameter Jij for 3d metals. It is demonstrated that the nearest neighbor (NN) interaction for bcc Fe has intriguing behavior, however, the contribution coming from the T2g orbitals favours the anti-ferromagnetic coupling behavior. Moreover, the Fermi surface for bcc Fe is formed mostly by the T2g orbitals and these are shown to be highly Heisenberg-like, i.e. do not depend significantly on the magnetic configuration. Later, the same approach was used to study other transition metals, such as Cr, Mn, Co and Ni. In the end, we have presented the results obtained with the implementation (c). Our results have shown the large dependence of the DMI values, both the strength and direction, with respect to which magnetic configuration they are calculated from. We argue that, for the investigated systems, the non-collinearity induces currents (spin and charge) that will influence directly the DMI vectors.

    List of papers
    1. Magnetic and electronic structure of Mn nanostructures on Ag(111) and Au(111)
    Open this publication in new window or tab >>Magnetic and electronic structure of Mn nanostructures on Ag(111) and Au(111)
    Show others...
    2016 (English)In: PHYSICAL REVIEW B, ISSN 2469-9950, Vol. 93, no 1, article id 014438Article in journal (Refereed) Published
    Abstract [en]

    We present results of the electronic and magnetic structure of Mn nanowires adsorbed on Ag(111) and Au(111) surfaces. For finite Mn nanowires on Ag(111) and Au(111) surfaces, our ab initio results show that the large difference between the spin-orbit splitting of these two surfaces leads to completely different magnetic configurations. The magnetic ordering for Mn nanowires adsorbed on Ag(111) is governed by the strong exchange interaction between Mn adatoms. For Mn nano-chains on Au(111), the competition between Heisenberg and Dzyaloshinskii-Moriya interactions leads to a complex magnetic structure of the clusters considered here. Among the more conspicuous results we note a spin-spiral helical type for the nanowire with seven atoms, and a complex magnetic configuration incommensurate with the substrate lattice for a double-sized Mn wire. The effect of the structural relaxation is also investigated, showing sensitivity of the exchange interactions to the bond distance to the substrate. We also demonstrate that small changes in the band filling of these Mn chains results in drastically different changes of the interatomic exchange. Finally, we show that dispersion of the electronic energy spectrum is possible even in nanostructures with bounded spatial extension.

    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-279629 (URN)10.1103/PhysRevB.93.014438 (DOI)000369216100007 ()
    Funder
    Swedish Research CouncileSSENCE - An eScience CollaborationKnut and Alice Wallenberg Foundation
    Available from: 2016-03-08 Created: 2016-03-02 Last updated: 2018-04-07Bibliographically approved
    2. The Bethe-Slater curve revisited; new insights from electronic structure theory
    Open this publication in new window or tab >>The Bethe-Slater curve revisited; new insights from electronic structure theory
    Show others...
    2017 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 4058Article in journal (Refereed) Published
    Abstract [en]

    The Bethe-Slater (BS) curve describes the relation between the exchange coupling and interatomic distance. Based on a simple argument of orbital overlaps, it successfully predicts the transition from antiferromagnetism to ferromagnetism, when traversing the 3d series. In a previous article [Phys. Rev. Lett. 116, 217202 (2016)] we reported that the dominant nearestneighbour (NN) interaction for 3d metals in the bcc structure indeed follows the BS curve, but the trends through the series showed a richer underlying physics than was initially assumed. The orbital decomposition of the inter-site exchange couplings revealed that various orbitals contribute to the exchange interactions in a highly non-trivial and sometimes competitive way. In this communication we perform a deeper analysis by comparing 3d metals in the bcc and fcc structures. We find that there is no coupling between the E-g orbitals of one atom and T-2g orbitals of its NNs, for both cubic phases. We demonstrate that these couplings are forbidden by symmetry and formulate a general rule allowing to predict when a similar situation is going to happen. In gamma-Fe, as in alpha-Fe, we find a strong competition in the symmetry-resolved orbital contributions and analyse the differences between the high-spin and low-spin solutions.

    Place, publisher, year, edition, pages
    NATURE PUBLISHING GROUP, 2017
    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:uu:diva-330728 (URN)10.1038/s41598-017-04427-9 (DOI)000403874900041 ()28642615 (PubMedID)
    Funder
    Swedish Research CouncilKnut and Alice Wallenberg Foundation
    Note

    Erratum

    doi:10.1038/s41598-017-09611-5

    In the original version of this Article, Y. O. Kvashnin was incorrectly affiliated with ‘Faculdade de Fisica, Universidade Federal do Para, Belem, PA, Brazil’. The correct affiliation is listed below.

    Department of Physics and Astronomy, Division of Materials Theory, Uppsala University, Box 516, SE-75120, Uppsala, Sweden.

    This error has now been corrected in the PDF and HTML versions of the Article.

    Available from: 2017-10-10 Created: 2017-10-10 Last updated: 2018-04-07Bibliographically approved
    3. Microscopic Origin of Heisenberg and Non-Heisenberg Exchange Interactions in Ferromagnetic bcc Fe
    Open this publication in new window or tab >>Microscopic Origin of Heisenberg and Non-Heisenberg Exchange Interactions in Ferromagnetic bcc Fe
    Show others...
    2016 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 116, no 21, article id 217202Article in journal (Refereed) Published
    Abstract [en]

    By means of first principles calculations, we investigate the nature of exchange coupling in ferromagnetic bcc Fe on a microscopic level. Analyzing the basic electronic structure reveals a drastic difference between the 3d orbitals of E-g and T-2g symmetries. The latter ones define the shape of the Fermi surface, while the former ones form weakly interacting impurity levels. We demonstrate that, as a result of this, in Fe the T-2g orbitals participate in exchange interactions, which are only weakly dependent on the configuration of the spin moments and thus can be classified as Heisenberg-like. These couplings are shown to be driven by Fermi surface nesting. In contrast, for the E-g states, the Heisenberg picture breaks down since the corresponding contribution to the exchange interactions is shown to strongly depend on the reference state they are extracted from. Our analysis of the nearest-neighbor coupling indicates that the interactions among E-g states are mainly proportional to the corresponding hopping integral and thus can be attributed to be of double-exchange origin. By making a comparison to other magnetic transition metals, we put the results of bcc Fe into context and argue that iron has a unique behavior when it comes to magnetic exchange interactions.

    National Category
    Other Physics Topics
    Identifiers
    urn:nbn:se:uu:diva-298894 (URN)10.1103/PhysRevLett.116.217202 (DOI)000376628800010 ()27284671 (PubMedID)
    Funder
    EU, European Research Council, 338957 FEMTO/NANOSwedish Research CouncileSSENCE - An eScience CollaborationKnut and Alice Wallenberg Foundation, 2012.0031 2013.0020
    Available from: 2016-07-12 Created: 2016-07-12 Last updated: 2018-04-07Bibliographically approved
    4. Magnetism and ultrafast magnetization dynamics of Co and CoMn alloys at finite temperature
    Open this publication in new window or tab >>Magnetism and ultrafast magnetization dynamics of Co and CoMn alloys at finite temperature
    Show others...
    2017 (English)In: Physical review B, ISSN 2469-9950, Vol. 95, no 21, article id 214417Article in journal (Refereed) Published
    Abstract [en]

    Temperature-dependent magnetic experiments such as pump-probe measurements generated by a pulsed laser have become a crucial technique for switching the magnetization in the picosecond time scale. Apart from having practical implications on the magnetic storage technology, the research field of ultrafast magnetization poses also fundamental physical questions. To correctly describe the time evolution of the atomic magnetic moments under the influence of a temperature-dependent laser pulse, it remains crucial to know if the magnetic material under investigation has magnetic excitation spectrum that is more or less dependent on the magnetic configuration, e.g., as reflected by the temperature dependence of the exchange interactions. In this paper, we demonstrate from first-principles theory that the magnetic excitation spectra in Co in fcc, bcc, and hcp structures are nearly identical in a wide range of noncollinear magnetic configurations. This is a curious result of a balance between the size of the magnetic moments and the strength of the Heisenberg exchange interactions, that in themselves vary with configuration, but put together in an effective spin Hamiltonian results in a configuration-independent effective model. We have used such a Hamiltonian, together with ab initio calculated damping parameters, to investigate the magnon dispersion relationship as well as ultrafast magnetization dynamics of Co and Co-rich CoMn alloys.

    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-308321 (URN)10.1103/PhysRevB.95.214417 (DOI)000404015400003 ()
    Funder
    Swedish Research CouncilKnut and Alice Wallenberg Foundation, 2013.0020, 2012.0031StandUp
    Available from: 2016-11-24 Created: 2016-11-24 Last updated: 2018-04-07Bibliographically approved
    5. Theory of noncollinear interactions beyond Heisenberg exchange: Applications to bcc Fe
    Open this publication in new window or tab >>Theory of noncollinear interactions beyond Heisenberg exchange: Applications to bcc Fe
    Show others...
    2017 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 96, no 14, article id 144413Article in journal (Refereed) Published
    Abstract [en]

    We show for a simple noncollinear configuration of the atomistic spins (in particular, where one spin is rotated by a finite angle in a ferromagnetic background) that the pairwise energy variation computed in terms of multiple-scattering formalism cannot be fully mapped onto a bilinear Heisenberg spin model even in the absence of spin-orbit coupling. The non-Heisenberg terms induced by the spin-polarized host appear in leading orders in the expansion of the infinitesimal angle variations. However, an E-g - T-2g symmetry analysis based on the orbital decomposition of the exchange parameters in bcc Fe leads to the conclusion that the nearest-neighbor exchange parameters related to the T-2g orbitals are essentially Heisenberg-like: they do not depend on the spin configuration, and can, in this case, be mapped onto a Heisenberg spin model even in extreme noncollinear cases.

    Place, publisher, year, edition, pages
    AMER PHYSICAL SOC, 2017
    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:uu:diva-340146 (URN)10.1103/PhysRevB.96.144413 (DOI)000412699400003 ()
    Funder
    Swedish Research CouncilKnut and Alice Wallenberg Foundation, 2012.0031Knut and Alice Wallenberg Foundation, 2013.0020EU, FP7, Seventh Framework Programme, 600382
    Available from: 2018-01-26 Created: 2018-01-26 Last updated: 2018-04-07Bibliographically approved
    6. First-principles Dzyaloshinskii-Moryia interaction in a non-collinear framework
    Open this publication in new window or tab >>First-principles Dzyaloshinskii-Moryia interaction in a non-collinear framework
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Including dierent terms in the spin-Hamiltonian, we have derived an expression for theDzyaloshinskii-Moryia vector interaction (DMI) where all the three components of the vector canbe calculated independently of the magnetic conguration. Here, we have chosen the Cr triangulartrimer on Au(111) and Mn triangular trimes on Ag(111) and Au(111) surfaces to study the implementationof the derived DMI into the RS-LMTO-ASA method. Our results have shown thatthe DMI value (module and direction) is drastically dierent for collinear and non-collinear states.Based on relation between the spin and charge currents owing in the system and the non-collinearmagnetic conguration of the triangular trimer, we argued that the drastic change between the DMIcalculated considering a collinear and a non-collinear magnetic conguration can be explained bythe mechanism behind the spin and charge currents owing through the atoms when the spins arealigned in a non-collinear fashion.

    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-347808 (URN)
    Available from: 2018-04-07 Created: 2018-04-07 Last updated: 2018-04-07
  • Public defence: 2018-05-29 10:15 Hörsal 2, Uppsala
    Andone, Irina
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Economics.
    Exchange Rates, Exports, Inflation, and International Monetary Cooperation2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis consists of three self-contained essays.

     

    Essay I: Exchange rate movements often cause anxiety among policy-makers, given the strong link between currency movements and export competitiveness, which may, in turn, affect economic growth. In this paper, I examine the strength of the effect of exchange rate movements on exports combining firm-level export data with an industry-level competitiveness index. The data span a broad sample of countries, comprising 21 advanced and 21 emerging market economies over the period 1989-2013. My findings suggest an economically and statistically significant negative effect of real appreciation on real exports. The effect is significantly larger for emerging markets as compared to advanced economies. ​Additionally, the results suggest that larger firms are particularly affected by exchange rate movements.

    Essay II: Simulations of a small open economy model à la Gali and Monacelli (2005) suggest that inflation should display similar levels, but higher volatility and higher persistence under a fixed exchange rate regime compared to a regime with a flexible exchange rate and some form of inflation targeting. I test these predictions using data for two clearly defined exchange rate regimes. One regime is the membership in the Economic and Monetary Union (EMU), which implies an irrevocably fixed exchange rate. The other is a flexible exchange rate with inflation targeting. The empirical analysis confirms the theoretical implications of the model in terms of persistence: inflation displays a higher degree of persistence in countries with a fixed exchange rate regime.

    Essay III (with Beatrice Scheubel): While the consequences and effectiveness of IMF conditionality have long constituted the focus of research, the possible negative impact of IMF conditionality on countries' willingness to start an IMF program has mainly focused on a country's own past experience. However, the recent policy debate has highlighted the existence of regional effects, unrelated to a country's own experience. In this paper, we investigate how past experience with IMF conditionality – own and peers' – affects countries' likelihood of signing an IMF arrangement again. Our results indicate strong learning from own experience, but hardly any learning from peers, except for members of the Association of Southeast Asian Nations (ASEAN). We conjecture that a negative effect associated with IMF conditionality may exist for individual country cases or specific regions, but that a more general effect cannot be related to observing how the IMF treats peers.

  • Public defence: 2018-05-29 13:15 Rosénsalen, Uppsala
    Tadesse, Amare Worku
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, International Maternal and Child Health (IMCH). Addis Continental Institute of Public Health, Ethiopia.
    Identification and Community Management of Severe Acute Malnutrition: Empirical evidence in rural Southern Ethiopia2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The current recommended standard management for all children with severe acute malnutrition (SAM) is Community-based Management of Acute Malnutrition (CMAM). CMAM has a community-based outpatient therapeutic program (OTP) to treat uncomplicated SAM and has been scaled-up and integrated with government health services in low-resource settings. How-ever, the context in which such large-scale programs are implemented modifies their effective-ness. This study aims at assessing factors of importance for the effectiveness of management of SAM in the community.

    A population-based survey of households with children aged under five years and a longitu-dinal study among children admitted to the integrated OTPs of rural Southern Ethiopia was undertaken. For Study I, children aged 6-59 months (n=4,297) from randomly selected house-holds were examined for differences between children identified as SAM by MUAC and WHZ. For Study II, subsets of 1,048 children admitted to OTPs were analyzed for program outcome and nutritional status at discharge (n=759) and 14 weeks after admission (n=991). For Study III, non-oedematous children (n=661) admitted to OTPs were analyzed for gains in anthropo-metric measures after 4 weeks of treatment. For Study IV, children with SAM (n=788) were studied in terms of factors of importance for their recovery. Home-visits were used to collect data and anthropometry was measured following standardized World Health Organization (WHO) techniques.

    The degree of agreement between the two anthropometric indicators of severe wasting dif-fered depending on the sex and age of the children. The indicators’ response to treatment varied according to the indicator used to define SAM at admission. While 32.7% achieved the program’s recovery criteria at discharge, 29.6% had SAM at discharge and 72.1% of children were acutely malnourished at the end of 14 weeks of follow-up. Despite low recovery rate, children of caregivers with the highest decision-making autonomy recovered faster from SAM than children of caregivers with lower autonomy.

    The poor agreement between MUAC and WHZ in diagnosing SAM within different groups of children indicates each anthropometric indicator may select different set of children for treatment. Our study provided empirical evidence that supports the current recommendation to use MUAC and WHZ independently for the management of SAM. Linking CMAM to other com-plementary programmes may improve the effectiveness of integrated large-scale nutrition programmes.

    List of papers
    1. Comparison of Mid-Upper Arm Circumference and Weight-for-Height to Diagnose Severe Acute Malnutrition: A Study in Southern Ethiopia
    Open this publication in new window or tab >>Comparison of Mid-Upper Arm Circumference and Weight-for-Height to Diagnose Severe Acute Malnutrition: A Study in Southern Ethiopia
    2017 (English)In: Nutrients, ISSN 2072-6643, E-ISSN 2072-6643, Vol. 9, no 3, article id 267Article in journal (Refereed) Published
    Abstract [en]

    Weight-for-height Z-score (WHZ) and mid-upper arm circumference (MUAC) are two independent anthropometric indicators for diagnosing and admitting children with severe acute malnutrition (SAM) for treatment. While severely wasted children are at high risk of mortality, MUAC and WHZ do not always identify the same population of children as having SAM. Understanding how this discrepancy relates to age and sex may provide valuable information for care programmes for children with SAM. Age and sex distribution for differences between children identified as SAM by MUAC and WHZ were examined and the degree of agreement calculated. Children (n = 4297) aged 6-59 months with validated anthropometric measures were recruited from a population-based survey conducted in rural southern Ethiopia. MUAC < 115 mm and WHZ < 3 were used to define severe wasting as per the World Health Organization (WHO) classification. The kappa coefficient (kappa) was calculated. There was fair agreement between the MUAC and WHZ definitions of severe wasting in boys (kappa = 0.37) and children younger than 24 months (kappa = 0.32) but poor agreement in girls (kappa = 0.15) and children aged 24 months and above (kappa = 0.13). More research is needed on response to treatment and prediction of mortality using different anthropometric measurements in relation to ages and sex of children.

    Place, publisher, year, edition, pages
    MDPI AG, 2017
    Keyword
    MUAC, WHZ, severe acute malnutrition, agreement, age, sex and children
    National Category
    Nutrition and Dietetics
    Identifiers
    urn:nbn:se:uu:diva-320872 (URN)10.3390/nu9030267 (DOI)000397023600086 ()
    Funder
    Sida - Swedish International Development Cooperation Agency, SWE-2010-179
    Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2018-04-08Bibliographically approved
    2. An integrated community-based outpatient therapeutic feeding programme for severe acute malnutrition in rural Southern Ethiopia: Recovery, fatality, and nutritional status after discharge.
    Open this publication in new window or tab >>An integrated community-based outpatient therapeutic feeding programme for severe acute malnutrition in rural Southern Ethiopia: Recovery, fatality, and nutritional status after discharge.
    2017 (English)In: Maternal and Child Nutrition, ISSN 1740-8695, E-ISSN 1740-8709Article in journal (Refereed) Epub ahead of print
    Abstract [en]

    A scaled up and integrated outpatient therapeutic feeding programme (OTP) brings the treatment of severely malnourished children closer to the community. This study assessed recovery from severe acute malnutrition (SAM), fatality, and acute malnutrition up to 14 weeks after admission to a programme integrated in the primary health care system. In this cohort study, 1,048 children admitted to 94 OTPs in Southern Ethiopia were followed for 14 weeks. Independent anthropometric measurements and information on treatment outcome were collected at four home visits. Only 32.7% (248/759) of children with SAM on admission fulfilled the programme recovery criteria at the time of discharge (i.e., gained 15% in weight, or oedema, if present at admission, was resolved at discharge). Of all children admitted to the programme for whom nutritional assessment was done 14 weeks later, 34.6% (321/928) were severely malnourished, and 37.5% (348/928) were moderately malnourished; thus, 72.1% were acutely malnourished. Of the children, 27/982 (2.7%) had died by 14 weeks, of whom all but one had SAM on admission. Children with severe oedema on admission had the highest fatality rate (12.0%, 9/75). The median length of admission to the programme was 6.6 weeks (interquartile range: 5.3, 8.4 weeks). Despite children participating for the recommended duration of the programme, many children with SAM were discharged still acutely malnourished and without reaching programme criteria for recovery. For better outcome of OTP, constraints in service provision by the health system as well as challenges of service utilization by the beneficiaries should be identified and addressed.

    Keyword
    Ethiopia, integrated outpatient therapeutic programme, outcome, recovery, severe acute child malnutrition
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-331991 (URN)10.1111/mcn.12519 (DOI)29024381 (PubMedID)
    Available from: 2017-10-20 Created: 2017-10-20 Last updated: 2018-04-08
    3. Choosing Anthropometric Indicators to Monitor the Response to Treatment for Severe Acute Malnutrition in Rural Southern Ethiopia: Empirical Evidence
    Open this publication in new window or tab >>Choosing Anthropometric Indicators to Monitor the Response to Treatment for Severe Acute Malnutrition in Rural Southern Ethiopia: Empirical Evidence
    2017 (English)In: Nutrients, ISSN 2072-6643, E-ISSN 2072-6643, Vol. 9, no 12, article id 1339Article in journal (Refereed) Published
    Abstract [en]

    The World Health Organization (WHO) recommends the assessment of nutritional recovery using the same anthropometric indicator that was used to diagnose severe acute malnutrition (SAM) in children. However, related empirical evidence from low-income countries is lacking. Non-oedematous children (n = 661) aged 6–59 months admitted to a community-based outpatient therapeutic program for SAM in rural southern Ethiopia were studied. The response to treatment in children admitted to the program based on the mid-upper arm circumference (MUAC) measurement was defined by calculating the gains in average MUAC and weight during the first four weeks of treatment. The children showed significant anthropometric changes only when assessed with the same anthropometric indicator used to define SAM at admission. Children with the lowest MUAC at admission showed a significant gain in MUAC but not weight, and children with the lowest weight-for-height/length (WHZ) showed a significant gain in weight but not MUAC. The response to treatment was largest for children with the lowest anthropometric status at admission in either measurement. MUAC and weight gain are two independent anthropometric measures that can be used to monitor sufficient recovery in children treated for SAM. This study provides empirical evidence from a low-income country to support the recent World Health Organization recommendation.

    National Category
    Public Health, Global Health, Social Medicine and Epidemiology
    Identifiers
    urn:nbn:se:uu:diva-336874 (URN)10.3390/nu9121339 (DOI)000419188600064 ()
    Available from: 2017-12-18 Created: 2017-12-18 Last updated: 2018-04-08Bibliographically approved
    4. Does caregivers’ autonomy influence recovery from Severe Acute Malnutrition in an integrated community-based outpatient Therapeutic Feeding Program?
    Open this publication in new window or tab >>Does caregivers’ autonomy influence recovery from Severe Acute Malnutrition in an integrated community-based outpatient Therapeutic Feeding Program?
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Caregivers’ autonomy is important for child nutritional status as it improves the availability of food and access to health resources necessary for children’s growth and recovery from illnesses. However, evidence on the extent of influence of caregivers’ autonomy during recovery from severe acute malnutrition (SAM) is limited. A cohort of children (n=788) aged 6-59 months admitted to community-based outpatient therapeutic programme (OTP) for SAM in rural southern Ethiopia were studied. Recovery from SAM was defined by MUAC ≥ 125 mm and absence of edema after treatment in OTP. A Kaplan Meier (KM) survival analysis was employed to estimate the recovery rates of the children treated for SAM for different level of caregivers’ autonomy and multivariable Cox proportional hazard regression analysis was used to control for confounding. Results from adjusted cox proportional hazard regression analysis indicated that children of caregivers with higher decision-making autonomy recovered more rapidly from SAM than children of caregivers with lower autonomy. Promotion of caregivers’ autonomy could augment effectiveness of a scaled up and integrated outpatient therapeutic feeding programme.

    Keyword
    Caregivers’ autonomy, severe acute malnutrition, outpatient therapeutic programme recovery, children
    National Category
    Nutrition and Dietetics
    Identifiers
    urn:nbn:se:uu:diva-347807 (URN)
    Projects
    COMSAM
    Funder
    Sida - Swedish International Development Cooperation Agency
    Available from: 2018-04-07 Created: 2018-04-07 Last updated: 2018-04-08
  • Public defence: 2018-05-30 09:00 ITC/2446, Uppsala
    Zhu, Yunyun
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Computer Systems.
    Caches, Transactions and Memories: Models, Coherence and Consistency2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Computers have brought us inestimable convenience in recent years. We have become dependent on them and more sensitive to their performance. During the past decades, we have been trying to improve program efficiency. The invention of multi-core systems is regarded as the new era of boosting performance of computer programs. When we focus on improving program efficiency, we also need to pay attention to program correctness. In some specific areas, errors, aka bugs, of programs can cause disastrous consequences. The dominant approach to bug detection is testing, which is conducted by executing a program against test cases generated based on scenarios. A bug is found when the output of the program does not match the expected output defined in the test case. One main drawback of testing is that it only shows the presence of bugs. An alternative approach is formal verification, which is a method that can exhaustively analyze the program executions and therefore show the absence of bugs. This thesis focuses on one of the main areas of formal verification - model checking. Model checking analyzes a mathematical model extracted from a program and automatically checks if it satisfies the desired properties.

    In this thesis, we first consider verifying safety and liveness properties for transactional memories. In particular, we consider the FlexTM hybrid transactional memory. We build a formal model of FlexTM, and apply a small model theorem that restricts the number of threads and variables in the model. This allows us to reduce the problem of verifying safety and liveness properties of FlexTM to checking language inclusion between the automata of FlexTM and a reference transactional memory. Second, we present a method for automatic verification of cache coherence protocols in the presence of transactional memories. We build a formal model containing a filter that represents the conflict resolution strategies of the transactional memory. We also apply a small model theorem which limits the number of cache lines of the protocol. To check cache coherence, we extend a backward reachability algorithm for infinite state systems, by removing the traces not allowed by the filter. Using this technique, we verify two cache protocols under different transactional memories respectively and conclude that they both maintain coherence.  Finally, we consider verification of safety properties of programs running over Self-Invalidate and Self-Downgrade cache coherence protocols. To that end, we define a formal model which captures the weak memory model induced by such protocols. We design an algorithm for inserting a set of optimal fences in the program, which guarantees the safety property while still maintaining the efficiency of a maximal degree.

    List of papers
    1. Verifying safety and liveness for the FlexTM hybrid transactional memory
    Open this publication in new window or tab >>Verifying safety and liveness for the FlexTM hybrid transactional memory
    Show others...
    2013 (English)Conference paper, Published paper (Refereed)
    Abstract [en]

    We consider the verification of safety (strict serializability and abort consistency) and liveness obstruction and livelock freedom) for the hybrid transactional memory framework FlexTM. This framework allows for flexible implementations of transactional memories based on an adaptation of the MESI coherence protocol. FlexTM allows for both eager and lazy conflict resolution strategies. Like in the case of Software Transactional Memories, the verification problem is not trivial as the number of concurrent transactions, their size, and the number of accessed shared variables cannot be a priori bounded. This complexity is exacerbated by aspects that are specific to hardware and hybrid transactional memories. Our work takes into account intricate behaviours such as cache line based conflict detection, false sharing, invisible reads or non-transactional instructions. We carry out the first automatic verification of a hybrid transactional memory and establish, by adopting a small model approach, challenging properties such as strict serializability, abort consistency, and obstruction freedom for both an eager and a lazy conflict resolution strategies. We also detect an example that refutes livelock freedom. To achieve this, our prototype tool makes use of the latest antichain based techniques to handle systems with tens of thousands of states.

    Place, publisher, year, edition, pages
    Grenoble, France: , 2013
    National Category
    Computer Systems
    Identifiers
    urn:nbn:se:uu:diva-213232 (URN)978-1-4503-2153-2 (ISBN)
    Conference
    Design, Automation and Test in Europe, DATE 13, Grenoble, France, March 18-22, 2013
    Projects
    UPMARC
    Available from: 2013-12-19 Created: 2013-12-19 Last updated: 2018-04-09
    2. Verification of Cache Coherence Protocols wrt. Trace Filters
    Open this publication in new window or tab >>Verification of Cache Coherence Protocols wrt. Trace Filters
    Show others...
    2015 (English)In: Proc. 15th Conference on Formal Methods in Computer-Aided Design, Piscataway, NJ: IEEE , 2015, p. 9-16Conference paper, Published paper (Refereed)
    Place, publisher, year, edition, pages
    Piscataway, NJ: IEEE, 2015
    National Category
    Computer Sciences
    Identifiers
    urn:nbn:se:uu:diva-272322 (URN)978-0-9835678-5-1 (ISBN)
    Conference
    FMCAD 2015, September 27–30, Austin, TX
    Projects
    UPMARC
    Available from: 2015-09-30 Created: 2016-01-13 Last updated: 2018-04-09
    3. Fencing programs with self-invalidation and self-downgrade
    Open this publication in new window or tab >>Fencing programs with self-invalidation and self-downgrade
    Show others...
    2016 (English)In: Formal Techniques for Distributed Objects, Components, and Systems, Springer, 2016, p. 19-35Conference paper, Published paper (Refereed)
    Place, publisher, year, edition, pages
    Springer, 2016
    Series
    Lecture Notes in Computer Science, ISSN 0302-9743 ; 9688
    National Category
    Computer Engineering
    Identifiers
    urn:nbn:se:uu:diva-300663 (URN)10.1007/978-3-319-39570-8_2 (DOI)000379297600002 ()978-3-319-39569-2 (ISBN)
    Conference
    FORTE 2016, June 6–9, Heraklion, Greece
    Projects
    UPMARC
    Available from: 2016-05-24 Created: 2016-08-10 Last updated: 2018-04-09Bibliographically approved
    4. Mending fences with self-invalidation and self-downgrade
    Open this publication in new window or tab >>Mending fences with self-invalidation and self-downgrade
    Show others...
    2018 (English)In: Logical Methods in Computer Science, ISSN 1860-5974, E-ISSN 1860-5974, Vol. 14, no 1, article id 6Article in journal (Refereed) Published
    National Category
    Computer Sciences
    Identifiers
    urn:nbn:se:uu:diva-347675 (URN)000426512000004 ()
    Available from: 2018-01-16 Created: 2018-04-06 Last updated: 2018-05-17Bibliographically approved
  • Public defence: 2018-05-30 09:00 Häggsalen, Uppsala
    Wani, Ishtiaq Hassan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Fabrication, functionalization and electrical conductance modulation of nanoparticle based molecular electronic Nano-devices2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Over the years many techniques have been proposed for the purpose of the formation of electrically conducting metal-molecule-metal junctions. One such technique utilizes gold-nanoparticles (AuNPs) that could assist in contacting small molecules between large gaps. The Ideal device structure then comprises of one nanoparticle and two molecules that are aligned as electrode1-molecule-AuNP-molecule-electrode2.

    In present work these AuNP-molecule hybrids were fabricated inside sub 20 nm sized nanogaps between nanoelectrodes. The nanogaps were fabricated by milling of thin gold wires using focused ion beam. The tuning of the ion dosage resulted in the tuning of the gap size and the smallest nanogap of 2.3 nm was achieved.

    The nano molecular electronic device (nanoMoED) platform comprised of the AuNPs that were assembled inside the nanogaps via dielectrophoresis. Two types of the AuNPs were used that were different from each other due to their functionalization chemistry. The low bias resistance 'RLB' of the nanoMoED platform was (i) reduced as compared to the nanogaps (ii) remained stable in toluene and air, and (iii) was reduced when exposed to the electron beam.

    The nanoMoED platform was functionalized with various molecules using the molecular place exchange method. The successful functionalization resulted in the reduction of the 'RLB'. The smallest value of the 'RLBof the nanoMoED devices was achieved when the inserted molecule was not only highly conducting but also its length was same as the initial spacing between the AuNPs.

    The nitrogen dioxide (NO2) molecules reduced the 'RLBof the nanoMoED devices that were made with 4,4'-biphenyl dithiol. The theoretical simulations showed that this reduction was due to the induced states at Fermi energy of the junction. The nanoMoED devices made with 1,8-octanedithiol showed conductance switching between two levels because of different geometries of the Au-S contact. This switching vanished when these devices were exposed to NO2 and a strong enhancement of signal to noise ratio was observed.

    On the basis of these results this thesis suggests possible routes for the fabrication of highly conducting nanoMoED devices as well as elucidates the possibility of using the nanoMoED devices for gas sensing applications.

    List of papers
    1. Fabrication of reproducible sub-5 nm nanogaps by a focused ion beam and observation of Fowler-Nordheim tunneling
    Open this publication in new window or tab >>Fabrication of reproducible sub-5 nm nanogaps by a focused ion beam and observation of Fowler-Nordheim tunneling
    Show others...
    2015 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 107, no 10, article id 103108Article in journal (Refereed) Published
    Abstract [en]

    Creating a stable high resistance sub-5 nm nanogap in between conductive electrodes is one of the major challenges in the device fabrication of nano-objects. Gap-sizes of 20 nm and above can be fabricated reproducibly by the precise focusing of the ion beam and careful milling of the metallic lines. Here, by tuning ion dosages starting from 4.6 x 10(10) ions/cm and above, reproducible nanogaps with sub-5 nm sizes are milled with focused ion beam. The resistance as a function of gap dimension shows an exponential behavior, and Fowler-Nordheim tunneling effect was observed in nanoelectrodes with sub-5 nm nanogaps. The application of Simmon's model to the milled nanogaps and the electrical analysis indicates that the minimum nanogap size approaches to 2.3 nm.

    National Category
    Physical Sciences Other Engineering and Technologies
    Identifiers
    urn:nbn:se:uu:diva-264851 (URN)10.1063/1.4930821 (DOI)000361640200043 ()
    Available from: 2015-10-19 Created: 2015-10-19 Last updated: 2018-04-12Bibliographically approved
    2. Designing sterically demanding thiolate coated AuNPs for electrical characterization of BPDT in a NP-molecule-nanoelectrode platform
    Open this publication in new window or tab >>Designing sterically demanding thiolate coated AuNPs for electrical characterization of BPDT in a NP-molecule-nanoelectrode platform
    Show others...
    2017 (English)In: MOLECULAR SYSTEMS DESIGN & ENGINEERING, ISSN 2058-9689, Vol. 2, no 2, p. 133-139Article in journal (Refereed) Published
    Abstract [en]

    Molecular electronics with single or few molecules requires a stable metal-molecule nanojunction platform. Herein, we report the design and synthesis of gold nanoparticles coated with sterically demanding thiol ligands that are essential to fabricate a versatile and stable nanoelectrode-molecule-nanoparticle platform suitable for electrical characterization of small organic molecules. By combining.-tetraphenylmethane ether functionalized alkyl thioacetate and alkyl thiols, we prepared highly stable gold nanoparticles in a one-phase reaction providing simple and efficient purification. This robust preparation gives highly pure nanoparticles in very high yields (up to 90%) with long-time shelf stability. The synthesis in this work has superior reproducibility compared to previous synthesis processes that are currently being used for such molecular electronics platforms. Electron microscopy confirms the formation of uniform and small nanoparticles in the range of 5 to 7 nm. These nanoparticles with different ligand surface coverages were placed in a 20 nm nanoelectrode setup using dielectrophoretic forces. This setup was utilized to characterize the conductivity of the molecular wire 4,4'-biphenyldithiol introduced via ligand placeexchange under ambient conditions.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2017
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-323512 (URN)10.1039/c6me00095a (DOI)000400987200003 ()
    Available from: 2017-06-14 Created: 2017-06-14 Last updated: 2018-04-12Bibliographically approved
    3. Investigation of the factors that affect the fabrication of highly conducting NP-molecule junctions inside sub 20 nm molecular electronic devices.
    Open this publication in new window or tab >>Investigation of the factors that affect the fabrication of highly conducting NP-molecule junctions inside sub 20 nm molecular electronic devices.
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-348337 (URN)
    Available from: 2018-04-11 Created: 2018-04-11 Last updated: 2018-04-12
    4. Sub 20 nm metal-conjugated molecule junctions acting as a nitrogen dioxide sensor
    Open this publication in new window or tab >>Sub 20 nm metal-conjugated molecule junctions acting as a nitrogen dioxide sensor
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-348341 (URN)
    Available from: 2018-04-11 Created: 2018-04-11 Last updated: 2018-04-12
    5. Change of random telegraph conductance signal in different gas atmospheres in a nano molecular electronic device
    Open this publication in new window or tab >>Change of random telegraph conductance signal in different gas atmospheres in a nano molecular electronic device
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-348338 (URN)
    Available from: 2018-04-11 Created: 2018-04-11 Last updated: 2018-04-12
  • Public defence: 2018-05-30 10:15 Universitetshuset, lärosal IX, Uppsala
    Bergman, Jon
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Law, Department of Law.
    Concentrations in the EU pharmaceutical sector: The protection of effective competition under Council Regulation No 139/2004 on the control of concentrations between undertakings2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    A central element of competition law consists in the control of concentrations, that is, the changes in the competitive structure resulting from mergers and acquisitions. By controlling concentrations with a Union Dimension, the European Commission ensures that effective competition will not be significantly impeded, in particular by the creation or strengthening of dominant positions. Within the EU, the central legislation is Council Regulation (EC) No 139/2004 of 20 January 2004 on the control of concentrations between undertakings. Under the Regulation, the Commission has the power to declare concentrations incompatible with the internal market and prohibit them in whole or in part. The dissertation examines the Commission's application of the Regulation in the pharmaceutical industry. The pharmaceutical industry exhibits many special features in comparison with other economic sectors, not least because it comprises extensive sector-specific regulation governing the development, manufacture and sale of pharmaceutical products.

    The study comprehensively explores situations where the control of concentrations is affected by the special conditions characterising the market for pharmaceuticals. Besides providing an overview of the reasons why mergers and acquisitions should be checked, the contents of the Merger Regulation, and the relevant sector-specific regulation, the dissertation examines the definition of the relevant market for pharmaceutical products, how the substantive test in the Regulation is interpreted and applied, and the remedies that may be necessary when pharmaceutical companies merge.

  • Public defence: 2018-05-30 13:00 Sal IX, Uppsala
    Ternström, Elin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Identification and Treatment of Women with a Fear of Birth2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Although a fear of birth affects many women during pregnancy and is associated with adverse birth outcomes, it is rarely measured in clinical practice and evidence-based treatments are lacking. The aim of this thesis was to assess the clinical utility of the Fear of Birth Scale, and to evaluate the effect of guided Internet-based cognitive behavior therapy compared with standard care on the levels of fear of birth in pregnant and postpartum women.

    This thesis consists of four papers originating from three studies. The Fear of Birth Scale was used to measure fear of birth among pregnant women in all three studies. In Study I, prevalence of fear of birth among Swedish-born and foreign-born pregnant women was measured, and in Study II, 31 pregnant women were interviewed about their thoughts when assessing fear of birth. In Study III, a multicenter randomized controlled trial was conducted to compare guided Internet-based cognitive behavior therapy (ICBT) with standard care for pregnant women with a fear of birth.

    Fear of birth was identified among 22% of the pregnant women. Prevalence was twice as high among the foreign-born women (37%) compared to the Swedish-born women (18%). When asking the participants what they thought when assessing their fear on the Fear of Birth Scale, they confirmed that they had understood the measurement intent of the scale. The randomized controlled trial showed that fear of birth decreased during pregnancy and postpartum in both groups. However, the levels of fear decreased more in the guided ICBT-group when measuring fear of birth up to one year postpartum. The changes in fear of birth over time did not differ between parity groups.

    Altogether, these results suggest that the Fear of Birth Scale is a suitable screening instrument for identifying pregnant women with a fear of birth in a clinical setting and that such screening would be beneficial, as it probably would increase the chance of achieving a more equitable care. As the effect of time during pregnancy and postpartum was most evident in reducing fear of birth, this can be communicated to pregnant women, along with a continuous dialogue about how the women experience fear during pregnancy.

    List of papers
    1. Higher prevalence of childbirth related fear in foreign born pregnant women: Findings from a community sample in Sweden
    Open this publication in new window or tab >>Higher prevalence of childbirth related fear in foreign born pregnant women: Findings from a community sample in Sweden
    2015 (English)In: Midwifery, ISSN 0266-6138, E-ISSN 1532-3099, Vol. 31, no 4, p. 445-450Article in journal (Refereed) Published
    Abstract [en]

    OBJECTIVE:

    to investigate the prevalence of childbirth related fear (CBRF) in early pregnancy among both Swedish born and foreign born women living in Sweden.

    DESIGN:

    a cross sectional prevalence study. Data was collected by a questionnaire, which was available in Swedish and eight other languages.

    SETTING:

    a university hospital in the middle of Sweden.

    PARTICIPANTS:

    the recruitment took place during a two month period where the participating women completed the Fear of Birth Scale (FOBS) in mid-pregnancy.

    MEASUREMENTS:

    prevalence of CBRF, the cut-point of 60 and above. Odds ratios with a 95% confidence interval were calculated between women born in Sweden and women born in a foreign country. Stratified analyses were also performed separately for Swedish born and foreign born women.

    FINDINGS:

    in total 606 women completed the survey, 78% were born in Sweden and 22% were born in a foreign country. About 22% of the total sample scored 60 or more on the FOBS-scale. Almost 18% (n=85) of the women born in Sweden reported CBRF whereas 37 % (n=49) of the foreign born women reported CBRF. Being born outside Sweden (OR 2.7; CI 1.7-4.0) and expecting the first baby (OR 1.9; CI 1.3-2.8) were associated with CBRF. There were no differences in age, civil status or level of education between women with or without FOBS≥60. However, a stratified analysis showed that primiparas born in a foreign country (OR 3.8; CI 1.8-8.0) were more likely to score 60 or more on the FOBS-scale compared to multiparas born in a foreign country.

    KEY CONCLUSIONS:

    childbirth related fear was almost three times as common among foreign born women when compared to Swedish women. Foreign born childbearing women are an extremely vulnerable group who need culturally sensitive and targeted support from caregivers. Further research is needed to clearly identify the components of women׳s childbirth related fear in various ethnic groups.

    National Category
    Obstetrics, Gynecology and Reproductive Medicine
    Identifiers
    urn:nbn:se:uu:diva-239490 (URN)10.1016/j.midw.2014.11.011 (DOI)000353526100007 ()25529841 (PubMedID)