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  • Disputas: 2019-02-21 13:15 Å80101, Ångströmlaboratoriet, Uppsala
    Pettersson, Joachim
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Kärnfysik.
    From Strange to Charm: Meson production in electron-positron collisions2019Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Decays of pseudoscalar mesons into a lepton-antilepton pair are very rare within the Standard Model since they cannot proceed via a single photon process. The C-even neutral mesons can be produced in electron-positron collisions by a two-photon intermediate state. Due to the rarity the of Pl+l- decays, measurements of their branching fractions are sensitive to physics beyond the Standard Model. This thesis report the first search for the process e+e-→ηusing the K±K0Sπ±K+0 and K+K-η final states to determine the branching fraction of the time reverse process ηc→e+e-. This study is an extension of the previous measurements of π0→e+e- and η→μ+μ-, and the upper limits set for η→e+e- and η'→μ+μ-. The analysis presented in this thesis uses data collected by the BESIII detector situated at the e+e- collider BEPCII in Beijing, China. The data set consist of 22 center-of-mass energy points between 2.000 to 3.080 GeV where a data point at the energy 2.981 GeV was recorded specifically for this study. Monte Carlo simulations are used to develop selection criteria and to estimate selection efficiency and corrections due to initial state radiation.

    No signal from e+e-→ηc was observed. Therefore, an upper limit is set for the branching fraction of the process ηce+e- using a profile likelihood method. The result for the 90% C.L. limit is BF(ηce+e-)<8.1×10-7 where systematic uncertainties are included. 

    In addition to the search for ηc→e+e-, the cross sections of the processes e+e-→K±K0π±e+e-→K+K-π0 and e+e-→K+K-η are measured at all 22 energies. These cross section measurements can be used to search for exotic resonances and to achieve an understanding of exotic states such as Y(2175) and X(2370).

  • Disputas: 2019-02-22 10:15 Häggsalen, Ångströmlaboratoriet, Uppsala
    Pavliuk, Mariia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
    Accumulative Charge Separation in Photocatalysis: From Molecules to Nanoparticles2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Photochemical energy conversion into solar fuel involves steps of light absorption, charge separation and catalysis. Nature has taught us that the effective accumulation of redox equivalents and charge separation are the key steps in sunlight conversion. The focus of this thesis is to unveil photophysical and photochemical processes that lead to accumulative charge separation. The optimization of electron transfer process will be held by minimization of losses via recombination, and extension of the lifetime of the charge separated state by usage of the electron relay.

    The goal is to couple light induced electron transfer process with the multi-electron catalytic process of hydrogen evolution. In this regard, light harvesters (molecules, metal nanostructures) that generate at least two electrons per absorbed photon will be studied. Additionally, semiconductors that generate long-lived charge separated states are utilized to accumulate several redox equivalents necessary for hydrogen evolution.

    The hybrid systems produced by the combination of the advantageous properties of molecules, semiconductors, and metal nanoparticles are under the scope of investigation. Metal nanoparticles are advantageous because of their high absorption cross-section. The molecular linkers provide control and flexibility in tuning the connection between the light absorber and the electron relay. Semiconductor nanoparticles offer the desired charge separation properties via prolonging the lifetime sufficiently to perform photocatalysis.

    The detailed understanding, investigation and development of the hybrid systems is at the heart of the progress of photochemical solar fuel production.

    Delarbeid
    1. Ultra long-lived electron-hole separation within water-soluble colloidal ZnO nanocrystals: Prospective Applications For Solar Energy Production
    Åpne denne publikasjonen i ny fane eller vindu >>Ultra long-lived electron-hole separation within water-soluble colloidal ZnO nanocrystals: Prospective Applications For Solar Energy Production
    Vise andre…
    2016 (engelsk)Inngår i: Nano Energy, ISSN 2211-2855, Vol. 30, s. 187-192Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Zinc oxide was one of the first semiconductors used in dye-sensitized solar cells but its instability in aqueous media precludes its use for large-scale applications. Herein, we report on a novel ZnO nanocrystal material derived by an organometallic approach that is simultaneously stable and soluble in water due to its carboxylate oligoethylene glycol shell strongly anchored to the inorganic core by the head groups. The resulting unique inorganic core-organic shell interface also stabilizes the photo-generated hole, leading to a dramatic slowing down of charge recombination, which otherwise is a major hurdle in using nanostructured ZnO.

    Emneord
    Water-soluble colloidal ZnO nanocrystals, Ultra long-lived electron-hole separation, Advanced laser based spectroscopy, Solar energy production prospectus
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-314050 (URN)10.1016/j.nanoen.2016.09.045 (DOI)000390636100023 ()
    Forskningsfinansiär
    Knut and Alice Wallenberg FoundationEU, European Research Council, 687008Swedish Research Council, 2015-03764
    Tilgjengelig fra: 2017-02-06 Laget: 2017-01-26 Sist oppdatert: 2018-12-17bibliografisk kontrollert
    2. Hydrogen evolution with nanoengineered ZnO interfaces decorated using a beetroot extract and a hydrogenase mimic
    Åpne denne publikasjonen i ny fane eller vindu >>Hydrogen evolution with nanoengineered ZnO interfaces decorated using a beetroot extract and a hydrogenase mimic
    Vise andre…
    2017 (engelsk)Inngår i: Sustainable Energy & Fuels, ISSN 2398-4902, Vol. 1, s. 69-73Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Herein, we report a nano-hybrid photo-system based on abundant elements for H2 production with visible light. The photo-system's proficiency relates to the novel ZnO nanocrystals employed. The ZnO carboxylate oligoethylene glycol shell enhances charge separation and accumulates reactive electrons for the photocatalytic process. 

    sted, utgiver, år, opplag, sider
    Royal Society of Chemistry, 2017
    Emneord
    H2 evolution
    HSV kategori
    Forskningsprogram
    Kemi med inriktning mot fysikalisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-335979 (URN)10.1039/c6se00066e (DOI)000422769100006 ()
    Tilgjengelig fra: 2017-12-11 Laget: 2017-12-11 Sist oppdatert: 2018-12-17bibliografisk kontrollert
    3. Magnetic Manipulation of Spontaneous Emission from Inorganic CsPbBr3 Perovskites Nanocrystals
    Åpne denne publikasjonen i ny fane eller vindu >>Magnetic Manipulation of Spontaneous Emission from Inorganic CsPbBr3 Perovskites Nanocrystals
    Vise andre…
    2016 (engelsk)Inngår i: ADVANCED OPTICAL MATERIALS, ISSN 2195-1071, Vol. 4, nr 12, s. 2004-2008Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Metal halide perovskites have shown great potential for both light-absorbing and light-emitting devices. It is demonstrated that the presence of a low-magnetic field decreases dramatically the photoluminescence of CsPbBr3. This is found to be due to a decrease in charge separated state lifetime. The effect is fully reversible, and can be exploited for simple and remote modulation of the output of light-emitting devices.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-315916 (URN)10.1002/adom.201600611 (DOI)000392405100014 ()
    Forskningsfinansiär
    Knut and Alice Wallenberg FoundationSwedish Research Council, 2015-03764EU, FP7, Seventh Framework Programme, 306733
    Tilgjengelig fra: 2017-02-23 Laget: 2017-02-23 Sist oppdatert: 2018-12-17bibliografisk kontrollert
    4. Hydrogen evolution with CsPbBr3 perovskite nanocrystals under visible light in solution
    Åpne denne publikasjonen i ny fane eller vindu >>Hydrogen evolution with CsPbBr3 perovskite nanocrystals under visible light in solution
    2018 (engelsk)Inngår i: MATERIALS TODAY COMMUNICATIONS, ISSN 2352-4928, Vol. 16, s. 90-96Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Direct proton photo-reduction to molecular hydrogen with a lead-halide perovskite photosystem is presented. The concept uses CsPbBr3 nanocrystals and Ru@TiO2 nanoparticles as light harvesters and catalyst, respectively. The photo-system attains charge transfer from donor to acceptor via collision events, established via static and ultrafast spectroscopy. The photo-system exhibits a photon-to-hydrogen efficiency of ca. 0.4%, a respectable efficiency for a system relying on effective collisions for the transference of electrons.

    Emneord
    Inorganic perovskites nanocrystals, H-2 evolution, Ultrafast spectroscopy, Charge transfer via collision
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-364171 (URN)10.1016/j.mtcomm.2018.05.001 (DOI)000443035000012 ()
    Forskningsfinansiär
    Swedish Research CouncilStiftelsen Olle Engkvist Byggmästare
    Tilgjengelig fra: 2018-11-06 Laget: 2018-11-06 Sist oppdatert: 2018-12-17bibliografisk kontrollert
    5. Nano-hybrid plasmonic photocatalyst for hydrogen production at 20% efficiency
    Åpne denne publikasjonen i ny fane eller vindu >>Nano-hybrid plasmonic photocatalyst for hydrogen production at 20% efficiency
    Vise andre…
    2017 (engelsk)Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, artikkel-id 8670Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The efficient conversion of light energy into chemical energy is key for sustainable human development. Several photocatalytic systems based on photovoltaic electrolysis have been used to produce hydrogen via water reduction. However, in such devices, light harvesting and proton reduction are carried separately, showing quantum efficiency of about 10–12%. Here, we report a nano-hybrid photocatalytic assembly that enables concomitant reductive hydrogen production and pollutant oxidation with solar-to-fuel efficiencies up to 20%. The modular architecture of this plasmonic material allows the fine-tuning of its photocatalytic properties by simple manipulation of a reduced number of basic components.

    HSV kategori
    Forskningsprogram
    Teknisk fysik med inriktning mot nanoteknologi och funktionella material; Teknisk fysik med inriktning mot nanoteknologi och funktionella material
    Identifikatorer
    urn:nbn:se:uu:diva-328630 (URN)10.1038/s41598-017-09261-7 (DOI)000407864400051 ()
    Forskningsfinansiär
    The Swedish Foundation for International Cooperation in Research and Higher Education (STINT), IB2015-6474
    Tilgjengelig fra: 2017-08-28 Laget: 2017-08-28 Sist oppdatert: 2018-12-17bibliografisk kontrollert
    6. Hydrated Electron Generation by Excitation of Localized Surface Plasmons in Copper Nanoparticles
    Åpne denne publikasjonen i ny fane eller vindu >>Hydrated Electron Generation by Excitation of Localized Surface Plasmons in Copper Nanoparticles
    Vise andre…
    (engelsk)Inngår i: Science Advances, ISSN 2375-2548Artikkel i tidsskrift, News item (Fagfellevurdert) Submitted
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-369929 (URN)
    Tilgjengelig fra: 2018-12-17 Laget: 2018-12-17 Sist oppdatert: 2018-12-17
  • Disputas: 2019-02-22 13:15 Geijersalen, Engelska parken, Uppsala
    Ekendahl, Karl
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Historisk-filosofiska fakulteten, Filosofiska institutionen, Avdelningen för praktisk filosofi.
    The Good, the Bad, and the Dead: An Essay on Well-Being and Death2019Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    This book examines some central arguments in the debate about the value of death. The first main chapter, Chapter 2, begins with an introduction to the debate and a clarification of Epicureanism, i.e. the view that it is not bad to die. I then go on to evaluate several versions of a popular Epicurean line of argument, according to which death’s failure or inability to cause its victim any unpleasant experiences gives us reason to deny that death can be bad for the person who dies. I argue that none of these arguments succeeds. In Chapter 3, I turn to a more promising argument against the badness of death: the Timing Argument. Because there is no time at which death can be bad for its victim, the argument goes, it cannot be bad for her at all. To clarify the nature of this rather obscure argument, I offer two different interpretations, only one of which, I argue, should be considered a challenge to the anti-Epicurean. In Chapter 4, I review different attempts at refuting the Timing Argument, many of which fail to address the argument in its most challenging form. I also argue that there is no time at which death is bad for its victim, but that the conclusion to draw from this is that death can be bad for its victim without being bad for her at any time. The final chapter, Chapter 5, starts with the widespread worry that Epicureanism is hard to combine with certain normative commonsense ideas, e.g. the idea that we often prudentially ought to avoid death. As it turns out, however, the anti-Epicurean faces similar problems: in certain cases where, intuitively, a person has prudential reasons to avoid her death, the most prominent anti-Epicurean accounts fail to yield that her death is bad for her. This is a serious problem for anti-Epicureanism, and I end with a few remarks on its potential implications.

  • Disputas: 2019-02-22 13:15 Samlingssalen, Västerås
    Husdal, Rebecka
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centrum för klinisk forskning, Västerås. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk diabetologi och metabolism.
    Key Features for Successful Swedish Primary Diabetes Care – Reality or Fiction?: Nationwide studies of longitudinal follow-up, HbA1c levels and all-cause mortality in an organizational context2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Aims To extend knowledge about the changes in Swedish primary diabetes care from 2006 to 2013 and investigate associations of personnel resources, organizational features and quality-of-work conditions of primary health-care centres (PHCCs) with individual HbA1c levels and all-cause mortality in people with type 2 diabetes mellitus (T2DM).

    Methods Information about organizational features, personnel resources and quality-of-work conditions were collected from responses of PHCC managers to the Swedish National Survey of the Quality and Organisation of Diabetes Care in Primary HealthCare (Swed-QOP) questionnaire. The longitudinal cross-sectional study included 74.3% and 76.4% of PHCCs in 2006 and 2013, respectively. Individual clinical data for 230,958 people with T2DM obtained from the Swedish National Diabetes Register were linked to the data from the Swed-QOP questionnaire. Individual data were linked to socio-economic and comorbidity data. All-cause mortality was followed up for a median of 4.2 years for 187,570 people with T2DM.

    Results The longitudinal follow-up study showed a decreased median PHCC list size but an increased median number of people with T2DM. The mean European Credit Transfer and Accumulation System (ECTS) credits in diabetes-specific education for registered nurses (RNs) increased. The number of PHCCs providing group education programs and involving the patient in goal setting remained low (I). PHCCs having diabetes teams and group education programs were associated with decreased HbA1c levels. Using call-recall system to general practitioners (GPs) was associated with increased HbA1c levels (II). Seven quality-of-work features were identified, of which Individualized treatment was associated with decreased HbA1c levels in people with controlled (≤ 52 mmol/mol), intermediate (53–69 mmol/mol) and uncontrolled (≥ 70 mmol/mol) HbA1c (III). GP staffing was associated with a decreased risk of early death and the mean ECTS credits in diabetes-specific and pedagogical education of RNs was associated with a decreased risk of early death in people aged ≥ 55 years and in men, respectively (IV).

    Conclusion This thesis adds to previous work on significant but less pronounced key features for successful organization of primary diabetes care, and indicates that the complexity of diabetes disease makes it difficult to identify success factors applicable to all people living with T2DM.

    Delarbeid
    1. Resource allocation and organisational features in Swedish primary diabetes care: Changes from 2006 to 2013
    Åpne denne publikasjonen i ny fane eller vindu >>Resource allocation and organisational features in Swedish primary diabetes care: Changes from 2006 to 2013
    Vise andre…
    2017 (engelsk)Inngår i: Primary Care Diabetes, ISSN 1751-9918, E-ISSN 1878-0210, Vol. 11, nr 1, s. 20-28Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    AIMS: To compare the resource allocation and organisational features in Swedish primary diabetes care for patients with type 2 diabetes mellitus (T2DM) between 2006 and 2013.

    METHODS: Using a repeated cross-sectional study design, questionnaires covering personnel resources and organisational features for patients with T2DM in 2006 and 2013 were sent to all Swedish primary health care centres (PHCCs) during the following year. In total, 684 (74.3%) PHCCs responded in 2006 and 880 (76.4%) in 2013.

    RESULTS: Compared with 2006, the median list size had decreased in 2013 (p<0.001), whereas the median number of listed patients with T2DM had increased (p<0.001). Time devoted to patients with T2DM and diabetes-specific education levels for registered nurses (RNs) had increased, and more PHCCs had in-house psychologists (all p<0.001). The use of follow-up systems and medical check-ups had increased (all p<0.05). Individual counselling was more often based on patients' needs, while arrangement of group-based education remained low. Patient participation in setting treatment targets mainly remained low.

    CONCLUSIONS: Even though the diabetes-specific educational level among RNs increased, the arrangement of group-based education and patient participation in setting treatment targets remained low. These results are of concern and should be prioritised as key features in the care of patients with T2DM.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-304779 (URN)10.1016/j.pcd.2016.08.002 (DOI)000392679200003 ()27578488 (PubMedID)
    Tilgjengelig fra: 2016-10-10 Laget: 2016-10-10 Sist oppdatert: 2019-01-25bibliografisk kontrollert
    2. Resources and organisation in primary health care are associated with HbA1c level: A nationwide study of 230958 people with Type 2 diabetes mellitus.
    Åpne denne publikasjonen i ny fane eller vindu >>Resources and organisation in primary health care are associated with HbA1c level: A nationwide study of 230958 people with Type 2 diabetes mellitus.
    Vise andre…
    2018 (engelsk)Inngår i: Primary Care Diabetes, ISSN 1751-9918, E-ISSN 1878-0210, Vol. 12, nr 1, s. 23-33Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    AIMS: To examine the association between personnel resources and organisational features of primary health care centres (PHCCs) and individual HbA1c level in people with Type 2 diabetes mellitus (T2DM).

    METHODS: People with T2DM attending 846 PHCCs (n=230958) were included in this cross-sectional study based on PHCC-level data from a questionnaire sent to PHCCs in 2013 and individual-level clinical data from 2013 for people with T2DM reported in the Swedish National Diabetes Register, linked to individual-level data on socio-economic status and comorbidities. Data were analysed using a generalized estimating equations linear regression models.

    RESULTS: After adjusting for PHCC- and individual-level confounding factors, personnel resources associated with lower individual HbA1c level were mean credits of diabetes-specific education among registered nurses (RNs) (-0.02mmol/mol for each additional credit; P<0.001) and length of regular visits to RNs (-0.19mmol/mol for each additional 15min; P<0.001). Organisational features associated with HbA1c level were having a diabetes team (-0.18mmol/mol; P<0.01) and providing group education (-0.20mmol/mol; P<0.01).

    CONCLUSIONS: In this large sample, PHCC personnel resources and organisational features were associated with lower HbA1c level in people with T2DM.

    Emneord
    HbA(1c), Organisation, Personnel resources, Primary health care system, Type 2 diabetes mellitus
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-332689 (URN)10.1016/j.pcd.2017.09.003 (DOI)000423008800003 ()28964673 (PubMedID)
    Tilgjengelig fra: 2017-10-31 Laget: 2017-10-31 Sist oppdatert: 2018-12-21bibliografisk kontrollert
    3. Associations between quality of work features in primary health care and glycaemic control in people with Type 2 diabetes mellitus: A nationwide survey
    Åpne denne publikasjonen i ny fane eller vindu >>Associations between quality of work features in primary health care and glycaemic control in people with Type 2 diabetes mellitus: A nationwide survey
    Vise andre…
    (engelsk)Inngår i: Primary Care Diabetes, ISSN 1751-9918, E-ISSN 1878-0210Artikkel i tidsskrift (Fagfellevurdert) Epub ahead of print
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-371494 (URN)
    Tilgjengelig fra: 2018-12-21 Laget: 2018-12-21 Sist oppdatert: 2018-12-21
    4. Organisation of primary diabetes care in people with type 2 diabetes in relation to all-cause mortality: a nationwide register-based cohort study
    Åpne denne publikasjonen i ny fane eller vindu >>Organisation of primary diabetes care in people with type 2 diabetes in relation to all-cause mortality: a nationwide register-based cohort study
    Vise andre…
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-369430 (URN)
    Tilgjengelig fra: 2018-12-13 Laget: 2018-12-13 Sist oppdatert: 2018-12-21
  • Disputas: 2019-02-25 13:00 Ekmansalen, Uppsala
    Weissensteiner, Matthias H.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Evolutionary genomics in Corvids: – From single nucleotides to structural variants2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Heritable genetic variation is the raw material of evolution and can occur in many different forms, from altering single nucleotides to rearranging stretches of millions at once. DNA mutations that result in phenotypic differences are the basis upon which natural selection can act, leading to a shift of the frequency of those mutations.

    In this thesis I aim to comprehensively characterize and quantify genetic variation in a natural system, the songbird genus Corvus.

    First, we expand on previous work from a hybrid zone of different populations of Eurasian crows. All black carrion crows and black-and-grey hooded crows meet in a narrow hybrid zone in central Europe, and also in central and Southeast Asia. Comparing population genetic data acquired from these three hybrid zones yielded no single genetic region as a candidate responsible for phenotypic divergence, yet a parallelism in sets of genes and gene networks was evident.

    Second, we capitalize on varying evolutionary timescales to investigate the driver of the heterogeneous genetic differentiation landscape observed in multiple avian species. Genetic diversity, and thus differentiation, seems to be correlated both between populations within single species and between species which diverged 50 million years ago. This pattern is best explained by conserved broad-scale recombination rate variation, which is in turn likely associated with chromosomal features such as centromeres and telomeres.

    Third, we introduce a de-novo assembly of the hooded crow based on long-read sequencing and optical mapping. The use of this technology allowed a glimpse into previously hidden regions of the genome, and uncovered large-scale tandem repeat arrays consisting of a 14-kbp satellite repeat or its 1.2-kpb subunit. Furthermore, these tandem repeat arrays are associated with regions of reduced recombination rate.

    Lastly, we extend the population genetic analysis to structural genomic variation, such as insertions and deletions. A large-scale population re-sequencing data set based on short-read and long-read technologies, spread across the entire genus is the foundation of a fine-scale genome-wide map of structural variation. A differentiation outlier approach between all-black carrion and black-and-grey hooded crows identified a 2.25-kilobase LTR retrotransposon inserted 20-kb upstream of the NDP gene. The element, which is fixed in the hooded crow population, is associated with decreased expression of NDP and may be responsible for differences in plumage color.

    Delarbeid
    1. Evolution of heterogeneous genome differentiation across multiple contact zones in a crow species complex
    Åpne denne publikasjonen i ny fane eller vindu >>Evolution of heterogeneous genome differentiation across multiple contact zones in a crow species complex
    Vise andre…
    2016 (engelsk)Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 7, artikkel-id 13195Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Uncovering the genetic basis of species diversification is a central goal in evolutionary biology. Yet, the link between the accumulation of genomic changes during population divergence and the evolutionary forces promoting reproductive isolation is poorly understood. Here, we analysed 124 genomes of crow populations with various degrees of genome-wide differentiation, with parallelism of a sexually selected plumage phenotype, and ongoing hybridization. Overall, heterogeneity in genetic differentiation along the genome was best explained by linked selection exposed on a shared genome architecture. Superimposed on this common background, we identified genomic regions with signatures of selection specific to independent phenotypic contact zones. Candidate pigmentation genes with evidence for divergent selection were only partly shared, suggesting context-dependent selection on a multigenic trait architecture and parallelism by pathway rather than by repeated single-gene effects. This study provides insight into how various forms of selection shape genome-wide patterns of genomic differentiation as populations diverge.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-308915 (URN)10.1038/ncomms13195 (DOI)000386500600001 ()27796282 (PubMedID)
    Forskningsfinansiär
    Knut and Alice Wallenberg FoundationSwedish Research Council, 621-2010-5553EU, European Research Council, ERCStG-336536
    Tilgjengelig fra: 2016-12-01 Laget: 2016-12-01 Sist oppdatert: 2019-01-07bibliografisk kontrollert
    2. Genomewide patterns of variation in genetic diversity are shared among populations, species and higher-order taxa
    Åpne denne publikasjonen i ny fane eller vindu >>Genomewide patterns of variation in genetic diversity are shared among populations, species and higher-order taxa
    Vise andre…
    2017 (engelsk)Inngår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 26, nr 16, s. 4284-4295Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Genomewide screens of genetic variation within and between populations can reveal signatures of selection implicated in adaptation and speciation. Genomic regions with low genetic diversity and elevated differentiation reflective of locally reduced effective population sizes (N-e) are candidates for barrier loci contributing to population divergence. Yet, such candidate genomic regions need not arise as a result of selection promoting adaptation or advancing reproductive isolation. Linked selection unrelated to lineage-specific adaptation or population divergence can generate comparable signatures. It is challenging to distinguish between these processes, particularly when diverging populations share ancestral genetic variation. In this study, we took a comparative approach using population assemblages from distant clades assessing genomic parallelism of variation in N-e. Utilizing population-level polymorphism data from 444 resequenced genomes of three avian clades spanning 50 million years of evolution, we tested whether population genetic summary statistics reflecting genomewide variation in N-e would covary among populations within clades, and importantly, also among clades where lineage sorting has been completed. All statistics including population-scaled recombination rate (rho), nucleotide diversity (pi) and measures of genetic differentiation between populations (F-ST, PBS, d(xy)) were significantly correlated across all phylogenetic distances. Moreover, genomic regions with elevated levels of genetic differentiation were associated with inferred pericentromeric and subtelomeric regions. The phylogenetic stability of diversity landscapes and stable association with genomic features support a role of linked selection not necessarily associated with adaptation and speciation in shaping patterns of genomewide heterogeneity in genetic diversity.

    sted, utgiver, år, opplag, sider
    WILEY, 2017
    Emneord
    background selection, genetic diversity, genetic draft, genetic hitchhiking, linked selection, recombination rate, speciation genetics
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-333716 (URN)10.1111/mec.14195 (DOI)000407255100013 ()28570015 (PubMedID)
    Forskningsfinansiär
    Swedish Research Council, 621-2010-5553, 2014-6325, 2013-08721EU, European Research Council, ERCStG-336536Knut and Alice Wallenberg FoundationSwedish National Infrastructure for Computing (SNIC)
    Tilgjengelig fra: 2017-11-16 Laget: 2017-11-16 Sist oppdatert: 2019-01-07bibliografisk kontrollert
    3. Combination of short-read, long-read, and optical mapping assemblies reveals large-scale tandem repeat arrays with population genetic implications
    Åpne denne publikasjonen i ny fane eller vindu >>Combination of short-read, long-read, and optical mapping assemblies reveals large-scale tandem repeat arrays with population genetic implications
    Vise andre…
    2017 (engelsk)Inngår i: Genome Research, ISSN 1088-9051, E-ISSN 1549-5469, Vol. 27, nr 5, s. 697-708Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Accurate and contiguous genome assembly is key to a comprehensive understanding of the processes shaping genomic diversity and evolution. Yet, it is frequently constrained by constitutive heterochromatin, usually characterized by highly repetitive DNA. As a key feature of genome architecture associated with centromeric and subtelomeric regions, it locally influences meiotic recombination. In this study, we assess the impact of large tandem repeat arrays on the recombination rate landscape in an avian speciation model, the Eurasian crow. We assembled two high-quality genome references using single-molecule real-time sequencing (long-read assembly [LR]) and single-molecule optical maps (optical map assembly [ OM]). A three-way comparison including the published short-read assembly (SR) constructed for the same individual allowed assessing assembly properties and pinpointing misassemblies. By combining information from all three assemblies, we characterized 36 previously unidentified large repetitive regions in the proximity of sequence assembly breakpoints, the majority of which contained complex arrays of a 14-kb satellite repeat or its 1.2-kb subunit. Using whole-genome population resequencing data, we estimated the population-scaled recombination rate (rho) and found it to be significantly reduced in these regions. These findings are consistent with an effect of low recombination in regions adjacent to centromeric or subtelomeric heterochromatin and add to our understanding of the processes generating widespread heterogeneity in genetic diversity and differentiation along the genome. By combining three different technologies, our results highlight the importance of adding a layer of information on genome structure that is inaccessible to each approach independently.

    sted, utgiver, år, opplag, sider
    COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT, 2017
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-323040 (URN)10.1101/gr.215095.116 (DOI)000400392400005 ()28360231 (PubMedID)
    Forskningsfinansiär
    Knut and Alice Wallenberg FoundationSwedish National Infrastructure for Computing (SNIC)Swedish Research Council, 621-2010-5553EU, European Research Council, ERCStG-336536
    Tilgjengelig fra: 2017-06-01 Laget: 2017-06-01 Sist oppdatert: 2019-01-07bibliografisk kontrollert
    4. Fine-scale analysis of Structural Genomic Variation in Natural Populations
    Åpne denne publikasjonen i ny fane eller vindu >>Fine-scale analysis of Structural Genomic Variation in Natural Populations
    Vise andre…
    (engelsk)Manuskript (preprint) (Annet (populærvitenskap, debatt, mm))
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-369880 (URN)
    Tilgjengelig fra: 2019-01-07 Laget: 2019-01-07 Sist oppdatert: 2019-01-07
  • Disputas: 2019-02-28 09:15 A1:111a, Uppsala
    Liu, Jingyi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Mikrobiologi.
    Characterization of secreted Giardia intestinalis cysteine proteases2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Giardia intestinalis, the causative agent of the diarrheal disease giardiasis, is a protozoan parasite that colonizes the upper small intestine of mammals, including humans. It can be divided into eight genotypes or assemblages (A through H) and only assemblage A and B are infective to humans. Giardiasis is a multi-factorial disease but few giardial virulence factors have been identified and characterized.

    In this thesis, we used proteomics to identify the major excretory-secretory products (ESPs) released by Giardia trophozoites of the WB and GS isolates during interaction with intestinal epithelial cells (IECs) in vitro (Paper I). To deepen our understanding of the role of ESPs in giardiasis, we focused on three specific secreted Giardia cysteine proteases (CPs; CP14019, CP16160 and CP16779). All the three CPs are capable of opening the apical junction complexes between IECs to degrade chemokines produced in response to Giardia (Paper II). This can partly explain the induction of symptoms and immunosuppression seen during giardiasis. We further studied the cleavage specificity of these CPs using substrate phage display and recombinant protein substrates. The preferred sequences were used to search potential human in vivo targets and a number of candidates were identified, including human immunoglobulins as well as defensins, that were subsequently shown to be efficiently cleaved by the CPs (Paper III). To investigate the involvement of CPs in mucus degradation, we tested the CPs on recombinant MUC2 constructs and full-length MUC2. MUC2 is the major component of the mucus layer in the small intestine. It was shown that CP14019 cleave MUC2 in the N-terminal, suggesting a mechanism that the parasite can use to disrupt/release the mucus gel network and get access to the intestinal epithelium of the host (Paper IV).

    In summary, this thesis has studied secreted Giardia CPs and their roles in Giardia infections, providing significant insights into the molecular pathogenesis of giardiasis.

    Delarbeid
    1. Characterization of the Giardia intestinalis secretome during interaction with human intestinal epithelial cells: The impact on host cells
    Åpne denne publikasjonen i ny fane eller vindu >>Characterization of the Giardia intestinalis secretome during interaction with human intestinal epithelial cells: The impact on host cells
    Vise andre…
    2017 (engelsk)Inngår i: PLoS Neglected Tropical Diseases, ISSN 1935-2727, E-ISSN 1935-2735, Vol. 11, nr 12, artikkel-id e0006120Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    BACKGROUND:

    Giardia intestinalis is a non-invasive protozoan parasite that causes giardiasis in humans, the most common form of parasite-induced diarrhea. Disease mechanisms are not completely defined and very few virulence factors are known.

    METHODOLOGY:

    To identify putative virulence factors and elucidate mechanistic pathways leading to disease, we have used proteomics to identify the major excretory-secretory products (ESPs) when Giardia trophozoites of WB and GS isolates (assemblages A and B, respectively) interact with intestinal epithelial cells (IECs) in vitro.

    FINDINGS:

    The main parts of the IEC and parasite secretomes are constitutively released proteins, the majority of which are associated with metabolism but several proteins are released in response to their interaction (87 and 41 WB and GS proteins, respectively, 76 and 45 human proteins in response to the respective isolates). In parasitized IECs, the secretome profile indicated effects on the cell actin cytoskeleton and the induction of immune responses whereas that of Giardia showed anti-oxidation, proteolysis (protease-associated) and induction of encystation responses. The Giardia secretome also contained immunodominant and glycosylated proteins as well as new candidate virulence factors and assemblage-specific differences were identified. A minor part of Giardia ESPs had signal peptides (29% for both isolates) and extracellular vesicles were detected in the ESPs fractions, suggesting alternative secretory pathways. Microscopic analyses showed ESPs binding to IECs and partial internalization. Parasite ESPs reduced ERK1/2 and P38 phosphorylation and NF-κB nuclear translocation. Giardia ESPs altered gene expression in IECs, with a transcriptional profile indicating recruitment of immune cells via chemokines, disturbances in glucose homeostasis, cholesterol and lipid metabolism, cell cycle and induction of apoptosis.

    CONCLUSIONS:

    This is the first study identifying Giardia ESPs and evaluating their effects on IECs. It highlights the importance of host and parasite ESPs during interactions and reveals the intricate cellular responses that can explain disease mechanisms and attenuated inflammatory responses during giardiasis.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-338331 (URN)10.1371/journal.pntd.0006120 (DOI)000419108500030 ()29228011 (PubMedID)
    Tilgjengelig fra: 2018-01-08 Laget: 2018-01-08 Sist oppdatert: 2019-01-10bibliografisk kontrollert
    2. Secreted Giardia intestinalis cysteine proteases disrupt intestinal epithelial cell junctional complexes and degrade chemokines
    Åpne denne publikasjonen i ny fane eller vindu >>Secreted Giardia intestinalis cysteine proteases disrupt intestinal epithelial cell junctional complexes and degrade chemokines
    Vise andre…
    2018 (engelsk)Inngår i: Virulence, ISSN 2150-5594, E-ISSN 2150-5608, Vol. 9, nr 1, s. 879-894Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Giardiasis is a common diarrheal disease caused by the protozoan parasite Giardia intestinalis. Cysteine proteases (CPs) are acknowledged as virulence factors in Giardia but their specific role in the molecular pathogenesis of disease is not known. Herein, we aimed to characterize the three main secreted CPs (CP14019, CP16160 and CP16779), which were identified by mass spectrometry in the medium during interaction with intestinal epithelial cells (IECs) in vitro. First, the CPs were epitope-tagged and localized to the endoplasmic reticulum and cytoplasmic vesicle-like structures. Second, we showed that recombinant CPs, expressed in Pichia pastoris, are more active in acidic environment (pH 5.5-6) and we determined the kinetic parameters using fluorogenic substrates. Third, excretory-secretory proteins (ESPs) from Giardia trophozoites affect the localization of apical junctional complex (AJC) proteins and recombinant CPs cleave or re-localize the AJC proteins (claudin-1 and -4, occludin, JAM-1, beta-catenin and E-cadherin) of IECs. Finally, we showed that the ESPs and recombinant CPs can degrade several chemokines, including CXCL1, CXCL2, CXCL3, IL-8, CCL2, and CCL20, which are up-regulated in IECs during Giardia-host cell interactions. This is the first study that characterizes the role of specific CPs secreted from Giardia and our results collectively indicate their roles in the disruption of the intestinal epithelial barrier and modulating immune responses during Giardia infections.

    Emneord
    parasite, diarrhea, tight junction, chemokine, intestinal barrier, secretion, cathepsin B, Host-pathogen interactions
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-355478 (URN)10.1080/21505594.2018.1451284 (DOI)000431949700001 ()29726306 (PubMedID)
    Forskningsfinansiär
    Swedish Research Council, 2012-03364
    Tilgjengelig fra: 2018-06-29 Laget: 2018-06-29 Sist oppdatert: 2019-01-10bibliografisk kontrollert
    3. Cleavage specificity of recombinant Giardia intestinalis cysteine proteases: Degradation of immunoglobulins and defensins
    Åpne denne publikasjonen i ny fane eller vindu >>Cleavage specificity of recombinant Giardia intestinalis cysteine proteases: Degradation of immunoglobulins and defensins
    2018 (engelsk)Inngår i: Molecular and biochemical parasitology (Print), ISSN 0166-6851, E-ISSN 1872-9428, Vol. 227, s. 29-38Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Giardia intestinalis is a protozoan parasite and the causative agent of giardiasis, a common diarrheal disease. Cysteine protease (CP) activities have been suggested to be involved in Giardia's pathogenesis and we have recently identified and characterized three secreted Giardia CPs; CP14019, CP16160 and CP16779. Here we have studied the cleavage specificity of these CPs using substrate phage display and recombinant protein substrates. The phage display analyses showed that CP16160 has both chymase and tryptase activity and a broad substrate specificity. This was verified using recombinant protein substrates containing different variants of the cleavage sites. Phage display analyses of CP14019 and CP16779 failed but the substrate specificity of CP14019 and CP16779 was tested using the recombinant substrates generated for CP16160. CP16160 and CP14019 showed similar substrate specificity, while CP16779 has a slightly different substrate specificity. The consensus sequence for cleavage by CP16160, obtained from phage display analyses, was used in an in silico screen of the human intestinal proteome for detection of potential targets. Immunoglobulins, including IgA and IgG and defensins (α-HD6 and β-HD1) were predicted to be targets and they were shown to be cleaved by the recombinant CPs in vitro. Our results suggest that the secreted Giardia CPs are key players in the interaction with host cells during Giardia infections since they can cleave several components of the human mucosal defense machinery.

    sted, utgiver, år, opplag, sider
    NETHERLANDS: , 2018
    Emneord
    Cysteine protease, Defensins, Diarrhea, Immunoglobulins, Parasite, Phage display
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-372982 (URN)10.1016/j.molbiopara.2018.10.004 (DOI)30458129 (PubMedID)
    Tilgjengelig fra: 2019-01-10 Laget: 2019-01-10 Sist oppdatert: 2019-01-15bibliografisk kontrollert
    4. MUC2 mucin is cleaved by Giardia intestinalis cysteine protease14019
    Åpne denne publikasjonen i ny fane eller vindu >>MUC2 mucin is cleaved by Giardia intestinalis cysteine protease14019
    Vise andre…
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-372985 (URN)
    Tilgjengelig fra: 2019-01-10 Laget: 2019-01-10 Sist oppdatert: 2019-01-10
  • Disputas: 2019-02-28 13:00 Sal IV, Uppsala
    Matar, Amal
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för folkhälso- och vårdvetenskap, Centrum för forsknings- och bioetik.
    Considering a Baby? Responsible Screening for the Future: Ethical and social implications for implementation and use of preconception expanded carrier screening in Sweden2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Preconception expanded carrier screening is a novel technology that involves the offer of a screening test for many recessive diseases (via an expanded screening panel) to prospective parents, with no priori risk. Test positive couples have a number of reproductive choices; prenatal diagnosis and aborting affected fetus, IVF and preimplantation genetic diagnosis, sperm or ovum donation or simply accept the risk. The test had been piloted in studies and can potentially be implemented in Europe. Therefore, it seemed pertinent to evaluate stakeholders’ perspectives on ethical and social implications of implementing and using preconception ECS in Sweden.

    Two main stakeholders were examined; healthcare professionals and health policymaking experts, via a mix of qualitative methods for data collection and data analysis. In Study I, we employed in-depth interviews to collect data and content analysis to analyze it. In Studies III and IV, expert interviews were used to gather data while thematic analysis was utilized to interpret it. Furthermore, in Study II, an ethical concept namely; reproductive autonomy, was critically discussed within a setting that expects a couple to make a conjoint reproductive decision about preconception ECS, while each partner still upholds his or her individual autonomy.

    The main findings of the empirical studies (Studies I, III and IV) echo to a great extent the prevailing ethical and social debates associated with the novel technology. Respondents expressed concerns with reproductive autonomy, medicalization, prioritization of health resources, discrimination and long term societal changes. Furthermore, respondents emphasized the importance to observe Swedish values, such as human dignity, equality and solidarity, when assessing a preconception ECS program. In addition, they described practicalities of implementation and political considerations that are pertinent to the Swedish context. Finally, some respondents recognized the advantages of reduced suffering and decrease in fetal anomalies and abortion as a consequence of preconception ECS.

    Study II, proposed a notion of couple autonomy, where certain demands if met, a couple’s reproductive decision can be accepted by healthcare staff as autonomous.

    The findings, in this thesis, steer towards non implementation of preconception ECS in its current status within the publicly-funded healthcare system in Sweden. This is because healthcare providers and experts were of the opinion that it would not solve a medical need, threaten Swedish values and use up resources extensively.

    Delarbeid
    1. Swedish healthcare providers' perceptions of preconception expanded carrier screening (ECS)—a qualitative study
    Åpne denne publikasjonen i ny fane eller vindu >>Swedish healthcare providers' perceptions of preconception expanded carrier screening (ECS)—a qualitative study
    2016 (engelsk)Inngår i: Journal of Community Genetics, ISSN 1868-6001, Vol. 7, nr 3, s. 203-214Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Reproductive autonomy, medicalization, and discrimination against disabled and parental responsibility are the main ongoing ethical debates concerning reproductive genetic screening. To examine Swedish healthcare professionals’ views on preconception expanded carrier screening (ECS), a qualitative study involving academic and clinical institutions in Sweden was conducted in September 2014 to February 2015. Eleven healthcare professionals including clinicians, geneticists, a midwife, and a genetic counselor were interviewed in depth using a semi-structured interview guide. The questionnaire was constructed after reviewing the main literature and meetings with relevant healthcare providers. The interviews were recorded, transcribed verbatim, and content analyzed for categories and subcategories. Participants nurtured many ethical and non-ethical concerns regarding preconception ECS. Among the ethical concerns were the potential for discrimination, medicalization, concerns with prioritization of healthcare resources, and effects on reproductive freedom. The effects of implementation of preconception ECS, its stakeholders, regulations, and motivation are some of non-ethical concerns. These concerns, if not addressed, may affect the uptake and usage of carrier screening within Swedish healthcare system. As this is a qualitative study with a small non-random sample size, the findings cannot be generalized. The participants had little to no working experience with expanded screening panels. Moreover, the interviews were conducted in English, a second language for the participants, which might have limited the expression of their views. However, the authors claim that the findings may be pertinent to similar settings in other Scandinavian countries.

    sted, utgiver, år, opplag, sider
    Springer, 2016
    Emneord
    reproductiion, autonomy, expanded carrier screening
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-294966 (URN)10.1007/s12687-016-0268-2 (DOI)000386778700004 ()27225888 (PubMedID)
    Tilgjengelig fra: 2016-05-31 Laget: 2016-05-31 Sist oppdatert: 2019-01-11bibliografisk kontrollert
    2. Couple autonomy in preconception expanded carrier screening
    Åpne denne publikasjonen i ny fane eller vindu >>Couple autonomy in preconception expanded carrier screening
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Background: Preconception Expanded Carrier Screening (ECS) is a genetic test offered to a general population or to couples who have no known risk of recessive and X-linked genetic diseases and are interested in becoming parents. A test may screen for carrier status of several autosomal recessive diseases at one go. Such a program has been piloted in the Netherlands and may become a reality in more European countries in the future. The ethical rationale for such tests is that they would enhance reproductive autonomy. The dominant conception of autonomy is individual-based. However, at the clinic, people deciding on preconception ECS will be counselled together and are expected to make a joint decision, as a couple. The aim of the present study was to develop an understanding of autonomous decisions made by couples in the context of reproductive technologies in general and of preconception ECS in particular. A further aim was to shed light on what occurs in reproductive clinics and to suggest concrete implications for the approach of healthcare professionals in those clinics. Discussion: Based on the shift in emphasis from individual autonomy to relational autonomy, a notion of couple autonomy was suggested and some features of this concept were outlined. First, that both partners are individually autonomous and that the decision is reached through a communicative process. In this process each partner should feel free to express his or her concerns and preferences, so no one partner dominates the discussion. Further, there should be adequate time for the couple to negotiate possible differences and conclude that the decision is right for them. The final decision should be reached through consensus of both partners without coercion, manipulation or miscommunication. Through concrete examples, the suggested notion of couple autonomy was applied to diverse clinical situations. Conclusions: A notion of couple autonomy can be fruitful for healthcare professionals by facilitating the ways in which close ones are vital for the decision-making concerning preconception ECS. A normative implication for healthcare staff is to allow the necessary time for decision-making and to promote a dialogue that can increase the power of the weaker part in a relationship.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-366363 (URN)
    Tilgjengelig fra: 2018-11-20 Laget: 2018-11-20 Sist oppdatert: 2019-01-11bibliografisk kontrollert
    3. “A perfect society”— Swedish policymakers’ ethical and social views on preconception expanded carrier screening
    Åpne denne publikasjonen i ny fane eller vindu >>“A perfect society”— Swedish policymakers’ ethical and social views on preconception expanded carrier screening
    2018 (engelsk)Inngår i: Journal of Community Genetics, ISSN 1868-310X, E-ISSN 1868-6001Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    To improve healthcare policymaking, commentators have recommended the use of evidence, health technology assessment, priority setting, and public engagement in the process of policymaking. Preconception expanded carrier screening, according to the World Health Organization’s definition, is a novel health technology and therefore warrants assessment, part of which involves evaluating ethical and social implications. We examined ten Swedish policymakers’ perspectives on ethical and social aspects of preconception expanded screening through in-depth expert interviewing, using a semi-structured questionnaire. Respondents were affiliated to governmental and non-governmental institutions that directly influence healthcare policymaking in Sweden. The interviews were recorded, transcribed verbatim, and analyzed via inductive thematic analysis method, which generated seven themes and several subthemes. Policymakers harbored concerns regarding the economics, Swedish and international political respects, implementation procedures, and societal effects, which included long-term ones. Moreover, participants detailed the role of public engagement, research, and responsibility in regard to preconception expanded carrier screening implementation. Since this is a qualitative study, with a small non-random sample, the results may not be generalizable to all policymakers in Sweden. However, the results give a profound insight into the process and interpretative knowledge of experts, in the Swedish milieu and the extent of readiness of Sweden to implement a preconception expanded carrier screening program.

    sted, utgiver, år, opplag, sider
    Springer, 2018
    Emneord
    Preconception Expanded carrier screening Genetic Policymakers Reproductive decision-making Ethics Social effects
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-362390 (URN)10.1007/s12687-018-0389-x (DOI)
    Tilgjengelig fra: 2018-10-04 Laget: 2018-10-04 Sist oppdatert: 2019-01-11bibliografisk kontrollert
    4. Values and value conflicts in implementation and use of preconception expanded carrier screening: an expert interview study
    Åpne denne publikasjonen i ny fane eller vindu >>Values and value conflicts in implementation and use of preconception expanded carrier screening: an expert interview study
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Background: Ethical values and principles have been incorporated in most aspects of healthcare, such as policy-making, communication, medical research and health technology assessment. Preconception expanded carrier screening is a genetic test offered to a general population or to couples with no known risk of recessive genetic diseases and planning a pregnancy. A test screens for carrier status of several autosomal recessive diseases simultaneously.

    Aim: To examine values and value conflicts experts recounted in implementation and use of preconception expanded carrier screening in Sweden. Methods: We interviewed ten experts, directly associated with influencing health policy- making in Sweden, and members of two non-governmental and three governmental organizations. We employed systematizing expert interviews to access experts’ specialist knowledge. There were four female and six male informants, of which four were physicians, three bioethicists, a legal expert, a theologian and a political party representative in the parliament. We used thematic analysis to identify themes and sub-themes in the data.

    Results: The main values that emerged were Respect for persons, Solidarity, Human dignity, Do no harm, Health, Love and Trust. Concepts relating to autonomy, integrity and privacy were the most commonly mentioned among the participants, followed by notions of equality, justice and social care. The experts’ descriptions of values were concordant to those in bioethical literature.

    Conclusions: Experts highlighted values that are distinctive of welfare states, as Sweden. Certain values were deemed more substantive than others, judging by the extent and detail of inference; for example, respect for persons and solidarity.

    Emneord
    Moral values; intrinsic and extrinsic values; preconception expanded carrier screening; respect for persons; Solidarity; human dignity.
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-366366 (URN)
    Tilgjengelig fra: 2018-11-20 Laget: 2018-11-20 Sist oppdatert: 2019-01-11bibliografisk kontrollert
  • Disputas: 2019-03-01 09:15 Rosénsalen, Uppsala
    Ehrstedt, Christoffer
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa.
    Glioneuronal tumours in childhood: Clinical picture, long-term outcome and possible new treatments2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Background: Glioneuronal tumours are a subgroup of low-grade tumours of the central nervous system (CNS), often causing epilepsy. Overall survival is excellent, but data regarding long-term seizure outcome and late effects are scarce.

    Aims: The overall aim was to gather data about pre- and postsurgical factors of importance and long-term outcomes to improve standards of care. Another aim was to explore the expression of somatostatin receptor (SSTR) subtypes and mTOR pathway markers.

    Methods: This thesis, based on four population-based studies with both retrospective and cross-sectional parts, was performed through a long-term follow-up of a Swedish cohort of children with glioneuronal tumours in the Uppsala-Örebro health region. Patients were identified from the National Brain Tumour Registry and the National Epilepsy Surgery Registry. Various methods were used: reviews of hospital medical records, patient interviews, health-related quality of life (HRQoL) assessments with generic (Short Form 36version2) and disease specific (Quality of Life in Epilepsy-31) questionnaires, neuropsychological evaluations with Wechsler Intelligence Scale for Children-IV or Wechsler Adult Intelligence Test-IV and Reys Complex Figure Test and evaluation for possible depression with Hospital Anxiety Depression Scale. Immunohistochemical analyses for SSTR subtypes 1, 2a, 3 and 5 and mTOR pathway components ezrin-radixin-moesin and pS6 were performed on tumour specimens.

    Results: Glioneuronal tumours seem to be more frequent than previously reported, accounting for 13.5% of all childhood CNS tumours. They often cause medically refractory epilepsy resulting in cognitive impairment. Neurosurgery was often delayed; mean time from symptom debut to lesionectomy was 4.6 years. Long-term seizure freedom was achieved in 84% of patients who had a gross total resection (GTR) and is important for long-term cognitive restitution, HRQoL, educational and vocational outcomes. SSTR2a and SSTR3 expression was a frequent finding in glioneuronal tumours. Signs of mTOR pathway activation were abundant in ganglioglioma.

    Conclusions: A safe GTR should be striven for and considered a first-line treatment. Long-term clinical follow-up should be offered to all patients and for those with an inoperable tumour/tumour remnant causing tumour growth and/or medically refractory epilepsy, somatostatin analogues and/or mTOR inhibitors might represent a therapeutic alternative worth exploring further.

    Delarbeid
    1. Clinical characteristics and late effects in CNS tumours of childhood: Do not forget long term follow-up of the low grade tumours
    Åpne denne publikasjonen i ny fane eller vindu >>Clinical characteristics and late effects in CNS tumours of childhood: Do not forget long term follow-up of the low grade tumours
    Vise andre…
    2016 (engelsk)Inngår i: European journal of paediatric neurology, ISSN 1090-3798, E-ISSN 1532-2130, Vol. 20, nr 4, s. 580-587Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Aim: To investigate clinical characteristics and late effects of CNS tumours in childhood with a special focus on low-grade tumours, especially low-grade astrocytoma and glib neuronal tumours. Methods: A retrospective population based study was performed at Uppsala University Children's Hospital, a tertiary referral centre for children with CNS tumours. Patients were identified from the National Brain Tumour Registry and the National Epilepsy Surgery Registry. Hospital medical records were analysed for patients with a follow up of >= 5 years after diagnosis. A re-evaluation of the neuro-pathological diagnosis was performed. Results: A total of 193 patients (age 0-17.99 years) during a twelve-year period (1995-2006) were included; 149 survived >= 5 years. Three larger subgroups could be identified: astrocytic, embryonal and glioneuronal tumours. A supratentorial location was found in 52%. Medical late effects were mainly neurological and endocrinological, affecting 81% and 26% of surviving patients. Cognitive late effects were a frequent finding in the whole group but also in low-grade astrocytoma and glioneuronal tumours (53% and 67%). Thirty per cent had some kind of pedagogic support in school. Conclusion: Late effects are common in long-term survivors of CNS tumours in childhood. Low-grade astrocytoma and glioneuronal tumours are no exception, and the findings support the need for long-term follow up.

    Emneord
    Childhood, CNS-tumour, Cognitive, Late effects, Low grade
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-300544 (URN)10.1016/j.ejpn.2016.04.009 (DOI)000379106700014 ()27157245 (PubMedID)
    Tilgjengelig fra: 2016-08-10 Laget: 2016-08-09 Sist oppdatert: 2019-01-07bibliografisk kontrollert
    2. Glioneuronal tumors in childhood - Before and after surgery. A long-term follow-up study
    Åpne denne publikasjonen i ny fane eller vindu >>Glioneuronal tumors in childhood - Before and after surgery. A long-term follow-up study
    Vise andre…
    2017 (engelsk)Inngår i: Epilepsy & Behavior, ISSN 1525-5050, E-ISSN 1525-5069, Vol. 72, s. 82-88Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Aim: To give a detailed description of the long-term outcome of a cohort of children with glioneuronal tumors regarding pre-and postsurgical factors, including "dual" and "double" pathology, seizure freedom, and psychosocial outcome.

    Methods: During a fifteen-year period (1995-2009), all patients (age 0-17.99 years) with a glioneuronal brain tumor diagnosed and treated at Uppsala University Children's Hospital were identified from the National Brain Tumor Registry and the National Epilepsy Surgery Registry. Hospital medical records were reviewed and neuroradiological and neuropathological findings were re-evaluated. A cross-sectional long-term follow-up prospective evaluation, including an interview, neurologic examination, and electroencephalogram, was accomplished in patients accepting participants in the study.

    Results: A total of 25 out of 28 (89%) eligible patientswere included. The M: F ratiowas 1.5: 1. Mean follow-up time after surgery was 12.1 years (range 5.0-19.3). Twenty patients were adults (N18 years) at follow-up. Seizure freedomwas achieved in 64%. Gross total resection (GTR) was the only preoperative factor significantly correlating to seizure freedom (p= 0.027). Thirty-eight percent were at some time postoperatively admitted for a psychiatric evaluation. There was a trend towards both higher educational level and employment status in adults who became seizure free.

    Conclusion: Long-termoutcome is good regarding seizure freedom if GTR can be achieved, but late seizure recurrence can occur. "Dual" and "double" pathology is uncommon and does not influence seizure outcome. Obtaining seizure freedomseems to be important for psychosocial outcome, but there is a risk for psychiatric comorbidities and long-term follow-up by a multi-professional team is advisable.

    sted, utgiver, år, opplag, sider
    ACADEMIC PRESS INC ELSEVIER SCIENCE, 2017
    Emneord
    Glioneuronal tumor, Childhood, "Dual" pathology, "Double" pathology, Seizure outcome, Psychosocial outcome
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-333399 (URN)10.1016/j.yebeh.2017.02.012 (DOI)000406321300015 ()28575773 (PubMedID)
    Tilgjengelig fra: 2017-11-16 Laget: 2017-11-16 Sist oppdatert: 2019-01-07bibliografisk kontrollert
    3. Cognition, health-related quality of life, and mood in children and young adults diagnosed with a glioneuronal tumor in childhood
    Åpne denne publikasjonen i ny fane eller vindu >>Cognition, health-related quality of life, and mood in children and young adults diagnosed with a glioneuronal tumor in childhood
    Vise andre…
    2018 (engelsk)Inngår i: Epilepsy & Behavior, ISSN 1525-5050, E-ISSN 1525-5069, Vol. 83, s. 59-66Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Aims: The aim of this study was to investigate long-term cognitive outcome, health-related quality of life (HRQoL), and psychiatric symptoms in children and young adults diagnosed with a glioneuronal tumor in childhood.

    Methods: Twenty-eight children and adolescents (0-17.99 years) with a minimum postoperative follow-up time of five years were eligible for the study; four persons declined participation. A cross-sectional long-term follow-up evaluation was performed using the following study measures: Wechsler Intelligence Scale for Children (WISC-IV) or Wechsler Adult Intelligence Scale (WAIS-IV), Reys Complex Figure Test (RCFT), Short Form 36 version 2 (SF-36v2), Short Form 10 (SF-10), Quality of Life in Epilepsy 31 (QOLIE-31), Hospital Anxiety Depression Scale (HADS) or Beck Youth Inventory Scales (BYI), and Rosenberg Self-Esteem Scale. Historical WISC-III and RCFT data were used to compare cognitive longitudinal data.

    Results: Mean follow-up time after surgery was 12.1 years. Sixty-three percent (15/24) were seizure-free. Despite a successive postoperative gain in cognitive function, a significant reduction relative to norms was seen in the seizure-free group with respect to perceptual reasoning index (PRI), working memory index (WMI), and full-scale intelligence quotient (FSIQ). Seizure freedom resulted in acceptable HRQoL. Thirty-two percent and 16% exceeded the threshold level of possible anxiety and depression, respectively, despite seizure freedom.

    Conclusion: Although lower than in corresponding reference groups, cognitive outcome and HRQoL are good provided that seizure freedom or at least a low seizure severity can be achieved. There is a risk of elevated levels of psychiatric symptoms. Long-term clinical follow-up is advisable.

    Emneord
    Glioneuronal brain tumors, Cognition, Quality of life, Mood, Long-term outcome
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-357694 (URN)10.1016/j.yebeh.2018.03.026 (DOI)000434400600009 ()29654937 (PubMedID)
    Tilgjengelig fra: 2018-08-22 Laget: 2018-08-22 Sist oppdatert: 2019-01-07bibliografisk kontrollert
    4. Somatostatin receptor expression and mTOR pathway activation in glioneuronal tumours of childhood
    Åpne denne publikasjonen i ny fane eller vindu >>Somatostatin receptor expression and mTOR pathway activation in glioneuronal tumours of childhood
    Vise andre…
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-371905 (URN)
    Tilgjengelig fra: 2019-01-03 Laget: 2019-01-03 Sist oppdatert: 2019-01-07
  • Disputas: 2019-03-01 13:00 80101, Uppsala
    Shukla, Vivekanand
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Computational Studies of 2D Materials: Application to Energy Storage and Electron Transport in Nanoscale Devices2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The field of two-dimensional (2D) layered materials provides a new platform for studying diverse physical phenomena that are scientifically interesting and relevant for technological applications. Novel applications in electronics and energy storage harness the unique electronic, optical, and mechanical properties of 2D materials for design of crucial components. Atomically thin, with large surface to volume ratio, these materials are attractive for broad applications for hydrogen storage, sensing, batteries and photo-catalysis. Theoretical predictions from atomically resolved computational simulations of 2D materials play a pivotal role in designing and advancing these developments.

    The central topic of this thesis is 2D materials studied using density functional theory and non-equilibrium Green’s function. The electronic structure and transport properties are discussed for several synthesized and predicted 2D materials, with diverse potential applications in nanoscale electronic devices, gas sensing, and electrodes for rechargeable batteries. Lateral and vertical heterostructures have been studied for applications in nanoscale devices such as graphene/hBN heterostructure nanogap for a potential DNA sequencing device, while in case of twisted bilayer black phosphorus nanojunction, where electronic and transport properties have been explored for diode-like characteristics device. We also have addressed the structural, electronic and transport properties of the recently synthesized polymorphs of 2D borons known as borophenes. We have explored the conventional methods of tuning the material’s properties such as strain in borophene and substitutional doping in black phosphorus with the further investigation of their gas sensing application.

    A significant portion of this thesis is also dedicated to the energy storage applications of different 2D materials. Energy storage technologies arise with vital importance in providing effective ways to transport and commercialize the produced energy, aiming at rechargeable batteries with high energy and power density. In this context, first-principles simulations have been applied together with other theoretical tools to evaluate structural properties, ion intercalation kinetics, specific capacity and open circuit voltage of selected 2D materials at the atomic level. The simulation study supports the understanding while improving the properties of the materials to increase their efficiency in battery operation.

    Delarbeid
    1. Prospects of Graphene-hBN Heterostructure Nanogap for DNA Sequencing
    Åpne denne publikasjonen i ny fane eller vindu >>Prospects of Graphene-hBN Heterostructure Nanogap for DNA Sequencing
    2017 (engelsk)Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, nr 46, s. 39945-39952Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Recent advances in solid-state nano-device-based DNA sequencing are at the helm of the development of a new paradigm, commonly referred to as personalized medicines. Paying heed to a timely need for standardizing robust nanodevices for cheap, fast, and scalable DNA detection, in this article, the nanogap formed by the lateral heterostructure of graphene and hexagonal boron nitride (hBN) is explored as a potential architecture. These heterostructures have been realized experimentally, and our study boasts the idea that the passivation of the edge of the graphene electrode with hBN will solve many of practical problems, such as high reactivity of the graphene edge and difficulty in controlled engineering of the graphene edge structure, while retaining the nanogap setup as a useful nanodevice for sensing applications. Employing first-principle density-functional-theory-based nonequilibrium Greens function methods, we identify that the DNA building blocks, nucleobases, uniquely couple with the states of the nanogap, and the resulting induced states can be attributed as leaving a fingerprint of the DNA sequence in the computed current-voltage (I-V) characteristic. Two bias windows are put forward: lower (1-1.2 V) and higher (2.7-3 V), where unique identification of all four bases is possible from the current traces, although higher sensitivity is obtained at the higher voltage window. Our study can be a practical guide for experimentalists toward development of a nanodevice DNA sensor based on graphene-hBN heterostructures.

    Emneord
    DNA sequencing, graphene-hBN heterostructure, nonequilibrium Green's function, density functional theory, I-V characteristics
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-343317 (URN)10.1021/acsami.7b06827 (DOI)000416614600012 ()
    Forskningsfinansiär
    Swedish Research CouncilStandUpCarl Tryggers foundation
    Tilgjengelig fra: 2018-03-13 Laget: 2018-03-13 Sist oppdatert: 2019-01-05bibliografisk kontrollert
    2. Rectifying properties in 90º rotated bilayer black phosphorus nanojunction: A first principle study
    Åpne denne publikasjonen i ny fane eller vindu >>Rectifying properties in 90º rotated bilayer black phosphorus nanojunction: A first principle study
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-369469 (URN)
    Tilgjengelig fra: 2018-12-13 Laget: 2018-12-13 Sist oppdatert: 2019-01-05
    3. Strain controlled electronic and transport anisotropies in two-dimensional borophene sheets
    Åpne denne publikasjonen i ny fane eller vindu >>Strain controlled electronic and transport anisotropies in two-dimensional borophene sheets
    2018 (engelsk)Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, nr 35, s. 22952-22960Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Two recent reports on realization of an elemental 2D analogue of graphene:borophene (Science, 2015, 350, 1513-1516; Nat. Chem., 2016, 8, 563-568) focus on the inherent anisotropy and directional dependence of the electronic properties of borophene polymorphs. Achieving stable 2D borophene structures may lead to some degree of strain in the system because of the substrate-lattice mismatch. We use first principles density functional theory (DFT) calculations to study the structural, electronic and transport properties of (12) and -borophene polymorphs. We verified the directional dependency and found the tunable anisotropic behavior of the transport properties in these two polymorphs. We find that strain as low as 6% brings remarkable changes in the properties of these two structures. We further investigate current-voltage (I-V) characteristics in the low bias regime after applying a strain to see how the anisotropy of the current is affected. Such observations like the sizeable tuning of transport and I-V characteristics at the expense of minimal strain suggest the suitability of 2D borophene for futuristic device applications.

    sted, utgiver, år, opplag, sider
    Royal Society of Chemistry, 2018
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-363428 (URN)10.1039/c8cp03815e (DOI)000445220500055 ()30156222 (PubMedID)
    Forskningsfinansiär
    Swedish Research CouncilSwedish National Infrastructure for Computing (SNIC), SNIC2017-11-28 SNIC2017-5-8 SNIC2017-1-237
    Tilgjengelig fra: 2018-10-18 Laget: 2018-10-18 Sist oppdatert: 2019-01-05bibliografisk kontrollert
    4. Toward the Realization of 2D Borophene Based Gas Sensor
    Åpne denne publikasjonen i ny fane eller vindu >>Toward the Realization of 2D Borophene Based Gas Sensor
    Vise andre…
    2017 (engelsk)Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 121, nr 48, s. 26869-26876Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    To the league of rapidly expanding 2D materials, borophene is a recent addition. Herein, a combination of ab initio density functional theory (DFT) and nonequilibrium Green's function (NEGF) based methods is used to estimate the prospects of this promising elemental 2D material for gas sensing applications. We note that the binding of target gas molecules such as CO, NO, NO2, NH3, and CO2 is quite strong on the borophene surface. Interestingly, our computed binding energies are far stronger than several other reported 2D materials like graphene, MoS2, and phosphorene. Further rationalization of stronger binding is made with the help of charge transfer analysis. The sensitivity of the borophene for these gases is also interpreted in terms of computing the vibrational spectra of the adsorbed gases on top of borophene, which show dramatic shift from their gas phase reference values. The metallic nature of borophene enables us to devise a setup considering the same substrate as electrodes. From the computation of the transmission function of system (gas + borophene), appreciable changes in the transmission functions are noted compared to pristine borophene surface. The measurements of current-voltage (I-V) characteristics unambiguously demonstrate the presence and absence of gas molecules (acting as ON and OFF states), strengthening the plausibility of a borophene based gas sensing device. As we extol the extraordinary sensitivity of borophene, we assert that this elemental 2D material is likely to attract subsequent interest.

    sted, utgiver, år, opplag, sider
    AMER CHEMICAL SOC, 2017
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-340255 (URN)10.1021/acs.jpcc.7b09552 (DOI)000417671500032 ()
    Forskningsfinansiär
    Swedish National Infrastructure for Computing (SNIC)Swedish Research CouncilCarl Tryggers foundation StandUp
    Tilgjengelig fra: 2018-01-30 Laget: 2018-01-30 Sist oppdatert: 2019-01-05bibliografisk kontrollert
    5. Ultrahigh-sensitive gas sensors based on doped phosphorene: A First-principles investigation
    Åpne denne publikasjonen i ny fane eller vindu >>Ultrahigh-sensitive gas sensors based on doped phosphorene: A First-principles investigation
    Vise andre…
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-372109 (URN)
    Tilgjengelig fra: 2019-01-05 Laget: 2019-01-05 Sist oppdatert: 2019-01-14
    6. The Curious Case of Two Dimensional Si2BN: A High-capacity Battery Anode Material
    Åpne denne publikasjonen i ny fane eller vindu >>The Curious Case of Two Dimensional Si2BN: A High-capacity Battery Anode Material
    2017 (engelsk)Inngår i: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 41, s. 251-260Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The ubiquity of silicon in the semiconductor industry and its unique charge transport features has consistently fueled interest in this element and recent realization 2D silicene is a new feather in its cap. In what could be considered as opening up the Pandora's box with many possible virtues, buckled silicene, planar graphene and a host of other newly discovered 2D materials have redefined a whole new paradigm of research. To this end, the quest for new 2D materials and finding potential applications, particularly to the realm of energy storage, is a curiosity driven task. From first principle density functional theory studies, a newly reported graphene like 2D material Si2BN is investigated as a probable anode material for Li and Na ion batteries. In contrast to pristine silicene, which is inherently buckled, the material Si2BN is planar. However, an interesting transition from planar to buckled structure takes place upon subsequent adsorption of Li and Na ions. Concomitantly, this transition is associated with superior specific capacity (1158.5 and 993.0 mA h/g respectively for Li and Na) which is significantly higher than several other 2D analogues. Furthermore, the substrate Si2BN regains the planar structure on subsequent desorption of ions and stability of the material remains intact, as evidenced from ab initio molecular dynamics simulations. As we delve deep into the electronic structure and compute the diffusion pathways and barriers, it is observed that the ionic diffusion is very fast with significantly lesser barrier heights, particularly for Na-ion. These findings suggest that for the 2D Si2BN, there is no diminution in order to be a potential anode material for Li and Na ion batteries.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-330765 (URN)10.1016/j.nanoen.2017.09.026 (DOI)000415302600027 ()
    Forskningsfinansiär
    StandUpSwedish Research CouncilCarl Tryggers foundation Swedish National Infrastructure for Computing (SNIC), SNIC-2017-11-28 SNIC-2017-1-237
    Tilgjengelig fra: 2017-10-03 Laget: 2017-10-03 Sist oppdatert: 2019-01-05bibliografisk kontrollert
    7. Borophane as a Benchmate of Graphene: A Potential 2D Material for Anode of Li and Na-Ion Batteries
    Åpne denne publikasjonen i ny fane eller vindu >>Borophane as a Benchmate of Graphene: A Potential 2D Material for Anode of Li and Na-Ion Batteries
    2017 (engelsk)Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, nr 19, s. 16148-16158Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Borophene, single atomic-layer sheet of boron (Science 2015, 350, 1513), is a rather new entrant into the burgeoning class of 2D materials. Borophene exhibits anisotropic metallic properties whereas its hydrogenated counterpart borophane is reported to be a gapless Dirac material lying on the same bench with the celebrated graphene. Interestingly, this transition of borophane also rendered stability to it considering the fact that borophene was synthesized under ultrahigh vacuum conditions on a metallic (Ag) substrate. On the basis of first-principles density functional theory computations, we have investigated the possibilities of borophane as a potential Li/Na-ion battery anode material. We obtained a binding energy of -2.58 (-1.08 eV) eV for Li (Na)-adatom on borophane and Bader charge analysis revealed that Li(Na) atom exists in Li+(Na+) state. Further, on binding with Li/Na, borophane exhibited metallic properties as evidenced by the electronic band structure. We found that diffusion pathways for Li/Na on the borophane surface are anisotropic with x direction being the favorable one with a barrier of 0.27 and 0.09 eV, respectively. While assessing the Li-ion anode performance, we estimated that the maximum Li content is Li0.445B2H2, which gives rises to a material with a maximum theoretical specific capacity of 504 mAh/g together with an average voltage of 0.43 V versus Li/Li+. Likewise, for Na-ion the maximum theoretical capacity and average voltage were estimated to be 504 mAh/g and 0.03 V versus Na/Na+, respectively. These findings unambiguously suggest that borophane can be a potential addition to the map of Li and Na-ion anode materials and can rival some of the recently reported 2D materials including graphene.

    sted, utgiver, år, opplag, sider
    AMER CHEMICAL SOC, 2017
    Emneord
    borophene, borophane, Dirac material, Li-ion battery, Na-ion battery, Li/Na-diffusion
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-327151 (URN)10.1021/acsami.7b01421 (DOI)000401782500026 ()28443653 (PubMedID)
    Forskningsfinansiär
    Swedish Research CouncilStandUpCarl Tryggers foundation
    Tilgjengelig fra: 2017-08-25 Laget: 2017-08-25 Sist oppdatert: 2019-01-05bibliografisk kontrollert
    8. Borophene's tryst with stability: exploring 2D hydrogen boride as an electrode for rechargeable batteries
    Åpne denne publikasjonen i ny fane eller vindu >>Borophene's tryst with stability: exploring 2D hydrogen boride as an electrode for rechargeable batteries
    2018 (engelsk)Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, nr 34, s. 22008-22016Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Graphene's emergence can be viewed as a positive upheaval in 2D materials research. Along the same line, the realization of a related elemental 2D material, borophene, is another breakthrough. To circumvent the stability issues of borophene, which is reported to have been synthesized on metallic substrates under extreme conditions, hydrogenation of borophene (otherwise called as borophane or hydrogen boride or boron hydride) has been a plausible solution, but only proposed computationally. A recent report (H. Nishino, T. Fujita, N. T. Cuong, S. Tominaka, M. Miyauchi, S. Iimura, A. Hirata, N. Umezawa, S. Okada, E. Nishibori, A. Fujino, T. Fujimori, S. Ito, J. Nakamura, H. Hosono and T. Kondo, J. Am. Chem. Soc., 2017, 139(39), 13761-13769) brings to fore its experimental realization. Our current study delves into the possibilities of employing this intriguing 2D hydrogen boride as anodes in Li/Na ion batteries. Using first-principles density functional theory methods, we computed relevant properties such as the ion (Li/Na) adsorption behavior, the possible pathways of ionic diffusion with the estimation of barriers as well as the theoretical specific capacities and average voltages to uniquely demonstrate that this material is of particular significance for battery applications. It is noted that the use of hydrogen boride leads to a high specific capacity of 861.78 mA h g(-1) for Li ions, which is remarkably higher than the value reported in relation to its computationally predicted structure. Furthermore, Na ion intercalation leads to negative voltage profiles, implying the unsuitability of 2D hydrogen boride for this particular ion. Our findings are timely and pertinent towards adding insightful details relevant to the progress of applications of 2D materials for energy storage.

    sted, utgiver, år, opplag, sider
    ROYAL SOC CHEMISTRY, 2018
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-369513 (URN)10.1039/c8cp03686a (DOI)000449394100021 ()30109880 (PubMedID)
    Forskningsfinansiär
    Swedish Research CouncilCarl Tryggers foundation StandUp
    Tilgjengelig fra: 2018-12-17 Laget: 2018-12-17 Sist oppdatert: 2019-01-05bibliografisk kontrollert
    9. Modeling High-performing Batteries with Mxenes: The case of S-functionalized two- Dimensional Nitride Mxene Electrode
    Åpne denne publikasjonen i ny fane eller vindu >>Modeling High-performing Batteries with Mxenes: The case of S-functionalized two- Dimensional Nitride Mxene Electrode
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-372108 (URN)
    Tilgjengelig fra: 2019-01-05 Laget: 2019-01-05 Sist oppdatert: 2019-01-05
  • Disputas: 2019-03-01 13:15 Humanistiska teatern, Uppsala
    Bengtson, Erik
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Historisk-filosofiska fakulteten, Litteraturvetenskapliga institutionen, Avdelningen för retorik.
    The Epistemology of Rhetoric: Plato, Doxa and Post-Truth2019Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    This thesis aims to develop an epistemology of rhetoric in light of the apparent contemporary post-truth condition of society. Epistemology is hereby understood as concerned with principles for knowledge production within the academic discipline of rhetoric, as well as with an understanding of knowledge production in the public realm.

    The first part of the thesis investigates the opposition between opinion (doxa) and true knowledge (epistēmē), which has been said to be at the very heart of the birth of rhetoric itself. I show through readings of Plato's Gorgias, Phaedrus, Theaetetus, Meno and Republic that the contemporary rendering of this birth is, however, haunted by simplification and misrepresentation. Nevertheless, locating and scrutinising these cracks provides avenues toward a contemporary epistemology of rhetoric, and thus to an alternative to the traditional way of re-assessing rhetoric in the wake of Aristotle.

    Part 2 investigates fives routes for a contemporary re-invention of doxa. Barthes represents the structuralist and poststructuralist route, Hariman rhetorical ontology, Amossy the pragmatic study of doxa, and Rosengren rhetorical-philosophical anthropology. These engagements draw inspiration from the general direction of Rosengren’s work, while striving for the analytical sharpness of Barthes and Amossy, as well as highlighting the importance of understanding of the function of metadiscourse. 

    In part 3, I present ways to reconsider rhetorical theory and how rhetoricians tend to understand argumentation. Seven principles for rhetorical theory are presented, sketching an understanding of the human position that includes embodiment, takes all forms of symbolic influence into account, and considers the sociality and historicity of being, as well as the capacity for human agency. The thesis concludes by presenting a model for rhetorical argumentation which portrays rhetoric as a process of sedimentation and erosion, constituted from an acknowledgement of the reasonableness of everyday wisdom, the establishment of new myths, and the denaturalisation of prevalent beliefs, desires and identities. In its final section, I return to the ethical challenge at the heart of the post-truth narrative, arguing for the potential inherent in the heroic figure of a champion of autonomy.

  • Disputas: 2019-03-01 13:15 Eva Netzelius, Uppsala
    Hofverberg, Hanna
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Fakulteten för utbildningsvetenskaper, Institutionen för pedagogik, didaktik och utbildningsstudier.
    Crafting Sustainable Development: Studies of Teaching and Learning Craft in Environmental and Sustainability Education2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The overall aim of the thesis is to contribute with new and deepened knowledge about the teaching and learning of craft when the crafting activity is considered as environmental and sustainability education (ESE). To achieve this, three objectives have been formulated: to examine what constitutes a craft subject content relevant for ESE, to examine what influences the learning process when the crafting activity is considered as ESE, and to examine how the crafting material participates in the learning process when the crafting activity is considered as ESE. The three research objectives are addressed by four studies: one literature study (Paper I) and three case studies where the empirical data is constructed through observations (video recordings) of a remake project (Papers II and IV) and an embroidery project (Paper III) in the craft subject ‘educational sloyd’ in Sweden. The main theories that the thesis draws on are Tim Ingold’s theory of making as a practice of correspondence and John Dewey’s transactional approach to meaning-making. Several methods that acknowledge learning in action are used, which makes it possible to explore how the student–material relations emerge and how both humans and more-than-humans participate in the learning activity. The findings show that a craft activity, for example a remake project, can have different purposes and pedagogies, which produce different learning experiences and sustainability outcomes. Further, I identify and distinguish a process content from a product content, which deepens our understanding of what students learn when the crafting activity is considered as ESE. By focusing on how the student–material relations emerge in the learning process – with concepts that I use and develop such as correspondence, stories, and transactant – I empirically show how the crafting material not only participates with its materiality but also creates the embodied stories that students recognise when they encounter the crafting material in the crafting activity. How humans learn in socio-material relations and what consequences these have for ESE are two key issues that are further discussed when the crafting activity is considered as ESE. 

    Delarbeid
    1. Crafting sustainability?: An Explorative Study of Craft in Three Countercultures as a Learning Path for the Future
    Åpne denne publikasjonen i ny fane eller vindu >>Crafting sustainability?: An Explorative Study of Craft in Three Countercultures as a Learning Path for the Future
    2017 (engelsk)Inngår i: Nordic Journal of Science and Technology Studies, ISSN 1894-4647, Vol. 5, nr 2, s. 8-21Artikkel i tidsskrift (Fagfellevurdert) Published
    HSV kategori
    Forskningsprogram
    Didaktik
    Identifikatorer
    urn:nbn:se:uu:diva-362795 (URN)
    Tilgjengelig fra: 2018-10-10 Laget: 2018-10-10 Sist oppdatert: 2019-01-09
    2. Recycling, crafting and learning: an empirical analysis of how students learn with garments and textile refuse in a school remake project
    Åpne denne publikasjonen i ny fane eller vindu >>Recycling, crafting and learning: an empirical analysis of how students learn with garments and textile refuse in a school remake project
    2018 (engelsk)Inngår i: Environmental Education Research, ISSN 1350-4622, E-ISSN 1469-5871, Vol. 24, nr 6, s. 775-790Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Creative remake assignments using garments and textile refuse are common educational projects to promote environmental and sustainability actions. However, very little empirical research has been carried out on the learning processes of remake projects. In this article, the aim is to examine how students learn with garments and textile refuse when engaging in a remake project. The exploration is conducted in a Swedish crafts class, educational sloyd, as a case. Practical epistemological analysis and the concept of transactant are used to analyse and be attentive to the learning process. The findings show how students transact with the idea of a product, the material's capabilities and the remake techniques. Further, the transactants show what participates and makes the learning process turn in specific directions, which is further discussed in the paper. Based on this empirical research, we may increase our understandings of how the learning processes is made in the remake project, and that knowledge can help us understand, and thus improve the quality of remake projects in relation to the environmental and sustainability aims.

    Emneord
    Recycling, remake, learning, arts and crafts, transactant
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-354263 (URN)10.1080/13504622.2017.1338672 (DOI)000430846200001 ()
    Tilgjengelig fra: 2018-06-28 Laget: 2018-06-28 Sist oppdatert: 2019-01-09bibliografisk kontrollert
    3. Human-material relationships in environmental and sustainability education: an empirical study of a school embroidery project
    Åpne denne publikasjonen i ny fane eller vindu >>Human-material relationships in environmental and sustainability education: an empirical study of a school embroidery project
    2018 (engelsk)Inngår i: Environmental Education Research, ISSN 1350-4622, E-ISSN 1469-5871, Vol. 24, nr 7, s. 955-968Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    In recent discussions about the widening and opening up of anthropocentric perspectives in environmental and sustainability education (ESE) research, a recurrent issue has been what reasonably could be a subject of inquiry and an agent of knowledge. This article aims to showcase an empirical study of the relevance of human-material relationships in crafting learning processes by following an embroidery project with year 8 students in the Swedish craft subject of educational sloyd. How the human-material correspondence unfolds in the crafting learning process is analysed with the aid of Ingold's practice of correspondence and SOrensen's notion of participation, performance and imagination. Rather than assuming that materials contribute to certain environmental and sustainability aims, the analysis empirically demonstrates how the human-material correspondence unfolds. The analysis identifies three human-material relationships: attuning, troubling and tracing correspondence. Drawing on the findings, the human-material relevance for environmental and sustainability education and research is further discussed.

    HSV kategori
    Forskningsprogram
    Didaktik
    Identifikatorer
    urn:nbn:se:uu:diva-362790 (URN)10.1080/13504622.2017.1358805 (DOI)000441636900003 ()
    Tilgjengelig fra: 2018-10-10 Laget: 2018-10-10 Sist oppdatert: 2019-01-09bibliografisk kontrollert
    4. Entangled threads and crafted meanings: Students’ learning for sustainability
    Åpne denne publikasjonen i ny fane eller vindu >>Entangled threads and crafted meanings: Students’ learning for sustainability
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Emneord
    Learning, handicraft, recycling clothes, remake pedagogy, mending
    HSV kategori
    Forskningsprogram
    Didaktik
    Identifikatorer
    urn:nbn:se:uu:diva-372975 (URN)
    Tilgjengelig fra: 2019-01-09 Laget: 2019-01-09 Sist oppdatert: 2019-01-09
  • Disputas: 2019-03-06 09:15 C8:301, Uppsala
    Pietrini, Alberto
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär biofysik.
    Statistical processing of Flash X-ray Imaging of protein complexes2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Flash X-ray Imaging (FXI) at X-ray Free Electron Lasers (XFELs) is a promising technique that permits the investigation of the 3D structure of molecules without the need for crystallization, by diffracting on single individual sample particles.

    In the past few years, some success has been achieved by using FXI on quite large biological complexes (40 nm-1 μm in diameter size). Still, the desired dream-goal of imaging a single individual of a molecule or a protein complex (<15 nm in diameter size) has not been reached yet. The main issue that prevented us from a complete success has been the low signal strength, almost comparable to background noise. That is particularly true for experiments performed at the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS).

    In this thesis, we provide a brief review of the CXI instrument (focusing on experiments there performed) and present a statistical method to deal with low signal-to-noise ratios. We take into account a variety of biological particles, showing the benefits of estimating a background model from sample data and using that for processing said data. Moreover, we present the results of some computer simulations in order to explore the limits and potentials of the proposed approach.

    Last, we show another method (named COACS) that, being fed with the previous findings from the background model, helps obtaining clearer results in the phase retrieval problem.

    Delarbeid
    1. Artifact reduction in the CSPAD detectors used for LCLS experiments
    Åpne denne publikasjonen i ny fane eller vindu >>Artifact reduction in the CSPAD detectors used for LCLS experiments
    2017 (engelsk)Inngår i: Journal of Synchrotron Radiation, ISSN 0909-0495, E-ISSN 1600-5775, Vol. 24, s. 1092-1097Artikkel i tidsskrift (Fagfellevurdert) Published
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-328543 (URN)10.1107/S160057751701058X (DOI)000408902800025 ()28862634 (PubMedID)
    Prosjekter
    eSSENCE
    Tilgjengelig fra: 2017-07-18 Laget: 2017-08-25 Sist oppdatert: 2019-01-14bibliografisk kontrollert
    2. A statistical approach to detect protein complexes at X-ray free electron laser facilities
    Åpne denne publikasjonen i ny fane eller vindu >>A statistical approach to detect protein complexes at X-ray free electron laser facilities
    Vise andre…
    2018 (engelsk)Inngår i: Communications Physics, E-ISSN 2399-3650, Vol. 1, s. 92:1-11, artikkel-id 92Artikkel i tidsskrift (Fagfellevurdert) Published
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-369876 (URN)10.1038/s42005-018-0092-6 (DOI)000452676300003 ()
    Prosjekter
    eSSENCE
    Tilgjengelig fra: 2018-12-07 Laget: 2018-12-17 Sist oppdatert: 2019-01-17bibliografisk kontrollert
    3. Using convex optimization of autocorrelation with constrained support and windowing for improved phase retrieval accuracy
    Åpne denne publikasjonen i ny fane eller vindu >>Using convex optimization of autocorrelation with constrained support and windowing for improved phase retrieval accuracy
    2018 (engelsk)Inngår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 26, s. 24422-24443Artikkel i tidsskrift (Fagfellevurdert) Published
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-360037 (URN)10.1364/OE.26.024422 (DOI)000444705000012 ()30469561 (PubMedID)
    Prosjekter
    eSSENCE
    Tilgjengelig fra: 2018-09-05 Laget: 2018-09-09 Sist oppdatert: 2019-01-14bibliografisk kontrollert
  • Disputas: 2019-03-07 10:00 A1:107a, Uppsala
    Titova, Olga E.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Funktionell farmakologi.
    Metabolic Health and Cognitive Function: The Roles of Lifestyle and Shift Work2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The risk of cognitive impairment and metabolic disturbances increases during aging. Healthy lifestyle habits, such as a regular intake of fatty fish and adherence to the Mediterranean diet (MeDi), have been shown to slow age-related cognitive decline and decrease the risk of metabolic disturbances. Conversely, poor lifestyle habits including habitual short sleep duration as well as irregular work schedules (e.g. night shift work) have been correlated with lower cognitive performance and increased risk of having metabolic syndrome (MetS). However evidence is not conclusive regarding the above mentioned associations. The aim of this thesis was to investigate associations of diet, sleep, and shift work with metabolic health or cognitive performance in two Swedish cohorts.

    In Paper I and II we examined whether the dietary intake of omega-3 fatty acids and adherence to MeDi were related to measures of brain health in elderly subjects. To this aim, we used scores from the 7-minute cognitive screening test (7MS) and brain volume determined by magnetic resonance imaging. In Paper I, self-reported dietary intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at age 70 was positively associated with cognitive performance and global gray matter volume at age 75. In Paper II, the fully-adjusted main analysis revealed that the MeDi score was not linked to measures of brain health. However, low intake of the MeDi component meat and meat products was associated with better performance on the 7MS and larger total brain volume.

    Paper III and IV included subjects aged 45-75 years. In Paper III we demonstrated that current and recent former shift workers (including shifts outside traditional working hours during the past 5 years at the time of the survey) performed worse on the trail making test (TMT) than non-shift workers. The TMT is a test evaluating executive cognitive function, and the performance on this test decreases with age. In Paper IV, sleep duration, sleep disturbances, and sleep-disordered breathing were all linked to an increased prevalence of MetS. Some of the observed associations were age-specific. For example, whereas both short and long sleep durations were linked to a higher prevalence of MetS in younger individuals (<65 years), only long sleep duration did so in the older participants. Collectively, the findings of this thesis suggest that maintaining healthy dietary habits, having high-quality sleep, and following a regular work schedule may be recommended strategies to mitigate age-related morbidities.

    Delarbeid
    1. Dietary intake of eicosapentaenoic and docosahexaenoic acids is linked to gray matter volume and cognitive function in elderly
    Åpne denne publikasjonen i ny fane eller vindu >>Dietary intake of eicosapentaenoic and docosahexaenoic acids is linked to gray matter volume and cognitive function in elderly
    Vise andre…
    2013 (engelsk)Inngår i: Age (Omaha), ISSN 0161-9152, E-ISSN 1574-4647, Vol. 35, nr 4, s. 1495-1505Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    In the present study, we tested whether elderly with a high dietary intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) would have higher cognitive test scores and greater brain volume than those with low dietary intake of these fatty acids. Data were obtained from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort. The dietary intake of EPA and DHA was determined by a 7-day food protocol in 252 cognitively healthy elderly (122 females) at the age of 70 years. At age 75, participants' global cognitive function was examined, and their brain volumes were measured by magnetic resonance imaging (MRI). Three different multivariate linear regression models were applied to test our hypothesis: model A (adjusted for gender and age), model B (additionally controlled for lifestyle factors, e.g., education), and model C (further controlled for cardiometabolic factors, e.g., systolic blood pressure). We found that the self-reported 7-day dietary intake of EPA and DHA at the age of 70 years was positively associated with global gray matter volume (P < 0.05, except for model C) and increased global cognitive performance score (P < 0.05). However, no significant associations were observed between the dietary intake of EPA and DHA and global white matter, total brain volume, and regional gray matter, respectively. Further, no effects were observed when examining cognitively impaired (n = 27) elderly as separate analyses. These cross-sectional findings suggest that dietary intake of EPA and DHA may be linked to improved cognitive health in late life but must be confirmed in patient studies.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-181452 (URN)10.1007/s11357-012-9453-3 (DOI)000321547300038 ()22791395 (PubMedID)
    Tilgjengelig fra: 2012-09-24 Laget: 2012-09-24 Sist oppdatert: 2019-01-17bibliografisk kontrollert
    2. Mediterranean diet habits in older individuals: Associations with cognitive functioning and brain volumes
    Åpne denne publikasjonen i ny fane eller vindu >>Mediterranean diet habits in older individuals: Associations with cognitive functioning and brain volumes
    Vise andre…
    2013 (engelsk)Inngår i: Experimental Gerontology, ISSN 0531-5565, E-ISSN 1873-6815, Vol. 48, nr 12, s. 1443-1448Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    To examine the association between dietary habits, cognitive functioning and brain volumes in older individuals, data from 194 cognitively healthy individuals who participated in the Prospective Investigation of the Vasculature in Uppsala Seniors cohort were used. At age 70, participants kept diaries of their food intake for 1week. These records were used to calculate a Mediterranean diet (MeDi) score (comprising dietary habits traditionally found in Mediterranean countries, e.g. high intake of fruits and low intake of meat), with higher scores indicating more pronounced MeDi-like dietary habits. Five years later, participants' cognitive capabilities were examined by the seven minute screening (7MS) (a cognitive test battery used by clinicians to screen for dementia), and their brain volumes were measured by volumetric magnetic resonance imaging. Multivariate linear regression analyses were constructed to examine the association between the total MeDi score and cognitive functioning and brain volumes. In addition, possible associations between MeDi's eight dietary features and cognitive functioning and brain volumes were investigated. From the eight dietary features included in the MeDi score, pertaining to a low consumption of meat and meat products was linked to a better performance on the 7MS test (P=0.001) and greater total brain volume (P=0.03), i.e. the sum of white and gray matter. Integrating all dietary features of MeDi into score did not explain additional variance. These observational findings suggest that keeping to a low meat intake could prove to be an impact-driven public health policy to support healthy cognitive aging, when confirmed by longitudinal studies. Further, they suggest that the MeDi score is a construct that may mask possible associations of single MeDi features with brain health domains in elderly populations.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-209899 (URN)10.1016/j.exger.2013.10.002 (DOI)000327489800009 ()24126083 (PubMedID)
    Tilgjengelig fra: 2013-10-28 Laget: 2013-10-28 Sist oppdatert: 2019-01-17bibliografisk kontrollert
    3. Association between shift work history and performance on the trail making test in middle-aged and elderly humans: the EpiHealth study
    Åpne denne publikasjonen i ny fane eller vindu >>Association between shift work history and performance on the trail making test in middle-aged and elderly humans: the EpiHealth study
    Vise andre…
    2016 (engelsk)Inngår i: Neurobiology of Aging, ISSN 0197-4580, E-ISSN 1558-1497, Vol. 45, s. 23-29Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Shift work has been proposed to promote cognitive disturbances in humans; however, conflicting evidence is also present. By using data from 7143 middle-aged and elderly humans (45-75 years) who participated in the Swedish EpiHealth cohort study, the present analysis sought to investigate whether self-reported shift work history would be associated with performance on the trail making test (TMT). The TMT has been proposed to be a useful neuropsychological tool to evaluate humans' executive cognitive function, which is known to decrease with age. After adjustment for potential confounders (e.g., age, education, and sleep duration), it was observed that current and recent former shift workers (worked shifts during the past 5 years) performed worse on the TMT than nonshift workers. In contrast, performance on the TMT did not differ between past shift workers (off from shift work for more than 5 years) and nonshift workers. Collectively, our results indicate that shift work history is linked to poorer performance on the TMT in a cohort of middle-aged and elderly humans.

    Emneord
    Shift work history, Trail making test, Cohort study
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-303263 (URN)10.1016/j.neurobiolaging.2016.05.007 (DOI)000381092900003 ()27459922 (PubMedID)
    Forskningsfinansiär
    Swedish Research CouncilThe Swedish Brain FoundationNovo Nordisk
    Tilgjengelig fra: 2016-10-05 Laget: 2016-09-15 Sist oppdatert: 2019-01-17bibliografisk kontrollert
    4. Associations Between the Prevalence of Metabolic Syndrome and Sleep Parameters Vary by Age
    Åpne denne publikasjonen i ny fane eller vindu >>Associations Between the Prevalence of Metabolic Syndrome and Sleep Parameters Vary by Age
    Vise andre…
    2018 (engelsk)Inngår i: Frontiers in Endocrinology, ISSN 1664-2392, E-ISSN 1664-2392, Vol. 9, artikkel-id 234Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Objective: To examine whether the relationship between the metabolic syndrome (MetS) and various sleep parameters [sleep duration, symptoms of sleep-disordered breathing (SDB), and sleep disturbances] varies by age. Methods: Waist circumference, blood pressure, triglycerides, high-density lipoprotein cholesterol, and fasting glucose were used to determine MetS status in a cohort (N = 19,691) of middle-aged (aged 45-64 years) and older (aged >= 65 years) subjects. Habitual sleep duration (short, <= 6 h/day; normal, 7-8 h/day; and long >= 9 h/day), sleep disturbances (such as problems with falling and staying asleep), and symptoms of sleep-disordered breathing (SDB, such as snoring and sleep apneas) were measured by questionnaires. Results: Among the participants, 4,941 subjects (25.1%) fulfilled the criteria for MetS. In the entire sample, both short and long sleep durations were associated with higher prevalence of MetS as compared to normal sleep duration. When stratified by age, a similar pattern was observed for middle-aged subjects (<65 years old; prevalence ratio (PR) [95% CI], 1.13 [1.06-1.22] for short sleep and 1.26 [1.06-1.50] for long sleep duration). In contrast, in older individuals (>= 65 years old), only long sleep duration was linked to a higher prevalence of MetS (1.26 [1.12-1.42]; P < 0.01 for sleep duration x age). In the entire cohort, having at least one SDB symptom >= 4 times per week was linked to an increased prevalence of MetS; however, the PR was higher in middle-aged subjects compared with older subjects (1.50 [1.38-1.63] vs. 1.36 [1.26-1.47], respectively; P < 0.001 for SDB x age). Finally, independent of subjects' age, reports of sleep disturbances (i.e., at least one symptom >= 4 times per week) were associated with a higher likelihood of having MetS (1.12 [1.06-1.18]; P > 0.05 for sleep disturbance x age). Conclusion: Our results suggest that age may modify the associations between some sleep parameters and the prevalence of MetS.

    Emneord
    sleep duration, sleep disturbance, sleep-disordered breathing, metabolic syndrome, age
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-356873 (URN)10.3389/fendo.2018.00234 (DOI)000431867800001 ()29867766 (PubMedID)
    Forskningsfinansiär
    Swedish Research Council, 2015-03100The Swedish Brain FoundationNovo Nordisk, NNF14OC0009349
    Tilgjengelig fra: 2018-08-09 Laget: 2018-08-09 Sist oppdatert: 2019-01-17bibliografisk kontrollert
  • Disputas: 2019-03-08 09:15 A1:111a, Uppsala
    Liljeruhm, Josefine
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylärbiologi.
    Exotic Ribosomal Enzymology2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis clarifies intriguing enzymology of the ribosome, the multiRNA/multiprotein complex that catalyzes protein synthesis (translation). The large ribosomal RNAs (23S and 16S rRNAs in E. coli) are post-transcriptionally modified by many specific modification enzymes, yet the functions of the modifications remain enigmatic. A deeper insight into two of the 23S rRNA S-adenosyl-methionine-requiring methyltransferase enzymes, RlmM and RlmJ, was given by investigating substrate specificity in vitro. Both enzymes were able to methylate in vitro-transcribed, modification-free, protein-free, 2659-nucleotide-long 23S rRNA. Furthermore, RlmM was able to methylate the 611-nucleotide-long Domain V of the 23S rRNA alone and RlmJ could modify the A2030 with only 25 surrounding nucleotides.

    Translation is evolutionary optimized to incorporate L-amino acids to the exclusion of D-amino acids in the cell. To understand how, and how to engineer around this restriction for pharmacological applications, detailed kinetics of ribosomal dipeptide formation with D- versus L-phenylalanine-tRNA were determined. This was done by varying the concentrations of EF-Tu (which delivers aminoacyl-tRNAs to the ribosome) and the ribosome, as well as changing the tRNA adaptor. Binding to EF-Tu was shown to be rate limiting for D-Phe-tRNA at a low concentration of EF-Tu. Surprisingly, at a higher (physiological) concentration of EF-Tu, binding and subsequent dipeptide synthesis became so efficient that D-Phe incorporation became competitive with L-Phe, and accommodation/peptide bond formation was unmasked as a new rate-limiting step. This highlighted the importance of D-aminoacyl-tRNA deacylase in restricting translation with D-amino acids in vivo.

    Although polypeptides are intrinsically colorless, it is remarkable that evolution has nevertheless enabled ribosomes to synthesize highly colored proteins (chromoproteins). Such eukaryotic proteins reside in coral reefs and undergo self-catalyzed, intramolecular, chromophore formation by reacting with oxygen in a manner highly similar to that of green fluorescent protein. The potential utility of different colored chromoproteins in E. coli was analyzed via codon-optimized over-expression and quantification of maturation times, color intensities and cellular fitness costs. No chromoprotein was found to have the combined characteristics of fast maturation, intense color and low fitness cost. However, semi-rational mutagenesis created different colored variants with identical fitness costs suitable for competition assays and teaching.

    Delarbeid
    1. Crystal structure of RlmM, the 2'O-ribose methyltransferase for C2498 of Escherichia coli 23S rRNA
    Åpne denne publikasjonen i ny fane eller vindu >>Crystal structure of RlmM, the 2'O-ribose methyltransferase for C2498 of Escherichia coli 23S rRNA
    Vise andre…
    2012 (engelsk)Inngår i: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 40, nr 20, s. 10507-20Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    RlmM (YgdE) catalyzes the S-adenosyl methionine (AdoMet)-dependent 2'O methylation of C2498 in 23S ribosomal RNA (rRNA) of Escherichia coli. Previous experiments have shown that RlmM is active on 23S rRNA from an RlmM knockout strain but not on mature 50S subunits from the same strain. Here, we demonstrate RlmM methyltransferase (MTase) activity on in vitro transcribed 23S rRNA and its domain V. We have solved crystal structures of E. coli RlmM at 1.9 Å resolution and of an RlmM-AdoMet complex at 2.6 Å resolution. RlmM consists of an N-terminal THUMP domain and a C-terminal catalytic Rossmann-like fold MTase domain in a novel arrangement. The catalytic domain of RlmM is closely related to YiiB, TlyA and fibrillarins, with the second K of the catalytic tetrad KDKE shifted by two residues at the C-terminal end of a beta strand compared with most 2'O MTases. The AdoMet-binding site is open and shallow, suggesting that RNA substrate binding may be required to form a conformation needed for catalysis. A continuous surface of conserved positive charge indicates that RlmM uses one side of the two domains and the inter-domain linker to recognize its RNA substrate.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-187880 (URN)10.1093/nar/gks727 (DOI)000310970700054 ()22923526 (PubMedID)
    Tilgjengelig fra: 2012-12-11 Laget: 2012-12-11 Sist oppdatert: 2019-01-25bibliografisk kontrollert
    2. Structural and functional insights into the molecular mechanism of rRNA m6A methyltransferase RlmJ
    Åpne denne publikasjonen i ny fane eller vindu >>Structural and functional insights into the molecular mechanism of rRNA m6A methyltransferase RlmJ
    Vise andre…
    2013 (engelsk)Inngår i: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 41, nr 20, s. 9537-9548Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    RlmJ catalyzes the m(6)A2030 methylation of 23S rRNA during ribosome biogenesis in Escherichia coli. Here, we present crystal structures of RlmJ in apo form, in complex with the cofactor S-adenosyl-methionine and in complex with S-adenosyl-homocysteine plus the substrate analogue adenosine monophosphate (AMP). RlmJ displays a variant of the Rossmann-like methyltransferase (MTase) fold with an inserted helical subdomain. Binding of cofactor and substrate induces a large shift of the N-terminal motif X tail to make it cover the cofactor binding site and trigger active-site changes in motifs IV and VIII. Adenosine monophosphate binds in a partly accommodated state with the target N6 atom 7 Å away from the sulphur of AdoHcy. The active site of RlmJ with motif IV sequence 164DPPY167 is more similar to DNA m(6)A MTases than to RNA m(6)2A MTases, and structural comparison suggests that RlmJ binds its substrate base similarly to DNA MTases T4Dam and M.TaqI. RlmJ methylates in vitro transcribed 23S rRNA, as well as a minimal substrate corresponding to helix 72, demonstrating independence of previous modifications and tertiary interactions in the RNA substrate. RlmJ displays specificity for adenosine, and mutagenesis experiments demonstrate the critical roles of residues Y4, H6, K18 and D164 in methyl transfer.

    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-211566 (URN)10.1093/nar/gkt719 (DOI)000326746400036 ()23945937 (PubMedID)
    Tilgjengelig fra: 2013-11-26 Laget: 2013-11-26 Sist oppdatert: 2019-01-25bibliografisk kontrollert
    3. Kinetics of D-amino acid incorporation in translation
    Åpne denne publikasjonen i ny fane eller vindu >>Kinetics of D-amino acid incorporation in translation
    Vise andre…
    2019 (engelsk)Inngår i: Artikkel i tidsskrift (Fagfellevurdert) In press
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-373508 (URN)10.1021/acschembio.8b00952 (DOI)
    Tilgjengelig fra: 2019-01-15 Laget: 2019-01-15 Sist oppdatert: 2019-01-25
    4. Engineering a palette of eukaryotic chromoproteins for bacterial synthetic biology
    Åpne denne publikasjonen i ny fane eller vindu >>Engineering a palette of eukaryotic chromoproteins for bacterial synthetic biology
    Vise andre…
    2018 (engelsk)Inngår i: Journal of Biological Engineering, ISSN 1754-1611, E-ISSN 1754-1611, Vol. 12, artikkel-id 8Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Background: Coral reefs are colored by eukaryotic chromoproteins (CPs) that are homologous to green fluorescent protein. CPs differ from fluorescent proteins (FPs) by intensely absorbing visible light to give strong colors in ambient light. This endows CPs with certain advantages over FPs, such as instrument-free detection uncomplicated by ultra-violet light damage or background fluorescence, efficient Forster resonance energy transfer (FRET) quenching, and photoacoustic imaging. Thus, CPs have found utility as genetic markers and in teaching, and are attractive for potential cell biosensor applications in the field. Most near-term applications of CPs require expression in a different domain of life: bacteria. However, it is unclear which of the eukaryotic CP genes might be suitable and how best to assay them.

    Results: Here, taking advantage of codon optimization programs in 12 cases, we engineered 14 CP sequences (meffRed, eforRed, asPink, spisPink, scOrange, fwYellow, amilGFP, amajLime, cjBlue, mefiBlue, aeBlue, amilCP, tsPurple and gfasPurple) into a palette of Escherichia coil BioBrick plasmids. BioBricks comply with synthetic biology's most widely used, simplified, cloning standard. Differences in color intensities, maturation times and fitness costs of expression were compared under the same conditions, and visible readout of gene expression was quantitated. A surprisingly large variation in cellular fitness costs was found, resulting in loss of color in some overnight liquid cultures of certain high-copy-plasmid-borne CPs, and cautioning the use of multiple CPs as markers in competition assays. We solved these two problems by integrating pairs of these genes into the chromosome and by engineering versions of the same CP with very different colors.

    Conclusion: Availability of 14 engineered CP genes compared in E coil, together with chromosomal mutants suitable for competition assays, should simplify and expand CP study and applications. There was no single plasmid-borne CP that combined all of the most desirable features of intense color, fast maturation and low fitness cost, so this study should help direct future engineering efforts.

    sted, utgiver, år, opplag, sider
    BIOMED CENTRAL LTD, 2018
    Emneord
    Chromoprotein, Fluorescent protein, Coral, Escherichia coli, Genetic marker, Reporter gene, Integration, Fitness cost, BioBrick, iGEM
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-356454 (URN)10.1186/s13036-018-0100-0 (DOI)000432246200001 ()29760772 (PubMedID)
    Forskningsfinansiär
    VINNOVASwedish Research Council, 349-2006-267Swedish Research Council, 2011-5787Swedish Research Council, 2016-1Swedish Research Council, 2017-04148Science for Life Laboratory - a national resource center for high-throughput molecular bioscience
    Tilgjengelig fra: 2018-07-30 Laget: 2018-07-30 Sist oppdatert: 2019-01-25bibliografisk kontrollert
  • Disputas: 2019-03-08 09:15 B8; BMC, Uppsala
    Saez-Ibañez, Ana Rosa
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk biokemi och mikrobiologi.
    Novel roles of ErbB3 receptor tyrosine kinase in vesicular trafficking2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    ErbB3 is a catalytically impaired receptor tyrosine kinase (RTK) from the EGFR family. Upon ligand binding, ErbB3 forms heterodimers with other members of the family and triggers phosphorylation cascades that promote crucial cellular functions as proliferation, differentiation and survival. ErbB3 is also an important player in cancer progression, where it mediates resistance to EGFR inhibitors and promotes metastasis.

    In this thesis we have identified, first, a role of ErbB3 in promoting vesicular recycling of different cargoes, as β1-Integrin or E-cadherin. Vesicular recycling is the process by which  cargo proteins are internalized and delivered back to the plasma membrane. This process allows fine tuning of the cargoes function, adjusting their availability on the membrane to different conditions. In the case of β1-Integrin, an important adhesion receptor that mediates association of cells with the extracellular matrix, proper recycling is required for cellular adhesion and migration, among other functions. E-cadherin, on the other hand, is the major cell-to-cell junctional molecule in between epithelial cells, and therefore its availability at the plasma membrane is required for the formation and maintenance of epithelial tissues.

    In addition, we also present the finding that ErbB3 plays a role in exosome release. Exosomes are small extracellular vesicles originated from the fusion of multivesicular bodies with the plasma membrane. Exosomes are crucial for intercellular communication and are able to act as cargo delivery units both under physiological conditions and in the context of disease. Our work shows that ErbB3 inhibits exosome release and dictates their cargo composition, which may have important implications for their function.

    Finally, we have also investigated novel mechanisms for regulation of ErbB3 function. Therefore, this thesis also includes our work on non-receptor tyrosine kinase Ack1, a multifaceted kinase which has been extensively linked to tumour progression and cancer cell survival. We show for the first time that Ack1 acts as an important negative regulation of ErbB3 protein level.

    Altogether, this thesis contributes to our understanding of ErbB3 cellular functions and modes of regulation, unveiling new roles of this RTK in vesicular trafficking and exosome release, and proposing Ack1 as a novel modulator of its function.  

    Delarbeid
    1. Ligand-independent role of ErbB3 in endocytic recycling
    Åpne denne publikasjonen i ny fane eller vindu >>Ligand-independent role of ErbB3 in endocytic recycling
    Vise andre…
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-373809 (URN)
    Tilgjengelig fra: 2019-01-16 Laget: 2019-01-16 Sist oppdatert: 2019-01-16
    2. Ligand-independent role of ErbB3 in recycling of E-cadherin and assembly of adherens junctions
    Åpne denne publikasjonen i ny fane eller vindu >>Ligand-independent role of ErbB3 in recycling of E-cadherin and assembly of adherens junctions
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-373806 (URN)
    Tilgjengelig fra: 2019-01-16 Laget: 2019-01-16 Sist oppdatert: 2019-01-16
    3. ErbB3 regulates release of extracellular vesicles
    Åpne denne publikasjonen i ny fane eller vindu >>ErbB3 regulates release of extracellular vesicles
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-373808 (URN)
    Tilgjengelig fra: 2019-01-16 Laget: 2019-01-16 Sist oppdatert: 2019-01-16
    4. Ack1 is a negative regulator of ErbB3 that acts both by promoting its degradation and suppressing its expression.
    Åpne denne publikasjonen i ny fane eller vindu >>Ack1 is a negative regulator of ErbB3 that acts both by promoting its degradation and suppressing its expression.
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-373813 (URN)
    Tilgjengelig fra: 2019-01-16 Laget: 2019-01-16 Sist oppdatert: 2019-01-16
  • Disputas: 2019-03-08 10:00 Sal IX, Universitetshuset, Uppsala
    Backvall, Karin
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Samhällsvetenskapliga fakulteten, Kulturgeografiska institutionen.
    Constructing the Suburb: Swedish Discourses of Spatial Stigmatisation2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    By exploring representations of place, this thesis treats practices of spatial stigmatisation in the context of segregated Swedish cities. In three papers, different aspects of stigmatisation and place-making are discussed and analysed, where the overarching ambition is to identify and critically deconstruct the ideology behind stigma as well as suggest ways of making representation positive. In other words, this thesis takes issue with the negative labels attached to certain urban areas by exploring dominant discursive trends and mechanisms, or techniques, of creating spatial stigma.

    Theoretically, the analysis is informed by postcolonial critical research on segregation and representations of people and place, where place-making is of particular importance. The case study consists of printed news media and political discourse concerning stigmatised urban areas in Sweden, and the method is inspired by critical discourse analysis.

    The empirical material covers a period of twenty years, and the analysis is particularly focused on constructions of ‘race’ and poverty and how these two dimensions intertwine. The main findings point to a dominant trend of representing stigmatised neighbourhoods as failed and miserable places that are not considered part of Sweden. They become racialised both through representations of the neighbourhoods as foreign and unintegrated places and through representations of the residents, usually categorised as the ‘immigrants’, as culturally different from ‘Swedes’.  There are signs of a more critical discourse which challenges the negative representations, but it remains weak compared to the predominance of the negative reporting.

    Delarbeid
    1. Mechanisms of media stigmatisation: Colonial discourse and the racialisation of Swedish suburbs
    Åpne denne publikasjonen i ny fane eller vindu >>Mechanisms of media stigmatisation: Colonial discourse and the racialisation of Swedish suburbs
    (engelsk)Inngår i: Artikkel i tidsskrift (Annet vitenskapelig) Submitted
    Abstract [en]

    Using Sweden and Swedish newspapers as our case, we analyse 16 years of news reports on stigmatised areas. Particular attention is paid to what we refer to as mechanisms of stigma, in other words; news media techniques of representing place and residents in a stigmatising manner. These consist of firstly grouping neighbourhoods together based on common traits; second, comparing and contrasting places with each other; and thirdly, racialised blame, which constructs ethnic minorities as problems. Mechanisms of stigma are placed in the context of dominant themes of news media reporting on stigmatised neighbourhoods, where we identified categories of hopelessness, violence and colonial representations as the most common framings of the news stories. In addition, the thematic analysis has allowed us to observe the increase of stories of violence and terrorism in news reports on stigmatised neighbourhoods, in turn connected to the overall inflation of islamophobia and nationalism, with focus on Muslims and Islam as threats to integration, safety and national unity.

    Emneord
    Stigmatisation, suburb, racialisation, colonialism, news media
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-373394 (URN)
    Tilgjengelig fra: 2019-01-14 Laget: 2019-01-14 Sist oppdatert: 2019-01-14
    2. Who’s to blame? Segregation, policy and stigma in Swedish editorial discourse
    Åpne denne publikasjonen i ny fane eller vindu >>Who’s to blame? Segregation, policy and stigma in Swedish editorial discourse
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Critical research on residential segregation has long emphasised issues of inequality and discrimination as crucial factors for its production and reproduction. Equally, research on spatial stigmatisation is recognised in scholarly debate as a highly problematic practice which not only shapes policy interventions but also affects the residents of targeted areas. With the ambition of problematising the relationship between residential segregation and stigmatisation, this article analyses printed newspaper editorial discourse in order to critically examine constructions of place. News media has been argued to be a key agent in the practice of stigmatisation, which makes editorial statements highly significant when it comes to how the newspaper perceives the importance of stigmatisation. In addition, the theoretical framework of residential segregation as a process based in structural inequalities provides the basis for identifying stigmatisation of poor and racialised neighbourhoods as an often neglected but indispensable piece of the puzzle. It is argued here that editorials’ neglect of practices of stigmatisation reproduce and simultaneously hide power relations inherent to processes of inequality.

    Emneord
    stigmatisation, segregation, policy, neighbourhood, media
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-373395 (URN)
    Tilgjengelig fra: 2019-01-14 Laget: 2019-01-14 Sist oppdatert: 2019-01-14
    3. Decolonising residential segregation and “cultural difference”
    Åpne denne publikasjonen i ny fane eller vindu >>Decolonising residential segregation and “cultural difference”
    (engelsk)Inngår i: Artikkel i tidsskrift (Annet vitenskapelig) Submitted
    Abstract [en]

    In the context of Swedish anti-segregation strategies and area-based policies, this article critically examines how parliamentary motions create and reproduce a racialised understanding of housing segregation. A close examination of political language reveals a predominantly negative framing of both people and place, where already stigmatised areas are demonised as segregated places where the ‘immigrants’ live. In particular, the disadvantaged position of many of the residents in stigmatised areas is expressed through a consistent construction of non-‘Swedishness’; of not being considered part of Sweden based on perceived cultural difference framed as an individual or spatial attribute. In addition, the condition of not belonging is believed to merge with a condition of ‘utanförskap’, (‘outsiderness’). Despite the ideological differences between the various political parties, de-colonisation is still lacking in the Swedish political discourse on ethnic residential segregation.

    Emneord
    Segregation, ‘utanförskap’, racialisation, racism, poverty
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-373396 (URN)
    Tilgjengelig fra: 2019-01-14 Laget: 2019-01-14 Sist oppdatert: 2019-01-14
  • Disputas: 2019-03-08 10:00 Häggsalen, Uppsala
    Shameem, Muhammad Anwar
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström.
    Low-Coordinate Organopnictogens: Synthesis and Optoelectronic properties2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis work is based on the development of novel organopnictogen compounds and the exploration of their potential applications in organic electronics. In particular, incorporation of phosphorus and arsenic into π-conjugated systems is known to modify the optoelectronic properties.

    The first chapter of this thesis is fully devoted to the development of a metal-free synthetic route that allows direct, sequential and stereoselective alkynylation of C,C-dibromophosphaalkenes. The subsequent unusual reactivity of thus synthesized C-mono and C,C-diacetylenicphosphaalkenes with terminal acetylenes afforded highly substituted 1-phoshpha-1,3-butadienes heavier analogue of all carbon 1,3-butadiene motifs. Optimization of the reaction condition favored exclusively the formation of 1-phospha-1,3-butadienes. Unveiling the unique cyclization of the 3-yne 1-phospha-1,3-butadiene gave highly substituted phosphole derivatives. Further, it has been experimentally shown that the P=C unit is essential for this rare cyclization and rearrangement to give π-conjugated phosphole derivatives.

    The second chapter of this thesis work deals with incorporation of P/As in the form of phosphinidene and or arsinidene units as an exocyclic substituent at the bridge of the fused rigid cyclpentadithiophenes (p-CPDT) core. Furthermore, it demonstrates how this chemical modification at the bridgehead position selectively lowers the LUMO level. At a later stage, substitutions at α and α` positions of the central CPDT core was used to modify the HOMO level without further affecting the LUMO level. We also performed DFT calculations on these phosphinide/arsinidene p-CPDT derivatives to theoretical evaluate the impact of P and or As incorporation. The phosphinidene/arsinidene p-CPDT derivatives were fully characterized using electrochemical and optical spectroscopic techniques including transient absorption spectroscopy. Additionally, the arsinidene-p-CPDT were electrochemically polymerized, and the resultant polymer film was characterized by means of SEM and EDX.

    The last chapter of this research work is dealing with the exploration and functionalization of open-ended small fragments of fullerene-C60 such as sumanene and truxene. Functionalisation of these motifs was achieved via the introduction of pnictogens (P/As), either in the form of phosphinidene/arsinidene or as heteroles. The optoelectronic spectra of the unprecedented pnictinidenotruxene exhibited significantly redshift absorption and three fully reversible reduction events upon electrochemical reduction.

    Delarbeid
    1. Direct, Sequential, and Stereoselective Alkynylation of C,C-Dibromophosphaalkenes
    Åpne denne publikasjonen i ny fane eller vindu >>Direct, Sequential, and Stereoselective Alkynylation of C,C-Dibromophosphaalkenes
    Vise andre…
    2016 (engelsk)Inngår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 22, nr 30, s. 10614-10619Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The first direct alkynylation of C,C-dibromophosphaalkenes by a reaction with sulfonylacetylenes is reported. Alkynylation proceeds selectively in the trans position relative to the P substituent to afford bromoethynylphosphaalkenes. Owing to the absence of transition metals in the procedure, the previously observed conversion of dibromophosphaalkenes into phosphaalkynes through the phosphorus analog of the Fritsch-Buttenberg-Wiechell rearrangement is thus suppressed. The bromoethynylphosphaalkenes can subsequently be converted to C,C-diacetylenic, cross-conjugated phosphaalkenes by following a Sonogashira coupling protocol in good overall yields. By using the newly described method, full control over the stereochemistry at the P=C double bond is achieved. The substrate scope of this reaction is demonstrated for different dibromophosphaalkenes as well as different sulfonylacetylenes.

    Emneord
    alkynylation, cross-conjugation, phosphaalkenes, Sonogashira coupling, sulfonyl coupling
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-302705 (URN)10.1002/chem.201601955 (DOI)000380273300043 ()27310813 (PubMedID)
    Eksternt samarbeid:
    Forskningsfinansiär
    Swedish Research CouncilCarl Tryggers foundation
    Tilgjengelig fra: 2016-09-08 Laget: 2016-09-08 Sist oppdatert: 2019-01-18bibliografisk kontrollert
    2. Highly branched 2,3-diyne-1-phospha-1,3-butadiene motifs via Pd/Cu mediated alkynyl addition
    Åpne denne publikasjonen i ny fane eller vindu >>Highly branched 2,3-diyne-1-phospha-1,3-butadiene motifs via Pd/Cu mediated alkynyl addition
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-373905 (URN)
    Tilgjengelig fra: 2019-01-17 Laget: 2019-01-17 Sist oppdatert: 2019-01-18
    3. Synthesis and Characterization of Cyclopentadithiophene Heterofulvenes: Design Tools for Light-Activated Processes
    Åpne denne publikasjonen i ny fane eller vindu >>Synthesis and Characterization of Cyclopentadithiophene Heterofulvenes: Design Tools for Light-Activated Processes
    Vise andre…
    2017 (engelsk)Inngår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 23, nr 24, s. 5673-5677Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The development of new materials for solar-to-energy conversion should consider stability, ease of fabrication, and beneficial photophysical properties. In this context, a set of novel -conjugated building blocks, with phospha- and arsaalkenes possessing a unique dithienyl annulated heterofulvenoid core, have been prepared as air- and moisture-stable sensitizers. These compounds unify electron-donor and -acceptor moieties, making them potential candidates for light-harvesting applications. Optical characterization of these systems was performed by steady-state and time-resolved absorption spectroscopy, supported by time-dependent DFT calculations. Tuning of the optical properties of these systems can be achieved by varying the pnictogen element at the bridgehead position, giving a bathochromic shift of approximate to 40nm and coordinating the phosphaalkene towards gold Au-I centers. The latter results in a approximate to 2000-fold extension of the approximate to 10ps lifetime of uncoordinated systems well into the ns regime.

    sted, utgiver, år, opplag, sider
    WILEY-V C H VERLAG GMBH, 2017
    Emneord
    arsaalkene, electrochemistry, main group elements, phosphaalkene, pnictogens, time-resolved spectroscopy
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-322721 (URN)10.1002/chem.201700917 (DOI)000400044400006 ()28248442 (PubMedID)
    Forskningsfinansiär
    Swedish Research Council, 2013-4763Knut and Alice Wallenberg FoundationÅForsk (Ångpanneföreningen's Foundation for Research and Development)
    Tilgjengelig fra: 2017-05-29 Laget: 2017-05-29 Sist oppdatert: 2019-01-18bibliografisk kontrollert
  • Disputas: 2019-03-08 13:15 Hörsal 2, Ekonomikum, Uppsala
    Sepahvand, Mohammad H.
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Samhällsvetenskapliga fakulteten, Nationalekonomiska institutionen.
    Essays on Risk Attitudes in Sub-Saharan Africa2019Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Essay I (submitted): Risk-taking is an important topic in Africa, as access to financial institutions and social security is scarce. Data on risk attitudes in Africa is limited and the available data collected might not be reliable. We investigate the determinants of risk attitudes in different domains and the reliability of survey data in a sub-Saharan African country, Burkina Faso, using a large representative panel survey of 31,677 individuals. Our results show that determinants such as individual’s sex and age are significantly associated with willingness to take risk. Reliability differs across determinants of risk taking and risk domains. Women, older individuals or those with high education have more reliable risk measures compared to men, younger individuals or people with low education. Risk taking in traffic has the highest test-retest reliability followed by willingness to take risk in general and financial matters.

  • Disputas: 2019-03-08 13:15 Sal IX, Uppsala
    Axelsson, Anton
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för visuell information och interaktion. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Bildanalys och människa-datorinteraktion.
    Knowledge elicitation as abstraction of purposive behaviour2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Researchers use knowledge elicitation methods to document expert knowledge for the primary purpose of understanding cognitive processes and with this understanding, technical solutions to resolve human factors issues can be produced. This dissertation offers a novel perspective on knowledge elicitation as an abstraction process. Such a theoretical framework has emerged by consolidating the ecological approach of Brunswikian psychology with the ideas of tacit and personal knowledge of Polanyian epistemology. Traditionally, knowledge elicitation has been considered an extraction process in which knowledge can be readily transferred from one individual to another. Here, this traditional position is rejected in favour of Polanyi’s premise that much of the knowledge individuals possess is tacit in nature, which implies that it cannot be documented easily, expressed in explicit form or explained. In this dissertation, knowledge is characterised as a personal process of knowing, highlighting context as a subjective knowledge structure of personal experiences that is formulated implicitly and indirectly over time through a dynamic interaction with the environment. Therefore, tacit knowledge cannot be articulated or shared; however, learners can be inspired by observing other individuals' purposive (i.e., goal-directed) behaviours and thus shape their own tacit knowledge once they practise the observed skills and develop conceptual understanding through reasoning about the learning process. Knowledge elicitation thereby makes use of observations, questions, or more structured process tracing methods in environments familiar to the observed individuals to elicit purposive behaviour from them. Accordingly, functional descriptions can be produced in this process that further conceptual understanding of a particular domain. Knowledge elicitation procedures are a powerful set of methods for reaching such functional descriptions. Moreover, by understanding the resulting knowledge elicitation data as an abstraction derived from multiple collection points in the same environment, the focus shifts from purely subjective mental constructs to the impact of environmental constraints.

    Delarbeid
    1. Eliciting strategies in revolutionary design: exploring the hypothesis of predefined strategy categories
    Åpne denne publikasjonen i ny fane eller vindu >>Eliciting strategies in revolutionary design: exploring the hypothesis of predefined strategy categories
    2018 (engelsk)Inngår i: Theoretical Issues in Ergonomics Science, ISSN 1463-922X, E-ISSN 1464-536X, Vol. 19, nr 1, s. 101-117Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Introducing automation in a human-machine system changes the tasks performed by human operators. It is difficult to analyse systems for which there are no experienced operators. This issue emerged within a project with the aim to develop a human–machine interface for a highly automated long-haul vehicle. To handle the problem, a formative strategies analysis method with promises to enable desktop analyses through predefined strategy categories was adopted. The method was used to investigate strategies for controlling the future long haul vehicle by conducting workshops with today's drivers. The method was shown to be a valuable asset in eliciting strategies for revolutionary design.

    Emneord
    Cognitive work analysis, strategies analysis, automation, revolutionary systems design, long haul trucks
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-292799 (URN)10.1080/1463922X.2017.1278805 (DOI)000428728900006 ()