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  • 1.
    Nilsson, Amalia C.
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Samhällsvetenskapliga fakulteten, Företagsekonomiska institutionen.
    A Lighter Shade of Dark: Exploring the Value Adding and Value Subtracting Effects of Headquarters Attention and Involvement in Subsidiary Activities2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Headquarters of multinational corporations are presented with a diverse range of stimuli that influences the issues that they pay attention to and ultimately get involved in. However, headquarters have to prioritize since their attention and resources are limited, and they cannot pay attention to all issues and get equally involved in all subsidiaries. To stand out and attract attention and involvement, subsidiaries can use different issue selling tactics to present headquarters with issues that are strategically important to the subsidiary. While headquarters can add value to their subsidiaries by paying attention and getting involved in subsidiary activities, there is also a risk of headquarters making different prioritizations than the subsidiaries, and instead subjecting them to misguided involvement and value subtraction. Existing research tends to assume that the more attention a subsidiary receives, the better off it will be. However, I reevaluate this assumption, and complement existing research by examining how subsidiaries experience headquarters attention and involvement, and the effects on subsidiary activities.

    Data were collected at the subsidiary level, using interviews and a survey to capture the subsidiary perspective of headquarters attention and involvement. More specifically, 115 interviews were conducted with subsidiary managers of European MNCs based in Japan, and survey data was collected from 93 Japanese subsidiaries of European MNCs. The empirical findings highlight circumstances under which headquarters attention and involvement can add or subtract value from subsidiary activities. Furthermore, subsidiaries can highlight strategic issues during their issue selling efforts to attract headquarters involvement that has a beneficial impact on subsidiary activities. I extend the parenting literature by developing an attention-based parenting typology and showing how misaligned priorities risk exposing subsidiaries to value subtraction rather than value added during headquarters involvement. This thesis also contributes to elaborating on the attention-based view by exploring mixed types and levels of attention, as well as circumstances under which negative attention can be perceived as beneficial and value adding by subsidiaries.

    By incorporating the attention-based view with the parenting literature and issue selling, this thesis extends our understanding of the headquarters-subsidiary relationship, highlights circumstances under which subsidiaries appreciate attention and involvement, and shows a darker side of headquarters’ parenting in which subsidiaries risk experiencing value subtraction.

    Delarbeid
    1. Value Generation in the Multinational Corporation
    Åpne denne publikasjonen i ny fane eller vindu >>Value Generation in the Multinational Corporation
    2015 (engelsk)Inngår i: The Future of Global Organizing: Progress in International Business Research / [ed] Rob Van Tulder, Alain Verbeke, Rian Drogendijk, Emerald Group Publishing Limited, 2015, s. 39-56Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Purpose

    As markets become increasingly competitive, it is important for multinational corporations to generate value. Both headquarters and subsidiaries are responsible for contributing to value generation, albeit they may do so in different ways. This builds on the notion from the literature that it is possible to discern two separate concepts that relate to the generation of value, namely, value creation and value added. These concepts are often used interchangeably, without a clear distinction what they de facto reflect or what the underlying mechanisms of value creation and value added are.

    Methodology/approach

    Based on a set of assumptions regarding headquarters–subsidiary relations conceptual arguments related to value generation are developed.

    Research implications

    Teasing out the differences between the concepts becomes important as it leads to a fuller understanding of what a headquarters do in different situations and of what a headquarters–subsidiary relationship entails for value generation.

    Originality/value

    In this chapter, it is argued that value-adding activities tend to be conducted by a headquarters, but are dependent on varying knowledge situations of headquarters, while the value creation process tends to take place at the subsidiary level.

    sted, utgiver, år, opplag, sider
    Emerald Group Publishing Limited, 2015
    Serie
    Progress in International Business Research, ISSN 1745-8862 ; 10
    HSV kategori
    Forskningsprogram
    Företagsekonomi
    Identifikatorer
    urn:nbn:se:uu:diva-265559 (URN)10.1108/S1745-886220150000010002 (DOI)978-1-78560-423-2 (ISBN)
    Tilgjengelig fra: 2015-11-02 Laget: 2015-11-02 Sist oppdatert: 2018-08-17bibliografisk kontrollert
    2. Headquarters Involvement in Subsidiary Activities: When and why do subsidiaries experience value subtraction?
    Åpne denne publikasjonen i ny fane eller vindu >>Headquarters Involvement in Subsidiary Activities: When and why do subsidiaries experience value subtraction?
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Emneord
    Headquarters-subsidiary relationship; headquarters role; parenting advantage; value subtraction; multinational corporation
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-354087 (URN)
    Tilgjengelig fra: 2018-06-19 Laget: 2018-06-19 Sist oppdatert: 2018-06-19
    3. Different Parenting Styles: Examining Supportive and Monitoring Attention from Headquarters to Subsidairies
    Åpne denne publikasjonen i ny fane eller vindu >>Different Parenting Styles: Examining Supportive and Monitoring Attention from Headquarters to Subsidairies
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Emneord
    Attention-based view; parenting; headquarters-subsidiary relationships; multinational corporations
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-354085 (URN)
    Tilgjengelig fra: 2018-06-19 Laget: 2018-06-19 Sist oppdatert: 2018-06-19
    4. Gauging subsidiary influence and performance through strategic issue selling and the involvement of headquarters in subsidiary activities
    Åpne denne publikasjonen i ny fane eller vindu >>Gauging subsidiary influence and performance through strategic issue selling and the involvement of headquarters in subsidiary activities
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Emneord
    Headquarters-subsidiary relationships; multinational corporations; subsidiary issue selling; headquarters involvement; subsidiary influence; subsidiary performance
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-354089 (URN)
    Tilgjengelig fra: 2018-06-19 Laget: 2018-06-19 Sist oppdatert: 2018-06-19
  • 2.
    Wilhelmsen, Vera
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Språkvetenskapliga fakulteten, Institutionen för lingvistik och filologi.
    A Linguistic Description of Mbugwe with Focus on Tone and Verbal Morphology2018Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Mbugwe is an endangered Bantu language spoken in north central Tanzania. This PhD dissertation is a description of the Mbugwe language with a focus on tone and verbal morphology, based on the author’s fieldwork. This is the first detailed description of the language. Thus far, only a short grammatical sketch of Mbugwe has been available.

    Mbugwe is a tonal language with a rich verbal system. Therefore, the focus of this dissertation is on tone and verbal morphology. The dissertation also contains a brief description of the phonology of Mbugwe as well as a description of the nominal system. Mbugwe has 7 vowels; length is distinctive. There are 21 consonant phonemes, not counting the NC sequences, which are analysed as clusters in this study. Mbugwe has 17 noun classes and the adnominals that agree with the noun are described and exemplified.

    The tones of the language are presented in detail. Mbugwe has two tones, high and low, and the low tone is considered the default tone. The tone-bearing unit is the mora. High tones spread one mora to the right, and the last high tone before a low tone is upstepped. There is both lexical tone and grammatical tone in Mbugwe, and grammatical tones that occur on the verb stem in certain verb forms are described.

    In the chapter on verb morphology, the structures of the simple and periphrastic verbs are presented, as well as a description of the infinitive and copula verbs. The various tenses, aspects and moods of Mbugwe are then presented. There are 25 affirmative forms and 15 negative forms. For the perfective verbs, there are three past tenses and a future tense. In the imperfective, there is only one past tense, as well as a present and one future tense. Other aspects are the progressive, the habitual and the persistive. Moods that are grammaticalized in Mbugwe are the subjunctive, the imperative and the counterfactual. Verb forms that are not readily categorized as tense, aspect or mood are the consecutive, the situative and the participial. They depend on other verbs for their time reference.

  • 3.
    Lammi, Inti José
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Samhällsvetenskapliga fakulteten, Företagsekonomiska institutionen. Uppsala University.
    A Practice Theory in Practice: Analytical Consequences in the Study of Organization and Socio-Technical Change2018Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Appealing calls are often made towards the study of phenomena through so-called practice theory. However, the implications of the use of practice theory, if taken seriously in analysis, are rarely discussed. The chief concern of this thesis is the applicability of the most radical dimensions of practice theory. By drawing from the key proponent of contemporary practice theory, Theodore Schatzki, this thesis assesses how practice theory can inform empirical analysis and what it can offer organizational studies in particular.

    Defining practice theory as an interpretative lens, this thesis proposes a methodology for the study of practices that finds organization in two senses, within practices and between them. Putting such a proposition to the test, a study of socio-technical change at the Swedish Social Insurance Agency is utilized as an illustration of the use of practice theory and how empirical issues tread forth in analysis.

    The illustration shows how classical organizational issues are re-imagined by proposing an alternate kind of context; practice as context. Not solely a descriptive effort to grasp what people do, the study presents how doing is explicable by examining the multiple contexts of organizational life. Having defined practices as unfolding phenomena, the practice analysis also presents a moderately processual analysis fitting for the study of material re-arrangement and the re-organization of practices. The distinctiveness of the practice analysis, and the interpretative work it demands, is further demonstrated by comparison with established ways of analyzing activity and organizational phenomena, including such approaches that imagine organizations as cohesive wholes and those that study organizing.

    This thesis offers an approach for those who want to undertake empirical research using practice theory, demonstrating its unique possibilities. Such an approach is of interest for those who want to heed calls to attend to the practicalities and materiality of organizations.

  • 4.
    Liao, Zhen
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Mikrobiologi.
    A small amoeba at the crossroads of the big RNAi world: MicroRNA biogenesis and Argonaute function in Dictyostelium discoideum2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Small non-coding RNA (ncRNA) mediated gene silencing, known as RNAi, is a key regulatory mechanism of gene expression in eukaryotes. MicroRNAs (miRNA), one major type of small ncRNAs, are about 21nt long and bound by Argonaute proteins. This RNA-protein complex, called RISC, silences post-transcriptionally target mRNAs containing partial or full complementary sequence to the miRNA.  

    MiRNAs are generated from step-wise endonucleolytic cleavages of long primary transcripts (pri-miRNAs) by RNase III nucleases. Biogenesis of miRNAs differs between uni- and multicellular eukaryotes, and also between plants and animals. In this thesis, I aimed to understand miRNA maturation in the social amoeba Dictyostelium discoideum, which stands at the crossroads between these phylogenetically distant groups. We showed that Dicer-like protein DrnB is essential for global maturation of D. discoideum miRNAs. The study of two pri-miRNAs revealed the conserved 5’ m7G-cap structures, but different 3’end formation from each other, and also from canonical miRNAs in plants and animals. In agreement with its evolutionary position, D. discoideum miRNA biogenesis showed unique and also shared features with both life groups.

    D. discoideum grows as a unicellular organism, but can switch to a multicellular development upon starvation. Most miRNAs, many other small ncRNAs, and Argonaute proteins, the core effectors of the RISC, are differentially expressed during development, indicative of a crucial role of RNAi mediated regulation throughout D. discoideum life cycle. Among the five Argonaute homologs in D. discoideum, I investigated the functions of three members, e.g. AgnB, C and E. Judging from their subcellular localization, the phenotypic consequences and transcriptional alteration resulting from single Argonaute gene deletion, our results suggested different roles of AgnB, C and E. Possibly AgnB associates with miRNAs and regulates gene expression post-transcriptionally; while AgnC seems to be involved in nuclear RNAi. Finally, the cytoplasmic AgnE inhibits D. discoideum cell growth and regulates developmental timing via an unknown mechanism.

    My thesis work expands our knowledge on D. discoideum RNAi with focuses on miRNA biogenesis and potential function of Argonaute proteins and, all together, sheds lights on the evolution of miRNA and RNAi.  

    Delarbeid
    1. Global characterization of the Dicer-like protein DrnB roles in miRNA biogenesis in the social amoeba Dictyostelium discoideum
    Åpne denne publikasjonen i ny fane eller vindu >>Global characterization of the Dicer-like protein DrnB roles in miRNA biogenesis in the social amoeba Dictyostelium discoideum
    Vise andre…
    2018 (engelsk)Inngår i: RNA Biology, ISSN 1547-6286Artikkel i tidsskrift (Fagfellevurdert) Accepted
    Abstract [en]

    Micro (mi)RNAs regulate gene expression in many eukaryotic organisms where they control diverse biological processes. Their biogenesis, from primary transcripts to mature miRNAs, have been extensively characterized in animals and plants, showing distinct differences between these phylogenetically distant groups of organisms. However, comparably little is known about miRNA biogenesis in organisms whose evolutionary position is placed in between plants and animals and/or in unicellular organisms. Here, we investigate miRNA maturation in the unicellular amoeba Dictyostelium discoideum, belonging to Amoebozoa, which branched out after plants but before animals. High-throughput sequencing of small RNAs and poly(A)-selected RNAs demonstrated that the Dicer-like protein DrnB is required, and essentially specific, for global miRNA maturation in D. discoideum. Our RNA-seq data also showed that longer miRNA transcripts, generally preceded by a T-rich putative promoter motif, accumulate in a drnB knock-out strain. For two model miRNAs we defined the transcriptional start sites (TSSs) of primary (pri)-miRNAs and showed that they carry the RNA polymerase II specific m7G-cap. The generation of the 3’-ends of these pri-miRNAs differs, with pri-mir-1177 reading into the downstream gene, and pri-mir-1176 displaying a distinct end. This 3´-end is processed to shorter intermediates, stabilized in DrnB-depleted cells, of which some carry a short oligo(A)-tail. Furthermore, we identified 10 new miRNAs, all DrnB dependent and developmentally regulated. Thus, the miRNA machinery in D. discoideum shares features with both plants and animals, which is in agreement with its evolutionary position and perhaps also an adaptation to its complex lifestyle: unicellular growth and multicellular development.

    sted, utgiver, år, opplag, sider
    UK: Taylor & Francis Group, 2018
    Emneord
    Dicer, microRNA, amoeba, biogenesis, evolution, transcriptional start site, intron, development, Dictyostelium discoideum
    HSV kategori
    Forskningsprogram
    Biologi
    Identifikatorer
    urn:nbn:se:uu:diva-354016 (URN)
    Forskningsfinansiär
    Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, 621-2013-4665Carl Tryggers foundation , CST12:485
    Tilgjengelig fra: 2018-06-19 Laget: 2018-06-19 Sist oppdatert: 2018-06-19
    2. The Dictyostelium discoideum Argonaute protein AgnE regulates cell growth
    Åpne denne publikasjonen i ny fane eller vindu >>The Dictyostelium discoideum Argonaute protein AgnE regulates cell growth
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Argonaute proteins play essential roles in the RNA interference (RNAi) pathways in eukaryotes. The members of this conserved class of proteins are guided to their target RNAs by their associated small RNAs and can thereby regulate gene expression. The number and function of Argonautes varies depending on the organism but it is clear that they together with their interacting small RNAs constitute the core of the RNA induced silencing complex, RISC. Little is known about the Argonautes in the social amoeba Dictyostelium discoideum, a unicellular organism that can go through multicellular development and evolutionary is placed between plants and animals. In this study, we investigated the phenotypic consequences of deleting the genes for three Argonautes, AgnB, AgnC, and AgnE in D. discoideum. All three Argonautes have an effect on growth since depletion of AgnB and AgnC impaired growth while AgnE depletion, surprisingly, resulted in faster cell division. The intriguing role of AgnE in growth regulation prompted us to further study this protein. We expressed an AgnE-GFP fusion protein and showed that this localize in the cytoplasm. High-throughput sequencing of mRNA from growing agnE- and wt cells showed that genes required for the nucleobase biosynthetic process as well as genes for ribosomal proteins are upregulated in the agnE knock-out strain, which is in line with its faster growth rate. Furthermore, the RNAi related gene encoding RNA-dependent RNA polymerase C is downregulated, which may result in accumulation of miRNAs. The possible connection between growth rate and miRNA levels was explored by analyzing growth rate in a strain depleted of miRNAs, i.e. where the gene for the Dicer-like protein DrnB had been knocked out. This strain grew much slower than wt and this phenotype could not be rescued by disrupting agnE in the drnB- background. This suggests that DrnB acts upstream of AgnE in regulating D. discoideum growth.

    Emneord
    RNAi, Argonautes, microRNAs, small RNAs, mRNA-seq
    HSV kategori
    Forskningsprogram
    Biologi med inriktning mot molekylärbiologi
    Identifikatorer
    urn:nbn:se:uu:diva-354019 (URN)
    Forskningsfinansiär
    Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, 621-2013-4665Carl Tryggers foundation , CST12:485
    Tilgjengelig fra: 2018-06-19 Laget: 2018-06-19 Sist oppdatert: 2018-06-19
    3. Functional analyses of RNA interference effectors in Dictyostelium discoideum during growth and development
    Åpne denne publikasjonen i ny fane eller vindu >>Functional analyses of RNA interference effectors in Dictyostelium discoideum during growth and development
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    RNA interference (RNAi) is a widespread biological process, which regulates gene expression in eukaryotic cells. A complex of proteins and small RNAs, RISC, mediates this gene regulation. Central to the function of RISC are the Argonaute effector proteins, which bind the small RNAs, e.g. micro (mi)RNAs and small interfering (si)RNAs. It has previously been shown that RNAi is important to control transposon mobilization in the social amoeba Dictyostelium discoideum, a unicellular eukaryote that upon starvation enters a multicellular developmental program. Information concerning the five Argonautes in D. discoideum is scarce but several of them appear to inhibit transposon mobilization by RNAi related mechanisms. In a recent study, we showed that three of the Argonautes in D. discoideum are involved in controlling cell division. In this study, we perform mRNA- and small RNA-seq. from growing and developing cells, combined with phenotypic studies of D. discoideum strains depleted of AgnB, AgnC, and AgnE. The previously observed effect on cell division, i.e. faster growth for agnE-, and slower for agnB- and agnC- cells, is associated with increased and decreased expression, respectively, of genes involved in nucleotide metabolism. Furthermore, all three argonautes appear to be involved in downregulation of ribosomal protein genes during development while AgnE also contributes to reduced expression of protein coding genes during growth. These effects are likely mediated by small RNAs. We further report the subcellular localization of the three Argonautes, where AgnB is mainly localized in the cytoplasm, AgnC in the nucleus, and the previously reported cytoplasmic localization for AgnE was confirmed. Finally, we present data indicating that AgnB is interacting with miRNAs, suggesting that this Argonaute is involved in miRNA mediated gene regulation in D. discoideum.  Taken together, our data indicate that none of the Argonautes components are essential for cell division and development, but all participate in fine-tuning of gene expression for optimal growth and synchronous multicellular development.

    Emneord
    RNAi, microRNA, Argonautes, Dictyostelium discoideum, amoeba, development
    HSV kategori
    Forskningsprogram
    Biologi med inriktning mot molekylär cellbiologi
    Identifikatorer
    urn:nbn:se:uu:diva-354021 (URN)
    Forskningsfinansiär
    Swedish National Infrastructure for Computing (SNIC), 621-2013-4665Carl Tryggers foundation , CST12:485
    Tilgjengelig fra: 2018-06-19 Laget: 2018-06-19 Sist oppdatert: 2018-06-19
  • 5.
    Thorisson, Arnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centrum för klinisk forskning, Västerås.
    Acute Colonic Diverticulitis: The role of computed tomography in primary diagnosis, prediction of complications and surgical intervention2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The overall aim of this thesis was to expand the current knowledge regarding the advantages and limitations of computed tomography (CT) for patients with acute diverticulitis and evaluate outpatient treatment for uncomplicated diverticulitis.

    Paper I: A retrospective evaluation of 602 patients with reported uncomplicated diverticulitis. Scans were re-evaluated and the degree of inflammation was graded. Signs of complications or other diseases were also noted. No radiological findings on CT could predict the development of complications or recurrence in patients with uncomplicated diverticulitis. However, 44 patients (7.3%) had signs of complicated diverticulitis that had been overlooked on the initial assessment. Despite small complications and a non-antibiotic treatment, the majority of patients recovered without incident, further strengthening the non-antibiotic treatment strategy.

    Paper II: A retrospective analysis of conservative treatment for perforated diverticulitis (n = 136) during a 5-year period. Twenty-nine of 136 patients were operated on within 24 h and not candidates for conservative management. Patients more than 75 years old, immunosuppressed patients, patients with free intraperitoneal air or free fluid in the abdominal cavity were at higher risk for emergency surgery within the first 24 h. Conservative treatment was successful in 101 of 107 patients (94%) when attempted. The presence of simultaneous abscess increased the risk for conservative treatment failure.

    Paper III: The aim of this prospective study was to determine if a non-enhanced low-dose CT was as sensitive as standard CT with intravenous (IV) contrast for patients with suspected acute diverticulitis. The included patients underwent both types of CT examinations. CT images were graded by three independent radiologists for the presence of diverticulitis, complications or other findings that could explain the patient’s symptoms. Sensitivity, specificity and both intra- and inter-reader agreement for low-dose CT were very high. Therefore, we recommend this examination for suspected diverticulitis.

    Paper IV: In this prospective study, 155 consecutive patients with CT-verified acute uncomplicated diverticulitis were treated as outpatients without antibiotics. Overall, only four patients (2.6%) returned to the hospital because of treatment failure, all of whom were hospitalized and received antibiotics. Outpatient treatment of uncomplicated diverticulitis is safe and recommended in selected patients.

     

    Delarbeid
    1. CT imaging for prediction of complications and recurrence in acute uncomplicated diverticulitis
    Åpne denne publikasjonen i ny fane eller vindu >>CT imaging for prediction of complications and recurrence in acute uncomplicated diverticulitis
    Vise andre…
    2016 (engelsk)Inngår i: International Journal of Colorectal Disease, ISSN 0179-1958, E-ISSN 1432-1262, Vol. 31, nr 2, s. 451-457Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    PURPOSE: The first randomized clinical trial of antibiotics in uncomplicated diverticulitis (the AVOD study) showed no benefit of antibiotics. The aim of this study was to re-evaluate the computed tomography (CT) scans of the patients in the AVOD study to find out whether there were CT findings that were missed and to study whether CT signs in uncomplicated diverticulitis could predict complications or recurrence.

    METHODS: The CT scan images from patients included in the AVOD study were re-evaluated and graded by two independent reviewers for different signs of diverticulitis, including complications, such as extraluminal gas or the presence of an abscess.

    RESULTS: Of the 623 patients included in the study, 602 CT scans were obtained and re-evaluated. Forty-four (7 %) patients were found to have complications on the admitting CT scan that had been overlooked. Twenty-seven had extraluminal gas and 17 had an abscess. Four of these patients deteriorated and required surgery, but the remaining patients improved without complications. Of the 18 patients in the no-antibiotic group, in whom signs of complications on CT were overlooked, 15 recovered without antibiotics. No CT findings in patients with uncomplicated diverticulitis could predict complications or recurrence.

    CONCLUSION: No CT findings that could predict complications or recurrence were found. A weakness in the initial assessment of the CT scans to detect extraluminal gas and abscess was found but, despite this, the majority of patients recovered without antibiotics. This further supports the non-antibiotic strategy in uncomplicated diverticulitis.

    Emneord
    Colonic diverticulitis; Complications; CT scan; Prediction
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-269592 (URN)10.1007/s00384-015-2423-3 (DOI)000369537500034 ()26490053 (PubMedID)
    Tilgjengelig fra: 2015-12-17 Laget: 2015-12-17 Sist oppdatert: 2018-08-03bibliografisk kontrollert
    2. Non-operativemanagement of perforated diverticulitis with extraluminal or free air
    Åpne denne publikasjonen i ny fane eller vindu >>Non-operativemanagement of perforated diverticulitis with extraluminal or free air
    Vise andre…
    (engelsk)Inngår i: Scandinavian Journal of Gastroenterology, ISSN 0036-5521, E-ISSN 1502-7708Artikkel i tidsskrift (Annet vitenskapelig) Submitted
    Abstract [en]

    Objectives The aim of this study was to describe characteristics and results of non-operative   management for patients presenting with computed tomography (CT) verified perforated diverticulitis.

    Methods All patients treated for diverticulitis (ICD-10: K-57) during 2010–2014 were identified and medical records were reviewed. Re-evaluations of CT examinations for all patients with complicated disease according to medical records were performed. All patients diagnosed with perforated diverticulitis on re-evaluation were included and characteristics of patients having immediate surgery and those whom non-operative management was attempted are described.

    Results Of 141 patients with perforated diverticulitis according to medical records, 136 were confirmed on CT re-evaluation. Emergency surgical intervention within 24 hours was performed in 29 (21%). Non-operative management with iv antibiotics was attempted for 107 patients and was successful in 101 (94%). The 30-day mortality rate was 2%. Non-operative management was more likely to fail in patients with a simultaneous abscess (67% compared to 16%, p = 0.013). More than one third of patients (34%) with free air were successfully managed conservatively. Patients that were operated within 24 hours from admission were more commonly on immunosuppressive therapy, had more commonly free intraperitoneal air and free fluid in the peritoneal cavity.

    Conclusions Non-operative management is successful in the majority of patients with CT-verified perforated diverticulitis with extraluminal air, and also in one-third of those with free air in the peritoneal cavity.

    HSV kategori
    Forskningsprogram
    Radiologi; Kirurgi
    Identifikatorer
    urn:nbn:se:uu:diva-356629 (URN)
    Tilgjengelig fra: 2018-08-02 Laget: 2018-08-02 Sist oppdatert: 2018-08-03bibliografisk kontrollert
    3. Diagnostic Accuracy of Acute Diverticulitis with Non-Enhanced Low-Dose CT
    Åpne denne publikasjonen i ny fane eller vindu >>Diagnostic Accuracy of Acute Diverticulitis with Non-Enhanced Low-Dose CT
    Vise andre…
    2018 (engelsk)Inngår i: Artikkel i tidsskrift (Annet vitenskapelig) Submitted
    Abstract [en]

    Purpose: To evaluate the diagnostic accuracy of non-enhanced low-dose computed tomography (LDCT) in acute colonic diverticulitis with contrast-enhanced standard-dose CT (SDCT) as the reference method.

    Materials and Methods: Consecutive patients with clinically suspected diverticulitis were included from two hospitals between January and October 2017. All patients underwent LDCT followed by SDCT. All CT examinations were assessed for signs of diverticulitis, complications, and other diagnoses by three independent radiologists (two radiology consultants and one fourth-year resident) using SDCT as the reference method. Sensitivity, specificity, and agreement were calculated.

    Results: In total, 149 patients (median age 68, 107 women) were included; 107 had diverticulitis on standard CT. Sensitivity for diverticulitis using LDCT was 100%; the values were 99% for consulting radiologists and 92% for the radiology resident. Specificity was 100% for both consultants and 84% for the resident. Sensitivity for identification of complications was 74%, 60%, and 54%, respectively. Twenty-six patients had other causes of abdominal symptoms on standard CT, 23 (88%) of whom were diagnosed correctly on LDCT. One case of splenic infarction and two cases of segment colitis were missed on LDCT.

    Conclusion: The diagnostic accuracy of LDCT was high for acute diverticulitis. Therefore, it is recommended as a standard method that should help to reduce radiation dose and cost. LDCT had lower sensitivity for complications, although discrimination between an inflamed diverticulum and small pericolic abscess accounted for a proportion of the discrepancies.

    HSV kategori
    Forskningsprogram
    Radiologi; Kirurgi
    Identifikatorer
    urn:nbn:se:uu:diva-356709 (URN)
    Tilgjengelig fra: 2018-08-03 Laget: 2018-08-03 Sist oppdatert: 2018-08-06bibliografisk kontrollert
    4. Outpatient, non-antibiotic management in acute uncomplicated diverticulitis: a prospective study
    Åpne denne publikasjonen i ny fane eller vindu >>Outpatient, non-antibiotic management in acute uncomplicated diverticulitis: a prospective study
    Vise andre…
    2015 (engelsk)Inngår i: International Journal of Colorectal Disease, ISSN 0179-1958, E-ISSN 1432-1262, Vol. 30, nr 9, s. 1229-1234Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The aim of this study was to evaluate outpatient, non-antibiotic management in acute uncomplicated diverticulitis with regard to admissions, complications, and recurrences, within a 3-month follow-up period. A prospective, observational study in which patients with computer tomography-verified acute uncomplicated diverticulitis were managed as outpatients without antibiotics. The patients kept a personal journal, were contacted daily by a nurse, and then followed up by a surgeon at 1 week and 3 months. In total, 155 patients were included, of which 54 were men; the mean age of the patients was 57.4 years. At the time of diagnosis, the mean C-reactive protein and white blood cell count were 73 mg/l and 10.5 x 10(9), respectively, and normalized in the vast majority of patients within the first week. The majority of the patients (97.4 %) were managed successfully as outpatients without antibiotics, admissions, or complications. In only four (2.6 %) patients, the management failed because of complications in three and deterioration in one. These patients were all treated successfully as inpatients without surgery. Five patients had recurrences and were treated as outpatients without antibiotics. Follow-up colonic investigations revealed cancer in two patients and polyps in 13 patients. Previous results of low complication rates with the non-antibiotic policy were confirmed. The new policy of outpatient management without antibiotics in acute uncomplicated diverticulitis is now shown to be feasible, well functioning, and safe.

    Emneord
    Diverticulitis, Outpatient management, Antibiotics
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-262965 (URN)10.1007/s00384-015-2258-y (DOI)000360542000011 ()25989930 (PubMedID)
    Merknad

    Correction in: International Journal of Colorectal Disease, 2015, vol. 30, issue 9, pages 1225-1235, doi: 10.1007/s00384-015-2284-9

    Tilgjengelig fra: 2015-09-24 Laget: 2015-09-23 Sist oppdatert: 2018-08-03bibliografisk kontrollert
  • 6.
    Zafari, Afshin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Tillämpad beräkningsvetenskap.
    Advances in Task-Based Parallel Programming for Distributed Memory Architectures2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    It has become common knowledge that parallel programming is needed for scientific applications, particularly for running large scale simulations. Different programming models are introduced for simplifying parallel programming, while enabling an application to use the full computational capacity of the hardware. In task-based programming, all the variables in the program are abstractly viewed as data. Parallelism is provided by partitioning the data. A task is a collection of operations performed on input data to generate output data. In distributed memory environments, the data is distributed over the computational nodes (or processes), and is communicated when a task needs remote data.

    This thesis discusses advanced techniques in distributed task-based parallel programming, implemented in the DuctTeip software library. DuctTeip uses MPI (Message Passing Interface) for asynchronous inter-process communication and Pthreads for shared memory parallelization within the processes. The data dependencies that determine which subsets of tasks can be executed in parallel are extracted from information about the data accesses (input or output) of the tasks. A versioning system is used internally to represent the task-data dependencies efficiently. A hierarchical partitioning of tasks and data allows for independent optimization of the size of computational tasks and the size of communicated data. A data listener technique is used to manage communication efficiently.

    DuctTeip provides an algorithm independent dynamic load balancing functionality. Redistributing tasks from busy processes to idle processes dynamically can provide an overall shorter execution time. A random search method with high probability of success is employed for locating idle/busy nodes.

    The advantage of the abstract view of tasks and data is exploited in a unified programming interface, which provides a standard for task-based frameworks to decouple framework development from application development. The interface can be used for collaboration between different frameworks in running an application program efficiently on different hardware.

    To evaluate the DuctTeip programming model, applications such as Cholesky factorization, a time-dependent PDE solver for the shallow water equations, and the fast multipole method have been implemented using DuctTeip. Experiments show that DuctTeip provides both scalability and performance. Comparisons with similar frameworks such as StarPU, OmpSs, and PaRSEC show competitive results.

    Delarbeid
    1. Programming models based on data versioning for dependency-aware task-based parallelisation
    Åpne denne publikasjonen i ny fane eller vindu >>Programming models based on data versioning for dependency-aware task-based parallelisation
    2012 (engelsk)Inngår i: Proc. 15th International Conference on Computational Science and Engineering, Los Alamitos, CA: IEEE Computer Society, 2012, s. 275-280Konferansepaper, Publicerat paper (Fagfellevurdert)
    sted, utgiver, år, opplag, sider
    Los Alamitos, CA: IEEE Computer Society, 2012
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-187446 (URN)10.1109/ICCSE.2012.45 (DOI)000317475000038 ()978-1-4673-5165-2 (ISBN)
    Konferanse
    CSE 2012
    Prosjekter
    eSSENCEUPMARC
    Tilgjengelig fra: 2013-01-24 Laget: 2012-12-06 Sist oppdatert: 2018-01-16bibliografisk kontrollert
    2. DuctTeip: An efficient programming model for distributed task based parallel computing
    Åpne denne publikasjonen i ny fane eller vindu >>DuctTeip: An efficient programming model for distributed task based parallel computing
    2018 (engelsk)Inngår i: Computing Research Repository, nr 1801.03578Artikkel i tidsskrift (Annet vitenskapelig) Submitted
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-338832 (URN)
    Prosjekter
    UPMARCeSSENCE
    Tilgjengelig fra: 2018-01-10 Laget: 2018-01-14 Sist oppdatert: 2018-04-18bibliografisk kontrollert
    3. TaskUniVerse: A Task-Based Unified Interface for Versatile Parallel Execution
    Åpne denne publikasjonen i ny fane eller vindu >>TaskUniVerse: A Task-Based Unified Interface for Versatile Parallel Execution
    2018 (engelsk)Inngår i: Parallel Processing and Applied Mathematics: Part I, Springer, 2018, s. 169-184Konferansepaper, Publicerat paper (Fagfellevurdert)
    sted, utgiver, år, opplag, sider
    Springer, 2018
    Serie
    Lecture Notes in Computer Science ; 10777
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-338836 (URN)10.1007/978-3-319-78024-5_16 (DOI)978-3-319-78023-8 (ISBN)
    Konferanse
    PPAM 2017
    Prosjekter
    eSSENCE
    Tilgjengelig fra: 2018-03-23 Laget: 2018-01-14 Sist oppdatert: 2018-03-26bibliografisk kontrollert
    4. Task parallel implementation of a solver for electromagnetic scattering problems
    Åpne denne publikasjonen i ny fane eller vindu >>Task parallel implementation of a solver for electromagnetic scattering problems
    Vise andre…
    2018 (engelsk)Inngår i: Computing Research Repository, nr 1801.03589Artikkel i tidsskrift (Annet vitenskapelig) Submitted
    HSV kategori
    Identifikatorer
    urn:nbn:se:uu:diva-338833 (URN)
    Prosjekter
    eSSENCE
    Tilgjengelig fra: 2018-01-11 Laget: 2018-01-14 Sist oppdatert: 2018-04-18bibliografisk kontrollert
    5. Distributed dynamic load balancing for task parallel programming
    Åpne denne publikasjonen i ny fane eller vindu >>Distributed dynamic load balancing for task parallel programming