Göttingen, Universiẗat, Diss., 2003. / Dateien in unterschiedlichen Formaten.

Background: As part of this thesis work, we developed a Shower Technique protocol (‘STP’) for hemodialysis patients with healed central venous catheter (catheter) exit sites, designed to permit showering but not increase infection risk. Research question: Is it feasible to conduct a randomized control trial called the Hemodialysis Infection Prevention using Polysporin Ointment with Shower Technique in Satellite Centres (HIPPO SAT) study comparing the rate of CRB in adult satellite hemodialysis patients using STP versus standard catheter care alone with 6 month follow up? Study Design: The HIPPO SAT pilot study is a multi-centre randomized control trial. Eligible participants will be randomized to STP versus standard care after meeting predefined criteria to confirm healed tunneled catheter exit site. Primary Outcome: Feasibility will be determined based on 5 outcome measures: accuracy of the CRB rate documentation in the satellite setting, and percentage of patients screened, recruited, educated successfully in the STP (intervention arm), and using aspects of STP (% of contaminated patients in the control arm). Study Setting: In satellite units affiliated with 2 academic and 3 community centres in south central Ontario, Canada. Patient Population: Adult satellite Hemodialysis patients dialyzing via catheter with healed catheter exit sites. Intervention: STP and standard catheter care; or Control: standard catheter care; Analysis: Each measure of feasibility has its statistical threshold for success. If the threshold is reached in 4 of the 5 measures, the full HIPPO SAT study will be deemed feasible. Discussion: A pilot feasibility study of the larger study is critical due to the potential challenges associated with recruitment, compliance and contamination. / Thesis / Master of Science (MSc)

Systematic reviews (SR) and meta-analysis (MA) of randomised controlled trials (RCT) are the trustworthy sources of evidence. However, most systematic reviews focus on pair-wise comparisons. Network-meta-analysis (NMA) offers quantitative methods of integrating data from all the available comparisons of many different treatments for each outcome. In a systematic review of interventions, Summary of Findings (SoF) tables present the main findings of a review in a transparent and simple form. However, it is unknown how to present NMA findings in a tabular format. Moreover, systematic reviews and meta-analysis of interventions can summarize bodies of evidence from randomized and non-randomized studies (NRS). Integrating both sources of evidence in a single study can be challenging particularly in the context of assessing the certainty of the evidence, as well as presenting findings of both RCTs and NRS sources of evidence. In our study, we described how 276 NMA were conducted and how authors reported their main findings. We also conducted 32 interviews with users of NMAs and we designed two final NMA-SoF tables. Furthermore, we conducted two systematic reviews that included RCTs and NRS to address methodological challenges. Based on our results, we developed two NMA-SoF table formats to report the main findings of NMAs. The final format was appealing for users and allowed them to better understand NMA findings. Assessment of quality of individual NRS remains challenging and further research is needed to increase its appropriateness in systematic reviews of NRS. We determined that quality assessment of individual NRS was particularly challenging to implement due to the complexity of NRS evaluation tools. Our evaluation revealed that effect estimates of RCTs and NRS were better presented separately. / Thesis / Doctor of Philosophy (PhD) / Systematic reviews (SR) are a summary of studies that address a particular clinical question. Frequently, SRs are complemented with a statistical aggregation of results of individual studies to produce a single estimate. Summary of findings (SoF) tables are designed to present the most relevant information of systematic reviews and meta-analysis. However, it is unknown how to present network meta-analysis (NMA) findings in SoF tables. Another challenge relates to the integration of randomized controlled trials (RCTs) and non-randomized (NRS) studies. Methodological challenges in systematic reviews need to be addressed through careful research. In our study, we appraised how NMA were conducted, and how they presented their main findings. We designed two versions of SoF tables to present NMA findings. Moreover, we conducted two systematic reviews that included RCTs and NRS to address potential challenges in analyzing and presenting their findings.

This thesis presents new domain-theoretic models for randomized algorithms. A randomized algorithm can use random bits from an oracle to control its computation. The possible random bits form a binary tree, where each random choice of a bit is a branching of the tree. The randomized algorithm then determines what the output should be for each branch. This idea forms the basis of our random choice functors. However, the functor only provides one half of the model. We must also show how multiple randomized algorithms can be combined or composed. This is where the monadic structure comes into play. If we wish to join multiple randomized algorithms to form one resulting algorithm, then we can run each algorithm in parallel, using the same random bits for each. Monads are used to add a computational effect to an existing semantic model. In order to work with models of the lambda calculus, it is important to work in a Cartesian closed category of domains, due to Lambek's theorem and Scott's corollary. Our first random choice monad is shown to be an endofunctor of the Cartesian closed category BCD. If we wish to add multiple computational effects, then we can compose monads as long as the monads enjoy a distributive law. It is shown that in the category BCD, our first random choice monad enjoys a distributive law with the lower powerdomain for nondeterminism. Two variations of the random choice monad are then given. The first variation has a distributive law with the convex powerdomain in the categories RB and FS, while the second variation has a distributive law with the upper powerdomain in BCD. We use the random choice monads to develop a new programming language, Randomized PCF. This extends the language PCF by adding in random choice, allowing for the programming of randomized algorithms. A full operational semantics is given for Randomized PCF, and a random choice monad is used to give it a mathematical model (denotational semantics). Finally, an implementation of Randomized PCF is developed, and the Miller-Rabin algorithm is implemented in Randomized PCF. / Tyler Barker

The current study examined the efficacy of a 1 month future time perspective modification intervention over a 1 month and 6 months period. Participants (N = 92) with elevated scores on measures of depressive symptoms or suicidal ideation were assigned to either the intervention condition or a no-intervention control condition. A repeated-measures manova revealed that those in the time perspective modification intervention condition showed significant reductions in psychache and hopelessness at 1 month, relative to those in the control condition. Repeated-measures manovas did not reveal significantly greater changes in depressive symptoms, suicidal ideation, or future time perspective. No results at 6 months were found to be significant. These results suggest that a future time perspective modification intervention can reduce important predictors of suicidality, although the sustainability of these gains and their relation to suicide is unclear. / Thesis (Master, Psychology) -- Queen's University, 2011-08-29 13:29:07.463

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2005. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Toronto, 2004. / Includes bibliographical references.

Women are thought to be under-represented as clinical trial participants and as clinical trialists in heart failure. We reviewed randomized controlled trials of heart failure published in high impact medical journals and examined the representation of women as both participants and authors. Furthermore, we explored clinical trial characteristics independently associated with women as clinical trial participants and as lead authors. Our analysis demonstrated that women are under-represented as both clinical trial participants and leaders, with no change in temporal trends over time. Addressing clinical trial characteristics associated with under-representation and developing strategies to overcome barriers may be a strategic way to improve the representation of women in heart failure research. / Thesis / Master of Science (MSc)

Class of 2012 Abstract / Specific Aims: To explore whether publishing requirements for human-centered randomized control trials, particularly the CONSORT criteria, have any relationship to impact as measured by the Journal Citation Reports TM Impact Factor. Methods: A worksheet was used to evaluate a methodically selected list of journals, including types of articles published, requirements of authors for human-focused randomized control trials, JCR Impact Factor and other JCR metrics for each specific journal title. A worksheet was filled out for each journal by each member of the research team and answers combined for consensus. Group means and SDs were calculated and the Student’s t-Test applied to values for selected journals. Main Results: 50 candidate pharmacy journals were identified and 41 met the criteria for publishing human-centered randomized control trials. Journals were grouped according to whether they required CONSORT or had other reporting requirements for human RCTs, or had no requirements for such studies. Few (6; 15%) pharmacy journals required authors to use CONSORT; and additional 15 (37%) journals provided as least some author guidelines similar to CONSORT. Pharmacy journals using CONSORT or other guidelines had a higher average impact factor (3.5; SD = 1.5) than did journals without guidelines (2.4; SD = 0.9; p = 0.007). Conclusions: There appears to be a statistical difference in average JCR metrics between journals which require specific RCT guidelines and those which do not. The use of reporting guidelines, such as CONSORT, by pharmacy journals is associated with increased impact as represented by JCR influence measures.

Increased interest has focused on associations between dietary fatty acids and cardiovascular disease (CVD). Current findings delineating effects of consuming saturated fatty acids (SFA) from dairy on CVD risk remain controversial. The objective of this thesis was to investigate the effects of consuming two types of dairy fat, namely those from cheese and butter on, human plasma and RBC fatty acid profiles, compared with monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA) and carbohydrate (CHO). A secondary objective was to investigate the association between consuming these dietary fatty acids and endogenous de novo fatty acid synthesis. A randomized, full-feeding, crossover, single-blinded clinical trial was conducted at the Institute of Nutrition and Functional Foods (INAF), Laval University and Richardson Centre for Functional Foods and Nutraceuticals (RCFFN), the University of Manitoba. A total of 92 women and men with abdominal obesity and relative low high density lipoprotein cholesterol (HDL-C) levels were randomized into a series of 5 treatments. The duration of each treatment was 4 weeks and separated by at least 4 weeks washout period. For plasma fatty acid profile, total plasma SFA after cheese treatment was found to be higher (P<0.05) than after MUFA, PUFA and CHO treatments, whereas total plasma SFA after butter treatment was only found to be higher (P<0.05) than after MUFA and PUFA treatments. Total plasma MUFA after MUFA treatment was higher (P<0.05) than after all other treatments, and total plasma PUFA after PUFA treatment was higher (P<0.05) than after all other treatments. Unlike plasma fatty acid profile, RBC total SFA after two dairy treatments were not higher than after CHO and PUFA treatments. Consistent with the plasma fatty acid profile, RBC total MUFA after MUFA treatment were found to be higher (P<0.05) than after all other treatments. Similarly, RBC total PUFA after PUFA treatment were higher (P<0.05) than after all other treatments. We did not detect any differences in de novo palmitic acid synthesis across all treatments in the present study. However, we did see a positive correlation between de novo palmitic acid synthesis and body fat mass. In summary, present results suggest that consuming dairy fats, from cheese or butter, can significantly modulate plasma fatty acids in a manner that increases plasma total SFA, including myristic acid (C14:0), pentadecanoic acid (C15:0), palmitic acid (C16:0) and heptadecanoic acid (C17:0). However, the effect of consuming dairy fats on RBC fatty acid profile is relatively minor. Additionally, the de novo fatty acid synthesis data suggests that the quality of dietary fatty acids does not associate with human endogenous fatty acid synthesis; unlike body fat mass. / May 2017