196 research outputs found

    Investigation of load transfer models for recycled plastic reinforcement for slope stabilization

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    The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract, appears in the public.pdf file.Title from PDF of title page (University of Missouri--Columbia, viewed on July 21, 2011).Thesis advisor: Eric Loehr.Includes bibliographical references.M.S. University of Missouri--Columbia 2011.Slope failures are not only hazardous to the public, but they are also costly to maintain and repair. A field testing program involving five test sites has been executed in an effort to develop better design practices for slopes reinforced with slender reinforcement. This thesis is directed at three of these sites, including a slope located along Interstate 70 near Emma, MO, a slope located along US 36 near Stewartsville, MO, and a slope located along Interstate 435 (at Wornall Road) in Kansas City, MO. This thesis describes analyses performed to evaluate current analysis models and to develop recommendations for future design of slopes stabilized with slender reinforcement. The analysis models were evaluated by comparing measured bending moments from the field test sites with predicted bending moments calculated using conventional soil-structure interaction models implemented in the commercial software, LPile, Version 5.0[copyright]. The models and input parameters for the soil-structure interaction analysis were varied to produce matches between the measured and predicted response of the reinforcement. The models that produced the best results for each site were then collectively assessed to develop recommendations for use in slope designs with slender reinforcement. Results of the analyses described suggest that the "API Sand (O'Neill)" model should be used when modeling reinforcement for long-term, drained loading conditions, regardless of the type of soil present. This model should be used with a p-multiplier selected based on the relative pile batter angle. The soil movement profile should be input as anticipated soil movements down to the sliding depth, and then zero below the sliding depth

    Mass media campaigns and the 'file drawer problem': A mixed methods study of how to avoid campaign failure.

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    Mass media campaigns are frequently used to address public health issues. Considering the considerable cost, there has been little analysis of why campaigns sometimes fail. This study used a sequential mixed methods approach to explore the mechanisms that can lead to failure and to identify what can be done to avoid or overcome common mistakes in campaign planning, implementation, and evaluation. We conducted interviews and a survey with 28 public health social marketing and mass media campaign experts over three rounds of research and analysed the data thematically, generating themes inductively. We identified four systemic factors that drive success: long-term strategic thinking and commitment, understanding the campaign context, doing and learning from evaluation, and fostering strong relationships. The factors did not operate in isolation, rather good (or poor) execution in one area was likely to influence performance in another. The experts also emphasised that a change of political context could drastically affect one or more of the identified factors. Our analysis showed that campaign failures are not simply individuals making mistakes. Systemic issues throughout the planning, execution, and evaluation phases need to be addressed if campaign outcomes are to improve

    Impact of the Make Healthy Normal mass media campaign (Phase 1) on knowledge, attitudes and behaviours.

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    Objective: To determine the impact of the first phase of the Make Healthy Normal mass media campaign on NSW adults’ active living and healthy eating knowledge, attitudes, intentions and behaviour. Methods: Cohort design with NSW adults, followed up three times over 12 months, with n=939 participants completing all three waves. We used generalised linear mixed models to examine campaign awareness, knowledge, attitudes, intentions and behaviours over time. Results: Campaign recognition built to a reasonable level (45% at Wave 3), although unprompted recall was low (9% at Wave 3). There were significant increases in knowledge of physical activity recommendations (46% to 50%), the health effects of obesity (52% to 64%), and weight loss benefits (53% to 65%), with stronger effects in campaign recognisers. Conversely, we found declines in self-efficacy and intention to increase physical activity (39% to 31%) and decrease soft drink consumption (31% to 24%). Conclusions: Overall, there are some positives for the campaign but intentions need to be a focus of future campaign phases. Continued investment over the medium- to long-term is needed. Implications: Mass media campaigns can play a role in obesity prevention but robust evaluations are needed to identify the characteristics of effective campaigns

    Variability between human experts and artificial intelligence in identification of anatomical structures by ultrasound in regional anaesthesia: a framework for evaluation of assistive artificial intelligence

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    Background: ScanNavTM Anatomy Peripheral Nerve Block (ScanNav™) is an artificial intelligence (AI)-based device that produces a colour overlay on real-time B-mode ultrasound to highlight key anatomical structures for regional anaesthesia. This study compares consistency of identification of sono-anatomical structures between expert ultrasonographers and ScanNav™. Methods: Nineteen experts in ultrasound-guided regional anaesthesia (UGRA) annotated 100 structures in 30 ultrasound videos across six anatomical regions. These annotations were compared with each other to produce a quantitative assessment of the level of agreement amongst human experts. The AI colour overlay was then compared with all expert annotations. Differences in human–human and human–AI agreement are presented for each structure class (artery, muscle, nerve, fascia/serosal plane) and structure. Clinical context is provided through subjective assessment data from UGRA experts. Results: For human–human and human–AI annotations, agreement was highest for arteries (mean Dice score 0.88/0.86), then muscles (0.80/0.77), and lowest for nerves (0.48/0.41). Wide discrepancy exists in consistency for different structures, both with human–human and human–AI comparisons; highest for sartorius muscle (0.91/0.92) and lowest for the radial nerve (0.21/0.27). Conclusions: Human experts and the AI system both showed the same pattern of agreement in sono-anatomical structure identification. The clinical significance of the differences presented must be explored; however the perception that human expert opinion is uniform must be challenged. Elements of this assessment framework could be used for other devices to allow consistent evaluations that inform clinical training and practice. Anaesthetists should be actively engaged in the development and adoption of new AI technology

    "...because I am something special" or "I think I will be something like a guinea pig": information and assent of legal minors in clinical trials – assessment of understanding, appreciation and reasoning

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study is to assess and evaluate the capacities for understanding, appreciation and reasoning of legal minors with psychiatric disorders and their parents and their competence to consent or assent to participation in clinical trials. The beliefs, fears, motivation and influencing factors for decision-making of legal minors and parents were also examined.</p> <p>Methods</p> <p>Using the MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR), an instrument developed for adults whose capacities to consent are unclear, we provided information about clinical trials and assessed understanding, appreciation and reasoning. We adapted this tool for legal minors and examined 19 children and adolescents between the ages of 7 and 15 with attention deficit/hyperactivity disorder (ADHD) or ADHD combined with oppositional defiant disorder (DSM-IV 314.00/314.01/312.8) enrolled in clinical trials. Parents were also examined using the MacCAT-CR.</p> <p>Results</p> <p>Facts such as the procedures involved in trials or their duration were well understood by legal minors, but more abstract issues like the primary purpose of the trial were not understood by children and adolescents or by many parents. Legal minors also had difficulties understanding the nature of placebo and the probability of receiving placebo. Children's and adolescents' decisions were influenced by fears about their disorder worsening and by problems in their relationship with their parents. Parents wanted the best therapy for their children in order to minimize problems in school.</p> <p>Conclusion</p> <p>Legal minors and parents need to be informed more precisely about specific issues like placebo and the primary purpose of trials. In general, the reasoning of children and adolescents was influenced by their experience with their disorder and decision making was based on reasonable arguments. Their fears were based on everyday experiences such as school performance or family relationships.</p

    LC-MSsim – a simulation software for liquid chromatography mass spectrometry data

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    <p>Abstract</p> <p>Background</p> <p>Mass Spectrometry coupled to Liquid Chromatography (LC-MS) is commonly used to analyze the protein content of biological samples in large scale studies. The data resulting from an LC-MS experiment is huge, highly complex and noisy. Accordingly, it has sparked new developments in Bioinformatics, especially in the fields of algorithm development, statistics and software engineering. In a quantitative label-free mass spectrometry experiment, crucial steps are the detection of peptide features in the mass spectra and the alignment of samples by correcting for shifts in retention time. At the moment, it is difficult to compare the plethora of algorithms for these tasks. So far, curated benchmark data exists only for peptide identification algorithms but no data that represents a ground truth for the evaluation of feature detection, alignment and filtering algorithms.</p> <p>Results</p> <p>We present <it>LC-MSsim</it>, a simulation software for LC-ESI-MS experiments. It simulates ESI spectra on the MS level. It reads a list of proteins from a FASTA file and digests the protein mixture using a user-defined enzyme. The software creates an LC-MS data set using a predictor for the retention time of the peptides and a model for peak shapes and elution profiles of the mass spectral peaks. Our software also offers the possibility to add contaminants, to change the background noise level and includes a model for the detectability of peptides in mass spectra. After the simulation, <it>LC-MSsim </it>writes the simulated data to mzData, a public XML format. The software also stores the positions (monoisotopic m/z and retention time) and ion counts of the simulated ions in separate files.</p> <p>Conclusion</p> <p><it>LC-MSsim </it>generates simulated LC-MS data sets and incorporates models for peak shapes and contaminations. Algorithm developers can match the results of feature detection and alignment algorithms against the simulated ion lists and meaningful error rates can be computed. We anticipate that <it>LC-MSsim </it>will be useful to the wider community to perform benchmark studies and comparisons between computational tools.</p

    LabKey Server: An open source platform for scientific data integration, analysis and collaboration

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    <p>Abstract</p> <p>Background</p> <p>Broad-based collaborations are becoming increasingly common among disease researchers. For example, the Global HIV Enterprise has united cross-disciplinary consortia to speed progress towards HIV vaccines through coordinated research across the boundaries of institutions, continents and specialties. New, end-to-end software tools for data and specimen management are necessary to achieve the ambitious goals of such alliances. These tools must enable researchers to organize and integrate heterogeneous data early in the discovery process, standardize processes, gain new insights into pooled data and collaborate securely.</p> <p>Results</p> <p>To meet these needs, we enhanced the LabKey Server platform, formerly known as CPAS. This freely available, open source software is maintained by professional engineers who use commercially proven practices for software development and maintenance. Recent enhancements support: (i) Submitting specimens requests across collaborating organizations (ii) Graphically defining new experimental data types, metadata and wizards for data collection (iii) Transitioning experimental results from a multiplicity of spreadsheets to custom tables in a shared database (iv) Securely organizing, integrating, analyzing, visualizing and sharing diverse data types, from clinical records to specimens to complex assays (v) Interacting dynamically with external data sources (vi) Tracking study participants and cohorts over time (vii) Developing custom interfaces using client libraries (viii) Authoring custom visualizations in a built-in R scripting environment.</p> <p>Diverse research organizations have adopted and adapted LabKey Server, including consortia within the Global HIV Enterprise. Atlas is an installation of LabKey Server that has been tailored to serve these consortia. It is in production use and demonstrates the core capabilities of LabKey Server. Atlas now has over 2,800 active user accounts originating from approximately 36 countries and 350 organizations. It tracks roughly 27,000 assay runs, 860,000 specimen vials and 1,300,000 vial transfers.</p> <p>Conclusions</p> <p>Sharing data, analysis tools and infrastructure can speed the efforts of large research consortia by enhancing efficiency and enabling new insights. The Atlas installation of LabKey Server demonstrates the utility of the LabKey platform for collaborative research. Stable, supported builds of LabKey Server are freely available for download at <url>http://www.labkey.org</url>. Documentation and source code are available under the Apache License 2.0.</p

    The rationale and design of the antihypertensives and vascular, endothelial, and cognitive function (AVEC) trial in elderly hypertensives with early cognitive impairment: Role of the renin angiotensin system inhibition

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    <p>Abstract</p> <p>Background</p> <p>Prior evidence suggests that the renin angiotensin system and antihypertensives that inhibit this system play a role in cognitive, central vascular, and endothelial function. Our objective is to conduct a double-blind randomized controlled clinical trial, the antihypertensives and vascular, endothelial, and cognitive function (AVEC), to compare 1 year treatment of 3 antihypertensives (lisinopril, candesartan, or hydrochlorothiazide) in their effect on memory and executive function, cerebral blood flow, and central endothelial function of seniors with hypertension and early objective evidence of executive or memory impairments.</p> <p>Methods/Design</p> <p>The overall experimental design of the AVEC trial is a 3-arm double blind randomized controlled clinical trial. A total of 100 community eligible individuals (60 years or older) with hypertension and early cognitive impairment are being recruited from the greater Boston area and randomized to lisinopril, candesartan, or hydrochlorothiazide ("active control") for 12 months. The goal of the intervention is to achieve blood pressure control defined as SBP < 140 mm Hg and DBP < 90 mm Hg. Additional antihypertensives are added to achieve this goal if needed. Eligible participants are those with hypertension, defined as a blood pressure 140/90 mm Hg or greater, early cognitive impairment without dementia defined (10 or less out of 15 on the executive clock draw test or 1 standard deviation below the mean on the immediate memory subtest of the repeatable battery for the assessment of neuropsychological status and Mini-Mental-Status-exam >20 and without clinical diagnosis of dementia or Alzheimer's disease). Individuals who are currently receiving antihypertensives are eligible to participate if the participants and the primary care providers are willing to taper their antihypertensives. Participants undergo cognitive assessment, measurements of cerebral blood flow using Transcranial Doppler, and central endothelial function by measuring changes in cerebral blood flow in response to changes in end tidal carbon dioxide at baseline (off antihypertensives), 6, and 12 months. Our outcomes are change in cognitive function score (executive and memory), cerebral blood flow, and carbon dioxide cerebral vasoreactivity.</p> <p>Discussion</p> <p>The AVEC trial is the first study to explore impact of antihypertensives in those who are showing early evidence of cognitive difficulties that did not reach the threshold of dementia. Success of this trial will offer new therapeutic application of antihypertensives that inhibit the renin angiotensin system and new insights in the role of this system in aging.</p> <p>Trial Registration</p> <p>Clinicaltrials.gov NCT00605072</p
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