636 research outputs found
Valuable assets: phase 2 of a general formal investigation into the role and status of classroom assistants in Scotland's secondary and special schools
The aim of this research is to extend existing data by considering classroom assistants in secondary and special schools in Scotland. The research examines the work and employment of classroom assistants and in particular explores the reasons for any role stretch amongst this group
Image-based Quantification of 3D Morphology for Bifurcations in the Left Coronary Artery: Application to Stent Design
Background
Improved strategies for stent‐based treatment of coronary artery disease at bifurcations require a greater understanding of artery morphology. Objective
We developed a workflow to quantify morphology in the left main coronary (LMCA), left anterior descending (LAD), and left circumflex (LCX) artery bifurcations. Methods
Computational models of each bifurcation were created for 55 patients using computed tomography images in 3D segmentation software. Metrics including cross‐sectional area, length, eccentricity, taper, curvature, planarity, branching law parameters, and bifurcation angles were assessed using open‐sources software and custom applications. Geometric characterization was performed by comparison of means, correlation, and linear discriminant analysis (LDA). Results
Differences between metrics suggest dedicated or multistent approaches should be tailored for each bifurcation. For example, the side branch of the LCX (i.e., obtuse marginal; OM) was longer than that of the LMCA (i.e., LCXprox) and LAD (i.e., first diagonal; D1). Bifurcation metrics for some locations (e.g., LMCA Finet ratio) provide results and confidence intervals agreeing with prior findings, while revised metric values are presented for others (e.g., LAD and LCX). LDA revealed several metrics that differentiate between artery locations (e.g., LMCA vs. D1, LMCA vs. OM, LADprox vs. D1, and LCXprox vs. D1). Conclusions
These results provide a foundation for elucidating common parameters from healthy coronary arteries and could be leveraged in the future for treating diseased arteries. Collectively the current results may ultimately be used for design iterations that improve outcomes following implantation of future dedicated bifurcation stents
Food habits and dietary adaptation of the English sole (Parophrys vetulus) in a recently disturbed habitat
ix, 77 leaves : ill. ; 29 cm
Notes Typescript
Thesis (M.S.)--University of Oregon, 1986
Includes vita and abstract
Bibliography: leaves 73-77
Another copy on microfilm is located in Archive
Enhancing structure relaxations for first-principles codes: an approximate Hessian approach
We present a method for improving the speed of geometry relaxation by using a
harmonic approximation for the interaction potential between nearest neighbor
atoms to construct an initial Hessian estimate. The model is quite robust, and
yields approximately a 30% or better reduction in the number of calculations
compared to an optimized diagonal initialization. Convergence with this
initializer approaches the speed of a converged BFGS Hessian, therefore it is
close to the best that can be achieved. Hessian preconditioning is discussed,
and it is found that a compromise between an average condition number and a
narrow distribution in eigenvalues produces the best optimization.Comment: 9 pages, 3 figures, added references, expanded optimization sectio
HIV-Associated Neurocognitive Disorder: Pathogenesis and Therapeutic Opportunities
Human immunodeficiency virus type 1 (HIV) infection presently affects more that 40 million people worldwide, and is associated with central nervous system (CNS) disruption in at least 30% of infected individuals. The use of highly active antiretroviral therapy has lessened the incidence, but not the prevalence of mild impairment of higher cognitive and cortical functions (HIV-associated neurocognitive disorders) as well as substantially reduced a more severe form dementia (HIV-associated dementia). Furthermore, improving neurological outcomes will require novel, adjunctive therapies that are targeted towards mechanisms of HIV-induced neurodegeneration. Identifying such molecular and pharmacological targets requires an understanding of the events preceding irreversible neuronal damage in the CNS, such as actions of neurotoxins (HIV proteins and cellular factors), disruption of ion channel properties, synaptic damage, and loss of adult neurogenesis. By considering the specific mechanisms and consequences of HIV neuropathogenesis, unified approaches for neuroprotection will likely emerge using a tailored, combined, and non-invasive approach
Efficacy of a bivalent killed whole-cell cholera vaccine over five years: a re-analysis of a cluster-randomized trial.
BACKGROUND: Oral cholera vaccine (OCV) is a feasible tool to prevent or mitigate cholera outbreaks. A better understanding of the vaccine's efficacy among different age groups and how rapidly its protection wanes could help guide vaccination policy. METHODS: To estimate the level and duration of OCV efficacy, we re-analyzed data from a previously published cluster-randomized, double-blind, placebo controlled trial with five years of follow-up. We used a Cox proportional hazards model and modeled the potentially time-dependent effect of age categories on both vaccine efficacy and risk of infection in the placebo group. In addition, we investigated the impact of an outbreak period on model estimation. RESULTS: Vaccine efficacy was 38% (95% CI: -2%,62%) for those vaccinated from ages 1 to under 5 years old, 85% (95% CI: 67%,93%) for those 5 to under 15 years, and 69% (95% CI: 49%,81%) for those vaccinated at ages 15 years and older. Among adult vaccinees, efficacy did not appear to wane during the trial, but there was insufficient data to assess the waning of efficacy among child vaccinees. CONCLUSIONS: Through this re-analysis we were able to detect a statistically significant difference in OCV efficacy when the vaccine was administered to children under 5 years old vs. children 5 years and older. The estimated efficacies are more similar to the previously published analysis based on the first two years of follow-up than the analysis based on all five years. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00289224
Malnutrition in healthcare settings and the role of gastrostomy feeding
Malnutrition can adversely affect physical and psychological function, influencing both morbidity and mortality. Despite the prevalence of malnutrition and its associated health and economic costs, malnutrition remains under-detected and under-treated in differing healthcare settings. For a subgroup of malnourished individuals, a gastrostomy (a feeding tube placed directly into the stomach) may be required to provide long-term nutritional support. In this review we explore the spectrum and consequences of malnutrition in differing healthcare settings. We then specifically review gastrostomies as a method of providing nutritional support. The review highlights the origins of gastrostomies, and discusses how endoscopic and radiological advances have culminated in an increased demand and placement of gastrostomy feeding tubes. Several studies have raised concerns about the benefits derived following this intervention and also about the patients selected to undergo this procedure. These studies are discussed in detail in this review, alongside suggestions for future research to help better delineate those who will benefit most from this intervention, and improve understanding about how gastrostomies influence nutritional outcomes
Computer-Enhanced Visual Learning Method to Teach Endoscopic Correction of Vesicoureteral Reflux: An Invitation to Residency Training Programs to Utilize the CEVL Method
Herein we describe a standardized approach to teach endoscopic injection therapy to repair vesicoureteral reflux utilizing the CEVL method, an internet-accessed platform. The content was developed through collaboration of the authors' clinical and computer expertises. This application provides personnel training, examination, and procedure skill documentation through the use of online text with narration, pictures, and video. There is also included feedback and remediation of skill performance and teaching “games.” We propose that such standardized teaching and procedure performance will ultimate in improved surgical results. The electronic nature of communication in this journal is ideal to rapidly disseminate this information and to develop a structure for collaborative research
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SLC45A2 protein stability and regulation of melanosome pH determine melanocyte pigmentation.
SLC45A2 encodes a putative transporter expressed primarily in pigment cells. SLC45A2 mutations cause oculocutaneous albinism type 4 (OCA4) and polymorphisms are associated with pigmentation variation, but the localization, function, and regulation of SLC45A2 and its variants remain unknown. We show that SLC45A2 localizes to a cohort of mature melanosomes that only partially overlaps with the cohort expressing the chloride channel OCA2. SLC45A2 expressed ectopically in HeLa cells localizes to lysosomes and raises lysosomal pH, suggesting that in melanocytes SLC45A2 expression, like OCA2 expression, results in the deacidification of maturing melanosomes to support melanin synthesis. Interestingly, OCA2 overexpression compensates for loss of SLC45A2 expression in pigmentation. Analyses of SLC45A2- and OCA2-deficient mouse melanocytes show that SLC45A2 likely functions later during melanosome maturation than OCA2. Moreover, the light skin-associated SLC45A2 allelic F374 variant restores only moderate pigmentation to SLC45A2-deficient melanocytes due to rapid proteasome-dependent degradation resulting in lower protein expression levels in melanosomes than the dark skin-associated allelic L374 variant. Our data suggest that SLC45A2 maintains melanosome neutralization that is initially orchestrated by transient OCA2 activity to support melanization at late stages of melanosome maturation, and that a common allelic variant imparts reduced activity due to protein instability
Barriers and outcomes of an evidence-based approach to diagnosis and management of chronic obstructive pulmonary disease (COPD) in Australia: a qualitative study
Background. Chronic obstructive pulmonary disease (COPD) is commonly managed in primary care but there is poor awareness of evidence-based guidelines and the quality and interpretation of spirometry is suboptimal. Objectives. The aims of this qualitative study were to explore how an intervention involving case finding and management of COPD was implemented, and the extent to which the GPs and practice nurses (PNs) worked in partnership to diagnose and manage COPD. Methods. Semi-structured interviews with PNs (n = 7), GPs (n = 4) and patients (n = 26) who had participated in the Primary care EarLy Intervention for Copd mANagement (PELICAN) study. The Theoretical Domains Framework was used to guide the coding and analysis of the interviews with PN and GPs. The patient interviews were analysed thematically. Results. PNs developed technical skills and understood the requirements for good-quality spirometry. However, many lacked confidence in its interpretation and felt this was not part of their professional role. This was reflected in responses from the GPs. Once COPD was diagnosed, the GPs tended to manage the patients with the PNs less involved. This was in contrast with PNs’ active role in managing patients with other chronic diseases such as diabetes. The extent to which the GPs and PNs worked in partnership to manage COPD varied. Conclusions. PNs improved their skills and confidence in performing spirometry. Beliefs about their professional role, identity and confidence influenced the extent to which PNs were involved in interpretation of the spirometry results and managing the patient in partnership with the GP
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