A note on the use of sensitivity analysis to explore the potential impact of declining institutional care utilisation on disability prevalence

Many health and disability surveys are conducted using the non-institutionalised population as a sampling frame. Consequently, it is possible that changes in the utilisation of institutional care could account for all or part of any change in the observed prevalence of functional limitation, disability or other health state, based on samples from the non-institutionalised population. Using conditional probability arguments, I present an adjustment formula for computing health state prevalences for the non-institutionalised population under a scenario in which health state prevalences are held constant except for movement into the non-institutionalised population of individuals who would formerly have been in institutional care. By comparing the adjusted prevalence with observed non-institutionalised health state prevalences the contribution of changes in institutionalisation to observed changes in the non-institutionalised health state prevalence can be assessed

Overexpression of mouse prion protein in transgenic mice causes a non-transmissible spongiform encephalopathy

Transgenic mice over-expressing human PRNP or murine Prnp transgenes on a mouse prion protein knockout background have made key contributions to the understanding of human prion diseases and have provided the basis for many of the fundamental advances in prion biology, including the first report of synthetic mammalian prions. In this regard, the prion paradigm is increasingly guiding the exploration of seeded protein misfolding in the pathogenesis of other neurodegenerative diseases. Here we report that a well-established and widely used line of such mice (Tg20 or tga20), which overexpress wild-type mouse prion protein, exhibit spontaneous aggregation and accumulation of misfolded prion protein in a strongly age-dependent manner, which is accompanied by focal spongiosis and occasional neuronal loss. In some cases a clinical syndrome developed with phenotypic features that closely resemble those seen in prion disease. However, passage of brain homogenate from affected, aged mice failed to transmit this syndrome when inoculated intracerebrally into further recipient animals. We conclude that overexpression of the wild-type mouse prion protein can cause an age-dependent protein misfolding disorder or proteinopathy that is not associated with the production of an infectious agent but can produce a phenotype closely similar to authentic prion disease

Moment-based parameter estimation in binomial random intersection graph models

Binomial random intersection graphs can be used as parsimonious statistical models of large and sparse networks, with one parameter for the average degree and another for transitivity, the tendency of neighbours of a node to be connected. This paper discusses the estimation of these parameters from a single observed instance of the graph, using moment estimators based on observed degrees and frequencies of 2-stars and triangles. The observed data set is assumed to be a subgraph induced by a set of $n_0$ nodes sampled from the full set of $n$ nodes. We prove the consistency of the proposed estimators by showing that the relative estimation error is small with high probability for $n_0 \gg n^{2/3} \gg 1$. As a byproduct, our analysis confirms that the empirical transitivity coefficient of the graph is with high probability close to the theoretical clustering coefficient of the model.Comment: 15 pages, 6 figure

Development of a quality assessment tool for systematic reviews of observational studies (QATSO) of HIV prevalence in men having sex with men and associated risk behaviours

<p>Abstract</p> <p>Background</p> <p>Systematic reviews based on the critical appraisal of observational and analytic studies on HIV prevalence and risk factors for HIV transmission among men having sex with men are very useful for health care decisions and planning. Such appraisal is particularly difficult, however, as the quality assessment tools available for use with observational and analytic studies are poorly established.</p> <p>Methods</p> <p>We reviewed the existing quality assessment tools for systematic reviews of observational studies and developed a concise quality assessment checklist to help standardise decisions regarding the quality of studies, with careful consideration of issues such as external and internal validity.</p> <p>Results</p> <p>A pilot version of the checklist was developed based on epidemiological principles, reviews of study designs, and existing checklists for the assessment of observational studies. The Quality Assessment Tool for Systematic Reviews of Observational Studies (QATSO) Score consists of five items: External validity (1 item), reporting (2 items), bias (1 item) and confounding factors (1 item). Expert opinions were sought and it was tested on manuscripts that fulfil the inclusion criteria of a systematic review. Like all assessment scales, QATSO may oversimplify and generalise information yet it is inclusive, simple and practical to use, and allows comparability between papers.</p> <p>Conclusion</p> <p>A specific tool that allows researchers to appraise and guide study quality of observational studies is developed and can be modified for similar studies in the future.</p

Th17 cells are more protective than Th1 cells against the intracellular parasite Trypanosoma cruzi

Th17 cells are a subset of CD4+ T cells known to play a central role in the pathogenesis of many autoimmune diseases, as well as in the defense against some extracellular bacteria and fungi. However, Th17 cells are not believed to have a significant function against intracellular infections. In contrast to this paradigm, we have discovered that Th17 cells provide robust protection against Trypanosoma cruzi, the intracellular protozoan parasite that causes Chagas disease. Th17 cells confer significantly stronger protection against T. cruzi-related mortality than even Th1 cells, traditionally thought to be the CD4+ T cell subset most important for immunity to T. cruzi and other intracellular microorganisms. Mechanistically, Th17 cells can directly protect infected cells through the IL-17A-dependent induction of NADPH oxidase, involved in the phagocyte respiratory burst response, and provide indirect help through IL-21-dependent activation of CD8+ T cells. The discovery of these novel Th17 cell-mediated direct protective and indirect helper effects important for intracellular immunity highlights the diversity of Th17 cell roles, and increases understanding of protective T. cruzi immunity, aiding the development of therapeutics and vaccines for Chagas disease

Robust tests for time-invariant individual heterogeneity versus dynamic state dependence

We derive tests for persistent effects in a general linear dynamic panel data context. Two sources of persistent behavior are considered: time-invariant unobserved factors (captured by an individual random effect) and dynamic persistence or “state dependence” (captured by autoregressive behavior). We will use a maximum likelihood framework to derive a family of tests that help researchers learn whether persistence is due to individual heterogeneity, dynamic effect, or both. The proposed tests have power only in the direction they are designed to perform, that is, they are locally robust to the presence of alternative sources of persistence, and consequently, are able to identify which source of persistence is active. A Monte Carlo experiment is implemented to explore the finite sample performance of the proposed procedures. The tests are applied to a panel data series of real GDP growth for the period 1960–2005

Undergraduate medical education in emergency medical care: A nationwide survey at German medical schools

Background Since June 2002, revised regulations in Germany have required "Emergency Medical Care" as an interdisciplinary subject, and state that emergency treatment should be of increasing importance within the curriculum. A survey of the current status of undergraduate medical education in emergency medical care establishes the basis for further committee work. Methods Using a standardized questionnaire, all medical faculties in Germany were asked to answer questions concerning the structure of their curriculum, representation of disciplines, instructors' qualifications, teaching and assessment methods, as well as evaluation procedures. Results Data from 35 of the 38 medical schools in Germany were analysed. In 32 of 35 medical faculties, the local Department of Anaesthesiology is responsible for the teaching of emergency medical care; in two faculties, emergency medicine is taught mainly by the Department of Surgery and in another by Internal Medicine. Lectures, seminars and practical training units are scheduled in varying composition at 97% of the locations. Simulation technology is integrated at 60% (n=21); problem-based learning at 29% (n=10), e-learning at 3% (n=1), and internship in ambulance service is mandatory at 11% (n=4). In terms of assessment methods, multiple-choice exams (15 to 70 questions) are favoured (89%, n=31), partially supplemented by open questions (31%, n=11). Some faculties also perform single practical tests (43%, n=15), objective structured clinical examination (OSCE; 29%, n=10) or oral examinations (17%, n=6). Conclusion Emergency Medical Care in undergraduate medical education in Germany has a practical orientation, but is very inconsistently structured. The innovative options of simulation technology or state-of-the-art assessment methods are not consistently utilized. Therefore, an exchange of experiences and concepts between faculties and disciplines should be promoted to guarantee a standard level of education in emergency medical care

Approaches to working in high-dimensional data spaces: gene expression microarrays

This review provides a focused summary of the implications of high-dimensional data spaces produced by gene expression microarrays for building better models of cancer diagnosis, prognosis, and therapeutics. We identify the unique challenges posed by high dimensionality to highlight methodological problems and discuss recent methods in predictive classification, unsupervised subclass discovery, and marker identification

Exploring the experiences of being an ethnic minority student within undergraduate nurse education: A qualitative study

© 2019 The Author(s). Background: Students studying in a country where another language is spoken face multiple challenges including their ability to fully integrate with peers and academic pressures in trying to obtain an undergraduate nursing degree. The aim of the study was to explore the lived experiences of students, from varying cultural and ethnic backgrounds, undertaking an undergraduate nursing degree. Methods: The study adopted a qualitative design and eight individual semi-structured interviews were conducted. The interviews were analysed using manifest content analysis according to Graneheim and Lundman. Results: Students reported feelings of isolation and the lack of opportunities to integrate with native students within academia and practice. The need for personal support was a crucial factor that was independent of gender and students reported challenges related to both language and culture during the programme. Conclusions: Suggestions arising from this study includes appropriate support systems within academia and practice. It is imperative that universities and practice settings promote and integrate cultural awareness within academia and practice in meeting the needs of students and providing culturally appropriate nursing care, thereby providing opportunities for all students to become competent and professional practitioners