3,723 research outputs found
Working with Patients at risk for Hereditary Degenerative Brain Disorders
Hereditary degenerative brain disorders (HDBDs) are a unique class of genetic conditions that result in progressive loss of function within the nervous system, many of which present during adulthood. Given this, the diagnosis of a HDBD can be daunting for both the patient and the genetic counselor assisting in medical care. The purpose of this study was to find themes among genetic counselors who see this patient population and help provide a framework to counselors entering this field by recognizing verified methods of HDBD counseling. Sixteen genetic counselors who routinely see patients at-risk for HDBDs were interviewed concerning how they prepared for and engaged with their patients, how they handled the complex emotions frequently associated with presymptomatic HDBD counseling, and how they perceived the stress levels and coping mechanisms of their patients. The results of this study showed that genetic counselors who see patients at-risk for HDBDs utilize agendas and/or protocols in preparing for and directing sessions. Additionally, these genetic counselors perceive their HDBD patients as capable of coping with their own presymptomatic testing results. There was not enough evidence from this study to determine if genetic counselors who see patients at risk for HDBDs are at any greater risk for compassion fatigue than other genetic counselors. Overall, the genetic counselors who see patients at risk for HDBDs are more similar to than different from genetic counselors who do not see this patient population. Given that a significant number of people are living at risk for HDBDs, experiences in case observation and counseling alongside expert HDBD counselors could benefit genetic counselors and the patients they serve
The Evolutionary Genetics of Behavioural Variation: multivariate perspectives on personality in the Trinidadian guppy.
Animal personality is found in a wide range of taxa, yet our knowledge of what maintains consistent among-individual variation in behaviour is still incomplete. Many personality traits are associated with fitness, leading to the expectation that, under selection, genetic (and among-individual) variation will be eroded over time. Several adaptive models have been developed in order to explain this maintenance of variation. These include state-dependence, state-behaviour feedback loops, life-history and behavioural coadaptation and the Pace of Life syndrome. These models represent good starting points for thinking about what drives and maintains among-individual variation in behaviour, and while empirical support for these models is mixed, one thing they do have in common is the assumption of a significant genetic basis underpinning personality traits. Significant heritability is required for an evolutionary response to selection and for among-individual variation to be adaptive. The univariate estimates of heritability for personality traits that are growing in the literature, while useful, are likely insufficient to predict how personality traits will respond to selection. This thesis uses the Trinidadian guppy, Poecilia reticulata, and other species to explore patterns of among-individual and genetic variation in personality traits, advocating the benefits of using multivariate perspectives throughout. Firstly, the among-individual covariance structure between measures of boldness, growth and metabolic rate are estimated in a test of the Pace of Life syndrome. Secondly, an appraisal of the relative strength of maternal and genetic effects on offspring personality and how it changes over ontogeny. Next, a comprehensive treatment of sexual dimorphism in behaviour and size followed by analysis of genotype-by-sex interactions using both univariate and multivariate methods. Finally, a comparative analysis of personality in 7 species of small fish, identifying the main axis of among-individual variation from a single assay in each and quantifying the phylogenetic signal
An educators’ perspective on reflexive pedagogy:identity undoing and issues of power
This article looks at reflexive pedagogical practice and the ‘identity undoing’ that such practice demands from educators. Such identity undoing is found to have strong connections to the impact on identity of power relations, resistance and struggle. A dialogic ‘testimonio’ approach is adopted tracing two of the authors’ experiences of attempting to introduce a reflexive pedagogy within a structured, accredited learning intervention. This approach analyses educators’ own reflexive dialogue to make visible the assumptions and tensions that are provoked between educators and students in a reflexively orientated learning process. In undertaking this analysis, we problematize the pursuit of a reflexive pedagogical practice within executive and postgraduate education and offer a paradox: the desire to engage students in reflexive learning interventions - and in particular to disrupt the power asymmetries and hierarchical dependencies of more traditional educator-student relationships - can in practice have the effect of highlighting those very asymmetries and dependencies. Successful resolution of such a paradox becomes dependent on the capacity of educators to undo their own reliance on and even desire for authority underpinned by a sense of theory-based expertise
Aspects of the tensile strength of brick-mortar joints.
The main purpose of this work is to assess the factors which affect the tensile bond strength of brick mortar joints and to verify their relative importance, both by reference to the literature, and by experimentation. From these investigations the most important aspects are seen to be the absorption of water from the mortar by the brick, and the grade of the mortar.Almost one thousand tensile bond couplets were tested using a newly devised apparatus which has several advantages over existing test methods. Four experimental programmes were carried out, each of which was designed to investigate one or more of the factors which were judged either to be of particular importance, or to be inconclusive, or both.Arising out of the main section of the work was the tensile strength hypothesis. This is capable of showing, in a qualitative way, how the tensile strength and mode of failure of a brick-mortar joint can be related to the properties of the mortar and the brick. The hypothesis draws upon concepts from other disciplines, such as soil physics, in order to describe the physical processes which are important. Accordingly, it is the way that a brick absorbs water from the mortar that will have the most profound effect on the subsequent processes of hydration and strength development within the mortar.In order to provide some evidence in favour of the hypothesis, pilot studies were carried out to determine the moisture characteristics of mortar and to furnish data on the hydration products within the joint. Whilst, these pilot studies had their limitations, the results were encouraging.Recommendations are made regarding future developments of the hypothesis from a theoretical and a practical viewpoint
Statistical methods for the time-to-event analysis of individual participant data from multiple epidemiological studies
Background Meta-analysis of individual participant time-to-event data from multiple prospective epidemiological studies enables detailed investigation of exposure–risk relationships, but involves a number of analytical challenges. Methods This article describes statistical approaches adopted in the Emerging Risk Factors Collaboration, in which primary data from more than 1 million participants in more than 100 prospective studies have been collated to enable detailed analyses of various risk markers in relation to incident cardiovascular disease outcomes. Results Analyses have been principally based on Cox proportional hazards regression models stratified by sex, undertaken in each study separately. Estimates of exposure–risk relationships, initially unadjusted and then adjusted for several confounders, have been combined over studies using meta-analysis. Methods for assessing the shape of exposure–risk associations and the proportional hazards assumption have been developed. Estimates of interactions have also been combined using meta-analysis, keeping separate within- and between-study information. Regression dilution bias caused by measurement error and within-person variation in exposures and confounders has been addressed through the analysis of repeat measurements to estimate corrected regression coefficients. These methods are exemplified by analysis of plasma fibrinogen and risk of coronary heart disease, and Stata code is made available. Conclusion Increasing numbers of meta-analyses of individual participant data from observational data are being conducted to enhance the statistical power and detail of epidemiological studies. The statistical methods developed here can be used to address the needs of such analyses
A review of methodologies applied in Australian practice to evaluate long-term coastal adaptation options
Rising sea levels have the potential to alter coastal flooding regimes around the world and local governments are beginning to consider how to manage uncertain coastal change. In doing so, there is increasing recognition that such change is deeply uncertain and unable to be reliably described with probabilities or a small number of scenarios. Characteristics of methodologies applied in Australian practice to evaluate long-term coastal adaptation options are reviewed and benchmarked against two state-of-the-art international methods suited for conditions of uncertainty (Robust Decision Making and Dynamic Adaptive Policy Pathways). Seven out of the ten Australian case studies assumed the uncertain parameters, such as sea level rise, could be described deterministically or stochastically when identifying risk and evaluating adaptation options across multi-decadal periods. This basis is not considered sophisticated enough for long-term decision-making, implying that Australian practice needs to increase the use of scenarios to explore a much larger uncertainty space when assessing the performance of adaptation options. Two Australian case studies mapped flexible adaptation pathways to manage uncertainty, and there remains an opportunity to incorporate quantitative methodologies to support the identification of risk thresholds. The contextual framing of risk, including the approach taken to identify risk (top-down or bottom-up) and treatment of uncertain parameters, were found to be fundamental characteristics that influenced the methodology selected to evaluate adaptation options. The small sample of case studies available suggests that long-term coastal adaptation in Australian is in its infancy and there is a timely opportunity to guide local government towards robust methodologies for developing long-term coastal adaptation plans
Characterizing and minimizing the effects of noise in tide gauge time series: Relative and geocentric sea level rise around Australia
We quantify the rate of sea level rise around the Australian continent from an analysis of tidegauge and Global Positioning System (GPS) data sets. To estimate the underlying linear ratesof sea level change in the presence of significant interannual and
A More Generalizable Method to Evaluate Changes in Health Care Costs with Changes in Health Risks Among Employers of All Sizes
The objective of this study was to estimate the association between changes in health care expenditures relative to changes in health risk status for employers of all sizes. Repeat health risk assessments (HRAs) were obtained from 50,005 employees and spouses with 2 years of health plan enrollment, and from 37,559 employees and spouses with 3 years of enrollment in employer-sponsored medical coverage. Changes in health care expenditures were measured from the year before completion of the first HRA to the years before and after the completion of the second HRA. Propensity score weighting was used to adjust for those who did not repeat the HRA so results could be extrapolated to the larger population. Propensity score weighted multiple regression analyses were used to estimate the relationship between changes in health care expenditures with changes in risk status for 9 risk categories. Significantly higher health care expenditures were associated with those who moved from low risk to medium or high risk, compared to those who remained low risk. Expenditure reductions estimated for those who improved their health status from high risk to medium or low risk were not statistically significant. This study is unique because of its large sample size, its use of data from a wide range of employer sizes, and its efforts to extend generalizability to those who did not complete both HRAs. These results demonstrate that the potential for short-term health care savings may be greater for programs that help maintain low risk than for programs focused on risk reduction. (Population Health Management 2014;17:297?305)Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140183/1/pop.2013.0103.pd
Raman Spectroscopy of Liquid-Based Cervical Smear Samples as a Triage to Stratify Women Who Are HPV-Positive on Screening
Persistent high-risk human papillomavirus (HPV) infection can lead to cervical precancer and cancer. Recently, HPV testing has been introduced for primary cervical screening, but the HPV DNA test cannot distinguish between transient and persistent HPV infection. Thus, there is an unmet clinical need to develop a new test to identify women with a high-risk persistent HPV infection. Raman spectra were recorded from cervical smear samples (n = 60) and, on the basis of HPV DNA and HPV mRNA test results, a classifier was developed to identify persistent HPV infection. A further blinded independent test set (n = 14) was used to validate the model, and sensitivity of 90% and specificity of 100% were achieved. Improved triage would allow women with a high-risk persistent HPV infection to be referred for immediate treatment, while women with a low-risk transient infection could avoid overtreatment
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