2,055 research outputs found
Establishing National Ocean Service Priorities for Estuarine, Coastal, and Ocean Modeling: Capabilities, Gaps, and Preliminary Prioritization Factors
This report was developed to help establish National Ocean Service priorities and chart new directions for research and development of models for estuarine, coastal and ocean ecosystems based on user-driven requirements and supportive of sound coastal management, stewardship, and an ecosystem approach to management. (PDF contains 63 pages
Categorisation of continuous risk factors in epidemiological publications: a survey of current practice
BACKGROUND: Reports of observational epidemiological studies often categorise (group) continuous risk factor (exposure) variables. However, there has been little systematic assessment of how categorisation is practiced or reported in the literature and no extended guidelines for the practice have been identified. Thus, we assessed the nature of such practice in the epidemiological literature. Two months (December 2007 and January 2008) of five epidemiological and five general medical journals were reviewed. All articles that examined the relationship between continuous risk factors and health outcomes were surveyed using a standard proforma, with the focus on the primary risk factor. Using the survey results we provide illustrative examples and, combined with ideas from the broader literature and from experience, we offer guidelines for good practice. RESULTS: Of the 254 articles reviewed, 58 were included in our survey. Categorisation occurred in 50 (86%) of them. Of those, 42% also analysed the variable continuously and 24% considered alternative groupings. Most (78%) used 3 to 5 groups. No articles relied solely on dichotomisation, although it did feature prominently in 3 articles. The choice of group boundaries varied: 34% used quantiles, 18% equally spaced categories, 12% external criteria, 34% other approaches and 2% did not describe the approach used. Categorical risk estimates were most commonly (66%) presented as pairwise comparisons to a reference group, usually the highest or lowest (79%). Reporting of categorical analysis was mostly in tables; only 20% in figures. CONCLUSIONS: Categorical analyses of continuous risk factors are common. Accordingly, we provide recommendations for good practice. Key issues include pre-defining appropriate choice of groupings and analysis strategies, clear presentation of grouped findings in tables and figures, and drawing valid conclusions from categorical analyses, avoiding injudicious use of multiple alternative analyses
Considerations for partnering with Ryan White Case Managers to create equitable opportunities for people with HIV to participate in research
Many research studies focus on recruitment from one or few HIV clinics or internet-engaged populations, but this may result in inequitable representation of people with HIV (PWH), across the rural/urban/suburban continuum. Ryan White Case Managers (RWCM) meet regularly with PWH, potentially positioning them as partners in gathering research-related data from diverse groups of low-income, marginalized, PWH. Yet, data collection in partnership with RWCM, particularly over large geographic areas, has been under-explored. We partnered with RWCM and their organizations throughout Florida to administer a 10-item technology use and willingness survey to clients living with HIV; RWCMs provided process-oriented feedback. Among 382 approached RWCM, 71% completed human subjects and survey administration training; 48% gathered data on 10 predetermined survey administration days; and 68% administered at least one survey during the entire period for survey administration. Altogether, 1,268 client surveys were completed, 2.7% by rural participants. Stigma, privacy concerns, and disinterest reportedly inhibited client participation; competing obligations, policies, and narrow recruitment windows prevented some RWCM from offering the survey to clients. Research should further explore strategies and best practices to ensure equitable access to participate in research among PWH
Look Who\u27s Talking: Differences in Rates of Interruptions and Proportion of Time Used by Male and Female U.S. Courts of Appeals Judges
During oral arguments, attorneys are given the chance to elaborate on their written briefs and answer questions from the judges deciding the case. Studying oral arguments can be a window into the power dynamics between judges and attorneys, and can shed light onto how factors like gender may affect judicial decision-making. While a growing body of research has examined gender dynamics in oral arguments in the United States Supreme Court, no existing studies have examined whether these findings hold up in the U.S. Court of Appeals, the second highest courts in the country. We collected data on two years of oral arguments from the 4th Circuit in order to test theories about gender and speech patterns, including interruptions and verbosity
Bayesian Hierarchical Factor Regression Models to Infer Cause of Death From Verbal Autopsy Data
In low-resource settings where vital registration of death is not routine it
is often of critical interest to determine and study the cause of death (COD)
for individuals and the cause-specific mortality fraction (CSMF) for
populations. Post-mortem autopsies, considered the gold standard for COD
assignment, are often difficult or impossible to implement due to deaths
occurring outside the hospital, expense, and/or cultural norms. For this
reason, Verbal Autopsies (VAs) are commonly conducted, consisting of a
questionnaire administered to next of kin recording demographic information,
known medical conditions, symptoms, and other factors for the decedent. This
article proposes a novel class of hierarchical factor regression models that
avoid restrictive assumptions of standard methods, allow both the mean and
covariance to vary with COD category, and can include covariate information on
the decedent, region, or events surrounding death. Taking a Bayesian approach
to inference, this work develops an MCMC algorithm and validates the FActor
Regression for Verbal Autopsy (FARVA) model in simulation experiments. An
application of FARVA to real VA data shows improved goodness-of-fit and better
predictive performance in inferring COD and CSMF over competing methods. Code
and a user manual are made available at https://github.com/kelrenmor/farva
ASPIRE-2-PREVENT: a survey of lifestyle, risk factor management and cardioprotective medication in patients with coronary heart disease and people at high risk of developing cardiovascular disease in the UK.
OBJECTIVE: To determine in patients with coronary heart disease (CHD) and people at high risk of developing cardiovascular disease (CVD) whether the Joint British Societies' guidelines on CVD prevention (JBS2) are followed in everyday clinical practice. DESIGN: A cross-sectional survey was undertaken of medical records and patient interviews and examinations at least 6 months after the recruiting event or diagnosis using standardised instruments and a central laboratory for measurement of lipids and glucose. SETTINGS: The ASPIRE-2-PREVENT survey was undertaken in 19 randomly selected hospitals and 19 randomly selected general practices in 12 geographical regions in England, Northern Ireland, Wales and Scotland. PATIENTS: In hospitals, 1474 consecutive patients with CHD were identified and 676 (25.6% women) were interviewed. In general practice, 943 people at high CVD risk were identified and 446 (46.5% women) were interviewed. RESULTS: The prevalence of risk factors in patients with CHD and high-risk individuals was, respectively: smoking 14.1%, 13.3%; obesity 38%, 50.2%; not reaching physical activity target 83.3%, 85.4%; blood pressure ≥130/80 mm Hg (patients with CHD and self-reported diabetes) or ≥140/85 mm Hg (high-risk individuals) 46.9%, 51.3%; total cholesterol ≥4 mmol/l 52.6%, 78.7%; and diabetes 17.8%, 43.8%. CONCLUSIONS: The potential among patients with CHD and individuals at high risk of developing CVD in the UK to achieve the JBS2 lifestyle and risk factor targets is considerable. CVD prevention needs a comprehensive multidisciplinary approach, addressing all aspects of lifestyle and risk factor management. The challenge is to engage and motivate cardiologists, physicians and other health professionals to routinely practice high quality preventive cardiology in a healthcare system which must invest in prevention
CRTFASTGEEPWR: A SAS Macro for Power of Generalized Estimating Equations Analysis of Multi-Period Cluster Randomized Trials with Application to Stepped Wedge Designs
Multi-period cluster randomized trials (CRTs) are increasingly used for the evaluation of interventions delivered at the group level. While generalized estimating equations (GEE) are commonly used to provide population-averaged inference in CRTs, there is a gap of general methods and statistical software tools for power calculation based on multi-parameter, within-cluster correlation structures suitable for multi-period CRTs that can accommodate both complete and incomplete designs. A computationally fast, nonsimulation procedure for determining statistical power is described for the GEE analysis of complete and incomplete multi-period cluster randomized trials. The procedure is implemented via a SAS macro, CRTFASTGEEPWR, which is applicable to binary, count and continuous responses and several correlation structures in multi-period CRTs. The SAS macro is illustrated in the power calculation of two complete and two incomplete stepped wedge cluster randomized trial scenarios under different specifications of marginal mean model and within-cluster correlation structure. The proposed GEE power method is quite general as demonstrated in the SAS macro with numerous input options. The power procedure and macro can also be used in the planning of parallel and crossover CRTs in addition to cross-sectional and closed cohort stepped wedge trials
Understanding Technology Fit Among People with HIV Based on Intersections of Race, Sex, and Sexual Behavior: An Equitable Approach to Analyzing Differences Across Multiple Social Identities
HIV disproportionately impacts individuals based on intersecting categories (e.g. gender, race/ethnicity, behavior), with groups most at-risk deemed priority populations. Using weighted effects coding to account for differential group sizes, this study used multilevel mixed logistic models to investigate differences in eHealth use and willingness to use eHealth for HIVrelated information among priority populations. Compared to the sample average, Black men who had sex with women were less likely to use all technologies except cellphones with text-messaging and less likely to be willing to use computers and tablets. White and Hispanic men who had sex with men were more likely to use all technologies. No significant differences existed for use or willingness to use cellphones with text-messaging. Future research should consider approaches used here to account for equity and multiple intersecting social identities; practitioners may use these findings or similar local data to ensure fit between eHealth programs and priority populations
Dynamics of cadmium acclimation in Daphnia pulex:linking fitness costs, cross-tolerance, and hyper-induction of metallothionein
Acclimation increases tolerance to stress in individuals but is assumed to contribute fitness costs when the stressor is absent, though data supporting this widely held claim are sparse. Therefore, using clonal (i.e., genetically identical) cultures of Daphnia pulex, we isolated the contributions of acclimation to the regulation of the metal response gene, metallothionein 1 (MT1), and defined the reproductive benefits and costs of cadmium (Cd)-acclimation. Daphnia pulex were exposed for 50 parthenogenetic generations to environmentally realistic levels (1 μg Cd/L), and tolerance to Cd and other metals assessed during this period via standard toxicity tests. These tests revealed (1) increased tolerance to Cd compared to genetically identical nonacclimated cultures, (2) fitness costs in Cd-acclimated Daphnia when Cd was removed, and (3) cross-tolerance of Cd-acclimated Daphnia to zinc and silver, but not arsenic, thereby defining a functional role for metallothionein. Indeed, Cd-acclimated clones had significantly higher expression of MT1 mRNA than nonacclimated clones, when Cd exposed. Both the enhanced induction of MT1 and tolerant phenotype were rapidly lost when Cd was removed (1–2 generations), which is further evidence of acclimation costs. These findings provide evidence for the widely held view that acclimation is costly and are important for investigating evolutionary principles of genetic assimilation and the survival mechanisms of natural populations that face changing environments
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