2,500 research outputs found
Agreement between methods of measurement with multiple observations per individual
Limits of agreement provide a straightforward and intuitive approach to agreement between different methods for measuring the same quantity. When pairs of observations using the two methods are independent, i.e., on different subjects, the calculations are very simple and straightforward. Some authors collect repeated data, either as repeated pairs of measurements on the same subject, whose true value of the measured quantity may be changing, or more than one measurement by one or both methods of an unchanging underlying quantity. In this paper we describe methods for analysing such clustered observations, both when the underlying quantity is assumed to be changing and when it is not
Parental Anxiety Associated with Summer Camp Experiences: A Comparative Analysis Across Volunteer and Employee-Staffed Camps
Parent anxiety can limit a parent’s willingness to involve their child in out-of-school time experiences such as summer camps. Researchers have studied anxiety within the context of camp, but these studies used narrow frameworks of anxiety. In this exploratory study, we collected open-ended responses about causes of parent anxiety associated with summer camp experiences from 656 parents whose children attended one of two Extension-administered camps. The camps represented different camp staffing models—one primarily staffed by volunteers and the other primarily staffed by employees. The primary purpose of the study was to identify salient categories of anxiety and to examine if anxiety differed based on staffing model. The secondary purpose was to develop a camp-related parent anxiety measure informed by the anxiety categories. Eleven categories were constructed from the data, which both affirmed and expanded existing literature on parent anxiety associated with camp experiences. No differences in parent anxiety were found based on staffing model, suggesting that parents were no more likely to perceive anxiety associated with camp when the program was staffed with volunteers as they were when the program was staffed by employees. Implications for practice and future directions are examined
Retrospective Exposure Estimation and Predicted versus Observed Serum Perfluorooctanoic Acid Concentrations for Participants in the C8 Health Project
Background: People living or working in eastern Ohio and western West Virginia have been exposed to perfluorooctanoic acid (PFOA) released by DuPont Washington Works facilities
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Exposure information in environmental health research: Current opportunities and future directions for particulate matter, ozone, and toxic air pollutants
Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media monitoring, and/or personal exposure modeling. However, emerging research reveals that the greatest progress comes from integration among two or more of these efforts
Rate of Decline in Serum PFOA Concentrations after Granular Activated Carbon Filtration at Two Public Water Systems in Ohio and West Virginia
Drinking water in multiple water districts in the Mid-Ohio Valley has been contaminated with perfluorooctanoic acid (PFOA), which was released by a nearby DuPont chemical plant. Two highly contaminated water districts began granular activated carbon filtration in 2007.To determine the rate of decline in serum PFOA, and its corresponding half-life, during the first year after filtration.Up to six blood samples were collected from each of 200 participants from May 2007 until August 2008. The primary source of drinking water varied over time for some participants; our analyses were grouped according to water source at baseline in May-June 2007.For Lubeck Public Service District customers, the average decrease in serum PFOA concentrations between May-June 2007 and May-August 2008 was 32 ng/mL (26%) for those primarily consuming public water at home (n = 130), and 16 ng/mL (28%) for those primarily consuming bottled water at home (n = 17). For Little Hocking Water Association customers, the average decrease in serum PFOA concentrations between November-December 2007 and May-June 2008 was 39 ng/mL (11%) for consumers of public water (n = 39) and 28 ng/mL (20%) for consumers of bottled water (n = 11). The covariate-adjusted average rate of decrease in serum PFOA concentration after water filtration was 26% per year (95% confidence interval, 2528% per year).The observed data are consistent with first-order elimination and a median serum PFOA half-life of 2.3 years. Ongoing follow-up will lead to improved half-life estimation
Gaia: Establishing the world’s first climate Command and Control (C2) centre
Establishing Gaia, a Command-and-Control Centre focused on climate activity, based in Wales. It aims to apply command and control principles to the evolving map of climate data and explore how such data can be integrated with policy, and with other information: resources and vulnerabilities to influence behaviour change on a regional and national level
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