292 research outputs found
The Demographic and Socioeconomic Factors Predictive for Populations at High-Risk for La Crosse Virus Infection in West Virginia
Although a large body of literature exists for the environmental risk factors for La Crosse virus (LACV) transmission, the demographic and socioeconomic risk factors for developing LACV infection have not been investigated. Therefore, this study investigated the demographic and socioeconomic risk factors for LACV infection in West Virginia from 2003 to 2007, using two forward stepwise discriminant analyses. The discriminant analyses were used to evaluate a number of demographic and socioeconomic factors for their ability to predict: 1) those census tracts with at least one reported case of LACV infection versus those census tracts with no reported cases of LACV infection and 2) to evaluate significantly high-risk clusters for LACV infection versus significantly low-risk clusters for LACV infection. In the first model, a high school education diploma or a general education diploma or less and a lower housing densit
Assessing Risk in Focal Arboviral Infections: Are We Missing the Big or Little Picture?
Focal arboviral infections affecting a subset of the overall population present an often overlooked set of challenges in the assessment and reporting of risk and the detection of spatial patterns. Our objective was to assess the variation in risk when using different at-risk populations and geographic scales for the calculation of incidence risk and the detection of geographic hot-spots of infection. We explored these variations using a pediatric arbovirus, La Crosse virus (LACV), as our model.Descriptive and cluster analyses were performed on probable and confirmed cases of LACV infections reported to the Tennessee Department of Health from 1997 to 2006, using three at-risk populations (the total population, the population 18 years and younger, and the population 15 years and younger) and at two geographic levels (county and census tract) to assess the variation in incidence risk and to investigate evidence of clustering using both global and local spatial statistics. We determined that the most appropriate at-risk population to calculate incidence risk and to assess the evidence of clustering was the population 15 years and younger. Based on our findings, the most appropriate geographical level to conduct spatial analyses and report incidence risk is the census tract level. The incidence risk in the population 15 years and younger at the county level ranged from 0 to 226.5 per 100,000 persons (median 41.5) in those counties reporting cases (n = 14) and at the census tract level it ranged from 50.9 to 673.9 per 100,000 persons (median 126.7) in those census tracts reporting cases (n = 51). To our knowledge, this is the highest reported incidence risk for this population at the county level for Tennessee and at the census tract level nationally.The results of this study indicate the possibility of missing disease clusters resulting from performing incidence risk investigations of focal diseases using inappropriate at-risk populations and/or at large geographic scales. Improved disease surveillance and health planning will result through the use of well defined at-risk populations and the use of appropriate geographic scales for the analysis and reporting of diseases. The finding of a high incidence risk of LACV infections in eastern Tennessee demonstrates that the vast majority of these infections continue to be under-diagnosed and/or underreported in this region. Persistent prevention and surveillance efforts will be required to reduce exposure to infectious vectors and to detect new cases of infection in this region. Application of this study's observations in future investigations will enhance the quantification of incidence risk and the identification of high-risk groups within the population
Metrics to evaluate research performance in academic institutions: A critique of ERA 2010 as applied in forestry and the indirect H2 index as a possible alternative
Excellence for Research in Australia (ERA) is an attempt by the Australian
Research Council to rate Australian universities on a 5-point scale within 180
Fields of Research using metrics and peer evaluation by an evaluation
committee. Some of the bibliometric data contributing to this ranking suffer
statistical issues associated with skewed distributions. Other data are
standardised year-by-year, placing undue emphasis on the most recent
publications which may not yet have reliable citation patterns. The
bibliometric data offered to the evaluation committees is extensive, but lacks
effective syntheses such as the h-index and its variants. The indirect H2 index
is objective, can be computed automatically and efficiently, is resistant to
manipulation, and a good indicator of impact to assist the ERA evaluation
committees and to similar evaluations internationally.Comment: 19 pages, 6 figures, 7 tables, appendice
A standardized framework for the validation and verification of clinical molecular genetic tests
The validation and verification of laboratory methods and procedures before their use in clinical testing is essential for providing a safe and useful service to clinicians and patients. This paper outlines the principles of validation and verification in the context of clinical human molecular genetic testing. We describe implementation processes, types of tests and their key validation components, and suggest some relevant statistical approaches that can be used by individual laboratories to ensure that tests are conducted to defined standards
Thermal Adaptation and Diversity in Tropical Ecosystems: Evidence from Cicadas (Hemiptera, Cicadidae)
The latitudinal gradient in species diversity is a central problem in ecology. Expeditions covering approximately 16°54′ of longitude and 21°4′ of latitude and eight Argentine phytogeographic regions provided thermal adaptation data for 64 species of cicadas. We test whether species diversity relates to the diversity of thermal environments within a habitat. There are general patterns of the thermal response values decreasing in cooler floristic provinces and decreasing maximum potential temperature within a habitat except in tropical forest ecosystems. Vertical stratification of the plant communities leads to stratification in species using specific layers of the habitat. There is a decrease in thermal tolerances in species from the understory communities in comparison to middle level or canopy fauna. The understory Herrera umbraphila Sanborn & Heath is the first diurnally active cicada identified as a thermoconforming species. The body temperature for activity in H. umbraphila is less than and significantly different from active body temperatures of all other studied species regardless of habitat affiliation. These data suggest that variability in thermal niches within the heterogeneous plant community of the tropical forest environments permits species diversification as species adapt their physiology to function more efficiently at temperatures different from their potential competitors
Direct Measurement of Perchlorate Exposure Biomarkers in a Highly Exposed Population: A Pilot Study
Exposure to perchlorate is ubiquitous in the United States and has been found to
be widespread in food and drinking water. People living in the lower Colorado
River region may have perchlorate exposure because of perchlorate in ground
water and locally-grown produce. Relatively high doses of perchlorate can
inhibit iodine uptake and impair thyroid function, and thus could impair
neurological development in utero. We examined human exposures to perchlorate in
the Imperial Valley among individuals consuming locally grown produce and
compared perchlorate exposure doses to state and federal reference doses. We
collected 24-hour urine specimen from a convenience sample of 31 individuals and
measured urinary excretion rates of perchlorate, thiocyanate, nitrate, and
iodide. In addition, drinking water and local produce were also sampled for
perchlorate. All but two of the water samples tested negative for perchlorate.
Perchlorate levels in 79 produce samples ranged from non-detect to 1816 ppb.
Estimated perchlorate doses ranged from 0.02 to 0.51 µg/kg of body
weight/day. Perchlorate dose increased with the number of servings of dairy
products consumed and with estimated perchlorate levels in produce consumed. The
geometric mean perchlorate dose was 70% higher than for the NHANES
reference population. Our sample of 31 Imperial Valley residents had higher
perchlorate dose levels compared with national reference ranges. Although none
of our exposure estimates exceeded the U. S. EPA reference dose, three
participants exceeded the acceptable daily dose as defined by bench mark dose
methods used by the California Office of Environmental Health Hazard
Assessment
Incidence, clinical spectrum, risk factors and impact of HIV-associated immune reconstitution inflammatory syndrome in South Africa.
Immune reconstitution inflammatory syndrome (IRIS) is a widely recognised complication of antiretroviral therapy (ART), but there are still limited data from resource-limited settings. Our objective was to characterize the incidence, clinical spectrum, risk factors and contribution to mortality of IRIS in two urban ART clinics in South Africa
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