33 research outputs found

    Anaplasma phagocytophilum in White-tailed Deer

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    We examined the reservoir potential of white-tailed deer for Anaplasma phagocytophilum. Results suggest that white-tailed deer harbor a variant strain not associated with human infection, but contrary to published reports, white-tailed deer are not a reservoir for strains that cause human disease. These results will affect surveillance studies of vector and reservoir populations

    St. Marks amphibian metacommunity encounter histories (2009-2014)

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    Amphibian metacommunity encounter histories, collected on St. Marks National Wildlife Refuge, 2009 to 2014. Fall and spring sampling occasions occurred each year during the months of September-October and March-April, respectively. Species codes are as follows: ATAL, Mole salamander (Ambystoma talpoideum); PORN, Ornate chorus frog (Pseudacris ornata); RGRY, Pig frog (Rana grylio); FISH, all fish species detected (see manuscript for further details)

    Data from: Species interactions and the effects of climate variability on a wetland amphibian metacommunity

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    Disentangling the role that multiple interacting factors have on species responses to shifting climate poses a significant challenge. However, our ability to do so is of utmost importance to predict the effects of climate change on species distributions. We examined how populations of three species of wetland breeding amphibians, which varied in life history requirements, responded to a six-year period of extremely variable in precipitation. This interval was punctuated by both extensive drought and heavy precipitation and flooding, providing a natural experiment to measure community responses to environmental perturbations. We estimated occurrence dynamics using a discrete hidden Markov modeling approach that incorporated information regarding habitat state and predator-prey interactions. This approach allowed us to measure how metapopulation dynamics of each amphibian species was affected by interactions among weather, wetland hydroperiod, and co-occurrence with fish predators. The pig frog, a generalist, proved most resistant to perturbations, with both colonization and persistence being unaffected by seasonal variation in precipitation or co-occurrence with fishes. The ornate chorus frog, an ephemeral wetland specialist, responded positively to periods of drought owing to increased persistence and colonization rates during periods of low-rainfall. Low probabilities of occurrence of the ornate chorus frog in long-duration wetlands were driven by interactions with predators due to low colonization rates when fishes were present. The mole salamander was most sensitive to shifts in water availability. In our study area, this species never occurred in short-duration wetlands and persistence probabilities decreased during periods of drought. At the same time, negative effects occurred with extreme precipitation because flooding facilitated colonization of fishes to isolated wetlands and mole salamanders did not colonize wetlands once fishes were present. We demonstrate that the effects of changes in water availability depend on interactions with predators and wetland type and are influenced by the life history of each of our species. The dynamic species occurrence modeling approach we used offers promise for other systems when the goal is to disentangle the complex interactions that determine species responses to environmental variability

    Middle school food environments and racial/ethnic differences in sugar-sweetened beverage consumption: findings from the Healthy Choices study

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    BACKGROUND: Prior studies have demonstrated disproportionate clustering of fast food outlets around schools. PURPOSE: The purpose of this study is to determine if racial/ethnic differences in middle school student self-reported sugar-sweetened beverage (SSB) consumption is explained by differential distributions of food outlets surrounding their schools. METHODS: Baseline (2005) data were analyzed from 18,281 middle school students in 47 Massachusetts schools participating in Healthy Choices, an obesity prevention program. Linear mixed effects models were used to examine the association of individual race/ethnicity and daily SSB consumption and the potential mediating effect of the density of food outlets (the number of fast food outlets and convenience stores in a 1500 m buffer area surrounding the school) on this association adjusting for individual and school demographics. RESULTS: More SSB consumption was reported by students of all racial/ethnic minority groups compared to their White peers except Asians. The density of fast food restaurants and convenience stores was not associated with individual SSB consumption (beta=0.001, p=0.875) nor did it mediate the association of race/ethnicity and SSB consumption. CONCLUSIONS: Racial and ethnic differences in SSB consumption among MA middle school students cannot be fully explained by the location of fast food restaurants and convenience stores

    The contribution of school environmental factors to individual and school variation in disordered weight control behaviors in a statewide sample of middle schools

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    We investigated the contribution of school environmental factors to individual and school variation in disordered weight control behaviors (DWCB). Analyses were based on self-report data gathered from 18,567 middle-school students in 2005 and publicly available data on school characteristics. We observed large differences across schools in percent of students engaging in DWCB in the past month, ranging from less than 1% of the student body to 12%. School-neighborhood poverty was associated with higher odds of DWCB in boys. Preventive strategies need to account for wide variability across schools and environmental factors that may contribute to DWCB in early adolescence
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