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Full-Text Articles in Life Sciences

Ecological Niche Of The 2003 West Nile Virus Epidemic In The Northern Great Plains Of The United States, Michael Wimberly, Michael B. Hildreth, Stephen P. Boyte, Erik Lindquist, Lon Kightlinger Dec 2008

Ecological Niche Of The 2003 West Nile Virus Epidemic In The Northern Great Plains Of The United States, Michael Wimberly, Michael B. Hildreth, Stephen P. Boyte, Erik Lindquist, Lon Kightlinger

Public Health Resources

Background: The incidence of West Nile virus (WNv) has remained high in the northern Great Plains compared to the rest of the United States. However, the reasons for the sustained high risk of WNv transmission in this region have not been determined. To assess the environmental drivers of WNv in the northern Great Plains, we analyzed the county-level spatial pattern of human cases during the 2003 epidemic across a seven-state region.
Methodology/Principal Findings: County-level data on WNv cases were examined using spatial cluster analysis, and were used to fit statistical models with weather, climate, and land use variables as predictors. …


Superfeminization As An Effect Of Bisphenol A In Marisa Cornuarietis & Response From Forbes Et Al. To Oehlmann Et Al., Jörg Oehlmann, Ulrike Schulte-Oehlmann, Jean Bachmann, Matthias Oetken, Ilka Lutz, Werner Kloas, Valery E. Forbes, John Aufderheide, Ryan Warbritton, Nelly Van Der Hoeven, Norbert Caspers Jan 2008

Superfeminization As An Effect Of Bisphenol A In Marisa Cornuarietis & Response From Forbes Et Al. To Oehlmann Et Al., Jörg Oehlmann, Ulrike Schulte-Oehlmann, Jean Bachmann, Matthias Oetken, Ilka Lutz, Werner Kloas, Valery E. Forbes, John Aufderheide, Ryan Warbritton, Nelly Van Der Hoeven, Norbert Caspers

Valery Forbes Publications

[Oehlmann et al.]: Recently, we had the opportunity to read two articles in volume 66 of Ecotoxicology and Environmental Safety. Forbes et al. (2007a, , 2007b) declare “to explore the reproducibility of prior work” showing that bisphenol A (BPA) induces superfeminization in the freshwater snail Marisa cornuarietis (Oehlmann et al., 2000, 2006; Schulte- Oehlmann et al., 2001). Based on the outcome of a toxicity test with the same species, the authors conclude that their results “do not support previous claims of enhanced reproduction in M. cornuarietis in response to exposure to BPA.” We take issue with the declaration of …


Plankton Stress Responses From Pah Exposure And Nutrient Enrichment, Morten Hjorth, Valery E. Forbes, Ingela Dahllöf Jan 2008

Plankton Stress Responses From Pah Exposure And Nutrient Enrichment, Morten Hjorth, Valery E. Forbes, Ingela Dahllöf

Valery Forbes Publications

The hypothesis that the nature and force of PAH stress responses from plankton systems are coupled to the nutrient status of that system was tested in a mesocosm experiment. Four treatments were applied consisting of control (Cn), pyrene exposed (Py). nutrient spiked (Nu), and nutrient spiked and pyrene exposed (NuPy) groups in replicate bags (n = 3) representing plankton communities including bacteria, phytoplankton and zooplankton. Regardless of nutrient status, all the Py mesocosms were affected directly with decreases in chlorophyll α concentrations to 20 % of control values on Day 1. Primary production was also significantly lower (< 50 %) than Cn communities in both Py and NuPy communities after the first pyrene exposure. Indirect effects were observed as increased bacterial activity due to nutrient release from algal death, thereby channelling growth to another trophic level. With time the plankton system became top-down controlled, dominated by zooplankton, which was also the trophic group experiencing the longest lasting effect on structure. The occurrence of late effects in the zooplankton communities were seen in all treatments, but the magnitude of the effects was dependent on the nutrient status, most probably because of a larger trophic transfer of the contaminant. To improve our understanding of contaminant effects on food webs in natural communities, it is imperative that interactions between trophic levels in relation to abiotic factors are investigated.


Life History And Population Dynamics Of The Opportunistic Polychaete Capitella Sp. I In Relation To Sediment Organic Matter, Tina Ramskov, Valery E. Forbes Jan 2008

Life History And Population Dynamics Of The Opportunistic Polychaete Capitella Sp. I In Relation To Sediment Organic Matter, Tina Ramskov, Valery E. Forbes

Valery Forbes Publications

Capitella sp. I is a deposit-feeding polychaete that occurs in estuarine and marine environments and that shows boom-bust population dynamics in response to organic pollution. A lifecycle experiment was carried out to quantify the relative importance of individual life-history traits for driving the dynamics of Capitella sp. I populations in response to changes in sediment organic matter concentrations. Individual-level effects were estimated as changes in survival, reproductive characteristics, and growth. Effects at the population-level were assessed by integrating the measured life-history traits in a simple 2-stage demographic model that was used to estimate the population growth rate (λ). Low organic …


Mixture Toxicity Of Three Toxicants With Similar And Dissimilar Modes Of Action To Daphnia Magna, Kristian Syberg, Anders Elleby, Henrik Pedersen, Nina Cedergreen, Valery E. Forbes Jan 2008

Mixture Toxicity Of Three Toxicants With Similar And Dissimilar Modes Of Action To Daphnia Magna, Kristian Syberg, Anders Elleby, Henrik Pedersen, Nina Cedergreen, Valery E. Forbes

Valery Forbes Publications

Mixture toxicity of similar- and dissimilar-acting toxicants can be predicted by the models concentration addition (CA) and independent action (IA) using single substance toxicity data. Knowledge of the toxicants mode of action is thus required in order to use the models. In order to test the predictive capability of the models, we conducted Daphnia magna 48 h immobilization experiments with three toxicants with known modes of action (dimethoate, pirimicarb and linear alkyl benzene sulfonate) singly, and in binary and ternary mixtures. Our results indicate that CA and IA predict binary mixtures of similar- and dissimilar-acting toxicants equally well. CA and …