Jeremy A. Leonard

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Many hospital and residential chemical dependency treatment facilities utilize Alcoholics Anonymous (AA) and Narcotics Anonymous (NA) principles and practices in therapeutic programming. Although well-known and broadly endorsed and supported, such AA/NA approaches have received little research attention especially in regard to chemically dependent(More)
Driven by major scientific advances in analytical methods, biomonitoring, computation, and a newly articulated vision for a greater impact in public health, the field of exposure science is undergoing a rapid transition from a field of observation to a field of prediction. Deployment of an organizational and predictive framework for exposure science(More)
Odor and greenhouse gas (GHG) emissions from stored pig (Sus scrofa) manure were monitored for response to changes in the crude protein level (168 or 139 g kg(-1), as-fed basis) and nonstarch polysaccharide (NSP) content [i.e., control, or modified with beet pulp (Beta vulgaris L.), cornstarch, or xylanase] of diets fed to pigs in a production setting. Each(More)
Zooplankton can influence the phytoplankton community through preferential grazing. In turn, nuisance cyanobacteria may affect zooplankton community structure by allowing certain species to out-compete others. We examined zooplankton-phytoplankton interactions, micro-zooplankton (< 200 μm) grazing, and biochemical components of the seston in the St. Johns(More)
The endocrine disrupting effects of estrogenic compounds in surface waters on fish, such as feminization of males and altered sex ratios, may also occur in aquatic invertebrates. However, the underlying mechanisms of action and toxicity, especially in native freshwater mussels (Order Unionoida), remain undefined. This study evaluated the effects of a 12-day(More)
Developing physiologically-based pharmacokinetic (PBPK) models for chemicals can be resource-intensive, as neither chemical-specific parameters nor in vivo pharmacokinetic data are easily available for model construction. Previously developed, well-parameterized, and thoroughly-vetted models can be a great resource for the construction of models pertaining(More)
Androgen-induced masculinization of female aquatic biota poses concerns for natural population stability. This research evaluated the effects of a twelve day exposure of fadrozole hydrochloride on the metabolism and reproductive status of the unionid mussel Lampsilis fasciola. Although this compound is not considered to be widespread in the aquatic(More)
The Clinch River in Virginia and Tennessee, USA, is well known for its diverse native freshwater mussel assemblages; however, notable declines in mussel populations in recent decades have prompted much concern and subsequent research. The authors examined the toxicity of recently deposited sediments on juveniles of the freshwater mussel Epioblasma brevidens(More)
The toxicity-testing paradigm has evolved to include high-throughput (HT) methods for addressing the increasing need to screen hundreds to thousands of chemicals rapidly. Approaches that involve in vitro screening assays, in silico predictions of exposure concentrations, and pharmacokinetic (PK) characteristics provide the foundation for HT risk(More)