The Use of Odors to Induce Avoidance Behavior in Pine Voles

Commercial orchards, ornamental nurseries, and residential horticulture in North Carolina experience economic losses due to pine vole (Microtus pinetorum) depredation. Predator odors and the herbicide Casoron were tested as potential repellents for pine voles. To test for avoidance behavior, animals were allowed to build a nest in one of two chambers attached to each arm of a Y-maze. The cage containing the nest was treated with either a test repellent compound, methylene chloride (solvent control), or left unmanipulated (control). Animals were categorized as either maintaining or changing nest cage preference between pre-test and test periods. The number of animals that changed cage preference in the control group was compared to the treatment groups. Only the Casoron treatments were significantly different, with approximately 50% of the animals changing preference. The difference in time spent in the nest cage during the pre-test and test periods for the treatment groups were compared to control groups. The Casoron and DTT treatments resulted in significant time differences. These results indicate that Casoron has repellent potential and warrants further investigation into its effectiveness in the field. The predator odors tested showed little promise as repellents

In Vivo Effects of Bisphenol A in Laboratory Rodent Studies

Concern is mounting regarding the human health and environmental effects of bisphenol A (BPA), a high-production-volume chemical used in synthesis of plastics. We have reviewed the growing literature on effects of low doses of BPA, below 50 mg/kg/day, in laboratory exposures with mammalian model organisms. Many, but not all, effects of BPA are similar to effects seen in response to the model estrogens diethylstilbestrol and ethinylestradiol. For most effects, the potency of BPA is approximately 10 to 1,000-fold less than that of diethylstilbestrol or ethinylestradiol. Based on our review of the literature, a consensus was reached regarding our level of confidence that particular outcomes occur in response to low-dose BPA exposure. We are confident that adult exposure to BPA affects the male reproductive tract, and that long-lasting, organizational effects in response to developmental exposure to BPA occur in the brain, the male reproductive system, and metabolic processes. We consider it likely, but requiring further confirmation, that adult exposure to BPA affects the brain, the female reproductive system, and the immune system, and that developmental effects occur in the female reproductive system

Isolation of bacterial extrachromosomal DNA from human dental plaque associated with periodontal disease,using transposonaided capture (TRACA)

The human oral cavity is host to a complex microbial community estimated to comprise > 700 bacterial species, of which at least half are thought to be not yet cultivable in vitro. To investigate the plasmids present in this community, we used a transposon-aided capture system, which allowed the isolation of plasmids from human oral supra- and subgingival plaque samples. Thirty-two novel plasmids and a circular molecule that could be an integrase-generated circular intermediate were isolated

A comparison of grass covers and meadow vole populations in North Carolina

Meadow vole (Microtus pennsylvanicus) populations were monitored in an experimental field for three years by mark and recapture in western North Carolina. The field was planted with 3 different species of grasses: Ky 31 fescue (Festuca arundinacea L.), blue grass (Poa protensis L.), and creeping red fescue {Festuca rubra L.). Voles were free to range from grass to grass due to adjacent plots in the design. Vole populations were highest in Ky 31 and blue grass, and lowest in creeping red fescue. Meadow voles strongly preferred Ky 31 fescue, a grass with high moisture content and a growth pattern compatible with nest construction

Lamarck Revisited: The Implications of Epigenetics for Environmental Law

For generations, a bedrock concept of biology was that genetic mutations are necessary to pass traits from one generation to the next, but new developments in genetics are challenging this fundamental assumption. A growing body of scientific evidence demonstrates that chemical alteration of the way a gene functions, whether through exposure to chemicals, foods or even traumatic experiences, may not only affect the exposed individual, but also the individual’s offspring for two generations or more. This interaction between genes and the environment, known as epigenetics, has revolutionized the understanding of how genes are expressed within an individual and how they affect that individual’s offspring. Epigenetics also presents novel challenges for chemical regulatory regimes in the United States and around the world. Chemical substances that do not cause mutations typically are not regulated based on their potential effects on future generations. They may be regulated based on their harms to living individuals, or perhaps to those exposed before birth, but until recently future generations were not thought to be at risk. We explore the implications of the new field of epigenetics for public and private regulation of toxics, and we suggest new legal strategies to reflect the new scientific understanding. We argue that new developments in public and private governance suggest optimism for the ability of the environmental regulatory regime to respond to new findings in the science of epigenetics

THE USE OF ODOR TO INDUCE AVOIDANCE BEHAVIOR IN PINE VOLES

Commercial orchards, ornamental nurseries, and residential horticulture in North Carolina experience economic losses due to pine vole (Microtus pinetorum) depredation. Predator odors and the herbicide Casoron were tested as potential repellents for pine voles. To test for avoidance behavior, animals were allowed to build a nest in one of two chambers attached to each arm of a Y-maze. The cage containing the nest was treated with either a test repellent compound, methylene chloride (solvent control), or left unmanipulated (control). Animals were categorized as either maintaining or changing nest cage preference between pre-test and test periods. The number of animals that changed cage preference in the control group was compared to the treatment groups. Only the Casoron treatments were significantly different, with approximately 50% of the animals changing preference. The difference in time spent in the nest cage during the pre-test and test periods for the treatment groups were compared to control groups. The Casoron and DTT treatments resulted in significant time differences. These results indicate that Casoron has repellent potential and warrants further investigation into its effectiveness in the field. The predator odors tested showed little promise as repellents

Developmental Exposure to Environmental Estrogens Alters Anxiety and Spatial Memory in Female Mice

Humans and wildlife are exposed to numerous anthropogenic drugs and pollutants. Many of these compounds are hormonally active, and recent evidence suggests that the presence of these endocrine disruptors permanently alters normal development and physiology in a variety of vertebrate species. Here, we report on the effects of developmental exposure to two common estrogenic pollutants, bisphenol A and ethinyl estradiol on sexually dimorphic, non-reproductive behavior. Mice (Mus musculus domesticus) were exposed to environmentally relevant levels of these chemicals (2 and 200 μg/kg/day for bisphenol A and 5 μg/kg/day for ethinyl estradiol) throughout prenatal and early postnatal development. As adults, the animals were observed in a variety of tests measuring sexually dimorphic behaviors including short-term spatial memory (in a radial-arm maze and a Barnes maze) and anxiety (in an elevated-plus maze and a light/dark preference chamber). Developmental exposure to ethinyl estradiol was found to masculinize behavior in all of the assays used. Bisphenol A increased anxious behavior in a dose-dependent fashion but had no effect on spatial memory. These results indicate that non-reproductive, sexually dimorphic behavior is sensitive to endocrine disruption. In addition, these experiments suggest that both humans and wildlife are being exposed to levels of these endocrine disrupting compounds that are sufficient to disrupt the development of the nervous system and that may have permanent consequences on sexually dimorphic behaviors