Most natural populations experience some density dependence, and longterm average rates of population growth are likely to be close to zero (i.e., steady state). An essential question, therefore, is how and to what extent do density-dependent effects influence the responses of populations to toxicant impacts? Here we consider three general types of interaction between density dependence and tox...

We present a dynamic energy budget (DEB) model for marine mammals, coupled with a pharmacokinetic model of a lipophilic persistent toxicant. Inputs to the model are energy availability and lipid-normalized toxicant concentration in the environment. The model predicts individual growth, reproduction, bioaccumulation, and transfer of energy and toxicant from mothers to their young. We estimated a...

The effects of toxicant metals on human health have been reported in peer-reviewed literature with increasing frequency. Toxicant metals are present in many diseases of aging, especially vascular diseases. Toxicant metals are a natural environmental phenomenon as well as a byproduct of industrialization. The historical experience of toxicologists who treated individuals poisoned by acutely toxi...

Epigenetic dysfunction is a known contributor in carcinogenesis, and is emerging as a mechanism involved in toxicant-induced malignant transformation for environmental carcinogens such as arsenicals or cadmium. In addition to aberrant DNA methylation of single genes, another manifestation of epigenetic dysfunction in cancer is agglomerative DNA methylation, which can participate in long-range e...

The within-field spatial distribution of beneficial arthropods was assessed using two-dimensional grids of pitfall traps and suction sampling across two winter wheat fields of 4 and 16 ha, before and after an application of dimethoate. An unsprayed 6 m wide buffer zone was left around half the edge of the larger field. Arthropod numbers fluctuated to varying extents prior to spraying. Two speci...

chromocolonoscopy using indigo carmine increases the detection of colorectal polyps remains controversial. Additional indigo carmine spraying during cap-assisted colonoscopy is expected to improve the detection rate of colon polyps, especially adenomatous polyps. Therefore, this study aimed to evaluate the usefulness of cap-assisted chromocolonoscopy in the proximal colon for routine colonoscop...