In the past decade, declines in amphibian populations have captured scientific and popular interest. The causes of the declines are likely to be complex and involve interactions between several environmental stressors. Using multifactorial experiments, I investigated the combined effects of several anthropogenic stressors on developing amphibians in Oregon, USA. In...
A survey of the major bodies of water, temporary and perennial,
in the region of Northern Utah revealed a limited distribution of
the Notostraca. Lepidurus (Linn.), the only representative
found, was restricted to a single temporary shallow lake. Dry Lake,
in the southern end of Cache County.
Dry Lake occupies...
Ultraviolet-B radiation (UVB) is an abiotic stressor in both terrestrial and aquatic systems. The stratospheric ozone layer, depleted due to anthropogenic activities and the cause of elevated UVB at earth's surface over the last four decades, is predicted to recover by 2065. However, UVB levels in aquatic systems may continue...
Current evidence suggests that temporal regulation of gene
expression in eucaryotic organisms relies primarily upon localized
structural modifications of chromatin. One possible means of
changing chromatin structure is through varying the level of
acetylation of the histone proteins. Sodium butyrate has been found
to inhibit the activity of histone deacetylase...
Predator-prey interactions have historically been studied to explain patterns of organization observed in populations and communities. They have also been important in understanding the evolution of antipredator responses in prey and counterstrategies in predators. Despite the breadth of knowledge that exists for heterospecific interactions, relatively few studies have investigated the...
The diverse community of bacteria living within and on host organisms, known as the microbiome, has an important role in maintaining host health. Dysbiosis, known as a change in the healthy community of the microbiome, has been associated with a number of diseases across host organisms and body sites including...
The earth is undergoing a “biodiversity crisis” characterized by loss of populations, species, genetic diversity, and ecosystem services. Part of this crisis consists of population declines, extinctions, and increased incidence of deformities in amphibians. It is unknown whether deformities contribute to these declines. Many cases of population declines in amphibians...
In recent years, studies dealing with temperature regulation,
temperature sensitivity, and physiological responses to temperature
in lizards and other reptiles have increased tremendously. It is
notable that snakes have been largely ignored in such studies. This
no doubt is due to their less direct relationship to ancestral endotherms.
However, problems...
Glutamine synthetase in the embryonic chick neural retina
shows a 50 fold increase in activity between the 16th and 17th day of
embryonic development. This increase in enzyme activity results
from de novo enzyme synthesis thus making it a useful marker of
differential gene expression. A precocious rise in activity...