Assessing the risk from exposure to a chemical mixture in the environment can seem prohibitively challenging. Most components of the mixture are not readily identifiable, chemicals may interact to cause other-than-additive toxicity, and the number of potential combinations of environmental contaminants is enormous. These challenges can make it seem impossible...
Land use alters the physical and biological structure of stream ecosystems and potentially alters their capacity to process nitrogen (N), an essential nutrient that has nearly doubled in abundance on the biosphere
during the past century from human activities. In this dissertation, I quantified uptake and transformation of nitrate (NO₃⁻)...
Lymphomas and leukemias are the most common cancer in children and young adults and in utero exposure to carcinogens may contribute to the etiology of these cancers. A polycyclic aromatic hydrocarbon (PAH), dibenzo[a,l]pyrene (DBP), was administered to pregnant mice (15 mg/Kg b.w., gavage) on gestation day 17. Significant mortalities in...
Glutathione, a ubiquitous intracellular tripeptide, protects cells by reacting with electrophiles and radicals that can damage cellular macromolecules. However, glutathione conjugation is now recognized as one mechanism by which drugs and xenobiotics can also be converted to reactive intermediates having toxic consequences to cells. The halogenated alkane 1,2-dichloroethane forms S-(2-chloroethyl)...
A method of calculating the normal vibrations of polymer molecules
is presented in detail. The method is based on that used by
Schachtschneider and Snyder in their analysis of polypropylene but
has not heretofore been published. The factoring of the infinite matrix
and reduction to the coordinates of the unit...
Epiphytic diatom assemblages in the intertidal zone of Yaquina
Bay and estuary were obtained from the following host macrophytes:
Zostera marina, Fucus evanescens, and species of Enteromorpha,
Polysiphonia, and Ulva. Samples were collected in September 1970
and in January and May 1971 from seven stations approximately evenly
spaced between the...
The study of parent attitudes in Portland, Oregon, elementary
schools was designed to accomplish three purposes: (1) To identify
the attitudes of Non-Negro parents toward integration of Negroes into
the schools and community, (2) To measure the effects of socioeconomic
classes (low, middle, upper), of schools (control versus
transfer), and...
Symbiosis is the close and protracted interaction between organisms. The molecular interactions that occur during symbiosis are complex with multiple barriers that must be overcome. Many Gram-negative, host-associated bacteria use a type III secretion system to mediate associations with their eukaryotic hosts. This secretion system is a specialized apparatus for...
This dissertation draws on ethnographic data and political ecological theory to analyze the experience of residents living in the IBM-Endicott Superfund site in Endicott, New York. Combining in-depth narratives and quantitative measures from a household survey, it highlights residents' perceptions of 1) environmental health risk, 2) risk mitigation, 3) deindustrialization...