The plant Senecio jacobaea (tansy ragwort) produces several macrocyclic pyrrolizidine alkaloids which cause irreversible liver cirrhosis. All of the pyrrolizidine alkaloids in Senecio jacobaea are macrocyclic diesters of the necine base retronecine, with the two most predominant being seneciphylline and jacobine. Unlike horses and cattle, sheep and goats are generally...
Purpose of the Study
The purpose of the study was to determine whether there were
significant differences in students' career maturity as a result of
exposure to the concepts of career education. The study evaluated the
relative effectiveness of a developing comprehensive career education
project to help students attain increased...
The rapid decline of marine ecosystems worldwide and the failure of traditional single species management pushed for the development of ecosystem-based conservation measures such as marine protected areas (MPA) to slow the loss of marine biodiversity. One approach to MPA creation advocates targeting marine megafauna (e.g., marine mammals, seabirds, sharks,...
Growth of individual goosegrass (Eleusine indica (L) Gaertn.) plants of
three dinitroaniline-herbicide resistant (R) and three susceptible (S) biotypes from
North Carolina, South Carolina, and Mississippi was analyzed in greenhouse
experiments. Leaf area and biomass measurements, including root, shoot,
above-ground, and total dry weights were similar among the biotypes studied....
The positions of the DNase I hypersensitive sites within the
galactose gene cluster of the yeast Saccharomyces cerevisiaa have
been determined. When yeast nuclei were incubated with DNase I, the
purified DNA restriction endonuclease digested and analyzed by
Southern hybridization, five hypersensitive regions were observed in
this cluster of three...
Anthropogenic activities have posed many threats to the oceans and marine life. Understanding how individuals are affected and physiologically respond to these threats is crucial and allows for management and conservation applications. I evaluated the overall health condition of a subpopulation of gray whales (Eschrichtius robustus) along the Oregon coast,...
Litter nutrient dynamics contribute significantly to biogeochemical cycling in
forest ecosystems. These dynamics may be influenced by site attributes, litter nutrient concentrations, and soil nutrient availability either independently or synergistically. Litter nutrient dynamics were examined in two decomposition studies in temperate coniferous forests of Oregon. I used ¹⁵N-labelled litter of...
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Mark E. Harmon Steven S. Perakis
Litter nutrient dynamics contribute significantly to
Summer drought is a major factor limiting the regrowth of perennial ryegrass seed crops. This phase of crop development has a strong influence on seed yield because most of the tillers that contribute towards next season's seed crop are produced or regrown during this period. In recent years many seed...
Most marine fishes experience high rates of mortality during their early life history stages with far reaching consequences for adult population dynamics. Within a few weeks of hatching, relatively small changes in larval growth and mortality rates can lead to orders of magnitude variability in year-class strength. Growth and survival...
The major consideration of this study was the testing of the
superiority of the whole or part method for developing basic arc welding
skills. Data were also generated which facilitated investigation of:
(1) the relationship of welding skill development to cognitive attainment
of welding information as measured by welding proficiency...