Life Sciences Commons^™

Effects Of Temperature And Ph On The Growth And Composition Of The Sporophyte And Gametophyte Generations Of Allomyces Arbusculus Butler (1911), Lawrence Wayne Lenz

Master's Theses

Pure cultures of the sporophyte and gametophyte generations of Allomyces arbusculus Butler (1911) were grown under varied conditions of temperature and pH. On solid media the gametophyte did not grow at 10 and 15 C; the sporophyte began slow growth after a long lag period at 15 C. There were no significant differences in growth between the sporophyte and gametophyte at 20 and 25 C. Increasing colony areas occurred for both generations at temperatures between 30 and 40 C, with the largest amount of growth for either generation at 35 C.

Colonies grown in broth media at various pH levels …

Changes In The (Na+ K+) - Dependent Atpase Activity In Gills Of The Euryhaline Teleost, Fundulus Heteroclitus, Upon Adaptation To Freshwater And Salt Water As Determined By Specific Activities And 3h - Ouabain Binding Sites, Mary Elizabeth Gilman

Master's Theses

Previous attempts to measure the (Na⁺+K⁺) - dependent ATPase in gills of euryhaline teleosts have yielded controversial results. In this study both the (Na⁺+K⁺) - dependent ATPase activity and the number of JH - ouabain binding sites, representing the number of ATPase molecules, were measured in gill tissue preparations of the killifish, Fundulus heteroclitus. The (Na⁺+K⁺) dependent ATPase activity and ouabain binding sites were greater in gills of fish fully adapted to freshwater than in those adapted to salinities of 17 ppt or 24 ppt. On the other …

Predicting Primary Productivity In Westhampton Lake, Richmond, Virginia., Gary Newton Moore

Master's Theses

Several predictive photosynthetic models were tested using light, temperature, nutrient, chlorophyll, and primary productivity data collected from Westhampton Lake, Richmond, Virginia from February-September, 1972. A simple linear model, the Kendall rank correlation coefficient, was used to relate photosynthesis to individual meteorological, physical, chemical, and biological factors. iii Of the parameters measured, only the daily maximum photosynthetic efficiency ((P/chl) max ) was significantly correlated with photosynthesis. Five multiple factor (non-linear) models were tested. In the best fitting model, primary productivity was a function of the maximum observed ratio of photosynthesis/chlorophyll concentration, light intensity, temperature, nutrient concentrations, and chlorophyll concentration. The Pearson …

The Nature Of Miniature Melanocytes In Murine Epidermis, John Thomas Earnhardt

Master's Theses

In the epidermis of PET/Wmr mice the population of melanocytes reaches a peak and begins to decline during the first postnatal week, and has disappeared within four weeks. During this period a small number of weakly DOPA reactive miniature melanocytes are seen dispersed among the generally large, highly DOPA reactive melano­cytes typical of the animal. These miniature melanocytes appear early, are among the last to disappear, and their population remains relatively constant against the drastically changing population of typical melanocytes. In attempts to determine the nature of the miniature melanocytes, heterologous grafting was employed whereby the melanocytes were subjected to …

Evidence For An Ambidirectional Magnesium-Activated, Sodium-Potassium Dependent Adenosine Triphosphatase, John Dale Hempel

Master's Theses

Controversy exists as to whether the Na-K ATPases of euryhaline fishes are the same enzyme.This study demonstrates that the phosphorylated enzyme from gills of Fundulus heteroclitus adapted to freshwater and salt water migrate to the same position in SDS polyacrylamide gels. Similar behavior of the enzyme from both sources in different ionic media is also shown. Additionally, the possible ability or the enzyme to couple an osmoregulatory influx to an excretory efflux in freshwater fish is demonstrated. The term "ambidirectional" is proposed for this enzyme, and its place in certain membrane models is discussed.

The Effects Of Ultraviolet Irradiation On The Pigment Cells Of The Pet/Wmr Mouse Epidermis, Vaughan Henry Howard Jr.

Master's Theses

Epidermal melanocytes in mammals are known to occur in a variety of shapes, sizes, and colors. The basic melanocyte morphology is dependent upon genetics, but there are a number of environmental factors that can cause modification.

In the epidermis of PET/\vrnr mice, the population of rnelanocytes reaches a peak and begins to decline during the first post-natal week, and has disappeared within four weeks. Dispersed among the large, highly DOPA-reactive melanocytes are miniature melanocytes. These miniature melanocytes are weakly DOPA-reactive and appear early in the post-natal period. The miniature melanocyte population is relatively constant and these miniature cells are among …