Physical Sciences and Mathematics Commons^™

The Synthesis And Evaluation Of 5-Phenyloxazolidines As Potential Cardiovascular Drugs, Tammy C. Wang

Chemistry & Biochemistry Theses & Dissertations

Drugs such as adrenoceptor antagonists and certain centrally acting agents are known to lower blood pressure and thus serve as clinically useful antihypertensive agents. Norepinephrine 4, a natural ∝-adrenoceptor agonist, is the major agent associated with increased blood pressure in the periphery. Based on a careful structure-activity comparison, a series of substituted oxazolidines, 20, 21, 22 and 23, have been designed as possible antihypertensive candidates. Specifically, 22 and 23 have been synthesized to serve as potential norepinephrine antagonists.

Preliminary evaluation of these compounds indicated that they were not antihypertensive in nature. The more active compound, 23, …

Survival And Reproduction Of The Freshwater Grass Shrimp Palaemonetes Paludosus (Gibbes 1850) (Decapoda:Palaemonidae), In Saline Water, Brian Thomas Lowe

OES Theses and Dissertations

To determine the effects of salinity on adult and larval survival, egg deposition, egg hatching and metamorphosis, shrimp were held in the laboratory and exposed to treatment salinities ranging from O to 35 ppt. Tests on adult survival indicate a 96 hour LC-50 between 30 and 35 ppt. Longer term tests on adult survival showed high mortality in salinities greater than 15 ppt. Shrimp became ovigerous in salinities of O - 20 ppt with egg hatching and metamorphosis limited to O - 5 ppt. Starved- larvae hatched from field captured ovigerous females in O ppt were able to metamorphose in …

Callianassa Trilobata (Crustacea: Thalassinidea) Influences Abundance Of Meiofauna And Biomass, Composition, And Physiologic State Of Microbial Communities Within Its Burrow, Fred C. Dobbs, James B. Guckert

OES Faculty Publications

Biochemical and traditional methods were used to determine the influence of Callianassa trilobata on microbiological and meiofaunal communities within its large, highly consolidated burrow. Sediment was collected from the lining of the shrimp's burrow, the burrow matrix, and ambient, subsurface sediment. The lining and matrix were composed of poorly sorted, fine-grained material compared to sandy ambient sediment. Meiofauna, predominantly nematodes, were most abundant in ambient sediment, not in the burrow as has been found for other species of macrofauna. Concentrations of chlorophyll a were very high in the lining, consistent with the suggestion that C. trilobata lines its burrow walls …

Microbial Food Resources Of The Macrofaunal-Deposit Feeder Ptychodera Bahamensis (Hemichordata: Enteropneusta), Fred C. Dobbs, James B. Guckert

OES Faculty Publications

Biochemical and traditional analyses were used to characterize the microbial food resources and digestive efficiency of Ptychodera bahamensis, an enteropneust hemichordate. Sediment was collected from freshly extruded fecal casts and adjacent feeding depressions. There were no significant differences between casts and depressions in median grain size, percent silt-clay, density of total meiofauna and of nematodes, and concentrations of chlorophyll a and phaeophytin. Nematodes in casts had a median diameter greater than those in depressions. Measures of total, viable microbial biomass were 30% (total phospholipid, ester-linked fatty acids) and 49% (extractible phospholipid phosphate) lower in casts. Concentrations of 33 fatty …

Use Of 52Cr For The Quantitative Determination Of Red Cell Volume, Claude Michael Hanbury

Chemistry & Biochemistry Theses & Dissertations

Chromium-52 has recently been suggested for use as a new agent to label red cells for the in vivo quantitation of red cell volume (1). In this paper, the development and validation of a routine ⁵²cr labeling procedure is described.

The accuracy, precision, and detection limits of chromium analysis by Zeeman effect atomic absorption spectroscopy was evaluated in the concentration range of 1 - 10 ug Cr/L.

Red cell chromium uptake was evaluated as a function of time, temperature, and concentration. Red cells labeled with a 2.5 mg/L chromium solution for 30 minutes at room temperature exhibited optimal label …

Reactions Of Aqueous Chlorine In The Gastric Fluid Of The Rat, Michael Gary Nickelsen

Chemistry & Biochemistry Theses & Dissertations

Gastric fluid was recovered from Sprague-Dawley rats that had been fasted for 24 hr or 48 hr and administered 4 mL deionized water. The protein, carbohydrate and chloride ion content of the gastric fluid was determined.

When gastric fluid is chlorinated with radiolabeled chlorine to concentrations between 323 and 375 mg/L, analyzed by high performance chromatography followed by liquid scintillation counting, as much as 59% of the radiolabeled chlorine was associated with organic components of the gastric fluid.

Model studies with the aromatic amino acids and the protein pepsin showed the formation of chlorinated analogs. Two chlorinated amino acid derivatives …

The Effects Of Siltation On Recruitment Of Spiny Lobsters, Panulirus Argus, William F. Herrnkind, Mark J. Butler, Richard A. Tankersley

Biological Sciences Faculty Publications

Fewer juvenile pinry lobsters were found in areas of the Florida Keys where their primary habitat was heavily silted as compared with similar, less silted habitat. Several hypotheses explaining this relationship were tested, and the time-to-metamorphosis was compared for settling pueruli within silted and nonsilted algae stands. Limited postlarval settlement and avoidance of silted algal habitats by juveniles, probably accounts for the paucity of young lobsters in heavily silted sites. In addition, although juvenile lobsters are nonselective predators, lower prey availability in silted algae probably promotes transciency which, in turn, causes increased mortality by predation while juveniles are exposed.

Consequences Of Thymidine Catabolism For Estimates Of Bacterial Production: An Example From A Coastal Marine Sediment, Kevin R. Carman, Fred C. Dobbs, James B. Guckert

OES Faculty Publications

Radioactively labeled thymidine (TdR) has been used extensively to measure bacterial production in aquatic environments, but critical assumptions of the TdR technique often have gone untested. In this study of a coastal marine sediment, the metabolic fate of methyl [³H]TdR and methyl [¹⁴C]TdR was at variance with the assumptions necessary for determining bacterial production. Only 2% of incorporated radioactivity was recovered in the DNA fraction of TCA-insoluble material following time-course incubations of l-300 min. At least the methyl group of TdR was extensively catabolized, as shown by copious production of ¹⁴C0₂. The temporal …

Evaluation Of Possible Reproductively Mediated Character Displacement In The Crayfishes, Orconectes Rusticus And O. Sanbornii, Mark J. Butler Iv

Biological Sciences Faculty Publications

Orconectes rusticus is replacing several species of crayfishes in north-central and northeastern North America, including O. sanbornii in Ohio. Recent evidence suggests that the species replacements may be driven by asymmetrical reproductive success favoring O. rusticus. Nonetheless, some sympatric associations appear locally persistent. Because crayfish demonstrate size assortative mating and there is a disparity in the sizes of the species, further divergence in the sizes of the species in sympatry could enhance reproductive isolation, ultimately providing a mechanism for character displacement. To test this hypothesis the size differentials between crayfish collected from allopatric and sympatric populations in east-central Ohio …