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Theses/Dissertations

1972

Articles 241 - 255 of 255

Full-Text Articles in Physical Sciences and Mathematics

Food Selectivity Of The Black Bullhead (Ictalurus Melas, Rafinesque) In Lake Poinsett, South Dakota, Andrew J. Repsys Jan 1972

Effects Of Polychlorinated Biphhenyls In The Ring-Necked Pheasant, Robert Bernard Dahlgren Jan 1972

Effects Of Polychlorinated Biphhenyls In The Ring-Necked Pheasant, Robert Bernard Dahlgren

Electronic Theses and Dissertations

In 1970 and 1971, cock pheasants (Phasianus colchicus) were given single capsules weekly containing 0 and 25 mg polychlorinated biphenyls (PCB), Aroclor 1254, and hens were given O, 12.5, and 50 mg. Egg production was reduced (P<0.01) in the hens given 50 mg PCB both years. Fertility, determined by visual inspection of incubated eggs, was unaffected by PCB. Hatchability was lowest in the group of hens given 50 mg in both years but significantly lower (P<0.01) only in 1971. PCB adversely affected the viability of the embryo both years, as the number of eggs pipped but not hatched in PCB groups was higher (P<0.05). PCB did not affect eggshell thickness. Behavior on the visual cliff shortly after hatching was affected among offspring of hens given 50 mg PCB in 1970 (P,0.01). Offspring of hens given 50 mg chose the visually-deep side of the cliff. No differences in behavior on the visual cliff were evident in 1971. Response to hand catching of offspring was affected in 1970 (P <0.01). The ability of penned pheasants to avoid hand capture was least where both parents received PCB, followed by those where hens only, cocks only and neither parent received PCB. No differences in response to hand capture among groups were found in 1971. Weights of chicks from hens on 50 mg were lower (P<0.01) at 6 weeks of age in 1970. This effect was not seen in 1971. Survival of chicks in brooders to 6 weeks of age was lower (P<0.01) in offspring of hens given 50 mg PCB weekly in 1970. No differences were found among offspring of treatment groups in 1971. Survival from 6 weeks of age to fall was similar in all groups. Overall survival from hatching to fall was less (P<.0.05) in offspring of hens given 50 mg weekly in both years combined. No differential effect was found between sexes for survival. PCB in doses varying front 10 mg to 210 mg daily caused hyper-excitability, weakness, tremoring, lack of appetite, lack of feathers, and a comatose death. Birds 11-weeks old given 10 or 20 mg PCB daily, birds 6 to 9 months old given 50 or 100 mg each 3.5 days, and adult hens given up to 50 mg once a week continued to eat. Eleven-week old birds given 210 mg daily stopped eating or those given 210 mg daily, the heaviest birds lost the greatest percentage of their weight (15 to 31 percent) before death occurred (1.3 to 4.3 days). Birds intentionally starved at the same time lost a greater percentage of weight (27 to 51 percent) before death (2.3 to 8.6 days). Some adult hens were given a single 50-mg capsule and samples of whole body, brain, liver, muscle, eggs, and feces were analyzed to determine patterns of storage and excretion. Levels of PCB were highest at 12 hours after capsule administration. Residues were highest in liver, followed by brain and muscle over 28 days following the single 50-mg capsule. From 94 to 98 percent of the administered dose was absorbed and 40.5 mg of the 50mg were in the body after 28 days. Hens were in a state of low egg production and excreted 4.2 mg in the eggs and 4.0 mg in the feces over 28 days. Excretion in the egg could be an important means of ridding the body of PCB. Four hens from the 1970 breeding experiment, given 17 capsules weekly containing 12.5 mg PCB and killed 1 week following the last capsule, had from 37 to 56 percent of the administered dose in their bodies. Four hens on the 50-mg level in 1970 had from 60 to 82 percent of the dose given. Five hens given 12.5 mg weekly for 16 weeks in 1971 had an average of 23.8 ppm PCB in their bodies 1 week after the last capsule, three hens had an average of 13.6 ppm after 3months on a clean diet, and three others had an average of 20.9 ppm after 6 months. Excretion was variable and slow. An analysis of brain, liver, and muscle tissues from dead and surviving birds fed PCB at various levels showed that brain residue levels from 300 to 400 ppm wet weight were indicative of death from FCB toxicosis. Liver and muscle levels were too variable to be useful in assessing cause of death. Administration of PCB decreased weights of heart and spleen (P <0. 01) at all levels given and increased weights of kidneys and livers in birds given 10- and 20-rng doses daily (P <0. 01) but not in birds given 210 mg daily. Splenic atrophy, where spleens were small, pale-tan color, and had wrinkled capsules resulting from depletion of lymphatic nodules, was characteristic of birds given PCB. PCB and dieldrin were given singly and jointly, and only additive, not synergistic, effects were noted. Livers of wild pheasants from Pennsylvania, Indiana, and South Dakota had no more than 2 ppm PCB. This indicates low-level contamination.

A Feasibility Study Of Commercial Upland Game Bird Farms In Waterloo County, Ontario, Robert John Mcclure Jan 1972

Iodine Metabolism In Sessile Stages Of Chesapeake Bay Semaeostome Jellyfish, Janet Evelyn Olmon Jan 1972

Serum Esterase, Lactate Dehydrogenase, And Tetrazolium Oxidase Polymorphisms In The Clupeidae, Walter Francis Eanes Jan 1972

Acute Toxicity Of No 6 Fuel Oil To Intertidal Organisms In The Lower York River, Virginia, Jeffrey L. Hyland Jan 1972

An Investigation Of One And Two State Molecular Systems Based On The Results Of Elastic Differential Scattering Experiments, Stephen Michael Bobbio Jan 1972

Equilibrium And Kinetic Study Of The Substitution Reactions Of Pentacarbonylaminetungsten (O) With Triphenylphosphine, William O. Bailey Jan 1972

A Paleomagnetic Reconnaissance Of The Platoro Caldera, Southeastern San Juan Mountains, Colorado, Jimmy F. Diehl Jan 1972

Applied Geology Of The Bismarck-Mandan Area, North Dakota, Gerald H. Groenewold Jan 1972

Septic Tank Nutrients In Groundwater Entering Lake Sallie, Minnesota, David Robert Lee Jan 1972

Groundwater Of The Spiritwood Lake Area, Stutsman County, North Dakota, Frank J. Schulte Jan 1972

Geology Of Southern Nelson County, North Dakota, Roger J. Reede Jan 1972

Synthesis And Reactions Of Benzyl 2-Bromo-2-Deoxy Hexoses, Terry Cady Tompkins Jan 1972

Birch Reduction Of Cinnamic Acid, John G. Little Jan 1972