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The Role Of The Renin-Angiotensin System In The Drinking Response To Isoproterenol, Marilyn Margaret Robinson

Digitized Theses

Beta-adrenergic drugs, such as isoproterenol, potently stimulate renin secretion and drinking. It is controversial, however, whether the renin-angiotensin system directly mediates the dipsogenic response.;Isoproterenol (0.1 mg/kg, S.C.) alone caused rats to drink. Low doses of captopril (0.1-1.0 mg/kg, S.C.) which inhibit angiotensin II synthesis in the circulation but not in the brain dose-dependently enhanced isoproterenol-induced drinking whereas higher doses of captopril (5.0-100 mg/kg, S.C.) which inhibit angiotensin II synthesis in the brain as well, caused a dose-dependent inhibition of the response. The highest doses of captopril, either 100 mg/kg, S.C. or 20 mg/h, I.V., completely blocked the drinking response to …

Distribution And Metabolism Of Dolichol And Its Derivatives, Nilabh Chaudhary

Digitized Theses

The phosphorylated derivatives of dolichol are essential intermediates in the biosynthesis of asparagine-linked glycoproteins. The aim of the research in this thesis was to obtain detailed information about the distribution and metabolism of these polyisoprenoid lipids in eukaryotic organisms and especially in rat tissues and liver subcellular fractions. Methods utilizing reverse-phase high performance liquid chromatography were developed for measuring tissue levels of dolichol, dolichyl phosphate and dolichyl fatty acyl esters. All rat tissues including serum contained varying concentrations of dolichol ranging from a high of 165(mu)g/g in the spleen and 60(mu)g/g in the liver to 23(mu)g/g in the heart. Only …

Thermal Shift-Induced Gene Expression And Regulation In Maize (Zea Mays L), Christopher Leon Baszczynski

Digitized Theses

Rapid elevation in the incubation temperature of maize seedlings leads to the new and(or) enhanced synthesis of a group of heat shock polypeptides (HSPs). The response is: (a) rapid (HSP synthesis is detectable within 15 minutes following thermal shifts); (b) reversible (the "pre-shift" pattern of polypeptide synthesis is re-established when seedlings are returned to the control temperature); and (c) transitory (maintenance of seedlings at the elevated temperature leads to a gradual reduction of HSP production and the establishment of a new pattern of polypeptide synthesis). The synthesis of an apparently identical set of HSPs is noted in maize plumules, mesocotyls, …

Mating Type, Vitamin E And Morphogenesis In Ustilago Violacea And Other Smut Fungi, Alan James Castle

Digitized Theses

The anther smut fungus, Ustilago violacea, grows either saprophytically (yeastlike cells) or as a parasite of the Caryophyllaceae (mycelial cells). Factors affecting two types of development controlled by the mating type gene, sporulation and myceliation, were examined.;Sporulation. Freshly isolated diploid cells, heterozygous for the mating type alleles, a(,1) and a(,2), develop into sexual phase precursor cells (SPP) on complete medium at temperatures below 20(DEGREES)C. The a(,1)/a(,2) diploid produces at least four different cell types, termed opaques, spontaneously at high frequencies (> 3 x 10('-3)). These types are: (1) neutral strains (op-N) which do not mate and still initiate sporulation but …

Arterial Baro- And Chemoreceptor Projections To The Amygdala In The Cat, David Floyd Cechetto

Digitized Theses

In this study baro- and chemoreceptor input to the amygdala was investigated with electrophysiological experiments in chloralose-anesthetized cats and with the neuroanatomical tracing method of retrograde transport of horseradish peroxidase.;Stimulation of the carotid sinus (CSN) and aortic depressor (ADN) nerves altered the firing frequency of 30% (73/241) and 20% (50/251), respectively, of single units in the central, lateral and basal nuclei of the amygdala.;Selective activation of carotid baro- and chemoreceptors altered the firing frequency of 23% (35/154) and 16% (24/154), respectively, of amygdalar units, with chemoreceptor responsive units located primarily in the dorsomedial amygdala and baroreceptor responsive units located primarily …

Murine Hepatitis Virus (Mhv) Replication: A Molecular Study, Stephen Benet Cheley

Digitized Theses

L-2 cells infected with murine coronavirus (MHV) strains MHV-3 and JHM shut off host cell protein synthesis and synthesized polypeptides with apparent molecular weights 180,000 (p180), 56,000 (p56), 24,000, (p24) and 22,000 (p22) after a 15 minute pulse with {lcub}('35)S{rcub}-methionine. During a 2 hour chase period performed late in infection (5.5 h PI) a fifth polypeptide of molecular weight 50,000 (p50) was detected. The corresponding p56 and p50 polypeptides of the two viruses were enriched in the basic amino acid arginine. Pulse-chase and peptide mapping experiments confirmed a precursor-product relationship between the p56 and p50 proteins. MHV-3 virions, however, showed …

Biosynthesis Of Peroxidase In Peanut Cells In Suspension Culture, Ravindra Nath Chibbar

Digitized Theses

Peroxidase (E.C.1.11.1.7) has been widely used as a marker of altered growth and development in plants. However, a definitive role of physiological significance has yet to be ascribed. This may be partially due to studies, that have been performed with a peroxidase molecule neither isolated to purity nor characterized from the system of investigation. A cationic peroxidase molecule (molecular weight 40 kD) had been purified to apparent homogenity and characterized from cultured peanut cells. Antibodies were raised against this peroxidase molecule in rabbits and used for monitoring biosynthetic studies on this peroxidase molecule in cultured peanut cells.;The cationic peroxidase constituted …

Hexose Transport In L6 Rat Myoblasts, Vincent Duronio

Digitized Theses

A number of different approaches were used in characterizing the nature and the regulation of the hexose transport system in the permanent cell line, L6. This rat myoblast line can differentiate in culture to form multinucleated myotubes, but in this study, only the undifferentiated cells were used. Kinetic and inhibition studies suggested that the uptake of the glucose analogues 2-deoxyglucose and 3-O-methylglucose proceeds via two different transport systems, or at least two distinct forms of the same system.;Glucose transport mutants were isolated by selecting cells which were resistant to 2-deoxyglucose. A number of mutants were obtained which had dramatically decreased …

The Life-History Tactics Of The Voles, Clethrionomys Gapperi And Microtus Pennsylvanicus, At Two Elevations, Duncan Gordon Innes

Digitized Theses

The life-history tactics of Clethrionomys gapperi and Microtus pennsylvanicus were examined at two elevations (1450m; 2240m) in southwestern Alberta (Kananaskis Country) to test the hypothesis that females in environments with shorter breeding seasons should produce fewer but larger litters and survive less well than those in environments with longer breeding seasons (Spencer and Steinhoff 1968). Other life-history traits such as body weights and the energetics of reproduction were also compared between elevations.;Life-history data were collected by mark-recapture techniques, kill-trapping and from laboratory colonies.;The high elevation was colder, had fewer frost-free days and more precipitation than the low elevation. The length …

Bioenergetics Of Breeding House Sparrows, David George Krementz

Digitized Theses

Between April, 1981 and July, 1983, I collected 563 (211 male, 352 female) house sparrows (Passer domesticus) around London, Ontario, weighed their nutrient reserves (protein, fat, calcium) and determined their food habits, to see if nutrient reserves proximately control clutch size in this species. Daily energy demands during egg production were evaluated by analyzing changes in nutrient reserves. Captive house sparrows were studied to determine if stored fat was deposited in eggs.;The proportion of males and females that consumed high-protein foods varied with the seasonal availability of insects. Insect use was low until egg laying but then increased and remained …

Algal Uptake Of Uranium, Barium, Cobalt, Nickel And Vanadium: Studies Of Natural And Experimental Systems, Henrietta Mann

Digitized Theses

Monocultures of freshwater green algae Ankistrodesmus sp. and Selenastrum sp. cultured in dilute solutions of metals chelated with EDTA, revealed massive uptake of U and Ba. For 2 ppm metal-spiked TBIM culture media at pH 8.1-8.2 and growth durations of 3-21 days at 13-16(DEGREES)C, both species accumulate U and Ba at levels of 1,000 to 10,000 ppm by dry weight. Uptake was comparable for passage of 100 ml spiked culture media through algal mats over 100 min. For 2 ppm Co-, Ni- and V-spiked culture media, algal uptake was 40-600 ppm Ni, 17 ppm Co and 12 ppm V, respectively. …

Control Of Compaction And Junctional Communication In Preimplantation Mouse Embryos, Jeanne Ruth Mclachlin

Digitized Theses

In the preimplantation mouse embryo, intercellular coupling is acquired in the 8-cell stage during the process of compaction. The presence of permeable cell-to-cell membrane channels (gap junctions) was detected by measuring ionic coupling and by observing the intercellular transfer of fluorescent dye. The rate of fluorescent dye movement within 8-cell embryos increases as they undergo compaction, suggesting that the number of junctional channels between cells increases as development progresses. Compacted 8-cell embryos, when aggregated, are capable of forming inter-embryonic junctional channels after 2 to 3 hours of contact; however the number of channels between embryos is small since aggregated embryos …

Factors That Influence The Size Of The Repair Patch In The Dna Of Cultured Human Cells, John Peng Th'ng

Digitized Theses

The buoyant density shift method was employed in the study of the enzymology and its regulation of DNA repair in cultured human cells. Measurements of the size of the DNA repair patch after treatments with UV-light or methylating agents revealed that about 30 nucleotides are replaced at each damage site, and that the extent of replacement is independent of the DNA-damaging agents employed.;In the examination of the role of poly(ADP-ribosyl)ation in DNA repair, the size of the repair patch was not increased by the presence of 3-aminobenzamide (3-AB), an inhibitor of poly(ADP-ribose) polymerase, as had been predicted by other investigators.;To …

The Reproductive Behaviour And Ecology Of Smallmouth Bass (Micropterus Dolomieui) In Long Point Bay, Lake Erie, Gregory Peter Goff

Digitized Theses

The reproductive behaviour and ecology of smallmouth bass, Micropterus dolomieui, was studied during the 1981 to 1983 spawning seasons at Long Point Bay, Lake Erie. SCUBA was used to find a observe nesting males. My observations of these fish revealed some behaviours that were not previously described. Other activities, e.g. parental guarding, were segregated into discrete behaviour patterns. These units were organized into an ethogram of reproductive behaviour. A mating system involving selectivity by males in choosing mates was discussed.;Reproductive success of individual male smallmouth was measured by collecting new "black-fry" from nests. Thirteen variables reflecting differences in biological characteristics …

Selectivity In Junctional Communication, Michael George Blennerhassett

Digitized Theses

The regulation of gap junction permeability may be important during development, since this could change the nature and rate of movement of molecules passing between cells. Results in developing insect epidermis show that intercellular channels close in a graded fashion, altering the kind of substances passing between cells over time, and that reduced junctional permeability at the intersegmental border establishes spatial patterns of coupling within the epidermis.;The nature of channel closure, which might be graded or all-or-none, determines how junctional permeability changes when the coupling level is varied. The passage of small fluorescent dyes and inorganic ions between cells was …

The Bush Tick, R B. Besier

Journal of the Department of Agriculture, Western Australia, Series 4

A newly discovered livestock parasite has focused attention on farms in the Walpole district in the south-west of Western Australia. Ticks submitted to the Department of Agriculture in December 983 were identified as the bush tick, Haemaphysalis longicornis. An intensive campaign to locate areas of infestation and to limit spread was started in January 1984.

The bush tick is a pest of livestock in some areas of New South Wales and Queensland. It is important in a narrow coastal strip from Sydney to Brisbane where total summer rainfall can exceed 1000 mm. In this area heavy tick infestation causes …

Oogenesis In Tubularia Larynx And Tubularia Indivisa (Hydrozoa, Athecata), Barry W. Spracklin

Doctoral Dissertations

In Tubularia larynx and T. indivisa, interstitial cells proliferate in the ectoderm of the gonophore stalk and peduncle of the raceme and migrate in the endoderm to the apex of the young gonophore buds where they proliferate in the endoderm to form the entocodon and germ cell mass. Eggs are produced sequentially in the gonophores of both species. Each egg is the result of fusion of 1200-2000 cells interconnected by cytoplasmic bridges into a large complex. At the center of each complex are 15-18 morphologically similar cells, all of which begin meiosis and form germinal vesicles and are considered oocytes. …

Nitrogen Metabolism And Iron Reduction In Aquaspirillum Magnetotacticum (Nitrate, Fixation, Magnetic Bacterium), Dennis Alfred Bazylinski

Doctoral Dissertations

Aquaspirillum magnetotacticum strain MS-1 grew microaerobically but not anaerobically with NO(,3)('-) or NH(,4)('+) as the sole nitrogen source. Cell yields varied directly with NO(,3)('-) concentration under microaerobic conditions. Products of NO(,3)('-) reduction by growing cells included NH(,4)('+), N(,2)O, NO, and N(,2) but not NO(,2)('-) or NH(,2)OH. The inclusion of NH(,4)('+) in growth medium prevented NO(,3)('-) reduction to NH(,4)('+) but not to N(,2)O or N(,2). Cells consumed O(,2) while denitrifying and this appears to be the first described species with an absolute requirement for O(,2) while denitrifying.

Cultures grown with NO(,3)('-), in contrast to NH(,4)('+), contained fewer cells without magnetosomes. Moreover, …

Ecology Of Rocky Subtidal Communities: The Role Of Modiolus Modiolus (L) And The Influence Of Disturbance, Competition, And Mutualism, Jon Drew Witman

Doctoral Dissertations

This study presents an analysis of physical and biological processes regulating the structure of rocky subtidal communities off coastal New Hampshire and southern Maine, USA, with emphasis on the ecology of the horse mussel Modiolus modiolus (L.). Quantitative sampling and multivariate analysis revealed 3 communities: (1) Modiolus community; (2) 30 m community of species with highest densities outside mussel beds; (3) 8-18 m community of species with maximal densities outside mussel beds.

Controlled field experiments, a natural grazing experiment, and long-term photographic monitoring (5 yrs) enabled patterns of Modiolus community structure to be related to the processes maintaining them. Bivalve, …

G84-717 Fleas And Their Management (Revised January 1993), Shripat T. Kamble, David L. Keith

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide provides information on flea biology and how to solve flea problems.

Fleas are among the most annoying pests known to humans. In ancient times, fleas were even indicted, found guilty and sentenced to condemnation. Today, the verdict remains the same.

In Nebraska, fleas are common household pests attacking dogs, cats and sometimes people. In addition to these, several other flea species occur in Nebraska, feeding principally on rodents and occasionally on poultry and livestock. The information provided in this publication will focus primarily on cat and dog fleas, as they are the most commonly encountered species.

Mutagenesis In Drosophila Melanogaster. I. Scheduled Synthesis Of Nuclear And Mitochondrial Dna And Unscheduled Dna Synthesis. Ii. Dosimetry Studies Using Phosphorus-33. Iii. Molecular Analysis Of Induced Mutations At The Adh Locus (Alcohol Dehydrogenase, Restriction, Cloning, Southern, Blotting)., Mark Richard Kelley

LSU Historical Dissertations and Theses

Presented here are three distinct, but interwoven areas of mutation research and molecular genetics using Drosophila melanogaster as the test organism. The first section describes the characterization of the DNA replication process and DNA repair in the oocyte. This involved sex-linked recessive lethal tests on ethyl methanesulfonate (EMS) treated females and unscheduled DNA synthesis (UDS) studies involving EMS, methyl methanesulfonate (MMS) and N-ethyl-N-nitrosourea (ENU). Oocytes were positive for UDS with EMS and MMS in a DNA repair competent strain and negative in excision repair deficient strains. ENU was negative in a DNA repair competent strain. Since UDS is not quantitative …

Progeny Studies And Genotype X Environment Interactions For Yield And Other Characters In Sweet Potatoes, Ipomoea Batatas, L. (Path Analysis, Heritability, Correlations)., Marc J. J Janssens

LSU Historical Dissertations and Theses

A multi-environmental trial was conducted in Rwanda, located in the highlands of Central Africa. The trial consisted of 26 cultivars of sweet potatoes repeated over 11 environments. Genotype X environment (G X E) interactions were highly significant for vine yield, fresh root yield, number of roots, and dry matter yield. Average root weight was not significant for G X E interactions. The G X E variance component was generally more important than the variance component for cultivars. From pathway analysis it was concluded that the G X E effects of dry matter yield were little determined by the G X …

The Relationship Between Photosynthesis And The Capacity For Nitrogen Fixation In Soybean., Eddie Paul Millhollon

LSU Historical Dissertations and Theses

Diurnal trends in leaf carbohydrate partitioning and nodule activity in soybeans under natural conditions and the irradiance level required to allocate sufficient carbohydrate to obtain maximum rates of N(,2)(C(,2)H(,2)) reduction were studied. Soybeans grown outdoors maintained constant levels of soluble carbohydrates in the leaves and constant rates of N(,2) fixation and root + nodule respiration when root temperature was kept constant but shoot temperature varied. When plants were subjected to a 40-hour dark period, then exposed to 200 to 1000 (mu)E m('-2) sec('-1), 200 (mu)E m('-2) sec('-1) resulted in maximum leaf soluble carbohydrate and nodule activity. Results suggest that nodule …

Life Cycle Of Alaria Marcianae In Louisiana (Trematoda, Transmammary, Milk-Borne)., Wesley Lawrence Shoop

LSU Historical Dissertations and Theses

The life cycle of Alaria marcianae (Trematoda) as found in Louisiana involves the planorbid snail, Helisoma trivolvis, as first intermediate host; tadpoles of Rana catesbiana, R. clamitans, R. utricularia, Hyla cinerea, and Gastrophryne carolinensis as second intermediate hosts; a wide range of amphibian, reptilian, and mammalian paratenic hosts; and the bobcat (Lynx rufus), domestic cat (Felis domesticus), and juvenile raccoon (Procyon lotor) as definitive hosts. Eggs defecated by the definitive host require an incubation period of approximately 20 days; a free swimming miracidium hatches from each egg and must penetrate a snail within 24 hr or die; the miracidium transforms …

Interactions Of Soybean Arthropods And Crop Weeds: Diversity, Moth Nutrition, And Stability (Foraging Behavior, Nectar Analysis, Lepidopterous)., Fred Lewis Collins

LSU Historical Dissertations and Theses

Weeds which occur in crop ecosystems may cause suppressive or stimulating effects on arthropod abundance. Yet, little is known about the weed-insect interactions in Louisiana soybean. A three-part study was conducted from 1980-1983 to measure the abundance of arthropods in soybean, Glycine max Merr., as affected by the presence of absence of various weeds. A survey of arthropod abundance was conducted in commercial soybean fields which were either weedy or weed-free in central and south central Louisiana during 1980. Weedy fields had greater abundance of spiders, Geocoris punctipes (Say), and Lebia analis Dejean. Late instar green cloverworm, Anticarsia gemmatalis Hubner, …

Oviposition Of Psorophora Columbiae (Dyar And Knab) In Louisiana Pastureland., Dwight Charles Williams

LSU Historical Dissertations and Theses

Cattle hoofprint samples from a permanent pasture in Vermilion Parish, Louisiana during 1980 yielded an average of 9.2 eggs and capsules of Psorophora columbiae (Dyar and Knab)/hoofprint. Pasture sections differed significantly (P < .0001) in number of eggs and capsules/hoofprint. Sections ranged from 2.7 to 20.6 eggs and capsules/hoofprint. The number of eggs and capsules collected/date also differed significantly (P < .01), but peaks in numbers did not always correspond with peaks in rainfall or adult mosquito collections. Hoofprint densities and herd movement did not influence egg distribution. Estimates of numbers of eggs and capsules on the 30 ha permanent pasture range from 2,633,621 in late February to 16,913,025 on June 2, 1980. Mosquito oviposition was compared in hoofprint samples taken from a permanent pasture and a fallow rice field in Vermilion Parish, Louisiana during 1981. Hoofprints from the permanent pasture contained significantly (P < .001) more Ps. columbiae eggs than did hoofprints from the fallow rice field, averaging 3.3 and 1.9 eggs/hoofprint respectively. However, estimates of egg density in the 2 sites did not differ significantly (P > .05) since hoofprint density was greater in the fallow rice field. Egg density estimates were 15.2/m('2) for the fallow rice field and 13.3/m('2) for the permanent pasture. Hoofprint depth, hoofprint location, and cattle movement did not influence egg distribution. Results of studies with caged Ps. columbiae exposed to natural lighting conditions indicated that the oviposition cycle was bimodal with the main peak occurring in the 2 h period …

Studies Of Plasma Membrane Domain-Specific Molecules In Isolated And Cultured Rat Hepatocytes, Pamela Leslie Zeitlin

Yale Medicine Thesis Digital Library

Single rat hepatocytes, prepared by collagenase perfusion of liver, lost the three morphologically and functionally distinct plasma membrane domains that exist in situ (sinusoidal, bile canalicular, and lateral). Hepatocytes placed in monolayer culture re-established morphologically distinct plasma membrane regions analogous to the original three domains. The behavior of several domain-specific markers was studied in these cells. The asialoglycoprotein (ASGP) receptor, an integral membrane glycoprotein normally restricted at the surface to the sinusoidal domain in situ, was retained in both single hepatocytes (> 95%) and in cells after 24 hr in monolayer culture but at lower levels. Cytochemistry with asialo-oroso-mucoid-horseradish peroxidase …

Rearrangement Of The Keratin Cytoskeleton After Combined Treatment With Microtubule And Microfilament Inhibitors, Loren W. Knapp, W. Michael O'Guin, Roger H. Sawyer

Faculty Publications

In addition to containing microtubule and microfilament systems, vertebrate epithelial cells contain an elaborate keratin intermediate-filament cytoskeleton. Little is known about its structural organization or function. Using indirect immunofluorescence microscopy with an antikeratin antiserum probe, we found that destabilization of microtubules and microfilaments with cytostatic drugs induces significant alterations in the cytoskeletal organizationof keratin filaments in HeLa and fetal mouse epidermal cells. Keratin filament organizationwas observed to undergo a rapid (1-2 h) transition from a uniform distribution to an open lattice of keratin fibers stabilized by membrane-associated focal centers . Since addition of any one drug alone did not elicit …

Habitat Utilization Of Mammals In A Man-Made Forest In The Sandhills Region Of Nebraska., Richard W. Manning

Student Work

The Sandhills Region of Nebraska is located in the central and northern portion of Nebraska. Within this region is the Bessey Division of the Nebraska National Forest. The Bessey Division encompasses 36,560 ha of which approximately 8,900 ha are forested; all forested lands are man-planted. Forest types include monocultures of three species; ponderosa pine (Pinus ponderosa), jack pine (Pinus banksiana), and Eastern red cedar (Juniperus virginiana). This represents the largest man-made Forest in the National Forest System of the United States. The remaining 27,660 ha are of native grasses. Also a narrow strip of riparian habitat runs along the northern …

Newsletter, University Of South Florida Botanical Garden Newsletter, No. 6, September 1983, University Of South Florida. Botanical Gardens

USF University Archives and Documents

September 1983 newsletter of the University of South Florida Botanical Gardens. Topics include plant sale, volunteering, and programming.