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Articles 37471 - 37500 of 39281
Full-Text Articles in Entire DC Network
A Species Diversity Study Of The Benthic Population Of Cedar Lake, Illinois, Noreen L. Connolly
A Species Diversity Study Of The Benthic Population Of Cedar Lake, Illinois, Noreen L. Connolly
Master's Theses
No abstract provided.
Microelectrophoretic Separation Of Isozymes In Relation To Aging In The Hydroids Campanularia Flexuosa And Cordylophora Lacustris, Patricia Marie Brown
Microelectrophoretic Separation Of Isozymes In Relation To Aging In The Hydroids Campanularia Flexuosa And Cordylophora Lacustris, Patricia Marie Brown
Master's Theses
No abstract provided.
The Effect Of Field Corn (Zea Mays) Residues On The Germination And Growth Of Field Corn, Alice J. Stubblefield
The Effect Of Field Corn (Zea Mays) Residues On The Germination And Growth Of Field Corn, Alice J. Stubblefield
Master's Theses
No abstract provided.
Selection Of Somatic Cell Hybrids Between Baby Hamster Kidney Cells And Human Embryonic Kidney Cells To Study Bk Virus Early Gene Expression, Sara Lynn Ehlke
Selection Of Somatic Cell Hybrids Between Baby Hamster Kidney Cells And Human Embryonic Kidney Cells To Study Bk Virus Early Gene Expression, Sara Lynn Ehlke
Master's Theses
No abstract provided.
The Terrestrial Flora Of South Padre Island, Texas, Robert I. Lonard, Frank W. Judd
The Terrestrial Flora Of South Padre Island, Texas, Robert I. Lonard, Frank W. Judd
School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)
The primary aim of this work is to enable the user to identify the flowering plants of South Padre Island; however, it should be useful for identification of plants on other Texas barrier islands and on the Mexican barrier islands. We hope that the keys will aid teachers, students, coastal zone managers, and individuals conducting environmental impact assessments.
Attributes Of Dispersing Meadow Voles In Open-Grid Populations, Raymond D. Dueser, Marcia L. Wilson, Robert K. Rose
Attributes Of Dispersing Meadow Voles In Open-Grid Populations, Raymond D. Dueser, Marcia L. Wilson, Robert K. Rose
Biological Sciences Faculty Publications
Dispersal was investigated in two open-grid populations of meadow voles, Microtus pennsylvanicus (Ord, 1815) an central Virginia (U.S.A.) from November 1974 to April 1978. "Dispersal" was defined as immigration onto open, occupied population grids. Dispersers were distinguished from residents by weight at first capture. Individuals first captured at weights <30 g were classified as residents; those first captured at >30 g were classified as dispersers. Three independent lines of evidence support the validity of the 30-g criterion for recognizing dispersers in these vole populations. With frequent trapping and high trappability, particularly of young animals, this open-grid method of study offers two advantages in the study of dispersal. First, dispersers identified …30>
Variation In Branch Growth Characteristics Of Pinus Contorta Infected With Arceuthobium Americanum, Lynn Anne Larsen
Variation In Branch Growth Characteristics Of Pinus Contorta Infected With Arceuthobium Americanum, Lynn Anne Larsen
Dissertations and Theses
Arceuthobium americanum is a flowering plant which parasitizes Pinus contorta (Lodgepole pine). This study examined branch performance of P. contorta infected to varying degrees with A. americanum.
The Metabolic Cost Of Behavioral Thermoregulation Of Body Temperature In The Northern Alligator Lizard Gerrhonotus Coeruleus, And How It Affects The Classical Concept Of Eurythermality, James Dudley Campbell
The Metabolic Cost Of Behavioral Thermoregulation Of Body Temperature In The Northern Alligator Lizard Gerrhonotus Coeruleus, And How It Affects The Classical Concept Of Eurythermality, James Dudley Campbell
Dissertations and Theses
The effect of total metabolic cost expenditures on the precision of behavioral thermoregulation was investigated for the purportedly eurythermic Northern Alligator lizard (Gerrhonotus coeruleus). An operant apparatus was designed to test metabolic output at different heat reinforcement magnitudes. The mean TB reflected in each trial was positively correlated to the length of reinforcement. The shuttle rate during each trial was inversely correlated to the length of reinforcement. The standard deviation and total metabolic costs did not vary significantly between trials undertaken at the same ambient temperature. Eurythermality in G. coeruleus is caused by fluctuations in preferred body temperature and …
The Ductuli Efferentes In Macaca Mulatta: Electron Microscopic Evaluation Of Changes After Vasectomy, Loyal Douglas Marsh
The Ductuli Efferentes In Macaca Mulatta: Electron Microscopic Evaluation Of Changes After Vasectomy, Loyal Douglas Marsh
Dissertations and Theses
After vasectomy, the passage of sperm antigen through the epithelium of the efferent duct in the rhesus macaque probably results in immune complex deposition. Immune complexes can be visualized in the thickened basement by fluorescence microscopy. Subsequent electron microscopic evaluation, with the appearance of electron-dense deposits in the basement membrane of the efferent ducts, substantiates these findings.
Phytogeography Of South Padre Island, Texas, Robert I. Lonard, Frank W. Judd
Phytogeography Of South Padre Island, Texas, Robert I. Lonard, Frank W. Judd
School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)
The phytogeographic affinities of the native flora of South Padre Island, Texas, are analyzed and the probable dispersal agent(s) for each species identified. The native flora consists of 99 species and 44% of the species also occur on the adjacent Texas mainland; 28% of the native species have tropical affinities. Only three species have probably dispersed from the island to the mainland. Two species may be endemic to Padre Island and the Tamaulipan barrier islands. Most of the tropical species have reached the island by oceanic drift, but birds are the most important dispersal agent for the native species. Man …
Arrangement Of Subunits In Microtubules With 14 Profilaments, George M. Langford
Arrangement Of Subunits In Microtubules With 14 Profilaments, George M. Langford
Biology - All Scholarship
The structure of 14-protofilament microtubules reassembled from dogfish shark brain tubulin was analyzed by high resolution electron microscopy and optical diffraction. The simultaneous imaging of the protofilaments from near and far sides of these tubules produces a moiré pattern with a period of approximately 96 nm. Optical diffraction patterns show that the 5-nm spots that arise from the protofilaments for the two sides of the tubule are not coincident but lie off the equator by a distance of 1/192 nm-1. These data provide evidence that in reassembled microtubules containing 14 protofilaments, the protofilaments are tilted 1.5 degrees with respect to …
Diversity And Dynamics Of Indigenous Rhizobium Japonicum Populations, K. Dale Noel, Winston J. Brill
Diversity And Dynamics Of Indigenous Rhizobium Japonicum Populations, K. Dale Noel, Winston J. Brill
Biological Sciences Faculty Research and Publications
A simple method, based upon the separation of cellular proteins by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, has been devised for distinguishing between isolates of Rhizobium japonicum. Eleven laboratory strains, previously classified into five serogroups, were analyzed by gel electrophoresis. Groups determined subjectively according to protein patterns matched the serogroups, with one exception. Most strains within serogroups could be distinguished from one another. For studying the ecology of Rhizobium, an important advantage of this technique compared with serology or phage typing is that it discriminates among previously unencountered indigenous bacterial isolates as well as among known laboratory strains. …
Alternative Male Life Histories In Bluegill Sunfish, Mart Gross, Eric Charnov
Alternative Male Life Histories In Bluegill Sunfish, Mart Gross, Eric Charnov
Biology Faculty & Staff Publications
Male bluegill sunfish are shown to have two alternative mating strategies: cuckoldry or parental care. Cuckolder males first mature at age 2. They follow a developmental sequence of sneaking and then mimicking female behavior to deceptively gain access to spawnings. Males who become parentals (construct nests, attract females, provide brood care) delay maturation until age 7. The parental investment of these males is parasitized by the cuckolders. This system is an example of a truly parasitically dependent mating strategy in vertebrates. A natural selection model is developed to predict the equilibrium frequencies of the two male types. A preliminary test …
Geochemical And Biogeochemical Interactions In A Hot Spring, William Delis Knox
Geochemical And Biogeochemical Interactions In A Hot Spring, William Delis Knox
Dissertations and Theses
Southeast Harney Lake Hot Spring and its effluent channel were examined for spatial and temporal variations in the concentrations of several chemical species, viz. dissolved oxygen, pH, alkalinity, phosphate-phosphorous, nitrate and nitrite-nitrogen, conductivity, chloride, flouride, temperature, calcium, magnesium, potassium, and sodium. Phosphate-phosphorous and nitrate-nitrogen both exhibited downstream increases in concentration. pH and alkalinity increased also, mainly due to CO2 evolution and temperature mediated carbon species redistribution. The diurnal pH and alkalinity curves exhibited depressions during the daylight hours due to the oxidation of ammonia to nitrate within the pool and effluent stream.
Zooplankton Abundance And Diversity In A Hydrilla Infested Central Florida Lake, Don C. Schmitz
Zooplankton Abundance And Diversity In A Hydrilla Infested Central Florida Lake, Don C. Schmitz
Retrospective Theses and Dissertations
Zooplankton abundance, hydrilla biomass, and physicochemical parameters were sampled for one year in a small central Florida lake. Annually, rotifers comprised most of the species collected and were the most abundant zooplankton group. Hydrilla biomass was lowest during winter and spring while orthophosphate and phtoplankton concentrations were highest. Zooplankton densities were highest when hydrilla biomass was low. Small-bodied limnetic herbivores comprised most of the zooplankton during the spring. Zooplanton abundances were lowest during summer and fall and may have been either directly or indirectly related to the hydrilla growth. Factors, such as lower phytoplankton and dissolved oxygen concentrations, possible increased …
Cytologic Characterization Of Human Constitutive Heterochromatin, Timothy Atchison Donlon
Cytologic Characterization Of Human Constitutive Heterochromatin, Timothy Atchison Donlon
Dissertations and Theses
A study was conducted to cytologically map certain subsets of constitutive heterochromatin onto specific portions of human chromosomes. This involved sequentially staining metaphase chromosomes from lymphocytes first with the Centromeric Dot, Giemsa-11, G-banding or Lateral Asymmetry staining techniques, which are cytochemical methods which stain particular chromosomes or chromosomal regions. Then those same metaphase chromosomes were stained using the C-banding technique, a method which is believed to denote constitutive heterochromatin. With the exception of the G-banding technique, areas depicted by the special staining techniques were found to reside only within the areas stained by the C-band technique and are thus believed …
Cellulase Activities Of Soil Fungi, Jacobo Ortega
Cellulase Activities Of Soil Fungi, Jacobo Ortega
School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)
The cellulase activities of 8 isolates of fungi obtained from agricultural soils of Hidalgo County, TX were investigated by measuring the changes in the viscosity of a buffered solution of carboxymethylcellulose (CMC), produced by the fluids obtained from liquid cultures of these isolates. The change in the viscosity of the reaction mixture incubated at constant temperature (30 C) was measured with Cannon-Fenske routine viscometers. A buffered cellulase solution was used as a control.
Due to the variability that existed among the isolates investigated, it was possible to select active producers of cellulase with the method followed in this investigation. The …
Cellular Response & Histopathological Studies Of Murine Pyelonephritis Experimentally Induced By Aspergillus Flavus, Anna Hansen
Cellular Response & Histopathological Studies Of Murine Pyelonephritis Experimentally Induced By Aspergillus Flavus, Anna Hansen
Masters Theses & Specialist Projects
Five-week-old male BALB/c mice were anesthetized and incised mid-dorsally to expose the fascia over the right kidney. The kidney was then palpated up and an inoculum of 0.05 ml containing approximately 100,000 viable Asperaillus flavus spores in phosphate-buffered saline was injected into the cortex. A second group of mice underwent similar surgical procedures, but were injected with phosphate-buffered saline only into the right kidney. This group was designated the sham-operated control mice. All mice, including controls, were bled for differential blood counts 24 and 48 h after surgical procedures and subsequently on an every-other-day basis for the duration of the …
Ultrastructure & Microtubule Patterns Of A Detached Cellular Oganelle, Peggy Mervine
Ultrastructure & Microtubule Patterns Of A Detached Cellular Oganelle, Peggy Mervine
Masters Theses & Specialist Projects
In the axopod, the cell appendage of heliozoans, a bundle of microtubules runs the length of the organelle with a lateral pattern depending on the species. In the species under study, Echinosphaerium nucleofilum, these microtubules are arranged in a double spiral pattern. Axopodia can be detached and the purpose of this study was to refine the detachment procedure, work out electron microscopy techniques and scrutinize the detached axopodia for differences from the organelle of a whole organism. Detached axopodia were fixed, embedded, sectioned, observed under the electron microscope and found to be similar in ultrastructure to undetached ones. Thus, …
Reproductive And Mutagenic Effects Of 5-Thio-D-Glucose Injections In Male Mice, Mus Musculus, Icr Strain, Mary E. Mcmanaway
Reproductive And Mutagenic Effects Of 5-Thio-D-Glucose Injections In Male Mice, Mus Musculus, Icr Strain, Mary E. Mcmanaway
Master's Theses
Adult male ICR mice of proven fertility were intraperitoneally injected daily with 60 mg/kg of 5-thio-D-glucose for 28 days. Body weights of treated male mice were unaffected during the experimental period. Relative testicular weights were significantly reduced at 121 days after initial injections in 5-thio treated males, but no significant decrease was observed at 28 days.
Onset of sterility was estimated to occur at approximately 4 weeks and persisted for 5 to 6 weeks after cessation of treatment at which time fertility was restored.
Beginning with the first injections and continuing for 121 days, the males were mated with untreated …
An Analysis Of Salt Eating In Birds, Kathryn Julia Herson
An Analysis Of Salt Eating In Birds, Kathryn Julia Herson
Masters Theses
No abstract provided.
The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of Male Mice, Mus Musculus, Icr Strain, Margaret Ann Shugart
The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of Male Mice, Mus Musculus, Icr Strain, Margaret Ann Shugart
Master's Theses
The reproductive effects of long (24L:OD), natural (14L:lOD), and short (1L:23D) photoperiods were studied in the male mouse, Mus musculus, ICR strain. One third of the mice in each photoperiodic regimen were sacrificed after 45 days. Half of the remaining mice in each regimen received daily melatonin (5-methoxy-N-acetyl tryptamine) injections for 45 additional days. Body weights, testicular and accessory sex organ weights were measured and microscopic examinations of the testes were made. Plasma testosterone levels were determined using radioimmunoassay. Other organ (pituitary, kidney, adrenal, thymus, thyroid) weights were also obtained.
Identification Of Fossil Wood From The Specimen Creek Area Of The Gallatin Petrified Forest, Yellowstone National Park, Montana, Tetsuya Yamamoto
Identification Of Fossil Wood From The Specimen Creek Area Of The Gallatin Petrified Forest, Yellowstone National Park, Montana, Tetsuya Yamamoto
Loma Linda University Electronic Theses, Dissertations & Projects
The petrified fossil forests in the Specimen Creek area of Gallatin Petrified Forest contain spectacular petrified tree stumps, trunks and logs in horizontal and vertical positions. These fossils forests are embedded in early middle Eocene volcaniclastic rocks and piled in sequential layers.
One hundred and nineteen fossil wood samples were collected from three selected layers [unit 1, unit 5 and unit 9, (DeBord 1977)] of the sequentially entombed Fossil Forests in the above area, and identified as follows: 3 families, 9 genera, in Gymnosperms; 13 families, 15 genera in Angiosperms.
PINACEAE: Keteleeria*, Larix*, Pinus, Tsuga*
PODOCARPACEAE: Podocarpus
TAXODIACEAE: Glyptostrobus*, Sequoia, …
Interpopulational & Species Comparisons Of The Genus Liquidambar, Diana Duckworth
Interpopulational & Species Comparisons Of The Genus Liquidambar, Diana Duckworth
Masters Theses & Specialist Projects
Growth patterns under controlled conditions and chemotaxonomic techniques involving protein and flavonoid analysis were used to investigate both interpopulational and species comparisons in the genus Liquidambar. Striking differences in budburstinq patterns after a dormant period were seen when comparing L. styraciflua and L. formosana. The latter species showed earlier initiation of growth. Dormancy patterns of L. styraciflua grown under growth chamber conditions showed a latitudinal cline. Cessation of growth occurred later in a Georgia population under both long and short day experimental periods than populations from Missouri and Kentucky. When grown under controlled conditions, flavonoid patterns from L. …
Attentiveness And Time Budget Of A Pair Of Nesting Wood Storks, E. Scott Clark
Attentiveness And Time Budget Of A Pair Of Nesting Wood Storks, E. Scott Clark
Retrospective Theses and Dissertations
An instantaneous sampling system was used to quantify nest attentiveness and time budget of a pair of Wood Storks (Mycteria americana) nesting at the Moore Creek colony on Merritt Island National Wildlife Refuge in 1977. The amount of time devoted to various activities during each stage of the 4-month reproductive cycle was examined and differences between stages evaluated. During the incubation period an adult was constantly at the nest site and the birds shared equally in the incubation duties. During the first four weeks of the 8-week pre-flight nestling stage, an adult was with the chicks continuously, although the adults …
Relationship Of Tecate Cypress Distribution To Soil Types, David E. Stottlemyer
Relationship Of Tecate Cypress Distribution To Soil Types, David E. Stottlemyer
Loma Linda University Electronic Theses, Dissertations & Projects
The Tecate Cypress (Cupressus forbesii Jeps.) is a gymnosperm tree of limited distribution. To determine if soil is an influencing factor in its distribution, the soil characteristics of a Tecate Cypress grove in the Santa Ana Mountains of Orange County, California, were compared with soils from neighboring communities and other Tecate Cypress groves. Soil samples were analyzed for texture, saturation percent, pH, and electrical conductivity. Tests were also run for nutrients such as nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese, copper and zinc.
Results seem to indicate that the Tecate Cypress soils are: 1) significantly more acidic than the soils …
The Effect Of Light Intensity On The Incorporation Of Calcium Into The Carbonate Skeleton In Bossiella Orbigniania, Carol D. Logan
The Effect Of Light Intensity On The Incorporation Of Calcium Into The Carbonate Skeleton In Bossiella Orbigniania, Carol D. Logan
Loma Linda University Electronic Theses, Dissertations & Projects
The effect of light intensity on the incorporation of calcium carbonate into the algal skeleton inBossiala orbigniana (Descaisne) Silva (1957) (Corallinaceae) was studied. Calcium-45 labeling of terminal segments under experimental laboratory conditions was used to estimate calcification rate. Plant sections were tested under each of six light intensities ranging between zero (darkness) and 1960 pW-2cm Calcium incorporation was found to be enhanced in light treatments as compared with dark treatment. Light of intensities ranging from 285 pW cm-2 to 1960 pW cm-2gave enhancement effects which were not significantly different from each other. Three alternate …
Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson
Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson
Publications (WR)
Density currents are commonly formed in reservoirs because of temperature or salinity induced density differences between inflowing and receiving waters. Anderson and Pritchard (1951) were among the first to demonstrate this in their investigations of density currents in Lake Mead. They found that the Colorado River formed an underflow in Lake Mead during the winter, an overflow in the spring and an interflow in the summer and fall. Wunderlich and Elder (1973) have since described the hydromechanics of these types of flow patterns, and density currents have been reported for several other large reservoirs (Carmack et al. 1979, Johnson and …
Macroinvertebrates And Reservoir Discharge: Effects Of The Cave Run Lake On Tailwater Communities, Stephen James Jordan
Macroinvertebrates And Reservoir Discharge: Effects Of The Cave Run Lake On Tailwater Communities, Stephen James Jordan
Morehead State Theses and Dissertations
A thesis presented to the faculty of the School of Sciences and Mathematics at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Stephen James Jordan on May 2, 1980.
A Comparison Of Vitamin A1 & A2 Levels & The Role Of Beta-Carotene & Lutein In The Synthesis Of Vitamin A In Freshwater Fishes, Benjamin Del Tito Jr.
A Comparison Of Vitamin A1 & A2 Levels & The Role Of Beta-Carotene & Lutein In The Synthesis Of Vitamin A In Freshwater Fishes, Benjamin Del Tito Jr.
Masters Theses & Specialist Projects
The objectives of this study were to determine naturally occurring concentrations of vitamin A1 and A2 in selected native fishes and, under laboratory conditions, to determine the possible role of beta-carotene and lutein in the synthesis of vitamin A by goldfish. The native fishes were selected to exhibit different feeding habits and were taken from different habitats (stream vs. lake) during different seasons of the year. In the laboratory, two possible precursors, beta-carotene and lutein, were incorporated into the diet to determine the role of these substances in the synthesis of vitamin A.
Species of fish differed in …