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Articles 3661 - 3690 of 4342

Full-Text Articles in Life Sciences

Cytosol Binding Of Steroid Hormones In Sheep Brains And Pituitaries, David Carl Marcusen Mar 1977

Cytosol Binding Of Steroid Hormones In Sheep Brains And Pituitaries, David Carl Marcusen

Theses and Dissertations

The uptake and binding of tritiated cortisol, corticosterone, and dexamethasone in cytosols isolated from various regions of non-adrenalectomized (intact) and adrenalectomized sheep brains and pituitaries were studied. [3H]-cortisol and [3H]-corticosterone were bound preferentially by cytosols from the hippocampal and septal regions of the brain, whereas, [3H]-dexamethasone was preferentially bound by cytosol from the pituitary. Cytosols isolated from the brains of adrenalectomized sheep bound significantly more [3H]-corticosterone than did cytosol from the brains of intact animals. Pre-incubation of cytosols from the hippocampus of adrenalectomized animals with non-radioactive testosterone or estradiol did not significantly block the subsequent binding of [3H]-cortisol. Results of …

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Utilization Of Nest Boxes By Birds In Three Vegetational Communities With Special Reference To The American Kestrel (Falco Sparverius), Laurence Barrett Mcarthur Mar 1977

Utilization Of Nest Boxes By Birds In Three Vegetational Communities With Special Reference To The American Kestrel (Falco Sparverius), Laurence Barrett Mcarthur

Theses and Dissertations

This study was designed to determine if, by providing artificial nest sites, a raptorial predator could be attracted into an area where suitable sites are limited. The American Kestrel (Falco sparverius) was a common species in the area and nest boxes designed for their use were placed in three vegetational types in western Utah and eastern Nevada. Seventy boxes were available in 1975 and 110 in 1976. Kestrels nested both years in the salt-desert shrub community but were absent from the pinyon-juniper and riparian areas. Four other bird species nested in the latter two areas, however. In 1975 the nesting …

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Certain Edaphic And Biotic Factors Affecting Vegetation In The Shadscale Community Of The Kaiparowits Area, Vane Orlan Campbell Mar 1977

Certain Edaphic And Biotic Factors Affecting Vegetation In The Shadscale Community Of The Kaiparowits Area, Vane Orlan Campbell

Theses and Dissertations

A study area on the southern extensions of the Great Basin cold desert (Kaiparowits Basin, Utah) was selected which has had varying amounts of disturbance. Areas with similar slope and exposure in the Shadscale community were sampled. At each site, soil samples were collected and percent sand, percent clay, percent silt, soluble salts, and hydrogen ion concentrations were measured. Cluster analysis based on percent frequency of the perennial species showed that eight groups or sub-communities were definable within the area sampled. Patterns within the vegetation were shown to be independent with the use of cluster analysis. Discriminant analysis on soil …

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Intermolecular Potential Surfaces From Electron Gas Methods. Ii. Angle And Distance Dependence Of The A’ And A” Ar–No(X^2ii) Interactions, Glen C. Nielson, Gregory A. Parker, Russell T. Pack Feb 1977

Intermolecular Potential Surfaces From Electron Gas Methods. Ii. Angle And Distance Dependence Of The A’ And A” Ar–No(X^2ii) Interactions, Glen C. Nielson, Gregory A. Parker, Russell T. Pack

Faculty Publications

Angle dependent intermolecular potential energy surfaces for the two states (2A’ and 2A”) that arise from the interaction of ground (X^2II) state NO with Ar are calculated using the electron gas model to obtain the short range interactions. The average and difference of the two interaction energies are fit to analytic forms convenient for use in scattering calculations and joined smoothly onto the long range van der Waals potential previously determined. The results, which appear to be of useful accuracy, and the applicability of the electron gas model to such open shell–closed shell interactions are discussed.

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Front Matter, Vol. 1 Dec 1976

Front Matter, Vol. 1

Great Basin Naturalist Memoirs

No abstract provided.

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End Matter, Vol. 1 Dec 1976

End Matter, Vol. 1

Great Basin Naturalist Memoirs

No abstract provided.

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Effect Of Altitude On The Peripheral Degradation Of Thyroxine In The Uinta Ground Squirrel (Citellus Armatus), Stuart K. Ware Dec 1976

Effect Of Altitude On The Peripheral Degradation Of Thyroxine In The Uinta Ground Squirrel (Citellus Armatus), Stuart K. Ware

Theses and Dissertations

Various methods were employed to detect changes in the peripheral degradation of thyroxine (T4) in adult Uinta ground squirrels (Citellus armatus) collected at two different altitudes (5400 and 9000 feet.) Plasma half-life of injected T4-125I (tl/2) was significantly decreased with altitude, as was T4-125I distribution space (TDS) and T4 degradation and secretion rate (TSR). In vitro deiodination of T4-125I by heart homogenates was not affected, while urinary excretion of thyroxine derived iodide was increased at high altitude 44-70 hours post-injection. Both total and free serum T4 concentrations were reduced at high altitude, although not significantly. The cause of the reduced …

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Population Characterization And Feeding Behavior Of A Subtidal Neogastropod, Amphissa Columbiana, Bruce C. Stone Dec 1976

Population Characterization And Feeding Behavior Of A Subtidal Neogastropod, Amphissa Columbiana, Bruce C. Stone

Theses and Dissertations

The neogastropod Amphissa columbiana is found abundantly in subtidal areas of the San Juan Archipelago. Two populations studied were composed of distinct age classes of sexually immature and mature specimens. Reproduction appears to take place in the fall by snails at least two years old. Amphissa is a chemoreceptive scavenger that usually feeds on carrion and on dead and injured animals. Feeding behavior is mediated by chemical attractants from dead and traumatized tissue. An unusual feeding association is formed where Amphissa congregate around feeding predators to share their meals. A specific defense mechanism is deployed by Amphissa especially in response …

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The Osteology And Myology Of The Head And Neck Region Of Callisaurus, Cophosaurus, Holbrookia, And Uma, The "Sand Lizards", Douglas Charles Cox Dec 1976

The Osteology And Myology Of The Head And Neck Region Of Callisaurus, Cophosaurus, Holbrookia, And Uma, The "Sand Lizards", Douglas Charles Cox

Theses and Dissertations

Blainville (1835) wrote the first description of a sand lizard and named it Callisaurus draconoides. Since his time various authors have published articles concerning sand lizards. Girard (1851) described Holbrookia maculata, Trochel (1852) described Cophosaurus texanus, and that same year Baird and Girard synonymized Cophosaurus with Holbrookia providing the name Holbrookia texana, which has stood for over 100 years. Subsequently, Baird (1858) described Uma notata.

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Potential Diets For Carp Production, Rex Carlton Infanger Dec 1976

Potential Diets For Carp Production, Rex Carlton Infanger

Theses and Dissertations

The objective of this study was to determine the feasibility of raising carp on pig manure and coli, Brassica campestris. The use of pig feces as a source of fish food has been questioned by researchers (Hickling 1968). Coli was selected for dietary intake by fish since it is used for human consumption by the Indians of Guatemala. Commercial fish food (Silver Cup) was used for a control diet. These diets were both combined and used as a single source of food.

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Spatial And Temporal Partitioning Between Sympatric Rodents: Zapus And Peromyscus, Emma Bernice Speer Dec 1976

Spatial And Temporal Partitioning Between Sympatric Rodents: Zapus And Peromyscus, Emma Bernice Speer

Theses and Dissertations

Partitioning space and time by seemingly sympatric rodents, Zapus princeps and Peromyscus maniculatus, were examined as possible mechanisms allowing coexistence. The two populations were studied in Central Utah with an electrically monitored grid. Spatial separation of individuals and the populations minimized confrontations and created local allopatric distribtuions. Temporal partitioning was not used as a mechanism to allow coexistence and was apparently independent of spatial partitioning. The Peromyscus population was composed primarily of males which may have been due to less favorable habitat and/or presence of Zapus. The data show that Peromyscus tend to avoid Zapus, possibly due to deleterious aggressive …

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A Taxonomic And Ecologic Study Of The Riverbottom Forest On St. Mary River, Lee Creek, And Belly River In Southwestern Alberta, Canada, Robert K. Shaw Sep 1976

A Taxonomic And Ecologic Study Of The Riverbottom Forest On St. Mary River, Lee Creek, And Belly River In Southwestern Alberta, Canada, Robert K. Shaw

Great Basin Naturalist

The riverbottom forest community of St. Mary River, Lee Creek, and Belly River in southwestern Alberta, Canada, is a unique ecological entity characterized by poplar species having their major Alberta distribution along these streams. Stands in the community are dominated by three tree species, six shrub species, and nine herb species. Establishment of the community is dependent on climate and substrate; destruction is the result of progressive lateral stream-flow erosion. Soils are sandy loams above gravel, with pH values of 7.7 to 8.0 and soluble salt concentrations of 176 to 458 parts per million. Trees in mature stands averaged 23.0 …

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The Snowy Egret (Egretta Thula Brewsteri) A Life History Study At Utah Lake With Comments On The Subspecies Status, Gerald Leigh Gunnell Aug 1976

The Snowy Egret (Egretta Thula Brewsteri) A Life History Study At Utah Lake With Comments On The Subspecies Status, Gerald Leigh Gunnell

Theses and Dissertations

This study was conducted to augment the limited information available regarding the Snowy Egret in the Utah Lake area of Utah. Field observations included the following: nesting habits; egg and clutch sizes; sexual, defense, and feeding behaviors. Analysis was made of the distinguishing subspecies characteristics (culmen, tarsus, and wing length) of the Snowy Egrets and of the distribution of the birds. Field observations showed that growth measurements of the young varied from 16.75 g at hatching to 260.58 g after 17 days. Culmen and tarsus measurements were 15.41 mm and 14.12 mm to 53.18 mm and 62.18 mm, respectively, after …

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Defense Mechanism And Feeding Behavior Of Pteraster Tesselatus Ives (Echinodermata, Asteroidea), James Milton Nance Aug 1976

Defense Mechanism And Feeding Behavior Of Pteraster Tesselatus Ives (Echinodermata, Asteroidea), James Milton Nance

Theses and Dissertations

Pteraster tesselatus is noted for its external secretion of massive amounts of mucus. The mucus repels most animals, and fouls their respiratory physiology, if contact is maintained for any length of time. It provides protection essentially 100% of the time from Solaster dawsoni and Pycnopodia helianthoides, the only local stars that attempt to feed on Pteraster. The mucus, which is a simple mucopolysaccride, is produced in three different types of unicellular glands located in the epidermal tissues along the supradorsal membrane. Pores along the lateral walls of the ambulacral grooves provide fresh sea water for the dermal branchiae contained in …

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Influence Of Preharvest Ethephon Applications On Ripening Of Japanese Plum (Prunus Salicina), George Marvin Leavitt Aug 1976

Influence Of Preharvest Ethephon Applications On Ripening Of Japanese Plum (Prunus Salicina), George Marvin Leavitt

Theses and Dissertations

Ethephon, applied to two plum cultivars, 'Queen Rosa' and 'El Dorado' , at 50 and 100 ppm, gave varying responses on the ripening process. Soluble solids remained unchanged while acid levels dropped. Increased ethylene evolution, color advancement and decreased flesh pr observed.

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Esr Study Of Free Radicals In Irradiated Single Crystals Of Potassium Hydroxylamine Disulfonate, B. J. Wilson, Robert W. Holmberg Aug 1976

Esr Study Of Free Radicals In Irradiated Single Crystals Of Potassium Hydroxylamine Disulfonate, B. J. Wilson, Robert W. Holmberg

Faculty Publications

Two free radicals formed when single crystals of potassium hydroxylamine disulfonate are irradiated with gamma rays at 77degrees K were studied by ESR. The ESR spectra result from a predominant center (radical A) exhibiting large 14N and 1H hyperfine splittings and from lesser amounts of Fremy's radical [O-dotN(SO3)2-2]. The g and hyperfine tensors of these radicals have been evaluated and are discussed. Radical A, whose identity remains in doubt, may be regarded as the precursor to Fremy's radical; on warming its lines decay and those of Fremy's radical are formed. Lines from radical A decrease in strength and those of …

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The Cryptogamic Flora Of Desert Soil Crusts In Southern Utah, Davic C. Anderson Aug 1976

The Cryptogamic Flora Of Desert Soil Crusts In Southern Utah, Davic C. Anderson

Theses and Dissertations

The cryptogamic flora of several soil crusts of arid regions in southern Utah was determined. Twenty-two lichens, Six mosses and fifty-four algal species were identified and their relative abundance estimated.

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Efficacy Of Zoalene And Clopidol In Dogs Experimentally Infected With Isospora Canis, James Carson Brown Aug 1976

Efficacy Of Zoalene And Clopidol In Dogs Experimentally Infected With Isospora Canis, James Carson Brown

Theses and Dissertations

Isospora canis (Protozoa:Nemeseri, 1959) is an important coccidian parasite of domestic dogs. Ingestion of the sporulated oocysts causes the release of sporozoites which invade the epithe-lial lining of the intestine. Schizogony and gametogony take place in the epithelial tissue resulting in a massive proliferation of the parasite and extensive destruction of the intestinal cells (Lepp and Todd, 1974). Severe infections cause loss of appetite, diarrhea and dysentery (Levine, 1973).

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A Phylogenetic Study Of The Suffrutescent Shrubs In The Genus Atriplex, C. Lorenzo Pope Aug 1976

A Phylogenetic Study Of The Suffrutescent Shrubs In The Genus Atriplex, C. Lorenzo Pope

Theses and Dissertations

Growing on dry saline soils throughout the Intermountain Region of the United States is a group of herbaceous, perennial species of Atriplex, including A. corrugata, A. cuneata, A. cuneata ssp. Introgressa, A. falcata, A. gardneri, A. tridentata, and A. welshii, designated as the Atriplex gardneri complex. Highly adaptive and competitive in the arid salt deserts, these species are valuable as forage for livestock and wildlife. Because of extensive variation present within this complex, considerable taxonomic confusion has resulted. To clarify taxonomic and phylogenetic relationships, selected populations and plants were analyzed morphologically, cytologically, ecologically, phenologically, and genetically. Polyploidy is common within …

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Evaluation Of Anhydrous Ammonia As A Control Of Northern Pocket Gophers Thomomys Talpoides On Rangelands In The Wasatch Mountain, Utah, Marc C. Wride Aug 1976

Evaluation Of Anhydrous Ammonia As A Control Of Northern Pocket Gophers Thomomys Talpoides On Rangelands In The Wasatch Mountain, Utah, Marc C. Wride

Theses and Dissertations

Anhydrous ammonia (NH3) was tested as a potential replacement for residual, non specific toxicants as an effective control agent. It was postulated that NH3 would effectively control northern pocket gophers (Thomomys talpoides) and also act as a fertilizer for rangeland vegetation. Compound 1080 was selected as a standard for comparison of gopher control efficiency. Over 700 burrow systems were treated or monitored. Results showed compound 1080 to be 81 percent and NH3 45 percent efficient in controlling gophers. Although fertilizing effects of NH3 were positive, the low control efficiency and high application costs make NH3 an unlikely replacement for the …

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Bionomics Of Two Aspen Bark Beetles : Trypophloeus Populi And Procryphalus Mucronatus (Coleoptera:Scolytidae), Jerold L. Petty Jul 1976

Bionomics Of Two Aspen Bark Beetles : Trypophloeus Populi And Procryphalus Mucronatus (Coleoptera:Scolytidae), Jerold L. Petty

Theses and Dissertations

Beetles of Trypophloeus populi attacked green bark of unhealthy aspen (Populus tremuloides) and hastened the death of the tree. Beetles of Procryphalus mucronatus favored dead bark and were of little significance in the death of the aspen. These two beetle species were distinguished from each other by their primary galleries, eggs, larvae, larval mines, and mating behavior. In T. populi, there were three larval instars and one to one and one-half generations per year; only larvae overwintered, and the eggs of the first generation were present by mid-July. In P. mucronatus, there were two larval instars and one and one-half …

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Endoparasites Of Cats In Two Central Utah Communities, Thomas W. Sawyer Jul 1976

Endoparasites Of Cats In Two Central Utah Communities, Thomas W. Sawyer

Theses and Dissertations

A survey of the endoparasites of 100 stray cats in central Utah was conducted. Each cat was euthanized, and the entire alimentary tract, gall bladder, bile duct, heart, respiratory and excretory systems were excised and examined for endoparasites. Fecal samples were examined by a sugar flotation technique. Parasites identified and number of cats infected were: Isospora felis 5; I. rivolta, 4; Dipylidium caninum, 1; Hydatigera taeniaformis, 10; Toxocara mystax, 43; and Physaloptera sp., 2. One ectoparasite, Cheyletiella parasitivorax, was identified in the feces of 4 cats. Dipylidium caninum and T. mystax are known to cause accidental infection in humans and …

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Front Matter, Vol. 20 No. 4 Jun 1976

Front Matter, Vol. 20 No. 4

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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End Matter, Vol. 20 No. 4 Jun 1976

End Matter, Vol. 20 No. 4

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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The Streblid Batflies Of Venezuela (Diptera: Streblidae), Rupert L. Wenzel Jun 1976

The Streblid Batflies Of Venezuela (Diptera: Streblidae), Rupert L. Wenzel

Brigham Young University Science Bulletin, Biological Series

This study was based on more than 36,000 Venezuelan Streblidae representing ca. 115 species and species complexes in 22 genera, taken from more than 6,800 hats of 95 species. Two new genera are proposed and 45 new species are described. The morphology is briefly discussed and terminology is revised. Collection data are given for each species, together with discussions on variability and host relationships when pertinent. Keys to genera and species arc included, as well as illustrations of most species. Noctiliostrebla dubia (Rudow) and the male of Parastrebla handleyi Wenzel are characterized, and relationships of Speiseria are discussed. New Taxa– …

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Ecological Investigations In Cercocarpus Ledifolius Nutt. Communities Of Utah, James Newton Davis Apr 1976

Ecological Investigations In Cercocarpus Ledifolius Nutt. Communities Of Utah, James Newton Davis

Theses and Dissertations

Cercocarpus ledifolius communities of Utah were sampled to determine which measured environmental characters were influential in determining community structure and dynamics. Nineteen, one-tenth acre stands were sampled by 25 equally spaced .25m2 quadrats. Plant frequency, cover, density, height, diameter, age, elevation, slope and exposure were determined for curl-leaf mahogany within the study area. Soil depth and soil samples were analyzed for texture, pH and soluble salts. Curl-leaf mahogany is found almost entirely on arid rocky slopes, canyon ledges, and plateaus at relatively high elevations on all exposures. The soils were invariably shallow and slightly acidic with sandy loam soils being …

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Correlations Between Plant Species Diversity And Flower Characteristics In The Wasatch Mountains Of Utah And Idaho, William Kent Ostler Apr 1976

Correlations Between Plant Species Diversity And Flower Characteristics In The Wasatch Mountains Of Utah And Idaho, William Kent Ostler

Theses and Dissertations

An analysis of the relative abundance of the prevalent species in 25 major plant communities of the Wasatch Mountains demonstrates that variation in species diversity is significantly correlated with many floral characteristics. Wind pollinated flowers decrease in abundance while animal pollinated flowers increase along the diversity gradient. Both relationships are highly significant statistically. Color diversity and species diversity are significantly and positively correlated in open communities but are not correlated in forest communities. The percent sum frequency of yellow and pink-magenta flowers decreased with increasing species diversity while blue and whitish flowers increased. Also, zygomorphic flowers and flowers in which …

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Modeling Studies Of Small Mammal Trapping Phenology, And Plant Succession In The Kaiparowits Region, Kane County, Utah, James A. Raines Apr 1976

Modeling Studies Of Small Mammal Trapping Phenology, And Plant Succession In The Kaiparowits Region, Kane County, Utah, James A. Raines

Theses and Dissertations

This study makes use of simple statistical models which may be manipulated for projection of changes in the Kaiparowits Region of Southern Utah. A method of determining habitat preferences of small rodents from capture-recapture trapping data is proposed. It is suggested that some aspects of animal behavior regarding trapping may also be explained. Timing of flowering of Oryzopsis hymenoides and Hilaria jamesii as related to enviromental conditions was investigated, and models of the requisite conditions proposed. It is suggested that similar models may be used to describe the timing of other phenological events. Succession on disturbed sites is considered to …

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Fixation Of Dormant Tilletia Teliospores For Thin Sectioning, John Scott Gardner Apr 1976

Fixation Of Dormant Tilletia Teliospores For Thin Sectioning, John Scott Gardner

Theses and Dissertations

Dormant Tilletia caries teliospores in fixative solution or distilled water were frozen onto specimen chucks of an FTS Sorvall- Christensen frozen thin sectioner and cut or fractured at various temperatures (-20 to -75 C) and thickness settings (10, 15, 20, and 25 um). Cytoplasm of dormant spores was well preserved and organelles were found to differ from those of germinated spores in morphology. Irregular electron dense and electron opaque areas of lipid bodies were sometimes evident in dormant and germinating Tilletia caries teliospores. When dormant teliospores were sectioned in buffered fixative, lipids had an appearance similar to lipids in thin …

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Differential Resource Utilization By The Sexes Of Dioecious Plants, Dwight Carl Freeman Apr 1976

Differential Resource Utilization By The Sexes Of Dioecious Plants, Dwight Carl Freeman

Theses and Dissertations

The distribution of male and female plants was examined in five dioecious, wind pollinated species representing five plant families and two classes (gymnosperms and angiosperms). The arid to semiarid habitats occupied by these species in northern Utah were stratified for sampling into two categories: chronically xeric and seasonally moist. Results show that for all species, males prevail on xeric microsites, while females dominate the more moist parts of each local environment. Habitat partitioning between the sexes is a strategy that maximizes seedset of females and pollen dispersal of males; it also tends to minimize intraspecific competition between the sexes.

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