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Articles 3691 - 3720 of 4342

Full-Text Articles in Life Sciences

A Revision Of The Genus Ranunculus (Ranunculaceae) For The State Of Utah, Margaret Doherty Palmieri Apr 1976

A Revision Of The Genus Ranunculus (Ranunculaceae) For The State Of Utah, Margaret Doherty Palmieri

Theses and Dissertations

This study is a taxonomic revision of the genus Ranunculus for Utah. Twenty-five species and 4 varieties are recognized, and are separated by means of a comprehensive key. A list of pertinent synonyms and types, a morphological description, habitat preference and a discussion are presented for each species and variety. Distribution maps and photographs are included. The basis of this study has been morphological comparison of herbarium specimens and collections and observations by the author throughout Utah.

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The Incidence And Life Cycle Of Diplostomum Spathaceum In Utah, R. Scott Evans Apr 1976

The Incidence And Life Cycle Of Diplostomum Spathaceum In Utah, R. Scott Evans

Theses and Dissertations

Diplostomum spathaceum (Rudolfi 1819), (Diplostomidae) the fish eye fluke which causes the disease diplostomatosis, was reported in Utah by the Division of Wildlife Resources in 1974. Previous to this date diplostomatosis was suspected to occur in three reservoirs in the state. Diplostomatosis, whi.ch is due to the presence of the metacercarial stage of this parasite, causes cataracts of the lens. The incidence of the disease in Utah has generated public and academic concern.

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Effect Of Supplemental Food On Population Estimates And Mortality Rates Of Desert Rodents In Utah, J. Steven Thiriot Apr 1976

Effect Of Supplemental Food On Population Estimates And Mortality Rates Of Desert Rodents In Utah, J. Steven Thiriot

Theses and Dissertations

The objective of this research is to assess the effects of various quantities of supplemental food (seed) on population estimates and mortality rates of desert rodents . The supplemental food is meant to stimulate natural vegetational productivity. If food availability significantly affects the population parameters methods of population estimators previously used may be in error. Hopefully this study will aid small mannnal research by designating whether, in part, population estimates and mortality rates are in error because of high vegetational productivity. The hypothesis of this study is that supplemental food in the natural environment decreases population estimates and mortality rates …

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Influence Of A Dry Wash Habitat On Distribution And Movement Of Heteromyid Rodents, Jeffrey S. Green Apr 1976

Influence Of A Dry Wash Habitat On Distribution And Movement Of Heteromyid Rodents, Jeffrey S. Green

Theses and Dissertations

Three heteromyid rodent species were studied in relation to a large dry wash in Millard County, Utah, during the summer, 1974. Data were gathered with three trapping grids and analyzed to determine if the dry wash influenced rodent movement and distribution patterns. Dipodomys ordii and Dipodomys microps were distributed non-randomly in the dry wash and adjacent habitat, but Perognathus Zongimembris seemed to be randomly distributed. Dipodomys ordii was significantly correlated with wash habitat, but D. microps was found most frequently in upland areas. Soil and vegetative differences and competition were possible causes for the observed distribution. The wash was observed …

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Vegetational Response To Three Environmental Gradients In A Salt Playa Near Goshen, Utah County, Utah, Michael Grant Skougard Apr 1976

Vegetational Response To Three Environmental Gradients In A Salt Playa Near Goshen, Utah County, Utah, Michael Grant Skougard

Theses and Dissertations

The plant communities and individual plant species in and around a salt playa near Goshen, Utah County, Utah were studied in relation to three environmental gradients. Forty-eight stands were sampled by means of meter square gradients. Frequency data for all participating plant species were taken. Soil samples were collected from each site and analyzed to establish the environmental gradients (i.e., total soluble salts, soil moisture and hydrogen ion concentration. Results indicate that community vegetation types respond differentially to the three gradients and can be segregated on the basis of one or more of the gradients. The total soluble salts gradient …

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Phytoseiid Predators Of Mite Pests In Utah Apple Orchards, Vichitra Mongkolprasith Mar 1976

Phytoseiid Predators Of Mite Pests In Utah Apple Orchards, Vichitra Mongkolprasith

Theses and Dissertations

Recent efforts to integrate certain Phytoseiid predators in pest (mite) management programs for apples have been somewhat successful and economical in many fruit growing areas. Convenient descriptions and reviews of the literature for species which have been collected from the state are provided to stimulate further work with Utah Phytoseiids. Seven species of Amblyseius and five Typhlodromus are described and notes provided concerning their respective geographic distributions and biologies.

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Tissue Chromium Levels :|Bautopsy Study In Diabetic And Non-Diabetic American (Pima) Indians, Leslie O. Hansen Mar 1976

Tissue Chromium Levels :|Bautopsy Study In Diabetic And Non-Diabetic American (Pima) Indians, Leslie O. Hansen

Theses and Dissertations

Tissues (liver, spleen, pancreas, and aorta) and hair taken at autopsy from diabetic and non-diabetic southwestern Indians (mainly Pima) were analyzed for chromium (Cr) using flameless atomic absorption spectrophotometry. The Cr levels in both tissues and hair from diabetic subjects were consistently lower than in those from non-diabetic individuals. There were so few individuals in each group that it was not possible to accurately correlate a given tissue either with any other tissues or hair.

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Van Der Waals Interactions Of Carbon Monoxide, Gregory A. Parker, Russell T. Pack Mar 1976

Van Der Waals Interactions Of Carbon Monoxide, Gregory A. Parker, Russell T. Pack

Faculty Publications

Pade approximant methods and experimental frequency dependent polarizabilities are used to calculate reliable van der Waals C6 coefficients for the interaction of CO with He, Ne, Ar, Kr, Xe, H, Li, Na, K, Rb, Cs, H2, N2, O2, CO2, and CO. Error bounds are given for the C6 coefficients and for the CO oscillator strength sums.

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Van Der Waals Interactions Of Ii-State Linear Molecules With Atoms. C6 For No(X 2Π) Interactions, Glen C. Nielson, Gregory A. Parker, Russell T. Pack Mar 1976

Van Der Waals Interactions Of Ii-State Linear Molecules With Atoms. C6 For No(X 2Π) Interactions, Glen C. Nielson, Gregory A. Parker, Russell T. Pack

Faculty Publications

Formulas are derived for the van der Waals Cn coefficients for the interaction of a diatomic molecule in a II electronic state with an S-state atom. Two triatomic states arise from the degenerate IIstate. The average of the two energies has the usual Legendre polynomial (PL) angular dependence, but the difference in energies of the two states is shown to have associated Legendre polynomial (PML with M=2) angular dependence. Procedures for including spin orbit coupling are included, and the extension to interactions of Delta- and Phi-state molecules is discussed. Values of the spherical part of the C6 coefficients for the …

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The Comparative Toxicity Of Developmental Inhibitors And Organophosphates On Mosquitoes, Richard L. Orr Feb 1976

The Comparative Toxicity Of Developmental Inhibitors And Organophosphates On Mosquitoes, Richard L. Orr

Theses and Dissertations

Four developmental inhibitors (Altosid, Altozar, ZR-619 and ZR-777) and two organophosphates (Parathion and Abate) were tested on Aedes aegypti under laboratory conditions. When applied to fourth-instar larvae, the organophosphates were more toxic than the developmental inhibitors. Concentrations required for standard kills (LC50 and LC95) were lower for Altosid and ZR-619 than for Altozar and ZR-777. Field applications of Altosid SR-10 controlled Culiseta inornata for two weeks at 4 ounces per acre. With the exception of Dolichopodidae, most non-target aquatic organisms showed little response to Altosid SR-10. Although the developmental inhibitors Altosid and ZR-619 require higher concentrations for mosquito control, they …

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Comment On ''Inelastic Scattering In Atom-Diatomic Molecule Collisions. I. Rotational Transitions In The Sudden Approximation'', Russell T. Pack Feb 1976

Comment On ''Inelastic Scattering In Atom-Diatomic Molecule Collisions. I. Rotational Transitions In The Sudden Approximation'', Russell T. Pack

Faculty Publications

It is argued that conflicting approximations in a recent paper [J. R. Stallcop, J. Chem. Phys. 61, 5085 (1974)] render the resulting theory invalid.

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Efficacy Of Bunamidine Hydrochloride Against Immature And Mature Stages Of Echinococcus Granulosus, Lauritz A. Jensen Dec 1975

Efficacy Of Bunamidine Hydrochloride Against Immature And Mature Stages Of Echinococcus Granulosus, Lauritz A. Jensen

Theses and Dissertations

A study was conducted to determine the efficacy of bunamidine hydrochloride against the immature and mature stages of Echinococcus granulosus found in Utah. Twenty-seven dogs were obtained from local animal shelters and experimentally infected with the parasite. The drug was given at dosage levels of 25 mg/kg to 50 mg/kg of bodyweight. It was from 85.9 to 98.8% effective against the immature stage, and 100% effective against the adult stage. The results suggest that this drug can feasibly be used under field conditions where hydatid disease is endemic.

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Studies Of N⁵, N¹⁰-Methylene Tetrahydrofolate Reductase From Porcine Kidney And Mouse L1210-Induced Tumor Tissues, Purification And Interaction With Antifolates, David W. Jayme Dec 1975

Studies Of N⁵, N¹⁰-Methylene Tetrahydrofolate Reductase From Porcine Kidney And Mouse L1210-Induced Tumor Tissues, Purification And Interaction With Antifolates, David W. Jayme

Theses and Dissertations

Methylene tetrahydrofolate reductase has been purified 1000-fold from porcine kidney and 400-fold from mouse L1210-induced tumor tissue by classical methods. The enzyme preparations have been demonstrated to be essentially free of contaminating methionine synthetase and serine transhydroxymethylase activity. Studies of the kinetic properties of the kidney and tumor enzymes, with respect to the reverse reaction using N5-methyl tetrahydrofolate as the variable substrate, have indicated Km values of 2.0 and 2.4 x 10-4 M, respectively. Inhibition of this key branch point enzyme in folate metabolism by a number of antimetabolites indicates that several of these antifolate compounds exhibit enzyme inhibition superior …

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Front Matter, Vol. 20 No. 2 Oct 1975

Front Matter, Vol. 20 No. 2

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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End Matter, Vol. 20 No. 2 Oct 1975

End Matter, Vol. 20 No. 2

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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Systematics Of Neotropical Hirstionyssus Mites With Special Emphasis With Special Emphasis On Venezuela (Acarina: Mesostigmata), C. Selby Herrin, Conrad E. Yunker Oct 1975

Systematics Of Neotropical Hirstionyssus Mites With Special Emphasis With Special Emphasis On Venezuela (Acarina: Mesostigmata), C. Selby Herrin, Conrad E. Yunker

Brigham Young University Science Bulletin, Biological Series

This paper presents the results of a systematic study of mites of the genus Hirstionyssus Fonseca collected from mammals, primarily in Venezuela, but including one collection each from Colombia, Nicaragua, and British Honduras. Previously described species from Panamá and Brazil are reviewed and new distributional records are listed. The known Neotropical fauna of Hirstionyssus mites includes 15 species, 7 of which are described here as new: H. proctolatus n. sp.; H. brachysternum n. sp.; H. dorsolatus n. sp.; H. rhipidomys n. sp.; H, venezuelensis n. sp.; H. brevicalcar n. sp.; and H. parvisoma n. sp. The previously unknown male and …

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Venezuelan Macronyssidae (Acarina: Mesostigmata), Robert C. Saunders Oct 1975

Venezuelan Macronyssidae (Acarina: Mesostigmata), Robert C. Saunders

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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Spinturnicid Mites Of Venezuela (Acarina: Spinturnicidae), C. Selby Herrin, Vernon J. Tipton Oct 1975

Spinturnicid Mites Of Venezuela (Acarina: Spinturnicidae), C. Selby Herrin, Vernon J. Tipton

Brigham Young University Science Bulletin, Biological Series

The results of an extensive survey of spinturnicid mites of bats from Venezuela are presented in this paper. Approximately 30,000 bats were collected from a wide variety of life zones and localities. A representative sample was searched for ectoparasites. There are 3 genera of the family Spinturnicidae in Venezuela: Cameronieta, Periglischrus, and Spinturnix. Three previously described species of Cameronieta were found in the Venezuelan collection. Of the 7 species of Spinturnix previously described from the New World, 4 are reported from Venezuela. The genus Periglischrus constitutes by far the most significant segment of the Venezuelan collection. It is represented by …

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Distribution And Abundance Of The Black-Billed Magpie (Pica Pica) In North America, Carl E. Bock, Larry W. Lepthien Sep 1975

Distribution And Abundance Of The Black-Billed Magpie (Pica Pica) In North America, Carl E. Bock, Larry W. Lepthien

Great Basin Naturalist

Analysis of Audubon Society Christmas bird count data and certain environmental variables shows the degree to which the Black-billed Magpie is a bird of cool arid regions in North America. The abundance and distribution of this species appear to be limited by two major climatic barriers: increasing summer temperatures in the Southwest and increasing summer humidity and precipitation on the central plains.

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End Matter, Vol. 20 No. 3 Sep 1975

End Matter, Vol. 20 No. 3

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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Mallophaga Of Venezuelan Mammals, K. C. Emerson, Roger D. Price Sep 1975

Mallophaga Of Venezuelan Mammals, K. C. Emerson, Roger D. Price

Brigham Young University Science Bulletin, Biological Series

Seven species of Mallophaga have been previously reported from Venezuelan mammals. In this paper an additional 28 species and subspecies, 7 of which are new, are reported from Venezuela; and 21 other species which have not been previously reported from Venezuela are included because their hosts are found there.

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Front Matter, Vol. 20 No. 3 Sep 1975

Front Matter, Vol. 20 No. 3

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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The Diatom Flora Of The Goshen Ponds And Wet Meadows, Larry L. St. Clair Aug 1975

The Diatom Flora Of The Goshen Ponds And Wet Meadows, Larry L. St. Clair

Theses and Dissertations

A taxonomic study of the diatoms of the Goshen ponds and adjacent wet meadows, Utah County, Utah, was conducted from April 1974 to March 1975. The diatom flora of these warm spring fed ponds consisted of thirty-five genera containing one hundred twenty-one species, twenty-eight varieties, and two forms. The flora was dominated primarily by the following genera: Achnanthes, Fragilaria, Synedra, Navicula, Cymbella, Terpsinoe, and Nitzschia. Nineteen plates with 150 illustrations accompany the text.

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The Effect Of Altitude On Thyroid Function Of The Uinta Ground Squirrel (Citellus Armatus), Wendell Lee Wells Aug 1975

The Effect Of Altitude On Thyroid Function Of The Uinta Ground Squirrel (Citellus Armatus), Wendell Lee Wells

Theses and Dissertations

Thyroid uptake and distribution of 125I, concentrations of T4 and T3 in serum and thyroids and concentrations of TSH in serum and pituitaries were measured to determine thyroid function of Uinta Ground Squirrels (Citellus armatus) native to 5,400 and 9,000 feet elevations to evaluate alterations in the state of the thyroid due to increased altitude. Uptake of 125I was 60 percent lower by squirrels from 9,000 feet. Incorporation of 125I into T3 was greater at the higher elevation, but absolute thyroid T3 concentrations were similar at both elevations. No significant differences were found in serum T3 concentrations, but squirrels living …

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The Effects Of Certain Steroids On The Growth Of Slime Mold, Physarum Polycephalum, Ching-Bun Paul Chen Aug 1975

The Effects Of Certain Steroids On The Growth Of Slime Mold, Physarum Polycephalum, Ching-Bun Paul Chen

Theses and Dissertations

The cortex of vertebrate adrenal glands secretes two major groups of hormones--glucocorticoids and mineralocorticoids. Glucocorticoids, which have an oxygen atom at carbon number 11, increase the rate of gluconeogenesis and increase the mobilization of lipids in mammals (Turner and Bagnara 1971). At the same time there is a decrease in protein synthesis. This latter effect may be homologous to a decrease in fibroblast growth in culture in the presence of certain corticosteroids (Ruhmann and Berliner 1965). The main function of mineralocorticoids, on the other hand, is to retain sodium ions. They have little or no gluconeogenic activity. Interestingly, however, these …

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The Effect Of Recreational Uses On Vegetation And Soil In The Buffalo Campground, Targhee National Forest, Island Park, Idaho, Susan Daines Foster Aug 1975

The Effect Of Recreational Uses On Vegetation And Soil In The Buffalo Campground, Targhee National Forest, Island Park, Idaho, Susan Daines Foster

Theses and Dissertations

The effect of trampling on vegetation and soil, as a result of recreational pressure, was studied in the Buffalo campground of the Targhee National Forest, Idaho. Site deterioration was most evident in the forty-two year old site. The tree stand had matured, but there were few young trees and tree reproduction had been reduced to ten seedlings per acre for Pinus contorta. Only two shrub species were sampled with a combined population of eight individuals per acre. Most of the grass species had been seeded; forbs provided 20% of the ground cover, 13% was bare ground and 71% litter. The …

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Bionomics Of Two Bark Beetles : Genus Chaetophloeus (Coleoptera : Scolytidae), John Wendell Aaron Aug 1975

Bionomics Of Two Bark Beetles : Genus Chaetophloeus (Coleoptera : Scolytidae), John Wendell Aaron

Theses and Dissertations

Shrubs are important as browse and cover for game animals and songbirds in the desert-shrub and chaparral plant communities in the Great Basin (Plummer, 1968). They also play a major role in soil binding and watershed maintenance (Colby and Weissert, 1975). Therefore, an understanding of the agents which affect the health and survival of the shrubs is important. Insects-have a great impact on the health and reproductive capacity of shrubs. Pollinators, defoliators, borers, etc. must be studied and known for proper management.

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Ultrastructural Investigations Of The Host-Parasite Interface Of Pumpkin Cotyledons And The Fungus Sclerotinia Sclerotiorum, Mark Edward Richtsteig Aug 1975

Ultrastructural Investigations Of The Host-Parasite Interface Of Pumpkin Cotyledons And The Fungus Sclerotinia Sclerotiorum, Mark Edward Richtsteig

Theses and Dissertations

Pumkin seedlings (Cucurbita maxima) were inoculated with the fungus Sclerotinia sclerotiorum (Lib.) de Bary. Center regions of non-infected and infected cotyledons of various lengths were cut into 1 x 2 mm strips and processed for ultrastructural investigations. Complementary portions of opposing non-infected cotyledons were also processed as control tissue, and contained fewer storage products in cells than cotyledons of comparable size from non-infected plants. Young non-infected cells contained distinct lipid bodies, protein bodies and electron dense inlusions which were translocated out of older cells by abundant plasmodesmata. Initally, infected cells became plasmolyzed, followed by breakdown of the cytoplasm. Host cells …

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The Effect Of Lead And Zinc On Selenium Poisoning In Mice, Cynthia Joy Call Aug 1975

The Effect Of Lead And Zinc On Selenium Poisoning In Mice, Cynthia Joy Call

Theses and Dissertations

Trace elements, because they are effective in catalytic amounts, must be held in delicate balance with each other as well as with the macronutrients of the diet. Disturbances of these balances result in deficiency and toxicity symptoms. Toxic doses of selenium, lead, and zinc, for example, are known to cause anemia (1, 2, 3, 4) and growth depression (5, 3) in experimental animals.

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Habitat Partitioning In A Community Of Passerine Birds, Robert C. Whitmore Aug 1975

Habitat Partitioning In A Community Of Passerine Birds, Robert C. Whitmore

Theses and Dissertations

Habitat partitioning was studied in a community of passerine birds in the Virgin River Valley of southwestern Utah. Ten habitat structure variables were measured for each of 24 species of passerine birds and several multivariate statistical techniques were used to determine the extent of habitat partitioning. Ordinations of species distributions along known environmental gradients were constructed using Principal Component Analysis and Stepwise Discriminant Analysis. Stepwise Discriminant Analysis was also used to determine which habitat variables were important in species separation. It was found that percent canopy cover was the most important variable. Two hundred seventy six pairs of species were …

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