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Articles 3631 - 3660 of 4342

Full-Text Articles in Life Sciences

End Matter, Vol. 20 No. 5 Jun 1978

End Matter, Vol. 20 No. 5

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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Mammals Of The Smithsonian Venezuelan Project, Charles O. Handley Jr. Jun 1978

Mammals Of The Smithsonian Venezuelan Project, Charles O. Handley Jr.

Brigham Young University Science Bulletin, Biological Series

Mammals and their ectoparasites were collected in all parts of Venezuela between 1965 and 1968 by the Smithsonian Venezuelan Project. Ecological and geographical data are summarized here for 38,213 specimens of 270 species of mammals obtained by the project.

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Front Matter, Vol. 20 No. 5 Jun 1978

Front Matter, Vol. 20 No. 5

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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Front Matter, Vol. 2 Mar 1978

Front Matter, Vol. 2

Great Basin Naturalist Memoirs

No abstract provided.

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Full Issue, Vol. 2 Mar 1978

Full Issue, Vol. 2

Great Basin Naturalist Memoirs

No abstract provided.

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End Matter, Vol. 2, Index Mar 1978

End Matter, Vol. 2, Index

Great Basin Naturalist Memoirs

No abstract provided.

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End Matter, Vol. 2 Mar 1978

End Matter, Vol. 2

Great Basin Naturalist Memoirs

No abstract provided.

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Photosynthetic Fractionation Of Oxygen Isotopes, A Study With Elodea Canadensis, Glen E. Martin Dec 1977

Photosynthetic Fractionation Of Oxygen Isotopes, A Study With Elodea Canadensis, Glen E. Martin

Theses and Dissertations

Bubbles of oxygen from Elodea canadensis were collected and found 5 per mil enriched in 0-18. This confirms the results of both Dole and Vinogradov, who found 0-18 enrichment of photosynthetic oxygen relative to its source, i.e. water. Photosynthesis and respiration appear to have produced the Dole effect, i.e. the 22 per mil 0-18 enrichment of atmospheric oxygen relative to ocean water, its probable source. These results are contrary to findings for both UV photolysis and electrolysis of water both evolving oxygen found depleted in 0-18.

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Feeding Biology And Ecological Aspects Of A Cancroid Crab Cancer Oregonensis (Dana) Rathbun (Decapoda, Brachyura), Gary L. Child Dec 1977

Feeding Biology And Ecological Aspects Of A Cancroid Crab Cancer Oregonensis (Dana) Rathbun (Decapoda, Brachyura), Gary L. Child

Theses and Dissertations

In the San Juan Archipelago, cancer oregonensis (Dana) Rathbun (Fig. 1) is abundant and distributed from the low intertidal zone to -435 m subtidally (Rathbun, 1904). Ricketts and Calvin (1974) refer to c. oregonensis as the most common Cancer species in this area.

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Leaf Litter Processing In Aquatic Systems Two Variable Model, Boyd Jay Hanson Dec 1977

Leaf Litter Processing In Aquatic Systems Two Variable Model, Boyd Jay Hanson

Theses and Dissertations

The adequacy of the negative exponential model with one independent variable, days or accumulated time, as a descriptive equation for aquatic leaf litter processing was examined. The effect of adding a second independent variable, degree days or accumulated temperature, to the model was also examined. The two variable negative exponential model was shown to have at least two advantages over the single variable model. The two variable model adequately fits litter processing data for more cases than the single variable model. The expanded model also allows determination of rate coefficients for various temperature levels of the experiment rather than assuming …

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Algal Response To A Thermal Effluent : Study Of A Power Station On The Provo River, Utah, Usa, Lorin E. Squires Dec 1977

Algal Response To A Thermal Effluent : Study Of A Power Station On The Provo River, Utah, Usa, Lorin E. Squires

Theses and Dissertations

The effect of a thermal effluent on the attached algae of the Provo River, Utah, USA, was studied from 1975 to 1977. Data for macroscopic and microscopic algae were collected and analyzed. Diatoms, Cladophora glomerata, and Hydrurus foetidus dominated the flora. The thermal effluent significantly affected the algal flora in a section of river 100 to 135 meters long immediately below the discharge point. Cladophora growth was increased and Hydrurus was absent in this area. In addition, diatom production was often higher and diversity lower than in the rest of the river. Community structure was unique from all other adjacent …

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The Accumulation And Metabolism Of Triphenyltin Hydroxide (Du-Ter) In Crayfish (Procambarus Clarkii) In A Model Ecosystem, John Gary Hollingshaus Aug 1977

The Accumulation And Metabolism Of Triphenyltin Hydroxide (Du-Ter) In Crayfish (Procambarus Clarkii) In A Model Ecosystem, John Gary Hollingshaus

Theses and Dissertations

Triphenyltin hydroxide (TPTH) appears to be relatively stable in soil. Only minor partitioning into water occurred because of the insolubility of TPTH in water and its adsorption to soil. Residues in the water were also relatively stable. The concentration. of TPTH in the tissues of crayfish exposed to 1.0 ppm of TPTH in the soil was 0.1 ppm or 10% that of the environment. Crayfish exposed to 0.01 ppm of TPTH in the soil had 0.005 ppm TPTH in their tissues or 50% that of the environment. Greater than 80% of the residue in the muscle tissue appeared to be …

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Ethionine-Resistant Mutants Of The Filamentous Blue-Green Alga Plectonema Boryanum /|Cby Wayne M. Hentsche, Wayne M. Hentschel Aug 1977

Ethionine-Resistant Mutants Of The Filamentous Blue-Green Alga Plectonema Boryanum /|Cby Wayne M. Hentsche, Wayne M. Hentschel

Theses and Dissertations

Ethionine-resistant mutans of Plectonema boryanum have been isolated and partially characterized. The mutant strains exhibit at least 100-fold increase in resistance to L-ethionine. The nature of the change which confers ethionine resistance is not known, but appears to result from the inability of the resistant strains to incorporate ethionine into acid-precipitable material. Initially, ethionine has no effect on the growth rate of the wild-type or the resistant strains, but several hours of exposure to the analog at a concentration greater than 0.5 μg/ml causes a marked inhibition of growth and bleaching in the wild-type cells. The onset of bleaching precedes …

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The Plant Communities Of Arches National Park, John Stevens Allan Aug 1977

The Plant Communities Of Arches National Park, John Stevens Allan

Theses and Dissertations

Arches National Park, located in southeastern Utah, lies in a transition zone between the southwestern hot desert and the western cold desert, but it is floristically most similar to the hot desert. The major plant communities are as follows: Juniper-pinyon, blackbrush, grasslands and sand dune association. Other community types occur but occupy very limited areas. All of the communities studied have a high degree of uniqueness and merit recognition as separate entities. Blackbrush showed the greatest overall similarity to other communities and was most similar to the sand dune communities. The hanging gardens were the most distinctive and covered the …

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The Sage Creek Mountain Local Fauna Of The Bridger Formation Near Lonetree, Wyoming, Steven W. Barker Aug 1977

The Sage Creek Mountain Local Fauna Of The Bridger Formation Near Lonetree, Wyoming, Steven W. Barker

Theses and Dissertations

The Bridger Formation in the Green River Basin has been divided into two members, the lower Black's Fork member and the upper Twin Buttes member. 'Ihe Black's Fork member is composed of' biostratigraphlc zones A and Band the Twin Buttes member is com-posed of biostratigraphic zones C, D and E. Recent workers have found that zones A and B contain the same fauna and therefore represent just one biostratigraphic zone (McGrew 1971, Robinson 1970). Future studies of the biostratigraphic zones of the Twin Buttes member are necessary to determine if the C, D and E zones are valid. Some are …

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Plant Dioecy, Ecology, Evolution And Sex Reversal, D. Carl Freeman Aug 1977

Plant Dioecy, Ecology, Evolution And Sex Reversal, D. Carl Freeman

Theses and Dissertations

The distribution of dioecious species among forty-four plant communities of western United States was examined. The dioecious habit is most prevalent in harsh environments. In many communities, over 20 percent of the species and 40 percent of the individuals are dioecious. Dioecy is most common among woody species which are pollinated by wind. It is concluded that inbreeding depression alone is insufficient to account for all known facts concerning dioecy. Disruptive selection acting upon differential success of gametes produced on sites of differing quality appears to have played a major role in producing separate sexed individuals. Dioecious species reported to …

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Drosophila Pseudoobscura Of The Great Basin, Monte E. Turner Aug 1977

Drosophila Pseudoobscura Of The Great Basin, Monte E. Turner

Theses and Dissertations

Four Utah populations of Drosophila pseudoobscura from the Wasatch Mountains in Utah were sampled and characterized for third chromosome gene arrangements. The original samples in this area were taken in 1940 and 1950. At that time the populations were essentially monomorphic for the Arrowhead arrangement, with small percentages of Pikes Peak and Chiricahua also found. The current samples show these populations to contain eight third chromosome arrangements; seven previously described (AR, PP, CH, ST, TL, OL, EP) and a newly discovered endemic arrangement (American Fork, AF), with breakpoints 63E and 70D. The frequency of AR had decreased to 25% in …

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Bionomics Of A Subterranean Gall Midge (Diptera : Cecidomyiidae) From Artemisia Ludoviciana, Ranasinghe Aug 1977

Bionomics Of A Subterranean Gall Midge (Diptera : Cecidomyiidae) From Artemisia Ludoviciana, Ranasinghe

Theses and Dissertations

Bionomics of a gall midge that emerged from nodulelike structures of herbaceous sage, Artemisia ludoviciana Nutt., was studied as a part of a larger investigation on possible nitrogen fixation by this plant. Infested plants collected from the field were regularly examined in the laboratory where some of them were grown in a liquid nutrient medium. In the laboratory, adult midges were reared from the pupae and induction of infestation was attempted. Apparent nodulation on these plants is caused by the subterranean bud galls of a previously unknown gall midge species, Rhopalomyia subhumilis Gagne. The life history of this midge is …

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A Revision Of The Herbaceous Members Of The Genus Atriplex (Chenopodiaceae) For The State Of Utah, K. H. Thorne Jul 1977

A Revision Of The Herbaceous Members Of The Genus Atriplex (Chenopodiaceae) For The State Of Utah, K. H. Thorne

Theses and Dissertations

The herbaceous Atriplex species which occur in Utah are revised. This study is based on herbarium specimens and field observations throughout the state. My treatment largely follows that of Rall and Clements (1923). A brief discussion of the history, diagnostic characteristics and phylogeny is given. A descriptive key that includes all taxa has been prepared: type locality, synonyms, general habitat and distribution is reported for each entity. Illustrations and maps are included. One variety is described as new.

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The Mammals Of Zion National Park With Emphasis On Ecology And Distribution Of Twelve Species Of Rodents, Paul A. Gardner Jul 1977

The Mammals Of Zion National Park With Emphasis On Ecology And Distribution Of Twelve Species Of Rodents, Paul A. Gardner

Theses and Dissertations

Information concerning the mammals of Zion National Park was needed for management purposes and general information. During the summers of 1975 and 1976, mammals observed throughout the park were recorded and habitat structure was measured for each animal at the immediate observation site. Ordinations based on stepwise discriminant analyses of the data on 12 rodent species were constructed and substantiated by Bray-Curtis analyses. The results showed that amounts of cover and boulders contrasted the habitats of Peromyscus eremicus, P. maniculatus, P. crinitus, P. boylii and P. truei. A second group of species--Eutamias minimus, E. umbrinus, Spermophilus variegatus, Tamiasciurus hudsonicus, Dipodomys …

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Phlox Longifolia Nuttall (Polemoniaceae) Complex Of North America, Frederick J. Peabody Jul 1977

Phlox Longifolia Nuttall (Polemoniaceae) Complex Of North America, Frederick J. Peabody

Theses and Dissertations

Over 1,000 herbarium specimens including 24 type specimens were examined in an attempt to achieve a clearer understanding of the Phlox longifolia complex. Four variables were measured for each specimen and the data were statistically analyzed by disciminant analysis. Using a previously published system of classification for the complex approximately 73% of the measured variation among the specimens was accounted for by that system. The clustering patterns produced in this first analysis indicated that a more conservative approach would be advisable. The formulataion and subsequent application of a modified system produced a grouping of specimens that accounted for 95% of …

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Behavior And Age Class Structure Of Wintering Northern Bald Eagles (Haliaeetus Leucocephalus Alascanus) In Western Utah, Ronald A. Joseph Jul 1977

Behavior And Age Class Structure Of Wintering Northern Bald Eagles (Haliaeetus Leucocephalus Alascanus) In Western Utah, Ronald A. Joseph

Theses and Dissertations

Bald Eagles in Cedar and Rush Valleys of western Utah were studied from 1975 to 1977. Arriving in mid-November, the eagles departed in mid-March. A statewide Bald Eagle census revealed 200 to 300 birds. Wintering eagle populations have remained stable for the past 10 years. Immatures comprised 35% of the population in 1975-76 and 33% in 1976-77. While Black-tailed jackrabbits are the primary food source of wintering eagles in western Utah, other mammalian carrion serve as supplementary food items. Eagles utilized 4 communal night roosts. Three day communal roosts were located on south facing slopes. The social existence of Bald …

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The Relationship Of Reduced Levels Of Atp To Inhibited Chondrogenesis In The Production Of Limb Deformity Induced By 6-Aminonicotinamide, Val C. Sheffield May 1977

The Relationship Of Reduced Levels Of Atp To Inhibited Chondrogenesis In The Production Of Limb Deformity Induced By 6-Aminonicotinamide, Val C. Sheffield

Theses and Dissertations

6-aminonicotinamide (6-AN), an analogue and antagonist of nicotinamide, impairs cartilage formation and results in shortening of the limb when administered to chick embryos. 6-AN forms an abnormal NAD analogue (6-ANAD), which inhibits the activity of NAD-dependent enzymes associated with the production of ATP. The mechanism of action of 6-AN was studied by measuring the biosynthesis of protein and DNA, and the sulfation and glycosylation of chondroitin sulfate in control and 6-AN treated cartilage from 8-day chick embryos. The cartilage was also assayed for ATP levels. Incorporation of Na235SO4 was inhibited by 6 h treatment with 10 μg/ml 6-AN, whereas 3H-thymidine …

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The Genus Haemolaelaps (Acarina: Laelapidae) In The Northwest Ethiopian Biogeographical Region, Calvin J. Sakamoto May 1977

The Genus Haemolaelaps (Acarina: Laelapidae) In The Northwest Ethiopian Biogeographical Region, Calvin J. Sakamoto

Theses and Dissertations

This paper presents the results of a taxonomic stury of mites of the genus Haemolaelaps collected from small mammals of 8 political subdivisions of the northwest portion of the Ethiopian Biogeographical Region. Specimens taken from 2,863 small mammals from a wide variety of habitats and localities were examined. The Haemolaelaps fauna includes 23 species, 10 of which are described as new: H. bellasoma, H. caurinus, H. chaetospinicus, H. crocidura, H. desmodilliscus, He. ebsi, H. malachela, H. parahirsti, H. sikapusi and H. taterakempi. Numerical taxonomic and multicariate analyses were used to assess variation and clustering. A key for identification of females …

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Sex-Linked Mental Retardation Without Physical Stigmata (Martin-Bell Or Renpenning Type) : A Genetic And Psychometric Approach, Craig L. Hanis Apr 1977

Sex-Linked Mental Retardation Without Physical Stigmata (Martin-Bell Or Renpenning Type) : A Genetic And Psychometric Approach, Craig L. Hanis

Theses and Dissertations

Screening the Utah State Training School (a resident institution for the mentally retarded) for kindreds having at least two institutionalized sibs generated 54 sib groups. Of these, 20-male only sibships had histories compatible with sex-linked mental retardation without physical stigmata (Martin-Bell or Renpenning type). Affected males had no characteristic physical stigmata (an appreciable number did have speech problems and/or seizure disorders) and exhibited IQs ranging from 5 to 74 with a mean of 34.2. Obligate carrier females had a mean IQ score of 91.9 (range, 79 to 106), which is as would be predicted due to random X-inactivation. Carrier females …

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Environmental Interaction In Summer Algal Communities Of Utah Lake, Mark C. Whiting Apr 1977

Environmental Interaction In Summer Algal Communities Of Utah Lake, Mark C. Whiting

Theses and Dissertations

Utah Lake is a shallow eutrophic lake located in central Utah. It is characterized by high nutrient and silt loads and by large algal blooms in late summer and early fall. Phytoplankton samples and environmental data were taken from June through August 1974. Phytoplankton species were identified and then quantified in a Palmer counting cell. Environmental continuum theory was employed to describe algal succession and regression analysis was used to discover interactions between algal communities and the environment. Phytoplankton communities in June were characterized by high species diversity. As the lake environment became stressed in late summer due to higher …

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Accumulation And Metabolism Of Triphenyltin Hydroxide (Du-Ter) In Channel Catfish, Hal B. Jenson Apr 1977

Accumulation And Metabolism Of Triphenyltin Hydroxide (Du-Ter) In Channel Catfish, Hal B. Jenson

Theses and Dissertations

The fate of ring-14C labeled triphenyltin hydroxide was studied in a model ecosystem consisting of soiI, water, and channel catfish (Ictalurus punctatus). Two initial levels of triphenyltin hydroxide concentration in soiI, 1.0 and 0.010 ppm, were compared. The soiI showed a gradual loss of 20 to 30% of the total 14C residues. Only about 33% of the remaining soil residues could be extracted and almost all of these were triphenyltin hydroxide. Total residues in the water were very low. Catfish muscle and viscera accumulated 14C residues continually throughout the treatment portion of the experiment. When the catfish were transferred to …

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Canopy Influence As A Factor In Determining Understory Community Composition, Richard B. Wilcox Apr 1977

Canopy Influence As A Factor In Determining Understory Community Composition, Richard B. Wilcox

Theses and Dissertations

Four tree species (i.e. Pinus ponderosa, Juiperus scopulorum, Quercus Gambelii, and Ceanothus velutinus were chosen for this study. Ten individuals of each species were selected and their associated understory communities and adjacent non-understory communities sampled. Data taken included biotic and abiotic parameters. The data was subjected to similarity index analysis, cluster analysis, discriminant analysis, and x^2 analysis. The results were confirmed by all tests. The forest canopy was shown to directly influence the understory community. The understory community is a shrub-grass dominated type while the non-understory community is an annual-forb dominated type. The different tree species were also shown to …

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Partitioning Of Space And Time By The Western Jumping Mouse, Zapus Princeps Utahensis Hall, John M. Deacon Apr 1977

Partitioning Of Space And Time By The Western Jumping Mouse, Zapus Princeps Utahensis Hall, John M. Deacon

Theses and Dissertations

Intraspecific competition is important in determining habitat utilization by members of a single species. Effective use of habitat may involve partitioning the available resources: space, time and food among individuals of different age, sex, and/or reproductive state. Numerous publications deal with interspecific competition (McCloskey and Fieldwick 1975, Cody 1973, Rosenzweig 1973, Stewart and Levin 1973, Gaby 1972, Brown 1971, Koshkina 1971, Sheppe 1967, Caldwell and Gentry 1965, Cameron 1964, Clough 1964, Gause 1932), but little has been written on intraspecific competition among populations of organisms in nature.

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Isolation, Purification, Scanning Electron Microscopy And Bacterial Dna Uptake Of Plant Protoplasts, Bronwyn G. Hughes Apr 1977

Isolation, Purification, Scanning Electron Microscopy And Bacterial Dna Uptake Of Plant Protoplasts, Bronwyn G. Hughes

Theses and Dissertations

Protoplasts were isolated from tobacco and barley leaves in sucrose or mannitol using commercially available cellulases and macerozymes. Barley growth and protoplast isolation and purification conditions were optimized so that protoplasts were obtained in high yields free of unwanted debris and organelles. A technique for processing barley and tobacco protoplasts for examination by scanning electron microscopy was developed in which protoplasts seem to have maintained their structural integrity. Barley and tobacco protoplasts took up 3H-B. subtilis DNA, 125I-B. subtilis DNA or 125I-M. luteus DNA as a linear function of time (0-6 hr) and DNA concentration (0-200 μg/ml). Up to 16 …

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