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Articles 3721 - 3750 of 4342

Full-Text Articles in Life Sciences

Analysis Of Macroinvertebrate Samples From Ten Rocky Mountain Streams, Fred A. Mangum Aug 1975

Analysis Of Macroinvertebrate Samples From Ten Rocky Mountain Streams, Fred A. Mangum

Theses and Dissertations

This study was an attempt to evaluate the effects on ten Rocky Mountain streams from management activities on U.S. Forest Service lands. Macroinvertebrate and water chemistry data were collected. Data analysis methods included: three diversity indices, a numerical taxonomy system of multivariate statistical analysis, numbers and biomass per selected taxa, percent composition per order, and total numbers and biomass. None of the methods of analysis were found to be adequate if used alone, but by using a combination of dendograms, biomass, and numbers data in addition to the diversity indices (SCI and d) stream stress could be detected. Although organic …

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Timpanogos Flora, Kelly W. Allred Aug 1975

Timpanogos Flora, Kelly W. Allred

Theses and Dissertations

A comprehensive floristic study of Mt. Timpanogos, Utah County, Utah, was undertaken. The Mt. Timpanogos area is a much used facility in recreation, biology, watershed development, livestock management, and education. It is also representative of a major segment of the overall flora of Utah. This study adds to the ever-increading knowledge of the flora of Utah, and provides a means of identifying the flora of this region, which is basic to any future management.

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Two New Species Of The Genus Cycadeoidea From The Lower Cretaceous Of Utah, H. Blaine Furniss Jul 1975

Two New Species Of The Genus Cycadeoidea From The Lower Cretaceous Of Utah, H. Blaine Furniss

Theses and Dissertations

Cyadeoidea medullara and C. cleavelandii, two new species of the genus Cycadeoidea, have been recovered from the Lower Cretaceous Cedar Mountain Formation of Utah. They have been described in histologic detail and relationships with similar species are set forth. Monoecism and pollination mechanisms have been discussed in connection with C. medullara. This data contributes to our knowledge of the diverse composition of Lower Cretaceous floras in Utah.

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A Paleocene Flora From The Fort Union Formation Near Baggs, Carbon County, Wyoming, John L. Roth Jul 1975

A Paleocene Flora From The Fort Union Formation Near Baggs, Carbon County, Wyoming, John L. Roth

Theses and Dissertations

A well-preserved Paleocene flora of 39 species from the Fort Union Formation near Baggs, Carbon County, Wyoming has been studied. This is the first study of the plant megafossils in this area. The most abundant species collected are: Carya antiquorum Platanus nobilis, Cercidiphyllum arcticum and Platanus raynoldsi. Together they represent 74% of the flora. The flora has been dated as Upper Middle Torrejonian. This report is also the first paleoecological study of any North American Paleocene flora. Two methods were used to determine the paleoclimatic conditions of the flora. The first was an analysis of leaf margin characteristics, comparing them …

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The Subfamily Leeuwenhoekinae In The Neotropics (Acarina: Trombiculidae), Jack T. Reed, James M. Brennan Jul 1975

The Subfamily Leeuwenhoekinae In The Neotropics (Acarina: Trombiculidae), Jack T. Reed, James M. Brennan

Brigham Young University Science Bulletin, Biological Series

Neotropical representatives of the subfamily Leeuwenhoekinae are reviewed. The genus Odontacarus comprises 66 percent of the chiggers examined, and 82 percent of this genus were identified as O. tubercularis (Brennan). The following genera are redescribed: Albeckia Veracammen-Grandjean and Watkins, Leeuwenhoekia Oudemans, Odontacarus Ewing, Sasacarus Brennan and Jones, Wagenaaria Brennan, and Whartonia Ewing. New taxa are: Odontacarus comosus comosus, O. c. novemsetus, O. dienteslargus, O. pugnosus, O. schoenesetosus, O. sunnianae, O. tiptoni, O. tuberculohirsutus, O. vanderhammeni, O. vergrandi, Sasacarus furmani panamensis, and Whartonia angulascuta. Odontacarus fieldi Brennan and Jones, 1961, and O. cayolargoensis Brennan, 1959, are synonymized under O. tubercularis Brennan, …

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End Matter, Vol. 20 No. 1 Jul 1975

End Matter, Vol. 20 No. 1

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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A List Of Venezuela Chiggers, Particularly Of Small Mammalian Hosts (Acarina: Trombiculidae), James M. Brennan, Jack T. Reed Jul 1975

A List Of Venezuela Chiggers, Particularly Of Small Mammalian Hosts (Acarina: Trombiculidae), James M. Brennan, Jack T. Reed

Brigham Young University Science Bulletin, Biological Series

Detailed or summarized records of 136 species in 38 genera with a key to the latter are provided. Of 86 described forms, 49 are new for Venezuela; the remaining undescribed taxa are coded for purposes of this report. A classified host-parasite list is appended.

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Front Matter, Vol. 20 No. 1 Jul 1975

Front Matter, Vol. 20 No. 1

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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Raptor Temperature Regulation And Energetics, James Arthur Mosher May 1975

Raptor Temperature Regulation And Energetics, James Arthur Mosher

Theses and Dissertations

A review of energetics studies of raptorial species introduces four separate studies of temperature regulation by raptors. Golden Eagle (Aquila chrysaetos) nest site selection, as influenced by direction of exposure, is discussed. The data show strong directional preferences to the NNW by southern populations and SSE by northern populations. The tarsometatarsus is shown to have a thermoregulatory function in large falcons, and adaptations of this mechanism to varied habitats are examined. Color phase in Screech Owls (Otus asio) is shown to be related to metabolic differences that may explain the distributions of the color morphs. Development of thermoregulation in Flammulated …

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Close Coupling Test Of Classical And Semiclassical Cross Sections For Rotationally Inelastic Ar-N2 Collisions, Russell T. Pack Apr 1975

Close Coupling Test Of Classical And Semiclassical Cross Sections For Rotationally Inelastic Ar-N2 Collisions, Russell T. Pack

Faculty Publications

Accurate quantum mechanical close coupling (CC) integral cross sections are reported for rotationally inelastic Ar-N2 collisions at room temperature using an empirical intermolecular potential. These cross sections are used to test the infinite order sudden (IOS) approximation and the results of several methods [classical trajectories (CT), full sudden (SA), generalized phase shift (GPS), and classical limit generalized phase shift (CGPS)] as reported in the preceding paper by Pattengill. The IOS approximation works very well for cross sections involving low rotational states. The CT method works well for all the cross sections examined, justifying the popular belief that the rotational motion …

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Small Mammal Survey In Two Geographically Separated Aspen Areas, Apichart Thammaruxs Apr 1975

Small Mammal Survey In Two Geographically Separated Aspen Areas, Apichart Thammaruxs

Theses and Dissertations

Small mammal surveys were conducted in two geographically separated aspen areas, in the Chicken Creek Watershed Management Unit, Utah, and Break Neck Flat, Wyoming. Four small mammal species, Peromyscus maniculatus, Clethrionomys gapperi, Zapus princeps and Eutamias minimus were caught most often in both areas of the aspen ecosystem. Peromyscus maniculatus was usually the most abundant animal trapped at all locations indicating the success of this species in aspen communities. The proportion of each species trapped, however, fluctuated, likely in accordance with responses to periodic biotic and abiotic factors. This data will serve as baseline information for the U.S. Forest Service …

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Folate Content Of Bacillus Subtilis, David Nelson Hintze Apr 1975

Folate Content Of Bacillus Subtilis, David Nelson Hintze

Theses and Dissertations

Bacillus subtilis can synthesize deoxythymidylate via either of two pathways. The working hypothesis is that the two reactions are very similar, differing only with respect to specificity for the type of folate required as substrate. The folates from B. subtilis were isolated and were determined by gel chromatography to be derivatives of pteroyltriglutamate and pteroyldiglutamate. Kav values for the two folate species are reported. Conjugase treatment revealed no other highly conjugated folates present. It was also observed that mutants deficient in one or the other of the two pathways grow at the same rate as wild-type cells under conditions allowing …

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Ecology Of The Ferruginous Hawk (Buteo Regalis) In Central Utah Population Dynamics And Nest Site Selection, Neil D. Woffinden Apr 1975

Ecology Of The Ferruginous Hawk (Buteo Regalis) In Central Utah Population Dynamics And Nest Site Selection, Neil D. Woffinden

Theses and Dissertations

Research was conducted to determine the effect of prey numbers on the nesting success of the Ferruginous Hawk (Buteo regalis). Conditions associated with nest site selection were also established. Frequent visits were made to active nests to determine clutch sizes, hatching dates and fledging success. Prey remains were collected from nests and analyzed. Kilometer square transects were made throughout the study area in 1974 to determine jackrabbit densities. A drastic decline in numbers of Ferruginous Hawks occurred. The number of young fledged also declined throughout the study while nestling mortality increased. Jackrabbit numbers were high in 1972 and then declined …

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A Comparative Study Of Some Population Characteristics Of Calyptraea Fastigiata Gould, Crepidula Lingulata Gould, And Crepidula Nummaria Gould (Gastropoda, Prosobranchia), Roger Harold Goodwill Apr 1975

A Comparative Study Of Some Population Characteristics Of Calyptraea Fastigiata Gould, Crepidula Lingulata Gould, And Crepidula Nummaria Gould (Gastropoda, Prosobranchia), Roger Harold Goodwill

Theses and Dissertations

A comparative study of the field populations of Crepidula lingulata, Crepidula nurnmaria, and Calyptraea fastigiata indicated all three preferred a rocky substrate but favored different size rocks. Their positions on the rocks varied but the greatest numbers were found attached to the undersides. Crepidula lingulata and C. nummaria preferred larger rocks and were found in intraspecific associations more often than C. fastigiata which preferred smaller rocks. These associations occurred with a 1:1 sex ratio; however, the overall population did not. Crepidula lingulata had a high female count and C. fastigiata a high male count. Males, of all three species, were …

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Manual Of The Flora Of The East Tintic Mountains, Utah, Glen T. Nebeker Apr 1975

Manual Of The Flora Of The East Tintic Mountains, Utah, Glen T. Nebeker

Theses and Dissertations

The study of the East Tintic Mountains was undertaken because no extensive research concerning the plant species present has ever been done. The East Tintic Mountains are in central Utah in Juab, Utah and Tooele Counties. They are about fifty five air miles south-southwest of Salt Lake City. The range is approximately forty two miles long and from one and one-half miles to twelve miles wide. An attempt was made to collect representatives of all vascular plants found on the mountain range. This work presents two hundred and eleven species, representing fifty two families.

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Diatom Phytoplankton And Periphyton Studies Of The Headwaters Of Henrys Fork Of The Snake River, Island Park, Idaho, Richard L. Clark Apr 1975

Diatom Phytoplankton And Periphyton Studies Of The Headwaters Of Henrys Fork Of The Snake River, Island Park, Idaho, Richard L. Clark

Theses and Dissertations

An ecological baseline study of the diatom flora was conducted on the headwaters of Henrys Fork of the Snake River, Idaho. The diatom flora of this spring fed drainage basin consisted of both phytoplankton and periphyton. Thirty-nine genera, two hundred forty-four species, eighty-two additional varieties, and seven additional forms were identified from these waters. Species of Melosira, Stephanodiscus, Fragilaria, Synedra, and Asterionella were found in the plankton of Henrys Lake and Island Park Reservoir. Diatoma, Fragilaria, Synedra, Eunotia, Achnanthes, Navicula, Pinnularia, Gomphonema, Cymbella, Nitzschia, and Surirella were the important genera present in the periphyton.

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An Assay Chamber For Quantitative Analysis Of Nitrogen Fixation Using Intact Plants, Thomas Adrie Leslie Apr 1975

An Assay Chamber For Quantitative Analysis Of Nitrogen Fixation Using Intact Plants, Thomas Adrie Leslie

Theses and Dissertations

A unique assay system for quantitative analysis of biological nitrogen fixation by intact plants has been constructed and successfully tested. With the system, it has been possible to detect acetylene reduction by intact legumes in situ under laboratory conditions. This assay method is designed to approximate field conditions and in spite of possible procedural errors in sampling, background noise of the gas chromatograph and ethylene contamination of the acetylene gas used in the assay, this method is sensitive ·enough to detect as little as 1 ppm enrichment of ethylene gas as a result of acetylene reduction by intact soybean plants. …

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Chemotaxonomical Comparison Of Astragalus Megacarpus, Astragalus Beckwithii, And Astragalus Oophorus In Utah, Marzilla Wright Anderson Apr 1975

Chemotaxonomical Comparison Of Astragalus Megacarpus, Astragalus Beckwithii, And Astragalus Oophorus In Utah, Marzilla Wright Anderson

Theses and Dissertations

This investigation was concerned with the taxonomic relationship between Astragalus beckwithii (Torr. & Gray) var. beckwithii, Astragalus oophorus (S. Wats) var. caulescens (Jones) Jones, and Astragalus megacarpus (A. Gray). An attempt was made to relate some chemical constituents and the toxic effects on rats to the taxonomy. A number of parameters were used; rat toxicity, lipid analysis, selenium atomic absorption, various salts and glucose percentages, as well as the usual morphological measurements taken from herbarium specimens, field observations, and pollen measurements. While the weight of the data indicates that A. beckwithii is a type of intermediary or intergressory product of …

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Breeding Biology And Ecology Of The Peregrine Falcon (Falco Peregrinus) In West Greenland, William A. Burnham Apr 1975

Breeding Biology And Ecology Of The Peregrine Falcon (Falco Peregrinus) In West Greenland, William A. Burnham

Theses and Dissertations

During the last twenty years marked declines in Peregrine Falcon populations have occurred in many parts of the world (Hickey, 1969). During recent years the peregrine has been placed on the list of Endangered Species. Several factors have been suggested as the cause of its decline. These include changing climatic conditions (Porter and White, 1973), human disturbance (Mattox, pers. comm.), and introduction of chlorinated hydrocarbons as pesticides into the environment (Ratcliffe, 1970). The third factor, introduction of chlorinated hydrocarbons, has occurred on the American, European and Asian continents. Even peregrines nesting in locations far from human population concentrations are exposed …

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An Investigation Of The Ecology Of Subalpine Fir On The Markagunt Plateau In Southern Utah, Ronald Beatty Bolander Apr 1975

An Investigation Of The Ecology Of Subalpine Fir On The Markagunt Plateau In Southern Utah, Ronald Beatty Bolander

Theses and Dissertations

The ecology of subalpine fir relative to broom rust was investigated. Broom rust infections were most common in trees growing on limestone soils, and seldom occurred on trees growing on basalt soils. Even though plant moisture stress was consistently higher in the plants from limestone soils, the studies indicated that moisture stress is not the major factor causing infection. The amounts of available magnesium and phosphorus were much lower in the limestone soil. It is postulated that the higher plant moisture stress of subalpine fir growing on limestone soils may aggrevate the lack of nutrients and be a contributing factor …

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Use Of Selected Macroinvertebrates As Indicators Of Sedimentation Effects On Huntington River, Utah, Michael Kenneth Reichert Mar 1975

Use Of Selected Macroinvertebrates As Indicators Of Sedimentation Effects On Huntington River, Utah, Michael Kenneth Reichert

Theses and Dissertations

Benthic macroinvertebrate communities of Huntington River, Emery County, Utah were studied to determine effects of sedimentation from construction of Electric Lake Dam, a state highway, and two bridges. Approximately 900 benthic samples were collected from riffle areas above, in, and below the construction zone from January, 1971 to December, 1973. Two settling basins below construction sites were effective in limiting scouring of downstream communities. Heavy silt deposition was limited to a 1-km stream reach. Number of indicators, density, and biomass were reduced in the construction zone during periods of sediment input. During periods of scouring, density and biomass were reduced; …

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Dance In The Church Of Jesus Christ Of Latter-Day Saints 1830-1940, Karl E. Wesson Jan 1975

Dance In The Church Of Jesus Christ Of Latter-Day Saints 1830-1940, Karl E. Wesson

Theses and Dissertations

The purpose of this study was to compile a history of dance in The Church of Jesus Christ of Latter-day Saints from 1830 to 1940.
The following subproblems have been investigated:
1. What was the history of dance in The Church of Jesus Christ of Latter-day Saints?
2. What was the philosophy of dance in the LDS Church?
3. What were the dance forms, music, and attire in dance within the LDS church?
4. What was the contribution of the LDS Church towards the preservation of folk dances in America?

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Cinemicrography Of Selected Parasites Of Fishes And Of Free-Living Stages Of Haemonchus Contortus, Stephen Homer Hilton Dec 1974

Cinemicrography Of Selected Parasites Of Fishes And Of Free-Living Stages Of Haemonchus Contortus, Stephen Homer Hilton

Theses and Dissertations

Two 16 mm color films were made to help fill a general need for instructional motion pictures in the area of Parasitology. One film "Haemonchus contortus, a Sheep Stomach Worm," deals with a nematode parasite of sheep, showing all stages of its external development and including a time-lapse sequence of the embryonation of the egg. The other film, "Some Parasites of Freshwater Fishes," shows six parasites; Ichthyophthirius multifiliis, Cotylurus erraticus, Dactylogyrus sp., Lernaea cyprinacea, Trichodina sp., and Diplostomum spathaceum for the first time in motion pictures. The films were photographed through a Wild dissecting scope and a Reichert Universal Camera …

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Life History And Ecology Of The Great Basin Sagebrush Swift, Sceloporus Graciosus Graciosus Baird And Girard, 1852, Gary L. Burkholder, Wilmer W. Tanner Dec 1974

Life History And Ecology Of The Great Basin Sagebrush Swift, Sceloporus Graciosus Graciosus Baird And Girard, 1852, Gary L. Burkholder, Wilmer W. Tanner

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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End Matter, Vol. 19 No. 5 Dec 1974

End Matter, Vol. 19 No. 5

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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Front Matter, Vol. 19 No. 5 Dec 1974

Front Matter, Vol. 19 No. 5

Brigham Young University Science Bulletin, Biological Series

No abstract provided.

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Activity Of A Dipodomys Ordii Population Using Recapture Methods, James R. Garcia Nov 1974

Activity Of A Dipodomys Ordii Population Using Recapture Methods, James R. Garcia

Theses and Dissertations

Activity curves for Dipodomys ordii were developed from data obtained from a study utilizing an electrically monitored trapping grid. The curves for non-perturbated populations showed an initial post-dusk peak, followed by increasing activity and a large pre-dawn peak; but after ten dominant animals had been removed, the largest activity peak was post-dusk. Differences in activity patterns were not found among sex, age or reproductive classes. Rising ambient temperatures, falling barometric pressures, winds over 3.2 km/hr and the absence of the moon depressed capture numbers; while increasing humidity (relative and absolute), decreasing soil temperatures at 20 and 40 cm below ground …

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The Effects Of Highway Construction On The Fish Populations In The Weber River Near Henefer, Summit County, Utah, Edward James Peters Nov 1974

The Effects Of Highway Construction On The Fish Populations In The Weber River Near Henefer, Summit County, Utah, Edward James Peters

Theses and Dissertations

Alterations of streams to facilitate highway construction and consumptive water use has become a fisheries management problem. To evaluate the effects of channeling concomitant to construction of Interstate 80 N. near Henefer, Utah, altered and unaltered sections of the Weber River were compared on the basis of fishes censused, population estimates and ordinations. Species compositions in particular areas were influenced by local rheologic conditions. Changes in species composition between samplings at a particular area were caused by fish movements. Data from altered sections, rehabilitated with deflectors and checkdams, were not noticeably different than data from unaltered areas. However, fish movements …

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Erratum: On Improved Wkb (Uniform Asymptotic) Quantum Conditions, Dunham Corrections, The Langer Modification, And Rkr Potentials, Russell T. Pack Nov 1974

Erratum: On Improved Wkb (Uniform Asymptotic) Quantum Conditions, Dunham Corrections, The Langer Modification, And Rkr Potentials, Russell T. Pack

Faculty Publications

In Eqs. (28) and (29) p should be changed to t.

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The Genus Hedysarum In North America, Terry Edwin Northstrom Aug 1974

The Genus Hedysarum In North America, Terry Edwin Northstrom

Theses and Dissertations

In North America, Hedysarum taxa extend from southern Arizona to Banks Island and from northern Alaska to Newfoundland. They exhibit a high degree of polymorphism which is usually expressed in the form of a gradient in morphological characteristics. Four species, one subspecies and four varieties are recognized, including one new combination, H. boreale ssp. boreale var. rivulare (Williams) Northstrom. Comparative anatomical and morphological studies revealed two basic patterns. Chromosome numbers of all taxa were determined. The basic chromosome number of H. alpinum, H. sulphurescens and H. occidentale is n=7. The basic chromosome number of H. boreale is n=8. Seed protein …

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