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Articles 4921 - 4950 of 5010
Full-Text Articles in Life Sciences
Life History Of The Desert Wood Rat, Robert Carr Stones
Life History Of The Desert Wood Rat, Robert Carr Stones
Theses and Dissertations
A life history field study of the widespread desert wood rat, Neotoma lepida lepida Thomas, was conducted periodically from August, 1959, to June, 1960, eight miles west of Jericho, Juab County, Utah. An estimation of the density of houses and population density of wood rats throughout the general region, accomplished by charted guadrats and a plotless quarter method, revealed an average densityof 4.9 houses of 3.1 adult wood rats per acre in a juniper-sagebrush community of the type frequently found throughout the area. Live-trapping within a well-wooded juniper-sagebrush community (twenty-four acre area) revealed twenty-seven wood rats captured sixty-eight times for …
Vegetational Changes In A Shadscale-Winterfat Plant Association During Twenty-Three Years Of Controlled Grazing, Kimball T. Harper
Vegetational Changes In A Shadscale-Winterfat Plant Association During Twenty-Three Years Of Controlled Grazing, Kimball T. Harper
Theses and Dissertations
This paper will report the results of a study commenced in 1935, at the Desert Experimental Range, Pine Valley, Millard County, Utah, to determine the relative effects of various grazing treatments upon the plant members of the shadscale [Atriplex confertifolia (Torr. And Frem.) S. Wats.] - winterfat [Eurotia lanata (Pursh) Moq.] plant association. Results of this study indicate that distinct vegetational changes have occurred within that plant association during twenty-three years of controlled grazing by sheep.
Studies On The Biological Oxidation Of Ferrous Iron And Chalcopyrite, Loral Alvin Decker
Studies On The Biological Oxidation Of Ferrous Iron And Chalcopyrite, Loral Alvin Decker
Theses and Dissertations
The purpose of this investigation was to determine the effectiveness of the leaching streams from waste copper ore dumps as a nutrient solution for subsequent biological oxidation and solubilization of sulfide minerals. The copper in the leaching streams is precipitated by displacement with iron. As a result of this procedure the solution is high in ferrous iron concentration and has a pH of near 3.7. The bacteria in the leaching streams are capable of oxidizing ferrous iron to the ferric state and sulfide minerals to sulfates. The effects of temperatures, pH, urea, and aeration rate on the oxidation of the …
Bionomics Of Culex Tarsalis Coquillett In Utah County, Stanley K. Taylor
Bionomics Of Culex Tarsalis Coquillett In Utah County, Stanley K. Taylor
Theses and Dissertations
This paper presents information concerning the bionomics of Culex tarsalis Coquillett in Utah County. Observations indicate that rock piles and talus slides are typical hibernation sites. The spring emergence from hibernation occurred between 28 March and 7 April 1959. Larvae breed in a great variety of habitats, including street-gutters, animal tracks, marshes and waste water from irrigation systems. The peak population density for both larvae and adults occurred during the first week in August. Charts, graphs, drawings and photographs are used in the presentation of data.
Identification Of Larval Ticks Of The Genus Ixodes Known To Occur In Utah, Leland D. White
Identification Of Larval Ticks Of The Genus Ixodes Known To Occur In Utah, Leland D. White
Theses and Dissertations
The purpose of this study is to present an analysis and key to the larvae of the nine species of Ixodes known to occur in Utah. These are I. kingi, I. muris, I. texanus, I. pacificus, I. spinipalpis, I. marmotae, I. ochotonoe, I angustus, and I. sculptus. Larvae from the first five of these nine species used in this study were reared in the laboratory by worked cited in the secion on Analysis of Species. those of the remaining four were identified on the basis of their presence with identifiable numphal and adult forms. Host specificity, although certainly variable with …
A Morphological Study Of The External Female Genitalia And Spermatheca Of Some Calendra, De Mar H. Curtis
A Morphological Study Of The External Female Genitalia And Spermatheca Of Some Calendra, De Mar H. Curtis
Theses and Dissertations
The genus Calendra is the largest genus of the sub-family Rhynchophorine. There have been 116 species described from the United States and Mexico. At the present time only 71 are recognized as valid species. About 50 of the 71 species occur in the United States and Canada.
Food Habits Of The Uinta Ground Squirrel (Citellus Armatus Kennicott) On Some Meadows Of Mt. Timpanogos, Utah, Robert K. Shaw
Food Habits Of The Uinta Ground Squirrel (Citellus Armatus Kennicott) On Some Meadows Of Mt. Timpanogos, Utah, Robert K. Shaw
Theses and Dissertations
Food habits of the Uinta ground squirrel were investigated on some open meadows on the south-east slope of Mt. Timpanogos. Special emphasis was placed on species of plants eaten; and preference of plants in relation to season, succulence, and phenology. Other investigations were made in reference to: parts of plants eaten, non-plant material eaten, daily and seasonal activities in relation to foraging, feeding procedures, and the relationship between plant cover and Uinta ground squirrel activity.
Bird Populations Of The Wasatch Foothills, Delwyn G. Berett
Bird Populations Of The Wasatch Foothills, Delwyn G. Berett
Theses and Dissertations
One of the more interesting and unique of the natural habitats in the state of Utah is its chaparral zone, extending along the western foothills of the Wasatch Range. The purpose of this study has been to make an analysis of the bird population of this region in order to determine the comparative abundance of the species, their seasonal distribution within the area, and their ecological preferences.
Genetic Variation In Bluebunch Wheatgrass, Max P. Dunford
Genetic Variation In Bluebunch Wheatgrass, Max P. Dunford
Theses and Dissertations
Agropyron spicatum (Pursh) Scribn, and Smith, an important forage grass distributed primarily throughout western United States and northward into Canada, exhibits considerable ecological, cytological, and genetic variation. Twenty-five populations of 100 plants each were scored to obtain data on morphological and ecological variation. Statistical analysis of the data from fourteen of the populations showed that correlations between awn divergence and length, rhizomes with number of culms, adn diameter with number of culms were inconsistent or not significant. However, the correltion between rhizomes and diameter was significant in all populations.
The Comparative Mineral Requirements Of Pioneer And Climax Range Grasses, Paul L. Steele
The Comparative Mineral Requirements Of Pioneer And Climax Range Grasses, Paul L. Steele
Theses and Dissertations
A study was made to determine the effects of variable levels of nitrogen, phosphorus, and potassium upon several species of pioneer and climax range grasses, and to determine if these grasses differ in their ability to grow when supplied with low levels of these nutrients. Five grasses were used. The climax grasses were Agropyron spicatum and Agropryon smithii, and the pioneer grasses were Aristida longiseta, Sporobous cryptandrus, and Oryzopsis hymenoides.
The External Morphology Of Pseudopanurgus Aethiops (Cresson), Glenn A. Hackwell
The External Morphology Of Pseudopanurgus Aethiops (Cresson), Glenn A. Hackwell
Theses and Dissertations
In comparing the head of Pseudopanurgus with Anthophora and Apis, the general outline appears rather similar, the most significant variation being found on the posterior surface. Extending ventrally from the postoccipital suture to the dorsal wall of the proboscidial fossa is a suture known as the fused hypostomal suture. The hypostomal area is rather small and makes up only a small portion of the dorsal and lateral walls of the proboscidial fossa, the remainder being formed by the postgena. If this is correct, the hypostomal carinae (a term with which the author does not agree) are actually located on the …
A Morphological Study Of The Subtribe Ithypori (Coleoptera: Curculionidae), Leslie J. Boothe
A Morphological Study Of The Subtribe Ithypori (Coleoptera: Curculionidae), Leslie J. Boothe
Theses and Dissertations
This is a morphological study of the subtrib!a Itb:ypori, undertaken to discover all that we can about the morphology and if possible justify the present classification. It includes four genera and fifteen identified species.
A Study Of Physoderma On Three Species Of Portulacaceae, David L. Mumford
A Study Of Physoderma On Three Species Of Portulacaceae, David L. Mumford
Theses and Dissertations
Three species of the Portulacaceae each infected by a Physoderma parasite were collected at several locations in Utah. The hosts have been identified as Claytonia lanceolata Pursh., Oreobroma pygmaeum (A. Gray) Howell, and Erocallis triphylla (S. Wats.) Rydb. Since our present knowledge of Physoderma on members of the Portulacaceae is meager, it seemed desirable to learn as much as possible about the parasite, its hosts, and the relationship between parasite and host. Plants of all three hosts activated from perennating organs were grown for extended periods of time under uniform conditions. Cold treatments were most successful in activating host perennating …
A Study Of Three Photochemical Activities Of Chloroplasts, Jimmy W. Hinkson
A Study Of Three Photochemical Activities Of Chloroplasts, Jimmy W. Hinkson
Theses and Dissertations
Chloroplasts of sugar beet leaves were subjected to treatment by heating, by incubation at pH 8.5 and pH 5.5, by incubation in ion low water, by sonic oscillation, by digestion with enzymes (lysozyme, pancreatin, and lipase), by extraction with digitonin, and by chemical compounds including 8-hydroxy-quinoline, sodium azide, zinc sulfate, phenyl mercuric acetate, potassium cyanide, 1-allylthiourea, 2,4-dinitrophenol, thymol, and p-chloromercuribenzoate. A comparative study was made of the effects of these treatments upon three photochemical reactions (the photoreduction of 2,6- dichlorophenol indophenol, the photoreduction of indigo carmine in the presence of a couple composed of 2,6-dichlorophenol indophenol and ascorbic acid, and …
The Cattle Industry Of San Juan County, Utah, 1875-1900, Franklin D. Day
The Cattle Industry Of San Juan County, Utah, 1875-1900, Franklin D. Day
Theses and Dissertations
The purpose of this study was to learn the reasons for the movement of cattle Into San Juan County, Utah, the development of the Industry, and its contribution to the growth of the county.
The few written accounts in existence of the cattle industry in San Juan are brief and found in widely separate areas. The whole and complete account will likely never be written, but there is need for gathering as much of the scattered information as possible.
A study of the early history of the inhabitants of San Juan was made, along with an examination of the geography …
A Preliminary Investigation Of The Role Of Selenium In The Growth Of Stanleya Pinnata, Richard F. Nelson
A Preliminary Investigation Of The Role Of Selenium In The Growth Of Stanleya Pinnata, Richard F. Nelson
Theses and Dissertations
Stanleya pinnata has been identified as an indicator plant for seleniferous soils. The apparent limitation of its distribution to seleniferous soils suggests that selenium may play an essential role in this species. This study is a preliminary investigation of the role of selenium to Stanleya pinnata. When fully ripe, seeds germinated readily. Concentrations of selenium of 100 parts per million and 1000 parts per million retarded germination. Seeds germiuated in lower concentrations were not affected which was probably due to the selenium content of the seed itself, being greater than in the germinating media. Stanleya pinnata plants were grown from …
Studies On The Periodicity Of Certain Plankton Species Of Salem Lake, Gene A. Pratt
Studies On The Periodicity Of Certain Plankton Species Of Salem Lake, Gene A. Pratt
Theses and Dissertations
Plankton samples were taken periodically from one station in Salem Lake from the fall of 1955 through the winter of 1957. Other data including the pH, dissolved oxygen content, turbidity, brightness of day, temperature, and time of day were recorded at the time of each collection. The plankton samples were centrifuged and preserved in a 4% formalin solution. They were later examined microscopically, and density, percent density, and percent frequency calculations were made from them for ten selected species and for the five phyla which they represent.
Chemosynthetic Microorganisms In Leaching Sulfide Minerals, A. Keith Jameson
Chemosynthetic Microorganisms In Leaching Sulfide Minerals, A. Keith Jameson
Theses and Dissertations
This investigation showed that a single bacterium was capable of sulfide oxidation in exposed ore bodies. This single bacterium was isolated and characterized. It exhibited different characteristics than any previously known organism. It was found to be a chemosynthetic autotroph. An optimum nutrient concentration was determined for pyrite oxidation. The nutrient concentration was determined for pyrite oxidation. The nutrient contains only a source of phosphate and nitrogen. Urea was found to be a better source of nitrogen than ammonium sulfate which had previously been used. The effect of various organic compounds on the oxidation of pyrite was observed. Glucose and …
A Morphological Study Of Some North American Sitona (Coleoptera: Curculionidae), George J. Kidd
A Morphological Study Of Some North American Sitona (Coleoptera: Curculionidae), George J. Kidd
Theses and Dissertations
This study was undertaken to identify, if possible, some morphological characteristics of the U. S. Sitona species that would help simplify the classification of this difficult group. Because of extreme difficulty in obtaining positively identified specimens of all species reported, the scope was limited to eight identified species and one unidentified series. External structures studied include mouth parts, appendages, eyes, wings, and genitalia. The spermathecae were the only internal structures analyzed. Mandibular profiles were compared throughout the species represented and variations were noted. Labia and maxillae were observed but no distinctive differences were noticed. Antennae were found to be quite …
The Incidence Of Nasal Mites In Over-Wintering Red-Wing Blackbirds In The Vicinity Of Utah Lake, Utah, George M. Talley
The Incidence Of Nasal Mites In Over-Wintering Red-Wing Blackbirds In The Vicinity Of Utah Lake, Utah, George M. Talley
Theses and Dissertations
This paper reports the incidence and associations of four species of mites, Paraneonyssus icteridius, Ptilonyssus n. sp. "A", Sternostoma n. sp. "A" , and Speleognathus sp., found in the nasal cavities of the common red-wing blackbird (Agelaius phoeniceus ssp.) and Brewer's blackbird (Euphagus cyanocephalus cyanocephalus Wagler) over-wintering in the vicinity of Provo, Utah County, Utah. Three species of mites are reported for the first time from these birds, and two of these three are undescribed species.
The Embryology Of The Paradise Fish, Macropodus Opercularis Linnaeus, Lewis M. Mulkay
The Embryology Of The Paradise Fish, Macropodus Opercularis Linnaeus, Lewis M. Mulkay
Theses and Dissertations
The development of Sacropodus opercularis Linnaeus, (Perciformes: Anabantidae), is described from cleavage to five days post hatching. For the most part M. opercularis follows the pattern of typical teleostean development except as noted below: 1. The heart develops under the left eye along the anterior margin of the yolk sac. This is similar to that reported by Ingesoll (1951) for the Blue Gourami, Trichogaster trichopterus. 2. The ear develps from the head mesenchyme alongside the brain rather than from a placode. 3. The gut develops first in the posterior region then differentiates cephalad. It was also learned that: 1. No …
Oviposition Habits Of The Tick Dermacentor Parumapertus Neumann And Factors Influencing Egg Development, Clive D. Jorgensen
Oviposition Habits Of The Tick Dermacentor Parumapertus Neumann And Factors Influencing Egg Development, Clive D. Jorgensen
Theses and Dissertations
This paper includes data concerning the influence of relative humidity, temperature, and percentage of engorgement on the pre-oviposition period, oviposition period, post-oviposition period, and incubation period of the tick Dermacentor parumapertus Neumann. The influence of the percentage of engorgement on the oviposition period, oviposition rate, and egg number is considered. Data on the disposition and number of eggs in nature are discussed.
A Taxonomic Study Of The Families Of Utah Coleoptera Excluding Rhynchophora, T. Blaine Moore
A Taxonomic Study Of The Families Of Utah Coleoptera Excluding Rhynchophora, T. Blaine Moore
Theses and Dissertations
During the years 1950-51 work was begun on a study of the Coleoptera by the author. In 1955, due to the lack of a workable set of keys to the Coleoptera of Utah, a study was undertaken to find a way to more easily classify the beetles of the state to their respective families. The collection of Brigham Young University was used as the basis for determining the families of beetles actually found in Utah. Then a thorough search of the literature was made to find positive records of Utah families not represented in that collection. It was found that …
An Ecological Survey Of The Vegetation Of The Dinosaur National Monument, Utah, Stanley L. Welsh
An Ecological Survey Of The Vegetation Of The Dinosaur National Monument, Utah, Stanley L. Welsh
Theses and Dissertations
The present work is a general survey of the vegetation of the Utah portion of the Dinosaur National Monument with special emphasis on some of the ecological aspects of the area. The vegetation ranges from xerophytic plant communities of the lower elevations to mesophytic communities of the higher elevations. Hydrophytic plant communities are also present to a limited extent along the Green River and where seeps or springs arise. Soils vary from fine clay to coarse gravel. The dividing lines between formations is often marked by extreme differences in soil type. During the author's first collecting trip into the Monument …
Introgression In Purshia Tridentata (Pursh) Dc. And Cowania Stansburiana Torr, Lindsey Kay Thomas
Introgression In Purshia Tridentata (Pursh) Dc. And Cowania Stansburiana Torr, Lindsey Kay Thomas
Theses and Dissertations
A study ot discordant variation in populations of Purshia tridentata, Purshia glandulosa, and Cowania Stansburiana has disclosed that introgressive hybridization can be expected whenever these species come in contact with each other. The introgression is not only of one pure species into that of another, but is also of introgressed populations into other introgressed populations and of pure populations into introgressed populations. Evidence was found showing that in all probability Purshia glandulosa is a stabilized segregant derived from introgressed populations. Evidence was also found and presented to show that introgression is responsible for the recent acquisition of stalked hypanthium glands …
Oxidation Of Molybdenite With The Aid Of Microorganisms, Ralph Anderson
Oxidation Of Molybdenite With The Aid Of Microorganisms, Ralph Anderson
Theses and Dissertations
This work represents a study on the biological oxidation of molybdenite, MoS2. The principal objective of this study was to investigate the possibility of the biological oxidation of molybdenite, to determine the physical and chemical conditions under which the oxidative process occurs, and to develop a strain of bacteria or alter the activity of the microorganisms by acclimatization to increase their activity on sulfide minerals, in particular molybdenite. Minerals used in this study were pyrite (FeS2), chalcopyrite (CuFeS2), molybdenite concentrate, and molybdenite ore. The microorganisms used in this investigation were autotrophic bacteria obtained from the leaching streams of Bingham Canyon, …
A Preliminary Investigation Of The Taxonomy And The Geographical Distribution Of The Chrysopidae (Neuroptera) Of Utah, Wayne A. Melander
A Preliminary Investigation Of The Taxonomy And The Geographical Distribution Of The Chrysopidae (Neuroptera) Of Utah, Wayne A. Melander
Theses and Dissertations
The writer undertook a preliminary investigation of the taxonomy and geographic distribution of a group of neuropterous insects, the Chrysopidae, in Utah. The main purposes of the investigation were to find what species and forms of these beneficial insects occur in Utah, to provide means for their identification, and to report upon their geographical distribution. Two main methods of investigation were employed. The first, a bibliographic method, was to carefully review the literature concerning the Chrysopidae of the United States for all references pertaining to their distribution and their taxonomy. The second method of investigation was to study insect specimens …
A Study Of The Utah Pocket Mice Of The Genus Perognathus, Merlin L. Killpack
A Study Of The Utah Pocket Mice Of The Genus Perognathus, Merlin L. Killpack
Theses and Dissertations
The objectives of this study were: (1) to make a detailed study of the distribution of the genus Parognathus in Utah; (2) to determine if any species or races not now recorded occur in the state; (3) to bring together notes on life histories of this genus, both from the literature and field studies; and (4) to determine habitat preferences of the species represented. This paper lists 14 subspecies belonging to 7 species of Perognathus occurring in Utah. One species is a new occurrence record, Perognathus fasciatus callistus, from northeastern Utah east of the Green River. The ranges of Perognathus …
A Study Of Utah Phoridae Diptera, A. Lavell King
A Study Of Utah Phoridae Diptera, A. Lavell King
Theses and Dissertations
This study was undertaken to determine the present status in Utah of the Dipterous family Phoridae, and to report which genera and species are found there. The work was done with the thought in mind of furthering the knowledae of this little-known family in Utah. In order to secure information about the family the writer studied entomological literature and specimens obtained from the entomological collections of the Brigham Young University and Utah State Agricultural College. Personal collecting in various areas of Utah was also done. During the study it was found that there were six genera and twenty-one species correctly …
A Study Of The Hydra Of Salem Pond, Mary Elizabeth Dumas
A Study Of The Hydra Of Salem Pond, Mary Elizabeth Dumas
Theses and Dissertations
The site of investigation for this work was Salem Pond, Salem (formerly known a.s Pond Town), Utah. It was settled in 1851 by David Crockett and David Fairbanks. Colonization began in 1856 when a fort of adobe and lumber houses was built near the pond, and later, several industries located there, benefited by the water wheels constructed by the pioneers (Huf4 l947).