Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Life Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 152821 - 152850 of 159536

Full-Text Articles in Entire DC Network

The Relationship Of Molybdenum To Iron Status In Pregnancy And Anemia In Rats And Humans, Jo Ann Mortensen May 1977

The Relationship Of Molybdenum To Iron Status In Pregnancy And Anemia In Rats And Humans, Jo Ann Mortensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Weanling male rats were made anemic and fed diets supplemented with 20 ppm iron and/or 2 ppm molybdenum. A decrease in serum iron was observed in the rats supplemented only with iron and a significant decrease in hemoglobin was observed in rats given no supplementation.

In a second experiment, pregnant female rats were also fed diets supplemented with 20 ppm iron and/or 2 ppm molybdenum. An inverse relationship was apparent between iron and copper in both the serum and the liver of the female rats. The livers of their pups displayed an inverse relationship between molybdenum and copper. Hemoglobin in …


Two Generational Study On The Effect Of Different Levels Of Fluoride On Rat Bone And Teeth, Madhav Prasad Upadhyay May 1977

Two Generational Study On The Effect Of Different Levels Of Fluoride On Rat Bone And Teeth, Madhav Prasad Upadhyay

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of different levels of fluoride in drinking water on different parameters of femurs and incisors of female rats were studied. Rats and their offspring, before and after weaning, were used for the study. Mother rats received 0, 1 and 5 ppm fluoride in drinking water. After weaning, the offspring were given the following treatments: 0-0, 0-1, 0-5, 1-0, 1-1, 1-5, 5-0, 5-1 and 5-5; the first number indicating fluoride level of mother's water during mating, pregnancy and lactation and the second number indicating the fluoride level of water given to the offspring. Femurs and top and bottom incisors …


A Process Incorporating Ultrafiltration Concentrated Whey Solids Into Cheese For Increased Cheese Yield, Rodney Jay Brown May 1977

A Process Incorporating Ultrafiltration Concentrated Whey Solids Into Cheese For Increased Cheese Yield, Rodney Jay Brown

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A process which incorporates whey sol ids, primarily protein, into cheese to increase cheese yield and eliminate whey handling problems was evaluated. Whey was concentrated by ultrafiltration to levels of 9.8 to 20.3 percent total solids (4.3 to 7.1 percent protein), heated at 70 C for 30 minutes and added to cheese milk with the coagulating enzyme.

Increase in cheese yield, on the basis of 39 percent moisture, for 10 pairs of samples was 4.0 ± 2.8 (S.D.) percent. This increase was significant at alpha less than 0.001. Moisture and protein content increased while fat content decreased. Setting time and …


Subtle Teratogenic Effects Of Locoweed In Rats, Benjamin K. Nelson May 1977

Subtle Teratogenic Effects Of Locoweed In Rats, Benjamin K. Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Locoweed, a well-known teratogenic plant affecting livestock, is prevalent in mountain regions of the Western United States. Two common species (Astragalus lentiginosus and A. wootoni), administered to pregnant rats, induced behavioral deviations in their offspring. Treated mothers consumed less feed and gained less wieght during gestation than controls when gavaged locoweed at the rate of 1 gram whole plant per day on days 7 through 17 of gestation. A. lentiginosus reduced pup weight at birth (13% less than controls) and this weight reduction (as much as 29% less than controls) continued at least four weeks. A. lentiginosus also …


The Influence Of Various Factors On Nitrogen Balance And Protein Quality Measured In Adult Human Beings, Arthur John Wittwer May 1977

The Influence Of Various Factors On Nitrogen Balance And Protein Quality Measured In Adult Human Beings, Arthur John Wittwer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of nitrogen intake, nitrogen source, calorie intake, body weight, adaptation time, research group and sex on the nitrogen balance of human adults was investigated. Data from studies reported in the literature were combined and analyzed statistically by multiple regression techniques. Analyses were made separately for six sources of nitrogen: egg, beef, rice, corn, wheat and wheat gluten.

Nitrogen intake, caloric intake and body weight exerted significant effects on nitrogen balance (5% level of confidence) for six, three and two of the six nitrogen sources, respectively. Other variables were not significant at the 5% level. Although differences were not …


Rodent Density And Species Composition In The Snake River Birds Of Prey Natural Area, Idaho, Jon R. Montan Jr. May 1977

Rodent Density And Species Composition In The Snake River Birds Of Prey Natural Area, Idaho, Jon R. Montan Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rodent densities were estimated in the major vegetation types of the Snake River Birds of Prey Natural Area in 1975 and 1976 by a combination of live-trapping and kill-trapping. Only deer mice (Peromyscus maniculatus) were numerous enough to permit reliable density estimates. Relative densities of other rodent species were indicated by kill-trap capture rates. Densities of deer mice correlated well (r = 0.99) with kill-trap capture rates. The use of kill-trapping in place of live-trapping in 1976 permitted extensive sampling throughout the 1930 km2 study area. Differences were found among the major vegetation and land-use types in …


Competitive Interaction In Plant Populations Exposed To Enhanced Uv-B Radiation, Fred M. Fox May 1977

Competitive Interaction In Plant Populations Exposed To Enhanced Uv-B Radiation, Fred M. Fox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Competitive balance and changes in individual plant growth parameters of eight pairs of plant species exposed to enhanced UV-B irradiation were determined under field conditions simulating ozone reductions of about 0.08 atm·cm. The levels of irradiance represented ozone decreases of about 25-30 percent from approximate ambient ozone concentrations for high solar altitudes on clear days during the study. A method for calculating and statistically analyzing relative crowding coefficients was developed and used to evaluate the competitive status of the species pairs sown in a modified replacement series. The effect of UV-B irradiance was generally detrimental to plant growth, and was …


Sheep Behavior And Vulnerability To Coyote Predation, Ernest Albert Gluesing May 1977

Sheep Behavior And Vulnerability To Coyote Predation, Ernest Albert Gluesing

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the activity patterns and social relation ships between individuals in a large herd of domestic sheep (Ovis aries) in an effort to determine if behavioral characteristics predisposed certain individuals to coyote (Canis latrans) predation.

The research was conducted on the Cook Ranch near Florence, Montana, from March through September of 1975. Data were collected from a herd of 627 ewes and 1082 lambs, each individually identifiable. A random sample of 44 ewes and their 75 lambs were intensively studied over a 16-wk period to establish activity budgets and the relationships between sheep activity …


The Effect Of Four Mine Spoil Treatments On The Seedling Water Relations Of Two Plant Species, Lorraine K. Van Kekerix May 1977

The Effect Of Four Mine Spoil Treatments On The Seedling Water Relations Of Two Plant Species, Lorraine K. Van Kekerix

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Surface mines in mountainous areas cause environmental deterioration at lower elevations in the watershed. The most successful long term solution to the downstream problem is revegetation. However, mine spoils are low in essential plant nutrients, have low water holding capacity, and are often acidic. These factors limit plant colonization. Plants must also be adapted to the environmental conditions of high elevations.

At the McLaren Mine, }1ontana, at 2800 m, it was observed that seedlings on revegetation plots were desiccated, indicating possible water deficits. Field and growth chamber studies were carried out to determine the effects of some spoil ameliorating treatments …


Biological Manipulation Of Blackbrush (Coleogyne Ramosissima Torr.) By Browsing With Goats, Frederick D. Provenza May 1977

Biological Manipulation Of Blackbrush (Coleogyne Ramosissima Torr.) By Browsing With Goats, Frederick D. Provenza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to provide data on responses of Angora goats and blackbrush (Coleogyne ramosissima) to a biological manipulation program. Blackbrush utilization levels averaged 30, 16, and 6 percent (545, 367, and 147 kg per hectare) for the heavily, moderately, and lightly browsed pastures, respectively; removal rates of 77, 38, and 19 percent (1164, 582, and 291 kg per hectare) were projected.

Statistically significant differences in body weight loss (P=0.052) were noted for goats browsing in different replications. Goats lost an average of 14 and 19 percent of body weight in replications one and two, …


Autoecology Of The Ruderal Weed Heterotheca Grandiflora With Emphasis On Germination Dimorphism, Stephan Dexter Flint May 1977

Autoecology Of The Ruderal Weed Heterotheca Grandiflora With Emphasis On Germination Dimorphism, Stephan Dexter Flint

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Weedy species, as they occupy diverse and unpredictable environments, are expected to possess considerable variability in numerous characteristics, including germination. The visually dimorphic achenes of Heterotheca grandiflora Nutt. (Asteraceae) were tested for potentially adaptive differences in their germination, the establishment of the resulting seedlings, and the relative production of the two achene types.

Achenes produced by the disc florets are adapted for dispersal and rapid germination while the ray florets produce smaller achenes lacking a dispersal mechanism, but possessing a more sophisticated physiological system capable of regulating germination. Ray achene germination rates were significantly influenced by different soil surfaces while …


Effects Of Low-Level Chronic Radiation On Plant Nuclear Parameters As Related To Successional Patterns, Eric A. Rechel May 1977

Effects Of Low-Level Chronic Radiation On Plant Nuclear Parameters As Related To Successional Patterns, Eric A. Rechel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A major issue facing nuclear power stations is how to effectively deal with radioactive waste. This waste, as it comes from a reactor, is emitting large quantities of ionizing radiation which is usually confined. Another form of radioactive wastes is the mill tailings from uranium processing plants. These tailings are sites characterized by low-level chronic radiation.

The mill tailings of the Vitro Chemical Plant, in Salt Lake City, Utah, have been a point of radionuclide concentration and environmental contamination for 20 years. These tailings may adversely affect both surrounding ecosystems and any biological systems seeking to become established on the …


Characteristics And Genesis Of The Payson And Trenton Soils, Hakeem T. Saif May 1977

Characteristics And Genesis Of The Payson And Trenton Soils, Hakeem T. Saif

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It is necessary to study the genesis of the Payson and Trenton polypedons in northern Utah to understand why the Payson polypedon is an Alfisol, while the Trenton polypedon is a Mollisol. Even though the soil-forming factors appear similar, the soils differ at the order level. Two pedons, one belonging to the Payson polypedons and the other belonging to the Trenton polypedon, have been described and sampled by genetic horizons. Both pedons have essentially the same climate, slope, age, elevation, and are developed on the parent material of Lake Bonneville sediments.

The differences in physical, chemical and mineralogical properties among …


The Influence Of Certain Growth Hormones On Plant Growth At Cold Temperatures, Michael D. Salvesen May 1977

The Influence Of Certain Growth Hormones On Plant Growth At Cold Temperatures, Michael D. Salvesen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies were conducted to determine the effect of externally applied growth hormones on winter rye (Secale cereale var. cougar). The rye was grown under the snow in a specially prepared tunnel on a mountain side near Logan, Utah. These plants showed a remarkable ability to grow at 0°C. Three growth hormones, kinetin, gibberellic acid (GA), and auxin (indole-3-acetic acid) were externally applied to rye seedlings growing in the tunnel. These seedlings were alter weighed, measured and tested for soluble protein content. The three hormone treatments had no significant effects on the fresh weights or shoot lengths of the …


Distribution And Habitat Characteristics Of The Kit Fox (Vulpes Macrotis) In Utah, John C. Mcgrew May 1977

Distribution And Habitat Characteristics Of The Kit Fox (Vulpes Macrotis) In Utah, John C. Mcgrew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The distribution of the kit fox (Vulpes macrotis) in Utah was studied from 1974 to 1976. A variety of methods were used, but a questionnaire sent annually to state and federal agencies, combined with interviews of field personnel of these agencies, was found to be the most valuable. Kit foxes occur in western Utah and Washington County as previously reported. In addition, range extensions were noted in central Utah, and in Carbon, Emery, Grand, Wayne, and Garfield counties in east-central Utah. These range extensions total approximately 4,600-square miles (12,000-square kilometers). The kit fox probably also inhabits San Juan …


Density And Diversity Responses Of Summer Bird Populations To The Structure Of Aspen And Spruce-Fir Communities On The Wasatch Plateau, Utah, Janet Lee Young May 1977

Density And Diversity Responses Of Summer Bird Populations To The Structure Of Aspen And Spruce-Fir Communities On The Wasatch Plateau, Utah, Janet Lee Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sixteen stands representing a range of structural variation in aspen, mixed aspen-conifer, and spruce-fir communities of the Wasatch Plateau, Utah, were censused by the sample count method. The stands were classified as eleven community types based on the understory dominants or indicator species and the cover types. Fifty bird species were recorded during the two seasons; thirty-two occurred in aspen cover, forty-four in mixed aspen-conifer cover, and twenty-two in spruce-fir.

Comparisons of the composition and density of bird populations were made between uniform stands of a single life form and more structurally complex stands of either single or mixed life …


Spawning Biology Of Channel Catfish Ictalurus Punctatus (Rafinesque) In Willard Bay Reservoir, Utah, Stuart Terry Shipman May 1977

Spawning Biology Of Channel Catfish Ictalurus Punctatus (Rafinesque) In Willard Bay Reservoir, Utah, Stuart Terry Shipman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was conducted on Willard Bay Reservoir, Utah, during the summers of 1972 and 1973, to study the spawning biology of the channel catfish (Ictalurus Punctatus), and to evaluate potential reproduction for this species in the reservoir. Potential reproduction was evaluated through examination of available natural habitat and use of artificial habitat provided for this study.

Channel catfish were found to mature by the end of their fourth year and spawn from mid-June through August. A total of 12 nesting channel catfish were observed along 15, 0.8 kilometer (0.5 mile) sections of dike. Ten of these 12 …


Influence Of Corynebacterium Insidiosum On The Water Relations Of Alfalfa, Rastri Dey May 1977

Influence Of Corynebacterium Insidiosum On The Water Relations Of Alfalfa, Rastri Dey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of Corynebacterium insidiosum (McCull) H. L. Jensen on the water relations of its host, alfalfa, was studied by field measurements made on a 6-year-old stand of Ranger alfalfa. Periodic measurements of stomatal conductance, xylem pressure potential Ψ, and root, stem, and leaf conductance were made in relation to soil moisture conditions. Water regain and electrolyte leakage studies were also made to test membrane integrity in diseased plant leaves.

At all times the xylem pressure potential Ψ was found to be much more negative in diseased plants than in healthy plants. Stomatal conductance was found to respond to the …


Genetic Control Of Spermiogenesis In Drosophila Melanogaster: The Effects Of Abnormal Association Of Centrosome And Nucleus In Mutant Ms(1)6s, Douglas Lee Habliston May 1977

Genetic Control Of Spermiogenesis In Drosophila Melanogaster: The Effects Of Abnormal Association Of Centrosome And Nucleus In Mutant Ms(1)6s, Douglas Lee Habliston

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mutant ms(l)6S of Drosophila melanogaster is characterized by a spectrum of abnormalities of spermatid differentiation. Included in these are failure of the basal body to make normal attachment to the nucleus, failure of acrosomes to develop, and lack of a normal pupulation of perinuclear microtubules. There is also a failure of normal chromatin condensation and nuclear elongation. The mitochondria do not form a normaI nebenkern, but nevertheless fuse, elongate, and develop paracrystalline bodies. The number of normal axonemes is markedly reduced as a result of the failure of some centrioles to form basal bodies. All of these aberrations can be …


A Preliminary Investigation Of The Lipid Of Halophilic Bacteria As A Food Additive, Neil F. Collins May 1977

A Preliminary Investigation Of The Lipid Of Halophilic Bacteria As A Food Additive, Neil F. Collins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was conducted to evaluate the feasibility of obtaining workable quantities of the unusual ether-linked phosphatidyl glycerophosphate of halophilic bacteria through batch culture of Halobacterium halobium. Once isolated and purified, physical, emulsification, and toxicological properties of the lipid were evaluated with respect to its use as a nonnutritive lipid substitute or an emulsifier by the food industry. These evaluations included physical descriptions, melting properties, hydrophile-lipophile balance (HLB) determination, and oral and intraperitoneal administration of the lipid to laboratory mice.


Fine Structural Aspects Of The Developing Eye Of The Honey Bee, Judith Susan Eisen May 1977

Fine Structural Aspects Of The Developing Eye Of The Honey Bee, Judith Susan Eisen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The post-embryonic development of the compound eye of the worker honey bee was investigated with the light and electron microscopes. The cells of the optic primordium were reorganized into preommatidial cell clusters during the late third and early fourth larval instars. Each cluster contained nine prospective retinula cells, the ninth was centrally located and shorter than the other eight; four prospective cone cells; and an undetennined number of prospective pigment cells.

Rhabdomere development began in the eight peripherally located retinula cells just prior to pupation. Following pupation, each ommatidium elongated. During ommatidial elongation, the short ninth retinula cell moved from …


Infrared Imagery Scanning Systems For Censusing Big Game, Peter S. Goldberg May 1977

Infrared Imagery Scanning Systems For Censusing Big Game, Peter S. Goldberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The primary objective of this study was to explore the potential of an airborne infrared scanner for the census of mule deer (Odocoileus hemionus) and elk (Cervus canadensis) in the Intermountain West. Flight altitude was varied in hopes of achieving species separation, and ground studies were conducted, using a hand-held radiometer and captive deer, to find the optimum time of morning to census. The problems and potentialities of infrared imagery scanning systems for censusing big game are discussed and compared to visual aerial census methods.


Aspects Of The Life History Of Three Catostomids Native To The Upper Colorado River Basin, Charles W. Mcada May 1977

Aspects Of The Life History Of Three Catostomids Native To The Upper Colorado River Basin, Charles W. Mcada

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The distribution, abundance and life history were studied for three catostomids -- the razorback sucker (Xyrauchen texanus), the flannel-mouth sucker (Catostomus latipinnis), and the bluehead sucker (Catostomus discobolus) -- all native to the upper Colorado River basin. The razorback sucker has declined in abundance due to man's impact upon the system and it has been recommended that this species be listed as ''threatened" on the U. S. Department of the Interior's list of Threatened or Endangered species [Personal corrmunication, G. C. Kobetich, U. S. Fish and Wildlife Service, Las Vegas, Nevada]. During this investigation, …


A Comparison Of Dewpoint And Psychrometric Mode In Leaf Water Potential Measurements, Gladys Durand-Campero May 1977

A Comparison Of Dewpoint And Psychrometric Mode In Leaf Water Potential Measurements, Gladys Durand-Campero

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Leaf water potential of two maize plants (Zea mays L.) two chlorophytum plants (Chlorophytwn capense, Kuntze), a schefflera (Brassaia actinophylla) and one aspen (Populus tremuloides Michx.), were measured under laboratory conditions with aluminum block in situ leaf hygrometers and with stainless steel single junction chamber hygrometer using excised entire leaves. Plants were subjected to a drying cycle. The hygrometers were controlled with a dewpoint microvoltmeter and all readouts were recorded on a chart recorder. A typical reading and control schedule included 20 second cooling before a first psychrometric reading allowing the output to …


In Vitro Morphogenesis And Mutation Of Glycine Max L., Thomas Daniel Wilson May 1977

In Vitro Morphogenesis And Mutation Of Glycine Max L., Thomas Daniel Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soybean (Glycine max L. c.v. Consoy) tissue cultures were grown in synthetic media containing various concentrations and combinations of minerals, auxins, cytokinins, pH levels, and inorganic growth factors in a systematic procedure to establish optimum media for initiation and maintenance of callus. Further modification of the hormone level was employed to initiate callus morphogenesis. Normally toxic levels of atrazine were established in soybean calli media, and ethyl methanesulfonate (EMS) and X ray-induced mutant calli were selected for atrazine tolerance.

Optimal media for initiation and maintenance of soybean calli were developed and a defined medium was determined that consistently yields …


Multiple Forms Of Deoxyribonucleic Acid-Dependent Ribonucleic Acid Polymerase In Barley Leaves (Hordeum Vulgare L.), Sachchidananda Javali May 1977

Multiple Forms Of Deoxyribonucleic Acid-Dependent Ribonucleic Acid Polymerase In Barley Leaves (Hordeum Vulgare L.), Sachchidananda Javali

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ribonucleic acid polymerases (E.C. 2.7.7.6) have been solubilized form whole green leaves of barley (Hordeum vulgare L.). Three major forms of the solubilized enzyme have been isolated by sonication in high ionic strength buffers, cation and anion exchange chromatography, and agarose gel permeation chromatography and designated I, II, and III. The enzyme fractions appear analogous to the Class I, II, and III ribonucleic acid polymerases defined in other eucaryotic systems. The ionic strength optima, amatoxin sensitivity, and relative activities with denatured calf thymus deoxyribonucleic acid were different for Class I, II, and III polymerases.

A simple, rapid, reproducible method …


When Is Sex Environmentally Determined?, Eric Charnov, James Bull Apr 1977

When Is Sex Environmentally Determined?, Eric Charnov, James Bull

Biology Faculty & Staff Publications

No abstract provided.


The Annual Meeting Of The Iowa Academy Of Science April 22-23, 1977 [Program, 89th Meeting], Iowa Academy Of Science Apr 1977

The Annual Meeting Of The Iowa Academy Of Science April 22-23, 1977 [Program, 89th Meeting], Iowa Academy Of Science

Iowa Academy of Science Documents

No abstract provided.


Verbena Bipinnatifida Nutt., R. M. Sims Apr 1977

Verbena Bipinnatifida Nutt., R. M. Sims

Specimens by Name

No abstract provided.


Claytonia Virginica L., S. J. Mcnabb Apr 1977

Claytonia Virginica L., S. J. Mcnabb

Specimens by Name

No abstract provided.