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Articles 631 - 660 of 686

Full-Text Articles in Biology

The Metabolic Cost Of Behavioral Thermoregulation Of Body Temperature In The Northern Alligator Lizard Gerrhonotus Coeruleus, And How It Affects The Classical Concept Of Eurythermality, James Dudley Campbell Jan 1981

The Metabolic Cost Of Behavioral Thermoregulation Of Body Temperature In The Northern Alligator Lizard Gerrhonotus Coeruleus, And How It Affects The Classical Concept Of Eurythermality, James Dudley Campbell

Dissertations and Theses

The effect of total metabolic cost expenditures on the precision of behavioral thermoregulation was investigated for the purportedly eurythermic Northern Alligator lizard (Gerrhonotus coeruleus). An operant apparatus was designed to test metabolic output at different heat reinforcement magnitudes. The mean TB reflected in each trial was positively correlated to the length of reinforcement. The shuttle rate during each trial was inversely correlated to the length of reinforcement. The standard deviation and total metabolic costs did not vary significantly between trials undertaken at the same ambient temperature. Eurythermality in G. coeruleus is caused by fluctuations in preferred body temperature and …


The Ductuli Efferentes In Macaca Mulatta: Electron Microscopic Evaluation Of Changes After Vasectomy, Loyal Douglas Marsh Dec 1980

The Ductuli Efferentes In Macaca Mulatta: Electron Microscopic Evaluation Of Changes After Vasectomy, Loyal Douglas Marsh

Dissertations and Theses

After vasectomy, the passage of sperm antigen through the epithelium of the efferent duct in the rhesus macaque probably results in immune complex deposition. Immune complexes can be visualized in the thickened basement by fluorescence microscopy. Subsequent electron microscopic evaluation, with the appearance of electron-dense deposits in the basement membrane of the efferent ducts, substantiates these findings.


Geochemical And Biogeochemical Interactions In A Hot Spring, William Delis Knox Oct 1980

Geochemical And Biogeochemical Interactions In A Hot Spring, William Delis Knox

Dissertations and Theses

Southeast Harney Lake Hot Spring and its effluent channel were examined for spatial and temporal variations in the concentrations of several chemical species, viz. dissolved oxygen, pH, alkalinity, phosphate-phosphorous, nitrate and nitrite-nitrogen, conductivity, chloride, flouride, temperature, calcium, magnesium, potassium, and sodium. Phosphate-phosphorous and nitrate-nitrogen both exhibited downstream increases in concentration. pH and alkalinity increased also, mainly due to CO2 evolution and temperature mediated carbon species redistribution. The diurnal pH and alkalinity curves exhibited depressions during the daylight hours due to the oxidation of ammonia to nitrate within the pool and effluent stream.


Cytologic Characterization Of Human Constitutive Heterochromatin, Timothy Atchison Donlon Oct 1980

Cytologic Characterization Of Human Constitutive Heterochromatin, Timothy Atchison Donlon

Dissertations and Theses

A study was conducted to cytologically map certain subsets of constitutive heterochromatin onto specific portions of human chromosomes. This involved sequentially staining metaphase chromosomes from lymphocytes first with the Centromeric Dot, Giemsa-11, G-banding or Lateral Asymmetry staining techniques, which are cytochemical methods which stain particular chromosomes or chromosomal regions. Then those same metaphase chromosomes were stained using the C-banding technique, a method which is believed to denote constitutive heterochromatin. With the exception of the G-banding technique, areas depicted by the special staining techniques were found to reside only within the areas stained by the C-band technique and are thus believed …


Storage And Use Of Glycogen By Juvenile Carcinonemertes Errans, D. Mitchell Wolgamott Jan 1980

Storage And Use Of Glycogen By Juvenile Carcinonemertes Errans, D. Mitchell Wolgamott

Dissertations and Theses

Juvenile C. errans do not feed on particulate matter and yet they can survive, apparently unchanged, for several months before maturing into the adult stage which feeds on the eggs of Cancer magister. The significance of glycogen as an energy source for maintenance of the juvenile form was investigated.


Culture And Growth Of Closterium Ehrenbergii (Desmidiaceae), David Bruce Renstrom Jul 1979

Culture And Growth Of Closterium Ehrenbergii (Desmidiaceae), David Bruce Renstrom

Dissertations and Theses

Methods were devised for the isolation and pure culture in defined mineral medium of Closteriurn ehrenbergii Menegh (Chlorophyceae). The effect of pH, type of nitrogen source, nitrate concentration, total hardness, and various buffers on growth were investigated. Best growth rates were obtained at pH 8 to 9, but good growth was observed even at pH 9.4. Nitrate, ammonia, or urea nitrogen could be utilized, but at concentrations greater than 10-2M urea was toxic to growth. At higher concentrations of ammonia and nitrate longer lag phases of growth were obtained but eventual higher cell yields were obtained. Good growth …


Ascorbic Acid, Lipid Peroxidation, And Aging, Brian Evan Leibovitz May 1979

Ascorbic Acid, Lipid Peroxidation, And Aging, Brian Evan Leibovitz

Dissertations and Theses

The role of ascorbic acid with regard to lipid peroxidation and aging has been examined. A thorough literature analysis indicates that free radical-induced lipid peroxidation is a plausible biochemical explanation for aging. Lipid peroxidation causes cellular damage due to altered enzyme activities, error-prone nucleic acid metabolism, and membrane dysfunction, as well as the accumulation of aging pigments in the lysomes. Ascorbic acid, a water soluble free radical quencher, was examined with regard to carbon tetra-chloride-induced lipid peroxidation and in vivo aging. Carbon tetrachloride, a well-known free radical inducer, caused marked increases in the ration of oxidized/reduced vitamin C only …


Androgen-Induced Immunosuppression, Debra Ann Weyant May 1979

Androgen-Induced Immunosuppression, Debra Ann Weyant

Dissertations and Theses

It is well established that females are more immunocompetent than males as evidenced by higher humoral antibody titers, lowered susceptibility to infection, and more efficient graft rejection.

Furthermore, females also exhibit a much higher incidence of autoimmune disease. These observations have led investigators to believe that the male hormonal environment may play a key role in the regulation of immune response. For this reason, this study is concerned with the expression of autoimmunity and of immune function in the mouse.

This study included the New Zealand Black (NZB) mouse strain, as an animal model for human SLE, as well as …


Some Physical And Biological Factors Affecting Red-Tailed Hawk Productivity, Stewart Wayne Janes Jan 1979

Some Physical And Biological Factors Affecting Red-Tailed Hawk Productivity, Stewart Wayne Janes

Dissertations and Theses

Various physical and biological factors affecting annual productivity in a Red-tailed Hawk population in north-central Oregon were investigated. The percentage of the population successfully fledging one or more young was the most important factor in determining the number of young fledged per pair in a given year. Neither clutch size nor the number of young fledged per successful nest varied significantly. Percent pair success was correlated with several January weather variables. A cold and dry January is positively correlated with Red-tailed Hawk productivity. This is apparently related to the onset of rapid vegetative growth and this in turn is positively …


The Effect Of Developmental Temperature On Morphology, Energy Metabolism, Growth Hormone And Thyroid Stimulating Hormone In Long-Evans Rats, Dana Elizabeth Quinn Nov 1978

The Effect Of Developmental Temperature On Morphology, Energy Metabolism, Growth Hormone And Thyroid Stimulating Hormone In Long-Evans Rats, Dana Elizabeth Quinn

Dissertations and Theses

Long-Evans rats were raised from birth to eight weeks of age at 5°C, 20°C and 30°C. Blood was taken from animals two to eight weeks of age and assayed for growth hormone and thyroid stimulating hormone. The 30°C reared rats were found to have the longest ear, tail and hind limbs, followed by the 20°C reared rats. The 5°C rats were found to have the shortest ear, tail and hind limb. The 30°C and 5°C reared rats were found to have similar masses at the termination of the experiment. The 20°C reared rats had the smallest mass. Differences in size …


Germination, Respiration And Photosynthesis In Seeds Of Dwarf Mistletoe (Arceuthobium), Steven Wayne Gustafson Jul 1978

Germination, Respiration And Photosynthesis In Seeds Of Dwarf Mistletoe (Arceuthobium), Steven Wayne Gustafson

Dissertations and Theses

Germination, respiration, and photosynthesis in seeds of dwarf mistletoe (Arceuthobium) were studied. The effects of 1 hour soakings of seeds in aqueous solutions of 1, 2, or 3% H2O2 or 1, 2, 3, 4, or 5% Chlorox on germination of seeds were tested. Germination rates for seeds from three consecutive years (1975-1977) were obtained. Germination rates varied widely. This variance transcended subtle changes in treatment. Pretreatment of seeds with Chlorox resulted in significantly lower germination rates than those of the control. Chlorophyll concentrations were determined for seeds and aerial shoot tissue of four species. Seeds …


Alpine Vegetation Of Steens Mountain, Paul Collins Jun 1978

Alpine Vegetation Of Steens Mountain, Paul Collins

Dissertations and Theses

A determination was made that the summit of Steens Mountain is an alpine tundra. The assessment was based on floristics, vegetation and community structure, environmental parameters, and geomorphological criteria. Microhabitats of Oxyria digyna at low elevations were found to approximate alpine conditions.


The Use Of Track Autoradiography To Determine Species-Specific Phytoplankton Productivity, Ralph Martin Vaga Jan 1978

The Use Of Track Autoradiography To Determine Species-Specific Phytoplankton Productivity, Ralph Martin Vaga

Dissertations and Theses

Methods of measuring primary productivity are discussed in terms of what information they provide concerning energy flow in the phytoplankton community. A track autoradiographic technique is presented which measures species-specific phytoplankton productivity and its use is demonstrated under laboratory conditions. Controls and standardized processing conditions are established which permit the use of the track technique in quantitative evaluations of primary productivity.


Small Mammal Dissemination Of Dwarf Mistletoe Seeds, Daniel Eugene Lemons Jan 1978

Small Mammal Dissemination Of Dwarf Mistletoe Seeds, Daniel Eugene Lemons

Dissertations and Theses

No study has been done in the western United States concerning dispersal of dwarf mistletoe by mammals. At the outset of the study it was determined that the red squirrel, the yellow pine chipmunk (Eutamias amoenus), the northern flying squirrel, and the bushy-tailed wood rat (Neotaoma cinerea), were all potential vectors of seeds. The red squirrel was chosen as the main object of study because it is diurnal and is closely associated with ponderosa pine (Pinus ponderosa), a heavily infected species. The study was undertaken to determine whether small mammals play a significant role in transporting mistletoe seeds to uninfected …


Genetic Transformation Among Azotobacter Species, Wayne H. Voth Dec 1977

Genetic Transformation Among Azotobacter Species, Wayne H. Voth

Dissertations and Theses

Previous methods for genetic transformation in Azotobacter vinelandii have employed poorly defined genetic markers or crude DNA extracts. An improved transformation technique has been developed for use in Azotobacter. The technique was used to transform several strains of Azotobacter with DNA carrying a defined genetic marker. A method for isolating pure, high molecular weight, biologically active DNA from Azotobacter is also presented. Purity of the extracted DNA was determined by standard chemical assays. The molecular weight was determined by boundary sedimentation techniques to be 18.2 megadaltons. DNA was obtained from several mutant strains of Azotobacter. Biological activity of these samples …


Distribution And Behavior Study Of Diurnal Tree Squirrels In Portland, Oregon, With Emphasis On The Western Gray Squirrel (Sciurus Griseus Griseus Ord) And The Western Fox Squirrel (S. Niger Rufiventer E. Geoffroy St.-Hilaire), Ira Young Rice Iii Aug 1977

Distribution And Behavior Study Of Diurnal Tree Squirrels In Portland, Oregon, With Emphasis On The Western Gray Squirrel (Sciurus Griseus Griseus Ord) And The Western Fox Squirrel (S. Niger Rufiventer E. Geoffroy St.-Hilaire), Ira Young Rice Iii

Dissertations and Theses

Populations of diurnal tree squirrels in the Portland area were located by mail surveys, personal interviews, and field inspections. Pine squirrels were found to reside in thickly wooded residential areas with dense understories and running water nearby. Western gray squirrels occupied habitats in relatively quiet residential neighborhoods, in areas well supplied with mast crops. Western fox squirrels were found to coexist with gray squirrels in their preferred habitat, and also to thrive in park settings with few mast trees and high activity and noise levels. In areas occupied by both fox and gray squirrels, dominant-subordinate relationships were noted. Each species …


Effects Of Types 1 And 2 Herpes Simplex Viruses On Several Fish Tissue Culture Systems, Raymond Charles Harry May 1977

Effects Of Types 1 And 2 Herpes Simplex Viruses On Several Fish Tissue Culture Systems, Raymond Charles Harry

Dissertations and Theses

The purpose of this investigation was to observe changes induced by types 1 and 2 herpes simplex viruses (HSV 1 and HSV 2) when these viruses were cultivated in fish cells. The possibility of attempting to use human strains of herpesviruses in order to transform normal fish tissue culture preparations was considered. Three different fish cell cultures were tested: CHSE-214 cell lines were derived from embryonic chinook salmon (Oncorhynchus tshawytscha), and STE-137 cell lines were obtained from embryonic steelhead trout (Salmo gairdneri). Cells isolated from immature ovaries of rainbow trout (Salmo gairdneri) were propagated …


A Behavioral Study Of A Small Group Of Pikas (Ochotona Princeps) On Mt. Hood, Oregon, Nancy A. Ewen Frazier May 1977

A Behavioral Study Of A Small Group Of Pikas (Ochotona Princeps) On Mt. Hood, Oregon, Nancy A. Ewen Frazier

Dissertations and Theses

Observations or a small group of pikas, (Ochotona princeps) occupying a southwest facing roadfill on Mt. Hood, Oregon (1518 m) were made during the fall or 1976. Territorial sizes of 305.5 m2 and 121 m2 were determined based on territorial displays. These territories were compared with those observed in other studies. The mean distance to the nearest neighbor was 15.1 m. A pair relationship between two of the pikas and a dominance order are discussed. The seasonal progression of the haypiles and the reactions of the pikas to other animals are also noted.


Behavioral Temperature Regulation In The Turtle Pseudemys Scripta Elegans, Michael H. Johnston May 1977

Behavioral Temperature Regulation In The Turtle Pseudemys Scripta Elegans, Michael H. Johnston

Dissertations and Theses

A group of red-eared turtles (Pseudemys scripta elegans) was acclimated to 18-20˚C and artificial photo-period for 21 days. The animals were then individually placed in a thermal gradient and their selected temperatures were continuously recorded for 24 hours. A second group of turtles was acclimatized to 7.5-11.0˚C and natural photoperiods for 28 days, and subsequently tested in the same manner as the first group. Lastly, the turtles in the first group, after being acclimated to 3.0˚C and the previous artificial photoperiod for 14 days, were retested in the gradient.


The Fatty Acid Composition Of Some North American Dwarf Mistletoe, Hwa Chen Feb 1977

The Fatty Acid Composition Of Some North American Dwarf Mistletoe, Hwa Chen

Dissertations and Theses

Fatty acid composition of five dwarf mistletoe species was analysed by Gas Liquid Chromatography. Because of the limitations of available equipment, only aerial shoots were analysed. Palmitic, oleic, linoleic and arachidic acids were the major components of total lipids. The sum of these acids accounted for 85-95 percent of total lipids present in the tissue. There was no apparent difference between species. The ratio of saturated acids to unsaturated acids in summer collections was higher than that of fall collections. Temperature may play an important role in controlling of these ratios. Lipid content varied from 3.25% to 8.5% on a …


A Study Of Home Range In Two Neotoma Fuscipes Colonies In Klamath County, Oregon, Brent D. Frazier Feb 1977

A Study Of Home Range In Two Neotoma Fuscipes Colonies In Klamath County, Oregon, Brent D. Frazier

Dissertations and Theses

Home ranges of dusky-footed wood rats (Neotoma fuscipes) were determined by the exclusive boundary strip method in two colonies 630 m apart in Klamath County, Oregon. The mean home range area was 1800 - 1900 m2 . Densities or trees and shrubs were determined on selected home ranges and densities of wood rat houses and nests were determined on all home ranges. No significant correlation was found between home range areas and densities of various trees and shrubs, home range areas and densities of woodrat houses and nests, or home range areas and weights of woodrats in …


The Dispersal And Dispersion Patterns Of Hydra Fusca In A Limited Environment, Faith E. Ruffing Jan 1977

The Dispersal And Dispersion Patterns Of Hydra Fusca In A Limited Environment, Faith E. Ruffing

Dissertations and Theses

The dispersal and dispersion patterns of Hydra fusca were examined. Hydra were placed in petri dishes at various densities. The water in the dishes was swirled forcing the animals to the center. The location of each animal was marked at time intervals thereafter. Analyses of the dispersal rates and dispersion patterns were made. Hydra dispersed from a central release point at a non-random rate. There was rapid movement from the center followed by a minimal daily movement. This eventually resulted in a uniform dispersion pattern at high densities in a limited environment. There was a relationship between the ratio of …


Localization Of Neurosecretory Cells Within The Cerebral Ganglia Of Amphiphorus Imparispinosus Griffin, 1898 (Hoplonemertea) And Their Possible Regulatory Role In The Annual Reproductive Cycle, Gail H. Jacobson Jan 1977

Localization Of Neurosecretory Cells Within The Cerebral Ganglia Of Amphiphorus Imparispinosus Griffin, 1898 (Hoplonemertea) And Their Possible Regulatory Role In The Annual Reproductive Cycle, Gail H. Jacobson

Dissertations and Theses

Nemerteans are common invertebrates along coastlines in both temperate and arctic climates throughout the world. Amphiphorus imparispinosus is a carnivorous member of this phylum that is found abundantly in the intertidal areas of the Oregon coast. As in many other invertebrate phyla, endocrine integration within the nemerteans is thought to be accomplished by neurosecretory mechanisms. In Amphiphorus the presence of these neurosecretory systems has not been previously shown. This project was undertaken to determine if neurosecretory cells are present within the central nervous system of this species and. further, to examine seasonal changes in the number and appearance of these …


Some Aspects Of The Ecology Of The Virginia Opossum (Didelphis Virginiana Virginiana Kerr 1792) In An Urban Environment, David Hopkins Nov 1976

Some Aspects Of The Ecology Of The Virginia Opossum (Didelphis Virginiana Virginiana Kerr 1792) In An Urban Environment, David Hopkins

Dissertations and Theses

Eighty-three Didelphis virginiana from the Portland metropolitan area were collected and studied from December 1974 through May 1976. Males averaged 3394 g, females 2318 g. An annual sex ratio of 68.7:31.3 was recorded. Data indicate the possibility of a year-round breeding season and suggest the occurrence of three peaks of reproductive activity: January-February, April-May and October-November. The six primary foods consumed annually are: leaf litter, mammals, gastropods, earthworms, grasses and pet food. Seasonal composition and diversity in the diet is marked. Five new parasite-host records were established. These include mites: Androlaelaps fahrenholsi, Haemogamasus nidi, Eulaelape stabularis tick, Ixodes angustus, and …


The Columbia River As A Barrier To Gene Flow In The Vagrant Shrew, Sorex Vagrans Vagrans Baird, James J. Kirk Nov 1976

The Columbia River As A Barrier To Gene Flow In The Vagrant Shrew, Sorex Vagrans Vagrans Baird, James J. Kirk

Dissertations and Theses

Twenty-one morphological characters were measured in shrews from four islands in the Columbia River and from the adjacent Oregon and Washington shores. Information on the history and characteristics of the river islands was gathered to facilitate interpretation of the shrew’s morphology data. Significant differences between character means of different populations were detected and average taxonomic distances between pairs of populations were calculated. The Columbia River is an incomplete barrier to gene flow, but its influence has been sufficient to allow divergence of island populations. Natural selection on the small gene pools of island populations has probably contributed to the divergence. …


Mammals Of The Bull Run, Edward M. Thatcher Sep 1976

Mammals Of The Bull Run, Edward M. Thatcher

Dissertations and Theses

This study of mammals of the Bull Run Planning Unit has a dual character. First, mammals of special scientific or natural history interest such as threatened or endangered species were sought. This was in conjunction with a Mt. Hood Bull Run Planning Unit. Second, a zoogeographical study of mammals of the Bull Run was performed. Abundance and distributional data was recorded for each species observed. This data was related to availability to moisture as indicated by plant associations trapped. Difference in habitat utilization along a moisture gradient was investigated as a possible coexistence mechanism for sympatric small mammals in the …


Thermal Ecology And Movement In The Leopard Lizard, Gambelia Wislizeni, Baird And Girard, Marvin Lynn Abts Aug 1976

Thermal Ecology And Movement In The Leopard Lizard, Gambelia Wislizeni, Baird And Girard, Marvin Lynn Abts

Dissertations and Theses

Thermal ecology and movement of the Leopard Lizard, G. wistizeniwere studied at Frog Spring, adjacent to the Alvord Desert, and at various locations throughout the Alvord Basin. Seasonal activity is known to occur from early May to mid-October, but abundance. gradually decreases after late July. During favorable late spring, and summer weather lizards exhibit a bimodal pattern of diel activity with some activity occurring at all hours of the day between 0600 and 1800 H. At other times activity was unimodal. Emergence was apparently largely temperature dependent and did not occur until sand temperature approximated 21°C. Retreat appeared to …


Influence Of Light On Algal Growth In The Lower Willamette River, Stephen Arthur Wille Jul 1976

Influence Of Light On Algal Growth In The Lower Willamette River, Stephen Arthur Wille

Dissertations and Theses

During the summer of 1974 chemical conditions in the lower reaches of the Willamette River, Oregon were similar to those in other rivers currently experiencing nuisance algal growth problems. Temperature and chemical nutrients are not limiting. Relatively high populations of phytoplankton and productivity values for upstream periphyton beds and surface waters suggest moderately eutrophic conditions. However, with increased depth in the lower river, and a constant euphotic zone, the amount of photosynthetically available light is reduced. With sufficient depth and complete mixing the critical depth is exceeded. Primary productivity rates are subsequently limited by low light availability in the lower …


The Chromosome Constitutions Of A Hybrid Salmonid And Its Parental Types: Salmo Gairdneri And Salmo Clarki, Peter Bruce Valentine Jacky May 1976

The Chromosome Constitutions Of A Hybrid Salmonid And Its Parental Types: Salmo Gairdneri And Salmo Clarki, Peter Bruce Valentine Jacky

Dissertations and Theses

A study was undertaken to investigate the application of tissue culture and histochemical banding techniques normally used in mammalian studies to fish cells and to examine the mechanisms of chromosome evolution and speciation in salmonids by comparing the chromosomes of the hybrid to those of the parental types. The application of banding techniques was generally unsuccessful in revealing bands, though quinacrine staining did reveal the presence of two fluorescent spots in the vicinity of the centromere. These were thought to be heterochromatic blocks, possibly related to the high incidence of centric fusion or fission in salmonids. Results of chromosome analysis …


A Survey Of Small Mammals On Islands In The Columbia And Willamette Rivers, Gayle Kirk Feb 1976

A Survey Of Small Mammals On Islands In The Columbia And Willamette Rivers, Gayle Kirk

Dissertations and Theses

A survey of small mammals on eight islands in the Columbia and Willamette Rivers near Portland, Oregon was conducted in 1974. The islands were Govermnent , Sand, Lemon, McGuire and Sandy Islands in the Columbia River and East, Ross and Hardtack Islands in the Willamette River. The objectives of the study were to ascertain and compare the kinds, distribution and relative densitites of small mammals . A variety of traps was used to capture the animals including Museum Special Rodent Traps , back- break mouse traps, scissor and guillotine- type stab mole traps , Sherman traps , modified Young traps …