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Articles 331 - 360 of 367

Full-Text Articles in Biology

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. …


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 …


The Androgenic Glands Of The Pacific Crayfish, Pacifastacus Leniusculus Trowbridgii Stimpson, 1859, Larry L. Sanders Jan 1976

The Androgenic Glands Of The Pacific Crayfish, Pacifastacus Leniusculus Trowbridgii Stimpson, 1859, Larry L. Sanders

Dissertations and Theses

The androgenic glands of the Pacific crayfish, Pacifastacus leniusculus trowbridgii Stimpson, 1859, were studied experimentally and by light and electron microscopy. The androgenic glands proliferate in the spring of the year concurrently with an increase in mitotic activity in the testes. Degeneration of a major portion of the glands occurs in the fall, when spermatogenic activity in the testes is near completion. Cellular development appears to progress from small undifferentiated cells through stages of vacuolization and hypertrophy and terminates with degeneration or lysis. The fine structure of the vacuolated gland cells is indicative of increased metabolic activity and probable hormone …


Mammals Of The Bull Run, Edward M. Thatcher Jan 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 …


Some Coyote Food Habitat Patterns In The Shrub-Steppe Of South-Central Washington, Peter Frederick Stoel Jan 1976

Some Coyote Food Habitat Patterns In The Shrub-Steppe Of South-Central Washington, Peter Frederick Stoel

Dissertations and Theses

Coyote food habits were ascertained by identifying the undigested material in 1143 scats collected at monthly intervals from specific road transects on the USERDA Hanford Reservation in Washington from 1974 to 1976. Tracks at artificially established scent posts along the principal transect provided evidence that the scats were left by coyotes and not bobcats or badgers. On the basin plain (150m elevation) where the Aptemisia tpidentata/Poa sandbepgii Association predominates, the average monthly percent occurrences in the 491 scats collected in 1975 2 were pocket mouse 60, leporid 39, pocket gopher 12, grasshopper 12, fruit 10, cricetine mice 7, darkling beetle …


The Role Of Zinc In Dihydroorotase, Pamela S. Gilchrist Aug 1975

The Role Of Zinc In Dihydroorotase, Pamela S. Gilchrist

Dissertations and Theses

Dihydroorotase (4,4—dihydroorotic acid amidolyase, EC 3.5.2.3.) which catalyzes the reversible cyclization of N-carbamyl-L-aspartate to L-dihydroorotate has been purified from orotate-grown Clostridium oroticum. The enzyme is stable in 0.3 M sodium chloride and 10 µ ZnSO4. Sodium dodecyl sulfate gel electrophoresis indicates the enzyme to be composed of two identical subunits each with a molecular weight of 58,000 + 6000. Dihydroorotase is shown to be a zinc-containing metalloenzyme with 2 g atoms of zinc per 58,000 g of protein. The role of zinc in dihydroorotase is discussed.


Biochemical Description Of A Lava Tube Lake In Southeast Oregon, John Edward Palmer Jul 1975

Biochemical Description Of A Lava Tube Lake In Southeast Oregon, John Edward Palmer

Dissertations and Theses

A Pleistocene lava tube cave in southeast Oregon has a seasonally fluctuating lake occupying the last 1200 to 2000 feet. Three endemic invertebrate species inhabit the lake: Kenkia rynchida Hyman; Asellus sp.; and Stygobromus hubbsi Shoemaker. Little is known however, about their environment. The purpose of this study was to describe various physical and chemical parameters of Malheur Cave Lake.


Effects Of Antifibroblast Antiserum On Cells Derived From Fibroblast Outgrowth Of Human Prostatic Tissues, Eva Shang-Lian King Jul 1975

Effects Of Antifibroblast Antiserum On Cells Derived From Fibroblast Outgrowth Of Human Prostatic Tissues, Eva Shang-Lian King

Dissertations and Theses

The purpose of this investigation was to provide pure cultures of normal human prostatic epithelium free of fibroblasts in order to study malignant conversion by chemical carcinogens. Normal epithelial cells were needed because this was the cell type implicated in prostatic malignancies of human subjects. Unfortunately fibroblasts grew faster than epithelial cells so that cultures were always overgrown with connective tissue elements. It was considered important to find a method which would eliminate fibroblasts so that normal epithelial cells could grow out in pure culture.


Interactions In The Frequencies Of Electric Organ Discharge By Eigenmannia Virescens (Sternopygidae, Pisces) During Social Behavior, Philip Gaddis Jul 1975

Interactions In The Frequencies Of Electric Organ Discharge By Eigenmannia Virescens (Sternopygidae, Pisces) During Social Behavior, Philip Gaddis

Dissertations and Theses

The extent to which individuals of Eigenmannia virescens modulate their electric organ discharge frequencies to accommodate the frequencies of others of the same species during social interactions was investigated. Recordings of the fish's discharge frequencies, taken with Tektronix 3L5 and 5L4N spectrum analyzers, showed that, although movements of up to 60 Hz in a day may be made, the frequency movements would be made more or less synchronously by all fish in the group. An apparent preference for, and a tendency of the fish to follow one another in frequency, at frequency ratios of 2:3 (a musical fifth), 3:4 (fourth), …


The Distribution Of The Deer Mouse, Peromyscus Maniculatus, On The Oregon Side Of The Columbia River Gorge, Ronald P. Neilson Jun 1975

The Distribution Of The Deer Mouse, Peromyscus Maniculatus, On The Oregon Side Of The Columbia River Gorge, Ronald P. Neilson

Dissertations and Theses

A study of the biogeography of Peromyscus maniculatus was undertaken in order to ascertain a few of the environmental parameters important in defining the distribution of this species and how the species in turn has adapted to these parameters. The Columbia Gorge was chosen as it presents a climatic gradient from maritime to continental with very little elevation gain. Changes along this gradient in topography, soils and vegetation community structure are discussed.


A Biochemical Analysis Of Viscin From Arceuthobium Tsugense, Peter J. Paquet May 1975

A Biochemical Analysis Of Viscin From Arceuthobium Tsugense, Peter J. Paquet

Dissertations and Theses

The viscin coating of seeds from Arceuthobium tsugense was analyzed histochemically. The results indicated that the viscin is composed of two components. The first is a muculagenous pectic compound which surrounds the entire seed and accounts for a number of observed phenomenon such as stickiness, water holding capacity and the ability to undergo repeated drying and rehydration. The second component is made up of a large number of cellulose strands which are attached to the endocarp and run throughout the pectic coating. Scanning electron micrographs show that they are thought to be important in maintaining the integrity of the pectic …


The Morphology Of The Eye Of The Purple Shore Crab, Hemigrapsus Nudus, Sharon E. Heisel Jan 1975

The Morphology Of The Eye Of The Purple Shore Crab, Hemigrapsus Nudus, Sharon E. Heisel

Dissertations and Theses

A structural analysis of the compound eye of Hemigrapsus nudus expands the basis of functional analysis of decapod Crustacean eyes. Contradictory evidence for disintegration of rhabdomeric microvilli in the absence of light prompted observation of H. nudus eyes after 146 days in darkness.

Eyes were fixed with formalin and glutaraldehyde and post fixed with osmium tetroxide for electron and light microscopy. Light- dark-adapted eyes were also observed with hot water fixation and paraffin embedment.

The eye of H. nudus is typical of decapod Crustacean compound eyes. Corneagenous cells underlie the transparent cuticle cone cells secrete the composite crystalline cone which …


A Study Of Rna Bacteriophage 7s Infection Of Pseudomonas Aeruginosa, Deanne Benson Aug 1974

A Study Of Rna Bacteriophage 7s Infection Of Pseudomonas Aeruginosa, Deanne Benson

Dissertations and Theses

A study was conducted to find the effect of magnesium, calcium, manganese and zinc ions on the infection of Psudomonas aeruginosa strain 1C by RNA bacteriophage 7s. When an 18 hour progeny experiment was performed, it was found that magnesium, calcium and manganese had different effects on bacteriophage production and was dependent on the bacterial growth conditions. RNA bacteriophage 7s progeny production was significantly enhanced by the addition of magnesium to cultures of Psudomonas aeruginosa 1C grown in a magnesium deficient medium. Under these environmental conditions there was a slight increase in progeny in the presence of calcium. When Psudomonas …


Enzyme Reactions Using Ureidosuccinate As A Substrate During Pyrimidine Biosynthesis And Degradation In Cl. Oroticum, Penny Amy Aug 1974

Enzyme Reactions Using Ureidosuccinate As A Substrate During Pyrimidine Biosynthesis And Degradation In Cl. Oroticum, Penny Amy

Dissertations and Theses

Cells of Clostridium oroticum, an anaerobic bacterium, were grown on orotate as a carbon and energy source. Ureidosuccinase, an inducible enzyme in the pathway for pyrimidine degradation has been shown to convert ureidosuccinate to aspartate, CO2 and NH3 as reported by Liebenmm and Kornberg (7). Aspartate and CO2 were formed in approximately a 1:1 ratio from ureidosuccinase activity.

Ureidosuccinase was found to be a Mn+2 requiring enzyme with a pH optimum of approximately pH 6.5. Enzyme activity is labile to O2, temperature, pH, dilution and high ionic strength. The optimum conditions for storage …


Effects Of The Nerve During The Dedifferentiative Phase Of Limb Regeneration In The Mexican Axolotl, Ambystoma Mexicanum, Roberta Gail Wald Jul 1974

Effects Of The Nerve During The Dedifferentiative Phase Of Limb Regeneration In The Mexican Axolotl, Ambystoma Mexicanum, Roberta Gail Wald

Dissertations and Theses

It is known that nerves are particularly critical during the early or dedifferentiative phase of limb regeneration. During this period in the innervated limb, cells just proximal to the amputation surface dedifferentiate, migrate to the limb tip, and undergo mitosis. These processes give rise to a population of undifferentiated mesenchymatous cells capable of redifferentiating into the missing components of the newly forming regenerate. The consequences of denervation stand in stark contrast to the normal events occurring in the innervated limb, because neither a blastema nor a regenerate forms.

Results from this study indicate that during the early portion of the …


Physiological And Behavior Studies Of Thelepus Crispus And Its Commensal Halosydna Brevisetosa, John B. Morgan Jan 1974

Physiological And Behavior Studies Of Thelepus Crispus And Its Commensal Halosydna Brevisetosa, John B. Morgan

Dissertations and Theses

Chemical, physical and physiological interactions between the marine commensal scaleworm Halosydna brevisetosa Kinberg and its terebellid host, Thelepus crispus Johnson were investigated. In an experiment designed to test for chemical attraction between the host and commensal, Halosydna were unable to identify the arm in a U-tube choice apparatus leading to the host. In 50 trials, 54% of the commensals crawled into the flow of water from their hosts. Other observations showed that Halosydna made contact with the host by random encounter. After contact, commensals followed tentacles down into the host’s tube and took up a characteristic position along the dorsum …


Lead Content Of Hair Of Urban And Rural Populations Of Small Mammals, Richard Brian Raymond Nov 1973

Lead Content Of Hair Of Urban And Rural Populations Of Small Mammals, Richard Brian Raymond

Dissertations and Theses

Hair from small mammals of roadside, urban parkland, wilderness, and antique populations was analyzed for lead by atomic absorption spectrophotometry. Hair from roadside populations had a significantly greater amount of lead than hair from the ether groups. Hair from antique populations did not differ in lead content from that of current populations which are removed from immediate exposure to automotive exhausts.


Characteristics Of Arginase From The Terebellid Polychaete Pista Pacifica Berkeley, Karen Laurel O'Malley Sep 1973

Characteristics Of Arginase From The Terebellid Polychaete Pista Pacifica Berkeley, Karen Laurel O'Malley

Dissertations and Theses

Arginase has been found to occur in the tentacles, gut, and body wall of Pista pacifica Berkeley. Partially purified arginase from the intestine has a molecular weight of 200,000, a Km of about 155 mM, an arginase/canavanase ratio of 22, a pH optimum of 10.5, and a temperature optimum of 60°C. In addition, P. pacifica arginase is competitively inhibited by ornithine but is not inhibited by high arginine concentrations, nor by sulfhydryl reagents. The enzyme is not stimulated by exogenous manganese and breaks down into an active subunit under harsh treatment. The subunit has a Km of about 118 mM …


Growth Of Selenastrum Capricornutum Printz In Natural Waters Treated With Copper Sulfate, Gerald Eugene Schulz Aug 1973

Growth Of Selenastrum Capricornutum Printz In Natural Waters Treated With Copper Sulfate, Gerald Eugene Schulz

Dissertations and Theses

The green alga, Selenastrum capricornutum Printz, was used in an algal bioassay to determine the toxic properties of copper in various natural lake waters of Oregon. Lake water was collected and brought back to the laboratory where it was treated with various copper concentrations and inoculated with a cell suspension of the test alga. Growth of the alga was determined by direct cell counts. The copper ion activity, pH, and absorbance of the test cultures were also determined. The growth of the alga was found to depend upon the water tested and also upon the copper concentration used.


Possible Avian Influences In The Distribution Of Dwarf Mistletoe, Paul James Zilka Jul 1973

Possible Avian Influences In The Distribution Of Dwarf Mistletoe, Paul James Zilka

Dissertations and Theses

The goal of this investigation was to determine the potential of birds as vectors for the movement of dwarf mistletoe seeds and the means by which such movement could occur. Birds would greatly speed the rate at which these parasites move horizontally or vertically through the forest. Five areas in Oregon, heavily infected by six species of Arceuthobium were studied. Observations of avian behavior point to 13 species whose general behavior make them potential vectors in the distribution of these parasites. More specifically, the roosting and subsequent bathing behavior of most forest birds proves a very important means of potential …


Life Cycle, Additions To Biology, And New Hosts Of Apophallus Donicus (Trematoda: Heterophyidae) In Oregon, Delbert Niemi May 1973

Life Cycle, Additions To Biology, And New Hosts Of Apophallus Donicus (Trematoda: Heterophyidae) In Oregon, Delbert Niemi

Dissertations and Theses

Apophallus donicus is examined, its life cycle is described, and certain additions are made to its biology.

It is thought, but not proven, that eggs are eaten by the first intermediate host, the local stream snail Flumenicola virens, and the miracidia escape internally. Mother and daughter rediae stages result, the later producing cercariae which are shed into the water. After burrowing just beneath the skin in suckers (Catostomus macrocheilus Girard), rainbow trout (Salmo gairdneri Richardson), coho salmon (Oncorhynchus kisutch (Walbaum)), squawfish (Ptychocheilus oregonensis Richardson), blackside dace (Rhinichthys osculus nubilus (Girard)), redside shiners (Richardsonius …