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Articles 661 - 684 of 684
Full-Text Articles in Biology
Some Coyote Food Habitat Patterns In The Shrub-Steppe Of South-Central Washington, Peter Frederick Stoel
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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 …
Agonistic Behavior And Dominance In Townsend's Chipmunks (Eutamias Townsendii), Paul Evan Sherman
Agonistic Behavior And Dominance In Townsend's Chipmunks (Eutamias Townsendii), Paul Evan Sherman
Dissertations and Theses
Agonistic behavior and dominance are described for captive Townsend's chipmunks (Eutamias townsendii). A total of 10,739 encounters was recorded; 6441 (59.9%) were agonistic. Chases (58.5%) and displacements (30.8%) were the predominant agonistic behaviors; threats (6.8%) and fights (4.l%) were relatively rare.
Stable, non-triangular hierarchies were rapidly established in 11 of the 12 groups of chipmunks observed; the presence of individuals of equal rank in some groups precluded strict linearity. Dominance positions did not change within a group, but reversals in rank and changes from equal to dominant-subordinate relationships occurred when the membership of groups was changed. One hierarchy …
A Survey For Leucocytozoon Simondi Mathis And Leger (1910) In Canada Geese Of The Malheur Wildlife Refuge, John Val Snively
A Survey For Leucocytozoon Simondi Mathis And Leger (1910) In Canada Geese Of The Malheur Wildlife Refuge, John Val Snively
Dissertations and Theses
Blood smears of blood collected in 1971 and 1972 from 291 Canada geese at Malheur National Wildlife Refuge were examined to determine the incidence of the avian malarial parasite, Leucocytozoon simondi. No parasites were found. Absence of blood parasites suggests that birds using migration routes to the north and northeast of Malheur are free of the disease.
The Leucocytozoon infections known in California waterfowl may be attributable to sources within the flyway east or northeast of California, to infected birds crossing over from other flyways, or abnormal conditions in the molting grounds of sub-adult and non-nesting birds where major flyways …
Photosynthesis And Respiration Of Arceuthobium Tsugense, James Roger Miller
Photosynthesis And Respiration Of Arceuthobium Tsugense, James Roger Miller
Dissertations and Theses
Dark respiration rates of the aerial shoots of Arceuthobium tsugense, obtained by manometric and IRGA techniques, show production of C02to range between 155-300 µl CO2 g-1h-1 with evidence of seasonal variation. Experiments with 14C02 indicate that the aerial shoots are capable of some photosynthetic CO2 fixation, with 10-15% of the available 14C incorporated by the plant tissue in one hour.The portions of the o aerial shoots which are most active in C02 fixation are the young terminal regions. Biochemical characterization of the products of photosynthesis reveals that 80-90% of …
Some Aspects Of The Water Economics Of Townsend's Chipmunks, Ali Mokhtar Rahima
Some Aspects Of The Water Economics Of Townsend's Chipmunks, Ali Mokhtar Rahima
Dissertations and Theses
Water consumption, and weight loss in response to water deprivation and saline water consumption, were studied in the Eutamias townsendii townsendii from Portland, Multnomah County, Oregon. These chipmunks occupy moist Pacific Northwest forests. The results of these studies suggest that Townsend's chipmunks are dependent on sources of drinking water, at least for normal above ground activity, that their tolerance for water deprivation is comparatively low, and that they are unable to obtain a net gain of water by drinking 0.2 M sodium chloride solutions. Chipmunks cannot drink 0.4 M NaCl solution and survive for more than a few days. Metabolic …
Vocalizations Of The Townsend Chipmunk (Eutamias Townsendii), Greig Michael Warner
Vocalizations Of The Townsend Chipmunk (Eutamias Townsendii), Greig Michael Warner
Dissertations and Theses
This study describes and analyzes the vocalizations of the Townsend chipmunk (Eutamias townsendii) in Oregon. Tape recordings of calls were collected primarily from Forest Park in Portland (Oregon) during 1970 and 1971, and sonograms of these recordings were produced. Findings were compared with those of Brand (1970) who investigated E. townsendii vocalizations in California. The prominent calls in the vocal repertoire of townsendii are the quist, the quirt, and the chipper. These calls all appear to be warning calls. The quist note is a a chevron-shaped (A) figure representing a sound which begins at a low frequency (1-2 KC), sharply …
Effects Of Insulin, Sodium And D-Glucose On Amino Acid Absorption In The Intestine Of Rats, Andre-Gerard Craan
Effects Of Insulin, Sodium And D-Glucose On Amino Acid Absorption In The Intestine Of Rats, Andre-Gerard Craan
Dissertations and Theses
Amino acid absorption across rat intestine in vitro was inhibited or stimulated by insulin depending on the hormone serosal concentration.
The absence of sodium ions from the incubating solution resulted in a significant decrease of L-alanine absorption. However, L-alanine was enhanced in a sodium-free medium by the addition of insulin on the serosal side of the intestine.
A sizable decrease in L-alanine and L-lysine absorption was produced by introduction of D-glucose (0.2 % and 2 %) in the Krebs-Ringer's incubating buffer. Nevertheless, the presence of D-glucose did not prevent the stimulatory effect of insulin on amino acid absorption.
The Biological Properties Of Pseudomonas Aeruginosa Bacteriophage 7v, Shirley Phillips Schnider
The Biological Properties Of Pseudomonas Aeruginosa Bacteriophage 7v, Shirley Phillips Schnider
Dissertations and Theses
The present study was undertaken to define the standard conditions for growth of bacteriophage 7V on its host Pseudomonas aeruginosa strain PS-7 and to determine the factors which affect the quantity and quality of plaques in the plaque count assay. Observations from the single-step growth experiment and single-burst experiment are also included.
Plaque count assays were performed under various environmental conditions. Conditions were selected as "standard" if they yielded: 1) relative maximum number of infective centers per ml of stock 7V phage, 2) clear, haloed plaques at least 2.0 mm in diameter, and 3) reproducible assays limited only by the …