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Articles 6091 - 6120 of 6689

Full-Text Articles in Physiology

Reproductive And Metabolic Characteristics In Peromyscus Leucopus Noveboracensis From Laboratory Populations And Females During Release From Reproductive Inhibition, Holly Anne Lavoie Jan 1989

Reproductive And Metabolic Characteristics In Peromyscus Leucopus Noveboracensis From Laboratory Populations And Females During Release From Reproductive Inhibition, Holly Anne Lavoie

Dissertations, Theses, and Masters Projects

No abstract provided.


The Effects Of Exogenous Triiodothyronine On Reproductively Inhibited Prairie Deer Mice (Peromyscus Maniculatus Bairdii) From Laboratory Populations, Paul Sumpter Hogg Jan 1989

The Effects Of Exogenous Triiodothyronine On Reproductively Inhibited Prairie Deer Mice (Peromyscus Maniculatus Bairdii) From Laboratory Populations, Paul Sumpter Hogg

Dissertations, Theses, and Masters Projects

No abstract provided.


Feeding By A “Nonfeeding” Larva: Uptake Of Dissolved Amino Acids From Seawater By Licithotrophic Larvae Of The Gastropod Haliotis Refescens, William Jaeckle Dec 1988

Feeding By A “Nonfeeding” Larva: Uptake Of Dissolved Amino Acids From Seawater By Licithotrophic Larvae Of The Gastropod Haliotis Refescens, William Jaeckle

William Jaeckle

No abstract provided.


Growth And Energy Imbalance During The Development Of A Lecithotrophic Molluscan Larva (Haliotis Rufescens), William Jaeckle, Donal T. Manahan Dec 1988

Growth And Energy Imbalance During The Development Of A Lecithotrophic Molluscan Larva (Haliotis Rufescens), William Jaeckle, Donal T. Manahan

William Jaeckle

Larvae of the gastropod Haliotis rufescens are classified as "nonfeeding" because they cannot capture particular foods. However, for only 1 out of 5 independent cultures was a net decrease observed in dry organic weight during the complete period of larval development (5 to 7 days). In fact, there were net increases in dry organic weight from the oocyte (day 0) to the newly formed veliger larvae (2-day-old). These weight increases during early development could be explained by increases in the amounts of specific biochemical components of the larvae, relative to oocytes. The metabolic rates of larvae were measured (oxygen consumption) …


The Prenatal Development Of The "Synaptic" Structures In The Guinea Pig Pineal Gland, Zhongrong Luo Dec 1988

The Prenatal Development Of The "Synaptic" Structures In The Guinea Pig Pineal Gland, Zhongrong Luo

Loma Linda University Electronic Theses, Dissertations & Projects

Pineal "synaptic" ribbons are a heterogeneous population of organelles. In addition to "synaptic" ribbons (SR) sensu stricto, which are electron-dense rods, "synaptic" spherules (SS) and intermediate forms (IMF) are present. The SS are electron-dense spherical structures, the diameter of which is two to three times the width of the SR. The IMF appear as irregularly formed structures. The SR, SS and IMF are surrounded by electron-lucent vesicles. Their function and origin are unknown and also a knowledge of their prenatal development is lacking. In order to gain an insight into the development of the "synaptic structures, the pineal glands …


Effect Of Dietary Factors On Mutagenesis, Metabolism, And Binding To Dna Of Benzo [A] Pyrene And Benzo [A] Pyrene 7, 8-Dihydrodiol, Robin E. Vance Dec 1988

Effect Of Dietary Factors On Mutagenesis, Metabolism, And Binding To Dna Of Benzo [A] Pyrene And Benzo [A] Pyrene 7, 8-Dihydrodiol, Robin E. Vance

Loma Linda University Electronic Theses, Dissertations & Projects

Ellagic acid (EA), a naturally occurring plant phenol, at concentrations of 5 to 50 pg/plate, inhibited rat liver S9 protein dependent benzo[a]pyrene (B[a]P)-induced mutagenesis in Salmonella typhimurium TA 100 by 30-81% and B[a]P 7,8-dihydrodiol (DHD)-induced mutagenesis by 29 to 75%. EA (5-40 juM) did not significantly affect the metabolism of B[a]P or B[a]P 7,8-DHD as determined by high performance liquid chromatographic analysis of the organosoluble fraction and by the quantification of watersoluble conjugates. At these concentrations EA inhibited 3 3 the covalent binding of [ H] B[a]P and [ H] B[a]P 7,8-DHD metabolites to calf thymus DNA by 5 to …


Full Issue, Vol. 12 Oct 1988

Full Issue, Vol. 12

Great Basin Naturalist Memoirs

No abstract provided.


End Matter, Vol. 12, Index Oct 1988

End Matter, Vol. 12, Index

Great Basin Naturalist Memoirs

No abstract provided.


Front Matter, Vol. 12 Oct 1988

Front Matter, Vol. 12

Great Basin Naturalist Memoirs

No abstract provided.


End Matter, Vol. 12 Oct 1988

End Matter, Vol. 12

Great Basin Naturalist Memoirs

No abstract provided.


An Analysis Of Protein-Ligand Interactions For Enzyme Ii-Mannitol From Escherichia Coli, Brent Lee Wood Sep 1988

An Analysis Of Protein-Ligand Interactions For Enzyme Ii-Mannitol From Escherichia Coli, Brent Lee Wood

Loma Linda University Electronic Theses, Dissertations & Projects

Enzyme IImtl of Escherichia coli was purified from mtlA-overexpressing E. coli strain LJ1112 extraction of isolated membranes with deoxycholate, followed by hexyl agarose and ω-amino hexyl agarose chromatography in Lubrol PX. A 10-fold increase in total pure protein and 2.5-fold increase in specific activity over previously reported procedures was obtained. Tryptic fragments of Enzyme IImtl were also purified and identified as the membrane and cytoplasmic domains by protein sequencing and SDS-PAGE. The fluorescence spectrum of Enzyme IImtl suggested that two populations of tryptophan residues existed with emission maxima at 322 and 344 nm, corresponding to buried …


Age-Related Changes In Meissner Corpuscles Of Diabetic Mice As Observed By Electron Microscopy, Vicky R. Ras Sep 1988

Age-Related Changes In Meissner Corpuscles Of Diabetic Mice As Observed By Electron Microscopy, Vicky R. Ras

Loma Linda University Electronic Theses, Dissertations & Projects

Light touch and low-frequency vibration sense are often impaired in diabetic patients. Meissner corpuscles are distally located mechanoreceptors that respond to these stimuli. Peripheral sensory neuropathy in diabetes progresses from distal to proximal, therefore, Meissner corpuscles are ideally suited to study diabetic neuropathy in the C57BL/Ks (db/db) mouse.

Corpuscles from the forepaw digital pads of 9 diabetic and 9 nondiabetic littermates were studied by electron microscopy. These were divided into 3 age groups; 2.5 months, 10 months, and 17 months old.

Ultrastructural changes observed within various receptor components were myelin figures, multivesicular bodies, vacuoles, basal lamina duplication, abnormal and enlarged …


Computer Analysis Of Cross Sections Of Leaves Of Chrysothamnus Taxa And Their Relation To Environmental Conditions, J. Huang, W. M. Hess, D. J. Weber, E. D. Mcarthur, S. E. Meyer, R. Seegmiller Jul 1988

Computer Analysis Of Cross Sections Of Leaves Of Chrysothamnus Taxa And Their Relation To Environmental Conditions, J. Huang, W. M. Hess, D. J. Weber, E. D. Mcarthur, S. E. Meyer, R. Seegmiller

Great Basin Naturalist

Thirty-eight accessions of 20 taxa (species and subspecies) of Chrysothamnus from a range of environments were grown in a uniform garden. During mid-June, terminal and lateral leaves were removed, fixed, and processed for light-microscopy studies. Area and perimeter measurements of ink tracings of midleaf vein cross sections were measured using computer-scan techniques. Leaf area and perimeter were compared with vein perimeter and area measurements. Area and perimeter of these Chrysothamnus leaves varied in response to the environment at the collection location. Plants native to hot, dry conditions had small, thick leaves, whereas plants native to cooler, more mesic conditions had …


A Descriptive Catalog Of Dimming Cells In The Purple Shore Crab Hemigrapsus Nudus, Eugene Pak Jun 1988

A Descriptive Catalog Of Dimming Cells In The Purple Shore Crab Hemigrapsus Nudus, Eugene Pak

Loma Linda University Electronic Theses, Dissertations & Projects

A population of cells responsive to the decrease or dimming of light was identified in the Purple shore crab Hemigrapsus nudus. Extracellular pin electrode recordings from the optic nerve tract measured responses to decremental changes in relative light levels over the range 40 to 0.08 lux. The observed activity revealed that these dimming cells could respond over this entire range. A catalog detailing the response characteristics for each of the thirty dimming cells in the study was generated. The parameters measured the receptive field size; response to mechanoreceptive tactile stimuli; response to abrupt On or Off light level changes; …


Effects Of Graded And Steady Exercise And Self-Confidence On Stress, Kristine M. Clarke May 1988

Effects Of Graded And Steady Exercise And Self-Confidence On Stress, Kristine M. Clarke

Dissertations and Theses

This study examined the effects of steady, graded, and no exercise on stress reduction, and the effects of self-confidence on stress reduction through exercise. Seventy-two male and female volunteers from the Portland area, ranging in age from 19-49 years, served as subjects. Subjects completed pre and post measures of the Tennessee Self-Concept Scale and the state portion of the Spielberger State-Trait Anxiety Inventory. Subjects were divided into two experimental and one control group matched according to age and exercise history. The control group kept its exercise at a minimum for eight weeks. Exercise programs for the two experimental groups consisted …


Skeletal Muscle Sugar Transport Alterations In Bacteremia, Margaret V. Westfall Jan 1988

Skeletal Muscle Sugar Transport Alterations In Bacteremia, Margaret V. Westfall

Dissertations

No abstract provided.


Age Differences In Bimanual Coordination, Paul Amrhein, George Stelmach, Noreen Goggin Jan 1988

Age Differences In Bimanual Coordination, Paul Amrhein, George Stelmach, Noreen Goggin

Department of Psychology Faculty Scholarship and Creative Works

A bimanual coordination experiment was conducted in which two groups of 10 male and female participants, elderly (67 to 75 years of age) and young (21 to 25 years of age), produced unimanual, bimanual symmetrical (equal extent amplitude), and bimanual asymmetrical (unequal extent amplitude) movements. In addition to an overall increase in performance latency, the elderly group exhibited a linear increase in response initiation (RT) with increases in task complexity similar to that of the young group. However, the elderly participants showed a proportional increase over the young participants in response execution latency (MT). Further, the elderly group had a …


A Model For Evaluating Time Constraints On Short-Term Reproductive Success In Altricial Birds1, Larry Clark Jan 1988

A Model For Evaluating Time Constraints On Short-Term Reproductive Success In Altricial Birds1, Larry Clark

Larry Clark

We develop a simple single dimension model incorporating the time and energy commitments of breeding altricial birds in an effort to understand the evolutionary constraints on parental care. We chose time as the dimension of preference, because it is a naturally bounded constraint, e.g., length of day or breeding season. The utility of the model was evaluated by comparing simulations of time allocation of various breeding scenarios for the European starling (Sturnus vulgaris) to field data. The structure of the model may prove useful in determining the evolutionary constraints on parental care imposed by the developmental pattern of chicks.


The Effect Of Caloric Restriction And Exercise On Plasma Lipid And Lipoprotein Concentration, Jeffrey J. Zachwieja Jan 1988

The Effect Of Caloric Restriction And Exercise On Plasma Lipid And Lipoprotein Concentration, Jeffrey J. Zachwieja

Masters Theses

The independent and combined effects of exercise training and caloric restriction on the plasma concentration of lipid and lipoprotein was studied. Thirty-two female volunteers were assigned to one of three treatment groups; exercise only, diet only or diet plus exercise. The exercise only group participated in a walk/jog program three days per week. For 30 to 45 minutes these individuals either walked or jogged at a intensity which elicited a heart rate that was 70% of the max heart rate reserve. The diet only group participated in a behavior modification weight loss program which restricted caloric intake to 1200 kcals …


Incubation Energetics Of The Laysan Albatross, Ted N. Pettit, K A. Nagy, Hugh I. Ellis, G Causey Whittow Jan 1988

Incubation Energetics Of The Laysan Albatross, Ted N. Pettit, K A. Nagy, Hugh I. Ellis, G Causey Whittow

Biology: Faculty Scholarship

The energy expenditure of incubating and foraging Laysan Albatross (Diomedea immutabilis, mean body weight 3.07 kg) was estimated by means of the doubly-la- belled water technique. During incubation, the energy expenditure was similar to that of resting birds that were not incubating an egg. The energy expenditure of foraging albatross (2072 kJ/day) was 2.6 times that of resting birds. It was concluded that the energy expenditure of the tropical Laysan Albatross was not less than that of species foraging over cold, high-latitude oceans. An energy budget compiled for an incubating pair of albatross revealed that the energy expenditure of the …


Correlations Between Serum Corticosterone Level And Reproductive Fitness In Laboratory Populations Of The White-Footed Mouse (Peromyscus Leucopus Noveboracensis), Sterling Neblett Ransone Jan 1988

Correlations Between Serum Corticosterone Level And Reproductive Fitness In Laboratory Populations Of The White-Footed Mouse (Peromyscus Leucopus Noveboracensis), Sterling Neblett Ransone

Dissertations, Theses, and Masters Projects

No abstract provided.


The Relationship Of Free And Total Serum Thyroxine Concentrations To The Reproductive Condition Of The White-Footed Mouse (Peromyscus Leucopus Noveboracensis), Gerald William Peden Jan 1988

The Relationship Of Free And Total Serum Thyroxine Concentrations To The Reproductive Condition Of The White-Footed Mouse (Peromyscus Leucopus Noveboracensis), Gerald William Peden

Dissertations, Theses, and Masters Projects

No abstract provided.


Steady State Oxygen Cost Of Arm Ergometry Using The Monark Rehab Trainer, Gregory R. Grazen Jan 1988

Steady State Oxygen Cost Of Arm Ergometry Using The Monark Rehab Trainer, Gregory R. Grazen

Masters Theses

This study was designed to determine the steady state oxygen cost of arm crank ergometry with the Monark Rehab Trainer, a device used for exercise training in many cardiac rehabilitation programs. Fifteen male (25.2 yrs. ± 4.1) and fifteen female (23.8 yrs. ± 4.0) subjects were tested in the seated position with the mid-point of the crank wheel adjusted to shoulder height. No attempt was made to stabilize the shoulder girdle, as this is typically not done when training with this device. The test protocol for both groups consisted of progressive three minute work stages followed by a thirty second …


Influx, Net Flux And Transepithelial Flux Of Amino Acids In The Hardshell Clam Mercenaria Mercenaria (Linne): Influence Of Salinity, Michael Rice, Grover Stephens Dec 1987

Influx, Net Flux And Transepithelial Flux Of Amino Acids In The Hardshell Clam Mercenaria Mercenaria (Linne): Influence Of Salinity, Michael Rice, Grover Stephens

Michael A Rice

1.1. The effects of salinity on the uptake and internal distribution of alanine and other free amino acids (FAA) in hardsell clams, Mercenaria, was studied by radiochemical and high performance liquid chromatography (HPLC) techniques.2.2. Exposure of animals to reduced salinity does not alter the rate of unidirectional alanine influx.3.3. In 34%o salinity, entry of labeled alanine reflects the net flux of the amino acid. However, in 17%o salinity, there is a net loss of alanine and other acids, mainly taurine, to the medium.4.4. Reduced salinity induces greater incorporation of radiolabeled FAA into macromolecular fractions throughout the animal.5.5. The major factors …


Stressors In The Learned Helplessness Paradigm: Effects On Body Weight And Conditioned Taste Aversion In Rats., Clinton Chapman, Nancy Dess, John Garcia, Jeffrey Raizer Dec 1987

Stressors In The Learned Helplessness Paradigm: Effects On Body Weight And Conditioned Taste Aversion In Rats., Clinton Chapman, Nancy Dess, John Garcia, Jeffrey Raizer

Clinton D Chapman

In Exp 1, 44 male rats drank saccharin or a control solution, followed by 100 inescapable shocks or simple restraint. Ss were weighed daily and were tested for saccharin aversion 2 days after the stress session. Shocked Ss gained less weight than restrained controls. Saccharin aversion was apparent only among Ss that had consumed saccharin before the stress session. In Exp 2, 72 Ss drank saccharin solution, followed by shock, restraint, or no treatment. Half of each group was injected with saline; the other half was injected with lithium chloride. Shock reduced body weight relative to restraint or no treatment …


Influx And Transepithelial Flux Of Amino Acids In The Mussel, Mytilus Edulis., Michael A. Rice, Grover C. Stephens Dec 1987

Influx And Transepithelial Flux Of Amino Acids In The Mussel, Mytilus Edulis., Michael A. Rice, Grover C. Stephens

Michael A Rice

The uptake of amino acids by the non-gill epithelia of the mantle cavity of Mytilus edulis L. was studied and compared with uptake by the gills. Amino acid entry rates and the subsequent distribution of amino acids to the other tissues of the animals were studied using high-performance liquid chromatography and radiochemical techniques. Uptake via the non-gill epithelia lining the mantle cavity was separated from uptake via the gill by employing a preparation in which the gills were surgically removed. Amino acid uptake by such animals was compared with that of suitably sham-operated controls. In short-term experiments (up to 2h), …


The Effect Of Cold Acclimation On The Temperature Preference Of The Goldfish, Carassius Auratus, And The Brown Bullhead, Ictalurus Nebulosus, Alfred Lord Nov 1987

The Effect Of Cold Acclimation On The Temperature Preference Of The Goldfish, Carassius Auratus, And The Brown Bullhead, Ictalurus Nebulosus, Alfred Lord

Dissertations and Theses

Two species of fish, Carassius auratus and Ictalurus nebulosus, were subjected to cold acclimation regimes. Acclimation temperatures were slowly lowered to 3°C, then held for a period of time. At various times during this regime, fish were taken out and allowed to spend time in a temperature gradient to determine their preferred temperatures. Carassius were left in the gradient just long enough to determine a measure of the acute temperature preference, while Ictalurus were left in the temperature gradient for longer periods of time to observe any changes that might occur as the fish adjusted to selected temperatures. In …


Signal Processing In Bacterial Chemotaxis, Jimmie Marquette Smith Sep 1987

Signal Processing In Bacterial Chemotaxis, Jimmie Marquette Smith

Loma Linda University Electronic Theses, Dissertations & Projects

This study localized 1) the site of ATP utilization in the signal transduction pathway of bacterial chemotaxis and 2) the point of convergence of the methylation-independent systems of chemotaxis with the methylation-dependent system. The site of ATP utilization was localized at the CheY protein/switch point. In an Eaeheriehia call strain (BT3077) containing the cheY, motor and switch genes, ATP depletion, accomplished by treating the cells with arsenate, suppressed the CheY protein-induced tumbling. ATP was not required by the switch for directing the clockwise and counterclockwise rotations of the flagellar motor. ATP did not appear to be required for normal steady-state …


Decrease In Selected Temperature After Intracranial Dopamine Injections In Goldfish, Hercules Theodore Panayiotides-Djaferis Aug 1987

Decrease In Selected Temperature After Intracranial Dopamine Injections In Goldfish, Hercules Theodore Panayiotides-Djaferis

Dissertations and Theses

Goldfish (Carassius auratus) (40-80g) were injected with dopamine into the forebrain to study the possible involvement of this amine in central temperature regulation in these fish. Dopamine caused a decrease in selected temperature after injection into the rostral nucleus preopticus periventricularis (NPP). This effect was dependent on the dose of dopamine administered. Doses of 25, 50, 100 and 250 ng were used, injected in a volume of 0.2μ1. Injections in regions adjacent to the NPP elicited hypothermic effects only at the higher dosages. These effects were not consistent. Injections in caudal regions of the NPP elicited no effect. …


Distribution Of Vertebrates Of The Bighorn Canyon National Recreation Area, Stanley H. Anderson, Wayne A. Hubert, Craig Patterson, Alan J. Redder, David Duvall Jul 1987

Distribution Of Vertebrates Of The Bighorn Canyon National Recreation Area, Stanley H. Anderson, Wayne A. Hubert, Craig Patterson, Alan J. Redder, David Duvall

Great Basin Naturalist

During a survey of the vertebrates in the Bighorn Canyon National Recreation Area, 46 mammal, 210 bird, 9 reptile, 5 amphibian, and 28 fish species were found. Habitat structure and moisture were two environmental variables associated with species numbers across this 1,820-ha area. Eight distinct habitats were evaluated. In coniferous forests, 27% of the birds and 54% of the mammals were observed. Sagebrush/grasslands and upland shrublands were very arid and had relatively few vertebrates. Five introduced game birds occurred in sagebrush habitat. Riparian and wetland habitats had the largest number of unique vertebrates, 38 and 77 respectively. The establishment of …