Segui questo link per vedere altri tipi di pubblicazioni sul tema: Physiological effect.
Tesi sul tema "Physiological effect"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Physiological effect".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
1
Hogan, Kyla B. "The hemostatic responses to exercise in hot and cold temperatures". Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1398717.
Testo completoAbstract (sommario):
Purpose: The impact of temperature on the coagulative response to exercise has not been well described. The purpose of this study was to assess the response of plasma thrombin-antithrombin (TAT) to exercise during exposure to both hot and cold temperatures, and to compare those responses to exercise under normal, temperate conditions. Methods: Fifteen healthy male subjects (25.3 + 4.3 years) volunteered to participate in this study. Subjects completed maximal cycle ergometer exercise tests in three different temperatures (20°C, 5° or 8° C, and 30°C) in an environmental chamber. All tests were conducted in random order and separated by at least seven days. Blood samples were obtained before and immediately after exercise and analyzed by Elisa to determine plasma concentrations of thrombin-antithrombin complex (TAT). Results: Subjects demonstrated significantly elevated plasma levels of TAT in all three temperatures immediately after exercise (normal =1.04 ± 0.44 ng/ml, cold =1.34 ± 0.79 ng/ml, hot =1.18 + 0.95 ng/ml) when compared to baseline measures (normal = 0.45 ± 0.26 ng/ml, cold = 0.88 + 0.57 ng/ml, hot = 0.64 + g/ml). Subjects also showed significant elevations in TAT concentrations both before and after exercise in the cold temperature when compared with the normal temperature. There was no significant difference between the hot and normal temperatures. Conclusion: An individual's coagulation potential is increased following maximal physical exertion and may be further increased by exposure to colder temperature. Key Words: coagulation, physical exertion, temperature, thrombosis.School of Physical Education, Sport, and Exercise Science
2
Anderson, Dawn E. "Effects of caffeine on the metabolic and catecholamine responses to exercise in 5 and 28p0sC environments". Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/833465.
Testo completoAbstract (sommario):
The influence of caffeine on the metabolic and catecholamine responses to mild exercise in a cold and a warm environment was studied in eight healthy males. The subjects performed 60 minutes of cycling at 50% VO2max in a cold environment (5°C and 70% relative humidity) and a warm environment (28°C and 50% relative humidity) 30 minutes after ingesting caffeine (5mg/kg body weight) or placebo (dextrose). Caffeine ingestion prior to exercise in the warm environment resulted in increased plasma epinephrine, with no effect on plasma norepinephrine. Neither lipid nor carbohydrate metabolism was altered by caffeine in the warm trial. Exercise in the cold environment (placebo) produced increased oxygen consumption and carbohydrate metabolism, decreased lipid metabolism, and no difference in plasma catecholamines compared with the warm-placebo trial. Responses to the combination of caffeine ingestion and the cold environment did not differ from cold-placebo responses in oxygen consumption or respiratory exchange ratio during the cycling bout. However, in the cold-caffeine trial plasma epinephrine was elevated. In addition, fat oxidation, serum free fatty acids, and serum glycerol were elevated in the cold-caffeine condition. Carbohydrate oxidation was depressed, while serum glucose and blood lactate were elevated in this trial. The results of this study indicate that caffeine increases plasma epinephrine; cold increases oxygen consumption and carbohydrate metabolism, while decreasing lipid metabolism; and the combination of caffeine and cold during exercise increases plasma epinephrine and lipid metabolism, but decreases carbohydrate metabolism.Human Performance Laboratory
3
Martin, David E. "The effect of heat stress on excess post exercise oxygen consumption". Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/834623.
Testo completoAbstract (sommario):
While a great deal of research has been directed towards the phenomena of excess post exercise oxygen consumption (EPOC), the effect of thermal stress on EPOC is not well defined. To assess the effect of heat stress on EPOC, seven healthy, active subjects (4 female, 3 male; 23.9 ± 2.0 years of age) performed 4 trials: one control (quiet rest) and one exercise (45 minutes of cycling at 65% VO2max workload) trial in moderate (23° C, 50% humidity) and hot (35° C, 50% humidity) environments. Oxygen consumption (V02), heart rate (HR) and rectal temperature (RT) were assessed pre, during and post control or exercise. Subjects were monitored until post exercise VO2 had returned to within ±2% of baseline. EPOC was determined by subtracting baseline VO2 from total V02 during the post exercise period. During the first 15 minutes (acute) post exercise, a significant EPOC (p = 0.0019) was seen in both exercise conditions over both control conditions. During the slow phase (> 15 minutes post exercise to baseline), there was no significant difference between the hot control (HC), moderate exercise (ME), or hot exercise (HE) EPOC. Total time post exercise until baseline was achieved was 35, 44, and 51 minutes for HC, ME, and HE respectively. HR was significantly elevated in both exercise conditions. During the acute post exercise period, HR in HE was elevated above MC, ME and HC (p < 0.05). RT was elevated in both exercise conditions during and post exercise. The present data indicate that heat stress does not have a significant effect on the magnitude or duration of EPOC.School of Physical Education
4
Shi, Xiaocai. "Effect of sodium and water intake on plasma aldosterone during prolonged exercise in warm environment". Virtual Press, 1990. http://liblink.bsu.edu/uhtbin/catkey/722232.
Testo completoAbstract (sommario):
Eight well-trained male and female cyclists were studied to determine the effect of sodium and/or water intake on plasma aldosterone during six hours of cycling (55% VO2max) in a warm environment (Tdb = 350C WBGT = 30°C). Each subject randomly completed three trials (water = W; saline = S and no fluid = NF) at one week intervals. Venous blood samples were obtained before dehydration, at 2, 4, 5 and 6 hours during exercise, and also after dehydration. Plasma samples were analyzed for hemoglobin, sodium, potassium, aldosterone and osmolality. Sweat and urine samples were also collected and analyzed for sodium content. Plasma volume based on hemoglobin decreased significantly ( P < 0.01 ) at 15 min in all three trials (Trial W = -7.6%±1.12%; Trial S = -8.6%±1.42% and Trial NF = -6.7%±0.88%) and continued to decrease significantly in Trial NF during exercise ( -10.99% ± 1.3% at the 2th hr; -15.5% ±1.3% at the 4th hr and -16.8%±1.32% at the 5th hr).No significant differences were found betwee trials. Plasma sodium concentration [Na+] decreased over time in Trials W and S and increased in Trial NF due to plasma volume loss. Significant differences in [ Na+ ] were found between Trial NF and Trials W or S. Plasma sodium [Na+ ] adjusted by plasma volume change decreased significantly at 2 hours ( P < 0.01) in the three trials. Average total sodium content of plasma decreased by 125.9 mEq during Trial S, 223.1 mEq during Trial W and 147.1 mEq during Trial NF. Plasma potassium increased significantly (P < 0.01) at 2 hours in all three trials. Plasma osmolality increased significantly (P < 0.01) during prolonged exercise (Trial W = 287.1±2.4 mEq/l; Trial S = 289.4±1.17 mEq/1 and Trial NF = 306±1.6 mEq/1). No significant differences were found between Trials W and S although osmolality was lower in Trial W than in Trial S. A significant difference in osmolality was obtained between Trial NF and Trials W and S (P < 0.01). Plasma aldosterone increased significantly (P < 0.01) during exercise and decreased after exercise. No significant differences existed between Trials W and S although aldosterone levels were lower in Trial S than in Trial W. However, a significant difference was found between Trial NF and Trials W or S. The results of this study suggest that plasma aldosterone has an inverse relationship with plasma volume changes and total sodium concentrations. An increase in plasma potassium and a decrease in plasma sodium during prolonged exercise in a warm environment significantly enhanced plasma aldosterone concentration. The intake of water significantly decreased plasma aldosterone during prolonged exercise in a warm environment, but the intake of sodium had no significant effect in this study.School of Physical Education
5
Heyns, Gerhardus Johannes. "Influence of macro- versus microcooling on the physiological and psychological performance of the human operator". Thesis, Rhodes University, 1995. http://hdl.handle.net/10962/d1016247.
Testo completoAbstract (sommario):
This study evaluated the effect of a macro- versus a microcooling system on the cognitive, psychomotor and physiological performance of human operators. Male subjects (n = 24) were acclimatized for four days and then subjected to three different environmental conditions: hot ambient (40°C; 40% RH), microcooling and macrocooling. Each environmental condition was repeated twice; once under a rest condition and once while simulating a physical workload of 40 W. Four performance tests (reasoning, eye-hand coordination, memory, reaction time) were conducted once every hour for four hours. Five physiological measurements, viz rectal temperature, skin temperature, heart rate, total sweat loss and sweat rate, were taken. A significant difference existed between the physiological responses under the hot ambient condition and both cooling conditions. For all five physiological parameters he human operator benefitted substantially whatever the cooling condition. The psychological performance results indicated a greater benefit under the cooling conditions, though various external factors may have influenced responses. User perception showed that macrocooling was perceived to be the optimal method of cooling. The results showed that there was no difference in the extent to which both rectal temperature and heart rate (for rest and work conditions) decreased over the 4-hour study period with micro- and macrocooling. In the baseline hot environment both increase. Sweat rate was lowest when resting or working in a microcooled environment and at its highest in the hot baseline environment. Mean skin temperature was lowest (for rest and work conditions) with microcooling and highest in the hot baseline environment. Reaction time and memory/attention were the same under all three environmental conditions. Eye-hand coordination was better with cooling than without, but did not differ between the two cooling conditions. Reasoning ability was poorest under the hot baseline condition and best in the macrocooled environment. User perception showed that the subjects found macrocooling highly acceptable. Microcooling was found to be uncomfortable, particularly because cold air (18 - 21°C) entered the jacket at one point which caused numbness of the skin at that point. Jackets did not always fit subjects well and the umbilical cord restricted free movement.
6
Dalal, Suntanu. "Amphetamine drugs potentiate morphine analgesia in the formalin test". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55488.
Testo completoAbstract (sommario):
There has been a great deal of research investigating drug combinations which can increase analgesia. A number of studies have been conducted with one particular combination--opioids combined with the amphetamine drugs. Despite the existing literature, this combination is rarely used in clinical practice. One purpose of this thesis is to review the literature pertaining to the opioid-amphetamine combination. Another purpose of this thesis is to investigate whether dextroamphetamine sulfate ($ circler$Dexedrine) can potentiate morphine sulfate analgesia in rats in the formalin test (Experiment 1). To investigate whether these results can be generalized to another psychostimulant, methylphenidate hydrochloride ($ circler$Ritalin) is used in Experiment 2. Methylphenidate has been chosen instead of another amphetamine drug because it is currently being used in clinical studies without supporting evidence from animal studies. The results of the two experiments indicate that low doses of d-amphetamine and methylphenidate can potentiate the analgesic effects of morphine.
7
Wall, Philippa Mary. "Food, hormones and neurotransmitters : three studies". Thesis, The University of Sydney, 1991. https://hdl.handle.net/2123/26331.
Testo completoAbstract (sommario):
Three studies on the relationship between food, hormones and neurotransmitters are presented for this thesis.
In the first study, a series of three experiments was conducted in 33 healthy human ratio volunteers. The aim was to investigate the effect of carbohydrate meals on the plasma of tryptophan (trp) to the sum of 5 other large neutral amino acids (LNAAs ) (trp: LNAA ratio). Synthesis s of serotonin, the brain neurotransmitter, depends on availability of its precursor trp from the bloodstream. Animal models have shown that the plasma trp:LNAA ratio, provides an index of trp uptake by the brain and of subsequent serotonin synthesis. A carbohydrate meal may increase the ratio because the elicited insulin response promotes selective uptake of the competing LNAAs into peripheral tissues. The first hypothesis was that carbohydrates with differing insulin responses would produce corresponding alterations in the size of the up:LNAA ratio response. The second hypothesis was that the trp:LNAA ratio response to a given carbohydrate meal would be greater in the evening compared to the morning. Different test meals were isoenergetic and presented in random order to each volunteer on separate occasions. Plasma glucose, plasma insulin and plasma LNAAs were measured sequentially for 4 h after each meal.
In the first experiment, different carbohydrates (sucrose, glucose or potato+bread) (64 g), were given at breakfast time as part of a mixed meal with added protein (25 g) and fat (17 g). No rise in the plasma up:LNAA ratio occurred after any of these meals. Protein, by providing relatively more of the competing LNAAs than of wyptophan counteracted any effect of carbohydrate on the ratio response. Therefore it is unlikely that carbohydrate eaten in the average mixed meal would influence serotonergic activity in the brain. In an attempt to maximise the ratio response, the carbohydrate portion in the second experiment, (sucrose or raw starch) was increased to 120 g; fat and protein were omitted. Plasma insulin and plasma glucose peaks were higher after sucrose than after raw starch (p<0.01) and the ratio rose correspondingly higher, by 34% after sucrose and by 20% after raw starch (p<0.05). In the third experiment the same test meals in the second study were given in the evening after standard meals during the day. Compared to the morning, evening plasma glucose and insulin responses were more sustained, although peak heights were not markedly different.
8
Morgan, Michael J. "Opioid-dopamine interactions in analgesia in the formalin test". Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74326.
Testo completoAbstract (sommario):
Controversy exists concerning the role that dopamine plays in analgesia. In the present studies, dopamine agonists produced analgesia, and D-amphetamine potentiated morphine analgesia, while treatment with 6-hydroxydopamine or mixed or selective D1 and D2 dopamine receptor antagonists attenuated or abolished morphine and D-amphetamine-induced analgesia, in the formalin test. Furthermore, microinjection of morphine into the ventral tegmental area (VTA) and ventral striatum produced analgesia, while intra-VTA microinjection of naloxone methylbromide antagonized the analgesia produced by systemic morphine, in the formalin test. In contrast, similar manipulations of dopamine had little or no effect in the tail flick test. Thus, dopamine appears to play a facilitatory role in formalin test analgesia, and there appear to be fundamental differences between the formalin and tail flick tests and parallels between the role of dopamine in the formalin test and in clinical pain, the vocalization after-discharge test and reward.
9
Wang, Yuan. "Studies of gonadotropin control of inhibin secretion and follicle development". Thesis, The University of Sydney, 2002. https://hdl.handle.net/2123/27898.
Testo completoAbstract (sommario):
The studies in this thesis were designed to investigate the gonadotropin control
of inhibin secretion, cellular localization, activin action pathway, and follicle
development. A human inhibin assay (ELISA) was validated for the
measurement of inhibins in mouse preparations. It was found that the serial
dilutions of human inhibin standards exhibited a significant deviation from
parallelism to a series of mouse preparations, whereas the different mouse
inhibin preparations appeared to dilute out parallel to each other. The result
suggests that human inhibin standard is not suitable for the inhibin
measurement in mouse samples. Mouse inhibin standards from conditioned
mouse follicle culture medium diluted in castrated male mouse serum were
therefore established for inhibin measurement in mouse serum.
The gonadotropin control of inhibin secretion was investigated by administration
of FSH and hCG to hpg mice in vivo. FSH significantly increased the serum
concentrations of inhibin A and inhibin B, while hCG alone had no stimulating
effect. However, when hCG was given in the presence of FSH, it significantly
increased inhibin A secretion without further effect on inhibin B secretion. The
acute, high dose of hCG to mimic ovulation suppressed the secretion of inhibin A
and inhibin B. These findings suggest that while FSH is important in stimulating
inhibin B production, LH may be more important than FSH in stimulating inhibin A
secretion during follicle maturation. In addition, the LH surge may be responsible
for the decline in inhibin secretion.
10
Hawley, John A. "The effect of treadmill running and swimming on citrate synthase activity and glycogen levels in the rat". Virtual Press, 1986. http://liblink.bsu.edu/uhtbin/catkey/450972.
Testo completoAbstract (sommario):
Thirty-eight female Wistar rats were studied to determine the response of citrate synthase (CS) and glycogen (GLY) to two similar programs of endurance training. Animals were randomly assigned to one of three groups: run-trained (RUN), swim-trained (SWIM) or sedentary control (CON). The treadmill trained animals ran at a speed of 27 m/min. up an eight degree incline. The swim-trained animals swam with 2% of body weight attached to their tails. The duration of the exercise protocols was 2 hours/day, the frequency 5 days/week and the length of the training regimen was 10 weeks. Liver GLY content (mmoles/g) for the exercise trained groups was significantly higher (p < 0.01) than CON. There were no significant differences between RUN and SWIM animals in the GLY levels of the hindlimb muscles. The GLY levels of the forelimb muscles were significantly greater (p0.01) in the SWIM animals compared to the RIJN animals, apart from the pectoralis (EEC). The CS activity in the soleus (SOL) and red -vastus (RV) of the RUN animals was significantly larger (p <; 0.01) than SWIM. The plantaris (PLANT) of the SWIM animals had significantly greater CS activity than the RUN animals. In the forelimb muscles, only -the deltoid (DEL) of the SWIM group was higher in CS activity than the RUN groups. The results of this study indicate that the mechanisms responsible for increased GLY storage in skeletal muscle are under independent control to those factors governing the changes in the oxidative enzyme CS. Differences in muscle GLY levels and CS activity between RUN and SWIM rats can be explained by contrasting mechanics in these two (nodes of exercise and the resulting fiber recruitment patterns.
11
Amend, Valerie A. "Implications of beverages and physical activity on hot flashes in menopausal women". CardinalScholar 1.0, 2009. http://liblink.bsu.edu/uhtbin/catkey/1538075.
Testo completoAbstract (sommario):
The purpose of this research study was to examine the effects of consumption of beverages (caffeinated and alcoholic) and physical activity on the frequency and severity of hot flashes in peri-menopausal, menopausal, and post-menopausal women by conducting an on-line survey of women over the age of 40 employed at a Midwestern University. One-hundred ninety-six women participated in this study. Majority of participants were age 50-59 (n=104, 53.1%), and were in the naturally post-menopausal reproductive stage (n=81, 41.3%). Overall, results revealed that the effects of self-reported physical activity, average daily caffeine and alcohol intake were not significant in predicting the frequency of hot flashes (R2=.043, F(6, 184) = 1.39, p= .221). However, results revealed a small, but statistically significant effect of physical activity, caffeine, and alcohol intake on severity of hot flashes (R2=.068, F(6,180) = 2.195, p = .046). Additionally, relatively more participation in aerobic physical activity increased frequency of hot flashes (p= .031); while higher intensity of aerobic physical activity had an inverse relationship on both frequency and severity of hot flashes (p=.011, p=.003, respectively).Department of Family and Consumer Sciences
12
Mahabeer, Rajeshree. "An investigation into the effects of inorganic toxins and tryptophan metabolites on the forebrain cholinergic system and the pineal gland of the rat". Thesis, Rhodes University, 1997. http://hdl.handle.net/10962/d1004078.
Testo completoAbstract (sommario):
As soon as the building of the body is completed, the ageing process begins. In the natural course of events, the functioning of some organ systems finally ebbs below the threshold necessary to maintain the body, resulting in death. This occurrence is relatively rare, because diseases superimpose themselves upon the ageing process, bringing premature death resulting from pathological causes. This study focused on the cholinergic system of the rat forebrain. The cholinergic neurons in the brain are said to be involved in memory and learning, and a decrease in the activity of its enzymes has been reported in certain diseases, such as Alzheimer's disease. In the present study, the in vitro effects on the cholinergic system, of aluminium and mercury and tryptophan metabolites, kynurenic acid and quinolinic acid, are determined. Aluminium has been considered as a possible factor in Alzheimer's disease. Mercury in high concentrations is toxic, and its use in amalgam for dental treatment is under consideration with regard to its possible role in promoting neurological disease. The tryptophan metabolites increase in the brain with age and may have a role in pathological diseases. Quinolinic acid, when administered in toxic concentrations produces a possible model for Huntington's disease. This study investigated the effects of the above mentioned toxins on: (1) The synthesis of acetylcholine by choline acetyltransferase; (2) The specific binding of acetylcholine muscarinic receptors; (3) The degradation of acetylcholine by acetyl cholinesterase, Choline acetyltransferase activity did not change in the presence of aluminium chloride, kynurenic acid and quinolinic acid from 1 nM to 1 mM. Mercuric chloride had no significant effect on the enzymes activity from a concentration of 1 nM- 1 pM. At 10 pM there was a significant decrease in cholineacetyltransferase activity (P < 0.001). Enzyme activity continued to decrease at 100 pM (P < 0.0002). At 1 mM, enzyme activity was virtually non existent (P < 0.0001). Acetyl cholinesterase activity was not affected by aluminium chloride, kynurenic acid and quinolinic acid. Mercuric chloride from 1 pM - 1 mM significantly reduced the enzyme activity (P < 0.05). The binding of the antagonist, [³H] quinuclidinyl benzilate (QNB), to acetylcholine muscarinic receptors, revealed that aluminium chloride did not affect the binding of the antagonist, in the concentration range of 1 nM - 100 pM, to the receptors. At 1 mM, aluminium chloride appears to increase the sensitivity of the receptors for the ligand (P < 0.01). Mercuric chloride also does not appear to have any significant effect on receptor binding in this range. However, at 1 mM there appears to be a very significant decrease in receptor binding (P < 0.01). This decrease may be attributed to the interaction of mercury with the sulfhydryl groups in muscarinic receptors. Kynurenic acid had no effect on the receptor binding. Quinolinic acid, in the concentration range from 10 nM - 1 mM increased the binding ofthe receptor to [3Hi QNB significantly (P < 0.001). The study also investigated the effect of the tryptophan metabolites of the kynurenine pathway on pineal indole metabolism. The kynurenine pathway is a major route of tryptophan metabolism in the pineal gland, along with indole metabolism. Investigations showed that kynurenic acid produced a decrease in N-acetylserotonin concentrations ( P < 0.001) and melatonin concentrations (P < 0.003). Further experiments using quinolinic acid produced a similar decrease in N-acetylserotonin (P < 0.001) and melatonin (P < 0.015). A decrease was also noted in the level of 5-methoxytryptophol (P < 0.0005). These findings suggest that aluminium chloride, kynurenic acid and quinolinic acid have no possible role in the decrease of activity of cholinergic enzymes which is observered in diseases such as Alzheimer's disease. The results regarding the effect of mercury chloride on the cholinergic system suggest that low exposure to the toxin will not adversely effect the enzymes. The decrease in N-acetylserotonin and melatonin concentrations reported here, may be a result of kynurenic acid and quinolinic acid having an inhibitory effect on the enzyme, serotonin Nacetyltransferase, which is responsible for the conversion of serotonin to N-acety/serotonin.
13
Anderson, Gregory Steven. "The relationship between excess CO2 and blood lactate in elite cyclists". Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28534.
Testo completoAbstract (sommario):
This study examined the relationship between expired non-metabolic CO₂ (EX CO₂) and the accumulation of blood lactate, while emphasis was placed on the ventilatory (EX CO₂ and VE/VO₂) and lactate threshold relationship. Twenty-one elite cyclists (15 males, 6 females) performed a progressive intensity bicycle ergometer test (PIT) during which ventilatory parameters were monitored on-line at 15 second intervals, and blood lactate sampling occured on each minute. Threshold values were determined for each of the three indices; excess CO₂ (EXTT), VE/V0₂ (VVTT), and blood lactate (LATT). The three threshold values (EXTT, VVTT, LATT) all correlated significantly (P<0.001) when each was expressed as an absolute VO₂ (1/min). A significant RM ANOVA (F=8.41, P<0. 001) and post hoc correlated t-tests demonstrated significant differences between the EIXTT and LATT (P<0.001) and the EXTT and VVTT values (P<0.025).
The LATT occured at an average blood lactate concentration of 3.35 mmol/1, while the mean expired excess CO₂ volume at the EXTT was 14.04 ml/kg/min. Over an 11 minute range across the threshold values (EXTT and LATT), which were used as relative points of reference, the expired EXC02 volume (ml/kg/min) and blood lactate concentration (mmol/1) correlated significantly (r=0. 69, P<0. 001). Higher individual correlations over the same period of time Curriculum and Pedagogy (EDCP), Department of
Graduate
14
Moore, Melinda Sheffield. "Functional and morphological responses of human skeletal muscle to resistance and aerobic exercise during simulated weightlessness". Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1063202.
Testo completoAbstract (sommario):
The conductor of a large instrumental ensemble is constantly confronted with the task of detecting and correcting rhythm and pitch performance errors in daily rehearsals. The purpose of this investigation was to design a computer-assisted instruction program for error detection skills development and then evaluate this program's effectiveness in training beginning conductors to identify rhythm and pitch errors within 2-, 3-, 4-, and 5-voice synthesized music excerpts from the existing band literature. The transfer of error detection skills from synthesized to acoustic sounds also was explored indirectly by virtue of utilizing taped excerpts from wind band performances to assess error detection skills.Subjects (N=24) in this study were drawn from the pool of undergraduate instrumental music education majors at Ball State University and were randomly assigned to control treatment groups prior to the administration of the Acoustic Error Detection Skills Inventory. Following this pretest, the treatment group used the Computer Error Detection Skills Program for approximately eight hours during an eight week treatment period. At the end of the treatment period, and control and treatment groups were administered the Acoustic Error Detection Skills Inventory posttest.The data were analyzed using a series of one-way, repeated measures analyses of variance (ANOVA) to assess pretest to posttest changes in subjects' scores on the Acoustic Error Detection Skills Inventory. Composite scores (reflecting general skill in error detection) improved significantly for the treatment group (p = .007), while the pretest to posttest gain for the control group was not statistically significant (p = .232). These results suggest that the Computer Error Detection Skills Program was effective in enhancing subjects' rhythm and pitch error detection skills and the viability of using synthesized sound sources for training was confirmed.The following recommendations were made: (1) Jazz directors need to do more listening to jazz music, (2) band directors who direct jazz programs should join IAJE, (3) jazz ensembles shouldtheir own improvisational skills, and rehearse in the fall, (4) jazz ensemble directors should develop (5) jazz ensemble directors should have their students sing their parts during rehearsals for increased learning efficiency and retention.Human Performance Laboratory
15
Kelich, Stephanie L. "Quantification of the potentiating effects of caffeine on the teratogenicity of acetazolamide in C57BL/6J mice". Virtual Press, 1988. http://liblink.bsu.edu/uhtbin/catkey/546141.
Testo completoAbstract (sommario):
The study was designed to determine what type of potentiation,.if any, occurred between caffeine and acetazolamide. Caffeine (75 mg/kg) and/or acetazolamide (200, 1000, or 1500 mg/kg) were administered to pregnant C57BL/6J dams on day 9 of gestation. Fetuses were removed on the eighteenth day of gestation via cesarean section and examined for gross morphological malformations using a Bausch & Lomb SKV1070P dissecting microscope. Treatment with HD-ACZM and HD+CAFF resulted in a reduction of fetal weight. Maternal exposure to MD-ACZM and HD-ACZM caused a statistically significant (P < .001) and dose-dependent increase in the percent of C57BL/6J fetuses with ectrodactyly along with increased severity of the defects displayed (relative to controls). An increase in the number of ectrodactylous fetuses and the severity of defects was also observed in all groups administered caffeine and acetazolamide, reaching statistical significance in the MD+CAFF and HD+CAFF groups (P < .001). Because potentiation of the teratogenic effects of acetazolamide was exhibited only in the MD+CAFF vs. MD-ACZM groups, the type of potentiation occurring between caffeine and acetazolamide can not be determined.Department of Physiology and Health Science
16
Winmill, Catherine Anne 1955. "EFFICACY OF CALCIUM AND VITAMIN D SUPPLEMENTATION IN REDUCING DIASTOLIC BLOOD PRESSURE IN A MILD HYPERTENSIVE MALE POPULATION". Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276386.
Testo completo
17
Carrithers, John A. "Effects of post-exercise carbohydrate-protein feedings on muscle glycogen restoration". Virtual Press, 1999. http://liblink.bsu.edu/uhtbin/catkey/1133741.
Testo completoAbstract (sommario):
The purpose of this investigation was to determine the effects of post-exercise carbohydrate-protein feedings on muscle glycogen restoration following exhaustive cycle ergometer exercise. Seven male collegiate cyclist (age=25.6±3.3y, ht.=180.9±8.5cm, wt.=75.4±10.7kg, VO2max=4.20±0.4 1•miri 1) performed three trials, each separated by -lwk, 1) 100% (x-D glucose (CHO), 2) 70% carbohydrate-20% protein-10% fat (CHOPRO), and 3) 86% carbohdyrate-14% amino acid (CHO-AA). All feedings were eucaloric, based upon 1.0 g•kgb.W.'1•hr"1 of carbohydrate, and administered every half hour during a four hour muscle glycogen restoration period in an 18% wt./vol. solution. Muscle biopsies were obtained immediately and four hours post exercise. Following the exhaustive exercise and every half hour for four hours a blood sample was drawn. Muscle glycogen concentrations increased 53%, 47%, and 57% for the CHO, CHO-PRO, and CHO-AA feedings, respectively, however no differences among the feedings were apparent in muscle glycogen restoration. The plasma glucose and insulin concentrations demonstrated no differences throughout the restoration period among the three feedings. These results suggest that muscle glycogen restoration does not appear to be enhanced with the addition of either protein or amino acids to an eucaloric carbohydrate feeding following an exhaustive cycle exercise. However, it appears that if adequate amounts of carbohydrates are consumed (greater than 0.70 g•kgb,W,."'•hf' carbohydrate) following exhaustive exercise, maximal muscle glycogen restoration occurs.School of Physical Education
18
Lee, Hing-lun, e 李慶麟. "Hemodynamic effects of endothelin-1 and platelet-activating factor after nitric oxide synthase inhibition in the rat". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31969628.
Testo completo
19
Lee, Jack Monroe Jr. "Seasonal Patterns of Melatonin, Cortisol, and Progesterone Secretion in Female Lambs Raised Beneath a 500-kV Transmission Line". PDXScholar, 1992. https://pdxscholar.library.pdx.edu/open_access_etds/1317.
Testo completoAbstract (sommario):
There is ongoing controversy about the possibility of adverse biological effects from environmental exposures to electric and magnetic fields. These fields are produced by all electrical equipment and appliances including electrical transmission lines. The objective of this environmental science study was to investigate the possible effects of a high voltage transmission line on domestic sheep (Ovis aries L,), a species that can often be found near such lines. The study was primarily designed to determine whether a specific effect of electric and magnetic fields found in laboratory animals also occurs in livestock under natural environmental conditions. The effect is the ability of fields, at levels found in the environment, to significantly depress the normally high nocturnal concentrations of the pineal hormone melatonin. Melatonin mediates the reproductive response to changes in photoperiod in seasonal breeders such as sheep. Factors which modify the production of nocturnal melatonin in sheep can have important effects on the timing of seasonal reproduction including the onset of puberty in this species. Ten female Suffolk lambs were penned for 10 months directly beneath a 500-kV transmission line near Estacada, Oregon. Ten other lambs of the same type were penned in a control area away from the transmission line where electric and magnetic fields were at ambient levels. Serum melatonin was analyzed by radioimmunoassay (RIA) from 6618 blood samples collected at 0.5 to 3-hour intervals over eight 48-hour periods. Serum progesterone was analyzed by RIA from blood samples collected twice weekly beginning when the lambs were 23 weeks old. This hormone was used to measure the onset of puberty. Serum cortisol was also assayed by RIA from the blood samples collected during the 48-hour samples. This was done to assess whether exposure to the transmission line produced stress in the growing lambs. Other supplemental biological data collected included body weight gain, wool growth, and behavior. An extensive study was conducted by engineers from the Bonneville Power Administration (BPA) to measure electric and magnetic fields and noise to which the lambs were exposed. This was accomplished by installing permanent monitors near both the control and line pens. Results showed that lambs in both the control and line groups had the typical pattern of melatonin secretion consisting of low daytime and high nighttime serum concentrations. There were no statistically significant differences between groups in melatonin levels, or in the phase or duration of the nighttime melatonin elevation. Age at puberty and number of reproductive cycles also did not differ between groups. Serum cortisol showed a circadian rhythm with highest concentrations during the day. Cortisol concentrations also seemed to reflect effects of known stressors on livestock, e.g., weaning, introduction to new housing, and vehicle transport. There were, however, no differences in cortisol concentrations between groups. Statistical analyses on other biological parameters revealed no differences between groups for body weight gain, wool growth, or behavior. The electrical monitoring program verified that the line group lambs were exposed to electric and magnetic fields at levels typical of those found beneath commercial 500-kV transmission lines. In summary, the large effect of electric and magnetic fields on melatonin concentrations reported in laboratory animals was not observed in this study of sheep.
20
Xu, Fan 1960. "Effect of prolonged exercise on running economy". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68149.
Testo completoAbstract (sommario):
The purpose of this study was to investigate the effect of prolonged exercise on running economy. Fourteen male long distance runners performed two 90 minute runs on an outdoor 400m track at velocities equal to 65 and 80% of VO$ sb2$max. Prior to and following each 90 minute run, running economy (RE) was measured as the steady-state VO$ sb2$ during treadmill runs at speeds of 188 and 228 m/min. During the 90-min run at 65% of VO$ sb2$max, the mean weight loss was 1.3 kg. The HR was 143 bpm between minutes 5-10 and increased to 150 bpm between minutes 85-90. During the 90-min run at 80% of VO$ sb2$max, the mean weight loss was 1.4 kg. The HR was 161 bpm between minutes 5-10 and increased to 165 bpm between minutes 85-90. When the post RE test was conducted following each 90-min run, there was a significant increase in VO$ sb2$ expressed in both l/min and ml/kg$ cdot$min (a decrease in running economy). The increase in oxygen cost of running following the 90-min run at 80% of VO$ sb2$max was greater than that following the run at 65% of VO$ sb2$max.
21
Woods, Barbara Jane Simmons. "Mirthful Laughter and Directed Relaxation: a Comparison of Physiological Response". Thesis, North Texas State University, 1985. https://digital.library.unt.edu/ark:/67531/metadc331273/.
Testo completoAbstract (sommario):
The differences among certain physiological changes occurring in response to mirthful laughter, directed relaxation, and verbal speech were investigated. These changes included amount of muscle tension, as measured with surface electromyography, in the forehead and in the upper body as recorded from the forearms bilaterally, peripheral surface skin temperature, heart rate, and respiration rate. The study sought to determine whether the net effect of laughter, as measured on these five variables after a three-minute refractory period, is a more relaxed state than existed before the laughter. Determination of the similarity between the changes following laughter and the changes following directed relaxation was made in comparison with the changes following verbal speech. Factors of prior anxiety, pre- and post-self-esteem levels, humor level, and laughter intensity were examined. Historical and theoretical perspectives were reviewed, as well as the known information on physiological responses to laughter.
22
潘玉琼 e Yuk-king Karen Poon. "The antagonistic effect of paracetamol on ethanol-induced gastric damage in rats". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1989. http://hub.hku.hk/bib/B31209415.
Testo completo
23
Porter, David A. "The effect of oral coenzyme Q10 on the exercise tolerance of middle-aged, untrained men". Virtual Press, 1991. http://liblink.bsu.edu/uhtbin/catkey/776715.
Testo completo
24
Lou, Yali, e 娄雅俐. "The effect of silver diammine fluoride on tooth tissue". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B4381430X.
Testo completo
25
Bruce, Kenneth R. "Effects of alcohol on emotionally salient memory". Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34509.
Testo completoAbstract (sommario):
Social drinkers (healthy males aged 18--34) participated in three experiments that examined some of the mechanisms that may be responsible for the effects of alcohol on emotionally charged memory. In a study on incidental learning, alcohol enhanced neutral, positive and negative memory, possibly by a nonselective consolidation mechanism. Alcohol's enhancement of memory was found to not be associated (contingently related) with its incentive reward and relief effects. In another study on intentional learning, alcohol enhanced positive memory and/or inhibited negative memory, possibly reflecting a contingent relationship to its incentive effects. When the role of individual differences was examined, relatively little influence was found in mediating the effects of alcohol on incidental memory. However, alcohol's effect on intentional memory was predicted by individual differences in response to some of alcohol's acute incentive effects. The studies demonstrate that alcohol's effects on memory are independent from, and can be combined with, its incentive effects. Further, consumption of alcohol may be influenced by separate effects on memory and incentive, and by their association.
26
Houmard, Joseph A. "Rate of heat acclimation : effects of exercise intensity and duration". Virtual Press, 1988. http://liblink.bsu.edu/uhtbin/catkey/533882.
Testo completo
27
Hand, Timothy Henry. "Effects of morphine on intracranial self-stimulation : the involvement of associative factors and the role of ventral tegmental dopamine neurons". Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72033.
Testo completoAbstract (sommario):
A series of experiments was carried out to clarify the effects of morphine (0.3 - 10 mg/kg) on intracranial self-stimulation (ICS) and to compare these with the effects of the stimulant amphetamine on this behavior. It was shown that the enhancement of ICS by morphine requires repeated drug exposure, is prevented by pre-exposure to the drug in a non-ICS context, is mimicked by administration of vehicle, and is not reliably reversed by naloxone. In contrast, facilitation of ICS by amphetamine was immediate and remained stable over repeated days of testing. It was concluded that ICS facilitation induced by morphine, but not by amphetamine, is largely the outcome of a learned association between the drug effect and the ICS procedure, and does not appear to be a direct, opiate receptor-mediated effect. Finally, 6-OHDA lesions of ventral tegmental dopamine neurons were shown to block the facilitation of ICS by morphine but not by amphetamine. These lesions were also shown to delay the development of tolerance to morphine-induced catalepsy.
28
Farmer, Bertrand. "The status of beta carotene and vitamin A in Quebec dairy herds and their effects on reproductive performance /". Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63167.
Testo completo
29
Fernie, Kimberly J. "Effects of electric and magnetic fields on selected physiological and reproductive parameters of American kestrels". Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34959.
Testo completoAbstract (sommario):
Birds nest under electric and magnetic fields (EMFs) generated by transmission liners which may affect their reproductive success and/or melatonin governing their circadian and circannual cycles. Over two years, captive kestrels were used to determine whether EMFs affect their plasma melatonin concentrations and their reproductive success. EMFs were equivalent to that which wild kestrels are exposed to while nesting under 735 kV transmission fines, and daily exposure used in the captive study (88--98% time budget) was potentially equivalent to that of wild kestrels (90% X, 80% X). Captive kestrels were housed in control or EMF conditions to determine short-term (one season; S-EMF) and longer-term EMF (two seasons; L-EMF) effects.Plasma melatonin in adult EMF males was suppressed at 42 d and elevated at 70 d of EMF exposure compared to controls. Melatonin levels in EMF males at mid-season were similar to controls at season's end, suggesting a seasonal phase-shift. Melatonin was suppressed in L-EMF fledgling birds but not in adult females or nudes (1995) at 70 d. Plasm melatonin, higher in adult males than females at 70 d post-pairing, was not directly associated with body mass changes in kestrels.
Captive EMF birds were more active and alert but groomed less often than controls. EMF exposure affected reproductive success of kestrels. Fertility and fledging success were higher, and hatching success lower in S-EMF clutches. Hatching success was higher, but fledging success lower in L-EMF clutches. In S-EMF clutches, mean egg volume and mass were greater, eggs had slightly more albumen but thinner eggshells, and embryos were larger than controls. L-EMF hatchlings were heavier than controls.
The melatonin results for male kestrels indicate that kestrels perceive EMFs as light, thus altering their photoperiod. Photoperiodic manipulations advance molt onset, which is associated with increased body mass in male kestrels. S-EMF males were heavier at 56 d of exposure when molt began, but this was unlikely related to feed intake winch was unchanged. EMF exposure had no effect on body mass and pectoral muscle scores of reproducing females. The sexually-dimorphic response in body mass and melatonin concentrations suggests that male kestrels may be more sensitive to EMF exposure than females.
30
Sun, Wai-yin Raymond, e 辛偉賢. "The antitumor and antiviral properties of gold (III) porphyrins and their related complexes". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31245973.
Testo completo
31
Chung, Sau-yu, e 鍾秀瑜. "The progression of CCI4-induced liver cirrhosis of rats and the protective effects of colchicine and green tea polyphenols". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B25018498.
Testo completo
32
Hibbard, John Arthur 1959. "A HIGH VOLTAGE D.C. PULSE SYSTEM AND ASSOCIATED ATHERMAL, IN VITRO EXPERIMENTS (POWER, SHORT, SYNERGISM)". Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/275500.
Testo completo
33
Davis, Christopher John. "Neuropharmacological investigations into the mechanisms of emesis caused by cytotoxic drugs and radiation". Thesis, University of Oxford, 1988. https://ora.ox.ac.uk/objects/uuid:b9afefde-a43e-415e-8754-ed2a8eaac620.
Testo completo
34
Manley, Elizabeth. "The effects of whole body immersion in cold water upon subsequent terrestrial aerobic performance : a study in hypothermia". Thesis, Rhodes University, 1998. http://hdl.handle.net/10962/d1007458.
Testo completoAbstract (sommario):
This study examined the extent to which physiological and psychological concomitants of aerobic terrestrial performance were affected by body cooling of varying degrees induced by cold water immersion (CWI). Thirteen male and 13 female subjects underwent three randomly assigned 30 min treadmill runs: a control run without prior manipulation of the subjects' thermal status and the same exercise after "central" (core temperature 1°C below pre-immersion) and "peripheral" cooling (skin heat loss 100kcal.m⁻².h⁻¹). During treadmill runs core temperature was measured, together with chest, leg, arm and hand temperatures, from which mean skin temperature (T [subscript]s[subscript]k) and mean body temperature (T[subscript]b) were calculated. Heart rate, oxygen consumption (VO₂,), carbon dioxide production (VCO₂), minute ventilation (V₂ (BTPS)), breathing frequency (f), cadence and ratings of perceived exertion (RPE) and thermal sensation (PTS) were also measured. Both central and peripheral cooling resulted in significantly reduced T[subscript]r[subscript]e (males : control 37.9±0. 3°C; central cooling : 36.8±0.5°C; peripheral cooling: 37.5±0.4°C; females: control: 37.9±0.4°C; central cooling: 37.2±0.5; p<0.05) during subsequent treadmill running, except following peripheral cooling for females (37.9±0.3°C) . For males and females T[subscript]s[subscript]k was lower following peripheral cooling than control values and lowest after central cooling (males: control: 30.0±1.3°C; central cooling: 36.8±0.5°C; peripheral cooling: 37.5±0.4°C; females: control: 30.5±1.2°C; central cooling: 25.9±1.8°C; peripheral cooling: 26.9±1.9°C; p<0.05). Female subjects experienced significantly higher T[subscript]r[subscript]e than males following central and peripheral cooling and a lower T[subscript]s[subscript]k following central cooling. Females experienced less of an increase in heart rate than males during exercise following central and peripheral cooling (control: l57.7±23.7b.min⁻¹; central cooling: 143.5±20.5b.min⁻¹; peripheral cooling 151.7±16.7b.min⁻¹; p<0 .05). Male responses were the same following central cooling but higher for peripheral cooling than control values (control: 139.1±7.3b.min⁻¹; central cooling 134.7±17.5b.min⁻¹; peripheral cooling: 145.0±16.4b.min⁻¹; p<0.05). These data indicate a depression in cardiovascular function for females following peripheral cooling that was not apparent for males. The VO₂ was not different between tests for males; only peripheral cooling resulted in a raised VO₂ of 28.6±3 .3ml.kg⁻¹.min⁻¹ (p<0 .05) for females compared to 27.6±2.6ml.kg⁻¹.min⁻¹ (control). A biphasic response was evident for VO₂ VCO₂ and V[subscript]B (BTPS). For both sexes overall RPE was lower for peripheral cooling (males: 9.4±1.9; females: 8.7±1.3; p<0 .05) than for control and central cooling. Central RPE was only changed for females following peripheral cooling. Changes in cadence and step length together with the effect of low skin and leg temperatures resulted in higher local RPE for females after central cooling (9.6±1.2; p<0.05) than control (9.4±1.9) and peripheral cooling (8.9±1.2 ). Males and females rated the same ambient temperature during the same exercise lower after peripheral cooling (males: 4.6±1.5; females : 5.3±1.3) than control values and lower still after central cooling (males: 3. 8±1.8; females: 2 .7±l. 5) In this study T[subscript]s[subscript]k was the primary determinant of PTS after precooling.KMBT_363
Adobe Acrobat 9.54 Paper Capture Plug-in
35
Bryant, Rebecca Jane. "Effects of vitamins E and C on exercise-induced lipid peroxidation". Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1020147.
Testo completoAbstract (sommario):
The aim of this study was to examine whether vitamins E (200 IU) and C (1 g) in combination would influence exercise-induced lipid peroxidation to a greater extent than vitamin E (400 IU) alone. A placebo-controlled study was carried out on 7 collegiate cyclists who were supplemented with 1) vitamin C (1 g); 2) vitamins E (200 IU) and C (1 g); and vitamin E (400 IU) during 3 treatments, each 3 weeks in duration. The serum concentrations of hematocrit and MDA, one marker of lipid peroxidation, were measured immediately before, immediately after, and 24 hours after each exercise bout. After the vitamin C treatment, MDA serum concentration of the athletes (n=7) increased 85% above the baseline values of the placebo values, the vitamin E/C treatment showed a 29% increase, and the vitamin E treatment showed a 39% decrease. Pre- to post-exercise serum MDA levels increased 64% in the placebo group, a 29% increase in the vitamin C treatment group, a 23.2% increase in the vitamins E/C treatment group, and a 46.9% increase in the vitamin E treatment group. It is concluded that exercise-induced lipid peroxidation is more greatly influenced post-exercise by a combination of vitamins E (200 IU) and C (1 g), than by either vitamin C (1 g) alone, or vitamin E (400 IU) alone.Department of Family and Consumer Sciences
36
Howell, Anne C. "Effects of antioxidant vitamin treatment on UV-irradiated cells". Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/941360.
Testo completoAbstract (sommario):
Ultraviolet (UV) radiation damages both eukaryotic and prokaryotic cells by causing the formation of free radicals which damage cell membranes and DNA. Antioxidant vitamins have been shown to protect cells from UV-induced damage by scavenging free radicals. The protection of skin and its normal flora is necessary for the health of individuals in resisting diseases caused by microorganisms and delaying the long-term damage caused by UV radiation.This research investigated the effects of the antioxidants vitamin A and ascorbic acid, as well as UV-irradiation on both prokaryotic (Staphylococcus epidermidis) cells and eukaryotic (human fibroblast skin) cells. This information is important in determining the effects of vitamin treatment on skin and its normal flora.Results indicate that ascorbic acid is rapidly (within six hours) degraded after being dissolved in water or medium. Treatment of cells with ascorbic acid must take into account this rapid degradation. S.epidermidis cells were protected from UV-induced damage by treatment with ascorbic acid but were more sensitive to UV-irradiation when treated with vitamin A. Human fibroblast cells treated with ascorbic acid did not exhibit morphological changes when compared to untreated cells.Department of Biology
37
Welsh, Belinda M. "Retinoid augmentation of ultraviolet radiation induced melanogenesis". Thesis, The University of Sydney, 1997. https://hdl.handle.net/2123/27563.
Testo completoAbstract (sommario):
The capacity of human skin to increase it's pigmentation in response to sunlight is an important protective mechanism employed by the body against the potential harmful effects of excess ultraviolet radiation These include the development of skin cancer and premature aging of the skin. Intense scientific research, particularly over the past two decades, has led to a greater understanding of the biology of the pigment producing cells in the skin, melanocytes, and their secretory product, melanin. Melanocyte function in the skin depends on a delicate and complex interaction with the surrounding skin cells, systemic hormones and external stimuli, especially ultraviolet radiation from the sun.
38
Kerr, Chadwick G. "Hypothermia during Olympic triathlon : influence of body heat storage during the swimming stage". Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1014852.
Testo completoAbstract (sommario):
The purpose of this study was to determine if mild heat stress induced by wearing a wet suit while swimming in relatively warm water (25.4 ± 0.1°C) increases the risk of heat injury during the subsequent cycling and running stages. Specificlly, during an Olympic distance triathlon in a hot and humid environment (32°C & 65% RH). Five male triathletes randomly completed two simulated triathlons (Swim=30 min; Bike=40 km; Run=10 km) in the laboratory using a swimming flume, cycle ergometer, and running treadmill. In both trials, all conditions were identical, except for the swimming portion in which a full length, sleeveless neoprene wet suit was worn during one trial (WS) and a competitive brief swimming suit during the other (SS). The swim portion consisted of a 30 min standardized swim in which oxygen consumption (V02) was replicated, regardless of WS or SS. During the cycling and running stages, however, the subjects were asked to complete the distances as fast as possible. Core Temperature (T) was not significantly different between the SS and WS trials at any time point during the triathlon. However, mean skin temperature (TSk) and mean body temperature (Tb) were higher (p<0.05) in the WS at 15 (TSk=+4.1°C, Tb=+1.5°C) and 30 min (TSk=+4°C, Tb=+1.6°C) of the swim. These TSk and Tb differences were eliminated by 15 min of the cycling stage and remained similar (p>0.05) through the end of the triathlon. Moreover, there were no differences (p>0.05) in V02, heart rate (HR), rating of perceived exertion (RPE), or thermal sensation (TS) between the WS and SS. Additionally, no significant differences were found in cycling (SS=1:14:46 ± 2:48 vs. WS=1:14:37 ± 2:54 min), running (SS=55:40 ± 1:49 vs. WS=57:20 ± 4:00 min) or total triathlon times (SS=2:40:26 ± 1:58 vs. WS=2:41:57 ± 1:37 min). Therefore, the primary finding was that wearing a wet suit during the swimming stage of an Olympic distance triathlon in 25.4°C water does not adversely affect the thermal responses or the triathlete's ability to perform on the subsequent cycling and running stages.School of Physical Education
39
Brien, Donald Michael. "The effect of induced alkalosis and acidosis on blood lactate appearance and performance capacity during simulated rowing". Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26756.
Testo completoAbstract (sommario):
In order to test the effect of artificially induced alkalosis and acidosis on the appearance of blood lactate and work production, six well-trained oarsmen (age= 23.8 ±2.5 wt = 82.0 ±7.5kg.) were tested on three separate occasions after ingestion of 0.3 gm/kg body wt. NH4C1 (acidosis) , NaHC03 (alkalosis) or a placebo (control). Blood was taken from a forearm vein immediately prior to exercise for determination of pH and bicarbonate (HC03). One hour following the ingestion period, subjects rowed on a stationary ergometer at a pre-determined sub-maximal rate for 4 minutes, then underwent an immediate transition to a maximal effort for 2 minutes. Blood samples from an indwelling catheter placed in the cephalic vein were taken at rest and every 30 seconds throughout the 6 minute exercise test, and every 3 minutes during a 30 minute passive recovery period. Pre-exercise blood values demonstrated significant differences (p<0.01) in pH and HC03 in all three conditions. Work outputs were unchanged in the submaximal test and in the maximal test (p>0.05), although a trend toward decreased production was evident in the acidotic condition. Analysis of exercise blood samples using ANOVA with repeated measures revealed that the linear increase in blood lactate
concentration([BLA]) during control was significantly greater than acidosis (p<0.01), although [BLa] during alkalosis were consistently elevated above control there was no significant difference in the linear trend (p>0.05). During recovery, there was no significant difference in the rate of lactate disappearance amongst the three conditions. It was concluded that under this protocol artificial manipulation of the acid-base status of the blood does not significantly influence work production despite significantly reduced [BLa] during acidosis. The inability of these pH changes to alter exercise performance emphasizes the relative importance of the intracellular and the extracellular buffer systems in well trained athletes.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
40
Chen, Qixuan, e 陳起萱. "Anti-obesity effect of bitter melon (Momordica charantia)". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31048778.
Testo completo
41
Poirier, Patrick. "Effect of chronic stress on prefrontal cortical function". Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=86861.
Testo completoAbstract (sommario):
The prefrontal cortex (PFC) is a brain region thought to mediate cognitive functions such as working memory. Chronic stress has been shown to reduce working memory. In this thesis study, the effect of chronic stress on PFC functions was assessed in adult rats.First, contrary to previous evidences, chronic stress induces working memory performance alterations differentially in two populations of rats. One group displayed a decrease of performance only at 30 second delay, while the other had a decrease and increase at 0 and 30 seconds respectively.
Then, the effect of chronic stress on synaptic plasticity induction in the hippocampus-PFC network was investigated. High-frequency tetanic stimulation (HFS) of the dorsal hippocampus that induced long-term potentiation (LTP) in the prelimbic and infralimbic cortex in normal conditions was unable to induce LTP after chronic stress in the infralimbic cortex, whereas long-term depression (LTD) instead of LTP was induced in the prelimbic cortex.
Given that synaptic plasticity has been shown to depend on NMDA receptors in the PFC, NMDA subunit expressions before and after chronic stress was examined. There was a decrease of NR1 subunits expression in the prelimbic, but not infralimbic cortex. In contrast, the NR2A/NR2B ratio was increased in the infralimbic, but not prelimbic cortex. These results suggest that chronic stress disrupts PFC functions through dynamic modulation of distinct neural networks within the PFC.
Le cortex préfrontal (PFC) est une région du cerveau qui contrôle les fonctions cognitives comme la mémoire de travail. Dans cette thèse, l'effet du stress chronique sur des fonctions du PFC a été analysé chez des rats adultes.
Premièrement, les performances de la mémoire de travail ont été mesurées avant et après exposition au stress chronique. Nous avons constaté que le stress chronique induit des changements de performances de la mémoire de travail différemment selon deux populations de rats. Une des populations a démontré une diminution de performance seulement à 30 secondes de délai. Au contraire, l'autre a démontré une diminution de performance à 0 seconde et une amélioration de performance à 30 secondes.
En plus, nous avons évalué l'effet du stress chronique sur l'induction de la plasticité synaptique dans le réseau reliant l'hippocampe au PFC. Dans les conditions initiales, une stimulation tétanique à haute fréquence (HFS) dans l'hippocampe dorsal provoquait une potentialisation à long terme (LTP) dans le cortex prélimbique et infralimbique Or après exposition au stress chronique, une stimulation tétanique à haute fréquence n'a pas entraîné de potentialisation à long terme dans le cortex infralimbique. De plus, une exposition au stress chronique a provoqué l'apparition dans le cortex prélimbique d'une dépression à long terme (LTD) plutôt qu'une potentialisation à long terme.
Étant donné que la plasticité synaptique dépend des récepteurs de NMDA dans le PFC, nous avons examiné l'expression de sous-unité de NMDA avant et après exposition au stress chronique. En accord avec les changements synaptiques distincts de plasticité entre le cortex prélimbique et infralimbique après exposition au stress chronique, nous avons observé que l'expression de la sous-unité NR1 a diminué dans le prélimbique, mais non dans l'infralimbique. En revanche, le ratio de NR2A/NR2B a augmenté dans le cortex infralimbique, mais non dans le prélimbique. Ces résultats suggèrent que le stress chronique perturbe les fonctions du PFC par la modulation dynamique des réseaux distincts neurologiques dans le PFC.
42
Rodrigue, Jean. "Utilisation du canard de Pékin (Anas platyrhynchos) comme bioindicateur de la contamination du milieu naturel par les substances bioaccumulables". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22796.
Testo completoAbstract (sommario):
Eighteen-month-old adult female Peking Ducks (Anas platyrhynchos) were placed in the Ottawa, and St. Lawrence rivers for periods varying between 14 and 72 days during the summers of 1987, 1988 and 1989. Two stations located on Lake St. Francis were selected for establishing a time-curve for the accumulation of organochlorine pesticides (OC) and PCB in the liver. The ducks rapidly lost weight during their first 20 days in the natural environment but stabilised after about 40 days. This weight loss was caused by the stress of habitat, change, the energetic costs in searching for food and moulting.There was a rapid increase in the number and concentration of contaminants detected in the livers of ducks exposed to pollutants in the natural environment. The concentrations found were low (99.9% of OC-PCB are under 1 mg/kg wet weight basis). These individuals were generally from 10 to 1000 times more contaminated than the control ducks for 40 days of exposure.
The use of domestic ducks as bioindicators has several advantages. They can be obtained readily and cheaply, and the sex and age of the individuals can be controlled. Since they are not very mobile and therefore are easy to locate, they provide information on the contamination (metals or OC-PCB) of specific sites. The use of Peking ducks has some limitations. There is a need for appropriate habitats to ensure their survival, and there is considerable stress caused by transferring the ducks from the breeding farm to the natural environment, thereby obliging them to search for food and exposing them to predators and poachers. (Abstract shortened by UMI.)
43
Rushing, Frances L. "Cytoskeletal rearrangements in human umbilical vein endothelial cells in response to Staphylococcus aureus". Virtual Press, 2006. http://liblink.bsu.edu/uhtbin/catkey/1339459.
Testo completoAbstract (sommario):
Staphylococcus aureus are Gram-positive bacteria that adhere to the extracellular matrix of susceptible host cells to initiate infection and induce a signal transduction pathway that includes PI3K causing the disruption of cytoskeletal elements within the cytosol. Confocal microscopy was applied to visualize actin within human umbilical vein endothelial cells (HUVEC) to discern behavior during infection. HUVEC lysates were analyzed through immunoprecipitation and Western blot analysis to determine the isoforms of PI3K present in HUVECs. Infection experiments and confocal microscopy reveal a time dependent disruption of actin and a dose dependent decrease in infection when HUVECs are treated with the PI3K inhibitor LY294002. Results of Western blot analysis reveal a distinct band corresponding to the pl l0a isoform of PI3K in HUVECs. These studies taken together suggest that PI3K is involved in the signal transduction pathway induced by the infection of HUVECs by S. aureus, and that infection causes the disruption of cytoskeletal actin fibers.Department of Biology
44
Mauritzon, Petra. "The effects of ribose supplementation on swimming performance in collegiate male swimmers". Virtual Press, 2000. http://liblink.bsu.edu/uhtbin/catkey/1180778.
Testo completoAbstract (sommario):
The purpose of this study was to investigate the effects of ribose supplementation on swimming performance in collegiate male swimmers. Twenty trained collegiate male swimmers (mean ± SE; age: 19.7 ± 0.4 years; height: 182.6 ± 1.2 cm; weight: 75.9 ± 0.6kg) completed three randomly assigned trials; two prior to the supplementation period and one immediately after supplementation. The period between the first and the second trial was used as a control period and all subjects (n=20) participated. During the supplementation period the ribose group (n=10) received 20 g of ribose per day, while the placebo group (n=10) received 20 g of dextrose. The first day involved body composition, swim bench, and swim power measurements. The second day a test set consisting of 15x45.8 m freestyle swimming was performed. A blood sample was obtained from the antecubical vein prior to the swim and 1 minute after the completion of the last repeat. Swimming performance during the test set showed significant improvements for either group from T1 to T3. (mean ± SE 27.44 ± 0.32 and 27.55 ± 0.26 for the ribose and placebo groups respectively at T1). The times at the end of the supplementation period were 27.33 ± 0.28 and 27.36 ± 0.22 seconds. No significantdifferences were reported in swim power or swim bench. Lactate, uric acid, ammonia, and hypoxanthine did not significantly change for either group between the trials. The results from the study suggest that swimming performance does not appear to be enhanced with the supplementation of ribose during exhaustive exercise in collegiate male swimmers.School of Physical Education
45
Biggs, Douglas Neil. "Effects of androstenedione supplementation on testosterone levels in older men". Virtual Press, 2002. http://liblink.bsu.edu/uhtbin/catkey/1233193.
Testo completoAbstract (sommario):
The purpose of this study was to examine the effects of androstenedione supplementation on testosterone levels in older men. Healthy men (n = 11) between the ages of58 and 69 were divided into two groups: 6 taking 300 mg of androstenedione (mean ± SE, 62.33 ± 2.57) supplement and 5 taking the 300 mg cellulose placebo (mean ± SE, 60.2 ± 1.02) for a period of seven days. Subjects in both groups had been participating in the Ball State University Adult Fitness Program (BSUAFP) for at least one year, incorporating both aerobic and resistance training into their workouts. Testing measures involved the subjects performing two exercises (leg extension and leg curl) while having blood drawn prior to, during, and post-exercise for a period of 20 minutes both pre-and post-supplementation. Specific weights for the subjects were determined with a ten-repetition maximum (10-RM) lift on both exercises. It appeared that the subjects in the androstenedione group were stronger with the exercises than the subjects
in the placebo group, but with no significance. Testosterone, estradiol, and androstenedione were analyzed via hormone assay pre-and post-supplementation. The analysis of the testosterone revealed a significant difference pre-(mean ± SE, 4.65 ± .51 ng/ml) to post-(mean ± SE, 6.72 ± .58 ng/ml) supplementation for the androstenedione group. Analysis of the androstenedione revealed a significant difference pre-(mean ± SE, 0.88 ± .20) to post-(mean ± SE, 7.46 ± 1.25) supplementation for the androstenedione group. The estradiol assay revealed no significant differences pre-to post-supplementation for either group. The placebo group did not demonstrate any significant differences pre-to post-supplementation for either testosterone or androstenedione. The results of this study concluded that supplementation with 300 mg. of androstenedione for a period of seven days significantly elevated blood testosterone in older men.School of Physical Education
46
Stenger, Travis D. "Pressure distribution in ergonomic car seats". CardinalScholar 1.0, 2010. http://liblink.bsu.edu/uhtbin/catkey/1569028.
Testo completoAbstract (sommario):
The purpose of the present study was to assess the pressure distribution responses to three hour seating bouts in a standard car seat condition compared to a Comfort Motion Technology (CMT) car seat condition. Twelve males participated in the study. Subjects came in for two separate sessions no more than one week apart. Pressure distribution on the backrest and seat pan was assessed in a three hour seating bout. Pressure variables associated with increased seating comfort were collected across six distinct 28 minute cycles and then averaged across these six cycles. The pressure variables were contact area, peak contact pressure, and force. The CMT car seat condition exhibited greater back contact area (p= .003) and less back peak pressure (p= .003) than the standard car seat condition. In addition, the CMT car seat condition had greater seat peak pressure (p< .001) and greater back force (p< .001) than the standard car seat condition. In conclusion, the CMT car seat condition is more comfortable than the standard car seat condition.School of Physical Education, Sport, and Exercise Science
47
Vigus, Tracy Lynn. "THE PHYSIOLOGICAL CORRELATES OF INTERNAL AND EXTERNAL IMAGERY (MENTAL PRACTICE, ELECTROMYOGRAPHY)". Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275467.
Testo completo
48
Osborne, Michael G. "The role of nitric oxide in carrageenan-induced hyperalgesia". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0025/MQ50848.pdf.
Testo completo
49
McKenna, John E. (John Erwin). "Analgesic effects of lidocaine microinjection into the rat dentate gyrus". Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59653.
Testo completoAbstract (sommario):
Previous studies in our laboratory have indicated that anesthetic block of neural activity at discrete sites within the limbic system, including the lateral hypothalamus and anterior cingulum bundle, causes a significant long-lasting analgesia during the formalin test. In this experiment, the local anesthetic lidocaine was microinjected into the dentate region of the hippocampus, an important limbic structure presumed to subserve the affective-motivational aspects of pain. The dentate gyrus is strategically situated at a point of convergence of widespread polysensory cortical input to the hippocampus, to allow modulation of cortical signals before they diverge into numerous limbic circuits. The results indicate that anesthetic block of the anterior region of the dentate gyrus produces analgesia in the rat during the formalin test. The analgesia produced by this procedure became apparent 30 minutes after regional block contralateral to the site of injury and persisted for the duration of the test period. These data provide further evidence that limbic forebrain structures are involved in pain and analgesia.
50
Davis, Jacqueline A. "The hypertensive response to repeated days of heat-exercise exposure". Virtual Press, 1989. http://liblink.bsu.edu/uhtbin/catkey/562777.
Testo completoAbstract (sommario):
The physiological responses of hypertensive subjects to a single bout of exercise in a hot environment have been investigated. It was the purpose of this study to compare the effect of successive days of exercise in the heat on borderline hypertensive and normotensive individuals, with particular interest being paid to the positive relationship that exists between plasma volume and blood pressure. Eight hypertensive subjects (HT) and 8 normotensive controls (NT) performed a standardized work task, (walking for 60 minutes at 3.5 mph on a 5% grade), in dry heat, (40C, 257. RH), on 7 successive days. Working capacity and acclimatization were compared during two, 90 minute heat tolerance tests (HTT), one prior to, and the other following the acclimation period.Both groups demonstrated a similar degree of heat acclimation, as reflected in significantly lower HTT2 core temperatures, (P< 0.05), and heart rates, (p< 0.01). Plasma volume expansion over the 9 days was also equal for both groups (+77.), but appeared to have no effect on their resting or exercising blood pressures. No differences were observed in the ability of either group to complete the work task, although the HT group exercised at a significantly higher percentage of their maximal oxygen uptake, (p< 0.05), than the NTs.These results indicate that no abbreviation in working capacity is experienced by borderline HT'% during exercise in the heat as a consequence of their high blood pressure. The anticipated elevation in blood pressure as a result of an expansion i n plasma volume did not occur. Consequently, these individuals show the same positive acclimation to exercise in the heat as their NT counterparts.School of Physical Education