The purpose of this study was to determine the effect of a 6-week ketogenic diet on maximal oxygen consumption (VO2max), high-intensity Wingate sprints, and work output during a 45-minute cycling bout. Twenty subjects were placed into either an intervention group (N=12) or a control group (N=8). Subjects in the dietary intervention group ingested a diet consisting of 61± 4% fat, 8± 3% carbohydrate, and 30± 5% protein while subjects in the control group were instructed to continue following their normal moderate carbohydrate diet. All subjects were instructed to maintain their current training status. On the first day subjects performed a VO2max test on an electronically braked cycle ergometer. On the second day subjects performed two 30-second Wingate sprints followed by a 30-minute rest. Following this subjects performed a 45-minute timed ride on a cycle ergometer set on isokinetic mode. Absolute VO2max decreased significantly (P<_ 0.05) in the ketogenic group while relative VO2max was unchanged. Rate of perceived exertion increased significantly at 9 and 11 minutes during the VO2max test. Absolute peak and mean power output during the first Wingate sprint was significantly less after the ketogenic diet compared with week 0. When analyzed relative to body weight, however, only peak power output was significantly decreased. Power output during the second sprint remained unchanged. Fat oxidation increased but work output decreased during the 45-minute cycling bout in the ketogenic group. The results of the present study suggest that a 6-week ketogenic diet results in metabolic adaptations that increase fat oxidation. However, the overall decreased performance during a VO2max test, 30-second Wingate sprints, and a 45-minute endurance test indicate that some aspect of the diet has an adverse effect on exercise performance. / School of Physical Education

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

Akt activation mediates increases in glycogen synthesis in response to insulin in humans, while extracellular signal-regulated kinase (ERK) activation increases gene transcription and protein translation in response to endurance and resistance exercise. Akt activation increases only in response to intense muscle contractions and during hypertrophy in rats. No study has examined Akt and ERK activation with increasing numbers of intense muscle contractions in humans. Therefore, the primary objectives of this investigation were to determine if Akt activation increases in response to resistance exercise in humans, and to compare the changes in Akt and ERK activation in response to increasing numbers of muscle contractions.Akt and ERK activation were compared in muscle biopsy samples from 7 men before (Pre) and after (Post) knee extension and control protocols using enzyme linkedimmunosorbent assays. Baseline information was obtained including body composition and maximal strength (1-RM). Subjects were familiarized with knee extensions performed at 70% of 1-RM and a specified repetition cadence (2sec up, 2sec down). Once/wk, subjects performed one protocol in random order: 1 repetition (rep), 10reps, 3 sets of l0reps (3x10), or 6min of sitting. Akt activation decreased 42%, while ERK activation increased 108% in response to 3x10 (p<0.05). Akt and ERK activation did not change with 1 and 10reps, and thus their responses were not dose-dependent with resistance exercise in humans. The findings from this study represent the first indication that Akt activation is reduced in response to resistance exercise in human skeletal muscle, possibly to help mediate reductions in glycogen synthesis. / Human Performance Laboratory

This thesis compared the loudness discomfort levels (LDL) for a group of normal hearing children to those for a group of children with sensori-neural hearing losses. The children with a loss were students at a school for the deaf. The LDL’s for the frequencies 250, 500, 1000, 2000, and 4000 Hz and for speech were obtained.It was found that the sensori-neural loss group had higher LDL’s for both pure tones and speech than the normal hearers. It was further found that for the normal hearers, the LDL’s were higher for speech than for the average of the pure tone speech frequencies. The results of this study were also higher than previous researchers had found. The possible reasons for the differences between the groups and between the results of this study and previous ones were discussed.

[Typewritten] / 300, xiv p. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, 1962

M.Tech. (Environmental Health) / Although evidence of the hazards of cigarette smoking has been in existence for many decades, millions of people around the world are still smoking, hundreds of thousands of teenagers take up smoking and the tobacco companies are allowed to continue promoting their products. To the annoyance of non-smokers, smoking is still allowed in many public places, such as restaurants and offices. This study serves, firstly, to provide an overview of the results of research on the dangers of smoking, nicotine addiction and passive smoking. Secondly, a self-completion questionnaire has been applied to a sample of students at eight technikons in South Africa. The questionnaire was designed to investigate the prevalence of smoking among the different population groups and genders to reveal some of the pattems of smoking of students, the factors influencing students' smoking status and to test students' beliefs, opinions and attitudes regarding smoking. The third objective of the study is to develop a theory on cigarette smoking and to propose anti-smoking measures at technikons. Researchers have produced conclusive proof that cigarette smoking is the cause of cancer, respiratory and heart disease and other diseases. Smoking maims and kills millions of people around the world annually and threatens the health of unborn babies and non-smokers, especially children. Tobacco companies apply the most sophisticated promotion techniques to persuade people to smoke and teenagers and certain other sectors' of the population are targeted by these activities. A study of nicotine addiction reveals that the need for this substance becomes as strong as any of man's basic physiological needs, such as those for food and water. This makes it very difficult, if not impossible, for many smokers to give up smoking. A multi-pronged strategy to combat smoking at education institutions is proposed, which includes health education and the banning of smoking on campuses.

No description available.

This thesis is a report of a study on bone blood flow in adult dogs and rabbits. The effects of epinephrine and some other factors were investigated: (1) by direct observation of bone bleeding through drill holes and in the medullary cavity; (2) by measurement of changes in intramedullary pressure of long bones; and (3) by quantitative estimation of bone blood flow by the Fick principle. A technique was developed for measurement of the initial Sr⁸⁵ clearance by bone by dividing the bone uptake of Sr⁸⁵ by the integrated average concentration of Sr⁸⁵ in the systemic arterial blood. This clearance will represent at least a minimum bone blood flow. It should be equivalent to effective bone blood flow on the assumption that bone clears Sr⁸⁵ rapidly and almost completely from blood circulating through bone by exchange with calcium in bone, just as PAH clearance gives a measure of effective renal blood flow. The normal rate of bone blood flow in adult rabbits by the rate of initial Sr⁸⁵ clearance appeared to be at least 16 ml. per minute per 100 gm. of fresh bone which would represent about 5-10% of the resting cardiac output. The average intramedullary pressure of the femur in dogs was about 55 mm Hg, about 1/2 of the systolic systemic arterial blood pressure. Epinephrine caused a profound reduction in bone blood flow as indicated by reduced bone bleeding, a marked (65%) reduction in intramedullary pressure of bone marrow in the presence of persistently increased systemic blood pressure, and a significant (75%) reduction in Sr⁸⁵ clearance by bone. The changes in intramedullary pressure and in Sr⁸⁵ clearance by bone thus appear to correlate very well with changes in bone blood flow. / Medicine, Faculty of / Cellular and Physiological Sciences, Department of / Graduate

The physiological effects of partially purified estrogenic extracts from forage plants of widespread economic importance have been studied, using the laboratory mouse and rat as experimental animals. The main purpose of these studies was to compare physiological activities of estrogenic substances from plants with those of a well known synthetic estrogen, diethylstilbestrol (D.E.S.). The latter, like many of the "natural" animal estrogens, is well known to influence the fundamental processes of animal production namely, reproduction, lactation, and growth. The estrogenic treatments were administered orally, either mixed with the diet, or by means of a rubber catheter. Dosage levels were in most cases designed with the grazing animal in mind, so as to allow some opportunity for tentative extrapolations of the results to farm animals which are the chief consumers of estrogen-like substances in forage plants. Red clover estrogenic extracts were used mainly, although some effects of subterranean clover, and birdsfoot trefoil are discussed. Non estrogenic timothy grass extracts were used to help control the experimental conditions. No effect of red clover "estrogens" on Maternal Performance of lactating mice as determined by the total weights of their litters at 12 days was detected. Performances calculated on the basis of 17th day total litter weights appeared to be adversely affected although not to the same extent as a similar level of D.E.S. The high estrogenic content of the diet is believed responsible for this result. Red clover "estrogens" induced increased testes weights, decreased seminal vesicle weights and lowered fertility in intact male mice. Remarkable recovery to normal, of these organs took place within eight days after cessation of estrogenic treatment. Some differences both in genital organ weights, and fertility data between males weaned from normally fed dams and those weaned from dams receiving estrogenic materials throughout the lactation period were observed. Per cent fertility data from females were essentially similar. The effects of red clover "estrogens" on uterine weight and histology, in intact, ovariectomized, hypophysectomized, and hypophysectomized-ovariectomized rats were studied. The absence of the hypophysis, and, or, the ovary does not interfere with the rate or degree of uterine response. The histology of uteri from "estrogen" treated animals is discussed in relation to fertilization, and implantation i.e. fertility. Method of administration of red clover "estrogens" influences the physiological effectiveness of a given dose. When mixed with feed their effect is more marked in terms of uterine response than when the same quantity is administered orally by means of a catheter, in two equal portions, twice daily. Once daily catheterization is even less effective. These results are discussed in relation to quantitative comparisons between injected or implanted doses of "natural" animal estrogens and D.E.S., and the quantities of estrogenic materials likely to be consumed by a grazing animal. Finally, red clover estrogenic extract from 8.4. gm. of dry ground forage increased thyroid uptake of radioactive sodium iodide (I¹³¹ ) in ovariectomized rats with a mean weight of 110 gm. Scintillation count data were confirmed by histological examination of carefully prepared thyroid sections. The likely endocrinological interpretation of this observation is discussed. / Land and Food Systems, Faculty of / Graduate

Isoidide dinitrate (IIDN), a new nitrate ester, an isomer of isosorbide dinitrate (ISDN) and isomannide dinitrate (IMDN), has been studied on the isolated rabbit intestine and on the anesthetized rat blood pressure. Potency was observed as was tachyphylaxis and the effect of certain blocking agents. On the isolated rabbit intestine similar results were obtained when nitroglycerin was substituted for IIDN. In both preparations IIDN was more potent than ISDN or IMDN and ISDN more potent than IMDN. The potency dependence on configuration suggests a possible action on specific receptor sites. A type of tachyphylaxis to IIDN which was prominent in the isolated rabbit intestine was almost absent in the anesthetized rat blood pressure. This is probably due to metabolism of the drug in the intact animal and further suggests an action on receptors. In these preparations the nitrate action was not blocked by: the beta adrenergic blocking agents DCI or nethalide, the alpha adrenergic blocking agent dibenzyline, or a combination of an alpha and a beta blocking agent. Drugs that are selectively blocked by these agents were used as controls to indicate the presence of the desired blocking action. Neither the primary bretylium-like action nor the secondary reserpine-like action of guanethidine blocked the effect of IIDN on the isolated rabbit intestine. Depletion of catechol amines by pretreating the animals with reserpine did not alter the response of either preparation to the nitrate esters. The antihistamine diphenhydramine did not block the vasodepressor action of IIDN on the anesthetized rat blood pressure. It was concluded that although IIDN probably does not exert its effect through combination with adrenergic or histaminergic receptors, it possibly acts on receptors which are specific for the nitrite or nitrate group. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate