No description available.

<p>Experiments were conducted on rainbow trout to analyse 1) the physiological mechanisms of short-term copper toxicity, 2) the effects of water hardness, pH, and alkalinity on copper toxicity, and 3) the physiological and biochemical mechanisms of acclimation to copper toxicity. Unidirectional and net sodium fluxes were the basic parameters measured. Disruption of the ionoregulatory functions of the gill accounted for short-term (24 h) and long-term (28 day) copper toxicity. Copper inhibited sodium uptake at concentrations as low as 12.5 μg/L, and stimulated sodium efflux at copper concentrations greater than 100 μg/L. High alkalinity water (i.e., 1000 μM Ca(CO)₃) significantly reduced copper effects on both sodium uptake and sodium efflux. Although water hardness (i.e., 25 vs. 1000 μM Ca(NO₃)₂) had no effect on sodium uptake (at either pH 7.8 or pH 5.0), hardwater fish were better able to reduce sodium efflux than softwater fish. At pH 5.0 (in both hard and softwater), a significant additional inhibition of sodium uptake was found at low levels of copper but not at higher levels. Juvenile trout were about twice as sensitive to copper as adult trout. Juvenile trout were able to acclimate to 55 μg/L copper. Acclimation was defined as the return of sodium uptake and whole body sodium to control levels during continuous exposure to copper. Sodium uptake kinetics and whole body sodium concentration were analysed weekly during 4 weeks of exposure. The recovery of sodium uptake took about 3 weeks to complete, but whole body sodium recovered within 1 week. The time necessary for the recovery of influx was provided by a reduction in efflux. The inhibition and recovery of sodium influx was correlated with the inhibition and recovery of the Na⁺-K⁺-ATPase transport pool of the gill. Metal binding proteins played no apparent protective role in the recovery of Na⁺-K⁺-ATPase. Metal binding proteins were induced in the liver, but a significant portions of the whole body copper burden was accumulated by other tissues.</p> / Doctor of Philosophy (PhD)

Thesis (M.S.P.H.)--University of Michigan, 1939.

Thesis (M.S.P.H.)--University of Michigan, 1939.

Meal pattern has been identified as a factor influencing the thermic effect of food (TEF) and metabolic status, and therefore health. This thesis investigated the effects of an irregular meal pattern, with a controlled energy intake, in normal-weight (n=11) and obese with insulin resistance (n=9) females over a 14-day period. Measurements were made of the TEF, circulating glucose, insulin, lipids concentration and appetite regulation, using a crossover design. The irregular intervention period led to a significant reduction in the TEF following a test drink consumption in both normal-weight and obese participants. Glucose iAUC responses to the test drink measured over 3h were higher after the irregular compared with the regular intervention with no difference in the insulin response in the normal-weight study. In the obese study, glucose responses were unaffected by the regular and irregular intervention periods, whilst there was a main effect of meal pattern in insulin responses. In the normal-weight study, fasting GLP-1 decreased after both interventions. In contrast, fasting GLP-1 increased after both interventions in the obese study. Furthermore, in the obese study, the regular intervention produced a higher GLP-1 iAUC compared with the irregular intervention, but there were no such effects in the normal-weight study. The normal-weight study showed that fasting PYY was lower after the interventions compared with before. Moreover, iAUC for PYY increased after the interventions compared with before. However, there were no significant differences in fasting and iAUC PYY responses between the two interventions in the obese study. A regular meal pattern appears to be associated with greater TEF, which might result in more favourable energy balance for weight maintenance. Also, it is likely that a regular meal pattern improved insulin sensitivity in healthy normal-weight females. Therefore, a regular meal pattern could be a lifestyle factor that may promote an individual’s health.

Thesis (M.D.) -- University of Pennsylvania, 1806. / Film 633 reel 62 is part of Research Publications Early American Medical Imprints collection (RP reel 62, no. 1167). DNLM Includes bibliographical references.

No abstract available. / Thesis (M.Sc.)-University of Durban-Westville, 1992.

No abstract available. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 1992.

The aim was to compare the movements of the mandible during chewing different food types. We hypothesized that the mandibular movements would vary significantly between the food types. For each participant, we built and affixed the dental appliances and attached infra red emitting diodes to record the mandibular movements using a 3D motion capture device (Optotrak). Participants chewed on four test foods that varied in texture: Italian bread stick, dried beef stick, carrot and cheese. Results indicated greater amplitude of the lateral displacement of the mandibular movements when chewing cheese. The velocity of the lateral displacement was greater for soft foods such as cheese. The velocity of the horizontal displacement increased during beef chewing. Furthermore, we found shorter movement cycle duration while chewing carrot. We concluded that the movements of the mandible vary significantly during chewing different food types.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1976. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 212-216).