This research was designed to study the perinatal and postweaning effects of the interaction between ethanol and low dietary zinc during gestation and lactation in the rat. Pregnant rats were fed liquid diets containing either 2 or 10 μg zinc/ml with or without 30% of kcal from ethanol throughout gestation and lactation. The liquid diet formulation was nutritionally adequate to insure offspring growth and survival during lactation. At weaning, dams and five of eight offspring from each litter were killed by exsanguination under sodium pentobarbital anesthesia. The remaining offspring were orally inoculated with Streptococcus mutans and fed a caries-promoting diet for six weeks. The low zinc diet produced a moderate zinc deficiency in dams as evidenced by a decrease in tissue zinc content, serum alkaline phosphatase activity, and urinary zinc concentration. Despite the presence of high zinc content in the diet, ethanol antagonized maternal zinc status to a level typical of that produced by the low zinc diet. The lowest zinc status, however, was found when low dietary zinc and ethanol were combined. The maternal interaction between ethanol and zinc also depressed offspring serum zinc and alkaline phosphatase activity in a similar manner but the magnitude was smaller. The maintenance of a lower than normal maternal tissue zinc and decreased maternal urinary excretion of zinc suggested a maternal attempt to support the growth and development of offspring despite zinc deficiency. Physiological consequences of ethanol-antagonized zinc status were evidenced by depressed activity of maternal and offspring serum alkaline phosphatase, increased maternal urinary excretion of hydroxyproline, decreased offspring molar enamel and dentin zinc content, increased dental caries score, and decreased cross-linking structure of mandibular second molar enamel. The liquid diet developed in the present study was nutritionally adequate and allowed for the investigation of a single nutrient deficiency, zinc, in ethanol fed rats during gestation and lactation without confounding effects of general malnutrition. Although the direction of interaction was predominately an effect of ethanol on zinc rather than the effect of zinc on ethanol, this study clearly indicates that zinc deficiency is an important consequence of maternal ethanol ingestion. / Graduation date: 1984

The over-tenderization of irradiated-sterilized meat is one of the more important adverse effects resulting from the use of irradiation for the preservation of meat. Although research has been reported on the activity and effect of the inherent proteolytic enzymes of irradiated meat, very little work has been directed toward the intimate causes of the textural problems induced by the irradiation treatment. In this study, the influence of irradiation-sterilization on some of the muscle characteristics involved in meat texture was investigated in an attempt to elucidate the over-tenderizing action of irradiation. In addition, the influence of treating the meat by several means prior to irradiation was also investigated to determine their effects upon the texture of the meat. Information relative to the above objectives was obtained by using analytical methods designed to show changes in muscle protein charges, water-holding capacity, acidic and basic groups, bound and free minerals, and disc electrophoretic analysis of the glycine soluble extracts of the treated and control samples. The results showed that the irradiation-sterilization of beef muscle at 4.5 megarads caused tenderization of the meat. Beef soaked in an equal amount of distilled water for 72 hours at 38°F prior to heat inactivation of the enzymes and irradiation was much firmer in texture than the unsoaked samples. Beef heated to an internal temperature of 160°F prior to irradiation also resulted in meat having a firm texture. However, irradiation tends to reverse the effects of both soaking and heating and/or the combination of these two treatments. When soaking, heating and irradiation are combined in one treatment, these factors tend to exert their effect individually and by different mechanisms. Soaking the meat appears to cause a partial denaturation and a net loss of anions of some of the muscle proteins resulting in a shift in the isoelectric region of such meat to a higher pH which results in a greater loss of water upon cooking and thus a firmer texture. Heating the meat to an internal temperature of 160°F results in a partial denaturation of the proteins and probably leads to the formation of stable cross linkages and a "salting-out" effect which may be responsible for a decrease in the water-holding capacity. Thus, meat would have a tighter or more "closed" structure and firmer texture. Irradiation exerts a fragmentation effect upon the beef muscle proteins. These fragments seem to be held together by hydrogen bonds and/or electrostatic forces. The fragmentary alterations of the muscle proteins, the incorporation of water within the fragments, and possibly a "salting-in" effect, appear to be the major factors responsible for effects of irradiation on beef muscle texture. The zinc cations appear to be involved with the heat-labile proteins or enzymes which are denaturated by heating to 160°F. The pH-water holding capacity curves were found to be a valuable technique for investigating some of the biochemical changes in the muscle proteins. / Graduation date: 1963

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Amorphous metals have been studied extensively recently and possess many interesting electronic properties. This thesis aims to examine some of these, with particular reference to the conductivity and Hall effect in such alloys. In an extensive review of recent theoretical and experimental work, the author attempts to examine (i) whether the data can be explained using the 'semi-classical' theory of transport, with the inbuilt assumption that the electron loses memory of all collisions before that immediately preceding the time of observation, or whether 'quantum interference' and 'electron correlation phenomena must be considered, and (ii) whether it is possible to provide a simple physical picture of such quantum interference phenomena which leads to results commensurate with those of formal theories and with experimental results. A good probe of electron correlation effects is the temperature dependence of the Hall coefficient. In conjunction with the conductivity a good idea of the importance of such phenomena can be obtained. The succeeding chapters discuss the rebuilding of a radio frequency sputtering system suitable for production of thin amorphous metal films, and the methods used in making high precision measurements of the properties mentioned, between 1.25 and 300K. A results chapter reports data taken on the Cu-Ti and Ni-Zr systems, which were chosen as representative transition metal - transition metal alloy systems showing a wide range of behaviour. Extensive analysis of these data is undertaken, in terms of quantum interference and other theories. The effects of clustering of magnetic centres, and of superconductivity, in Ni-Zr films, is discussed. It is shown that the results are in broad agreement with these theories and first evidence is presented that electron correlation phenomena may be affected by inelastic electron scattering at intermediate temperatures. Confirmation of a simple relationship between the change in Hall coefficient and of conductivity due to electron correlation, predicted by theory, is provided. A short conclusion makes suggestions for future experimental work.

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