The experimental work described in this thesis forms part of a study of the biochemical effects of gonadal hormones in the fowl. It is well known that the onset of reproductive activity in the bird is accompanied by profound morphological and physiological changes. The external changes include the reddening and slight enlargement of comb and wattles, the swelling and moist appearance of the cloaca, the widening of the distance between the sternum and pubes and the softening of the pubes.

Acidification of low acid vegetables reduces their pH level to below 4.5 thereby facilitating their processing below 100 degrees Celsius, thus reducing thermal damage, and yielding better product quality. We sought to determine the acidification kinetics of turnip and radish in acetic or citric acid solutions, specifically the time for the treated tissue to reach pH 4.5, and the concurrent percent acidity of the tissue. The two vegetables' response to acidification with citric acid were compared. Experiments followed a central composite rotatable design, with three process variables (temperature, acid concentration and sample: solution ratio), each at five levels. All process variables showed significant effects (P ≤ 0.05) on both time to pH 4.5 and concurrent tissue acidity. Higher acid concentration, temperature or solution: sample ratio resulted in a shorter response time, and higher sample acidity. Optimum processing conditions (shortest time to reach pH 4.5) and the corresponding acidity were determined using a response surface methodology. This acidification process was successfully completed in practice. / L'acidification de légumes hypoacides réduit leur pH en dessous de 4.5, facilitant ainsi leur transformation à des températures n'excédant pas 100degrees celsius, réduisant les dommages thermiques, et donnant un produit de plus grande qualité. Nous avons étudié la cinétique d'acidification avec acide acétique ou acide citrique de morceaux de navet ou de radis, en particulier le temps requis pour que les tissues atteignent un pH de 4.5, ainsi que le pourcentage d'acidité à ce moment. La réponse des deux légumes à une acidification par acide citrique fut comparée. Les expériences suivirent un plan central composé rotatif avec trois variables de transformation (température, teneur en acide, et rapport échantillon:solution), chacun à cinq niveaux. Toutes les variables de transformation eurent un effet significatif (P ≤ 0.05) sur le temps pour atteindre un pH de 4.5, ainsi que l'acidité des tissus à ce moment. Une concentration en acide, température, ou rapport échantillon:solution plus élevé donna un temps de réponse plus court, et une acidité du tissus plus élevé. Les conditions de transformation idéales (temps le plus court pour atteindre pH = 4.5) et l'acidité correspondante des tissus, furent déterminés grâce à une méthode de surface de réponse. Cette transformation par acidification fût mise en pratique.

No description available.

No description available.

The soil color components of 127 samples from five Arizona Agricultural Research Centers and 52 WEPP samples occurring in various parts of the U.S.A. were evaluated using a Minolta Chroma Meter. This instrument is designed to minimize the variability in color determination utilizing a built-in light source to generate a primary source of radiation. Simple and multiple linear regression equations relating Hue, Value, and Chroma color components were obtained to predict the organic carbon and iron content of these soils. The results show that using global data is less reliable than specific groupings of soils. Moist value and moist chroma moist are the two most important color components in estimating the organic carbon content of soils. Chroma and Hue were highly correlated to iron at all moisture levels. Chroma was least affected by soil moisture, but Value and Hue consistently decreased for all soils.

A dynamic process of the nonstructural carbohydrate translocation in rice plants is presented based on observation during one growing season. Differing amounts of nonstructural carbohydrates might be lost through rice plants due to the experimental plant manipulation. Relative to the CH$\sb4$ flux from the area of normal plants, significant increases in methane emission were observed in the area of manipulated plants. It is proposed that due to the experimental plant manipulation, more organic deposition entered the soil through rice plants than that under normal condition and, the lost nonstructural carbohydrate resulted in methane emission through the anaerobic methanogenesis in the rice field.

Microcapsules are comprised of particles or droplets surrounded by ultrathin polymeric membranes. The process of microencapsulation is currently used in the immobilization of biocatalysts, including enzymes and biological cells. A study of the possible use of encapsulated lactic acid bacteria in the dairy industry was performed for the purpose of comparing three methods of immobilizing Lactococcus lactis subsp. cremoris. A new immobilization method involving microencapsulation of L. lactis subsp. cremoris within a cross-linked polyethyleneimine membrane was developed. This technique was compared to existing alginate bead and nylon membrane microcapsule immobilization in terms of the microorganism viability and lactic acid production activity. The alginate bead, surrounded by a poly-L-lysine membrane, afforded the greatest viability and activity of the encapsulated cells. The nylon encapsulation procedure did not result in the maintenance of viable cells, and the polyethyleneimine encapsulation procedure did not provide evidence of lactic acid production by the cells. / The rate of lactic acid production by Lactococcus lactis subsp. cremoris encapsulated in alginate-PLL is less than that produced by unencapsulated or free cells. The difference diminishes with increasing cell concentrations. At a concentration of approximately 10$ sp9$ cells/ml of milk, the time required to acidify the milk to the point at which it is useful in the dairy industry is identical for both free and encapsulated cells.

Solid-state and solution NMR technique, were used in order to study the transformation of various functional groups present in lignin and cellulose when wood is exposed to a wide range of pH's and pulping reagents. / Solid-state proton spin-lattice relaxation times (T1H) allowed the determination of the molecular mobilities of carbohydrates and lignin as a function of PH for black spruce softwood. Similar measurements on isolated cellulose and cuoxam lignin were also conducted. These studies showed that the mobilities of the polymeric constituents of wood are affected by ionization processes occurring on the various functional groups present in lignin and cellulose. / Quantitative 31P NMR Spectroscopy was also used to derive the fundamental thermodynamic parameters that are involved in the stereoselective degradation of the two diastereomeric forms of the most abundant structural (arylglycerol-beta-aryl ether) units of lignin under kraft pulping conditions. It was shown that the erythro isomers of the arylglycerol-beta-aryl ether units in softwood milled wood lignin cleave faster than their threo counterparts. The general stability of the threo diastereomers toward kraft pulping seems to be the manifestation of a considerably slower reaction of the pulping reagents with the threo diastereomers of arylglycerol-beta-aryl ethers. Quantitative 31P NMR Was also used for the identification and quantification of accumulated condensed diphenyimethane (DPW moieties during conventional kraft, extended modified continuous cooking (EMCCRTM) and soda pulping processes. / A novel method that permits the quantitative detection and classification of various carbonyls in lignin was also developed. The proposed selective fluoride-induced trifluoromethylation method was optimized for a series of carbonyl-containing lignin-like model compounds. This was followed by 19F NMR spectral analyses of the resulting fluorine derivatives allowing for thorough understanding of their structure/19F NMR chemical shift relationships' our studies demonstrated that the Proposed method is a new analytical tool for the classification and quantification of various carbonyl groups that may be present in soluble lignins.

A tandem Michael-Claisen (4C + 2C) annelation reaction based on the propensity of siloxy diene, 1-(tert-butyldimethylsiloxy)-1-methoxy-3-(phenylthio)-$ 5$-(methoxycarbonyl)-penta-1,3-dienoate, to undergo Michael reaction with 2-cyclohexen-1-one under Lewis acid catalyzed conditions was developed to give 3-(phenylthio)-4-methoxycarbonyl-$ 4$a,5,6,8a-tetrahydronaphthalene-1,8(4H,7H)-dione. / Two functionalized 1,8-$ beta$-dicarbonyl decalin compounds, prepared via the tandem Michael-Claisen condensation, were hydroxymethylated at the angular position as the benzyloxymethoxy derivatives with diisopropylethylamine and benzyl chloromethyl ether in the presence of paraformaldehyde. The nature of this reaction was examined. The stereochemistry of cis-8a- ( ((benzyloxy)methoxy) methyl) -3-(phenylthio)-4a,5,6,8a-tetrahydronaphthalene-1,8(4H,7H)-dione was confirmed by X-ray analysis of its ethylene ketal derivative. / The ((benzyloxy)methoxy) methyl derivative mentioned above was employed as the intermediate in the preparation of a variety of angularly functionalized decalin compounds leading to the synthesis of three key keto diacetates. The methylenation of these keto diacetates was not successful, due to the steric hindrance experienced by the ketone functionality in these cis-fused decalin systems. / When the angularly functionalized decalin compounds were tested for their biological activity against the spruce budworm, Choristoneura fumiferana, seven compounds were found to exhibit moderate activity similar to a specionin analog prepared earlier in this laboratory.

Abstract not available.