This thesis investigates the expression of a T-cell differentiation antigen, (XTLA- 1), in various strains and species of Xenopus, and demonstrates the effect of early-thymectomy, (by microcautery), on XTLA-1 expression. It further examines restoration of the T-cell dependent immune system, (particularly with respect to transplantation responses), and the extent to which tolerance to donor antigens is achieved by implantation of xenogeneic, as well as allogeneic, thymi into early- thymectomised Xenopus larvae. The means by which transplantation tolerance is maintained in intact, control Xenopus, following perimetamorphic skin grafting, is also addressed. Initial work, reported in Chapter 2, showed that XTLA-1 is expressed by the majority of thymocytes and by a proportion of splenocytes from all X.laevis, X.borealis, and hybrid clonal Xenopus,(X.laevis x X.gilli and hybrid X.laevis x X.muelleri),examined. X.tropicalis lymphocytes, however, do not express XTLA- 1. Early-thymectomy by microcautery effectively removes T-cells, as detected by XTLA-1 expression. In Chapter 3, normal adult and larval tissue distribution of XTLA-1 positive cells is described, and the XTLA-1 and X.borealis,(quinacrine fluorescence), markers are employed to demonstrate the differentiation of T-cells derived from early- thymectomised hosts within xenogeneic, (X.tropicalis), thymus implants. The effects of implantation of allogeneic and xenogeneic larval thymi into early-thymectomised hosts, in terms of T-cell responses and of induction of tolerance to thymus donor antigens, is explored in Chapter 4; X.borealis xenogeneic thymus implants are apparently as effective in these regards as are allogeneic implants, but X.tropicalis xenogeneic thymus implants do not fully restore thymus-dependent immune responses. Preliminary investigations of skin graft rejection, mixed leukocyte culture and T-cell mitogen responses of X.tropicalis, in comparison to those of other Xenopus species, are reported in Chapter 5; the results of these experiments raise the possibility that X.tropicalis splenocytes are less responsive, in mixed leukocyte culture, to xenogeneic stimulators than are splenocytes of other Xenopus species. In Chapter 6, histological examination of skin grafts, accepted by virtue of the tolerance induced by prior implantation of a thymus gland from the skin graft donor into the early-thymectomised hosts, reveals some rapid alteration in the composition of these skin grafts; infiltration of the tolerated skin grafts by host-derived lymphocytes suggests that tolerance induced by thymus implantation does not abrogate recognition of thymus donor antigens. Finally, also in Chapter 6, tolerance induced in control, intact Xenopus by perimetamorphic skin grafting is shown to be susceptible to cyclophosphamide injection, suggesting that the maintenance of this tolerance is mediated by suppressor cells.

The aim of this thesis is to investigate the peripheral organization of the chromatophore system of Eledone cirrhosa at the level of the chromatic and physiological units.The structure of the chromatic elements is investigatedwith light and electron-microscopy. The structure of the leucophores and iridophores of E. cirrhosa is similar to thestatic elements of other octcpods. The leucophores consistof a central cell body bearing ovoid electron-dense protrusions (leucosomes). The iridophores are made of a central cell body surrounded by stacks of electron-dense discoidal platelets(iridosomes). The chromatophores are true organs made of a central cell containing the pigment granules, surrounded by fifteen to twenty radially arranged muscle fibers. The contraction of the muscles produces expansion of the pigmentcell. The radial muscles are of the obliquely striated type. They differ from those of squids in that the contractile filaments occupy the core of the fiber and they contain fewer mitochondriae. Most of the chromatophore muscles are innervated in an "en passant" fashion by thin varicose axons whichcontact some of the muscles of several chromatophores. The f chromatic units represent morphological groupings of the three elements.The innervation of the chromatophore muscles investigated with cobalt filling or stimulation of nerve bundles in the skin with suction electrodes. The chromatophores forming a motor unit are dispersed over several chromatic units and probablyrepresent parts of particular patterns. There is evidence that variations of the stimulus frequency modifies the numberof chromatophores triggered by a single axon. It is thus suggested that recruitment of motor units is responsible for the different patterns seen in vivo while recruitment through frequency could account for the intensity with which these patterns are expressed.

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No description available.

The important focus of this research is to describe nd explain male consumer behaviour in the purchase of beauty and skin care products. In the Thai context there appears to be a change in behaviour as an increasing number of males, predominately in their working years (21-50 years), are purchasing these products. Until recently the general view was that males pruchased products that were more functional wheras females were more likely to buy symbolic and self-expressive products. The chief purpose of this research is to examine in some depth the phenomena of male consumer bevaviour in buying skin care products in Thailand as it suggests that a significant change may be taking place. / Thesis (DBusinessAdministration)--University of South Australia, 2008.

Thesis (M.S.)--Drexel University, 2007. / Includes abstract. Includes bibliographical references (leaves 50-51).

Thesis (Ph.D.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaves 144-159) Also available in print.

Thesis (DR. P.H.)--University of Michigan.