BACKGROUND:The memory response to LCMV in mice persists for months to years with only a small decrease in the number of epitope specific CD8 T cells. This long persistence is associated with resistance to lethal LCMV disease. In contrast to studies focused on the number and surface phenotype of the memory cells, relatively little attention has been paid to the diversity of TCR usage in these cells. CD8+ T cell responses with only a few clones of identical specificity are believed to be relatively ineffective, presumably due to the relative ease of virus escape. Thus, a broad polyclonal response is associated with an effective anti-viral CD8+ T cell response.RESULTS:In this paper we show that the primary CD8+ T cell response to the LCMV gp33-41 epitope is extremely diverse. Over time while the response remains robust in terms of the number of gp33-tetramer+ T cells, the diversity of the response becomes less so. Strikingly, by 26months after infection the response is dominated by a small number TCRbeta sequences. In addition, it is of note the gp33 specific CD8+ T cells sorted by high and low tetramer binding populations 15 and 22months after infection. High and low tetramer binding cells had equivalent diversity and were dominated by a small number of clones regardless of the time tested. A similar restricted distribution was seen in NP396 specific CD8+ T cells 26months after infection. The identical TCRVbeta sequences were found in both the tetramerhi and tetramerlo binding populations. Finally, we saw no evidence of public clones in the gp33-specific response. No CDR3 sequences were found in more than one mouse.CONCLUSIONS:These data show that following LCMV infection the CD8+ gp33-specific CD8 T cell response becomes highly restricted with enormous narrowing of the diversity. This narrowing of the repertoire could contribute to the progressively ineffective immune response seen in aging.

The morphological characters, pollen viability, and molecular markers are used in this study to assess the inter-species differentiation in Taiwan Trema( T. orientalis, T. tomentosa, T. cannabina, and the hybrid ). The hybrid was proposed to have been originated from T. tomentosa and T. cannabina natural hybridization with morphological, pollen viability and molecular marker evidences. The four taxa are variable in the following morphological characters: growth form, terminal bud color, leaf size, leaf apex, leaf base, leaf vestiture, leaf texture, leaf nerves, petiole, stipule size, inflorescence sex, male and female inflorescence length, flower number, mature fruit color, perianth vestiture, male flower perianth size, pistillode size, pistillode shape, filament length, and female flower size. The author also found differences in leaf shape, leaf size, leaf base, and leaf vestiture between adult and juvenile individuals of T. orientalis are ontogenetical variations. The hybrid is morphological intermediate between T. tomentosa and T. cannabina, possessing species-specific morphological characters of either species. Leaf trichome morphology was observed under scanning electronic microscope, and a unicellular trichome type with bulbous base, smooth surface, and creeping looking, is specific to T. orientalis leaf abaxial surface. In pollen viability tests, the hybrid had the lowest average pollen stainbility among tour taxa, but varied widely from 48.5 % to 81.6 %. In additivity test of molecular markers, for all 8 species-specific molecular markers of T. tomentosa, 6 were detected in hybrid; for all 14 species-specific molecular markers of T. cannabina, 11 were detected in hybrid; and none of 14 species-specific molecular markers of T. orientalis were detected in hybrid. Additionally, there were some recessive homozygote alleles detected in hybrid molecular marker, and even missing in T. tomentosa molecular markers. According to this evidence, there was a possible introgression between the hybrid and parental species-T. cannabina. In similarity dendrogram derived from molecular markers, all samples were clustered into four taxa-corresponded groups, the hybrid was placed between T. tomentosa and T. cannabina, and closely related to T. cannabina.

Thesis (Ph. D.)--Catholic University of America. / Includes bibliographical references (p. 111-117) and index.

Thesis (M.A.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 52-54).

Thesis (M.A.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 52-54). Also available in print.

No description available.

The rising demand for electricity and heat raises a big challange for the society and engineers. Many products have been introduced to the market to supply more energy to the energy systems. Absolicon AB is a Swedish company that develops and markets a combined heat and power generating product. The product, Absolicon X10, uses a parabolic trough to concentrate the radiation of the sun onto a receiver. The receiveris equipped with mono crystalline solar cells and is cooled by a circulating liquid media. The electricity is supplied to the local grid and the heat is supplied to a local heating system. In this master thesis, the author has developed a number of tests for the Absolicon X10 with the superior goal to enhance the quality and electrical performance. The main areas of interest were: The ribbon connecting the solar cells The correlation between indoor and outdoor performance How the position of the receiver in the trough affects the electrical output A test method for evaluation of ribbons was developed and was applied to a new type of ribbon. The method showed that this new type of ribbon was not good enough for implementation in the production chain. Two types of indoor testing methods were developed, with the aim of determine the electrical performance of receivers. Both methods were unable to do so, but one of them might be good enough with some improvements. A position of the receiver which gives higher electrical output and higher tolerance for the tilt angle of the through was found.

Chagas¡¦ disease induced by Trypanosoma cruzi infection causes damages in heart and digestive tract of the host, but trypanosomes were rarely found in blood and tissue during chronic infection. Although trypanosomes could not be found in the peripheral blood of Trypanosoma musculi infected mice during chronic stage, trypanosomes detected in vasa recta of kidney became a unique kidney form (KF). In this investigation, BALB/c mouse was used as animal model to examine if kidney form of T. cruzi exists in chronic stage. Kidney sections were made on the 20, 40, 60, and 80th day after infection of each mouse with 1,000 bloodstream trypanosomes. In order to compare with chronic stage, kidney sections obtained from mice 20 and 40 days after infection were regarded as acute phase. Amastigotes of T. cruzi as well as significant tissue damages were found in both acute and chronic stages. The results indicated that T. cruzi may exist in amastigote form in mouse kidney during chronic infection. ELISA was employed to measure mouse serum specific antibody titers which recognize mouse kidney antigen infected with trypanosomes 20 to 300 days respectively. Peak titer was observed on the 40th day of infection. Results showed that the ability of acute serum recognizing infected kidney antigen was better than chronic serum. On the other hand, antibody titers that recognize amastigote antigens increased gradually during the infection. It seems correlated with trypanosomes existing and releasing antigen during chronic infection. Antisera from rat immunized with epimastigote or amastigote could recognize infected and normal mouse kidney antigen. Anti-epimastigote sera detected 27 and 49 kDa proteins and anti-amamastigote sera detected 28 and 48 kDa proteins of infected mouse kidney antigen. Functions of these molecules are still not clear and require further characterization in the future.

Thesis (M.S.)--University of Toledo, 2009. / Typescript. "Submitted as partial fulfillment of the requirements for The Master of Science in Biology." "A thesis entitled"--at head of title. Bibliography: leaves 88-97.

Thesis (Ph. D.)--Universität Basel, 1934. / Vita. "Diese Arbeit ist der erste Teil des demnächst im Verlag "Die Runde" Berlin erscheinenden Buches: E.T.A. Hoffmann. Ein Kampf um das Bild des Menschen"--T.p. verso. Includes bibliographical references in "Anmerkungen" (p. 133-140).