Thesis (Ph.D.)--McMaster University, 2006. / Supervisor: Turlough M. Finan.

Erlangen, Nürnberg, Universiẗat, Diss., 2007. / Enth. 1 Sonderabdr. aus: American journal of reproductive immunology ; Vol. 53. 2005. - Beitr. teilw. dt., teilw. engl.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Zugl.: Giessen, Universiẗat, Diss., 2007.

Zugl.: Berlin, Humboldt-Univ., Diss., 2007

<p>In todays GSM network more and more interfaces are run over IP instead of classic synchronized networks. This rises new issues to be solved, for example handling of jitter that use of IP networks introduces. The jitter can be handled by a jitter buffer which ensures that the packets are forwarded in evenly spaced intervals.</p><p>In GSM, data is requested a certain time in advance before delivery to a cellphone. This "time in advance" needs to be adjusted according to the delay of the channel. For an IP network this delay varies (jitter), which means that it would be beneficial to have an algorithm which continuously adjusts how long in advance the packets should be requested. The adjustment is made according to current channel delay and jitter size.</p><p>In this thesis work a model of a general IP network has been developed and isthen used for development of two algorithms for jitter buffer handling. Once the algorithms have been developed they are evaluated and compared to each other and previous solutions to the problem. One of the algorithms is new and the other is an already existing algorithm that has been extended.</p><p>The simplified conclusion is that the behaviors of both algorithms are very similar. They mainly have small packet loss but sometimes the packets are requested earlier than needed and therefore are kept in the buffer a bit longer than necessary. When comparing the two developed algorithms with previous solutions it is visible that they improve the buffer handling a great deal.</p>

<p>Plant non specific lipid transfer proteins (nsLTPs) enhance <em>in vitro</em> transfer of phospholipids between membranes. Our analysis exploited the large amount of <em>Arabidopsis</em> transcriptome data in public databases to learn more about the function of nsLTPs. The analysis revealed that some nsLTPs are expressed only in roots, some are seed specific, and others are specific for tissues above ground whereas certain nsLTPs show a more general expression pattern. Only few nsLTPs showed a strong up or downregulation after that the <em>Arabidopsis </em>plant had suffered from biotic or abiotic stresses. However, salt, high osmosis and UV-B radiation caused upregulation of some nsLTP genes. Further, when the coexpression pattern of the <em>A.thaliana</em> nsLTPs were investigated, we found that there were several modules of nsLTP genes that showed strong coexpression indicating an involvement in related biological processes. Our finding reveals that the nsLTPs gene was significantly correlated with lipase and peroxidase activity. Hence we concluded that the nsLTPs may play a role in seed germination, signalling and ligning biosynthesis.</p>

Lactococcus lactis subsp. cremoris Ropy 352 and L. lactis subsp. cremoris Hollandicus produce an exopolysaccharide (EPS) that imparts commercially desirable textural and rheological properties to fermented milk products. This ropy phenotype is expressed under specific environmental conditions. A mucoid EPS phenotype, also expressed under specific environmental conditions, but not involved in the fermentation of ropy milk was identified. The two EPS phenotypes can be expressed individually or concurrently. Genetic regulators involved in expression of the EPS phenotypes were sought. DNA probes and polyclonal antiserum specific to two regulators of EPS in Escherichia coli, Lon protease and RcsA protein, were used to probe ropy and non-ropy strains of L. lactis. The two ropy strains of L. lactis subsp. cremoris, Ropy 352 and Hollandicus, expressed significantly less of the Lon protein than non-ropy strains. Southern and Western blot analysis was extended to a number of Gram negative and Gram positive bacteria. All of the Gram negative bacteria probed contained DNA sequences that hybridized to the Ion and rcsA gene probes, and all of these bacteria has at least one protein that reacted with antiserum to E. coli Lon and RcsA proteins. Two of the Gram positive bacteria contained DNA sequences that hybridized to the E. coli rcsA probe. None of the other Gram positive organisms contained DNA sequences that hybridized to the rcsA or the Ion probes. However, all the Gram positive bacteria contained one high molecular weight protein that reacted with Lon antiserum. In addition, Streptococcus salivarius expressed a protein that reacted with RcsA antiserum. In the course of this study, a second RcsA protein was identified in E. coll. The two RcsA proteins are expressed from one rcsA gene. One RcsA protein is not the proteolytic product of the other RcsA protein. Limited peptide digest profiles of each RcsA protein reveals almost identical peptides indicating the two proteins share a high degree of homology but are not identical. Ferguson plot analysis strongly suggests that the two RcsA proteins differ by size not by charge. Neither RcsA protein can be detected in cells mutant for Ion and rcsB. / Graduation date: 1997

The immune systems of various teleost fish have been studied in some detail for the past several decades. One aspect of fish immunity, that of endogenously produced modulating factors, has recently received a great deal of attention. Understanding the functions and roles of endogenous factors that regulate fish immunity is paramount to expanding the fields of fish immunology and vaccinology. It is know that several lymphoid cell derived factors are detectable in in vitro cell culture systems and exhibit immune modulating effects similar to well studied proteins in mammals. However in comparison, few genes or gene products involved in the modulation of the trout immune responses have been isolated, cloned and characterized. The studies described herein were designed to isolate specific genes from rainbow trout (0ncorhynchus mykiss) and characterize their involvement in the modulation and regulation of the trout immune system. Two distinct genes were isolated cloned and sequenced. The first, non-specific cytotoxic cell enhancement factor (NCEF) gene is closely related to a human gene termed "natural killer enhancement factor" (NKEF) which is important in the modulation of human natural killer cell activity. The second gene is closely related to a group of recently characterized mammalian genes involved in the signal transduction of cytokines termed "STATs". The role of these genes and their respective protein products will be examined and discussed. The antigenic structures of the fish proteins (NCEF and STAT5) were examined by western blot and immunohistochemistry. Monoclonal antibodies derived against the respective human proteins were found to cross react with the corresponding trout proteins, demonstrating antigenic relatedness. The monoclonal regents were also used to analyze the expression of these proteins in fish cells of lymphoid and non lymphoid origin. In vitro cell culture analysis was used to determine the effects and roles of NCEF and STAT5 gene products in the trout immune system. The cytolytic and apoptotic killing activities of spleen, head kidney and peripheral blood leukocytes were found to be enhanced by NCEF. Mitogenic stimulation of peripheral blood lymphoid cells resulted in the trout STAT5 protein binding to a know sequences contained with in the promoters of genes transcriptionally activated in response to cytokine exposure. / Graduation date: 1996

Thesis (M.A. (Clinical Psychology))--North-West University, Potchefstroom Campus, 2007.