Published Article / The LPS, endotoxin of Gram-negative organisms in communal growth as compared to pure culture was the focus of this research. The experiment aimed to show pure and communal samples grown in the presence of the extrinsic stresses. The change in toxicity was measured using the Limulus Amoebocyte Lysate (LAL) test. The overall sensitivity of organisms was similar for the same sanitiser and the same detergent. Growth in community was found not to be the arithmetic sum of the individual growth patterns. The detergents had a marked effect on the growth of all samples throughout the growth cycle. This finding reveals that the acceptable refrigeration temperatures still allows for pathogen growth and thus for biofilm formation. The quantification by LAL showed that the enumeration of the food-borne pathogens isolated from households might not be indicative of acclimatisation obtained over short periods of time and the causal stress could turn these organisms into more or less toxic pathogens.

No description available.

No description available.

KefB and KefC are glutathione-gated potassium channels that play a protective role during the detoxification of electrophiles in Gram negative bacteria. The KefC channel from Klebsiella aerogenes has been characterised and the gene cloned and sequenced. The KefC channel from K. aerogenes is analogous to KefC from Escherichia coli. The electrophile compounds NEM and CDNB are strong activators of potassium loss via the channel, whereas, methylglyoxal is a weak activator of potassium loss. At the amino acid level the putative protein shows a high degree of similarity with KefC from E. coli. While sequencing the kefC gene from K. aerogenes a difference in the genome organisation of K. aerogenes and E. coli was observed, highlighting the presence of an unassigned ORF, yabF, that overlaps the kefC by 8 bp. Clones of the K. aerogenes kefC gene that lack the first 129 bp of yabF exhibit reduced KefC activity. Analysis of the sequence surrounding the kefB gene from E. coli revealed an ORF, yhaH, that encodes a homologue of the putative YabF protein. The amino acid distribution of YabF and YhaH predict soluble proteins with significant similarity to the NAD(P)H dehydrogenase quinone oxidoreductase, DHQV. To investigate the function of YabF, a strain lacking the yabF-kefC region in E. coli was constructed. The strain was transduced into a kefB background and when transformed with a plasmid expressing only KefC channel activity was greatly reduced. The data suggest that the YabF protein is required in trans for the activity of KefC and preliminary evidence from in vitro-galactosidase fusion studies suggest that yabF and kefC genes may form an operon.

In this thesis, we provide several applications of Gram-Charlier expansions in derivative pricing. We first give an exposition on how to calculate swaption prices under the the CIR2 model. Then we extend this method to CIR2++ model. We also develop a procedure to calculate European call options under Heston’s model of stochastic volatility by Gram-Charlier Expansions.

No description available.

In this thesis, we provide several applications of Gram-Charlier expansions in derivative pricing. We first give an exposition on how to calculate swaption prices under the the CIR2 model. Then we extend this method to CIR2++ model. We also develop a procedure to calculate European call options under Heston’s model of stochastic volatility by Gram-Charlier Expansions.

München, Techn. Univ., Diss., 2010. / Zsfassung in dt. Sprache.

University, Diss., 2006--Würzburg.

München, Techn. Univ., Diss., 2000.