Reemergence of Epidemic Vibrio cholerae O139, Bangladesh

During March and April 2002, a resurgence of Vibrio cholerae O139 occurred in Dhaka and adjoining areas of Bangladesh with an estimated 30,000 cases of cholera. Patients infected with O139 strains were much older than those infected with O1 strains (p<0.001). The reemerged O139 strains belong to a single ribotype corresponding to one of two ribotypes that caused the initial O139 outbreak in 1993. Unlike the strains of 1993, the recent strains are susceptible to trimethoprim, sulphamethoxazole, and streptomycin but resistant to nalidixic acid. The new O139 strains carry a copy of the Calcutta type CTXCalc prophage in addition to the CTXET prophage carried by the previous strains. Thus, the O139 strains continue to evolve, and the adult population continues to be more susceptible to O139 cholera, which suggests a lack of adequate immunity against this serogroup. These findings emphasize the need for continuous monitoring of the new epidemic strains

Lipolytic enzymes from the bovine rumen : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biochemistry at Massey University

1.1. Lipid metabolism in the ruminants and significance of hydrolysis and hydrogenation in the rumen. The digestion pattern of ruminants differs from other mammals in that the food of ruminants is subjected to a microbial fermentation in the rumen before passing into the true stomach. Carbohydrates, proteins, organic acids and many other food constituents are attacked by the micro organisms in the rumen and as a result short-chain fatty acids (VFA), CO2 , CH4 , NH3 etc. are produced as the end product of microbial metabolism. This ruminal fermentation has a considerable effect on the metabolic processes of the animal and moreover the functions of the rumen microorganisms are intimately associated with certain metabolic disorders of the ruminant (Bryant, 1959) e.g. Ketosis, bloat etc. It is now generally believed that the organisms of functional significance in the rumen are protozoa and bacteria which are capable of growth under the anaerobic conditions prevailing. The rumen provides an ideal anaerobic environment for a large and diverse microbial population at a temperature of 39°-40°C. The pH of the ingesta is slightly acid and the bacteria are adapted to live between pH 5.5 and 7.0 (Hungate, 1966). It is apparent from earlier studies that the lipids of ruminants differ in several respects from those of non-ruminant herbivorous animals in particular. Occurrence of unusually high proportions of stearic acid and the presence of trans acids and isomeric forms of oleic, linoleic and linolenic acid in depot fats and tissue lipids are peculiar to ruminants. [From Introduction

Rotavirus infections and climate variability in Dhaka, Bangladesh: a time-series analysis.

Attempts to explain the clear seasonality of rotavirus infections have been made by relating disease incidence to climate factors; however, few studies have disentangled the effects of weather from other factors that might cause seasonality. We investigated the relationships between hospital visits for rotavirus diarrhoea and temperature, humidity and river level, in Dhaka, Bangladesh, using time-series analysis adjusting for other confounding seasonal factors. There was strong evidence for an increase in rotavirus diarrhoea at high temperatures, by 40.2% for each 1 degrees C increase above a threshold (29 degrees C). Relative humidity had a linear inverse relationship with the number of cases of rotavirus diarrhoea. River level, above a threshold (4.8 m), was associated with an increase in cases of rotavirus diarrhoea, by 5.5% per 10-cm river-level rise. Our findings provide evidence that factors associated with high temperature, low humidity and high river-level increase the incidence of rotavirus diarrhoea in Dhaka

Dynamic Response of Foundations on Two-Parameter Media

A finite element algorithm is presented to analyze the dynamic response of rectangular foundations resting on an elastic medium. The foundation is modeled by rectangular thin plate elements and the supporting elastic medium is represented by the two parameter model proposed by Vlasov. The natural frequencies of the foundation-elastic medium are investigated. A parametric study is conducted to examine the effects of the edge and corner forces, that are accounted for in the two parameter model, on the dynamic response of a plate subjected to a moving vertical force

Modeling and optimization of liquefied natural gas process

Ph.DDOCTOR OF PHILOSOPH