Enterotoxigenic \(Escherichia\) \(coli\) (ETEC) is a major cause of traveller’s and infantile diarrhoea in developing countries, and results in considerable mortality in under 5 year olds. Disease is mediated through adhesion of ETEC cells to the intestinal brush border and the secretion of the heat-stable and/or heat-labile toxin. Whilst the toxins have been well studied it is still not clear how their expression is regulated.
This work has defined binding of CRP, H-NS and σ\(^7\)\(^0\) across the genome of the prototypical ETEC strain H10407. We demonstrate a central role for all three factors in regulating pathogenicity in ETEC H10407. Hence, we show that CRP directly regulates expression of both \(estA2\) and \(estA1\), which encode the heat-stable toxins. Furthermore, CRP indirectly represses expression of the heat-labile toxin. This work also identifies a role for CRP in controlling transcription of a small open reading frame, imbedded within a gene, at the 3’ end of an operon encoding a type I secretion system.
Erik Westman and Chris Haycocks, Department of Mining and Minerals Engineering, initiated a study of Virginia coal reserves in 1996. The goal of this project is to develop an estimate of Virginia's mineable coal reserves that is responsive to market price. They addressed this goal by assembling public information about coal seam thicknesses at various locations, coal quality, areas where mining has been completed, and impediments to mining such as surface features.
Results have been summarized as follows:
Coal mining and timber are the two primary industries supporting the people of Southwest Virginia. Coal mining has occurred for more than 100 years, but production has dropped since reaching a peak in 1990. In order to properly plan with remaining coal production a study was conducted to characterize and estimate coal resources. Seam thickness was found to be the parameter which most influenced resource levels. An economic model was developed to determine which portion of the reserves could economically be extracted. It was found that 3.95 billion tons, or 14% of the remaining resource, is economic under current mining conditions. More than 60% of these reserves, however, are in deep seams which require shafts to be constructed prior to initiation of mining.
Westman, E.C., C. Haycocks, and C.E. Zipper. 2000. Estimation of Southwest Virginia Coal Reserves. Virginia Cooperative Extension Publication 460-139. 8 pages.
Westman, E.C. 1999. Virginia Coal Reserves. <http://www.energy.vt.edu/reserves/ >
Westman, Erik. 1999. A Characterization and Determination of the Coal Reserves and Resources of Southwest Virginia. Ph.D. Dissertation. Department of Mining and Minerals Engineering.
Westman, Erik., C. Haycocks and M. Karmis. 1998. Resources vs. mineable reserves: The future of central Appalachian coal mining. American Society for Mining Engineers Annual Meeting. Orlando, Florida.
Westman, Erik., C. Haycocks and M. Karmis. 1998. Resources vs. mineable reserves: The future of central Appalachian coal. Mining Engineering. P. 33-37. December, 1998.
Westman, Erik, J. Luo, C. Haycocks, and M. Karmis. 1997. Ground control criteria for coal reserve optimization in multipleseam mines. In: Pyng, S. (ed.). Proceedings of the 16th International Conference on Ground Control in Mining. Aug 5-7, 1997. Morgantown. WV.
Crabtree, Walter. 1995. Forecast of Virginia Coal Production. M.S. Thesis Mining and Minerals Engineering.