Jeff Williams

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Thirty-three enteric isolates from Australian (Escherichia coli only) and United Kingdom (U.K.) (Salmonella sp., Citrobacter spp., and E. coli) piggeries were characterized with respect to their copper resistance. The copper resistance phenotypes of four new Australian E. coli isolates were comparable with that of the previously studied E. coli K-12 strain(More)
Standard methods for risk assessments resulting from human exposures to mixed radiation fields in Space consisting of different particle types and energies rely upon quality factors. These are generally defined as a function of linear energy transfer (LET) and are assumed to be proportional to the risk. In this approach, it is further assumed that the risks(More)
Difluoromethylornithine (DFMO) depletes cells of polyamines, sensitizing cells against the action of antineoplastic drugs and altering ability to repair radiation-induced DNA strand breaks. Others have hypothesized that the mechanism by which polyamine depletion sensitizes cells is through inhibition of DNA strand break repair or through altering the(More)
We compare models of radiation transport and biological response to physical and biological dosimetry results from astronauts on the Mir space station. Transport models are shown to be in good agreement with physical measurements and indicate that the ratio of equivalent dose from the Galactic Cosmic Rays (GCR) to protons is about 3/2:1 and that this ratio(More)
OBJECTIVES To investigate the ability of consultant rheumatologists and orthopaedic surgeons to communicate well with patients and to determine the validity of a structured proforma used to assess medical students' communication skills. METHODS Seventy new patient appointments with consultant rheumatologists and orthopaedic surgeons were assessed for(More)
We investigate the stability of a three spin state mixture of ultracold fermionic 6Li atoms over a range of magnetic fields encompassing three Feshbach resonances. For most field values, we attribute decay of the atomic population to three-body processes involving one atom from each spin state and find that the three-body loss coefficient varies by over 4(More)
The cell cycle dependence of sister chromatid exchange (SCE) induced by topoisomerase II inhibitors was studied in Chinese hamster V79 cells. 4'-(9-Acridinylamino)methansulfon-m-anisidide, which increases the concentration of covalently linked DNA-topoisomerase II complexes (cleavable complexes), induces SCE strongly in only a short period of the cell(More)
BACKGROUND Photodynamic therapy employs photosensitive agents such as porphyrins to treat a variety of tumors accessible to light-emitting probes. This approach capitalizes on the selective retention of porphyrins by cancer cells. Cancer cells also have elevated levels of mitochondrial benzodiazepine receptors which bind porphyrins with high affinity. (More)
Small cell lung cancer (SCLC) accounts for 25% of all lung cancers, and is almost uniformly fatal. Unlike other lung cancers, ras mutations have not been reported in SCLC, suggesting that activation of ras-associated signal transduction pathways such as the raf-MEK mitogen-activated protein kinases (MAPK) are associated with biological consequences that are(More)