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Full-Text Articles in Biology
Oxidative Stress Detection With Escherichia Coli Harboring A Katg'::Lux Fusion, S. Belkin, D. R. Smulski, Amy Cheng Vollmer, T. K. Van Dyk, R. A. Larossa
Oxidative Stress Detection With Escherichia Coli Harboring A Katg'::Lux Fusion, S. Belkin, D. R. Smulski, Amy Cheng Vollmer, T. K. Van Dyk, R. A. Larossa
Biology Faculty Works
A plasmid containing a transcriptional fusion of the Escherichia coli katG promoter to a truncated Vibrio fischeri lux operon (luxCDABE) was constructed. An E. coli strain bearing this plasmid (strain DPD2511) exhibited low basal levels of luminescence, which increased up to 1,000-fold in the presence of hydrogen peroxide, organic peroxides, redox-cycling agents (methyl viologen and menadione), a hydrogen peroxide-producing enzyme system (xanthine and xanthine oxidase), and cigarette smoke. An oxyR deletion abolished hydrogen peroxide-dependent induction, confirming that oxyR controlled katG'::lux luminescence. Light emission was also induced by ethanol by an unexplained mechanism. A marked synergistic response was observed when cells …
Neotropical Bird Migration During The Ice Ages: Orientation And Ecology, Timothy C. Williams , '64, T. Webb Iii
Neotropical Bird Migration During The Ice Ages: Orientation And Ecology, Timothy C. Williams , '64, T. Webb Iii
Biology Faculty Works
Reconstruction of breeding habitat of North American Neotropical migrants 18,000 years ago and 9,000 years ago indicated major shifts in both location and composition of plant communities relative to present conditions. Increased vegetation in xeric areas may have compensated, at least in part, for the reduction in breeding habitat due to glaciation. Autumnal flights of Neotropical passerine migrants flying on constant headings from North America to Central and South America were simulated under present wind conditions and for winds during periods of glaciation at 18,000 and 9,000 years ago. The 155 degrees average headings currently observed for Atlantic migrants were …