Fatty Acid Composition of Escherichia coli as a Possible Controlling Factor of the Minimal Growth Temperature.

Shaw, Maxwell K. (University of California, Davis), and John L. Ingraham. Fatty acid composition of Escherichia coli as a possible controlling factor of the minimal growth temperature. J. Bacteriol. 90:141-146. 1965.-If Escherichia coli ML30 is shifted from 37 to 10 C during exponential growth in glucose minimal medium, a 4.5-hr lag results. During this lag, the proportion of unsaturated fatty acids increases in the cellular lipids. However, the adjustment of the fatty acid composition does not appear to be prerequisite to growth at 10 C. If shifts are made to 10 C into minimal medium containing glucose after starvation for glucose at 37 C for 0.5 and 16 hr, the lag periods at 10 C are 4.5 and 6 hr, respectively. Withholding glucose during the lag periods does not affect the duration of the lag periods, but no change in fatty acid composition occurs if glucose is not present. Supplementing the medium with glucose after the lag period permits immediate growth at 10 C; however, the fatty acid composition is still typical of cells grown at 37 C. It is concluded that the fatty acid composition of cells does not determine the minimal temperature of growth.     

A pattern-directed approach to flexible manufacturing: A framework for intelligent scheduling,learning, and control

The planning, scheduling, and control of manufacturing systems can all be viewed as problem-solving activities. In flexible manufacturing systems (FMSs), the computer program carrying out these problem-solving activities must additionally be able to handle the shorter lead time, the flexibility of job routing, the multiprocessing environment, the dynamic changing states, and the versatility of machines. This article presents an artificial intelligence (AI) method to perform manufacturing problem solving. Since the method is driven by manufacturing scenarios represented by symbolic patterns, it is referred to as pattern-directed. The method is based on three AI techniques. The first is the pattern-directed inference technique to capture the dynamic nature of FMSs. The second is the nonlinear planning technique to construct schedules and assign resources. The third is the inductive learning method to generate the pattern-directed heuristics. This article focuses on solving the FMS scheduling problem. In addition, this article reports the computation results to evaluate the utility of various heuristic functions, to identify important design parameters, and to analyze the resulting computational performance in using the pattern-directed approach for manufacturing problem-solving tasks such as scheduling.     

A new DNA marker (D4S90) is located terminally on the short arm of chromosome 4, close to the Huntington disease gene

Genetic linkage studies have mapped Huntington's disease (HD) to the distal portion of the short arm of chromosome 4 (4p16.3), 4 cM distal to D4S10 (G8). To date, no definite flanking marker has been identified. A new DNA marker, D4S90 (D5), which maps to the distal region of 4p16.3, is described. The marker was used in a genetic linkage study in the CEPH reference families with seven other markers at 4p16. The study, together with knowledge of the physical map of the region, places D4S90 as the most distal marker, 6 cM from D4S10. A provisional linkage study with HD gave a maximum lod score of 2.14 at a θ of 0.00 and no evidence of linkage disequilibrium. As D4S90 appears to be located terminally, it should play an important role in the accurate mapping and cloning of the HD gene.     

Lipid peroxidation, iron mobilization and radical generation induced by alcohol

Increasing evidence points to a major role for free radicals in the pathogenesis of alcohol-induced liver injury. In vitro, free radicals may be generated during ethanol metabolism by the further metabolism of acetaldehyde by molybdenum-dependent oxidases such as xanthine oxidase. Ferritin iron mobilized by such free radicals may serve as catalytic iron. Increased stores of ferritin iron and induction of microsomal P-450 reductase activity are mechanisms by which chronic alcohol feeding may potentiate the acute effects of alcohol.