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Various Efforts (various + effort)
Selected AbstractsBacteria as computers making computersFEMS MICROBIOLOGY REVIEWS, Issue 1 2009Antoine Danchin Abstract Various efforts to integrate biological knowledge into networks of interactions have produced a lively microbial systems biology. Putting molecular biology and computer sciences in perspective, we review another trend in systems biology, in which recursivity and information replace the usual concepts of differential equations, feedback and feedforward loops and the like. Noting that the processes of gene expression separate the genome from the cell machinery, we analyse the role of the separation between machine and program in computers. However, computers do not make computers. For cells to make cells requires a specific organization of the genetic program, which we investigate using available knowledge. Microbial genomes are organized into a paleome (the name emphasizes the role of the corresponding functions from the time of the origin of life), comprising a constructor and a replicator, and a cenome (emphasizing community-relevant genes), made up of genes that permit life in a particular context. The cell duplication process supposes rejuvenation of the machine and replication of the program. The paleome also possesses genes that enable information to accumulate in a ratchet-like process down the generations. The systems biology must include the dynamics of information creation in its future developments. [source] Zymomonas mobilis: an alternative ethanol producerJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 4 2006Parmjit S Panesar Abstract Zymomonas mobilis is a unique bacterium in the microbial world, and offers a number of advantages over the existing ethanol-producing microorganisms. Being a prokaryote, it is more amenable to genetic manipulations. Thus, it has attracted great attention in the ethanol production world and efforts have been made to commercialize its application for the purpose. Despite the various efforts made worldwide, none of the processes using this microbe has been commercialized owing to certain bottlenecks. To circumvent the hindrances currently associated with a Zymomonas process, researchers have made various attempts to improve the technology using different techniques. This paper reviews the different substrates and the genetic improvement techniques with special emphasis on mutagenesis and recombinant DNA technology used for ethanol production by Zymomonas strains. Copyright © 2006 Society of Chemical Industry [source] An Economic Analysis of Auto Compensation Systems: Choice Experiences From New Jersey and PennsylvaniaJOURNAL OF RISK AND INSURANCE, Issue 4 2003Joan T. Schmit Nearly since the first automobile traveled on U.S. soil, questions about how best to compensate people injured by their use have been raised. As early as in 1932, in fact, the tort system of imposing costs on negligent drivers was strongly criticized, and a system of compensation without regard to negligence recommended. Yet despite various efforts to identify and implement improved systems during the past more than 70 years, no clear best compensation mechanism has been found. Current discussions have focused on the "choice" system, under which insureds are allowed to select either a tort system or a no-fault system of compensation at the time of insurance purchase. New Jersey and Pennsylvania, which implemented very similar choice programs in 1989 and 1990, respectively, offer an opportunity to observe the effects of choice on outcomes such as: use of attorneys, speed of payment, and consistency (equity) of payment. Our results indicate outcomes consistent with expectations in New Jersey (NJ), which switched from no-fault to choice, but inconsistent with expectations in Pennsylvania (PA), which switched from tort to choice. Furthermore, analysis of tort versus no-fault selectors postchoice in New Jersey and Pennsylvania does not offer clear evidence of no-fault's lower administrative costs and speedier, more equitable payment in these jurisdictions. [source] EXIT GHOST: DOUGLAS HUEBLER'S FACE VALUEART HISTORY, Issue 5 2009GORDON HUGHES Beginning with his early systems-based works, Douglas Huebler's photo-conceptualism takes direct aim at various efforts to heighten or exaggerate the expressive content of photography. This essay examines a heretofore unnoticed but crucial strategy in this practice of negation: Huebler's use of images broadly associated with surrealism's efforts to tap into ,the Marvellous', mannequins, identical twins, extreme coincidence, and ghosts. Far from reinforcing the uncanny effects of such images and tropes, Huebler, I claim, is on the contrary concerned to flatten and drain all traces of subjective resonance from these once expressive forms. Examining a range of works in which Huebler effectively transforms the Marvellous into the risible, I argue that one reason for this transformation is that the historical conditions by which photography could be charged with uncanny affect are no longer in place. As a result, we are now able to recognize only signs and images of the Marvellous/uncanny in photography, but our emotive response, like Huebler's photographs, is essentially empty. The essay concludes with Roland Barthes' mournful description of the loss of the photographic uncanny, or what he calls the ,madness' of photography, as it occurs in the final pages of Camera Lucida. [source] Copolymerization of Cyclohexene Oxide with CO2 by Using Intramolecular Dinuclear Zinc CatalystsCHEMISTRY - A EUROPEAN JOURNAL, Issue 12 2005Youli Xiao Abstract The intramolecular dinuclear zinc complexes generated in situ from the reaction of multidentate semi-azacrown ether ligands with Et2Zn, followed by treatment with an alcohol additive, were found to promote the copolymerization of CO2 and cyclohexene oxide (CHO) with completely alternating polycarbonate selectivity and high efficiency. With this type of novel initiator, the copolymerization could be accomplished under mild conditions at 1 atm pressure of CO2, which represents a significant advantage over most catalytic systems developed for this reaction so far. The copolymerization reaction was demonstrated to be a living process as a result of the narrow polydispersities and the linear increase in the molecular weight with conversion of CHO. In addition, the solid-state structure of the dinuclear zinc complex was characterized by X-ray crystal structural analysis and can be considered as a model of the active catalyst. On the basis of the various efforts made to understand the mechanisms of the catalytic reaction, including MALDI-TOF mass analysis of the copolymers' end-groups, the effect of alcohol additives on the catalysis and CO2 pressure on the conversion of CHO, as well as the kinetic data gained from in situ IR spectroscopy, a plausible catalytic cycle for the present reaction system is outlined. The copolymerization is initiated by the insertion of CO2 into the ZnOEt bond to afford a carbonate,ester-bridged complex. The dinuclear zinc structure of the catalyst remains intact throughout the copolymerization. The bridged zinc centers may have a synergistic effect on the copolymerization reaction; one zinc center could activate the epoxide through its coordination and the second zinc atom may be responsible for carbonate propagation by nucleophilic attack by the carbonate ester on the back side of the cis -epoxide ring to afford the carbonate. The mechanistic implication of this is particularly important for future research into the design of efficient and practical catalysts for the copolymerization of epoxides with CO2. [source] | ||||||||||