944 resultados para Coenzyme Q
Resumo:
Human CGI-58 (for comparative gene identification-58) and YLR099c, encoding Ict1p in Saccharomyces cerevisiae, have recently been identified as acyl-CoA-dependent lysophosphatidic acid acyltransferases. Sequence database searches for CGI-58 like proteins in Arabidopsis (Arabidopsis thaliana) revealed 24 proteins with At4g24160, a member of the alpha/beta-hydrolase family of proteins being the closest homolog. At4g24160 contains three motifs that are conserved across the plant species: a GXSXG lipase motif, a HX4D acyltransferase motif, and V(X)(3)HGF, a probable lipid binding motif. Dendrogram analysis of yeast ICT1, CGI-58, and At4g24160 placed these three polypeptides in the same group. Here, we describe and characterize At4g24160 as, to our knowledge, the first soluble lysophosphatidic acid acyltransferase in plants. A lipidomics approach revealed that At4g24160 has additional triacylglycerol lipase and phosphatidylcholine hydrolyzing enzymatic activities. These data establish At4g24160, a protein with a previously unknown function, as an enzyme that might play a pivotal role in maintaining the lipid homeostasis in plants by regulating both phospholipid and neutral lipid levels.
Resumo:
Accompanying the decrease in serum cholesterol and increase in concentration of ubiquinone in liver and its microsomes, the activity, but not the protein, of HMG-CoA reductase decreased in ubiquinone-supplemented rats. A soluble 58-kDa preparation of HMG-CoA reductase was partially inhibited on addition of ubiquinone indicating a possible feedback type of action.
Resumo:
An overview of the Centre for Accident Research and Road Safety - Queensland and its main areas of research. Background to CARRS-Q Established in 1996 as joint initiative of: - Queensland University of Technology - Queensland Motor Accident Insurance Commission - Based in the Faculty of Health - Our Vision is for: A safer world in which injury-related harm is uncommon and unacceptable
Resumo:
We propose two algorithms for Q-learning that use the two-timescale stochastic approximation methodology. The first of these updates Q-values of all feasible state–action pairs at each instant while the second updates Q-values of states with actions chosen according to the ‘current’ randomized policy updates. A proof of convergence of the algorithms is shown. Finally, numerical experiments using the proposed algorithms on an application of routing in communication networks are presented on a few different settings.
Resumo:
Domestic violence is currently undergoing a period of heightened visibility in Australia. This article uses social media to analyze public discussions about this violence with respect to a specific theoretical frame, which Adrian Howe has called the “Man” question: where and how are men visible or invisible in narratives about their violence against women? The article presents a qualitative study of the Twitter conversation surrounding a special episode of the Australian Broadcasting Corporation's television program Q&A, themed around family violence, which aired in February 2015. We found that the place of men in this conversation was contested. Some tweets privileged men's voices and concerns, as did the organization and production of the program. However, feminist voices were also highly visible via presenting facts, legitimating survivor voices, and recuperating anti-feminist memes to challenge hegemonic patriarchal discourses on men's violence against women. La violence conjugale connait actuellement une visibilité accrue en Australie. Les auteures du présent article utilisent les réseaux sociaux pour analyser les débats publics sur cette violence selon un cadre théorique précis, qu'Adrian Howe a appelé la question de « l'homme » : où et comment les hommes sont-ils visibles ou invisibles dans les récits de leur violence envers les femmes? L'article présente une étude qualitative d'une conversation sur Twitter au sujet d'un épisode axé sur la famille diffusé en février 2015 dans le cadre de l'émission Q & A, à la télévision nationale d'Australie. Nous avons remarqué que dans cette conversation la place des hommes était remise en question. Certains tweets privilégiaient les voix et les craintes des hommes, comme l'ont fait les organisateurs et les producteurs de l'émission. Cependant, il y avait une forte présence de voix féministes dans la présentation des faits, légitimant le point de vue des survivantes et relevant des éléments culturels antiféministes afin de défier les discours hégémoniques et patriarcaux sur la violence des hommes envers les femmes.
Resumo:
Coenzyme A is an indispensable cofactor for all organisms and holds a central position in a number of pathways. Prokaryotic enzymes involved in the synthesis of CoA are quite different from their mammalian counterparts; hence, they are good targets for the development of antimicrobials to treat many diseases. There are antimicrobials that act by inhibiting CoA biosynthesis. It has been suggested that pantothenol exhibits antibacterial activity by competitively inhibiting pantothenate kinase, a key regulatory enzyme for CoA synthesis. Contrary to these suggestions, in this paper, we demonstrate that pantothenol acts as a substrate for Mycobacterium tuberculosis and Escherichia coli pantothenate kinases. The product, 4'-phosphopantothenol, thus formed inhibits competitively the utilization of 4'-phosphopantothenate by CoaBC. Thus, it is the failure of CoaBC to utilize 4'-phosphopantothenol as a substrate that accounts for the bactericidal activity of pantothenol. (C) 2007 Elsevier Inc. All rights reserved.
Resumo:
Considering the method of broad-band coupling a series resonant RLC load to a resistive source using a uniform quarter-wave transmission-line inverter, it is shown that the 3-dB bandwidth of the network insertion loss reckoned with respect to a 0-dB loss attains a maximum for a particular value of the center frequency insertion loss in the range 0-3 dB. The center frequency Ioss and the corresponding value of the maximum 3-dB bandwidth are calculated for various loads and the results graphically presented.
Resumo:
A report of the design, development ana periom~ance characteristics of a Q-band (8 nim) confoal. mned, aielectric lens beam waveguide is presented.
Resumo:
Consideration is given to a 25-foot long Q-band (8 mm) confocal, zoned dielectric lens beam waveguide. Numerical expressions for the axial and radial fields are presented. The experimental set-up consisted of uniformly spaced zoned dielectric lenses, a transmitting horn and a receiving horn. It was found that: (1) the wave beam is reiterated when confocal, zoned dielectric lenses act as phase transformers in place of smooth surfaced transformers in beam waveguides; (2) the axial field is oscillatory near the source and the oscillation persists for about 25 cm from the source; (3) the oscillation disappears after one lens is used; (4) higher order modes with higher attenuation rates die out faster than fundamental modes; (5) phase transformers do not alter beam modes; (6) without any lens the beam cross-section broadens significantly in the Z-direction; (7) with one lens the beam exhibits the reiteration phenomenon; and (8) inserting a second lens on the axial and cross-sectional field distribution shows further the reiteration principle.
Resumo:
The problem of quantification of intelligence of humans, and of intelligent systems, has been a challenging and controversial topic. IQ tests have been traditionally used to quantify human intelligence based on results of test designed by psychologists. It is in general very difficult to quantify intelligence. In this paper the authors consider a simple question-answering (Q-A) system and use this to quantify intelligence. The authors quantify intelligence as a vector with three components. The components consist of a measure of knowledge in asking questions, effectiveness of questions asked, and correctness of deduction. The authors formalize these parameters and have conducted experiments on humans to measure these parameters