939 resultados para Active joint count of zero
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The active site of the allosteric chorismate mutase (chorismate pyruvatemutase, EC 5.4.99.5) from yeast Saccharomyces cerevisiae (YCM) was located by comparison with the mutase domain (ECM) of chorismate mutase/prephenate dehydratase [prephenate hydro-lyase (decarboxylating), EC 4.2.1.51] (the P protein) from Escherichia coli. Active site domains of these two enzymes show very similar four-helix bundles, each of 94 residues which superimpose with a rms deviation of 1.06 A. Of the seven active site residues, four are conserved: the two arginines, which bind to the inhibitor's two carboxylates; the lysine, which binds to the ether oxygen; and the glutamate, which binds to the inhibitor's hydroxyl group in ECM and presumably in YCM. The other three residues in YCM (ECM) are Thr-242 (Ser-84), Asn-194 (Asp-48), and Glu-246 (Gln-88). This Glu-246, modeled close to the ether oxygen of chorismate in YCM, may function as a polarizing or ionizable group, which provides another facet to the catalytic mechanism.
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MyoD, a member of the family of helix-loop-helix myogenic factors that plays a crucial role in skeletal muscle differentiation, is a nuclear phosphoprotein. Using microinjection of purified MyoD protein into rat fibroblasts, we show that the nuclear import of MyoD is a rapid and active process, being ATP and temperature dependent. Two nuclear localization signals (NLSs), one present in the basic region and the other in the helix 1 domain of MyoD protein, are demonstrated to be functional in promoting the active nuclear transport of MyoD. Synthetic peptides spanning these two NLSs and biochemically coupled to IgGs can promote the nuclear import of microinjected IgG conjugates in muscle and nonmuscle cells. Deletion analysis reveals that each sequence can function independently within the MyoD protein since concomittant deletion of both sequences is required to alter the nuclear import of this myogenic factor. In addition, the complete cytoplasmic retention of a beta-galactosidase-MyoD fusion mutant protein, double deleted at these two NLSs, argues against the existence of another functional NLS motif in MyoD.
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Mode of access: Internet.
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Mode of access: Internet.
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"Effective March 15, 1921."
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Thesis (Ph.D.)--University of Washington, 2016-06
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This paper presents an analysis of the thermomechanical behavior of hollow circular cylinders of functionally graded material (FGM). The solutions are obtained by a novel limiting process that employs the solutions of homogeneous hollow circular cylinders, with no recourse to the basic theory or the equations of non-homogeneous thermoclasticity. Several numerical cases are studied, and conclusions are drawn regarding the general properties of thermal stresses in the FGM cylinder. We conclude that thermal stresses necessarily occur in the FGM cylinder, except in the trivial case of zero temperature. While heat resistance may be improved by sagaciously designing the material composition, careful attention must be paid to the fact that thermal stresses in the FGM cylinder are governed by more factors than are its homogeneous counterparts. The results that are presented here will serve as benchmarks for future related work. (C) 2003 Elsevier Science Ltd. All rights reserved.
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A bacterium (MJ-PV) previously demonstrated to degrade the cyanobacterial toxin microcystin LR, was investigated for bioremediation applications in natural water microcosms and biologically active slow sand filters. Enhanced degradation of microcystin LR was observed with inoculated (1 x 10(6) cell/mL) treatments of river water dosed with microcystin LR (> 80% degradation within 2 days) compared to uninoculated controls. Inoculation of MJ-PV at lower concentrations (1 x 10(2)-1 x 10(5)cells/mL) also demonstrated enhanced microcystin LR degradation over control treatments. Polymerase chain reactions (PCR) specifically targeting amplification of 16S rDNA of MJ-PV and the gene responsible for initial degradation of microcystin LR (mlrA) were successfully applied to monitor the presence of the bacterium in experimental trials. No amplified products indicative of an endemic MJ-PV population were observed in uninoculated treatments indicating other bacterial strains were active in degradation of microcystin LR, Pilot scale biologically active slow sand filters demonstrated degradation of microcystin LR irrespective of MJ-PV bacterial inoculation. PCR analysis detected the MJ-PV population at all locations within the sand filters where microcystin degradation was measured. Despite not observing enhanced degradation of microcystin LR in inoculated columns compared to uninoculated column, these studies demonstrate the effectiveness of a low-technology water treatment system like biologically active slow sand filters for removal of microcystins from reticulated water supplies. Crown Copyright (c) 2006 Published by Elsevier Ltd. All rights reserved.
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We have successfully linked protein library screening directly with the identification of active proteins, without the need for individual purification, display technologies or physical linkage between the protein and its encoding sequence. By using 'MAX' randomization we have rapidly constructed 60 overlapping gene libraries that encode zinc finger proteins, randomized variously at the three principal DNA-contacting residues. Expression and screening of the libraries against five possible target DNA sequences generated data points covering a potential 40,000 individual interactions. Comparative analysis of the resulting data enabled direct identification of active proteins. Accuracy of this library analysis methodology was confirmed by both in vitro and in vivo analyses of identified proteins to yield novel zinc finger proteins that bind to their target sequences with high affinity, as indicated by low nanomolar apparent dissociation constants.
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The environment may act as a reservoir for pathogens that cause healthcare-associated infections (HCAIs). Approaches to reducing environmental microbial contamination in addition to cleaning are thus worthy of consideration. Copper is well recognised as having antimicrobial activity but this property has not been applied to the clinical setting. We explored its use in a novel cross-over study on an acute medical ward. A toilet seat, set of tap handles and a ward entrance door push plate each containing copper were sampled for the presence of micro-organisms and compared to equivalent standard, non-copper-containing items on the same ward. Items were sampled once weekly for 10 weeks at 07:00 and 17:00. After five weeks, the copper-containing and non-copper-containing items were interchanged. The total aerobic microbial counts per cm2 including the presence of ‘indicator micro-organisms’ were determined. Median numbers of microorganisms harboured by the copper-containing items were between 90% and 100% lower than their control equivalents at both 07:00 and 17:00. This reached statistical significance for each item with one exception. Based on the median total aerobic cfu counts from the study period, five out of ten control sample points and zero out of ten copper points failed proposed benchmark values of a total aerobic count of <5 cfu/cm2. All indicator micro-organisms were only isolated from control items with the exception of one item during one week. The use of copper-containing materials for surfaces in the hospital environment may therefore be a valuable adjunct for the prevention of HCAIs and requires further evaluation.
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Two ways to increase efficiency of components based on Talbot effect are considered: optimization of waveguide wall impedance and corrections of waveguide cross-section. It is shown that for many cases undesired scattering losses can be made several times less than that for usual cases of infinite of zero impedance and rectangular waveguide cross-section.
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In this paper we present algorithms which work on pairs of 0,1- matrices which multiply again a matrix of zero and one entries. When applied over a pair, the algorithms change the number of non-zero entries present in the matrices, meanwhile their product remains unchanged. We establish the conditions under which the number of 1s decreases. We recursively define as well pairs of matrices which product is a specific matrix and such that by applying on them these algorithms, we minimize the total number of non-zero entries present in both matrices. These matrices may be interpreted as solutions for a well known information retrieval problem, and in this case the number of 1 entries represent the complexity of the retrieve and information update operations.
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Structural monitoring and dynamic identification of the manmade and natural hazard objects is under consideration. Math model of testing object by set of weak stationary dynamic actions is offered. The response of structures to the set of signals is under processing for getting important information about object condition in high frequency band. Making decision procedure into active monitoring system is discussed as well. As an example the monitoring outcome of pillar-type monument is given.
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In ensuring the quality of learning and teaching in Higher Education, self-evaluation is an important component of the process. An example would be the approach taken within the CDIO community whereby self-evaluation against the CDIO standards is part of the quality assurance process. Eight European universities (Reykjavik University, Iceland; Turku University of Applied Sciences, Finland; Aarhus University, Denmark; Helsinki Metropolia University of Applied Sciences, Finland; Ume? University, Sweden; Telecom Bretagne, France; Aston University, United Kingdom; Queens University Belfast, United Kingdom) are engaged in an EU funded Erasmus + project that is exploring the quality assurance process associated with active learning. The development of a new self-evaluation framework that feeds into a ?Marketplace? where participating institutions can be paired up and then engage in peer evaluations and sharing around each institutions approach to and implementation of active learning. All of the partner institutions are engaged in the application of CDIO within their engineering programmes and this has provided a common starting point for the partnership to form and the project to be developed. Although the initial focus will be CDIO, the longer term aim is that the approach could be of value beyond CDIO and within other disciplines. The focus of this paper is the process by which the self-evaluation framework is being developed and the form of the draft framework. In today?s Higher Education environment, the need to comply with Quality Assurance standards is an ever present feature of programme development and review. When engaging in a project that spans several countries, the wealth of applicable standards and guidelines is significant. In working towards the development of a robust Self Evaluation Framework for this project, the project team decided to take a wide view of the available resources to ensure a full consideration of different requirements and practices. The approach to developing the framework considered: a) institutional standards and processes b) national standards and processes e.g. QAA in the UK c) documents relating to regional / global accreditation schemes e.g. ABET d) requirements / guidelines relating to particular learning and teaching frameworks e.g. CDIO. The resulting draft self-evaluation framework is to be implemented within the project team to start with to support the initial ?Marketplace? pairing process. Following this initial work, changes will be considered before a final version is made available as part of the project outputs. Particular consideration has been paid to the extent of the framework, as a key objective of the project is to ensure that the approach to quality assurance has impact but is not overly demanding in terms of time or paperwork. In other words that it is focused on action and value added to staff, students and the programmes being considered.
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INTRODUCTION Zero-G parabolic flight reproduces the weightlessness of space for short periods of time. However motion sickness may affect some fliers. The aim was to assess the extent of this problem and to find possible predictors and modifying factors. METHODS Airbus Zero-G flights consist of 31 parabolas performed in blocks. Each parabola consisted of 20s 0g sandwiched by 20s hypergravity of 1.5-1.8g. The survey covered n=246 person-flights (193 Males 53 Females), aged (M+/-SD) 36.0+/-11.3 years. An anonymous questionnaire included motion sickness rating (1=OK to 6=Vomiting), Motion Sickness Susceptibility Questionnaire (MSSQ), anti-motion sickness medication, prior Zero-G experience, anxiety level, and other characteristics. RESULTS Participants had lower MSSQ percentile scores 27.4+/-28.0 than the population norm of 50. Motion sickness was experienced by 33% and 12% vomited. Less motion sickness was predicted by older age, greater prior Zero-G flight experience, medication with scopolamine, lower MSSQ scores, but not gender nor anxiety. Sickness ratings in fliers pre-treated with scopolamine (1.81+/-1.58) were lower than for non-medicated fliers (2.93+/-2.16), and incidence of vomiting in fliers using scopolamine treatment was reduced by half to a third. Possible confounding factors including age, sex, flight experience, MSSQ, could not account for this. CONCLUSION Motion sickness affected one third of Zero-G fliers, despite being intrinsically less motion sickness susceptible compared to the general population. Susceptible individuals probably try to avoid such a provocative environment. Risk factors for motion sickness included younger age and higher MSSQ scores. Protective factors included prior Zero-G flight experience (habituation) and anti-motion sickness medication.