2,807 research outputs found

    Work Engagement: Evolution of the Concept and a New Inventory

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    To provide a more integrated framework for the study of work engagement, the literature on this concept was reviewed in order to develop a clearer definition of this construct that (instead of being based on the separate construct of burnout) is based on the original theory of work engagement, which allowed a new, more precise measure of work engagement to be created. The new work engagement items were tested to assess their psychometrics. Their integrity was tested via exploratory and confirmatory factor analyses, which retained 18 items for a three-component model having satisfactory fit indexes with three 6-item subscales named Cognitive, Emotional, and Physical Work Engagement. The reliabilities and validities of the new scales were also empirically tested, with reliabilities ranging from .78 to .91; and correlation tests yielded statistical support for the convergent, divergent, and concurrent validities of the new measure. The scales were also tested for application to organizations, with Self-Efficacy as a positive predictor that explained 10% to 16% of the variance for all three work engagement measures. Also, the three work engagement scales were all negative predictors of, and, together, explained 12% of the variance for Turnover Intention. Moreover, work engagement and burnout were empirically shown to be independent constructs

    Identity of acyl group conformations in the active sites of papain and cathepsin B by resonance Raman spectroscopy.

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    Resonance Raman spectroscopic data provide conclusive evidence for the existence of an acyl-enzyme intermediate during the reaction of a thionoester substrate, N-methyloxycarbonylphenylalanylglycine methyl thionoester (CH3OC(=O)-Phe-NHCH2C(=S) OCH3), with cathepsin B from porcine spleen. The resonance Raman spectrum of CH3OC(=O)-Phe-NHCH2C(=S)S-cathepsin B, where the thiol S is from the active-site cysteine residue, is compared to that of the corresponding papain acyl-enzyme. Within the limits of experimental error (+/-2 cm-1 for peak positions), there are no detectable spectral differences. Since the resonance Raman spectrum is sensitive to the torsional angles in the glycinic bonds and the cysteine linkages, the conformations are identical in those parts of the acyl-enzymes where chemical transformation occurs. A conformational analysis of the model compound CH3OC(=O)-Phe-NHCH2C(=S)SC2H5 demonstrates that the dithioacyl group in both dithioacyl-enzymes is present as a single population of a form known as conformer B. Conformer B is characterized by a small torsional angle about the glycinic NHCH2-CS(thiol) bond such that the nitrogen and S (thiol) atoms are in close contact. This conformer is widespread among the dithioacyl intermediates of plant cysteine proteinases, and it is apparent that the same chemistry is retained in a mammalian cysteine proteinase. Steady-state kinetic parameters are also reported for CH3OC(=O)-Phe-NHCH2C(=S)OCH3 reacting with papain and cathepsin B. The similarity of the Kcat values, 0.53 and 1.15 s-1, for papain and cathepsin B, respectively, provides further evidence for a conserved deacylation process

    Assessing the Long-term Success of Reigate Stone Conservation at Hampton Court Palace and the Tower of London

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    Reigate stone was extensively used in medieval London and is prone to rapid decay. A variety of different conservation treatments has been applied in the past; in many cases, these have not mitigated on-going decay. This paper presents an overview of wax, limewash, silane and ammonium tartrate treatment at the Tower of London and Hampton Court Palace. Documentary analysis and visual inspection indicate that whilst these methods have provided protection to some stones, no single method has resulted in the protection of all stones. Non-destructive and minimally-destructive testing is used to more closely assess the effects of ammonium tartrate treatment. The results imply that inherent stone mineralogy, past decay pathways and/or present environmental factors are a greater influence on on-going decay than treatment histories

    Loss of mass and stability of galaxies in MOND

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    The self-binding energy and stability of a galaxy in MOND-based gravity are curiously decreasing functions of its center of mass acceleration towards neighbouring mass concentrations. A tentative indication of this breaking of the Strong Equivalence Principle in field galaxies is the RAVE-observed escape speed in the Milky Way. Another consequence is that satellites of field galaxies will move on nearly Keplerian orbits at large radii (100 - 500 kpc), with a declining speed below the asymptotically constant naive MOND prediction. But consequences of an environment-sensitive gravity are even more severe in clusters, where member galaxies accelerate fast: no more Dark-Halo-like potential is present to support galaxies, meaning that extended axisymmetric disks of gas and stars are likely unstable. These predicted reappearance of asymptotic Keplerian velocity curves and disappearance of "stereotypic galaxies" in clusters are falsifiable with targeted surveys.Comment: 4 pages, 2 figures, ApJ Letter

    Eliminating latent tuberculosis in low-burden settings: are the principal beneficiaries to be disadvantaged groups or the broader population?

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    Tuberculosis (TB) remains a leading cause of morbidity and mortality worldwide, and the burdens of this disease continue to track prior disadvantage. In order to galvanise a coordinated global response, WHO has recently launched the End TB Campaign that aims to eliminate TB by 2050. Key to this is the introduction of population screening programmes in low-burden settings to identify and treat people who have latent TB infection (LTBI). The defining features of LTBI are: that it is not an active disease but confers an increased risk of disease; the socially disadvantaged are those most in danger and uncertainty persists as to who will be harmed or benefitted from screening-led prophylactic interventions. Systematic screening programmes that include surveillance, case-finding and treatment of asymptomatic individuals inevitably redistribute the risk of harms and the potential for benefits within a population. The extent to which those targeted within such programmes should be exposed to higher levels of risk in the pursuit of individual or community benefits requires careful consideration prior to implementation. As currently construed, it remains unclear who stands to benefit most from how LTBI screening in high-income countries is being organised, and whose health is being prioritised: members of disadvantaged groups or the broader community. Unless the aims of LTBI screening programmes in these settings are made transparent and their prioritisation ethically justified, there is a significant danger that such a targeted intervention will further disadvantage those who have the least capacity to bear the burdens of TB elimination.NHMRC Centre for Research Excellence in TB Control (CRE 1043225)

    Requirements for Developing the Model of Spatial Orientation into an Applied Cockpit Warning System

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    Refinements have been made to a model of spatial disorientation (SD) to improve simulation of acceleration stimuli and visual-vestibular interactions. The improved model has been applied to aviation mishaps. The model is considered a technological countermeasure for SD because it is implemented as prototype software to aid the identification of mishap contributors in a way that should benefit didactic training. There is a more direct way this countermeasure can prevent SD, which is by adapting it for use as part of a cockpit warning system. The idea is to expand the model from one which explains mishaps post-hoc into one that warns pilots proactively whenever they are most likely to experience SD. This report introduces the general requirements that must be met to successfully expand the model for use as a proactive cockpit warning system, as well as the key criteria for determining whether it is effective

    Carbon bridged biphenolate ligands in rare earth chemistry

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    Rare earth biphenolate species have become an increasingly studied series of complexes, owing to the diversity they offer over mononuclear aryloxide complexes, as well as their efficacy as catalysts and initiators in a range of organic transformations and polymerisation reactions. Compared to monodentate aryloxide ligands, biphenolate ligand systems are still in their infancy in rare earth coordination chemistry. In their limited use, the ligand 2,2 '-methylenebis(6-tert-butyl-4-methylphenol) (mbmpH(2)) has been a popular candidate. This review aims to highlight the chemistry that has been explored thus far with these carbon bridged lanthanoid biphenolate systems

    An ecological approach to problems of Dark Energy, Dark Matter, MOND and Neutrinos

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    Modern astronomical data on galaxy and cosmological scales have revealed powerfully the existence of certain dark sectors of fundamental physics, i.e., existence of particles and fields outside the standard models and inaccessible by current experiments. Various approaches are taken to modify/extend the standard models. Generic theories introduce multiple de-coupled fields A, B, C, each responsible for the effects of DM (cold supersymmetric particles), DE (Dark Energy) effect, and MG (Modified Gravity) effect respectively. Some theories use adopt vanilla combinations like AB, BC, or CA, and assume A, B, C belong to decoupled sectors of physics. MOND-like MG and Cold DM are often taken as opposite frameworks, e.g. in the debate around the Bullet Cluster. Here we argue that these ad hoc divisions of sectors miss important clues from the data. The data actually suggest that the physics of all dark sectors is likely linked together by a self-interacting oscillating field, which governs a chameleon-like dark fluid, appearing as DM, DE and MG in different settings. It is timely to consider an interdisciplinary approach across all semantic boundaries of dark sectors, treating the dark stress as one identity, hence accounts for several "coincidences" naturally.Comment: 12p, Proceedings to the 6-th Int. Conf. of Gravitation and Cosmology. Neutrino section expande

    Lopsidedness of cluster galaxies in modified gravity

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    We point out an interesting theoretical prediction for elliptical galaxies residing inside galaxy clusters in the framework of modified Newtonian dynamics (MOND), that could be used to test this paradigm. Apart from the central brightest cluster galaxy, other galaxies close enough to the centre experience a strong gravitational influence from the other galaxies of the cluster. This influence manifests itself only as tides in standard Newtonian gravity, meaning that the systematic acceleration of the centre of mass of the galaxy has no consequence. However, in the context of MOND, a consequence of the breaking of the strong equivalence principle is that the systematic acceleration changes the own self-gravity of the galaxy. We show here that, in this framework, initially axisymmetric elliptical galaxies become lopsided along the external field's direction, and that the centroid of the galaxy, defined by the outer density contours, is shifted by a few hundreds parsecs with respect to the densest point.Comment: accepted for publication in JCA

    College Students’ Attitudes Toward Counseling for Mental Health Issues in Two Developing Asian Countries

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    This study examines 300 college students in Iran and China. It clarifies that students from China have more positive attitudes toward counseling than those from Iran using a quantitative survey with well-established existing scales in the literature. The regression tests show different indictors for college students’ attitudes toward mental health counseling in these two developing countries. Anticipated risk has been found as the most negative and powerful predictor of attitudes toward counseling in Iran. Stigma has been found as the most negative and powerful predictor of attitudes toward counseling in China. Implications have been discussed for educational departments and governments to advocate positive evaluations on mental health counseling services
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