896 research outputs found

    Chitin Binding Proteins Act Synergistically with Chitinases in Serratia proteamaculans 568

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    Genome sequence of Serratia proteamaculans 568 revealed the presence of three family 33 chitin binding proteins (CBPs). The three Sp CBPs (Sp CBP21, Sp CBP28 and Sp CBP50) were heterologously expressed and purified. Sp CBP21 and Sp CBP50 showed binding preference to β-chitin, while Sp CBP28 did not bind to chitin and cellulose substrates. Both Sp CBP21 and Sp CBP50 were synergistic with four chitinases from S. proteamaculans 568 (Sp ChiA, Sp ChiB, Sp ChiC and Sp ChiD) in degradation of α- and β-chitin, especially in the presence of external electron donor (reduced glutathione). Sp ChiD benefited most from Sp CBP21 or Sp CBP50 on α-chitin, while Sp ChiB and Sp ChiD had major advantage with these Sp CBPs on β-chitin. Dose responsive studies indicated that both the Sp CBPs exhibit synergism ≥0.2 µM. The addition of both Sp CBP21 and Sp CBP50 in different ratios to a synergistic mixture did not significantly increase the activity. Highly conserved polar residues, important in binding and activity of CBP21 from S. marcescens (Sm CBP21), were present in Sp CBP21 and Sp CBP50, while Sp CBP28 had only one such polar residue. The inability of Sp CBP28 to bind to the test substrates could be attributed to the absence of important polar residues

    Learning and climate change

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    Learning – i.e. the acquisition of new information that leads to changes in our assessment of uncertainty – plays a prominent role in the international climate policy debate. For example, the view that we should postpone actions until we know more continues to be influential. The latest work on learning and climate change includes new theoretical models, better informed simulations of how learning affects the optimal timing of emissions reductions, analyses of how new information could affect the prospects for reaching and maintaining political agreements and for adapting to climate change, and explorations of how learning could lead us astray rather than closer to the truth. Despite the diversity of this new work, a clear consensus on a central point is that the prospect of learning does not support the postponement of emissions reductions today.Learning; Uncertainty; Climate change; Decision analysis

    Opposite ends of the same stick? Multi-method test of the dimensionality of individualism and collectivism

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    Cataloged from PDF version of article.The construct of individualism–collectivism (IND-COL) has become the definitive standard in cross-cultural psychology, management, and related fields. It is also among the most controversial, in particular, with regard to the ambiguity of its dimensionality: Some view IND and COL as the opposites of a single continuum, whereas others argue that the two are independent constructs. We explored the issue through seven different tests using original individual-level data from 50 studies and meta-analytic data from 149 empirical publications yielding a total of 295 samplelevel observations that were collected using six established instruments for assessing IND and COL as separate constructs. Results indicated that the dimensionality of IND-COL may depend on (a) the specific instrument used to collect the data, (b) the sample characteristics and the cultural region from which the data were collected, and (c) the level of analysis. We also review inconsistencies, deficiencies, and challenges of conceptualizing IND-COL and provide guidelines for developing and selecting instruments for measuring the construct, and for reporting and meta-analyzing results from this line of research

    Priority for the Worse Off and the Social Cost of Carbon

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    The social cost of carbon (SCC) is a monetary measure of the harms from carbon emission. Specifically, it is the reduction in current consumption that produces a loss in social welfare equivalent to that caused by the emission of a ton of CO2. The standard approach is to calculate the SCC using a discounted-utilitarian social welfare function (SWF)—one that simply adds up the well-being numbers (utilities) of individuals, as discounted by a weighting factor that decreases with time. The discounted-utilitarian SWF has been criticized both for ignoring the distribution of well-being, and for including an arbitrary preference for earlier generations. Here, we use a prioritarian SWF, with no time-discount factor, to calculate the SCC in the integrated assessment model RICE. Prioritarianism is a well-developed concept in ethics and theoretical welfare economics, but has been, thus far, little used in climate scholarship. The core idea is to give greater weight to well-being changes affecting worse off individuals. We find substantial differences between the discounted-utilitarian and non-discounted prioritarian SCC

    Consumers\u27 Misunderstanding of Health Insurance.

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    We report results from two surveys of representative samples of Americans with private health insurance. The first examines how well Americans understand, and believe they understand, traditional health insurance coverage. The second examines whether those insured under a simplified all-copay insurance plan will be more likely to engage in cost-reducing behaviors relative to those insured under a traditional plan with deductibles and coinsurance, and measures consumer preferences between the two plans. The surveys provide strong evidence that consumers do not understand traditional plans and would better understand a simplified plan, but weaker evidence that a simplified plan would have strong appeal to consumers or change their healthcare choices

    Activity, stability and 3-D structure of the Cu(II) form of a chitin-active lytic polysaccharide monooxygenase from Bacillus amyloliquefaciens

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    The enzymatic deconstruction of recalcitrant polysaccharide biomass is central to the conversion of these substrates for societal benefit, such as in biofuels. Traditional models for enzyme-catalysed polysaccharide degradation involved the synergistic action of endo-, exo-and processive glycoside hydrolases working in concert to hydrolyse the substrate. More recently this model has been succeeded by one featuring a newly discovered class of mononuclear copper enzymes: lytic polysaccharide monooxygenases (LPMOs; classified as Auxiliary Activity (AA) enzymes in the CAZy classification). In 2013, the structure of an LPMO from Bacillus amyloliquefaciens, BaAA10, was solved with the Cu centre photoreduced to Cu(I) in the X-ray beam. Here we present the catalytic activity of BaAA10. We show that it is a chitin-active LPMO, active on both α and β chitin, with the Cu(II) binding with low nM KD, and the substrate greatly increasing the thermal stability of the enzyme. A spiral data collection strategy has been used to facilitate access to the previously unobservable Cu(II) state of the active centre, revealing a coordination geometry around the copper which is distorted from axial symmetry, consistent with the previous findings from EPR spectroscopy
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