1,233 research outputs found

    Reconnaisance geological observations on Precambrian and Palaeozoic rocks of the New and Salisbury Rivers, Southern Tasmania

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    Phyllite and quartzite, probably Precambrian, trend meridionally and dip steeply in the New River Gorge above the junction with the Salisbury River in southern Tasmania. Further upstream an association of silty dolomite and conglomerate is less deformed and may be younger. Siliceous conglomerate boulders occur in the New River below the gorge. Late Ordovician carbonates of the Gordon Group are exposed in the New River valley just above the junction with the Salisbury River and up the Salisbury to Vanishing Falls, above which a sheet of Jurassic dolerite seems to have been intruded along the unconformity between the Ordovician rocks and almost horizontal Late Palaeozoic sedimentary rocks of the Parmeener Supergroup

    IMPACT OF CFTA/NAFTA ON U.S. AND CANADIAN AGRICULTURE

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    CFTA/NAFTA is estimated annually to add 1,430millionofU.S.agriculturalexportstoCanadaand1,430 million of U.S. agricultural exports to Canada and 1,884 million of Canadian agricultural exports to the United States. Thus CFTA/NAFTA contributed an estimated 25 percent of the 5.8billionofU.S.agriculturalexportstoCanadain1995.Classicalwelfareanalysiswasusedtoestimatetheimplicationsoffreetradeinthedairy,poultry,sugar,andotherindustriesthatcontinuetobeprotected.Inaggregate,consumersbenefitfromliberalizationbynearly5.8 billion of U.S. agricultural exports to Canada in 1995. Classical welfare analysis was used to estimate the implications of free trade in the dairy, poultry, sugar, and other industries that continue to be protected. In aggregate, consumers benefit from liberalization by nearly 1 billion per year in each country. Losses to Canadian producers are absolutely and relatively greater than to U.S. producers. Overall deadweight gains are positive to each country. The annual combined two-country addition to national income (292million)totalsapresentvalueof292 million) totals a present value of 5.8 billion when discounted in perpetuity at a 5 percent rate.International Relations/Trade,

    Bayesian regression discontinuity designs: Incorporating clinical knowledge in the causal analysis of primary care data

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    The regression discontinuity (RD) design is a quasi-experimental design that estimates the causal effects of a treatment by exploiting naturally occurring treatment rules. It can be applied in any context where a particular treatment or intervention is administered according to a pre-specified rule linked to a continuous variable. Such thresholds are common in primary care drug prescription where the RD design can be used to estimate the causal effect of medication in the general population. Such results can then be contrasted to those obtained from randomised controlled trials (RCTs) and inform prescription policy and guidelines based on a more realistic and less expensive context. In this paper we focus on statins, a class of cholesterol-lowering drugs, however, the methodology can be applied to many other drugs provided these are prescribed in accordance to pre-determined guidelines. NHS guidelines state that statins should be prescribed to patients with 10 year cardiovascular disease risk scores in excess of 20%. If we consider patients whose scores are close to this threshold we find that there is an element of random variation in both the risk score itself and its measurement. We can thus consider the threshold a randomising device assigning the prescription to units just above the threshold and withholds it from those just below. Thus we are effectively replicating the conditions of an RCT in the area around the threshold, removing or at least mitigating confounding. We frame the RD design in the language of conditional independence which clarifies the assumptions necessary to apply it to data, and which makes the links with instrumental variables clear. We also have context specific knowledge about the expected sizes of the effects of statin prescription and are thus able to incorporate this into Bayesian models by formulating informative priors on our causal parameters.Comment: 21 pages, 5 figures, 2 table

    Improving Design Characteristic to Estimate Load for Future Rock Climbing Studies

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    Rock climbing is an increasingly popular physical activity with indoor competition climbing accepted for inclusion at the summer 2020 Olympic Games in Tokyo. The International Olympic Committee consensus statement recommends the accurate monitoring of training load to reduce injury risk in athletes (Soligard, et al., 2016). Differences in acute/chronic training loads have been found to be predictive of injury occurrence (Gabbett, 2016). In published climbing literature to date, differences in injury terminology, data collection procedures, calculation of exposure and operational measures of performance used by authorship teams impedes comparison. At present, there is no consensus on design characteristics for use in epidemiological cohort studies in rock climbing. The aim of this article is to report a critical appraisal of methodologies used to estimate load and recommends an amendment to the IRCRA comparative grading scale to include British adjectival grade and design characteristics for future studies

    Binding branched and linear DNA structures: from isolated clusters to fully bonded gels

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    The proper design of DNA sequences allows for the formation of well defined supramolecular units with controlled interactions via a consecution of self-assembling processes. Here, we benefit from the controlled DNA self-assembly to experimentally realize particles with well defined valence, namely tetravalent nanostars (A) and bivalent chains (B). We specifically focus on the case in which A particles can only bind to B particles, via appropriately designed sticky-end sequences. Hence AA and BB bonds are not allowed. Such a binary mixture system reproduces with DNA-based particles the physics of poly-functional condensation, with an exquisite control over the bonding process, tuned by the ratio, r, between B and A units and by the temperature, T. We report dynamic light scattering experiments in a window of Ts ranging from 10{\deg}C to 55{\deg}C and an interval of r around the percolation transition to quantify the decay of the density correlation for the different cases. At low T, when all possible bonds are formed, the system behaves as a fully bonded network, as a percolating gel and as a cluster fluid depending on the selected r.Comment: 15 pages, 11 figure

    Mutants of phage bIL67 RuvC with enhanced Holliday junction binding selectivity and resolution symmetry

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    Viral and bacterial Holliday junction resolvases differ in specificity with the former typically being more promiscuous, acting on a variety of branched DNA substrates, while the latter exclusively targets Holliday junctions. We have determined the crystal structure of a RuvC resolvase from bacteriophage bIL67 to help identify features responsible for DNA branch discrimination. Comparisons between phage and bacterial RuvC structures revealed significant differences in the number and position of positively-charged residues in the outer sides of the junction binding cleft. Substitutions were generated in phage RuvC residues implicated in branch recognition and six were found to confer defects in Holliday junction and replication fork cleavage in vivo. Two mutants, R121A and R124A that flank the DNA binding site were purified and exhibited reduced in vitro binding to fork and linear duplex substrates relative to the wild-type, while retaining the ability to bind X junctions. Crucially, these two variants cleaved Holliday junctions with enhanced specificity and symmetry, a feature more akin to cellular RuvC resolvases. Thus, additional positive charges in the phage RuvC binding site apparently stabilize productive interactions with branched structures other than the canonical Holliday junction, a feature advantageous for viral DNA processing but deleterious for their cellular counterparts

    VLT spectroscopy of NGC 3115 globular clusters

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    We present results derived from VLT-FORS2 spectra of 24 different globular clusters associated with the lenticular galaxy NGC 3115. A subsample of 17 globular clusters have sufficiently high signal-to-noise to allow precision measurements of absorption line-strengths. Comparing these indices to new stellar population models by Thomas et al. we determine ages, metallicities and element abundance ratios. For the first time these stellar population models explicitly take abundance ratio biases in the Lick/IDS stellar library into account. Our data are also compared with the Lick/IDS observations of Milky Way and M 31 globular clusters. Unpublished higher order Balmer lines (HgammaA ,F and HdeltaA ,F) from the Lick/IDS observations are given in the Appendix. Our best age estimates show that the observed clusters which sample the bimodal colour distribution of NGC 3115 are coeval within our observational errors (2-3 Gyr). Our best calibrated age/metallicity diagnostic diagram (Hbeta / vs. [MgFe]) indicates an absolute age of 11-12 Gyr consistent with the luminosity weighted age for the central part of NGC 3115. We confirm with our accurate line-strength measurements that the (V-I) colour is a good metallicity indicator within the probed metallicity range (-1.5 < [Fe/H] < 0.0). The abundance ratios for globular clusters in NGC 3115 give an inhomogeneous picture. We find a range from solar to super-solar ratios for both blue and red clusters. This is similar to the data for M 31 while the Milky Way seems to harbour clusters which are mainly consistent with [alpha / Fe] =~ 0.3. From our accurate recession velocities we detect, independent of metallicity, clear rotation in the sample of globular clusters. In order to explain the metallicity and abundance ratio pattern, particularly the range in abundance ratios for the metal rich globular clusters in NGC 3115, we favour a formation picture with more than two distinct formation episodes. Based on observations collected at the European Southern Observatory, Cerro Paranal, Chile (ESO No. 66.B-0131)

    The use of touch in developing a therapeutic relationship

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    The use of touch within health and social care is the focus of this article. The different types of touch will first be defined, before moving on to examine the many benefits that expressive touch can bring to the health and social care role and to developing a supportive therapeutic relationship between the support worker and their patient. Relevant sections of the Code of Conduct for Healthcare Support Workers and Adult Social Care Workers in England (Skills for Care and Skills for Health, 2013) will be highlighted throughout. The important aspects of communication, compassion and empathy will be explored. Touch is not always appropriate or welcomed by the patient, and the support worker must take into account preferences, cultural needs and beliefs while also gaining consent

    Evolution since z = 0.5 of the Morphology-Density relation for Clusters of Galaxies

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    Using traditional morphological classifications of galaxies in 10 intermediate-redshift (z~0.5) clusters observed with WFPC-2 on the Hubble Space Telescope, we derive relations between morphology and local galaxy density similar to that found by Dressler for low-redshift clusters. Taken collectively, the `morphology-density' relationship, M-D, for these more distant, presumably younger clusters is qualitatively similar to that found for the local sample, but a detailed comparison shows two substantial differences: (1) For the clusters in our sample, the M-D relation is strong in centrally concentrated ``regular'' clusters, those with a strong correlation of radius and surface density, but nearly absent for clusters that are less concentrated and irregular, in contrast to the situation for low redshift clusters where a strong relation has been found for both. (2) In every cluster the fraction of elliptical galaxies is as large or larger than in low-redshift clusters, but the S0 fraction is 2-3 times smaller, with a proportional increase of the spiral fraction. Straightforward, though probably not unique, interpretations of these observations are (1) morphological segregation proceeds hierarchically, affecting richer, denser groups of galaxies earlier, and (2) the formation of elliptical galaxies predates the formation of rich clusters, and occurs instead in the loose-group phase or even earlier, but S0's are generated in large numbers only after cluster virialization.Comment: 35 pages, 19 figures, uses psfig. Accepted for publication in Ap
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