752 research outputs found

    Developing and enhancing biodiversity monitoring programmes: a collaborative assessment of priorities

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    1.Biodiversity is changing at unprecedented rates, and it is increasingly important that these changes are quantified through monitoring programmes. Previous recommendations for developing or enhancing these programmes focus either on the end goals, that is the intended use of the data, or on how these goals are achieved, for example through volunteer involvement in citizen science, but not both. These recommendations are rarely prioritized. 2.We used a collaborative approach, involving 52 experts in biodiversity monitoring in the UK, to develop a list of attributes of relevance to any biodiversity monitoring programme and to order these attributes by their priority. We also ranked the attributes according to their importance in monitoring biodiversity in the UK. Experts involved included data users, funders, programme organizers and participants in data collection. They covered expertise in a wide range of taxa. 3.We developed a final list of 25 attributes of biodiversity monitoring schemes, ordered from the most elemental (those essential for monitoring schemes; e.g. articulate the objectives and gain sufficient participants) to the most aspirational (e.g. electronic data capture in the field, reporting change annually). This ordered list is a practical framework which can be used to support the development of monitoring programmes. 4.People's ranking of attributes revealed a difference between those who considered attributes with benefits to end users to be most important (e.g. people from governmental organizations) and those who considered attributes with greatest benefit to participants to be most important (e.g. people involved with volunteer biological recording schemes). This reveals a distinction between focussing on aims and the pragmatism in achieving those aims. 5.Synthesis and applications. The ordered list of attributes developed in this study will assist in prioritizing resources to develop biodiversity monitoring programmes (including citizen science). The potential conflict between end users of data and participants in data collection that we discovered should be addressed by involving the diversity of stakeholders at all stages of programme development. This will maximize the chance of successfully achieving the goals of biodiversity monitoring programmes

    The McDonald Observatory Planet Search: New Long-Period Giant Planets, and Two Interacting Jupiters in the HD 155358 System

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    We present high-precision radial velocity (RV) observations of four solar-type (F7-G5) stars - HD 79498, HD 155358, HD 197037, and HD 220773 - taken as part of the McDonald Observatory Planet Search Program. For each of these stars, we see evidence of Keplerian motion caused by the presence of one or more gas giant planets in long-period orbits. We derive orbital parameters for each system, and note the properties (composition, activity, etc.) of the host stars. While we have previously announced the two-gas-giant HD 155358 system, we now report a shorter period for planet c. This new period is consistent with the planets being trapped in mutual 2:1 mean-motion resonance. We therefore perform an in-depth stability analysis, placing additional constraints on the orbital parameters of the planets. These results demonstrate the excellent long-term RV stability of the spectrometers on both the Harlan J. Smith 2.7 m telescope and the Hobby-Eberly telescope.Comment: 38 pages, 10 figures, 6 tables. Accepted for publication in Ap

    Dynamical Reduction of Discrete Systems Based on the Renormalization Group Method

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    The renormalization group (RG) method is extended for global asymptotic analysis of discrete systems. We show that the RG equation in the discretized form leads to difference equations corresponding to the Stuart-Landau or Ginzburg-Landau equations. We propose a discretization scheme which leads to a faithful discretization of the reduced dynamics of the original differential equations.Comment: LaTEX. 12pages. 1 figure include

    Design of the liraglutide effect and action in diabetes: evaluation of cardiovascular outcome results (LEADER) trial.

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    BACKGROUND: Diabetes is a multisystem disorder associated with a nearly twofold excess risk for a broad range of adverse cardiovascular outcomes including coronary heart disease, stroke, and cardiovascular death. Liraglutide is a human glucagon-like peptide receptor analog approved for use in patients with type 2 diabetes mellitus (T2DM). STUDY DESIGN: To formally assess the cardiovascular safety of liraglutide, the Liraglutide Effect and Action in Diabetes: Evaluation of cardiovascular outcome Results (LEADER) trial was commenced in 2010. LEADER is a phase 3B, multicenter, international, randomized, double-blind, placebo-controlled clinical trial with long-term follow-up. Patients with T2DM at high risk for cardiovascular disease (CVD) who were either drug naive or treated with oral antihyperglycemic agents or selected insulin regimens (human NPH, long-acting analog, or premixed) alone or in combination with oral antihyperglycemics were eligible for inclusion. Randomized patients are being followed for up to 5 years. The primary end point is the time from randomization to a composite outcome consisting of the first occurrence of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. CONCLUSIONS: LEADER commenced in September 2010, and enrollment concluded in April 2012. There were 9,340 patients enrolled at 410 sites in 32 countries. The mean age of patients was 64.3 ± 7.2 years, 64.3% were men, and mean body mass index was 32.5 ± 6.3 kg/m2. There were 7,592 (81.3%) patients with prior CVD and 1,748 (18.7%) who were high risk but without prior CVD. It is expected that LEADER will provide conclusive data regarding the cardiovascular safety of liraglutide relative to the current standard of usual care for a global population of patients with T2DM

    Electroweak Effective Charges and their relation to Physical Cross Sections

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    In quantum electrodynamics with fermions f = e,\mu..., knowledge of the vacuum polarization spectral function determined from the tree level e^+e^- -> f^+f^- cross sections, together with a single low energy measurement of the fine structure constant \alpha, enables the construction of the one-loop effective charge \alpha_eff(q^2) for all q^2. It is shown how an identical procedure can be followed in the electroweak sector of the Standard Model to construct three gauge-, scale- and scheme-independent one-loop electroweak effective charges and an effective weak mixing angle from the tree level e^+e^- -> W^+W^-, ZH and e^+\nu_e -> W^+Z, W^+\gamma, W^+H differential cross sections, together with three low energy measurements, which may be chosen to be \alpha and the masses of the W and Z bosons. It is found that the corresponding proper self-energy-like functions thus constructed are identical to those obtained in the pinch technique framework. In this way, it is shown how the concept of effective charges in the electroweak Standard Model is as well-defined and unique as in quantum electrodynamics.Comment: 40 pages, 7 figs, Latex, uses epsf.sty, axodraw.sty (included), fig 6 scale correcte

    Precision Physics at LEP

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    1 - Introduction 2 - Small-Angle Bhabha Scattering and the Luminosity Measurement 3 - Z^0 Physics 4 - Fits to Precision Data 5 - Physics at LEP2 6 - ConclusionsComment: Review paper to appear in the RIVISTA DEL NUOVO CIMENTO; 160 pages, LateX, 70 eps figures include

    Germline variants are associated with increased primary melanoma tumor thickness at diagnosis

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    Germline genetic variants have been identified, which predispose individuals and families to develop melanoma. Tumor thickness is the strongest predictor of outcome for clinically localized primary melanoma patients. We sought to determine whether there is a heritable genetic contribution to variation in tumor thickness. If confirmed, this will justify the search for specific genetic variants influencing tumor thickness. To address this, we estimated the proportion of variation in tumor thickness attributable to genome-wide genetic variation (variant-based heritability) using unrelated patients with measured primary cutaneous melanoma thickness. As a secondary analysis, we conducted a genome-wide association study (GWAS) of tumor thickness. The analyses utilized 10 604 individuals with primary cutaneous melanoma drawn from nine GWAS datasets from eight cohorts recruited from the general population, primary care and melanoma treatment centers. Following quality control and filtering to unrelated individuals with study phenotypes, 8125 patients were used in the primary analysis to test whether tumor thickness is heritable. An expanded set of 8505 individuals (47.6% female) were analyzed for the secondary GWAS meta-analysis. Analyses were adjusted for participant age, sex, cohort and ancestry. We found that 26.6% (SE 11.9%, P = 0.0128) of variation in tumor thickness is attributable to genome-wide genetic variation. While requiring replication, a chromosome 11 locus was associated (P < 5 Ă— 10-8) with tumor thickness. Our work indicates that sufficiently large datasets will enable the discovery of genetic variants associated with greater tumor thickness, and this will lead to the identification of host biological processes influencing melanoma growth and invasion.E.M. was supported by the Malaysian Ministry of Higher Education and Universiti Sains Malaysia to study for a PhD at the University of Leeds. A.E.C. was supported by a National Health and Medical Research Council (NHMRC) of Australia Career Development Fellowship (1147843). K.K. was supported by an NHMRC Career Development Fellowship (1125290). M.M.I. was supported by Cancer Research UK (c588/a19167) and the NIH (ca083115). R.A.S. and G.V.L. are supported by NHMRC Practitioner Fellowships; R.A.S. and J.F.T. also acknowledge support from an NHMRC program grant. D.C.W., S.M. and N.K.H were supported by NHMRC Research Fellowships (1058522, 1155413, 1154543 and 1117663). We thank Nicholas G. Martin for assistance with access to data from the Q-MEGA cohort and with manuscript writing. This work was conducted using the UK Biobank Resource (application number 25331)
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