254 research outputs found

    Spring wheat yield assessment under drought conditions using vegetation health index: case of Canadian prairies

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    Non-Peer ReviewedAgricultural drought is a major climate concern which occurs frequently on Canadian prairies. It acts negatively on crop production, which directly affects the Canadian economy. The Normalized Difference Vegetation Index (NDVI) has been widely used to assess crop yield losses related to drought events. However, this index suffers from some shortcomings such as the apparent time lag between drought impact due to rainfall deficit and NDVI response. This study was undertaken to investigate the effectiveness of the integrated Vegetation Health Index (iVHI) for the assessment of spring wheat yield across Canadian prairies. A time series of five years from the Advanced Very High Resolution Radiometer (AVHRR) sensor were used to develop a spring wheat yield model for three agroclimatic regions: subarid, semiarid and subhumid. The results demonstrated that spring wheat yield assessment is feasible through the use of iVHI, especially in subarid and semiarid regions where it reached a correlation coefficient of 0.75 and 0.61, respectively. This finding shows that iVHI can be used to estimate spring wheat yield losses due to agricultural drought across the Canadian prairies. However, in subhumid regions where spring wheat growing conditions are favourable because of adequate water supply, the integrated NDVI (iNDVI) outperforms iVHI with a correlation coefficient of 0.44 compared to 0.34. Consequently, to develop an efficient tool, it suggested coupling the iVHI with iNDVI to better estimate spring wheat yield in the Canadian prairies

    Analysis of Last Development Results for High Voltage Circuit-breakers Using New G3 Gas

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    Among many alternative gases proposed to replace SF6 as insulating gas, g3 (green gas for grid), fluoronitril based component officially introduced at CIGRE 2014, can be now used for insulation projects and new environmental friendly circuit breakers. This gas mixture g3, presents a reduction of the global warming potential by 98% compared to SF6 gas and shows quite good dielectric withstand capability. Many new investigations about thermal and chemical behavior have been done and are precised in this paper. Last switching test campaigns will be presented for 145 kV applications. Simulation tools should be updated to be applicable to these projects. Developments and comparisons with last test results will be analyzed

    2015 ACVIM Small Animal Consensus Statement on Seizure Management in Dogs

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    This report represents a scientific and working clinical consensus statement on seizure management in dogs based on current literature and clinical expertise. The goal was to establish guidelines for a predetermined, concise, and logical sequential approach to chronic seizure management starting with seizure identification and diagnosis (not included in this report), reviewing decision‐making, treatment strategies, focusing on issues related to chronic antiepileptic drug treatment response and monitoring, and guidelines to enhance patient response and quality of life. Ultimately, we hope to provide a foundation for ongoing and future clinical epilepsy research in veterinary medicine

    A prospective cohort study assessing clinical referral management & workforce allocation within a UK regional medical genetics service

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    Abstract Ensuring patient access to genomic information in the face of increasing demand requires clinicians to develop innovative ways of working. This paper presents the first empirical prospective observational cohort study of UK multi-disciplinary genetic service delivery. It describes and explores collaborative working practices including the utilisation and role of clinical geneticists and non-medical genetic counsellors. Six hundred and fifty new patients referred to a regional genetics service were tracked through 850 clinical contacts until discharge. Referral decisions regarding allocation of lead health professional assigned to the case were monitored, including the use of initial clinical contact guidelines. Significant differences were found in the cases led by genetic counsellors and those led by clinical geneticists. Around a sixth, 16.8% (109/650) of referrals were dealt with by a letter back to the referrer or re-directed to another service provider and 14.8% (80/541) of the remaining patients chose not to schedule an appointment. Of the remaining 461 patients, genetic counsellors were allocated as lead health professional for 46.2% (213/461). A further 61 patients did not attend. Of those who did, 86% (345/400) were discharged after one or two appointments. Genetic counsellors contributed to 95% (784/825) of total patient contacts. They provided 93.7% (395/432) of initial contacts and 26.8% (106/395) of patients were discharged at that point. The information from this study informed a planned service re-design. More research is needed to assess the effectiveness and efficiency of different models of collaborative multi-disciplinary working within genetics services. Keywords (MeSH terms) Genetic Services, Genetic Counseling, Interdisciplinary Communication, Cohort Studies, Delivery of Healthcare, Referral and Consultation

    International Veterinary Epilepsy Task Force consensus proposal: Medical treatment of canine epilepsy in Europe

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    In Europe, the number of antiepileptic drugs (AEDs) licensed for dogs has grown considerably over the last years. Nevertheless, the same questions remain, which include, 1) when to start treatment, 2) which drug is best used initially, 3) which adjunctive AED can be advised if treatment with the initial drug is unsatisfactory, and 4) when treatment changes should be considered. In this consensus proposal, an overview is given on the aim of AED treatment, when to start long-term treatment in canine epilepsy and which veterinary AEDs are currently in use for dogs. The consensus proposal for drug treatment protocols, 1) is based on current published evidence-based literature, 2) considers the current legal framework of the cascade regulation for the prescription of veterinary drugs in Europe, and 3) reflects the authors’ experience. With this paper it is aimed to provide a consensus for the management of canine idiopathic epilepsy. Furthermore, for the management of structural epilepsy AEDs are inevitable in addition to treating the underlying cause, if possible

    Roadmap on Wilson loops in 3d Chern-Simons-matter theories

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    This is a compact review of recent results on supersymmetric Wilson loops in ABJ(M) and related theories. It aims to be a quick introduction to the state of the art in the field and a discussion of open problems. It is divided into short chapters devoted to different questions and techniques. Some new results, perspectives and speculations are also presented. We hope this might serve as a baseline for further studies of this topic

    Gamma-ray observations of Tycho's SNR with VERITAS and Fermi

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    High-energy gamma-ray emission from supernova remnants (SNRs) has provided a unique perspective for studies of Galactic cosmic-ray acceleration. Tycho's SNR is a particularly good target because it is a young, type Ia SNR that is well-studied over a wide range of energies and located in a relatively clean environment. Since the detection of gamma-ray emission from Tycho's SNR by VERITAS and Fermi-LAT, there have been several theoretical models proposed to explain its broadband emission and high-energy morphology. We report on an update to the gamma-ray measurements of Tycho's SNR with 147 hours of VERITAS and 84 months of Fermi-LAT observations, which represents about a factor of two increase in exposure over previously published data. About half of the VERITAS data benefited from a camera upgrade, which has made it possible to extend the TeV measurements toward lower energies. The TeV spectral index measured by VERITAS is consistent with previous results, but the expanded energy range softens a straight power-law fit. At energies higher than 400 GeV, the power-law index is 2.92±0.42stat±0.20sys2.92 \pm 0.42_{\mathrm{stat}} \pm 0.20_{\mathrm{sys}}. It is also softer than the spectral index in the GeV energy range, 2.14±0.09stat±0.02sys2.14 \pm 0.09_{\mathrm{stat}} \pm 0.02_{\mathrm{sys}}, measured by this study using Fermi--LAT data. The centroid position of the gamma-ray emission is coincident with the center of the remnant, as well as with the centroid measurement of Fermi--LAT above 1 GeV. The results are consistent with an SNR shell origin of the emission, as many models assume. The updated spectrum points to a lower maximum particle energy than has been suggested previously.Comment: Accepted for publication in The Astrophysical Journa

    Gamma-ray Observations Under Bright Moonlight with VERITAS

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    Imaging atmospheric Cherenkov telescopes (IACTs) are equipped with sensitive photomultiplier tube (PMT) cameras. Exposure to high levels of background illumination degrades the efficiency of and potentially destroys these photo-detectors over time, so IACTs cannot be operated in the same configuration in the presence of bright moonlight as under dark skies. Since September 2012, observations have been carried out with the VERITAS IACTs under bright moonlight (defined as about three times the night-sky-background (NSB) of a dark extragalactic field, typically occurring when Moon illumination > 35%) in two observing modes, firstly by reducing the voltage applied to the PMTs and, secondly, with the addition of ultra-violet (UV) bandpass filters to the cameras. This has allowed observations at up to about 30 times previous NSB levels (around 80% Moon illumination), resulting in 30% more observing time between the two modes over the course of a year. These additional observations have already allowed for the detection of a flare from the 1ES 1727+502 and for an observing program targeting a measurement of the cosmic-ray positron fraction. We provide details of these new observing modes and their performance relative to the standard VERITAS observations

    Dark Matter Constraints from a Joint Analysis of Dwarf Spheroidal Galaxy Observations with VERITAS

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    We present constraints on the annihilation cross section of WIMP dark matter based on the joint statistical analysis of four dwarf galaxies with VERITAS. These results are derived from an optimized photon weighting statistical technique that improves on standard imaging atmospheric Cherenkov telescope (IACT) analyses by utilizing the spectral and spatial properties of individual photon events. We report on the results of ∌\sim230 hours of observations of five dwarf galaxies and the joint statistical analysis of four of the dwarf galaxies. We find no evidence of gamma-ray emission from any individual dwarf nor in the joint analysis. The derived upper limit on the dark matter annihilation cross section from the joint analysis is 1.35×10−23cm3s−11.35\times 10^{-23} {\mathrm{ cm^3s^{-1}}} at 1 TeV for the bottom quark (bbˉb\bar{b}) final state, 2.85×10−24cm3s−12.85\times 10^{-24}{\mathrm{ cm^3s^{-1}}} at 1 TeV for the tau lepton (τ+τ−\tau^{+}\tau^{-}) final state and 1.32×10−25cm3s−11.32\times 10^{-25}{\mathrm{ cm^3s^{-1}}} at 1 TeV for the gauge boson (γγ\gamma\gamma) final state.Comment: 14 pages, 9 figures, published in PRD, Ascii tables containing annihilation cross sections limits are available for download as ancillary files with readme.txt file description of limit

    Factors influencing the practice of new graduate nurses : a focused ethnography of acute care settings

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    Aim: To explore the influence of an acute care setting on competency deployment of new graduate nurses (NGNs) from a competency -based undergraduate programme . Background: In the last 15 years, nursing education has shifted to competency -based education (CBE). Few studies have focused on how NGNs from these reformed programmes use the competencies they have developed. To be paradigmatically coherent with the nature of a competence, studies should also examine how context influences nursing practice and competency deployment. Design: A focused ethnography of three acute care units from one academic hospital in Canada. Methods: Purposive and snowball sampling strategies were used to recruit 19 participants: NGNs (n = 4), nurse preceptors (n = 2), clinical nurse specialists (n = 9) , and nurse managers (n = 4). Data were collected through individual interviews, focus groups , observation and documentation. Data were analysed according to Roper and Shapira’s (2000) ethnographic nursing analysis framework. Results: Organizational and individual factors were identified as influencing NGNs ’ competenc y deployment. Organizational factors are orientation, stability, workload, and the scientific culture of the unit. Personal factors have been linked to groups of professionals: for NGNs, personality and clinical placements during their initial education; for nurses working with NGNs, to be role models, to promote integration and to denounce bullying; and for other health professionals, to recognize nursing expertise. Conclusion: One way to s mooth the transition from academic to clinical settings for NGNs is by offering transition or orientation programmes that will provide them with stability and a reduced workload, allowing them to progressively deploy their competencies. Relevance to clinical practice: Organizational and individual factors influence how new graduate nurses deploy their competencies. Clinical educators and nurse managers can help new nurses by acting on these factors
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