182 research outputs found

    Why isn’t the transition period getting the attention it deserves? Farm advisors’ opinions and experiences of managing dairy cow health in the transition period

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    During the transition period three weeks before and after calving the dairy cow is at greater risk of developing disease, to the detriment of welfare and production. An understanding of the reasons why and how farmers and their advisors engage in efforts to control metabolic disease during the transition period is required if these diseases are to be more successfully controlled. The study reported here, based on interview research, investigates the opinions and behaviours of farm advisors on transition cow management and nutrition, their experiences of working with their respective farm clients, and interactions with other farm advisors to help manage transition cow health and productivity. Semi-structured interviews were conducted with 12 veterinary advisors and 12 non-veterinary advisors (nutritionists, feed company representatives and independent consultants) in England. A key theme emerging from this qualitative data was a perceived lack of focussed transition management advice provided by advisors. Reasons for suboptimal or lack of appropriate advice included: time pressures for advisors to visit as many farms as possible; avoiding the investigation of areas of potential improvement, for fear of not meeting transition health and performance targets; financial disincentives for nutritionists, as the sales commission attributed to transition cow feeding was small relative to the main milking herd; and a lack of confidence in the subject. Other aspects included the responsibility of providing transition advice which was perceived to be high-risk, a lack of cooperation between veterinarians and nutritionists, and the perceived varying competencies of nutritionists. The findings demonstrate the importance of the varied influences of ‘people factors’ on transition cow health such as the nature of the advisor-farmer relationship, advisor-farmer communication and herd-level advisor collaboration on transition cow health and management

    Gamma-Ray spectroscopy in the vicinity of Zr-108

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    F. Browne et al.; 4 págs.; 2 figs.; Presented at the Zakopane Conference on Nuclear Physics “Extremes of the Nuclear Landscape”, Zakopane, Poland, August 31–September 7, 2014; PACS numbers: 21.10.Re, 21.10.Tg, 23.20.Js, 27.60.+jThe half-lives of 2+121+ states were measured for 102,104102,104Zr and 106,108106,108Mo to test a new implementation of a LaBr33(Ce) array at the RIBF, RIKEN, Japan. The nuclei of interest were produced through the fission of a 345~MeV/nucleon 238238U beam and selected by the BigRIPS separator. Fission fragments were implanted into the WAS3ABi active stopper, surrounding which, 18 LaBr33(Ce) detectors provided fast γγ-ray detection. Timing between the LaBr33(Ce) array and plastic scintillators allowed for the measurement of half-lives of low-lying states. The preliminary results, which agree with literature values, are presented along with experimental details.This work was supported in part by the UK STFC, the UK NMO and D.O.E. grant No. DE-FG02-91ER-40609Peer Reviewe

    Field Measurements of Terrestrial and Martian Dust Devils

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    Surface-based measurements of terrestrial and martian dust devils/convective vortices provided from mobile and stationary platforms are discussed. Imaging of terrestrial dust devils has quantified their rotational and vertical wind speeds, translation speeds, dimensions, dust load, and frequency of occurrence. Imaging of martian dust devils has provided translation speeds and constraints on dimensions, but only limited constraints on vertical motion within a vortex. The longer mission durations on Mars afforded by long operating robotic landers and rovers have provided statistical quantification of vortex occurrence (time-of-sol, and recently seasonal) that has until recently not been a primary outcome of more temporally limited terrestrial dust devil measurement campaigns. Terrestrial measurement campaigns have included a more extensive range of measured vortex parameters (pressure, wind, morphology, etc.) than have martian opportunities, with electric field and direct measure of dust abundance not yet obtained on Mars. No martian robotic mission has yet provided contemporaneous high frequency wind and pressure measurements. Comparison of measured terrestrial and martian dust devil characteristics suggests that martian dust devils are larger and possess faster maximum rotational wind speeds, that the absolute magnitude of the pressure deficit within a terrestrial dust devil is an order of magnitude greater than a martian dust devil, and that the time-of-day variation in vortex frequency is similar. Recent terrestrial investigations have demonstrated the presence of diagnostic dust devil signals within seismic and infrasound measurements; an upcoming Mars robotic mission will obtain similar measurement types

    Academic requirements for Certificate of Completion of Training in surgical training: Consensus recommendations from the Association of Surgeons in Training/National Research Collaborative Consensus Group.

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    BACKGROUND: Surgical trainees are expected to demonstrate academic achievement in order to obtain their certificate of completion of training (CCT). These standards are set by the Joint Committee on Surgical Training (JCST) and specialty advisory committees (SAC). The standards are not equivalent across all surgical specialties and recognise different achievements as evidence. They do not recognise changes in models of research and focus on outcomes rather than process. The Association of Surgeons in Training (ASiT) and National Research Collaborative (NRC) set out to develop progressive, consistent and flexible evidence set for academic requirements at CCT. METHODS: A modified-Delphi approach was used. An expert group consisting of representatives from the ASiT and the NRC undertook iterative review of a document proposing changes to requirements. This was circulated amongst wider stakeholders. After ten iterations, an open meeting was held to discuss these proposals. Voting on statements was performed using a 5-point Likert Scale. Each statement was voted on twice, with ≄80% of votes in agreement meaning the statement was approved. The results of this vote were used to propose core and optional academic requirements for CCT. RESULTS: Online discussion concluded after ten rounds. At the consensus meeting, statements were voted on by 25 delegates from across surgical specialties and training-grades. The group strongly favoured acquisition of 'Good Clinical Practice' training and research methodology training as CCT requirements. The group agreed that higher degrees, publications in any author position (including collaborative authorship), recruiting patients to a study or multicentre audit and presentation at a national or international meeting could be used as evidence for the purpose of CCT. The group agreed on two essential 'core' requirements (GCP and methodology training) and two of a menu of four 'additional' requirements (publication with any authorship position, presentation, recruitment of patients to a multicentre study and completion of a higher degree), which should be completed in order to attain CCT. CONCLUSION: This approach has engaged stakeholders to produce a progressive set of academic requirements for CCT, which are applicable across surgical specialties. Flexibility in requirements whilst retaining a high standard of evidence is desirable

    Glauber Dynamics for the mean-field Potts Model

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    We study Glauber dynamics for the mean-field (Curie-Weiss) Potts model with q≄3q\geq 3 states and show that it undergoes a critical slowdown at an inverse-temperature ÎČs(q)\beta_s(q) strictly lower than the critical ÎČc(q)\beta_c(q) for uniqueness of the thermodynamic limit. The dynamical critical ÎČs(q)\beta_s(q) is the spinodal point marking the onset of metastability. We prove that when ÎČ<ÎČs(q)\beta<\beta_s(q) the mixing time is asymptotically C(ÎČ,q)nlog⁥nC(\beta, q) n \log n and the dynamics exhibits the cutoff phenomena, a sharp transition in mixing, with a window of order nn. At ÎČ=ÎČs(q)\beta=\beta_s(q) the dynamics no longer exhibits cutoff and its mixing obeys a power-law of order n4/3n^{4/3}. For ÎČ>ÎČs(q)\beta>\beta_s(q) the mixing time is exponentially large in nn. Furthermore, as ÎČ↑ÎČs\beta \uparrow \beta_s with nn, the mixing time interpolates smoothly from subcritical to critical behavior, with the latter reached at a scaling window of O(n−2/3)O(n^{-2/3}) around ÎČs\beta_s. These results form the first complete analysis of mixing around the critical dynamical temperature --- including the critical power law --- for a model with a first order phase transition.Comment: 45 pages, 5 figure

    Effects of environmental pollutants on the reproduction and welfare of ruminants

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    Anthropogenic pollutants comprise a wide range of synthetic organic compounds and heavy metals, which are dispersed throughout the environment, usually at low concentrations. Exposure of ruminants, as for all other animals, is unavoidable and while the levels of exposure to most chemicals are usually too low to induce any physiological effects, combinations of pollutants can act additively or synergistically to perturb multiple physiological systems at all ages but particularly in the developing foetus. In sheep, organs affected by pollutant exposure include the ovary, testis, hypothalamus and pituitary gland and bone. Reported effects of exposure include changes in organ weight and gross structure, histology and gene and protein expression but these changes are not reflected in changes in reproductive performance under the conditions tested. These results illustrate the complexity of the effects of endocrine disrupting compounds on the reproductive axis, which make it difficult to extrapolate between, or even within, species. Effects of pollutant exposure on the thyroid gland, immune, cardiovascular and obesogenic systems have not been shown explicitly, in ruminants, but work on other species suggests that these systems can also be perturbed. It is concluded that exposure to a mixture of anthropogenic pollutants has significant effects on a wide variety of physiological systems, including the reproductive system. Although this physiological insult has not yet been shown to lead to a reduction in ruminant gross performance, there are already reports indicating that anthropogenic pollutant exposure can compromise several physiological systems and may pose a significant threat to both reproductive performance and welfare in the longer term. At present, many potential mechanisms of action for individual chemicals have been identified but knowledge of factors affecting the rate of tissue exposure and of the effects of combinations of chemicals on physiological systems is poor. Nevertheless, both are vital for the identification of risks to animal productivity and welfare
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