215 research outputs found

    Why Do Cows Bloat?

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    Why do cows bloat on alfalfa or clover pastures but not on bluegrass? Is there something in clover or alfalfa and not in bluegrass or other grass pastures that causes bloat

    Raising dairy calves

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    The first essential for raising a healthy calf is feeding the cow well during gestation. During heavy lactation the cow loses proteins, fats, vitamins and minerals. The cow needs 6-8 weeks dry period with good feed to rebuild these body stores. Having access to good pasture, hay or silage solves most of the problems of feeding dry cows.1 If cows are in poor condition, or if the roughage is of poor quality, from 4 to 8 pounds of concentrates should be fed daily. The cows can be fed the same concentrate mixture used for the milking herd

    Milk production functions, hay/grain substitution rates and economic optima in dairy cow rations

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    Interest in possibilities of forage-grain substitution in the dairy cow ration has been increased by recent agricultural developments. One development is acreage control which allows farmers to grow forage as a replacement crop for grain. Another is the continuing interest in conservation: Erosion control plans ordinarily require an increased acreage of grasses and legumes and fewer acres of grains and row crops. Both of these developments increase the supply of forages relative to grains and give rise to questions of using forage profitably. One possibility is the substitution of forage for grain in rations of ruminants. The feasibility of this adjustment depends, however, on the rate at which the various classes of feeds substitute for each other. Recent changes in price structures, with dairy product prices depressed relative to feed and labor costs, also have caused farmers to examine substitution possibilities as a means of lowering costs and increasing profits. Then, too, yearly and geographic differentials in the costs of concentrates relative to forages and to the price of milk give rise to questions of the most profitable ration under particular economic circumstances. To what extent should the grain-forage ration be varied as the price of grain changes relative to the price of forage at particular locations? To what extent should the most profitable ration differ between grain surplus and grain deficit areas or other areas where concentrates are priced at different levels? These questions can be answered only if information is available on substitution ratios. The optimum ration, in terms of profit maximization, can be determined only by relating substitution ratios to price ratios. Finally, determining the nature of the milk production surface with its expression of feed/milk transformation ratios and feed substitution coefficients is a central problem in dairy cow nutrition

    Ultra-High Energy Cosmic Rays in a Structured and Magnetized Universe

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    We simulate propagation of cosmic ray nucleons above 10^{19} eV in scenarios where both the source distribution and magnetic fields within about 50 Mpc from us are obtained from an unconstrained large scale structure simulation. We find that consistency of predicted sky distributions with current data above 4 x 10^{19} eV requires magnetic fields of ~0.1 microGauss in our immediate environment, and a nearby source density of ~10^{-4}-10^{-3} Mpc^{-3}. Radio galaxies could provide the required sources, but only if both high and low-luminosity radio galaxies are very efficient cosmic ray accelerators. Moreover, at ~10^{19} eV an additional isotropic flux component, presumably of cosmological origin, should dominate over the local flux component by about a factor three in order to explain the observed isotropy. This argues against the scenario in which local astrophysical sources of cosmic rays above ~10^{19} eV reside in strongly magnetized (B~0.1 microGauss) and structured intergalactic medium. Finally we discuss how future large scale full-sky detectors such as the Pierre Auger project will allow to put much more stringent constraints on source and magnetic field distributions.Comment: 11 revtex pages, 10 postscript figures included, final version to appear in PR

    Am I just not good enough? The creation, development and questioning of a high performance coaching identity

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    While the career experiences and trajectories of various sports workers have received increased scholarly attention, those of professional coaches have, in comparison, received scant consideration. This paper focuses on the career experiences of Maeve (a pseudonym), a high performance coach, and the critical incidents related to the creation, development, and, ultimately, questioning of her professional identity. Data were collected through a series of narrative-biographical interviews and were subject to a process of iterative data analysis. The results indicated that her significant investment into her coaching self, combined with the vagaries and uncertain nature of work in high performance coaching, led her to experience a biographical disruption that interrupted the narrative coherence of her coaching life. The findings add further credence to recent critiques of only understanding and representing coaching careers in a linear and chronically staged fashion

    Minimal changes in health status questionnaires: distinction between minimally detectable change and minimally important change

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    Changes in scores on health status questionnaires are difficult to interpret. Several methods to determine minimally important changes (MICs) have been proposed which can broadly be divided in distribution-based and anchor-based methods. Comparisons of these methods have led to insight into essential differences between these approaches. Some authors have tried to come to a uniform measure for the MIC, such as 0.5 standard deviation and the value of one standard error of measurement (SEM). Others have emphasized the diversity of MIC values, depending on the type of anchor, the definition of minimal importance on the anchor, and characteristics of the disease under study. A closer look makes clear that some distribution-based methods have been merely focused on minimally detectable changes. For assessing minimally important changes, anchor-based methods are preferred, as they include a definition of what is minimally important. Acknowledging the distinction between minimally detectable and minimally important changes is useful, not only to avoid confusion among MIC methods, but also to gain information on two important benchmarks on the scale of a health status measurement instrument. Appreciating the distinction, it becomes possible to judge whether the minimally detectable change of a measurement instrument is sufficiently small to detect minimally important changes

    Efficacy of brief behavioral counselling by allied health professionals to promote physical activity in people with peripheral arterial disease (BIPP): study protocol for a multi-center randomized controlled trial

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    Background: Physical activity is recommended for people with peripheral arterial disease (PAD), and can improve walking capacity and quality of life; and reduce pain, requirement for surgery and cardiovascular events. This trial will assess the efficacy of a brief behavioral counselling intervention delivered by allied health professionals to improve physical activity in people with PAD. Methods: This is a multi-center randomised controlled trial in four cities across Australia. Participants (N = 200) will be recruited from specialist vascular clinics, general practitioners and research databases and randomised to either the control or intervention group. Both groups will receive usual medical care, a written PAD management information sheet including advice to walk, and four individualised contacts from a protocol-trained allied health professional over 3 months (weeks 1, 2, 6, 12). The control group will receive four 15-min telephone calls with general discussion about PAD symptoms and health and wellbeing. The intervention group will receive behavioral counselling via two 1-h face-to-face sessions and two 15-min telephone calls. The counselling is based on the 5A framework and will promote interval walking for 3 × 40 min/week. Assessments will be conducted at baseline, and 4, 12 and 24 months by staff blinded to participant allocation.Objectively assessed outcomes include physical activity (primary), sedentary behavior, lower limb body function, walking capacity, cardiorespiratory fitness, event-based claudication index, vascular interventions, clinical events, cardiovascular function, circulating markers, and anthropometric measures. Self-reported outcomes include physical activity and sedentary behavior, walking ability, pain severity, and health-related quality of life. Data will be analysed using an intention-to-treat approach. An economic evaluation will assess whether embedding the intervention into routine care would likely be value for money. A cost-effectiveness analysis will estimate change in cost per change in activity indicators due to the intervention, and a cost-utility analysis will assess change in cost per quality-adjusted life year. A full uncertainty analysis will be undertaken, including a value of information analysis, to evaluate the economic case for further research. Discussion: This trial will evaluate the efficacy and cost-effectiveness of a brief behavioral counselling intervention for a common cardiovascular disease with significant burden. Trial registration: ACTRN 12614000592640 Australian New Zealand Clinical Trials Registry. Registration Date 4 June 2014

    Evidence for Extended Hydrogen-Poor CSM in the Three-Peaked Light Curve of Stripped Envelope Ib Supernova

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    We present multi-band ATLAS photometry for SN 2019tsf, a stripped-envelope Type Ib supernova (SESN). The SN shows a triple-peaked light curve and a late (re-)brightening, making it unique among stripped-envelope systems. The re-brightening observations represent the latest photometric measurements of a multi-peaked Type Ib SN to date. As late-time photometry and spectroscopy suggest no hydrogen, the potential circumstellar material (CSM) must be H-poor. Moreover, late (>150 days) spectra show no signs of narrow emission lines, further disfavouring CSM interaction. On the contrary, an extended CSM structure is seen through a follow-up radio campaign with Karl G. Jansky Very Large Array (VLA), indicating a source of bright optically thick radio emission at late times, which is highly unusual among H-poor SESNe. We attribute this phenomenology to an interaction of the supernova ejecta with spherically-asymmetric CSM, potentially disk-like, and we present several models that can potentially explain the origin of this rare Type Ib supernova. The warped disc model paints a novel picture, where the tertiary companion perturbs the progenitors CSM, that can explain the multi-peaked light curves of SNe, and here we apply it to SN 2019tsf. This SN 2019tsf is likely a member of a new sub-class of Type Ib SNe and among the recently discovered class of SNe that undergo mass transfer at the moment of explosionComment: 23 pages, Comments are welcome, Submitted to Ap
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