5,643 research outputs found

    Effects of daily herbage allowance and stage of lactation on the intake and performance of dairy cows in early summer

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    peer-reviewedThis research was part-funded by European Union Structural Funds (EAGGF).The aim of this study was to investigate the relationship between daily herbage allowance (DHA) and the performance of dairy cows at two stages of lactation. Spring-calving (n=42, mean calving date 17 February) and autumn-calving (n=42, mean calving date 22 September) Friesian cows were divided into three equal groups and assigned to three levels of DHA (above a cutting height of 35 mm), 17 (L), 20 (M) and 23 (H) kg of dry matter (DM) per head, from late April to late June, 1996. The spring-calving cows grazed to sward heights (mm) of 47, 56 and 65 (s.e. 0.6) and residual herbage organic matter (OM) masses (above 35 mm) of 294, 408 and 528 (s.e. 12.1) kg/ha for L, M and H, respectively. The autumn-calving cows grazed to corresponding sward heights of 51, 60 and 69 (s.e. 1.1) mm and leftresidual herbage OM masses of 364, 445 and 555 (s.e. 12.9) kg/ha for L, M and H, respectively. Pastures were mechanically topped post grazing. Spring-calving cows consumed 13.3, 14.7 and 15.5 kg OM (s.e. 0.47) per day, and autumn-calving cows consumed 13.3, 13.8 and 14.9 kg OM (s.e. 0.43) per day for L, M and H, respectively. Mean daily solids-corrected milk yield was 23.1, 23.8 and 24.8 (s.e. 0.34) kg for the spring-calving cows, and 17.5, 18.4 and 18.7 (s.e. 0.35) kg for the autumncalving cows, for L, M and H, respectively. Milk yield could be predicted from preexperimental yield (PMY) and daily herbage organic matter allowance (DOMA, kg) according to the following equation: y = −1.13 + 0.76 (s.e. 0.030) PMY + 0.22 (s.e. 0.057) DOMA (r.s.d. 1.32, R2 0.89). The results indicate that high individual cow and herd production levels can be achieved from high quality herbage alone during early summer at a DHA of 23 kg DM for spring-calving cows and 20 kg DM for autumn-calving cows.European Unio

    Uncertainties in nuclear transition matrix elements for neutrinoless ββ\beta \beta decay II: the heavy Majorana neutrino mass mechanism

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    Employing four different parametrization of the pairing plus multipolar type of effective two-body interaction and three different parametrizations of Jastrow-type of short range correlations, the uncertainties in the nuclear transition matrix elements MN(0ν)M_{N}^{(0\nu)} due to the exchange of heavy Majorana neutrino for the 0+→0+0^{+}\rightarrow 0^{+} transition of neutrinoless double beta decay of 94^{94}Zr, 96^{96}Zr, 98^{98}Mo, 100^{100}Mo, 104^{104}Ru, 110^{110}Pd, 128,130^{128,130}Te and 150^{150}Nd isotopes in the PHFB model are estimated to be around 25%. Excluding the nuclear transition matrix elements calculated with Miller-Spenser parametrization of Jastrow short range correlations, the uncertainties are found to be 10%-15% smaller

    Bilateral temporal spinous projections overshadowing the sphenoidal spines: an anatomical and radiological evaluation

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    The infratemporal fossa has traditionally been described as a post-maxillary space, which is open below, to the rear and laterally. The most reliable osseous landmarks of the infratemporal and parapharyngeal spaces are the pterygoid and styloid processes and the sphenoidal spine. In the present study the skull exhibited the normal sphenoidal spines along with a prominent spinous projection emanating bilaterally from the tympanic plate of the temporal bone. The objective of the present paper is to report an anatomical and radiological evaluation of the sphenoidal spines coexistent with bilateral temporal spinous projections. Additionally, the topographical relationship of this osseous variation is discussed with particular reference to neurovascular structures. Unduly prominent temporal spinous projections may cause obstruction, thus reducing the operative field. The anatomical variations relating to bony and vascular structures in this region are of paramount importance to neurosurgeons and otorhinolaryngologists

    Evaporative Cooling of a Guided Rubidium Atomic Beam

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    We report on our recent progress in the manipulation and cooling of a magnetically guided, high flux beam of 87Rb^{87}{\rm Rb} atoms. Typically 7×1097\times 10^9 atoms per second propagate in a magnetic guide providing a transverse gradient of 800 G/cm, with a temperature ∼550\sim550 μ\muK, at an initial velocity of 90 cm/s. The atoms are subsequently slowed down to ∼60\sim 60 cm/s using an upward slope. The relatively high collision rate (5 s−1^{-1}) allows us to start forced evaporative cooling of the beam, leading to a reduction of the beam temperature by a factor of ~4, and a ten-fold increase of the on-axis phase-space density.Comment: 10 pages, 8 figure

    Determination of the Kobayashi-Maskawa-Cabibbo matrix element V_{us} under various flavor-symmetry-breaking models in hyperon semileptonic decays

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    We study the success to describe hyperon semileptonic decays of four models that incorporate second-order SU(3) symmetry breaking corrections. The criteria to assess their success is by determining V_{us} in each of the three relevant hyperon semileptonic decays and comparing the values obtained with one another and also with the one that comes from K_{l3} decays. A strong dependence on the particular symmetry breaking model is observed. Values of V_{us} which do not agree with the one of K_{l3} are generally obtained. However, in the context of chiral perturbation theory, only the model whose corrections are O(m_s) and O(m_s^{3/2}) is successful. Using its predictions for the f_1 form factors one can quote a value of V_{us} from this model, namely, V_{us}=0.2176\pm 0.0026, which is in excellent agreement with the K_{l3} one.Comment: Final versio
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