6,746 research outputs found

    Animal Transport: Developing optimum animal handling procedures and effective transport strategies in the food production chain to improve animal welfare and food quality

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    End of project reportA series of studies were performed to investigate the effect of transport on liveweight, physiological and haematological responses of cattle. The first study was carried out over a 6 week period in the Spring of 2004. Eighty-four continental x bulls (mean weight (s.d.) 367 (35) kg), naïve to transport, were randomly assigned to one of six journey (J) times of 0, 6, 9, 12, 18 and 24h transport at a stocking density of 1.02m2/bull. Blood samples were collected by jugular venipuncture before, immediately after and at 1, 2, 4, 6, 8, 12 and 24h and bulls were weighed before, immediately after, and at 4, 12 and 24h. Bulls travelling for 6h (280 km), 9h (435 km), 12h (582 km), 18h (902 km) and 24h (1192 km) lost 4.7, 4.5, 5.7 (P=0.05), 6.6 (P=0.05) and 7.5 (P=0.05) percentage liveweight compared with baseline. During the 24h recovery period liveweight was regained to pre-transport levels. Lymphocyte percentages were lower (P=0.001) and neutrophil percentages were higher (P=0.05) in all animals. Blood protein and creatine kinase, glucose and NEFA concentrations were higher (P=0.05) in the bulls following transport and returned to baseline within 24h. In conclusion, liveweight and some physiological and haematological responses of bulls returned to pre-transport levels within 24h having had access to feed and water. Transport of bulls from 6 – 24hours did not impact negatively on animal welfare

    Physiological and behavioural aspects of housing stress in cattle

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    End of project reportThe effect of various space allowances on pituitary, adrenal, immune responses and performance was investigated in 72 Holstein x Friesian bulls. Bulls (403 ± 3.5 kg) were blocked by weight and randomly assigned into two groups (familiar, F and unfamiliar, UF) x three (1.2, 2.7 and 4.2 m2 per bull; n = 24 bulls per space allowance) treatments and housed for 83 days in 18 pens (n = 4 per pen). Blood samples were collected on day –1, 0, 3, 14, 36 and 77 with respect to mixing and housing on day 0. The bulls were administered with adrenocorticotrophic hormone (ACTH) on day 3 and corticotrophin-releasing hormone (CRH) on days 14, 36 and 77. The basal cortisol concentrations were not affected (P>0.05) by mixing of familiar and unfamiliar bulls. On day 3, basal cortisol was greater (P0.05) of treatment and treatment x time on ACTH. On day 14, interferon-? production was lower (P0.05) different for those housed at 1.2 m2. Bulls housed at either space allowances had (P<0.05) neutrophilia, lymphopenia, eosinopenia and decreased haemoglobin on day 3 compared with day 0. The liveweight gain from days 0 to 83 was lower (P< 0.05) in bulls housed at 1.2 compared with those at 2.7 and 4.2 m2. Housing bulls at 1.2 m2 space allowance had a detrimental effect on their growth and was associated with an acute rise in plasma cortisol concentration (on day 3) compared with space allowances of 2.7 and 4.2 m2/bull.European Union Structural Funds (EAGGF

    Anomalous reaction-transport processes: the dynamics beyond the Mass Action Law

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    In this paper we reconsider the Mass Action Law (MAL) for the anomalous reversible reaction ABA\rightleftarrows B with diffusion. We provide a mesoscopic description of this reaction when the transitions between two states AA and BB are governed by anomalous (heavy-tailed) waiting-time distributions. We derive the set of mesoscopic integro-differential equations for the mean densities of reacting and diffusing particles in both states. We show that the effective reaction rate memory kernels in these equations and the uniform asymptotic states depend on transport characteristics such as jumping rates. This is in contradiction with the classical picture of MAL. We find that transport can even induce an extinction of the particles such that the density of particles AA or BB tends asymptotically to zero. We verify analytical results by Monte Carlo simulations and show that the mesoscopic densities exhibit a transient growth before decay.Comment: 4 pages, 3 figure

    Synchronization of globally coupled two-state stochastic oscillators with a state dependent refractory period

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    We present a model of identical coupled two-state stochastic units each of which in isolation is governed by a fixed refractory period. The nonlinear coupling between units directly affects the refractory period, which now depends on the global state of the system and can therefore itself become time dependent. At weak coupling the array settles into a quiescent stationary state. Increasing coupling strength leads to a saddle node bifurcation, beyond which the quiescent state coexists with a stable limit cycle of nonlinear coherent oscillations. We explicitly determine the critical coupling constant for this transition

    The Mass-Metallicity Relation for Giant Planets

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    Exoplanet discoveries of recent years have provided a great deal of new data for studying the bulk compositions of giant planets. Here we identify 47 transiting giant planets (20M<M<20MJ20 M_\oplus < M < 20 M_{\mathrm{J}}) whose stellar insolation is low enough (F<2×108  erg  s1  cm2F_* < 2\times10^8\; \text{erg}\; \text{s}^{-1}\; \text{cm}^{-2}, or roughly Teff<1000T_\text{eff} < 1000) that they are not affected by the hot Jupiter radius inflation mechanism(s). We compute a set of new thermal and structural evolution models and use these models in comparison with properties of the 47 transiting planets (mass, radius, age) to determine their heavy element masses. A clear correlation emerges between the planetary heavy element mass MzM_z and the total planet mass, approximately of the form MzMM_z \propto \sqrt{M}. This finding is consistent with the core accretion model of planet formation. We also study how stellar metallicity [Fe/H] affects planetary metal-enrichment and find a weaker correlation than has been previously reported from studies with smaller sample sizes. We confirm a strong relationship between the planetary metal-enrichment relative to the parent star Zplanet/ZstarZ_{\rm planet}/Z_{\rm star} and the planetary mass, but see no relation in Zplanet/ZstarZ_{\rm planet}/Z_{\rm star} with planet orbital properties or stellar mass. The large heavy element masses of many planets (>50>50 MM_{\oplus}) suggest significant amounts of heavy elements in H/He envelopes, rather than cores, such that metal-enriched giant planet atmospheres should be the rule. We also discuss a model of core-accretion planet formation in a one-dimensional disk and show that it agrees well with our derived relation between mass and Zplanet/ZstarZ_{\rm planet}/Z_{\rm star}.Comment: Accepted to The Astrophysical Journal. This revision adds a substantial amount of discussion; the results are the sam

    Evolution and impact of defects in a p-channel CCD after cryogenic proton-irradiation

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    P-channel CCDs have been shown to display improved tolerance to radiation-induced charge transfer inefficiency (CTI) when compared to n-channel CCDs. However, the defect distribution formed during irradiation is expected to be temperature dependent due to the differences in lattice energy caused by a temperature change. This has been tested through defect analysis of two p-channel e2v CCD204 devices, one irradiated at room temperature and one at a cryogenic temperature (153K). Analysis is performed using the method of single trap pumping. The dominant charge trapping defects at these conditions have been identified as the donor level of the silicon divacancy and the carbon interstitial defect. The defect parameters are analysed both immediately post irradiation and following several subsequent room-temperature anneal phases up until a cumulative anneal time of approximately 10 months. We have also simulated charge transfer in an irradiated CCD pixel using the defect distribution from both the room-temperature and cryogenic case, to study how the changes affect imaging performance. The results demonstrate the importance of cryogenic irradiation and annealing studies, with large variations seen in the defect distribution when compared to a device irradiated at room-temperature, which is the current standard procedure for radiation-tolerance testing

    State Gladiators Go High Tech with Records--Will the Feds Follow?

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    The Broadband X-Ray Spectrum of the X-Ray-obscured Type 1 AGN 2MASX J193013.80+341049.5

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    We present results from modeling the broadband X-ray spectrum of the Type 1 active galactic nucleus (AGN) 2MASX J193013.80+341049.5 using NuSTAR, Swift, and archival XMM-Newton observations. We find this source to be highly X-ray obscured, with column densities exceeding 10²³ cm⁻² across all epochs of X-ray observations, spanning an 8 yr period. However, the source exhibits prominent broad optical emission lines, consistent with an unobscured Type 1 AGN classification. We fit the X-ray spectra with both phenomenological reflection models and physically motivated torus models to model the X-ray absorption. We examine the spectral energy distribution of this source and investigate some possible scenarios to explain the mismatch between X-ray and optical classifications. We compare the ratio of reddening to X-ray absorbing column density (E_(B−V)/N_H) and find that 2MASX J193013.80+341049.5 likely has a much lower dust-to-gas ratio relative to the Galactic interstellar medium, suggesting that the broad line region itself could provide the source of extra X-ray obscuration, being composed of low-ionization, dust-free gas

    Effect of road transport for up to 24 hours followed by twenty-four hour recovery on live weight and physiological responses of bulls

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    peer-reviewedBackground: The transport of livestock can have major implications for their welfare, and there is strong public interest and scientific endeavour aimed at ensuring that the welfare of transported animals is optimal. The objective of the study was to investigate the effect of transport on live weight, physiological and haematological responses of bulls after road transport of 0, 6, 9, 12, 18 and 24 hours (h). Seventy-two Charolais bulls (mean weight (s.d.) 367 (35) kg), naïve to transport, were randomly assigned to one of six journey (J) times of 0 h, 6 h, 9 h, 12 h, 18 h and 24 h transport (n = 12 animals/treatment) at a stocking density of 1.02 m2/bull. Blood samples were collected by jugular venipuncture before transport (-0.25 h), immediately after (0 h) and at 1 h, 2 h, 4 h, 6 h, 8 h, 12 h and 24 h relative to time 0 h. The bulls were weighed before transport (- 24 h and - 0.25 h), immediately after (0 h), and at 4 h, 12 h and 24 h relative to time 0 h. Control animals were blood sampled before assignment (-0.25 h) to novel pens, after (24 h), and at 1 h, 2 h, 4 h, 6 h, 8 h, 12 h and 24 h relative to the 24 h sampling time point. Results: Bulls travelling for 6 h (280 km), 9 h (435 km), 12 h (582 km), 18 h (902 km) and 24 h (1192 km) lost 4.7, 4.5, 5.7 (P < 0.05), 6.6 (P < 0.05) and 7.5 (P < 0.05) percentage (%) live weight compared with baseline. Live weight re-gained to pre-transport levels during the 24 h recovery period. Lymphocyte percentages were lower (P < 0.05) and neutrophil percentages were greater (P < 0.05) in all animals. Blood protein, glucose and NEFA concentrations and creatine kinase activity were greater (P < 0.05) in the bulls following transport and returned to baseline within 24 h. Conclusions: Under the conditions of the present study, transport of bulls on journeys by road, ranging from 6 h (280 km) to 24 h (1192 km) duration, affected live weight, haematological and physiological measurements of metabolism and inflammation. Our findings showed that live weight and some physiological and haematological responses of bulls returned to pre-transport levels within 24 h with animals having had access to feed and water

    Postirradiation behavior of p-channel charge-coupled devices irradiated at 153 K

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    The displacement damage hardness that can be achieved using p-channel charge-coupled devices (CCD) was originally demonstrated in 1997, and since then a number of other studies have demonstrated an improved tolerance to radiation-induced CTI when compared to n-channel CCDs. A number of recent studies have also shown that the temperature history of the device after the irradiation impacts the performance of the detector, linked to the mobility of defects at different temperatures. This study describes the initial results from an e2v technologies p-channel CCD204 irradiated at 153 K with a 10 MeV equivalent proton fluences of 1.24×109 and 1.24×1011 protons cm-2. The dark current, cosmetic quality and the number of defects identified using trap pumping immediately were monitored after the irradiation for a period of 150 hours with the device held at 153 K and then after different periods of time at room temperature. The device also exhibited a flatband voltage shift of around 30 mV / krad, determined by the reduction in full well capacity
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