613 research outputs found

    Development of a facial expression scale using footrot and mastitis as models of pain in sheep

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    Management of pain in sheep is limited by the challenges of recognising and accurately quantifying pain in this species. The use of facial expression scoring to assess pain is a well-utilised, practical tool in both humans and non-human animals. The objective of this study was to develop a standardised facial expression pain scale for adult sheep, that could be used reliably and accurately to detect pain associated with naturally occurring painful diseases, such as footrot and mastitis. We also investigated whether the scale could be reliably and accurately utilised by observers after training, enabling the development of an on-farm pain assessment tool. The Sheep Pain Facial Expression Scale (SPFES) was able to correctly identify sheep suffering from disease with a high degree of accuracy (AUC; Footrot: 0.81, Mastitis: 0.80). Diseased sheep scored higher on the scale than controls on the day of disease identification (P<0.05) and diseased sheep showed changes in their facial expression after treatment (P<0.001). The abnormal facial expressions of diseased sheep reduced over time, and at recovery were in line with control sheep. Control sheep did not change their facial expression over time. Five scorers who were trained to use the developed scale also assessed the facial expressions of sheep. The scorers were blind to treatment and session. Scorers reliably (ICC: 0.86) and accurately (α = 0.86) identified changes in the facial expression of sheep with footrot over time (P<0.05), and scored control sheep consistently low over time. The SPFES offers a reliable and effective method of assessing pain in sheep after minimal training.We would like to thank the EU VII Framework Program (FP7-KBBE-2010-4) for funding this study as part of the AWIN project. Boehringer Imgelheim Ltd are thanked for providing the meloxicam used in this study.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.applanim.2016.01.00

    Vacuum Stability, Perturbativity, and Scalar Singlet Dark Matter

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    We analyze the one-loop vacuum stability and perturbativity bounds on a singlet extension of the Standard Model (SM) scalar sector containing a scalar dark matter candidate. We show that the presence of the singlet-doublet quartic interaction relaxes the vacuum stability lower bound on the SM Higgs mass as a function of the cutoff and lowers the corresponding upper bound based on perturbativity considerations. We also find that vacuum stability requirements may place a lower bound on the singlet dark matter mass for given singlet quartic self coupling, leading to restrictions on the parameter space consistent with the observed relic density. We argue that discovery of a light singlet scalar dark matter particle could provide indirect information on the singlet quartic self-coupling.Comment: 25 pages, 10 figures; v2 - fixed minor typos; v3 - added to text discussions of other references, changed coloring of figures for easier black and white viewin

    Winter distribution and size structure of Antarctic krill Euphausia superba populations in-shore along the West Antarctic Peninsula

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    Antarctic krill Euphausia superba are a key component of food webs in the maritime West Antarctic Peninsula, and their life history is tied to the seasonal cycles of sea ice and primary production in the region. Previous work has shown a general in-shore migration of krill in winter in this region; however, the very near-shore has not often been sampled as part of these surveys. We investigated distribution, abundance, and size structure of krill in 3 fjordic bays along the peninsula, and in the adjacent Gerlache Strait area using vertically stratified MOCNESS net tows and ADCP acoustic biomass estimates. Krill abundance was high within bays, with net estimated densities exceeding 60 krill m-3, while acoustic estimates were an order of magnitude higher. Krill within bays were larger than krill in the Gerlache Strait. Within bays, krill aggregations were observed near the seafloor during the day with aggregations extending to the sediment interface, and exhibited diel vertical migration higher into the water column at night. We suggest these high winter krill abundances within fjords are indicative of an active seasonal migration by krill in the peninsula region. Potential drivers for such a migration include reduced advective losses and costs, and availability of sediment food resources within fjords. Seasonally near-shore krill may also affect stock and recruitment assessments and may have implications for managing the krill fishery in this area

    On the importance of the 1-loop finite corrections to seesaw neutrino masses

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    In the standard seesaw mechanism, finite corrections to the neutrino mass matrix arise from 1-loop self-energy diagrams mediated by a heavy neutrino. We study in detail these corrections and demonstrate that they can be very significant, exceeding in several cases the tree-level result. We consider the normal and inverted hierarchy spectra for light neutrinos and compute the finite corrections to the different elements of the neutrino mass matrix. Special attention is paid to their dependence with the parameters of the seesaw model. Among the cases in which the corrections can be large, we identify the fine-tuned models considered previously in the literature, where a strong cancellation between the different parameters is required to achieve compatibility with the experimental data. As a particular example, we also analyze how these corrections modify the tribimaximal mixing pattern and find that the deviations may be sizable, in particular for θ13\theta_{13}. Finally, we emphasize that due to their large size, the finite corrections to neutrino masses have to be taken into account if one wants to properly scan the parameter space of seesaw models.Comment: 24 pages, 11 figure

    Flavor Physics in an SO(10) Grand Unified Model

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    In supersymmetric grand-unified models, the lepton mixing matrix can possibly affect flavor-changing transitions in the quark sector. We present a detailed analysis of a model proposed by Chang, Masiero and Murayama, in which the near-maximal atmospheric neutrino mixing angle governs large new b -> s transitions. Relating the supersymmetric low-energy parameters to seven new parameters of this SO(10) GUT model, we perform a correlated study of several flavor-changing neutral current (FCNC) processes. We find the current bound on B(tau -> mu gamma) more constraining than B(B -> X_s gamma). The LEP limit on the lightest Higgs boson mass implies an important lower bound on tan beta, which in turn limits the size of the new FCNC transitions. Remarkably, the combined analysis does not rule out large effects in B_s-B_s-bar mixing and we can easily accomodate the large CP phase in the B_s-B_s-bar system which has recently been inferred from a global analysis of CDF and DO data. The model predicts a particle spectrum which is different from the popular Constrained Minimal Supersymmetric Standard Model (CMSSM). B(tau -> mu gamma) enforces heavy masses, typically above 1 TeV, for the sfermions of the degenerate first two generations. However, the ratio of the third-generation and first-generation sfermion masses is smaller than in the CMSSM and a (dominantly right-handed) stop with mass below 500 GeV is possible.Comment: 44 pages, 5 figures. Footnote and references added, minor changes, Fig. 2 corrected; journal versio

    Non-unitary Leptonic Mixing and Leptogenesis

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    We investigate the relation between non-unitarity of the leptonic mixing matrix and leptogenesis. We discuss how all parameters of the canonical type-I seesaw mechanism can, in principle, be reconstructed from the neutrino mass matrix and the deviation of the effective low-energy leptonic mixing matrix from unitary. When the mass M' of the lightest right-handed neutrino is much lighter than the masses of the others, we show that its decay asymmetries within flavour-dependent leptogenesis can be expressed in terms of two contributions, one depending on the unique dimension five (d=5) operator generating neutrino masses and one depending on the dimension six (d=6) operator associated with non-unitarity. In low-energy seesaw scenarios where small lepton number violation explains the smallness of neutrino masses, the lepton number conserving d=6 operator contribution generically dominates over the d=5 operator contribution which results in a strong enhancement of the flavour-dependent decay asymmetries without any resonance effects. To calculate the produced final baryon asymmetry, the flavour equilibration effects directly related to non-unitarity have to be taken into account. In a simple realization of this non-unitarity driven leptogenesis, the lower bound on M' is found to be about 10^8 GeV at the onset of the strong washout regime, more than one order of magnitude below the bound in "standard" thermal leptogenesis.Comment: 19 pages, REVTeX4, 2 eps and 2 axodraw figure

    Circulating Fatty Acids and Risk of Coronary Heart Disease and Stroke: Individual Participant Data Meta-Analysis in Up to 16 126 Participants

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    BACKGROUND We aimed at investigating the association of circulating fatty acids with coronary heart disease (CHD) and stroke risk. METHODS AND RESULTS We conducted an individual‐participant data meta‐analysis of 5 UK‐based cohorts and 1 matched case‐control study. Fatty acids (ie, omega‐3 docosahexaenoic acid, omega‐6 linoleic acid, monounsaturated and saturated fatty acids) were measured at baseline using an automated high‐throughput serum nuclear magnetic resonance metabolomics platform. Data from 3022 incident CHD cases (13 104 controls) and 1606 incident stroke cases (13 369 controls) were included. Logistic regression was used to model the relation between fatty acids and odds of CHD and stroke, adjusting for demographic and lifestyle variables only (ie, minimally adjusted model) or with further adjustment for other fatty acids (ie, fully adjusted model). Although circulating docosahexaenoic acid, but not linoleic acid, was related to lower CHD risk in the fully adjusted model (odds ratio, 0.85; 95% CI, 0.76–0.95 per standard unit of docosahexaenoic acid), there was evidence of high between‐study heterogeneity and effect modification by study design. Stroke risk was consistently lower with increasing circulating linoleic acid (odds ratio for fully adjusted model, 0.82; 95% CI, 0.75–0.90). Circulating monounsaturated fatty acids were associated with higher CHD risk across all models and with stroke risk in the fully adjusted model (odds ratio, 1.22; 95% CI, 1.03–1.44). Saturated fatty acids were not related to increased CHD risk in the fully adjusted model (odds ratio, 0.94; 95% CI, 0.82–1.09), or stroke risk. CONCLUSIONS We found consistent evidence that linoleic acid was associated with decreased risk of stroke and that monounsaturated fatty acids were associated with increased risk of CHD. The different pattern between CHD and stroke in terms of fatty acids risk profile suggests future studies should be cautious about using composite events. Different study designs are needed to assess which, if any, of the associations observed is causal

    Beyond the standard seesaw: neutrino masses from Kahler operators and broken supersymmetry

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    We investigate supersymmetric scenarios in which neutrino masses are generated by effective d=6 operators in the Kahler potential, rather than by the standard d=5 superpotential operator. First, we discuss some general features of such effective operators, also including SUSY-breaking insertions, and compute the relevant renormalization group equations. Contributions to neutrino masses arise at low energy both at the tree level and through finite threshold corrections. In the second part we present simple explicit realizations in which those Kahler operators arise by integrating out heavy SU(2)_W triplets, as in the type II seesaw. Distinct scenarios emerge, depending on the mechanism and the scale of SUSY-breaking mediation. In particular, we propose an appealing and economical picture in which the heavy seesaw mediators are also messengers of SUSY breaking. In this case, strong correlations exist among neutrino parameters, sparticle and Higgs masses, as well as lepton flavour violating processes. Hence, this scenario can be tested at high-energy colliders, such as the LHC, and at lower energy experiments that measure neutrino parameters or search for rare lepton decays.Comment: LaTeX, 34 pages; some corrections in Section

    Seesaw Neutrino Signals at the Large Hadron Collider

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    We discuss the scenario with gauge singlet fermions (right-handed neutrinos) accessible at the energy of the Large Hadron Collider. The singlet fermions generate tiny neutrino masses via the seesaw mechanism and also have sizable couplings to the standard-model particles. We demonstrate that these two facts, which are naively not satisfied simultaneously, are reconciled in the five-dimensional framework in various fashions, which make the seesaw mechanism observable. The collider signal of tri-lepton final states with transverse missing energy is investigated for two explicit examples of the observable seesaw, taking account of three types of neutrino mass spectrum and the constraint from lepton flavor violation. We find by showing the significance of signal discovery that the collider experiment has a potential to find signals of extra dimensions and the origin of small neutrino masses.Comment: 27 pages, 4 figure

    Lepton flavour violation in the MSSM

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    We derive new constraints on the quantities delta_{XY}^{ij}, X,Y=L,R, which parametrise the flavour-off-diagonal terms of the charged slepton mass matrix in the MSSM. Considering mass and anomalous magnetic moment of the electron we obtain the bound |delta^{13}_{LL} delta^{13}_{RR}|<0.1 for tan beta=50, which involves the poorly constrained element delta^{13}_{RR}. We improve the predictions for the decays tau -> mu gamma, tau -> e gamma and mu -> e gamma by including two-loop corrections which are enhanced if tan beta is large. The finite renormalisation of the PMNS matrix from soft SUSY-breaking terms is derived and applied to the charged-Higgs-lepton vertex. We find that the experimental bound on BR(tau -> e gamma) severely limits the size of the MSSM loop correction to the PMNS element U_{e3}, which is important for the proper interpretation of a future U_{e3} measurement. Subsequently we confront our new values for delta^{ij}_{LL} with a GUT analysis. Further, we include the effects of dimension-5 Yukawa terms, which are needed to fix the Yukawa unification of the first two generations. If universal supersymmetry breaking occurs above the GUT scale, we find the flavour structure of the dimension-5 Yukawa couplings tightly constrained by mu -> e gamma.Comment: 37 pages, 15 figures; typo in Equation (35) and (49) correcte
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