2,298 research outputs found

    Prevalence of sarcopenia in the French senior population

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    Introduction A muscle mass normalized for height2 (MMI) or for body weight (SMI) below 2SD under the mean for a young population defines sarcopenia. This study aimed at setting the cutoffs and the prevalence of sarcopenia in the French elderly population. Another objective was to compare the results obtained with SMI and MMI.Methods: Muscle mass was assessed by bioelectrical impedance analysis in 782 healthy adults (<40 years) to determine skeletal mass index (SMI, muscle mass*100/weight) and muscle mass index (MMI, muscle mass/height2). Prevalence was estimated in 888 middle aged (40–59 years) and 218 seniors (60–78 years). All were healthy people.Results: For women mean-2SD were 6.2 kg/m2 (MMI) and 26.6% (SMI); for men limits were 8.6 kg/m2 (MMI) and 34.4% (SMI). In middle aged persons a small number of them were identified as sarcopenic. In healthy seniors, 2.8% of women and 3.6% of men were sarcopenic (MMI). The prevalence was 23.6% in women and 12.5% in men with SMI. MMI and SMI identified different sarcopenic populations, leaner subjects for MMI while fatter subjects for SMI.Conclusion: Cutoff values for the French population were defined. Prevalence of sarcopenia was different from that in the US population

    Discovery of spatial periodicities in a coronal loop using automated edge-tracking algorithms

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    A new method for automated coronal loop tracking, in both spatial and temporal domains, is presented. Applying this technique to TRACE data, obtained using the 171 Ã… filter on 1998 July 14, we detect a coronal loop undergoing a 270 s kink-mode oscillation, as previously found by Aschwanden et al. However, we also detect flare-induced, and previously unnoticed, spatial periodicities on a scale of 3500 km, which occur along the coronal loop edge. Furthermore, we establish a reduction in oscillatory power for these spatial periodicities of 45% over a 222 s interval. We relate the reduction in detected oscillatory power to the physical damping of these loop-top oscillations

    Spectrometric method to detect exoplanets as another test to verify the invariance of the velocity of light

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    Hypothetical influences of variability of light velocity due to the parameters of the source of radiation, for the results of spectral measurements of stars to search for exoplanets are considered. Accounting accelerations of stars relative to the barycenter of the star - a planet (the planets) was carried out. The dependence of the velocity of light from the barycentric radial velocity and barycentric radial acceleration component of the star should lead to a substantial increase (up to degree of magnitude) semi-major axes of orbits detected candidate to extrasolar planets. Consequently, the correct comparison of the results of spectral method with results of other well-known modern methods of detecting extrasolar planets can regard the results obtained in this paper as a reliable test for testing the invariance of the velocity of light.Comment: 11 pages, 5 figure

    Planning the Future of U.S. Particle Physics (Snowmass 2013): Chapter 4: Cosmic Frontier

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    These reports present the results of the 2013 Community Summer Study of the APS Division of Particles and Fields ("Snowmass 2013") on the future program of particle physics in the U.S. Chapter 4, on the Cosmic Frontier, discusses the program of research relevant to cosmology and the early universe. This area includes the study of dark matter and the search for its particle nature, the study of dark energy and inflation, and cosmic probes of fundamental symmetries.Comment: 61 page

    The Concordance Cosmic Star Formation Rate: Implications from and for the Supernova Neutrino and Gamma Ray Backgrounds

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    We constrain the Cosmic Star Formation Rate (CSFR) by requiring that massive stars produce the observed UV, optical, and IR light while at the same time not overproduce the Diffuse Supernova Neutrino Background as bounded by Super-Kamiokande. With the massive star component so constrained we then show that a reasonable choice of stellar Initial Mass Function and other parameters results in SNIa rates and iron yields in good agreement with data. In this way we define a `concordance' CSFR that predicts the optical SNII rate and the SNIa contribution to the MeV Cosmic Gamma-Ray Background. The CSFR constrained to reproduce these and other proxies of intermediate and massive star formation is more clearly delineated than if it were measured by any one technique and has the following testable consequences: (1) SNIa contribute only a small fraction of the MeV Cosmic Gamma-Ray Background, (2) massive star core-collapse is nearly always accompanied by a successful optical SNII, and (3) the Diffuse Supernova Neutrino Background is tantalizingly close to detectability.Comment: Improved discussion. Version accepted for publication in JCA

    Indirect Detection of a Light Higgsino Motivated by Collider Data

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    Kane and Wells recently argued that collider data point to a Higgsino-like lightest supersymmetric partner which would explain the dark matter in our Galactic halo. They discuss direct detection of such dark-matter particles in laboratory detectors. Here, we argue that such a particle, if it is indeed the dark matter, might alternatively be accessible in experiments which search for energetic neutrinos from dark-matter annihilation in the Sun. We provide accurate analytic estimates for the rates which take into account all relevant physical effects. Currently, the predicted signal falls roughly one to three orders of magnitude below experimental bounds, depending on the mass and coupling of the particle; however, detectors such as MACRO, super-Kamiokande, and AMANDA will continue to take data and should be able to rule out or confirm an interesting portion of the possible mass range for such a dark-matter particle within the next five years.Comment: 10 pages, RevTe

    Baryogenesis from Gravitational Decay of TeV-Particles in Theories with Low Scale Gravity

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    In models with the fundamental gravity scale in the TeV range, early cosmology is quite different from the standard picture, because the universe must have arisen at a much lower temperature and the electroweak symmetry was probably never restored. In this context, baryogenesis appears to be problematic: if the involved physics is essentially that of the Standard Model, ``conventional'' non-conserving baryon number processes are completely negligible at such low temperatures. In this paper we show that the observed matter-antimatter asymmetry of the universe may be generated by gravitational decay of TeV-mass particles: such objects can be out of equilibrium after inflation and, if their mass is of the same order of magnitude as the true quantum gravity scale, they can quickly decay through a black hole intermediate state, violating global symmetries, in particular, baryon number. In this context, we take advantage of the fact that the ``Sakharov conditions'' for baryogenesis can be more easily satisfied with a low fundamental scale of gravity.Comment: 18 pages, added reference

    Case series on granulosa cell tumour in cattle with practical hints on diagnostics and outcome

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    Granulosa cell tumours are the most common neoplasm of the bovine ovary and present with a wide range of clinical signs. This case series comprises five case reports of ovarian granulosa cell tumours in cattle. The affected animals had different breeds (Red Holstein, Eringer, Swiss Braunvieh, crossbred beef) and ranged in age from 1 year 4 months to 20 years 11 months. The diversity of the cases gives an overview of the diagnostic possibilities as well as the possible treatments and outcomes of the disease. Anti-mullerian hormone (AMH) was measured in one of the affected animals, and was extremely elevated (>150 pmoL/L) compared to reported normal values (<3 pmoL/L). Three animals underwent standing laparotomy with unilateral ovariectomy, and the remaining two animals were slaughtered. One of the cases confirms the previously published reports that malignancy or metastasis is possible in cattle. Another case indicates that successful surgical treatment with subsequent resumption of reproduction is possible. In summary, the initial tentative diagnosis of GCT is made by ultrasound-assisted rectal examination of the genital tract or ovaries and can subsequently be supported by evaluation of AMH levels. The decision to proceed with treatment should be made without delay, as surgical removal of the altered ovary with subsequent resumption of reproductive activity and cessation of undesirable behaviour is possible

    Mode regularization of the susy sphaleron and kink: zero modes and discrete gauge symmetry

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    To obtain the one-loop corrections to the mass of a kink by mode regularization, one may take one-half the result for the mass of a widely separated kink-antikink (or sphaleron) system, where the two bosonic zero modes count as two degrees of freedom, but the two fermionic zero modes as only one degree of freedom in the sums over modes. For a single kink, there is one bosonic zero mode degree of freedom, but it is necessary to average over four sets of fermionic boundary conditions in order (i) to preserve the fermionic Z2_2 gauge invariance ψ→−ψ\psi \to -\psi, (ii) to satisfy the basic principle of mode regularization that the boundary conditions in the trivial and the kink sector should be the same, (iii) in order that the energy stored at the boundaries cancels and (iv) to avoid obtaining a finite, uniformly distributed energy which would violate cluster decomposition. The average number of fermionic zero-energy degrees of freedom in the presence of the kink is then indeed 1/2. For boundary conditions leading to only one fermionic zero-energy solution, the Z2_2 gauge invariance identifies two seemingly distinct `vacua' as the same physical ground state, and the single fermionic zero-energy solution does not correspond to a degree of freedom. Other boundary conditions lead to two spatially separated ω∼0\omega \sim 0 solutions, corresponding to one (spatially delocalized) degree of freedom. This nonlocality is consistent with the principle of cluster decomposition for correlators of observables.Comment: 32 pages, 5 figure
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