5,572 research outputs found

    Effects of coffee with different roasting degrees on obesity and related metabolic disorders

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    This study aimed to assess the effect of unroasted, dark and very dark roasted coffee on obesity and metabolic disorders in obese rats. All coffee samples significantly reduced weight gain (∌17%) compared to obese control. Coffee reduced glucose levels (∌17%) upon a glucose tolerance test in all cases compared to the control, while fasting glucose only decreased (∌26%) with very dark coffee. Insulin levels and insulin resistance significantly decreased (∌77% and 65% respectively) with all coffee samples compared to the control. Unroasted and dark roasted coffee decreased triglycerides (∌21% and ∌ 11%, respectively), and unroasted coffee also reduced free fatty acids (∌43%) and adipocyte size. Coffee decreased liver steatosis (∌55%) and Caspase-3 levels (∌27%), regardless of the roasting degree. Overall, coffee plays a positive role in restraining obesity and related metabolic disorders but, depending on the metabolic pathway and relevant marker, an effect of roasting could be either found or not

    Infall Signatures in a Prestellar Core embedded in the High-Mass 70 ΌΌm Dark IRDC G331.372-00.116

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    Using Galactic Plane surveys, we have selected a massive (1200 M⊙_\odot), cold (14 K) 3.6-70 ÎŒ\mum dark IRDC G331.372-00.116. This IRDC has the potential to form high-mass stars and, given the absence of current star formation signatures, it seems to represent the earliest stages of high-mass star formation. We have mapped the whole IRDC with the Atacama Large Millimeter/submillimeter Array (ALMA) at 1.1 and 1.3 mm in dust continuum and line emission. The dust continuum reveals 22 cores distributed across the IRDC. In this work, we analyze the physical properties of the most massive core, ALMA1, which has no molecular outflows detected in the CO (2-1), SiO (5-4), and H2_2CO (3-2) lines. This core is relatively massive (MM = 17.6 M⊙_\odot), subvirialized (virial parameter αvir=Mvir/M=0.14\alpha_{vir}=M_{vir}/M=0.14), and is barely affected by turbulence (transonic Mach number of 1.2). Using the HCO+^+ (3-2) line, we find the first detection of infall signatures in a relatively massive, prestellar core (ALMA1) with the potential to form a high-mass star. We estimate an infall speed of 1.54 km s−1^{-1} and a high accretion rate of 1.96 ×\times 10−3^{-3} M⊙_\odot yr−1^{-1}. ALMA1 is rapidly collapsing, out of virial equilibrium, more consistent with competitive accretion scenarios rather than the turbulent core accretion model. On the other hand, ALMA1 has a mass ∌\sim6 times larger than the clumps Jeans mass, being in an intermediate mass regime (MJ=2.7<Mâ‰ČM_{J}=2.7<M\lesssim 30 M⊙_\odot), contrary to what both the competitive accretion and turbulent core accretion theories predict

    Anomalous processes at high temperature and density in a 2-dimensional linear σ\sigma model

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    We use the 2-dimensional σ\sigma model as a toy model to study the behavior of anomalous amplitudes in the limit where the constituent quark mass is small. Symmetry arguments tell that the πo→γ\pi^o\to\gamma amplitude should vanish if m→0m\to 0, but we show that this conclusion is spoiled by infrared singularities. When a proper regularization (resummation of a thermal mass, for instance) is taken into account, this amplitude vanishes as expected. We also study the amplitude πoÏƒâ†’Îł\pi^o\sigma\to\gamma and show that it does not vanish in the same limit.Comment: 15 pages Latex document, 2 postscript figure

    Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

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    Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{6×10196\times 10^{19}eV}. The anisotropy was measured by the fraction of arrival directions that are less than 3.1∘3.1^\circ from the position of an active galactic nucleus within 75 Mpc (using the V\'eron-Cetty and V\'eron 12th12^{\rm th} catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is (38−6+7)(38^{+7}_{-6})%, compared with 2121% expected for isotropic cosmic rays. This is down from the early estimate of (69−13+11)(69^{+11}_{-13})%. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201

    Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

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    The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E>Eth=5.5×1019E>E_{th}=5.5\times 10^{19} eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E>EthE>E_{th} are heavy nuclei with charge ZZ, the proton component of the sources should lead to excesses in the same regions at energies E/ZE/Z. We here report the lack of anisotropies in these directions at energies above Eth/ZE_{th}/Z (for illustrative values of Z=6, 13, 26Z=6,\ 13,\ 26). If the anisotropies above EthE_{th} are due to nuclei with charge ZZ, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies

    Highlights from the Pierre Auger Observatory

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    The Pierre Auger Observatory is the world's largest cosmic ray observatory. Our current exposure reaches nearly 40,000 km2^2 str and provides us with an unprecedented quality data set. The performance and stability of the detectors and their enhancements are described. Data analyses have led to a number of major breakthroughs. Among these we discuss the energy spectrum and the searches for large-scale anisotropies. We present analyses of our Xmax_{max} data and show how it can be interpreted in terms of mass composition. We also describe some new analyses that extract mass sensitive parameters from the 100% duty cycle SD data. A coherent interpretation of all these recent results opens new directions. The consequences regarding the cosmic ray composition and the properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray Conference, Rio de Janeiro 201

    Advanced functionality for radio analysis in the Offline software framework of the Pierre Auger Observatory

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    The advent of the Auger Engineering Radio Array (AERA) necessitates the development of a powerful framework for the analysis of radio measurements of cosmic ray air showers. As AERA performs "radio-hybrid" measurements of air shower radio emission in coincidence with the surface particle detectors and fluorescence telescopes of the Pierre Auger Observatory, the radio analysis functionality had to be incorporated in the existing hybrid analysis solutions for fluoresence and surface detector data. This goal has been achieved in a natural way by extending the existing Auger Offline software framework with radio functionality. In this article, we lay out the design, highlights and features of the radio extension implemented in the Auger Offline framework. Its functionality has achieved a high degree of sophistication and offers advanced features such as vectorial reconstruction of the electric field, advanced signal processing algorithms, a transparent and efficient handling of FFTs, a very detailed simulation of detector effects, and the read-in of multiple data formats including data from various radio simulation codes. The source code of this radio functionality can be made available to interested parties on request.Comment: accepted for publication in NIM A, 13 pages, minor corrections to author list and references in v

    Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory

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    We present the results of searches for dipolar-type anisotropies in different energy ranges above 2.5×10172.5\times 10^{17} eV with the surface detector array of the Pierre Auger Observatory, reporting on both the phase and the amplitude measurements of the first harmonic modulation in the right-ascension distribution. Upper limits on the amplitudes are obtained, which provide the most stringent bounds at present, being below 2% at 99% C.L.C.L. for EeV energies. We also compare our results to those of previous experiments as well as with some theoretical expectations.Comment: 28 pages, 11 figure

    Anomalous mesonic interactions near a chiral phase transition

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    Using constituent quarks coupled to a linear sigma model at nonzero temperature, I show that many anomalous mesonic amplitudes, such as π0→γγ\pi^0 \rightarrow \gamma \gamma, vanish in a chirally symmetric phase. Processes which are allowed, such as π0Ïƒâ†’ÎłÎł\pi^0 \sigma \rightarrow \gamma \gamma, are computed to leading order in a loop expansion.Comment: 4 pages, REVTeX, submitted to Phys. Rev. Let

    Ultrahigh-energy neutrino follow-up of Gravitational Wave events GW150914 and GW151226 with the Pierre Auger Observatory

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    On September 14, 2015 the Advanced LIGO detectors observed their first gravitational-wave (GW) transient GW150914. This was followed by a second GW event observed on December 26, 2015. Both events were inferred to have arisen from the merger of black holes in binary systems. Such a system may emit neutrinos if there are magnetic fields and disk debris remaining from the formation of the two black holes. With the surface detector array of the Pierre Auger Observatory we can search for neutrinos with energy above 100 PeV from point-like sources across the sky with equatorial declination from about -65 deg. to +60 deg., and in particular from a fraction of the 90% confidence-level (CL) inferred positions in the sky of GW150914 and GW151226. A targeted search for highly-inclined extensive air showers, produced either by interactions of downward-going neutrinos of all flavors in the atmosphere or by the decays of tau leptons originating from tau-neutrino interactions in the Earth's crust (Earth-skimming neutrinos), yielded no candidates in the Auger data collected within ±500\pm 500 s around or 1 day after the coordinated universal time (UTC) of GW150914 and GW151226, as well as in the same search periods relative to the UTC time of the GW candidate event LVT151012. From the non-observation we constrain the amount of energy radiated in ultrahigh-energy neutrinos from such remarkable events.Comment: Published version. Added journal reference and DOI. Added Report Numbe
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