5,314 research outputs found

    A novel phospholipid delivery system of curcumin (Meriva\uae) preserves muscular mass in healthy aging subjects

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    Curcumin is known to interrupt pro-inflammatory signalling and increases anti-oxidant protection, thus inhibiting the expression of inflammatory cytokines and the expression and function of inducible inflammatory enzymes. Together, these effects contribute to limit the onset and the progression of sarcopenia, due to the major role played by inflammation in the pathophysiology of this disease. This registry study evaluates the effects of Meriva\uae supplementation in otherwise healthy elderly subjects

    Length measurement and stabilization of the diagonals of a square area laser gyroscope

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    Large frame ring laser gyroscopes are top sensitivity inertial sensors able to measure absolute angular rotation rate below prad s-1 in few seconds. The GINGER project is aiming at directly measuring the Lense-Thirring effect with an 1% precision on an Earth based experiment. GINGER is based on an array of large frame ring laser gyroscopes. The mechanical design of this apparatus requires a micrometric precision in the construction and the geometry must be stabilized in order to keep constant the scale factor of the instrument. The proposed control is based on square cavities, and relies on the length stabilization of the two diagonals, which must be equal at micrometric level. GP2 is the prototype devoted to the scale factor control test. As a first step, the lengths of the diagonals of the ring cavity have been measured through an interferometric technique with a statistical accuracy of some tens of nanometers, and they have been locked to the wavelength of a reference optical standard. Continuous operation has been obtained over more than 12 h, without loss of sensitivity. GP2 is located in a laboratory with standard temperature stabilization, with residual fluctuations of the order of 1 C. Besides the demonstration of the control effectiveness, the analysis of the Sagnac frequency demonstrates that relative small and low-cost ring lasers (around one meter of side) can also achieve a sensitivity of the order of nrad s-1 in the range 0.01-10 Hz in a standard environment, which is the target sensitivity in many different applications, such as rotational seismology and next generation gravitational waves detectors

    Passing to the Limit in a Wasserstein Gradient Flow: From Diffusion to Reaction

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    We study a singular-limit problem arising in the modelling of chemical reactions. At finite {\epsilon} > 0, the system is described by a Fokker-Planck convection-diffusion equation with a double-well convection potential. This potential is scaled by 1/{\epsilon}, and in the limit {\epsilon} -> 0, the solution concentrates onto the two wells, resulting into a limiting system that is a pair of ordinary differential equations for the density at the two wells. This convergence has been proved in Peletier, Savar\'e, and Veneroni, SIAM Journal on Mathematical Analysis, 42(4):1805-1825, 2010, using the linear structure of the equation. In this paper we re-prove the result by using solely the Wasserstein gradient-flow structure of the system. In particular we make no use of the linearity, nor of the fact that it is a second-order system. The first key step in this approach is a reformulation of the equation as the minimization of an action functional that captures the property of being a curve of maximal slope in an integrated form. The second important step is a rescaling of space. Using only the Wasserstein gradient-flow structure, we prove that the sequence of rescaled solutions is pre-compact in an appropriate topology. We then prove a Gamma-convergence result for the functional in this topology, and we identify the limiting functional and the differential equation that it represents. A consequence of these results is that solutions of the {\epsilon}-problem converge to a solution of the limiting problem.Comment: Added two sections, corrected minor typos, updated reference

    Breeding for grapevine downy mildew resistance via gene editing

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    Downy mildew (DM) caused by the oomycete Plasmopara viticola ranks in the top diseases affecting grapevine (Vitis vinifera L.) cultivation and its control requires every year a large use of fungicides. The Farm to Fork strategy newly promoted by the EU aims to accelerate the transition to a sustainable food system and has set very ambitious targets including the reduction by 50% of the use and risk of pesticides by 2030. The introduction of disease-tolerant grapevine varieties or clones clearly represents a step forward to reach this goal. The recent advent of new breeding tools such as genome editing and cis-genesis offers a great opportunity to obtain resistant plants with higher precision and speed than by conventional breeding, either by knocking down susceptibility genes or by introducing known resistance-genes in commercial cultivars. Based on reports in other crops, the family of Downy Mildew Resistant 6 (DMR6) and DMR6-like oxygenases (DLOs) are candidate susceptibility genes for the control of DM resistance in V. vinifera. Deep-sequencing the putative susceptibility genes in 190 genetically diverse grapevine genotypes identified several Single Nucleotide Polymorphisms then screened for their impact on protein structure/function and association with DM resistant genotypes. Gene expression and gene network analysis suggested that grapevine DMR6 and DLO genes have distinct functions, and that VviDMR6-1 is co-regulated with several Pathogenesis-related genes. Based on this evidence, we generated a large collection of DMR6-1 and DMR6-2 single and double knock-out mutants in multiple grapevine cultivars and evaluated their resistance to DM. Phenotypic resistance data upon artificial infection are being collected and will be presented here. In parallel, we also developed a new DNA-free gene editing methodology and obtained non-transgenic and non-chimeric edited grapevine plants regenerated from a single cell

    Exact formulae for Higgs production through e gamma --> e H in the non-linear R_\xi gauge

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    We study the production of the SM Higgs boson (H^0) at future e gamma colliders, through the reaction e gamma --> e H^0. The amplitude is evaluated using the non-linear R_\xi gauge, which greatly simplifies the calculation. Complete analytical expressions for the amplitudes are presented, which include the contributions from 1-loop triangles "gamma gamma^* H^0" and "gamma Z^* H^0" as well as the W- and Z-boxes with their related eeH0eeH^0 triangle graphs. The resulting cross section for this mechanism indicates that it could be used to detect the Higgs signal and to test its properties.Comment: 6 pages, 2 figures, RevTe

    Kaon versus Antikaon Production at SIS Energies

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    We analyse the production and propagation of kaons and antikaons in Ni + Ni reactions from 0.8--1.85 GeV/u within a coupled channel transport approach including the channels BBK+YN,πBK+Y,BBNNKKˉ,πBNKKˉ,K+BK+B,KˉBKˉB,YNKˉNN,ππKKˉBB \to K^+YN, \pi B\to K^+Y, BB \to NN K \bar{K}, \pi B\to N K\bar{K}, K^+B\to K^+B, \bar{K} B\to \bar{K}B, Y N\to \bar{K} NN, \pi \pi\to K \bar{K} as well as πYKˉN\pi Y\to \bar{K}N and KˉNπY\bar{K} N\to \pi Y for the antikaon absorption. Whereas the experimental K+K^+ spectra can be reproduced without introducing any selfenergies for the mesons in Ni + Ni collisions from 0.8 to 1.8 GeV/u, the KK^- yield is underestimated by a factor of 5--7 at 1.66 and 1.85 GeV/u. However, introducing density dependent antikaon masses as proposed by Kaplan and Nelson, the antikaon spectra can be reasonably well described.Comment: 16 pages, LaTeX, plus 12 postscript figures, submitted to Nucl. Phys.

    α-Synuclein Aggregated with Tau and β-Amyloid in Human Platelets from Healthy Subjects: Correlation with Physical Exercise

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    The loss of protein homeostasis that has been associated with aging leads to altered levels and conformational instability of proteins, which tend to form toxic aggregates. In particular, brain aging presents characteristic patterns of misfolded oligomers, primarily constituted of β-amyloid (Aβ), tau, and α-synuclein (α-syn), which can accumulate in neuronal membranes or extracellular compartments. Such aging-related proteins can also reach peripheral compartments, thus suggesting the possibility to monitor their accumulation in more accessible fluids. In this respect, we have demonstrated that α-syn forms detectable hetero-aggregates with Aβ or tau in red blood cells (RBCs) of healthy subjects. In particular, α-syn levels and its heteromeric interactions are modulated by plasma antioxidant capability (AOC), which increases in turn with physical activity. In order to understand if a specific distribution of misfolded proteins can occur in other blood cells, a cohort of human subjects was enrolled to establish a correlation among AOC, the level of physical exercise and the concentrations of aging-related proteins in platelets. The healthy subjects were divided depending on their level of physical exercise (i.e., athletes and sedentary subjects) and their age (young and older subjects). Herein, aging-related proteins (i.e., α-syn, tau and Aβ) were confirmed to be present in human platelets. Among such proteins, platelet tau concentration was demonstrated to decrease in athletes, while α-syn and Aβ did not correlate with physical exercise. For the first time, α-syn was shown to directly interact with Aβ and tau in platelets, forming detectable hetero-complexes. Interestingly, α-syn interaction with tau was inversely related to plasma AOC and to the level of physical activity. These results suggested that α-syn heterocomplexes, particularly with tau, could represent novel indicators to monitor aging-related proteins in platelets

    SUPERSYMMETRY REACH OF AN UPGRADED TEVATRON COLLIDER

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    We examine the capability of a s=2\sqrt{s}=2 TeV Tevatron ppˉp\bar p collider to discover supersymmetry, given a luminosity upgrade to amass 25 fb125\ fb^{-1} of data. We compare with the corresponding reach of the Tevatron Main Injector (1 fb11\ fb^{-1} of data). Working within the framework of minimal supergravity with gauge coupling unification and radiative electroweak symmetry breaking, we first calculate the regions of parameter space accessible via the clean trilepton signal from \tw_1\tz_2\to 3\ell +\eslt production, with detailed event generation of both signal and major physics backgrounds. The trilepton signal can allow equivalent gluino masses of up to mtg600700m_{\tg}\sim 600-700 GeV to be probed if m0m_0 is small. If m0m_0 is large, then mtg500m_{\tg}\sim 500 GeV can be probed for μ0\mu 0 and large values of m0m_0, the rate for \tz_2\to\tz_1\ell\bar{\ell} is suppressed by interference effects, and there is {\it no} reach in this channel. We also examine regions where the signal from \tw_1\overline{\tw_1}\to \ell\bar{\ell}+\eslt is detectable. Although this signal is background limited, it is observable in some regions where the clean trilepton signal is too small. Finally, the signal \tw_1\tz_2\to jets+\ell\bar{\ell} +\eslt can confirm the clean trilepton signal in a substantial subset of the parameter space where the trilepton signal can be seen. We note that although the clean trilepton signal may allow Tevatron experiments to identify signals in regions of parameter space beyond the reach of LEP II, the dilepton channels generally probe much the same region as LEP II.Comment: 19 page REVTEX file; a uuencoded PS file with PS figures is available via anonymous ftp at ftp://hep.fsu.edu/preprints/baer/FSUHEP950301.u

    Baryon polarization in low-energy unpolarized meson-baryon scattering

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    We compute the polarization of the final-state baryon, in its rest frame, in low-energy meson--baryon scattering with unpolarized initial state, in Unitarized BChPT. Free parameters are determined by fitting total and differential cross-section data (and spin-asymmetry or polarization data if available) for pKpK^-, pK+pK^+ and pπ+p\pi^+ scattering. We also compare our results with those of leading-order BChPT
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