307 research outputs found

    Non-linear corrections to inflationary power spectrum

    Full text link
    We study non-linear contributions to the power spectrum of the curvature perturbation on super-horizon scales, produced during slow-roll inflation driven by a canonical single scalar field. We find that on large scales the linear power spectrum completely dominates and leading non-linear corrections remain totally negligible, indicating that we can safely rely on linear perturbation theory to study inflationary power spectrum. We also briefly comment on the infrared and ultraviolet behaviour of the non-linear corrections.Comment: (v1) 14 pages, 2 figures; (v2) references added and discussions expanded, including a new version of Figure 2, to appear in Journal of Cosmology and Astroparticle Physic

    A boundary value problem for the five-dimensional stationary rotating black holes

    Full text link
    We study the boundary value problem for the stationary rotating black hole solutions to the five-dimensional vacuum Einstein equation. Assuming the two commuting rotational symmetry and the sphericity of the horizon topology, we show that the black hole is uniquely characterized by the mass, and a pair of the angular momenta.Comment: 16 pages, no figure

    Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube

    Full text link
    We have studied the afterpulse of a hemispherical photomultiplier tube for an upcoming reactor neutrino experiment. The timing, the amplitude, and the rate of the afterpulse for a 10 inch photomultiplier tube were measured with a 400 MHz FADC up to 16 \ms time window after the initial signal generated by an LED light pulse. The time and amplitude correlation of the afterpulse shows several distinctive groups. We describe the dependencies of the afterpulse on the applied high voltage and the amplitude of the main light pulse. The present data could shed light upon the general mechanism of the afterpulse.Comment: 11 figure

    Capicua deficiency induces autoimmunity and promotes follicular helper T cell differentiation via derepression of ETV5

    Get PDF
    High-affinity antibody production through the germinal centre (GC) response is a pivotal process in adaptive immunity. Abnormal development of follicular helper T (T(FH)) cells can induce the GC response to self-antigens, subsequently leading to autoimmunity. Here we show the transcriptional repressor Capicua/CIC maintains peripheral immune tolerance by suppressing aberrant activation of adaptive immunity. CIC deficiency induces excessive development of T(FH) cells and GC responses in a T-cell-intrinsic manner. ETV5 expression is derepressed in Cic null T(FH) cells and knockdown of Etv5 suppresses the enhanced T(FH) cell differentiation in Cic-deficient CD4+ T cells, suggesting that Etv5 is a critical CIC target gene in T(FH) cell differentiation. Furthermore, we identify Maf as a downstream target of the CIC-ETV5 axis in this process. These data demonstrate that CIC maintains T-cell homeostasis and negatively regulates T(FH) cell development and autoimmunity. ? The Author(s) 2017.117Nsciescopu

    Cosmological Perturbations in a Big Crunch/Big Bang Space-time

    Full text link
    A prescription is developed for matching general relativistic perturbations across singularities of the type encountered in the ekpyrotic and cyclic scenarios i.e. a collision between orbifold planes. We show that there exists a gauge in which the evolution of perturbations is locally identical to that in a model space-time (compactified Milne mod Z_2) where the matching of modes across the singularity can be treated using a prescription previously introduced by two of us. Using this approach, we show that long wavelength, scale-invariant, growing-mode perturbations in the incoming state pass through the collision and become scale-invariant growing-mode perturbations in the expanding hot big bang phase.Comment: 47 pages, 4 figure

    Spatial infinity in higher dimensional spacetimes

    Full text link
    Motivated by recent studies on the uniqueness or non-uniqueness of higher dimensional black hole spacetime, we investigate the asymptotic structure of spatial infinity in n-dimensional spacetimes(n4n \geq 4). It turns out that the geometry of spatial infinity does not have maximal symmetry due to the non-trivial Weyl tensor {}^{(n-1)}C_{abcd} in general. We also address static spacetime and its multipole moments P_{a_1 a_2 ... a_s}. Contrasting with four dimensions, we stress that the local structure of spacetimes cannot be unique under fixed a multipole moments in static vacuum spacetimes. For example, we will consider the generalized Schwarzschild spacetimes which are deformed black hole spacetimes with the same multipole moments as spherical Schwarzschild black holes. To specify the local structure of static vacuum solution we need some additional information, at least, the Weyl tensor {}^{(n-2)}C_{abcd} at spatial infinity.Comment: 6 pages, accepted for publication in Physical Review D, published versio

    Golgi Outpost Synthesis Impaired by Toxic Polyglutamine Proteins Contributes to Dendritic Pathology in Neurons

    Get PDF
    Dendrite aberration is a common feature of neurodegenerative diseases caused by protein toxicity, but the underlying mechanisms remain largely elusive. Here, we show that nuclear polyglutamine (polyQ) toxicity resulted in defective terminal dendrite elongation accompanied by a loss of Golgi outposts (GOPs) and a decreased supply of plasma membrane (PM) in Drosophila class IV dendritic arborization (da) (C4 da) neurons. mRNA sequencing revealed that genes downregulated by polyQ proteins included many secretory pathway-related genes, including COPII genes regulating GOP synthesis. Transcription factor enrichment analysis identified CREB3L1/CrebA, which regulates COPII gene expression. CrebA overexpression in C4 da neurons restores the dysregulation of COPII genes, GOP synthesis, and PM supply. Chromatin immunoprecipitation (ChIP)-PCR revealed that CrebA expression is regulated by CREB-binding protein (CBP), which is sequestered by polyQ proteins. Furthermore, co-overexpression of CrebA and Rac1 synergistically restores the polyQ-induced dendrite pathology. Collectively, our results suggest that GOPs impaired by polyQ proteins contribute to dendrite pathology through the CBP-CrebA-COPII pathway. ? 2017 The Author(s)113Ysciescopu

    Knowledge, attitudes, beliefs and behaviors regarding fruits and vegetables among cost-offset community-supported agriculture (csa) applicants, purchasers, and a comparison sample

    Get PDF
    Community-supported agriculture (CSA) participation has been associated with high fruit and vegetable (FV) consumption, which may be due to better access to FV for CSA purchasers, or to positive knowledge, attitudes, and beliefs (KAB) regarding healthy eating among CSA applicants. The objective of this study was to examine KAB and consumption, in association with application to a cost-offset CSA (CO-CSA) program, and with CO-CSA purchase among applicants. We conducted a cross-sectional survey of CO-CSA applicants and a comparison sample in August 2017. All respondents were English-reading adults with a child 2–12 years old and household income of < 185% of the federal poverty level. Among CO-CSA applicants, some were CO-CSA purchasers (n = 46) and some were not (n = 18). An online comparison sample met equivalent eligibility criteria, but had not participated in CSA for three years (n = 105). We compared CO-CSA applicants to the comparison sample, and compared purchasers and non-purchaser sub-groups, using Mann- Whitney U tests and chi-square analysis. CO-CSA applicants reported better knowledge, selfefficacy, home habits, and diet than the comparison sample. Among applicants, CO-CSA purchasers and non-purchasers had equivalent KAB, but children in purchaser households had higher FV consumption than in non-purchaser households (4.14 vs. 1.83 cups, P = 0.001). Future research should explore associations between CO-CSA participation and diet using experimental methods

    Mass Splitting and Production of Σc0\Sigma_c^0 and Σc++\Sigma_c^{++} Measured in 500GeV500 {GeV} π\pi^- -N Interactions

    Full text link
    From a sample of 2722±782722 \pm 78 Λc+\Lambda_c^+ decaying to the pKπ+pK^-\pi^+ final state, we have observed, in the hadroproduction experiment E791 at Fermilab, 143±20143 \pm 20 Σc0\Sigma_c^0 and 122±18122 \pm 18 Σc++\Sigma_c^{++} through their decays to Λc+π±\Lambda_c^+ \pi^{\pm}. The mass difference M(Σc0)M(Λc+M(\Sigma_c^0) - M(\Lambda_c^+) is measured to be (167.38±0.29±0.15)MeV(167.38\pm 0.29\pm 0.15) {MeV}; for M(Σc++)M(Λc+)M(\Sigma_c^{++}) - M(\Lambda_c^+), we find (167.76±0.29±0.15)MeV(167.76\pm 0.29\pm0.15) {MeV}. The rate of Λc+\Lambda_c^+ production from decays of the Σc\Sigma_c triplet is (22\pm 2\pm 3) {%} of the total Λc+\Lambda_c^+ production assuming equal rate of production from all three, as measured for Σc0\Sigma_c^0 and Σc++\Sigma_c^{++}. We do not observe a statistically significant Σc\Sigma_c baryon-antibaryon production asymmetry. The xFx_F and pt2p_t^2 spectra of Λc+\Lambda_c^+ from Σc\Sigma_c decays are observed to be similar to those for all Λc+\Lambda_c^+'s produced.Comment: 15 pages, uuencoded postscript 3 figures uuencoded, tar-compressed fil

    Measurement of Pressure Dependent Fluorescence Yield of Air: Calibration Factor for UHECR Detectors

    Full text link
    In a test experiment at the Final Focus Test Beam of the Stanford Linear Accelerator Center, the fluorescence yield of 28.5 GeV electrons in air and nitrogen was measured. The measured photon yields between 300 and 400 nm at 1 atm and 29 deg C are Y(760 Torr, air) = 4.42 +/- 0.73 and Y(760 Torr, nitrogen) = 29.2 +/- 4.8 photons per electron per meter. Assuming that the fluorescence yield is proportional to the energy deposition of a charged particle traveling through air, good agreement with measurements at lower particle energies is observed.Comment: 22 pages, 14 figures, 2 tables, submitted to Astroparticle Physic
    corecore