55,300 research outputs found

    Revisit cosmic ray propagation by using 1^{1}H, 2^{2}H, 3^{3}He and 4^{4}He

    Full text link
    The secondary-to-primary ratios are unique tools to investigate cosmic ray propagation mechanisms. In this work, we use the latest data of deuteron-to-helium~4 ratio and helium~3-to-helium~4 ratio measured by PAMELA combined with other Z≤\leq2 primary fluxes measured by PAMELA and Voyager-1, to constrain the cosmic ray acceleration and propagation models. The analysis is performed by interfacing statistical tools with the GALPROP propagation package. To better fit both the modulated and unmodulated low energy cosmic ray data, we find that a time-, charge- and rigidity-dependent solar modulation model is better than the force-field approximation. Among all the studied cosmic ray propagation models, the diffusion-reacceleration-convection model is strongly supported by the derived Bayesian evidence. The robustness of the estimated diffusion slope δ\delta is cross-checked by another low-mass secondary-to-primary ratio, i.e. the antiproton-to-proton ratio. It is shown that the diffusion-reacceleration-convection model can reconcile well with the high energy antiproton-to-proton ratio. This indicates that the estimated value of δ\delta is reliable. The well constraint δ\delta from the `best' model is found to be close to 1/3, inferring a Kolmogorov-type interstellar magnetic turbulence.Comment: Accepted by Physics Letters

    A probabilistic method for gradient estimates of some geometric flows

    Full text link
    In general, gradient estimates are very important and necessary for deriving convergence results in different geometric flows, and most of them are obtained by analytic methods. In this paper, we will apply a stochastic approach to systematically give gradient estimates for some important geometric quantities under the Ricci flow, the mean curvature flow, the forced mean curvature flow and the Yamabe flow respectively. Our conclusion gives another example that probabilistic tools can be used to simplify proofs for some problems in geometric analysis.Comment: 22 pages. Minor revision to v1. Accepted for publication in Stochastic Processes and their Application

    Recombinant human PDCD5 (rhPDCD5) protein is protective in a mouse model of multiple sclerosis.

    Get PDF
    BackgroundIn multiple sclerosis (MS) and its widely used animal model, experimental autoimmune encephalomyelitis (EAE), autoreactive T cells contribute importantly to central nervous system (CNS) tissue damage and disease progression. Promoting apoptosis of autoreactive T cells may help eliminate cells responsible for inflammation and may delay disease progression and decrease the frequency and severity of relapse. Programmed cell death 5 (PDCD5) is a protein known to accelerate apoptosis in response to various stimuli. However, the effects of recombinant human PDCD5 (rhPDCD5) on encephalitogenic T cell-mediated inflammation remain unknown.MethodsWe examined the effects of intraperitoneal injection of rhPDCD5 (10 mg/kg) on EAE both prophylactically (started on day 0 post-EAE induction) and therapeutically (started on the onset of EAE disease at day 8), with both of the treatment paradigms being given every other day until day 25. Repeated measures two-way analysis of variance was used for statistical analysis.ResultsWe showed that the anti-inflammatory effects of rhPDCD5 were due to a decrease in Th1/Th17 cell frequency, accompanied by a reduction of proinflammatory cytokines, including IFN-Îł and IL-17A, and were observed in both prophylactic and therapeutic regimens of rhPDCD5 treatment in EAE mice. Moreover, rhPDCD5-induced apoptosis of myelin-reactive CD4+ T cells, along with the upregulation of Bax and downregulation of Bcl-2, and with activated caspase 3.ConclusionsOur data demonstrate that rhPDCD5 ameliorates the autoimmune CNS disease by inhibiting Th1/Th17 differentiation and inducing apoptosis of predominantly pathogenic T cells. This study provides a novel mechanism to explain the effects of rhPDCD5 on neural inflammation. The work represents a translational demonstration that rhPDCD5 has prophylactic and therapeutic properties in a model of multiple sclerosis

    Teleportation of an arbitrary multipartite state via photonic Faraday rotation

    Full text link
    We propose a practical scheme for deterministically teleporting an arbitrary multipartite state, either product or entangled, using Faraday rotation of the photonic polarization. Our scheme, based on the input-output process of single-photon pulses regarding cavities, works in low-Q cavities and only involves virtual excitation of the atoms, which is insensitive to both cavity decay and atomic spontaneous emission. Besides, the Bell-state measurement is accomplished by the Faraday rotation plus product-state measurements, which could much relax the experimental difficulty to realize the Bell-state measurement by the CNOT operation.Comment: 11 pages, 2 figures

    Using an Adapted Cover-Copy-Compare Math Intervention in China: A Pilot Study

    Get PDF
    The math fluency skills of a student with an IQ three standard deviations below the mean were improved using an adapted version of cover-copy-compare (CCC) in China. The student’s digits correct per minute and the number of problems correct increased substantially. Evidence of generalization to novel items is also demonstrated. This pilot study suggests that an adapted version of CCC can be effectively used in China, with someone whose FSIQ is three standard deviations below the mean, and that the acquired skill can be generalized
    • …
    corecore