55,300 research outputs found
Revisit cosmic ray propagation by using H, H, He and He
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 Z2 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 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 is reliable. The well constraint 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
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.
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
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
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
- …