324 research outputs found
Cosmological post-Newtonian expansions to arbitrary order
We prove the existence of a large class of one parameter families of
solutions to the Einstein-Euler equations that depend on the singular parameter
\ep=v_T/c (0<\ep < \ep_0), where is the speed of light, and is a
typical speed of the gravitating fluid. These solutions are shown to exist on a
common spacetime slab M\cong [0,T)\times \Tbb^3, and converge as \ep
\searrow 0 to a solution of the cosmological Poisson-Euler equations of
Newtonian gravity. Moreover, we establish that these solutions can be expanded
in the parameter \ep to any specified order with expansion coefficients that
satisfy \ep-independent (nonlocal) symmetric hyperbolic equations
Microscopic calculation of proton capture reactions in mass 60-80 region and its astrophysical implications
Microscopic optical potentials obtained by folding the DDM3Y interaction with
the densities from Relativistic Mean Field approach have been utilized to
evaluate S-factors of low-energy reactions in mass 60-80 region
and to compare with experiments. The Lagrangian density FSU Gold has been
employed. Astrophysical rates for important proton capture reactions have been
calculated to study the behaviour of rapid proton nucleosynthesis for waiting
point nuclei with mass less than A=80
Post-Newtonian expansions for perfect fluids
We prove the existence of a large class of dynamical solutions to the
Einstein-Euler equations that have a first post-Newtonian expansion. The
results here are based on the elliptic-hyperbolic formulation of the
Einstein-Euler equations used in \cite{Oli06}, which contains a singular
parameter \ep = v_T/c, where is a characteristic velocity associated
with the fluid and is the speed of light. As in \cite{Oli06}, energy
estimates on weighted Sobolev spaces are used to analyze the behavior of
solutions to the Einstein-Euler equations in the limit \ep\searrow 0, and to
demonstrate the validity of the first post-Newtonian expansion as an
approximation
Trispecific antibody targeting HIV-1 and T cells activates and eliminates latently-infected cells in HIV/SHIV infections.
Agents that can simultaneously activate latent HIV, increase immune activation and enhance the killing of latently-infected cells represent promising approaches for HIV cure. Here, we develop and evaluate a trispecific antibody (Ab), N6/αCD3-αCD28, that targets three independent proteins: (1) the HIV envelope via the broadly reactive CD4-binding site Ab, N6; (2) the T cell antigen CD3; and (3) the co-stimulatory molecule CD28. We find that the trispecific significantly increases antigen-specific T-cell activation and cytokine release in both CD4 <sup>+</sup> and CD8 <sup>+</sup> T cells. Co-culturing CD4 <sup>+</sup> with autologous CD8 <sup>+</sup> T cells from ART-suppressed HIV <sup>+</sup> donors with N6/αCD3-αCD28, results in activation of latently-infected cells and their elimination by activated CD8 <sup>+</sup> T cells. This trispecific antibody mediates CD4 <sup>+</sup> and CD8 <sup>+</sup> T-cell activation in non-human primates and is well tolerated in vivo. This HIV-directed antibody therefore merits further development as a potential intervention for the eradication of latent HIV infection
Real or imagined women? Staff representations of international women postgraduate students
In Australia\u27s globalising universities many support staff and teaching staff now work with international women postgraduate students. But are they aware of the issues facing these women, and is their understanding of them adequate? Indeed, how do they represent them? In this paper we draw on a small-scale pilot study involving key university personnel. We argue that the ways in which such staff represent this group of students is problematic. Focusing primarily on academic issues and on the literature on learning styles, we analyse these staff members\u27 representations of international women postgraduate students from a postcolonial perspective. We explore the extent to which such representations, and the learning styles literature that reflects and informs them, are what Edward Said calls \u27Orientalist\u27. In so doing, we point to both the constitution of the international woman student as postcolonial female subject and show how this situates her in relation to the prevalent learning styles discourse. Further we argue that such representations of the students differ in crucial ways from the students\u27 self-representations, suggesting that in certain subtle ways such staff members are engaging with \u27imagined\u27 rather than \u27real\u27 women. <br /
Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET
The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR
Relationship of edge localized mode burst times with divertor flux loop signal phase in JET
A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM
A baby steps/giant steps Monte Carlo algorithm for computing roadmaps in smooth compact real hypersurfaces
International audienceWe consider the problem of constructing roadmaps of real algebraic sets. The problem was introduced by Canny to answer connectivity questions and solve motion planning problems. Given polynomial equations with rational coefficients, of degree in variables, Canny's algorithm has a Monte Carlo cost of operations in ; a deterministic version runs in time . The next improvement was due to Basu, Pollack and Roy, with an algorithm of deterministic cost for the more general problem of computing roadmaps of semi-algebraic sets ( is the dimension of an associated object). We give a Monte Carlo algorithm of complexity for the problem of computing a roadmap of a compact hypersurface of degree in variables; we also have to assume that has a finite number of singular points. Even under these extra assumptions, no previous algorithm featured a cost better than
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
Minimum mesh design criteria for blast wave development and structural response - MMALE method
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