Relativistic Dynamos in Magnetospheres of Rotating Compact Objects

The kinematic evolution of axisymmetric magnetic fields in rotating magnetospheres of relativistic compact objects is analytically studied, based on relativistic Ohm's law in stationary axisymmetric geometry. By neglecting the poloidal flows of plasma in simplified magnetospheric models, we discuss self-excited dynamos due to the frame-dragging effect (originally pointed out by Khanna & Camenzind), and we propose alternative processes to generate axisymmetric magnetic fields against ohmic dissipation. The first process (which may be called induced excitation) is caused by the help of a background uniform magnetic field in addition to the dragging of inertial frames. It is shown that excited multipolar components of poloidal and azimuthal fields are sustained as stationary modes, and outgoing Poynting flux converges toward the rotation axis. The second one is self-excited dynamo through azimuthal convection current, which is found to be effective if plasma rotation becomes highly relativistic with a sharp gradient in the angular velocity. In this case no frame-dragging effect is needed, and the coupling between charge separation and plasma rotation becomes important. We discuss briefly the results in relation to active phenomena in the relativistic magnetospheres.Comment: 16 pages, AASLaTeX macros v4.

Cyclin kinase inhibitor p21: a mediator of immune tolerance: direct and indirect evidence

*Background:* Uncontrolled proliferation of T-cells is considered a barrier to the induction of transplantation tolerance by T regulatory cells. Therefore, cyclin kinase inhibitor p21, one of the most potent inhibitors of cell proliferation, may exert an important role in the induction/generation of T regulatory cells.
*Methods:* CD4^+^CD25^+^ and CD4^+^CD25^-^ cells were isolated from normal healthy blood donors (n=6), p21^-/-^ mice (n=9) and wild type mice (n=9). Proliferation with and without cyclosporine was quantified by ^3^H-thymidine uptake assay (expressed as counts per minute) and FoxP3 mRNA was studied by real-time quantitative RT-PCR. 
*Results:* The difference in proliferation (p<0.003) among CD4^+^CD25^+^ (15236 ± 1190) and CD4^+^CD25^-^ (50317 ± 974) T cells were proportionately similar to the difference in proliferation (p<0.001) of lymphocytes from wild type (28206 ± 2812) and p21^-/-^ mice (49624 ± 2164), proliferation of CD4^+^CD25^-^ and p21 deficient cells was resistant to cyclosporine. The number of T regulatory cells in p21^-/-^ mice were significantly (p<0.002) lower (2.6 ± 0.8%) than wild type mice (14.5 ± 1.6%,) and similar to CD4^+^CD25^-^ T cells, CD4^+^25^+^ T cells from p21^-/-^ mice lacked FoxP3 gene expression. T lymphocytes from wild type inhibited the proliferation of T lymphocytes from p21^-/-^ mice similar to the effect of CD4^+^CD25^+^ T cells on the proliferation of CD4^+^CD25^-^ cells. 
*Conclusions:* Presence of the p21 creates a milieu favorable for immune tolerance and consistent with antiproliferative and immunosuppressive effect of CD4^+^CD25^+^ T-regulatory cells. These findings support the notion that p21 could be used clinically in controlling allo-immune activation to achieve prolongation of graft survival

The CBE Hardware Accelerator for Numerical Relativity: A Simple Approach

Hardware accelerators (such as the Cell Broadband Engine) have recently received a significant amount of attention from the computational science community because they can provide significant gains in the overall performance of many numerical simulations at a low cost. However, such accelerators usually employ a rather unfamiliar and specialized programming model that often requires advanced knowledge of their hardware design. In this article, we demonstrate an alternate and simpler approach towards managing the main complexities in the programming of the Cell processor, called software caching. We apply this technique to a numerical relativity application: a time-domain, finite-difference Kerr black hole perturbation evolver, and present the performance results. We obtain gains in the overall performance of generic simulations that are close to the theoretical maximum that can be obtained through our parallelization approach.Comment: 5 pages, 2 figures; Accepted for publication in the International Journal of Modeling, Simulation, and Scientific Computing (IJMSSC

HEMOGLOBIN A1C IMPROVEMENTS AND BETTER DIABETES-SPECIFIC QUALITY OF LIFE AMONG PARTICIPANTS COMPLETING DIABETES SELF-MANAGEMENT PROGRAMS: A NESTED COHORT STUDY

Background: Numerous primary care innovations emphasize patient-centered processes of care. Within the context of these innovations, greater understanding is needed of the relationship between improvements in clinical endpoints and patient-centered outcomes. To address this gap, we evaluated the association between glycosylated hemoglobin (HbA1c) and diabetes-specific quality of life among patients completing diabetes self-management programs. Methods: We conducted a retrospective cohort study nested within a randomized comparative effectiveness trial of diabetes self-management interventions in 75 diabetic patients. Multiple linear regression models were developed to examine the relationship between change in HbA1c from baseline to one-year follow-up and Diabetes-39 (a diabetes-specific quality of life measure) at one year. Results: HbA1c levels improved for the overall cohort from baseline to one-year follow-up (t (74) = 3.09, p = .0029). One-year follow up HbA1c was correlated with worse overall quality of life (r = 0.33, p = 0.004). Improvements in HbA1c from baseline to one-year follow-up were associated with greater D-39 diabetes control (β = 0.23, p = .04) and D-39 sexual functioning (β = 0.25, p = .03) quality of life subscales. Conclusions: Improvements in HbA1c among participants completing a diabetes self-management program were associated with better diabetes-specific quality of life. Innovations in primary care that engage patients in self-management and improve clinical biomarkers, such as HbA1c, may also be associated with better quality of life, a key outcome from the patient perspective

On the magnetohydrodynamic description of a two-component plasma in the Kerr metric

The magnetohydrodynamic equations describing an inviscid, fully ionized plasma in the vicinity of a rotating black hole are derived from a two-component plasma theory within the framework of the 3+1 split of the Kerr metric. Of central interest is the generalized Ohm's law. In the limit of quasi-neutral plasma it contains no new terms as compared with special relativity. Gravitomagnetic terms appear in Ohm's law only if the plasma is charged in its rest frame or the magnetohydrodynamic approximation is not applied. It is argued that a relativistic single-fluid description of a multiple-component plasma is possible only for cold (i.e. intrinsically non-relativistic) components. As seen by local stationary observers, close to the horizon the electron collision time becomes longer than dynamical timescales, i.e. the plasma appears to behave as particles.Comment: 8 pages, no figures, MNRAS, see also http://www.lsw.uni-heidelberg.de/~rkhanna/publications.htm

Cellulosic Biofuels: Are They Economically Viable and Environmentally Sustainable?

Miscanthus, Corn Stover, Switchgrass, Cost of Production, Greenhouse Gas Intensity, Resource /Energy Economics and Policy, Q01, Q54, Q55,