A Conformal Mapping and Isothermal Perfect Fluid Model

Instead of conformal to flat spacetime, we take the metric conformal to a spacetime which can be thought of as ``minimally'' curved in the sense that free particles experience no gravitational force yet it has non-zero curvature. The base spacetime can be written in the Kerr-Schild form in spherical polar coordinates. The conformal metric then admits the unique three parameter family of perfect fluid solution which is static and inhomogeneous. The density and pressure fall off in the curvature radial coordinates as $R^{-2},$ for unbounded cosmological model with a barotropic equation of state. This is the characteristic of isothermal fluid. We thus have an ansatz for isothermal perfect fluid model. The solution can also represent bounded fluid spheres.Comment: 10 pages, TeX versio

Advances in molecular and genomic research to safeguard food and feed supply from aflatoxin contamination

Worldwide recognition that aflatoxin contamination of agricultural commodities by the fungus Aspergillus flavus is a global problem has significantly benefitted from global collaboration for understanding the contaminating fungus, as well as for developing and implementing solutions against the contamination. The effort to address this serious food and feed safety issue has led to a detailed understanding of the taxonomy, ecology, physiology, genomics and evolution of A. flavus, as well as strategies to reduce or control pre-harvest aflatoxin contamination, including (1) biological control, using atoxigenic aspergilli, (2) proteomic and genomic analyses for identifying resistance factors in maize as potential breeding markers to enable development of resistant maize lines, and (3) enhancing host-resistance by bioengineering of susceptible crops, such as cotton, maize, peanut and tree nuts. A post-harvest measure to prevent the occurrence of aflatoxin contamination in storage is also an important component for reducing exposure of populations worldwide to aflatoxins in food and feed supplies. The effect of environmental changes on aflatoxin contamination levels has recently become an important aspect for study to anticipate future contamination levels. The ability of A. flavus to produce dozens of secondary metabolites, in addition to aflatoxins, has created a new avenue of research for understanding the role these metabolites play in the survival and biodiversity of this fungus. The understanding of A. flavus, the aflatoxin contamination problem, and control measures to prevent the contamination has become a unique example for an integrated approach to safeguard global food and feed safety

Schwarzschild black hole with global monopole charge

We derive the metric for a Schwarzschild black hole with global monopole charge by relaxing asymptotic flatness of the Schwarzschild field. We then study the effect of global monopole charge on particle orbits and the Hawking radiation. It turns out that existence, boundedness and stability of circular orbits scale up by $(1-8 \pi\eta^2)^{-1}$, and the perihelion shift and the light bending by $(1-8 \pi\eta^2)^{-3/2}$, while the Hawking temperature scales down by $(1 - 8 \pi \eta^2)^2$ the Schwarzschild values. Here $\eta$ is the global charge.Comment: 12 pages, LaTeX versio

Diffractive triangulation of radiative point sources

We describe a general method to determine the location of a point source of waves relative to a twodimensional single-crystalline active pixel detector. Based on the inherent structural sensitivity of crystalline sensor materials, characteristic detector diffraction patterns can be used to triangulate the location of a wave emitter. The principle described here can be applied to various types of waves, provided that the detector elements are suitably structured. As a prototypical practical application of the general detection principle, a digital hybrid pixel detector is used to localize a source of electrons for Kikuchi diffraction pattern measurements in the scanning electron microscope. This approach provides a promising alternative method to calibrate Kikuchi patterns for accurate measurements of microstructural crystal orientations, strains, and phase distributions

Curvature driven acceleration : a utopia or a reality ?

The present work shows that a combination of nonlinear contribution from the Ricci curvature in Einstein field equations can drive a late time acceleration of expansion of the universe. The transit from the decelerated to the accelerated phase of expansion takes place smoothly without having to resort to a study of asymptotic behaviour. This result emphasizes the need for thorough and critical examination of models with nonlinear contribution from the curvature.Comment: 8 pages, 4 figure

An ansatz for spacetimes of zero gravitational mass : global monopoles and textures

We propose a geometric ansatz, a restriction on Euclidean / Minkowski distance in the embedding space being propotional to distance in the embedded space, to generate spacetimes with vanishing gravitational mass ($R_{ik} u^i u^k = 0, u_i u^i = 1$). It turns out that these spacetimes can represent global monopoles and textures. Thus the ansatz is a prescription to generate zero mass spacetimes that could describe topological defects, global monopoles and textures.Comment: 9 pages, LaTeX versio

Inhomogeneous imperfect fluid spherical models without Big-Bang singularity

So far all known singularity-free cosmological models are cylindrically symmetric. Here we present a new family of spherically symmetric non-singular models filled with imperfect fluid and radial heat flow, and satisfying the weak and strong energy conditions. For large $t$ anisotropy in pressure and heat flux tend to vanish leading to a perfect fluid. There is a free function of time in the model, which can be suitably chosen for non-singular behaviour and there exist multiplicity of such choices.Comment: 8 pages, LaTeX versio

Study of effects of metformin on C-reactive protein level in Type-2 diabetes mellitus

Background: Diabetes mellitus (DM) is extremely common; represent a significant global health problem. Type-2 DM is considered to be associated with a low grade inflammation, which may play a significant role in development of cardiovascular complications evidenced by C-reactive protein (CRP) is a an extremely sensitive marker of systemic inflammation. The study was undertaken to check the effect of metformin on CRP level in Type-2 DM.Methods: The study was prospective and non-randomized. Thirty newly diagnosed Type-2 DM selected for metformin therapy by medicine personnel were enrolled in the study based on inclusion and exclusion criteria. Patients were divided into pre-treatment (before starting metformin therapy) and post-treatment group. Fasting blood sugar (FBS), postprandial blood sugar (PP2BS), CRP level were measured at the time of enrolment and 3 months after starting metformin monotherapy.Results: Results were analyzed using pair t-test. Metformin therapy was found to decrease CRP level significantly along with FBS, PP2BS level. p<0.05 value considered as statistically significant. Value was expressed as mean ± standard deviation.Conclusions: Treatment with 3 months metformin monotherapy for newly diagnosed Type-2 DM has shown a significant decrease in high-sensitivity-CRP level in Type 2 diabetes. This positive effect may be because of the decreased in the expression of proinflammatory cytokines and other mediators, including adhesion molecules, suggests that these processes may contribute to atherogenesis because atherosclerosis is also an inflammatory condition. However, this effect is probably dependent on improving glycemic control

Scalar and Spinor Perturbation to the Kerr-NUT Spacetime

We study the scalar and spinor perturbation, namely the Klein-Gordan and Dirac equations, in the Kerr-NUT space-time. The metric is invariant under the duality transformation involving the exchange of mass and NUT parameters on one hand and radial and angle coordinates on the other. We show that this invariance is also shared by the scalar and spinor perturbation equations. Further, by the duality transformation, one can go from the Kerr to the dual Kerr solution, and vice versa, and the same applies to the perturbation equations. In particular, it turns out that the potential barriers felt by the incoming scalar and spinor fields are higher for the dual Kerr than that for the Kerr. We also comment on existence of horizon and singularity.Comment: 31 pages including 20 figures, RevTeX style: Final version to appear in Classical and Quantum Gravit

Role of glipizide therapy on oxidative stress parameters in the patient with Type-II diabetes mellitus

Background: Oxidative stress has an important role in the pathophysiology of diabetes mellitus (DM) Type-II. Oxidative stress has an important role in the progression of DM Type-II and its related complications such as retinopathy, neuropathy and many others. The present study was carried out to evaluate the effect of glipizide therapy on oxidative stress parameters in Type-II DM.Methods: Thirty newly diagnosed diabetes patients were given glipizide therapy on 1st day and continue for 3 months. 30 non-diabetic healthy volunteers served as a control. Plasma malondialdehyde (MDA), superoxide dismutase (SOD) and catalase levels were measured at the time of enrollment and at the end of 3 months of glipizide treatment.Result: Theresults are analyzed using paired t-test. Plasma MDA was significantly increased, whereas SOD and catalase were significantly reduced in newly diagnosed diabetic patients as compared to control. After 3 months of glipizide therapy, plasma MDA was significantly reduced, whereas SOD and catalase were significantly increased.Conclusion: Glipizide therapy significantly reduced oxidative free radicals and increased antioxidant mechanism, which reduced oxidative stress, progression DM-II and its related complication