Giant Meterwave Radio Telescope observations of an M2.8 flare: insights into the initiation of a flare-coronal mass ejection event

We present the first observations of a solar flare with the GMRT. An M2.8 flare observed at 1060 MHz with the GMRT on Nov 17 2001 was associated with a prominence eruption observed at 17 GHz by the Nobeyama radioheliograph and the initiation of a fast partial halo CME observed with the LASCO C2 coronograph. Towards the start of the eruption, we find evidence for reconnection above the prominence. Subsequently, we find evidence for rapid growth of a vertical current sheet below the erupting arcade, which is accompanied by the flare and prominence eruption.Comment: Accepted for publication in Solar Physic

Oxidation mechanism in metal nanoclusters: Zn nanoclusters to ZnO hollow nanoclusters

Zn nanoclusters (NCs) are deposited by Low-energy cluster beam deposition technique. The mechanism of oxidation is studied by analysing their compositional and morphological evolution over a long span of time (three years) due to exposure to ambient atmosphere. It is concluded that the mechanism proceeds in two steps. In the first step, the shell of ZnO forms over Zn NCs rapidly up to certain limiting thickness: with in few days -- depending upon the size -- Zn NCs are converted to Zn-ZnO (core-shell), Zn-void-ZnO, or hollow ZnO type NCs. Bigger than ~15 nm become Zn-ZnO (core-shell) type: among them, NCs above ~25 nm could able to retain their initial geometrical shapes (namely triangular, hexagonal, rectangular and rhombohedral), but ~25 to 15 nm size NCs become irregular or distorted geometrical shapes. NCs between ~15 to 5 nm become Zn-void-ZnO type, and smaller than ~5 nm become ZnO hollow sphere type i.e. ZnO hollow NCs. In the second step, all Zn-void-ZnO and Zn-ZnO (core-shell) structures are converted to hollow ZnO NCs in a slow and gradual process, and the mechanism of conversion proceeds through expansion in size by incorporating ZnO monomers inside the shell. The observed oxidation behaviour of NCs is compared with theory of Cabrera - Mott on low-temperature oxidation of metal.Comment: 9 pages, 8 figure

Chemical Reaction and Radiation Effects on the Hydro-Magnetic Free Convection Flow of Visco-Elastic Fluid along an Infinite Vertical Porous Plate in a Porous Medium

An unsteady hydro magnetic laminar free convection heat and mass transfer flow of a visco-elastic, dissipative fluid along an infinite vertical Porous plate through porous medium is analyzed in the presence of chemical reaction and thermal radiation.  The solution of the problem is obtained in the form of power series of  which is very small. Analytical expressions for the velocity, temperature and concentration fields are given, as well as for the skin friction, the rate of heat transfer and the rate of mass transfer coefficient at the plate.  The influence.......

The true reinforced random walk with bias

We consider a self-attracting random walk in dimension d=1, in presence of a field of strength s, which biases the walker toward a target site. We focus on the dynamic case (true reinforced random walk), where memory effects are implemented at each time step, differently from the static case, where memory effects are accounted for globally. We analyze in details the asymptotic long-time behavior of the walker through the main statistical quantities (e.g. distinct sites visited, end-to-end distance) and we discuss a possible mapping between such dynamic self-attracting model and the trapping problem for a simple random walk, in analogy with the static model. Moreover, we find that, for any s>0, the random walk behavior switches to ballistic and that field effects always prevail on memory effects without any singularity, already in d=1; this is in contrast with the behavior observed in the static model.Comment: to appear on New J. Phy

Prospective, randomized double blind comparative study of safety and efficacy of carvedilol versus atenolol in patients of mild to moderate hypertension

Background: Carvedilol is a new cardiovascular compound with the combined pharmacologic properties of nonselective ß-blockade and vasodilation. The Aim of the study was to compare the safety and antihypertensive efficacy of 25mg Carvedilol once daily with 50mg atenolol once daily in patients with mild to moderate essential hypertension.Methods: This was a single center study conducted in Rangaraya Medical College, Kakinada. 80 eligible patients with mild to moderate hypertension were randomized to receive 25mg Carvedilol once daily (40 patients) or 50mg atenolol (40 patients) in a double-blind 12-week treatment phase. At each visit 0, 4, 8 and 12 weeks of treatment, sitting Blood Pressure (BP) and heart rate were measured. The effect on BP reduction within the group is compared by paired “t”test and the effect on reduction of BP between two study groups compared by unpaired “t”test.Results: After 12 weeks of treatment, the mean reduction of SBP (Systolic Blood Pressure) with carvedilol is 22.33±8.31mmHg with no Significant difference (p >0.05) compared to atenolol group mean reduction in SBP of 21.37±10mm Hg. The mean reduction in DBP (Diastolic Blood Pressure) after completion of the study in carvedilol group is 6.75±4.82mm Hg with no Significant difference (p >0.05) compared to atenolol group mean reduction in DBP of 8.55±5.25mm Hg. No significant difference seen in the efficacy parameters of both the drugs. The incidence of adverse effects such as bradycardia, headache, nausea, vomiting, hypotension and rash is less with carvedilol.Conclusions: In patients with mild to moderate hypertension, there was no statistically significant difference between efficacy of carvedilol or atenolol with regard to the degree of reduction in BP or the percentage of patients achieving a response to therapy but carvedilol showed a better safety profile when compared to atenolol

Immunohistochemical and Molecular Detection of pH1N1 in NecropsiedPulmonary Tissues of Fatal Cases with Indeterminate Conventional Testing

The rapid emergence of a novel influenza A/H1N1 virus designated pH1N1 2009 caused one of the fastest pandemics of the twentieth century. The rapid development of an accurate detection test for this pandemic virus using reverse transcription-real time polymerase chain reaction (rRT-PCR) helped in timely diagnosis. In India this pandemic peaked between August to October 2009. The r-RT PCR for pH1N1 2009 was the main diagnostic test used on throat/nasopharyngeal swabs in all cases. While in majority of the cases this test provided reliable confirmation of the virus, it gave negative or indeterminate results in a subset of cases meeting the standard case definition for the pandemic infection and negative for seasonal flu. In the present study we examined 4 such fatal cases where microscopic pathology of the lung was consistent with viral bronchopneumonia for the presence of pH1N1 2009 using r-RT PCR on nucleic acid extracted from the paraffin sections that showed presence of viral antigens by immunohistochemistry. In all 4 cases pH1N1 sequences could be identified. These findings therefore emphasize the important role of microscopic pathology techniques in conjunction with molecular tools in the diagnostic confirmation of novel agents during a public health emergency

Development of Novel Character in Okra [Abelmoschus esculentus (L.) Moench]

Transgressive segregation in the population of IIHR-31-1-2 x Arka Anamika BC3 F1-F6 generations led to the development of, various novel characters such as, ridgeless fruits (round fruit) and enhanced nodal productivity bearing short internodal length in okra selection-1, which was found to be promising for cultivation with high yield and good fruit quality. It can be grown both during Kharif and summer seasons. Okra selection-1 was also found to exhibit smooth fruits, high yield potential with sturdy plant habit and field tolerance to fusarium wilt and YVMV. Due to rapid rate of increase of processing in okra by freezing and canning, Okra selection I may be an ideal fruit type for freezing because of its short, smooth, dark green and round or multifaceted fruits with low mucilage content

An application of 3-D kinematical conservation laws: propagation of a 3-D wavefront

Three-dimensional (3-D) kinematical conservation laws (KCL) are equations of evolution of a propagating surface Omega(t) in three space dimensions. We start with a brief review of the 3-D KCL system and mention some of its properties relevant to this paper. The 3-D KCL, a system of six conservation laws, is an underdetermined system to which we add an energy transport equation for a small amplitude 3-D nonlinear wavefront propagating in a polytropic gas in a uniform state and at rest. We call the enlarged system of 3-D KCL with the energy transport equation equations of weakly nonlinear ray theory (WNLRT). We highlight some interesting properties of the eigenstructure of the equations of WNLRT, but the main aim of this paper is to test the numerical efficacy of this system of seven conservation laws. We take several initial shapes for a nonlinear wavefront with a suitable amplitude distribution on it and let it evolve according to the 3-D WNLRT. The 3-D WNLRT is a weakly hyperbolic 7 × 7 system that is highly nonlinear. Here we use the staggered Lax–Friedrichs and Nessyahu–Tadmor central schemes and have obtained some very interesting shapes of the wavefronts. We find the 3-D KCL to be suitable for solving many complex problems for which there presently seems to be no other method capable of giving such physically realistic features