Further evidence for intra-night optical variability of radio-quiet quasars

Although well established for BL Lac objects and radio-loud quasars, the occurrence of intra-night optical variability (INOV) in radio-quiet quasars is still debated, primarily since only a handful of INOV events with good statistical significance, albeit small amplitude, have been reported so far. This has motivated us to continue intra-night optical monitoring of bona-fide radio-quiet quasars (RQQs). Here we present the results for a sample of 11 RQQs monitored by us on 19 nights. On 5 of these nights a given RQQ was monitored simultaneously from two well separated observatories. In all, two clear cases and two probable case of INOV were detected. From these data, we estimate an INOV duty cycle of $\sim$8% for RQQs which would increase to 19% if the `probable variable' cases are also included. Such comparatively small INOV duty cycles for RQQs, together with the small INOV amplitudes ($\sim$1%), are in accord with the previously deduced characteristics of this phenomenon.Comment: 15 Pages, 4 Tables, 24 Figures; Accepted in BAS

Proton decay and new contribution to neutrino-less double beta decay in SO(10) with low-mass Z-prime boson, observable n-nbar oscillation, lepton flavor violation, and rare kaon decay

Conventionally for observable $n-{\bar n}$ oscillation through Pati-Salam intermediate gauge symmetry in $SO(10)$, the canonical seesaw mechanism is also constrained by $M_R \sim M_C \le 10^6$ GeV which yields light neutrino masses much larger than the neutrino oscillation data. Recently, this difficulty has been evaded via inverse seesaw mechanism, but with proton lifetime far beyond the experimentally accessible limits. In the present work, adopting the view that we may have only a TeV scale $Z^{\prime}$ gauge boson, we show how a class of non-SUSY $SO(10)$ models allow experimentally verifiable proton lifetime and the new contributions to neutrinoless double beta decay in the $W_L-W_L$ channel, lepton flavor violating branching ratios, observable $n-{\bar n}$ oscillation, and lepto-quark gauge boson mediated rare kaon decays. The occurrence of Pati-Salam gauge symmetry with unbroken D-parity and two gauge couplings at the highest intermediate scale guarantees precision unification in such models. This symmetry also ensures vanishing GUT threshold uncertainy on $\sin^2\theta_W$ or on the highest intermediate scale. Although the proton lifetime prediction is brought closer to the ongoing search limits with GUT threshold effects in the minimal model, no such effects are needed in a non-minimal model. We derive a new analytic expression for the $0\nu\beta\beta$ decay half-life and show how the existing experimental limits impose the lower bound on the lightest of the three heavy sterile neutrino masses, $M_{S_1}\ge 14\pm 4$ GeV. We also derive a new lower bound on the lepto-quark gauge boson mass mediating rare kaon decay, $M_{\rm lepto} \ge (1.53{\pm 0.06})\times 10^6$ GeV. The $n-{\bar n}$ mixing times are predicted in the range$\tau_{n-{\bar n}}\simeq 10^8-10^{13}$ sec.Comment: 36 pages Latex, 9 figures and 5 table

SN 2002ap, the hypernova of class Ic

The supernova SN 2002ap was discovered in the outer regions of the nearby spiral M74 on January 29.4 UT. Early photometric and spectroscopic observations indicate the supernova belongs to the class of Ic hypernova. Late time (After JD 2452500) light curve decay slopes are similar to that of the hypernovae SN 1997ef and SN 1998bw. We present here the $BVRI$ photometric light curves and colour evolutions of SN 2002ap to investigate the late time nature of the light curve.Comment: 2 pages,1 figure, Poster contribution, Submitted to proceedings of Astronomical Society of India (ASI) meeting, 200

A COMPARATIVE STUDY OF THE ANTI-OXIDATIVE AND ANTI-DIABETIC POTENTIAL OF IN VITRO AND IN VIVO ROOT AND LEAF EXTRACTS OF WITHANIA SOMNIFERA ON STREPTOZOTOCIN INDUCED DIABETIC RATS

Objective: The present investigation explores the possibilities of using the in vitro and in vivo root and leaf extracts of Withania somnifera for anti-diabetic and anti-hyperlipidaemic effects on streptozotocin-induced diabetic rats.Methods: In vitro shoot cultures of Withania somnifera were raised by the axillary proliferation in nodal explants from a garden grown plant using Murashige and Skoog medium then in vitro raised roots and shoots were used for the anti-hyperglycemic and anti-hyperlipidaemic experiment. After 72 h of STZ administration, the fasting blood glucose levels were measured and the rats showing FBG level>220 mg/dl were considered to be diabetic and were used for the hyperglycemic study. In vitro and in vivo methanolic root and leaf extracts were orally administered daily to diabetic rats for eight weeks. After the treatment period, blood glucose and serum enzymes like aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total cholesterol, triglycerides, HDL-c high density lipoprotein-bound cholesterol, LDL-c low density lipoprotein-bound cholesterol, LDH, serum protein level, total phenolics and anti-oxidative analysis (DPPH and FRAP) were determined.Results: The levels of blood glucose, AST, ALT, ALP, LDH, HDL-c significantly increased by the use of in vitro methanolic root extracts compared to normal control rats. However, remarkable loss of total protein, albumin, albumin: globulin (A: G) ratio was reported in streptozotocin-induced diabetic rats by using in vitro root extracts. Methanolic in vitro root extract at the dose levels of 300 mg/kg body weight produced a significant decrease in fasting blood glucose (FBG) level by 102.65 with respect to initial fasting blood glucose level after 30 d of the treatment. In vitro root extract demonstrated highest DPPH and FRAP free radical scavenging activity, i.e. 86.55±1.77 and 48.87±2.55 than other extracts.Conclusion: It may be concluded that methanolic in vitro root extract W. somnifera at the dose (300 mg/kg) has more potent anti-hyperglycaemic activity than the other in vitro and in vivo extracts of leaf and root on streptozotocin induced diabetic rats and was also found to be similar in effect to that of the standard drug ‘Glibenclamide'

Magnetic Proximity induced efficient charge-to-spin conversion in large area PtSe2_{2}/Ni80_{80}Fe20_{20} heterostructures

As a topological Dirac semimetal with controllable spin-orbit coupling and conductivity, PtSe$_2$, a transition-metal dichalcogenide, is a promising material for several applications from optoelectric to sensors. However, its potential for spintronics applications is yet to be explored. In this work, we demonstrate that PtSe$_{2}$/Ni$_{80}$Fe$_{20}$ heterostructure can generate a large damping-like current-induced spin-orbit torques (SOT), despite the absence of spin-splitting in bulk PtSe$_{2}$. The efficiency of charge-to-spin conversion is found to be $(-0.1 \pm 0.02)$~nm$^{-1}$ in PtSe$_{2}$/Ni$_{80}$Fe$_{20}$, which is three times that of the control sample, Ni$_{80}$Fe$_{20}$/Pt. Our band structure calculations show that the SOT due to the PtSe$_2$ arises from an unexpectedly large spin splitting in the interfacial region of PtSe$_2$ introduced by the proximity magnetic field of the Ni$_{80}$Fe$_{20}$ layer. Our results open up the possibilities of using large-area PtSe$_{2}$ for energy-efficient nanoscale devices by utilizing the proximity-induced SOT.Comment: 18 pages, 4 figure

Type IIP Supernova SN 2004et: A Multi-Wavelength Study in X-Ray, Optical and Radio

We present X-ray, broad band optical and low frequency radio observations of the bright type IIP supernova SN 2004et. The \cxo observed the supernova at three epochs, and the optical coverage spans a period of $\sim$ 470 days since explosion. The X-ray emission softens with time, and we characterise the X-ray luminosity evolution as \Lx \propto t^{-0.4}. We use the observed X-ray luminosity to estimate a mass-loss rate for the progenitor star of \sim \ee{2}{-6} M_\odot \mathrm{yr}^{-1}. The optical light curve shows a pronounced plateau lasting for about 110 days. Temporal evolution of photospheric radius and color temperature during the plateau phase is determined by making black body fits. We estimate the ejected mass of $^{56}$Ni to be 0.06 $\pm$ 0.03 M$_\odot$. Using the expressions of Litvinova & Nad\"{e}zhin (1985) we estimate an explosion energy of (0.98 $\pm$ 0.25) $\times 10^{51}$ erg. We also present a single epoch radio observation of SN 2004et. We compare this with the predictions of the model proposed by Chevalier et al. (2006). These multi-wavelength studies suggest a main sequence progenitor mass of $\sim$ 20 M$_\odot$ for SN 2004et.Comment: 13 Figures, Accepted for Publication in MNRA

Evolution of the Type IIb SN 2011fu

The UBVRI photometric follow-up of SN 2011fu has been initiated a few days after the explosion, shows a rise followed by steep decay in all bands and shares properties very similar to that seen in case of SN 1993J, with a possible detection of the adiabatic cooling phase at very early epochs. The spectral modeling performed with SYNOW suggests that the early-phase line velocities for H and Fe ii features were ~ 16000 km s−1 and ~ 14000 km s−1, respectively. Studies of rare class of type IIb SNe are important to understand the evolution of the possible progenitors of core-collapse SNe in more details

Science of malaria elimination: using knowledge of bottlenecks and enablers from the Malaria Elimination Demonstration Project in Central India for eliminating malaria in the Asia Pacific region

Malaria poses a major public health challenge in the Asia Pacific. Malaria Elimination Demonstration Project was conducted as a public-private partnership initiative in Mandla between State government, ICMR, and FDEC India. The project employed controls for efficient operational and management decisions. IEC campaigns found crucial in schools and communities. Capacity building of local workers emphasized for better diagnosis and treatment. SOCH mobile app launched for complete digitalization. Better supervision for Indoor Residual Sprays and optimized Long Lasting Insecticidal Nets distribution. Significant malaria cases reduction in Mandla. Insights from MEDP crucial for malaria elimination strategies in other endemic regions of the Asia Pacific

Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|$\eta$|<0.8) and transverse momentum range 0.2< $p_{\rm T}$< 5.0 GeV/$c$. The elliptic flow signal v$_2$, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 $\pm$ 0.002 (stat) $\pm$ 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v$_2(p_{\rm T})$ reaches a maximum of 0.2 near $p_{\rm T}$ = 3 GeV/$c$. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389