GRB000301C with peculiar afterglow emission

The CCD magnitudes in Johnson V and Cousins R and I photometric passbands are determined for GRB 000301C afterglow starting ~ 1.5 day after the gamma-ray burst. In fact we provide the earliest optical observations for this burst. Light curves of the afterglow emissions in U, B, V, R, I, J and K' passbands are obtained by combining the present measurements with the published data. Flux decay shows a very uncommon variation relative to other well observed GRBs. Overall, there is a steepening of the optical and near-infrared flux decay caused by a geometric and sideways expanding jet. This is superimposed by a short term variability especially during early time (Delta t < 8 days). The cause of variability is not well understood, though it has occurred simultaneously with similar amplitude in all the filters. We derive the early and late time flux decay constants using jet model. The late time flux decay is the steepest amongst the GRB OTs observed so far with alpha ~ 3. Steepening in the flux decay seems to have started simultaneously around Delta t ~ 7.6 day in all passbands. The value of spectral index in the optical-near IR region is ~ -1.0. Redshift determination with z=2.0335 indicates cosmological origin of the GRB having a luminosity distance of 16.6 Gpc. Thus it becomes the second farthest amongst the GRBs with known distances. An indirect estimate of the fluence > 20 keV indicates, if isotropic,> =10^53 ergs of release of energy. The enormous amount of released energy will be reduced, if the radiation is beamed which is the case for this event. Using a jet break time of 7.6 days, we infer a jet opening angle of ~ 0.15 radian. This means the energy released is reduced by a factor of ~ 90 relative to the isotropic value.Comment: LaTeX file, 11 pages including 4 figures, uses psfig.sty, Bull. Astron. Society of India(accepted, Sept, 2000 issue

Fluctuations and Correlations of Conserved Charges in the (2+1)(2+1) Polyakov Quark Meson Model

We consider the $(2+1)$ flavor Polyakov Quark Meson Model and study the fluctuations (correlations) of conserved charges upto sixth (fourth) order. Comparison is made with lattice data wherever available and overall good qualitative agreement is found, more so for the case of the normalised susceptibilities. The model predictions for the ratio of susceptibilities go to that of an ideal gas of hadrons as in Hadron Resonance Gas Model at low temperatures while at high temperature the values are close to that of an ideal gas of massless quarks. Our study provides a strong basis for the use of PQM as an effective model to understand the topology of the QCD phase diagram.Comment: modified text, version accepted for publication in PR

BVRI CCD photometric standards in the field of GRB 990123

The CCD magnitudes in Johnson $BV$ and Cousins $RI$ photometric passbands are determined for 18 stars in the field of GRB 990123. These measurements can be used in carrying out precise CCD photometry of the optical transient of GRB 990123 using differential photometric techniques during non--photometric sky conditions. A comparison with previous photometry indicates that the present photmetry is more precise.Comment: Tex file, 5 pages with 1 figure. Bull. Astron. Society India, Vol. 27 (accepted

Inhibitory effect of bacterial antagonists on the growth of Macrophomina phaseolina (Tassi.) Goid. Causing charcoal rot of sunflower (Helianthus annus L.) invitro

Charcoal rot caused by Macrophominaphaseolinais a major disease causing in sunflower plant. The pathogen invasion occurs from the seedling to maturity stage. To overcome this problem in vitro, sensitivity of M. phaseolina was determined through inhibition zone technique to various isolates of antagonistic bacteria like seven isolates of Pseudomonas fluorescens (EPf2, EDPf3, APf4, CPf5, MPf6, KPf7 and Pf1)and seven isolates Bacillus subtilis (EBs1, EDBs2, ABs3, CBs4, MBs5, KBs6 and Bs10) amended into PDA medium. The results showed that the entire bacterial antagonist were effective against the fungus M. phaseolina and exhibited appreciable amount of inhibition. Among these bacterial antagonist significantly compared to the control P.fluorescens (Pf1) proved to be the most effective (71.49 %) with an inhibition zone of 5.00 mm reducing the colony growth of M. Phaseolina followed B. subtilis (65.92 %)inhibition zone of 17.80 mm respectively over control. However, from these studies it is concluded that an isolate of various antagonist can vary in its sclerotia producing ability on root

Multidrug-resistant tuberculosis

Multidrug-resistant tuberculosis (MDR-TB) caused by Mycobacterium tuberculosis resistant to both isoniazid and rifampicin with or without resistance to other drugs is among the most worrisome elements of the pandemic of antibiotic resistance. Globally, about three per cent of all newly diagnosed patients have MDR-TB. The proportion is higher in patients who have previously received antituberculosis treatment reflecting the failure of programmes designed to ensure complete cure of patients with tuberculosis. While host genetic factors may probably contribute, incomplete and inadequate treatment is the most important factor leading to the development of MDR-TB. The definitive diagnosis of MDR-TB is difficult in resource poor low income countries because of non-availability of reliable laboratory facilities. Efficiently run tuberculosis control programmes based on directly observed treatment, short-course (DOTS) policy is essential for preventing the emergence of MDR-TB. Management of MDR-TB is a challenge which should be undertaken by experienced clinicians at centres equipped with reliable laboratory service for mycobacterial culture and in vitro sensitivity testing as it requires prolonged use of expensive second-line drugs with a significant potential for toxicity. Judicious use of drugs, supervised individualised treatment, focussed clinical, radiological and bacteriological follow up, use of surgery at the appropriate juncture are key factors in the successful management of these patients. In certain areas, currently available programme approach may not be adequate and innovative approaches such as DOTS-plus may have to be employed to effectively control MDR-TB

Sarcoidosis in India: not so rare

Sarcoidosis is a systemic inflammatory disease of unknown aetiology. In India, sarcoidosis is an under-diagnosed disease. All ethnic groups in the Indian sub-continent are affected by sarcoidosis. Most of the Indian patients with sarcoidosis are males, and a majority of them present in their fourth or fifth decade of life. Many patients with sarcoidosis are asymptomatic with incidental findings on the chest radiograph. Depending on the organ systems involved, patients with sarcoidosis present themselves to various specialities, with pulmonary involvement being the commonest. The diagnosis is based on a compatible clinical and/or radiological picture, histopathological evidence of non-caseating granulomas in tissue biopsy specimens, and exclusion of other diseases that can produce similar clinical or histopathological appearances. The disease runs a benign course with spontaneous remission of the activity. Only a minority of the patients develop complicated disease though some degree of residual pulmonary function abnormality persists. A high index of clinical suspicion and focussed attempts to secure histopathological confirmation of the diagnosis early in the illness are required to ascertain the diagnosis. For asymptomatic patients with pulmonary sarcoidosis, no therapy is required. In symptomatic patients, or those with complications, corticosteroids remain the mainstay of treatment and sometimes steroid-sparing alternative treatments may be beneficial. Treatment should be tailored to suit the needs of the individual patient under close clinical monitoring

Planetary Nebulae with Ultra-Violet Imaging Telescope (UVIT): Far Ultra-violet halo around the Bow Tie nebula (NGC 40)

Context. NGC 40 is a planetary nebula with diffuse X-ray emission, suggesting an interaction of the high speed wind from WC8 central star (CS) with the nebula. It shows strong Civ 1550 {\AA} emission that cannot be explained by thermal processes alone. We present here the first map of this nebula in C IV emission, using broad band filters on the UVIT. Aims. To map the hot C IV emitting gas and its correspondence with soft X-ray (0.3-8 keV) emitting regions, in order to study the shock interaction with the nebula and the ISM. This also illustrates the potential of UVIT for nebular studies. Methods. Morphological study of images of the nebula obtained at an angular resolution of about 1.3" in four UVIT filter bands that include C IV 1550 {\AA} and C II] 2326 {\AA} lines and UV continuum. Comparisons with X-ray, optical, and IR images from literature. Results. The C II] 2326 {\AA} images show the core of the nebula with two lobes on either side of CS similar to [N II]. The C IV emission in the core shows similar morphology and extant as that of diffuse X-ray emission concentrated in nebular condensations. A surprising UVIT discovery is the presence of a large faint FUV halo in FUV Filter with {\lambda}eff of 1608 {\AA}. The UV halo is not present in any other UV filter. FUV halo is most likely due to UV fluorescence emission from the Lyman bands of H2 molecules. Unlike the optical and IR halo, FUV halo trails predominantly towards south-east side of the nebular core, opposite to the CS's proper motion direction. Conclusions. Morphological similarity of C IV 1550 {\AA} and X-ray emission in the core suggests that it results mostly from interaction of strong CS wind with the nebula. The FUV halo in NGC 40 highlights the existence of H2 molecules extensively in the regions even beyond the optical and IR halos.Comment: 4 pages, 5 figures, accepted for publication as a letter in Astronomy & Astrophysic

Interference enhanced Raman spectroscopy of ultra thin crystalline Ge films

We report Raman study of ultra thin Ge films using interference enhanced Raman scattering which uses a trilayer structure of Al, CeO2 and crystalline Ge films. The use of CeO2 allows the growth of crystalline Ge films at relatively low substrate temperatures (300°C). With a decrease of Ge film thickness, the Raman line exhibits an increased red shift of the peak position and line broadening. The latter can be quantitatively explained on the basis of phonon confinement in the growth direction. Raman spectra of the 2 nm and 4 nm thick Ge films show shoulder at similar to -280 cm-1 which could be attributed to surface phonons. The changes in the Raman shift as a function of thickness showed that the films were compressively strained up to a thickness of similar to -7 nm beyond which the strain is released

Egg removal device for the management of three stored product pests

Investigations were carried out to assess the efficiency of pulse beetle egg removal device in the removal of eggs of Tribolium castaneum and Rhyzopertha dominica from infested sorghum, wheat, maize and paddy grains and the eggs of Lasioderma serricorne from infested coriander. The efficiency of the device or the impact of rotation was assessed based on the number of offspring adults emerged and percentage reduction in adult emergence compared to untreated controls. Rotation of the grains for three consecutive days for 15 min/day gave the highest reduction in the emergence of offspring adults. Reductions in emergence of T. castaneum and R. dominica were found to be 54 and 57% in sorghum; 69 and 69% in wheat; and 71 and 76% in maize, respectively. There was a 77% reduction in L. serricorne on coriander seed, and a similar level for R. dominica on paddy. Keywords: Pulse beetle egg removal device, Tribolium castaneum, Rhyzopertha dominica, Lasioderma serricorn