Early observations of the Afterglow of GRB000301c

We report multiband observations of the Optical Transient (OT) associated with GRB000301c carried out between 2--4 March 2000 using the 2.34-m Vainu Bappu Telescope (VBT) at Kavalur, India. When combined with other reported data, the initial decline in the R-band magnitude with log ($t-t_0$), the time since the burst is fit with a slope $\alpha_{1}$ = -0.70 $\pm$ 0.07 which steepens after about 6.0 days to a slope of $\alpha_{2}$ = -2.44 $\pm$ 0.29. This change in slope does not occur smoothly but there is an indication for a bimodal distribution. The available measurements of the evolution of (B--R) color do not show any discernible evolution in the first 12 days.Comment: 14 pages, 2 postscript figures, Accepted for Publication in ApJ Letter

Narrow band photometry of selected asteroids

The CCD photometry of selected asteroids was carried out to check for possible cometary activity in them. To distinguish the asteroids with possible cometary activity from those of the main belt, each object of interest was observed in two filters; one centered on the C2 emission band at 5140A (90A bandpass) and the other centered on the nearby continuum at 4845A (65A bandpass). None of the observed asteroids appear to have any C2 emission

Variational Monte Carlo and Configurational Interaction Studies of C60C_{60} and its Fragments

The $C_{60}$ molecule and its fragments are studied using Configuration Interaction (CI) and Variational Monte Carlo (VMC) techniques, within the Hubbard model. Using benzene as a test case, we compare the results of the approximate calculations with exact calculations. The fragments of $C_{60}$ studied are pyracylene, fluoranthene and corannulene. The energies, bond orders, spin-spin and charge-correlation functions of these systems are obtained for various values of the Hubbard parameter, $U$. The analysis of bond orders and correlation functions of these individual molecules allow us to visualise pyracylene as a naphthalene unit with two ethylenic moieties and fluoranthene as weakly bridged benzene and naphthalene units. Corannulene is the largest fragment of $C_{60}$ that we have studied. The hexagon-hexagon(h-h) bond orders are slightly larger than those of the hexagon-pentagon bonds(h-p), a feature also found in other fragments. We also find bonds between two co-ordinated carbon sites to be stronger than bonds involving three coordinated carbon sites. In $C_{60}$, the h-h bonds are stronger than in corannulene and the h-p bonds weaker than in corannulene for all correlation strengths. Introducing bond alternation in the buckyball enhances this difference.Comment: 42 pages, 5 figures available on request, to appear in J. Phys. Che

Estimation of properties of low-lying excited states of Hubbard models : a multi-configurational symmetrized projector quantum Monte Carlo approach

We present in detail the recently developed multi-configurational symmetrized projector quantum Monte Carlo (MSPQMC) method for excited states of the Hubbard model. We describe the implementation of the Monte Carlo method for a multi-configurational trial wavefunction. We give a detailed discussion of issues related to the symmetry of the projection procedure which validates our Monte Carlo procedure for excited states and leads naturally to the idea of symmetrized sampling for correlation functions, developed earlier in the context of ground state simulations. It also leads to three possible averaging schemes. We have analyzed the errors incurred in these various averaging procedures and discuss and detail the preferred averaging procedure for correlations that do not have the full symmetry of the Hamiltonian. We study the energies and correlation functions of the low-lying excited states of the half-filled Hubbard model in 1-D. We have used this technique to study the pair-binding energies of two holes in $4n$ and $4n+2$ systems, which compare well the Bethe ansatz data of Fye, Martins and Scalettar. We have also studied small clusters amenable to exact diagonalization studies in 2-D and have reproduced their energies and correlation functions by the MSPQMC method. We identify two ways in which a multiconfigurational trial wavefunction can lead to a negative sign problem. We observe that this effect is not severe in 1-D and tends to vanish with increasing system size. We also note that this does not enhance the severity of the sign problem in two dimensions.Comment: 29 pages, 2 figures available on request, submitted to Phys. Rev.

Changing trends of causative factors in antenatal mothers with bad obstetric history: a retrospective study

Background: The death of an infant, in utero or after birth has been a devastating experience for parents and clinicians alike. Various efforts are being made to make an accurate diagnosis of such pregnancy losses at the earliest to prevent the emotional and physical stress that the woman undergoes. This study aims to assess the changing trends in risk factors and outcome of pregnancies in cases of bad obstetric history (BOH) and to identify the newly emerging maternal and fetal factors contributing to incidence of pregnancy loss.Methods: This study is a retrospective analysis of antenatal women with BOH attending the obstetrics and gynecology OPD at Chettinad hospital. The study was conducted during a time period of 1 year (May 2019 to May 2020).Results: The medical complications and underlying causes for BOH were analysed among the study group. Out of 41 women, 6 were diagnosed to have gestational diabetes mellitus (GDM), 8 were found to be hypertensive and 1 APLA positive. Neonatal mortality was encountered in 2 cases, attributing to Inborn error of metabolism. However, the cause for BOH remained unexplained in 3 individuals.Conclusions: A full work-up can be initiated after two consecutive losses to identify and treat the various causes responsible for BOH. Lot of further studies and research are being conducted to unravel the mystery in these cases. Despite these efforts, the male factors contributing to recurrent pregnancy loss have remained largely unexplored

INFLUENCE OF PHARMACEUTICAL CARE ACTIVITIES ON KNOWLEDGE ATTITUDE AND PRACTICE (KAP) AMONG DIABETIC PATIENTS IN A TERTIARY CARE HOSPITAL

Objective: To assess the influence of pharmaceutical care activities on Knowledge, Attitude and Practice (KAP) among type 2 diabetic patients. Methods: A total of about 301 patients with type 2 Diabetes Mellitus were recruited from a tertiary care hospital. Patients were educated about their disease condition, lifestyle modifications and diet regimen to be followed and were given instructions for improving medication adherence. In the initial session, no pharmaceutical care was given, in the second session patient counseling was given verbally and in the last session patient counseling was given both verbally and non-verbally by means of pamphlet distribution. KAP questionnaire and glycemic levels (glycated hemoglobin, fasting blood sugar and post-prandial blood sugar) of participants were obtained at baseline and at follow up. Results: The baseline values of FBS in patients before intervention was found to be 176.5±74.46 mg/dL and it was reduced to 140.7±43.9 mg/dL after 3 mo. Henceforth, there was also an improvement in the PPBS values which was found to be 254±77.3 mg/dL at the baseline and was 212.9±54.2 mg/dL after intervention. The baseline values of HbA1c is 8.144±1.727% and after intervention, value reduced to about 7.173±2.768%. After the intervention, it was found to be that 30%, 16% and 12% reduction in FBS, PPBS and HbA1c values and the P-value (<0.0001) found to be statistically significant. KAP scores also found to be improved after the intervention and statistically significant. The results clearly indicate that through proper guidance and educating the patients by the pharmacist is beneficial in managing the glycemic levels and reduce further complications. Conclusion: The study concluded that the pharmaceutical care by the pharmacist is highly essentially and useful for the patients to manage the glycemic index and prevent further diabetic complications

Optical Photometry of the GRB 010222 Afterglow

The optical afterglow of GRB 010222 was observed using the recently installed 2-m telescope at the Indian Astronomical Observatory, Hanle, and the telescopes at the Vainu Bappu Observatory, Kavalur, beginning ~ 0.6 day after the detection of the event. The results based on these photometric observations combined with others reported in the literature are presented in this paper. The R band light curve shows an initial decline of intensities proportional to t^{-0.542} which steepens, after 10.3 hours, to t^{-1.263}. Following the model of collimated outflow, the early break in the light curve implies a very narrow beam angle (~ 2-3 deg). The two decay rates are consistent with the standard jet model in a uniform density ambient medium, but require a hard spectrum of electron power density with p ~ 1.5. The R band light between 14 and 17 hours since outburst departs from the power law fit by 0.1 mag and shows some evidence for fluctuations over timescales of an hour in the observer's frame. Such deviations are expected due to density inhomogeneities if the ambient medium is similar to the local interstellar medium. GRB 010222 is thus an example of a highly collimated outflow with a hard spectrum of electron energy distribution in normal interstellar environment.Comment: 15 pages, Latex, including 2 postscript figures, to appear in the Bull. astro. Soc. India, September 2001 issu

Ferromagnetism as a universal feature of nanoparticles of the otherwise nonmagnetic oxides

Room-temperature ferromagnetism has been observed in the nanoparticles (7 - 30 nm dia) of nonmagnetic oxides such as CeO2, Al2O3, ZnO, In2O3 and SnO2. The saturated magnetic moments in CeO_2 and Al_2O_3 nanoparticles are comparable to those observed in transition metal doped wide band semiconducting oxides. The other oxide nanoparticles show somewhat lower values of magnetization but with a clear hysteretic behavior. Conversely, the bulk samples obtained by sintering the nanoparticles at high temperatures in air or oxygen became diamagnetic. As there were no magnetic impurities present, we assume that the origin of ferromagnetism may be due to the exchange interactions between localized electron spin moments resulting from oxygen vacancies at the surfaces of nanoparticles. We suggest that ferromagnetism may be a universal characteristic of nanopartilces of metal oxidesComment: 6 pages, 4 figure

Searching for GRB remnants in nearby galaxies

Gamma Ray Bursts (GRBs) are expected to leave behind GRB remnants, similar to how ``standard'' supernovae (SN) leave behind SN remnants. The identification of these remnants in our own and in nearby galaxies would allow a much closer look at GRB birth sites, and possibly lead to the discovery of the compact object left behind. It would also provide independent constraints on GRB rates and energetics. We have initiated an observational program to search for GRB remnants in nearby galaxies. The identification is based on specific line ratios, such as OIII/$H_{\beta}$ and HeII/$H_{\beta}$, which are expected to be unusually high in case of GRB remnants according to the theoretical predictions of Perna et al. (2000). The observing strategies and preliminary studies from a test run at 2.34 m VBT as well as archival data from planetary nebulae surveys of spiral galaxies are discussed.Comment: 4 pages, uses aipproc.cls To appear in AIP, proceeding of GRB conference '30 years after the discovery' held at Santa Fe, NM from 8-12 Sept, 200