A high resolution daily gridded rainfall dataset (1971-2005) for mesoscale meteorological studies

In this communication, we discuss the development of a very high resolution (0.5° 0.5°) daily rainfall dataset for mesoscale meteorological studies over the Indian region. The dataset was developed using quality-controlled rainfall data from more than 3000 rain gauge stations over India. The analysis consists of daily rainfall data for all the seasons for the period 1971-2005. A well-tested interpolation method (Shepard's method) was used to interpolate the station data into regular grids of 0.5° 0.5° lat. long. After proper validation, it has been found that the present dataset is better compared to other available datasets. A few case studies have been shown to demonstrate the utility of the dataset for different mesoscale meteorological analyses. However, since the data density is not kept uniform, there is a possibility of temporal inhomogeneity and therefore, the present dataset cannot be used for trend analysis. The dataset is freely available from the India Meteorological Department, Pune

Launch window analysis of satellites in high eccentricity or large circular orbits

Numerical methods and computer programs for studying the stability and evolution of orbits of large eccentricity are presented. Methods for determining launch windows and target dates are developed. Mathematical models are prepared to analyze the characteristics of specific missions

Active and break spells of the Indian summer monsoon

In this paper, we suggest criteria for the identification of active and break events of the Indian summer monsoon on the basis of recently derived high resolution daily gridded rainfall dataset over India (1951-2007). Active and break events are defined as periods during the peak monsoon months of July and August, in which the normalized anomaly of the rainfall over a critical area, called the monsoon core zone exceeds 1 or is less than −1.0 respectively, provided the criterion is satisfied for at least three consecutive days. We elucidate the major features of these events. We consider very briefly the relationship of the intraseasonal fluctuations between these events and the interannual variation of the summer monsoon rainfall. We find that breaks tend to have a longer life-span than active spells. While, almost 80% of the active spells lasted 3-4 days, only 40% of the break spells were of such short duration. A small fraction (9%) of active spells and 32% of break spells lasted for a week or longer. While active events occurred almost every year, not a single break occurred in 26% of the years considered. On an average, there are 7 days of active and break events from July through August. There are no significant trends in either the days of active or break events. We have shown that there is a major difference between weak spells and long intense breaks. While weak spells are characterized by weak moist convective regimes, long intense break events have a heat trough type circulation which is similar to the circulation over the Indian subcontinent before the onset of the monsoon. The space-time evolution of the rainfall composite patterns suggests that the revival from breaks occurs primarily from northward propagations of the convective cloud zone. There are important differences between the spatial patterns of the active/break spells and those characteristic of interannual variation, particularly those associated with the link to ENSO. Hence, the interannual variation of the Indian monsoon cannot be considered as primarily arising from the interannual variation of intraseasonal variation. However, the signature over the eastern equatorial Indian Ocean on intraseasonal time scales is similar to that on the interannual time scales

Development of a perfect prognosis probabilistic model for prediction of lightning over south-east India

A prediction model based on the perfect prognosis method was developed to predict the probability of lightning and probable time of its occurrence over the south-east Indian region. In the perfect prognosis method, statistical relationships are established using past observed data. For real time applications, the predictors are derived from a numerical weather prediction model. In the present study, we have developed the statistical model based on Binary Logistic Regression technique. For developing the statistical model, 115 cases of lightning that occurred over the south-east Indian region during the period 2006–2009 were considered. The probability of lightning (yes or no) occurring during the 12-hour period 0900–2100 UTC over the region was considered as the predictand. The thermodynamic and dynamic variables derived from the NCEP Final Analysis were used as the predictors. A three-stage strategy based on Spearman Rank Correlation, Cumulative Probability Distribution and Principal Component Analysis was used to objectively select the model predictors from a pool of 61 potential predictors considered for the analysis. The final list of six predictors used in the model consists of the parameters representing atmospheric instability, total moisture content in the atmosphere, low level moisture convergence and lower tropospheric temperature advection. For the independent verifications, the probabilistic model was tested for 92 days during the months of May, June and August 2010. The six predictors were derived from the 24-h predictions using a high resolution Weather Research and Forecasting model initialized with 00 UTC conditions. During the independent period, the probabilistic model showed a probability of detection of 77% with a false alarm rate of 35%. The Brier Skill Score during the independent period was 0.233, suggesting that the prediction scheme is skillful in predicting the lightning probability over the south-east region with a reasonable accuracy

Two Cases of Guillain-Barré Syndrome Variants Presenting With Dysautonomia

We describe 2 pediatric cases presenting with posterior reversible encephalopathy syndrome secondary to autonomic dysfunction preceding the onset of motor symptoms in Guillain-Barré syndrome variants. Patient 1 presented acutely with encephalopathy, cerebellar signs, hypertension, lower limb weakness, and respiratory decompensation. Magnetic resonance imaging (MRI) brain showed occipital lesions consistent with posterior reversible encephalopathy syndrome. Nerve conduction studies were consistent with Miller-Fisher syndrome. After intravenous immunoglobulin and plasmapheresis, he improved clinically with radiological resolution. Patient 2 presented with headache, leg pain, seizures, and significant hypertension. Brain MRI was normal but spine MRI revealed enhancement of the cauda equina ventral nerve roots. She was areflexic with lower limb weakness a few days after intensive care unit admission and made a significant improvement after treatment with intravenous immunoglobulin. In children presenting with posterior reversible encephalopathy syndrome in the absent of other causes of primary hypertension, Guillain-Barré syndrome variants are an important differential etiology, presenting with autonomic dysfunction, even before signs of motor weakness become evident

Studies on production of peptide antibiotic by thermotolerant Bacillus sp.

The soil sample was collected and screened for isolation of higher antibiotic producing bacterial strain. The isolated bacterial strain was tentatively identified as Bacillus sp. by biochemical characters using Bergey’s manual. The present study is focused on the optimization of different parameters for production of peptide antibiotic (Bacitracin) using synthetic medium. The antibacterial activity of isolate was analyzed against S. aureus. The nutritional ingredients for bacitracin production were found as glucose (1%) and L-glutamic acid (0.5 %) as carbon and nitrogen source respectively. The prominent bacitracin production was obtained after 48 hrs incubation at 40°C temperature and at 7 pH

Sequence dependence of the folding of collagen-like peptides: Single amino acids affect the rate of triple-helix nucleation

The refolding of thermally denatured model collagen-like peptides was studied for a set of 21 guest triplets embedded in a common host framework: acetyl-(Gly-Pro-Hyp)3-Gly-Xaa-Yaa-(Gly-Pro-Hyp)4-Gly-Gly-amide. The results show a strong dependence of the folding rate on the identity of the guest Gly-Xaa-Yaa triplet, with the half-times for refolding varying from 6 to 110 min (concentration = 1 mg/ml). All triplets of the form Gly-Xaa-Hyp promoted rapid folding, with the rate only marginally dependent on the residue in the Xaa position. In contrast, triplets of the form Gly-Pro-Yaa and Gly-Xaa-Yaa were slower and showed a wide range of half-times, varying with the identity of the residues in the triplet. At low concentrations, the folding can be described by third-order kinetics, suggesting nucleation is rate-limiting. Data on the relative nucleation ability of different Gly-Xaa-Yaa triplets support the favorable nature of imino acids, the importance of hydroxyproline, the varying effects of the same residue in the Xaa position versus the Yaa position, and the difficulties encountered when leucine or aspartic acid are in the Yaa position. Information on the relative propensities of different tripeptide sequences to promote nucleation of the triple-helix in peptides will aid in identification of nucleation sites in collagen sequences

Fracture in Mode I using a Conserved Phase-Field Model

We present a continuum phase-field model of crack propagation. It includes a phase-field that is proportional to the mass density and a displacement field that is governed by linear elastic theory. Generic macroscopic crack growth laws emerge naturally from this model. In contrast to classical continuum fracture mechanics simulations, our model avoids numerical front tracking. The added phase-field smoothes the sharp interface, enabling us to use equations of motion for the material (grounded in basic physical principles) rather than for the interface (which often are deduced from complicated theories or empirical observations). The interface dynamics thus emerges naturally. In this paper, we look at stationary solutions of the model, mode I fracture, and also discuss numerical issues. We find that the Griffith's threshold underestimates the critical value at which our system fractures due to long wavelength modes excited by the fracture process.Comment: 10 pages, 5 figures (eps). Added 2 figures and some text. Removed one section (and a figure). To be published in PR

Long-term oral antibiotic use in people with acne vulgaris in UK primary care: a drug utilization study

BACKGROUND: The inappropriate use of antibiotics is understood to contribute to antimicrobial resistance. Oral antibiotics are regularly used to treat moderate-to-severe acne vulgaris. In practice, we do not know the typical length of oral antibiotic treatment courses for acne in routine primary care and what proportion of people receive more than one course of treatment following a new acne diagnosis. OBJECTIVES: To describe how oral antibiotics are prescribed for acne over time in UK primary care. METHODS: We conducted a descriptive longitudinal drug utilization study using routinely collected primary care data from the Clinical Practice Research Datalink GOLD (2004-2019). We included individuals (8-50 years) with a new acne diagnosis recorded between 1 January 2004 and 31 July 2019. RESULTS: We identified 217 410 people with a new acne diagnosis. The median age was 17 years [interquartile range (IQR) 15-25] and median follow-up was 4.3 years (IQR 1.9-7.6). Among people with a new acne diagnosis, 96 703 (44.5%) received 248 560 prescriptions for long-term oral antibiotics during a median follow-up of 5.3 years (IQR 2.8-8.5). The median number of continuous courses of antibiotic therapy (≥ 28 days) per person was four (IQR 2-6). The majority (n = 59 010, 61.0%) of first oral antibiotic prescriptions in those with a recorded acne diagnosis were between the ages of 12 and 18. Most (n = 71 544, 74.0%) first courses for oral antibiotics were for between 28 and 90 days. The median duration of the first course of treatment was 56 days (IQR 50-93 days) and 18 127 (18.7%) of prescriptions of ≥ 28 days were for < 6 weeks. Among people who received a first course of oral antibiotic for ≥ 28 days, 56 261 (58.2%) received a second course after a treatment gap of ≥ 28 days. The median time between first and second courses was 135 days (IQR 67-302). The cumulative duration of exposure to oral antibiotics during follow-up was 255 days (8.5 months). CONCLUSIONS: Further work is needed to understand the consequences of using antibiotics for shorter periods than recommended. Suboptimal treatment duration may result in reduced clinical effectiveness or repeated exposures, potentially contributing to antimicrobial resistance

Vitamin D Deficiency or Supplementation and the Risk of Human Herpesvirus Infections or Reactivation: A Systematic Review and Meta-analysis.

BACKGROUND: Vitamin D may protect against respiratory virus infections, but any association with herpesviruses is unclear. METHODS: We undertook a systematic review of vitamin D deficiency or supplementation and the risk of 8 human herpesviruses. Six databases and 4 gray literature databases were searched for relevant cohort studies, case-control studies, and clinical trials. RESULTS: Ten studies were included, all conducted among immunosuppressed patients. There was no evidence that vitamin D deficiency is associated with cytomegalovirus (CMV) disease (pooled risk ratio, 1.06; 95% CI, 0.66-1.7), herpes zoster after transplantation (1 study), or HHV-8 among HIV patients (1 study). Vitamin D supplementation may decrease herpes zoster among hemodialysis patients (1 study) or CMV disease after renal transplantation (1 study), but supplementation was not associated with reduced EBV viral load among multiple sclerosis patients (1 study). CONCLUSIONS: Any association between vitamin D and herpesviruses remains inconclusive. Further studies in the general population are needed