46 research outputs found

    Cloud liquid water content responses to hygroscopic seeding of warm clouds

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    The cloud liquid water content (CLWC) data in time and space from a total of 96 pairs of target (T) and control (C) experiments were analysed in this study to compare the responses of CLWC to hygroscopic seeding of warm clouds. Our results of various approaches taken for this analysis have indicated significant modifications in the CLWC for the T clouds as against C clouds. Analysis of changes in CLWC in the T clouds after and before seeding has pointed out their increasing trend of values with increment in the number of seeded traverses in most cases. These results have shown that CLWC in the T clouds increases following the seeding treatment in the range 9-26. Similar comparisons in the C clouds have indicated obvious diminution in CLWC that lies in the range 5-11. These results clearly indicate the influence on microphysical growth and decay of such clouds that arises from hygroscopic seeding and not seeding of warm clouds. Analysis of spatial responses of CLWC to seeding has shown that the optimum effect of seeding may be achieved for a suitable cloud in the altitude range 5750-6250 ft (asl) in the Pune area. It is believed that this study has provided adequate support in favour of the hypothesis of hygroscopic seeding of warm clouds

    A study of lightning activity over land and oceanic regions of India

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    Monthly variations of lightning activity over typical land and oceanic regions of India were examined using satellite data (OTD) for a 5-year period (1995-1999). It is noted that the nature of variation between surface air maximum temperature (Tmax), thunderstorm days (Thn), and lightning flash count over ER and WR showed remarkable correspondence and sensitivity with each other on monthly time scale. As we move out of winter season and enter the monsoon season, via pre-monsoon season, the WR undergoes cooling relative to the ER in the range 0.1-1.2°C. As a result, WR experiences reduction of thunder days and lowering in flash count. This decrease in Tmax, Thn, and flash count over WR may also be associated with relatively small values of Tθw and CAPE in comparison with similar values over ER during the monsoon season. Our observation of associated reduction in Thn and lightning count per 1°C cooling in surface air maximum temperature suggests reduction of ~3.5 thunderstorms per station and 73 flashes. Comparison of lightning flashes between pairs of coastal, oceanic, arid-zone, hilly, and island stations reveals distinct relationship between climate regime and intensity of lightning activity. We may conclude the results of this study by saying that the overhead lightning activity is a clear reflection of the status of the underlying ground-earth properties. A close and continuous monitoring of lightning activity may be considered as a need of present day scientific studies

    Diurnal and seasonal variations of space charge, electric field and cloud condensation nuclei in the lowest layer of the atmosphere

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    The association between the onset of the monsoon and the subsequent rainfall distribution over three west coast subdivision of of India has been examined for the 50 years period

    Purinergic signalling and immune cells

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    This review article provides a historical perspective on the role of purinergic signalling in the regulation of various subsets of immune cells from early discoveries to current understanding. It is now recognised that adenosine 5'-triphosphate (ATP) and other nucleotides are released from cells following stress or injury. They can act on virtually all subsets of immune cells through a spectrum of P2X ligand-gated ion channels and G protein-coupled P2Y receptors. Furthermore, ATP is rapidly degraded into adenosine by ectonucleotidases such as CD39 and CD73, and adenosine exerts additional regulatory effects through its own receptors. The resulting effect ranges from stimulation to tolerance depending on the amount and time courses of nucleotides released, and the balance between ATP and adenosine. This review identifies the various receptors involved in the different subsets of immune cells and their effects on the function of these cells

    Mapping geographical inequalities in oral rehydration therapy coverage in low-income and middle-income countries, 2000-17

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    Background Oral rehydration solution (ORS) is a form of oral rehydration therapy (ORT) for diarrhoea that has the potential to drastically reduce child mortality; yet, according to UNICEF estimates, less than half of children younger than 5 years with diarrhoea in low-income and middle-income countries (LMICs) received ORS in 2016. A variety of recommended home fluids (RHF) exist as alternative forms of ORT; however, it is unclear whether RHF prevent child mortality. Previous studies have shown considerable variation between countries in ORS and RHF use, but subnational variation is unknown. This study aims to produce high-resolution geospatial estimates of relative and absolute coverage of ORS, RHF, and ORT (use of either ORS or RHF) in LMICs. Methods We used a Bayesian geostatistical model including 15 spatial covariates and data from 385 household surveys across 94 LMICs to estimate annual proportions of children younger than 5 years of age with diarrhoea who received ORS or RHF (or both) on continuous continent-wide surfaces in 2000-17, and aggregated results to policy-relevant administrative units. Additionally, we analysed geographical inequality in coverage across administrative units and estimated the number of diarrhoeal deaths averted by increased coverage over the study period. Uncertainty in the mean coverage estimates was calculated by taking 250 draws from the posterior joint distribution of the model and creating uncertainty intervals (UIs) with the 2 center dot 5th and 97 center dot 5th percentiles of those 250 draws. Findings While ORS use among children with diarrhoea increased in some countries from 2000 to 2017, coverage remained below 50% in the majority (62 center dot 6%; 12 417 of 19 823) of second administrative-level units and an estimated 6 519 000 children (95% UI 5 254 000-7 733 000) with diarrhoea were not treated with any form of ORT in 2017. Increases in ORS use corresponded with declines in RHF in many locations, resulting in relatively constant overall ORT coverage from 2000 to 2017. Although ORS was uniformly distributed subnationally in some countries, within-country geographical inequalities persisted in others; 11 countries had at least a 50% difference in one of their units compared with the country mean. Increases in ORS use over time were correlated with declines in RHF use and in diarrhoeal mortality in many locations, and an estimated 52 230 diarrhoeal deaths (36 910-68 860) were averted by scaling up of ORS coverage between 2000 and 2017. Finally, we identified key subnational areas in Colombia, Nigeria, and Sudan as examples of where diarrhoeal mortality remains higher than average, while ORS coverage remains lower than average. Interpretation To our knowledge, this study is the first to produce and map subnational estimates of ORS, RHF, and ORT coverage and attributable child diarrhoeal deaths across LMICs from 2000 to 2017, allowing for tracking progress over time. Our novel results, combined with detailed subnational estimates of diarrhoeal morbidity and mortality, can support subnational needs assessments aimed at furthering policy makers' understanding of within-country disparities. Over 50 years after the discovery that led to this simple, cheap, and life-saving therapy, large gains in reducing mortality could still be made by reducing geographical inequalities in ORS coverage. Copyright (c) 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

    Study of the association of surface potential gradient with the onset of monsoon at Pune

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    349-354Simultaneous measurements of fair weather surface potential gradient, vapour pressure, westerly wind (speed and direction), mean sea level pressure, and dry bulb temperature at Pune (18°32 'N, 73°51 'E: 559 m AMSL) during April-June of 1973-77 were analysed and examined for monthly and seasonal variations. The results suggested about 17 and 50% diminution in potential gradient in May and June over the period of study with respect to the values in April and about 50 to 100% increase only in vapour pressure and westerly wind among other meteorological parameters. This was suggestive of their preferential influence to decrease the potential gradient. The study also showed that the year to year lower or higher monthly mean value of potential gradient bore a fairly good correspondence with the early or late onset of monsoon. This was suggestive of about 25% and 10% higher values of potential gradient in April and May than the net average for delay in monsoon by about a week

    Influence of thermal power plant emissions on surface atmospheric electrical parameters

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    Variations in the atmospheric electric field at tropical station during 1930-1987

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    The variations noticed in the atmospheric electric field recorded at Pune (18°32′N, 73°51′E, 559 m ASL), a tropical inland station located in Deccan Plateau, India, during the period 1930–1987, have been examined in relation to the variations observed in the Angstrom turbidity coefficient (β) and selected meteorological parameters. The monthly and annual mean values of the atmospheric electric field, Angstrom turbidity coefficient (β), rainfall, temperature and relative humidity for the years 1930–1938, 1957–1958, 1964–1965, 1973–1974 and 1987 were considered in the study. The results of the above study indicated gradual increases in the atmospheric electric field over the period of study (1930–1987) which is statistically significant at less than 5%level. The increases noticed during different periods varied from 30 to 109%. The increase noticed during the period (1930–1938) and (1973–1974) was maximum (109%). The Angstrom turbidity coefficient also showed systematic increases during the period of study, which is consistent. The diurnal curve of the atmospheric electric field at the station by and large, showed a double oscillation, which is generally observed in the continental environments

    Small ion mean life times at 5 typical locations in Indian region

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