In Vitro Tuberization and Quantitative Analysis of Colchicine Using Hptlc in Gloriosa Superba . L an Endangered Medicinal Plant of Pachamalai Hills, a Part of Eastern Ghats, Tamil Nadu.

Gloriosa superba. L has been a source of medicine right from ancient times. The tubers of this plant are sold in Indian herbal market as an important source of an alkaloid colchicine. Surface sterilized seeds of Gloriosa superba were soaked overnight in 1% GA3 on the next day seeds were planted on germinating media containing MS basal salts with 0.5 mg/l GA3 and 1.0 mg/l BA, 1% sucrose and 0.8% agar. 72.5% of seed germination was observed. The germinated seeds were transplanted on MS basal medium supplemented with 1.0 mg/l BAP, 0.05 mg/l GA3, 9.5 mg/l NAA and 6% sucrose which led to 90% tuber induction within 6 weeks of culture. Since there is a great demand of colchicine in the market, we have made an attempt to estimate the colchicine content in different parts of the plant like leaf, seed, pericarp, tuber and in vitro produced tuber using High Performance Thin Layer Chromatography, using a mixture of Ethyl acetate:Methanol (10:1.3 v/v) as mobile phase and precoated silica gel F254 TLC aluminium sheets as the stationary phase. The detection of spot was carried out at 350nm. The calibration curve was found to be linear between 100 to 600 ng/spot for colchicines. The results revealed that in vitro tuber had highest amount (0.14249%) of cochicine, followed by in vivo seed (0.10900%), tuber (0.05761%), leaves (0.46470%) and pericarp (0.04574%). The proposed method can be used to determine the colchicine content in Gloriosa superba

Precipitation and temperature extremes and association with large-scale climate indices: An observational evidence over India

Climate change exposes more frequent natural hazards and physical vulnerabilities to the built and natural environments. Extreme precipitation and temperature events will have a significant impact on both the natural environment and human society. However, it is unclear whether precipitation and temperature extremes increase physical vulnerabilities across scales and their links with large-scale climate indices. This study investigates the relationship between precipitation and temperature extremes, as recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI), and large scale climatological phenomenon indices (Indian Summer Monsoon Index (ISMI), Arctic Oscillation (AO), and North Atlantic Oscillation (NAO)), using India as a case study. Our findings show that extreme warm indices were primarily negatively related to ISMI and positively related to extreme cold indices. According to Pearson’s correlation coefficients and Wavelet Transform Coherence (WTC), extreme warm indices were negatively related to ISMI and positively related to extreme cold indices. The extreme precipitation indices had a significant positive relationship, primarily with AO. Furthermore, from 1951 to 2018, India experienced an increase in warm extremes over western, central, and peninsular India, while cold indices increased over northwest India. Precipitation extremes of more than one day, more than one days, very wet and extremely wet days have increased across India except in the Indo-Gangetic plains, while heavy and very heavy precipitation days, consecutive wet days, and consecutive dry days have decreased

Historical and Projected Surface Temperature over India during the 20th and 21st century.

Surface Temperature (ST) over India has increased by ~0.055 K/decade during 1860-2005 and follows the global warming trend. Here, the natural and external forcings (e.g., natural and anthropogenic) responsible for ST variability are studied from Coupled Model Inter-comparison phase 5 (CMIP5) models during the 20th century and projections during the 21st century along with seasonal variability. Greenhouse Gases (GHG) and Land Use (LU) are the major factors that gave rise to warming during the 20th century. Anthropogenic Aerosols (AA) have slowed down the warming rate. The CMIP5 projection over India shows a sharp increase in ST under Representative Concentration Pathways (RCP) 8.5 where it reaches a maximum of 5 K by the end of the 21st century. Under RCP2.6 emission scenarios, ST increases up to the year 2050 and decreases afterwards. The seasonal variability of ST during the 21st century shows significant increase during summer. Analysis of rare heat and cold events for 2080-2099 relative to a base period of 1986-2006 under RCP8.5 scenarios reveals that both are likely to increase substantially. However, by controlling the regional AA and LU change in India, a reduction in further warming over India region might be achieved

Validation of the COSMIC Radio Occultation Data over Gadanki (13.48°N, 79.2°E): A Tropical Region

Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC), consisting of six Low Earth Orbit (LEO) Global Position System (GPS) receivers, on board the Formosat Satellite 3 (FORMOSAT-3) is providing dense observations of density, refractivity, temperature and water vapor profiles of the neutral atmosphere since middle of July 2006. Special radiosonde (Väisälä) campaign was conducted at Gadanki (13.48°N, 79.18°E), a tropical site in India, during July 2006 to March 2007 to validate these meteorological parameters. Co-located Nd: YAG Rayleigh lidar was also operated during the overpass of COSMIC and is utilized to validate the temperatures in the height range of 30 to 40 km. Atotal of 142 overpasses occurred during the above mentioned period within 300 km distance from Gadanki out of which 41 overpasses occurred within a time difference of ±4 hours of radiosonde launch. In addition, 18 overpasses occurred within the time difference of ±4 hours of lidar operation. A detailed comparison has been made with all these overpasses for the refractivity, temperature and water vapor obtained from COSMIC. The water vapor comparison has shown generally a good agreement with a mean difference of 5 - 10% below 6 - 7 km. Although there is a colder bias between COSMIC and radiosonde, a very good comparison in temperature is also found between 10 and 27 km with a mean difference of less than 1 K (RMS difference is only 0.64 K). There exists a large difference in temperature of about 8 K between 30 and 40 km (between COSMIC and lidar). Possible reasons for these large differences are given. There was one event that occurred just over Gadanki for which a detailed comparison has been made with special emphasis on water vapor retrievals. Sensitivity test is also done on the fractional difference in N for the event that occurred on 24 July 2006 between COSMIC (1D-var) and radiosonde and found that pressure plays a key role than temperature in determining the refractivity

Vertical and latitudinal variation of the intertropical convergence zone derived using GPS radio occultation measurements

Using GPS radio occultation refractivity data collected over the period of 2002-2013, we present a new method for identification of the intertropical convergence zone (ITCZ). The ITCZ is identified by estimating the maximum in the monthly meridional refractivity and specific humidity field by applying a Gaussian fit at each longitude. The interannual variability and climatology of the ITCZ is presented from 12. years of refractivity data. This new method captures all the general features of ITCZ extent and its variability. We also examine the effects of the ITCZ vertically during different seasons. The ITCZ is observed mostly at eastern Pacific in May month, and it is zonally distributed in the September and October months of each year. The zonal variability is large between lower and higher levels, particularly over the Indian monsoon and western Pacific. The latitudinal difference in the vertical extent between 850. hPa and higher levels is larger during the northern hemisphere (NH) summer than NH winter

Influence of Indian Summer Monsoon on Tropopause, Trace Gases and Aerosols in Asian Summer Monsoon Anticyclone Observed by COSMIC, MLS and CALIPSO

The existence of the Asian Summer Monsoon Anticyclone (ASMA) during the summer in the northern hemisphere, upper troposphere and lower stratosphere (UTLS) region plays a significant role in confining the trace gases and aerosols for a long duration, thus affecting regional and global climate. Though several studies have been carried out, our understanding of the trace gases and aerosols variability in the ASMA is limited during different phases of the Indian monsoon. This work quantifies the role of Indian Summer Monsoon (ISM) activity on the tropopause, trace gases (Water Vapor (WV), Ozone (O3), Carbon Monoxide (CO)) and aerosols (Attenuated Scattering Ratio (ASR)) obtained from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC), Microwave Limb Sounder (MLS), Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite observations, respectively, during the period 2006–2016. Enhancement in the tropopause altitude, WV, CO, ASR and low tropopause temperatures, O3 in the ASMA region is clearly noticed during peak monsoon months (July and August) with large inter-annual variability. Further, a significant increase in the WV and CO, and decrease in O3 during the active phase of the ISM, strong monsoon years and strong La Niña years in the ASMA is noticed. An enhancement in the ASR values during the strong monsoon years and strong La Niña years is also observed. In addition, our results showed that the presence of deep convection spreading from India land regions to the Bay of Bengal with strong updrafts can transport the trace gases and aerosols to the upper troposphere during active spells, strong monsoon years and La Niña years when compared to their counterparts. Observations show that the ASMA is very sensitive to active spells, strong monsoon years and La Niña years compared to break spells, weak monsoon years and El Niño years. It is concluded that the dynamics play a significant role in constraining several trace gases and aerosols in the ASMA and suggested considering the activity of the summer monsoon while dealing with them at sub-seasonal scales

Lower and middle atmospheric responses to the 22 July 2009 total solar eclipse

91-102In the present study, the effect of total solar eclipse, occurred on 22 July 2009, on water vapour in the troposphere, refractivity and temperature in the troposphere and the stratosphere using the observations available from COSMIC GPS RO, is reported. The investigation is extended to the entire middle atmosphere using SABER aboard TIMED satellite to study the response in the temperature and ozone. A significant enhancement in the water vapour and the refractivity in the lower and middle troposphere are noticed on the eclipse day when compared to non-eclipse days. Using the GPS RO observations, it is also found that the temperature responds differently at different altitudes, i.e. cooling in the troposphere and warming in the stratosphere. Similar features in temperature are also noticed in SABER observations below 40 km. Above 40 km altitude, cooling is observed up to an altitude of 70 km, therein again warming is noticed. An increase in ozone concentration is found throughout the middle atmosphere except near 30 km. Tropopause altitude is also observed to vary significantly during the solar eclipse with decrease (increase) in the altitude (temperature) of about 1-1.5 km (3-5 K). Large perturbations in the temperature, due to gravity waves in the stratosphere and the mesosphere, are noticed on the eclipse day and found westward propagating as expected. For the first time, evidences of solar eclipse in the entire lower and middle atmosphere is presented using ground based and satellite borne observations. </span