12 research outputs found
Aerosol optical depth studies during INDOEX: comparison of the spectral features over coastal India with the pristine southern hemispheric environment over Mauritius
Aerosol spectral optical depths, estimated using a ground-based network of multi wavelength radiometers (MWR) along the west coast of India [Trivandrum (TVM; 8.5°N, 77°E), and Minicoy (MCY; 8.3°N, 73.04°E)] and the pristine southern hemispheric environment at Mauritius (MRU; 20.26°S, 57.54°E) during the period January to June 1998 along with those obtained over the Arabian Sea and Indian Ocean during the INDOEX FFP-98 cruise (SK133) of ORV Sagar Kanya, are used to study the inter-hemispheric features of aerosols. Results indicate that there is a significant hemispherical difference for aerosol spectral optical depth (AOD) at shorter wavelengths (λ≤ 650 nm), while at the longer wavelengths (λ > 650 nm), AOD does not show any appreciable variation with location. The spectral variation of AOD at TVM and MCY (for March 1998) depicted a similar pattern with the AOD values between 0.5 and 0.6 at shorter wavelengths and between 0.2 and 0.4 at longer wavelengths. In contrast to this, the AOD at MRU are very low, lying in the range 0.1 to 0.2 in the shorter wavelengths, whereas at the longer wavelengths the AOD values are more or less comparable (in the range 0.2 to 0.4) with the northern hemispheric stations. The cruise data clearly showed that the transition occurs generally across the ITCZ. The increased AOD at shorter wavelengths in the northern hemisphere indicates higher concentration of sub-micron aerosols in these environments arising mainly due to anthropogenic activities, while the AOD at the longer wavelengths is attributed mainly to be of marine origin. In the post-cruise period, the spectral optical depths showed a gradual increase from March to June at MRU, while at TVM, the pattern followed more or less the climatological mean. By May the AOD at shorter wavelengths decreased at TVM (due to increased rainfall) and by June, the AOD at TVM are very much comparable with those seen at MRU, indicating a dominating marine aerosol influence at both these locations. The implications are discussed
Optical properties of atmospheric aerosols over the Arabian Sea and Indian Ocean: North-South contrast across the ITCZ
Extensive estimates of aerosol spectral optical depths are made over the Arabian Sea and south-western Indian Ocean, using a 10-channel multi-wavelength solar radiometer (MWR) and a 4- channel hand held EKO sun-photometer (ESP) on-board the cruise # 133 of ORV Sagar Kanya during the First Field Phase (FFP- 98) of the Indian Ocean experiment (INDOEX) in February and March 1998. High values of optical depths, particularly in the visible wavelengths, are encountered in the coastal areas, with a gradual increase from Goa to Male, The optical depths decrease sharply as the ship moves out to the south western Indian Ocean across the equator; the effect is more significant at shorter wavelengths. Over the pris-tine environment south of the ITCZ, extremely low optical depths appear at the visible wavelengths, while at the NIR wavelengths, the optical depths remain nearly the same as on the northern side. On the return Ieg, again higher optical depths are encountered north of the ITCZ with those at the visible wavelengths sharply increased. Over the north-western Arabian Sea, higher optical depthvalues occur farther away from the coast, suggesting additional input of aerosols over mid ocean, possibly transported by various wind trajectories from the west Asian deserts. Comparing air trajectories both at the surface and 850 h Pa reveals that in addition to those advected from continental India, winds transporting aerosols from various north/west Asian regions contribute significantly to the aerosol optical depths over the Arabian Sea
Enhanced production of lupeol through elicitation in in vitro shoot cultures of snake grass (Clinacanthus nutans)
Clinacanthus nutans (Acanthaceae), generally known as ‘snake grass’, has diverse uses in customary system of herbal medicine. The species is endowed with various bioactive compounds exhibiting extensive pharmacological properties. The present investigation focused on elicitor-intervened in vitro shoot biomass cultivation and scale-up production of the anti-cancerous compound ‘lupeol’, one of the foremost constituents in this species. For the augmented production of lupeol, the shoot cultures were elicited with various concentrations of yeast extract (YE), chitosan and methyl jasmonate (MeJA). Maximum shoot biomass yield and production of lupeol was detected in MS medium supplemented with 1.0 mgl-1 BA and 400 mgl-1 YE. The petroleum ether extracts of selected samples upon TLC analysis proved Rf values corresponding to lupeol. HPTLC analysis revealed that the sample treated with YE displayed relatively higher amount (975.50 ng) of lupeol than the in vivo plant (713.69 ng). Hence the in vitro shoot culture system with elicitor (YE) treatment propose an appropriate method for the elevated synthesis of lupeol which can be scaled up via bio-reactor technology in doing so profiting the pharmaceutical appliances
Inter-annual variations of selected oceanographic parameters and its relation to fishery of small pelagics off Kochi, southwest coast of India
The availability as well as abundance of selected small
pelagics along Kerala coast (south west coast of India) was
highly variable during the past three decades. During the
period 1980-2012 there have been several periods of
abundance as well as population crashes in the oil sardine
fishery. The present study revealed that the occurrence of low
sea level during the month of May implies either early wind
driven upwelling or early intensification of equator-ward
coastal current and consequent upsloping of isopycnals. The
occurrence of low sea level (6857) as early as in May and
upwelled water in August with low dissolved oxygen (0.68
ml l-1) with low sea water temperature (24˚C) at the bottom
at 10 m depth, off Kochi was found to affect the sardine
fishery in the year 1994, when the landing at Kochi was only
15 t. Mean sea level was found to be a sign of upwelling and
the real time observations of dissolved oxygen indicated wide
variations during the upwelling period
Report from a symposium on catalyzing primary and secondary prevention of cancer in India
PurposeOral, breast, and cervical cancers are amenable to early detection and account for a third of India’s cancer burden. We convened a symposium of diverse stakeholders to identify gaps in evidence, policy, and advocacy for the primary and secondary prevention of these cancers and recommendations to accelerate these efforts. MethodsIndian and global experts from government, academia, private sector (health care, media), donor organizations, and civil society (including cancer survivors and patient advocates) presented and discussed challenges and solutions related to strategic communication and implementation of prevention, early detection, and treatment linkages.ResultsInnovative approaches to implementing and scaling up primary and secondary prevention were discussed using examples from India and elsewhere in the world. Participants also reflected on existing global guidelines and national cancer prevention policies and experiences.ConclusionsSymposium participants proposed implementation-focused research, advocacy, and policy/program priorities to strengthen primary and secondary prevention efforts in India to address the burden of oral, breast, and cervical cancers and improve survival
Aerosol mass-size distributions at a tropical coastal environment: response to mesoscale and synoptic processes
Regular measurements of total mass concentration and mass-size distribution of near-surface aerosols, made using a ten-channel Quartz Crystal Microbalance (qcm) Impactor for the period October 1998-December 1999 at the tropical coastal station Trivandrum (8.5°N, 77°E), are used to study the response of aerosol characteristics to regional mesoscale and synoptic processes. Results reveal that aerosol mass concentrations are generally higher under land breeze conditions. The sea breeze generally has a cleansing effect, depleting the aerosol loading. The continental air (LB regime) is richer in accumulation mode (submicron) aerosols than the marine air. On a synoptic scale, aerosol mass concentration in the submicron mode decreased from an average high value of ~86 μg m-3 during the dry months (January-March) to ~11 μg m-3 during the monsoon season (June-September). On the contrary mass concentration in the supermicron mode increased from a low value of ~15 μg m-3 during the dry months to reach a comparatively high value of ~35 μg m-3 during April, May. Correspondingly, the effective radius (Reff) increased from a low value of 0.15-0.17 μm to ~0.3 μm indicating a seasonal change in the size distribution. The mass-size distribution shows mainly three modes, a fine mode (~0.1 μm); a large mode (~0.5 μm) and a coarse mode (~3 μm). The fine mode dominates in winter. In summer the large mode becomes more conspicuous and the coarse mode builds up. The fine mode is highly reduced in monsoon and the large and coarse modes continue to remain high (replenished) so that their relative dominance increases. The size distribution tends to revert to the winter pattern in the post-monsoon season. Accumulation (submicron) aerosols account for ~98% of the total surface area and ~70% of the total volume of aerosols during winter. During monsoon, even though they still account for ~90% of the area, their contribution to the volume is reduced to ~50%; the coarse aerosols account for the rest
A study of PM, PM10 and PM2.5 concentration at a tropical coastal station
Using estimates of particulate matter (PM), PM10 and PM2.5 made from the mass size distributions measured regularly using a Quartz Crystal Microbalance (QCM) impactor for the period October 1998-December 2000 at the coastal station Trivandrum, the long-term average values (for 27 months) of PM10 and PM2.5 are estimated. The season wise shares of PM10 and PM2.5 to PM are computed. Results indicate highest contribution of PM10 to PM during local summer/pre-monsoon while the contribution of PM2.5 to PM peaks during local winter. These shares are lowest during monsoon months. Average values of PM10 and PM2.5 were found to be around 50 and 43 μg m-3 under ambient conditions. For making an environmental assessment these values are corrected for humidity changes and reduced to a constant RH level of 50%. An order of magnitude estimate is made of the sea salt contribution to the total based on recent measurements during the INDOEX. After these apportionments, it is found that even though the PM10 concentration is well below the standards set by several national environmental agencies, the PM2.5 concentration appears to be quite critical. The findings are discussed
Aerosol optical depths over peninsular India and adjoining oceans during the INDOEX campaigns: Spatial, temporal, and spectral characteristics
Wintertime spatial characteristics of boundary layer aerosols over peninsular India
During an intense field campaign for generating a spatial composite of aerosol characteristics over peninsular India, collocated measurements of the mass concentration and size distribution of near-surface aerosols were made onboard instrumented vehicles along the road network during the dry, winter season (February–March) of 2004. The study regions covered coastal, industrial, urban, village, remote, semiarid, and vegetated forestlands. The results showed (1) comparatively high aerosol (mass) concentrations (exceeding 50 μg m−3), in general, along the coastal regions (east and west) and adjacent to urban locations, and (2) reduced mass concentration (<30 μg m−3) over the semiarid interior continental regions. Fine, accumulation-mode particles (<1 μm) contribute more than 50% to the total aerosol mass concentration in the coastal regions, which is more conspicuous along the east coast than the west coast, while the interior regions showed abundance (>50% of the total) of coarse-mode aerosols (>1 μm). The spatial composite of accumulation-mode share to the total aerosol mass concentration agreed very well with the monthly mean spatial composite of aerosol fine-mode fraction for February 2004, deduced from Moderate-Resolution Imaging Spectroradiometer data for the study region, while a point by point comparison yielded a linear association with a slope of 1.09 and correlation coefficient of 0.79 for 76 independent data pairs. Pockets of enhanced aerosol concentration were observed around the industrialized and urban centers along the coast as well as inland. Aerosol size distributions were parameterized using a power law. Spatial variation of the retrieved aerosol size index shows relatively high values (>4) along the coast compared to interior continental regions except at a few locations. Urban locations showed steeper size spectra than the remote locations
Wintertime spatial characteristics of boundary layer aerosols over peninsular India
During an intense field campaign for generating a spatial composite of aerosol characteristics over peninsular India, collocated measurements of the mass concentration and size distribution of near-surface aerosols were made onboard instrumented vehicles along the road network during the dry, winter season (February-March) of 2004. The study regions covered coastal, industrial, urban, village, remote, semiarid, and vegetated forestlands. The results showed (1) comparatively high aerosol (mass) concentrations (exceeding 50 μ g m(-3)), in general, along the coastal regions (east and west) and adjacent to urban locations, and (2) reduced mass concentration (<30 μ g m(-3)) over the semiarid interior continental regions. Fine, accumulation-mode particles (<1 μ m) contribute more than 50% to the total aerosol mass concentration in the coastal regions, which is more conspicuous along the east coast than the west coast, while the interior regions showed abundance (>50% of the total) of coarse-mode aerosols (>1 μ m). The spatial composite of accumulation-mode share to the total aerosol mass concentration agreed very well with the monthly mean spatial composite of aerosol fine-mode fraction for February 2004, deduced from Moderate-Resolution Imaging Spectroradiometer data for the study region, while a point by point comparison yielded a linear association with a slope of 1.09 and correlation coefficient of 0.79 for 76 independent data pairs. Pockets of enhanced aerosol concentration were observed around the industrialized and urban centers along the coast as well as inland. Aerosol size distributions were parameterized using a power law. Spatial variation of the retrieved aerosol size index shows relatively high values (>4) along the coast compared to interior continental regions except at a few locations. Urban locations showed steeper size spectra than the remote locations