Bio-Prospecting of a Few Brown Seaweeds for Their Cytotoxic and Antioxidant Activities

Methanolic extracts (MEs) of seven brown seaweeds occurring in the Indian coastal waters were screened for their cytotoxic and antioxidant properties following various assays. The methanolic extracts of seaweeds in the order of Dictyopteris australis > Spatoglossum variabile > Stoechospermum marginatum > Spatoglossum aspermum showed significant cytotoxic activity. A very high DPPH radical scavenging activity was exhibited by the methanolic extracts prepared from St. marginatum, Padina tetrastromatica, Dictyopteris delicatula and S. aspermum. The total phenolic content of the MEs varied from 13.19 ± 0.32 to 25.29 ± 0.445 gallic acid equivalents (mg g−1 of methanolic extract). The reducing power assay indicated a dose dependency, at concentrations of 0.1, 0.5 and 1.0 and 2.0 mg mL−1 of MEs and decreased in the following order: Butylated hydroxy toluene > P. tetrastromatica > D. delicatula > S. aspermum > S. variabile > S. marginatum > D. australis > S. marginatum. Furthermore, D. australis, S. aspermum, S. variabile and S. marginatum demonstrated good metal ion chelating properties. All the above evidences suggest that, the antioxidant compounds found in brown seaweeds scavenge free radicals through effective intervention. This decisively promotes them as a potential source of natural antioxidants

"The fruits of independence": Satyajit Ray, Indian nationhood and the spectre of empire

Challenging the longstanding consensus that Satyajit Ray's work is largely free of ideological concerns and notable only for its humanistic richness, this article shows with reference to representations of British colonialism and Indian nationhood that Ray's films and stories are marked deeply and consistently by a distinctively Bengali variety of liberalism. Drawn from an ongoing biographical project, it commences with an overview of the nationalist milieu in which Ray grew up and emphasizes the preoccupation with colonialism and nationalism that marked his earliest unfilmed scripts. It then shows with case studies of Kanchanjangha (1962), Charulata (1964), First Class Kamra (First-Class Compartment, 1981), Pratidwandi (The Adversary, 1970), Shatranj ke Khilari (The Chess Players, 1977), Agantuk (The Stranger, 1991) and Robertsoner Ruby (Robertson's Ruby, 1992) how Ray's mature work continued to combine a strongly anti-colonial viewpoint with a shifting perspective on Indian nationhood and an unequivocal commitment to cultural cosmopolitanism. Analysing how Ray articulated his ideological positions through the quintessentially liberal device of complexly staged debates that were apparently free, but in fact closed by the scenarist/director on ideologically specific notes, this article concludes that Ray's reputation as an all-forgiving, ‘everybody-has-his-reasons’ humanist is based on simplistic or even tendentious readings of his work

Georeferenced soil information system: assessment of database

Land-use planning is a decision-making process that facilitates the allocation of land to different uses that provide optimal and sustainable benefit. As land-use is shaped by society–nature interaction, in land-use planning different components/facets play a significant role involving soil, water, climate, animal (ruminant/ non-ruminant) and others, including forestry and the environment needed for survival of mankind. At times these components are moderated by human interference. Thus land-use planning being a dynamic phenomenon is not guided by a single factor, but by a complex system working simultaneously,which largely affects the sustainability. To address such issues a National Agricultural Innovation Project (NAIP) on ‘Georeferenced soil information system for land-use planning and monitoring soil and land quality for agriculture’ was undertaken to develop threshold values of land quality parameters for land-use planning through quantitative land evaluation and crop modelling for dominant cropping systems in major agro-ecological sub-regions (AESRs) representing rice–wheat cropping system in the Indo-Gangetic Plains (IGP) and deep-rooted crops in the black soil regions (BSR). To assess the impact of landuse change, threshold land quality indicator values are used. A modified AESR map for agricultural landuse planning is generated for effective land-use planning

Soil information system: use and potentials in humid and semi-arid tropics

The articles presented in this special section emanated from the researches of consortium members of the National Agricultural Innovative Project (NAIP, Component 4) of the Indian Council of Agricultural Research (ICAR), New Delhi. These researches have helped develop a soil information system (SIS). In view of the changing scenario all over the world, the need of the hour is to get assistance from a host of researchers specialized in soils, crops, geology, geography and information technology to make proper use of the datasets. Equipped with the essential knowledge of data storage and retrieval for management recommendations, these experts should be able to address the issues of land degradation, biodiversity, food security, climate change and ultimately arrive at an appropriate agricultural land-use planning. Moreover, as the natural resource information is an essential prerequisite for monitoring and predicting global environmental change with special reference to climate and land use options, the SIS needs to be a dynamic exercise to accommodate temporal datasets, so that subsequently it should result in the evolution of the soil information technology. The database developed through this NAIP would serve as an example of the usefulness of the Consortium and the research initiative of ICAR involving experts from different fields to find out the potentials of the soils of humid and semi-arid bioclimatic systems of the country

Revisiting the stringent response, ppGpp and starvation signaling

Microbial adaptation to environmental stress plays an important role in survival. It is necessary to understand the mechanisms underlying the survival of microbes under stress, as they may eventually aid in the successful control of the growth and persistence of these organisms. During nutrient starvation, Escherichia coli elicits a stringent response to conserve energy. The hallmark of the stringent response is the accumulation of guanosine tetra- (ppGpp) and pentaphosphates (pppGpp), which probably bind RNA polymerase to regulate gene expression at certain promoters. Recently, there has been renewed interest in the stringent responses of other microbes, with a view to correlating it with sporulation, virulence and long-term persistence

Revisiting the stringent response, ppGpp and starvation signaling

Microbial adaptation to environmental stress plays an important role in survival. It is necessary to understand the mechanisms underlying the survival of microbes under stress, as they may eventually aid in the successful control of the growth and persistence of these organisms. During nutrient starvation, Escherichia coli elicits a stringent response to conserve energy. The hallmark of the stringent response is the accumulation of guanosine tetra- (ppGpp) and pentaphosphates (pppGpp), which probably bind RNA polymerase to regulate gene expression at certain promoters. Recently, there has been renewed interest in the stringent responses of other microbes, with a view to correlating it with sporulation, virulence and long-term persistence

Seaweeds – Promising Organic Fertilizers

34-35Seaweeds can be a boon for farmers as they are source of some of the best organic fertilizer