Soumitra Biswas

Bio: Soumitra Biswas is an academic researcher from Council of Scientific and Industrial Research. The author has contributed to research in topics: Coal & Combustion. The author has an hindex of 12, co-authored 36 publications receiving 639 citations. Previous affiliations of Soumitra Biswas include Zoological Survey of India & Jadavpur University.

Prey abundance and food habit of tigers (Panthera tigris tigris) in Pench National Park, Madhya Pradesh, India

Abstract: Food habits of tigers Panthera tigris and population attributes of prey species (population structure, density and biomass) were studied in the tropical dry deciduous forest of Pench National Park, Central India, from November 1998 to April 1999. Scat analysis and line transect method were used to estimate tiger food habits and density of major prey species, respectively. The 61.1 km2 intensive study area was found to have very high ungulate density (90.3 animals km−2) with chital Axis axis being the most common species (80.7 animals km−2), followed by sambar Cervus unicolor (6.1 animals km−2). Common langur Presbytis entellus was the most abundant (77.2 animals km−2) primate species. When the density figures were multiplied by the average weight of each prey species, a high biomass density of 6013.25 kg km−2 was obtained for the intensive study area. Chital (47.3%) along with sambar (14.5%) and wild pig Sus scrofa (10.9%) constituted the major part of the tiger's diet. If there is food choice, tigers seem to kill medium- and large-sized species more often. Wild pig and sambar were consumed more than their availability, whereas chital were taken in proportion to their availability. Gaur Bos gaurus and nilgai Bosephalus tragocamelus were not represented in the tiger's diet. Common langur was consumed in lesser proportion by tigers than expected by estimates of its density. The average weight of animals consumed by tigers in the intensive study area was 82.1 kg. The analyses revealed that Pench harbours very high prey density and tigers are mostly dependent on the wild ungulates rather than on domestic livestock as is the case in many other areas in the Indian subcontinent. These two factors thus make Pench National Park a potential area for long-term conservation of tigers.

Derivatives and Applications of Lignin - An Insight

Abstract: Lignin, a component of plants, has great potential for its conversion into value-added products that could signicantly improve the economics of a biorenery. The derivatives from lignin assume importance towards an effective & efcient utilization of biomass. It is a non-toxic and renewable raw material contributing ~ 30% of the weight and ~40% of the energy content of lignocellulosic biomass. Due to complex nature of lignin, this highly abundant biomass product is undervalued and it is mainly used as boiler fuel for paper & pulp industry. The increasing fuel prices with changing fuel specications are some of the key drivers, which lead to development of new technologies. The polymeric lignin can be converted into low molecular weight and monomeric aromatic forms, that serve as the building block for chemical syntheses of high-value products. This paper covers in detail the utilization of lignin to derive value-added products, their applications and business opportunities. It also contains various other applications for lignin, their production and current market potential.

Plant Cell, Tissue and Organ Culture

Abstract: The origin of plant cell and tissue culture can be found in a treatise published during the mid-18th century, entitled La Physique des Arbes, that describes the formation of callus tissue following the for mation of a ring of cortex from elm trees. Over the next two centuries, the discovery of plant growth hormones, in particular auxins and cytokinins, and detailed analyses on the nutritional requirements of plants, led to the formulation of media that could maintain actively dividing cultures derived from gymnosperms, and both dicotyledon ous and monocotyledonous angiosperms. However, much of the prog ress and technological development in the in vitro propagation of plant cells, tissues, and organs has occurred during the last 25 years. Recently, plant tissue culture techniques have been used as basic tools in the rapidly expanding field of plant biotechnology for the development and clonal propagation of new and/or improved plant varieties. Plant tissue culture is used for the micropropagation of commercially valuable cultivars that include ornamentals, oil palm, Glycyrrhiza, Pyrethrum, pine, Eucalyptus, sugar cane, and potatoes. Cultured plant tissue is also used for the selection of cells and, ul timately, the regeneration of plants that are tolerant to physical stresses such as pathogens, drought, and temperature extremes, and to chemical stress agents such as salinity, herbicides, proteins, and pyrethrins. In addition, new plants have been produced by the fusion of protoplasts prepared from cultured cells of different species in cluding sunflower and french bean, tomato and potato, and various cultivars of Datura. Finally, bacterial vectors and various mechanical methods have been used to introduce foreign genes into cultured plant tissues. Genetic transformation can result in profound changes in the phenotype and/or biochemical profile of the regenerated trans genic plants that are not characteristic of the wild type. An impressive variety of technologies in tissue culture, genetic manipulation, and molecular biology have been developed for nu merous plant species. Many of these techniques, sometimes referred to as plant biotechnology, have been extensively summarized and compiled in a well-balanced collection of easy-to-follow protocols presented in three separate, but complimentary, volumes. Plant Cell, Tissue and Organ Culture consists of 22 chapters (with 86 figures) and 5 appendices. The chapters cover critical aspects of (a) the es sential requirements for the operation of a plant tissue culture lab oratory; (b) the basic procedures of micropropagation, regeneration, and somatic embryogenesis; (c) some specific applications of organ culture systems such as embryo rescue and culture, and anther and microspore culture for haploid and double haploid production; (d) elementary transformation technology; and (e) useful microtechnique and analytical protocols specifically adapted to cultured tissues and cells. The appendices provide a convenient summary of media for mulations and commercial suppliers for the materials described in the text.

Human-felid conflict: a review of patterns and priorities worldwide.

Abstract: Conflict between people and felids is one of the most urgent wild cat conservation issues worldwide, yet efforts to synthesize knowledge about these conflicts have been few. For management strategies to be effective a thorough understanding of the dynamics of human-felid conflicts is necessary. Here we present the results of a cross-species, systematic review of human-felid conflicts worldwide. Using a combination of literature review and geographical information system analyses, we provide a quantitative as well as qualitative assessment of patterns and determinants that are known to influence the severity of human-felid conflicts, and a geographical overview of the occurrence of conflict worldwide. We found evidence of conflict affecting over 75% of the world's felid species. The severity of conflict increases with felid body mass and is of greatest conservation significance to nine species: caracal, cheetah, Eurasian lynx, jaguar, leopard, lion, puma, snow leopard and tiger. We also reveal specific gaps in knowledge about human-felid conflicts, and required actions within this aspect of felid conservation. With only 31% of implemented management strategies having been evaluated scientifically, there is a need for greater and more rigorous evaluation and a wider dissemination of results. Also urgently required are standardized reporting techniques to reduce the current disparity in conflict reporting methods and facilitate resolution of patterns and trends in the scale of human-felid conflict worldwide. This review provides a basis both for further synthesis and for the coordination of human-felid conflict management among researchers, practitioners and organizations.

A review on commercial-scale high-value products that can be produced alongside cellulosic ethanol.

Abstract: The demand for fossil derivate fuels and chemicals has increased, augmenting concerns on climate change, global economic stability, and sustainability on fossil resources. Therefore, the production of fuels and chemicals from alternative and renewable resources has attracted considerable and growing attention. Ethanol is a promising biofuel that can reduce the consumption of gasoline in the transportation sector and related greenhouse gas (GHG) emissions. Lignocellulosic biomass is a promising feedstock to produce bioethanol (cellulosic ethanol) because of its abundance and low cost. Since the conversion of lignocellulose to ethanol is complex and expensive, the cellulosic ethanol price cannot compete with those of the fossil derivate fuels. A promising strategy to lower the production cost of cellulosic ethanol is developing a biorefinery which produces ethanol and other high-value chemicals from lignocellulose. The selection of such chemicals is difficult because there are hundreds of products that can be produced from lignocellulose. Multiple reviews and reports have described a small group of lignocellulose derivate compounds that have the potential to be commercialized. Some of these products are in the bench scale and require extensive research and time before they can be industrially produced. This review examines chemicals and materials with a Technology Readiness Level (TRL) of at least 8, which have reached a commercial scale and could be shortly or immediately integrated into a cellulosic ethanol process.

Living with large carnivores: predation on livestock by the snow leopard (Uncia uncia)

Abstract: Livestock predation by large carnivores and their retaliatory persecution by pastoralists are worldwide conservation concerns. Poor understanding of the ecological and social underpinnings of this human?wildlife conflict hampers effective conflict management programs. The endangered snow leopard Uncia uncia is involved in conflict with people across its mountainous range in South and Central Asia, where pastoralism is the predominant land use, and is widely persecuted in retaliation. We examined human-snow leopard conflict at two sites in the Spiti region of the Indian Trans-Himalaya, where livestock outnumber wild ungulates, and the conflict is acute. We quantified the snow leopard's dependence on livestock by assessing its diet in two sites that differed in the relative abundance of livestock and wild ungulates. We also surveyed the indigenous Buddhist community's attitudes towards the snow leopard in these two sites. Our results show a relatively high dependence of snow leopards on livestock. A higher proportion of the snow leopard's diet (58%) was livestock in the area with higher livestock (29.7 animals km?2) and lower wild ungulate abundance (2.1?3.1 bharal Pseudois nayaur km?2), compared with 40% of diet in the area with relatively lower livestock (13.9 km?2) and higher wild ungulate abundance (4.5?7.8 ibex Capra ibex km?2). We found that the community experiencing greater levels of livestock losses was comparatively more tolerant towards the snow leopard. This discrepancy is explained by the presence of a conservation-incentive program at the site, and by differences in economic roles of livestock between these two communities. The former is more dependent on cash crops as a source of income while the latter is more dependent on livestock, and thereby less tolerant of the snow leopard. These data have implications for conflict management strategies. They indicate that the relative densities of livestock and wild prey may be reasonable predictors of the extent of predation by the snow leopard. However, this by itself is not an adequate measure of the intensity of conflict even in apparently similar cultural settings.