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Showing papers by "Jawaharlal Nehru University published in 2001"


Journal ArticleDOI
TL;DR: In this article, the authors track some of the major myths on driving forces of land cover change and propose alternative pathways of change that are better supported by case study evidence, concluding that neither population nor poverty alone constitute the sole and major underlying causes of land-cover change worldwide.
Abstract: Common understanding of the causes of land-use and land-cover change is dominated by simplifications which, in turn, underlie many environment-development policies. This article tracks some of the major myths on driving forces of land-cover change and proposes alternative pathways of change that are better supported by case study evidence. Cases reviewed support the conclusion that neither population nor poverty alone constitute the sole and major underlying causes of land-cover change worldwide. Rather, peoples’ responses to economic opportunities, as mediated by institutional factors, drive land-cover changes. Opportunities and

3,330 citations


Journal ArticleDOI
TL;DR: In this paper, the impact of the Deccan Traps on chemical weathering and atmospheric CO2 consumption on Earth is evaluated based on the study of major elements, strontium and 87Sr/86Sr isotopic ratios of the main rivers flowing through the traps, using a numerical model.

434 citations


Journal ArticleDOI
TL;DR: The addition of proline to the culture medium alleviated the salt stress-induced decline in fresh weight accumulation and reduced peroxidative damage to the lipid membranes, both in a concentration-dependent manner.
Abstract: Cell lines of a salt-sensitive cultivar of groundnut (Arachis hypogaea L. cv. JL24) were selected on media amended with high NaCl concentrations. Comparative analyses of the water status and ionic relations of salt-sensitive and salt-tolerant cell lines showed a decrease in the water potential (ψw) and solute potential (ψπ) with increases in salt stress. However, the maintenance of cellular turgor indicated active osmotic adjustments in response to salinity stress. In addition to the extrusion of Na+ in the NaCl-selected cell lines, a significant accumulation of proline was observed, which was probably associated with osmotic adjustments and the protection of membrane integrity. The addition of proline to the culture medium alleviated the salt stress-induced decline in fresh weight accumulation and reduced peroxidative damage to the lipid membranes, both in a concentration-dependent manner.

370 citations


Journal ArticleDOI
TL;DR: The results show that proline is a very effective singlet oxygen quencher and since proline accumulation is one of the important solutes which accumulate in many organisms when they are exposed to environmental stresses, it is likely that pro line accumulation is related to the protection of these organisms against singletoxy production during stress conditions.
Abstract: Molecular oxygen in electronic singlet state is a very powerful oxidant. Its damaging action in a variety of biological processes has been well recognized. Here we report the singlet oxygen quenching action of proline. Singlet oxygen (1O2) was produced photochemically by irradiating a solution of sensitiser and detected by following the formation of stable nitroxide radical yielded in the reaction of 1O2 with the sterically hindered amine (2,2,6,6-tetramethylpiperidine, TEMP). Illumination of a sensitiser, toluidine blue led to a time dependent increase in singlet oxygen production as detected by the formation of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) by EPR spectrometry. Interestingly, the production of TEMPO was completely abolished by the presence of proline at concentration as low as 20mM. These results show that proline is a very effective singlet oxygen quencher. Other singlet oxygen generating photosensitizer like hematopophyrin and fluorescein also produced identical results with proline. Since proline is one of the important solutes which accumulate in many organisms when they are exposed to environmental stresses, it is likely that proline accumulation is related to the protection of these organisms against singlet oxygen production during stress conditions. A possible mechanism of singlet oxygen quenching by proline is discussed.

302 citations


Journal ArticleDOI
TL;DR: The therapeutic role of Trigonella seed powder in type1 diabetes as exemplified in this study can be attributed to the change of glucose and lipid metabolising enzyme activities to normal values, thus stabilizing glucose homeostasis in the liver and kidney.
Abstract: Trigonella foenum graecum (fenugreek) seed powder has been suggested to have potential antidiabetic effects. The effect of oral administration of Trigonella whole seed powder (5% in the diet) for 21 days on glycolytic, gluconeogenic and NADPlinked lipogenic enzymes were studied in liver and kidney tissues of alloxan-induced diabetic Wistar rats. Diabetic rats were characterised by a 4fold higher blood glucose level and a 0.7fold lower body weight compared to normal controls. The activities of the glycolytic enzymes were significantly lower in the diabetic liver and higher in the diabetic kidney. The activities of gluconeogenic enzymes were higher in both liver and kidney during diabetes, however the activities of the lipogenic enzymes were decreased in both tissues during diabetes. Trigonella seed powder treatment to diabetic rats for 21 days brought down the elevated fasting blood glucose levels to control levels. The altered enzyme activities were significantly restored to control values in both the liver and kidney after Trigonella seed powder treatment. The therapeutic role of Trigonella seed powder in type1 diabetes as exemplified in this study can be attributed to the change of glucose and lipid metabolising enzyme activities to normal values, thus stabilizing glucose homeostasis in the liver and kidney. These biochemical effects exerted by Trigonella seeds make it a possible new therapeutic in type1 diabetes.

297 citations


Journal ArticleDOI
TL;DR: In this paper, the authors used cosmogenic radionuclide 10 Be and 26 Al to date strath terraces along the Alaknanda River in lower Garhwal Himalaya to provide an estimate of ; 4m m a y1 for the rate of regional denudation throughout the Holocene.

211 citations


Journal ArticleDOI
TL;DR: The potential offered by technological progress in the information and communication technologies (ICTs) industries for the health sector in developing countries is outlined, some examples of positive experiences in India are presented, and the difficulties in achieving this potential are considered.
Abstract: This paper outlines the potential offered by technological progress in the information and communication technologies (ICTs) industries for the health sector in developing countries, presents some examples of positive experiences in India, and considers the difficulties in achieving this potential. The development of ICTs can bring about improvements in health in developing countries in at least three ways: as an instrument for continuing education they enable health workers to be informed of and trained in advances in knowledge; they can improve the delivery of health and disaster management services to poor and remote locations; and they can increase the transparency and efficiency of governance, which should, in turn, improve the availability and delivery of publicly provided health services. These potential benefits of ICTs do not necessarily require all the final beneficiaries to be reached directly, thus the cost of a given quantum of effect is reduced. Some current experiments in India, such as the use of Personal Digital Assistants by rural health workers in Rajasthan, the disaster management project in Maharashtra and the computerized village offices in Andhra Pradesh and Pondicherry, suggest creative ways of using ICTs to improve the health conditions of local people. However, the basic difficulties encountered in using ICTs for such purposes are: an inadequate physical infrastructure; insufficient access by the majority of the population to the hardware; and a lack of the requisite skills for using them. We highlight the substantial cost involved in providing wider access, and the problem of resource allocation in poor countries where basic infrastructure for health and education is still lacking. Educating health professionals in the possible uses of ICTs, and providing them with access and "connectivity", would in turn spread the benefits to a much wider set of final beneficiaries and might help reduce the digital divide.

187 citations


Journal ArticleDOI
TL;DR: In this article, the rare earth element chemistry of the floodplain sediments, along with their major and trace element composition in different size fractions, are discussed and a strong coherence between REE and TiO2 contents in the sediments is observed, which is suggestive of strong control by titanite, or its weathered products, on the REE chemistry.

181 citations


Journal ArticleDOI
TL;DR: The results clearly indicate the commercial potential of P. indica for large-scale cultivation of S. calva and W. somnifera and show a significant increase in growth and yield relative to uninoculated controls.
Abstract: The medicinal plants Spilanthes calva and Withania somnifera were inoculated with Piriformospora indica, a plant growth-promoting root endophyte, in nurseries and subsequently transferred to the field. A significant increase in growth and yield of both plant species was recorded relative to uninoculated controls. Shoot and root length, biomass, basal stem, leaf area, overall size, number of inflorescences and flowers and seed production were all enhanced in the presence of the fungus. Net primary productivity was also higher than in control plants. The results clearly indicate the commercial potential of P. indica for large-scale cultivation of S. calva and W. somnifera.

177 citations


Journal ArticleDOI
TL;DR: In this paper, the authors pointed out that the focus is shifting away from professionals in specific occupations, like doctors, engineers, scientists, architects, bankers, to information technology (IT) professionals embodying, in a way, more generic skills.
Abstract: Globalization of human capital through international migration is no longer about global physical presence only; it is also about global applicability of skills across various fields of specialization. This marks the main characteristics of skilled migration from India to developed countries in the twenty-first century. The focus is shifting away from professionals in specific occupations, like doctors, engineers, scientists, architects, bankers, to information technology (IT) professionals embodying, in a way, more generic skills. In other words, it is the generic applicability of information and communications technology (ICT) which has led to large-scale migration of Indians skilled in IT. Moreover, the exodus comprises not only the fully trained and educated workers going abroad for employment, but also students - the semi-finished human capital - pursuing higher education in onshore as well as offshore universities of the developed countries. The new emigration is directed towards traditional host countries in the West such as the UK, Canada, and the US, but also towards newly emerging destinations in continental Europe (Germany, France, Belgium, Italy, Denmark), Australasia (Australia, New Zealand), East Asia (Japan, Republic of Korea), and South-East Asia (Singapore, Malaysia). By using mainly current information and informal data as reported in the media, this article perceives emerging trends and changes in the context of the global labour market for skills, and suggests a possible framework towards evolving strategies of remedial development.

163 citations


Journal ArticleDOI
TL;DR: The variation of the Lyapunov exponent, and the qualitative and quantitative aspects of its local fluctuation properties, have emerged as an important means of studying fractal attractors, and this analysis finds useful application here.
Abstract: Aperiodic dynamics which is nonchaotic is realized on Strange Nonchaotic Attractors (SNAs). Such attractors are generic in quasiperiodically driven nonlinear systems, and like strange attractors, are geometrically fractal. The largest Lyapunov exponent is zero or negative: trajectories do not show exponential sensitivity to initial conditions. In recent years, SNAs have been seen in a number of diverse experimental situations ranging from quasiperiodically driven mechanical or electronic systems to plasma discharges. An important connection is the equivalence between a quasiperiodically driven system and the Schrodinger equation for a particle in a related quasiperiodic potential, showing a correspondence between the localized states of the quantum problem with SNAs in the related dynamical system. In this review we discuss the main conceptual issues in the study of SNAs, including the different bifurcations or routes for the creation of such attractors, the methods of characterization, and the nature of dynamical transitions in quasiperiodically forced systems. The variation of the Lyapunov exponent, and the qualitative and quantitative aspects of its local fluctuation properties, have emerged as an important means of studying fractal attractors, and this analysis finds useful application here. The ubiquity of such attractors, in conjunction with their several unusual properties, suggests novel applications.

Journal ArticleDOI
TL;DR: Human erythrocytes exposed in a dose dependent manner to various ethanolic plant extracts, and fractions obtained from plant parts of Calotropis procera and gum--oleo resin of Commiphora wightii extracts were representative.

Journal ArticleDOI
TL;DR: The timing of glaciation in the Lahul Himalaya of northern India was ascertained using the concentrations of cosmogenic 10Be and 26Al from boulders on moraines and drumlins, and from glacially polished bedrock surfaces.
Abstract: The timing of glaciation in the Lahul Himalaya of northern India was ascertained using the concentrations of cosmogenic 10Be and 26Al from boulders on moraines and drumlins, and from glacially polished bedrock surfaces. Five glacial stages were identified: Sonapani I and II, Kulti, Batal and Chandra. Of these, cosmogenic exposure ages were obtained on samples representative of the Batal and Kulti glacial cycles. Stratigraphical relationships indicate that the Sonapani I and II are younger. No age was obtained for the Chandra glacial advance. Batal Glacial Stage deposits are found throughout the valley, indicating the presence of an extensive valley glacial system. During the Kulti Stage, glaciers advanced ca. 10 km beyond their current positions. Moraines produced during the Batal Stage, ca. 12–15.5 ka, are coeval with the Northern Hemisphere Late-glacial Interstadial (Bolling/Allerod). Deglaciation of the Batal Glacial Stage was completed by ca. 12 ka and was followed by the Kulti Glacial Stage during the early Holocene, at ca. 10–11.4 ka. On millennial time-scales, glacier oscillations in the Lahul Himalaya apparently reflect periods of positive mass-balance coincident with times of increased insolation. During these periods the South Asian summer monsoon strengthened and/or extended its influence further north and west, thereby enhancing high-altitude summer snowfall. Copyright © 2001 John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: In this article, the Nanda Devi Biosphere Reserve, a World Heritage Site in Indian Himalaya, was analyzed through participatory discussions covering 419 households distributed in 10 villages in the buffer zone.

Journal ArticleDOI
28 Jun 2001-Nature
TL;DR: A surprising source of ozone is discovered — namely, the exuberant mass of colour-emitting sparklers that are lit during the Diwali festivities, which take place every year during October and November in Delhi, India.
Abstract: Ozone is a secondary pollutant and greenhouse gas that is formed from molecular oxygen in the presence of sunlight and nitrogen oxides. The extent of production also depends on the presence of volatile hydrocarbons, carbon monoxide and methane1,2,3,4,5,6. But we have discovered a surprising source of ozone which is generated in spontaneous bursts even in the absence of sunlight and nitrogen oxides — namely, the exuberant mass of colour-emitting sparklers that are lit during the Diwali festivities, which take place every year during October and November in Delhi, India. The underlying process of ozone formation resembles that induced by ultraviolet radiation in the stratosphere7,8.

Journal ArticleDOI
TL;DR: Pre-treatment with S. fusiformis significantly reduced the chromosomal damage and lipid peroxidation with concomitant changes in antioxidants and detoxification systems and all the three tested doses were effective in exerting a protective effect against CP and MMC.

Book ChapterDOI
01 Jan 2001
TL;DR: Soil microflora influence plant growth and health both beneficially and adversely by providing plant growth substances and increasing the availability of nutrients at the root zone.
Abstract: Soil microflora influence plant growth and health both beneficially and adversely. The microorganisms used as biofertilisers stimulate plant growth response by providing necessary nutrients as a result of their colonisation of the rhizosphere (Azotob acter, Azospirillum, phosphate-solubilising bacteria and cyanobacteria) or by symbiotic association (Rhizobium, mycorrhizae fungi and Frankia). They may also regulate the physiological processes in the ecosystems by involvement in the decomposition of organic matter, fixation of atmospheric nitrogen, secretion of growth-promoting substances, increase in the availability of mineral nutrients, immobilisation of these assimilable nutrients and protection of plants from pathogens (Mukerji et al. 1998). Thus, rhizosphere effects through microbial activities, modify the plants by providing plant growth substances and increasing the availability of nutrients at the root zone. Plant root anatomy and tissue articulation play a significant role in the symbiotic processes (Lynch 1995).

Journal ArticleDOI
TL;DR: It is suggested that pretreatment with saffron can significantly inhibit the genotoxicity of CIS, CPH, MMC and urethane and this inhibitory effect was not always dose-dependent.
Abstract: Experiments were carried out to ascertain whether or not saffron (dried stigmas of Crocus sativus L.), a commonly used agent for flavoring and coloring food can exert modulatory effects on the in v...

Journal ArticleDOI
TL;DR: It is suggested that in the locus coeruleus cholinergic input modulates the frequency of induction of rapid eye movement sleep and this action is mediated through GABA interneurons, whereas the length of rapidEye movement sleep per episode is maintained by the presence of an optimum level of GABA.

Journal ArticleDOI
TL;DR: Results suggest that additional carbon sources are available during sexual development in Aspergillus nidulans, including alpha-1,3 glucan, which is considered the main reserve material accumulated during vegetative growth as a cell wall component and consumed duringSexual development.

Journal ArticleDOI
TL;DR: The radioresponse of antioxidant enzymes seemed to be significantly different in the liver of tumorburdened mice compared to controls, and the enhanced activities might be due to relatively more damage caused by radiation.
Abstract: Since the radiation dose tolerance of normal tissues/organs away from the site of tumor influences the success of radiation therapy of cancer, and antioxidant status is likely to be one of the factors to determine the tolerance; the radioresponse of antioxidant enzymes has been examined in the liver as a representative distant organ in the tumorbearing mice.

Journal ArticleDOI
TL;DR: A critical role of ERKs and JNK is suggested in HBx-mediated cell transformation as a consequence of continued HBx expression, which led to sustained stimulation of further downstream events, such as increased levels of c-Jun and c-Fos proteins along with the persistent induction of activator protein 1 binding activity.
Abstract: Transcriptional activation of diverse cellular genes by the X protein (HBx) of hepatitis B virus (HBV) has been suggested as one of the mechanisms for HBV-associated hepatocellular carcinoma. However, such functions of HBx have been studied using transformed cells in culture and have not been examined in the normal adult hepatocytes, a natural host of HBV. Using an efficient hepatocyte-specific virus-based gene delivery system developed in our laboratory earlier, we studied the HBx action in vivo. We demonstrate that following virosome-mediated delivery of HBx DNA, a large population (>50%) of hepatocytes express the HBx protein in a dose-dependent manner, which induces a significant increase in the activity of extracellular signal-regulated kinases (ERKs) in the livers of HBx-transfected mice. Inhibition of HBx-induced ERK activation following intravenous administration of PD98059, a mitogen-activated protein kinase kinase kinase (MEK) inhibitor, confirmed the requirement for MEK in the activation of ERKs by HBx. Induction of ERK activity by HBx was sustained for up to 30 days. Interestingly, sustained activation of c-Jun N-terminal kinases (JNKs) for up to 30 days was also noted. Such constitutive ERK and JNK activation as a consequence of continued HBx expression also led to sustained stimulation of further downstream events, such as increased levels of c-Jun and c-Fos proteins along with the persistent induction of activator protein 1 binding activity. Taken together, our data suggest a critical role of these molecules in HBx-mediated cell transformation.

Journal ArticleDOI
TL;DR: In this paper, the reverse micelles of water-AOT-isooctane have been modeled as spheres from geometrical considerations and for W0>20, these conformationaly resemble deformed spheres.

Journal ArticleDOI
TL;DR: A simple phenomenological model is formulated to explain the dynamics of phase separation in binary mixtures near a surface with a preferential attraction for one of the components of the mixture.
Abstract: We study the dynamics of phase separation in binary mixtures near a surface with a preferential attraction for one of the components of the mixture. We obtain detailed numerical results for a range of mixture compositions. In the case where the minority component is attracted to the surface, wetting layer growth is characterized by a crossover from a surface-potential-dependent growth law to a universal law. We formulate a simple phenomenological model to explain our numerical results.

Journal ArticleDOI
TL;DR: The floodplain sediments of the Kaveri River, southern India, derived from Archean gneissic and charnockitic source regions, show interbedding of silty and sandy units as discussed by the authors.
Abstract: The floodplain sediments of the Kaveri River, southern India, derived from Archean gneissic and charnockitic source regions, show interbedding of silty (4-4.7 ) and sandy units (1.4-3.7 ). The geochemistry of silty beds is remarkably uniform at a given location and over a lateral distance of nearly 250 km; the sandy beds have more variable chemical compositions, yet are comparable to those of silty beds except for the diluting effect of quartz. Silty sediments retain the geochemical signature of prominently exposed source rocks for almost all elements and provide evidence of tectonic instability in the source region. The floodplain sediments contain all size grades (sand, silt, and clay), which may have resulted in minimizing the biases imposed on suspended and bedload sediments due to sorting. The low Chemical Index of Alteration (CIA), the dominance of unweathered primary minerals, and the minor proportion of smectitic clay all suggest that the region has been subjected to little chemical weathering. This is possible if the region has undergone recent uplift, exposing fresh Archean rock to surface denudation. The formation of fertile farmland along the Kaveri River course and its delta is related to these recent geological processes.

Journal ArticleDOI
TL;DR: Both trans-anethole and eugenol exerted dose-related antigenotoxic effects against PCB and URE and inhibited the genotoxicity of ethyl methane sulfonate (EMS).

Journal ArticleDOI
TL;DR: Findings indicate the chemopreventive potential of Andrographis paniculata against chemotoxicity including carcinogenicity.
Abstract: The effects of two doses (50 and 100 mg/kg body wt/day for 14 days) of an 80% hydroalcohol extract of Andrographis paniculata and butylated hydroxyanisole (BHA) were examined on drug metabolizing enzymes, antioxidant enzymes, glutathione content, lactate dehydrogenase (LDH) and lipid peroxidation in the liver of Swiss albino mice (6-8 weeks old). The effect of the extract and BHA were also examined on lung, kidney and forestomach for the activities of glutathione S-transferase (GST), DT-diaphorase (DTD), superoxide dismutase (SOD) and catalase. A significant increase in the levels of acid soluble sulphydryl (-SH) content, cytochrome P450, cytochrome P450 reductase, cytochrome b5 reductase, GST, DTD and SOD were observed at both dose levels of extract treatment while catalase, glutathione peroxidase and glutathione reductase (GR) showed significant increases only at the higher dose in the liver. Both Andrographis treated groups showed a significant decrease in activity of LDH and malondialdehyde (MDA) formation. BHA treated mice showed a significant increase in the levels of cytochrome b(5), GST, DTD, -SH content, GR and catalase in liver; while LDH and MDA levels were reduced significantly compared with their control values. In the lung, SOD, catalase and DTD, in the kidney catalase, DTD and GST, and in the forestomach SOD and DTD showed a significant increase at both dose levels of treatment. In BHA treated mice GST, DTD and catalase were significantly induced in the lung and along with these enzymes SOD was also induced in the kidney. In the case of the forestomach of BHA treated mice GST, DTD and SOD were enhanced significantly. These findings indicate the chemopreventive potential of Andrographis paniculata against chemotoxicity including carcinogenicity.

Journal ArticleDOI
TL;DR: The activity of Na(+), K(+)-ATPase and GST was enhanced; that of GPx was unaffected; the MUA was increased while the levels of LP and LF were decreased.

Journal ArticleDOI
01 Dec 2001-Synapse
TL;DR: The results of this study suggest that GABAergic inputs from prepositus hypoglossi act on locus coeruleus and regulate REM sleep, possibly by inhibition of REM‐OFF neurons.
Abstract: GABA in locus coeruleus modulates REM sleep. Apart from the presence of interneurons, locus coeruleus also receives GABAergic inputs from prepositus hypoglossi in the medulla, where the presence of REM-ON-like neurons have been reported. Therefore, it was hypothesized that GABAergic projections from prepositus hypoglossi to locus coeruleus may modulate REM sleep. The experiments were conducted on chronic rats prepared for recording EEG, EOG, and EMG in freely moving conditions. Bipolar stimulating electrodes were implanted in prepositus hypoglossi bilaterally, while chemitrodes were implanted bilaterally in locus coeruleus. The prepositus hypoglossi were bilaterally stimulated (3 Hz, 250 μsec, 100 μA) for 8 h in the presence and absence of picrotoxin (0.25 μg/250 nl) microinjection bilaterally in locus coeruleus, followed by poststimulation recording for 4 h. It was observed that stimulation of prepositus hypoglossi alone significantly increased REM sleep primarily by increasing the REM sleep duration per episode. However, when it was stimulated in the presence of picrotoxin in LC, REM sleep decreased, predominantly due to decreased REM sleep duration per episode. The results of this study suggest that GABAergic inputs from prepositus hypoglossi act on locus coeruleus and regulate REM sleep, possibly by inhibition of REM-OFF neurons. Synapse 42:141–150, 2001. © 2001 Wiley-Liss, Inc.

Journal ArticleDOI
TL;DR: A Candida albicans mutant with mutations in the N-acetylglucosamine (GlcNAc) catabolic pathway gene cluster was not able to grow on amino sugars, exhibited highly attenuated virulence in a murine systemic candidiasis model, and was less adherent to human buccal epithelial cells in vitro.
Abstract: A Candida albicans mutant with mutations in the N-acetylglucosamine (GlcNAc) catabolic pathway gene cluster, including the GlcNAc-6-phosphate deacetylase (DAC1), glucosamine-6-phosphate deaminase (NAG1), and GlcNAc kinase (HXK1) genes, was not able to grow on amino sugars, exhibited highly attenuated virulence in a murine systemic candidiasis model, and was less adherent to human buccal epithelial cells in vitro. No germ tubes were formed by the mutant after induction with GlcNAc, but the mutant exhibited hyperfilamentation under stress-induced filamentation conditions. In addition, the GlcNAc catabolic pathway played a vital role in determining the colony phenotype. Our results imply that this pathway is very important because of its diverse links with pathways involved in virulence and morphogenesis of the organism.