Showing papers by "Jawaharlal Nehru University published in 1998"

Piriformospora indica, gen. et sp. nov., a new root-colonizing fungus

Abstract: A new fungus isolate was discovered in an arbuscular mycorrhizal fungal spore from a desert soil in India. It could easily be cultivated on various synthetic media, and formed pear-shaped chlamydos...

Empire and Information: Intelligence Gathering and Social Communication in India, 1780–1870 . By C. A. Bayly. Cambridge Studies in Indian History and Society. Cambridge: Cambridge University Press, 1996. xiv, 412 pp. $64.95(cloth).

Abstract: List of maps Preface Glossary List of abbreviations Introduction 1. Prologue: surveillance and communication in early modern India 2. Political intelligence and indigenous informants during the conquest of India, c. 1785-1815 3. Misinformation and failure on the fringes of empire 4. Between human intelligence and colonial knowledge 5. The Indian ecumene: an indigenous public sphere 6. Useful knowledge and godly society, c. 1830-50 7. Colonial controversies: astronomers and physicians 8. Colonial controversies: language and land 9. The information order, the Rebellion of 1857-9 and pacification 10. Epilogue: information, surveillance and the public arena after the Rebellion Conclusion: 'knowing the country' Bibliography Index.

The Geopolitics of Refugee Studies: A View from the South

Abstract: In the post-1945 period the policy of Northern states has moved from the neglect of refugees in the Third World, to their use as pawns in Cold War politics, to their containment now. The paper explores in these shifting policy contexts the geopolitics of knowledge production in the field of refugee studies. The arrival of the 'new asylum seekers' in the 1980s signalled the expansion of refugee studies. A 'new approach' took shape which critiqued the established positivist approach to refugee law and created the myth of difference (the idea that great dissimilarities characterized refugee flows in Europe and the Third World). It advocated the rejection of the exile bias of refugee law; reliance on the solution of voluntary repatriation; and responsibility of the state of physical origin. In legitimizing the 'new approach', a key role, so far ignored, has been played by the knowledge production and dissemination functions of UNHCR.

Temperature-stress-induced impairment of chlorophyll biosynthetic reactions in cucumber and wheat

Abstract: Chlorophyll (Chl) biosynthesis in chill (7°C)- and heat (42°C)-stressed cucumber (Cucumis sativus L. cv poinsette) seedlings was affected by 90 and 60%, respectively. Inhibition of Chl biosynthesis was partly due to impairment of 5-aminolevulinic acid biosynthesis both in chill- (78%) and heat-stress (70%) conditions. Protochlorophyllide (Pchlide) synthesis in chill- and heat-stressed seedlings was inhibited by 90 and 70%, respectively. Severe inhibition of Pchlide biosynthesis in chill-stressed seedlings was caused by inactivations of all of the enzymes involved in protoporphyrin IX (Proto IX) synthesis, Mg-chelatase, and Mg-protoporphyrin IX monoester cyclase. In heat-stressed seedlings, although 5-aminolevulinic acid dehydratase and porphobilinogen deaminase were partially inhibited, one of the porphyrinogen-oxidizing enzymes, uroporphyrinogen decarboxylase, was stimulated and coproporphyrinogen oxidase and protoporphyrinogen oxidase were not substantially affected, which demonstrated that protoporphyrin IX synthesis was relatively more resistant to heat stress. Pchlide oxidoreductase, which is responsible for phototransformation of Pchlide to chlorophyllide, increased in heat-stress conditions by 46% over that of the control seedlings, whereas it was not affected in chill-stressed seedlings. In wheat (Triticum aestivum L. cv HD2329) seedlings porphobilinogen deaminase, Pchlide synthesis, and Pchlide oxidoreductase were affected in a manner similar to that of cucumber, suggesting that temperature stress has a broadly similar effect on Chl biosynthetic enzymes in both cucumber and wheat.

Thermal Stability of Proteins in Aqueous Polyol Solutions: Role of the Surface Tension of Water in the Stabilizing Effect of Polyols

Abstract: Polyols and sugars are known to increase the thermal stability of proteins in aqueous solutions and lead to their preferential hydration. While the mechanism of action of sugars has been proposed to be essentially due to the increase in the surface tension of water in their presence, polyols including glycerol have been reported to lower the surface tension of water and act via the solvophobic effect. Surface tension measurements of polyols in water carried out by us, on the contrary, indicate a substantial increase in the surface free energy of water. These increments are comparable to those found in the case of sugars. To investigate the role of the surface tension of the solvent medium on the thermal stability of proteins, we have carried out a comprehensive study on the effects of a series of polyols with varying numbers of hydroxyl groups and stereochemistry, such as mannitol, inositol, sorbitol, xylitol, and adonitol, on the thermal stability of five proteins varying in their physicochemical charact...

Distribution and fractionation of heavy metals in the surface sediments of the Ganges- Brahmaputra-Meghna river system in the Bengal basin

Abstract: The lower Ganges-Brahmaputra-Meghna (G-B-M) drainage basin occupies the total Bengal Basin, which is one of the unique basins of the world because of its location and size, density of population, and catastrophic deposition of sediments. The increased heavy metal concentration in the 63 m fraction of surface sediments shows similarity among major segments of the G-B-M system in the basin, which reflects the homogenization of lithologic and chemical diversity of the greater denudation regime by the river processes. The differences in heavy metal concentation in the lower G-B-M system with that of its upper and middle counterpart is mainly related to the contrast between Himalayan rivers and the other major South Asian rivers, and may be due to the geological differences of their denudation regime. Heavy metals in the Lower G-B-M system have an affinity towards the clay fraction of the sediments. The correlation matix of heavy metals in the lower Brahmaputra and Meghna suggests the importance of Fe-Mn oxyhydroxides in their accumulations. Iron, Ti and Mn are higher in the Meghna main channel, Zn is higher in the Meghna tributaries, and Cr is higher in both the Brahmaputra and Meghna compared to the value for standard shale. The enrichment factor is ≤1 for most of the metals except Mn which is relatively higher in the Meghna and lower Ganges main channels. The geoaccumulation index (Igeo) for most of the heavy metals lies below grade zero, suggesting unpolluted sediment quality. The lower Ganges system shows relatively higher concentration in the nondetrital fraction of heavy metals, probably due to the presence of petroleum refinery, industrial and mining effluents, and agricultural runoff in the drainage basin. The relative uniformity in concentration of heavy metals in vertical profiles may be due to the uniformity in sediment grain size and catastrophic deposition of sediments, where the time period represented by the vertical sediment column is not enough to reflect the cultural accumulation of heavy metals. The Bengal basin thus represents a relatively unperturbed alluvial basin with regards to heavy metal pollution.

Regulation of metabolic pathways in liver and kidney during experimental diabetes: Effects of antidiabetic compounds.

Abstract: Diabetes has been classified as a disease of glucose overproduction by tissues, mainly liver and glucose underutilization by insulin requiring tissues like liver, adipose and muscle due to lack of insulin. There is, however, glucose over utilization in tissues not dependent on insulin for glucose transport like kidney, nerve and brain. There are serious complications due to this excess glucose in these tissues and their reversal is important for a good metabolic control and normalisation of other parameters. Insulin, trace metals and some plant extracts have been used to see the reversal effects of the complications of diabetes in liver and kidney in experimental diabetes. Almost complete reversal of the metabolic changes has been achieved in the activities of key enzymes of metabolic pathways in liver and kidney and an effective glucose control has been achieved suggesting a combination of therapies in the treatment of metabolic disturbance of the diabetic state.

Major ion chemistry and weathering control in a high altitude basin : Alaknanda River, Garhwal Himalaya, India

Abstract: An analytical study of major cations and anions of the glacier fed Alaknanda River and its tributaries has been carried out to assess the weathering and geochemical processes in the high altitude river basin. The Alaknanda and its tributaries were sampled during pre-monsoon (June 1992) and post-monsoon (October 1992) season for the present hydrogeochemical study. Calcium and magnesium are the major cations, accounting for 85% of the total cations. Among the anions, bicarbonate is the most dominant (78%) with minor contribution from sulphate (19%) and chloride (3%). The average (Ca+Mg)/HCO3 equivalent ratio of 1.2, a relatively high contribution of (Ca+Mg) to the total cations (TZ+) and high (Ca+Mg)/(Na+K) ratio indicate that the carbonate weathering could be the primary source of the major ions to these waters. Wide seasonal and spatial variations are observed in the total dissolved solids (TDS) and total suspended matter (TSM) concentration in the Alaknanda river basin. The chemical denudation r...

The Pursuit of Persian: Language in Mughal Politics

Abstract: The Mughal literary culture has been noted for its notable achievements in poetry and a wide range of prose writings in Persian. In terms of profusion and variety of themes this literary output was also perhaps incomparable. The court's patronage has rightly been suggested as an important reason for this. This patronage, however, was not consistent throughout; much of the detail of its detour thus requires a closer scrutiny. The phenomenal rise of the language defies explanation in the first instance. The Mughals were Chaghtā'i Turks and we know that, unlike them, the other Turkic rulers outside of Iran, such as the Ottomans in Turkey and the Uzbeks in Central Asia, were not so enthusiastic about Persian. Indeed, in India also, Persian did not appear to hold such dominance at the courts of the early Mughals. In his memoir, Bābur (d. 1530), the founder of the Mughal empire in India, recounted the story of his exploits in Turkish. The Prince was a noted poet and writer of Turkish of his time, second only to ‘Alī Sheēr Nawā’ī (d. 1526). Turkish was the first language of his son and successor, Humāyūn (d. 1556), as well.

Postcolonialism — Or postcolonial studies

Abstract: (1998). Postcolonialism — Or postcolonial studies. Interventions: Vol. 1, Ideologies of the Postcolonial, pp. 39-42.

Expression of CDR1, a multidrug resistance gene of Candida albicans: transcriptional activation by heat shock, drugs and human steroid hormones

Abstract: We have examined the expression of CDR1 (Candida drug resistance gene) in different stress conditions. There was a significant but transient enhancement of CDR1 expression associated with elevated temperatures. Most noteworthy transcriptional activation was observed with miconazole and vinblastine. Interestingly, β-estradiol and progesterone were also able to enhance CDR1 expression. Elevated levels of CDR1 and CDR2 (a homologue of CDR1) mRNA were found in some azole-resistant clinical isolates of C. albicans. CaMDR1 (benomyl-resistant) expression, however, did not differ among all the resistant isolates. Our results confirm the existence of multiple mechanisms of azole resistance in C. albicans.

Protein Kinases and Phosphatases and Their Role in Cellular Signaling in Plants

Abstract: Plants respond very efficiently to changes in the external environment and accordingly regulate their growth and development. They also have the ability to sense stress conditions and pathogen presence and subsequently activate stress or defense-related functions. Lately, progress has been made in identification of cis- and trans-acting factors that mediate gene expression induced by variable external factors. However, in most of the cases our understanding is limited in relation to the molecular signal transduction events that couple perception of the signal and changes in the gene expression. It is now realized that protein phosphorylation/dephosphorylation has a very important role in signal transduction and also in regulating metabolic activities. During the last decade, a large number of serine/threonine protein kinases have been isolated from plants. Some of these belong to the same category as reported in animal systems, like MAP kinases, receptor kinases, cell division controlling kinases, whereas...

Identification of polymorphic mutant alleles of CaMDR1, a major facilitator of Candida albicans which confers multidrug resistance, and its in vitro transcriptional activation.

Abstract: CaMDR1 (Candida albicans Multi Drug Resistance) encodes a major facilitator whose expression in Saccharomyces cerevisiae confers resistance to several unrelated drugs. We describe here the identification and molecular characterization of seven mutant alleles of CaMDR1 (CaMDR1-1 to 1-7). The complete sequencing of CaMDR1 alleles revealed several in-frame point mutations leading to a change in amino-acid residues where insertion/replacement of an aspartate residue in a serine-asparagine-aspartate-rich domain was most noteworthy. Interestingly, these alleles showed a distinct drug resistance profile. The expression of CaMDR1, or of its alleles, in C. albicans cells was enhanced by benomyl, methotrexate and several other unrelated drugs, and was more pronounced in at least one of the azole-resistant clinical isolates.

Impact of Fly Ash from Coal-Fired Power Stations in Delhi, with Particular Reference to Metal Contamination

Abstract: Indraprastha Power Station (IPP Stn) and Rajghat Power House (RPH), owned by Delhi Electric Supply Undertaking, are both coal-fired power stations located on Ring Road in New Delhi. Ash content of the coal used ranges between 38–47%. The ash is collected in electrostatic precipitators which have an efficiency of 99.3% (IPP station), and 99.7% (RPH). There are instances of major dust pollution around the power stations from fly ash dispersal. The main method of disposal of fly ash from the power stations is by mixing with water, the resultant slurry is pumped through pipes to ash disposal ponds. The supernatant from these ponds is discharged into River Yamuna. Field studies have revealed large quantities of fly ash being deposited into the river. Local populations of Eichhornia crassipes have reduced dramatically between 1987–1995, with a marked reduction in the year 1994–1995. Field studies, conducted in January, 1995 have investigated the impact of fly ash dispersal in the Delhi region with particular reference to metal contamination. Elemental concentrations for a range of elements are determined by ICP-AES in fly ash and top soils along four transects from the power stations up to a distance of 8 km. The effects of fly ash leachates from the ash settling ponds on the river are determined by analyzing river overbank soils and vegetation for their elemental contents. It is concluded that fly ash dispersal from the stacks are a source of alkali, alkaline-earth and to some extent heavy metals in soils in the vicinity of the power stations, and enrichment of elements in river overbank soils are a result of discharge of fly ash leachates from ash disposal ponds. However, the impact from both these sources of metal contamination is not large enough to give cause for concern. Marked reduction in populations of Eichhornia crassipes downstream of the river where it receives leachates from the ash disposal ponds are attributed to turbidity of the ash pond leachates and metal toxicity. Elemental enrichment in the floodplain soils, as a result of fly ash particle deposition during monsoons, may enhance the horticultural value of these soils as is shown by a healthy cultivated crop of Brassica juncea.

Strange nonchaotic attractors in the quasiperiodically forced logistic map

Abstract: Different mechanisms for the creation of strange nonchaotic dynamics in the quasiperiodically forced logistic map are studied. These routes to strange nonchaos are characterized through the behavior of the largest nontrivial Lyapunov exponent, as well as through the characteristic distributions of finite-time Lyapunov exponents. Strange nonchaotic attractors can be created at a saddle-node bifurcation when the dynamics shows type-I intermittency; this intermittent transition, which is studied in detail, is characterized through scaling exponents. Band-merging crises through which dynamics remains nonchaotic are also studied, and correspondence is made with analogous behavior in the unforced logistic map. Robustness of these phenomena with respect to additive noise is investigated.

Characterisation of human steroid hormone transport mediated by Cdr1p, a multidrug transporter of Candida albicans, belonging to the ATP binding cassette super family

Abstract: Cdr1p, a multidrug transporter from a pathogenic yeast Candida albicans, confers resistance to several unrelated drugs including anti-Candida drugs. We demonstrate that Cdr1p can specifically transport human steroid hormones namely β-estradiol and corticosterone. Saccharomyces cerevisiae transformant S-12, harbouring the CDR1 gene, accumulated about 3-fold less [3H]β-estradiol and about 2-fold less [3H]corticosterone than the non-transformed strain. When CDR1 was expressed in AD strain (AD-CDR1) which had seven ATP binding cassette (ABC) superfamily of putative transporter genes disrupted, the net accumulation of these hormones as compared to S-12 was significantly lower. Efflux of β-estradiol and corticosterone was inhibited by a 100-fold higher (200 nM) concentration of β-estradiol, corticosterone, ergosterol or dexamethasone, but progesterone which could not be transported by Cdr1p did not affect the efflux and thus accumulation. Interestingly, some of the drugs viz. cycloheximide, chloramphenicol, fluconazole and o-phenanthroline, to which CDR1 confers resistance, could also prevent efflux and enhance accumulation to some extent. In conclusion, we show that human steroid hormones could be the substrates for Cdr1p and the energy dependent transport mediated by it is specific for estradiol and corticosterone.

Agroforestry systems in the rural landscape – a case study in Garhwal Himalaya, India

Abstract: A mid altitude (700-1200 m amsl.) village in Garhwal Himalaya was analysed in terms of energy and economic efficiency of different land use-land cover types constituting the landscape. Simultaneous agroforestry, sequential agroforestry, home garden and community forests accounted for 27.47%, 27.47%, 1.1% and 43.96% of the total geographical area of the village. Simultaneous agroforestry is the traditional land use involving substantial input of manure derived from forest litter and animal excreta and was practised on terraced slopes in private ownership. Tree cover in this system was represented by nine species with total average density of 390 trees ha -1 , Grewia optiva and Boehmeria rugulosa being the most dominant. Sequential agroforestry system involving slash-burn practice and cultivation on unterraced slopes without tillage and manuring was an illicit land use on community lands where forestry land use is desirable as per the government policy. Per ha annual energy input in simultaneous agroforestry system was 305267 MJ compared to 279 MJ in sequential agroforestry and 27047 MJ in home garden. In monetary terms, highest per ha annual output was obtained from simultaneous agroforestry (Rs 25370, Rs 35 = US$1) followed by home garden (Rs 18200) and sequential agroforestry (Rs 9426). Local food, fodder and fuelwood production was in excess of the local consumption. While most of the surplus food was stored, surplus fodder and fuelwood were sold for cash. Production in simultaneous agroforestry system in private lands was sustained with substantial biomass and nutrient inputs from the community and government forests. Land use-land cover changes in the region are driven by the interaction of ecological, policy and human factors. It is concluded that present policy of treating forests and agriculture as closed and independent ecological or production systems needs to be replaced by an integrated land use policy.

Dielectric behaviour of gelatin solutions and gels

Abstract: Sol and Gel state properties of aqueous gelatin solutions of concentrations 4%, 6%, 8% and 10% (w/v) have been investigated through dielectric relaxation studies done at various temperatures in the range T=20–60 °C carried out over a frequency range f=20 Hz–10 MHz and no relaxation of any nature was observed. The sharp transition observed at the gelation temperature Tgel provided an excellent matching with the same measured through differential scanning calorimetry (DSC). The capacitance (Cp) values above f=100 kHz became increasingly negative as the gel was melted to the sol state. However, in the gel state Cp was found to be almost independent of temperature for frequencies above 100 kHz. At frequencies lower than 10 kHz, Cp measured was ∼105 F, implying pronounced interfacial polarization either due to electro-chemical reaction or because of ions getting trapped at some interface within the bulk.

Fifty years of hydrobiological research in India

Abstract: The paper provides an overview of the developments in hydrobiological studies in India during the past fifty years, and links them with a historical perspective of the pre-independence studies. Hydrobiological studies which were well developed in the beginning of this century, gained momentum soon after independence as all kinds of aquatic habitats were investigated for the assessment, conservation and optimum utilization of inland fishery resources of the country. However, the environmental issues which dominated since the 1972 Stockholm Conference, and growing realization of the problem of water pollution, resulted in a rapid proliferation of hydrobiological studies which tend to focus on correlation between the distribution of various organisms and degree of water pollution or the effects of various organic and inorganic pollutants. A sampling of published literature reveals that long-term, analytical and experimental studies of the whole ecosystems (natural or experimental), and studies of population interactions, biomanipulation, food chain dynamics, and energy flows are wholly lacking. The paper calls for the strengthening of field and laboratory facilities, and establishment of regional and national institutes of aquatic ecology which will be necessary for the management of both the water quality and aquatic biological resources for sustainable development.

Dynamic Light Scattering Study of Gelatin−Surfactant Interactions

Abstract: Binding of anionic (sodium dodecyl sulfate, SDS), cationic (cetyl trimethyl ammonium bromide, CTAB), and nonionic (TX-100) surfactants to gelatin chains in aqueous buffer (pH = 7.0) medium has been studied by dynamic light-scattering technique performed at T = 30 °C. In the surfactant concentration range varying from 0 to 100 mM, SDS exhibited electrostatic binding to the charged groups of the polypeptide chain resulting in considerable reduction in the hydrodynamic radius (Rh) of gelatin up to the critical association concentration (CAC), and at higher concentrations both the SDS micelles and gelatin−SDS complexes were found to be coexisting in equilibrium. In the case of CTAB, almost the opposite was observed: the gelatin chains showed small increase in size up to the CAC. Beyond this, the gelatin−CTAB complexes were observed to grow significantly, and these were found to be in equilibrium with CTAB micelles. TX-100 exhibited little hydrophobic binding to gelatin, and no observable change in gelatin si...

Turbulence and Multiscaling in the Randomly Forced Navier-Stokes Equation

Abstract: We present a pseudospectral study of the randomly forced Navier-Stokes equation (RFNSE) stirred by a stochastic force with zero mean and a variance $\ensuremath{\sim}{k}^{4\ensuremath{-}d\ensuremath{-}y}$, with $k$ the wave vector and the dimension $d\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}3$. We provide the first evidence for multiscaling of velocity structure functions for $y\ensuremath{\ge}4$. We extract the multiscaling exponent ratios ${\ensuremath{\zeta}}_{p}/{\ensuremath{\zeta}}_{2}$ by using extended self-similarity, examine their dependence on $y$, and show that, if $y\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}4$, they are in agreement with those obtained for the Navier-Stokes equation forced at large spatial scales (3DNSE). Also well-defined vortex filaments, which appear clearly in studies of the 3DNSE, are absent in the RFNSE.

Deletion of transmembrane domain 12 of CDR1, a multidrug transporter from Candida albicans, leads to altered drug specificity: Expression of a yeast multidrug transporter in baculovirus expression system

Abstract: Cdr1p, an ATP-binding cassette transporter from the pathogenic yeast Candida albicans, confers resistance to several unrelated drugs including anti-Candida drugs (Prasad et al., 1995b). We demonstrate that the deletion of 237 bp (79 aa) from the 3' end of CDR1 (which encompasses the transmembrane domain (TM) 12 of the putative transporter) did not result in the total loss of its ability to efflux cytotoxic agents. While the expression of deltaCDR1 in yeast resulted in impaired sensitivity to drugs like cycloheximide, anisomycin, sulfomethuron methyl and antifungal nystatin, its ability to confer resistance remained unaltered to drugs such as o-phenanthroline, 4-nitroquinoline-N-oxide, cerulenin, azoles, oligomycin, erythromycin, and benomyl. Similar to human MDR1p. Cdr1p might also have localized drug binding sites in TM 12, but that might not be the case for all the drugs. The TM 12 deletion also did not lead to any significant impairment in NTPase activities. Both ATPase and UTPase activities of complete Cdr1p and deltaCdr1p were not significantly altered, as was the case with respect to their ability to efflux Rh123 and steroid hormone like [3H]-beta-estradiol. To further dissect the functionality of Cdr1p, its truncated version was overexpressed in a baculovirus-insect cell expression system. The synthesis of deltaCdr1p in Sf9 cells was temporally regulated as a function of the baculovirus polyhedrin gene promoter. The Sf9 derived deltaCdr1p was approximately 130 kDa, which was lower than the expected size, probably due to the differences in glycosylation. This, however, did not affect the functionality of deltaCdr1p. The deletion of TM 12 did not affect the targeting of the protein and deltaCdr1p was exclusively localized in plasma membrane of Sf9 cells as detected by immunofluorescence. The expression of deltaCdr1p in the baculovirus-insect expression system generated a high drug-stimulated plasma membrane-bound ATPase activity which was not demonstrable when deltaCdr1p was expressed in yeast.

Geochemical factors controlling the chemical nature of water and sediments in the Gomti River, India

Abstract: R-mode factor analysis of the recently acquired data on water and sediment chemistry has been performed. Basic chemical parameters have been merged together which aid in interpreting a few empirical geochemical factors controlling the chemical nature of water and sediments of the Gomti River, a major Himalayan tributary of the Ganges drainage basin. Water chemistry seems to be controlled by three factors: bicarbonate, rainfall and silicate and phosphate factors. Sediment chemistry is largely controlled by the following four factors: clay, adsorption/desorption, Fe-Mn hydroxide and mercury factors. These factors show spatial and temporal variability in terms of their R-scores.