Showing papers by "Jawaharlal Nehru University published in 1987"

Heavy metals distribution in the sediments of ganges and Brahmaputra rivers

Abstract: Bed sediments were collected from the entire region of the Ganges basin and some parts of the Brahmaputra. In addition, selected stations were sampled for suspended sediments as well. The samples were analysed for a number of heavy metals (Fe, Mn, Ni, Cr, Cu, and Zn) by the thin-film energy dispersive X-ray fluorescence technique. There are pronounced temporal and spatial variations in the heavy metals distributions. Suspended sediments are 5–10 times richer than the bed sediments. None of the tributaries contribute significant heavy metal load, but around urban areas in Yamuna (tributary of Ganges), very high levels due to the distribution from the drainage network are observed. Compared to the Brahmaputra, the distribution and fractionation of heavy metals in the Ganges sediments are more erratic and highly variable. All the metals considered show high correlation among themselves. Given the high flux of suspended sediments from the Himalayan rivers (nearly 20% of the global flux), the worldwide budget for heavy metal transport may need to be suitably revised.

Environmental geochemistry of Indian river basins: a review

Abstract: Based on extensive observations, the sediment and the chemical load- both quantity and quality - have been computed for the Indian sub continent. Indian rivers carry total dissolved solids of 159 ppm, which is about 25% more than the world average river water. Indian rivers are also relatively enriched in Na and Cl. They also carry a sediment load of about 1.4 billion tonnes/yr representing 10% of the global sediment flux. The northern rivers carry dominantly illite-kaolinite-chlorite in suspension while the southern rivers carry high exchange capacity clays. The sediment chemistry is comparable to world surface rocks, with corrections for the mobile elements. Heavy metals occur predominantly in the chemically extractable sinks within the river sediments. Limited studies on base metal mining areas in Khetri and Zawar indicated contamination of soil, plants and water in that area.

Signal sequence and DNA‐mediated expression of human lysosomal α‐galactosidase A

Abstract: Twelve complementary DNA clones for human lysosomal alpha-galactosidase A were isolated from an Okayama-Berg library constructed from SV40-transformed human fibroblasts. The identity of these clones was confirmed by complete colinearity of the nucleotide-deduced amino acid sequence with that determined by direct chemical sequencing of human placental alpha-galactosidase A. Hybridization of the alpha-galactosidase A cDNA to genomic DNA from individuals with varying numbers of X chromosomes as well as from interspecies somatic-cell hybrids showed only a single locus in the genome at Xq 13.1-Xq 22. One cDNA clone (pcD-AG210) contained the complete coding sequence for both the signal peptide and mature alpha-galactosidase A. The signal peptide of 31 amino acids contains the expected hydrophobic domains consisting of Leu-Gly-Cys-Ala-Leu-Ala-Leu and Phe-Leu-Ala-Leu-Val and has Ala at the signal peptidase cleavage site. Twelve out of fifteen G residues flanking the 5' end of the cDNA in pcD-AG210 were removed and the truncated fragment was ligated into the original vector. This construct, pcD-AG502, encoded enzymatically active human alpha-galactosidase A in monkey COS cells.

Environmental Geology of Peninsular River Basins of India

Abstract: An attempt is made to evaluate the environmental geology of non-Himalayan rivers of India. These twenty river basins including eleven medium basins together drain nearly 25 per cent of the sub-continent. The annual transport of suspended sediments and dissolved salts by these rivers have been estimated to be around 370 million tonnes and 61 million tonnes respectively. The rate of physical erosion among these basins range from 799 tonnes/km 2 /yr to 16 tonnes/km 2 /yr. Similarly, chemical erosion ranged from 110 tonnes/km 2 /yr to 22 tonnes/km 2 /yr. Among the rivers considered, the chemical composition of water indicates that Cauvery carries a large silica load (39 ppm), while the TDS is low (172 ppm), whereas Sabarmati has the highest TDS (352 ppm). Krishna waters show the highest alkalinity. In all the rivers, conductivity shows good correlation with TDS. Sediment chemistry indicates that Cauvery river sediments are most siliceous while that of Godavari are least siliceous. In both these cases, average SiO 2 is higher than the Indian average river sediment. Similarly, Fe in southern river sediments is very high while P is very low compared to the Indian or world average. Apparently local geology (Shield area hard rocks in southern India and Deccan Traps in central India) control the water and sediment characteristics of the peninsular rivers.

Environmental geology of the Ganga River Basin

Abstract: The lithology of the Ganga basin especially the carbonates of the recent alluvium, controls the river water chemistry. Illites and kaolinite are the dominant clay minerals in the suspended sediments. The average TOS is 171 ppm and essentially reflects the Indian river-water average. Considering the sediment transport at Farakka (744 million tonnes/yr) as a measure, the Ganga is placed as the third largest sediment transporting river of the world after the Yellow and Amazon rivers. Basin area and discharge, rather than the basin elevation, control the erosion rate. The total erosion rate (549 t/km 2 /yr) of the basin at Calcutta is almost three times that of Amazon and three and half times that of the world average (150 t/km 2 /yr). The high sedimentation fate (42 mm/yr) in the Yamuna around Delhi is mainly due to the solid waste supply from urban areas. For selective heavy metals, the total drain anthropogenic contribution to the river Yamuna is Mn (42%), Fe (76%), Cu (62%), Zn (90%) and Pb (50%) of the metal increase in the sediments from Wazirabad to Okhla. Excellent correlation among Cu, Zn and Pb in the core and in surface sediments indicates their common source. The additional metals carried into the surface and core sediments of the Yamuna due to increased human utilization of the river basin are in relatively mobile fractions of the sediments and hence pose clear environmental hazards.

Reversal of heat-induced alterations in photochemical activities in wheat primary leaves.

Abstract: Chloroplasts isolated from elevated temperature treated 8-day-old continuous-white-light-grown wheat primary leaves lost the ability to photo-oxidize water. Also, the ability of ascorbate to donate electrons to photosystem II declined. However, a significant increase in reduced dichlorophenolindophenol-supported photosystem-I-mediated methylviologen photo-reduction activity was observed. The plants stressed at 45°C and 47°C were subsequently grown at 25°C and the partial photochemical activities were measured in chloroplasts isolated from the plants at 24-h intervals. The post stress alterations observed are (1) a significant restoration of water oxidation capacity in 45°C- and partial restoration in 47°C-treated leaves. Ascorbate-supported photochemical activities recovered more or less in similar fashion; (2) reversal of enhanced photosystem I activity in both 45°C- and 47°C-treated leaves. These results suggest that the restoration in water oxidation capacity is possible in 45°C-treated leaves and is limited by the severity of heat stress in 47°C-treated leaves. Restoration of water oxidation capacity vis-a-vis to the reversal of heat-enhanced photosystem I activity also indicates the existence of possible endogenous control for repair of alterations during the post stress.

A calmodulin inhibitor blocks morphogenesis in Candida albicans

Abstract: A calmodulin inhibitor, trifluoperazine (TFP), can block yeast-to-germ-tube morphogenesis of Candida albicans induced by N-acetyl-d-glucosamine at 37°C. Furthermore, the ionophore A23187 can also block germ tube formation, which can be reversed by Ca2+. This indicates the possible involvement of calcium and calmodulin in morphogenesis of C. albicans. During germ tube formation, there is a progressive increase in the rate of protein phosphorylation, which is completely absent in non-germinating cells (yeast form). Trifluoperazine can also inhibit this phosphorylation indicating that protein phosphorylation may also be involved in this process.

Alterations in fatty acyl composition can selectively affect amino acid transport in Saccharomyces cerevisiae.

Abstract: The fatty acid composition of yeast lipid was manipulated by using auxotrophic strain of S.cerevisiae, KD115, which requires unsaturated fatty acid (UFA) for its growth. It was possible to specifically enrich the yeast with different fatty acyl residues. As compared to wild type strain (S288C), the uptake of amino acids viz., L-alanine, glycine, L-glutamic acid, L-valine in KD115 was drastically reduced, however, the uptake of L-leucine and L-lysine was not affected by the change in lipid unsaturation. Kinetic studies revealed that KT and Jmax values for L-alanine were altered whereas for L-lysine they remained unaffected by UFA modification. Furthermore, unsaturation index for wild type cells was found to be fairly constant while it was variable in KD115 supplemented with different UFAs. It is observed that the variation in amino acid permeases activity which was affected by fluctuations in fatty acyl composition corresponds more to degree of unsaturation rather than growth stage of KD115.

In vitro regeneration of plants from hypocotyl segments of Amaranthus paniculatus

Abstract: Hypocotyl segments, 5 to 8 mm length from 4 to 7 day old seedlings, callused on B5 medium supplemented with Kn (0.5 ppm) and NAA (0.1 ppm). Even without transfer, shoots were formed in such cultures. About 20% of the cultures produced multiple shoots. In medium with 1 ppm each of Kn and NAA direct shoots were formed at one end of the hypocotyl segment and callusing was initiated at the other end. The plants obtained in either medium formed roots and could be transferred to soil for further growth.

Fields as Kolmogzrov flows

Abstract: It is widely recognized that for highly unstable dynamical systems there exists a fundamental limitation on predictability and determinism. An important class of such highly unstable systems is the class of K-flow, which is further characterized by the existence of time-asymmetric objects in the form of K-partition. Our recent approach to the problem of irreversibility has shown that when the implications of the limitation on determinism arising from strong form of instability and those of the existence of K-partition are consistently taken into account, one is naturally led from the physically unrealizable deterministic evolution of phase points to an entropy-increasing stochastic Markovian evolution. Furthermore, this transition is not the result of extraneously imposed coarse graining and/or approximation schemes, but can be brought about by an invertible transformation whose existence and construction are determined by the nature of the instability of the dynamical system itself. After a brief review of this theory which also contains some relatively new remarks, we prove that classical Klein-Gordon field (both massive and massless) possess the structure of K-flow. This seems to provide the first examples of relativistic systems that are K-flows. Some of the implications of this result are briefly discussed. From a mathematical point of view, this seems to be a first step toward an ergodic theory of partial differential equations. In the process, we also provide an independant group-theoretic proof of the existence of incoming and outgoing subspaces of the scattering theory of Lax and Phillips for the wave equation.

‘Why growth rates differ’ within India: An alternative approach

Abstract: This article develops an analytical framework based on the economics of steady and non‐steady growth states for explaining variations in growth performance in the context of the Indian economy. This approach follows two directions. The first one is based on a decomposition of growth, as in Denison's work, but along different lines. Some of the results, particularly in respect of contribution of the interaction effect and of labour, emerge to be different from those expected. The second strand of analysis identifies four sets of variables, whose role is assessed, first, as determinants of the pace of growth ‐ over time ‐ at the national level and, second, as determinants of regional growth rates. Finally, the collective role of the variables is analysed through a combination of factor analysis and step‐wise regression.

Anther Culture and Haploid Production in Potato

Abstract: The commercial potato (Solarium tuberosum L.) is essentially an autotetraploid (2n = 4x = 48). The importance of the reduction of the tetraploid potato to the dihaploid level (with 24 chromosomes) for breeding better clones was first emphasized by Chase (1963). He proposed crossing four different dihaploid parents to produce two different diploid hybrids, which in turn, can be crossed and polyploidized to create a tetraploid potato with genomes of four different parents.

Use of the plasmid pRK 2013 as a vehicle for transposition inAzotobacter vinelandii

Abstract: Plasmid stability inAzotobacter vinelandii has been determined and a way to introduce transposon into these cells using the plasmid pRK 2013 has been devised. Transposition of both Tn3 and Tn10 has been attained.

Are Patna and Bisanattam Granites (Adjoining the Kolar Schist Belt) cogenetic

Abstract: Structural and geochemical evidence including major and trace elements, and Pb-isotopic data on K-feldspars, froin the granitoid rocks adjoining the Kolar Schist Belt are presented to show (1) that the Patna Granite an the NW of the belt is dissimilar to any granitoid rock E of the belt and (2) that the main granitoid gneiss immediately E of the belt, the Karnbha Gneiss, is nearly identical to the Bisanattam Granite of Narayanaswamy er al (1960).

Transport and Fractionation of Pb in River Sediments from the Indian Sub-Continent

Abstract: The distribution of Ph and As in the bed sediments as particulates from the Ganges. Brahmaputra, Godavari, Krishna and Cauvery rivers has been studied. While the Pb levels in bed sediments vary from a low of 2 μg Pb/gm in the Ganges to a high of 32 μg Pb/gm in Godavari, the corresponding particulate Pb load varies by a factor of 5-40 times the bed load from a low value of 5 μg Pb/gm particulates of Krishna to a high value of 1075 μg Pb/gm in the same river. Downstream variations in all rivers are generally erratic both for particulate and bed Pb-Ievels. All the river sediments indicate a very good correlation between Pb and As on the one hand and heavy metals such as Fe, Zn, Cu etc. on the other. The Himalayan river sediments generally exhibit strong grain-size control on the fractionation of Pb and As, whereas the peninsular rivers do not show a systematic partitioning of Pb and As in various size populations.

Effect of cobalt on the primary productivity of Spirulina platensis.

Abstract: Cobalt, a micronutrient for biological organisms, is a metal of wide use. Main sources of Co to the environment are combustion of fossil fuels, smelters, cobalt processing facilities, sewage and industrial wastes. Atomic power plants and nuclear weapon detonations form an important source of radioisotopes of this metal to the environment. Cobalt has been included in the 14 toxic trace elements of critical importance from the point of view of environmental pollution and health hazards. Cobalt deficiency leads to diseases like stunted growth. At toxic level, Co inhibits heme biosynthesis and enzyme activities. The present study reports the effect of cobalt on biomass productivity of blue-green alga Spirulina platensis.

Regulation of Protein Synthesis in Plant Embryo by Protein Phosphorylation : I. Purification and Characterization of a cAMP-Independent Protein Kinase and Its Endogenous Substrate.

Abstract: A cyclic AMP-independent protein kinase, which strongly inhibits in vitro protein synthesis, was purified to homogeneity from barley embryo by affinity and ion exchange chromatography. The Mr of the purified enzyme is 95,000 with two nonidentical subunits of Mr 58,000 and 39,000. The enzyme activity is not stimulated by cAMP, cGMP, or calmodulin. The endogenous phosphate acceptor of this kinase is a protein of Mr 52,000, was isolated by purified protein kinase immobilized Sepharose column. Using antibodies raised against this protein kinase, the levels of the enzyme during embryogenesis and germination are determined. An inverse relationship has been observed between protein kinase level and rate of protein synthesis.