Showing papers by "Jawaharlal Nehru University published in 1983"

Selenium in soil, plant, and animal systems

Abstract: Selenium is a paradox because the essentiality of Se to animals ends at about 0.1 ppm, while toxicity may begin at < 1 ppm diet. Seen from the point of view of animal nutrition, selenium may occur in either toxic or deficient concentrations in fodder crops in different areas of the world. Highly seleniferous soils are the sources of potential Se intoxication for animals, while selenium‐deficient soils cause deficiency disorders in cattle. Though Se has not been proved essential for plants, its essentiality for animal nutrition is well known. This is the prime reason that makes Se studies in soil‐plant‐animal systems assume greater importance. Since the study is of practical significance, efforts have been made by the scientists all over the world to study the sources of selenium in soils, their movement and absorption by plants, and finally the health consequences in animals. A significant amount of literature on reducing the Se toxicity in animals was gathered in the past, but a keen perusal indicates th...

Effect of dye on the performance of a double basin solar still

Abstract: The use of single basin solar stills for water distillation has been well demonstrated. However, the amount of distilled water produced per unit area is fairly low which makes the single basin solar still unacceptable in situations where space is a limitation. Malik has suggested a new conceptual design of a double basin solar still to overcome the above problem partially. The relative results obtained on a double basin as opposed to a single basin solar still are reported here with reference to (a) its performance, (b) the effect of dye in the lower basin, and (c) the effect of maintaining the raw water level in the basins.

Heavy metals in Indian coals and corresponding fly‐ash and their relationship with particulate size

Abstract: Pulverised coal and corresponding fly‐ash collected from the stack precipitator of thermal power plants were analysed for eight heavy metals. Fly‐ash was separated into various sized fractions which were then chemically characterized. The fly‐ash contained higher concentrations of heavy metals with respect to their coal. Except in the case of Pb, Cd and Co, the heavy metals were more concentrated in the 150 μm fraction. For the probable contribution of these metals to atmospheric emission and waste ash, it is necessary to estimate the enrichment factors from coal to fly‐ash.

On a controversy over Ricardo's theory of distribution

Abstract: The long-present controversies over the evaluation of Ricardo's contribution, approach and mode of theorising have recently intensified. There have been concerted efforts, on the one hand, to revive and advance 'surplus-based' theories, investigating their origin and development in Smith, Ricardo and Marx and, on the other hand, to argue, as did Marshall, for a doctrinal continuity from Smith to the modern neoclassicists. Samuel Hollander's The Economics of David Ricardo (1979)1 underlines the continuity thesis, maintaining that both Smith and Ricardo shared a theory of resource allocation which rested upon a supply and demand analysis, akin to 'neoclassical procedures'. Thus Hollander argues against the idea of dual development in analytical history. His canvas is as vast2 and controversial as are the interpretations. Here we take up only one theme: Ricardo's theory of value and distri bution with which Hollander is 'particularly concerned' as forming the 'analytical core' and which Ricardo himself regarded as his original contribution. After presenting some comments on the overall position of Hollander on this issue, we examine his interpretation of the genesis and development of Ricardo's theory of profits in three chronological parts: (1) the early period of the bullionist controversy; (2) the pre-Essay* correspondence of 1814, the Essay, and the post-Essay debates between Ricardo and Malthus; and, (3) the Principles.* In the last section we take up Hollander's view of Ricardo as a precursor of general equilibrium theory.

Soviet treaties with third world countries

Abstract: (1983). Soviet treaties with third world countries. Soviet Studies: Vol. 35, No. 1, pp. 53-70.

Comparison of seasonal and diurnal patterns of some physico‐chemical parameters of the open and closed parts of Loktak Lake, Manipur, India

Abstract: A comparative study of the periodic and aperiodic variations of some physico‐chemical parameters of the open and closed parts of the Loktak Lake, Manipur, India, was carried out for a period of three years from 1976–78 to investigate the effects, if any, of human activities on these variations. The closed part of the lake, used for controlled fishing was well protected, whereas the open part was subjected to considerable human activities. The variation in the physico chemical parameters in the open lake were different from those of the closed lake in that (a) there was distinct seasonal variation in DO which was not evident in the closed lake and (b) there was direct relationship between diurnal variation of CO2 and pH instead of an indirect relationship in the closed lake. The variation in pH, electrical conductivity, bicarbonate, free carbon dioxide and chloride between 1976–78 had a similar pattern in the two parts of the lake.

Role of Nitrate in the Induction of Nitrite Reductase Activity during Wheat Seed Germination

Abstract: Nitrate could not induce NR activity for the first 20 h during the early phase of wheat embryo germination, in spite of considerable accumulation of nitrate inside the tissue. Nitrate, however, induced NR without a lag phase in seeds germinated in water for 24, 32 and 48 h. NiR induction by NO- 3 was found to be independent of NR induction, since NiR activity was observed during the lag phase of NR synthesis and in the presence of tungstate-an inhibitor of NR synthesis. Studies with inhibitors of transcription and translation suggest that nitrate acts at the translation level for the induction of NiR during early germination of wheat embryos.

Impact of thermal power plant emissions on vegetation and soil

Abstract: Studies were made to assess the impact of a thermal power plant located at Obra on vegetation and soil in surrounding areas. Pollutant concentration in the area gradually decreased along a belt in the prevailing wind direction and a gradient of structural and functional changes in plants and soil was observed. Natural vegetation in the area varied significantly at different sites and on the basis of plant responses can be classified as insensitive, intermediate and sensitive. The effect of the power plant emissions on soil and eco-physiological characteristics such as pH, organic matter and N, P, K and S concentrations in soil; leaf injury symptoms, number and distribution of plant species; chlorophyll content in leaves, percentages of photosynthetically active leaf area; accumulation of N, P, K, and S in leaves etc. seemed to be a function of the pollutant gradient existing in the area. There was a relationship between plant responses and changes in the chemical factors of soil and plants due to pollution. This study indicates possible elimination of plant species, first the trees then the shrubs and lastly the herbs and grasses from the environs of the thermal power plant. The increase in soil acidity in the area may cause cation-anion imbalance and microbe population reduction to affect soil fertility.

Changes in Hexokinase Isoenzymes in Regions of Rat Brain During Insulin‐Induced Hypoglycemia

Abstract: Activities of hexokinase isoenzymes were determined during insulin-induced hypoglycemia in soluble and total particulate fractions from three regions of rat brain. Type I hexokinase isoenzyme activity showed a small decrease in both soluble and particulate fractions from the cerebral hemispheres. In cerebellum and brain stem, however, Type I isoenzyme showed a decrease only in the soluble fraction. A significant increase was observed in hexokinase Type II isoenzyme from both the fractions, in all the three brain regions 1 h after insulin administration.

A new fourth order method for computing eigenvalues of two-point boundary value problems: An addendum

Abstract: (We assume familiarity with the notat ion and discussion in [1]; there, Q-(qlj) is the diagonal matrix with qu = q(xi), and B = (bij) is the tr idiagonal matrix with bll = 10/12, bl, i+l = 1/12.) Now, in the Noumerov discretization (2) even though both B and D are tridiagonal, B-~D is a completely filled matrix. Therefore, for comput ing eigenvalues, it is natural to ask for a discretization of (1) in the form:

Phytochrome regulation of nitrate reductase in wheat

Abstract: In excised wheat leaves, the activity of nitrate reductase was enhanced by a brief pulse of red light and this increase was reversed by far-red light irradiation. Even under continuous far-red light, nitrate reductase activity increased by 258% after 18 h. When leaves were kept in distilled water during exposure to red light and then transferred to potassium nitrate, there was no difference in endogenous nitrate concentration. The nitrate reductase activity was the same whether leaves were floated in potassium nitrate or in distilled water during irradiation. Partial to complete inhibition of enzyme activity was observed when leaves were incubated in actinomycin-D and cycloheximide respectively, following 4 h of red light irradiation.In vitro irradiation of extract had no significant effect on nitrate reductase activity

The Utilization of Inorganic Pyrophosphate, Tripolyphosphate, and Tetrapolyphosphate as Energy Sources for the Growth of Anaerobic Bacteria

Abstract: Inorganic pyrophosphate (PPi) has been shown to be utilized as a source of energy for the growth of a number of pure cultures of anaerobic bacteria and isolates from marine and fresh water environments. The microorganisms generally require a source of fixed carbon such as yeast extract for growth but with some of the sulfate reducing bacteria, acetate and sulfate were also required. Growth, as determined by optical density, cell numbers, or protein, is proportional to the concentration of PPi over a limited range and growth is always accompanied by the hydrolysis of PPi to orthophosphate. PPi was also demonstrated to modify fermentations without effecting growth Thus, methane formation by Methanosarcina barkeri from acetate, methanol or H2 plus CO2 is stimulated 2–3 fold in the presence of PPi and, with the latter two substrates, an accumulation of acetate is observed without a significant increase in growth. Enrichment cultures have been obtained using tripolyphosphate and tetrapolyphosphate and it is evident that these polyphosphates can also be utilized as a source of energy for the growth of anaerobic microorganisms. An enzyme has been purified from Thermoanaerobacter ethanolicus which exhibits both PPi:acetate kinase and ATP:acetate kinase activities and it is suggested that this kinase may be responsible for the widespread ability among anaerobic bacteria to utilize PPi as a source of energy.

The Effects of δ-Aminolevulinic Acid and Inhibitors of RNA and Protein Synthesis on Phytochrome Mediated Chlorophyll Accumulation in Sorghum bicolor

Abstract: In 5 - d - old etiolated seedlings of Sorghum bicolor, 12 h of darkness after 5 min in red light eliminated a lag before the accumulation of chlorophylls in subsequent continuous white light. Increasing the dark period to 24 h and 36 h, increased the rate of chlorophyll accumulation in the later stages of greening. Exogenous δ - aminolevulinic acid neither completely removed the lag, nor increased the rate of chlorophyll accumulation. Cycloheximide (25 µg ml -1 ) and 6 - methyl purine (5.0 µg ml -1 ), given continuously or only until the 12 h dark period following the red light irradiation, restored the lag and decreased the rate of chlorophyll accumulation. D - threo - chloramphenicol (400 µg ml -1 ) also decreased the rate of chlorophyll accumulation but did not restore the lag. Addition of these inhibitors even 12 h after red light irradiation decreased the rate of chlorophyll accumulation. Rifampicin (Rifamycin SV, 400 µg ml -1 ) did not have such effects.

Regulation of Nitrate Reductase Synthesis During Early Germination in Seeds of Barley (Hordeum vulgare)

Abstract: During seed germination in barley, a non - inducible phase of 24 - 26 h was found to exist for the induction of nitrate reductase (NR) in both light and dark. The non - inducible phase for NR was not due to the non - availability of nitrate ions or the presence of an enzyme inactivating factor or the synthesis of an inactive NR. At the initiation of the inducible phase, the enzyme was synthesized de novo but did not require synthesis of fresh mRNA. This was evident from the studies with inhibitors of RNA and protein synthesis. The metabolic activity during the non -inducible phase, probably synthesis of a protein, was essential to make the embryos sensitive to NR induction in the inducible phase. Actinomyc in- D, superinduced the enzyme. By examining various possibilities a post - transcriptional control for the superinduction has been suggested.

Soliton-like solutions of some nonlinear theories and transformations among them

Abstract: The observation that the soliton-like solutions of a given second-order nonlinear differential equation define the separatrix of the equivalent autonomous system is used to obtain the one-soliton solutions for theφ4 theories (the usual and the one with the wrong sign of the mass term), theφ6, theφ8, the sine-Gordon theories and the KdV equation. Transformations are given which transform the sine-Gordon equation into an equation belonging to theφ2n class of theories. A procedure is evolved for obtaining the two-soliton solutions for the sine-Gordon theory without the use of Backlund transformations; it is suggested that this procedure may be useful for investigating the existence of similar solutions for theories of the polynomial type.