Showing papers by "Shivaji University published in 1982"

A static cosmological model in Einstein-Cartan theory.

Abstract: A static cosmological model in the Einstein-Cartan theory based on Lyra's modified Riemannian geometry is proposed. We assume that the spins of the individual particles composng the fluid are all aligned in the radial direction and observe the very interesting fact that if spin is there in this static Einstein universe, it should be constant and it can be given in terms of central density ρ0 as\(K = A = (1/4\pi )[(8\pi \rho _0 - 3/R^2 ) + \tfrac{3}{4}\beta ^2 ]^{1/2}\). The geometry and properties of the model are discussed.

Effect of salt stress on the structure and carbon flow mechanism in a noxious weed Parthenium hysterophorus L.

Abstract: Summary Effect of salt stress on structural changes, ion uptake, rate of photosynthesis and path of carbon in the exotic weed Parthenium hysterophorus have been investigated. Photosynthetic leaf area, chlorophyll and carbon assimilation rates were adversely affected by salt stress. Increased Na+ uptake caused decrease in K+ and Ca2+ absorption. Originally a C3 plant, P. hysterophorus appears to form aspartate as a primary product of photosynthesis when exposed to NaCl. The stimulation of PEP carboxylase activity also occurred due to salt stress. Excessive accumulation of malate during steady state of photosynthesis was possibly due to inhibition of malic enzyme. It appears that although the plant switches over to an ‘aspartate producer’ when exposed to salt, further utilization of photosynthetically assimilated carbon is through malate. Being a weed, the plant appears to be highly adaptive to stress conditions. Resume Effets de la salure sur la structure el le mouvement du carbone dans une mauvaise herbe Parthenium hysterophorus L. Les effets de la salure sur les modifications structurelles, l'absorption ionique, l'intensite photosynthetique et les mouvements du carbone, ont eteetudies dans une mauvaise herbe exotique. Parthenium hysterophorus L. L'intensite photosynthetique, l'assimilation de la chlorophylle et du carbone ont ete diminuees par la salure. Une augmentation de l'absorption des ions Na+ entraine une diminution de l'absorption des ions K+ et Ca2+. En principe, une plante de P. hysterophorus devrait produire de l'aspartate comme compose primaire de photosynthese quand elle est exposee au NaCl. On note egalement une stimulation de la PEP carboxylase dans les rnemes conditions. Une accumulation de malate pendant la phase stable de la photosynthese peut etre due a l'inhibition de l'enzyme malique. II semble que malgre une production d'aspartate lorsque la plante est exposee au sel, l'utilisation ulterieure de carbone assimilable se fait a partir du malate. En tant que mauvaise herbe, cette plante apparait comme capable de s'adapter aux conditions de sol sale. Zusammenfassung Wirkung von Salzstress auf die Struktur und den Mechanismus des Kohlenstoffumsatzes bei dem Unkraut Parthenium hysterophorus L. Die Wirkung von Salzstress auf strukturelle Veranderungen, Ionenaufnahme, Photosyntheserate und den Mechanismus des Kohlenstoffumsatzes wurde bei der exotischen Unkrautart Parthenium hysterophorus untersucht. Durch Salzstress wurden die photosynthetisch aktive Blattflache und die Chlorophyll- und Kohlenstoff-assimilation negativ beeinflusst. Eine vermehrte Na+ -Aufnahme reduzierte die K+- und Ca2+-Aufnahme. Die ursprungliche C3P. hysterophorus scheint unter dem Einfluss von Kochsalz als primares Photosyntheseprodukt Aspartat zu bilden. Weiterhin wurde durch Salzstress die PEP-Carboxylaseaktivitat stimuliert. Die ausserordentlich starke Anreicherung von Malat wahrend des ‘steady state’ der Photosynthese, wurde moglicherweise durch eine Hemmung des sog. malic enzyme hervorgerufen. Obwohl die Pflanze, wenn sie einem Salzstress unterliegt zum ‘Aspartat-Produzenten’ wird, scheint doch die weitere Verwendung von photo-synthetisch assimiliertem Kohlenstoff uber Malat zu taufen. Dieses Unkraut ist offensichtlich in der Lage, sich Stressituationen sehr gut anpassen zu konnen.

Estuarine ecosystem of India

Abstract: An estuary is considered as a partly enclosed body of water that is formed when a river joins the sea. The water of the former is salinated by sea water. Such an estuarine environment is obviously to be found at the mouth of a river and will extend to as far as sea water can reach. The river, flowing over a considerable distance, brings a large amount of silt with it which is deposited on the banks of the river and, which is at the same time responsible for island formations in the river. These islands, which are barren at first, are soon subjected to the process of succession and develop into stable ecosystems.

Effect of salt-stress on translocation of photosynthates in pigeon-pea

Abstract: An investigation was carried out in order to study the effect of salts namely NaC1 and Na2SO4 on the rate of translocation of photosynthates in pigeonpea, at the pod filling stage. At the concentration of 10 EC NaC1 only 17% of the14C assimilates are translocated from the source leaf to the other parts of the plant. Out of this pods receive about 8%. On the other hand even at a concentration of 15 EC Na2SO4 about 30% of the total14C assimilates get translocated and out of this pods receive about 12%. From this it may be concluded that under salt-stress conditions the rate of translocation of photosynthates is adversely affected and between the two salts, NaC1 was discovered to have a marked inhibitory effect.

Histochemical studies on non-specific esterases in epididymis of the bat,Cynopterus sphinx sphinx

Abstract: Non-specific esterases were studied in the epididymis of the bat,C. sphinx sphinx by employing α-naphthyl acetate and 5-bromoindoxyl acetate as substrates and eserine sulphate (10−4 M) as an enzyme inhibitor. The enzyme activity in epididymal cells was diffused cytoplasmic and granular in nature. The granular activity was eserine resistant. Holocrine cells were also observed in the epididymis of this bat. Seasonal variations in epididymal esterases are described.

Dispersion of dielectric constant and resistivity of Cux Zn1−x Fe2O4 samples

Abstract: Cux Zn1−x Fe2O4 samples exhibit dispersion of dielectric constant, tanδ and resistivity in the frequency range of 1 kHz to 50 MHz. The dispersion exhibited is in general accord with Koops’ model. However, the details of the conducting and non-conducting regions must be taken into account when composition tends to change interrelationship between the elementary capacitor resistor circuits.

Extraction chromatography of quadrivalent titanium and zirconium from succinate solution

Abstract: Liquid ion exchangers such as tri-n-octyl amine (TOA), tri-iso-octylamine (TTOA) and Aliquat 336 have been used in this laboratory for analytical separation of vanadium(V) and niobium(V)1, indium(III), thallium(III)2, thorium(IV), cerium(IV)3 from succinate solutions. Extension of this study has revealed that benzene solutions of TOA, TIOA and Aliquat 336 could be used for anion exchange extraction of quadrivalent titanium and zirconium from succinate solution. The metal ions from the organic phase are stripped and determined spectrophotometrically.