Showing papers by "University of Madras published in 1993"

Spermatophores and Sperm Transfer in Marine Crustaceans

Abstract: Publisher Summary This chapter discusses spermatophores and sperm transfer in marine crustaceans. The use of spermatophores as the main mode of sperm transfer by crustaceans is important in two respects. First, most crustacean spermatozoa, and all decapod spermatozoa, are aflagellate and non-motile spermatozoa, are aflagellate and non-motile, and hence need a vehicle for their transference to females in the absence of a copulatory organ. Secondly, crustaceans have employed spermatophores as an effective method for sperm transfer in aquatic media inasmuch as the cryptozoic arthropods have used them in land habitat. This chapter reviews the morphological diversity of spermatophores and the mechanism of sperm release from spermatophores. Special attention is paid to the origin of spermatophoric components in the male reproductive tract, spermatophore hardening, biochemistry of the seminal plasma with reference to sperm survival, and maintenance during storage inside the female reproductive tract, deals first with the brachyuran crabs, whose breeding is best known, and then goes in the reverse of the usual taxonomic order to the lobsters and prawns and less studied orders of Crustacea.

Effect of Plumbagin on some glucose metabolising enzymes studied in rats in experimental hepatoma

Abstract: Plumbagin (5-hydroxy-2-methyl-1, 4-naphthoquinone) isolated from Plumbago zeylanica Linn, when administered orally, at a dosage of 4 mg/kg body weight induces tumour regression in 3-methyl-4-dimethyl aminoazobenzene (3Me-DAB) induced hepatoma in Wistar male rats. The purpose of this investigation was to identify the changes in the rate of glycolysis and gluconeogenesis in tumour-bearing rats and the effects of treatment with Plumbagin. The levels of certain glycolytic enzymes, namely, hexokinase; phosphoglucoisomerase; and aldolase levels increased (p<0.001) in hepatoma bearing rats, whereas they decreased in Plumbagin administered rats to near normal levels. Certain gluconeogenic enzymes, namely, glucose-6-phosphatase and fructose-1,6-diphosphatase decreased (p<0.001) in tumour hosts, whereas Plumbagin administration increased the gluconeogenic enzyme levels in the treated animals. These investigations indicate the molecular basis of the different biological behaviour of 3MeDAB induced hepatoma and the anticarcinogenic property of Plumbagin against hepatoma studied in rats.

Distribution of vesicular-arbuscular mycorrhizae in the plants and rhizosphere soils of the tropical plains, Tamil Nadu, India

Abstract: We examined 737 plant species from 121 families of angiosperms and four species of pteridophytes for mycorrhizal association. Only 372 species showed infection. Mycorrhizal colonization was recorded in 49% of the total flora. The quantum of colonization ranged from 10% to 90%. In all, 35 species exhibited mycorrhizal colonization higher than 75%. Of the four pteridophytes, Isoetes coromandelina showed mycorrhizal colonization by Entrophospora schenckii and Glomus aggregation in its rhizosphere. For the first time in India, 102 of these species were reported to be mycorrhizal. Glomus fasciculatum (13.8%) and G. aggregation (11%) were prevalent in the rhizosphere soils. Acaulospora foveata (0.2%), A. longula (0.5%) and Glomus hoi (0.9%) were the least represented as mycorrhizal spores. A total of 40 vesicular-arbuscular mycorrhizal fungal species belonging to Acaulospora, Entrophospora, Gigaspora, Glomus, Sclerocystis and Scutellospora were isolated from the rhizosphere soils of different ecosystems.

Mycorrhizal status of plant species colonizing a magnesite mine spoil in India

Abstract: The present study reports the vesicular arbuscular mycorrhizal fungal association with 14 plant species colonizing a magnesite mine spoil in Salem, Tamil Nadu state, India. The soil was poor in Olsen-available P (5–45 kg/ha-1). Hyphal, arbuscular and vesicular infection was noticed. Infection ranged from 32 to 82%. Thirteen VAM fungal species were identified. Spores of Glomus fasciculatum and Gigaspora gigantea were commonly found in the magnesite mine spoil.

Impact of power plant heated effluent on the abundance of sedentary organisms, off Kalpakkam, East coast of India

Abstract: The impact of heated effluents from the condenser outfall of the Madras Atomic Power Station (MAPS), on the flora and fauna settled on an iron pile in the discharge area was studied. At temperatures ranging between 27.2 to 31.0 °C, the sedentary community was composed of epiphytic algae, sea anemones, tubeworms, polychaetes, crabs, amphipods, barnacles, periwinkles, mussels and ascidians. During January–February, ambient temperature ranged between 37.0 to 37.6 °C, and almost all the macroepifauna and flora, except for periwinkles and Cthamalid barnacles perished.

Serum protein, ascorbic acid & iron & tissue collagen in oral submucous fibrosis--a preliminary study.

Abstract: A study of 36 patients with oral submucous fibrosis, revealed that all patients had the habit of chewing betel nut, pan masala or the traditional mixture (betel nut, betel leaf and lime) suggesting a link between fibrosis and arecanut. There was an increase in the globulin fraction of protein and hence a decreased A/G ratio in these patients. There was a significant increase in total protein levels possibly due to the increase in globulin fractions and other serum proteins. Ascorbate and iron levels decreased perhaps because of their utilisation in collagen synthesis. The total tissue collagen content increased significantly in patients with advanced disease and, it increased with the progression of the disease leading to hypomobility of the tongue, lips, cheeks, soft palate and faucial pillars.

The kinetics of the polymerization reaction of toluene diisocyanate with HTPB prepolymer

Abstract: The uncatalysed and catalysed polymerization of a hydroxyl-terminated polybutadiene with toluene diisocyanate has been studied in toluene solution at four different temperatures. The rate constants (k1, k2) and the activation parameters (Ea1, Ea2, ΔS1‡, ΔS2‡) for the isocyanate groups in the 4 and 2 positions were calculated. It was found that the catalysts enhance the reactivity of the 2 position isocyanate group rather than the 4 position isocyanate group. It was also found that diethylcyclohexylamine has higher selectivity than dibutyltin dilaurate to enhance the reactivity of the isocyanate group in the 2 position. The effect of solvent has also been studied. The reactivity decreased in the following order; benzene = toluene > chlorobenzene > dioxane > nitrobenzene. © 1993 John Wiley & Sons, Inc.

Restoration of tissue antioxidants and prevention of renal stone deposition in vitamin B6 deficient rats fed with vitamin E or methionine.

Abstract: Observed loss in body weight gain, increased lipid peroxidation reaction, decreased concentrations of antioxidants, ascorbic acid, alpha-tocopherol and reduced glutathione and antioxidant enzymes, glutathione peroxidase and catalase and increased concentration of hydroperoxides and hydroxyl radicals in vitamin B6 deficient rat liver [J Nutri Biochem, 2 (1991) 245] and kidney [Biochem International, 21 (1991) 599] were nearly normalized on feeding with vitamin E or methionine. Accumulation of oxalate and calcium during vitamin B6 deficiency was abolished by feeding vitamin E or methionine. Calcium oxalate deposition observed in vitamin B6 deficient kidney was completely prevented when fed along with vitamin E or methionine. However the hyperoxaluria and hypercalciuria persisted even after feeding with vitamin E or methionine.

Compatibility of ferritic and duplex stainless steels as implant materials: in vitro corrosion performance

Abstract: The pitting corrosion, crevice corrosion and accelerated leaching of iron, chromium and nickel of super-ferritic and duplex stainless steels, and for effective comparison the presently used 316L stainless steel, have been studied in an artificial physiological solution (Hank's solution) by the potentiodynamic anodic polarization method. The results of the above studies have shown the new super-ferritic stainless steel to be immune to pitting and crevice corrosion attack. The pitting and crevice corrosion resistances of duplex stainless steel were found to be superior to those of the commonly used type 316L stainless steel implant materials. The accelerated leaching study conducted for the above alloys showed very little tendency for the leaching of metal ions when compared with 316L stainless steel. Thus the present study indicated that super-ferritic and duplex stainless steels can be adopted as implant materials due to their higher pitting and crevice corrosion resistance.

Effect of chronic alcoholism on semen--studies on lipid profiles.

Abstract: The effect of chronic alcoholism on various seminal parameters (sperm concentration, rate of forward motility, percentage of abnormal spermatozoa, lipid profiles of seminal plasma and spermatozoa) was studied together with the serum levels of testosterone and oestradiol. In chronic alcoholics there was a marked reduction in sperm concentration and in the rate of their forward motility, and increase in the number of spermatozoa with morphological abnormalities when compared to age-matched normal fertile subjects. Serum levels of testosterone were decreased while oestradiol levels were increased in chronic alcoholic men. Studies of lipid profiles showed a marked decrease in the total phospholipid concentration in spermatozoa, primarily in sphingomyelin, phosphatidyl choline and ethanolamine fractions. The cholesterol:phospholipid ratio in spermatozoa was increased in alcoholics. In the seminal plasma of chronic alcoholics, there was a decrease in total lipid, in glyceride glycerol and in free and esterified cholesterol. Of the phospholipid classes, sphingomyelin and phosphatidyl ethanolamine showed a significant reduction. In general, the present study provides evidence for the adverse effects of chronic alcoholism on serum hormones, sperm count, morphology, motility and seminal lipid profiles. These may be responsible for the fertility disorders common in chronic alcoholics.

Anatomical studies on ectomycorrhizas

Abstract: Ectomycorrhizas of 5-month-old Pinus patula plants grown in autoclaved shola soil (forest soil) inoculated with basidiospores of Rhizopogon luteolus and Scleroderma citrinum are described. The main emphasis is on the organisation of the mantle tissue as seen in plan view and the features of associated hyphae and strands. The different layers in the mantle produced by the different fungi are described and illustrated.

Transient Solution of an M/M/1 Queue with Balking

Abstract: An infinite capacityM/M/1 queue with balking is discussed. Defining the generating function in an unusual and direct way, the time-dependent solution for the system size is obtained elegantly.

Effect of aspirin on isoproterenol induced changes in lipid metabolism in rats.

Abstract: The effect of aspirin on isoproterenol induced changes in lipid metabolism in rats was studied. Aspirin (1.2 mg/100 g/day) was administered orally for a period of 60 days along with/without isoproterenol (20 mg/100g sc twice at a time interval of 24 h for 2 days). Isoproterenol treated rats showed an increase in the levels of heart cholesterol, triglycerides and free fatty acids. The activity of cholesterol ester synthetase CES was increased significantly with concomitant increase in heart lipid peroxide levels in isoproterenol treatement. Aspirin treatment could restore the enzyme activity to near normal and also reduce the level of lipid peroxides. The lipid changes were minimum in rats treated with aspirin and isoproterenol

Efficacy of Gliocladium virens and Trichoderma longibrachiatum as biological control agents of groundnut root and stem rot diseases

Abstract: The biocontrol potential of Gliocladium virens (G1 and G2) and Trichodenma longibrachiatum (T1 and T2) against groundnut root and stem rot diseases, their survival patterns and effects on the pathogen survivability have been investigated. Isolates G1 and T1, delivered as a wheat bran‐sawdust (WBSD) preparation gave significant protection (65–74%) against root rot incited by Rhizoctonia solani. A linear correlation was obtained between the dosage (g/kg soil) of antagonists and their disease control efficacy. Seed coating with spore suspension (1 × 109spores/ml) also considerably reduced the root rot incidence but to a lesser degree than the WBSD preparation. On the other hand, only moderate protection (21–36%) against stem rot caused by Sclerotium rolfsii was recorded with either of the antagonists. The antagonists applied to soil, despite a sharp decrease by the 7th day, gradually increased in their population density over a period of time. G1 exerted a 65% reduction in R. solani viability follow...

Growth and Characterisation of Pure and Nickel‐doped Strontium Tartrate Tetrahydrate Single Crystals

Abstract: Strontium tartrate tetrahydrate single crystals doped with nickel have been grown in silica gel. The grown crystals have been characterized by X-ray, atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA), and etching technique.

Studies on toluenediisocyanate blocked by benzophenone oximes

Abstract: Toluene diisocyanate blocked by substituted benzophenone oximes were prepared and were found to be highly soluble in polyethylene glycol at low temperature. Dissociation temperature of blocked isocyanates were accurately determined

A Method for Demonstrating Prophenoloxidase after Electrophoresis

Abstract: The demonstration of prophenoloxidase after electrophoresis is based on its activation by sodium dodecyl sulfate (SDS) or sodium oleate and staining the activated phenoloxidase with dopamine and 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH). A rapid method is presented for demonstrating the presence of activated phenoloxidase using polyacrylamide gel electrophoresis followed by staining in the presence of SDS or sodium oleate.

Cyclohexanone oxime‐blocked polyisocyanates

Abstract: Cyclohexanone oxime-blocked isophorone diisocyanate and cyclohexanone oxime-blocked toluene diisocyanate were synthesized and analyzed by infrared spectra, nuclear magnetic resonance spectra, elemental analysis, etc. Decomposition temperatures of the blocked isocyanates were determined by thermogravimetry. The solubilities of blocked isocyanates in various polyols were tested. © 1993 John Wiley & Sons, Inc.

Chaotic behavior in Chern-Simons-Higgs systems.

Abstract: We investigate the dynamical behavior of the Chern-Simons-Higgs system, with and without the Maxwell term for the case of spatial homogeneity. The pure Chern-Simons-Higgs system is shown to be integrable. Inclusion of the Maxwell term renders the system chaotic. A Painlev\'e analysis for the Maxwell-Chern-Simons-Higgs (MCSH) system is carried out to indicate its nonintegrability. Numerical studies of the Poincar\'e plots and Lyapunov exponents are used to establish chaotic behavior in the MCSH system.