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  • Author or Editor: N. G. Nair x
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The baya weaver Ploceus philippinus, despite its purely tropical origin and tropical/subtropical distribution, exhibits all features of a typically photoperiodic species. The onset of reproduction in this species is triggered by increasing daylength and breeding is terminated by the development of distinct photorefractory phase. In order to ascertain the involvement of androgens in the development of photorefractoriness the long day response of birds was tested after a prior exposure to varied doses of testosterone. Testosterone treatment accelerated the onset of photorefractoriness as judged from the gonadal status, LH-dependent yellow plumage and testosterone-dependent beak pigmentation. While gonadal development and yellow plumage occurred in the control birds due to the stimulatory long photoperiod, the testosterone administered birds failed to show such developments. These findings indicate that testosterone might impair the higher photoresponding mechanisms resulting in the development of photorefractoriness.

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Primary photochemical reactions and the activities of the antioxidant enzymes chloroplastic superoxide dismutase (SOD), glutathione reductase (GR) and glutathione-S-transferase (GST) were determined in water-stressed pearl millet ( Pennisetum glaucum L. cv. HHB-67) plants sprayed with the thiol compounds dithiothreitol (DTT), thioglycolic acid (TGA) and thiourea (TU) and the thiol modifiers 5,5′-dithio-bis-2-nitrobenzoic acid (DTNB) and N-ethylmaleimide (NEM) at the earhead emergence stage (47 days after sowing, DAS), together with a control. Sampling was done at 54 and 67 days after sowing. Photosystem I and II (PS I and II) activities (ferricyanide site) were found to increase in plants sprayed with TU, TGA and DTT at both stages (54 and 67 DAS), but a reduction in PS II activity (DCQ Site) compared with the control was caused by NEM (66.66%) and DTNB (27.77%) at 54 DAS. A similar decrease in the activity of PS II (ferricyanide site) was found at 67 DAS for DTNB (55.55%). The chloroplastic SOD activity increased in chloroplasts isolated from leaves sprayed with thiol compounds at both sampling stages, except for NEM at 54 and 67 DAS. The activities of GR and GST in the leaves were higher in thiol-treated plants than in the control at 54 and 67 DAS, while the lowest GR activity was seen for the sulphydryl modifiers (DTNB and NEM) in leaves at 54 DAS. The experimental data suggest an enhancement in the primary photochemistry and antioxidant enzyme activities of water-stressed pearl millet in response to foliar spraying with thiol compounds.

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Summary  

Twenty bhasmas based on Ca, Fe, Zn, Hg, Ag, K, As, Cu, Sn and gemstones have been analyzed for main constituent elements along with minor (Na, K, Mg, Ca, P), trace (Cr, Mn, Fe, Co, Cu, Zn, Hg) and toxic elements by instrumental neutron activation analysis (INAA) including their C, H, N and S contents. Siddhamakaradhwaja, an Hg preparation and Swet parpati of K were found to be stoichiometrically HgS and KNO3

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Summary  

Eight different brands of Trifala and its three constituents, Amalaki (Embilica officinalis), Bibhitaki (Terminalia bellirica) and Haritaki (T.chebula) were analyzed for 6 minor (Na, K, Mg, Ca, Cl and P) and 19 trace (Al, Ba, Br, Co, Cr, Cs, Fe, Eu, Hf, Hg, La, Mn, Rb, Sb, Sc, Se, Th, V and Zn) elements by instrumental neutron activation analysis (INAA). Two candidate reference materials Tea Leaves (TL-1) and Mixed Polish Herbs (MPH-2) were also analyzed as a part of Intercomparison Study besides several reference materials (RMs) for quality control. The samples along with RMs were irradiated with thermal neutrons in APSARA/Dhruva reactors at BARC, Mumbai and their activity measured on HPGe detector and 8K MCA system. Also Ni, Cu, Cd and Pb contents were determined by AAS. Bibhitaki is found to be enriched in Fe (0.98 mg/g), P (1.10 mg/g), Co (1.74 mg/g) and Se (240 ng/g) including alkali and alkaline earth metals. Availability of many nutrient elements such as Mg, Ca, K, Fe, and Se in Trifala is attributed to its usefulness in the treatment of liver disorder, heart ailments, hepatic diseases and cancer, as expectorant, powerful eye rejuvenator and an antioxidant.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
R.N. Acharya
,
K. Sudarshan
,
A.G.C. Nair
,
Y.M. Scindia
,
A. Goswami
,
A.V.R. Reddy
, and
S.B. Manohar

Abstract  

The guided thermal neutron beam at 100 MW Dhruva research reactor facility of Bhabha Atomic Research Centre (BARC) was used to carry out prompt gamma-ray neutron activation analysis (PGNAA). The prompt k 0-factors have been determined for the isotopes of the elements H, B, K, Co, Cu, Ca, Ti, Cr, Cd, Ba, Hg and Gd with respect to 1951 keV gamma-line of 36Cl. The prompt k 0-factors for H, Cl and Cu were also measured with respect to the 1381 keV gamma-line of 49Ti. Different samples like NH4Cl, Ti metal, cobalt chloride and other stoichiometric compounds and pure metals were used for this purpose. Prompt gamma-rays were accumulated using a 22% HPGe detector connected to a PC based 8k MCA in single mode counting. The energy calibration in the range of 100–8500 keV was carried out using gamma-rays from 152Eu and 60Co, and the prompt gamma-rays from 36Cl whereas the absolute detection efficiency for this energy range was determined using 152Eu and prompt gamma-rays from 36Cl and 49Ti.

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