North Eastern Hill University

About: North Eastern Hill University is a education organization based out in Shillong, Meghalaya, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 2318 authors who have published 4476 publications receiving 48894 citations.

Aggregation, adsorption, and clouding behaviors of Triton X-100 in formamide

Abstract: The critical micelle concentration (cmc) of TX-100 in formamide (FA) was determined from surface tension measurements as functions of temperature and NaCl concentration. At 25 degrees C, cmc was also determined by the fluorescence method. For the sake of comparison, micellization parameters of TX-100 were also determined in water. cmc, aggregation number, and standard free energy of micellization in FA are about 400 times higher, 10 times lower, and 2 times higher than in water, respectively. On increasing the temperature, cmc in FA shows a slight increase, whereas in water it decreases. The logarithm of relative cmc decreases linearly with added NaCl concentration in both FA and water, and the rate of this decrease is surprisingly equal in the two solvents. Micellization of TX-100 is exothermic in FA, but endothermic in water. The cloud point (CP) of TX-100 was determined in FA+water medium and that in pure FA was estimated to be approximately 233 degrees C when [TX-100]=0.15 mol kg(-1). Surface excess values of TX-100 were calculated from Gibbs and Langmuir adsorption isotherms. Values of standard free energy of adsorption calculated from the Rosen-Aronson equation and from the Langmuir adsorption isotherm are comparable. The ratio of the surface tension of the solvent to that at the cmc has been demonstrated as a novel scale for measuring solvophobicity.

Reproductive Strategies of Trachypithecus pileatus in Arunachal Pradesh, India

Abstract: We studied reproductive behavior of free-ranging capped langurs (Trachypithecus pileatus) in the Pakhui Wildlife Sanctuary, Arunachal Pradesh, India. Four species of primates —Trachypithecus pileatus, Macaca mulatta, M. assamensis, and Nycticebus bengalensis— live there. We studied the mating seasons, mating frequency, copulatory attempts, time spent in copulation, and interval between 2 successive copulations, gestation length, and interbirth interval of 4 groups of capped langurs during 2001–2003. We observed 2 mating seasons in a year. The first was larger, comprising 5 months (September–January), and the second was short, April and May. Mating was intensive in the morning session (0600–1000 h); 57% of total mating events occurred then. The average gestation period was 200 d. November was the most favorable month for breeding. In a year, 107 mating events occurred involving 5 adult females. Average time per mounting attempt is 12 s. Duration of mounting was the maximum in November. Interbirth interval was 23 months and 10 d. The birth season was 129 days, December–April; 53% of births occurred in February and March. Average birth rate is 0.386 birth/female/yr.

In vitro anthelmintic efficacy of Carex baccans (Cyperaceae): ultrastructural, histochemical and biochemical alterations in the cestode, Raillietina echinobothrida

Abstract: The aqueous juice of the root extract of Carex baccans (Family: Cyperaceae) is used as an anthelmintic in Meghalaya, India. The present investigation was carried out to evaluate the extent of ultrastructural, histochemical and biochemical alterations caused by the plant derived component(s) on Raillietina echinobothrida, a cestode parasite of domestic fowl. Live tapeworms, collected from the freshly slaughtered host, were exposed to different concentrations of the crude ethanolic root extract of C. baccans for varying time durations. The treated parasites revealed complete inactivation and flaccid paralysis leading to death; they were processed for ultrastructural, histochemical and biochemical observations, as soon as paralysis set in. Compared to controls, the treated parasites showed extensive distortion and destruction of the surface fine topography of the tegument, erosion of microtriches, disruption of muscle layers, intense vacuolization of tegumental and subtegumental layers, swelling and vacuolization of mitochondria and a significantly reduced activity of tegumental enzymes like AcPase and AlkPase. Phytochemicals from the root of C. baccans seem to be effective against soft-bodied cestode parasites and need to be characterized and identified.