Showing papers by "North Eastern Hill University published in 1987"
TL;DR: Observations strengthen an earlier suggestion made that active ureogenesis did exist in some freshwater teleosts such as H. fossilis and indicates that this fish is either relatively primitive to the purely aquatic freshwaterTeleosts retaining the ancestral character of a functional o-u cycle or the genes for the synthesis of o-U cycle enzymes might have been derepressed as a secondary modification for its adaptation to temporary dehydration or hyper-ammonia environment.
Abstract: Activities of all the enzymes of ornithine-urea (o-u) cycle and uricolytic pathway were assayed in different tissues of a freshwater air-breathing teleost, Heteropneustes fossilis. High activity of all o-u cycle enzymes as observed in the liver and kidney, were comparable to those of actively ureogenic fishes and amphibians. All the three enzymes of uricolytic pathway were found only in liver tissue. These observations strengthen an earlier suggestion made that active ureogenesis did exist in some freshwater teleosts such as H. fossilis. Presence of an active o-u cycle in H. fossilis indicates that this fish is either relatively primitive to the purely aquatic freshwater teleosts retaining the ancestral character of a functional o-u cycle or the genes for the synthesis of o-u cycle enzymes might have been derepressed as a secondary modification for its adaptation to temporary dehydration or hyper-ammonia environment.
88 citations
TL;DR: Since domain III of the albumin is devoid of tryptophan, it is concluded that the formation of intermediate in the unfolding-refolding transition of serum albumin involves unfolding of domain III, minor structural transformations in domain II, and/or the separation of the sub-domains ofdomain III from each other.
Abstract: Urea-induced unfolding of bovine serum albumin and one of its fragments containing domain II + III has been studied by difference spectral and fluorescence emission measurements. The unfolding-refolding curves of both the proteins showed the presence of at least one stable intermediate when the transition was monitored at 288 nm. The presence of the intermediate was not detectable at 293 nm where only tryptophan contributed towards the protein absorption. However, both the proteins did show the presence of intermediate when the denaturation was monitored fluorometrically. Since domain III of the albumin is devoid of tryptophan, it is concluded that the formation of intermediate in the unfolding-refolding transition of serum albumin involves (i) unfolding of domain III, (ii) minor structural transformations in domain II, and/or (iii) the separation of the sub-domains of domain III from each other.
60 citations
TL;DR: In this article, the authors evaluated the 1:1 molar stoichiometry of the oxidation of n -butanol, iso-propanol, benzyl alcohol, or cyclohexanol involving pyridinium fluorochromate, C5H5NHCrO3F (PFC), in dichloromethane, and the reduction product of PFC, isolated after such oxidations, has been identified from the results of chemical analyses, chemical determination of the oxide state of chromium, magnetic susceptibility, ESR and IR spectral studies as
43 citations
TL;DR: In this paper, the influence of soil moisture on the fungal population, bacterial population, CO2-evolution and dehydrogenase activity was discussed. But the authors focused on the relationship between various parameters of the soil with different moisture regimes.
Abstract: This paper deals with the influence of soil moisture on the fungal population, bacterial population, CO2-evolution and dehydrogenase activity. Correlation coefficients of various parameters of the soil with different moisture regimes are given. It is demonstrated that soil moisture significantly alters the microbial population, its activity and the relationships between various parameters.
28 citations
TL;DR: Findings seem to suggest that while melatonin influences gonadal activity, body weight growth, and thyroid activity by acting directly at the hypothalamo-hypophyseal complex, it counteracts the effect of LH at the feather papillae level.
26 citations
TL;DR: Higher biomass and productivity of this species was comparable with that reported for high-productivity species like P. caribaea in Malaysia and P. radiata in New Zealand, and could be accounted as due to high net assimilation rate of needles due to prolonged photosynthetic activity produced in three flushes during the year.
25 citations
TL;DR: Thirty-one species of Brachionids (Eurotatoria: Brachionidae) are reported from India, with two new records and two new synonyms proposed.
Abstract: Thirty-one species of Brachionids (Eurotatoria: Brachionidae) are reported from India. Brachionus bennini (Leissling) and B. patulus macracanthus (Daday) are new records from this country. Two new synonyms are proposed. Comments are made on the distribution of the different taxa.
24 citations
TL;DR: The population size of Mikania micrantha H.B. is considerably enhanced by fire in 2-, 4-and 8-year-old fallows developing after slash-and-burn agriculture in northeastern India.
Abstract: Summary: Resume: Zusammenfassung
The population size of Mikania micrantha H.B.K. is considerably enhanced by fire in 2-, 4- and 8-year-old fallows developing after slash-and-burn agriculture (jhum) in northeastern India. The recruitment pattern in burnt and unburnt sites in each fallow differed. Seedling recruitment was restricted only to burnt sites in 2- and 4-year-old fallows, whereas it occurred in both burnt and unburnt sites in an 8-year-old fallow. Sexual reproductive potential of the species was affected by the age of the fallow and by fire in each fallow plot. These results are related to micro-environmental changes in the habitat as a consequence of fire in different fallow plots.
Effet du feu sur la dynamique des populations de Mikania micrantha H.B.K. dans un mode de conduite alternatif coupe-brulage dans le nord-est de l'Inde
L'importance des populations de Mikania micrantha a ete considerablement augmentee par le feu dans des vieilles jacheres de 2, 4 et 8 ans conduites selon la technique coupe-brulage dans le Nord-Est de l'Inde. Le processus de reprise dans les zones brulees et non brulees a ete different pour chacune des jacheres. La reprise de plantules n'a eu lieu que dans les zones brulees pour les jacheres vieilles de 2 et 4 ans. mais elle est survenue en tout lieu dans la jachere de 8 ans. Le potentiel de reproduction sexuee a ete affectea la fois par l'âge de la jachere et par le feu dans chaque parcelle. Ces resultats sont lies a des changements microenvironnementaux dans l'habitat, consequence du feu dans les differentes parcelles en jachere.
Der Einfluss von Feuer auf die Populationsdynamik von Mikania micrantha H.B.K. wahrend der Fruhentwicklung einer Folgevegetation nach Brandhackbau in NO-Indien
Die Populationsdichte von Mikania micrantha H.B.K. wird nach Rodung und Abbrennen auf 2, 4 und 8 Jahre altem Brachland durch Feuer betrachtlich erhoht. Auf den einzelnen Brachflachen war die Wiederbesiedelung von abgebrannten und nicht abgebrannten Parzellen verschieden. Die Entwicklung einer Samlingspopulation war auf 2 resp. 4 Jahre altem Brachland auf abgebrannte Flachen beschrankt, wahrend auf 8 Jahre alter Brache sowohl auf abgebrannten als auch nicht abgebrannten Flachen die Entwicklung einer Samlingspopulation stattfand. Die sexuelle Reproduktionskraft der Species wird durch die Dauer der Brache und die Wirkung des Feuers beeinflusst. Diese Ergebnisse stehen in Beziehungzu kleinflachigen Umweltveranderungen im Biotop, als Folge des Feuers und des Alters der Brache.
22 citations
TL;DR: In this paper, the UO 2 2+ group is maintained in all these complexes with the ligand atoms arranged in the equatorial plane perpendicular to the linear uranyl group, indicating that the ligands function as tetrabasic hexadentate ligands.
20 citations
TL;DR: In this article, α-oxoketene dithioacetals derived from various cyclic and acyclic ketones are shown to be useful intermediates for the synthesis of substituted and fused quinolizinium derivatives by reaction with 2-picolyllithium followed by cyclization in the presence of borontrifluoride etherate.
18 citations
TL;DR: In this paper, the vibrational relaxation and non-coincidence effect in liquid cyclohexanone have been studied and explained in terms of molecular attraction parameters and van der Waals interactions.
TL;DR: In this paper, a simple experimental technique has been described for measuring range and energy-loss of any heavy ion in any complex medium with the help of a sensitive solid state nuclear track detectors (SSNTDs).
Abstract: A simple experimental technique has been described for measuring range and energy-loss of any heavy ion in any complex medium with the help of a sensitive solid state nuclear track detectors (SSNTDs). In this paper we present the results obtained from our measurements of ranges and energy-loss of 16.34 MeV/u238U in Makrofol-N using CR-39 track detector. Experimental ranges are compared with the corresponding theoretical values. The significance and scope of the present work are discussed.
TL;DR: In this paper, the presence of very significant mismatchings in α(M w ) in some GUT predictions where superheavy particle effects have been included, and adopt a new method to correct them leading to new solutions for the GUT coupling, τ p or sin 2 θ w.
TL;DR: The population dynamics of Eupatorium adenophorum Spreng.
Abstract: Summary
The population dynamics of Eupatorium adenophorum Spreng. and E. riparium Regel was studied in the field for 2 years, in relation to burning, by following the fate of individuals in permanent quadrats at short and regular time intervals. Both species showed increased population density and longevity of individuals on the burnt site. Adult and seedling populations of both species showed greater survival in the burnt plot. Eupatorium riparium survived better than E. adenophorum adults after burning. In the unburnt plot, however, the seedling survival of both species was nil. The heavy juvenile mortality of both species in the unburnt situation is attributed to the accumulation of a thick layer of pine needles and the growth of herbaceous vegetation. Moisture stress and low temperature in winter months also seem involved in the regulation of seedling population of these two weeds.
Resume
Dynamique des populations de Eupatorium adenophorum Spreng. et de E. riparium Regel en relation avec l'ecobuage
La dynamique des populations de Eupatorium adenophorum Spreng. et d'E. riparium Regel a eteetudiee au champ pendant deux ans en relation avec l'ecobuage, en suivant le devenir d'individus dans des zones permanentes a des intervalles de temps reguliers. Les deux especes ont exprime une augmentation de la densite de population et de la longevite des individus sur site brule. Les populations adultes et semencieres des deux especes ont montre une meilleure survie dans les parcelles brulees. Eupatorium riparium a mieux subsiste que les adultes de E. adenophorum apres brulage. Dans les parcelles non brulees, cependant la survivance des semences de deux especes dans les situations de non brulage est attribuee a l'accumulation d'une epaisse couche d'aiguilles de pin et a la poussee d'une vegetation herbacee. L'humidite importante et les basses temperatures durant les mois d'hiver semblent egalement etre impliquees dans la regulation des populations grainieres de ces deux adventices.
Zusammenfassung
Ueber die Populationsdynamik von Eupatorium adenophorum Spreng. und E. riparium Regel und ihre Beziehung zum Abbrennen.
Wahrend zwei Jahren wurde in Feldversuchen die Populationsdynamik von Eupatorium adenophorum Spreng. und E. riparium Regel in Bezug auf das Abbrennen der Vegetation untersucht. Zu diesem Zweck wurde in permanent festgelegten Quadraten das Schicksal der einzelnen Individuen in kurzen und regelmassigen Intervallen beobachtet. Beide Arten zeigten auf den abgebrannten Flachen erhohte Populationsdichten und Langlebigkeit. Die Populationen adulter Pflanzen von Samlingen wiesen auf den Brandflachen hohere Ueberlebensraten auf. Adulte Pflanzen von E. ripariumuberlebten das Abbrennen besser als E. adenophorum. Auf den nicht abgebrannten Flachen uberlebten praktisch keine Samlinge beider Arten. Diese hohe Mortalitat der jugendlichen Pflanzen wird der Akkumulation einer dicken Schicht von Koniferennadeln und der Entwicklung einer dichten Krautschicht zugeschrieben. Es scheint, dass ausserdem Feuchtigkeitsmangel und tiefe Wintertemperaturen an der Regulation der Samlingspopulationen dieser zwei Unkrautarten beteiligt sind.
TL;DR: In this paper, the toxic effects of vanadium on the human skeletal system were investigated at 37°C in 0.165 M sodium chloride solution, and a theoretical interpretation based on changes in lattice and hydration energies resulting from isomorphous ionic substitution was advanced.
Abstract: To understand the toxic effects of vanadium on the human skeletal system, the solubility products of phosphate and vanadate apatites of calcium and eight of their solid solutions, spread over the entire compositional range, were investigated at 37° C in 0.165 M sodium chloride solution. They were found to increase with increase in the vanadium content, the dissolution being found to be stoichiometric. A theoretical interpretation based on changes in lattice and hydration energies resulting from isomorphous ionic substitution is advanced.
TL;DR: A novel aromatic annelation leading to fused thioresorcinol dimethylethers has been developed by reacting cyclic ∝-oxoketene dithioacetals with propargylmagnesium bromide followed by treatment of the resulting carbinolacetal with borontrifluoride etherate in methanol as mentioned in this paper.
TL;DR: Ten species of Lepadella Bory de St. Vincent, 1826, including one new species and one new form, are documented from North-Eastern India, two of these species are new records from this country and six are new reports from N.E. region.
Abstract: Ten species of Lepadella Bory de St. Vincent, 1826, including one new species and one new form, are documented from North-Eastern India. Two of these species are new records from this country and six are new reports from N.E. region. Comments are also made on the status and distribution of various Indian taxa.
TL;DR: In this article, a facile method for highly stereoselective synthesis of α -arylidene (4a−4d, 4f−4h and 4j ) and α-ethylidene( 4e,4i )-γ -butyrolactones has been developed by acid catalyzed lactonization of the corresponding α-ylidene-γ, δ-unsaturated esters 3a−3j.
TL;DR: In this article, temperature-dependent Raman spectra of oriented single crystals of [N(CH3)4]2CoCl4 are reported and an assignment of the observed Raman bands has been made and it was found that the N(CH 3)4+ and CoCl42− groups occupied sites of Cs symmetry in the lattice at room temperature.
Abstract: Temperature-dependent Raman spectra of oriented single crystals of [N(CH3)4]2CoCl4 are reported. An assignment of the observed Raman bands has been made and it was found that the N(CH3)4+ and CoCl42− groups occupy sites of Cs symmetry in the lattice at room temperature. However, because of rapid reorientation, the CoCl42− groups retain an effective tetrahedral symmetry. The prototypic to incommensurate to commensurate phase transitions are associated with the orientational dynamics of the CoCl4 tetrahedra. The monoclinic to orthorhombic super lattice phase transition at 122 K in [N(CH3)4]2CoCl4 is triggered by the distortion of the N(CH3)4+ groups in the lattice.
TL;DR: CO2 evolution, fungal biomass and microbial population of two maize field soils differing in agricultural systems Viz., permanent agriculture on plain lands in valleys and ‘slash and burn’ type of shifting agriculture, were estimated at monthly intervals for one crop cycle.
Abstract: CO2 evolution, fungal biomass and microbial population of two maize field soils differing in agricultural systemsviz., permanent agriculture on plain lands in valleys and ‘slash and burn’ type of shifting agriculture, were estimated at monthly intervals for one crop cycle. The results showed significant positive correlation among CO2 evolution, fungal biomass, microbial population, organic C and total N. There was significant positive correlation between bacterial population and moisture content in both the agricultural systems. Microbial population and CO2 evolution were always higher in the soils of permanent agriculture as compared to that of ‘slash and burn’ type of shifting agriculture.
TL;DR: In this article, the validity of Vegard's law established the homogeneity of the solid solutions of strontium apatites and six of their solid solutions, spread over the entire compositional range, were characterized by chemical, X-ray, electron microscopic and infrared analyses.
Abstract: Samples of phosphate and arsenate apatites of strontium and six of their solid solutions, spread over the entire compositional range, were prepared by a wet method. They were characterized by chemical, X-ray, electron microscopic and infrared analyses. The validity of Vegard's law established the homogeneity of the solid solutions.
TL;DR: In this article, the effect of averaging interval, employed for data reduction, on the coherence widths as obtained from the autocorrelation function has been studied, and fluctuating features of the cross-sections turn out to be consistent with the statistical model expectations.
Abstract: The data on the ϑc.m.=180° excitation functions of12C+24Mg,12C* (4.43 MeV)+24Mg and12C+24Mg*(1.36 MeV) from 12.27 to 22.80 MeV, 16.53 to 27.47 MeV, and 11.33 to 26.40 MeV(c.m.) respectively have been subjected to statistical analysis. The effect of averaging interval, employed for data reduction, on the coherence widths as obtained from the autocorrelation function has been studied. The fluctuating features of the cross-sections turn out to be consistent with the statistical model expectations.
TL;DR: It is concluded that photosensitive and photorefractory female redheaded bunting monitor the photoperiodic time by means of a circadian rhythm.
TL;DR: In this paper, the laser Raman spectra of a solid state proton conductor MoO 3 · 2H 2 Ois reported with the d.c. field "on" and two new peaks at 795 and 414 cm −1 appeared in the laser-Raman spectra and their intensities grow with increasing time.
TL;DR: In this article, the authors used fits to the available data on the pion and deuteron electromagnetic form factors and the Chou-Yang model, and computed values of differential cross-sections for high energy pion-deuteron elastic scattering agree reasonably well with the available experimental data.
Abstract: Using fits to the available data on the pion and deuteron electromagnetic form factors and the Chou-Yang model, the computed values of differential cross-sections for high-energy pion-deuteron elastic scattering agree reasonably well with the available experimental data. Whereas only a shoulder is expected to appear up to energies of several hundreds of GeV, a dip and a secondary maximum are predicted to be conspicuous only forPlab≫400 GeV/C. The position of the dip starts at a much lower value, |td| ≅ 0.5–0.6 GeV2, as compared to the corresponding position in thepp scattering. The positions of the first dip are plotted against total cross-section which can be verified by future high-energy experiments. Limitations of the model predictions for ultrahigh energies are pointed out.
Journal Article•
TL;DR: It was concluded that cathepsin B can act for a limited period even at physiological temperature, pH, etc. before it is inactivated.
Abstract: Some properties of cathepsin B from a hitherto unstudied source (goat spleen) have been reported. The activity of the enzyme was optimal at pH 6.8 and it was fairly stable between pH 4.0-7.0. The maximum activity was observed at 37 degrees C and the enzyme could withstand temperature shocks up to 40 degrees C for 20 min without any significant loss of activity. Gamma-irradiation of the enzyme led to an increase in its activity in the beginning (up to 10 Gy) followed by a gradual decrease to about half of its activity at 1200 Gy. The enzyme was most active at an ionic strength of 0.022 and lost its activity substantially as the ionic strength was raised above the optimum value. The preferred protein substrate for the enzyme was found to be casein. The enzyme also hydrolyzed hemoglobin and serum albumin, but to lesser extents. In contrast to prevailing opinion, it was concluded that cathepsin B can act for a limited period even at physiological temperature, pH, etc. before it is inactivated.
TL;DR: In this article, sound velocities in methanol, ethanol, n-propanol, n -butanol, acetonitrile, carbon tetra- chloride and in their binary and ternary systems were measured in order to study the weak interaction between methanoline, ethanol and n-butanol in carbon tetrachloride.
Journal Article•
TL;DR: Both the immunoreactivity of both the fractions was regained when C-terminus of GnRH free acid was blocked by MDP-Lys, Lys or Ala-Ala-Thr-L Lys-Pro-Arg-OH indicating the importance of C- terminus amide in the recognition ability of antibodies.
Abstract: Monoclonal anti-GnRH(MoAb) antibodies generated by using azo-GnRH-TT conjugate were purified by affinity chromatography using azo-GnRH-BSA-Sepharose 4B column. The affinity column bound (A-MoAb) and unbound (U-MoAb) fractions were tested for immunoreactivity towards GnRH(NH2), azo-GnRH(NH2) and GnRH free acid and its fragments of sequence 4-6, 7-10 and 4-10. Both fractions reacted best with native GnRH and about 20 times less to azo-GnRH. The cross-reactivity with other GnRH(OH) fragments and affinity characteristics of A-MoAb, and U-MoAb was comparable with those of MoAb. The immunoreactivity of both the fractions was regained when C-terminus of GnRH free acid was blocked by MDP-Lys, Lys or Ala-Ala-Thr-Lys-Pro-Arg-OH indicating the importance of C-terminus amide in the recognition ability of antibodies.
TL;DR: The study reveals that algal community structural parameters like relative abundance and diversity could be, irrespective of the time of sampling, effectively used for monitoring the quality of effluents in oil refineries.
Abstract: Cyanophyta was the dominant algal group in the effluents of Mathura Oil Refinery and its relative abundance decreased with the removal of pollutants; the composition of this group, however, never decreased below 60%. Some members of Bacillariophyta and Chlorophyta were also recorded. Among the blue greens, Oscillatoria was the most abundant genus throughout and this is a reflection of the marked capability of this organism to withstand oil pollution. The diversity (d) of the algal community increased owing to the removal of oils and phenols in effluent treatment ponds. No marked seasonal variation in the abundance of various algal taxa and diversity was apparent. Even slight changes in the concentration of oil and phenol from 5.1 to 1.2 mg/l and 1.56 to 0.20 mg/l, respectively, resulted in an appreciable increase in diversity. The study reveals that algal community structural parameters like relative abundance and diversity could be, irrespective of the time of sampling, effectively used for monitoring the quality of effluents in oil refineries.
Journal Article•
TL;DR: Effect of salt concentration on the activity and stability of cathepsin B from buffalo spleen has been investigated and a 0.1 M sodium phosphate or other buffer of equivalent ionic strength has been recommended for storage of the enzyme.
Abstract: Effect of salt concentration on the activity and stability of cathepsin B from buffalo spleen has been investigated. Catheptic activity was maximal at a buffer concentration of 5.5 x 10(-3) M. The enzyme was, however, highly unstable at a salt concentration lower than 1.5 x 10(-2) M. The use of 0.02 M sodium phosphate buffer has been suggested for the assay of cathepsin B activity. For storage of the enzyme, however, a 0.1 M sodium phosphate or other buffer of equivalent ionic strength has been recommended.