Mahata M.,University of California at San Diego |
Zhang K.,University of California at San Diego |
Nandi S.,University of California at San Diego |
Brar B.K.,University of California at San Diego |
And 7 more authors.
Cell and Tissue Research | Year: 2011
Pituitary adenylyl cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) augment the biosynthesis of tyrosine hydroxylase (TH). We tested whether secretin belonging to the glucagon/PACAP/VIP superfamily would increase transcription of the tyrosine hydroxylase (Th) gene and modulate catecholamine secretion. Secretin activated transcription of the endogenous Th gene and its transfected promoter (EC50 ∼4.6 nM) in pheochromocytoma (PC12) cells. This was abolished by pre-treatment with a secretin receptor (SCTR) antagonist and by inhibition of protein kinase A (PKA), mitogen-activated protein kinase, or CREB (cAMP response element-binding protein). In agreement, secretin increased PKA activity and induced phosphorylation of CREB and binding to Th CRE, suggesting secretin signaling to transcription via a PKA-CREB pathway. Secretin stimulated catecholamine secretion (EC50 ∼3.5 μM) from PC12 cells, but this was inhibited by pre-treatment with VIP-preferring receptor (VPAC1)/PACAP-preferring receptor (PAC1) antagonists. Secretin-evoked secretion occurred without extracellular Ca2+ and was abolished by intracellular Ca2+ chelation. Secretin augmented phospholipase C (PLC) activity and increased inositol-1,4,5-triphosphate (IP3) levels in PC12 cells; PLC-β inhibition blocked secretin-induced catecholamine secretion, indicating the participation of intracellular Ca2+ from a phospholipase pathway in secretion. Like PACAP, secretin evoked long-lasting catecholamine secretion, even after only a transient exposure. Thus, transcription is triggered by nanomolar concentrations of the peptide through SCTR, with signaling along the cAMP-PKA and extracellular-signal-regulated kinase 1/2 pathways and through CREB. By contrast, secretion is triggered only by micromolar concentrations of peptide through PAC1/VPAC receptors and by utilizing a PLC/intracellular Ca 2+ pathway. © 2011 Springer-Verlag.
Akhouri B.P.,Birsa College |
Akhtar K.,Ranchi College
Oriental Journal of Chemistry | Year: 2016
Analysis of the equations of state of the hard convex body chain and hard spheres has been done for predicting the vapor liquid equilibrium of simple fluids of n-alkanes. The repulsive part of the Boublik equation of state for the hard convex body chain has been found as an equivalent alternative either for the well known Carnahan-Starling repulsive term or the established van der Waals repulsive part of hard spheres equations of state. The attractive parts of these equations of state have the similar form as that of the van der Waals and are obeying the power-law temperature dependency. Add-on separation method of compressibility factor has been used for these equations of state. The simulated data for VLE densities from these equations of state are found to agree well with the available experimental data for n-alkane fuids.
Singh N.,Ranchi College |
Varshney D.,Devi Ahilya University |
Kapoor A.,Ranchi University |
Dey S.K.,Ranchi University
Optik | Year: 2013
The propagation characteristics of electromagnetic waves through eccentric core optical fibers have been discussed making use of scalar wave equation in conjunction with Graf's addition theorem for cylindrical Bessel's functions. The system under investigation consists of three media with eccentric location of the inner core region. This makes the system birefringent and lifts up the degeneracy present in the corresponding structure with cylindrically symmetric inner core region. Furthermore, the birefringence increases with the increase in eccentricity up to an allowed limit dictated by the geometrical parameters of the system and makes the propagation truly single mode single polarization. © 2013 Elsevier GmbH. All rights reserved.
Allu P.K.R.,Indian Institute of Technology Madras |
Chakraborty B.,Ranchi University |
Das M.,University of Calcutta |
Mahapatra N.R.,Indian Institute of Technology Madras |
Ghosh S.,Ranchi College
Aquaculture International | Year: 2014
High consumer preference together with its polyculture potential has undoubtedly driven Rohu (Labeo rohita) and Catla (Catla catla) to top the list of the most preferred fishes among the Indian major carps. Commonly found in these fishes are hybrids that can be natural or man-made. Increasing emphasis on biodiversity issues has necessitated proper stock management of these through molecular genetics techniques. Also with few morphological differences that can be used to differentiate wild types and hybrids properly, the problem demands a straightforward molecular approach. Here, we report a simple PCR-based technique that can differentiate the hybrid variety from wild types easily using three different microsatellite markers. Three sets of primers were used to amplify three different microsatellite markers from the genomic DNA isolated from pectoral fins. When the PCR products using all three primer sets were analyzed, 'hybrid-Rohu' could be distinguished from wild types. Whereas the hybrid-Rohu DNA yielded specific PCR products with all three primer pairs, only two PCR products were obtained either from wild-type Catla DNA (by primer sets 1 and 2) or from wild-type Rohu DNA (by primer sets 1 and 3). This study clearly demonstrates that a simple PCR-based technique will help the fish breeders and hatcheries to identify and differentiate suspected hybrid-Rohu carp from the wild types within a few hours. © 2013 Springer Science+Business Media Dordrecht.
Srivastava R.,J N College |
Gupta D.K.,J N College |
Choudhary A.K.,K C B College |
Sinha M.P.,Ranchi College
Nature Environment and Pollution Technology | Year: 2013
Biomass variation, secondary production and turn-over of the earthworm Drawida willsi (Michaelsen) was assessed from a tropical agroecosystem site at Ranchi for 18 months. The total biomass ranged between 0.88 ± 0.33 and 29.55 ± 3.15 g dry weight m-2. Secondary production of 53.37 g dry weight m-2 yr-1 was obtained which in terms of calorific value amounts to 246.57 kcal m-2 yr-1. Biomass turnover value was 4.99.
Kapil J.C.,Snow and Avalanche Study Establishment SASE |
Kumar A.,Ranchi College |
Negi P.S.,Snow and Avalanche Study Establishment SASE
Annals of Glaciology | Year: 2010
Under melt-freeze conditions crusts may evolve within a snowpack, which may favour avalanche initiation by forming a hard bed surface for weakly bonded faceted grains. We used a parallelprobe saturation profiler (PPSP) to record the distribution of water contents within the snowpack. Diurnal effects of melt-freeze action on the growth of crusts were monitored with the help of the PPSP device. Saturation profiles were collected from a partially wet snow cover. Snow stratigraphy was conducted manually in the morning, after overnight freezing, to identify the location and the granular compositions of the crusts that had evolved. A one-to-one correspondence between the saturation spikes collected using the PPSP and the actual positions of the crusts was established. The PPSP was also used to monitor three-dimensional variations in the maximum percolation depths within a south-facing snowpack. The operation of the PPSP is faster than existing dielectric measurement techniques, so it was applied to study the spatial variability of maximum percolation depths on the slopes of different aspects.
Saw S.K.,Central Instrumentation Facility |
Akhtar K.,Ranchi College |
Yadav N.,BIT |
Singh A.K.,Central Instrumentation Facility
Journal of Natural Fibers | Year: 2014
The action of water in natural fiber-reinforced composite material was studied so as to produce great swelling with resultant changes in the fine structure, dimensional stability, and mechanical properties. Water absorption and thickness swelling test reveal that hybrid composite shows water absorption moderately, which is 15.3% for hybrid coir/jute/coir composite and 11.2% for hybrid jute/coir/jute composite. The thickness swelling, water absorption, and mechanical properties of the hybrid composites slightly increased as the layering pattern of hybrid composites changed. Hybridization of coir fibers composites with jute fibers can improve the dimensional stability, extensibility and density of pure coir composites. Microstructures of the composites were examined to understand the mechanisms for the fiber-matrix interaction in relation to mechanical properties. © 2014 Copyright © Taylor & Francis Group, LLC.
Mukherjee B.,Ranchi College |
Nivedita M.,Ranchi College |
Mukherjee D.,Ranchi College
Journal of Environmental Biology | Year: 2014
Modelling system dynamics in a hyper-eutrophic lake is quite complex especially with a constant influx of detergents and sewage material which continually changes the state variables and interferes with the assessment of the chemical rhythm occurring in polluted conditions as compared to unpolluted systems. In this paper, a carbon and nutrient mass balance model for predicting system dynamics in a complex environmentwas studied. Studies were conducted at Ranchi lake to understand the altered environmental dynamics in hyper-eutrophic conditions, and its impact on the plankton community. The lake was monitored regularly for five years (2007-2011) and the data collected on the carbon flux, nitrates, phosphates and silicates was used to design a mass balance model for evaluating and predicting the system. The model was then used to correlate the chemical rhythm with that of the phytoplankton dynamics and diversity. Nitrates and phosphates were not limiting (mean nitrate and phosphate concentrations were 1.74 and 0.83 mgl-1 respectively). Free carbon dioxide was found to control the system and, interacting with other parameters determined the diversity and dynamics of the plankton community. N/P ratio determined which group of phytoplankton dominated the community, above 5 it favoured the growth of chlorophyceae while below 5 cyanobacteria dominates. TOC/TIC ratio determined the abundance. The overall system was controlled by the availability of free carbon dioxide which served as a limiting factor. © Triveni Enterprises, Lucknow (India).
Roy N.K.,Ranchi College
Journal of Failure Analysis and Prevention | Year: 2014
Vanadium microalloyed hot rolled steel of 13.8 mm thickness, when hot formed at 900 °C into axle housings were rejected because of a prominent crack running along the length of the component. A detailed metallurgical investigation revealed that the cracking during forming was the result of the opening up of pre-existing fine crack along the length of the hot rolled coils. These crackswere barely visible on the hot rolled coils thatwere formed into the axle housings. Metallographic and hardness tests indicated that these cracks might have been generated as a result of decarburization of the slab during soaking that led to a softer surface layer of the slab. During subsequent hot rolling mechanical defect might have been caused on the decarburized surface that is much softer than a material with a usual carbon content. It was concluded that soaking in the reheating furnacewith lowcarbon potential might have led to extensive decarburization of the slabs. Soaking in a furnace atmosphere with adequate carbon potential was recommended as a remedial measure to prevent decarburization of the surface layers of the slabs. © ASM International 2014.