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Sharma N.K.,Indira Gandhi National Tribal University
Biodiversity and Conservation | Year: 2015

Human activities have long been recognized as a major force shaping the biosphere. Advancing urbanization is one such transformation with unforeseen effect on the soil microbiota, including the cyanobacteria. This includes the loss of agronomically important nitrogen fixing cyanobacteria, which may negatively affect the agricultural productivity of peri-urban soils. However, empirical studies are lacking to validate the statement. Even, in journals specifically dealing with diversity and distribution of organisms, urban ecology and ecosystems. Here, I describe a critical area beset with challenges that needs to be investigated. © 2015, Springer Science+Business Media Dordrecht.

Das R.,CSIR - National Chemical Laboratory | Jaiswal A.,Indira Gandhi National Tribal University | Poddar P.,CSIR - National Chemical Laboratory
Journal of Physics D: Applied Physics | Year: 2013

Single-phase orthorhombic DyMnO3 and GdMnO3 nanoparticles in the size range 60-70 and 35-45 nm, respectively, were synthesized using a modified hydrothermal method. The magnetic property measurements of DyMnO3 nanocrystals show anomalies around ∼43 K (antiferromagnetic (AFM) coupling between Mn3+ spins) and at 7 K in the form of a peak in the zero-field-cooled curve (AFM coupling between Dy 3+ spins). Whereas, GdMnO3 undergoes a phase transition at ∼42 K from paramagnetic to an incommensurate-antiferromagnetic phase (ICAFM) followed by a second anomaly at ∼22 K, which could be associated with the transition from ICAFM into a canted A-type AFM ordering of the Mn 3+ spins. This transition is followed by a long-range ordering of the Gd3+ moments at 6 K yielding the canting of the Gd3+ spins with a ferromagnetic (FM) component antiparallel to the FM moment of the canted Mn3+ spins. No anomaly near the Néel temperature of the Mn moments for both DyMnO3 and GdMnO3 nanoparticles was observed in ac magnetization which were observed in dc magnetization. The room temperature Raman spectra of DyMnO3 shows two most intense Raman modes at 480 and 609 cm-1 which can be assigned to an antisymmetric Jahn-Teller stretching mode and a symmetric or breathing stretching mode, respectively, involving Mn-O bond stretching. © 2013 IOP Publishing Ltd.

Prasad C.P.,Skane University Hospital | Chaurasiya S.K.,Skane University Hospital | Chaurasiya S.K.,Indira Gandhi National Tribal University | Axelsson L.,Skane University Hospital | Andersson T.,Skane University Hospital
Molecular Oncology | Year: 2013

An important role for WNT-5A is implicated in a variety of tumors, including breast carcinoma. We previously showed that WNT-5A signaling inhibits migration and metastasis of breast cancer cells, and that patients with primary breast cancer in which WNT-5A was expressed have a better prognosis. Despite the fact that RhoGTPase Cdc42 is commonly associated with increased cell migration, we here show that recombinant WNT-5A activates the Cdc42 in breast cancer cells (lines MDA-MB468 and MDA-MB231) in a time-dependent manner. Activation of Cdc42 was also observed in MDA-MB468 cells that were stably transfected with a WNT-5A plasmid (MDA-MB468-5A). In all situations, increased Cdc42 activity was accompanied by decreased migration and invasion of the breast cancer cells. To explore these findings further we also investigated the effect of WNT-5A signaling on ERK1/2 activity. Apart from an initial Ca2+-dependent rWNT-5A-induced activation of ERK1/2, Cdc42 activity was inversely correlated with ERK1/2 activity in both rWNT-5A-stimulated parental MDA-MB468 and MDA-MB468-5A cells. We also demonstrated increased ERK1/2 activity in MDA-MB468-5A cells following siRNA knockdown of Cdc42. Consistent with these results, breast cancer cells transfected with constitutively active Cdc42 exhibited reduced ERK1/2 activity, migration and invasion, whereas cells transfected with dominant negative Cdc42 had increased ERK1/2 activity in response to rWNT-5A. To gain information on how ERK1/2 can mediate its effect on breast cancer cell migration and invasion, we next investigated and demonstrated that WNT-5A signaling and constitutively active Cdc42 both decreased matrix metalloproteinase 9 (MMP9) activity. These data indicate an essential role of Cdc42 and ERK1/2 signaling and MMP9 activity in WNT-5A-impaired breast cancer cells. © 2013 Federation of European Biochemical Societies.

Shukla P.N.,Banaras Hindu University | Pandey K.D.,Banaras Hindu University | Mishra V.K.,Banaras Hindu University | Mishra V.K.,Indira Gandhi National Tribal University
Critical Reviews in Environmental Science and Technology | Year: 2013

Methane (CH4) is one of the strongest greenhouse gases. Sources of CH4 are anthropogenic and natural, former playing ∼60% role. Major sink for CH4 are the atmospheric OH and Cl radicals (originating from CFCs), and biological system. Biological CH4 sink is mediated through the CH4 oxidation by the specialized group of bacteria called methanotrophs (MB). Methanotrophs have been reported from almost all the soil systems such as sediments, oceans, extremes of pH, salinity, and temperature. They oxidize methane aerobically in the presence of the enzyme methane monooxygenase (MMO). Anaerobic methane oxidation (AOM) also occurs in marine ecosystem where sulfate is final electron acceptor. Methanotrophs are of two types, first is cultured and low affinity group while the second is uncultured and high affinity group. Most of them can be grouped as Type I and Type II belonging to γ-and α-Proteobacteria, respectively. They may constitute up to 2% of total bacterial population in soil depending on physical factors such as water, temperature, soil depth, pH, texture, gaseous atmosphere (methane, oxygen, and CO2), soil organic content, and biological factors such as vegetation and microbial consortia. Besides, anthropogenic factors such as fertilizers, agro-and organochemicals, and land use pattern have strong influence over them. Global climate change including acid rain, high temperature, increasing rainfall, and drought have potential to affect the global methane sink activity. The authors attempt to review the recent advances made regarding CH4 oxidation and methanotrophic population size as well as community structure as affected by the various natural and anthropogenic factors. © 2013 Taylor and Francis Group, LLC.

Shrivas K.,Guru Ghasidas University | Dewangan K.,Indira Gandhi National Tribal University
Journal of Surfactants and Detergents | Year: 2015

A technique of selective and sensitive surfactant-assisted dispersive liquid-liquid microextraction combined with spectrophotometry was developed for determination of iron in water and food samples. This method involves the formation of a red-colored iron-thiocyanate complex in the presence of cetyltrimethylammonium bromide (CTAB) as cationic surfactant. The use of CTAB assisted in color formation and effective extraction of the complex into the organic solvent through micelle formation prior to spectrophotometric and flame atomic absorption spectrometry measurement. Optimum absorbance and extraction of the iron complex was obtained with concentrations of ammonium thiocyanate, N-phenylbenzimidoyl thiourea, CTAB and sodium chloride of 0.30 M, 3.0 × 10-3 M, 0.40 × 10-3 M and 1.0 %, respectively. The calibration curve was linear over a range of 20-350 ng mL-1 iron with correlation of estimation (R 2) of 0.997. The proposed method was successfully applied to the determination of iron in food (cereal, fruit and vegetable) and water samples. © 2015 AOCS.

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