187 research outputs found

    Glucose induced in-situ reduction of chloroaurate ions entrapped in a fatty amine film: formation of gold nanoparticle-lipid composites

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    The formation of gold nanoparticle-lipid composite films by glucose-induced reduction of chloroaurate ions entrapped in thermally evaporated fatty amine films is described. Simple immersion of films of the salt of octadecylamine and chloroaurate ions (formed by immersion of thermally evaporated fatty amine films in chloroauric acid solution) in glucose solution leads to the facile in-situ reduction of the metal ions to form gold nanoparticles in the fatty amine matrix. The formation of gold nanoparticles is readily detected by the appearance of a violet color in the film and thus forms the basis of a possible new, gold nanoparticle-based colorimetric sensor for glucose. The formation of the fatty amine salt of chloroauric acid and the subsequent reduction of the metal ions by glucose has been followed by quartz crystal microgravimetry, Fourier transform infrared spectroscopy, X-ray photoemission spectroscopy and transmission electron microscopy measurements

    Isolation of Two Strong Poly (U) Binding Proteins from Moderate Halophile Halomonas eurihalina and Their Identification as Cold Shock Proteins

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    Cold shock proteins (Csp) are known to be expressed in response to sudden decrease in temperature. They are thought to be involved in a number of cellular processes viz., RNA chaperone activity, translation, transcription, nucleoid condensation. During our studies on ribosomal protein S1 in moderate halophile Halomonas eurihalina, we observed the presence of two strong poly (U) binding proteins in abundance in cell extracts from cells grown under normal growth conditions. The proteins can be isolated in a single step using Poly (U) cellulose chromatography. The proteins were identified as major cold shock proteins belonging to Csp A family by MALDI-TOF and bioinformatic analysis. Csp 12 kDa was found in both exponential and stationary phases whereas Csp 8 kDa is found only in exponential phase

    Unravelling the Mechanism of Summer Monsoon Rainfall Modes over the West Coast of India using Model Simulations

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    A transition from a predominantly offshore to an onshore rainfall phase over the west coast of India was simulated using three one-way nested domains with 12-, 4-, and 1.33-km horizontal grid spacing in the Weather Research and Forecasting model. The mechanism of offshore-onshore rainfall oscillation and the orographic effects of the Western Ghats are studied. A convective parameterization scheme was employed only in the 12-km domain. A trough extending offshore from the west coast facilitates offshore rainfall. This trough is absent during the onshore phase, and rainfall occurs over the coast mainly via orographic uplift by the Western Ghats. The model overestimates rainfall over the Western Ghats at all resolutions as it consistently underestimates the boundary layer stratification along the coast. Weaker stratification weakens the blocking effect of the Western Ghats, resulting in anomalous deep convection and rainfall over its windward slopes. The 4- and 1.33-km domains simulate the offshore-to-onshore transition of rainfall but fail to capture a sufficient contrast in rainfall between land and sea compared to observations. The 12-km domain produces light rainfall, anchored along the coast, throughout the simulation period, and hence gravely underestimates the offshore rainfall. The offshore rainfall persisted in the 4- and 1.33-km domains in a sensitivity experiment in which the Western Ghats were flattened. This suggests that orographic effects do not significantly influence offshore rainfall. In another experiment, the convective parameterization scheme in the 12-km domain was turned off. This experiment simulated the offshore and onshore rainfall phases correctly to some extent but the rainfall intensity was unrealistically high. Thus, a model with a horizontal grid spacing of O(∼ 1 km), in which convection evolves explicitly, is desired for simulating the west coast rainfall variations. However, improvements in the representation of boundary layer processes are needed to capture the land-sea contrast

    Groundwater recharge and age-depth profiles of intensively exploited groundwater resources in northwest India

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    Intensive irrigation in northwest India has led to growing concerns over the sustainability of current and future groundwater abstraction. Environmental tracers and measurements of groundwater residence times can help quantify the renewal processes. Results from 16 paired locations show the interquartile ranges for residence times in shallow alluvial groundwater (8–50 m deep) to be 1–50 years and significantly less than those from deeper groundwater (76–160 m deep) at 40–170 years. The widespread occurrence of modern tracers in deep groundwater (>60% of sites had >10% modern recharge) suggests that there is low regional aquifer anisotropy and that deep aquifers are recharged by a significant component of recent recharge via vertical leakage. Stable isotope and noble gas results at all depths conform to modern meteoric sources and annual average temperatures, with no evidence of significant regional recharge from canal leakage in this study area close to the Himalayas

    A Novel Cold-Regulated Cold Shock Domain Containing Protein from Scallop Chlamys farreri with Nucleic Acid-Binding Activity

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    Background: The cold shock domain (CSD) containing proteins (CSDPs) are one group of the evolutionarily conserved nucleic acid-binding proteins widely distributed in bacteria, plants, animals, and involved in various cellular processes, including adaptation to low temperature, cellular growth, nutrient stress and stationary phase. Methodology: The cDNA of a novel CSDP was cloned from Zhikong scallop Chlamys farreri (designated as CfCSP) by expressed sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE) approach. The full length cDNA of CfCSP was of 1735 bp containing a 927 bp open reading frame which encoded an N-terminal CSD with conserved nucleic acids binding motif and a C-terminal domain with four Arg-Gly-Gly (RGG) repeats. The CSD of CfCSP shared high homology with the CSDs from other CSDPs in vertebrate, invertebrate and bacteria. The mRNA transcripts of CfCSP were mainly detected in the tissue of adductor and also marginally detectable in gill, hepatopancreas, hemocytes, kidney, mantle and gonad of healthy scallop. The relative expression level of CfCSP was up-regulated significantly in adductor and hemocytes at 1 h and 24 h respectively after low temperature treatment (P,0.05). The recombinant CfCSP protein (rCfCSP) could bind ssDNA and in vitro transcribed mRNA, but it could not bind dsDNA. BX04, a cold sensitive Escherichia coli CSP quadruple-deletion mutant, was used to examine the cold adaptation ability of CfCSP. After incubation at 17uC for 120 h, the strain of BX04 containing the vector pINIII showed growth defect and failed to form colonies, while strain containing pINIII-CSPA or pINIII

    WriteSim TCExam - An open source text simulation environment for training novice researchers in scientific writing

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    BACKGROUND: The ability to write clearly and effectively is of central importance to the scientific enterprise. Encouraged by the success of simulation environments in other biomedical sciences, we developed WriteSim TCExam, an open-source, Web-based, textual simulation environment for teaching effective writing techniques to novice researchers. We shortlisted and modified an existing open source application - TCExam to serve as a textual simulation environment. After testing usability internally in our team, we conducted formal field usability studies with novice researchers. These were followed by formal surveys with researchers fitting the role of administrators and users (novice researchers) RESULTS: The development process was guided by feedback from usability tests within our research team. Online surveys and formal studies, involving members of the Research on Research group and selected novice researchers, show that the application is user-friendly. Additionally it has been used to train 25 novice researchers in scientific writing to date and has generated encouraging results. CONCLUSION: WriteSim TCExam is the first Web-based, open-source textual simulation environment designed to complement traditional scientific writing instruction. While initial reviews by students and educators have been positive, a formal study is needed to measure its benefits in comparison to standard instructional methods

    Scientific writing: a randomized controlled trial comparing standard and on-line instruction

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    <p>Abstract</p> <p>Background</p> <p>Writing plays a central role in the communication of scientific ideas and is therefore a key aspect in researcher education, ultimately determining the success and long-term sustainability of their careers. Despite the growing popularity of e-learning, we are not aware of any existing study comparing on-line vs. traditional classroom-based methods for teaching scientific writing.</p> <p>Methods</p> <p>Forty eight participants from a medical, nursing and physiotherapy background from US and Brazil were randomly assigned to two groups (n = 24 per group): An on-line writing workshop group (on-line group), in which participants used virtual communication, google docs and standard writing templates, and a standard writing guidance training (standard group) where participants received standard instruction without the aid of virtual communication and writing templates. Two outcomes, manuscript quality was assessed using the scores obtained in Six subgroup analysis scale as the primary outcome measure, and satisfaction scores with Likert scale were evaluated. To control for observer variability, inter-observer reliability was assessed using Fleiss's kappa. A post-hoc analysis comparing rates of communication between mentors and participants was performed. Nonparametric tests were used to assess intervention efficacy.</p> <p>Results</p> <p>Excellent inter-observer reliability among three reviewers was found, with an Intraclass Correlation Coefficient (ICC) agreement = 0.931882 and ICC consistency = 0.932485. On-line group had better overall manuscript quality (p = 0.0017, SSQSavg score 75.3 ± 14.21, ranging from 37 to 94) compared to the standard group (47.27 ± 14.64, ranging from 20 to 72). Participant satisfaction was higher in the on-line group (4.3 ± 0.73) compared to the standard group (3.09 ± 1.11) (p = 0.001). The standard group also had fewer communication events compared to the on-line group (0.91 ± 0.81 vs. 2.05 ± 1.23; p = 0.0219).</p> <p>Conclusion</p> <p>Our protocol for on-line scientific writing instruction is better than standard face-to-face instruction in terms of writing quality and student satisfaction. Future studies should evaluate the protocol efficacy in larger longitudinal cohorts involving participants from different languages.</p

    Deep Eutectic Solvents (DESs) and their applications [forthcoming]

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    Deep Eutectic Solvents (DESs) and Their Application
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