126 research outputs found

    Integrated Approach for Stabilisation of Varunavat Parvat Landslide – A Case Study

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    Uttarkashi Township, located on the toe of the Varunavat Parvat, in the State of Uttarakhand in North India is known for having a history of a number of natural disasters. One of such disaster was a major landslide on the slopes of the Varunavat Parvat, in the year 2003. There had been huge loss of property of residential complexes, office buildings, hotels and many other business apartments. The risk of further such slides continuously hovered over the town which was the serious concern of District and State Authorities. An integrated approach of long term stabilization measures with flattening of slopes with suitable berms, effective drainage arrangement (surface & sub-surface), suitable erosion control measures , multistage protection measures by providing catch pits, wide platforms, retaining walls and construction of tunnel on the national highway for mitigating the rock fall hazards are being adopted, to minimize the impact of disaster in future so that people of Uttarkashi Town can live safely without fear. The paper highlights the description of the problem, probable causes of the Landslide, Geology of the area, stability analysis, measures adopted for averting future landslide and subsequent rock fall hazard

    Initial Filling of Tehri Reservoir — Analysis of Seepage Data

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    Initial Filling of reservoirs in dams, particularly the embankment type, is a very important phase as unusual behaviour / accidents of many dams have been reported during this period. A regular observation / analysis of quantum of seepage vis-à-vis the reservoir level is a significant activity so that any serious development inside the body of dam and foundation / abutments rocks are revealed in advance and remedial measures are taken up timely to prevent catastrophic failures. At Tehri, a 260.5m high earth & rockfill dam has been constructed across river Bhagirathi, a tributary of mighty river Ganga in India. Seepage discharge data of first two years of Initial Filling of Tehri reservoir has been analysed, which has led to a few important conclusions. The Analysis of Seepage data for the Initial Filling of Tehri reservoir is presented in the paper

    Initial Filling of Tehri Reservoir — Analysis of Seepage Data

    Get PDF
    Initial Filling of reservoirs in dams, particularly the embankment type, is a very important phase as unusual behaviour / accidents of many dams have been reported during this period. A regular observation / analysis of quantum of seepage vis-à-vis the reservoir level is a significant activity so that any serious development inside the body of dam and foundation / abutments rocks are revealed in advance and remedial measures are taken up timely to prevent catastrophic failures. At Tehri, a 260.5m high earth & rockfill dam has been constructed across river Bhagirathi, a tributary of mighty river Ganga in India. Seepage discharge data of first two years of Initial Filling of Tehri reservoir has been analysed, which has led to a few important conclusions. The Analysis of Seepage data for the Initial Filling of Tehri reservoir is presented in the paper

    ProteinHistorian: Tools for the Comparative Analysis of Eukaryote Protein Origin

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    The evolutionary history of a protein reflects the functional history of its ancestors. Recent phylogenetic studies identified distinct evolutionary signatures that characterize proteins involved in cancer, Mendelian disease, and different ontogenic stages. Despite the potential to yield insight into the cellular functions and interactions of proteins, such comparative phylogenetic analyses are rarely performed, because they require custom algorithms. We developed ProteinHistorian to make tools for performing analyses of protein origins widely available. Given a list of proteins of interest, ProteinHistorian estimates the phylogenetic age of each protein, quantifies enrichment for proteins of specific ages, and compares variation in protein age with other protein attributes. ProteinHistorian allows flexibility in the definition of protein age by including several algorithms for estimating ages from different databases of evolutionary relationships. We illustrate the use of ProteinHistorian with three example analyses. First, we demonstrate that proteins with high expression in human, compared to chimpanzee and rhesus macaque, are significantly younger than those with human-specific low expression. Next, we show that human proteins with annotated regulatory functions are significantly younger than proteins with catalytic functions. Finally, we compare protein length and age in many eukaryotic species and, as expected from previous studies, find a positive, though often weak, correlation between protein age and length. ProteinHistorian is available through a web server with an intuitive interface and as a set of command line tools; this allows biologists and bioinformaticians alike to integrate these approaches into their analysis pipelines. ProteinHistorian's modular, extensible design facilitates the integration of new datasets and algorithms. The ProteinHistorian web server, source code, and pre-computed ages for 32 eukaryotic genomes are freely available under the GNU public license at http://lighthouse.ucsf.edu/ProteinHistorian/

    Synonymous Codon Ordering: A Subtle but Prevalent Strategy of Bacteria to Improve Translational Efficiency

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    Background: In yeast coding sequences, once a particular codon has been used, subsequent occurrence of the same amino acid tends to use codons sharing the same tRNA. Such a phenomenon of co-tRNA codons pairing bias (CTCPB) is also found in some other eukaryotes but it is not known whether it occurs in prokaryotes. Methodology/Principal Findings: In this study, we focused on a total of 773 bacterial genomes to investigate their synonymous codon pairing preferences. After calculating the actual frequencies of synonymous codon pairs and comparing them with their expected values, we detected an obvious pairing bias towards identical codon pairs. This seems consistent with the previously reported CTCPB phenomenon, since identical codons are certainly read by the same tRNA. However, among co-tRNA but non-identical codon pairs, only 22 were often found overrepresented, suggesting that many co-tRNA codons actually do not preferentially pair together in prokaryotes. Therefore, the previously reported co-tRNA codons pairing rule needs to be more rigorously defined. The affinity differences between a tRNA anticodon and its readable codons should be taken into account. Moreover, both within-gene-shuffling tests and phylogenetic analyses support the idea that translational selection played an important role in shaping the observed synonymous codon pairing pattern in prokaryotes. Conclusions: Overall, a high level of synonymous codon pairing bias was detected in 73 % investigated bacterial species

    In-situ local phase-transitioned MoSe2 in La0.5Sr0.5CoO3-?? heterostructure and stable overall water electrolysis over 1000 hours

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    Developing efficient bifunctional catalysts for overall water splitting that are earth-abundant, cost-effective, and durable is of considerable importance from the practical perspective to mitigate the issues associated with precious metal-based catalysts. Herein, we introduce a heterostructure comprising perovskite oxides (La0.5Sr0.5CoO3?????) and molybdenum diselenide (MoSe2) as an electrochemical catalyst for overall water electrolysis. Interestingly, formation of the heterostructure of La0.5Sr0.5CoO3????? and MoSe2 induces a local phase transition in MoSe2, 2???H to 1???T phase, and more electrophilic La0.5Sr0.5CoO3????? with partial oxidation of the Co cation owing to electron transfer from Co to Mo. Together with these synergistic effects, the electrochemical activities are significantly improved for both hydrogen and oxygen evolution reactions. In the overall water splitting operation, the heterostructure showed excellent stability at the high current density of 100???mA???cm???2 over 1,000???h, which is exceptionally better than the stability of the state-of-the-art platinum and iridium oxide couple

    Structure and Age Jointly Influence Rates of Protein Evolution

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    What factors determine a protein's rate of evolution are actively debated. Especially unclear is the relative role of intrinsic factors of present-day proteins versus historical factors such as protein age. Here we study the interplay of structural properties and evolutionary age, as determinants of protein evolutionary rate. We use a large set of one-to-one orthologs between human and mouse proteins, with mapped PDB structures. We report that previously observed structural correlations also hold within each age group – including relationships between solvent accessibility, designabililty, and evolutionary rates. However, age also plays a crucial role: age modulates the relationship between solvent accessibility and rate. Additionally, younger proteins, despite being less designable, tend to evolve faster than older proteins. We show that previously reported relationships between age and rate cannot be explained by structural biases among age groups. Finally, we introduce a knowledge-based potential function to study the stability of proteins through large-scale computation. We find that older proteins are more stable for their native structure, and more robust to mutations, than younger ones. Our results underscore that several determinants, both intrinsic and historical, can interact to determine rates of protein evolution

    Proteins with Complex Architecture as Potential Targets for Drug Design: A Case Study of Mycobacterium tuberculosis

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    Lengthy co-evolution of Homo sapiens and Mycobacterium tuberculosis, the main causative agent of tuberculosis, resulted in a dramatically successful pathogen species that presents considerable challenge for modern medicine. The continuous and ever increasing appearance of multi-drug resistant mycobacteria necessitates the identification of novel drug targets and drugs with new mechanisms of action. However, further insights are needed to establish automated protocols for target selection based on the available complete genome sequences. In the present study, we perform complete proteome level comparisons between M. tuberculosis, mycobacteria, other prokaryotes and available eukaryotes based on protein domains, local sequence similarities and protein disorder. We show that the enrichment of certain domains in the genome can indicate an important function specific to M. tuberculosis. We identified two families, termed pkn and PE/PPE that stand out in this respect. The common property of these two protein families is a complex domain organization that combines species-specific regions, commonly occurring domains and disordered segments. Besides highlighting promising novel drug target candidates in M. tuberculosis, the presented analysis can also be viewed as a general protocol to identify proteins involved in species-specific functions in a given organism. We conclude that target selection protocols should be extended to include proteins with complex domain architectures instead of focusing on sequentially unique and essential proteins only
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