43 research outputs found

    Peristaltic flow and hydrodynamic dispersion of a reactive micropolar fluid-simulation of chemical effects in the digestive process

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    The hydrodynamic dispersion of a solute in peristaltic flow of a reactive incompressible micropolar biofluid is studied as a model of chyme transport in the human intestinal system with wall effects. The long wavelength approximation, Taylor's limiting condition and dynamic boundary conditions at the flexible walls are used to obtain the average effective dispersion coefficient in the presence of combined homogeneous and heterogeneous chemical reactions. The effects of various pertinent parameters on the effective dispersion coefficient are discussed. It is observed that average effective dispersion coefficient increases with amplitude ratio which implies that dispersion is enhanced in the presence of peristalsis. Furthermore average effective dispersion coefficient is also elevated with the micropolar rheological and wall parameters. Conversely dispersion is found to decrease with cross viscosity coefficient, homogeneous and heterogeneous chemical reaction rates. The present simulations provide an important benchmark for future chemo-fluid-structure interaction computational models

    Polyamide-Scorpion Cyclam Lexitropsins Selectively Bind AT-Rich DNA Independently of the Nature of the Coordinated Metal

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    Cyclam was attached to 1-, 2- and 3-pyrrole lexitropsins for the first time through a synthetically facile copper-catalyzed “click” reaction. The corresponding copper and zinc complexes were synthesized and characterized. The ligand and its complexes bound AT-rich DNA selectively over GC-rich DNA, and the thermodynamic profile of the binding was evaluated by isothermal titration calorimetry. The metal, encapsulated in a scorpion azamacrocyclic complex, did not affect the binding, which was dominated by the organic tail

    Variations of Flexor Digitorum Superficialis and Lumbrical Muscles of the Hand: A Study in South Indian Cadavers

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    A study on the variations of the forearm and hand muscles was carried out at the Kasturba Medical College International Centre, Manipal, India. Eighty one limbs were included in the study. In 2 limbs (2.46%) the flexor digitorum superficialis muscle (FDS) had only three tendons; Accessory bellies of the FDS were found in 22 limbs (27.16%); The accessory belly of FDS was dividing into two tendons in 1 limb (1.23%) and in 2 limbs (2.46%), a high origin (in the carpal tunnel) of lumbricals was noted. The variations reported here may be of importance for the orthopedic surgeons, plastic surgeons and other medical disciplines.Keywords: Flexor digitorum superficialis, Lumbrical, Muscle variation, Forearm, Additional bell

    Evaluation of gene prediction software using a genomic data set: application to Arabidopsis thaliana sequences

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    Motivation: The annotation of the Arabidopsis thaliana genome remains a problem in terms of time and quality. To improve the annotation process, we want to choose the most appropriate tools to use inside a computer-assisted annotation platform. We therefore need evaluation of prediction programs with Arabidopsis sequences containing multiple genes. Results: We have developed AraSet, a data set of contigs of validated genes, enabling the evaluation of multi-gene models for the Arabidopsis genome. Besides conventional metrics to evaluate gene prediction at the site and the exon levels, new measures were introduced for the prediction at the protein sequence level as well as for the evaluation of gene models. This evaluation method is of general interest and could apply to any new gene prediction software and to any eukaryotic genome. The GeneMark.hmm program appears to be the most accurate software at all three level's for the Arabidopsis genomic sequences. Gene modeling could be further improved by combination of prediction software

    Protected areas and biodiversity conservation in India

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    Three well-supported generalizations in conservation biology are that developing tropical countries will experience the greatest biodiversity declines in the near future, they are some of the least studied areas in the world, and in these regions especially, protection requires local community support. We assess these generalizations in an evaluation of protected areas in India. The 5% of India officially protected covers most ecoregions and protected areas have been an important reason why India has suffered no documented species extinctions in the past 70 years. India has strong legislation favouring conservation, government investment focused on 50 Tiger Reserves, and government compensation schemes that facilitate local support, all of which brighten future prospects. However, many protected areas are too small to maintain a full complement of species, making connectivity and species use of buffer zones a crucial issue. Conservation success and challenges vary across regions according to their development status. In less developed areas, notably the biodiverse northeast Himalaya, protected areas maintaining the highest biodiversity result from locally-focused efforts by dedicated individuals. Across India, we demonstrate considerable opportunities to increase local income through ecotourism. Our evaluation confirms a lack of data, increasing threats, and the importance of local support. Research on biodiversity in buffer zones, development of long-term monitoring schemes, and assessment of cash and conservation benefits from tourism are in particular need. For policy makers, two main goals should be the development of monitoring plans for ‘eco-sensitive zones’ around protected areas, and a strong emphasis on preserving established protected areas

    Computational identification of promoters and first exons in the human genome

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    The identification of promoters and first exons has been one of the most difficult problems in gene-finding. We present a set of discriminant functions that can recognize structural and compositional features such as CpG islands, promoter regions and first splice-donor sites. We explain the implementation of the discriminant functions into a decision tree that constitutes a new program called FirstEF. By using different models to predict CpG-related and non-CpG-related first exons, we showed by cross-validation that the program could predict 86% of the first exons with 17% false positives. We also demonstrated the prediction accuracy of FirstEF at the genome level by applying it to the finished sequences of human chromosomes 21 and 22 as well as by comparing the predictions with the locations of the experimentally verified first exons. Finally, we present the analysis of the predicted first exons for all of the 24 chromosomes of the human genome
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