168 research outputs found

    Estimation of combining ability for yield and yield component traits in upland rice (Oryza Sativa L.) of Uttarakhand hills

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    Combining ability for grain yield and its component characters in rainfed upland rice (Oryza sativa L.) were studied during Kharif 2014 using half diallel involving ten parents viz., VL Dhan 221, Vivek Dhan 154, VL 30240, VL 7620, VL 30560, VL 8116, VL 8549, VL 8724, VL 8732 and Sukradhan1. Both general combining ability (gca) and specific combining ability (sca) variances were found to be highly significant for the characters viz., plant height (gca=85.42; sca=23.12), days to 50% flowering (gca=101.61; sca=42.61), days to maturity (gca=90.37; sca=37.73), tillers per plant (gca=4.63; sca=1.38), panicle per plant (gca=2.36; sca=0.90),kernel length (gca=28.88; sca=23.61), kernel width (gca=1.64; sca=1.92),1000 grain weight (gca=3.60; sca=4.91), grain yield per plot (gca=8.57; sca=3.03), fertile grains per panicle (gca=690.67; sca=300.95) and grains per panicle (gca=1050.58; sca=437.75) indicating the importance of additive and non-additive gene actions in the expression of these traits. However, predominance of non-additive gene action was recorded for all the characters. Parents VL Dhan 221, VL 7620, VL 30560, Sukradhan 1 were good general combiners for grain yield and related characters. VL Dhan 221 and Vivek Dhan 154 were good general combiners for plant height and earliness. On the basis of specific combining ability effects, cross combinations Vivek Dhan 154 x VL 8549, VL 7620 x VL 30560, VL 8549 x VL 8732, VL 30560 x VL 8116 and VL 30240 x VL 8116 were the best specific combiner for grain yield per plot and other associated characters viz., plant height, days to 50% flowering, days to maturity, kernel length and kernal width

    Eye-tunes: role of music in ophthalmology and vision sciences

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    Although the healing effect of music has been recognized since time immemorial, there has been a renewed interest in its use in modern medicine. This can be attributed to the increasing focus on holistic healing and on the subjective and objective aspects of well-being. In ophthalmology, this has ranged from using music for patients undergoing diagnostic procedures and surgery, as well as for doctors and the operation theatre staff during surgical procedures. Music has proven to be a potent nonpharmacological sedative and anxiolytic, allaying both the pain and stress of surgery. This review aims to explore the available evidence about the role of music as an adjunct for diagnostic and surgical procedures in current ophthalmic practices.Ophthalmic researc

    Threshold-dominated regulation hides genetic variation in gene expression networks

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    <p>Abstract</p> <p>Background</p> <p>In dynamical models with feedback and sigmoidal response functions, some or all variables have thresholds around which they regulate themselves or other variables. A mathematical analysis has shown that when the dose-response functions approach binary or on/off responses, any variable with an equilibrium value close to one of its thresholds is very robust to parameter perturbations of a homeostatic state. We denote this threshold robustness. To check the empirical relevance of this phenomenon with response function steepnesses ranging from a near on/off response down to Michaelis-Menten conditions, we have performed a simulation study to investigate the degree of threshold robustness in models for a three-gene system with one downstream gene, using several logical input gates, but excluding models with positive feedback to avoid multistationarity. Varying parameter values representing functional genetic variation, we have analysed the coefficient of variation (<it>CV</it>) of the gene product concentrations in the stable state for the regulating genes in absolute terms and compared to the <it>CV </it>for the unregulating downstream gene. The sigmoidal or binary dose-response functions in these models can be considered as phenomenological models of the aggregated effects on protein or mRNA expression rates of all cellular reactions involved in gene expression.</p> <p>Results</p> <p>For all the models, threshold robustness increases with increasing response steepness. The <it>CV</it>s of the regulating genes are significantly smaller than for the unregulating gene, in particular for steep responses. The effect becomes less prominent as steepnesses approach Michaelis-Menten conditions. If the parameter perturbation shifts the equilibrium value too far away from threshold, the gene product is no longer an effective regulator and robustness is lost. Threshold robustness arises when a variable is an active regulator around its threshold, and this function is maintained by the feedback loop that the regulator necessarily takes part in and also is regulated by. In the present study all feedback loops are negative, and our results suggest that threshold robustness is maintained by negative feedback which necessarily exists in the homeostatic state.</p> <p>Conclusion</p> <p>Threshold robustness of a variable can be seen as its ability to maintain an active regulation around its threshold in a homeostatic state despite external perturbations. The feedback loop that the system necessarily possesses in this state, ensures that the robust variable is itself regulated and kept close to its threshold. Our results suggest that threshold regulation is a generic phenomenon in feedback-regulated networks with sigmoidal response functions, at least when there is no positive feedback. Threshold robustness in gene regulatory networks illustrates that hidden genetic variation can be explained by systemic properties of the genotype-phenotype map.</p

    The role and potential of umbilical cord blood in an era of new therapies: a review

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    In light of pioneering findings in the 1980s and an estimation of more than 130 million global annual births, umbilical cord blood (UCB) is considered to be the most plentiful reservoir of cells and to have regenerative potential for many clinical applications. Although UCB is used mainly against blood disorders, the spectrum of diseases for which it provides effective therapy has been expanded to include non-hematopoietic conditions; UCB has also been used as source for regenerative cell therapy and immune modulation. Thus, collection and banking of UCB-derived cells have become a popular option. However, there are questions regarding the cost versus the benefits of UCB banking, and it also raises complex ethical and legal issues. This review discusses many issues surrounding the conservation of UCB-derived cells and the great potential and current clinical applications of UCB in an era of new therapies. In particular, we describe the practical issues inherent in UCB collection, processing, and long-term storage as well as the different types of ‘stem’ or progenitor cells circulating in UCB and their uses in multiple clinical settings. Given these considerations, the trend toward UCB will continue to provide growing assistance to health care worldwide

    PHDcleav: A SVM based method for predicting human Dicer cleavage sites using sequence and secondary structure of miRNA precursors

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    Background: Dicer, an RNase III enzyme, plays a vital role in the processing of pre-miRNAs for generating the miRNAs. The structural and sequence features on pre-miRNA which can facilitate position and efficiency of cleavage are not well known. A precise cleavage by Dicer is crucial because an inaccurate processing can produce miRNA with different seed regions which can alter the repertoire of target genes.Results: In this study, a novel method has been developed to predict Dicer cleavage sites on pre-miRNAs using Support Vector Machine. We used the dataset of experimentally validated human miRNA hairpins from miRBase, and extracted fourteen nucleotides around Dicer cleavage sites. We developed number of models using various types of features and achieved maximum accuracy of 66% using binary profile of nucleotide sequence taken from 5p arm of hairpin. The prediction performance of Dicer cleavage site improved significantly from 66% to 86% when we integrated secondary structure information. This indicates that secondary structure plays an important role in the selection of cleavage site. All models were trained and tested on 555 experimentally validated cleavage sites and evaluated using 5-fold cross validation technique. In addition, the performance was also evaluated on an independent testing dataset that achieved an accuracy of ~82%.Conclusion: Based on this study, we developed a webserver PHDcleav (http://www.imtech.res.in/raghava/phdcleav/) to predict Dicer cleavage sites in pre-miRNA. This tool can be used to investigate functional consequences of genetic variations/SNPs in miRNA on Dicer cleavage site, and gene silencing. Moreover, it would also be useful in the discovery of miRNAs in human genome and design of Dicer specific pre-miRNAs for potent gene silencing.Peer reviewedBiochemistry and Molecular Biolog

    Estimation of combining ability for yield and yield component traits in upland rice (Oryza Sativa L.) of Uttarakhand hills

    Get PDF
    Combining ability for grain yield and its component characters in rainfed upland rice (Oryza sativa L.) were studied during Kharif 2014 using half diallel involving ten parents viz., VL Dhan 221, Vivek Dhan 154, VL 30240, VL 7620, VL 30560, VL 8116, VL 8549, VL 8724, VL 8732 and Sukradhan1. Both general combining ability (gca) and specific combining ability (sca) variances were found to be highly significant for the characters viz., plant height (gca=85.42; sca=23.12), days to 50% flowering (gca=101.61; sca=42.61), days to maturity (gca=90.37; sca=37.73), tillers per plant (gca=4.63; sca=1.38), panicle per plant (gca=2.36; sca=0.90),kernel length (gca=28.88; sca=23.61), kernel width (gca=1.64; sca=1.92),1000 grain weight (gca=3.60; sca=4.91), grain yield per plot (gca=8.57; sca=3.03), fertile grains per panicle (gca=690.67; sca=300.95) and grains per panicle (gca=1050.58; sca=437.75) indicating the importance of additive and non-additive gene actions in the expression of these traits. However, predominance of non-additive gene action was recorded for all the characters. Parents VL Dhan 221, VL 7620, VL 30560, Sukradhan 1 were good general combiners for grain yield and related characters. VL Dhan 221 and Vivek Dhan 154 were good general combiners for plant height and earliness. On the basis of specific combining ability effects, cross combinations Vivek Dhan 154 x VL 8549, VL 7620 x VL 30560, VL 8549 x VL 8732, VL 30560 x VL 8116 and VL 30240 x VL 8116 were the best specific combiner for grain yield per plot and other associated characters viz., plant height, days to 50% flowering, days to maturity, kernel length and kernal width

    Thermal effects in externally pressurized porous conical bearings with variable viscosity

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    The present paper analyzes the porous constant gap externally pressurized conical bearings when the slider is rotating with uniform angular velocity. The lubricant is assumed to be incompressible, and its viscosity varies exponentially with temperature. The lubricant inertia due to rotation of the slider is considered but the convective inertia is neglected. The energy equation is used to determine the temperature generated in the lubricant Film. The governing system of coupled momentum and energy equation is solved numerically, using finite difference method, to determine various bearing characteristics. It is observed that for the surfaces which are highly porous the inlet pressure decreases remarkably, resulting in reduced load capacity of the bearing, and the torque remains unaffected with respect to variation in the permeability

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    Not AvailableNine fine grain rice genotypes viz., VL 30925, VL 30926, VL 30928, VL 30929, VL 30938, VL 31486, VL 31632, VL 31634, VL 31638 were crossed with four basmati varieties Pusa Basmati 1, Pusa Sugandh 2, Pusa Sugandh 3 and Pusa Sugandh 5 in a line x tester mating design. The preponderance of dominant gene action was observed for plant height, days to 50% flowering, days to maturity, grains per panicle, fertile grains per panicle, 1000 grain weight, kernel length, kernel width, L/B ratio and grain yield per plant. Five genotypes viz., VL 30928, VL 30929, VL 31632, VL 30925 and VL 31634 were found to be good general combiners and could be utilized to generate desirable segregants for future breeding programmes. High sca effects were observed in the crosses VL 30926 x P. Sug 5, VL 30929 x P. Sug 3, VL 30938 x P. Sug 5, VL 31486 x P. Sug 2, VL 31632 x P. Sug 5, VL 31634 x P. Bas 1 and VL 31638 x P. Bas 1 for grain yield and components traits.ICA
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