149 research outputs found

    Persistence probabilities in centered, stationary, Gaussian processes in discrete time

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    Lower bounds for persistence probabilities of stationary Gaussian processes in discrete time are obtained under various conditions on the spectral measure of the process. Examples are given to show that the persistence probability can decay faster than exponentially. It is shown that if the spectral measure is not singular, then the exponent in the persistence probability cannot grow faster than quadratically. An example that appears (from numerical evidence) to achieve this lower bound is presented.Comment: 9 pages; To appear in a special volume of the Indian Journal of Pure and Applied Mathematic

    Paternal imprinting of the SLC22A1LS gene located in the human chromosome segment 11p15.5

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    BACKGROUND: Genomic imprinting is an epigenetic chromosomal modification in the gametes or zygotes that results in a non-random monoallelic expression of specific autosomal genes depending upon their parent of origin. Approximately 44 human genes have been reported to be imprinted. A majority of them are clustered, including some on chromosome segment 11p15.5. We report here the imprinting status of the SLC22A1LS gene from the human chromosome segment 11p15.5 RESULTS: In order to test for allele specific expression patterns, PCR primer sets from the SLC22A1LS gene were used to look for heterozygosity in DNA samples from 17 spontaneous abortuses using PCR-SSCP and DNA sequence analyses. cDNA samples from different tissues of spontaneous abortuses showing heterozygosity were subjected to PCR-SSCP analysis to determine the allele specific expression pattern. PCR-SSCP analysis revealed heterozygosity in two of the 17 abortuses examined. DNA sequence analysis showed that the heterozygosity is caused by a G>A change at nucleotide position 473 (c.473G>A) in exon 4 of the SLC22A1LS gene. PCR-SSCP analysis suggested that this gene is paternally imprinted in five fetal tissues examined. CONCLUSIONS: This study reports the imprinting status of the SLC22A1LS gene for the first time. The results suggest imprinting of the paternal allele of this gene in five fetal tissues: brain, liver, placenta, kidneys and lungs

    Optimization of Squeeze Cast Process Parameters Using Taguchi and Grey Relational Analysis

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    AbstractThe near-net shape manufacturing capabilities of squeeze casting process have greater potential to achieve smooth uniform surface and internal soundness in the cast components. In squeeze casting process, casting density and surface finish is influenced majorly by process variables. Proper control of the process variables is essential to achieve better results. Hence in the present work an attempt made using taguchi method to analyze the squeeze cast process variables such as squeeze pressure, die and pouring temperature considering at three different levels using L9 orthogonal array. Pareto analysis of variance performed on each response to find out optimum process parameter levels and significant contribution of each individual process parameter towards surface roughness and density of LM20 alloy. Grey relation analysis used as a multi-response optimization technique to obtain the single optimal process parameter setting for both the responses surface roughness and casting density

    Forward and Reverse Process Models for the Squeeze Casting Process Using Neural Network Based Approaches

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    The present research work is focussed to develop an intelligent system to establish the input-output relationship utilizing forward and reverse mappings of artificial neural networks. Forward mapping aims at predicting the density and secondary dendrite arm spacing (SDAS) from the known set of squeeze cast process parameters such as time delay, pressure duration, squeezes pressure, pouring temperature, and die temperature. An attempt is also made to meet the industrial requirements of developing the reverse model to predict the recommended squeeze cast parameters for the desired density and SDAS. Two different neural network based approaches have been proposed to carry out the said task, namely, back propagation neural network (BPNN) and genetic algorithm neural network (GA-NN). The batch mode of training is employed for both supervised learning networks and requires huge training data. The requirement of huge training data is generated artificially at random using regression equation derived through real experiments carried out earlier by the same authors. The performances of BPNN and GA-NN models are compared among themselves with those of regression for ten test cases. The results show that both models are capable of making better predictions and the models can be effectively used in shop floor in selection of most influential parameters for the desired outputs

    Role of Nitrogen Source for L-Glutaminase Production from Fungal Strain using through Submerged Fermentation

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    L-glutaminase has attracted much attention due its wide range of applications in several fields. The L-glutaminase widely used in pharmaceutical and food industries. L-glutaminase is generally regarded as a key enzyme that controls the delicious taste of fermented foods such as soy sauce. L-glutaminase production was carried out by using supplementation of organic and inorganic nitrogen sources such as yeast extract, malt extract, peptone and urea at concentration ranging from 0.25% to 1.25% with increments of 0.25% and also different inorganic nitrogen sources like ammonium sulphate and ammonium chloride at concentration ranging from 0.025% to 0.125% with increments of 0.025%. The malt extract (1%) produced 399.9 IU, were best organic nitrogen source and ammonium sulphate (0.1%) appear to be good inorganic nitrogen source under submerged fermentation process and showed 546 IU. Current study is an exploring step to industrial sector to upscale their L-glutaminase production and it will useful strategy to commercial sector and alternative to old method

    SHARE AND USE

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    Android is one of the most user friendly mobile platforms that have grasped the attention of smart phone users around the globe. According to stats available there are 1.4 billion people who have used Android mobile platform. And this has led to the development of android application exponentially; there are around 2.8 million android applications available in play store. Many of the available application do not fit into low specification smart phones due to some reasons. Share and Use is an android application that lets you use another smart phones application by your phone without actually installing it on your phone. Share and Use lets user to use application installed on other phones and access applications on their smart phones. Share and Use helps phones with lower specification android phones to use applications that are not be able to install in them

    Biological relationship of Bean common mosaic virus (BCMV) infecting cowpea with leguminous plant species

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    Bean common mosaic virus (BCMV) associated with cowpea mechanically inoculated to different legumi-nous plants. Out of nineteen including cowpea Var.C-152, the virus was easily transferred to ten different legumi-nous hosts. All other hosts assessed for the presence of BCMV were found to be uninfected. The number of days taken for symptom expression and symptoms were varied within plant species. Pole bean expressed mosaic symp-tom after long incubation period (15-18 days) whereas, shorter incubation period was observed in common bean and rice bean (7- 10 days). BCMV produced chlorosis, mosaic, leaf distortion, puckering, vein banding, vein clearing and vein netting on cowpea(C-152). A typical virus symptom, mosaic was observed in green gram, common bean, lime bean, rice bean and yard long bean, whereas, leaf rolling and leaf distortion was observed in black gram, pole bean and snap bean. The virus-host relationship was confirmed by back inoculation test to C. amaranticolor. Further symptomatic plants were subjected for Reverse Transcriptase polymerase chain reaction (RT-PCR) for molecular confirmation using BCMV coat protein (CP) specific primer pair. A PCR fragment size of 439bp was amplified for the symptomatic plants. The results generated indicated the ability of a plant to support virus expression and host speci-ficity of BMCV within the leguminous plant species

    Crystallographic identification of an ordered C-terminal domain and a second nucleotide-binding site in RecA: new insights into allostery

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    RecA protein is a crucial and central component of the homologous recombination and DNA repair machinery. Despite numerous studies on the protein, several issues concerning its action, including the allosteric regulation mechanism have remained unclear. Here we report, for the first time, a crystal structure of a complex of Mycobacterium smegmatis RecA (MsRecA) with dATP, which exhibits a fully ordered C-terminal domain, with a second dATP molecule bound to it. ATP binding is an essential step for all activities of RecA, since it triggers the formation of active nucleoprotein filaments. In the crystal filament, dATP at the first site communicates with a dATP of the second site of an adjacent subunit, through conserved residues, suggesting a new route for allosteric regulation. In addition, subtle but definite changes observed in the orientation of the nucleotide at the first site and in the positions of the segment preceding loop L2 as well as in the segment 102–105 situated between the 2 nt, all appear to be concerted and suggestive of a biological role for the second bound nucleotide

    Corrosion behaviour of high-strength Al 7005 alloy and its composites reinforced with industrial waste-based fly ash and glass fibre: comparison of stir cast and extrusion conditions

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    The stringent demand to develop lightweight materials with enhanced properties suitable for various engineering applications is the focus of this research work. Industrial wastes such as fly ash (FA) and S-glass-fibres (GF) were used as reinforcement materials for high-strength alloy, i.e., Al 7005. Stir casting routes were employed for fabricating the four samples, Al 7005, Al 7005 + 5% GF, Al 7005 + 6% FA and Al 7005 + 5% GF + 6% FA. The extrusion process with different extrusion ratios (ER: 5.32:1, and 2.66:1) was used to examine the properties of all four samples. Extruded samples with ER: 5.32: 1 resulted in equiaxed grains with refined structure compared to stir casting parts. The effect of the extrusion process and the addition of reinforcements (GF and FA) on the gravimetric, electrochemical, and electrochemical impedance corrosion behaviour of Al 7005 composites in 1M HCl (Hydrochloric acid) solution were investigated. The results of all three corrosion methods showed that Al 7005 + 6% FA exhibited higher corrosion resistance. Corrosion rate of Al 7005, Al 7005 + 5% GF, Al 7005 + 6% FA and Al 7005 + 5% GF + 6% FA is found equal to 3.25, 2.41, 0.34, and 0.76 mpy, respectively. The FA particles remain inert and act as a physical barrier with corrosive media during the corrosion test. GF undergoes fibre degradation or disrupts the continuity of the glass network as a result of fibre leaching, which increases the corrosion rate in the sample. The gravimetric study showed that the corrosion rates decreased with an increase in extrusion ratio, which might be due to corrosion passivation increases and improved properties. The scanning electron microscopy reveals that corrosion fits, flakes and micro-cracks were observed more in the as-cast composites than that of extrusion composites, promoting the corrosion rate
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