377 research outputs found

    Optimization of Carbon and Nitrogen Sources for L-asparaginase Production by Enterobacter aerogenes using Response Surface Methodology

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    A full factorial central composite design (CCD) was applied to study various effects of sodium citrate, diammonium hydrogen phosphate (DAHP) and L-asparagine to determine the optimal concentration (γ) of these compounds on L-asparaginase production by Enterobacter aerogenes MTCC 2823 under shake flask fermentation conditions. A second order polynomial model describing the relationship between the variables and the L-asparaginase activity was fitted in coded units of variables. The statistical reliability and significance of the model was validated by F-test for analysis of variance at higher R2 value (R2 = 0.871). The optimum estimated concentration of sodium citrate (X1), DAHP (X2) and L-asparagine (X3) was 18.76, 5.72 and 8.58 g L–1 respectively with maximum L-asparaginase activity of 19.129 IU mL–1. The composite desirability of 98.38 % reveals the validity of the model and predicted values. The L-asparaginase activity was increased by 5.96 % than predicted activity, after optimization of carbon and nitrogen sources for L-asparaginase production by Enterobacter aerogenes MTCC 2823 using CCD

    Gene effects and heterosis for grain Fe and Zn content in barnyard millet (Echinochloa frumentacea (Roxb.) link)

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    Barnyard millet (Echinochloa frumentacea) is an unexplored nutri-rich crop that thrives well in harsh environments and supports many small farmers in Southern and Eastern Asia. Although it has rich sources of micronutrients, the genetic studies are very limited which further impedes in its genetic improvement. Therefore, we attempted to assess the genetic diversity for Fe and Zn content in 40 barnyard millet germplasm and to evaluate the combining ability and heterosis in sixteen F1 cross combinations through line Ă— tester model. The Mahalanobis D2 analysis grouped the 40 genotypes into nine different clusters. Cluster III and I were the largest groups containing 22 and 6 genotypes, respectively and the rest of seven clusters were the lowest group containing one or two genotypes. Positive correlation was observed between Fe and Zn content though both had a non-significant association with grain yield. This indicate that there would not be any compromise on increase or decrease of grain yield while breeding for varieties high in micronutrient content. Combining ability analysis revealed that lines, testers, and their interaction components are significant. The predictability ratio indicated the predominance of additive variance for Fe and Zn content and non-additive variance in the inheritance of yield components. Genotypes, ACM 331, ACM 333, ACM 335 and MA 10 exhibited positive gca effects for Fe and Zn content and grain yield. Two cross combinations, ACM 331 Ă— ACM 335 and ACM 331 Ă— MA 10 involved one or both the parents with good gca effects exhibited, high mean, positive mid-parent heterosis and sca effects for Fe, Zn content and yield components. Thus, the present investigation provided a significant understanding of the gene action and the possibility of utilizing the selected parents and cross combination for exploiting micronutrient traits in barnyard millet crop

    Nitrogen-containing carbon nanotubes

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    Carbon nanotubes containing small amounts of nitrogen are produced by the pyrolysis of aza-aromatics such as pyridine, methylpyrimidine and triazine over cobalt nanoparticles in an Ar atmosphere; good yields of such nanotubes are obtained by carrying out the pyrolysis of a mixture of pyridine and Fe(CO)5 in flowing Ar+H2

    An openflow-based approach to failure detection and protection for a multicasting tree

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    Software Defined Networking (SDN) has received considerable attention for both experimental and real networks. The programmability of the centralized control plane utilizes the global view of the network to provide better solutions for complex problems in SDN. This results in an increase in robustness and reliability of network functions running in SDN. This paper is motivated by recent advancement in SDN and increasing popularity of multicasting applications by proposing a technique to increase the resiliency of multicasting in SDN. Multicasting is a group communication technology, which uses the network infrastructure efficiently by sending the data only once from one or multiple sources to a group of receivers. Multicasting applications, e.g., live video streaming and video conferencing, are popular and delay sensitive applications in the Internet. Failures in the ongoing multicast session can cause packet losses and delay and hence affect quality of service (QoS). In this paper, we present a technique to protect a multicasting tree constructed by Openflow switches in SDN. The proposed algorithm can detect link or node failures from the multicasting tree and then determines which part of the multicasting tree requires changes in the flow table to recover from the failure. We also implement a prototype of the algorithm in the POX control

    Schistosomiasis and the risk of bladder cancer in Alexandria, Egypt.

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    The relationship between history of schistosomiasis and bladder cancer risk was investigated using data from a case-control study conducted between January 1994 and July 1996 in Alexandria, Egypt. Cases were 190 subjects with incident, histologically confirmed invasive cancer of the bladder, and controls were 187 subjects admitted to hospital for acute, non-neoplastic, non-urinary tract conditions. Eighty-six cases (45%) vs 69 controls (37%) reported a history of urinary schistosomiasis. The corresponding multivariate odds ratio (OR) of bladder cancer -- after allowance for age, sex, education, smoking, other urinary infections and high-risk occupations -- was 1.72 (95% confidence interval (CI) 1.0-2.9). The ORs were 0.22 (95% CI 0.1-0.4) for intestinal schistosomiasis and 0.32 (95% CI 0.1-1.9) for schistosomiasis of other types. The OR for urinary schistosomiasis was higher in subjects who were younger at first diagnosis (OR of 3.3 for <15 years) and in those with a long time since first diagnosis (OR of 3.0 for > or = 35 years). The ORs were 15.8 for male ever-smokers with a history of urinary schistosomiasis, compared with never-smokers without such a history, and 3.2 for men ever-infected with urinary Schistosoma haematobium and ever-employed in high-risk occupations, compared with those never-infected and with no high-risk occupational history. This study confirms that clinical history of urinary schistosomiasis is significantly, but modestly, associated with increased bladder cancer risk, explaining some 16% of bladder cancer cases in this Egyptian population

    Long non-coding RNA SNHG8 drives stress granule formation in tauopathies

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    Tauopathies are a heterogenous group of neurodegenerative disorders characterized by tau aggregation in the brain. In a subset of tauopathies, rare mutations in the MAPT gene, which encodes the tau protein, are sufficient to cause disease; however, the events downstream of MAPT mutations are poorly understood. Here, we investigate the role of long non-coding RNAs (lncRNAs), transcripts \u3e200 nucleotides with low/no coding potential that regulate transcription and translation, and their role in tauopathy. Using stem cell derived neurons from patients carrying a MAPT p.P301L, IVS10 + 16, or p.R406W mutation and CRISPR-corrected isogenic controls, we identified transcriptomic changes that occur as a function of the MAPT mutant allele. We identified 15 lncRNAs that were commonly differentially expressed across the three MAPT mutations. The commonly differentially expressed lncRNAs interact with RNA-binding proteins that regulate stress granule formation. Among these lncRNAs, SNHG8 was significantly reduced in a mouse model of tauopathy and in FTLD-tau, progressive supranuclear palsy, and Alzheimer\u27s disease brains. We show that SNHG8 interacts with tau and stress granule-associated RNA-binding protein TIA1. Overexpression of mutant tau in vitro is sufficient to reduce SNHG8 expression and induce stress granule formation. Rescuing SNHG8 expression leads to reduced stress granule formation and reduced TIA1 levels in immortalized cells and in MAPT mutant neurons, suggesting that dysregulation of this non-coding RNA is a causal factor driving stress granule formation via TIA1 in tauopathies

    Inhibiting ACK1-mediated phosphorylation of C-terminal Src kinase counteracts prostate cancer immune checkpoint blockade resistance

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    Solid tumours are highly refractory to immune checkpoint blockade (ICB) therapies due to the functional impairment of effector T cells and their inefficient trafficking to tumours. T-cell activation is negatively regulated by C-terminal Src kinase (CSK); however, the exact mechanism remains unknown. Here we show that the conserved oncogenic tyrosine kinase Activated CDC42 kinase 1 (ACK1) is able to phosphorylate CSK at Tyrosine 18 (pY18), which enhances CSK function, constraining T-cell activation. Mice deficient in the Tnk2 gene encoding Ack1, are characterized by diminished CSK Y18-phosphorylation and spontaneous activation of CD
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