372 research outputs found

    Reinforcement learning based multi core scheduling (RLBMCS) for real time systems

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    Embedded systems with multi core processors are increasingly popular because of the diversity of applications that can be run on it. In this work, a reinforcement learning based scheduling method is proposed to handle the real time tasks in multi core systems with effective CPU usage and lower response time. The priority of the tasks is varied dynamically to ensure fairness with reinforcement learning based priority assignment and Multi Core MultiLevel Feedback queue (MCMLFQ) to manage the task execution in multi core system

    Antidiabetic activity of compounds isolated from the roots of Premna latifolia Roxb

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    Purpose: To evaluate the hypoglycaemic activity of the ethanol extract, chloroform  fraction, and three compounds isolated from Premna latifolia.Methods: The ethanol extract, chloroform fraction, and compounds 1 – 3 (isolated from the chloroform fraction) of P. latifolia were characterised by nuclear magnetic resonance (1H NMR, 13C NMR and 2D NMR). In vitro activity was assessed by α-amylase and α-glucosidase inhibitory activity assays. In vivo antidiabetic activity was evaluated in a streptozotocin-nicotinamide-induced rat model of diabetes. Fasting blood glucose (FBG), glycosylated haemoglobin (HbA1C), serum creatinine, blood urea nitrogen (BUN), liver enzymes, and antioxidant enzymes were  determined. Liver and pancreas histopathology was assessed.Results: Compounds 2 and 3 exhibited significant hypoglycaemic activity by reducing elevated FBG and HbA1C (p ≤ 0.001) and also exerted positive effects on blood and liver enzyme profiles, which were largely altered in diabetic control group. These compounds also showed significant antioxidant activity, increasing catalase, superoxide dismutase, and glutathione reductase, while lowering malondialdehyde (p ≤ 0.001). The histopathology results for the rats that received these compounds suggested regeneration of pancreatic β-cells.Conclusion: Compounds 2 and 3 isolated from the dried roots of P. latifolia possess significant hypoglycaemic activity, reno- and hepatoprotective effects, and antioxidant activity. They show promise as potential treatments for patients with diabetes.Keywords: Antioxidant, Hypoglycaemic, Premna latifolia, Stigmanstan-3β-olyl n-octadec-9ʹ, 12ʹ- dienoate, n-Tetracosanol, n-Tridecanyl n-Tetracosanoat

    A Unique Test Bench for Various System-on-a-Chip

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    This paper discusses a standard flow on how an automated test bench environment which is randomized with constraints can verify a SOC efficiently for its functionality and coverage. Today, in the time of multimillion gate ASICs, reusable intellectual property (IP), and system-on-a-chip (SoC) designs, verification consumes about 70 % of the design effort. Automation means a machine completes a task autonomously, quicker and with predictable results. Automation requires standard processes with well-defined inputs and outputs. By using this efficient methodology it is possible to provide a general purpose automation solution for verification, given today’s technology. Tools automating various portions of the verification process are being introduced. Here, we have Communication based SOC The content of the paper discusses about the methodology used to verify such a SOC-based environment. Cadence Efficient Verification Methodology libraries are explored for the solution of this problem. We can take this as a state of art approach in verifying SOC environments. The goal of this paper is to emphasize the unique testbench for different SOC using Efficient Verification Constructs implemented in system verilog for SOC verification

    Anti-proliferative activity of silver nanoparticles

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

    Enhanced Genotoxicity of Silver Nanoparticles in DNA Repair Deficient Mammalian Cells

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    Silver nanoparticles (Ag-np) have been used in medicine and commercially due to their anti-microbial properties. Therapeutic potentials of these nanoparticles are being explored extensively despite the lack of information on their mechanism of action at molecular and cellular level. Here, we have investigated the DNA damage response and repair following Ag-np treatment in mammalian cells. Studies have shown that Ag-np exerts genotoxicity through double-strand breaks (DSBs). DNA-PKcs, the catalytic subunit of DNA dependent protein kinase, is an important caretaker of the genome which is known to be the main player mediating Non-homologous End-Joining (NHEJ) repair pathway. We hypothesize that DNA-PKcs is responsible for the repair of Ag-np induced DNA damage. In vitro studies have been carried out to investigate both cytotoxicity and genotoxicity induced by Ag-np in normal human cells, DNA-PKcs proficient, and deficient mammalian cells. Chemical inhibition of DNA-PKcs activity with NU7026, an ATP-competitive inhibitor of DNA-PKcs, has been performed to further validate the role of DNA-PKcs in this model. Our results suggest that Ag-np induced more prominent dose-dependent decrease in cell viability in DNA-PKcs deficient or inhibited cells. The deficiency or inhibition of DNA-PKcs renders the cells with higher susceptibility to DNA damage and genome instability which in turn contributed to greater cell cycle arrest/cell death. These findings support the fact that DNA-PKcs is involved in the repair of Ag-np induced genotoxicity and NHEJ repair pathway and DNA-PKcs particularly is activated to safeguard the genome upon Ag-np exposure

    Molecular mechanisms of toxicity of silver nanoparticles in zebrafish embryos.

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    addresses: Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK. [email protected]: Journal Article; Research Support, Non-U.S. Gov'tThis is an open access article that is freely available in ORE or from the publisher's web site. http://pubs.acs.org/doi/abs/10.1021/es401758d. Please cite the published version© 2013 American Chemical SocietySupporting Information: Further details on the methodology and results for the characterization of the silver particles used for the exposures, mortality curves, sequencing analysis, and a number of supporting figures and tables. This material is available free of charge via the Internet at http://pubs.acs.org.Silver nanoparticles cause toxicity in exposed organisms and are an environmental health concern. The mechanisms of silver nanoparticle toxicity, however, remain unclear. We examined the effects of exposure to silver in nano-, bulk-, and ionic forms on zebrafish embryos (Danio rerio) using a Next Generation Sequencing approach in an Illumina platform (High-Throughput SuperSAGE). Significant alterations in gene expression were found for all treatments and many of the gene pathways affected, most notably those associated with oxidative phosphorylation and protein synthesis, overlapped strongly between the three treatments indicating similar mechanisms of toxicity for the three forms of silver studied. Changes in oxidative phosphorylation indicated a down-regulation of this pathway at 24 h of exposure, but with a recovery at 48 h. This finding was consistent with a dose-dependent decrease in oxygen consumption at 24 h, but not at 48 h, following exposure to silver ions. Overall, our data provide support for the hypothesis that the toxicity caused by silver nanoparticles is principally associated with bioavailable silver ions in exposed zebrafish embryos. These findings are important in the evaluation of the risk that silver particles may pose to exposed vertebrate organisms.Natural Environment Research Council (NERC)NERC Biomolecular Analysis FacilityUK Environment AgencySystems Biology Seed fund, University of Exete

    Influence of silver content on the tribomechanical behavior on Ag-TiCN bioactive coatings

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    Surface modification of bulk materials used in biomedical applications has become an important prerequisite for better biocompatibility. In particular, to overcome the particle generation, low-wear coatings based on carbon (nitrogen) and containing antimicrobial elements such as silver are promising candidates. Thus, the present work explores the potentialities of silver-containing carbonitride-based (Ag-TiCN) thin films prepared by direct current unbalanced reactive magnetron sputtering. The silver content in the coatings was varied from 0 to 26.7 at.% by changing the targets and the fraction of C2H2 and N2 in the gas mixture with Ar. The obtained Ag-TiCN based coatings were characterized in terms of composition and microstructure. Mechanical and tribological properties of the films were studied by nanoindentation and reciprocating pin-on disk testing in a fetal bovine serum solution, respectively. Raman, scanning electron microscope and energy dispersive X-ray analysis was carried out in the contact region after tribological tests to obtain information about the friction mechanism. The cytotoxicity of the coatings was assessed by in vitro tests using fibroblast cells. The coatings comprised a mixture of TiCxN1−x, Ag and a-C(N)x phases whose relative proportion varied depending on the Ag/Ti ratio. The mechanical, tribological and cytotoxicity properties were correlated with the chemical and phase composition. When the Ag/Ti ratios were below 0.20 (Ag contents b6.3 at.%) the films resulted harder (~18 GPa) with higher wear resistance (~10−6 mm3/Nm), showing similar friction coefficient (~0.3) and good biocompatibility.The authors are grateful to the financial support of the CRUP Institution by the project "Accao No E-1007/08", the Spanish Ministry of Science and Innovation (projects FUNCOAT CSD2008-00023 and HP2007-0116), Junta de Andalucia (project TEP 06782) and CSIC-FCT institutions (2007PT0043). The work was financially supported by Portuguese national funds through the FCT-Fundacao para a Ciencia e a Tecnologia, (project PTDC/CTM/102853/2008) and partially sponsored by FEDER funds through the program COMPETE - Programa Operacional Factores de Competitividade

    Engineered nanomaterials: toward effective safety management in research laboratories

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    It is still unknown which types of nanomaterials and associated doses represent an actual danger to humans and environment. Meanwhile, there is consensus on applying the precautionary principle to these novel materials until more information is available. To deal with the rapid evolution of research, including the fast turnover of collaborators, a user-friendly and easy-to-apply risk assessment tool offering adequate preventive and protective measures has to be provided.Results: Based on new information concerning the hazards of engineered nanomaterials, we improved a previously developed risk assessment tool by following a simple scheme to gain in efficiency. In the first step, using a logical decision tree, one of the three hazard levels, from H1 to H3, is assigned to the nanomaterial. Using a combination of decision trees and matrices, the second step links the hazard with the emission and exposure potential to assign one of the three nanorisk levels (Nano 3 highest risk; Nano 1 lowest risk) to the activity. These operations are repeated at each process step, leading to the laboratory classification. The third step provides detailed preventive and protective measures for the determined level of nanorisk.Conclusions: We developed an adapted simple and intuitive method for nanomaterial risk management in research laboratories. It allows classifying the nanoactivities into three levels, additionally proposing concrete preventive and protective measures and associated actions. This method is a valuable tool for all the participants in nanomaterial safety. The users experience an essential learning opportunity and increase their safety awareness. Laboratory managers have a reliable tool to obtain an overview of the operations involving nanomaterials in their laboratories; this is essential, as they are responsible for the employee safety, but are sometimes unaware of the works performed. Bringing this risk to a three-band scale (like other types of risks such as biological, radiation, chemical, etc.) facilitates the management for occupational health and safety specialists. Institutes and school managers can obtain the necessary information to implement an adequate safety management system. Having an easy-to-use tool enables a dialog between all these partners, whose semantic and priorities in terms of safety are often different

    Silver ions disrupt K+ homeostasis and cellular integrity in intact barley (Hordeum vulgare L.) roots

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    The heavy metals silver, gold, and mercury can strongly inhibit aquaporin-mediated water flow across plant cell membranes, but critical examinations of their side effects are rare. Here, the short-lived radiotracer 42K is used to demonstrate that these metals, especially silver, profoundly change potassium homeostasis in roots of intact barley (Hordeum vulgare L.) plants, by altering unidirectional K+ fluxes. Doses as low as 5 μM AgNO3 rapidly reduced K+ influx to 5% that of controls, and brought about pronounced and immediate increases in K+ efflux, while higher doses of Au3+ and Hg2+ were required to produce similar responses. Reduced influx and enhanced efflux of K+ resulted in a net loss of >40% of root tissue K+ during a 15 min application of 500 μM AgNO3, comprising the entire cytosolic potassium pool and about a third of the vacuolar pool. Silver also brought about major losses of UV-absorbing compounds, total electrolytes, and NH4+. Co-application, with silver, of the channel blockers Cs+, TEA+, or Ca2+, did not affect the enhanced efflux, ruling out the involvement of outwardly rectifying ion channels. Taken together with an examination of propidium iodide staining under confocal microscopy, the results indicate that silver ions affect K+ homeostasis by directly inhibiting K+ influx at lower concentrations, and indirectly inhibiting K+ influx and enhancing K+ efflux, via membrane destruction, at higher concentrations. Ni2+, Cd2+, and Pb2+, three heavy metals not generally known to affect aquaporins, did not enhance K+ efflux or cause propidium iodide incorporation. The study reveals strong and previously unknown effects of major aquaporin inhibitors and recommends caution in their application
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