21 research outputs found

    Intelligent agent for formal modelling of temporal multi-agent systems

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    Software systems are becoming complex and dynamic with the passage of time, and to provide better fault tolerance and resource management they need to have the ability of self-adaptation. Multi-agent systems paradigm is an active area of research for modeling real-time systems. In this research, we have proposed a new agent named SA-ARTIS-agent, which is designed to work in hard real-time temporal constraints with the ability of self-adaptation. This agent can be used for the formal modeling of any self-adaptive real-time multi-agent system. Our agent integrates the MAPE-K feedback loop with ARTIS agent for the provision of self-adaptation. For an unambiguous description, we formally specify our SA-ARTIS-agent using Time-Communicating Object-Z (TCOZ) language. The objective of this research is to provide an intelligent agent with self-adaptive abilities for the execution of tasks with temporal constraints. Previous works in this domain have used Z language which is not expressive to model the distributed communication process of agents. The novelty of our work is that we specified the non-terminating behavior of agents using active class concept of TCOZ and expressed the distributed communication among agents. For communication between active entities, channel communication mechanism of TCOZ is utilized. We demonstrate the effectiveness of the proposed agent using a real-time case study of traffic monitoring system

    Genetic variation in the interleukin-28B gene is associated with spontaneous clearance and progression of hepatitis C virus in Moroccan patients

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    Genetic variation in the IL28B gene has been strongly associated with treatment outcomes, spontaneous clearance and progression of the hepatitis C virus infection (HCV). The aim of the present study was to investigate the role of polymorphisms at this locus with progression and outcome of HCV infection in a Moroccan population. We analyzed a cohort of 438 individuals among them 232 patients with persistent HCV infection, of whom 115 patients had mild chronic hepatitis and 117 had advanced liver disease (cirrhosis and hepatocellular carcinoma), 68 individuals who had naturally cleared HCV and 138 healthy subjects. The IL28B SNPs rs12979860 and rs8099917 were genotyped using a TaqMan 5' allelic discrimination assay. The protective rs12979860-C and rs8099917-T alleles were more common in subjects with spontaneous clearance (77.9% vs 55.2%; p = 0.00001 and 95.6% vs 83.2%; p = 0.0025, respectively). Individuals with clearance were 4.69 (95% CI, 1.99-11.07) times more likely to have the C/C genotype for rs12979860 polymorphism (p = 0.0017) and 3.55 (95% CI, 0.19-66.89) times more likely to have the T/T genotype at rs8099917. Patients with advanced liver disease carried the rs12979860-T/T genotype more frequently than patients with mild chronic hepatitis C (OR = 1.89; 95% CI, 0.99-3.61; p = 0.0532) and this risk was even more pronounced when we compared them with healthy controls (OR = 4.27; 95% CI, 2.08-8.76; p = 0.0005). The rs8099917-G allele was also associated with advanced liver disease (OR = 2.34; 95% CI, 1.40-3.93; p = 0.0100). In the Moroccan population, polymorphisms near the IL28B gene play a role both in spontaneous clearance and progression of HCV infection

    L-Ornithine-L-Aspartate and Intermittent Renal Replacement Therapy in Fulminant Hepatitis A

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    Hepatitis A is a common viral infection worldwide that is transmitted via the fecal-oral route. Since the introduction of an efficient vaccine, the incidence of infection has decreased but the number of cases has risen due to widespread community outbreaks among unimmunized individuals. Classic symptoms include fever, malaise, dark urine, and jaundice, and are more common in older children and adults. People are often most infectious 14 days prior to and 7 days following the onset of jaundice. We will discuss the case of a young male patient, diagnosed with acute hepatitis A, leading to fulminant hepatitis refractory to conventional therapy and the development of subsequent kidney injury. The medical treatment through the course of hospitalization was challenging and included the use of L-ornithine-L-aspartate and prolonged intermittent hemodialysis, leading to a remarkable outcome. Hepatitis A is usually self-limited and vaccine-preventable; supportive care is often sufficient for treatment, and chronic infection or chronic liver disease rarely develops. However, fulminant hepatitis, although rare, can be very challenging to manage as in the case of our patient

    Predicting sequelae and death after bacterial meningitis in childhood: A systematic review of prognostic studies

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    Background: Bacterial meningitis (BM) is a severe infection responsible for high mortality and disabling sequelae. Early identification of patients at high risk of these outcomes is necessary to prevent their occurrence by adequate treatment as much as possible. For this reason, several prognostic models have been developed. The objective of this study is to summarize the evidence regarding prognostic factors predicting death or sequelae due to BM in children 0-18 years of age. Methods: A search in MEDLINE and EMBASE was conducted to identify prognostic studies on risk factors for mortality and sequelae after BM in children. Selection of abstracts, full-text articles and assessment of methodological quality using the QUIPS checklist was performed by two reviewers independently. Data on prognostic factors per outcome were summarized. Results: Of the 31 studies identified, 15 were of moderate to high quality. Due to substantial heterogeneity in study characteristics and evaluated prognostic factors, no quantitative analysis was performed. Prognostic factors found to be statistically significant in more than one study of moderate or high quality are: complaints > 48 hours before admission, coma/impaired consciousness, (prolonged duration of) seizures, (prolonged) fever, shock, peripheral circulatory failure, respiratory distress, absence of petechiae, causative pathogen Streptococcus pneumoniae, young age, male gender, several cerebrospinal fluid (CSF) parameters and white blood cell (WBC) count. Conclusions: Although several important prognostic factors for the prediction of mortality or sequelae after BM were identified, the inability to perform a pooled analysis makes the exact (independent) predictive value of these factors uncertain. This emphasizes the need for additional well-conducted prognostic studie

    Formal Specification and Verification of Real-Time Multi-Agent Systems using Timed-Arc Petri Nets

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    In this study we have formally specified and verified the actions of communicating real-time software agents (RTAgents). Software agents are expected to work autonomously and deal with unfamiliar situations astutely. Achieving cent percent test cases coverage for these agents has always been a problem due to limited resources. Also a high degree of dependability and predictability is expected from real-time software agents. In this research we have used Timed-Arc Petri Net's for formal specification and verification. Formal specification of e-agents has been done in the past using Linear Temporal Logic (LTL) but we believe that Timed-Arc Petri Net's being more visually expressive provides a richer framework for such formalism. A case study of Stock Market System (SMS) based on Real Time Multi Agent System framework (RTMAS) using Timed-Arc Petri Net's is taken to illustrate the proposed modeling approach. The model was verified used AF, AG, EG, and EF fragments of Timed Computational Tree Logic (TCTL) via translations to timed automata

    Growth and yield response of wheat (Triticum aestivum L.) to tillage and row spacing in maize-wheat cropping system in semi-arid region

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    Tillage practices and row spacing can be manipulated to optimize spatial distribution and plant growth, therefore maximizing sunlight, soil water use efficiency, nutrients and grain yield on sustainable basis. A field study was conducted to determine the effect of tillage and row spacing on growth and yield of wheat (Triticum aestivum L.) at Agronomic Research Area, University of Agriculture, Faisalabad, Pakistan during wheat season. The treatments were comprised of two tillage practices viz. zero tillage and conventional tillage and four row spacing viz. 15 cm, 20 cm, 25 cm and 30 cm. The experimental results revealed that zero tillage significantly enhanced the plant height, tillers m-2, spike length, 1000 kernel weight and yield and yield components of wheat plants as compared to conventional tillage. Wheat plants resulted in a significant increase in tillers m-2 and accumulated higher biomass and grain yield under 15-cm row spacing than all three other row spacing. The grain yield increase was mainly attributed to more tillers m-2 at 15-cm than the other row spacing. So, zero tillage and narrow row spacing (15 cm) proved to be involved in higher wheat yield for the wheat-maize cropping system in semi-arid regions

    Cadmium minimization in wheat: A critical review

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    International audienceCadmium (Cd) accumulation in wheat (Triticum aestivum L.) and its subsequent transfer to food chain is a major environmental issue worldwide. Understanding wheat response to Cd stress and its management for aiming to reduce Cd uptake and accumulation in wheat may help to improve wheat growth and grain quality. This paper reviewed the toxic effects, tolerance mechanisms, and management of Cd stress in wheat. It was concluded that Cd decreased germination, growth, mineral nutrients, photosynthesis and grain yield of wheat and plant response to Cd toxicity varies with cultivars, growth conditions and duration of stress applied. Cadmium caused oxidative stress and genotoxicity in wheat plants. Stimulation of antioxidant defense system, osmoregulation, ion homeostasis and over production of signalling molecules are important adaptive strategies of wheat under Cd stress. Exogenous application of plant growth regulators, inorganic amendments, proper fertilization, silicon, and organic, manures and biochar, amendments are commonly used for the reduction of Cd uptake in wheat. Selection of low Cd-accumulating wheat cultivars, crop rotation, soil type, and exogenous application of microbes are among the other agronomic practices successfully employed in reducing Cd uptake by wheat. These management practices could enhance wheat tolerance to Cd stress and reduce the transfer of Cd to the food chain. However, their long-term sustainability in reducing Cd uptake by wheat needs further assessment. (C) 2016 Elsevier Inc. All rights reserved
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