3,608 research outputs found

    Towards semantic software engineering environments

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    Software tools processing partially common set of data should share an understanding of what these data mean. Since ontologies have been used to express formally a shared understanding of information, we argue that they are a way towards Semantic SEEs. In this paper we discuss an ontology-based approach to tool integration and present ODE, an ontology-based SEE

    Extreme events and event size fluctuations in biased random walks on networks

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    Random walk on discrete lattice models is important to understand various types of transport processes. The extreme events, defined as exceedences of the flux of walkers above a prescribed threshold, have been studied recently in the context of complex networks. This was motivated by the occurrence of rare events such as traffic jams, floods, and power black-outs which take place on networks. In this work, we study extreme events in a generalized random walk model in which the walk is preferentially biased by the network topology. The walkers preferentially choose to hop toward the hubs or small degree nodes. In this setting, we show that extremely large fluctuations in event-sizes are possible on small degree nodes when the walkers are biased toward the hubs. In particular, we obtain the distribution of event-sizes on the network. Further, the probability for the occurrence of extreme events on any node in the network depends on its 'generalized strength', a measure of the ability of a node to attract walkers. The 'generalized strength' is a function of the degree of the node and that of its nearest neighbors. We obtain analytical and simulation results for the probability of occurrence of extreme events on the nodes of a network using a generalized random walk model. The result reveals that the nodes with a larger value of 'generalized strength', on average, display lower probability for the occurrence of extreme events compared to the nodes with lower values of 'generalized strength'

    Screening for HLA-B*1502 Polymorphism in Febrile Seizure Predicted Lead to Epilepsy

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    Mutation in neuronal sodium channel -1-subunit gene (SCN1A) and neuronal sodium channel -1-subunit gene (SCN1B) has been linked with forms of generalized epilepsy with febrile seizure plus (GEFS+) and epileptic infantile syndrome like severe myoclonic epilepsy of infancy (SMEI) (Mulley et al., 2005; Scheffer et al., 2007). Since this idiopathic epilepsy typically begins with prolonged febrile seizures (FS) in the first year of life, therefore febrile seizure patient with mutation in SCN1A has a high risk to develop epilepsy on their later life (Dube et al., 2009). Carbamazepine (CBZ) has been known as the most common anti-epileptic drug which can cause Steven-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) in patients with HLA-B*1502 polymorphism. Since the Javanese population have 16,67% of these allele, studying the presence of these allele in patients predicted epilepsy is important. Furthermore, this study was intended to develop a PCR-based diagnostic protocol to screen HLA-B*1502 polymorphism in epileptic patients to prevent SJS/TEN by carbamazepine. Focusing on epileptic predicted patients, HLA-B*1502 genotyping by sequence specific primer (SSP)-PCR was performed on 31 repeated FS patients with mutation in SCN1A and SCN1A/SCN1B gene. The result show that the HLA-B*1502 polymorphism was detected in 14 (45,2%) individuals including 8 cases related to mutation SCN1A gene and 6 to SCN1A/SCN1B gene. It illustrates that HLA-B*1502 allele is frequent in these patients. It can thus be suggested that detection of this allele should be done before epilepsy treatment. Later, patients with this allele should avoid CBZ to prevent SJS/TEN during drug administration

    Levels of mercury and arsenic contamination in popular fish and shrimp brands consumed in Saudi Arabia

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    ABSTRACT. Fish and shrimp are public sources of healthy protein for a large fragment of the Saudi population. Therefore, the present work was conducted to assess the level of possible arsenic (As) and mercury (Hg)          con­tamination of these sea foods. Eight species of ïŹsh and two species of shrimp were collected from the local mar­kets of Eastern Province, Saudi Arabia. Mercury and arsenic concentration of samples was determined by hydride generation atomic absorption spectrometry (HG-AAS). Highest average concentration of total Hg was found in Siganus canaliculatus (0.54 ± 0.06 ”g/g) while the lowest level was detected in Lethrinus miniatus (0.24 ± 0.07 ”g/g). For shrimp species, the levels varied from 0.13 to 0.91 ”g/g for mercury and 0.19 to 0.53 ”g/g for arsenic. The rank order of shrimp species based upon mercury level was Penaeus semisulcatus > Penaeus indicus; whereas based upon arsenic level it was almost similar. Mean levels of both Hg and As in all the species studied are lower than the limits set by international health agencies; 0.550 ”g/g for mercury and 6.0 ”g/g for arsenic.               KEY WORDS: Arabian Gulf, Fish, Shrimp, Arsenic, Mercury Bull. Chem. Soc. Ethiop. 2019, 33(3), 573-578.      DOI: https://dx.doi.org/10.4314/bcse.v33i3.1

    Developing an Equivalent Solid Material Model for BCC Lattice Cell Structures Involving Vertical and Horizontal Struts

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    In this study, a body-centered cubic (BCC) lattice unit cell occupied inside a frame structure to create a so-called “InsideBCC” is considered. The equivalent quasi-isotropic properties required to describe the material behavior of the InsideBCC unit cell are equivalent Young’s modulus ( E e ) , equivalent shear modulus ( G e ) , and equivalent Poisson’s ratio ( Îœ e ) . The finite element analysis (FEA) based computational approach is used to simulate and calculate the mechanical responses of InsideBCC unit cell, which are the mechanical responses of the equivalent solid. Two separates finite element models are then developed for samples under compression: one with a 6 × 6 × 4 cell InsideBCC lattice cell structure (LCS) and one completely solid with equivalent solid properties obtained from a unit cell model. In addition, 6 × 6 × 4 cell specimens are fabricated on a fused deposition modeling (FDM) uPrint SEplus 3D printer using acrylonitrile butadiene styrene (ABS) material and tested experimentally under quasi-static compression load. Then, the results extracted from the finite element simulation of both the entire lattice and the equivalent solid models are compared with the experimental data. A good agreement between the experimental stress–strain behavior and that obtained from the FEA models is observed within the linear elastic limit
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