405 research outputs found

    Fast-Sec: an approach to secure Big Data processing in the cloud

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    Group Security is an important concern in computer systems, which is especially remarkable when the system has to handle large amounts of data and some different users accessing this data with different accessing permissions. This work proposes an innovative approach for providing a security infrastructure support to Big Data Analytic in Cloud-based systems named Fast-sec. Fast-Sec handles systems with large volumes of data from heterogeneous sources, in which users may access the system by different platforms, consuming or providing data. The security infrastructure proposed in Fast-Sec provides an authentication mechanism for users, and data access control adapted to high demands from cloud-based Big Data environment. The reported results show the adequacy of the proposed safety infrastructure to the cloud-based systems processing Big Data. © 2017 Informa UK Limited, trading as Taylor & Franci

    Wheat-barley hybridization – the last forty years

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    Abstract Several useful alien gene transfers have been reported from related species into wheat (Triticum aestivum), but very few publications have dealt with the development of wheat/barley (Hordeum vulgare) introgression lines. An overview is given here of wheat 9 barley hybridization over the last forty years, including the development of wheat 9 barley hybrids, and of addition and translocation lines with various barley cultivars. A short summary is also given of the wheat 9 barley hybrids produced with other Hordeum species. The meiotic pairing behaviour of wheat 9 barley hybrids is presented, with special regard to the detection of wheat– barley homoeologous pairing using the molecular cytogenetic technique GISH. The effect of in vitro multiplication on the genome composition of intergeneric hybrids is discussed, and the production and characterization of the latest wheat/barley translocation lines are presented. An overview of the agronomical traits (b-glucan content, earliness, salt tolerance, sprouting resistance, etc.) of the newly developed introgression lines is given. The exploitation and possible use of wheat/barley introgression lines for the most up-to-date molecular genetic studies (transcriptome analysis, sequencing of flow-sorted chromosomes) are also discussed

    Na+ current expression in human atrial myofibroblasts: identity and functional roles

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    In the mammalian heart fibroblasts have important functional roles in both healthy conditions and diseased states. During pathophysiological challenges, a closely related myofibroblast cell population emerges, and can have distinct and significant roles.Recently, it has been reported that human atrial myofibroblasts can express a Na+ current, INa. Some of the biophysical properties and molecular features suggest that this INa is due to expression of Nav 1.5, the same Na+ channel α subunit that generates the predominant INa in myocytes from adult mammalian heart. In principle, expression of Nav 1.5 could give rise to regenerative action potentials in the fibroblasts/myofibroblasts. This would suggest an active as opposed to passive role for fibroblasts/myofibroblasts in both the ‘trigger’ and the ‘substrate’ components of cardiac rhythm disturbances.Our goals in this preliminary study were: (i) to confirm and extend the electrophysiological characterization of INa in a human atrial fibroblast/myofibroblast cell population maintained in conventional 2-D tissue culture; (ii) to identify key molecular properties of the α and β subunits of these Na+ channel(s); (iii) to define the biophysical and pharmacological properties of this INa ; (iv) to integrate the available multi-disciplinary data, and attempt to illustrate its functional consequences, using a mathematical model in which the human atrial myocyte is coupled via connexins to fixed numbers of fibroblasts/myofibroblasts in a syncytial arrangement.Our experimental findings confirm that a significant fraction (~40-50%) of these human atrial myofibroblasts can express INa. However, our results suggest that INa may be generated by Nav 1.9, Nav 1.2, and Nav 1.5. Our findings, when complemented with mathematical modeling, provide a background for re-evaluating pharmacological management of supraventricular rhythm disorders, e.g. persistent atrial fibrillation

    Trebinje - Orguljaški koncert Željke Spinčić

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    Female southern elephant seals, Mirounga leonina, assemble in large groups and each gives birth to a single pup which is nursed for some 3 weeks. Weaning mass is highly variable; some pups are three times as heavy as others at weaning. After weaning, the pup fasts for several weeks before departing to sea. The function of this fast is unknown. We examined the relationships between maternal mass, pup weaning mass, and pup behaviour during the postweaning fast in 377 pups and 128 adult females over four breeding seasons at South Georgia. Pup weaning mass was positively related to maternal postpartum mass, which accounted for 55% of the variation in weaning mass. Over all 4 years male pups were significantly heavier at weaning than female pups (130 vs. 123 kg) but this difference disappeared after maternal mass was controlled for. After fasting for 21–66 days, weaned pups went to sea at an average of 68% of weaning mass. Heavier pups remained on the beach longer after weaning than lighter pups. There was no evidence that pups synchronized their departure to sea. Only male pups were observed to take part in mock fights. With increasing age, weaned pups spent more time in the water. Mortality during the postweaning fast was negligible (0.1 %). The timing of departure of weaned pups may involve a trade-off between an early departure with greater fat (energy) stores but poorer foraging ability and a late departure with increased swimming, diving, and social skills but reduced fat stores

    EDGeS: a bridge between desktop grids and service grids

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    Desktop grids and service grids widely used by their different users communities as efficient solutions for making full use of computing power and achieving loads balances across Intranet or Internet. Nevertheless,little work has been done to combine these two grids technologies together to establish a seamless and vast grid resources pool. In this paper we will present a new European FP7 infrastructure project:EDGeS (enabling desktop grids for e-science), which aim to build technological bridges to facilitate interoperability between desktop grid and service grid. We give also a taxonomy of existing grid systems: desktop grids such as BONIC and XtremWeb, service grids such as EGEE. Then we describe furtherly our solution for identifying translation technologies for porting applications between desktop grids and service grids, and vice versa. There are three themes in our solution, which discuss actual popular bridging technologies, user access issues, and distributed data issues about deployment and application development

    Cytomolecular identification of individual wheat-wheat chromosome arm associations in wheat-rye hybrids

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    Chromosome pairing in the meiotic metaphase I of wheatrye hybrids has been characterized by sequential genomic and fluorescent in situ hybridization allowing not only the discrimination of wheat and rye chromosomes, but also the identification of the individual wheat and rye chromosome arms involved in the chromosome associations. The majority of associations (93.8%) were observed between the wheat chromosomes. The largest number of wheat-wheat chromosome associations (53%) was detected between the A and D genomes, while the frequency of B-D and A-B associations was significantly lower (32 and 8%, respectively). Among the A-D chromosome associations, pairing between the 3AL and 3DL arms was observed with the highest frequency, while the most frequent of all the chromosome associations (0.113/ cell) was found to be the 3DS-3BS. Differences in the pairing frequency of the individual chromosome arms of wheat-rye hybrids have been discussed in relation to the homoeologous relationships between the constituent genomes of hexaploid wheat
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