995 research outputs found

    Trace checking of Metric Temporal Logic with Aggregating Modalities using MapReduce

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    Modern complex software systems produce a large amount of execution data, often stored in logs. These logs can be analyzed using trace checking techniques to check whether the system complies with its requirements specifications. Often these specifications express quantitative properties of the system, which include timing constraints as well as higher-level constraints on the occurrences of significant events, expressed using aggregate operators. In this paper we present an algorithm that exploits the MapReduce programming model to check specifications expressed in a metric temporal logic with aggregating modalities, over large execution traces. The algorithm exploits the structure of the formula to parallelize the evaluation, with a significant gain in time. We report on the assessment of the implementation - based on the Hadoop framework - of the proposed algorithm and comment on its scalability.Comment: 16 pages, 6 figures, Extended version of the SEFM 2014 pape

    Development and Use of a Tool for Automated Alignments of Genes in the Rice BAC\u27s GenBank Card Against Other Species

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    In many cases, the analysis of the genetic bases of any trait requires molecular markers and if possible co-dominant PCR-based ones. In perennial fodder species, the number of publicly available markers (microsatellites and Sequence Tagged Site (STS)) is limited. Our goal is to use sequences from model grass species, i.e. rice, wheat, maize, barley, in L. perenne in order to develop STS markers in interesting regions such as under a QTL (Quantitative Trait Loci) or around a candidate gene,. As the genome sequence of rice is now available, the objective was to use the sequences of genes included in the BAC’s GenBank card from rice. As there are almost no available sequences in L. perenne, we are designing consensus primers from an alignment of at least two different species. The problem is that for all the genes included in a BAC, just a few have their sequences known in at least two species. It is very laborious to check “by hand” if each gene has an homologous sequence known in another species

    Estimation of the Coefficient of Double-Reduction in Autotetraploid Lucerne

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    Polyploidy plays an important role in the evolution of species and many cultivated species, particularly in angiosperms, are polyploids (Bever and Felber, 1992; Gallais, 2003). Autopolyploid species that show a tetrasomic inheritance have complex genetics. However, some theoretical models were built for: (1) genetic mapping (Hackett et al., 1998), (2) quantitative genetics (Gallais, 2003) and (3) population genetics (Ronfort et al., 1998). But in practice, most data analyses ignore one essential feature of tetrasomic inheritance that is double-reduction. Indeed, in an autotetraploid species, homologous chromosomes can form tetravalents at meiosis. In this case, a double-reduction is observed if crossing-over occurs between a locus and its centromere, and if the sister chromatids migrate to the same pole at anaphase I. The gametes may, thus, carry a pair of sister alleles. Double-reduction frequency is represented by the index of separation (α) (Demarly, 1963; Mather, 1935; Mather, 1936). The parameter α is considered as a product of four probabilities: α = q e a s (Gallais, 2003) in which “ q ” is the probability of multivalent formation, “ e ” the probability of first equational division, related to the frequency of crossing-over, “ a ” is the probability of non-disjunction at first anaphase and “s” is the probability of having two sister chromatids in the same gamete. If separation during anaphase II is random, s = ½. Consequently, α will be low for a gene located in the vicinity of the centromere and will increase with distance between the gene and the centromere. It was demonstrated that double-reduction events alter the rate of progression towards equilibrium under inbreeding or under random mating, modify the recombination rate between loci and also alter the rate of decay of linkage disequilibrium under random mating (Bever and Felber, 1992). Current theoretical models allow drawing genetic maps taking into account double-reduction (Luo et al., 2004). Thus, it is possible to estimate α for codominant loci in tetraploid species. To date, we have few estimates of the double-reduction frequency. Haynes and Douches (1993) on potato and Julier et al. (2003) on lucerne found that double-reduction occurs sporadically. In both studies, the low number of progenies hampered a precise estimation of α. The aim of our study was to estimate the frequency of double-reduction in a mapping population of lucerne that includes a large number of individuals

    Efficient Large-scale Trace Checking Using MapReduce

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    The problem of checking a logged event trace against a temporal logic specification arises in many practical cases. Unfortunately, known algorithms for an expressive logic like MTL (Metric Temporal Logic) do not scale with respect to two crucial dimensions: the length of the trace and the size of the time interval for which logged events must be buffered to check satisfaction of the specification. The former issue can be addressed by distributed and parallel trace checking algorithms that can take advantage of modern cloud computing and programming frameworks like MapReduce. Still, the latter issue remains open with current state-of-the-art approaches. In this paper we address this memory scalability issue by proposing a new semantics for MTL, called lazy semantics. This semantics can evaluate temporal formulae and boolean combinations of temporal-only formulae at any arbitrary time instant. We prove that lazy semantics is more expressive than standard point-based semantics and that it can be used as a basis for a correct parametric decomposition of any MTL formula into an equivalent one with smaller, bounded time intervals. We use lazy semantics to extend our previous distributed trace checking algorithm for MTL. We evaluate the proposed algorithm in terms of memory scalability and time/memory tradeoffs.Comment: 13 pages, 8 figure

    Wigner crystal versus Fermionization for one-dimensional Hubbard models with and without long-range interactions

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    The ground state properties of Hubbard model with or without long-range interactions in the regime with strongly repulsive on-site interaction are investigated by means of the exact diagonalization method. We show that the appearance of NN-crests in the density profile of a trapped N-fermion system is a natural result of "fermionization" between antiparallel-spin fermions in the strongly repulsive limit and can not be taken as the only signature of Wigner crystal phase, as the static structure factor does not show any signature of crystallization. On the contrary, both the density distribution and static structure factor of Hubbard model with strong long-range interactions display clear signature of Wigner crystal. Our results indicate the important role of long-range interaction in the formation of Wigner crystal.Comment: 7 pages, 7 figure

    Simian immunodeficiency virus infection in wild-caught chimpanzees from Cameroon

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    Simian immunodeficiency viruses (SIVcpz) infecting chimpanzees (Pan troglodytes) in west central Africa are the closest relatives to all major variants of human immunodeficiency virus type 1 ([HIV-1]; groups M, N and O), and have thus been implicated as the source of the human infections; however, information concerning the prevalence, geographic distribution, and subspecies association of SIVcpz still remains limited. In this study, we tested 71 wild-caught chimpanzees from Cameroon for evidence of SIVcpz infection. Thirty-nine of these were of the central subspecies (Pan troglodytes troglodytes), and 32 were of the Nigerian subspecies (Pan troglodytes vellerosus), as determined by mitochondrial DNA analysis. Serological analysis determined that one P. t. troglodytes ape (CAM13) harbored serum antibodies that cross-reacted strongly with HIV-1 antigens; all other apes were seronegative. To characterize the newly identified virus, 14 partially overlapping viral fragments were amplified from fecal virion RNA and concatenated to yield a complete SIVcpz genome (9,284 bp). Phylogenetic analyses revealed that SIVcpzCAM13 fell well within the radiation of the SIVcpzPtt group of viruses, as part of a clade including all other SIVcpzPtt strains as well as HIV-1 groups M and N. However, SIVcpzCAM13 clustered most closely with SIVcpzGAB1 from Gabon rather than with SIVcpzCAM3 and SIVcpzCAM5 from Cameroon, indicating the existence of divergent SIVcpzPtt lineages within the same geographic region. These data, together with evidence of recombination among ancestral SIVcpzPtt lineages, indicate long-standing endemic infection of central chimpanzees and reaffirm a west central African origin of HIV-1. Whether P. t. vellerosus apes are naturally infected with SIVcpz requires further study

    QTLs for Morphogenetic Traits in Medicago Truncatula

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    Plant morphogenesis that includes growth, development and flowering date, drives a large number of agronomical important traits in both grain and forage crops. Quantitative trait locus (QTL) mapping is a way to locate zones of the genome that are involved in the variations observed in a segregating population. Co-location of QTLs and candidate genes is an indication of the involvement of the genes in the variation. The objective of this study was to analyse segregation of aerial morphogenetic traits in a mapping population of recombinant inbred lines of the model legume species M. truncatula , to locate QTLs and candidate genes

    Genetic Diversity Among Alfalfa Cultivars Using SSR Markers

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    Alfalfa (Medicago sativa) is an autotetraploid, allogamous and heterozygous species. Cultivated varieties are synthetic cultivars, usually obtained through 3 or 4 generations of panmictic reproduction of a set of various numbers of parents. The parents can be clones, half-sib or full-sib families. The breeders apply selection pressure for some agronomic traits, to induce changes in the genetic background. The objective of this study was to investigate the differentiation level among seven cultivars originating from one breeding program, and between these cultivars and the breeding pool, with eight SSR markers

    Best Practices for the Prevention and Management of Diabetes and Obesity-Related Chronic Disease among Indigenous Peoples in Canada: A Review

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    AbstractObjectivesTo carry out a systematic review of interventions that have aimed at improving screening, treatment, prevention and management of type 2 diabetes and obesity-related chronic disease in Indigenous communities in Canada from 2008 to 2014, with the aim of identifying current best practices.MethodsA comprehensive literature review was carried out through an electronic database search using Medline, EMBASE, PubMED and Google scholar.ResultsWe identified 17 publications, comprising 13 evaluated interventions. Of them, 7 were school-based programs focused on children, 5 focused on adults, and 1 included both adults and children. Most interventions aimed at encouraging behaviour change, especially dietary change, but did little to address the underlying context of systemic marginalization and colonialism experienced in many Indigenous communities. Interventions focused on improving fitness were more effective than those aimed at dietary change. Overall, we found a range of successes among these interventions. Those that met with limited success reported that complex social issues and poverty presented challenges to effective intervention work in these communities. Participatory action research methods and community ownership of the intervention were found to be essential for project success.ConclusionsDiabetes-focused intervention research in Indigenous communities appears to be a low priority for Canadian funders and policymakers. More intervention research is urgently needed in these communities. To be effective, this work must take an approach that is historically deep and sufficiently broad as to enable the ideologic, policy and institutional changes necessary in order to achieve true equity. This will involve addressing colonialism, racism and social exclusion as broader determinants of health

    Possibilità di sviluppo della coltivazione del sorgo per l'alimentazione del bestiame in Somalia

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    In 1979, a trial concerning yield differences between 2 different periods of harvesting (soft dough and complete maturation of the grain) of a sorghum hybrid BR has been carried out in Afgoy (Somalia). The effects of four nitrogen level have been also evaluated. The results show no effect of different nitrogen levels on total dry matter production and grain quality. Maximum dry matter yield and maximum F.U. production has been reached at complete maturation of the grain. General level of grain yield has been restricted in consequence of bird damage in spite of the presence of the gene BR
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