97 research outputs found

    Scaling Static Analyses at Facebook

    Get PDF

    Logahedra: A new weakly relational domain

    Get PDF
    Weakly relational numeric domains express restricted classes of linear inequalities that strike a balance between what can be described and what can be efficiently computed. Popular weakly relational domains such as bounded differences and octagons have found application in model checking and abstract interpretation. This paper introduces logahedra, which are more expressiveness than octagons, but less expressive than arbitrary systems of two variable per inequality constraints. Logahedra allow coefficients of inequalities to be powers of two whilst retaining many of the desirable algorithmic properties of octagons

    Nuclear and chloroplast microsatellite diversity in Phaseolus vulgaris L. from Sardinia (Italy).

    Get PDF
    Studies of the level and the structure of the genetic diversity of local varieties of Phaseolus vulgaris are of fundamental importance, both for the management of genetic resources and to improve our understanding of the pathways of dissemination and the evolution of this species in Europe. We have here characterized 73 local bean populations from Sardinia (Italy) using seed traits and molecular markers (phaseolins, nuSSRs and cpSSRs). American landraces and commercial varieties were also included for comparison. We see that: (a) the Sardinian material is distinct from the commercial varieties considered; (b) the variation in the seed traits is high and it mostly occurs among populations (95%); (c) compared to the American sample and the commercial varieties, the Sardinian collection has a low level of diversity; (d) the majority ([95%) of the Sardinian individuals belong to the Andean gene pool; (e) the Sardinian material shows a strong genetic structure, both for cpSSRs and nuSSRs; (f) the nuSSRs and cpSSRs concur in differentiating between gene pools, but a lack of congruence between nuclear and chloroplast has been observed within gene pools; and (g) there are three putative hybrids between the Andean and Mesoamerican gene pools. Despite the relatively low level of diversity, which is probably due to a strong founder effect, the Sardinian landraces are worth being conserved and studied further because of their distinctiveness and because hybridization within and between the gene pools could generate variation that will be useful for breeding

    THE POTENTIAL OF PHYSIOLOGICAL ANALYSIS USING ELECTROMYOGRAPHY IN THE DESIGN OF MOTORCYCLES

    Get PDF
    Two-wheel vehicle comfort is usually assessed by means of subjective scorings or by measuring physical quantities such as acceleration, sound pressure, etc. which do not depend on the human response. This study has chosen a different approach, which is to use electromyography for evaluating the levels of muscle activity. It focuses more specifically on comfort in relation to aerodynamic loads. The loads were simulated by a wind tunnel. ANOVA statistical analysis was used to establish the impact of aerodynamic loads and of various motorcycle models on muscle activity levels. The results showed that aerodynamic loads generally cause an increase of muscle activity, although their impact varies in relation to the design of the motorcycle: each model ofmotorcycle produces a specific distribution of activity levels among muscles. The methodology can be used for vehicle-design purposes as well as organising motorbike training programmes.Keywords: Motorcycle; Aerodynamic loads; SEM; Ergonomics; Comfor

    Breeding effects on durum wheat traits detected using GWAS and haplotype block analysis

    Get PDF
    IntroductionThe recent boosting of genomic data in durum wheat (Triticum turgidum subsp. durum) offers the opportunity to better understand the effects of breeding on the genetic structures that regulate the expression of traits of agronomic interest. Furthermore, the identification of DNA markers useful for marker-assisted selection could also improve the reliability of technical protocols used for variety protection and registration.MethodsWithin this motivation context, 123 durum wheat accessions, classified into three groups: landraces (LR), ancient (OC) and modern cultivars (MC), were evaluated in two locations, for 34 agronomic traits, including UPOV descriptors, to assess the impact of changes that occurred during modern breeding.ResultsThe association mapping analysis, performed with 4,241 SNP markers and six multi-locus-GWAS models, revealed 28 reliable Quantitative Trait Nucleotides (QTNs) related to plant morphology and kernel-related traits. Some important genes controlling flowering time and plant height were in linkage disequilibrium (LD) decay with QTNs identified in this study. A strong association for yellow berry was found on chromosome 6A (Q.Yb-6A) in a region containing the nadh-ubiquinone oxidoreductase subunit, a gene involved in starch metabolism. The Q.Kcp-2A harbored the PPO locus, with the associated marker (Ku_c13700_1196) in LD decay with Ppo-A1 and Ppo-A2. Interestingly, the Q.FGSGls-2B.1, identified by RAC875_c34512_685 for flag leaf glaucosity, mapped less than 1 Mb from the Epistatic inhibitors of glaucousness (Iw1), thus representing a good candidate for supporting the morphological DUS traits also with molecular markers. LD haplotype block approach revealed a higher diversity, richness and length of haploblocks in MC than OC and LR (580 in LR, 585 in OC and 612 in MC), suggesting a possible effect exerted by breeding programs on genomic regions associated with the agronomic traits.DiscussionOur findings pave new ways to support the phenotypic characterization necessary for variety registration by using a panel of cost-effectiveness SNP markers associated also to the UPOV descriptors. Moreover, the panel of associated SNPs might represent a reservoir of favourable alleles to use in durum wheat breeding and genetics

    Interval Slopes as Numerical Abstract Domain for Floating-Point Variables

    Full text link
    The design of embedded control systems is mainly done with model-based tools such as Matlab/Simulink. Numerical simulation is the central technique of development and verification of such tools. Floating-point arithmetic, that is well-known to only provide approximated results, is omnipresent in this activity. In order to validate the behaviors of numerical simulations using abstract interpretation-based static analysis, we present, theoretically and with experiments, a new partially relational abstract domain dedicated to floating-point variables. It comes from interval expansion of non-linear functions using slopes and it is able to mimic all the behaviors of the floating-point arithmetic. Hence it is adapted to prove the absence of run-time errors or to analyze the numerical precision of embedded control systems

    Multivariant Assertion-based Guidance in Abstract Interpretation

    Full text link
    Approximations during program analysis are a necessary evil, as they ensure essential properties, such as soundness and termination of the analysis, but they also imply not always producing useful results. Automatic techniques have been studied to prevent precision loss, typically at the expense of larger resource consumption. In both cases (i.e., when analysis produces inaccurate results and when resource consumption is too high), it is necessary to have some means for users to provide information to guide analysis and thus improve precision and/or performance. We present techniques for supporting within an abstract interpretation framework a rich set of assertions that can deal with multivariance/context-sensitivity, and can handle different run-time semantics for those assertions that cannot be discharged at compile time. We show how the proposed approach can be applied to both improving precision and accelerating analysis. We also provide some formal results on the effects of such assertions on the analysis results.Comment: Pre-proceedings paper presented at the 28th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2018), Frankfurt am Main, Germany, 4-6 September 2018 (arXiv:1808.03326

    Information-flow Analysis of Hibernate Query Languages

    Get PDF
    Hibernate Query Language (HQL) provides a framework for mapping object-oriented domain models to traditional relational databases. In this context, existing information leakage analyses cannot be applied directly, due to the presence and interaction of high-level application variables and SQL database attributes. The paper extends the Abstract Interpretation framework to properly deal with this challenging applicative scenario, by using the symbolic domain of positive propositional formulae to capture variable dependences affecting (directly or indirectly) the propagation of confidential data

    The International Cancer Expert Corps: A Unique Approach for Sustainable Cancer Care in Low and Lower-Middle Income Countries

    Get PDF
    The growing burden of non-communicable diseases including cancer in low- and lower-middle income countries (LMICs) and in geographic-access limited settings within resource-rich countries requires effective and sustainable solutions. The International Cancer Expert Corps (ICEC) is pioneering a novel global mentorship–partnership model to address workforce capability and capacity within cancer disparities regions built on the requirement for local investment in personnel and infrastructure. Radiation oncology will be a key component given its efficacy for cure even for the advanced stages of disease often encountered and for palliation. The goal for an ICEC Center within these health disparities settings is to develop and retain a high-quality sustainable workforce who can provide the best possible cancer care, conduct research, and become a regional center of excellence. The ICEC Center can also serve as a focal point for economic, social, and healthcare system improvement. ICEC is establishing teams of Experts with expertise to mentor in the broad range of subjects required to establish and sustain cancer care programs. The Hubs are cancer centers or other groups and professional societies in resource-rich settings that will comprise the global infrastructure coordinated by ICEC Central. A transformational tenet of ICEC is that altruistic, human-service activity should be an integral part of a healthcare career. To achieve a critical mass of mentors ICEC is working with three groups: academia, private practice, and senior mentors/retirees. While in-kind support will be important, ICEC seeks support for the career time dedicated to this activity through grants, government support, industry, and philanthropy. Providing care for people with cancer in LMICs has been a recalcitrant problem. The alarming increase in the global burden of cancer in LMICs underscores the urgency and makes this an opportune time fornovel and sustainable solutions to transform cancer care globally
    corecore