74 research outputs found

    Computable decision making on the reals and other spaces via partiality and nondeterminism

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    Though many safety-critical software systems use floating point to represent real-world input and output, programmers usually have idealized versions in mind that compute with real numbers. Significant deviations from the ideal can cause errors and jeopardize safety. Some programming systems implement exact real arithmetic, which resolves this matter but complicates others, such as decision making. In these systems, it is impossible to compute (total and deterministic) discrete decisions based on connected spaces such as R\mathbb{R}. We present programming-language semantics based on constructive topology with variants allowing nondeterminism and/or partiality. Either nondeterminism or partiality suffices to allow computable decision making on connected spaces such as R\mathbb{R}. We then introduce pattern matching on spaces, a language construct for creating programs on spaces, generalizing pattern matching in functional programming, where patterns need not represent decidable predicates and also may overlap or be inexhaustive, giving rise to nondeterminism or partiality, respectively. Nondeterminism and/or partiality also yield formal logics for constructing approximate decision procedures. We implemented these constructs in the Marshall language for exact real arithmetic.Comment: This is an extended version of a paper due to appear in the proceedings of the ACM/IEEE Symposium on Logic in Computer Science (LICS) in July 201

    LifeGene : a large prospective population-based study of global relevance

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    Studying gene-environment interactions requires that the amount and quality of the lifestyle data is comparable to what is available for the corresponding genomic data. Sweden has several crucial prerequisites for comprehensive longitudinal biomedical research, such as the personal identity number, the universally available national health care system, continuously updated population and health registries and a scientifically motivated population. LifeGene builds on these strengths to bridge the gap between basic research and clinical applications with particular attention to populations, through a unique design in a research-friendly setting. LifeGene is designed both as a prospective cohort study and an infrastructure with repeated contacts of study participants approximately every 5 years. Index persons aged 18-45 years old will be recruited and invited to include their household members (partner and any children). A comprehensive questionnaire addressing cutting-edge research questions will be administered through the web with short follow-ups annually. Biosamples and physical measurements will also be collected at baseline, and re-administered every 5 years thereafter. Event-based sampling will be a key feature of LifeGene. The household-based design will give the opportunity to involve young couples prior to and during pregnancy, allowing for the first study of children born into cohort with complete pre-and perinatal data from both the mother and father. Questions and sampling schemes will be tailored to the participants' age and life events. The target of LifeGene is to enroll 500,000 Swedes and follow them longitudinally for at least 20 years.Stockholm County CouncilVetenskapsrådetKarolinska InstitutetTorsten and Ragnar Söderbergs FoundationAFA FörsäkringarManuscrip

    Roadmap for a precision-medicine initiative in the Nordic region

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    The Nordic region, comprising primarily Denmark, Estonia, Finland, Iceland, Norway and Sweden, has many of the necessary characteristics for being at the forefront of genome-based precision medicine. These include egalitarian and universal healthcare, expertly curated patient and population registries, biobanks, large population-based prospective cohorts linked to registries and biobanks, and a widely embraced sense of social responsibility that motivates public engagement in biomedical research. However, genome-based precision medicine can be achieved only through coordinated action involving all actors in the healthcare sector. Now is an opportune time to organize scientists in the Nordic region, together with other stakeholders including patient representatives, governments, pharmaceutical companies, academic institutions and funding agencies, to initiate a Nordic Precision Medicine Initiative. We present a roadmap for how this organization can be created. The Initiative should facilitate research, clinical trials and knowledge transfer to meet regional and global health challenges.Non peer reviewe

    The Swedish Twin Registry in the Third Millennium: An Update

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    Abstract The Swedish Twin Registry was first established in the late 1950s. Today it includes more than 170,000 twins — in principle all twins born in Sweden since 1886. In this article we describe some ongoing and recently completed projects based on the registry. In particular, we describe recent efforts to screen all twins born between 1959 and 1985, and young twin pairs when they turn 9 and 12 years of age. For these studies, we present initial frequencies of common conditions and exposures

    Variation in the Structure of Bird Nests between Northern Manitoba and Southeastern Ontario

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    Traits that converge in appearance under similar environmental conditions among phylogenetically independent lineages are thought to represent adaptations to local environments. We tested for convergence in nest morphology and composition of birds breeding in two ecologically different locations in Canada: Churchill in northern Manitoba and Elgin in southeastern Ontario. We examined nests from four families of passerine birds (Turdidae: Turdus, Parulidae: Dendroica, Emberizidae: Passerculus and Fringillidae: Carduelis) where closely related populations or species breed in both locations. Nests of American Robins, Yellow Warblers, and Carduelis finches had heavier nest masses, and tended to have thicker nest-walls, in northern Manitoba compared with conspecifics or congenerics breeding in southeastern Ontario. Together, all species showed evidence for wider internal and external nest-cup diameters in northern Manitoba, while individual species showed varying patterns for internal nest-cup and external nest depths. American Robins, Yellow Warblers, and Carduelis finches in northern Manitoba achieved heavier nest masses in different ways. American Robins increased all materials in similar proportions, and Yellow Warblers and Common Redpolls used greater amounts of select materials. While changes in nest composition vary uniquely for each species, the pattern of larger nests in northern Manitoba compared to southeastern Ontario in three of our four phylogenetically-independent comparisons suggests that birds are adapting to similar selective pressures between locations

    Tripping on Acid: Trans-Kingdom Perspectives on Biological Acids in Immunity and Pathogenesis

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    Micronutrient malnutrition and biofortification: recent advances and future perspectives

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    Micronutrients malnutrition is of great public health importance in several parts of the world, especially the developing and underdeveloped countries. It has been estimated that about 2 billion people, about one third of the world’s population, are deficient in one or more mineral elements. Although required in traces, these mineral elements are involved in many vital metabolic functions. Micronutrient deficiencies in humans can be remedied through food diversification, mineral supplementation, food fortification, and biofortification. Biofortification is the strategy of increasing the content of bioavailable nutrients in the edible parts of staple food crops for better human nutrition. Staple crops such as maize, rice, and wheat provide most of the calories for low-income families around the globe. However, staple crop-based diets fall far short in providing the required amounts of micronutrients and heavy reliance on staple food is the root cause of micronutrient malnutrition. Biofortification includes the enhanced uptake of such minerals from soils, their transport to edible plant parts, and improving the bioavailability of these minerals. International initiatives have recently released several plant cultivars with increased bioavailable micronutrient concentrations in their edible parts. The use of these biofortified cultivars is expected to mitigate micronutrient malnourishment in large populations especially in Africa. Crop breeding, genetic manipulation, and application of mineral fertilizers are the bases of biofortification strategies and have enormous potential to address micronutrient malnourishment. In this chapter, crop biofortification for zinc, iron, vitamin A, and iodine has been discussed. Biofortification is a proven strategy to combat micronutrient deficiency in large populations, particularly for those living in developing countries. However, to make it more effective, efficient, and acceptable for people, better planning, implementation, monitoring, and evaluation of biofortification programs are needed to produce cost-effective and socially acceptable biofortified food crops. Food safety, quality assurance, and legal framework also need to be considered while developing any biofortification strategy

    Heterogeneity in vaccination coverage explains the size and occurrence of measles epidemics in German surveillance data

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    The objective of this study was to characterize empirically the association between vaccination coverage and the size and occurrence of measles epidemics in Germany. In order to achieve this we analysed data routinely collected by the Robert Koch Institute, which comprise the weekly number of reported measles cases at all ages as well as estimates of vaccination coverage at the average age of entry into the school system. Coverage levels within each federal state of Germany are incorporated into a multivariate time-series model for infectious disease counts, which captures occasional outbreaks by means of an autoregressive component. The observed incidence pattern of measles for all ages is best described by using the log proportion of unvaccinated school starters in the autoregressive component of the model
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