173 research outputs found

    Task Scheduling with RT Constraints

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    This paper addresses the problem of scheduling reactive realtime transactions (task groups) implementing a network of extended Finite State Machines communicating asynchronously. Task instances are..

    An automatic abstraction technique for verifying featured, parameterised systems

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    A general technique combining model checking and abstraction is presented that allows property based analysis of systems consisting of an arbitrary number of featured components. We show how parameterised systems can be specified in a guarded command form with constraints placed on variables which occur in guards. We prove that results that hold for a small number of components can be shown to scale up. We then show how featured systems can be specified in a similar way, by relaxing constraints on guards. The main result is a generalisation theorem for featured systems which we apply to two well known examples

    Schools and civil society : corporate or community governance

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    School improvement depends upon mediating the cultural conditions of learning as young people journey between their parochial worlds and the public world of cosmopolitan society. Governing bodies have a crucial role in including or diminishing the representation of different cultural traditions and in enabling or frustrating the expression of voice and deliberation of differences whose resolution is central to the mediation of and responsiveness to learning needs. A recent study of governing bodies in England and Wales argues that the trend to corporatising school governance will diminish the capacity of schools to learn how they can understand cultural traditions and accommodate them in their curricula and teaching strategies. A democratic, stakeholder model remains crucial to the effective practice of governing schools. By deliberating and reconciling social and cultural differences, governance constitutes the practices for mediating particular and cosmopolitan worlds and thus the conditions for engaging young people in their learning, as well as in the preparation for citizenship in civil society

    Characteristics productive and meat quality of broiler chickens fed finisher diet without vitamin-mineral supplement or limestone and dicalcium phosphate and submitted to heat stress pre-slaughter

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    Search mechanisms that can reduce the cost of production of poultry is an important factor in the poultry industry. Thus the objective of this study was to evaluate the removal of vitamin and mineral supplement or limestone and dicalcium phosphate feed during the finishing phase, further of the broilers chickens to heat stress pre-slaughter. Hybro male broiler (n=108) aged 42 days old were evaluated until 49 days old to evaluate the performance, carcass and cuts yield, blood biochemistry and meat quality. The results showed that the removal of vitamin and mineral supplement or limestone and dicalcium phosphate feed during the finishing phase did not impair the performance, carcass characteristics and meat quality, as well as showing a possible mechanism to reduce production costs. While heat stress pre-slaughter provided a poor meat quality of poultry.3323371337

    POTENCIAL ALCALINIZANTE DA SOLUÇÃO DE RINGER COM LACTATO EM OVELHAS SADIAS

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    The alkalinizing power of Lactated Ringer’s Solution (LRS) was searched in this work. Six crossbred healthy ewes, nonpregnant and nonlactating, weighting approximately 40 kg, received 4 L of LRS by 4 hours continuous intravenous infusion at a rate of  25 mL/kg/h. The venous blood samples were obtained before the infusion (0 hours), during the infusion (2 hours), at the end of the infusion (4 hours), and 2 hours after the end of the infusion (6 hours). Values of pH, pCO2, HCO3-, TCO2, BE, Na+, K+, Cl- and lactate L were determined. The LRS induced mild increase in the alkali reserve confirming its low magnitude alkalinizing power, as a result of the small sodium lactate concentration present in the solution.   KEY WORDS: Sheep, acid-base balance, sodium lactate, intravenous solution

    A General Framework for Architecture Composability

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    Architectures depict design principles: paradigms that can be understood by all, allow thinking on a higher plane and avoiding low-level mistakes. They provide means for ensuring correctness by construction by enforcing global properties characterizing the coordination between components. An architecture can be considered as an operator A that, applied to a set of components B, builds a composite component A(B) meeting a characteristic property Φ. Architecture composability is a basic and common problem faced by system designers. In this paper, we propose a formal and general framework for architecture composability based on an associative, commutative and idempotent architecture composition operator ⊕. The main result is that if two architectures A1 and A2 enforce respectively safety properties Φ1 and Φ2 , the architecture A1 ⊕ A2 enforces the property Φ1 ∧ Φ2 , that is both properties are preserved by architecture composition. We also establish preservation of liveness properties by architecture composition. The presented results are illustrated by a running example and a case study

    Genetic and Functional Role of TNF-alpha in the Development Trypanosoma cruzi Infection

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    TNF-alpha plays an important role in trypanocidal mechanisms and is related to tissue injury. This cytokine has been detected in the heart of human chagasic patients where it is associated with tissue damage. This study investigated whether TNF-alpha levels and the presence of genetic polymorphisms are associated with the presence of T. cruzi infection and/or with the development of the cardiac form in chronic chagasic patients. Genomic DNA of 300 subjects from an endemic area was extracted and analyzed by PCR using specific primers. TNF-alpha was assayed in culture supernatants by ELISA. An association was observed between the absence of the TNF-238A allele and negative serology. Furthermore, seropositive individuals carrying the TNF-238A allele produced significantly higher TNF-alpha levels without stimulation (p = 0.04) and after stimulation with LPS (p = 0.007) and T. cruzi antigens (p = 0.004). The present results suggest that the polymorphism at position -238 influences susceptibility to infection and that this allele is associated with higher TNF-alpha production in seropositive individuals
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