595 research outputs found

    Simulation-based solution of stochastic mathematical programs with complementarity constraints: Sample-path analysis

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    We consider a class of stochastic mathematical programs with complementarity constraints, in which both the objective and the constraints involve limit functions or expectations that need to be estimated or approximated. Such programs can be used for modeling \\average" or steady-state behavior of complex stochastic systems. Recently, simulation-based methods have been successfully used for solving challenging stochastic optimization problems and equilibrium models. Here we broaden the applicability of so-called the sample-path method to include the solution of certain stochastic mathematical programs with equilibrium constraints. The convergence analysis of sample-path methods rely heavily on stability conditions. We first review necessary sensitivity results, then describe the method, and provide sufficient conditions for its almost-sure convergence. Alongside we provide a complementary sensitivity result for the corresponding deterministic problems. In addition, we also provide a unifying discussion on alternative set of sufficient conditions, derive a complementary result regarding the analysis of stochastic variational inequalities, and prove the equivalence of two different regularity conditions

    Flea beetles (Coleoptera: Chrysomelidae: Alticinae) collected by malaise trap method in Gölcük Natural Park (Isparta, Turkey), with a new record for Turkish fauna

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    This study is based on Alticinae (Coleoptera: Chrysomelidae) material collected by Malaise trapping which is different from other standardized collecting methods. A total of 19 flea beetle species belonging to 6 genera were collected from Gölcük Natural Park, Isparta (Turkey) during 2009. The species are listed in a table together with distributional data in Turkey. Among them, Longitarsus curtus (Allard, 1860) is recorded for the first time in Turkey. L. monticola Kutschera, 1863 and L. curtus are recently separated synonyms and thus all data referring to the distribution of both species are currently important. Hence, the zoogeographical distribution of the new record is reviewed with some remarks; habitus and genitalia are illustrated

    Spraying opened sugar beet pulp silage with oregano essential oil helps to sustain quality and stability

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    This study was conducted to determine the effects of spraying oregano essential oil (OEO) onto sugar beet pulp silage (SBPS) on silage quality and aerobic stability after opening. A factorial experiment with three replicates of three treatments and four time periods was conducted using laboratory-type plastic silos. The treatments were an untreated control, silage sprayed with 10 ml/75 cm2 OEO, and silage sprayed with 20 ml/75 cm2 OEO. The silages were sampled at 0, 72, 120, and 168 hours after spraying. Temperature, L*, a*, and b* colour values, pH, water-soluble carbohydrates, crude nutrient contents, Fleig score, metabolizable energy (ME) value, lactic acid bacteria (LAB), total live bacteria (TLB), yeast, and mould formation were assessed. Spraying OEO onto SBPS did not affect L*, a*, and b* values, pH, water-soluble carbohydrates, and Fleig score values, but decreased temperature. Spraying OEO onto the silage increased organic matter, ether extract, acid detergent fibre, neutral detergent fibre and acid detergent lignin contents without affecting crude protein, crude fibre, nitrogen free extract, and ME contents. Irrespective of treatment, crude protein, ether extract, acid detergent fibre, acid detergent lignin, nitrogen free extract, Fleig score, and ME contents of silages increased with time after spraying. The OEO spraying reduced LAB, TLB, and yeast contents in silages. In conclusion, OEO spraying onto opened SBPS reduced LAB, TLB, and yeast formation and stopped mould growth up to 72 hours without affecting their nutritional properties, suggesting that OEO could be used to ensure the stability of SBPS. Keywords: aerobic stability, mould growth, silage microbiology, nutrients, feeding managemen

    Critical Binder cumulant and universality: Fortuin-Kasteleyn clusters and order-parameter fluctuations

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    We investigate the dependence of the critical Binder cumulant of the magnetization and the largest Fortuin-Kasteleyn cluster on the boundary conditions and aspect ratio of the underlying square Ising lattices. By means of the Swendsen-Wang algorithm, we generate numerical data for large system sizes and we perform a detailed finite-size scaling analysis for several values of the aspect ratio rr, for both periodic and free boundary conditions. We estimate the universal probability density functions of the largest Fortuin-Kasteleyn cluster and we compare it to those of the magnetization at criticality. It is shown that these probability density functions follow similar scaling laws, and it is found that the values of the critical Binder cumulant of the largest Fortuin-Kasteleyn cluster are upper bounds to the values of the respective order-parameter's cumulant, with a splitting behavior for large values of the aspect ratio. We also investigate the dependence of the amplitudes of the magnetization and the largest Fortuin-Kasteleyn cluster on the aspect ratio and boundary conditions. We find that the associated exponents, describing the aspect ratio dependencies, are different for the magnetization and the largest Fortuin-Kasteleyn cluster, but in each case are independent of boundary conditions.Comment: 8 pages, 8 figures, 2 tables, version as published in Phys Rev

    Colouration in amphibians as a reflection of nutritional status : the case of tree frogs in Costa Rica

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    Colouration has been considered a cue for mating success in many species; ornaments in males often are related to carotenoid mobilization towards feathers and/or skin and can signal general health and nutrition status. However, there are several factors that can also link with status, such as physiological blood parameters and body condition, but there is not substantial evidence which supports the existence of these relationships and interactions in anurans. This study evaluated how body score and blood values interact with colouration in free-range Agalychnis callidryas and Agalychnis annae males. We found significant associations between body condition and plasmatic proteins and haematocrit, as well as between body condition and colour values from the chromaticity diagram. We also demonstrated that there is a significant relation between the glucose and plasmatic protein values that were reflected in the ventral colours of the animals, and haematocrit inversely affected most of those colour values. Significant differences were found between species as well as between populations of A. callidryas, suggesting that despite colour variation, there are also biochemical differences within animals from the same species located in different regions. These data provide information on underlying factors for colouration of male tree frogs in nature, provide insights about the dynamics of several nutrients in the amphibian model and how this could affect the reproductive output of the animals
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