31 research outputs found

    The Biology and Economics of Coral Growth

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    To protect natural coral reefs, it is of utmost importance to understand how the growth of the main reef-building organisms—the zooxanthellate scleractinian corals—is controlled. Understanding coral growth is also relevant for coral aquaculture, which is a rapidly developing business. This review paper provides a comprehensive overview of factors that can influence the growth of zooxanthellate scleractinian corals, with particular emphasis on interactions between these factors. Furthermore, the kinetic principles underlying coral growth are discussed. The reviewed information is put into an economic perspective by making an estimation of the costs of coral aquaculture

    Defining locality as a problem difficulty measure in genetic programming

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    A mapping is local if it preserves neighbourhood. In Evolutionary Computation, locality is generally described as the property that neighbouring genotypes correspond to neighbouring phenotypes. A representation has high locality if most genotypic neighbours are mapped to phenotypic neighbours. Locality is seen as a key element in performing effective evolutionary search. It is believed that a representation that has high locality will perform better in evolutionary search and the contrary is true for a representation that has low locality. When locality was introduced, it was the genotype-phenotype mapping in bitstring-based Genetic Algorithms which was of interest; more recently, it has also been used to study the same mapping in Grammatical Evolution. To our knowledge, there are few explicit studies of locality in Genetic Programming (GP). The goal of this paper is to shed some light on locality in GP and use it as an indicator of problem difficulty. Strictly speaking, in GP the genotype and the phenotype are not distinct. We attempt to extend the standard quantitative definition of genotype-phenotype locality to the genotype-fitness mapping by considering three possible definitions. We consider the effects of these definitions in both continuous- and discrete-valued fitness functions. We compare three different GP representations (two of them induced by using different function sets and the other using a slightly different GP encoding) and six different mutation operators. Results indicate that one definition of locality is better in predicting performance.Science Foundation IrelandIrish Research Council for Science, Engineering and Technologyti, ke, ab - TS 02.1

    <i>In vivo</i> inhibition of hepatic <sup>125</sup>I-glucagon binding in the hGCGR mouse following (A) acute and (B) chronic dosing with GRA1.

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    <p>The data are mean (¹SEM) percent reductions in liver <sup>125</sup>I-glucagon content measured (A) 1, 3, 5, and 8 h after a single oral dose of 3 mg/kg GRA1, and (B) after treatment for 30 days with control diet or food/drug admixtures that provided 3, 6, 10, or 30 mg/kg¡day GRA1. Pharmacokinetic analysis performed during the experiment in (A) determined that mean plasma GRA1 concentrations were 0.5, 0.6, 0.5, and 0.7 ¾M at 1, 3, 5, and 8 h postdose, respectively.</p

    Blunting of glucagon-induced blood glucose excursions by GRA1 treatment in the (A) hGCGR mouse and (B) rhesus monkey.

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    <p>In (A), mice (n = 8) were administered vehicle or 3, 10 or 30 mg/kg GRA1, then challenged 1 h later (time 0) by intraperitoneal injection of 15 µg/kg glucagon or vehicle. Pharmacokinetic analysis determined that these animals had mean plasma GRA1 concentrations of 0.4, 0.9, and 4.7 µM, respectively, at 1 h postdose. In (B), monkeys (n = 4) were administered 1 mg/kg GRA1 4 h prior to intramuscular injection of 15 µg/kg glucagon or vehicle. At 1 h postdose, the mean plasma GRA1 concentration in these animals was 0.2 µM. *p<0.05; **p<0.01; and ***p<0.001 vs. glucagon-treated control animals.</p
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