Understanding the reciprocal interactions between the evolved characteristics of species and the environment in which each species is embedded is a major priority for evolutionary ecology. Here we use the perspective of ecological stoichiometry to test the hypothesis that natural selection on body growth rate affects consumer body stoichiometry. As body elemental composition (nitrogen, phosphorus) of consumers influences nutrient cycling and trophic dynamics in food webs, such differences should also affect biogeochemical processes and trophic dynamics. Consistent with the growth rate hypothesis, body growth rate and phosphorus content of individuals of the Daphnia pulex species complex were lower in Wisconsin compared to Alaska, where the brevity of the growing season places a premium on growth rate. Consistent with stoichiometric theory, we also show that, relative to animals sampled in Wisconsin, animals sampled in Alaska were poor recyclers of P and suffered greater declines in growth when fed low‐quality, P‐deficient food. These results highlight the importance of evolutionary context in establishing the reciprocal relationships between single species and ecosystem processes such as trophic dynamics and consumer‐driven nutrient recycling.

The origin of turbulence in fluids is a long-standing problem being in focus of researches through decades due to its great importance in a variety of engineering applications. Meanwhile, the study of turbulence origin is a part of the fundamental physical problem of the turbulence description and the philosophical problem of determinism and chaos. This paper is concern to a review of new findings in the field of laminar-turbulent transition of near-wall flows.

BACKGROUND AND PURPOSEDiscoverRx's PathHunter™ assay measures GPCR agonist potency, via the recruitment of b-arrestin, independent of the subtype of Ga protein activated. This assay is frequently used in drug discovery although little is known about the agonist pharmacology generated. Here we have compared agonist potency, efficacy and affinity values obtained in PathHunter™ assays with those from more established radioligand binding and functional techniques. EXPERIMENTAL APPROACHUsing cells expressing the human sphingosine-1-phosphate S1P3 receptor at four different densities, we compared pharmacological affinity and efficacy values of four structurally distinct ligands -FTY720-P, VPC24191, CYM5442 and the endogenous agonist S1P -obtained from competition binding, functional Ca 2+ release and PathHunter™ assays. KEY RESULTSThe pKi values for S1P were significantly different (9.34 Ϯ 0.10 and 8.92 Ϯ 0.15) in clones expressing different receptor levels using the binding assay. In the PathHunter™ and Ca 2+ assays, S1P and CYM5442 were full agonists, FTY720-P was a partial agonist, while the efficacy of VPC24191 could not be detected in PathHunter™ assays. VPC23019, previously described as a S1P1/3 receptor antagonist, behaved as an S1P3 receptor partial agonist in the Ca 2+ release assay. CONCLUSIONS AND IMPLICATIONSComparison of data from the PathHunter™ assay with binding and functional Ca 2+ assays suggest that PathHunter™ assays measured a different agonist-bound receptor conformation. While this assay has great utility in drug discovery, care must be taken as high-efficacy, low-affinity agonist compounds would not be detected. Therefore highly amplified, more traditional assays are necessary to identify agonists with low efficacy. AbbreviationsCYM5442, 2-(4-(5-(3,4-diethoxyphenyl)-

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Abstract-The size and complexity of hardware and software systems continues t o grow, making the introduction of subtle errors a more likely possibility. A major goal of software engineering is t o enable developers t o construct systems that operate reliably despite increased size and complexity. One approach t o achieving this goal is through formal methods: mathematically based languages, techniques and tools for specifying and verifying complex software systems. In this paper, we apply a theoretical tool that is supported by many formal methods, the correctness preserving transformation (CPT), t o a real software engineering problem: the need for optimization during the maintenance of code. We present four program transformations and a model t h a t forms a framework for proof of correctness. We prove the transformations correct and then apply them t o a cryptography application implemented in CS+. Our experience shows that CPTs can facilitate generation of more efficient code while guaranteeing the preservation of original behavior.