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Classic Theory (classic + theory)
Selected AbstractsSexual selection did not contribute to the evolution of male lifespan under curtailed age at reproduction in a seed beetleECOLOGICAL ENTOMOLOGY, Issue 5 2009ALEXEI A. MAKLAKOV Abstract. 1. Sexual selection is a powerful evolutionary force that is hypothesised to play an important role in the evolution of lifespan. Here we test for the potential contribution of sexual selection to the rapid evolution of male lifespan in replicated laboratory populations of the seed beetle, Callosobruchus maculatus. 2. For 35 generations, newly hatched virgin male beetles from eight different populations were allowed to mate for 24 h and then discarded. Sexual selection was removed in half of these populations by enforcing random monogamy. 3. Classic theory predicts that because of sexual competition, males from sexually selected lines would have higher age-specific mortality rates and shorter lifespan than males from monogamous lines. 4. Alternatively, condition-dependent sexual selection may also favour genes that have positive pleiotropic effects on lifespan and ageing. 5. Males from all eight populations evolved shorter lifespans compared with the source population. However, there was no difference in lifespan between males from populations with or without sexual selection. Thus, sexual selection did not contribute to the evolution of male lifespan despite the fact that such evolution did occur in our study populations. [source] Reversed Crystal Growth: Implications for Crystal EngineeringADVANCED MATERIALS, Issue 28 2010Wuzong Zhou Abstract The discovery of reversed crystal growth routes in zeolite analcime and zeolite A implies that crystal growth does not always follow the classic theory established 100 years ago. Aggregation of nanoparticles may dominate in the early stages of crystal growth, followed by surface crystallization, and then extension from surface to core of the disordered aggregates. A perfect polyhedral morphology can be developed in a thin surface crystalline layer of a particle with a disordered core. Evidence of such a novel crystal growth phenomenon can be also found in many other materials. This article highlights the recent achievements in this topic, which might have a significant impact on crystal engineering, materials science, and mineralogy. [source] Goals of Action and Emotional Reasons for Action.JOURNAL FOR THE THEORY OF SOCIAL BEHAVIOUR, Issue 2 2008A Modern Version of the Theory of Ultimate Psychological Hedonism ABSTRACT In this paper we present a modern version of the classic theory of "ultimate psychological hedonism" (UPH). As does the UPH, our two-dimensional model of metatelic orientations also postulates a fundamentally hedonistic motivation for any human action. However, it makes a distinction between "telic" or content-based goals of actions and "metatelic" or emotional reasons for actions. In our view, only the emotional reasons for action, but not the goals of action, conform to the UPH. After outlining our model, we will elucidate the similarities and differences between our model and classic UPH. In this context we will clarify several basic misconceptions regarding classic UPH. In a next step, two major criticisms of the theory of ultimate psychological hedonism will be discussed, that is (1) the statement that the hedonistic principle has no motivating effect at all and (2) the argument that the hedonistic motivation is only one of many motivations of human actions. We believe that both of these arguments can be refuted. Finally, we will discuss the compatibility of our model with evolutionary theory. [source] Chemical Diffusivity of BaTiO3,,: IV, Acceptor-Doped CaseJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2000Chang-Rock Song The chemical diffusivity of 1.8 mol% aluminum-doped BaTiO3,, was measured on single-crystal specimens, as a function of ambient oxygen partial pressure, in the range 10,18 atm ,PO2, 1 atm and at temperatures of 800°,T, 1100°C, via a conductivity-relaxation technique. As in the polycrystalline, undoped BaTiO3,, described in Part II of this work, the chemical diffusivity exhibited a maximum, of thermodynamic origin, approximately at the stoichiometric composition (,= 0). The measured diffusivity was analyzed, based on the defect structure proposed and Wagner's classic theory of chemical diffusion, and the mobilities of the electrons and holes, as well as all of the relevant defect-equilibrium constants, then were evaluated with no prior assumptions. The evaluated parameters were compared with those for the undoped BaTiO3,,. [source] | ||||||||||