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Functional Equivalence (functional + equivalence)
Selected AbstractsResolving the biodiversity paradoxECOLOGY LETTERS, Issue 8 2007James S. Clark Abstract The paradox of biodiversity involves three elements, (i) mathematical models predict that species must differ in specific ways in order to coexist as stable ecological communities, (ii) such differences are difficult to identify, yet (iii) there is widespread evidence of stability in natural communities. Debate has centred on two views. The first explanation involves tradeoffs along a small number of axes, including ,colonization-competition', resource competition (light, water, nitrogen for plants, including the ,successional niche'), and life history (e.g. high-light growth vs. low-light survival and few large vs. many small seeds). The second view is neutrality, which assumes that species differences do not contribute to dynamics. Clark et al. (2004) presented a third explanation, that coexistence is inherently high dimensional, but still depends on species differences. We demonstrate that neither traditional low-dimensional tradeoffs nor neutrality can resolve the biodiversity paradox, in part by showing that they do not properly interpret stochasticity in statistical and in theoretical models. Unless sample sizes are small, traditional data modelling assures that species will appear different in a few dimensions, but those differences will rarely predict coexistence when parameter estimates are plugged into theoretical models. Contrary to standard interpretations, neutral models do not imply functional equivalence, but rather subsume species differences in stochastic terms. New hierarchical modelling techniques for inference reveal high-dimensional differences among species that can be quantified with random individual and temporal effects (RITES), i.e. process-level variation that results from many causes. We show that this variation is large, and that it stands in for species differences along unobserved dimensions that do contribute to diversity. High dimensional coexistence contrasts with the classical notions of tradeoffs along a few axes, which are often not found in data, and with ,neutral models', which mask, rather than eliminate, tradeoffs in stochastic terms. This mechanism can explain coexistence of species that would not occur with simple, low-dimensional tradeoff scenarios. [source] Constitutionalism and Dissonances: Has Europe Paid Off Its Debt to Functionalism?EUROPEAN LAW JOURNAL, Issue 3 2009Marco Dani This impression seems confirmed by the recent Presidency Conclusions of the European Council which, although salvaging many important solutions contained in the Constitutional Treaty, explicitly sanction that ,the constitutional concept . . . is abandoned'. In the light of this context, what role could the constitutional scholarship play? How to make sense of a polity in which the claims of constitutionalism as a form of power are politically unappealing though legally plausible? This article tries to respond to these questions by reaffirming functionalism as a valid analytical and normative perspective in facing the current constitutional reality of European integration. The analytical value associated with functionalism is evidenced by testing against the current context of the EU legal framework the accounts for EU constitutionalism which postulate functional equivalence between the EU and the Member States. The normative potential of functionalism, then, is discussed by arguing that there may be a value worth preserving in a degree of functional discrepancy between the EU and state constitutionalism and, notably, that the transformative and civilising dividend inherent in functionalism could still be exploited, at least in certain areas of EU policy making. Finally, the article suggests that the difficulties in accounting for EU constitutionalism in the light of state-centred constitutional theory could be regarded as symptoms of European integration marking a moment in the theoretical evolution of constitutionalism. [source] Metabolic rate models and the substitutability of predator populationsJOURNAL OF ANIMAL ECOLOGY, Issue 2 2004David R. Chalcraft Summary 1Much of the debate surrounding the consequences of biodiversity loss centres around the issue of whether different species are functionally similar in their effects on ecological processes. In this study, we examined whether populations consisting of smaller, more abundant individuals are functionally similar to populations of the same species with larger, fewer individuals. 2We manipulated the biomass and density of banded sunfish (Enneacanthus obesus) and measured their impact on populations of Southern leopard frog (Rana sphenocephala) larvae. We also evaluated the ability of models relating metabolic rate to body size to predict the relative impacts of populations that differ in average body size and population density. 3Our results indicate that population biomass, density and their interaction each play a large role in determining the effect of a predator population on its food resource. Populations with smaller but more abundant individuals had effects as large or larger than those populations with larger but fewer individuals. 4Although we found qualitative agreement between the observed relative effects of populations with that predicted by allometric models, we also found that density-dependence can cause effects of a population to differ from that expected based on allometry. 5The substitutability of populations differing in average body size appears to depend on complex relationships between metabolic rate, population density and the strength of density-dependence. The restrictive conditions necessary to establish functional equivalence among different populations of the same species suggests that functional equivalence should be rare in most communities. [source] Lost in Translation: Methodological Considerations in Cross-Cultural ResearchCHILD DEVELOPMENT, Issue 4 2007Elizabeth D. Peņa In cross-cultural child development research there is often a need to translate instruments and instructions to languages other than English. Typically, the translation process focuses on ensuring linguistic equivalence. However, establishment of linguistic equivalence through translation techniques is often not sufficient to guard against validity threats. In addition to linguistic equivalence, functional equivalence, cultural equivalence, and metric equivalence are factors that need to be considered when research methods are translated to other languages. This article first examines cross-cultural threats to validity in research. Next, each of the preceding factors is illustrated with examples from the literature. Finally, suggestions for incorporating each factor into research studies of child development are given. [source] | ||||||||||