منابع مشابه
Contrast Enhancement at Borders Spatial Contrast Enhancement at Borders
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1 The issue The purpose of this essay is to shed some light on a certain type of sentence, which I call a borderline contradiction. A borderline contradiction is a sentence of the form F a ∧ ¬F a, for some vague predicate F and some borderline case a of F , or a sentence equivalent to such a sentence. For example, if Jackie is a borderline case of 'rich', then 'Jackie is rich and Jackie isn't r...
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The phenotypic variance-covariance matrix (P) describes the multivariate distribution of a population in phenotypic space, providing direct insight into the appropriateness of measured traits within the context of multicollinearity (i.e., do they describe any significant variance that is independent of other traits), and whether trait covariances restrict the combinations of phenotypes availabl...
متن کاملAllee effects, invasion pinning, and species' borders.
All species' ranges are the result of successful past invasions. Thus, models of species' invasions and their failure can provide insight into the formation of a species' geographic range. Here, we study the properties of invasion models when a species cannot persist below a critical population density known as an "Allee threshold." In both spatially continuous reaction-diffusion models and spa...
متن کاملTheoretical models of species’ borders: single species approaches
ly in terms of spatial demography / how birth, death, and dispersal rates vary across space and time / rather than of detailed mechanisms. Theoretical models of population dynamics in spatially heterogeneous environments (e.g. along gradients) provide useful tools for characterizing the demographic underpinning of species’ borders. Our aim here is to provide a conceptual framework that captures...
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ژورنال
عنوان ژورنال: BMC Evolutionary Biology
سال: 2013
ISSN: 1471-2148
DOI: 10.1186/1471-2148-13-105