47 resultados para Gordo, James Wright (1809-1953)


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An essay relating 'The Dragon House' by John James to 'Thoughts on the Esterhazy Court Uniform' by J. H. Prynne

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Theoretical and empirical studies of life history aim to account for resource allocation to the different components of fitness: survival, growth, and reproduction. The pioneering evolutionary ecologist David Lack [(1968) Ecological Adaptations for Breeding in Birds (Methuen and Co.,London)] suggested that reproductive output in birds reflects adaptation to environmental factors such as availability of food and risk of predation, but subsequent studies have not always supported Lack’s interpretation. Here using a dataset for 980 bird species (Dataset S1), a phylogeny, and an explicit measure of reproductive productivity, we test predictions for how mass-specific productivity varies with body size, phylogeny,and lifestyle traits. We find that productivity varies negatively with body size and energetic demands of parental care and positively with extrinsic mortality. Specifically: (i) altricial species are 50% less productive than precocial species; (ii) species with female-only care of offspring are about 20% less productive than species with other methods of parental care; (iii) nonmigrants are 14% less productive than migrants; (iv) frugivores and nectarivores are about 20% less productive than those eating other foods; and (v) pelagic foragers are 40% less productive than those feeding in other habitats. A strong signal of phylogeny suggests that syndromes of similar life-history traits tend to be conservative within clades but also to have evolved independently in different clades. Our results generally support both Lack’s pioneering studies and subsequent research on avian life history.

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Containment, as conceived by the US government official George Kennan, was an aggressive attempt to cause the Soviet Cold War empire to disintegrate. This can is demonstrated by the case study of how the USA, Britain, and France tried to instrumentalise renegade Tito's Yugoslavia as a wedge to break up the cohesion of the Communist regimes within the Soviet sphere. They supported Tito against subversion and planned Soviet-orchestrated military attack from its neighbouring states; Western plans for the support of Yugoslavia included plans for a selective use of nuclear weapons.