منابع مشابه
On Ridges and Valleys
Ridges and valleys are earth’s relief structures. They can have an imaging counterpart provided we model a digital image as a landscape by considering grey level values as height. These two dual entities have received comparatively little attention from the computer vision community with regard to others like edges or corners. In this paper we first propose a taxonomy or classification of the s...
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We develop a systematic treatment for the quasi-zero modes, which play an important role in nonabelian gauge theories. It can be used to derive the analytic forms for the constrained instantons in the Yang-Mills-Higgs theory. This will automatically sum up contributions to all orders in ρ, the instanton size. We also give the analytic expressions for the instanton-antiinstanton pair, with an ar...
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In the basic fitness landscape metaphor for molecular evolution, evolutionary pathways are presumed to follow uphill steps of increasing fitness. How evolution can cross fitness valleys is an open question. One possibility is that environmental changes alter the fitness landscape such that low-fitness sequences reside on a hill in alternate environments. We experimentally test this hypothesis o...
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By reconstructing how an influenza protein collected in 1968 might have evolved into one collected in 2007, researchers have obtained new insights into the interactions between genetic mutations.
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Road traffic is a serious problem in the Chamonix Valley, France: traffic, noise and above all air pollution worry the inhabitants. The big fire in the Mont-Blanc tunnel made it possible, in the framework of the POVA project (POllution in Alpine Valleys), to undertake measurement campaigns with and without heavy-vehicle traffic through the Chamonix and Maurienne valleys, towards Italy (before a...
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ژورنال
عنوان ژورنال: Geological Magazine
سال: 1924
ISSN: 0016-7568,1469-5081
DOI: 10.1017/s0016756800086404