Results for 'Hydra'

6 found
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  1. The Hydra Model - a Model for What?Alfred Gierer - 2012 - International Journal of Developmental Biology 56:437-445.
    The introductory personal remarks refer to my motivations for choosing research projects, and for moving from physics to molecular biology and then to development, with Hydra as a model system. Historically, Trembley’s discovery of Hydra regeneration in 1744 was the begin¬ning of developmental biology as we understand it, with passionate debates about preformation versus de novo generation, mechanisms versus organisms. In fact, seemingly conflicting bottom-up and top-down concepts are both required in combination to understand development. In modern terms, (...)
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  2. Regeneration of Hydra From Aggregated Cells.Alfred Gierer, S. Berking, H. Bode, C. N. David, K. Flick, G. Hansmann, H. Schaller & E. Trenkner - 1972 - Nature New Biology 239:98-101.
    • Aggregates of previously isolated cells of Hydra are capable, under suitable solvant conditions, of regeneration forming complete animals. In a first stage, ecto- and endodermal cells sort out, producing the bilayered hollow structure characteristic of Hydra tissue; thereafter, heads are formed (even if the original cell preparation contained no head cells), eventually leading to the separation of normal animals with head, body column and foot. Hydra appears to be the highest type of organism that allows for (...)
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  3. Colin Wilson As Hydra.Vaughan Rapatahana - 2011 - Philosophy Now 85:21-23.
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  4. A Theory of Biological Pattern Formation.Alfred Gierer & Hans Meinhardt - 1972 - Kybernetik, Continued as Biological Cybernetics 12 (1):30 - 39.
    The paper addresses the formation of striking patterns within originally near-homogenous tissue, the process prototypical for embryology, and represented in particularly purist form by cut sections of hydra regenerating, by internal reorganisation of the pre-existing tissue, a complete animal with head and foot. The essential requirements are autocatalytic, self-enhancing activation, combined with inhibitory or depletion effects of wider range – “lateral inhibition”. Not only de-novo-pattern formation, but also well known, striking features of developmental regulation such as induction, inhibition, and (...)
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  5. Generation of Biological Patterns and Form: Some Physical, Mathematical and Logical Aspects.Alfred Gierer - 1981 - Progress in Biophysics and Molecular Biology 37 (1):1-48.
    While many different mechanisms contribute to the generation of spatial order in biological development, the formation of morphogenetic fields which in turn direct cell responses giving rise to pattern and form are of major importance and essential for embryogenesis and regeneration. Most likely the fields represent concentration patterns of substances produced by molecular kinetics. Short range autocatalytic activation in conjunction with longer range “lateral” inhibition or depletion effects is capable of generating such patterns (Gierer and Meinhardt, 1972). Non-linear reactions are (...)
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  6. Ten Men and Women Got Married Today: Noun Coordination and the Intersective Theory of Conjunction.Lucas Champollion - 2016 - Journal of Semantics 33 (3):561–622.
    The word 'and' can be used both intersectively, as in 'John lies and cheats', and collectively, as in 'John and Mary met'. Research has tried to determine which one of these two meanings is basic. Focusing on coordination of nouns ('liar and cheat'), this article argues that the basic meaning of 'and' is intersective. This theory has been successfully applied to coordination of other kinds of constituents (Partee & Rooth 1983; Winter 2001). Certain cases of noun coordination ('men and women') (...)
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