2,049 research outputs found
Classical Lie symmetries and reductions of a nonisospectral Lax pair
The classical Lie method is applied to a nonisospectral problem associated
with a system of partial differential equations in 2+1 dimensions (Maccari A,
J. Math. Phys. 39, (1998), 6547-6551). Identification of the classical Lie
symmetries provides a set of reductions that give rise to different nontrivial
spectral problems in 1+1 dimensions. The form in which the spectral parameter
of the 1+1 Lax pair is introduced is carefully described.Comment: 11 pages (v2: A typo corrected in the authors' names
Coordinated regulation of chromatophore differentiation and melanogenesis during the ontogeny of skin pigmentation of Solea senegalensis (Kaup, 1858)
Abnormal pigmentation of Senegalese sole has been described as one problem facing the full exploitation of its commercial production. To improve our understanding of flatfish pigmentation of this commercially important species we have evaluated eleven genes related to two different processes of pigmentation: melanophore differentiation, and melanin production. The temporal distribution of gene expression peaks corresponds well with changes in pigmentation patterns and the intensity of skin melanization. Several gene ratios were also examined to put in perspective possible genetic markers for the different stages of normal pigmentation development. Further, the phenotypic changes that occur during morphogenesis correspond well with the main transitions in gene expression that occur. Given the dramatic phenotypic alterations which flatfish undergo, including the asymmetric coloration that occurs between the ocular and the blind side, and the synchrony of the two processes of morphogenesis and pigmentation ontogenesis, these species constitute an interesting model for the study of pigmentation. In this study we present a first approximation towards explaining the genetic mechanisms for regulating pigmentation ontogeny in Senegalese sole, Solea senegalensis.Ministry of Science and Innovation (MICIIN) of the Spanish Government [AGL2008-03897-C04-01/ACU]; European Community [FP7/2007-2013-222719-LIFECYCLE]; Spanish Governmentinfo:eu-repo/semantics/publishedVersio
Non-classical symmetries and the singular manifold method: A further two examples
This paper discusses two equations with the conditional Painleve property.
The usefulness of the singular manifold method as a tool for determining the
non-classical symmetries that reduce the equations to ordinary differential
equations with the Painleve property is confirmed once moreComment: 9 pages (latex), to appear in Journal of Physics
Miura Transformation between two Non-Linear Equations in 2+1 dimensions
A Dispersive Wave Equation in 2+1 dimensions (2LDW) widely discussed by
different authors is shown to be nothing but the modified version of the
Generalized Dispersive Wave Equation (GLDW). Using Singularity Analysis and
techniques based upon the Painleve Property leading to the Double Singular
Manifold Expansion we shall find the Miura Transformation which converts the
2LDW Equation into the GLDW Equation. Through this Miura Transformation we
shall also present the Lax pair of the 2LDW Equation as well as some
interesting reductions to several already known integrable systems in 1+1
dimensions.Comment: 14 pages, latex. Journal of Mathematical Physics (to appear
Research activities on turbot industrial procedures in Spain
This technical report deals with the evolution during the last decade of the research
activities of the governmental institutions working on the development of turbot
(Scophthalmus maximus L.) culture. The Instituto Español de Oceanografía (Santander
and Vigo), the CSIC (Vigo and Castellón), the Xunta de Galicia (Villajuán and
Couso) and The University of Santiago are the institutions analyzed. A general review
of the different projects on turbot farming is given, including those with grants from the
institutions and from the CICYT (Comite Interministerial de Ciencia y Tecnología),
C.D.T.I (Centro de Desarrollo Tecnologico e Industrial) and the EC (European
Community). Finally, an analysis is given of the present situation and bottlenecks to
development are highlighted. leading to priorities for future research.Versión del edito
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