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Search Results: 1 - 10 of 22289 matches for " Sigfredo Francisco "
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La caza mayor y le economía rural en la provincia de Toledo
Martín Fernández, ángel Julián,Ortu?o Pérez, Sigfredo Francisco
Estudios Geográficos , 2004,
Abstract: Leisure or business? Is it the hunt a really profitable activity? If it is like that, who are the biggest beneficiaries? How it has influenced in the most disadvantaged rural zones? Here there are some of the questions about economic and social reality of hunting, and its answers are tried to be approached in this work, for a confirmed hunting tradition zone as Los Montes de Toledo , in the province of the same name, where are placed the most of the best major hunting areas in the Toledo province. The Mounts of Toledo, due to its excellent natural resources for the hunting and to the crisis of the agrarian traditional utilizations, constitute an area where the major hunt is the most adapted use to contribute to the biological balance with a rational management. [es] Ocio o negocio?, es la caza una actividad verdaderamente rentable? Si es así, quiénes son los mayores beneficiarios?, cómo repercute en las zonas rurales más desfavorecidas? Estas son algunas de las cuestiones que la caza, como realidad económica y social, plantea, y cuyas respuestas se pretende abordar en este trabajo desarrollado en una zona de contrastada tradición cinegética como es la comarca de los Montes de Toledo en la provincia del mismo nombre, como lo demuestra el hecho de que la mayor parte de los cotos de caza mayor de la provincia de Toledo, se hallen en esta comarca. Los Montes de Toledo debido a sus excelentes recursos naturales para la caza y a la crisis de los aprovechamientos agrarios tradicionales, constituyen un espacio en el que la práctica de la caza mayor, es el uso más adecuado para contribuir a la conservación del equilibrio biológico, siempre que este aprovechamiento se realice racionalmente. [fr] Loisir ou affaire? Est-ce que la chasse est une activité vraiment rentable? Le cas échéant, qui sont leur principaux bénéficiaires?, quelles sont leur conséquences dans les espaces ruraux les plus défavorisés? Ce sont quelques-unes des questions que la chasse pose en tant que réalité économique et sociale, et dont on essaie d'aborder leurs réponses dans ce travail, qu'a été développé dans une zone qui compte sur une longue tradition cynégétique, telle que les Montes de Toledo, dans la province de Toledo, d'après le fait que la plupart des chasse gardées se sont concentrées dans ce pays. Compte tenu de leur excellents ressources naturels pour la chasse, et de la crise des systèmes d'aménagement rural traditionnels, les Montes de Toledo sont l'un des espaces où la chasse de gros gibier c'est l'une des utilisations les plus convenables pour la conservation de l'équilibr
Estimación del aprovechamiento máximo sostenible y distribución diamétrica estable de masas irregulares de pinus nigra mediante modelos matriciales
López Torres,Ignacio; Ortu?o Pérez,Sigfredo Francisco; Martín Fernández,ángel Julián; Fullana Belda,Carmen;
Interciencia , 2008,
Abstract: a matrix model is presented for the projection in time and maximal profiting that ensures sustainability and stability of diameter distributions of three qualities of pinus nigra. considering projection periods of 10 years, trunks were grouped in five diameter classes: 0-10, 10-20, 20-30, 30-40 and >40cm. transition probabilities were calculated adjusting diameter growth curves by cubic approximations and assuming uniform diameter distributions within each class. a condition is proposed for the sustainable management of the tree mass that permits to reach and maintain in time a stable diameter distribution. the results indicate that, in order to ensure population sustainability/stability, for each projection time interval the maximal extraction rate should be between 17.21 and 40.09%, depending on quality level, for recruitments between 200 and 840 trunks/ha and total sectional areas of 20 to 30m2·ha-1. finally, for each quality level the stable diameter distributions in relation to recruitment for total sectional areas of 20, 25 and 30m2·ha-1 were obtained.
Desafíos y perspectivas en la investigación sobre el magisterio
Chiroque Chunga, Sigfredo;
Educa??o & Sociedade , 2007, DOI: 10.1590/S0101-73302007000200010
Abstract: in research in general and in research on education and teaching it is worth specifying "what for" and "who for". both decisions should combine in the option of transforming society. this can be done in our countries, in spite of the inequality divide and of the relative control on the development of research. in research on teaching, we should overcome the economical-financial control, with its methodological focus, and the one that - sometimes - hides under the name of making "political incidence". in latin america, we have specified the themes of research on teaching. nevertheless, their focuses have to do with the assumptions of neo-liberalism and qualitative-ethnographic research, on the one hand, and with those of the liberating education and of the social practices of latin-american teaching, on the other. important prospects emerge from this last option, which need to be specified and coordinated.
La política forestal espa ola en el último cuarto de siglo
Alcanda Vergara, Pedro F.,Oortu?o Pérez, Sigfredo F.
Estudios Geográficos , 2006,
Abstract:
Presentación de dos casos interesantes de divertículos epifrénicos operados por toracoscopia Presentation of two interesting cases of epiphrenic diverticula operated on by thoracoscopy
Jorge Gerardo Pereira Fraga,Miguel ángel Martínez Alfonso,Sigfredo de la Caridad Montero Ferrer,Rosalba Roque González
Revista Cubana de Cirugía , 2011,
Abstract: El divertículo epifrénico es una enfermedad poco frecuente, pero constituye el 20 % de los divertículos del esófago, y se consideran falsos porque están constituidos, fundamentalmente, por mucosa y submucosa, y se deben a trastornos de la motilidad esofágica e incoordinación del esfínter esofágico inferior. Su localización más frecuente es en los últimos 10 a 12 cm del esófago distal, por lo que muchos lo llaman supra diafragmáticos. Su síntoma fundamental es la disfagia, aunque en ocasiones cursan asintomáticos, sobre todo, los peque os, y tienen indicaciones quirúrgicas precisas. Se presentan 2 pacientes operados en el Centro Nacional de Cirugía Endoscópica en los meses comprendidos entre noviembre de 2009 y marzo de 2010, con diagnóstico de divertículos esofágicos epifrénicos. Se muestran los complementarios para el diagnóstico, el proceder quirúrgico con la vía utilizada y las complicaciones. The epiphrenic diverticulum is an uncommon disease, but account for the 20 % of esophageal diverticula and are considered as falses due to its constitution mainly by mucosa and submucosa and are provoked by esophageal motility disorders and no coordination of lower esophageal sphincter therefore called supradiaphragmatic. Its fundamental symptom is the dysphagia, although occasionally becomes asymptomatic mainly the small ones and have precise surgical prescriptions. Author present two cases operated on the National Center of Endoscopic Surgery during November, 2009 and March, 2010 diagnosed with epiphrenic esophageal diverticula. Complementary analysis for diagnosis, the surgical procedure and the route used as well as the complications are showed.
Are the Economically Optimal Harvesting Strategies of Uneven-Aged Pinus nigra Stands Always Sustainable and Stabilizing?
Ignacio López-Torres,Sigfredo Ortu?o-Pérez,Fernando García-Robredo,Carmen Fullana-Belda
Forests , 2013, DOI: 10.3390/f4040830
Abstract: Traditional uneven-aged forest management seeks a balance between equilibrium stand structure and economic profitability, which often leads to harvesting strategies concentrated in the larger diameter classes. The sustainability (i.e., population persistence over time) and influence of such economically optimal strategies on the equilibrium position of a stand (given by the stable diameter distribution) have not been sufficiently investigated in prior forest literature. This article therefore proposes a discrete optimal control model to analyze the sustainability and stability of the economically optimal harvesting strategies of uneven-aged Pinus nigra stands. For this model, we rely on an objective function that integrates financial data of harvesting operations with a projection matrix model that can describe the population dynamics. The model solution reveals the optimal management schedules for a wide variety of scenarios. To measure the distance between the stable diameter distribution and the economically optimal harvesting strategy distribution, the model uses Keyfitz’s delta, which returns high values for all the scenarios and, thus, suggests that those economically optimal harvesting strategies have an unstabilizing influence on the equilibrium positions. Moreover, the economically optimal harvesting strategies were unsustainable for all the scenarios.
Electromagnetic Gauges and Maxwell Lagrangians Applied to the Determination of Curvature in the Space-Time and their Applications  [PDF]
Francisco Bulnes
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2012, DOI: 10.4236/jemaa.2012.46035
Abstract: If we consider the finite actions of electromagnetic fields in Hamiltonian regime and use vector bundles of geodesic in movement of the charges with a shape operator (connection) that measures the curvature of a geometrical space on these geodesic (using the light caused from these points (charges) acting with the infinite null of gravitational field (background)) we can establish a model of the curvature through gauges inside the electromagnetic context. In partular this point of view is useful when it is about to go on in a quantized version from the curvature where the space is distorted by the interactions between particles. This demonstrates that curvature and torsion effect in the space-time are caused in the quantum dimension as back-reaction effects in photon propagation. Also this permits the observational verification and encodes of the gravity through of light fields deformations. The much theoretical information obtained using the observable effects like distortions is used to establish inside this Lagrangian context a classification of useful spaces of electro-dynamic configuration for the description of different interactions of field in the Universe related with gravity. We propose and design one detector of curvature using a cosmic censor of the space-time developed through distortional 3-dimensional sphere. Some technological applications of the used methods are exhibited.
Penrose Transform on D-Modules, Moduli Spaces and Field Theory  [PDF]
Francisco Bulnes
Advances in Pure Mathematics (APM) , 2012, DOI: 10.4236/apm.2012.26057
Abstract: We consider a generalization of the Radon-Schmid transform on coherent D-modules of sheaves of holomorphic complex bundles inside a moduli space, with the purpose of establishing the equivalences among geometric objects (vector bundles) and algebraic objects as they are the coherent D-modules, these last with the goal of obtaining conformal classes of connections of the holomorphic complex bundles. The class of these equivalences conforms a moduli space on coherent sheaves that define solutions in field theory. Also by this way, and using one generalization of the Penrose transform in the context of coherent D-modules we find conformal classes of the space-time that include the heterotic strings and branes geometry.
Penrose Transform on Induced DG/H-Modules and Their Moduli Stacks in the Field Theory  [PDF]
Francisco Bulnes
Advances in Pure Mathematics (APM) , 2013, DOI: 10.4236/apm.2013.32035
Abstract:

We consider generalizations of the Radon-Schmid transform on coherent DG/H-Modules, with the intention of obtaining the equivalence between geometric objects (vector bundles) and algebraic objects (D-Modules) characterizing conformal classes in the space-time that determine a space moduli [1] on coherent sheaves for the securing solutions in field theory [2]. In a major context, elements of derived categories like D-branes and heterotic strings are considered, and using the geometric Langlands program, a moduli space is obtained of equivalence between certain geometrical pictures (non-conformal world sheets [3]) and physical stacks (derived sheaves), that establishes equivalence between certain theories of super symmetries of field of a Penrose transform that generalizes the implications given by the Langlands program. With it we obtain extensions of a cohomology of integrals for a major class of field equations to corresponding Hecke category.

Mathematical Nanotechnology: Quantum Field Intentionality  [PDF]
Francisco Bulnes
Journal of Applied Mathematics and Physics (JAMP) , 2013, DOI: 10.4236/jamp.2013.15005
Abstract:

Considering the finite actions of a field on the matter and the space which used to infiltrate their quantum reality at level particle, methods are developed to serve to base the concept of intentional action of a field and their ordered and supported effects (synergy) that must be realized for the organized transformation of the space and matter. Using path integrals, these transformations are decoded and their quantum principles are shown.

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