Desarrollo de un proyecto de ecoturismo rural, en Potrerillo, Sierra de Zongolica, Veracruz, México

Como parte de sus programas educativos, la Universidad Autónoma Chapingo (UACh) tiene establecidos viajes de estudio generacionales cuyo objetivo es estudiar y aplicar in situ los procesos agrícolas y ambientales de diferentes regiones de México. Aquí presentamos un proyecto para hacer un centro ecoturístico en Potrerillo, un pequeño pueblo de Zongolica, localizado en Veracruz, México, en el cual los estudiantes participan en las actividades de la comunidad y realizan las colectas y la descripciónes necesarias para caracterizar los recursos. Los representantes de la comunidad en el proyecto y los académicos de la UACh, con apoyo gubernamental, participan en el avance del mismo y actualmente ya se cuenta con los servicios básicos (hospedaje y alimentación) para la visita de estudiantes, académicos, investigadores y turistas. Para la región este proyecto que respeta y protege sus recursos se ha convertido en un modelo turístico de aprovechamiento sustentable que puede ser replicable en otras regiones.The Universidad Autónoma Chapingo (UACh) has as part of its educative programs field trips whose main objective is that students study and apply in situ the agricultural and environmental processes in different regions of Mexico. Here we present a proyect to develop a touristic center in Potrerillo, a small town of Zongolica, located in Veracruz, Mexico. Students participate in the local activities and descrive the sorroundings and the diversity of the area. Local representatives and UACh professors, with the support from governmet, have developed the proyect and now the touristic center has the basic services (lodging and food) to welcome students, professors, reseachers and tourists. For the region this project that respects and protects its resources represents a touristic sustainable model that can be replicable in other regions.Eje: A3: Economía y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Desarrollo de un proyecto de ecoturismo rural, en Potrerillo, Sierra de Zongolica, Veracruz, México

Como parte de sus programas educativos, la Universidad Autónoma Chapingo (UACh) tiene establecidos viajes de estudio generacionales cuyo objetivo es estudiar y aplicar in situ los procesos agrícolas y ambientales de diferentes regiones de México. Aquí presentamos un proyecto para hacer un centro ecoturístico en Potrerillo, un pequeño pueblo de Zongolica, localizado en Veracruz, México, en el cual los estudiantes participan en las actividades de la comunidad y realizan las colectas y la descripciónes necesarias para caracterizar los recursos. Los representantes de la comunidad en el proyecto y los académicos de la UACh, con apoyo gubernamental, participan en el avance del mismo y actualmente ya se cuenta con los servicios básicos (hospedaje y alimentación) para la visita de estudiantes, académicos, investigadores y turistas. Para la región este proyecto que respeta y protege sus recursos se ha convertido en un modelo turístico de aprovechamiento sustentable que puede ser replicable en otras regiones.The Universidad Autónoma Chapingo (UACh) has as part of its educative programs field trips whose main objective is that students study and apply in situ the agricultural and environmental processes in different regions of Mexico. Here we present a proyect to develop a touristic center in Potrerillo, a small town of Zongolica, located in Veracruz, Mexico. Students participate in the local activities and descrive the sorroundings and the diversity of the area. Local representatives and UACh professors, with the support from governmet, have developed the proyect and now the touristic center has the basic services (lodging and food) to welcome students, professors, reseachers and tourists. For the region this project that respects and protects its resources represents a touristic sustainable model that can be replicable in other regions.Eje: A3: Economía y AgroecologíaFacultad de Ciencias Agrarias y Forestale

A SAURON study of dwarf elliptical galaxies in the Virgo Cluster: kinematics and stellar populations

Dwarf elliptical galaxies (dEs) are the most common galaxy type in nearby galaxy clusters; even so, many of their basic properties have yet to be quantified. Here we present the results of our study of 4 Virgo dwarf ellipticals obtained with the SAURON integral field unit on the William Herschel Telescope (La Palma, Spain). While traditional long-slit observations are likely to miss more complicated kinematic features, with SAURON we are able to study both kinematics and stellar populations in two dimensions, obtaining a much more detailed view of the mass distribution and star formation histories. What is visible even in such a small sample is that dEs are not a uniform group, not only morphologically, but also as far as their kinematic and stellar population properties are concerned. We find the presence of substructures, varying degrees of flattening and of rotation, as well as differences in age and metallicity gradients. We confirm that two of our galaxies are significantly flattened, yet non-rotating objects, which makes them likely triaxial systems. The comparison between the dwarf and the giant groups shows that dEs could be a low-mass extension of Es in the sense that they do seem to follow the same trends with mass. However, dEs as progenitors of Es seem less likely as we have seen that dEs have much lower abundance ratios.Comment: 8 pages, 6 figures; to appear in the proceedings of the JENAM 2010 Symposium on Dwarf Galaxies (Lisbon, September 9-10, 2010); minor edits and references adde

Robust Design of Artificial Neural Networks Methodology in Neutron Spectrometry

Applications of artificial neural networks (ANNs) have been reported in literature in various areas. [1–5] The wide use of ANNs is due to their robustness, fault tolerant and the ability to learn and generalize, through training process, from examples, complex nonlinear and multi input/output relationships between process parameters using the process data. [6–10] The ANNs have many other advantageous characteristics, which include: generalization, adaptation, universal function approximation, parallel data processing, robustness, etc. Multilayer perceptron (MLP) trained with backpropagation (BP) algorithm is the most used ANN in modeling, optimization classification and prediction processes. [11, 12] Although BP algorithm has proved to be efficient, its convergence tends to be very slow, and there is a possibility to get trapped in some undesired local minimum. [4, 10, 11, 13] Most literature related to ANNs focused on specific applications and their results rather than the methodology of developing and training the networks. In general, the quality of the developed ANN is highly dependable not only on ANN training algorithm and its parameters but also on many ANN architectural parameters such as the number of hidden layers and nodes per layer which have to be set during training process and these settings are very crucial to the accuracy of ANN model. [8, 14–19

Scalar-field Pressure in Induced Gravity with Higgs Potential and Dark Matter

A model of induced gravity with a Higgs potential is investigated in detail in view of the pressure components related to the scalar-field excitations. The physical consequences emerging as an artifact due to the presence of these pressure terms are analysed in terms of the constraints parting from energy density, solar-relativistic effects and galactic dynamics along with the dark matter halos.Comment: 26 pages, 3 figures, Minor revision, Published in JHE

Fluids in cosmology

We review the role of fluids in cosmology by first introducing them in General Relativity and then by applying them to a FRW Universe's model. We describe how relativistic and non-relativistic components evolve in the background dynamics. We also introduce scalar fields to show that they are able to yield an inflationary dynamics at very early times (inflation) and late times (quintessence). Then, we proceed to study the thermodynamical properties of the fluids and, lastly, its perturbed kinematics. We make emphasis in the constrictions of parameters by recent cosmological probes.Comment: 34 pages, 4 figures, version accepted as invited review to the book "Computational and Experimental Fluid Mechanics with Applications to Physics, Engineering and the Environment". Version 2: typos corrected and references expande

Clear lens phacoemulsification in the anterior lenticonus due to Alport Syndrome: two case reports

<p>Abstract</p> <p>Introduction</p> <p>Alport Syndrome has a prevalence of 1 case per 5,000 people and 85% of patients have the X-linked form, where affected males develop renal failure and usually have high-tone sensorineural deafness by age 20. The main abnormality is deficient synthesis of type IV collagen, the main component of basement membranes. Common ocular abnormalities of this syndrome consist of dot-and-fleck retinopathy, posterior polymorphous corneal dystrophy, and anterior lenticonus, but other ocular defects such as cataracts, posterior lenticonus, and retinal detachments have also been reported.</p> <p>Case presentation</p> <p>We report two cases of anterior lenticonus due to Alport Syndrome and describe clear lens phacoemulsification and foldable intraocular lens implantation as an effective and safe refractive procedure in the four eyes of these two patients.</p> <p>Conclusion</p> <p>All four eyes of the two patients were in good condition after surgery and achieved satisfactory optical and visual results and had no remarkable complications at six-months follow-up. Clear lens phacoemulsification with foldable intraocular lens implantation can be used as an efficient and safe procedure for vision disorders in these patients.</p

Reversible, Opto-Mechanically Induced Spin-Switching in a Nanoribbon-Spiropyran Hybrid Material

It has recently been shown that electronic transport in zigzag graphene nanoribbons becomes spin-polarized upon application of an electric field across the nanoribbon width. However, the electric fields required to experimentally induce this magnetic state are typically large and difficult to apply in practice. Here, using both first-principles density functional theory (DFT) and time-dependent DFT, we show that a new spiropyran-based, mechanochromic polymer noncovalently deposited on a nanoribbon can collectively function as a dual opto-mechanical switch for modulating its own spin-polarization. These calculations demonstrate that upon mechanical stress or photoabsorption, the spiropyran chromophore isomerizes from a closed-configuration ground-state to a zwitterionic excited-state, resulting in a large change in dipole moment that alters the electrostatic environment of the nanoribbon. We show that the electronic spin-distribution in the nanoribbon-spiropyran hybrid material can be reversibly modulated via noninvasive optical and mechanical stimuli without the need for large external electric fields. Our results suggest that the reversible spintronic properties inherent to the nanoribbon-spiropyran material allow the possibility of using this hybrid structure as a resettable, molecular-logic quantum sensor where opto-mechanical stimuli are used as inputs and the spin-polarized current induced in the nanoribbon substrate is the measured output.Comment: Accepted by Nanoscal

Non-L\'evy mobility patterns of Mexican Me'Phaa peasants searching for fuelwood

We measured mobility patterns that describe walking trajectories of individual Me'Phaa peasants searching and collecting fuelwood in the forests of "La Monta\~na de Guerrero" in Mexico. These one-day excursions typically follow a mixed pattern of nearly-constant steps when individuals displace from their homes towards potential collecting sites and a mixed pattern of steps of different lengths when actually searching for fallen wood in the forest. Displacements in the searching phase seem not to be compatible with L\'evy flights described by power-laws with optimal scaling exponents. These findings however can be interpreted in the light of deterministic searching on heavily degraded landscapes where the interaction of the individuals with their scarce environment produces alternative searching strategies than the expected L\'evy flights. These results have important implications for future management and restoration of degraded forests and the improvement of the ecological services they may provide to their inhabitants.Comment: 15 pages, 4 figures. First version submitted to Human Ecology. The final publication will be available at http://www.springerlink.co

Bibliotecas virtuales, acceso abierto y derechos de autor

The book gathers the works presented in III Environmental Observatory Colloquium organized by El Colegio de Chihuahua with the theme of Virtual libraries and their use in research. The purpose is to lay the groundwork for a necessary analysis and permanent in the way that are being given these dizzying changes and the impact they are producing, mainly in the investigation from technical, legal, ethical, economic and social perspectives, among other. For this, a variety of works are presented by professionals who work constantly with information producers, users or as intermediaries of the same. The book should be of interest and useful for those people who fall into one of these categories, which increasingly, we are all