Agroecosistemas periurbanos, un potencial latente : contribución al análisis de la multifuncionalidad a partir de indicadores de sustentabilidad

Los agroecosistemas (AE) periurbanos revisten una gran importancia para las ciudades que circundan debido a las múltiples funciones que cumplen. Sin embargo, en los últimos años se han ido abandonando y sustituyendo por otras actividades, lo que sugiere un manejo no sustentable de los mismos. El propósito de este estudio fue analizar, a través de la incorporación de indicadores de sustentabilidad en un estudio de caso en el sur del Distrito Federal, los potenciales que presenta la agricultura periurbana, en la construcción de alternativas de soluciones ante los problemas de autosuficiencia alimentaria y sus consecuencias socioecológicas. Para el diseño de los indicadores se tomó como base la metodología del Marco para la Evaluación de Sistemas de Manejo de recursos naturales incorporando Indicadores de Sustentabilidad (MESMIS). De acuerdo a los indicadores, los AE muestran una tendencia hacia la no sustentabilidad principalmente en la dimensión socioeconómica, pero presentan una gran fortaleza en los aspectos sociocultural y ecológico, pues existe satisfacción e interés por continuar, debido a una valoración distinta a la económica de los AE, y unas características positivas del suelo y la vegetación que sugieren un proceso de control más que de degradación de los recursos naturales.Periurban Agroecosystems (AE) are of great importance to the surrounding cities due to the multiple roles they fulfill. However, in recent years they have been abandoned and replaced by other activities, suggesting an unsustainable management of them. The purpose of this study was to analyze, through the incorporation of sustainability indicators in a case study in the southern Mexico City, potential having peri-urban agriculture, construction of alternative solutions to the problems of food self-sufficiency and socio-ecological consequences. For the design of the indicators was based on the methodology of the Framework for the Evaluation of natural resources Management Systems incorporating Sustainability Indicators (MESMIS). According to the indicators, the AE show a trend towards unsustainability especially in the socioeconomic dimension, but it has a great strength in sociocultural aspects and ecological, as there is satisfaction and interest to continue, due to a different value to theeconomy of the AE, and positive characteristics of soil and vegetation control suggest a process rather than natural resource degradation

Diferencias en el desempeno en pruebas de software visual en función del género. Un estudio con jugadores y jugadoras de baloncesto de 13 anos

The paper presents a study based on a sample of thirteen-year-old boys and girls from the Spanish Basketball Federations team of talented young players. The aim was to try and evaluate the influence of gender in reactions to visual software tests, measured in response times and an awareness of anticipatory action in one-to-one situations in basketball. The participants took part in two tests, using the Reflex programme and Pantallex system, which had been designed and developed by the authors of this study. The number of correct answers and mistakes were measured, together with the response time in milliseconds. The results show that the female players got a higher number of correct answers when their capacity for perceptual anticipation and awareness of anticipatory action was tested with the Reflex programme. Likewise, their response time was better in both tests, with significant differences between both groups in the number of correctanswers with the Reflex programme and in the three perceptual anticipation indexes (one for each test and a third mean index of both the latter)

Using Desalination to Improve Agricultural Yields: Success Cases in Mexico

Water scarcity is a global problem, motivating growth and development of new technologies for water treatment, reuse and desalination. For many arid regions in Mexico, especially in the northwest, agriculture is an important economic activity. The Yaqui Valley in Sonora, Mexico, faces problems related to aquifer overexploitation and saline intrusion, which have increased salt concentration in well water to 2000–9000 mg/L total dissolved solids (TDS) and led to soil salinization and low crop yields. This work evaluates the effect of TDS in irrigation water on crop yield. A 150 m3/d desalination plant was used, consisting of 12 SWC4B-MAX membrane modules, with 98% rejection and 75% recovery. Two crops were irrigated with control (4000 mg/L) and desalinated water (200 mg/L). Sorghum (Sorghum) had yields of 7.9 and 8.8 ton/ha, whereas tomatillo (Physalis philadelphica) had yields of 30.82 and 35.88 ton/ha, respectively. Evidently, the desalination process influences agricultural yields

Revisión bibliográfica de implantología bucofacial del año 2010. Segunda parte

La gran cantidad de publicaciones que existen en las múltiples fuentes de información de la literatura científica junto a la baja disponibilidad de tiempo para consultarlas de la que disponen los profesionales de la Odontología, ha motivado a los autores de este artículo a efectuar una revisión de la literatura científica publicada a lo largo del año 2010 en el campo de la Implantología Bucofacial. Se han agrupado los diferentes trabajos en distintos temas (regeneración ósea guiada, elevación del seno maxilar y otras técnicas especiales, factores de crecimiento, implantes cigomáticos, implantes ortodóncicos y complicaciones en la cirugía implantológica), con el fin de facilitar una buena puesta al día

Revisión bibliográfica de implantología bucofacial del año 2010. Segunda parte

La gran cantidad de publicaciones que existen en las múltiples fuentes de información de la literatura científica junto a la baja disponibilidad de tiempo para consultarlas de la que disponen los profesionales de la Odontología, ha motivado a los autores de este artículo a efectuar una revisión de la literatura científica publicada a lo largo del año 2010 en el campo de la Implantología Bucofacial. Se han agrupado los diferentes trabajos en distintos temas (regeneración ósea guiada, elevación del seno maxilar y otras técnicas especiales, factores de crecimiento, implantes cigomáticos, implantes ortodóncicos y complicaciones en la cirugía implantológica), con el fin de facilitar una buena puesta al día

Focusing of in-plane hyperbolic polaritons in van der Waals crystals with tailored infrared nanoantennas

Phonon polaritons (PhPs),light coupled to lattice vibrations,with in-plane hyperbolic dispersion exhibit ray-like propagation with large wavevectors and enhanced density of optical states along certain directions on a surface. As such, they have raised a surge of interest as they promise unprecedented possibilities for the manipulation of infrared light with planar circuitry and at the nanoscale. Here, we demonstrate, for the first time, the focusing of in-plane hyperbolic PhPs propagating along thin slabs of MoO3. To that end, we developed metallic nanoantennas of convex geometries for both the efficient launching and focusing of the polaritons. Remarkably, the foci obtained exhibit enhanced near-field confinement and absorption compared to foci produced by in-plane isotropic PhPs. More intriguingly, foci sizes as small as lamdap/5 =lamda0/50 were achieved (lamdap is the polariton wavelength and lamda0 the photon wavelength). Focusing of in-plane hyperbolic polaritons introduces a first and most basic building block developing planar polariton optics utilizing in-plane anisotropic van der Waals materials and metasurfaces

Processing and characterisation of standard and doped alite-belite-ye'elimite ecocement pastes and mortars

Supplementary data to this article can be found online at https://doi.org/10.1016/j.cemconres.2019.105911.Cement and Concrete Research 127 (2020) 105911Here, we report the processing optimisation of two laboratory-prepared alite-belite-ye'elimite ecocements (standard and doped) that release to the atmosphere ~13% less CO2 than Portland Cement during fabrication. The processing was optimised through rheological measurements, where homogeneous pastes and mortars were finally prepared through the study and optimisation of both the superplasticiser content and the water-to-cement ratio. Both parameters were correlated with the phase assembly of selected pastes and compressive strength of the corresponding mortars. After optimisation, mortars with high compressive strengths (~72 and ~77 MPa for the standard mortar, and ~41 and ~75 MPa for the doped one, at 7 and 28 days, respectively) were prepared. Furthermore, the important increase in compressive strength from 7 to 28 days of the optimised mortar prepared from the doped ecocement is due to its composition (the higher content of belite jointly with the reaction of its active polymorph (α'H-belite)).This work is part of the PhD of Mr. Jesus D. Zea-Garcia. This research has been supported by Spanish MINECO and FEDER [BIA2017- 82391-R research project and I3 (IEDI-2016-0079) program]

Infrared permittivity of the biaxial van der Waals semiconductor α\alpha-MoO3_3 from near- and far-field correlative studies

The biaxial van der Waals semiconductor $\alpha$-phase molybdenum trioxide ($\alpha$-MoO$_3$) has recently received significant attention due to its ability to support highly anisotropic phonon polaritons (PhPs) -infrared (IR) light coupled to lattice vibrations in polar materials-, offering an unprecedented platform for controlling the flow of energy at the nanoscale. However, to fully exploit the extraordinary IR response of this material, an accurate dielectric function is required. Here, we report the accurate IR dielectric function of $\alpha$-MoO$_3$ by modelling far-field, polarized IR reflectance spectra acquired on a single thick flake of this material. Unique to our work, the far-field model is refined by contrasting the experimental dispersion and damping of PhPs, revealed by polariton interferometry using scattering-type scanning near-field optical microscopy (s-SNOM) on thin flakes of $\alpha$-MoO$_3$, with analytical and transfer-matrix calculations, as well as full-wave simulations. Through these correlative efforts, exceptional quantitative agreement is attained to both far- and near-field properties for multiple flakes, thus providing strong verification of the accuracy of our model, while offering a novel approach to extracting dielectric functions of nanomaterials, usually too small or inhomogeneous for establishing accurate models only from standard far-field methods. In addition, by employing density functional theory (DFT), we provide insights into the various vibrational states dictating our dielectric function model and the intriguing optical properties of $\alpha$-MoO$_3$

Revisión bibliográfica de implantología bucofacial del año 2007

Se expone una revisión de la literatura científica publicada en revistas indexadas durante el año 2007 sobre Implantología Bucofacial. La escasez de tiempo de que disponen los profesionales para consultar las múltiples fuentes de información, ha motivado a los autores a resumir los artículos publicados y clasificarlos en los siguientes apartados: generalidades, pacientes especiales, superficies y diseños, tejidos blandos, implantes inmediatos, carga inmediata, complicaciones, elevación sinusal, técnicas avanzadas, plasma rico en plaquetas y factores de crecimiento, cirugía guiada, cirugía mínimamente invasiva y miniimplantes, con la intención de facilitar una puesta al día