2,970 research outputs found

    Acercamientos teórico-metodológicos para el estudio de las áreas naturales protegidas (pdf)

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    En esta publicación se reúne una serie de trabajos de investigadores afiliados a la RILACREB que, desde diversos campos disciplinarios abordan la gestión de las Áreas Naturales Protegidas (ANP). Su objetivo es contribuir tanto en la investigación como en la docencia, además de apoyar las tareas de organizaciones sociales y profesionales que laboran en el área operativa de las ANP

    Genotoxicity by Electromagnetic Fields

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    Modern life implies a constant exposure of living organisms to many sources of radiation, especially electromagnetic fields (EMFs) generated by our technological devices. The question of whether or not EMFs in the non-ionizing extremely low frequency (ELF) range can induce genotoxic effects is currently a subject of interest. People of industrialized societies are commonly exposed to EMFs and waves in a very broad range of frequencies, including power lines, telecommunications, and domestic and industrial equipment. In this review, we present controversial evidence from our research group and others of genotoxicity induced by ELF-EMFs, since scientific community consider EMF devices produce marginal amounts of energy, which does not justify any DNA alterations, together with conflicting laboratory results and few epidemiological studies. However, in 2002 the International Agency for Research on Cancer (IARC) categorized ELF-EMFs as being potential carcinogenic and genotoxic agents to humans. The aim of the present chapter is to discuss the role of ELM-EMFs on human genotoxicity

    Propiedades físicas y cristalinas del Cd1-x Znx Te (0 <= x <= 1)

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    El Cd1-xZnxTe (0 <= x <= 1) y el ZnTe son semiconductores de la familia II-VI, que se usan en forma monocristalina porque así poseen mejores propiedades estructurales y eléctricas. El CZT y el ZnTe deben poseer alta calidad cristalina y eléctrica para ser usados, el primero en detectores de rayos X y ?, y como sustratos ordenadores de películas epitaxiales aptas para la detección de la radiación IR y el segundo para la fabricación de diodos láser y emisores de luz de alta intensidad, ambos casos en el verde. En este trabajo el CZT se sintetizó por el método de Bridgman, bajo un gradiente de temperatura de 10ºC/cm a velocidades de 1, 66 mm/h y 3, 22 mm/h para diferentes concentraciones de Zn. Por otro lado, el ZnTe se sintetizó por transporte físico en fase vapor bajo un gradiente de temperatura de 6ºC/cm a una velocidad de 6mm/día. Por medio de revelado químico y microscopía electrónica de transmisión convencional TEM y de alta resolución (HRTEM) se estudió la calidad cristalina de ambos materiales. Se observó que los lingotes de CZT tenían una densidad de dislocaciones promedio similar en todos los lingotes crecidos en ambas velocidades y para todas las concentraciones mientras que el ZnTe mostró una menor densidad de dislocaciones. Las micrografías de TEM mostraron en todos estos materiales un orden estructural importante. Estas características indicaron que la calidad cristalina del CZT y del ZnTe era adecuada para fabricar dispositivos optoelectrónicos. También se midió la Conductividad Eléctrica, Difusividad Térmica, Calor Específico y Coeficiente Seebeck en función de la temperatura en estos materiales. Se analizó la influencia de las propiedades estructurales en sus propiedades físicas con el objeto de determinar la relación con los defectos cristalinos observados. Cd1-xZnxTe (0 = x = 1) and ZnTe are II-VI semiconductors, which are used in single crystalline structure to improve their crystalline and electrical properties. The CZT and ZnTe must possess high crystalline and electrical quality to be used, the first in x or ¿-ray detectors, and as substrates for suitable epitaxial films for detecting IR radiation and the second for the manufacture of laser diodes and high intensity light emitters, both cases in the green wavelengths. In this work CZT was synthesized by the Bridgman method employing a temperature gradient of 10ºC/cm at speeds of 1.66 mm/h and 3.22 mm/h for different Zn concentrations. Meanwhile ZnTe was synthesized by physical vapor transport employing a temperature gradient of 6ºC/cm at a speed of 6 mm/day. Chemical etching and low and high transmission electron microscopy (LRTEM and HRTEM) were employed to determine the crystalline quality of all materials. It was observed that CZT ingots had an average dislocations density similar in all ingots grown in both speeds and all concentrations while the ZnTe showed a lower dislocation density. HRTEM micrographs showed in all semiconductors an important structural order. These characteristics showed that the crystalline quality of CZT and ZnTe was suitable for manufacturing optoelectronic devices. Furthermore, Electrical Conductivity, Thermal Diffusivity, Specific Heat and Seebeck Coefficient were measured as temperature function in all these materials. The influence of structural properties in physical properties was analyzed in order to determine the relationship with the observed crystal defects

    Escenarios y modelo de usos-suelo dentro de una área natural protegida: ejido de san Antonio Acahualco

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    Prospective is an approach to planning that offers future alternatives of fact scenarios, taking into consideration aspects that influence the behavior of the phenomenon being studied. Therefore, it is useful for the design of strategies of actions based on proactivity and on theoretical models, to reverse socio-territorial costs. This study presents three future alternatives regarding land requirements for agricultural, housing and green area uses, sustained on territorial fragmentation, which has fostered a disproportionate growth of the three productive sectors, mostly in the decline of activities from the primary sector and the creation of gray spaces. The first scenario is the catastrophic, which evidences that the availability of land will be affected in 20 years. The second scenario is the trending and it projects that in 30 years there will be a land deficit for agricultural, housing and green area uses; and the third scenario is the desirable and feasible, which postpones the land deficit to 60 years. Faced with these prospective behaviors, traditional knowledge is reconsidered proactively for applying agro-forestry and conserving agro-biodiversity, to reverse the socio-territorial costs that social and economic welfare implies for peasant families.La prospectiva es un enfoque de la planeación que ofrece alternativas futuras de hechos a través de escenarios, considerando aspectos que influyen en el comportamiento del fenómeno estudiado. Por tanto, es útil para el diseño de estrategias de acciones fundamentadas en la proactividad y en modelos teóricos, para revertir costos socio-territoriales. El presente trabajo presenta tres alternativas de futuro sobre requerimientos de suelo para uso agrícola, vivienda y área verde, sustentados en la fragmentación territorial; la cual ha propiciado un crecimiento desproporcionado de los tres sectores productivos, principalmente en la declinación de las actividades del sector primario y la creación de espacios grises. El primer escenario es el catastrófico, que evidencia que la disponibilidad de tierra se verá afectada dentro de 20 años. El segundo escenario es el tendencial y proyecta que en 30 años habrá déficit de suelo para los usos agrícola, vivienda y área verde; y el tercer escenario es el deseable y factible, que pospone el déficit de suelo a 60 años. Ante estos comportamientos prospectivos, se reconsidera el conocimiento tradicional proactivamente para la práctica de la agroforestería y la conservación de la agrobiodiversidad, para revertir los costos socio-territoriales que implica el bienestar social y económico de las familias campesinas

    Multidisciplinary, evidence-based consensus guidelines for human papillomavirus (HPV) vaccination in highrisk populations, Spain, 2016

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    Introduction: Although human papillomavirus (HPV) routine vaccination programmes have been implemented around the world and recommendations have been expanded to include other high-risk individuals, current recommendations often differ between countries in Europe, as well as worldwide. Aim: To find and summarise the best available evidence of HPV vaccination in high-risk patients aiding clinicians and public health workers in the day-to-day vaccine decisions relating to HPV in Spain. Methods: We conducted a systematic review of the immunogenicity, safety and efficacy/effectiveness of HPV vaccination in high-risk populations between January 2006 and June 2016. HPV vaccination recommendations were established with levels of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Results: A strong recommendation about HPV vaccination was made in the following groups: HIV infected patients aged 9-26 years; men who have sex with men aged 9-26 years; women with precancerous cervical lesions; patients with congenital bone marrow failure syndrome; women who have received a solid organ transplant or hematopoietic stem cell transplantation aged 9-26 years; and patients diagnosed with recurrent respiratory papillomatosis. Conclusions: Data concerning non-routine HPV vaccination in populations with a high risk of HPV infection and associated lesions were scarce. We have developed a document to evaluate and establish evidence- based guidelines on HPV vaccination in highrisk populations in Spain, based on best available scientific evidence

    Potential use of isomaltulose to produce healthier marshmallows

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    Isomaltulose is a non-cariogenic sugar with a lower glycemic index but with the same caloric value and visual appearance as sucrose. Therefore, isomaltulose could potentially be used to produce healthier candies. In this regard, the aim of this research was to evaluate isomaltulose as a traditional sugar replacer in soft marshmallow type candies, in order to provide added value to these widely consumed products, making it possible to capture a new market niche. 18 formulations were studied combining different sugars (sucrose, glucose syrup, fructose and isomaltulose) and different percentages of gelatine (4, 5 and 6). Analyses of composition (degrees Brix and moisture content), pH and water activity (a(w)), instrumental colour and texture as well as a sensorial analysis were performed. Marshmallows with isomaltulose combined with fructose exhibited the lowest values of pH (4.99-5.14). Moreover, formulations with similar amount of isomaltulose and fructose presented lower instrumental hardness, higher cohesiveness and springiness, and the best sensory acceptance. A PLS multivariate analysis showed a good correlation between instrumental and sensory mechanical parameters. Therefore, instrumental measures of texture could be suitable for discerning an overall preference for marshmallows without using trained panellists. (C) 2014 Elsevier Ltd. All rights reserved.The authors thank the Universitat Politecnica de Valencia for funding the project PAID 2011-ref: 2012 and the PhD scholarship.Periche Santamaría, A.; Heredia Gutiérrez, AB.; Escriche Roberto, MI.; Andrés Grau, AM.; Castelló Gómez, ML. (2015). Potential use of isomaltulose to produce healthier marshmallows. Food Science and Technology. 62(1):605-612. https://doi.org/10.1016/j.lwt.2014.12.024S60561262

    Multidisciplinary, evidence-based consensus guidelines for human papillomavirus (HPV) vaccination in high-risk populations, Spain, 2016.

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    Introduction: Although human papillomavirus (HPV) routine vaccination programmes have been implemented around the world and recommendations have been expanded to include other high-risk individuals, current recommendations often differ between countries in Europe, as well as worldwide. Aim: To find and summarise the best available evidence of HPV vaccination in high-risk patients aiding clinicians and public health workers in the day-to-day vaccine decisions relating to HPV in Spain. Methods: We conducted a systematic review of the immunogenicity, safety and efficacy/effectiveness of HPV vaccination in high-risk populations between January 2006 and June 2016. HPV vaccination recommendations were established with levels of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Results: A strong recommendation about HPV vaccination was made in the following groups: HIV infected patients aged 9-26 years; men who have sex with men aged 9-26 years; women with precancerous cervical lesions; patients with congenital bone marrow failure syndrome; women who have received a solid organ transplant or hematopoietic stem cell transplantation aged 9-26 years; and patients diagnosed with recurrent respiratory papillomatosis. Conclusions: Data concerning non-routine HPV vaccination in populations with a high risk of HPV infection and associated lesions were scarce. We have developed a document to evaluate and establish evidence-based guidelines on HPV vaccination in high-risk populations in Spain, based on best available scientific evidence

    Transportability of non-target arthropod field data for the use in environmental risk assessment of genetically modified maize in Northern Mexico

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    In country, non-target arthropod (NTA) field evaluations are required to comply with the regulatory process for cultivation of genetically modified (GM) maize in Mexico. Two sets of field trials, Experimental Phase and Pilot Phase, were conducted to identify any potential harm of insect-protected and glyphosate-tolerant maize (MON89Ø34-3 × MON-88Ø17-3 and MON-89Ø34-3 × MON-ØØ6Ø3-6) and glyphosatetolerant maize (MON-ØØ6Ø3-6) to local NTAs compared to conventional maize. NTA abundance data were collected at 32 sites, providing high geographic and environmental diversity within maize production areas from four ecological regions (ecoregions) in northern Mexico. The most abundant herbivorous taxa collected included field crickets, corn flea beetles, rootworm beetles, cornsilk flies, aphids, leafhoppers, plant bugs and thrips while the most abundant beneficial taxa captured were soil mites, spiders, predatory ground beetles, rove beetles, springtails (Collembola), predatory earwigs, ladybird beetles, syrphid flies, tachinid flies, minute pirate bugs, parasitic wasps and lacewings. Across the taxa analysed, no statistically significant differences in abundance were detected between GM maize and the conventional maize control for 69 of the 74 comparisons (93.2%) indicating thatthe single or stacked insect-protected and herbicide-tolerant GM traits generally exert no marked adverse effects on the arthropod populations compared with conventional maize. The distribution of taxa observed in this study provides evidence that irrespective of variations in overall biodiversity of a given ecoregion, important herbivore, predatory and parasitic arthropod taxa within the commercial maize agroecosystem are highly similar indicating that relevant data generated in one ecoregion can be transportable for the risk assessment of the same or similar GM crop in another ecoregion
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