219 research outputs found

    Renewable energy research progress in Mexico: a review

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    Mexico ranks 9th in the world in crude oil reserves, 4th in natural gas reserves in America and it is also highly rich in renewable energy sources (solar, wind, biomasss, hydropower and geothermal). However, the potential of this type of energy has not been fully exploited. Hydropower is the renewable energy source with the highest installed capacity within the country (11,603 MW), while geothermal power capacity (958 MW) makes Mexico to be ranked 4th in the use of this energy worldwide. Wind energy potential is concentrated in five different zones, mainly in the state of Oaxaca, and solar energy has a high potential due to Mexico's ideal location in the so called Solar Belt. Biomass energy has the highest potential (2635 to 3771 PJ/year) and has been the subject of the highest number of research publications in the country during the last 30 years (1982-2012). Universidad Nacional Autonoma de Mexico has led research publications in hydropower, wind, solar and biomass energy and Instituto de Investigaciones Electricas in geothermal energy during this period. According to the General Law for Climate Change the country has set the goal of generating 35% of its energy needs from renewable sources by 2024. This paper presents an overview of the renewable energy options available in Mexico, current status, main positive results to date and future potential. It also analyses barriers hindering improvements and proposes pertinent solutions. © 2014 The Authors

    Design and implementation of an ultrasonic sensor for rapid monitoring of industrial malolactic fermentation of wines

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    Ultrasound is an emerging technology that can be applied to monitor food processes. However, ultrasonic techniques are usually limited to research activities within a laboratory environment and they are not extensively used in industrial processes. The aim of this paper is to describe a novel ultrasonic sensor designed to monitor physical–chemical changes that occur in wines stored in industrial tanks. Essentially, the sensor consists of an ultrasonic transducer in contact with a buffer rod, mounted inside a stainless steel tube section. This structure allows the ultrasonic sensor to be directly installed in stainless steel tanks of an industrial plant. The operating principle of this design is based on the measurement of ultrasonic velocity of propagation. To test its proper operation, the sensor has been used to measure changes of concentration in aqueous samples and to monitor the progress of a malolactic fermentation of red wines in various commercial wineries. Results show the feasibility of using this sensor for monitoring malolactic fermentations in red wines placed in industrial tanks.Postprint (author's final draft

    La educación física en la ciudad de Chihuahua 1900-1950

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    El origen de la Educación Física en Chihuahua, como educación pública está vinculado a la construcción del Estadio Olímpico de la ciudad deportiva de la Ciudad de Chihuahua en la década de los años 40´s del siglo pasado. El diseño arquitectónico es correspondiente al proyecto de modernidad que esta ciudad del desierto se planteaba. La educación física formal se vio favorecida por este discurso arquitectónico, sumándose diversas ideas pedagógicas y procesos socioeconómicos y culturales posrevolucionarios como la educación socialista. Se resaltan los enfoques  y políticas educativas en México desde el siglo XX hasta el año 2009. Se identifican al Instituto Científico y Literario, la Universidad Autónoma de Chihuahua y la primera escuela de Educación Física en el Estado

    Ensayos de biodegradabilidad anaerobia de efluentes cerveceros con lodo granular y lodo floculento

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    Desde comienzos de la década de los noventa la industria cervecera del país ha venido implementando tecnologías anaerobias, particularmente del tipo UASB (Upflow Anaerobic Sludge Blanket), para el tratamiento de las aguas residuales de sus plantas industriales en diferentes regiones del país. Por diferentes razones estas instalaciones están funcionando con algunas deficiencias, lo cual es motivo de preocupación tanto para el sector industrial como para las entidades de control. El presente artículo constituye la segunda parte de una investigación encaminada a establecer criterios para la selección y mejoramiento de lodos utilizados en estos sistemas. También se busca analizar la influencia de otros factores asociados como características del desecho, condiciones de operación y parámetros de diseño. El estudio se desarrolló en dos etapas, en las que se emplearon lodo granular y lodo floculento para evaluar la degradabilidad de los residuos líquidos de dos plantas de cerveceras. Igualmente, se incluyó el lodo propio de una de esas instalaciones.At the beginning of nineties the colombian beer industry begun the application of anaerobic technology for the treatment of their wastewater efluents throught different regions of the country. These treatment plants have not been working appropriately due to different factors, and are creating concern among the industrial sector and the water pollution control agencies. This work constitutes the second phase of a research project designed to establish a selection and improvement criteria of the sludges used in the systems. It also looks to analyze other associated factors such as: waste, characteristics, operation conditions and design parameters. The investigation was conducted in two phases using granular and floculent sludges. This method was used for determining the anaerobic biodegradability of wastewater from two industrial plants

    Phosphomannosylation and the functional analysis of the extended Candida albicans MNN4-like gene family

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    We thank Luz A. López-Ramírez (Universidad de Guanajuato) for technical assistance. This work was supported by Consejo Nacional de Ciencia y Tecnología (ref. CB2011/166860; PDCPN2014-247109, and FC 2015-02-834), Universidad de Guanajuato (ref. 000025/11; 0087/13; ref. 1025/2016; Convocatoria Institucional para Fortalecer la Excelencia Académica 2015; CIFOREA 89/2016), Programa de Mejoramiento de Profesorado (ref. UGTO-PTC-261), and Red Temática Glicociencia en Salud (CONACYT-México). NG acknowledges the Wellcome Trust (086827, 075470, 101873, and 200208) and MRC Centre for Medical Mycology for funding (N006364/1). KJ was supported by a research visitor grant to Aberdeen from China Scholarship Council (CSC No. 201406055024). The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmicb.2017.02156/full#supplementary-materialPeer reviewedPublisher PD

    Temperature compensation of ultrasonic velocity during the malolactic fermentation process

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    Ultrasonic properties of materials present a strong dependence on temperature and in turn the ultrasonic velocity of propagation in the material under test. It is precisely for this reason that most ultrasonic measurements are often carried out with thermostated samples by using either water tanks or climate chambers. This approach is viable in a laboratory and when the measured or characterized samples are relatively small. However, this procedure is highly improbable to be applied when in situ measurements in industrial environments must be performed. This goes for the case of, for example, ultrasonic velocity measurements in wine while it is performing malolactic fermentation inside a tank of hundreds of thousands of litres. In this paper two different practical approaches to temperature compensation are studied. Then, the two temperature compensation methods are applied to the measured ultrasonic velocity values along a whole malolactic fermentation process. The results of each method are discussed.Peer ReviewedPostprint (author's final draft

    Adhesion mechanisms of Actinobacillus pleuropneumoniae to the porcine respiratory system and biofilm formation

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    Actinobacillus pleuropneumoniae is a Gram-negative bacterium and the causative agent of porcine pleuropneumonia, a highly contagious disease of pigs characterised by fibrinohaemorrhagic necrotising pneumonia. Although it has been well controlled in some developed countries, outbreaks can occur in pigs of all ages in contact with asymptomatic carriers, leading to significant economic losses to the swine industry due to the high morbidity and mortality rates. Adhesion is a critical step in the colonisation of the swine respiratory tract and the pathogenesis of the porcine pleuropneumonia; however, a literature review of this process is not available to date. Therefore, this review aims to provide information regarding the molecules that have been described in the adhesion of A. pleuropneumoniae to cells and tissues of the porcine respiratory tract. Since adhesion is the first step in biofilm formation, we included a section to describe the genes involved in this process; some of these genes could participate directly or indirectly in the adhesion of A. pleuropneumoniae to the porcine respiratory system. Although the role of biofilms in porcine pleuropneumonia is still not clear, these molecules could be considered in the future as candidates for vaccine development

    Trastorno por déficit de atención e hiperactividad dual en niños y adolescentes internados en un centro para el tratamiento de adicciones

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    Introducción: El trastorno por déficit de atención e hiperactividad es el trastorno psiquiátrico más frecuente en la edad escolar y múltiples estudios han evidenciado que es un factor de riesgo independiente para desarrollar abuso o dependencia de sustancias. El objetivo principal de este trabajo es determinar la frecuencia de este trastorno y otros trastornos externalizantes en niños y adolescentes internados en un centro de referencia, así como el impacto de estas patologías en la escolarización, inicio precoz del consumo de sustancias, caracterización de las conductas adictivas y perfil de los pacientes. Sujetos y métodos: Se analizaron las historias clínicas de la totalidad de niños y adolescentes internados en un centro de referencia durante los meses de junio y julio de 2013, todos ellos con el diagnóstico de trastorno por uso de sustancias. Se realizaron entrevistas estructuradas para los diagnósticos de déficit de atención e hiperactividad y otros trastornos externalizantes. Resultados: Se determinó la presencia de comorbilidad con déficit de atención e hiperactividad en el 40% de los pacientes y de comorbilidad con trastorno disocial en 95% de los pacientes. Los pacientes con déficit de atención e hiperactividad presentaron mayores dificultades en la escolarización y en el inicio precoz en el uso de sustancias. Conclusión: el trastorno por déficit de atención e hiperactividad es frecuentemente minimizado en sus síntomas y sobre todo en las posibles consecuencias negativas para el paciente; si su diagnóstico no se realiza a tiempo, no será posible un buen abordaje terapéutico del niño y adolescente

    Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

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    The macrozoobenthos of Mejillones Bay (23°S; Humboldt Current) was quantitatively investigated over a 7-year period from austral summer 1995/1996 to winter 2002. About 78 van Veen grab samples taken at six stations (5, 10, 20 m depth) provided the basis for the analysis of the distribution of 60 species and 28 families of benthic invertebrates, as well as of their abundance and biomass. Mean abundance (2,119 individuals m-2) was in the same order compared to a previous investigation; mean biomass (966 g formalin wet mass m-2), however, exceeded prior estimations mainly due to the dominance of the bivalve Aulacomya ater. About 43% of the taxa inhabited the complete depth range. Mean taxonomic Shannon diversity (H', Log e) was 1.54 ± 0.58 with a maximum at 20 m (1.95 ± 0.33); evenness increased with depth. The fauna was numerically dominated by carnivorous gastropods, polychaetes and crustaceans (48%). About 15% of the species were suspensivorous, 13% sedimentivorous, 11% detritivorous, 7% omnivorous and 6% herbivorous. Cluster analyses showed a significant difference between the shallow and the deeper stations. Gammarid amphipods and the polychaete family Nephtyidae characterized the 5-mzone, the molluscs Aulacomya ater, Mitrella unifasciata and gammarids the intermediate zone, while the gastropod Nassarius gayi and the polychaete family Nereidae were most prominent at the deeper stations. The communities of the three depth zones did not appear to be limited by hypoxia during non-El Niño conditions. Therefore, no typical change in community structure occurred during El Niño 1997–1998, in contrast to what was observed for deeper faunal assemblages and hypoxic bays elsewhere in the coastal Humboldt Current system

    Reporte de un caso: Fractura expuesta del mediopie por accidente de tránsito en paciente VIH/SIDA: Case report: Exposed midfoot fracture due to traffic accident in HIV/AIDS patient

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    Currently there is a high incidence of traffic accidents in the world, many of them cause severe disability in people. These limb injuries cause high morbidity even reaching an amputation. This is aggravated in HIV/AIDS patients, especially in treatment and evolution. A clinical case of a patient with severe midfoot injury that ends in amputation is presented and a surgical management review of the trauma patient with HIV/AIDS is made.Actualmente hay una alta incidencia de accidentes de tránsito en el mundo, muchos de ellos provocan una discapacidad grave en las personas. Estas lesiones en las extremidades provocan alta morbilidad llegando incluso a una amputación. Esto se agrava en pacientes VIH/SIDA, sobre todo en el tratamiento y la evolución. Se presenta un caso clínico de un paciente con lesión severa del mediopie que termina en amputación y se hace una revisión del manejo quirúrgico del paciente traumatológico con VIH/SIDA
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