3,950 research outputs found

    Controlled nucleation of topological defects in the stripe domain patterns of Lateral multilayers with Perpendicular Magnetic Anisotropy: competition between magnetostatic, exchange and misfit interactions

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    Magnetic lateral multilayers have been fabricated on weak perpendicular magnetic anisotropy amorphous Nd-Co films in order to perform a systematic study on the conditions for controlled nucleation of topological defects within their magnetic stripe domain pattern. A lateral thickness modulation of period ww is defined on the nanostructured samples that, in turn, induces a lateral modulation of both magnetic stripe domain periods λ\lambda and average in-plane magnetization component MinplaneM_{inplane}. Depending on lateral multilayer period and in-plane applied field, thin and thick regions switch independently during in-plane magnetization reversal and domain walls are created within the in-plane magnetization configuration coupled to variable angle grain boundaries and disclinations within the magnetic stripe domain patterns. This process is mainly driven by the competition between rotatable anisotropy (that couples the magnetic stripe pattern to in-plane magnetization) and in-plane shape anisotropy induced by the periodic thickness modulation. However, as the structural period ww becomes comparable to magnetic stripe period λ\lambda, the nucleation of topological defects at the interfaces between thin and thick regions is hindered by a size effect and stripe domains in the different thickness regions become strongly coupled.Comment: 10 pages, 7 figures, submitted to Physical Review

    Chikungunya, Zika y otras Neuroarbovirosis: Importancia en América Latina

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    Durante los últimos 4 años, América Latina ha sido testigo de epidemias causadas por arbovirus, como ha sido el caso especialmente de chikungunya y Zika. Los arbovirus, virus transmitidos por artrópodos, tienen un impacto particular en zonas tropicales y subtropicales, por las importantes densidades de vectores como Aedes aegypti y Aedes albopictus, por condiciones ambientales y sociales, que, aunado a la globalización y el turismo, han permitido la llegada al continente desde diciembre 2013 (chikungunya). Viajeros infectados, sintomáticos o asintomáticos, que tienen estos virus ARN en la sangre (viremia), cuando llegan a zonas con el vector, son fuente para la generación de casos autóctonos. Esto fue lo que ocurrió en las islas del Caribe con chikungunya y luego en 2013-2015 en Brasil con Zika

    Chikungunya, Zika y otras Neuroarbovirosis: Importancia en América Latina

    Get PDF
    Durante los últimos 4 años, América Latina ha sido testigo de epidemias causadas por arbovirus, como ha sido el caso especialmente de chikungunya y Zika. Los arbovirus, virus transmitidos por artrópodos, tienen un impacto particular en zonas tropicales y subtropicales, por las importantes densidades de vectores como Aedes aegypti y Aedes albopictus, por condiciones ambientales y sociales, que, aunado a la globalización y el turismo, han permitido la llegada al continente desde diciembre 2013 (chikungunya). Viajeros infectados, sintomáticos o asintomáticos, que tienen estos virus ARN en la sangre (viremia), cuando llegan a zonas con el vector, son fuente para la generación de casos autóctonos. Esto fue lo que ocurrió en las islas del Caribe con chikungunya y luego en 2013-2015 en Brasil con Zika

    The socio-ecology of zoonotic infections

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    AbstractThe resurgence of infectious diseases of zoonotic origin observed in recent years imposes a major morbidity/mortality burden worldwide, and also a major economic burden that extends beyond pure medical costs. The resurgence and epidemiology of zoonoses are complex and dynamic, being influenced by varying parameters that can roughly be categorized as human-related, pathogen-related, and climate/environment-related; however, there is significant interplay between these factors. Human-related factors include modern life trends such as ecotourism, increased exposure through hunting or pet owning, and culinary habits, industrialization sequelae such as farming/food chain intensification, globalization of trade, human intrusion into ecosystems and urbanization, significant alterations in political regimes, conflict with accompanying breakdown of public health and surveillance infrastructure, voluntary or involuntary immigration, loosening of border controls, and hierarchy issues in related decision-making, and scientific advances that allow easier detection of zoonotic infections and evolution of novel susceptible immunocompromised populations. Pathogen-related factors include alterations in ecosystems and biodiversity that influence local fauna synthesis, favouring expansion of disease hosts or vectors, pressure for virulence/resistance selection, and genomic variability. Climate/environment-related factors, either localized or extended, such as El Niño southern oscillation or global warming, may affect host–vector life cycles through varying mechanisms. Emerging issues needing clarification include the development of predictive models for the infectious disease impact of environmental projects, awareness of the risk imposed on immunocompromised populations, recognition of the chronicity burden for certain zoonoses, and the development of different evaluations of the overall stress imposed by a zoonotic infection on a household, and not strictly a person

    Changes in Number and Weight of Wheat and Triticale Grains to Manipulation in Source-Sink Relationship

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    The source-sink ratio experimental manipulation has helped to define whether a crop is limited by source or sink or co-limited by both. There is no evidence in triticale of source-sink manipulations effects on yield and yield components. Two experiments were accomplished during 2008 and 2009 growing seasons at the Universidad Autónoma del Estado de México, México, and one in 2010 at the National Institute of Agricultural Technology in Pergamino, Argentina. Two triticale cultivars (line 4 and 7) and one wheat cultivar (Tollocan) were used. Source-sink relations were modified at anthesis by thinning, degraining, shading, and total defoliation procedures. Changes in the source-sink relation affected yields in both species differentially. The changes in yield due to cultivars and treatments were explained mainly by the number of grains rather than by their individual grain weight. The number of grains was affected by all treatments in both species, while the individual grain weight was increased by thinning and degraining mainly in triticale. A greater number of fertile florets in triticale were associated with their higher rate of abortion compared to wheat. These results could help to better understand crop management and genetic improvement.Fil: Ballesteros Rodriguez, E.. Universidad Nacional Autónoma de México; MéxicoFil: Martinez Rueda, C.G.. Universidad Nacional Autónoma de México; MéxicoFil: Morales Rosales, E.J.. Universidad Nacional Autónoma de México; MéxicoFil: Estrada Campuzano, G.. Universidad Nacional Autónoma de México; MéxicoFil: González, Fernanda Gabriela. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Pergamino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Validation of a Microwave-Assisted Derivatization Gas Chromatography-Mass Spectrometry Method for the Quantification of 2-Hydroxybutyrate in Human Serum as an Early Marker of Diabetes Mellitus

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    Circulating levels of 2-hydroxybutyrate (2HB) are highly related to glycemic status in different metabolomic studies. According to recent evidence, 2HB is an early biomarker of the future development of dysglycemia and type 2 diabetes mellitus and may be causally related to the progression of normal subjects to impaired fasting glucose or insulin resistance. In the present study, we developed and validated a simple, specific and sensitive gas chromatography-mass spectrometry (GC-MS) method specifically intended to quantify serum levels of 2HB. Liquid-liquid extraction with ethyl acetate was followed by 2 min of microwave-assisted derivatization. The method presented acceptable accuracy, precision and recovery, and the limit of quantification was 5 µM. Levels of 2HB were found to be stable in serum after three freeze-thaw cycles, and at ambient temperature and at a temperature of 4 °C for up to 24 h. Extracts derivatized under microwave irradiation were stable for up to 96 h. No differences were found in 2HB concentrations measured in serum or plasma EDTA samples. In summary, the method is useful for a rapid, precise and accurate quantification of 2HB in serum samples assessed for the evaluation of dysglycemia and diabetes mellitus

    Flexible Laser-Reduced Graphene Oxide Thermistor for Ubiquitous Electronics

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    This work presents a versatile sensing platform, intended for ubiquitous and flexible electronics based on a laser reduced-Graphene-Oxide thermistor. This technique enables the fast and ecological production of reduced Graphene Oxide without the need of masks or expensive lithography processes. The final transducer is fabricated on a flexible plastic substrate in order to use it as a superficial patch. Finally, a full demonstrator, which integrates this flexible thermistor with a low power System on Chip with wireless transmission, is presented.This work has been partially supported by the Spanish Ministry of Education, Culture and Sport (MECD) through the pre-doctoral grant FPU16/01451 , the National Excellence Research Project TEC2017-89955-P and the University of Granada through the scholarship ”Initiation to Research
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