70 research outputs found

    Dispersal of transgenes through maize seed systems in Mexico.

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    ObjectivesCurrent models of transgene dispersal focus on gene flow via pollen while neglecting seed, a vital vehicle for gene flow in centers of crop origin and diversity. We analyze the dispersal of maize transgenes via seeds in Mexico, the crop's cradle.MethodsWe use immunoassays (ELISA) to screen for the activity of recombinant proteins in a nationwide sample of farmer seed stocks. We estimate critical parameters of seed population dynamics using household survey data and combine these estimates with analytical results to examine presumed sources and mechanisms of dispersal.ResultsRecombinant proteins Cry1Ab/Ac and CP4/EPSPS were found in 3.1% and 1.8% of samples, respectively. They are most abundant in southeast Mexico but also present in the west-central region. Diffusion of seed and grain imported from the United States might explain the frequency and distribution of transgenes in west-central Mexico but not in the southeast.ConclusionsUnderstanding the potential for transgene survival and dispersal should help design methods to regulate the diffusion of germplasm into local seed stocks. Further research is needed on the interactions between formal and informal seed systems and grain markets in centers of crop origin and diversification

    Transgenes in Mexican maize: molecular evidence and methodological considerations for GMO detection in landrace populations

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    A possible consequence of planting genetically modified organisms (GMOs) in centres of crop origin is unintended gene flow into traditional landraces. In 2001, a study reported the presence of the transgenic 35S promoter in maize landraces sampled in 2000 from the Sierra Juarez of Oaxaca, Mexico. Analysis of a large sample taken from the same region in 2003 and 2004 could not confirm the existence of transgenes, thereby casting doubt on the earlier results. These two studies were based on different sampling and analytical procedures and are thus hard to compare. Here, we present new molecular data for this region that confirm the presence of transgenes in three of 23 localities sampled in 2001. Transgene sequences were not detected in samples taken in 2002 from nine localities, while directed samples taken in 2004 from two of the positive 2001 localities were again found to contain transgenic sequences. These findings suggest the persistence or re-introduction of transgenes up until 2004 in this area. We address variability in recombinant sequence detection by analyzing the consistency of current molecular assays. We also present theoretical results on the limitations of estimating the probability of transgene detection in samples taken from landraces. The inclusion of a limited number of female gametes and, more importantly, aggregated transgene distributions may significantly lower detection probabilities. Our analytical and sampling considerations help explain discrepancies among different detection efforts, including the one presented here, and provide considerations for the establishment of monitoring protocols to detect the presence of transgenes among structured populations of landraces

    Phenological variation of Rhizophora mangle and ground water chemistry associated to changes of the precipitation

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    Mangrove forests are vulnerable to long term changes of temperature and precipitation. In this study, we want to know if the precipitation regime significantly varies among years and seasons during a five-yr period (2006-2010) at the North of Laguna de Términos, Campeche, Mexico. In addition, we want to know how the salinity and the redox potential of the ground water of a monospecific mangrove forest of Rhizophora mangle are modified according to this variation. Finally, we describe the total litterfall, and the flowers and hypocotiles production of the studied mangrove and analyze these responses as a function of the environment variables. A repeated measures ANOVA showed that precipitation significantly varied among years and seasons (F=15.83, p<0.003; F=29.8, p<0.0001). The salinity and the redox potential were also significant effects of the same temporal variation (F=1003.25, p<0.0001; F=213.32, p<0.0001), as well as the total litterfall and the hypocotile production (F=39.35, p<0.001; F=8.74, p<0.025). Precipitation was directly proportional to the hypocotile production (r=0.43, p<0.005) and inversely proportional to the salinity ground water (r= - 0.36, p<0.02). The precipitation and the salinity play significant roles on the variation of the litterfall and the hypocotile production of the studied mangrove (R2= 0.85; p<0.05 and R2= 0.70; p<0.05). Our study suggests a resilient ability of R. mangle, whichallows it to tolerate seasonal and annual changes of the precipitation

    Descrição dos achados histopatológicos em cordeiros intoxicados com selênio por bolos intraruminais

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    Selenium is an essential micronutrient for ruminants, it participates in the optimal functioning of proteins and enzymes that can combat oxidative stress in the body. However, its toxicity is documented in different species. The objective of this work was to describe the histopathological findings in lambs intoxicated with selenium administered through intraruminal boluses. 4 lambs of 3 months of age and 15 kg average supplemented with selenium by intraruminal bolus found intoxicated. The main findings at necropsy were pulmonary edema, necrosis, hemorrhage and hyperkeratosis in the reticulo-rumen. The histopathology of these organs showed congestion of alveolar capillaries, hemorrhage, edema, and hyaline membranes in the lungs; areas of hemorrhage in the liver parenchyma, congested liver sinusoids, degeneration and necrosis of hepatocytes, hepatocellular lipid degeneration; reticulum with areas of necrosis, denigration of the mucosa and areas of hyperplasia, as well as hyperkeratosis; multiple areas of degeneration and necrosis of cardiac muscle fibers; areas of hemorrhage and congestion in the renal parenchyma, degeneration and tubular necrosis. This study evidences the lesions related to selenium intoxication in lambs supplemented with the mineral through intraruminal boluses.El selenio es un micronutriente esencial para los rumiantes, participa en el funcionamiento óptimo de proteínas y enzimas que pueden combatir el estrés oxidante en el organismo. Sin embargo, su toxicidad está documentada en diferentes especies. El objetivo del presente trabajo fue describir los hallazgos histopatológicos en corderos intoxicados con selenio administrado a través de bolos intrarruminales. 4 corderos de 3 meses de edad y 15 kg promedio suplementados con selenio mediante bolos intrarruminales murieron intoxicados. Los principales hallazgos a la necropsia fueron edema pulmonar, necrosis, hemorragia e hiperqueratosis en retículo-rumen. La histopatología de los órganos mostró congestión de capilares alveolares, hemorragia, edema y membranas hialinas en pulmón; zonas de hemorragia en parénquima hepático, sinusoides hepáticos congestionados, degeneración y necrosis de hepatocitos, degeneración lipídica hepatocelular; retículo con zonas de necrosis, denegeración de la mucosa y zonas de hiperplasia, además de hiperqueratosis; múltiples áreas de degeneración y necrosis de fibras musculares cardíacas; zonas de hemorragia y congestión en parénquima renal, degeneración y necrosis tubular. Este estudio se evidenciaron las principales lesiones relacionas a la intoxicación con selenio en corderos sumplementados con el mineral mediante bolos intrarruminales.O selênio é um micronutriente essencial para ruminantes, participa do funcionamento ideal de proteínas e enzimas que podem combater o estresse oxidativo no organismo. No entanto, sua toxicidade é documentada em diferentes espécies. O objetivo deste trabalho foi descrever os achados histopatológicos em cordeiros intoxicados com selênio administrado por meio de bolos intraruminais. Quatro cordeiros de 3 meses de idade e 15 kg em média, suplementados com selênio por meio de bolos intraruminais, morreram por intoxicação. Os principais achados da necropsia foram edema pulmonar, necrose, hemorragia e hiperqueratose no retículo-rúmen. A histopatologia dos órgãos mostrou congestão dos capilares alveolares, hemorragia, edema e membranas hialinas nos pulmões; áreas de hemorragia no parênquima hepático, sinusóides hepáticos congestos, degeneração e necrose de hepatócitos, degeneração lipídica hepatocelular; retículo com áreas de necrose, denegrição da mucosa e áreas de hiperplasia, além de hiperqueratose; múltiplas áreas de degeneração e necrose das fibras musculares cardíacas; áreas de hemorragia e congestão no parênquima renal, degeneração e necrose tubular. Este estudo evidenciou as principais lesões relacionadas à intoxicação por selênio em cordeiros suplementados com o mineral por meio de bolos intraruminais

    Economic impact of Melanaphis sacchari (Zehntner) ON Sorghum bicolor (L) Moench, and its management in the southwestern of Puebla, Mexico

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    ABSTRACT Objective: To evaluate the economic impact of the sorghum aphid (Melanaphis sacchari) and the sorghum crop profitability in Western Puebla, Mexico. Considering the management practices application-index (IAPM), related to the control practices suggested by the State Plant Health Committee (CESAVEG) was obtained. Design/methodology/approximation: Data on socioeconomic aspects of the producer and the production units were collected. The questionnaire was applied to producers affilliated to PROAGRO. Results are shown using descriptive statistics. Results: The aphid infestation in sorghum had its most relevant effect on yield during 2014-2016. Income obtained from sorghum sales is decreasing due to a downward trend in the purchase price per ton. After the arrival of M. sacchari the primary control strategy was to increase the number of insecticide applications, increasing production costs. Limitations of the study/implications: Since producers' incomes do not depend solely on sorghum production, the effect of the pest on their economy was relatively minor. Findings/conclusions: The management practices application index indicates a moderate use of the recommended practices to manage this pest. The B/C ratio suggests that even after the establishment of M. sacchari, sorghum is still a profitable activity.Objective: To evaluate the economic impact of sorghum aphid (Melanaphis sacchari)and the sorghum crop profitability in Western Puebla, Mexico, considering themanagement practices application-index (IAPM), related to the control practicessuggested by the State Plant Health Committee (CESAVEG).Design/Methodology/Approach: Data on socioeconomic aspects of the producer andthe production units were collected. The questionnaire was applied to producersaffiliated to PROAGRO. Results are shown using descriptive statistics.Results: The aphid infestation in sorghum had its most relevant effect on yield during2014-2016. Income obtained from sorghum sales is decreasing due to a downwardtrend in the purchase price per ton. After the arrival of M. sacchari the primary controlstrategy was to increase the number of insecticide applications, increasing productioncosts.Limitations of the study/implications: Since producers; incomes do not depend solely on sorghum production, the effect of the pest on their economy was relatively minor. Findings/Conclusions: The management practices application index indicates amoderate use of the recommended practices to manage this pest. The B/C ratiosuggests that even after the establishment of M. sacchari, sorghum is still a profitableactivity

    Symptom cluster analysis of long COVID-19 in patients discharged from the Temporary COVID-19 Hospital in Mexico City.

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    INTRODUCTION: Several reports have emerged describing the long-term consequences of COVID-19 and its effects on multiple systems. METHODS: As further research is needed, we conducted a longitudinal observational study to report the prevalence and associated risk factors of the long-term health consequences of COVID-19 by symptom clusters in patients discharged from the Temporary COVID-19 Hospital (TCH) in Mexico City. Self-reported clinical symptom data were collected via telephone calls over 90 days post-discharge. Among 4670 patients, we identified 45 symptoms across eight symptom clusters (neurological; mood disorders; systemic; respiratory; musculoskeletal; ear, nose, and throat; dermatological; and gastrointestinal). RESULTS: We observed that the neurological, dermatological, and mood disorder symptom clusters persisted in >30% of patients at 90 days post-discharge. Although most symptoms decreased in frequency between day 30 and 90, alopecia and the dermatological symptom cluster significantly increased (p < 0.00001). Women were more prone than men to develop long-term symptoms, and invasive mechanical ventilation also increased the frequency of symptoms at 30 days post-discharge. CONCLUSION: Overall, we observed that symptoms often persisted regardless of disease severity. We hope these findings will help promote public health strategies that ensure equity in the access to solutions focused on the long-term consequences of COVID-19

    1er. Coloquio de educación para el diseño en la sociedad 5.0

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    Las memorias del 1er. Coloquio de Educación para el Diseño en la Sociedad 5.0 debenser entendidas como un esfuerzo colectivo de la comunidad de académicos de la División de Ciencias y Artes para el Diseño, que pone de manifiesto los retos y oportunidades que enfrenta la educación en diseño en un contexto de cambio acelerado y rompimiento de paradigmas.El evento se realizó el pasado mes de mayo de 2018 y se recibieron más de 50 ponencias por parte de las profesoras y profesores de la División.Las experiencias y/o propuestas innovadoras en cuanto a procesos de enseñanza y aprendizaje que presentan los autores en cada uno de sus textos son una invitación a reflexionar sobre nuestra situación actual en la materia, y emprender acciones en la División para continuar brindando una educación de calidad en diseño a nuestras alumnas, alumnos y la sociedad.Adicionalmente, se organizaron tres conferencias magistrales sobre la situación actual de la educación en Diseño y de las Instituciones de Educación Superior, impartidas por el Mtro. Luis Sarale, profesor de la Universidad Nacional de Cuyo en Mendoza (Argentina), y Presidente en su momento, de la Red de Carreras de Diseño en Universidades Públicas Latinoamericanas (DISUR), el Dr. Romualdo López Zárate, Rector de la Unidad Azcapotzalco, así como del Mtro. Luis Antonio Rivera Díaz, Jefe de Departamento de Teoría y Procesos del Diseño de la División de la Ciencias de la Comunicación y Diseño, en la Unidad Cuajimalpa de nuestra institución.La publicación de estas memorias son un esfuerzo divisional, organizado desde la Coordinación de Docencia Divisional y la Coordinación de Tecnologías del Aprendizaje, del Conocimiento y la Comunicación, para contribuir a los objetivos planteados en el documento ACCIONES:Agenda CyAD2021, en particular al eje de Innovación Educativa. Es necesario impulsar a todos los niveles de la División espacios de discusión orientados a reflexionar sobre el presente y futuro en la educación del diseñador, que contribuya a mejorar la calidad de la docencia y favorezca al fortalecimiento de los procesos de enseñanza y aprendizaje.Finalmente, extiendo un amplio reconocimiento a todos los miembros de la División que hicieron posible este evento, así como a todos los ponentes y participantes por compartir su conocimiento para que la División sea cada día mejor

    Verminosis pulmonar en pequeños rumiantes, descripción de la enfermedad, prevención, control y tratamiento

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    Pulmonary verminosis is one of the most important parasites affecting sheep and goats. It is caused by Dictyocaulus filaria, Protostrongylus rufescens and Muellerius capillaris nematodes. The objective of this work was to present recent information on verminosis in sheep and goats. Its pathogenicity depends on the number of larvae and their location in the lung parenchyma, which can cause bronchopneumonia, sometimes fatal. The disease can be clinical or subclinical, with signs such as cough, tachypnea, runny nose, and growth retardation. Diagnosis can be made by detecting first-stage larvae (L1) in feces, using the Baermann technique. Benzimidazoles, macrocyclic lactones and imidazothiazoles can be used for treatment. Despite the little importance that is usually given to the disease, it can affect production parameters, and decrease weight gain, as well as predispose to secondary bronchopneumonia, affecting the profitability of production units.La verminosis pulmonar en ovinos y caprinos es una de las parasitosis más importantes que afectan a ambas especies. Es causada por los nematodos Dictyocaulus filaria, Protostrongylus rufescens y Muellerius capillaris. El objetivo de este trabajo fue presentar información reciente sobre verminosis en ovinos y caprinos. Su patogenicidad depende de la cantidad de larvas presentes y su ubicación en el parenquima pulmonar, lo que puede provocar una bronconeumonía, que en ocasiones es mortal. La enfermedad puede ser clínica o subclínica, con signos como tos, taquipnea, secreción nasal y retraso en el crecimiento. El diagnóstico se puede realizar mediante detección de larvas del primer estadio (L1) en heces, utilizando la técnica de Baermann. Para el tratamiento se pueden utilizar benzimidazoles, lactonas macrocíclicas e imidazotiazoles. A pesar de la poca importancia que se le suele dar como verminosis pulmonar, puede provocar afectación a los parámetros productivos y disminuir la ganancia de peso, así como, predisponer a bronconeumonías secundarias, afectando la rentabilidad de las unidades de producción
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