94 research outputs found

    \u3ci\u3eIn Vitro\u3c/i\u3e Gas Production Technique to Predict DMD of Ensiled Forage Ruminant Based Diets

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    The in vitro gas production technique was used as a tool to develop an improved prediction model of dry matter digestibility of ensiled forage based diets. Eleven diets were tested through conventional experiments of in vivo dry matter digestibility (DMD). The same diets were evaluated by the in vitro gas production technique using a gas pressure transducer . The parameters of the model y = A - B Qt Z√t were calculated with data from the accumulated gas curves, i.e. y=cumulative gas production (ml), Q=e-b, Z=e-c, B=ebT+c√T , being A the value for gas pool size (ml), plus lag time, minimum lag time, time for 50% gas production and time for 95% gas production. A stepwise linear regression procedure was used to obtain a model with the best fit. The higher adjusted R2 (0.85) was obtained for a model with: 1. accumulated gas, 2. lag time, 3. Q, 4. B, 5. time for 50% gas production and 6. minimum lag time were included in the model

    Efectos de corto plazo de la interacción riego-fertilización en la producción y composición de un campo natural de basalto en Uruguay

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    Supplementary irrigation is a strategic option to ensure the forage production in a scenario of high climate variability. Nevertheless, Uruguay lacks of information to be able to generate technical coefficients about responses. An experiment was performed with the objective to evaluate the effects of irrigation and N-P fertilization on forage yield and botanical composition in a basaltic natural grassland. In the period October 2011 to June 2012 was carried out an experiment to determine the effect of supplemental irrigation and fertilization N-P in a split plot design. Supplementary irrigation and rainfed were located in the big plots, while the fertilizer ones were established at smaller plots. Fertilizer treatments consisted on one unfertilized control and seven fertilization treatments: one with phosphorus only (80 kg P2O5.ha-1), three nitrogen rates (50, 100 and 200 kg N.ha-1) and three N-P combinations (80 P2O5-50 N, 80 P2O5-100 N, P2O5 and 80-200 N). The interaction of irrigation with nitrogen fertilization explained the short-term variations in productivity and botanical composition. Irrigation improved the response to nitrogen fertilization doubling forage production, and allowed conditions to increase the contribution of the most valuable forage productive types.El riego suplementario es una opción estratégica para asegurar la producción de forraje en un escenario de alta variabilidad climática, pero en Uruguay falta información para generar coeficientes técnicos de respuesta. Se realizó un experimento con el objetivo de evaluar los efectos del riego y la fertilización N-P en la producción de forraje y composición botánica de un campo natural de basalto. En el período octubre de 2011 a Junio 2012 se desarrolló un ensayo con un diseño de parcelas divididas. En las parcelas mayores se ubicaron el riego suplementario y el secano, mientras que en las parcelas menores se ubicaron un testigo sin fertilizar y siete tratamientos de fertilización: una dosis de fósforo (80kg P2O5.ha-1), tres dosis de nitrógeno (50, 100 y 200 kg N.ha-1) y tres combinaciones N-P (80 P2O5-50 N; 80 P2O5-100 N; y 80 P2O5-200 N). La interacción del riego con la fertilización nitrogenada explicó las variaciones a corto plazo de la productividad y composición botánica de la vegetación. El riego incrementó la respuesta a la fertilización nitrogenada duplicando la producción de forraje del campo natural y generando condiciones para el aumento de la contribución de los tipos productivos más valiosos desde el punto de vista forrajero

    Effect of condensed tannins in the methanogenic potential and in vitro digestion efficiency of ryegrass

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    Los rumiantes son capaces de degradar y fermentar los componentes de la pared celular de forrajeras. En el retículo-rumen, la fermentación microbiana particiona la energía bruta del sustrato en ácidos grasos volátiles, biomasa microbiana (BM) y gases de desecho (e.g. metano, CH4). Estos últimos son eliminados y representan, no solo contaminación ambiental por su efecto invernadero; sino también una pérdida de la energía disponible en el alimento. Numerosas especies vegetales poseen metabolitos secundarios, tales como los taninos condensados (TC), que, aunque tienen propiedades antimicrobianas y astringentes, su uso racional podría generar un mejor aprovechamiento de los forrajes con potenciales efectos mitigadores del CH4 entérico. En este contexto, se evaluó el efecto de cuatro dosis de TC de Quebracho (Schinopsis balansae, 0, 1,5, 3,0 y 4,5 mg TC cada 100 mg de sustrato; correspondientes a los tratamientos Ctrl, TC1, TC2 y TC3) mediante la técnica de producción de gas in vitro (PGiv), en presencia o ausencia de polietilenglicol (inhibidor específico de los TC), para determinar el impacto en la fermentación ruminal del raigrás (Lolium perenne). La digestibilidad disminuyó en TC3, mientras que la PGiv aumentó asociada a las mayores tasas iniciales. No hubo efecto de los TC sobre la producción de CH4, tampoco en la síntesis de BM. Por otro lado, el agregado de TC disminuyó la concentración de ácido propiónico, aumentado la relación acético: propiónico. Se concluye que los TC de Quebracho a las dosis estudiadas, no produjeron un efecto mitigador del CH4, además de modificar los parámetros de fermentación, sobre todo con una inclusión de 4,5 mg de TC/100 mg de sustrato incubado.Ruminants are capable of degrading and fermenting the forage cell wall components. In reticulo-rumen, the microbial fermentation partition gross energy of the substrate into volatile fatty acids, microbial biomass (MB) and waste gases (e.g. methane, CH4). These gases are eliminated and they represent, not only environmental pollution due to its greenhouse effect, but they also represent loss of the energy available in the forage. Numerous plant species have secondary compounds, such as condensed tannins (CT), although they have antimicrobial and astringent properties, their rational use could generate a better use of forages with potential mitigating effects of enteric CH4. In this context, it was evaluated the effect of four doses of Quebracho (Schinopsis balansae, 0, 1.5, 3.0 and 4.5 mg of CT per 100 mg of substrate, correspond to treatments Ctrl, TC1, TC2 and TC3) using the in vitro gas production technique (ivGP), in the presence or absence of polyethylene glycol (specific inhibitor of CT), to determine the impact on ruminal fermentation of ryegrass (Lolium perenne). The digestibility decreased in TC3, while the ivGP increased asociated with the higher initial rates. There was no effect of the CT on the CH4 production, neither in the synthesis of MB. On the other hand, the addition of CT decreased propionic acid concentration, increasing the acetic: propionic ratio. It is concluded that the CT of Quebracho, at the doses studied, did not produce a CH4 mitigating effect, in addition to modifying the fermentation parameters, especially with an inclusion of 4.5 mg of CT/ 100 mg of incubated substrate.Fil: Cantet, Juan Manuel. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Neumann Reiter, A. M.. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; ArgentinaFil: Colombatto, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; ArgentinaFil: Wawrzkiewicz, Marisa. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; ArgentinaFil: Jaurena, Gustavo. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Animal; Argentin

    Racismo, adolescencia e inmigración : reconocer y afrontar el racismo desde una perspectiva educativa

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    Este texto se presentó como comunicación al II Congreso Internacional de Etnografía y Educación: Migraciones y Ciudadanías. Universidad Autónoma de Barcelona, Barcelona, 5-8 Septiembre 2008.El racismo es una realidad compleja que, pese a estar presente en nuestra experiencia cotidiana, tanto dentro como fuera de los centros educativos, suele, sin embargo, ignorarse o negarse. Por ello, no resulta fácil hablar de racismo. Partiendo de esta reflexión nos planteamos en este proyecto acercarnos a las percepciones y experiencias de los adolescentes en torno a este fenómeno, a sus manifestaciones sutiles o explícitas, a sus implicaciones y consecuencias. Nuestra intención era tratar de comprender el fenómeno del racismo desde el punto de vista de los afectados, lo que implica básicamente: • Conocer la percepción de los jóvenes en relación con experiencias/situaciones de racismo. • Reconocer el racismo implícito en situaciones cotidianas, dentro y fuera del ámbito educativo. • Apreciar las dificultades con las que se encuentran jóvenes de diversos orígenes en su vida fuera y dentro del medio escolar. Pretendíamos dar voz a los chicos y chicas que viven, sufren o afrontan el racismo, con la finalidad de obtener información relevante para elaborar una Guía, dirigida al profesorado y adultos en general, y también a los propios adolescentes, que les ayudara a reconocer, comprender, interpretar y manejar situaciones de racismo desde una perspectiva educativa. Para ello contactamos con adolescentes cuyas características nos hicieron prejuzgar que podían formar parte de grupos que sufren cotidianamente el peso del racismo: sobre todo, chicas y chicos a los que solemos asociar con la categoría de «inmigrante». Los abordamos no sólo en los centros educativos, sino también en las calles y en los parques, allí donde pensamos que podían compartir sus ideas y experiencias en un clima de confianza. Descubrimos que los adolescentes tienen una visión clara y amplia del racismo y sus implicaciones, y son capaces de distinguir y narrar sus experiencias en torno a él. Así mismo, reclaman que se hable de racismo, que se trate abiertamente, que sus vivencias y percepciones se tengan en cuenta y reciban algún tipo de respuesta por parte de los adultos. Tomando como referente esta idea, construimos una Guía articulada en torno a sus narraciones, que trata de ofrecer ideas y propuestas que respondan a cinco cuestiones: qué es el racismo, por qué y para qué se da, cómo se produce, cómo se reproduce y cómo se afronta

    Openness in Education as a Praxis: From Individual Testimonials to Collective Voices

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    Why is Openness in Education important, and why is it critically needed at this moment? As manifested in our guiding question, the significance of Openness in Education and its immediate necessity form the heart of this collaborative editorial piece. This rather straightforward, yet nuanced query has sparked this collective endeavour by using individual testimonies, which may also be taken as living narratives, to reveal the value of Openness in Education as a praxis. Such testimonies serve as rich, personal narratives, critical introspections, and experience-based accounts that function as sources of data. The data gleaned from these narratives points to the understanding of Openness in Education as a complex, multilayered concept intricately woven into an array of values. These range from aspects such as sharing, access, flexibility, affordability, enlightenment, barrier-removal, empowerment, care, individual agency, trust, innovation, sustainability, collaboration, co-creation, social justice, equity, transparency, inclusivity, decolonization, democratisation, participation, liberty, and respect for diversity. This editorial, as a product of collective endeavour, invites its readers to independently engage with individual narratives, fostering the creation of unique interpretations. This call stems from the distinctive character of each narrative as they voice individual researchers’ perspectives from around the globe, articulating their insights within their unique situational contexts

    Tendências temporais de índices de vegetação nos campos do Pampa do Brasil e do Uruguai

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    O objetivo deste trabalho foi avaliar a redução do vigor vegetativo da cobertura vegetal do Pampa do Brasil e do Uruguai, por meio da identificação de tendências negativas em séries temporais de imagens. Utilizaram-se séries temporais de imagens de NDVI/EVI do sensor Modis, de 2000 a 2011; imagens de índices de umidade do solo do "climate forecast system reanalysis"; e dados de precipitação pluvial de estações meteorológicas. O estudo quantificou tendências lineares e não lineares nas séries de NDVI e EVI, em áreas de campos. Na tendência monotônica de Mann-Kendall, a 5% de probabilidade, 81,9% da área total estudada foi significativa com o NDVI, e 74,8%, com o EVI; no entanto, o EVI apresentou contraste superior na estimativa dos parâmetros. Os resultados mostraram maior sinal negativo a oeste, com valores médios de R²>0,15, r<-0,3 e τ <-0,15 na tendência dos índices de vegetação, e tendência decrescente para NDVI, EVI e precipitação pluvial, com menores valores médios de umidade do solo. A tendência negativa dos índices de vegetação, relacionada à combinação da ocorrência de deficit hídrico em solos rasos com o sobrepastoreio, indica alterações no padrão de cobertura vegetal do Pampa, com redução do vigor vegetativo

    Enteric methane mitigation strategies for ruminant livestock systems in the Latin America and Caribbean region: a meta-analysis.

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    Latin America and Caribbean (LAC) is a developing region characterized for its importance for global food security, producing 23 and 11% of the global beef and milk production, respectively. The region?s ruminant livestock sector however, is under scrutiny on environmental grounds due to its large contribution to enteric methane (CH4) emissions and influence on global climate change. Thus, the identification of effective CH4 mitigation strategies which do not compromise animal performance is urgently needed, especially in context of the Sustainable Development Goals (SDG) defined in the Paris Agreement of the United Nations. Therefore, the objectives of the current study were to: 1) collate a database of individual sheep, beef and dairy cattle records from enteric CH4 emission studies conducted in the LAC region, and 2) perform a meta-analysis to identify feasible enteric CH4 mitigation strategies, which do not compromise animal performance. After outlier?s removal, 2745 animal records (65% of the original data) from 103 studies were retained (from 2011 to 2021) in the LAC database. Potential mitigation strategies were classified into three main categories (i.e., animal breeding, dietary, and rumen manipulation) and up to three subcategories, totaling 34 evaluated strategies. A random effects model weighted by inverse variance was used (Comprehensive Meta-Analysis V3.3.070). Six strategies decreased at least one enteric CH4 metric and simultaneously increased milk yield (MY; dairy cattle) or average daily gain (ADG; beef cattle and sheep). The breed composition F1 Holstein × Gyr decreased CH4 emission per MY (CH4IMilk) while increasing MY by 99%. Adequate strategies of grazing management under continuous and rotational stocking decreased CH4 emission per ADG (CH4IGain) by 22 and 35%, while increasing ADG by 22 and 71%, respectively. Increased dietary protein concentration, and increased concentrate level through cottonseed meal inclusion, decreased CH4IMilk and CH4IGain by 10 and 20% and increased MY and ADG by 12 and 31%, respectively. Lastly, increased feeding level decreased CH4IGain by 37%, while increasing ADG by 171%. The identified effective mitigation strategies can be adopted by livestock producers according to their specific needs and aid LAC countries in achieving SDG as defined in the Paris Agreement

    Registro Español de Trasplante Cardiaco. XXXI Informe Oficial de la Asociación de Insuficiencia Cardiaca de la Sociedad Española de Cardiología

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    Introducción y objetivos Se presentan las características clínicas y los resultados de los trasplantes cardiacos realizados en España con la actualización correspondiente a 2019. Métodos Se describen las características clínicas y los resultados de los trasplantes cardiacos realizados en 2019, así como las tendencias de estos en el periodo 2010-2018. Resultados En 2019 se realizaron 300 trasplantes (8.794 desde 1984; 2.745 entre 2010 y 2019). Respecto a años previos, los cambios más llamativos son el descenso hasta el 38% de los trasplantes realizados en código urgente, y la consolidación en el cambio de asistencia circulatoria pretrasplante, con la práctica desaparición del balón de contrapulsación (0, 7%), la estabilización del uso del oxigenador extracorpóreo de membrana (9, 6%) y el aumento de los dispositivos de asistencia ventricular (29%). La supervivencia en el trienio 2016-2018 es similar a la del trienio 2013-2015 (p = 0, 34), y ambas mejores que la del trienio 2010-2012 (p = 0, 002 y p = 0, 01 respectivamente). Conclusiones Se mantienen estables tanto la actividad del trasplante cardiaco en España como los resultados en supervivencia en los últimos 2 trienios. Hay una tendencia a realizar menos trasplantes urgentes, la mayoría con dispositivos de asistencia ventricular. Introduction and objectives: The present report describes the clinical characteristics and outcomes of heart transplants in Spain and updates the data to 2019. Methods: We describe the clinical characteristics and outcomes of heart transplants performed in Spain in 2019, as well as trends in this procedure from 2010 to 2018. Results: In 2019, 300 transplants were performed (8794 since 1984; 2745 between 2010 and 2019). Compared with previous years, the most notable findings were the decreasing rate of urgent transplants (38%), and the consolidation of the type of circulatory support prior to transplant, with an almost complete disappearance of counterpulsation balloon (0.7%), stabilization in the use of extracorporeal membrane oxygenation (9.6%), and an increase in the use of ventricular assist devices (29.0%). Survival from 2016 to 2018 was similar to that from 2013 to 2015 (P = .34). Survival in both these periods was better than that from 2010 to 2012 (P = .002 and P = .01, respectively). Conclusions: Heart transplant activity has remained stable during the last few years, as have outcomes (in terms of survival). There has been a trend to a lower rate of urgent transplants and to a higher use of ventricular assist devices prior to transplant

    Openness in Education as a Praxis: From Individual Testimonials to Collective Voices

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    Why is Openness in Education important, and why is it critically needed at this moment? As manifested in our guiding question, the significance of Openness in Education and its immediate necessity form the heart of this collaborative editorial piece. This rather straightforward, yet nuanced query has sparked this collective endeavour by using individual testimonies, which may also be taken as living narratives, to reveal the value of Openness in Education as a praxis. Such testimonies serve as rich, personal narratives, critical introspections, and experience-based accounts that function as sources of data. The data gleaned from these narratives points to the understanding of Openness in Education as a complex, multilayered concept intricately woven into an array of values. These range from aspects such as sharing, access, flexibility, affordability, enlightenment, barrier-removal, empowerment, care, individual agency, trust, innovation, sustainability, collaboration, co-creation, social justice, equity, transparency, inclusivity, decolonization, democratisation, participation, liberty, and respect for diversity. This editorial, as a product of collective endeavour, invites its readers to independently engage with individual narratives, fostering the creation of unique interpretations. This call stems from the distinctive character of each narrative as they voice individual researchers’ perspectives from around the globe, articulating their insights within their unique situational contexts
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