312 research outputs found

    El roedor silvestre Akodon azarae (Cricetidae: Sigmodontinae) como hospedador intermediario de Taenia taeniaeformis (Cestoda: Cyclophyllidea) en granjas avícolas del centro de Argentina

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    This work reports strobilocerci of Taenia taeniaeformis in the rodent Akodon azarae. A total of 289 rodents were captured on poultry farms in Central Argentina, belonging to the following species: A. azarae, Calomys laucha, C. musculinus, Oligoryzomys flavescens, and Mus musculus. All rodents were examined for parasites. Only A. azarae was parasitized with strobilocerci larvae. Prevalence, mean intensity, and mean abundance of the infection in the liver were 8.33%, 2.09 and 0.17, respectively. No differences were observed between the sexes of the infected rodents. Since in natural environments no cysts were reported, A. azarae is susceptible to get infected with T. taeniaeformis when frequents domestic and peridomestic habitats. Taenia taeniaeformis may have three different life cycles in the studied area: 1) one domestic cycle between Rattus norvegicus and pets in the surrounding of the farms, since R. norvegicus was observed to be parasitized; 2) another domestic cycle between A. azarae and the pets when such pets come to the farm fences; and 3) a wild cycle between A. azarae and Leopardus geoffroyi (Carnivora: Felidae), since it was observed that A. azarae is preyed by this felid and their feces were found parasitized with eggs of Taenia sp. in the study area.Este trabajo informa la presencia de estrobilocercos de Taenia taeniaeformis en el roedor Akodon azarae. Un total de 289 roedores pertenecientes a las especies A. azarae, Calomys laucha, C. musculinus, Oligoryzomys flavescens y Mus musculus fueron capturados en granjas avícolas del centro de Argentina. Todos los roedores fueron examinados en busca de parásitos. Sólo A. azarae presentó quistes de cestodes en el hígado. Los valores de prevalencia, intensidad media y abundancia media de la infestación fueron 8.33%, 2.09 y 0.17, respectivamente, y no se observó ninguna diferencia entre los sexos de los roedores infectados. Se concluye que A. azarae es susceptible de infectarse con T. taeniaeformis cuando frecuenta hábitats domésticos y peridomésticos, ya que en ambientes naturales nunca fue registrada su presencia en estos roedores. Los resultados de este estudio sugieren que T. taeniaeformis mantiene tres tipos diferentes de ciclos de vida en el área estudiada: 1) un ciclo doméstico entre Rattus norvegicus y mascotas (perros y gatos), ya que R. norvegicus ha sido encontrada parasitada en las granjas; 2) otro ciclo doméstico entre A. azarae y mascotas cuando estas últimas se acercan a los alambrados de las granjas; y 3) un ciclo silvestre entre A. azarae y Leopardus geoffroyi (Carnivora: Felidae), ya que se ha observado en el área de estudio que A. azarae es predado por este felino en cuyas heces se han encontrado huevos de Taenia sp.Facultad de Ciencias Naturales y Muse

    El roedor silvestre Akodon azarae (Cricetidae: Sigmodontinae) como hospedador intermediario de Taenia taeniaeformis (Cestoda: Cyclophyllidea) en granjas avícolas del centro de Argentina

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    This work reports strobilocerci of Taenia taeniaeformis in the rodent Akodon azarae. A total of 289 rodents were captured on poultry farms in Central Argentina, belonging to the following species: A. azarae, Calomys laucha, C. musculinus, Oligoryzomys flavescens, and Mus musculus. All rodents were examined for parasites. Only A. azarae was parasitized with strobilocerci larvae. Prevalence, mean intensity, and mean abundance of the infection in the liver were 8.33%, 2.09 and 0.17, respectively. No differences were observed between the sexes of the infected rodents. Since in natural environments no cysts were reported, A. azarae is susceptible to get infected with T. taeniaeformis when frequents domestic and peridomestic habitats. Taenia taeniaeformis may have three different life cycles in the studied area: 1) one domestic cycle between Rattus norvegicus and pets in the surrounding of the farms, since R. norvegicus was observed to be parasitized; 2) another domestic cycle between A. azarae and the pets when such pets come to the farm fences; and 3) a wild cycle between A. azarae and Leopardus geoffroyi (Carnivora: Felidae), since it was observed that A. azarae is preyed by this felid and their feces were found parasitized with eggs of Taenia sp. in the study area.Este trabajo informa la presencia de estrobilocercos de Taenia taeniaeformis en el roedor Akodon azarae. Un total de 289 roedores pertenecientes a las especies A. azarae, Calomys laucha, C. musculinus, Oligoryzomys flavescens y Mus musculus fueron capturados en granjas avícolas del centro de Argentina. Todos los roedores fueron examinados en busca de parásitos. Sólo A. azarae presentó quistes de cestodes en el hígado. Los valores de prevalencia, intensidad media y abundancia media de la infestación fueron 8.33%, 2.09 y 0.17, respectivamente, y no se observó ninguna diferencia entre los sexos de los roedores infectados. Se concluye que A. azarae es susceptible de infectarse con T. taeniaeformis cuando frecuenta hábitats domésticos y peridomésticos, ya que en ambientes naturales nunca fue registrada su presencia en estos roedores. Los resultados de este estudio sugieren que T. taeniaeformis mantiene tres tipos diferentes de ciclos de vida en el área estudiada: 1) un ciclo doméstico entre Rattus norvegicus y mascotas (perros y gatos), ya que R. norvegicus ha sido encontrada parasitada en las granjas; 2) otro ciclo doméstico entre A. azarae y mascotas cuando estas últimas se acercan a los alambrados de las granjas; y 3) un ciclo silvestre entre A. azarae y Leopardus geoffroyi (Carnivora: Felidae), ya que se ha observado en el área de estudio que A. azarae es predado por este felino en cuyas heces se han encontrado huevos de Taenia sp.Facultad de Ciencias Naturales y Muse

    The Relativistic Hopfield network: rigorous results

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    The relativistic Hopfield model constitutes a generalization of the standard Hopfield model that is derived by the formal analogy between the statistical-mechanic framework embedding neural networks and the Lagrangian mechanics describing a fictitious single-particle motion in the space of the tuneable parameters of the network itself. In this analogy the cost-function of the Hopfield model plays as the standard kinetic-energy term and its related Mattis overlap (naturally bounded by one) plays as the velocity. The Hamiltonian of the relativisitc model, once Taylor-expanded, results in a P-spin series with alternate signs: the attractive contributions enhance the information-storage capabilities of the network, while the repulsive contributions allow for an easier unlearning of spurious states, conferring overall more robustness to the system as a whole. Here we do not deepen the information processing skills of this generalized Hopfield network, rather we focus on its statistical mechanical foundation. In particular, relying on Guerra's interpolation techniques, we prove the existence of the infinite volume limit for the model free-energy and we give its explicit expression in terms of the Mattis overlaps. By extremizing the free energy over the latter we get the generalized self-consistent equations for these overlaps, as well as a picture of criticality that is further corroborated by a fluctuation analysis. These findings are in full agreement with the available previous results.Comment: 11 pages, 1 figur

    Dirofilariosis canina: microfilaremia en perros de la ribera del Río de la Plata, Argentina

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    La dirofilariosis es una enfermedad zoonótica causada por Dirofilaria immitis y transmitida por mosquitos. Este trabajo presenta un relevamiento de la microfilaremia en perros en la ribera del Río de la Plata utilizando la técnica de Knott modificada y estudia posibles especies de mosquitos como vectores. A través de consultorios veterinarios y centros de zoonosis de Villa Domínico, Quilmes Este, La Plata y Berisso (Buenos Aires) se obtuvieron 265 muestras de sangre de perros y se completó una encuesta (sexo, edad, pedigree, talla, largo del pelo, manejo de las mascotas y tratamiento con ivermectina). Se capturaron y disecaron 412 mosquitos con aspirador manual sobre cebo humano en la ribera del Río de la Plata para observar formas filariformes. El 78,8% de las muestras de sangre correspondieron a hembras, el 76,2% de los perros fueron mestizos, las tallas chicas a medianas (30,1% y 41,1% respectivamente) y el 38,2% de las mascotas permanecía las 24 horas fuera de la vivienda. El 73% de las muestras correspondieron a perros menores de 6 años. Se detectaron 6 casos Knott positivos (prevalencia 2,26%). El 50% de los casos positivos eran asintomáticos. Si bien los machos estuvieron más parasitados que las hembras (diferencias significativas), se estima que ello está asociado a un manejo especial de las mascotas hembras por parte de los dueños. Éstas suelen permanecer mayor tiempo en el interior de la vivienda y así tendrían menor probabilidad de contacto con mosquitos. Se observaron diferencias significativas entre edades. Los adultos estuvieron más parasitados que los jóvenes. No se hallaron formas filariformes en los mosquitos disecados. Se recomienda el test de Knott modificado como técnica rápida, económica y efectiva para el diagnóstico de dirofilariosis, siempre que el canino no haya sido tratado con ivermectin

    In quest of reducing the environmental impacts of food production and consumption

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    AbstractFood supply chains are increasingly associated with environmental and socio-economic impacts. An increasing global population, an evolution in consumers' needs, and changes in consumption models pose serious challenges to the overall sustainability of food production and consumption. Life cycle thinking (LCT) and assessment (LCA) are key elements in identifying more sustainable solutions for global food challenges. In defining solutions to major global challenges, it is fundamentally important to avoid burden shifting amongst supply chain stages and amongst typologies of impacts, and LCA should, therefore, be regarded as a reference method for the assessment of agri-food supply chains. Hence, this special volume has been prepared to present the role of life cycle thinking and life cycle assessment in: i) the identification of hotspots of impacts along food supply chains with a focus on major global challenges; ii) food supply chain optimisation (e.g. productivity increase, food loss reduction, etc.) that delivers sustainable solutions; and iii) assessment of future scenarios arising from both technological improvements and behavioural changes, and under different environmental conditions (e.g. climate change). This special volume consists of a collection of papers from a conference organized within the last Universal Exposition (EXPO2015) "LCA for Feeding the planet and energy for life" in Milan (Italy) in 2015 as well as other contributions that were submitted in the year after the conference that addressed the same key challenges presented at the conference. The papers in the special volume address some of the key challenges for optimizing food-related supply chains by using LCA as a reference method for environmental impact assessment. Beyond specific methodological improvements to better tailor LCA studies to food systems, there is a clear need for the LCA community to "think outside the box", exploring complementarity with other methods and domains. The concepts and the case studies presented in this special volume demonstrate how cross-fertilization among difference science domains (such as environmental, technological, social and economic ones) may be key elements of a sustainable "today and tomorrow" for feeding the planet

    The role of life cycle assessment in supporting sustainable agri-food systems: A review of the challenges

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    Abstract Life cycle thinking is increasingly seen as a key concept for ensuring a transition towards more sustainable production and consumption patterns. As food production systems and consumption patterns are among the leading drivers of impacts on the environment, it is important to assess and improve food-related supply chains as much as possible. Over the years, life cycle assessment has been used extensively to assess agricultural systems and food processing and manufacturing activities, and compare alternatives "from field to fork" and through to food waste management. Notwithstanding the efforts, several methodological aspects of life cycle assessment still need further improvement in order to ensure adequate and robust support for decision making in both business and policy development contexts. This paper discusses the challenges for life cycle assessment arising from the complexity of food systems, and recommends research priorities for both scientific development and improvements in practical implementation. In summary, the intrinsic variability of food production systems requires dedicated modelling approaches, including addressing issues related to: the distinction between technosphere and ecosphere; the most appropriate functional unit; the multi-functionality of biological systems; and the modelling of the emissions and how this links with life cycle impact assessment. Also, data availability and interpretation of the results are two issues requiring further attention, including how to account for consumer behaviour

    The role of life cycle assessment in supporting sustainable agri-food systems: A review of the challenges

    Get PDF
    Life cycle thinking is increasingly seen as a key concept for ensuring a transition towards more sustainable production and consumption patterns. As food production systems and consumption patterns are among the leading drivers of impacts on the environment, it is important to assess and improve foodrelated supply chains as much as possible. Over the years, life cycle assessment has been used extensively to assess agricultural systems and food processing and manufacturing activities, and compare alternatives “from field to fork” and through to food waste management. Notwithstanding the efforts, several methodological aspects of life cycle assessment still need further improvement in order to ensure adequate and robust support for decision making in both business and policy development contexts. This paper discusses the challenges for life cycle assessment arising from the complexity of food systems, and recommends research priorities for both scientific development and improvements in practical implementation. In summary, the intrinsic variability of food production systems requires dedicated modelling approaches, including addressing issues related to: the distinction between technosphere and ecosphere; the most appropriate functional unit; the multi-functionality of biological systems; and the modelling of the emissions and how this links with life cycle impact assessment. Also, data availability and interpretation of the results are two issues requiring further attention, including how to account for consumer behaviour.info:eu-repo/semantics/publishedVersio

    In quest of reducing the environmental impacts of food production and consumption

    Get PDF
    Food supply chains are increasingly associated with environmental and socio-economic impacts. An increasing global population, an evolution in consumers' needs, and changes in consumption models pose serious challenges to the overall sustainability of food production and consumption. Life cycle thinking (LCT) and assessment (LCA) are key elements in identifying more sustainable solutions for global food challenges. In defining solutions to major global challenges, it is fundamentally important to avoid burden shifting amongst supply chain stages and amongst typologies of impacts, and LCA should, therefore, be regarded as a reference method for the assessment of agri-food supply chains. Hence, this special volume has been prepared to present the role of life cycle thinking and life cycle assessment in: i) the identification of hotspots of impacts along food supply chains with a focus on major global challenges; ii) food supply chain optimisation (e.g. productivity increase, food loss reduction, etc.) that delivers sustainable solutions; and iii) assessment of future scenarios arising from both technological improvements and behavioural changes, and under different environmental conditions (e.g. climate change). This special volume consists of a collection of papers from a conference organized within the last Universal Exposition (EXPO2015) “LCA for Feeding the planet and energy for life” in Milan (Italy) in 2015 as well as other contributions that were submitted in the year after the conference that addressed the same key challenges presented at the conference. The papers in the special volume address some of the key challenges for optimizing food-related supply chains by using LCA as a reference method for environmental impact assessment. Beyond specific methodological improvements to better tailor LCA studies to food systems, there is a clear need for the LCA community to “think outside the box”, exploring complementarity with other methods and domains. The concepts and the case studies presented in this special volume demonstrate how cross-fertilization among difference science domains (such as envi- ronmental, technological, social and economic ones) may be key elements of a sustainable “today and tomorrow” for feeding the planet.info:eu-repo/semantics/publishedVersio

    El roedor silvestre Akodon azarae (Cricetidae: Sigmodontinae) como hospedador intermediario de Taenia taeniaeformis (Cestoda: Cyclophyllidea) en granjas avícolas del centro de Argentina

    Get PDF
    This work reports strobilocerci of Taenia taeniaeformis in the rodent Akodon azarae. A total of 289 rodents were captured on poultry farms in Central Argentina, belonging to the following species: A. azarae, Calomys laucha, C. musculinus, Oligoryzomys flavescens, and Mus musculus. All rodents were examined for parasites. Only A. azarae was parasitized with strobilocerci larvae. Prevalence, mean intensity, and mean abundance of the infection in the liver were 8.33%, 2.09 and 0.17, respectively. No differences were observed between the sexes of the infected rodents. Since in natural environments no cysts were reported, A. azarae is susceptible to get infected with T. taeniaeformis when frequents domestic and peridomestic habitats. Taenia taeniaeformis may have three different life cycles in the studied area: 1) one domestic cycle between Rattus norvegicus and pets in the surrounding of the farms, since R. norvegicus was observed to be parasitized; 2) another domestic cycle between A. azarae and the pets when such pets come to the farm fences; and 3) a wild cycle between A. azarae and Leopardus geoffroyi (Carnivora: Felidae), since it was observed that A. azarae is preyed by this felid and their feces were found parasitized with eggs of Taenia sp. in the study area.Este trabajo informa la presencia de estrobilocercos de Taenia taeniaeformis en el roedor Akodon azarae. Un total de 289 roedores pertenecientes a las especies A. azarae, Calomys laucha, C. musculinus, Oligoryzomys flavescens y Mus musculus fueron capturados en granjas avícolas del centro de Argentina. Todos los roedores fueron examinados en busca de parásitos. Sólo A. azarae presentó quistes de cestodes en el hígado. Los valores de prevalencia, intensidad media y abundancia media de la infestación fueron 8.33%, 2.09 y 0.17, respectivamente, y no se observó ninguna diferencia entre los sexos de los roedores infectados. Se concluye que A. azarae es susceptible de infectarse con T. taeniaeformis cuando frecuenta hábitats domésticos y peridomésticos, ya que en ambientes naturales nunca fue registrada su presencia en estos roedores. Los resultados de este estudio sugieren que T. taeniaeformis mantiene tres tipos diferentes de ciclos de vida en el área estudiada: 1) un ciclo doméstico entre Rattus norvegicus y mascotas (perros y gatos), ya que R. norvegicus ha sido encontrada parasitada en las granjas; 2) otro ciclo doméstico entre A. azarae y mascotas cuando estas últimas se acercan a los alambrados de las granjas; y 3) un ciclo silvestre entre A. azarae y Leopardus geoffroyi (Carnivora: Felidae), ya que se ha observado en el área de estudio que A. azarae es predado por este felino en cuyas heces se han encontrado huevos de Taenia sp.Facultad de Ciencias Naturales y Muse
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