876 resultados para Roma-Historia-Imperio, 30 a.C.-476 d.C
Resumo:
Ischemia and reperfusion of the small intestine disrupts gut barrier, causes bacterial translocation and activates inflammatory responses. An experimental study was planned to evaluate if 99mTc labelled Escherichia coli translocates to mesenteric lymph nodes, liver, spleen, lung and serum of rats submitted to mesenteric ischemia/reperfusion. Additionally, it was observed if the time of reperfusion influences the level of translocation. METHODS: Forty male Wistar rats underwent 45 minutes of gut ischemia by occlusion of the superior mesenteric artery. The translocation of labelled bacteria to different organs and portal serum was determined in rats reperfused for 30 minutes, 24 hours, sham(S) and controls(C), using radioactivity count and colony forming units/g (CFU). RESULTS: All the organs from rats observed for 24 hours after reperfusion had higher levels of radioactivity and positive cultures (CFU) than did the organs of rats reperfused for 30 minutes, C and S, except in the spleen (p<0,01). CONCLUSION: The results of this study indicated that intestinal ischemia/reperfusion led to bacterial translocation, mostly after 24 hours of reperfusion
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Coffee is predicted to be severely affected by climate change. We determined the thermal tolerance of the coffee berry borer, Hypothenemus hampei, the most devastating pest of coffee worldwide, and make inferences on the possible effects of climate change using climatic data from Colombia, Kenya, Tanzania, and Ethiopia. For this, the effect of eight temperature regimes (15, 20, 23, 25, 27, 30, 33 and 35 degrees C) on the bionomics of H. hampei was studied. Successful egg to adult development occurred between 20-30 degrees C. Using linear regression and a modified Logan model, the lower and upper thresholds for development were estimated at 14.9 and 32 degrees C, respectively. In Kenya and Colombia, the number of pest generations per year was considerably and positively correlated with the warming tolerance. Analysing 32 years of climatic data from Jimma (Ethiopia) revealed that before 1984 it was too cold for H. hampei to complete even one generation per year, but thereafter, because of rising temperatures in the area, 1-2 generations per year/coffee season could be completed. Calculated data on warming tolerance and thermal safety margins of H. hampei for the three East African locations showed considerably high variability compared to the Colombian site. The model indicates that for every 1 degrees C rise in thermal optimum (T(opt)), the maximum intrinsic rate of increase (r(max)) will increase by an average of 8.5%. The effects of climate change on the further range of H. hampei distribution and possible adaption strategies are discussed. Abstracts in Spanish and French are provided as supplementary material Abstract S1 and Abstract S2.
Resumo:
Ischemia and reperfusion of the small intestine disrupts gut barrier, causes bacterial translocation and activates inflammatory responses. An experimental study was planned to evaluate if 99mTc labelled Escherichia coli translocates to mesenteric lymph nodes, liver, spleen, lung and serum of rats submitted to mesenteric ischemia/reperfusion. Additionally, it was observed if the time of reperfusion influences the level of translocation. METHODS: Forty male Wistar rats underwent 45 minutes of gut ischemia by occlusion of the superior mesenteric artery. The translocation of labelled bacteria to different organs and portal serum was determined in rats reperfused for 30 minutes, 24 hours, sham(S) and controls(C), using radioactivity count and colony forming units/g (CFU). RESULTS: All the organs from rats observed for 24 hours after reperfusion had higher levels of radioactivity and positive cultures (CFU) than did the organs of rats reperfused for 30 minutes, C and S, except in the spleen (p<0,01). CONCLUSION: The results of this study indicated that intestinal ischemia/reperfusion led to bacterial translocation, mostly after 24 hours of reperfusion
Resumo:
A novel, anaerobic, chemo-organotrophic bacterium, designated strain Ra1766HT, was isolated from sediments of the Guaymas basin (Gulf of California, Mexico) taken from a depth of 2002 m. Cells were thin, motile, Gram-stain-positive, flexible rods forming terminal endospores. Strain Ra1766H(T) grew at temperatures of 25-45 degrees C (optimum 30 degrees C), pH 6.7-8.1 (optimum 7.5) and in a salinity of 5-60 g l(-1) NaCl (optimum 30 g l(-1)). It was an obligate heterotrophic bacterium fermenting carbohydrates (glucose and mannose) and organic acids (pyruvate and succinate). Casamino acids and amino acids (glutamate, aspartate and glycine) were also fermented. The main end products from glucose fermentation were acetate, butyrate, ethanol, H-2 and CO2. Sulfate, sulfite, thiosulfate, elemental sulfur, fumarate, nitrate, nitrite and Fe(III) were not used as terminal electron acceptors. The predominant cellular fatty acids were C-14 : 0, C-16:1 omega 7, C-16:1 omega 7 DMA and C-16:0. The main polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phospholipids. The G +C content of the genomic DNA was 33.7 molo/o. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain Ra1766H(T) was affiliated to cluster XI of the order Clostridia les, phylum Firmicutes. The closest phylogenetic relative of Ra1766H(T) was Geosporobacter subterraneus (94.2% 16S rRNA gene sequence similarity). On the basis of phylogenetic inference and phenotypic properties, strain Ra1766H(T) (=DSM 27501(T)=JCM 19377(T)) is proposed to be the type strain of a novel species of a novel genus, named Crassaminicella pro funda.
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Climate may affect broiler production, especially where there are heat waves, which may cause high mortality rates due to the heat stress. Heat wave prediction and characterization may allow early mitigation actions to be taken. Data Mining is one of the tools used for such a characterization, particularly when a large number of variables is involved. The objective of this study was to classify heat waves that promote broiler chicken mortality in poultry houses equipped with minimal environmental control. A single day of heat, a heat-shock day, is capable of producing high broiler mortality. In poultry houses equipped with fans and evaporative cooling, the characterization of heat waves affecting broiler mortality between 29 days of age and market age presented 89.34% Model Accuracy and 0.73 Class Precision for high mortality. There was no influence on high mortality (HM) of birds between 29 and 31 days of age. Maximum temperature humidity index (THI) above 30.6 ºC was the main characteristic of days when there was a heat wave, causing high mortality in broilers older than 31 days. The high mortality of broilers between 31 and 40 days of age occurred when maximum THI was above 30.6 ºC and maximum temperature of the day was above 34.4 ºC. There were two main causes of high mortality of broilers older than 40 days: 1) maximum THI above 30.6 ºC and minimum THI equal or lower than 15.5 ºC; 2) maximum THI above 30.6 ºC, minimum THI lower than 15.5 ºC, and the time of maximum temperature later than 15:00h. The heat wave influence on broiler mortality lasted an average of 2.7 days.
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Voces de la Asamblea Nacional Constituyente de Colombia de 1991 es un libro de entrevistas producto del proyecto de investigación: "La participación ciudadana en el proceso constituyente de 1991" realizado por el Grupo de Investigaciones Jurídicas de la Universidad de Medellín. Este proyecto, financiado por COLCIENCIAS y la Facultad de Derecho de la Universidad de Medellín, terminó en febrero de 2014. El texto pretende mostrar el proceso constituyente, a través de la mirada y las reflexiones de sus protagonistas: integrantes del Movimiento de la Séptima Papeleta, de las Mesas preparatorias, Asesores y Constituyentes quienes son, por excelencia, los testigos directos de uno de los acontecimientos políticos y jurídicos más importantes de la historia colombiana reciente.
Resumo:
ResumenEn este trabajo se ofrece una comparación inicial de los modelos tecnológicos explícitos e implícitos propuestos o supuestos por los autores de una serie de tratados generales, manuales y estudios sobre caficultura, tanto europeos o estadounidenses como caribeños y latinoamericanos. También se contrastan las recomendaciones técnicas como las diversas prácticas de cultivo y procesamiento que se traslucen a través de las páginas de dichos textos.AbstractThe study offers an initial comparison of the explicit and implicit technological models suggested or assumed by the author of a series of general treatises, manuals and studies on coffee, both by Europeans or North Americans and by Caribbeans or Latin Americans. Technical recommendations are also contrasted with the various agricultural and processing systems actually in use, as reflected in the pages of those same texts.
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ResumenLos autores identifican y señalan características de los principales sistemas de producción cafeteros en la zona central de Veracruz. Con información de encuestas a productores y otras fuentes, analizan su viabilidad en el contexto de la más reciente crisis cafetalera.AbstractThe authors identify and define characteristics of the main coffee production systems in central Veracruz. Based on information from interviews to farmers and other sources, they discuss the viability of such systems in the context of the latest coffee crisis.
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ResumenEste estudio analiza el cultivo del café en dos regiones en Nicaragua, concluyendo que hay mayores perspectivas para su desarrollo en el Interior Central. La situación microeconómica presta condiciones favorables para un desarrollo tecnológico enfocado en el mejoramiento de los sistemas tradicionales, pero menos para el plan de renovación con un enfoque productivista promovido por el gobierno.AbstractThis study discusses coffee cultivation in two regions of Nicaragua, and reaches the conclusion that there are better prospects for its development in the Central Interior region. The macroeconomic situation provides favorable conditions for a technological development geared toward the improvement of traditional systems, more than for the productivist approach adopted by the government.
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ResumenLa información de las planillas semanales de la empresa González Flores para 1946 y 1961 sirve de base para un estudio de los ciclos laborales y sistemas de trabajo en varias plantaciones de café pertenecientes a ella. Junto con otros datos tomados del archivo de la empresa, de informantes y de fuentes secundarias, ello permite formular algunas conclusiones iniciales sobre los intentos de intensificar la producción mediante aplicación de más abonos e insumos laborales.AbstractInformation from weekly payrolls of the González Flores coffee firm, for the years 1946 and 1961, is applied to a study of labor cycles and systems on several coffee plantations belonging to the firm. Together with other data form the company archives, form informants and form secondary sources, certain initial conclusions are reached regarding attempts to intensify production by means of additional fertilizers and labor.
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ResumenEn este breve ensayo se plantean de modo general e introductorio ciertas relaciones históricas entre expansión cafetalera y procesos migratorios, concretamente referidos a la colonización agrícola y procesos migratorios, concretamente referidos a la colonización agrícola. Alude algunos casos caribeños y continentales, para luego sugerir posibles líneas de comparación y discusión comparada.AbstractThis brief essay provides a general introduction to certain historical relations between the expansion of coffee cultivation and migratory processes, specifically land settlement. Several Caribbean and mainland cases are mentioned, and possibilities of comparative research and discussion are suggested.
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ResumenEn este trabajo los autores explicitan en primer lugar la relación histórica entre expansión ganadera. Migración campesina y desarrollo cafetalero en el interior de Honduras, para luego proponer una caracterización de las inserciones ocupacionales de los caficultores. Exploran especialmente sus distintas participaciones en la producción de granos básicos, las combinaciones de actividades principales y secundarias así como sus variaciones durante el año y las categorías ocupacionales o relaciones de trabajo en la caficultura.AbstractThe authors first explain the historical connections among expansion of livestock raising, peasant migrations and development of coffee production in Honduras. Subsequently, they suggest characteristics of the occupational status of coffee farmers. They also explore the participation in the production of staple grain, their combination of activities during the years, as well as occupational categories or labor relations in coffee production.
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ResumenLa baja de precios del café desde 1989 sorprendió a los pequeños productores en un momento en que tienen que adaptarse a las nuevas reglas de producción y comercialización impuestas por las políticas de modernización del gobierno de Salinas de Gortari (1988-1994). Las migraciones son una respuesta, entre otras, a la(s) crisis, a primera vista individual pero que afecta el devenir social, político y cultural de las comunidades. En este estudio se analizan los procesos migratorios nacientes en el centro de Veracruz, y se plantea que si bien algunas comunidades pueden lograr una cierta “reconversión” gracias a la cercanía de centros urbanos que ofrecen alternativas de trabajo, en otras se inician procesos de migración lejana y colectiva que amenazan la reproducción misma de la comunidad rural en cuanto tal.AbstractThe sharp drop in the price of coffee since 1989 took small farmers by surprise at the time when they must adapt to the new rules of productions and marketing under the modernizing polices of the Salinas de Gortari government (1988-1994). Migrations are one response to the crisis (or crises). While seemingly an individual one, they affect the social, political and cultural future of those communities. This study discusses the emerging migratory processes in central Veracruz, and suggests that while some communities may attain a degree of “retrofitting” thanks to nearby urban centers offering job opportunities, others are undergoing long-distance, collective migratory processes which threaten the very reproduction of the rural community per se.
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ResumenA partir de la notoria diversidad en las características socioeconómicas y en las historias políticas de los países o regiones en que el café fue el principal producto de exportación, se plantea una secuencia de preguntas para la investigación y el análisis sobre las estructuras de poder, la conflictividad social y los significados históricos de la caficultura para las sociedades latinoamericanasAbstractGiven the diversity of socioeconomic characteristics and political histories of countries or regions where coffee was the main export product, a number of questions are raised for research and analysis on power structures, social conflict, and the historical meaning of coffee production for Latin American societies.
El Estado y la organización social en la producción y distribución del café en los Andes venezolanos
Resumo:
ResumenLa penetración del Estado venezolano en la producción y comercialización del café entre 1974 y 1991 no logró desplazar el control social y económico a los grupos tradicionales de poder en la región de los Andes; estos se organizaron en nuevos núcleos de poder junto con los burócratas de las instituciones cafetaleras, demostrando la persistencia de elementos económicos en la organización social andina.AbstractThe involvement of Venezuelan State in production and marketing of coffee from 1974 to 1991 did not put an end to social and economic control by traditional power groups in the Andean region. Such groups organized into new power nuclei together with bureaucrats from coffee sector institutions, thus demonstrating the persistence of non-economic components of Andean social organization.