82 research outputs found

    Sobre algunas de las posibilidades de la historia

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    Este texto presenta una referencia a distintos enfoques de la disciplina de la historia que se han constituido como hitos en diversos momentos de su trayectoria. El autor escoge seis de ellos para discutirlos en sus aportes y falencias respecto a temas alusivos a la cultura, la identidad y los movimientos sociales. El artículo esboza un panorama muy general que puede servir como guía para no expertos en el tema o estudiantes de historia

    Editorial

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    Editorial

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    Regiones, ciudades, empresarios y trabajadores en la historia de Colombia

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    Tunja, Universidad Pedagógica y Tecnológia de Colombia,Archivo General de la Nación, Asociación Colombiana de Historiadores, 1995 Como suele suceder en los libros que reúnen artículos dispares, en el presente texto nos encontramos con una gran variedad de trabajos a propósito del tema sugerido en el título, sin que nadie pueda intentar darles unidad y coherencia. Esto se debe a que el texto recopila las  memorias del IX Congreso de Historia de Colombia (Tunja, 2 al 5 de mayo de 1995), que fue organizado en tres simposios temáticos: Fronteras y regiones en la Historia de Colombia, Historia Urbana y de los movimientos sociales, e Historia económica, empresarial y agraria

    Documentos sobre lenguas aborígenes de Colombia del archivo de Paul Rivet

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    Documentos sobre lenguas aborígenes de Colombia del archivo de Paul Rivet Jon Landaburu (compilador) Vol. 1: Lenguas de la Amazonía colombiana.Ediciones Uniandes, Centro Colombiano de Estudios de Lenguas Aborígrnes Colciencias, 1996 En el Museo del Hombre de París, buscando inéditos, los autores de este libro lograron acceder al archivo de Paul Rivet, que normalmente permanece cerrado al público, encontrando una masa de información interesante y digna de rescatar para la ilustración de los investigadores colombianos y colombianistas. Del examen detenido de estos archivos resulta este primer volumen, lenguas de la Amazonía colombiana, cuyo cuerpo principal es la transcripción de algunos manuscritos importantes de aquel archivo, provenientes de múltiples corresponsales de Rivet. Los manuscritos luego son comentados por especialistas en lenguas de la Amazonía, anexando datos actuales equivalentes a aquellos encontrados por los corresponsales de Rivet. Además, el libro presenta dos artículos relacionados con la vida de Paul Rivet de y de uno de sus corresponsales más importantes, el Padre Constant Tastevin

    Comparación del grado de filtración de los materiales de restauración temporal Cavit® y MD-Temp™ en cavidades clase I y II modificadas para acceso endodóntico, utilizando la prueba de penetración del colorante azul de metileno.

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    Diferentes estudios han demostrado que la calidad del sellado coronal es  importante  para la salud de los tejidos periapicales después del tratamiento endodóntico. Cuando no se realiza el tratamiento endodóntico en una sola sesión, hay que colocar en la cavidad de acceso un material de restauración temporal, el éxito del  tratamiento depende, en gran medida, de la protección que brinde el material de restauración temporal. En el mercado se encuentra materiales disponibles que prometen un buen sellado, entre ellos, Cavit® y  MD-Temp™. La investigación realizada,  es un estudio descriptivo, experimental, de corte transversal;  El objetivo fue  analizar el grado de filtración de los materiales de restauración temporal Cavit® y MD-Temp™ en cavidades Clase I y II modificadas para acceso endodóntico, esto se realizó sometiendo a ambos cementos a pruebas de envejecimiento térmico y  sumergiéndolos en azul de metileno, en donde se demostró que el Cavit® en las cavidades clase I mostró una menor filtración que el MD-Temp™, y en las cavidades Clase II ninguno de los materiales impidió el paso del tinte; concluyendo que ninguno de los materiales es  impermeable al paso del tinte y que en las cavidades Clases II ninguno de los materiales ofrece una verdadera protección

    Palynological and chemical volatile components of tipically autumnal honeys of the western Mediterranean

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    [EN] Twenty-five samples of autumnal honeys from the western Mediterranean (Mallorca and Eivissa, Balearic Islands) were examined for pollen content (qualitative and quantitative melissopalynological analysis), moisture, electrical conductivity, colour, sensorial qualities and volatile components. Quantitative analysis showed that the honey contained Maurizio's Class II: 64%, Class III: 28%, Class IV: 4% and Class V: 4%. Fifty-four pollen types, with an average number of 16.68 per sample, were identified, belonging to 29 botanical families. Only two taxa (Ceratonia siliqua and Erica multiflora) were found in all samples. Seventeen samples were unifloral (68%) - ten (40%) of C. siliqua, six (24%) of E. multiflora and one (4%) of Hedera helix. All honeys have a low honeydew index (<?0.09%), while the values for electrical conductivity and water content were high. The major honey volatile components are: cis- and trans-linalool oxides (64.2%) and hotrienol (10.4%) for the carob (C. siliqua) and trans-linalool oxide (13.4%), p-menthane-1,8-diol (11.1%), safranal (9.7%), limonene (5,4%), -pinene (3.7%) and oxoisophorone (3.4%) for the winter heather (E. multiflora).The authors would like to extend their gratitude to the Mallorca Rural 'Leader plus' programme and the beekeepers of Mallorca and Eivissa for their support and friendly collaboration. The authors also thank an anonymous reviewer for useful comments and suggestions on an earlier version of the manuscript.Boi, M.; Llorens Molina, JA.; Cortés, L.; Lladó, G.; Llorens, L. (2013). Palynological and chemical volatile components of tipically autumnal honeys of the western Mediterranean. Grana. 52(2):93-105. doi:10.1080/00173134.2012.744774S93105522Andrade, P. B., Amaral, M. T., Isabel, P., Carvalho, J. C. M. F., Seabra, R. M., & Proença da Cunha, A. (1999). Physicochemical attributes and pollen spectrum of Portuguese heather honeys. Food Chemistry, 66(4), 503-510. doi:10.1016/s0308-8146(99)00100-4Anklam, E. (1998). A review of the analytical methods to determine the geographical and botanical origin of honey. Food Chemistry, 63(4), 549-562. doi:10.1016/s0308-8146(98)00057-0Bosch, J., Del Pino, F. G., Ramoneda, J., & Retana, J. (1996). FRUITING PHENOLOGY AND FRUIT SET OF CAROB, CERATONIA SILIQUA L. (CESALPINACEAE). Israel Journal of Plant Sciences, 44(4), 359-368. doi:10.1080/07929978.1996.10676657Bouseta, A., Collin, S., & Dufour, J.-P. (1992). Characteristic aroma profiles of unifloral honeys obtained with a dynamic headspace GC-MS system. Journal of Apicultural Research, 31(2), 96-109. doi:10.1080/00218839.1992.11101268Cajka, T., Hajslova, J., Pudil, F., & Riddellova, K. (2009). Traceability of honey origin based on volatiles pattern processing by artificial neural networks. Journal of Chromatography A, 1216(9), 1458-1462. doi:10.1016/j.chroma.2008.12.066Castro-Vázquez, L., Díaz-Maroto, M. C., González-Viñas, M. A., & Pérez-Coello, M. S. (2009). Differentiation of monofloral citrus, rosemary, eucalyptus, lavender, thyme and heather honeys based on volatile composition and sensory descriptive analysis. Food Chemistry, 112(4), 1022-1030. doi:10.1016/j.foodchem.2008.06.036Conti, M. E., Stripeikis, J., Campanella, L., Cucina, D., & Tudino, M. B. (2007). Characterization of Italian honeys (Marche Region) on the basis of their mineral content and some typical quality parameters. Chemistry Central Journal, 1(1). doi:10.1186/1752-153x-1-14Custódio, L., Serra, H., Nogueira, J. M. F., Gonçalves, S., & Romano, A. (2006). Analysis of the Volatiles Emitted by Whole Flowers and Isolated Flower Organs of the Carob Tree Using HS-SPME-GC/MS. Journal of Chemical Ecology, 32(5), 929-942. doi:10.1007/s10886-006-9044-9Cuevas-Glory, L., Ortiz-Vázquez, E., Pino, J. A., & Sauri-Duch, E. (2012). Floral classification of Yucatan Peninsula honeys by PCA & HS-SPME/GC-MS of volatile compounds. International Journal of Food Science & Technology, 47(7), 1378-1383. doi:10.1111/j.1365-2621.2012.02983.xDe Bolòs, O., & Molinier, R. (1984). Vegetation of the Pityusic Islands. Biogeography and Ecology of the Pityusic Islands, 185-221. doi:10.1007/978-94-009-6539-3_9De Maria, C. A. B., & Moreira, R. F. A. (2003). Compostos voláteis em méis florais. Química Nova, 26(1), 90-96. doi:10.1590/s0100-40422003000100016Guyot, C., Scheirman, V., & Collin, S. (1999). Floral origin markers of heather honeys: Calluna vulgaris and Erica arborea. Food Chemistry, 64(1), 3-11. doi:10.1016/s0308-8146(98)00122-8Herrera, J. (1988). Pollination Relationships in Southern Spanish Mediterranean Shrublands. The Journal of Ecology, 76(1), 274. doi:10.2307/2260469Jerković, I., & Marijanović, Z. (2010). Volatile Composition Screening of Salix spp. Nectar Honey: Benzenecarboxylic Acids, Norisoprenoids, Terpenes, and Others. Chemistry & Biodiversity, 7(9), 2309-2325. doi:10.1002/cbdv.201000021Jones, G. D., & Bryant, Jr, V. M. (2004). The use of ETOH for the dilution of honey. Grana, 43(3), 174-182. doi:10.1080/00173130410019497Kummerow, J. (1983). Comparative Phenology of Mediterranean-Type Plant Communities. Ecological Studies, 300-317. doi:10.1007/978-3-642-68935-2_17La‐Serna Ramos, I. E., & GÓmez Ferreras, C. (2006). Pollen and sensorial characterization of different honeys from El Hierro (Canary Islands). Grana, 45(2), 146-159. doi:10.1080/00173130600578658Del Carmen Llasat, M., Ramis, C., & Barrantes, J. (1996). The meteorology of high‐intensity rainfall events over the west Mediterranean region. Remote Sensing Reviews, 14(1-3), 51-90. doi:10.1080/02757259609532313Louveaux, J., Maurizio, A., & Vorwohl, G. (1978). Methods of Melissopalynology. Bee World, 59(4), 139-157. doi:10.1080/0005772x.1978.11097714Martins, R. C., Lopes, V. V., Valentão, P., Carvalho, J. C. M. F., Isabel, P., Amaral, M. T., … Silva, B. M. (2008). Relevant principal component analysis applied to the characterisation of Portuguese heather honey. Natural Product Research, 22(17), 1560-1582. doi:10.1080/14786410701825004Melliou, E., & Chinou, I. (2011). Chemical constituents of selected unifloral Greek bee-honeys with antimicrobial activity. Food Chemistry, 129(2), 284-290. doi:10.1016/j.foodchem.2011.04.047Pendleton, M. (2006). Descriptions of melissopalynological methods involving centrifugation should include data for calculating Relative Centrifugal Force (RCF) or should express data in units of RCF or gravities (g). Grana, 45(1), 71-72. doi:10.1080/00173130500520479Pérez, R. A., Sánchez-Brunete, C., Calvo, R. M., & Tadeo, J. L. (2002). Analysis of Volatiles from Spanish Honeys by Solid-Phase Microextraction and Gas Chromatography−Mass Spectrometry. Journal of Agricultural and Food Chemistry, 50(9), 2633-2637. doi:10.1021/jf011551rPersano Oddo, L., Piana, L., Bogdanov, S., Bentabol, A., Gotsiou, P., Kerkvliet, J., … von der Ohe, K. (2004). Botanical species giving unifloral honey in Europe. Apidologie, 35(Suppl. 1), S82-S93. doi:10.1051/apido:2004045Persano Oddo, L., & Piro, R. (2004). Main European unifloral honeys: descriptive sheets. Apidologie, 35(Suppl. 1), S38-S81. doi:10.1051/apido:2004049Piana, M. L., Persano Oddo, L., Bentabol, A., Bruneau, E., Bogdanov, S., & Guyot Declerck, C. (2004). Sensory analysis applied to honey: state of the art. Apidologie, 35(Suppl. 1), S26-S37. doi:10.1051/apido:2004048Piasenzotto, L., Gracco, L., & Conte, L. (2003). Solid phase microextraction (SPME) applied to honey quality control. Journal of the Science of Food and Agriculture, 83(10), 1037-1044. doi:10.1002/jsfa.1502Radovic, B. S., Careri, M., Mangia, A., Musci, M., Gerboles, M., & Anklam, E. (2001). Contribution of dynamic headspace GC–MS analysis of aroma compounds to authenticity testing of honey. Food Chemistry, 72(4), 511-520. doi:10.1016/s0308-8146(00)00263-6RAMÓN-LACA, L., & MABBERLEY, D. J. (2004). The ecological status of the carob-tree (Ceratonia siliqua, Leguminosae) in the Mediterranean. Botanical Journal of the Linnean Society, 144(4), 431-436. doi:10.1111/j.1095-8339.2003.00254.xRetana, J., Ramoneda, J., Garcia Del Pino, F., & Bosch, J. (1994). Flowering phenology of carob,Ceratonia siliquaL. (Cesalpinaceae). Journal of Horticultural Science, 69(1), 97-103. doi:10.1080/14620316.1994.11515254Ricciardelli d’Albore, G. & Vorwohl, G. (1979). Mieles monoflorales en el Mediterráneo documentado con ayuda del análisis microscópico de mieles. Actas de XXVII Congreso Internacional de Apicultura, Athens, Greece, 14–20 September 1979, 201–208.Pilar de Sá‐Otero, M., Armesto‐Baztan, S., & DÍaz‐Losada, E. (2006). A study of variation in the pollen spectra of honeys sampled from the Baixa Limia‐Serra do Xurés Nature Reserve in north‐west Spain. Grana, 45(2), 137-145. doi:10.1080/00173130600708537Seijo, M. C., Jato, M. V., Aira, M. J., & Iglesias, I. (1997). Unifloral honeys of Galicia (north-west Spain). Journal of Apicultural Research, 36(3-4), 133-140. doi:10.1080/00218839.1997.11100939Terrab, A., Diez, M. J., & Heredia, F. J. (2003). Palynological, physico-chemical and colour characterization of Moroccan honeys: III. Other unifloral honey types. International Journal of Food Science and Technology, 38(4), 395-402. doi:10.1046/j.1365-2621.2003.00713.xTERRAB, A., PONTES, A., HEREDIA, F. J., & DÍEZ, M. J. (2004). A preliminary palynological characterization of Spanish thyme honeys. Botanical Journal of the Linnean Society, 146(3), 323-330. doi:10.1111/j.1095-8339.2004.00335.xTerrab, A., Valdés, B., & Josefa Díez, M. (2003). Pollen analysis of honeys from the Mamora forest region (NW Morocco). 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    Factors Affecting Infestation by Triatoma infestans in a Rural Area of the Humid Chaco in Argentina: A Multi-Model Inference Approach

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    Vector-borne transmission of Chagas disease remains a major public health problem in parts of Latin America. Triatoma infestans is the main vector in the countries located in the South American Cone, particularly in the Gran Chaco ecoregion where residual insecticide control has achieved only a moderate, irregular impact. To contribute to improved control strategies, we analyzed the factors associated with the presence and abundance of T. infestans in 327 inhabited houses in a well-defined rural area with no recent vector control interventions in the humid Argentine Chaco. Bugs were found mainly in domiciles, kitchens, storerooms, and chicken coops and nests, particularly where adequate refuge and animal hosts (humans, dogs, cats or poultry) were available. Domiciles constructed from mud were the most often infested, but brick-and-cement domiciles, even in good conditions, were also found infested. Availability of refuge and hosts for T. infestans are key targets for vector control. Ten-fold variations in domestic infestation observed across neighboring villages, and differences in the relevant factors for T. infestans presence with respect to other areas of the Gran Chaco region suggest that host management, building techniques and insecticide use need to be tailored to the local environment, socio-economic characteristics, and climatic conditions

    What controls star formation in the central 500 pc of the Galaxy?

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    The star formation rate (SFR) in the Central Molecular Zone (CMZ, i.e. the central 500 pc) of the Milky Way is lower by a factor of ≥10 than expected for the substantial amount of dense gas it contains, which challenges current star formation theories. In this paper, we quantify which physical mechanisms could be responsible. On scales larger than the disc scaleheight, the low SFR is found to be consistent with episodic star formation due to secular instabilities or possibly variations of the gas inflow along the Galactic bar. The CMZ is marginally Toomre-stable when including gas and stars, but highly Toomre-stable when only accounting for the gas, indicating a low condensation rate of self-gravitating clouds. On small scales, we find that the SFR in the CMZ may be caused by an elevated critical density for star formation due to the high turbulent pressure. The existence of a universal density threshold for star formation is ruled out. The H I–H2 phase transition of hydrogen, the tidal field, a possible underproduction of massive stars due to a bottom-heavy initial mass function, magnetic fields, and cosmic ray or radiation pressure feedback also cannot individually explain the low SFR. We propose a self-consistent cycle of star formation in the CMZ, in which the effects of several different processes combine to inhibit star formation. The rate-limiting factor is the slow evolution of the gas towards collapse – once star formation is initiated it proceeds at a normal rate. The ubiquity of star formation inhibitors suggests that a lowered central SFR should be a common phenomenon in other galaxies. We discuss the implications for galactic-scale star formation and supermassive black hole growth, and relate our results to the star formation conditions in other extreme environments
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