Integración montecarlo

Este documento presenta un método para evaluar integrales definidas utilizando números aleatorios, método que es muy poderoso sobre todo cuando se trata de resolver integrales en múltiples dimensiones

Detrital zircon typology and U/Pb geochronology for the Miocene Ladrilleros-Juanchaco sedimentary sequence, Equatorial Pacific (Colombia) : new constraints on provenance and paleogeography in northwestern South America

Typology and internal texture analyses were performed on detrital zircons obtained from the Miocene sandstones of the Ladrilleros-Juanchaco sedimentary sequence (Colombia, Equatorial Pacific). This analysis was complemented with zircon U/Pb dating to identify typology-age associations as indicators of provenance of these sediments. Our results show that zircons with S and P dominant typology have internal structures/zoning that indicate mostly igneous and possibly some metamorphic origins. Morphometric results suggest little transport from source areas. Both typology and U/Pb data point to the Western Cordillera as the main source of the detrital materials of this sedimentary sequence. A paleogeographic reconstruction shows that during Late Miocene times there were significant portions of the Western Cordillera uplifted, eroding away and acting as a fluvio-topographic barrier blocking sediments from the Central Cordillera to reach the Pacific basins. Miocene plutons at the axis of the Western Cordillera were also probably exhumed and played a role as geomorphologically active massifs. This study demonstrates that typologic analysis on detrital zircon grains is a powerful tool as indicator of provenance and paleogeography in complex litho-tectonic areas where overlapping U/Pb signatures can lead to contradictory results

Blastocystis spp.: Literary review a highly prevalent intestinal parasite

Introducción. Blastocystis spp., se ha identificado como un patógeno emergente causante de diarrea en hombre y en animales. Objetivo: Realizar una revisión sobre las principales características de este parásito y su rol patogénico. Metodología: Se realizó una revisión bibliográfica sobre ciclo de vida, subtipos, epidemiología, y sus posibles factores de virulencia Estas revisiones fueron extraídas de bases de datos como PUBMED, SCIENCE DIRECT, SCIELO, EBSCO y HINARI. Resultados: Blastocystis spp., es de interés por su alta prevalencia en diferentes grupos poblacionales, constante en los estudios epidemiológicos de las parasitosis humanas. Se ha evidenciado en pacientes asintomáticos y en otros con síntomas gastrointestinales, lo que depende del subtipo presente en el portador, sin embargo, esta divergencia se presta para problemas de interpretación. Conclusiones: A pesar de los estudios epidemiológicos, terapéuticos e inmunológicos que se han realizado aún no se tiene claro su ciclo de vida completo, factores de virulencia y patogenicidad.Introduction: Blastocystis spp., has been identified as an emerging pathogen causing diarrhea in humans and animals. Objective: To conduct a review of the main features of this parasite and its pathogenic role. Methodology: A literature review on the major characteristics of Blastocystis spp., life cycle, subtypes, epidemiology and potential virulence factors was performed Reviews and research articles were extracted from databases such as PUBMED, SCIENCE DIRECT, SCIELO, HINARI and EBSCO. Results: Blastocystis spp.is of interest because of its high prevalence in different population groups, being constant in epidemiological studies of human parasitosis. It has been shown in asymptomaticpatients with gastrointestinal symptoms in others, depending on the subtype present in the carrier. However, this difference is due to problems of interpretation. Conclusions: Although epidemiological, therapeutic and immunological studies have been conducted yet, it is not clear its entire life cycle, virulence factors and pathogenicity

Blastocystis spp.: Literary review a highly prevalent intestinal parasite

Introducción. Blastocystis spp., se ha identificado como un patógeno emergente causante de diarrea en hombre y en animales. Objetivo: Realizar una revisión sobre las principales características de este parásito y su rol patogénico. Metodología: Se realizó una revisión bibliográfica sobre ciclo de vida, subtipos, epidemiología, y sus posibles factores de virulencia Estas revisiones fueron extraídas de bases de datos como PUBMED, SCIENCE DIRECT, SCIELO, EBSCO y HINARI. Resultados: Blastocystis spp., es de interés por su alta prevalencia en diferentes grupos poblacionales, constante en los estudios epidemiológicos de las parasitosis humanas. Se ha evidenciado en pacientes asintomáticos y en otros con síntomas gastrointestinales, lo que depende del subtipo presente en el portador, sin embargo, esta divergencia se presta para problemas de interpretación. Conclusiones: A pesar de los estudios epidemiológicos, terapéuticos e inmunológicos que se han realizado aún no se tiene claro su ciclo de vida completo, factores de virulencia y patogenicidad.Introduction: Blastocystis spp., has been identified as an emerging pathogen causing diarrhea in humans and animals. Objective: To conduct a review of the main features of this parasite and its pathogenic role. Methodology: A literature review on the major characteristics of Blastocystis spp., life cycle, subtypes, epidemiology and potential virulence factors was performed Reviews and research articles were extracted from databases such as PUBMED, SCIENCE DIRECT, SCIELO, HINARI and EBSCO. Results: Blastocystis spp.is of interest because of its high prevalence in different population groups, being constant in epidemiological studies of human parasitosis. It has been shown in asymptomaticpatients with gastrointestinal symptoms in others, depending on the subtype present in the carrier. However, this difference is due to problems of interpretation. Conclusions: Although epidemiological, therapeutic and immunological studies have been conducted yet, it is not clear its entire life cycle, virulence factors and pathogenicity

Pronóstico de las tasas de cambio. una aplicación al yen japonés mediante redes neuronales artificiales

En este artículo se muestra la aplicabilidad de las redes neuronales artificiales al mercado de divisas mediante el estudio de la tasa de cambio del Yen japonés con respecto al Dólar americano. En primer lugar se entrena un conjunto de redes neuronales con los datos históricos de la tasa de cambio y los días de la semana; posteriormente se incluyen los seis de los indicadores económicos más importantes que afectan directamente al dólar americano. Se demuestra como la información de estos últimos indicadores mejora considerablemente la capacidad de pronóstico de las redes neuronales

PROCESO DE INFORMACIÓN EN EL FORTALECIMIENTO DE LA GESTIÓN COMUNITARIA PARA EL SANEAMIENTO BÁSICO. CENTRO POBLADO LA FLORIDA, MUNICIPIO DE PEREIRA

En la cuenca media del río Otún, municipio de Pereira, Colombia, se dio inicio al fortalecimiento de la gestión comunitaria para la apropiación del servicio de alcantarillado, como aspecto clave de la sostenibilidad de las soluciones implementadas en la localidad de La Florid

Interlaboratory evaluations of the performance of elemental analytical methods for the forensic analysis and comparisons of electrical tapes

Adhesive tapes are an important type of evidence related to violent crimes such as the construction of improvised explosive devices and kidnappings as well as involved in other types of common evidence such as drug packaging. The methods of comparison of tape evidence consist of physical and microscopic examination followed by chemical analysis of the organic and inorganic components inherent to the tapes as part of their formulations. This work evaluates the performance of the conventional methods used in forensic analysis of adhesive tapes (physical and microscopic examination, FTIR, Py-GC-MS, and SEM-EDS) and the more recently developed elemental methods, LIBS and LA-ICP-MS, for the comparison of tape samples in different laboratories. Two interlaboratory exercises were designed to study the performance of the different analytical methods for the forensic analysis of electrical tapes. The exercises were developed with the objective to imitate forensic case scenarios where known and question tapes are compared following the laboratory’s analytical protocol. The participants were asked to compare the tape samples as in a regular forensic case. Seven (7) laboratories participated in the two interlaboratory exercises. All the laboratories performing SEM-EDS in both interlaboratory exercises (#1 and #2) were able to correctly associate the pairs of tapes originating from the same rolls, therefore the rate of false negatives was zero. Two of the laboratories performing SEM-EDS for the first interlaboratory exercise incorrectly associated two pairs of tapes belonging to different rolls, resulting in a 17% false positive rate. One of the laboratories performing SEM-EDS for interlaboratory exercise #2 incorrectly associated two pairs of tapes belonging to different rolls, resulting in a 13% false positive rate. Up to 7 and 8 elements were detected by SEM-EDS for interlaboratory exercise #1 and #2, respectively. The increased sensitivity and selectivity of LIBS and LA-ICP-MS methods allowed to distinguish all the pairs of tapes originating from different sources and for correctly associate the tapes originating from the same rolls, resulting in no false positives or false negatives. In addition, increased characterization of the samples was obtained by detecting up to 14 elements by LIBS and 27 elements by LA-ICP-MS for interlaboratory exercise #1, and 17 elements by LIBS and 32 elements by LA-ICP-MS for interlaboratory exercise #2. A match criterion of ±5 s allowed to numerically compare LIBS ratios and LA-ICP-MS signal areas for a more objective assessment of the differences between the tape samples

The long-term legacy of plastic mass production

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordMismanaged plastic waste is transported via rivers or city drains into the ocean where it accumulates in coastal sediments, ocean gyres and the deep ocean. Plastic harms marine biota and may ultimately return to humans via the food chain. Private initiatives proposing to collect plastic from the sea and rivers have gained widespread attention, especially in the media. However, few of these methods are proven concepts and it remains unclear how effective they are. Here we estimate the amount of plastic in the global surface ocean to assess the long-term legacy of plastic mass production, calculate the time required to clean up the oceans with river barriers and clean up devices, and explore the fate of collected plastic waste. We find that the projected impact of both single and multiple clean up devices is very modest. A significant reduction of plastic debris in the ocean can be only achieved with collection at rivers or with a combination of river barriers and clean up devices. We also show that the incineration and production of plastic has a significant long-term effect on the global atmospheric carbon budget. We conclude that a combination of reduced plastic emissions and reinforced collection is the only way to rid the ocean of plastic waste