112 research outputs found

    Descripción de una nueva subespecie de leptotila verreauxi bonaparte,1855 (aves: columbidae) del sureste de colombia

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    La especie Leptotila verreauxi se conocía en Colombia en la región suroccidental, mitad meridional de la cuenca del río Cauca y la ladera occidental de los Andes occidentales en el Departamento del Cauca, hacia el sur y en la ladera amazónica de los Andes en el sureste de Nariño (cf. Meyer De Schauensee,1952: 4) con la subespecie L. v. decolor (SALVIN, 1892). Al norte del país y en el valle del río Magdalena está representada por L. v, verreauxi (BONAPARTE,1855) de la cual para el oriente del país sólo se dispone de un macho adulto obtenido en el raudal de San Borja en el río Orinoco, al sur de Puerto Carreno, NE de la Comisaría del Vichada, coleccionado el 17 de marzo por el doctor Polidoro Pinto E. y don Pablo Bernal, del Instituto de Ciencias Naturales de la Universidad Nacional de Colombia

    Pig manure treatment with housefly (Musca domestica) rearing – an environmental life cycle assessment

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    The largest portion of a product’s environmental impacts and costs of manufacturing and use results from decisions taken in the conceptual design phase long before its market entry. To foster sustainable production patterns, applying life cycle assessment in the early product development stage is gaining importance. Following recent scientific studies on using dipteran fly species for waste management, this paper presents an assessment of two insect-based manure treatment systems. Considering the necessity of manure treatment in regions with concentrated animal operations, reducing excess manure volumes with the means of insects presents a potentially convenient method to combine waste reduction and nutrient recovery. An analytical comparison of rearing houseflies on fresh and pre-treated pig manure is reported with reference to agricultural land occupation, water and fossil depletion potential. Based on ex-ante modelled industrial scale rearing systems, the driving factors of performance and environmentally sensitive aspects of the rearing process have been assessed. Expressed per kg manure dry matter reduction, the estimated agricultural land occupation varied between 1.4 and 2.7 m2yr, fossil depletion potential ranged from 1.9 to 3.4 kgoil eq and the obtained water depletion potential was calculated from 36.4 to 65.6 m3. System improvement potential was identified for heating related energy usage and water consumption. The geographical context and the utility of the co-products, i.e. residue substrates and insect products, were determined as influential variables to the application potential of this novel manure treatment concept. The results of this study, applied at the earliest stages of the design of the process, assist evaluation of the feasibility of such a system and provide guidance for future research and development activities.The research leading to these results has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 312084 (PROteINSECT)

    Análisis Comparativo del Posicionamiento Preciso Utilizando el Receptor de Bajo Costo GNSS ZED-F9P en Conjunto con la Antena BEIBT300 y Diferentes Modelos de Antena de Orden Geodésico

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    Con el avance de la Geodesia y la mejora de las especificaciones técnicas de los receptores de bajo costo, los GNSS abren nuevas alternativas para investigar las capacidades técnicas y rendimiento real que proveen este tipo de receptores para diferentes propósitos geodésicos. En este contexto, la precisión alcanzable fue analizada usando el receptor de bajo costo GNSS ZED-F9P en conjunto con dos antenas de orden geodésico (ASH701975.01B y LEIAS10 NONE) y una antena de bajo costo (BEIBT300 NONE). Las observaciones GNSS fueron llevadas a cabo en un periodo de dos días para cada modelo de antena. El análisis fue realizado en tiempos de observación de 12, 6 y 1 h, respectivamente. Estas observaciones fueron procesadas usando el método relativo estático mediante la inclusión de una estación de referencia continua del Instituto Nacional de Estadística y Geografía, la cual está localizada a una distancia aproximada de 4 km. Los resultados demuestran que la mayor precisión es lograda en un periodo de 12 h, con diferencias mínimas de 3 cm para la componente Norte y 33 cm para la vertical. En este sentido, la solución menos precisa es obtenida en el periodo de 1 h resultando diferencias de 70 cm, 46 cm y 2.3 m para la componente Norte, Este y vertical respectivamente.   With advancements in geodesy and enhancements in the technical specifications of low-cost receivers, GNSS opens up new avenues for investigating the capabilities and performance provided by these receivers for various geodetic purposes. In this context, the precision achievable using the low-cost GNSS receiver ZED-F9P in conjunction with two geodetic antennas (ASH701975.01B and LEIAS10 NONE) and a low-cost antenna (BEIBT300 NONE) was analyzed. GNSS observations were conducted over a 2-day period for each antenna model. The analysis involved observation durations of 12, 6, and 1 h. These observations were processed using the static relative method alongside a continuously operating GNSS station from the Active National Geodetic Network of the National Institute of Statistics and Geography, situated at ~4 km. The results demonstrate that the highest precision was achieved over a 12 h period, with minimal differences of 3 cm for the North component and 33 cm for the vertical component. Conversely, the least accurate solution was obtained within a 1 h observation period, resulting in differences of up to 70 cm, 46 cm, and 2.3 m for the North, East, and vertical components, respectively

    Mortars Modified with Geothermal Nanosilica Waste: Effect on the Electrochemical Properties of Embedded Steel Rods

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    Nowadays, it is a common practice the incorporation of industrial wastes as alternative materials to replace ordinary Portland cement in the concrete manufacture. This technological implementation has as main objectives, the enhancement of concretes properties as well as mitigation of durability problem related to the corrosion phenomena; in order to increase the service life of reinforced concrete structures. Therefore, in this research was studied the electrochemical properties of black steel embedded in mortars. Mortars were fabricated using as a partial substitute of cement (0, 10, 20 and 30 wt. %) a geothermal nanosilica waste composed of amorphous nanosilica of ~20ηm and chlorides (0 and 0.4 wt. %). Mortars were subjected to a cure at 20°C (80% of relative humidity) and 60ºC (100% of relative humidity). The corrosion behaviour was periodically monitorized up to 65 days using electrochemical techniques of corrosion potential (Ecorr) and corrosion current density (icorr). Values of current density (icorr) were obtained by linear polarization resistance (LPR) technique applying Stern-Geary relation to Rp values. Electrochemical results were validated by comparing with gravimetric losses. The porosity, pH and loss of the evaporated water were also evaluated in mortars. Results obtained showed that the integrity of reinforcement rods was affected with the increase of GNW at high temperatures as well as the total chlorides content in mortars

    Sarcoma fibromixoide intracraneal primario de bajo grado: reporte de caso y revisión de la literatura.

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    Low-grade fibromyxoid sarcoma (LGFMS) is a soft tissue tumor of mesenchymal origin. Sarcomas are a heterogeneous group, representing 1% of all neoplasm diagnoses. Primary sarcomas of the central nervous system (CNS) are rare, and represent only 0.7% of all sarcomas, with an estimated incidence of 3 per 10 million people per year. The case of a 59-year-old woman who developed a low-grade intracranial fibromyxoid sarcoma in the right parietal region, is described. The clinical course, imaging studies, histopathological features, and treatment approach of this unusual diagnosis, are discussed. Low-grade intracranial fibromyxoid sarcoma is a rare and probably under- reported condition. The definitive diagnosis is usually made through histo-pathological studies.El sarcoma fibromixoide de bajo grado (LGFMS) es un tumor de tejidos blandos de origen mesenquimal. Los sarcomas son un grupo heterogéneo, que representa el 1% de todas las neoplasias. Los sarcomas primarios del sistema nervioso central (SNC) son raros y representan solo el 0,7% del total de sarcomas, con una incidencia estimada de 3 por cada 10 millones de personas por año. En este artículo, se describe el caso de una mujer de 59 años que presentó un sarcoma fibromixoide intracraneal de bajo grado, localizado en la región parietal derecha. Se discute el curso clínico, estudios de imágenes, características histopatológicas y tratamiento de este diagnóstico infrecuente y, por lo mismo, muy poco reportado. El diagnóstico definitivo se obtiene, ciertamente, mediante estudios histo- patológicos

    Association between Ancestry-Specific 6q25 Variants and Breast Cancer Subtypes in Peruvian Women

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    Background: Breast cancer incidence in the United States is lower in Hispanic/Latina (H/L) compared with African American/ Black or Non-Hispanic White women. An Indigenous American breast cancer-protective germline variant (rs140068132) has been reported near the estrogen receptor 1 gene. This study tests the association of rs140068132 and other polymorphisms in the 6q25 region with subtype-specific breast cancer risk in H/Ls of high Indigenous American ancestry. Methods: Genotypes were obtained for 5,094 Peruvian women with (1,755) and without (3,337) breast cancer. Associations between genotype and overall and subtype-specific risk for the protective variant were tested using logistic regression models and conditional analyses, including other risk-associated polymorphisms in the region. Results: We replicated the reported association between rs140068132 and breast cancer risk overall [odds ratio (OR), 0.53; 95% confidence interval (CI), 0.47-0.59], as well as the lower odds of developing hormone receptor negative (HR-) versus HR+ disease (OR, 0.77; 95% CI, 0.61-0.97). Models, including HER2, showed further heterogeneity with reduced odds for HR+HER2+ (OR, 0.68; 95% CI, 0.51-0.92), HR-HER2+ (OR, 0.63; 95% CI, 0.44-0.90) and HR-HER2- (OR, 0.77; 95% CI, 0.56-1.05) compared with HR+HER2-. Inclusion of other risk-associated variants did not change these observations. Conclusions: The rs140068132 polymorphism is associated with decreased risk of breast cancer in Peruvians and is more protective against HR- and HER2+ diseases independently of other breast cancer-associated variants in the 6q25 region. Impact: These results could inform functional analyses to understand the mechanism by which rs140068132-G reduces risk of breast cancer development in a subtype-specific manner. They also illustrate the importance of including diverse individuals in genetic studies.National Institutes of HealthRevisión por pare

    Precipitation regionalization, anomalies and drought occurrence in the Yucatan Peninsula, Mexico

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    © 2020 The Authors. International Journal of Climatology published by John Wiley & Sons Ltd on behalf of the Royal Meteorological Society. Climate change projections have identified the Yucatan Peninsula as being vulnerable to increasing drought. Understanding spatial and temporal precipitation variability and drought occurrence are therefore important. Drought monitoring in Mexico has been carried out only relatively recently and often without considering the long-term variability in both droughts and precipitation. This research explores the spatio-temporal variability of precipitation and occurrence of droughts at a much finer spatial resolution and over a longer temporal period than previous studies. Using statistical (cluster analysis and standardized precipitation index) and geostatistical (kriging) techniques, maps of precipitation and droughts are generated for the period 1980–2011. These show that whilst many previous studies have regarded the Yucatan Peninsula as a homogenous region with respect to precipitation, there are actually four distinctive clusters of precipitation amount, showing climatic variability across the Peninsula. The analyses also show that droughts in the Peninsula are regionalised. Twelve-month Standardized Precipitation Indices (SPI), calculated for individual stations and for precipitation surfaces, reveal distinct patterns of spatial and temporal variability. SPI surfaces indicate the occurrence of major droughts in 1981, 1986–1987, 1994, 1996, 2003, 2004 and 2009, but these rarely affect the whole Yucatan Peninsula uniformly. Wetter years, such as 1983, 1984, 1988, 1992, 1995, 2002 and 2005 sometimes reflect the impact of individual extreme events, such as hurricane Isidore in 2002. Our results show that drought can be regionalised, thus enhancing the quality of information about droughts in the area and providing evidence and support for future drought mitigation and environmental protection. These methods could usefully be applied elsewhere
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