2,064 research outputs found
El estado del comercio, la competitividad y el bienestar económico en la región fronteriza México-Estados Unidos
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Cloud tomography applied to sky images: a virtual testbed
Two tomographic techniques are applied to two simulated sets of sky images with different cloud fraction. The Algebraic Reconstruction Technique (ART) is applied to optical depth maps from sky images to reconstruct 3-D cloud extinction coefficients without considering multiple scattering effects. Reconstruction accuracy is explored for different products, including surface irradiance and extinction coefficients, and as a function of the number of available sky imagers and setup distance. Increasing the number of imagers improves the accuracy of the 3-D reconstruction: for surface irradiance, the error decreases significantly up to four imagers at which point the improvements become marginal. But using nine imagers gives more robust results in practical situations in which the circumsolar region of images has to be excluded due to poor cloud detection. The ideal distance between imagers was also explored: for a cloud height of 1 km, increasing distance up to 3 km (the domain length) improved the 3-D reconstruction. An iterative reconstruction technique that iteratively updated the source function improved the results of the ART by minimizing the error between input red radiance images and reconstructed red radiance simulations. For the best case of a nine-imager deployment, the ART and iterative method resulted in 53.4% and 33.6% relative mean absolute error for the extinction coefficients, respectively.The authors acknowledge funding from the California Energy Commission EPIC program. Felipe Mejia was supported by the National Science Foundation Graduate Research Fellowship under Grant No. (DGE-1144086). In addition, Íñigo de la Parra has been partially supported by the Spanish State Research Agency (AEI) and FEDER-UE under grants DPI2016-80641-R and DPI2016-80642-R
Vesicle-micelle structural transition of phosphatidylcholine bilayers and Triton X-100
Metabolismo de un tramo en la cuenca baja del río Cesar, departamento del Cesar, en una época de sequía, Colombia
The functionalities of aquatic systems are the result of biological interactions, the physicochemical conditions of water and the terrestrial environment, these relationships are affected by anthropic actions, such as: deforestation, mining, agriculture, solid waste discharges and domestic and industrial liquids, general harmful practices for aquatic ecosystems. This investigation was carried out with the purpose of estimating the variation of the metabolism and physicochemical variables in the lower basin of the Cesar River, during the period of maximum dry season, the trophic state of the lower basin of the aquatic ecosystem was determined by observations in the changes of the O2 consumption and CO2 accumulation, the processes of photosynthesis and respiration were quantified. Two samplings were carried out in four stations, between February-April 2013, equivalent to the dry period. Physicochemical variables in situ and some nutrients were measured. The metabolism protocol was applied, using the Winkler method (clear and dark bottles), with measurements every hour for 24 h (daily curve). The net metabolism was -10732.23 O2/m3-h, the dark one of -10731.41 02/m3-h and the gross primary production of the entire aquatic community of -10736.91 02/m3-h. These results suggest that the variations in the net and dark metabolism, as well as the primary productivity of the community were almost nil. Additionally, the oxygen produced during the day was consumed quickly at night. Our data show that the trophic state of the lower basin of the Cesar River is eutrophic-heterotrophic, the respiration exceeds the production of O2, which generates deficit of the same and a decrease in the quality of this ecosystem, results that are corroborated with the analyzes of the physicochemical variables measured at the site.Los atributos funcionales de los sistemas acuáticos son resultado de interacciones biológicas, las condiciones fisicoquímicas del agua y el ambiente terrestre. Estas relaciones son afectadas por acciones antrópicas, como: la deforestación, la minería, la agricultura, los vertimientos de residuos sólidos y líquidos domésticos e industriales, en general cualquier práctica nociva para los ecosistemas acuáticos. Este trabajo se realizó con el fin de estimar la variación del metabolismo y las variables fisicoquímicas en un tramo bajo del río Cesar durante la época de máximo estiaje. Se determinó el estado trófico de la cuenca baja del ecosistema acuático por observaciones en los cambios del consumo de O2 y acumulación de CO2, y se cuantificaron los procesos de fotosíntesis y respiración. Se realizaron dos muestreos en cuatro estaciones entre febrero y abril de 2013 (periodo seco). Se midieron los variables fisicoquímicos in situ y algunos nutrientes. Se aplicó el protocolo del metabolismo, utilizando el método de Winkler (botellas clara y oscura), con mediciones cada hora durante 24 h (curva diaria). El metabolismo neto fue de 10732,23 O2/m3-h, el oscuro de -10731,41 O2/m3-h y la producción primaria bruta de toda la comunidad acuática de -10736,91 O2/m3-h. Estos resultados sugieren que las variaciones en el metabolismo neto y oscuro, así como la productividad primaria de la comunidad fueron casi nulas. Adicionalmente, el oxígeno producido durante el día fue consumido rápidamente durante la noche. Nuestros datos demuestran que el estado trófico de la cuenca baja del río Cesar es eutrófico-heterotrófico, la respiración excede la producción de O2, lo que genera déficit del mismo y una disminución de la calidad de este ecosistema, estos datos coinciden con los análisis de las variables fisicoquímicas medidas en el sitio
Lesiones premalignas y malignas en cirugía menor de un centro de salud. Las apariencias engañan
ObjetivoDescribir las características de las lesiones malignas y premalignas detectadas en las intervenciones de cirugía menor realizadas en un centro de saludDiseñoEstudio descriptivo retrospectivoParticipantesSe analizaron 682 lesiones correspondientes a todas las lesiones extirpadas remitidas a anatomía patológica, exceptuando los quistes epidérmicos y triquilemales, lipomas, molluscum, verrugas vulgares y uñasEmplazamientoCentro de Salud Rochapea (Pamplona)Mediciones principalesAnalizamos los diagnósticos anatomopatológicos y la distribución por sexos, grupos de edad, localización, técnica y afección de bordes en 27 lesiones displásicas y 11 lesiones malignasResultadosEncontramos una mayor frecuencia de lesiones malignas y premalignas en mujeres, entre 15 y 44 años de edad para las displasias y entre 45 y 64 años para las malignas. La localización más frecuente fue la espalda, y la técnica más empleada la escisión fusiforme. Con esta técnica encontramos el mayor porcentaje de bordes sin lesión en las displasias. Las lesiones que tenían afectados los bordes corresponden a muestras de punch y escisión circular. Ninguna de las lesiones malignas presentaba afección de bordesConclusionesLa mayor parte de las lesions malignas no se sospechan, aparecen en muestras que se remiten con un diagnóstico de benignidad. El empleo de ciertas técnicas como la escisión fusiforme en las lesiones en que existe una potencial malignidad, aunque en principio parezcan benignas, nos permite una extirpación con bordes libresObjectiveTo describe the characteristics of the malignant and pre-malignant lesions found in the minor surgical interventions performed at a health centreDesignRetrospective, descriptive studyParticipants682 lesions: all the lesions extirpated and referred to pathology except for epidermal and trichilemmal cysts, lipomas, molluscum, common warts, and nailsSettingRochapea Health Centre, PamplonaMain measurementsWe analysed the anatomical-pathological results and the distribution by sex, age-group, location, technique and edges affected in 27 dysplasias and 11 malignant lesionsResultsWe found that malignant and premalignant lesions were more common in women, aged 15 to 44 for dysplasias and 45- 64 for malignant lesions. The most common location was on the back; the most frequent technique, fusiform excision. This technique had the highest percentage of edges without lesion in dysplasias. The lesions whose edges were affected corresponded to punch and circular excision samples. None of the malignant lesions had their edges affectedConclusionsMost malignant lesions are not suspected. They appear in samples referred with a diagnosis of benign. Employment of techniques such as fusiform excision in lesions which are potentially malign, even though in principle they seem benign, enables them to be extirpated with free edge
Liposome formation with wool lipid extracts rich in ceramides
Internal wool lipids (IWLs) are rich in cholesterol, free fatty acids, cholesteryl sulfate, and, mainly, ceramides.
The repairing effect of these lipids structured as liposomes was demonstrated by reinforcing the
skin-barrier integrity and increasing the water-holding capacity when applied onto the skin. This work
was focused on the formation of liposomes with IWLs rich in ceramides, obtained at pilot plant level with
organic solvent extraction by using methanol and acetone. The lipid composition of the two extracts was
quantitatively analyzed. IWL extracts containing different amounts of sterol sulfate were used to form liposomes
at physiologic pH. Vesicle size distribution, polydispersity index, and zeta potential of all liposomes
were determined to characterize them and to study their stability. The results obtained showed that IWL
extract composition, which was different depending on the extraction methodologies used, greatly influences
the characteristics of the liposomes formed. Vesicular size and polydispersity index liposomes were
smaller when the extract composition contained a higher proportion of either free fatty acids or sterol
sulfate. Moreover, liposome stability was improved when some amount of sterol sulfate was added to the
composition of methanol and acetone extracts. This natural mixture with keratinaceous origin could have
a special interest for cosmetic or dermopharmaceutical companies.We acknowledge Mr. G. von Knorring for his expert technical assistance. We are also indebted to the DGICYT Program (PPQ 2002-94136-C02-01 and C02-02) for financial support
Land use change in a Mediterranean metropolitan region and its periphery: Assessment of conservation policies through CORINE land cover data and Markov models
Sustainable territorial management requires reliable assessment of the impact of conservation policies on landscape structure and dynamics. Euro-Mediterranean regions present a remarkable biodiversity which is linked in part to traditional land use practices and which is currently threatened by global change. The effectiveness of one-decade conservation policies against land use changes was examined in Central Spain (Madrid Autonomous Community). A Markov model of landscape dynamics was parameterized with CORINE Land Cover information and transition matrices were obtained. The methods were applied in both protected and unprotected areas to examine whether the intensity and direction of key land use changes —urbanisation, agricultural intensification and land abandonment— differed significantly depending on the protection status of those areas. Protected areas experienced slower rates of agricultural intensification processes and faster rates of land abandonment, with respect to those which occurred in unprotected areas. It illustrates how simple mathematical tools and models —parameterized with available data— can provide to managers and policy makers useful indicators for conservation policy assessment and identification of land use transitions
Intellectual disability and ageing: a new challenge for the twenty-first century
[Resumen] OBJETIVO: Mediante el presente trabajo se pretende conocer las características de la población con retraso mental que ha supera- do la edad de 45 años.
MÉTODO: Estudio descriptivo de carácter transversal, entre una muestra representativa de 189 personas mayores de 45 años, con certificado de minusvalía que acredite la discapacidad psíquica, seleccionadas aleatoriamente entre las institucionalizadas en los centros de la comunidad autónoma gallega. La herramienta para recoger la información ha sido un cuestionario de elaboración propia, debidamente contrastado.
RESULTADOS: El 60% de los entrevistados reside con sus familias, con las que mantienen una relación calificada como buena en el 49,7% de los casos. El 48,7% presenta un coeficiente intelectual con un retraso moderado, y profundo en el 36,5%; no se conoce el origen del retraso mental en el 42,85% de los casos.
CONCLUSIONES: Las necesidades detectadas en la calidad asistencial llevan a concluir la urgencia de actuar sobre los recursos, equipamientos y el grado de especialización de los profesionales implicados, sin obviar a las familias, que constituyen el verdadero soporte asistencial.[Abstract] OBJECTIVE: The aim of this study was to determine the characteristics of adults with intellectual disability who survive for more than45 years.
METHODS: We performed a cross-sectional, descriptive study of a representative sample of 189 individuals aged more than 45 years with certified intellectual disability. The subjects were randomly selected from individuals attending centres of the Autonomous Community of Galicia in Spain. The instrument used to gather information was a specifically-designed and validated questionnaire.
RESULTS: Sixty percent of subjects lived with their families, with whom 49.7% reported a good relationship. The degree of intellectual disability was moderate in 49.7% and severe in 36.5%. Aetiology was unknown in 42.5%.
CONCLUSIONS: Shortfalls detected in the quality of care indicate that urgent action should be taken to improve resources and the degree of specialisation among staff, as well as to aid families, who provide the main support to individuals with mental disability
El estado de la sustentabilidad y los retos emergentes en la gestión del medio ambiente en la frontera México-Estados Unidos
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