973 resultados para Natural fibre
Resumo:
We aimed to study the selective pressures interacting on SLC45A2 to investigate the interplay between selection and susceptibility to disease. Thus, we enrolled 500 volunteers from a geographically limited population (Basques from the North of Spain) and by resequencing the whole coding region and intron 5 of the 34 most and the 34 least pigmented individuals according to the reflectance distribution, we observed that the polymorphism Leu374Phe (L374F, rs16891982) was statistically associated with skin color variability within this sample. In particular, allele 374F was significantly more frequent among the individuals with lighter skin. Further genotyping an independent set of 558 individuals of a geographically wider population with known ancestry in the Spanish population also revealed that the frequency of L374F was significantly correlated with the incident UV radiation intensity. Selection tests suggest that allele 374F is being positively selected in South Europeans, thus indicating that depigmentation is an adaptive process. Interestingly, by genotyping 119 melanoma samples, we show that this variant is also associated with an increased susceptibility to melanoma in our populations. The ultimate driving force for this adaptation is unknown, but it is compatible with the vitamin D hypothesis. This shows that molecular evolution analysis can be used as a useful technology to predict phenotypic and biomedical consequences in humans.
Resumo:
A phase-locking fibre laser array with up to 60 W of coherent output power based on two large-core fibre is reported. The slope efficiency of the in-phase mode is 37%. For two cases of spacings between the cores, steady high-contrast interference stripes are observed. When the whole system operates under a high pump power level, no thermal effects for the spatial filter have been observed, which means that we can increase the coherent output power further by increasing the individual fibre laser power.
Resumo:
Demonstrations of cw lasing in Cr2+:ZnSe poly-crystal are reported. The laser consists of a 1.7-mm-thick Cr2+:ZnSe poly-crystal disc pumped by a Tm-silica double-clad fibre laser at 2050nm. Using a concave high-reflection mirror with a radius of curvature of 500mm as the rear mirror, the laser delivers up to 1030mW of radiation around 2.367 mu m.
Crack advancement in a carbon-fibre epoxy composite observed by dynamic scanning electron microscopy
Resumo:
La idea del proyecto consiste en crear una asociación orientada a la gestión de actividades recreativo-deportivas en el medio natural. En un enclave puramente rural, la asociación tendrá su sede en Jaurrieta, un pueblo del Pirineo Navarro con menos de 200 habitantes. La intención es que el pueblo de Jaurrieta y el propio Valle de Salazar, formen parte de esta asociación, involucrando a un gran número de personas. Se considera que la unión y la heterogeneidad de cada una de estas personas, potenciarán positivamente la propuesta. Con el objetivo de ofrecer actividades recreativo-deportivas y servicios complementarios, se aprovecharán los recursos naturales del entorno para proporcionar al visitante un mayor conocimiento de la zona y su estilo de vida rural. La oferta de actividades recreativo-deportivas en el medio natural, estará dirigida a aquellas personas que decidan pasar su tiempo de ocio en el Pirineo Navarro. Por esto, surge la necesidad de elaborar un “Plan Estratégico” que facilite la creación y desarrollo de esta asociación. Como misión o fin último de la propuesta, se pretende contribuir en el desarrollo rural del Valle de Salazar; desde una perspectiva de progreso económico y social.