944 resultados para Duval, David


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Background Past and recent evidence shows that radionuclides in drinking water may be a public health concern. Developmental thresholds for birth defects with respect to chronic low level domestic radiation exposures, such as through drinking water, have not been definitely recognized, and there is a strong need to address this deficiency in information. In this study we examined the geographic distribution of orofacial cleft birth defects in and around uranium mining district Counties in South Texas (Atascosa, Bee, Brooks, Calhoun, Duval, Goliad, Hidalgo, Jim Hogg, Jim Wells, Karnes, Kleberg, Live Oak, McMullen, Nueces, San Patricio, Refugio, Starr, Victoria, Webb, and Zavala), from 1999 to 2007. The probable association of cleft birth defect rates by ZIP codes classified according to uranium and radium concentrations in drinking water supplies was evaluated. Similar associations between orofacial cleft birth defects and radium/radon in drinking water were reported earlier by Cech and co-investigators in another of the Gulf Coast region (Harris County, Texas).50, 55 Since substantial uranium mining activity existed and still exists in South Texas, contamination of drinking water sources with radiation and its relation to birth defects is a ground for concern. ^ Methods Residential addresses of orofacial cleft birth defect cases, as well as live births within the twenty Counties during 1999-2007 were geocoded and mapped. Prevalence rates were calculated by ZIP codes and were mapped accordingly. Locations of drinking water supplies were also geocoded and mapped. ZIP codes were stratified as having high combined uranium (≥30μg/L) vs. low combined uranium (<30μg/L). Likewise, ZIP codes having the uranium isotope, Ra-226 in drinking water, were also stratified as having elevated radium (≥3 pCi/L) vs. low radium (<3 pCi/L). A linear regression was performed using STATA® generalized linear model (GLM) program to evaluate the probable association between cleft birth defect rates by ZIP codes and concentration of uranium and radium via domestic water supply. These rates were further adjusted for potentially confounding variables such as maternal age, education, occupation, and ethnicity. ^ Results This study showed higher rates of cleft births in ZIP codes classified as having high combined uranium versus ZIP codes having low combined uranium. The model was further improved by adding radium stratified as explained above. Adjustment for maternal age and ethnicity did not substantially affect the statistical significance of uranium or radium concentrations in household water supplies. ^ Conclusion Although this study lacks individual exposure levels, the findings suggest a significant association between elevated uranium and radium concentrations in tap water and high orofacial birth defect rates by ZIP codes. Future case-control studies that can measure individual exposure levels and adjust for contending risk factors could result in a better understanding of the exposure-disease association.^

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El autor presenta esquemáticamente y con justa profundidad para el lector no especializado, un completo panorama de todo lo referente a la práctica del arte adivinatorio y oracular. El lector emprenderá un agradable viaje a través de los paisajes religiosos, literarios, filosóficos y culturales de la Grecia arcaica y clásica.

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Fil: Leónidas Aguirre, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas

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En este trabajo se plantea, más allá de examinar las tesis principales del "revisionismo", la propia naturaleza del conocimiento histórico. ¿Son válidas todas las interpretaciones de un hecho histórico? ¿Se trata en tales casos de "otra lectura", de una "versión alternativa", es decir, de otra apreciación de los datos disponibles? ¿Cómo saber cuando hay mala interpretación deliberada o falsificación de la evidencia? ¿Puede detectarse si la argumentación tendenciosa es deshonesta? El "revisionismo histórico" se ha definido a sí mismo como una corriente historiográfica que ofrece otra versión de Hitler y su régimen. Cerca de una veintena de autores, desde los años cuarenta del siglo XX, se adscriben en esta tendencia, algunos de los cuales han desplegado una sostenida actividad y han logrado una llamativa repercusión en los medios de difusión. Este es el caso de David Irving. Autor de más de treinta libros, artículos, conferencias y discursos dedicados al III Reich, ha pasado largos años de su vida rastreando y estudiando archivos alemanes. Pero muy lejos de constituir un nuevo enfoque historiográfico del nazismo, el "revisionismo" de David Irving está imbuido de política e ideología y sus métodos de trabajo incluyen la adulteración y la distorsión intencional de la historia.