5 resultados para BARRIOS MARGINADOS
em CentAUR: Central Archive University of Reading - UK
Resumo:
Objective: To determine the risk of lung cancer associated with exposure at home to the radioactive disintegration products of naturally Occurring radon gas. Design: Collaborative analysis of individual data from 13 case-control studies of residential radon and lung cancer. Setting Nine European countries. Subjects 7148 cases Of lung cancer and 14 208 controls. Main outcome measures: Relative risks of lung cancer and radon gas concentrations in homes inhabited during the previous 5-34 years measured in becquerels (radon disintegrations per second) per cubic incite (Bq/m(3)) Of household air. Results: The mean measured radon concentration in homes of people in tire control group was 97 Bq/m(3), with 11% measuring > 200 and 4% measuring > 400 Bq/m(3). For cases of lung cancer the mean concentration was 104 Bq/m(3). The risk of lung cancer increased by 8.4% (95% confidence interval 3.0% to 15.8%) per 100 Bq/m(3) increase in measured radon (P = 0.0007). This corresponds to an increase of 16% (5% to 31%) per 100 Bq/m(3) increase in usual radon-that is, after correction for the dilution caused by random uncertainties in measuring radon concentrations. The dose-response relation seemed to be linear with no threshold and remained significant (P=0.04) in analyses limited to individuals from homes with measured radon < 200 Bq/m(3). The proportionate excess risk did not differ significantly with study, age, sex, or smoking. In the absence of other causes of death, the absolute risks of lung cancer by age 75 years at usual radon concentrations of 0, 100, and 400 Bq/m(3) would be about 0.4%, 0.5%, and 0.7%, respectively, for lifelong non-smokers, and about 25 times greater (10%, 12%, and 16%) for cigarette smokers. Conclusions: Collectively, though not separately, these studies show appreciable hazards from residential radon, particularly for smokers and recent ex-smokers, and indicate that it is responsible for about 2% of all deaths from cancer in Europe.
Resumo:
We have calculated the concentrations of Mg in the bulk and surfaces of aragonite CaCO3 in equilibrium with aqueous solution, based on molecular dynamics simulations and grand-canonical statistical mechanics. Mg is incorporated in the surfaces, in particular in the (001) terraces, rather than in the bulk of aragonite particles. However, the total Mg content in the bulk and surface of aragonite particles was found to be too small to account for the measured Mg/Ca ratios in corals. We therefore argue that most Mg in corals is either highly metastable in the aragonite lattice, or is located outside the aragonite phase of the coral skeleton, and we discuss the implications of this finding for Mg/Ca paleothermometry.
Resumo:
We have investigated the (001) surface structure of lithium titanate (Li2TiO3) using auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and scanning tunneling microscopy (STM). Li2TiO3 is a potential fusion reactor blanket material. After annealing at 1200 K, LEED demonstrated that the Li2TiO3(001) surface was well ordered and not reconstructed. STM imaging showed that terraces are separated in height by about 0.3 nm suggesting a single termination layer. Moreover, hexagonal patterns with a periodicity of ∼0.4 nm are observed. On the basis of molecular dynamics (MD) simulations, these are interpreted as a dynamic arrangement of Li atoms.
Resumo:
This essay will examine and compare the production of women's writing during and after the Nicaraguan and Cuban Revolutions, a corpus that includes novels, poetry, and testimonies, but also features considerable generic hybridity. Since both revolutions are separated by some twenty years, each must be understood in the context of the specific ideological conditions that framed women’s participation in culture and revolution, and must also be considered in light of evolving gender discourses, both national and international. As such, these texts respond to both local and transnational paradigms of feminine subjectivity, and highlight the particular problems that arise from women’s insertion into the revolution and its representation in literature. These writers also have to negotiate the evolving context of revolution itself, with its moments of euphoria and disenchantment – and it is here that the greatest contrasts can be found between the two revolutionary instances and their political features: whilst Cuba’s revolutionary process has somehow survived economic crisis and created a level of political stability and continuity (not without its own problems), the Nicaraguan case is characterised by ruptures and resentments which are clearly reflected in the work of writers before, during, and after the Sandinista revolution, and which continue to the present day. This chapter will address the work of the most prominent woman writer of the Nicaraguan revolution, Gioconda Belli, whose main work reflects her involvement in the Sandinista struggle; ex-commander Mónica Baltodano has recently compiled a four volume piece with testimonials of men and women who participated in the organization and actions led by the Frente Sandinista de Liberación Nacional, and Violeta Barrios de Chamorro, former president of Nicaragua, who has recently co-authored an autobiography. There are other women poets to consider, especially under the auspices of the Asociación de Mujeres Nicaraguenses Luisa Amanda Espinoza, such as Vidaluz Meneses, Michele Najlis and Daisy Zamora. The testimonios compiled by Margaret Randall are also important pieces to consider for both Nicaragua and Cuba. The most important voices of the Cuban revolution still resident on the island are poet Nancy Morejón and writers Mirta Yáñez and Aida Bahr, with younger writers such as Adelaida Fernández de Juan and Marilyn Bobes representing a more recent generation.