61 resultados para Autonomous study time


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Thesis submitted in the fulfillment of the requirements for the Degree of Master in Biomedical Engineering

Relevância:

30.00% 30.00%

Publicador:

Resumo:

ABSTRACT – Background: According to the Report on Carcinogens, formaldehyde ranks 25th in the overall U.S. chemical production, with more than 5 million tons produced each year. Given its economic importance and widespread use, many people are exposed to formaldehyde environmentally and/or occupationally. Presently, the International Agency for Research on Cancer classifies formaldehyde as carcinogenic to humans (Group 1), based on sufficient evidence in humans and in experimental animals. Manyfold in vitro studies clearly indicated that formaldehyde can induce genotoxic effects in proliferating cultured mammalian cells. Furthermore, some in vivo studies have found changes in epithelial cells and in peripheral blood lymphocytes related to formaldehyde exposure. Methods: A study was carried out in Portugal, using 80 workers occupationally exposed to formaldehyde vapours: 30 workers from formaldehyde and formaldehyde-based resins production factory and 50 from 10 pathology and anatomy laboratories. A control group of 85 non-exposed subjects was considered. Exposure assessment was performed by applying simultaneously two techniques of air monitoring: NIOSH Method 2541 and Photo Ionization Detection equipment with simultaneously video recording. Evaluation of genotoxic effects was performed by application of micronucleus test in exfoliated epithelial cells from buccal mucosa and peripheral blood lymphocytes. Results: Time-weighted average concentrations not exceeded the reference value (0.75 ppm) in the two occupational settings studied. Ceiling concentrations, on the other hand, were higher than reference value (0.3 ppm) in both. The frequency of micronucleus in peripheral blood lymphocytes and in epithelial cells was significantly higher in both exposed groups than in the control group (p < 0.001). Moreover, the frequency of micronucleus in peripheral blood lymphocytes was significantly higher in the laboratories group than in the factory workers (p < 0.05). A moderate positive correlation was found between duration of occupational exposure to formaldehyde (years of exposure) and micronucleus frequency in peripheral blood lymphocytes (r = 0.401; p < 0.001) and in epithelial cells (r = 0.209; p < 0.01). Conclusions: The population studied is exposed to high peak concentrations of formaldehyde with a long-term exposure. These two aspects, cumulatively, can be the cause of the observed genotoxic endpoint effects. The association of these cytogenetic effects with formaldehyde exposure gives important information to risk assessment process and may also be used to assess health risks for exposed worker

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Master Erasmus Mundus Crossways in European Humanities

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A Thesis submitted for the co-tutelle degree of Doctor in Physics at Universidade Nova de Lisboa and Université Pierre et Marie Curie

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertação para obtenção do grau de mestre em Engenharia de Materiais

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertação para obtenção do Grau de Doutor em Bioquímica – Ramo Bioquímica Estrutural

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper summarises the results of the first systematic, detailed prosopographic study of the MPs – the deputados of the Lower Chamber - of the First Portuguese Republic (1910-1926). Data are presented both by legislature and for the overall period. Two kinds of background variables are explored: sociodemographic (birthplace, age, education and profession) and political (previous experience in other elite positions). Regime change in 1910 resulted in the replacement of the former political elite by homines novi. Most MPs of the Republican regime were born in small towns and communities, had carried out higher educational studies (with prevalence for law training), were mainly drawn from the professions (practising lawyers and doctors) and the Army, and were elected for the first-time at relatively young ages. Parliamentary turnover was high (two-thirds of the representatives held just one mandate) and a large proportion of MPs had a consistent connection (birth, family ties, occupation) to the constituencies to which they had been elected.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Tese de mestrado em Antropologia, especialização natureza e conservação

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.