14 research outputs found
Atmospheric Evolution
Earth's atmosphere has evolved as volatile species cycle between the
atmosphere, ocean, biomass and the solid Earth. The geochemical, biological and
astrophysical processes that control atmospheric evolution are reviewed from an
"Earth Systems" perspective, with a view not only to understanding the history
of Earth, but also to generalizing to other solar system planets and
exoplanets.Comment: 34 pages, 3 figures, 2 tables. Accepted as a chapter in
"Encyclopaedia of Geochemistry", Editor Bill White, Springer-Nature, 201
Endotoxin concentration in poultry houses for laying hens kept in cages or in alternative housing systems
Mass Balance Applied to Brazilian Conventional Broiler Houses during One Production Cycle
Outcome (competency) based education: an exploration of its origins, theoretical basis, and empirical evidence
Lung cancer mortality in a cohort of UK cotton workers: an extended follow-up
Background: a recent systematic review and meta-analysis suggested that occupational exposure to endotoxins protects against lung cancer. To explore this hypothesis further, the follow-up of mortality of a cohort of 3551 workers, who were employed in the British cotton industry during 1966–1971, was extended by 23 years.Methods: subjects had originally been recruited to a survey of respiratory disease, which collected information about occupation and smoking habits. Cumulative exposures to endotoxins were estimated from data on endotoxin levels by work areas in cotton mills. Risks of lung cancer were estimated using survival modelling.Results: during follow-up, 2018 deaths were recorded before the age of 90 years, including 128 deaths from lung cancer. After adjustment for smoking, hazard ratios (95% confidence intervals) for cumulative endotoxin exposures of less than or equal to30?000, >30?000 and less than or equal to200?000, >200?000 and less than or equal to400?000, >400?000 and less than or equal to600?000 and >600?000 endotoxin units (EU)?m?3 years were 1, 0.8 (0.5–1.6), 0.7 (0.4–1.3), 0.6 (0.3–1.0) and 0.5 (0.3–0.9), respectively (P for trend=0.005).Conclusion: our findings strengthen the evidence that occupational exposure to endotoxins protects against lung cancer, and suggest that the effect depends on cumulative dose and persists after exposure cease