RESUMO
Processes determining the carbon (C) balance of a forest ecosystem are influenced by a number of climatic and environmental factors. In Northern Europe, a rise in atmospheric humidity and precipitation is predicted. The study aims to ascertain the effect of elevated atmospheric humidity on the components of the C budget and on the C-sequestration capacity of a young birch forest. Biomass production, soil respiration, and other C fluxes were measured in young silver birch (Betula pendula Roth) stands growing on the Free Air Humidity Manipulation (FAHM) experimental site, located in South-East Estonia. The C input fluxes: C sequestration in trees and understory, litter input into soil, and methane oxidation, as well as C output fluxes: soil heterotrophic respiration and C leaching were estimated. Humidified birch stands stored C from the atmosphere, but control stands can be considered as C neutral. Two years of elevated air humidity increased C sequestration in the understory but decreased it in trees. Humidification treatment increased remarkably the C input to the soil. The main reason for such an increase was the higher root litter input into the soil, brought about by the more than two-fold increase of belowground biomass production of the understory in the humidification treatment. Elevated atmospheric humidity increased C sequestration in young silver birch stands, mitigating increasing CO2 concentration in the atmosphere. However, the effect of elevated atmospheric humidity is expected to decrease over time, as plants and soil organisms acclimate, and new communities emerge.
Assuntos
Biomassa , Sequestro de Carbono , Florestas , Umidade , Solo/química , Atmosfera , Betula , EstôniaRESUMO
OBJECTIVES: To compare the incidence and survival of acute de novo leukaemias with particular reference to political/socio-economic and environmental factors in two neighbouring countries over the three 5-year periods (1982-1996). PATIENTS: The present report covers only patients diagnosed when aged > or =65 years. SETTING: A well-defined area of Sweden, the so-called Western Swedish Health Care Region and Estonia. Population-wise, the western Swedish Region and Estonia are very similar; area-wise they are also well comparable. RESULTS: The number of acute de novo leukaemias was quite dissimilar in the two countries (Estonia, n = 137, Sweden, n = 354). The age standardized incidence rates regarding the total number of acute de novo leukaemias was 5.31 per 100,000 inhabitants/year for Estonia and 7.99 for Sweden, this difference being statistically significant. However, the difference was merely attributable to incidence rates as regards acute myeloblastic leukaemias (AML); on the contrary, differences as regards acute lymphoblastic leukaemias (ALL) and non-classifiable, undifferentiated or biphenotypic acute leukaemias (uAL) were negligible. The relative survival for the total material of patients was significantly higher for Swedish when compared with Estonian patients (P < 0.001). Thus, the relative survival for the total material of patients aged > or =65 years in Estonia at 1 year was 8.5% and at 3 years 3.5% respectively. The corresponding figures for the Swedish patients were considerably higher, 22.7 and 7.7% respectively. This difference, however, applied only for patients with AML (P < 0.001), whereas the results for patients with ALL and uAL were equally dismal. CONCLUSION: The results clearly reflect how political and socio-economic factors may influence the survival of acute leukemia patients in two neighbouring countries.
Assuntos
Leucemia/epidemiologia , Idoso , Atenção à Saúde , Meio Ambiente , Estônia/epidemiologia , Feminino , Humanos , Incidência , Leucemia/mortalidade , Masculino , Fatores de Risco , Fatores Socioeconômicos , Taxa de Sobrevida , Suécia/epidemiologiaRESUMO
Circulating immune complexes were identified in 143 patients with malignant tumors (70--solid cancer, 37--acute leukemia, 21--chronic lympholeukemia and 15--myelomatosis) as well as in 64 patients with chronic inflammatory diseases. Immune complexes were detected in 40% with the aid of precipitation with polyethylene glycol alone and in 50%--by using it in combination with an anticomplementary method. Immune complexes occurred more often in acute myeloid leukemia (66%) than in pancreatic cancer (23%) or chronic lymphoid leukemia (29%). The immunoglobulin profile of complexes varied: in patients with pancreatic cancer, mainly IgM was found; in leukemic patients--different combinations of IgM, IgA and IgG. In the immune complexes of some patients with pancreatic disease, CEA and normal pancreatic antigens were detected.