Modelling the Radiative Effects of Biomass Burning Aerosols on Carbon Fluxes in the Amazon Region

Every year, a dense smoke haze covers a large portion of South America originating from fires in the Amazon Basin and central parts of Brazil during the dry/biomass-burning season between August and October. Over a large portion of South America, the average aerosol optical depth at 550 nm exceeds 1.0 during the fire season while the background value during the rainy season is below 0.2. Biomass burning aerosol particles increase scattering and absorption of the incident solar radiation. The regional-scale aerosol layer reduces the amount of solar energy reaching the surface, cools the near surface air, and increases the diffuse radiation fraction over a large disturbed area of the Amazon rainforest. These factors affect the energy and CO2 fluxes at the surface. In this work, we applied a fully integrated atmospheric model to assess the impact of biomass burning aerosols in CO2 fluxes in the Amazon region during 2010. We address the effects of the attenuation of the global solar radiation and the enhancement of the diffuse solar radiation flux inside the vegetation canopy. Our results indicate that the biomass burning aerosols led to increases of about 27% of gross primary productivity of Amazonia, 10% of plant respiration and a decline in soil respiration of 3%. Consequently, in our model Amazonia, became a net carbon sink; net ecosystem exchange during September 2010 dropped from +101 to -104 TgC when the aerosol effects are considered, mainly due to the aerosol diffuse radiation effect. For the forest biome, our results point to a dominance of the diffuse radiation effect on CO2 fluxes, reaching a balance of 50% - 50% between the diffuse and direct aerosol effects for high aerosol loads. For C3 grasses and Savanna (cerrado), as expected, the contribution of the diffuse radiation effect is much lower, tending to zero with the increase of aerosol load. Taking all biomes together, our model shows the Amazon during the dry season, in the presence of high biomass burning aerosol loads, changing from being a source to being a sink of CO2 to the atmosphere

A simplified minimal residual disease polymerase chain reaction method at early treatment points can stratify children with acute lymphoblastic leukemia into good and poor outcome groups

Background Minimal residual disease is an important independent prognostic factor in childhood acute lymphoblastic leukemia. The classical detection methods such as multiparameter flow cytometry and real-time quantitative polymerase chain reaction analysis are expensive, time-consuming and complex, and require considerable technical expertise. Design and Methods We analyzed 229 consecutive children with acute lymphoblastic leukemia treated according to the GBTLI-99 protocol at three different Brazilian centers. Minimal residual disease was analyzed in bone marrow samples at diagnosis and on days 14 and 28 by conventional homo/heteroduplex polymerase chain reaction using a simplified approach with consensus primers for IG and TCR gene rearrangements. Results At least one marker was detected by polymerase chain reaction in 96.4%, of the patients. By combining the minimal residual disease results obtained on days 14 and 28, three different prognostic groups were identified: minimal residual disease negative on days 14 and 28, positive on day 14/negative on day 28, and positive on both. Five-year event-free survival rates were 85%, 75.6%,, and 27.8%, respectively (p<0.0001). The same pattern of stratification held true for the group of intensively treated children. When analyzed in other subgroups of patients such as those at standard and high risk at diagnosis, those with positive B-derived CD10, patients positive for the TEL/AML1 transcript, and patients in morphological remission on a day 28 marrow, the event-free survival rate was found to be significantly lower in patients with positive minimal residual disease on day 28. Multivariate analysis demonstrated that the detection of minimal residual disease on day 28 is the most significant prognostic factor. Conclusions This simplified strategy for detection of minimal residual disease was feasible, reproducible, cheaper and simpler when compared with other methods, and allowed powerful discrimination between children with acute lymphoblastic leukemia with a good and poor outcome.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[2005/02279-6

Evolução da ocorrência (1980-1999) da doença de Crohn e da retocolite ulcerativa idiopática e análise das suas características clínicas em um hospital universitário do sudeste do Brasil Trends in the occurrence (1980-1999) and clinical features of Crohn's disease and ulcerative colitis in a university hospital in southeastern Brazil

Racional - A doença de Crohn e a retocolite ulcerativa idiopática são consideradas pouco freqüentes nos países em desenvolvimento, sendo escassos os estudos sobre a sua ocorrência no Brasil. Objetivos - Estudar a freqüência de admissão de casos da doença de Crohn e da retocolite ulcerativa inespecífica em um hospital universitário ao longo de 20 anos (1980-99) e descrever características demográficas e clínicas desses casos. Métodos - Calculou-se a freqüência de admissão de casos da doença de Crohn e da retocolite ulcerativa inespecífica de janeiro de 1980 a dezembro de 1999 e analisaram-se todos os casos destas doenças admitidos nos últimos 10 anos desse período. Resultados - No período estudado, registraram-se 257 casos novos, sendo 126 da doença de Crohn e 131 da retocolite ulcerativa inespecífica. A freqüência de admissão de casos de ambas as doenças aumentou de 40 para 61 casos/10.000 atendimentos, do primeiro para o segundo qüinqüênio, com menor crescimento subseqüente, sendo que a doença de Crohn tornou-se, gradualmente, mais freqüente que a retocolite ulcerativa inespecífica. Em ambas as doenças, houve predomínio de casos do gênero feminino, na faixa etária entre 20 e 50 anos, da cor branca, do estado civil casado e de não-tabagistas. Ambas as doenças apresentaram-se com os sintomas digestivos próprios e não houve diferenças entre elas quanto às freqüências de manifestações sistêmicas e extra-intestinais (29,5% vs 23,3%), incluindo as tromboembólicas (5,9% vs 5,5%). Na doença de Crohn, 59,2% dos casos apresentaram complicações (obstrução e/ou perfuração), enquanto que 53,7% dos casos de retocolite ulcerativa inespecífica foram de formas mais graves. Nos casos de doença de Crohn com obstrução, o tabagismo foi significativamente mais freqüente que nas formas não-complicadas. Na retocolite ulcerativa inespecífica, as manifestações sistêmicas e as extra-intestinais, bem como o acometimento de todo o cólon, foram significativamente mais freqüentes nas formas mais graves. Conclusões - Houve aumento da freqüência das doenças inflamatórias intestinais, com a doença de Crohn tornando-se mais comum que a retocolite ulcerativa inespecífica. Tanto uma como outra das afecções, apresentaram-se com as características habituais, destacando-se o predomínio das formas mais graves.<br>Background - Crohn's disease and ulcerative colitis are regarded as uncommon in developing countries, but studies on their occurrence in Brazil are scarce. Aims - To determine the occurrence of Crohn's disease and ulcerative colitis in a Brazilian university hospital throughout a 20-year period, and analyze the demographical, clinical and evolutive features of these cases. Methods - The frequencies of new cases of Crohn's disease and ulcerative colitis admitted from January 1980 up to December 1999 were calculated and a descriptive analysis of the features of all cases seen from January 1990 up to December 1999 was performed. Results - A total of 257 new cases (126 with Crohn's disease and 131 with ulcerative colitis) was recorded. The frequencies of admissions for both Crohn's disease and ulcerative colitis have increased progressively from 40 up to 61 cases/10.000 new admissions and Crohn's disease gradually became more common than ulcerative colitis. For both diseases, there was predominance of women, age at admission in the range of 30-40 years, Caucasian origin, married state and non-smokers. Digestive symptoms presented were similar to those already described for both diseases and there were no differences between Crohn's disease and ulcerative colitis regarding the frequencies of general complaints and extra-intestinal manifestations (29.5% vs 23.3%), including thromboembolism (5.9% vs 5.4%). Obstruction and/or perforation were seen in up to 59.2% of Crohn's disease cases, whereas 53.7% of all ulcerative colitis cases presented as severe forms. In Crohn's disease cases with obstruction, smoking was significantly more common than in non-complicated cases. In ulcerative colitis cases of increased severity, general complaints, extra-intestinal manifestations and pancolitis were significantly more frequent than in less severe forms. Conclusions - For the last 20 years, there have been an increased frequency of admission of inflammatory bowel diseases, and Crohn's disease have become more prevalent than ulcerative colitis. Demographical, clinical and evolutive features of these diseases seems to be similar to those already described, but there seems to be a predominance of more severe forms of both diseases

Neotropical freshwater fisheries : A dataset of occurrence and abundance of freshwater fishes in the Neotropics

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications