Eutrofização do Reservatório Cruzeta na bacia representativa do rio Seridó RN

Eutrophication has been listed as one of the main problems of water pollution on a global level. In the Brazilian semi-arid areas this problem takes even greater proportions due to characteristical water scarcity of the region. It is extremely important to the predictive eutrophication models development and to the reservoirs management in the semi-arid region, studies that promotes understanding of the mechanisms responsible for the expansion and control of algae blooms, essential for improving the water quality of these environments. The present study had as its main aims, evaluate the temporal pattern of trophic state, considering the influence of nutrients (N and P) and the light availability in the water column in the development of phytoplankton biomass, and perform the mathematical modelling of changes in phosphorus and chlorophyll a concentrations in the Cruzeta man-made lake located on Seridó, a typical semi-arid region of Rio Grande do Norte. To this, a fortnightly monitoring was performed in the reservoir in 05 stations over the months of March 2007 to May 2008. Were measured the concentrations of total phosphorus, total organic nitrogen, chlorophyll a, total, fixed and volatile suspended solids, as well as the measure of transparency (Secchi) and the profiles of photosynthetic active radiation (PAR), temperature, pH, dissolved oxygen and electrical conductivity in the water column. Measurements of vertical profiles have shown some periods of chemical and thermal stratification, especially in the rainy season, due to increased water column depth, however, the reservoir can be classified as warm polimitic. During the study period the reservoir was characterized as eutrophic considering the concentrations of phosphorus and most of the time as mesotrophic, based on the concentrations of chlorophyll a, according to the Thornton & Rast (1993) classification. The N:P relations suggest N limitation, conversely, significant linear relationship between the algae biomass and nutrients (N and P) were not observed in our study. However, a relevant event was the negative and significant correlation presented by Kt and chlorophyll a (r ² = 0.83) at the end of the drought of 2007 and the rainy season of 2008, and the algal biomass collapse observed at the end of the drought season (Dec/07). The equation used to simulate the change in the total phosphorus was not satisfactory, being necessary inclusion of parameters able to increase the power of the model prediction. The chlorophyll a simulation presented a good adjustment trend, however there is a need to check the calibrated model parameters and subsequent equation validation

Investigação da capacidade intelectiva de pacientes pediátricos diagnosticados com tumores de fossa posterior

Central Nervous System are the most common pediatric solid tumors. 60% of these tumors arise in posterior fossa, mainly in cerebellum. The first therapeutic approach is surgical resection. Malignant tumors require additional strategies - chemotherapy and radiotherapy. The increasing survival evidences that childhood brain tumors result in academic and social difficulties that compromise the quality of life of the patients. This study investigated the intellectual functioning of children between 7 to 15 years diagnosed with posterior fossa tumors and treated at CEHOPE - Recife / PE. 21 children were eligible - including 13 children with pilocytic astrocytoma (G1) who underwent only surgery resection, and eight children with medulloblastoma (G2) - submitted to surgical resection, chemotherapy and craniospinal radiotherapy. Participants were evaluated by the Wechsler Intelligence Scale for Children - WISC-III. Children of G1 scored better than children of G2. Inferential tools (Mann-Whitney Ü Test) identified significant diferences (p ≤ 0.05) between the Performance IQ (PIQ) and Processing Speed Index (PSI) as a function of treatment modality; Full Scale IQ (FSIQ), PIQ and PSI as a function of parental educational level; PIQ, FSIQ, IVP and Freedom from Distractibility (FDI) as a function of time between diagnosis and evaluation. These results showed the late and progressive impact of radiotherapy on white matter and information processing speed. Furthermore, children whose parents have higher educational level showed better intellectual performance, indicating the influence of xxii socio-cultural variables on cognitive development. The impact of cancer and its treatment on cognitive development and learning should not be underestimated. These results support the need to increase the understanding of such effects in order to propose therapeutic strategies which ensure that, in addition to the cure, the full development of children with this pathology