TRATAMENTO DE EFLUENTES DE TANQUES DE PISCICULTURA APLICANDO A TECNOLOGIA DE ELETROCOAGULAÇÃO

Para a realização deste trabalho, foi utilizada a técnica da eletrocoagulação (EC) para o tratamento de efluente de piscicultura. Um reator de EC em escala de laboratório, com capacidade de 1,5 L foi montado, utilizando um conjunto de quatro placas de eletrodos de alumínio, um agitador mecânico de alto torque microprocessado, fios condutores com garras de jacaré e uma fonte de tensão com potência regulável. Os eletrodos foram arranjados dentro da célula eletrolítica de forma monopolar, em paralelo e a uma distância de 11 mm. O efluente utilizado neste estudo foi coletado em tanques de piscicultura do centro de criação de peixes do Departamento de Engenharia de Pesca da Universidade Federal do Ceará. Para a determinação da melhor condição de operação do reator, foi feito um planejamento experimental por intermédio do Software “Statgrafics”, definindo, as variáveis operacionais e os seus respetivos intervalos de variação (pH inicial de 4 a 8, condutividade de 1000 a 4000 μS cm-1, tempo de eletrolise de 15 a 35 min., agitação de 200 a 600 rpm e corrente de 1 a 2,5 A), que combinadas entre si totalizaram um total de 35 ensaios experimentais. Com base nos resultados obtidos por meio das análises físico-químicas em laboratório, pode-se afirmar que o pH inicial=8, condutividade=1000 μS cm-1, tempo=35 min., agitação=200 rpm e corrente=2,5 A, são as condições ótimas de operação do reator. Nestas condições, alcançaram remoção de 84,95% para DQO, 98,06% para nitrito, 82,43% para nitrato, 98,05% para fósforo total e 95,32% para a turbidez, sendo o custo operacional de 4,59 R$/m3 de efluente tratado. Com base nos resultados obtidos, pode-se concluir que alguns dos parâmetros analisados (pH, turbidez, temperatura, STD, nitrito, nitrato e fósforo total) estão de acordo com os padrões estabelecidos para água doce, classe 2, pela Resolução CONAMA nº 357/05, e de acordo com a Resolução CONAMA nº 430/2011 e a Portaria nº 154/2002 da SEMACE (CE), para lançamento do efluente final nos corpos receptores. A técnica de eletrocoagulação além de ser um método alternativo, eficiente e promissor para tratamento de efluentes de piscicultura, também mostrou ser ecologicamente correto por dispensar o consumo elevado de reagentes, ao contrário do que acontece no tratamento convencional.

Phase II study of imatinib in patients with recurrent gliomas of various histologies: a European Organisation for Research and Treatment of Cancer Brain Tumor Group Study.

PURPOSE: To evaluate the safety and the efficacy of imatinib in recurrent malignant gliomas. PATIENTS: AND METHODS: This was a single-arm, phase II study. Eligible patients had recurrent glioma after prior radiotherapy with an enhancing lesion on magnetic resonance imaging. Three different histologic groups were studied: glioblastomas (GBM), pure/mixed (anaplastic) oligodendrogliomas (OD), and low-grade or anaplastic astrocytomas (A). Imatinib was started at a dose of 600 mg/d with dose escalation to 800 mg in case of no toxicity; during the trial this dose was increased to 800 mg/d with escalation to 1,000 mg/d. Trial design was one-stage Fleming; both an objective response and 6 months of progression-free survival (PFS) were considered a successful outcome to treatment. RESULTS: A total of 112 patients (51 patients with GBM, 25 patients with A, and 36 patients with OD) were enrolled. Imatinib was in general well tolerated. The median number of cycles was 2.0 (range, 1 to 43 cycles). Five patients had an objective partial response, including three patients with GBM; all had 6 months of PFS. The 6-month PFS rate was 16% (95% CI, 8.0% to 34.0%) in GBM, 4.0% (95% CI, 0.3% to 15.0%) in OD, and 9% (95% CI, 2.0% to 25.0%) in A. The exposure to imatinib was significantly lower in patients using enzyme-inducing antiepileptic drugs. The presence of ABCG2 point mutations were not correlated with pharmacokinetic findings. No somatic activating mutations of KIT or platelet-derived growth factor receptor-A or -B were found. CONCLUSION: In the dose range of 600 to 1,000 mg/d, single-agent imatinib is well tolerated but has limited antitumor activity in patients with recurrent gliomas.

BAFF-R, a newly identified TNF receptor that specifically interacts with BAFF.

B cell homeostasis has been shown to critically depend on BAFF, the B cell activation factor from the tumor necrosis factor (TNF) family. Although BAFF is already known to bind two receptors, BCMA and TACI, we have identified a third receptor for BAFF that we have termed BAFF-R. BAFF-R binding appears to be highly specific for BAFF, suggesting a unique role for this ligand-receptor interaction. Consistent with this, the BAFF-R locus is disrupted in A/WySnJ mice, which display a B cell phenotype qualitatively similar to that of the BAFF-deficient mice. Thus, BAFF-R appears to be the principal receptor for BAFF-mediated mature B cell survival.

Computation of multiple correspondence analysis, with code in R

The generalization of simple correspondence analysis, for two categorical variables, to multiple correspondence analysis where they may be three or more variables, is not straighforward, both from a mathematical and computational point of view. In this paper we detail the exact computational steps involved in performing a multiple correspondence analysis, including the special aspects of adjusting the principal inertias to correct the percentages of inertia, supplementary points and subset analysis. Furthermore, we give the algorithm for joint correspondence analysis where the cross-tabulations of all unique pairs of variables are analysed jointly. The code in the R language for every step of the computations is given, as well as the results of each computation.

Research joint ventures and optimal R&D policy with asymmetric information

When to allow Research Joint Ventures (RJVs) or not is an importantinstrument in the development of an optimal R&D policy. Theregulator, however, is unlikely to know all the relevant informationto regulate R&D optimally. The extent to which there existappropriability problems between the firms is one such variable thatis private information to the firms in the industry. In a duopolysetting we analyze the characteristics of a second-best R&D policywhere the government can either allow RJVs or not and give lump-sumsubsidies to the parties involved. The second-best R&D policy withoutsubsidies will either block some welfare improving RJVs or allow somewelfare reducing ones. With lump-sum subsidies, the second-best policytrades off the expected subsidy cost with allowing welfare decreasingRJVs or blocking welfare increasing ones.