Computational system to create an entry file for replicating I-125 seeds simulating brachytherapy case studies using the MCNPX code

Purpose: A computational system was developed for this paper in the C++ programming language, to create a 125I radioactive seed entry file, based on the positioning of a virtual grid (template) in voxel geometries, with the purpose of performing prostate cancer treatment simulations using the MCNPX code.Methods: The system is fed with information from the planning system with regard to each seed’s location and its depth, and an entry file is automatically created with all the cards (instructions) for each seed regarding their cell blocks and surfaces spread out spatially in the 3D environment. The system provides with precision a reproduction of the clinical scenario for the MCNPX code’s simulation environment, thereby allowing the technique’s in-depth study.Results and Conclusion: The preliminary results from this study showed that the lateral penumbra of uniform scanning proton beams was less sensitive In order to validate the computational system, an entry file was created with 88 125I seeds that were inserted in the phantom’s MAX06 prostate region with initial activity determined for the seeds at the 0.27 mCi value. Isodose curves were obtained in all the prostate slices in 5 mm steps in the 7 to 10 cm interval, totaling 7 slices. Variance reduction techniques were applied in order to optimize computational time and the reduction of uncertainties such as photon and electron energy interruptions in 4 keV and forced collisions regarding cells of interest. Through the acquisition of isodose curves, the results obtained show that hot spots have values above 300 Gy, as anticipated in literature, stressing the importance of the sources’ correct positioning, in which the computational system developed provides, in order not to release excessive doses in adjacent risk organs. The 144 Gy prescription curve showed in the validation process that it covers perfectly a large percentage of the volume, at the same time that it demonstrates a large decline for short distances.------------------------------Cite this article as: Boia LS, Junior J, Menezes AF, Silva AX. Computational system to create an entry file for replicating I-125 seeds simulating brachytherapy case studies using the MCNPX code. Int J Cancer Ther Oncol 2014; 2(2):02023.DOI: http://dx.doi.org/10.14319/ijcto.0202.

pH E CEs EM SOLO SOB IRRIGAÇÃO COM ÁGUA SALINA NO CULTIVO DE TOMATE EM AMBIENTE PROTEGIDO

Objetivou-se com este trabalho verificar pH (potencial hidrogeniônico) e CEs (condutividade elétrica da solução) em água drenada de solo de textura arenosa cultivado com tomate (Solanum Lycopersicum) irrigado com água salina em ambiente protegido. O experimento foi conduzido no Instituto Federal do Ceará – IFCE/Campus Sobral em vasos de polietileno distribuídos em arranjo fatorial de 3 x 2, sendo três níveis de sais (0,3; 1,5; e 3,0 dS m-1) e duas doses de composto orgânico (0,75 e 1,0 L vaso1) com quatro repetições. A coleta do material drenado se deu aos 30, 50, 75 e 90 dias após o transplantio de tomate – DAT. Na solução drenada avaliou-se o potencial hidrogeniônico – pH (usando pH-metro digital) e condutividade elétrica da solução lixiviada – CEs (usando condutivimétro digital). Os valores de CEs foram influenciados pelos diferentes níveis salinos, apresentando valores crescentes proporcionais ao aumento do nível salino. O pH sofreu influencia do diferentes períodos de coleta e dos diferentes níveis salinos, havendo também interação entre ambos. A matéria orgânica não apresentou influencia no pH e CEs dos resultados obtidos

Behavior of water in soil cultivated with sunflower under water stress

Various soil attributes allow inferring about their behavior and function in the environment. With this work, the objective was to analyze the behavior of water retention in the soil after irrigation suppression for the BRS 323 hybrid sunflower cultivation in a sandy loam soil. The experiment was conducted at the Agrometeorological Station of the Federal University of Ceará, Brazil, from August to November, 2015. The behavior of soil water was evaluated by means of the retention curve, available water content, grain size, total porosity, and soil particle density in the 0.0 to 0.20 m soil layer. The water in the depth of 0.0 – 0.10 m drains rapidly in relation to the 0.10 – 0.20 m depth between potentials from -0.1 to -1.500 kPa after irrigation suppression, in this depth, at -4 kPa, there was greater water retention along the curve. The maximum water retained in the soil at field capacity in the layer depths of 0.0 – 0.10 m and 0.10 – 0.20 m is: 0.195 cm3 cm-3 and 0.221 cm3 cm-3, respectively. The 0.10 – 0.20 m depth presented a larger volume of available water influenced by density and porosity. It was concluded that the water in the soil cultivated with sunflower, 80 days after the irrigation ceases, gradually drains into larger pores, then retained in the smaller pores, being limited to the plants in the soil layer

Análise dos elementos estruturais físicos, pedagógicos e metodológicos de escolas ribeirinhas amazônicas

A construção de usinas hidrelétricas nos leitos dos rios amazônicos tornou-se uma saída para o déficit energético no Brasil, porém para que fossem sanadas as deficiências energéticas algumas ações causaram impactos decorrentes de suas construções, com destaque para o remanejamento, comumente decorrente do alagamento que surge às margens dos rios onde populações tradicionais geralmente habitam. Sendo assim, este artigo busca analisar os elementos: estruturais físicos e pedagógicos metodológicos, utilizados pelos professores de escolas localizadas em comunidades ribeirinhas amazônicas atingidas pela construção de usinas hidrelétricas. Destacamos que o cenário educacional da Amazônia, não abrange apenas a mudança da estrutura física das escolas; implica, as estruturas pedagógicas e metodológicas desenvolvidas pelos professores. O estudo ainda busca contextualizar o cenário amazônico onde situam-se escolas ribeirinhas amazônicas que foram atingidas pela construção de usinas do Madeira, com isso, identificando os elementos estruturais pedagógicos e metodológicos relacionados a ambientes educacionais ribeirinhos. Vale salientar que a educação na Amazônia precisa de visibilidade, para que seja tratada de forma particular, dadas as suas singularidades, onde as maiores mudanças atingem a conjuntura humana, especialmente, o processo educativo

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Computational system to create an entry file for replicating I-125 seeds simulating brachytherapy case studies using the MCNPX code

Purpose: A computational system was developed for this paper in the C++ programming language, to create a 125I radioactive seed entry file, based on the positioning of a virtual grid (template) in voxel geometries, with the purpose of performing prostate cancer treatment simulations using the MCNPX code.Methods: The system is fed with information from the planning system with regard to each seed’s location and its depth, and an entry file is automatically created with all the cards (instructions) for each seed regarding their cell blocks and surfaces spread out spatially in the 3D environment. The system provides with precision a reproduction of the clinical scenario for the MCNPX code’s simulation environment, thereby allowing the technique’s in-depth study.Results and Conclusion: The preliminary results from this study showed that the lateral penumbra of uniform scanning proton beams was less sensitive In order to validate the computational system, an entry file was created with 88 125I seeds that were inserted in the phantom’s MAX06 prostate region with initial activity determined for the seeds at the 0.27 mCi value. Isodose curves were obtained in all the prostate slices in 5 mm steps in the 7 to 10 cm interval, totaling 7 slices. Variance reduction techniques were applied in order to optimize computational time and the reduction of uncertainties such as photon and electron energy interruptions in 4 keV and forced collisions regarding cells of interest. Through the acquisition of isodose curves, the results obtained show that hot spots have values above 300 Gy, as anticipated in literature, stressing the importance of the sources’ correct positioning, in which the computational system developed provides, in order not to release excessive doses in adjacent risk organs. The 144 Gy prescription curve showed in the validation process that it covers perfectly a large percentage of the volume, at the same time that it demonstrates a large decline for short distances.------------------------------Cite this article as: Boia LS, Junior J, Menezes AF, Silva AX. Computational system to create an entry file for replicating I-125 seeds simulating brachytherapy case studies using the MCNPX code. Int J Cancer Ther Oncol 2014; 2(2):02023.DOI: http://dx.doi.org/10.14319/ijcto.0202.3</p