854 research outputs found
Towards EPID-based 3D in vivo dosimetry for modern radiation therapy
Modern radiotherapy techniques, such as Intensity Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT), can deliver highly conformal dose distributions, with steep dose gradients between the target and organs at risk. This increases the demands on proper quality assurance and dose verification before (pre-treatment) and during (in vivo) patient irradiation. This project proposes a methodology for EPID-based in vivo dosimetry, combining the accuracy of Monte Carlo (MC) methods for dose simulation in patient geometry, with the time-efficiency of deep neural networks. The Deep Dose Estimation (DDE) network, originally developed for dose estimation in radiological computed tomography (CT) exams, has been extended and trained to predict 3D dose distributions due to IMRT fields, inside a patient, with accuracy comparable to MC methods.
The DDE uses as input a patient CT image and an approximated dose distribution,
called first order dose approximation (FOD), reconstructed from simulated EPID signals. The network was trained to map this two-channel input to an accurate dose distribution (ADD) inside the same patient CT, simulated using MC methods. The FODs are simplified 3D dose distributions produced as backprojections of the simulated EPID signals, accounting for magnification and inverse square law corrections, and attenuation through the virtual patient model. The FODs do not account for several effects, such as the build-up, beam hardening and scattering within the patient, all of which were properly considered in the ADDs.
Hence, the methodology relies strongly on the MC model used to produce both the
ADD and the transmitted EPID signals. A reliable MC model of the linac considered in this work was constructed and extensively validated. The patient-dependent part of the linac head, namely the multi-leaf collimator (MLC) system, was produced based entirely on information available in the literature. A virtual model of the EPID was also included in the patient-dependent part, to simultaneously record the transmitted signal through the virtual patient. The patient-independent part, i.e. the static parts of the linac head, was constructed based on confidential information provided by the vendor, and used to produce phase space (PhSp) files. These PhSp files were subsequently used as primary particle generators to simulate the ADDs and EPID signals. An alternative methodology for optimization of existing IAEA PhSp files was developed as a side project, which can be used to model the patient-independent part of the linac head when confidential vendor information is not available.
The ADDs for clinical prostate IMRT fields, and respective transmitted EPID signals,
were simulated inside 83 pelvic CTs, with gantry at 0�. In total, 581 different ADD-FOD sets were produced, with seven different fields per patient CT. The network was trained using the data sets of 67 patients (training set). The data of the remaining 16 patients were used for validation (test set). An additional dataset with eight fields simulated with gantry at 90� (lateral set) was used for evaluating the performance of the trained DDE for other irradiation directions.
The quality of the DDE-predicted dose distributions (DDEP) on the test and lateral
sets was quantified in terms of the gamma analysis with respect to the ADD (3%, 2 mm criteria). To evaluate the improvement obtained with the DDE, the same evaluation was performed for FODs and respective ADDs. The gamma passing rates between FODs and ADDs were as low as 46%, while for DDEPs the passing rates were above 97% for all fields on the test set. For the fields in the lateral set, the DDE was able to improve the passing rates from 88% to above 95%. The high passing rates for DDEPs indicate that the DDE was able to convert the FODs into ADDs, properly accounting for all missing effects. Moreover, once trained, the DDE can predict the dose inside a patient CT within 0.6 s per field (using a GPU), in contrast to 14 h needed for MC simulations (using a CPU-cluster). The dose delivered to a patient due to an entire prostate treatment session can therefore be predicted in less than one minute. With the proposed methodology, 3D in vivo dose
distributions due to clinical patient irradiation can be obtained within seconds, potentially paving the way towards a clinically viable, real-time EPID-based in vivo dosimetry
Manual de etnobotânica
Trata-se de uma resenha de um Manual de etnobotânica recém-lançado, em português, baniwa e tukano. É discutida a abordagem proposta, à luz da Terminologia etnográfica, portanto, focada nos Estudos do Léxico de lÃnguas amerÃndias
ACTUACIÓN DE LOS PROFESIONALES DE SALUD EN LA REALIZACIÓN DE LAS ACCIONES A FAVOR DEL AMAMANTAMIENTO: REVISIÓN DE LA LITERATURA
Revisão integrativa da literatura com o objetivo de investigar o conteúdo da produção cientÃfica acerca das práticas dos profissionais na implementação da Iniciativa Hospital Amigo da Criança. A seleção dos artigos foi realizada em outubro de 2012, nas bases de dados LILACS e MEDLINE. Foram identificados 187 estudos e, após a aplicação dos critérios de inclusão e exclusão, foram analisados sete artigos. A análise de dados foi realizada a partir da categorização em unidades temáticas, com identificação de variáveis de interesse e conceitos chaves e possibilitou a identificação de três temáticas: oimpacto da implantação da Iniciativa Hospital Amigo da Criança; a consolidação dos Dez Passos Para o Sucesso do Aleitamento Materno; a prática profissional voltada para a promoção do aleitamento materno.Verifica-se que a prática profissional ainda se apresenta de forma reducionista, o que evidencia a necessidade da revisão.This integrative literature review aims to investigate the content of the scientific production regarding professionals’ practices in the implementation of the Baby Friendly Hospital Initiative. The articles were selected in October 2012, in the LILACS and MEDLINE databases. 187 studies were identified; after the application of the inclusion and exclusion criteria, seven articles were analyzed. Data analysis was undertaken based on categorization in thematic units, with identification of the variables of interest and key concepts, allowing the identification of three issues: The impact of the implantation of the Baby Friendly Hospital Initiative; The consolidation of the Ten Steps to Successful Breastfeeding; and The professional practice directed at the promotion of breastfeeding. It is ascertained that the professional practice is still presented in a reductionist form, which evidences the need for the review.Revisión integrativa de la literatura que tuvo la finalidad de investigar el contenido de la producción cientÃfica acerca de las prácticas de los profesionales en la implementación de la Iniciativa Hospital Amigo da Criança. La selección de los artÃculos fue realizada en octubre de 2012, en las bases de datos LILACS y MEDLINE. Fueron identificados 187 estudios y, después de la aplicación de los criterios de inclusión y exclusión, fueron analizados siete artÃculos. El análisis de datos fue realizada considerando la categorización en unidades temáticas, con identificación de variables de interés y conceptos claves y ha posibilitado la identificación de tres temáticas: el impacto de la implantación de la Iniciativa Hospital Amigo da Criança; la consolidación de los Diez Pasos Para el Suceso del Amamantamiento Materno; la práctica profesional para la promoción del amamantamiento materno.Se verifica que la práctica profesional todavÃa se presenta de forma reducionista, lo que muestra la necesidad de la revisión.
A PALAVRA EM MOVIMENTO NO ROMANCE OUTROS CANTOS, DE MARIA VALÉRIA REZENDE: MAIS QUE UM FILME PROJETADO FORA DA ORDEM
A definição de uma linguagem própria no cinema deve muito à literatura, especialmente naquilo que se tornou seu elemento essencial: a montagem. Ao longo de sua breve história, no entanto, o cinema soube retribuir essa contribuição, emprestando à escrita literária vários dos elementos constitutivos de sua linguagem. O artigo discute a presença de técnicas do fazer fÃlmico no romance Outros Cantos, de Maria Valéria Rezende (2016), a partir de estudos de Leone e Mourão (1987), Vieira (2007), Xavier (2003), entre outros. As articulações que a autora promove, na narrativa, seja na montagem de imagem e sons, na alternância de planos e ângulos, e na descrição de imagens, possibilitam ao leitor, em muitos momentos, a sensação de estar diante de um filme
Salvamento de Bracara Augusta: projeto de reabilitação do Claustro e da Domus Romana no Seminário Conciliar de S. Pedro e S. Paulo (Seminário Conciliar de S. Pedro e S. Paulo e Museu Pio XII/ Braga)
Os trabalhos arqueológicos realizados no Seminário Conciliar de S. Pedro e S. Paulo e
no Museu Pio XII, de Braga, inseriram-se no âmbito do ‘Projeto de Reabilitação do Claustro e da domus romana no Seminário Conciliar de S. Pedro e S. Paulo’. Este projeto visa a revalorização do conjunto de ruÃnas romanas identificado em 1966 no referido claustro, através de uma nova
cobertura e de uma melhor contextualização dos vestÃgios já conhecidos, tendo em vista torná-los visitáveis e mais compreensÃveis para o público, através da criação de um núcleo
arqueológico interpretado. O supramencionado projeto pretende ainda criar uma maior
articulação entre as ruÃnas romanas do Seminário e o acervo arqueológico do Museu Pio XII, garantindo-se, por essa via, uma melhor integração dos dois conjuntos patrimoniais.info:eu-repo/semantics/publishedVersio
O papel do gestor escolar nos conselhos escolares: um olhar a partir de seus membros
http://dx.doi.org/10.18316/2237-8049.2016.4 O artigo trata do papel do Gestor Escolar nos Conselhos Escolares, levando em consideração a perspectiva democrática de gestão. Trata-se de um Estudo de Caso, na modalidade quali-quantitativo, tendo por instrumentos para a coleta de dados um questionário, análise documental e diário de campo. Os respondentes são os segmentos que formam o Conselho Escolar, a saber: pais, professores e direção das 31 Escolas Municipais de Educação Infantil do municÃpio de Canoas, Rio Grande do Sul, Brasil. Os resultados classificam e reforçam a noção de hierarquização do gestor escolar como o grande responsável pela gestão de sua instituição, mesmo este sendo apenas um membro do Conselho Escolar, em que a paridade é uma das premissas legais. De fato, as demandas da escola para a comunidade ou mesmo com a mantenedora e deliberações diversas recaem, na maioria das vezes, sobre o gestor escolar, quando, de direito e dever, caberia a todo o Conselho Escolar. Conclui-se pela necessidade da oferta de programas de formação e capacitação de todos os membros do Conselho Escolar para sua efetividade. Palavras-chave: Gestão escolar. Gestor escolar. Conselhos escolares. Gestão democrática. The role of the school manager in school councils: a view from their members AbstractThe article deals with the School Manager role in School Boards, taking into account the democratic management perspective. It is a Case Study, in the qualitative and quantitative form, having as instruments for data collection a questionnaire, documentary analysis and field diary. The respondents are the segments that form the School Board, namely: parents, teachers and managers of the 31 Municipal Schools of Early Childhood Education of Canoas, Rio Grande do Sul, Brazil. The results classify and reinforce the notion of the hierarchy of school management as the primary responsible for its management, even being only a member of the School Board, where parity is one of  legal premises. Indeed, the school's demands for the community or even with the sponsor and various decisions fall, in most cases, on the school manager as of right and duty would fit the entire School Board. The results confirmed the need for the provision of training programs and training of all members of the School Board for its effectiveness. Keywords: School management. School manager. School boards. Democratic management
Antibodies For Rickettsia Spp. In Patients With Negative Serology For Dengue Virus, Leptospirosis, And Meningococcal Disease In Municipalities Of Sao Paulo State, Brazil
Brazilian spotted fever is an infectious disease with a high mortality rate if not treated early. Differential diagnosis is difficult, as the first clinical signs are non-specific and can be confused with other diseases. The aim of the study was to investigate evidence of infection with Rickettsia rickettsii and Rickettsia parkeri in negative sera samples, collected in 2014, from patients with suspected leptospirosis, dengue fever, and meningococcal disease in Atibaia and Braganca Paulista municipalities of the State of Sao Paulo. Methods: The samples stored at the Institute Adolfo Lutz in Campinas were tested using an indirect immunofluorescence assay (IFA) with IgG and IgM against R. rickettsii and R. parkeri. Real-time polymerase chain reaction (PCR) testing was performed for the sera samples of patients who died (n = 3), those with initial suspicion of meningococcal disease (n = 6), and those with positive IFA results. Results: Of 258 samples from Braganca Paulista, 4 (1.6%) were positive, with IgG titers of 1: 64 and 1: 128 against R. rickettsii and R. parkeri, respectively. Of 155 samples from Atibaia, 2 (1.3%) were positive, with IgG titers of 1: 64 and 1: 128 against R. rickettsii and R. parkeri, respectively. No sample showed positive PCR results. Conclusions: This serological investigation suggests there is evidence of exposure to Rickettsia spp. in residents of areas that have environmental conditions favorable to the spread of bacteria, in which Brazilian spotted fever incidence was not previously confirmed.49556757
Endividamento de longo prazo e desempenho em tempos de crise: evidências de empresas no Brasil e América Latina
This study aimed at examining the effect of long-term debt on the performance of Brazilian and Latin American companies, encompassing the previous economic scenario, during and after the global crisis of 2008. It was considered in this study the accounting data from public companies listed in stock exchanges of Brazil, Chile, Argentina, Colombia, Mexico and Peru within the period of 2007 to 2015. It was elaborated a multiple linear regression model with panel data based on the literature of the subject. It was used Stata software for data analysis. The results indicated that for companies from Latin America, except Brazilians, there is a negative relationship between long-term debt and performance. In the case of Brazilian companies, for such relationship, the results were inconclusive.Este trabalho teve como objetivo examinar o efeito do endividamento de longo prazo no desempenho de empresas brasileiras e latino-americanas, de modo a abranger o cenário econômico anterior, durante e após a crise mundial de 2008. Considerou-se no estudo os dados contábeis referentes à s companhias abertas listadas nas Bolsas de Valores do Brasil, Chile, Argentina, Colômbia, México e Peru, durante o perÃodo compreendido entre 2007 e 2015. Foi elaborado um modelo de regressão linear múltipla com dados em painel baseados na literatura sobre o tema. O software Stata foi utilizado para a análise dos dados. Os resultados indicaram que para as empresas da América Latina, exceto para as do Brasil, existe relação negativa entre o endividamento de longo prazo e o desempenho. No caso das empresas brasileiras, para tal relação, os resultados se mostraram inconclusivos
Avaliação e tratamento fÃsioterápico da incontinência urinaria de esforço: estudo de caso
Though a literature review about the evaluation and treatment of stress urinary incontinence using vaginal cones and pelvic floor's exercises. A case report was made to compare and adequate this treatment to the attendance at the physical therapy ambulatory ofthe Hospital Universitário Regional do Norte do Paraná, having in mind the social-cultural conditions ofthe observed patients and the avaiable resourses in these servise, with the objective to create in attendence ambulatorial register and to compare our results to the literature wich shows dialy vaginal cones aplication by themselves at home. This procedure is unviable to our service's and patient's reality. The results of this study showed a more reliable evaluation about the pelvic floor's muscle power and a treatment with a satisfactory result applied at the ambulatory twice a week. The gained results allowed the achievment of in attendence register about patients with stress urinary incontinence and, a research project that has been developed.Através de uma revisão da literatura sobre a avaliação e tratamento da Incontinência Urinaria de Esforço (IUE), utilizando cones vaginais e exercÃcios do assoalho pélvico, realizou-se um estudo de caso para comparação e adequação deste tratamento à realidade do atendimento no Ambulatório de Fisioterapia do Hospital Universitário Regional do norte do Paraná, tendo em vista as condições sócioculturais das pacientes atendidas e os recursos disponÃveis neste serviço, com objetivo de criar um protocolo de atendimento ambulatorial e comparar os resultados obtidos com os encontrados na literatura, que nos mostra uma aplicação diária dos cones vaginais pela própria paciente, em sua casa, sendo esta medida inviável a realidade do nosso serviço e das pacientes atendidas neste setor. O resultado deste estudo demonstrou uma avaliação mais fidedigna da força muscular do assoalho pélvico e um tratamento com resultado satisfatório aplicado no ambulatório, duas vezes por semana. Os resultados obtidos propiciaram a realização de um protocolo de atendimento a pacientes com Incontinência Urinaria de Esforço e um Projeto de pesquisa que vem sendo desenvolvido
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