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

Barriers to Social Participation in Caregivers of Older People: A Systematic Review

Some aspects of care contribute for decreased quality of life, health status and well-being among caregivers of older people. Care conditions may affect caregivers’ social participation increasing the odds of those negative outcomes. Then, to maintain a high level of social engagement configures a strategy to protect caregivers against burden and allow them to provide a better care. This study aimed at investigates what are the barriers to social participation in caregivers of older people. A systematic review of the literature was performed in PubMed, Web of Science, PsycINFO and Abstracts in Social Gerontology databases, using social participation, social involvement, social engagement, social activities, social relations, elderly, aged, aging, older people, seniors and caregivers as terms. Twenty-three articles fit the inclusion and exclusion criteria. The barriers to social participation were: characteristics and tasks related to care, caregiver’s mental health, low social support, sex, care receiver’s health, concurrent paid work, age, caregiver’s physical health, financial situation, education  and quality of life. Those barriers need to be approached by professionals and politicians in order to prevent social isolation and promote better quality of life among caregivers

Interviews with artists as a device for contention and the discursive dispute in the 1960s and 1970s

This article proposes to reflect on the role of interviews with artists as a contention device in the interaction between two subjects, considering that the desire to apprehend works of art through their various ways turns the artist’s word into a privileged object. That can be seen by understanding the context of the 1960s/1970s, when a discursive dispute took place in the field of art as artists claim speech spaces. Artists’ words are not the truth about their works, since they are as historically, socially and culturally determined as the works themselves; therefore, interviews can be seen as mechanisms that open meaning-making and expand it in the crossing of internal and external views about artistic practice

Prevalencia de males tratos en niños del 1º al 4º grado de la ciudad de Ribeirão Preto-SP

O presente estudo buscou mensurar a prevalência de maus-tratos em crianças matriculadas de 1ª a 4ª série em escolas da rede pública e particular da cidade de Ribeirão Preto-SP, Brasil, a partir de informações do setor da educação. A investigação adotou uma abordagem descritiva, de caráter epidemiológico. O instrumento utilizado para a coleta de dados foi a Cartilha Epidemiológica, aplicada junto aos professores para obter informações sobre o número e as características de casos suspeitos de maus-tratos presentes em sua sala de aula. A amostra aleatória e estratificada foi composta por 151 professores responsáveis por 3.885 crianças. A prevalência obtida foi de 3,9% e as categorias de maus-tratos mais freqüentes foram: Maltrato Emocional, Abandono Emocional e Falta de Controle Parental. A prevalência oficial para a mesma faixa etária foi de 0,36% confirmando as indicações da literatura quanto ao fato de os dados oficiais serem somente a ponta do iceberg.This study aimed to estimate the prevalence of maltreatment in children, enrolled in 1st to 4th grades in Public and Private schools in Ribeirão Preto-SP, Brazil, using information from the field of education. This is a descriptive study with epidemiological framework. Teachers were interviewed through the instrument Cartilha Epidemiológica (Epidemiological Booklet). It collected information on the number and characteristics of maltreated children attending these teachers' classes. An epidemiological descriptive approach was used to analyze data and 151 teachers, who were responsible for 3,885 children, answered the instrument. The results appointed a prevalence of 3.9%. The most frequent types of child maltreatment were: Emotional Maltreatment, Emotional Abandonment and Lack of Parental Supervision. Official data indicates a prevalence of 0.36%, which is in agreement with literature suggestions that official data report just the tip of iceberg.El actual estudio se propuso evaluar la prevalencia de los malos tratos en niños matriculados del 1º al 4º grado de escuelas públicas y particulares en la ciudad de Ribeirão Preto-SP, Brasil, partir de informaciones del sector educativo. La investigación adoptó un abordaje descriptivo, de carácter epidemiológico. El instrumento utilizado para la colecta de datos fue la Cartilha Epidemiológica (Cartilla Epidemiológica), que fue aplicada a los profesores para obtener informaciones de número y características de acontecimientos de malos tratos conocidos en sus clases. La muestra aleatoria y estratificada fue compuesta por 151 profesores responsables por 3.885 niños. La prevalencia obtenida fue de 3,9% y los tipos de malos tratos más frecuentes fueron: Maltrato emocional, Abandono emocional y Falta de control de los padres. La prevalencia oficial para la misma faja de edad fue de 0,36% confirmando las indicaciones de la literatura cuanto al hecho de los datos oficiales sean solamente la punta de un iceberg

Evolução e análise funcional de uma domus romana. A unidade habitacional da zona arqueológica das “antigas Cavalariças” de Braga

This work aims to give notice of the characteristics and evolution of a Roman domus in Bracara Augusta city, based on the results of the excavations conducted by the Unit of Archaeology at the University of Minho in the archaeological area of ‘Antigas Cavalariças de Braga’. The plentiful of data resulting from the excavations allowed to functionally analyze some of the domus spaces that have been described in accordance with its architectural evolution, between the flavian period and Late Antiquity. As a result different planimetric proposals for the various phases of the building are discussed and it is expected to contribute to a better understanding the Roman domestic architecture in Bracara Augusta.Instituto de Estudios Medievales de la Universidad de LeónUnidade de Arqueologia de la Universidade do Minh

UASB reactor in residual wastewater treatment - dairy industry

The discharge of wastewater into water bodies is still quite common in developing countries, such as the case of Angola. The application of the UASB reactor - Upflow Anaerobic Sludge Blanket process is presented as a viable alternative to be used, given the characteristics of the domestic / industrial wastewater to be treated and local economic needs. Thus, this study was developed with an anaerobic treatment technology using an UASB reactor, analysing its effectiveness in relation to the removal of organic matter and solids, evaluating the application of different volumetric organic loads under conditions similar to the real ones, in a laboratory pilot plant. The UASB reactor shaping a “Y” was constructed with PVC and a useful volume of 12 litres; it was designed to operate at steady state at a temperature around 35ºC. The most promising results showed COD removal efficiencies of approximately 76%, BOD 79% and TSS 88%.Apresentação financiada pela FCT e FEDER ao abrigo do Programa PT2020 (Projeto UID/EQU/50020/2013).info:eu-repo/semantics/publishedVersio

Tratamento de efluente da indústria de lacticínios usando reator UASB

A descarga de águas residuais sem tratamento nos ecossistemas aquáticos ainda é bastante frequente nos países em desenvolvimento, como é o caso de Angola. A aplicação de um reator de leito de lamas de escoamento ascendente (UASB – Upflow Anaerobic Sludge Blanket) apresenta-se como uma alternativa viável a ser adoptada, atendendo às características do efluente doméstico/industrial a tratar e as necessidades económicas locais. Neste contexto, desenvolveu-se um estudo com uma tecnologia de tratamento anaeróbio usando um reator UASB, analisando a sua eficácia relativamente à remoção de matéria orgânica e sólidos, avaliando a aplicação de diferentes cargas volumétricas, sob condições próximas das reais, numa instalação piloto laboratorial. O reator UASB foi construído em PVC com configuração em "Y" e volume útil de 12 L. Registaram-se eficiências de remoção de 76% de CQO, 79% de CBO5 e 88% para os SST.info:eu-repo/semantics/publishedVersio

Currículo por campos de experiência na educação infantil: ainda é possível preservar o ensino desenvolvente?

This paper presents a general characterization and critical examination of what the current Brazilian legislation for Early Childhood Education imposes, with the aim of exploring possible paths for the formulation of curricular proposals of historical-critical orientation in the face of the notion of “experience fields”. Based on the analysis of the chapter of the “Base Nacional Comum Curricular” (National Common Curricular Base) dedicated to Early Childhood Education and the document "Campos de experiências: efetivando direitos e aprendizagens na Educação Infantil" (Experience fields: assuring rights and learning in Early Childhood Education), launched in 2018, valid aspects are identified at the same time as the persistence of the anti-schooling approach and its liberal and idealistic conception of education is problematized. The paper concludes with the search for possible paths for pedagogical work, by focusing children's experiences and their contents.El artigo efectúa la caracterización general y el examen crítico del que impone la legislación actual para la educación de niños menores de seis años en Brasil, con el objetivo de búsqueda de caminos posibles para la formulación de proposiciones curriculares de orientación histórica-crítica frente a la vigencia de la noción de “campos de experiencia”. El análisis del capítulo de la Base Nacional Común Curricular dedicado a la Educación Infantil y del documento “Campos de experiencias: garantizando derechos y aprendizaje en la Educación Infantil”, de 2018, lleva a la identificación de aspectos válidos y problematización de la persistencia del enfoque anti-escolar y de la concepción liberal y idealista de educación. El artigo se concluye con la exploración de caminos posibles para el trabajo pedagógico, focalizando las experiencias infantiles y sus contenidos.O presente artigo efetua a caracterização geral e o exame crítico daquilo que impõe a legislação atual para a Educação Infantil, com o objetivo explorar caminhos possíveis para a formulação de propostas curriculares de orientação histórico-crítica diante da vigência da noção de “campos de experiência”. A partir da análise do capítulo da Base Nacional Comum Curricular dedicado à Educação Infantil e do documento “Campos de experiências: efetivando direitos e aprendizagens na Educação Infantil”, de 2018, identificam-se aspectos válidos e problematiza-se a persistência do enfoque antiescolar e da concepção liberal e idealista de educação. Conclui-se com busca de caminhos possíveis para o trabalho pedagógico colocando em tela as experiências infantis e seus conteúdos