Semi-automatic 3D Segmentation Of Costal Cartilage In CT Data From Pectus Excavatum Patients

One of the current frontiers in the clinical management of Pectus Excavatum (PE) patients is the prediction of the surgical outcome prior to the intervention. This can be done through computerized simulation of the Nuss procedure, which requires an anatomically correct representation of the costal cartilage. To this end, we take advantage of the costal cartilage tubular structure to detect it through multi-scale vesselness filtering. This information is then used in an interactive 2D initialization procedure which uses anatomical maximum intensity projections of 3D vesselness feature images to efficiently initialize the 3D segmentation process. We identify the cartilage tissue centerlines in these projected 2D images using a livewire approach. We finally refine the 3D cartilage surface through region-based sparse field level-sets. We have tested the proposed algorithm in 6 noncontrast CT datasets from PE patients. A good segmentation performance was found against reference manual contouring, with an average Dice coefficient of 0.75±0.04 and an average mean surface distance of 1.69±0.30mm. The proposed method requires roughly 1 minute for the interactive initialization step, which can positively contribute to an extended use of this tool in clinical practice, since current manual delineation of the costal cartilage can take up to an hour.

Computer-aided recognition of dental implants in X-ray images

Dental implant recognition in patients without available records is a time-consuming and not straightforward task. The traditional method is a complete user-dependent process, where the expert compares a 2D X-ray image of the dental implant with a generic database. Due to the high number of implants available and the similarity between them, automatic/semi-automatic frameworks to aide implant model detection are essential. In this study, a novel computer-aided framework for dental implant recognition is suggested. The proposed method relies on image processing concepts, namely: (i) a segmentation strategy for semi-automatic implant delineation; and (ii) a machine learning approach for implant model recognition. Although the segmentation technique is the main focus of the current study, preliminary details of the machine learning approach are also reported. Two different scenarios are used to validate the framework: (1) comparison of the semi-automatic contours against implant’s manual contours of 125 X-ray images; and (2) classification of 11 known implants using a large reference database of 601 implants. Regarding experiment 1, 0.97±0.01, 2.24±0.85 pixels and 11.12±6 pixels of dice metric, mean absolute distance and Hausdorff distance were obtained, respectively. In experiment 2, 91% of the implants were successfully recognized while reducing the reference database to 5% of its original size. Overall, the segmentation technique achieved accurate implant contours. Although the preliminary classification results prove the concept of the current work, more features and an extended database should be used in a future work.

Processo de trabalho e grupos semi-autônomos: a evolução da experiência sueca de Kalmar aos anos 90

Este trabalho visa a apresentar o desenvolvimento recente de novas formas de organização da produção e do trabalho na Suécia, em especial no que se refere ao setor automotivo (ônibus, caminhões e automóveis). Apresentam-se em detalhes as características da mais recente planta do grupo Volvo, denominada Uddevalla, projetada segundo o conceito de dock-assembly. É introduzida também uma discussão sucinta acerca de semelhanças e diferenças entre esse caso e outros como, por exemplo, o da planta da Toyota no Japão. Por fim, procurase reforçar a importância da consideração de soluções novas - e adaptadas - ao caso brasileiro, no que diz respeito a formas de organização do trabalho que contribuam para aumento da produtividade (em um sentido amplo) dos sistemas de produção.

Teaching and learning production and operations management: the journey from identity crisis to a cross, disciplinary approach

Este artigo tem suas raízes em algumas questões relacionadas à "forma" e ao "conteúdo" do que nós, professores, ensinamos na área de Administração da Produção e Operações. Inicialmente, descrevo a evolução histórica desse campo no Brasil. Em seguida, discuto a crise de identidade que o campo está sofrendo. Com o objetivo de apresentar respostas para essa situação, apresento seis propostas para o desenvolvimento e consolidação do campo. Finalmente, descrevo uma iniciativa prática, envolvendo uma disciplina específica da área, ensinada para alunos de pós-graduação. Essa iniciativa enfatiza a "dimensão do conteúdo" (de uma abordagem técnico-operacional para uma abordagem estratégico-gerencial) como também a "dimensão da forma" (do foco no ensino para o foco no aprendizado). O sucesso dessa experiência em curso confirma a coerência da agenda proposta e induz futuros aperfeiçoamentos.

O professor frente aos processos de aprendizagem da leitura : o combate às dificuldades

RESUMO: A aprendizagem da leitura é uma conquista primordial na trajetória de vida de uma criança. A educação, atualmente, percorre grandes e diferentes discussões, e as dificuldades de aprendizagem na leitura são uma realidade visível, comprovadas através de pesquisas. Contudo devem ser vencidas. O presente estudo tem como proposta identificar as concepções e estratégias de um grupo de professores que atuam diretamente com o aluno no âmbito da aprendizagem formal da leitura, no processo do ato de ler. Conhecer as práticas pedagógicas que são desenvolvidas na sala de aula, as explicações para o sucesso e o insucesso na aprendizagem da leitura. A forma como o aluno aprende e verificar diretamente, a partir de um grupo de alunos, suas dificuldades de não saber ler, sentidas pelos próprios, e como o professor as soluciona, suas explicações encontradas para as dificuldades de aprendizagem, e o impacto que causam na vida pessoal e social do aprendente e do ensinante. Saber o que fazer e como fazer quando se descobrem falhas do aluno ou do método na compreensão da leitura é uma das características das mais desejáveis e essencial no desenvolvimento do ensino da leitura e uma das diferenças mais acentuadas entre professores aplicados e os destituídos de um compromisso sagrado no seu papel de educador. Para atender aos objetivos pretendidos, foram realizadas entrevistas semi–estruturadas, sustentadas por roteiros, com alunos (20) e professores (10) em duas escolas públicas municipais do ciclo fundamental na cidade de Aracaju. Os resultados apontam para um desconhecimento dos métodos e das teorias cognitivas. No que tange aos alunos percebe-se a dificuldade, sentida pelo próprio aluno em não saber ler, como algo corriqueiro. Os achados deste estudo nos fazem pensar que o professor munícipe precisa rever seus métodos e processos de educação, sem os quais continuaremos a assistir um sistema educacional desmotivado e indiferente ao desenvolvimento de competências e capacidades críticas no processamento da aprendizagem da leitura no primeiro ano do Ciclo Básico. ABSTRACT: The learning of reading is a prime achievement on the path of a child‟s life. Education, nowadays, courses large and different discussions and the learning difficulties are easily seen, proved by researches. However they must be overcome. This article has as proposal to identify the conceptions and strategies of a teacher‟s group that acts directly with the student in the area of formal learning of reading, it means the reading process. And also to know the teaching practices that are developed in classroom, the explanations to the achievement or failure of reading. The way how the student learns and to verify directly, based on a group of students, their difficulties experienced by themselves, and how the teacher solve those, his explanations about the difficulties that were found, and the impact they bring to learner‟s and teacher‟s personal and social lives. to know what to do and how to do when student‟s flaws or imperfections on the reading comprehension method are found is one of the most desirable and essential characteristics on the development of (he reading learning)and one of the most pointed differences by teachers concerned and unconcerned about their commitment to the teacher role. To attend to the claimed aims, it has been done semi structured interviews, held by a list of topics, with twenty students and ten teachers in two public schools in Aracaju city. The results show ignorance on the methods and theories. When it comes to the students it‟s easy to see that the difficulty is faced by those who can‟t read, as something normal. The results of this work make us think that the public teacher needs to review his methods and educational processes; otherwise we are going to continue watching an educational system despondent and unconcerned about the development of criticizing skills on the process of reading learning in Junior High.

Systems thinking: learning or driving?

The ability to foresee how behaviour of a system arises from the interaction of its components over time - i.e. its dynamic complexity – is seen an important ability to take effective decisions in our turbulent world. Dynamic complexity emerges frequently from interrelated simple structures, such as stocks and flows, feedbacks and delays (Forrester, 1961). Common sense assumes an intuitive understanding of their dynamic behaviour. However, recent researches have pointed to a persistent and systematic error in people understanding of those building blocks of complex systems. This paper describes an empirical study concerning the native ability to understand systems thinking concepts. Two different groups - one, academic, the other, professional – submitted to four tasks, proposed by Sweeney and Sterman (2000) and Sterman (2002). The results confirm a poor intuitive understanding of the basic systems concepts, even when subjects have background in mathematics and sciences.

A Feedback Learning and Mental Models Perspective on Strategic Decision Making

This study aims to be a contribution to a theoretical model that explains the effectiveness of the learning and decision-making processes by means of a feedback and mental models perspective. With appropriate mental models, managers should be able to improve their capacity to deal with dynamically complex contexts, in order to achieve long-term success. We present a set of hypotheses about the influence of feedback information and systems thinking facilitation on mental models and management performance. We explore, under controlled conditions, the role of mental models in terms of structure and behaviour. A test based on a simulation experiment with a system dynamics model was performed. Three out of the four hypotheses were confirmed. Causal diagramming positively influences mental model structure similarity, mental model structure similarity positively influences mental model behaviour similarity, and mental model behaviour similarity positively influences the quality of the decision.

Systems thinking: learning or driving?

The ability to foresee how behaviour of a system arises from the interaction of its components over time - i.e. its dynamic complexity – is seen an important ability to take effective decisions in our turbulent world. Dynamic complexity emerges frequently from interrelated simple structures, such as stocks and flows, feedbacks and delays (Forrester, 1961). Common sense assumes an intuitive understanding of their dynamic behaviour. However, recent researches have pointed to a persistent and systematic error in people understanding of those building blocks of complex systems. This paper describes an empirical study concerning the native ability to understand systems thinking concepts. Two different groups - one, academic, the other, professional – submitted to four tasks, proposed by Sweeney and Sterman (2000) and Sterman (2002). The results confirm a poor intuitive understanding of the basic systems concepts, even when subjects have background in mathematics and sciences.

A Feedback Learning and Mental Models Perspective on Strategic Decision Making

This study aims to be a contribution to a theoretical model that explains the effectiveness of the learning and decision-making processes by means of a feedback and mental models perspective. With appropriate mental models, managers should be able to improve their capacity to deal with dynamically complex contexts, in order to achieve long-term success. We present a set of hypotheses about the influence of feedback information and systems thinking facilitation on mental models and management performance. We explore, under controlled conditions, the role of mental models in terms of structure and behaviour. A test based on a simulation experiment with a system dynamics model was performed. Three out of the four hypotheses were confirmed. Causal diagramming positively influences mental model structure similarity, mental model structure similarity positively influences mental model behaviour similarity, and mental model behaviour similarity positively influences the quality of the decision

Mortality problems in Brazil and in Germany: past-present-future. Learning from each other?

This article was written by a Swiss-German historical demographer after having visited different Brazilian Universities in 1984 as a guest-professor. It aims at promoting a real dialog between developed and developing countries, commencing the discussion with the question: Can we learn from each other? An affirmative answer is given, but not in the superficial manner in which the discussion partners simply want to give each other some "good advice" or in which the one declares his country's own development to be the solely valid standard. Three points are emphasized: 1. Using infant mortality in S. Paulo from 1908 to 1983 as an example, it is shown that Brazil has at its disposal excellent, highly varied research literature that is unjustifiably unknown to us (in Europe) for the most part. Brazil by no means needs our tutoring lessons as regards the causal relationships; rather, we could learn two things from Brazil about this. For one, it becomes clear that our almost exclusively medical-biological view is inappropriate for passing a judgment on the present-day problems in Brazil and that any conclusions so derived are thus only transferable to a limited extent. For another, we need to reinterpret the history of infant mortality in our own countries up to the past few decades in a much more encompassing "Brazilian" sense. 2. A fruitful dialog can only take place if both partners frankly present their problems. For this reason, the article refers with much emprasis to our present problems in dealing with death and dying - problems arising near the end of the demographic and epidemiologic transitions: the superanuation of the population, chronic-incurable illnesses as the main causes of death, the manifold dependencies of more and more elderly and really old people at the end of a long life. Brazil seems to be catching up to us in this and will be confronted with these problems sooner or later. A far-sighted discussion already at this time seems thus to be useful. 3. The article, however, does not want to conclude with the rather depressing state of affairs of problems alternatingly superseding each other. Despite the caution which definitely has a place when prognoses are being made on the basis of extrapolations from historical findings, the foreseeable development especially of the epidemiologic transition in the direction of a rectangular survival curve does nevertheless provide good reason for being rather optimistic towards the future: first in regards to the development in our own countries, but then - assuming that the present similar tendencies of development are stuck to - also in regard to Brazil.

A bot spooler architecture to integrate virtual worlds with e-learning management systems for corporate training

Joining efforts of academic and corporate teams, we developed an integration architecture - MULTIS - that enables corporate e-learning managers to use a Learning Management System (LMS) for management of educational activities in virtual worlds. This architecture was then implemented for the Formare LMS. In this paper we present this architecture and concretizations of its implementation for the Second Life Grid/OpenSimulator virtual world platforms. Current systems are focused on activities managed by individual trainers, rather than groups of trainers and large numbers of trainees: they focus on providing the LMS with information about educational activities taking place in a virtual world and/or being able to access within the virtual world some of the information stored in the LMS, and disregard the streamlining of activity setup and data collection in multi-trainer contexts, among other administrative issues. This architecture aims to overcome the limitations of existing systems for organizational management of corporate e-learning activities.

Learning and Knowledge in the Context of Absorptive Capacity

Develop a new model of Absorptive Capacity taking into account two variables namely Learning and knowledge to explain how companies transform information into knowledge

A supervised versus home-based program effects on liver transplanted familial amyloidotic polyneuropathy patients: walking, fatigue and quality of life

Purpose: To evaluate the effects of a six months exercise training program on walking capacity, fatigue and health related quality of life (HRQL). Relevance: Familial amyloidotic polyneuropathy disease (FAP) is an autossomic neurodegenerative disease, related with systemic deposition of amyloidal fibre mainly on peripheral nervous system and mainly produced in the liver. FAP often results in severe functional limitations. Liver transplantation is used as the only therapy so far, that stop the progression of some aspects of this disease. Transplantation requires aggressive medication which impairs muscle metabolism and associated to surgery process and previous possible functional impairments, could lead to serious deconditioning. Reports of fatigue are common feature in transplanted patients. The effect of supervised or home-based exercise training programs in FAP patients after a liver transplant (FAPTX) is currently unknown.

A supervised versus home-based program effects on liver transplanted familial amyloidotic polyneuropathy patients: walking, fatigue and quality of life

Familial amyloidotic polyneuropathy is a systemic deposition of amyloidal fibre mainly on peripheral nervous system (but also in other systems like heart, gastrointestinal tract, kidneys, etc) and mainly produced in the liver. Purpose of this study: to evaluate the effects of a six months exercise training program(supervised or home-based) on walking capacity, fatigue and health related quality of life (HRQL) on Familial Amyloidotic Polyneuropathy patients submitted to a liver transplant.

Prática do aleitamento materno em comunidades rurais do semi-árido baiano

Com o objetivo de conhecer p estabelecimento e duração do aleitamento materno total e exclusivo em comunidades rurais do Semi-Árido Baiano, Brasil, foram estudadas 226 crianças de O a 2 anos de idade, filhas de pequenos produtores rurais que vivem numa das regiões mais secas do nordeste brasileiro, de pobreza absoluta. Os dados referem-se a todas as crianças da família que à data do estudo tinham até 2 anos de idade. Os dados foram coletados por meio de formulários aplicados às mães ou responsáveis pelo menor, no período de 1988 a 1989. A tábua de vida foi o recurso estatístico utilizado para o cálculo da duração mediana do evento. Das 226 crianças que integraram o estudo, 91,6 iniciaram a amamentação ao peito. A duração mediana do aleitamento total foi de 90,28 dias e o aleitamento exclusivo apresentou duração mediana de 0,1 dia. Ainda que o estabelecimento da amamentação ao peito possa ser considerado alto, a duração mediana do aleitamento total foi extrememente curta, e o aleitamento exclusivo foi desprezível.