9,410 research outputs found
Capturing "attrition intensifying" structural traits from didactic interaction sequences of MOOC learners
This work is an attempt to discover hidden structural configurations in
learning activity sequences of students in Massive Open Online Courses (MOOCs).
Leveraging combined representations of video clickstream interactions and forum
activities, we seek to fundamentally understand traits that are predictive of
decreasing engagement over time. Grounded in the interdisciplinary field of
network science, we follow a graph based approach to successfully extract
indicators of active and passive MOOC participation that reflect persistence
and regularity in the overall interaction footprint. Using these rich
educational semantics, we focus on the problem of predicting student attrition,
one of the major highlights of MOOC literature in the recent years. Our results
indicate an improvement over a baseline ngram based approach in capturing
"attrition intensifying" features from the learning activities that MOOC
learners engage in. Implications for some compelling future research are
discussed.Comment: "Shared Task" submission for EMNLP 2014 Workshop on Modeling Large
Scale Social Interaction in Massively Open Online Course
Can maternal physical activity modulate the nutrition-induced fetal programming?
Existe considerável evidência para a indução de diferentes fenótipos em reposta às variações no ambiente fetal e neonatal. O aporte inadequado de nutrientes no período crítico do desenvolvimento está associado ao risco alto de doenças metabólicas na vida adulta, este fenômeno biológico é chamado de programação. A atividade física durante a gestação resulta em adaptações fisiológicas da mãe e no aumento da disponibilidade de nutrientes e oxigênio no espaço feto-placentário. Este trabalho tem como objetivo discutir os mecanismos da indução de programação fetal pela nutrição e o provável efeito modulador da atividade física durante a gestação. Foram utilizadas as bases de dados do Medline Pubmed, Lilacs e Bireme, com publicações entre 1990 até 2008. Os termos de indexação utilizados foram: nutrition, fetal programming, gestation, physical activity, physical exercise, metabolism. Em conclusão, o aporte inadequado de nutrientes programa o aparecimento de doenças metabólicas na vida adulta, enquanto que a atividade física durante a gestação aumenta a disponibilidade de nutrientes e oxigênio, repercutindo positivamente no crescimento fetal e no peso ao nascer.There is considerable evidence for the induction of different phenotypes by variations in fetal and neonatal environment. Undernutrition during this critical development period is associated with risk of metabolic disease in adult life; this biological phenomenon is termed programming. Physical activity during gestation results in maternal physiological adaptations and increased oxygen and nutrients in the fetoplacental compartment. The main goal of this work is to discuss the mechanisms of fetal programming induced by nutrition and the probable modulating effect of physical activity during gestation. Papers published between 1990 and 2008 listed in the Medline Pubmed, Lilacs and Bireme databases were used. The search keywords were: nutrition, fetal programming, gestation, physical activity, physical exercise, and metabolism. In conclusion, undernutrition can program the onset of metabolic diseases in adult life, while physical activity during gestation increases the availability of nutrients and oxygen for the fetus, thereby positively impacting fetal growth and birth weight
A ROOT Tool for 3D Event Visualization in ATLAS Calorimeters
The ATLAS (A Toroidal LHC ApparatuS) detector is being tested with cosmic rays before LHC (Large Hadron Collider) starts its full operation by the midle of the year 2008. For the ongoing commissioning phase, it is necessary to develop specific tools that can perform efficient cosmic ray data analysis. An important issue for final analysis is to provide a way to visualize cosmic muon tracks and the corresponding activated cells in the detector, so that one can check visually the coherence of the reconstructed data and seek for potential problems. This work presents a 3D visualization tool for cosmic muon track visualization based on activated cells in the highly segmented ATLAS calorimeter system. This tool was developed in the ROOT framework, which allows a smooth integration between specifics analyses from ATLAS community and the visualization tool. This tool uses the ROOT embedded geometry package to create the ATLAS calorimeter, cell by cell, and provides routines to fill calorimeter cells with the reconstructed data information. Energy thresholds can be set by the user so that only relevant information is displayed. The tool structure and some applicationand with reconstructed data are presented
Envisioning and evolving: Future evolution of the concept and the practice of service design
ervice Design is evolving from an emerging field, breaking new ground in the design and service research areas, to a more mature stage, developing a set of fundamental concepts, methods and principles that can provide the foundation for its further significance and impact in both research and practice. This paper reflects on the roots and recent evolution of service design in terms of fundamental concepts, methods and outcomes, taking into account the papers in the Envisioning and Evolving track. It considers how the growing interrelation with close fields of service research is introducing useful “contaminations” and reports how the Service perspective is revealing its potential to bring life to technical and entrenched systems. It goes on to argue that design should aim to bring services to life to prove its real, distinguishing value and contribution
Volumetric assessment of the dental crown for sex estimation by means of cone-beam computed tomography
Orientador: Francisco Haiter NetoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: A determinação do sexo possui um papel importante para a solução de casos forenses, principalmente quando há a necessidade de identificação de umgrande número de vítimas. Geralmente essa tarefa é realizada com base na análise do crânio e da pelve. No entanto, nas situações em que estas estruturas não podem ser analisadas, os dentes podem ser utilizados com este intuito, pois são geralmente preservados em virtude da sua maior resistência aos efeitos destrutivos post mortem e por apresentarem dimorfismo sexual. O dimorfismo sexual pode ser definido como a diferença em tamanho ou aparência entre os sexos masculino e feminino. No entanto, a acurácia na determinação do sexo depende do grau de dimorfismo sexual que varia em cada população. Desta forma, o objetivo deste estudo foi avaliar a acurácia na determinação do sexo em brasileiros por meio do volume da coroa dentária. A amostra foi selecionada após a análise de 300 volumes de TCFC adquiridos no aparelho Picasso Trio®, com os mesmos parâmetros de aquisição (80 kVp e 3.7mA) e tamanho de voxel (0.2mm). A amostra foi composta por 78 incisivos centrais superiores, 78 caninos superiores, 78 incisivos laterais inferiores e 78 caninos inferiores. Havia a mesma proporção entre indivíduos do sexo masculino e feminino com idades variando entre 8 e 36 anos. Um único examinador realizou a segmentação manual das coroas dentárias, utilizando o programa 3D slicer®. Após 15 dias, 20% da amostra foi reavaliada. Os dados foram analisados utilizando o teste de Mann-Whitney, o teste t não pareado, a correlação de Pearson, a regressão logística Backward Stepwise condicional e o coeficiente de correlação intraclasse (ICC). As análises adotaram um nível de significância de 5%. O volume da coroa dentária foi significativamente maior nos indivíduos do sexo masculino. Não houve nenhuma relação entre a idade e o volume das coroas dentárias considerando todos os dentes juntos ou quando analisado cada dente separadamente. Quanto à acurácia na predição sexual, quando avaliados de forma isolada, o volume das coroas do incisivo central e canino, superiores, e do canino inferior permitiram, em média, um acerto de 64,1%, 74,4%, e 79,5%, respectivamente. O volume da coroa dentária do incisivo lateral inferior, apesar de possuir dimorfismo sexual, apresentou uma acuráciamédia de 59% o que é muito próxima ao acaso, tendo por isso sido descartada a sua utilização para estimativa do sexo. A análise combinada do volume das coroas dentárias dos caninos, superior e inferior, permitiu uma acurácia, em média, de 83,7% na determinação correta do sexo. Análise conjunta do volume das coroas dentárias do canino e incisivo central, superiores, permitiu uma acurácia média de 76% e aquela avaliando o volume da coroa dentária dos quatro dentes em conjunto apresentou uma acurácia média de 64,1%. O ICC indicou reprodutibilidade excelente. Foi possível concluir que a análise combinada do volume das coroas dentárias dos caninos, superior e inferior, pode ser utilizada para a estimativa do sexoAbstract: Sex determination plays an important role in the solution of forensic cases, especially when it is necessary to identify a large number of victims. Usually the analysis of the skull and pelvis are used for this purpose. However, when these structures cannot be analyzed, sex estimation can be performed based on the teeth analysis as they are generally well preserved because of their greater resistance to postmortem destructive effects and because of their sexual dimorphism. The sexual dimorphism can be defined as the difference in size or appearance between males and females. However, the accuracy in determining sex depends on the degree of sexual dimorphism that varies in each population. Thus, the objective of this study was to evaluate the sex determination accuracy in Brazilians based on the crown dental volume. The sample was selected after the analysis of 300 CBCT scans acquired on Picasso Trio®, with the same acquisition parameters (80 kVp and 3.7mA) and voxel size (0.2mm). The sample was composed by 78 upper central incisors, 78 upper canines, 78 lower lateral incisors and 78 lower canines. There was the same proportion of males and females, aged between 8 and 36 years old. A single operator performed manual segmentation of the dental crowns on 3D slicer® software. After 15 days, 20% of the sample was reevaluated. The Mann-Whitney test, the unpaired t test, the Pearson correlation test, the conditional Backward Stepwise logistic regression and the intraclass correlation coefficient (ICC) were performed to analyze the data. A 5% level of significance was used. The males¿ crown volume was significantly greater than the females¿ crown volume. There was not a relationship between age and the dental crown volume when considering all teeth together or when analyzing each tooth separately. Regarding the sexual estimation accuracy, when the upper central incisor, the upper canine and the lower canine crown volumes were evaluated it was obtained the percentage of 64.1%, 74.4%, and 79. 5%, respectively. Despite the presence of sexual dimorphism on the lower lateral incisor crown volume, it presented an average accuracy of 59%, which is very close to chance and because of that its use for the estimation of sex was discarded. The combined analysis of the upper and lower canines crown volume allowed an average accuracy of 83.7% for correct sex determination. A combined analysis of the upper central incisor and the upper canine crown volumes allowed an average accuracy of 76%. When the four teeth wereanalyzed, an average accuracy of 64.1% was obtained. The ICC indicated excellent reproducibility. It could be concluded that the combined analysis of the upper and lower canines can be used to estimate sexMestradoRadiologia OdontologicaMestra em Radiologia OdontológicaCAPE
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