3D single breath-hold MR methodology for measuring cardiac parametric mapping at 3T

Mención Internacional en el título de doctorOne of the foremost and challenging subfields of MRI is cardiac magnetic resonance imaging (CMR). CMR is becoming an indispensable tool in cardiovascular medicine by acquiring data about anatomy and function simultaneously. For instance, it allows the non-invasive characterization of myocardial tissues via parametric mapping techniques. These mapping techniques provide a spatial visualization of quantitative changes in the myocardial parameters. Inspired by the need to develop novel high-quality parametric sequences for 3T, this thesis's primary goal is to introduce an accurate and efficient 3D single breath-hold MR methodology for measuring cardiac parametric mapping at 3T. This thesis is divided into two main parts: i) research and development of a new 3D T1 saturation recovery mapping technique (3D SACORA), together with a feasibility study regarding the possibility of adding a T2 mapping feature to 3D SACORA concepts, and ii) research and implementation of a deep learning-based post-processing method to improve the T1 maps obtained with 3D SACORA. In the first part of the thesis, 3D SACORA was developed as a new 3D T1 mapping sequence to speed up T1 mapping acquisition of the whole heart. The proposed sequence was validated in phantoms against the gold standard technique IR-SE and in-vivo against the reference sequence 3D SASHA. The 3D SACORA pulse sequence design was focused on acquiring the entire left ventricle in a single breath-hold while achieving good quality T1 mapping and stability over a wide range of heart rates (HRs). The precision and accuracy of 3D SACORA were assessed in phantom experiments. Reference T1 values were obtained using IR-SE. In order to further validate 3D SACORA T1 estimation accuracy and precision, T1 values were also estimated using an in-house version of 3D SASHA. For in-vivo validation, seven large healthy pigs were scanned with 3D SACORA and 3D SASHA. In all pigs, images were acquired before and after administration of MR contrast agent. The phantom results showed good agreement and no significant bias between methods. In the in-vivo experiments, all T1-weighted images showed good contrast and quality, and the T1 maps correctly represented the information contained in the T1-weighted images. Septal T1s and coefficients of variation did not considerably differ between the two sequences, confirming good accuracy and precision. 3D SACORA images showed good contrast, homogeneity and were comparable to corresponding 3D SASHA images, despite the shorter acquisition time (15s vs. 188s, for a heart rate of 60 bpm). In conclusion, the proposed 3D SACORA successfully acquired a whole-heart 3D T1 map in a single breath-hold at 3T, estimating T1 values in agreement with those obtained with the IR-SE and 3D SASHA sequences. Following the successful validation of 3D SACORA, a feasibility study was performed to assess the potential of modifying the acquisition scheme of 3D SACORA in order to obtain T1 and T2 maps simultaneously in a single breath-hold. This 3D T1/T2 sequence was named 3D dual saturation-recovery compressed SENSE rapid acquisition (3D dual-SACORA). A phantom of eight tubes was built to validate the proposed sequence. The phantom was scanned with 3D dual-SACORA with a simulated heart rate of 60 bpm. Reference T1 and T2 values were estimated using IR-SE and GraSE sequences, respectively. An in-vivo study was performed with a healthy volunteer to evaluate the parametric maps' image quality obtained with the 3D dual-SACORA sequence. T1 and T2 maps of the phantom were successfully obtained with the 3D dual-SACORA sequence. The results show that the proposed sequence achieved good precision and accuracy for most values. A volunteer was successfully scanned with the proposed sequence (acquisition duration of approximately 20s) in a single breath-hold. The saturation time images and the parametric maps obtained with the 3D dual-SACORA sequence showed good contrast and homogeneity. The septal T1 and T2 values are in good agreement with reference sequences and published work. In conclusion, this feasibility study's findings open the door to the possibility of using 3D SACORA concepts to develop a successful 3D T1/T2 sequence. In the second part of the thesis, a deep learning-based super-resolution model was implemented to improve the image quality of the T1 maps of 3D SACORA, and a comprehensive study of the performance of the model in different MR image datasets and sequences was performed. After careful consideration, the selected convolutional neural network to improve the image quality of the T1 maps was the Residual Dense Network (RDN). This network has shown outstanding performance against state-of-the-art methods on benchmark datasets; however, it has not been validated on MR datasets. In this way, the RDN model was initially validated on cardiac and brain benchmark datasets. After this validation, the model was validated on a self-acquired cardiac dataset and on improving T1 maps. The RDN model improved the images successfully for the two benchmark datasets, achieving better performance with the brain dataset than with the cardiac dataset. This result was expected as the brain images have more well-defined edges than the cardiac images, making the resolution enhancement more evident. On the self-acquired cardiac dataset, the model also obtained an enhanced performance on image quality assessment metrics and improved visual assessment, particularly on well-defined edges. Regarding the T1 mapping sequences, the model improved the image quality of the saturation time images and the T1 maps. The model was able to enhance the T1 maps analytically and visually. Analytically, the model did not considerably modify the T1 values while improving the standard deviation in both myocardium and blood. Visually, the model improved the T1 maps by removing noise and motion artifacts without losing resolution on the edges. In conclusion, the RDN model was validated on three different MR datasets and used to improve the image quality of the T1 maps obtained with 3D SACORA and 3D SASHA. In summary, a 3D single breath-hold MR methodology was introduced, including a ready to-go 3D single breath-hold T1 mapping sequence for 3T (3D SACORA), together with the ideas for a new 3D T1/T2 mapping sequence (3D dual-SACORA); and a deep learning-based post-processing implementation capable of improving the image quality of 3D SACORA T1 maps.This thesis has received funding from the European Union Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement N722427.Programa de Doctorado en Multimedia y Comunicaciones por la Universidad Carlos III de Madrid y la Universidad Rey Juan CarlosPresidente: Carlos Alberola López.- Secretario: María Jesús Ledesma Carbayo.- Vocal: Nathan Mewto

Nonlinearities and synchronization of business cycles : a novel approach

Mestrado em EconomiaEsta dissertação estuda os padrões de sincronização de ciclos económicos numa amostra composta por 18 países desenvolvidos e a Zona Euro ao longo do período 1970:1-2008:1. Para realizar este estudo, propomos um novo modelo de componentes não observáveis multivariado com markov-switching e interdependência de estados variável no tempo, no qual a sincronização é modelizada como uma componente comum variável no tempo entre os ciclos económicos. Para estimar o modelo, desenvolvemos um filtro de Kalman adequado, que permite a projecção das componentes não observáveis e a estimação dos hiperparâmetros por máxima verosimilhança. Propomos também um novo fullsample smoother para recalcular as componentes não observáveis do modelo com base em toda a informação amostral. Usamos este modelo para testar 3 hipóteses: se a criação da União Monetária Europeia promoveu um aumento na sincronização dos ciclos económicos entre os seus membros; se a integração promoveu uma mudança na filiação cíclica com o ciclo económico dos EUA; se existe o surgimento de um ciclo económico agregado da Zona Euro. Os resultados mostram que a sincronização cíclica dos países da Zona Euro com a Zona Euro agregada foi superior à dos restantes países. No entanto, para a maioria dos países da Zona Euro, a sincronização com a Zona agregada aumentou até ao início da década de 90, e diminuiu a partir desse período. Apesar de existir um ligeiro aumento na sincronização com a Zona Euro agregada para algumas economias participantes em torno do momento da introdução da moeda única, não somos capazes de detectar um “efeito Euro” claro. Por outro lado, para a maioria das economias, a introdução da moeda única é coincidente com uma redução na sincronização com o ciclo dos EUA. Finalmente, não encontramos evidência do surgimento de um ciclo económico agregado da Zona Euro. ABSTRACT: This dissertation studies the patterns of business cycle synchronization across a sample of 18 developed countries and the aggregate Euro Area over the period 1970:1-2008:1. To perform this study, we propose a novel multivariate unobservedcomponents model with markov-switching and time-varying state interdependence, in which synchronization is modelled as a time-varying common component between the business cycles. To estimate the model, we develop an adequate Kalman filter, which allows the projection of the unobserved components and the estimation of the hyperparameters by maximum likelihood. We also propose a new full-sample smoother to recompute the unobserved components of the model based on all in-sample information. We use this model to test 3 hypothesis: whether the creation of the European Monetary Union promoted an increase in business cycle synchronization among its members; whether the integration has promoted a change in the cyclical affiliation with the US business cycle; and whether there is an emergence of an aggregate Euro Area business cycle. The results show that synchronization between the Euro Area countries with the aggregate Euro Area has been higher than for the remaining countries. Nevertheless, for the majority of the Euro Area countries, synchronization with the aggregate Area increased until the beginning of the 1990s, and dropped from that period onwards. Moreover, despite the existence of a slight increase in synchronization with the aggregate Euro Area for some participant economies around the timing of the introduction of the common currency, we are not able to uncover a clear “Euro effect”. On the other hand, for most of the economies, the introduction of the common currency is shown to be coincident with a drop in synchronization with the US business cycle. Finally, we do not find evidence of the emergence of an aggregate Euro-Area business cycle

Nortear: A platform to support higher education applicants’ decisions

Project Work presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Knowledge Management and Business IntelligenceData can have immense public value, and although Open Data has been made available on the internet mostly by governments and public institutions having as a main justification the “public interest”, most of what is turned public, is done so in formats not suitable to the eyes of most of the public which they are aimed to. The high level of digital literacy needed to turn this data into useful information continues to keep virtually inaccessible what was supposed to be Open Data. This work aims exclusively on data over the education sector, but this situation is also true for data involving other sectors of organized society. This Open Data which is virtually “locked data” have grave relevance to students, parents, and society. This work aims to give a humble step towards exploring the lack of accessibility for information extracted from Open Data on the Portuguese educational sector to collect data that are relevant to future graduates on the choice for a university aiming to create a platform where these students can access visualizations linked to key decision factors relevant when choosing a place to study, including information about the city, the country, and the university. This way, this work intends also to create encouragement to more initiatives which can help to “translate” data for the good of the broad public

Autonomia e participação das crianças na pedagogia Jenaplan: estudo dos dispositivos estruturantes da aprendizagem numa escola holandesa

A comunicação proposta pretende apresentar algumas das perspectivas teóricas, estratégias e conclusões obtidas de uma investigação com orientação etnográfica, desenvolvida no âmbito do Mestrado em Sociologia da Infância na Universidade do Minho. A investigação empírica decorreu durante seis meses numa escola primária com pedagogia Jenaplan, na Holanda. O tema do estudo era a participação das crianças na escola, através da investigação da influência do modelo pedagógico adoptado – a pedagogia Jenaplan, as relações entre professores e crianças e a organização dos espaços, materiais e dos tempos, na participação das crianças. Baseando-se no paradigma interpretativo de investigação, foram utilizadas metodologias qualitativas e metodologias visuais – o desenho e a fotografia - como meio de recolha de dados, em que estes últimos tiveram a participação das crianças, para captar de modo mais genuíno as suas percepções. Observaram-se nesta escola a presença de rotinas e de actividades básicas, decorrentes da pedagogia Jenaplan, e de instrumentos construídos pelos professores, que contribuem significativamente para a regulação autónoma das crianças, permitindo-lhes participar e gerir responsável e conscientemente as suas aprendizagens. A autonomia na gestão dos espaços para o trabalho e para o jogo, e na planificação dos projectos de aprendizagem, são alguns exemplos de autonomia evidenciadas nas crianças.Fundação para a Ciência e a Tecnologia (FCT) - Universidade do Minho. Centro de Investigação em Estudos da Criança (CIEC) unidade 31

Baum-Bott residue of flags of holomorphic distributions

In this work we extend the residue theory from flag of holomorphic foliations to flag of holomorphic distributions and we provide an effective way to calculate this class in certain cases. As a consequence, we show that if we consider a flag $\mathcal{F} = (\mathcal{F}_{1}, \mathcal{F}_{2})$ of holomorphic distributions on $\mathbb{P}^{3}$, we get a relation between the degrees of the distributions in the flag, the tangency order of distributions, the Euler characteristic and the degree of the curve $C.$Comment: 15 page

Lama guanicoe remains from the Chaco ecoregion (Córdoba, Argentina): An osteological approach to the characterization of a relict wild population

Guanacos (Lama guanicoe) are large ungulates that have been valued by human populations in South America since the Late Pleistocene. Even though they were very abundant until the end of the 19th century (before the high deforestation rate of the last decades), guanacos have nearly disappeared in the Gran Chaco ecoregion, with relicts and isolated populations surviving in some areas, such as the shrubland area near the saline depressions of Córdoba province, Argentina. In this report, we present the first data from a locally endangered guanaco wild population, through the study of skeletal remains recovered in La Providencia ranch. Our results showed that most of the elements belonged to adults aged between 36 and 96 months; sex evaluation showed similar numbers of males and females. Statistical analysis of the body size of modern samples from Córdoba demonstrated that guanacos from the Chaco had large dimensions and presented lower size variability than the modern and archaeological specimens in our database. Moreover, they exhibited dimensions similar to those of modern guanacos from Patagonia and San Juan, and to archaeological specimens from Ongamira and Cerro Colorado, although further genetic studies are needed to corroborate a possible phylogenetic relationship. Finally, we used archaeozoological techniques to provide a first characterization of a relict guanaco population from the Chaco ecoregion, demonstrating its value to the study of modern skeletal remains and species conservation biology.Fil: Silva Ferreira Da Costa, Thiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Antropología de Córdoba. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades. Instituto de Antropología de Córdoba; ArgentinaFil: Barri, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Síntese mecânica e caracterização do compósito de matriz metálica de ni reforçado com adição de Fe-NbC

Anais do VI Encontro de Iniciação Científica e II Encontro Anual de Iniciação ao Desenvolvimento Tecnológico e Inovação – EICTI 2017 - 04 a 06 de outubro de 2017 - temática EngenhariaO desenvolvimento de novos pós, composições e rotas de produção envolvendo métodos modernos de conformação e sinterização têm contribuído para o aperfeiçoamento de compósitos de matrizes metálicas. Um artifício utilizado para aumentar a densidade e a resistência mecânica de materiais sinterizados é dispersar partículas de segunda fase na matriz metálica (SILVA JR, GOMES, et al., 2012). O níquel apresenta uma boa resistência à corrosão e é uma alternativa interessante às ligas ferrosas para aplicações em ferramentas e moldes. Enquanto isso, há uma crescente demanda de Nióbio (Nb) e seus compostos, para aplicações na indústria que coloca o Brasil numa posição de destaque por deter jazidas destes metais refratários (SEN QIN, 2014)Universidade Federal da Integração Latino-Americana (Unila); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação Araucária; Parque Tecnológico Itaipu (PTI) e Companhia de Saneamento do Paraná (SANEPAR

Fatores associados a sibilância recorrente em lactentes : há diferença entre os sexos?

Orientador: Prof. Dr. Herberto José Chong NetoDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Saúde Coletiva. Defesa : Curitiba, 22/06/2020Inclui referênciasResumo: Sibilância recorrente em lactentes caracteriza-se, por três ou mais episódios de chiados e/ou sibilos agudos em um curto período, tornando-se, relevante a morbidade e mortalidade respiratória, sobretudo na possível associação de cada sexo. Objetiva-se identificar os fatores associados à sibilância recorrente entre os sexos e revisar o papel do gênero na patogênese da asma utilizando dados de estudos epidemiológicos e clínicos. Estudo transversal, utilizando os dados do questionário padronizado do Estudio Internacional sobre Sibilancias em Lactantes (EISL). O instrumento foi aplicado aos pais de crianças com idade entre 12 e 15 meses de vida no momento da imunização ou consulta de rotina em Belo Horizonte, Belém, Curitiba, Recife e São Paulo, na fase I do EISL realizado em 2005 e 2006. E uma revisão bibliográfica não sistemática da literatura de cunho exploratório sobre a temática. Foram envolvidos 9349 lactentes, sendo mil duzentos e sessenta e um (13,5%) meninos sibilantes recorrentes, e novecentos e sessenta e duas (10,3%) meninas, respectivamente (p 10 episódios de resfriado (OR = 3,46; IC 95% 2,35-5,07), poluição intradomiciliar (OR = 1,33; IC 95% 1,12-1,59), mofo em casa (OR = 1,23; IC 95% 1,03-1,47), afrodescendentes (OR = 1,42; IC 95% 1,20-1,69), diagnóstico de pneumonia (OR = 1,40; IC 95% 1,13-1,74), episódios graves de sibilância no primeiro ano (OR = 1,56; IC 95% 1,29-1,89), tratamento com broncodilatadores (OR = 1,60; IC 95% 1,21-2,10), com corticosteróides orais (OR = 1,23; IC 95% 1,01- 1,52). Os fatores associados a sibilância recorrente em meninas foram tabagismo passivo (OR = 1,24; IC 95% 1,01-1,51), pais com diagnóstico de asma (OR = 1,32; IC 95% 1,08-1,62), pais com rinite alérgica (OR = 1,26; IC 95% 1,04-1,53), frequência à creche (OR = 1,48; IC 95% 1,17-1,88), resfriados nos primeiros 6 meses de vida (OR = 2,19; IC 95% 1,69-2,82), diagnóstico pessoal de asma (OR = 1,84; IC 95% 1,39-2,44), atendimentos de emergência (OR = 1,78; IC 95% 1,44- 2,21), sintomas noturnos (OR = 2,89; IC 95% 2,34-3,53) e imunização atualizada (OR = 0,62; IC 95% 0,41-0,96). Quanto a revisão de literatura evidenciou que os fatores como ambiente, genética, etnia, obesidade, sexo e fenótipos específicos podem ter implicações importantes nos sintomas e tratamento da asma. As diferenças relacionadas aos sexos na prevalência, fisiopatologia e morbidade da asma devem ser consideradas na avaliação e escolha do tratamento dos pacientes com asma. Conclui-se que existem diferenças nos fatores associados à sibilância recorrente entre os sexos. A identificação dessas diferenças pode ser útil para abordar e tratar a sibilância recorrente entre meninos e meninas.Abstract: Recurrent wheezing in infants characterized by three or more episodes of wheezing or wheezing in a short period of time, reproducing, do not affect respiratory morbidity and mortality, especially in the intrinsic association with each sex. Objective identify associated factors for recurrent wheezing infants between the genders and to review the role of gender in the pathogenesis of asthma using data from epidemiological and clinical studies. Cross-sectional multicentric study using the standardized questionnaire from the Estudio Internacional sobre Sibilancias en Lactantes (EISL). The questionnaire was applied to parents of 9,345 infants aged 12 to 15 months at the time of immunization or routine visits. It is a non-systematic bibliographic review of the exploratory literature on the subject. One thousand two hundred and sixty-one (13.5%) males and nine hundred sixty-three (10.3%) females have had recurrent wheezing (? 3 episodes), respectively (p10 colds episodes (OR=3.46; IC 95% 2.35-5.07), indoor air pollution (OR=1.33; IC 95% 1.12-1.59), molds at home (OR=1.23; IC 95% 1.03-1.47), afrodescendents (OR=1.42; IC 95% 1.20-1.69), hospitalized for asthma (OR=1.41; IC; 1.11-1.78), severe episodes of wheezing in the first year (OR=1.56; IC 95% 1.29-1.89), treatment with bronchodilators (OR=1.60; IC 95% 1.22-2,1) treatment with oral corticosteroids (OR=1,23; IC 95% 1.00-1,52). Associated factors for recurrent wheezing for females were passive smoking (OR=1.24; IC 95% 1.01- 1,51), parents diagnosed with asthma (OR=1.32; IC 95% 1,08-1,62), parents with allergic rhinitis (OR=1.26; IC 95% 1.04-1.53), daycare attendance (OR=1.48; IC 95% 1.17-1,88), colds in the first 6 months of life (OR=2.19; IC 95% 1.69-2.82), personal diagnosis of asthma (OR=1.84; IC 95% 1.39-2.44), emergency room visits (OR=1.78; IC 95% 1.44-2.21), nighttime symptoms (OR=2.89; IC 95% 2.34-3.53) and updated immunization record (OR=0.62; IC 95% 0.41-0.96). As for the literature review, it was shown that factors such as environment, genetics, ethnicity, obesity, sex and specific phenotypes can have important implications for asthma symptoms and treatment. Differences related to sex in the prevalence, pathophysiology and morbidity of asthma must be considered in the assessment and choice of treatment of patients with asthma. Conclusion there are differences in associated factors for recurrent wheezing between genders. Identification of these differences could be useful to approach and management of recurrent wheezing between boys and girls

Das Gespräch Zwischen Hölderlin, Hegel und Schelling über Kants antinomien

«Die Art, wie er den Mechanismus der Natur mit ihrer Zweckmäßigkeit vereiniget, scheint mir eigentlich den ganzen Geist seines Systems zu enthalten»: This quotation, which originated the present essay, is solely extracted from a letter sent by Hölderlin to Hegel, and yet, it condensates three different approaches from the three Tübingen friends to the problem of Kant’s philosophy of religion and to its possible resolution between 1795 and 1796. From this epistolary dialogue emerges a simultaneous study of Kant, originated by the growing dissension towards the orthodox thought of the Stift. The turning point – or the maximum cumulative point – of this discordance happens precisely with the discovery of the «spirit of Kant’s system», as a combined explanation of the religious and philosophical phenomena [«Die Art, wie er den Mechanismus der Natur mit ihrer Zweckmässigkeit vereiniget»]. This, I think, is something which the three friends discover gradually and not independently from the concept of «providence», which Kant himself, according to Hölderlin, had used to «attenuate his antinomies», which Hegel uses in his first religious writings and the initial formation of his own philosophy and which Schelling will later explore in his System of Transcendental Idealism. In a word, providence is consensually the comprehension axis between man, God and nature and, thus, the explanatory link between the antinomical poles which regulate human existence. On the other hand, however – this being the aspect I would like to stress –, this decisive moment for a whole generation, for the history of philosophy itself, means the consummation of a new revolutionary perspective born in Kant, a new vision of the absolute and the divine and, therefore, a new way to write philosophy about philosophy, less philosophical than before, to the extent that the new situation of man and his reflection within the problem ultimately destined them – as is the case in the three young philosophers – to silence and death. The final aim of this essay is, therefore, to know what this «last step of philosophy» is and what dies along with it, what such a step may have meant and what it already foretold in terms of the development of philosophy