Fully-automated deep learning pipeline for 3D fetal brain ultrasound

Three-dimensional ultrasound (3D US) imaging has shown significant potential for in-utero assessment of the development of the fetal brain. However, in spite of the potential benefits of this modality over its two-dimensional (2D) counterpart, its widespread adoption remains largely limited by the difficulty associated with its analysis. While more established 3D neuroimaging modalities, such as Magnetic Res- onance Imaging (MRI), have circumvented similar challenges thanks to reliable, automated neuroimage analysis pipelines, there is currently no comparable pipeline solution for 3D neurosonography. With the goal of facilitating medical research and encouraging the adoption of 3D US for clinical assessment, the main objective of my doctoral thesis is to design, develop, and validate a set of fundamental automated modules that comprise a fast, robust, fully automated, general-purpose pipeline for the neuroimage analysis of fetal 3D US scans. For the first module, I propose the fetal Brain Extraction Network (fBEN), a fully-automated, end-to-end 3D Convolutional Neural Network (CNN) with an encoder-decoder architecture. It predicts an accurate binary brain mask for the automated extraction of the fetal brain from standard clinical 3D US scans. For the second module I propose the fetal Brain Alignment Network (fBAN), a fully-automated, end-to-end regression network with a cascade architecture that accurately predicts the alignment parameters required to rigidly align standard clinical 3D US scans to a canonical reference space. Finally, for the third module, I propose the fetal Brain Fingerprinting Net- work (fBFN), a fully-automated, end-to-end network based on a Variational AutoEncoder (VAE) architecture, that encodes the entire structural information of the 3D brain into a relatively small set of parameters in a continuously distributed latent space. It is a general-purpose solution aimed at facilitating the assessment of the 3D US scans by recharacterising the fetal brain into a representation that is easier to analyse. After exhaustive analysis, each module of this pipeline has proven to achieve state-of-the-art performance that is consistent across a wide gestational range, as well as robust to image quality, while requiring minimal pre-processing. Additionally, this pipeline has been designed to be modular, and easy to modify and expand upon, with the purpose of making it as easy as possible for other researchers to develop new tools and adapt it to their needs. This combination of performance, flexibility, and ease of use may have the potential to help 3D US become the preferred imaging modality for researching and assessing fetal development

Aplicação do método prescritivo de etiquetagem em edificações no campus Mato Alto: Uma discussão entre a eficiência energética e o conforto ambiental de seus usuários

TCC (graduação) - Universidade Federal de Santa Catarina. Campus Araranguá. Engenharia de Energia.Com a crescente demanda de energia no planeta, cada vez mais faz-se necessário disseminar o conceito de eficiência energética, de forma aplicada. Edificações Comerciais e Públicas são responsáveis por cerca de 43% do consumo de energia elétrica no Brasil, e mais de 55% em países desenvolvidos. Em paralelo, as atividades humanas precisam ser realizadas com cada vez maior qualidade e eficácia, e tais necessidades demandam boas condições ambientais para execução do trabalho. O presente estudo buscou avaliar a aplicabilidade do método prescritivo de etiquetagem de eficiência energética em edificações, e também verificar, através de simulação luminotécnica, se os ambientes acadêmicos da edificação oferecem conforto visual aos seus ocupantes, de forma com que possam realizar suas atividades nas salas de aula, em boas condições. O método de etiquetagem é apresentado pelo Regulamento Técnico de Qualidade de Eficiência em Edificações Comerciais, de Serviços, e Públicas (RTQ-C), e a edificação utilizada para o estudo de caso foi o campus da Universidade Federal de Santa Catarina, localizado em Araranguá, no bairro Mato Alto. Os resultados apontaram algumas limitações bastante significativas na aplicação da metodologia prescritiva do RTQ-C, principalmente na avaliação dos sistemas de iluminação e condicionamento de ar. A edificação foi avaliada em nível C de eficiência, porém com um bom potencial de alcançar o nível B. No que diz respeito ao conforto visual, verificou-se um sistema de iluminação que oferece boas condições visuais aos seus ocupantes, respeitando o descrito na norma brasileira NBR 5413

Firms and the Decline in Earnings Inequality in Brazil

We document a large decrease in earnings inequality in Brazil between 1996 and 2012. Using administrative linked employer-employee data, we fit high-dimensional worker and firm fixed-effects models to understand the sources of this decrease. Firm effects account for 40 percent of the total decrease and worker effects for 29 percent. Changes in observable worker and firm characteristics contributed little to these trends. Instead, the decrease is primarily due to a compression of returns to these characteristics, particularly a declining firm productivity-pay premium. Our results shed light on potential drivers of earnings inequality dynamics

Firms and the Decline in Earnings Inequality in Brazil

We document a large decrease in earnings inequality in Brazil between 1996 and 2012. Using administrative linked employer-employee data, we fit high-dimensional worker and firm fixed-effects models to understand the sources of this decrease. Firm effects account for 40 percent of the total decrease and worker effects for 29 percent. Changes in observable worker and firm characteristics contributed little to these trends. Instead, the decrease is primarily due to a compression of returns to these characteristics, particularly a declining firm productivity-pay premium. Our results shed light on potential drivers of earnings inequality dynamics

Normative spatiotemporal fetal brain maturation with satisfactory development at 2 years

Maturation of the human fetal brain should follow precisely scheduled structural growth and folding of the cerebral cortex for optimal postnatal function1 . We present a normative digital atlas of fetal brain maturation based on a prospective international cohort of healthy pregnant women2 , selected using World Health Organization recommendations for growth standards3 . Their fetuses were accurately dated in the first trimester, with satisfactory growth and neurodevelopment from early pregnancy to 2 years of age4,5 . The atlas was produced using 1,059 optimal quality, three dimensional ultrasound brain volumes from 899 of the fetuses and an automated analysis pipeline6–8 . The atlas corresponds structurally to published magnetic resonance images9 , but with finer anatomical details in deep grey matter. The between study site variability represented less than 8.0% of the total variance of all brain measures, supporting pooling data from the eight study sites to produce patterns of normative maturation. We have thereby generated an average representation of each cerebral hemisphere between 14 and 31 weeks’ gestation with quantification of intracranial volume variability and growth patterns. Emergent asymmetries were detectable from as early as 14 weeks, with peak asymmetries in regions associated with language development and functional lateralization between 20 and 26 weeks’ gestation. These patterns were validated in 1,487 three-dimensional brain volumes from 1,295 different fetuses in the same cohort. We provide a unique spatiotemporal benchmark of fetal brain maturation from a large cohort with normative postnatal growth and neurodevelopment

Structure of the Lassa virus glycan shield provides a model for immunological resistance

Lassa virus is an Old World arenavirus endemic to West Africa that causes severe hemorrhagic fever. Vaccine development has focused on the envelope glycoprotein complex (GPC) that extends from the virion envelope. The often inadequate antibody immune response elicited by both vaccine and natural infection has been, in part, attributed to the abundance of N-linked glycosylation on the GPC. Here, using a virus-like-particle system that presents Lassa virus GPC in a native-like context, we determine the composite population of each of the N-linked glycosylation sites presented on the trimeric GPC spike. Our analysis reveals the presence of underprocessed oligomannose-type glycans, which form punctuated clusters that obscure the proteinous surface of both the GP1 attachment and GP2 fusion glycoprotein subunits of the Lassa virus GPC. These oligomannose clusters are seemingly derived as a result of sterically reduced accessibility to glycan processing enzymes, and limited amino acid diversification around these sites supports their role protecting against the humoral immune response. Combined, our data provide a structure-based blueprint for understanding how glycans render the glycoprotein spikes of Lassa virus and other Old World arenaviruses immunologically resistant targets.Peer reviewe

Optogenetics and electron tomography for structure-function analysis of cochlear ribbon synapses

Ribbon synapses of cochlear inner hair cells (IHCs) are specialized to indefatigably transmit sound information at high rates. To understand the underlying mechanisms, structure-function analysis of the active zone (AZ) of these synapses is essential. Previous electron microscopy studies of synaptic vesicle (SV) dynamics at the IHC AZ used potassium stimulation, which limited the temporal resolution to minutes. Here, we established optogenetic IHC stimulation followed by quick freezing within milliseconds and electron tomography to study the ultrastructure of functional synapse states with good temporal resolution in mice. We characterized optogenetic IHC stimulation by patch-clamp recordings from IHCs and postsynaptic boutons revealing robust IHC depolarization and neurotransmitter release. Ultrastructurally, the number of docked SVs increased upon short (17–25 ms) and long (48–76 ms) light stimulation paradigms. We did not observe enlarged SVs or other morphological correlates of homotypic fusion events. Our results indicate a rapid recruitment of SVs to the docked state upon stimulation and suggest that univesicular release prevails as the quantal mechanism of exocytosis at IHC ribbon synapses

More than a canopy cover metric: Influence of canopy quality, water-use strategies and site climate on urban forest cooling potential

11 Pág.The authors would like to thank the Australia–Germany Joint Research Cooperation Scheme by the Universities Australia and the German Academic Exchange Service (DAAD) (Project-ID: 57601120) for funding several trips of MAR, EF, TR, SL and PT to initiate the research collaboration on this article. Thanks also to the German Science Foundation (Deutsche Forschungsgemeinschaft) for providing funds for the projects PR 292/21-1 and PA 2626/3-1 ‘Impact of trees on the urban microclimate under climate change: Mechanisms and ecosystem services of urban tree species in temperate, Mediterranean and arid major cities’. Additionally, the authors want thank student assistant A. Islam for his support during the data analyses.Peer reviewe