Made available in DSpace on 2014-10-09T12:54:15Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:00Z (GMT). No. of bitstreams: 1 12709.pdf: 3501983 bytes, checksum: d0d74c465390f06fe4437cbb8a2991a5 (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo, Sao Paulo

Made available in DSpace on 2014-10-09T12:47:24Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:38Z (GMT). No. of bitstreams: 1 08341.pdf: 2872842 bytes, checksum: f20063d416599129e1e3c28c68b2304c (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo

O principal problema desta tese é a aplicação da teoria psicoacústica sobre percepção de dissonância em novas ferramentas de computação musical em tempo real. Os objetivos e contribuições incluem: Prover uma revisão critica do Estado da Arte em teoria psicoacústica de modelos de dissonância, projetar trabalhos futuros; Explorar um potencial criativo negligenciado de modelos psicoacústicos de dissonância em Eletrônica ao Vivo; Desenvolver novas ferramentas computacionais baseadas na teoria; Investigar o potencial e limitações da teoria e técnicas. Discutir sua pertinência e impacto; Tornar a teoria e técnicas mais acessíveis a músicos por meio deste texto e as ferramentas desenvolvidas. A percepção de Dissonância é um fenômeno complexo em que a abordagem psicoacústica cobre apenas uma porção. Além disso, ainda há muito debate na área da psicoacústica sobre o desenvolvimento de modelos de dissonância. Portanto, a tese apresenta uma revisão crítica do Estado da Arte da teoria psicoacústica, apontando pontos fracos e fortes do atual conhecimento, e futuros desenvolvimentos no campo. Um teste perceptivo também foi elaborado para gerar ponderações relevantes. Os modelos foram implementados em Pure Data, e uma série de patches foi desenvolvida para testar o potencial criativo em eletrônica ao vivo. Esse processo culminou em um sistema desenvolvido em Pure Data que agrega diversas das técnicas baseadas nos modelos psicoacústicos. Suas possibilidades incluem, por exemplo, encontrar intervalos consonantes de acordo com um espectro, ou alterar componentes espectrais para que estejam de acordo com uma escala musical ou afinação particular. Essas ferramentas foram empregadas em um duo de improvisação livre com o autor e um saxofonista. O autor também compôs uma peça orquestral que utilizou o sistema desenvolvido na parte de eletrônica ao vivo. / The problem of this research is to apply the state of the art in psychoacoustic theories about dissonance perception in the development of novel creative computer music tools for composition and live electronics. Goals and contributions include: To provide a critical review of the State of the Art in Psychoacoustic theory regarding dissonance modeling, project further work; To explore neglected creative potential of psychoacoustic dissonance models in Live Electronics; To develop novel computer music tools based on the theory; To investigate the potential and limitations of the theory and techniques; To discuss its creative musical impact and pertinence; To make the theory and techniques more accessible to musicians through the text and the free developed tools. The perception of Dissonance is a complex phenomenon in which the psychoacoustical approach covers just a portion thereof. Not only that, but psychoacoustic theory is still in debate about the development of dissonance models. Therefore, the thesis provides a critical review of the state of the art in psychoacoustic theory, pointing out weaknesses and strong points of the current knowledge, and future developments in the field. A perceptual test was also designed to generate data for relevant insights. Apart from the theoretical review, the models were implemented in Pure Data, and a series of patches was developed in order to test their creative potential in Live Electronics. This culminated in a system developed as a Pure Data Patch that aggregates several techniques based on the psychoacoustic models. Their possibilities include, for example, finding consonant intervals according to a spectrum, or altering spectral components so they are in accordance to musical intervals and particular tunings. These tools were used in a Free Improvisation duo with the author and a sax player, and the author also composed an orchestral piece that applied the developed system in the Live Electronics section.

Objectifs : Développer un traitement HIFU (High-Intensity Focused Ultrasound) des anomalies placentaires au moyen d’un transducteur torique. Les essais ont été menés à partir d’un modèle ex-vivo, puis la faisabilité, l’efficacité et l’innocuité du traitement a été évaluée sur un modèle de guenons gestantes. Les premières applications thérapeutiques envisagées à l’échelle humaine, concernent le traitement du syndrome transfuseur-transfusé (STT) et les accrétions placentaires pour lesquelles un protocole d’essai clinique a été établi. Matériels et méthodes : Un transducteur torique fonctionnant à 3 MHz et muni d’une cellule d’imagerie échographique intégrée fonctionnant à 7,5 MHz ont été utilisés. Des simulations numériques de séquences de traitement HIFU ont été menées à partir d’une étude préliminaire sur la caractérisation acoustique du tissu placentaire humain. Ces séquences ont été testées au cours d’une étude ex-vivo sur des placentas humains. Deux modèles ex-vivo ont été conçus. Dans un premier temps, un modèle de traitement extracorporis. Dans un second temps, des traitements HIFU ont été réalisés à des distances variables du transducteur, par modification de la taille du ballonnet, afin de simuler un traitement per-césarienne. Le transducteur était placé au contact de la face foetale du placenta afin de simuler la séreuse utérine. A partir des résultats issus de ces essais ex-vivo, un protocole in-vivo sur des guenons gestantes a été mené afin de valider la faisabilité, l’efficacité et l’innocuité de la réalisation de lésions HIFU dans le placenta de guenons gestantes de manière totalement non-invasive. La qualité du monitoring échographique était évaluée au cours des trois études, et corrélée à l’analyse macroscopique. Une étude histologique a également été menée. Résultats : L’atténuation placentaire a été mesurée à partir de 12 échantillons placentaires humains pour un âge gestationnel compris entre 17 et 40 semaines d’aménorrhées (SA). L’atténuation augmentait en fonction de l’âge gestationnel et était compris entre 0,072 et 0,098 Np.cm-1.MHz-1. Lors d’un premier essai ex-vivo, 33 échantillons placentaires humains ont été inclus et soumis à une séquence HIFU, le temps d’insonification était de 55 secondes, la puissance acoustique utilisée était de 90 Watts. Au total, vingt-cinq lésions élémentaires étaient produites pour un diamètre et une profondeur moyens respectifs de 7,1 ± 3,2 et de 8,0 ± 3,1 millimètres. Huit lésions HIFU ont également été produites à partir de la juxtaposition de 6 tirs, pour un diamètre et une profondeur moyenne respectifs de 23,0 ± 5,0 et 11,0 ± 4,7 millimètres. Aucune lésion située en amont de la lésion produite n’a été observée pour une épaisseur de paroi abdominale similaire à celle d’une guenon gestante (10,8 ± 1,7 millimètres). Dans un second temps, 8 placentas humains pour un âge gestationnel compris entre 39 et 40 SA, ont été soumis à une séquence de traitement HIFU sans interposition de paroi abdominale. Le temps d’exposition était de 75 secondes pour une puissance acoustique de 90 Watts. Les lésions placentaires ont été produites à 2 (n=4), 6 (n=4), 7 (n=4) et 8 (n=7) millimètres de la surface du placenta. Au total, 19 lésions placentaires ont été produites, pour un diamètre et une profondeur moyenne respectifs de 14,6 ± 2,1 et de 14,1 ± 2,3 millimètres. Au cours de l’étude in-vivo, 8 guenons ont été incluses pour un âge gestationnel moyen de 72 ± 4 jours. Les puissances acoustiques utilisées étaient de 65, 80, 110 et 120 Watts pour un temps de traitement de 30, 15, 20 et 20 secondes respectivement. Au total 6 lésions placentaires ont été produites à l’issu de 13 insonifications pour des diamètres moyens de 6,4 ± 0,5 mm, 7,8 ± 0,7 mm et une profondeur moyenne de 3,8 ± 1,5 mm [etc…] / Objectives: To develop a High-intensity Focused Ultrasound (HIFU) treatment for placental abnormalities. Trials were first conducted using an ex-vivo model. Then the safety, feasibility and efficacy were demonstrated using a pregnant monkey model. The first therapeutic applications for human concern the treatment of the twin-to-twin transfusion syndrome (TTTS) and placenta accreta, for which, a clinical trial has already been established. Materials and Methods: A toroidal HIFU transducer, with an integrated ultrasound imaging probe was used. Numerical simulations have allowed identifying HIFU treatment parameters based on a preliminary experiment measuring the acoustic attenuation of human placentae. These HIFU parameters were tested during an ex-vivo study on human placentae. Two models were used. First, an extracorporis model of treatment was developed. Second, a percesarean model was developed. HIFU lesions were performed at different distances from the transducer, by adjusting the quantity of water between the transducer and tissues. The transducer was placed in contact with the fetal side of the placenta in order to simulate the uterine serosa. Using the results of these studies, an in-vivo study was conducted in a pregnant monkey model. The aim was to evaluate the feasibility, the efficacy and the harmlessness of the HIFU treatment applied to the placenta non invasively. The ultrasound monitoring was assessed during these three studies, and was correlated to the macroscopic examination. A histological study was also performed. Results: The placental attenuation was measured using 12 placental samples for a gestational age from 17 to 40 weeks of gestation (WG). The attenuation coefficient increased according to the gestational age, and was ranged from 0,072 to 0,098 Np.cm-1.MHz-1. During the first experimental ex-vivo study, 33 human placental samples were included and treated with HIFU. The treatment parameters were an exposure time of 55 seconds and an acoustic power of 90 Watts. Twenty-five HIFU singles lesions were created with an average diameter and depth of 7.1 ± 3.2 and 8.0 ± 3.1 millimeters, respectively. Eight HIFU lesions were also created by juxtaposing 6 single HIFU lesions. The average diameter and depth of these juxtaposed lesions were 23.0 ± 5.0 and 11.0 ± 4.7 millimeters, respectively. No secondary lesion was observed in overlying abdominal tissues. The thickness of these intervening tissues was similar to a pregnant monkey (10.8 ± 1.7 millimeters). In a second set of experiments, 8 human placentae for a gestational age ranging between 39 and 40 weeks were treated without intervening tissues. The time of exposure was 75 seconds and the acoustic power was 90 Watts. The placental lesions were created at 2 (n=4), 6 (n=4), 7 (n=4) and 8 (n=7) millimeters from the surface of the placenta. In total, 19 placental lesions were created with an average diameter and depth of 14.6 ± 2.1 and 14.1 ± 2.3 millimeters, respectively. Eight pregnant monkeys were included in the in-vivo experiments. The average gestational age was 72 ± 4 days. The placenta was treated non-invasively with acoustic powers of 65, 80, 110 and 120 Watts for a time of exposure of 30, 15, 20 and 20 seconds, respectively. In total, 6 placental lesions were created from 13 insonifications. The average diameters and depths of these lesions were 7.8 ± 0.7 and 3.8 ± 1.5 mm, respectively. No significant variation in maternal or fetal parameters was observed. All placental lesions appear hyperechoic in sonograms and well correlated with the macroscopic measurements. The ultrasound monitoring was better invivo when compared with ex-vivo results. The histological examination demonstrated a well delimited lesion of coagulation in all cases

Alzheimer’s disease (AD) is a neurodegenerative disorder resulting in the decline of cognitive function, memory formation and retrieval, and abrupt changes in personality. Damage to brain networks occur during prodromal stages of AD, prior to the development of clinical symptoms of dementia. Further characterising this state and identifying reliable biomarkers for early detection are priorities in AD research. I characterised neuronal changes within the dorsal CA1 and subiculum regions of the hippocampal formation (HF) in the well-characterised 3xTgAD mouse model of AD. These regions are well-established sites for early neurodegeneration in both AD patients and AD animal models. We inserted multi-electrode recording arrays into CA1 and subiculum of urethane anaesthetised 3xTgAD mice and recorded spontaneous local field potential activity. Using traditional and novel information theoretic approaches, I determined the information carrying capacity of the CA1- subiculum network during different network rhythms, and how this altered with age and AD-like pathology. A bipolar stimulating electrode was inserted into CA1, allowing the assessment of synaptic integrity between CA1 and subiculum. Results showed that synaptic and network changes occur in CA1 and subiculum during the early stages of AD-like pathology and correlates with the development of intracellular beta-amyloid. There is a progressive breakdown in synaptic facilitation as early as 3 months in the 3xTgAD mouse. These data support an advanced ageing-like phenotype in AD model mice, with an enhanced age/pathology-dependent breakdown in neuronal communication compared to age-matched controls. In agreement with other studies, 3xTgAD mice demonstrate evidence of pathology-related changes in the network rhythms of the HF. 3xTgAD mice show an increase in the power of alpha and beta rhythms, and a concurrent reduction in the power of delta oscillations. Application of novel information theoretic techniques results in a breakdown in the information carrying capacity of the hippocampal system. This deficit manifests as a reduction in information flow during delta-dominant periods of EEG rhythms, with a specific reduction during slow-wave ripple activity. This change in neuronal communication correlates with the onset of memory-retention/consolidation deficits. These network changes are complex, with alterations in the information carrying capacity of the system during theta rhythms at 6 months, and during slow-wave components by 9 months in the 3xTgAD mouse. This study provides the first evidence of an early and progressive decline in neuronal connectivity and communication that correlates with changes in cognition in the 3xTgAD mouse. Application of novel analytical techniques to multi-site EEG recording revealed early and measureable changes in information processing during the onset of AD-like pathology. These are important new biomarkers for early AD characterisation.

TEETH AND OTHER TALES is a novella and a collection of short stories that explore the blurry lines between illusion and reality. Teeth, the novella, is narrated backward in time, chronicling the life of Lucy from the age of sixty-five back to seventeen. After years of surviving an oppressive marriage, Lucy escapes her husband, but in doing so abandons her three children. In order to rationalize her decisions, Lucy uses selective memory to create her own reality to the extent that she comes to believe her own delusions. The four short stories in the collection feature protagonists who create their own personal myths and struggle to protect their distorted truths, with mixed results. These struggles between the “real,” as conventionally defined, and personal fictions are complicated by elements of magical realism and surrealism. The stories were influenced by the short fiction of Nikolai Gogol, Franz Kafka and Haruki Murakami.

Recent approaches in depression therapeutics include triple reuptake inhibitors, drugs that target three monoamine systems. Using in vivo electrophysiological and microdialysis techniques, the effects of 2- and 14-day treatments of escitalopram, nomifensine and the co-administration of these two drugs (TRI) were examined in male Sprague-Dawley rats. Short- and long-term TRI administration decreased NE firing and had no effect on DA neurons. Normal 5-HT firing rates were maintained after 2-day TRI administration compared to the robust inhibitory action of selective serotonin reuptake inhibitors (SSRIs). Escitalopram treatment enhanced the tonic activation of the 5-HT1A receptors given the increase in firing observed following WAY100635 administration. Nomifensine treatment enhanced tonic activation of the α2–adrenoceptors following idazoxan administration. TRI treatment caused a robust increase in extracellular DA levels that was in part mediated by a serotonergic contribution. Therapeutic effects of the drugs examined in this study may be due to the enhancement of 5-HT, NE and/or DA neurotransmission.

Over the past decade the concept that the hair follicle plays an important role in cutaneous wound repair has been established. Several elegant lineage tracing studies have demonstrated that hair follicle derived cells contribute to the long term maintenance of the epidermis following repair, while an absence of hair follicles is known to delay repair. The exact mechanisms surrounding hair follicle derived repair are unknown. Moreover, while multiple stem cell niches are present within the hair follicle, their relative importance during wound repair is still unclear. The hair follicle is also a regenerative mini-organ, undergoing regular cycles of growth and regression throughout life, yet surprisingly this has not been previously investigated with respect to wound repair. Data presented in this thesis reveals an unappreciated, yet fundamental link between the independent processes of hair cycle and wound repair, with a substantial acceleration in the rate of repair (~50%) observed in anagen phase. Importantly, the hair follicle appears to play a global role in repair, with differences in the contribution of multiple cell types to wound repair. In addition, this thesis addresses the early kinetics of hair follicle wound response for the first time. Anagen hair follicles are found predisposed to a more rapid and extensive response to injury, suggesting a higher overall percentage of repair derived from the hair follicle in anagen phase. Surprisingly, the bulge stem cell region, while critical for hair cycle appears to play little role in the events immediately following injury, and is not required for initiation of re-epithelialisation. Gene expression profiling reveals numerous genes associated with anagen accelerated repair, and identifies altered modulation of the immune system as a key mechanism. Further, anagen wounds are associated with an upregulation of developmental transcription factors, which may imply a more regenerative healing phenotype. These data reveal numerous targets with the potential to accelerate repair, which now require validation for their therapeutic potential. These targets could be of importance in promoting the repair of chronic wounds, an area of unmet clinical need. More generally, this thesis has established hair cycle as an important experimental variable, which must be controlled for in all future in vivo murine wounding studies.

Submitted by Fernanda Rodrigues de Lima (fernanda.rlima@ufpe.br) on 2018-09-20T20:34:18Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE Victor de Almeida Nobre Pires.pdf: 1733472 bytes, checksum: fd561a8955380cd7ec58cf521d612cfe (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-09-21T18:39:50Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE Victor de Almeida Nobre Pires.pdf: 1733472 bytes, checksum: fd561a8955380cd7ec58cf521d612cfe (MD5) / Made available in DSpace on 2018-09-21T18:39:50Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE Victor de Almeida Nobre Pires.pdf: 1733472 bytes, checksum: fd561a8955380cd7ec58cf521d612cfe (MD5) Previous issue date: 2017-02-03 / O presente trabalho analisa a música ao vivo, a partir do estudo de concertos realizados em salas de estar de fãs com ênfase no caso da rede Sofar Sounds e de suas práticas de produção musical, sob uma perspectiva crítica da Teoria do Ator-Rede (TAR). Aqui, o objetivo é entender a música ao vivo não como uma categoria a priori, ou autoexplicativa, mas como uma rede que conforma diversas relações e associações entre actantes humanos e não-humanos para a conformação de fenômenos que compreendem muito mais que apenas a música em sentido estrito. Assim, traçarei análises a partir de controvérsias e pontos tensivos da própria rede para entender dinâmicas e práticas por vezes negligenciadas na agenda da pesquisa acadêmica na área, fornecendo bases para se pensar, dentre outras coisas, os aspectos midiáticos, produtivos, coletivos, sonoros e espaciais de uma importante rede que agencia a produção e o consumo de shows em formato intimistas em mais de 40 países. / This work analyzes live music, from the case study of living room concerts with emphasis on the Sofar Sounds network and its musical production practices from a critical perspective of the Actor-Network Theory (ANT). Here, the goal is to understand live music not as an “a priori” concept, or as a self-explanatory category, but as a network that cover diverse relationships and associations between human and non-human actants for the conformation of a phenomena that comprise much more than just music in the strict sense. Thus, I will draw analyzes from the network's controversies and tensions to understand the, sometimes neglected, dynamics and practices in the academic research agenda in the area, providing bases for thinking about, among other things, the media, the productive practices, the collective formations, and the spatiality of an important music network that organizes the production and consumption of shows in intimate formats in more than 40 countries.

A escolaridade materna tem sido amplamente reconhecida como um indicador das condições ambientais e sociais que afetam o peso ao nascer. No entanto, embora o assunto seja considerado relevante, não foram realizados estudos no Brasil que investigaram a relação da escolaridade materna sobre o peso de nascimento numa perspectiva temporal. O presente estudo avaliou as médias de peso ao nascer conforme os diferentes níveis de escolaridade materna. Trata-se de um estudo de série temporal que incluiu os nascidos vivos das 27 capitais estaduais brasileiras no período de 1996 a 2013. Os dados foram obtidos por meio do Sistema de Informação de Nascidos Vivos (SINASC) donde foram incluídos os recém-nascidos vivos únicos, com peso entre 500 e 8.000 gramas, de mães que residiam e tiveram seus partos nas capitais. As médias de peso ao nascer foram calculadas ano a ano nos três níveis de escolaridade materna – alto (≥ 12 anos), médio (8 a 11 anos) e baixo (< 8 anos). A estimativa da diferença anual de peso entre os níveis de escolaridade foi desenvolvida utilizando-se a técnica de Modelos Lineares Mistos, na qual também foram inseridas as covariáveis, idade da mãe, número de filhos nascidos vivos anteriores, número de consultas de pré-natal, duração da gestação e tipo de parto, de modo a avaliar seu impacto nas diferenças de peso ao nascer. O processamento e análise dos dados foram realizados pelo Programa “Statistical Package for Social Sciences” (SPSS) – versão 18.0. Foram analisados 12.546.282 de nascidos vivos que representaram 23,2% do total de nascimentos do país. As maiores médias anuais de peso ao nascer em relação à região geográfica foram observadas na região Norte e as menores, na região Sudeste, sendo que este padrão foi mantido durante todo o período avaliado. Em relação às médias de peso, segundo o nível de escolaridade materna, verificou-se que, no início da série, a média entre os filhos das mulheres com alta escolaridade era superior à dos filhos de mães de média e baixa, com 35 gramas e 91 gramas de diferença respectivamente. Essa diferença foi sendo reduzida e, a partir do ano de 2007, a média dos filhos das mulheres com escolaridade média foi maior do que a dos filhos das mulheres com alta escolaridade, com manutenção deste padrão até o final do período analisado, quando foi 17 gramas superior. A diferença de peso entre a alta e a baixa escolaridade também foi sendo reduzida e, em 2013, foi de 13 gramas. As análises ajustadas para o ano e região de nascimento mostraram que, no período de 1996 a 2003, as diferenças do peso ao nascer entre a média e a baixa escolaridade em relação à alta eram 7,21 gramas/ano e 11,42 gramas/ano, respectivamente; no segundo período, de 2004 a 2013, essas diferenças foram reduzidas para 1,76 gramas/ano e 1,47 gramas/ano. Quando inseridas as demais covariáveis, se evidenciou que o número de consultas de pré-natal exibiu relação positiva em reduzir a diferença de peso entre os três níveis de escolaridade materna, nos dois períodos analisados. Os ajustes efetuados para as covariáveis, idade da mãe, número de filhos nascidos vivos, duração da gestação e tipo de parto, mostraram diferente desempenho nas estimativas da diferença de peso ao nascer entre os níveis de escolaridade materna e o período avaliado, apontando as mudanças demográficas, sociais e assistencias do país, que evidenciaram aumento da faixa etária materna e da primiparidade, assim como uma elevação da prematuridade e de partos cesarianos. Os resultados revelaram as transformações observadas no país nas duas últimas décadas nos diferentes estratos sociais, fazendo diminuir as diferenças de peso ao nascimento e marcando uma transição demográfica, epidemiológica e perinatal em todas as regiões, mesmo que, em diferentes estágios. A redução na diferença de peso entre os três níveis de escolaridade materna, ocorreu principalmente devido à diminuição nos estratos mais favorecidos, pois a elevação observada nas médias de peso dos filhos das mulheres com baixa escolaridade foi pequena, mesmo com a ampliação das políticas sociais neste estrato. Devido à relação multifatorial do peso ao nascer é possível que o aumento da idade materna e a existência de comorbidades prévias ou desenvolvidas durante a gestação, a maior utilização de intervenções médicas, uso de substâncias como álcool e tabaco, a presença de sobrepeso e obesidade, assim como deficiências nutricionais, possam ter relação com as médias de peso observadas. Destacou-se a relevância na utilização do Sistema de Informações sobre Nascidos Vivos permitindo conhecer e analisar as caraterísticas dos nascimentos no Brasil, como também o desafio de aprimorar a assistência materno-infantil com vistas à obtenção de melhores resultados em todos os estratos sociais. / Maternal schooling has been widely recognized as an indicator of environmental and social conditions that affect birth weight. Although the subject is considered of significant relevance, studies that investigated the influence of maternal schooling on birth weight in a temporal perspective have not yet been conducted in Brazil. The present research evaluated the means of birth weight according to the different levels of maternal schooling. It is a time-series study that included live births throughout the 27 state capitals of Brazil in the period from 1996 to 2013. Data were obtained from the National Information System of Live Birth (SINASC), which recorded single newborns weighing between 500 and 8,000 grams of mothers who had their children in the capitals. The mean birth weight was calculated year by year against three levels of maternal education - high (≥ 12 years), medium (8-11 years) and low (< 8 years). Estimated annual weight difference between the levels of education was developed using the Linear Mixed Models technique, in which covariate maternal age, number of previous live births, number of prenatal visits, duration of gestation and type of delivery evaluate their impact on differences in birth weight. The processing and analysis of data were performed by the program "Statistical Package for Social Sciences" (SPSS) - version 18.0. A total of 12,546,282 live births were analyzed during the 18-year period, representing 23.2% of the country's total births. The highest annual average birth weight in relation to the geographical region was observed in the Northern region and the lowest in the Southeastern region, and this pattern was maintained throughout the studied period. Regarding weight averages, considered against the level of maternal schooling, results show that the average among the children of women with high schooling was higher than that of the children of mothers of medium and low, with 35 grams and 91 grams of difference, respectively. This difference was later reduced and, from the year 2007, the average of the children of women with medium education was higher than that of children of women with high education, maintaining this standard by the end of the period analyzed, when the birth weight difference was 17 grams higher. The difference in weight between high and low schooling was also reduced, and in 2013, it was 13 grams. The analyzes adjusted for year and region of birth showed that, in the period from 1996 to 2003, the differences in birth weight between the medium and the low education in relation to high were 7.21 grams/year and 11.42 grams/year, respectively. In the period from 2004 to 2013, these differences were reduced to 1.76 grams/year and 1.47 grams/year. When the other covariates were considered, it was evident that the number of prenatal visits has a positive relation in the reduction of the weight difference between the three levels of maternal education, in the two periods analyzed. However, the adjustments for covariates, mother's age, number of previous live births, duration of pregnancy and mode of delivery, showed dissimilar effects on annual differences in weight between the different levels of maternal education, in both periods evaluated. These results are related to the demographic, social and assistance changes of the country, which evidenced an increase in maternal age and primiparity, as well as prematurity increase and cesarean deliveries. The findings revealed the changes observed in the country in the last two decades in the various social strata, reducing weight differences at birth and marking a demographic, epidemiological and pe This was probably because the observed increase in the average weight of children of women with low education was modest, even with the expansion of maternal schooling and the prenatal follow-up verified in this social stratum. Thus, the changes in maternal age and parity, together with the increase in medical interventions, as demonstrated by the percentage of cesarean delivery, negatively impacted the birth weight of the three levels of education. It is possible that other factors not investigated in this study also play a role in the reduction of weight differences between the different levels of mother's education. Among these factors can be mentioned the existence of previous or developed maternal diseases during pregnancy, hypertension and diabetes, malnutrition or maternal obesity, use of licit and illicit drugs during pregnancy, as well as the quality of prenatal care received. Results also indicate the relevance of using the Information System on Live Births to know and analyze the characteristics of births in Brazil, as well as the challenge of improving maternal and childcare across in all social strata.