A intervenção do Estado no ensino comercial: o caso da Aula do Comércio, 1759 (I)

Em 1759, foi criada a Aula de Comércio como parte de uma ampla agenda de reformas educacionais que foram implementadas pelo Marquês de Pombal com o objectivo de melhorar o estado geral da educação em Portugal. Este artigo, cuja primeira parte é agora publicada, explora as mudanças ocorridas no ensino comercial no século XVIII e o papel que o Estado teve nessas alterações. Os autores tentam refutar a afirmação de que a Aula do Comércio portuguesa foi a primeira escola oficial a oferecer instrução formal em comércio, incluindo o ensino das partidas dobradas e da contabilidade

Reliability based design optimization of a multi‐axial load cell using genetic algorithm

A construção de uma célula de carga multiaxial requer ferramentas robustas a fim de analisar o comportamento da mesma quando submetida a carregamentos estáticos e dinâmicos. Neste trabalho, é dada uma ênfase ao problema da otimização de um modelo de célula de carga multiaxial (6 componentes de força) do tipo Lywood, utilizando‐se do conceito de otimização baseada em confiabilidade. É tratado o problema da análise de confiabilidade estrutural, incluindo o efeito da variabilidade geométrica de suas propriedades físicas. A célula de carga foi analisada pelo método de elementos finitos e a restrição da confiabilidade é aplicada para o limite de falha do material. Por meio de mudanças em sua geometria objetivou‐se a maximização da primeira frequência natural e, ao mesmo tempo, a redução de massa e consequente aumento da deformação medida sem que a restrição de confiabilidade das tensões seja violada. São mostradas comparações entre o procedimento determinístico de otimização e o proposto, onde constatou‐se que a otimização determinística apresentou pontos com elevada probabilidade de falha, sendo justificada a aplicação da otimização baseada em confiabilidade para este tipo de problema. Também foram aplicados diferentes valores do fator de segurança ao modelo de otimização, onde foi possível analisar, a posteriori , a confiabilidade do resultado da otimização.The manufacturing process of a multi‐axial load cell requires robust tools to analyze the structural behavior when it is subjected to static and dynamic loads. In this work, it is given focus to the problem of optimizing a multi‐axial load cell model (6 load components) of Lywood type considering concepts of reliability‐based design optimization. The reliability structural analysis problem is handled including the variability effect of geometric and physical properties. The load cell is analyzed by finite element method and the reliability constraint is applied to the strength limit. The objective is the maximization of the first natural frequency and simultaneously reducing the mass and corresponding strains without violating reliability limit set as a limit. Comparisons between the deterministic optimization procedure and the proposed method are presented and it is found that the deterministic optimization points may have a high probability of failure so justifying in this type of problem the reliability‐based optimization. Different values of the safety factor were also tested with the optimization model, and it was possible to analyze, a posteriori, the reliability of the optimization results.La construcción de una célula de carga multiaxial requiere herramientas robustas para analizar el comportamiento de los mismos cuando se somete a cargas estáticas y dinámicas. En este trabajo se da un énfasis al problema de la optimización de un modelo de célula de carga multiaxial (6 componentes de fuerza) de tipo Lywood utilizando el concepto de optimización basado en la confiabilidad. Se abordó el problema de análisis de fiabilidad estructural incluyendo el efecto de la variabilidad geométrica de sus propiedades físicas. La célula de carga se analizó por el método de elementos finitos y la restricción de fiabilidad se aplica al límite de falla del material. A través de cambios en la geometría destinadas a aumentar al máximo la primera frecuencia natural, mientras que se viola la reducción de la masa y el consiguiente aumento de la deformación medido sin la fiabilidad de la restricción de tensiones sea violada. Las comparaciones se muestran entre el procedimiento de optimización determinista y propusieron, donde se encontró que los puntos de optimización deterministas con alta probabilidad de fallo. Fueron también aplicados diferentes valores del factor de seguridad para el modelo de optimización, donde fue posible analizar, retrospectivamente, la confiabilidad del resultado de la optimización.Peer Reviewe

Urinary Estrogen Metabolites and Self-Reported Infertility in Women Infected with Schistosoma haematobium

Schistosomiasis is a neglected tropical disease, endemic in 76 countries, that afflicts more than 240 million people. The impact of schistosomiasis on infertility may be underestimated according to recent literature. Extracts of Schistosoma haematobium include estrogen-like metabolites termed catechol-estrogens that down regulate estrogen receptors alpha and beta in estrogen responsive cells. In addition, schistosome derived catechol-estrogens induce genotoxicity that result in estrogen-DNA adducts. These catechol estrogens and the catechol-estrogen-DNA adducts can be isolated from sera of people infected with S. haematobium. The aim of this study was to study infertility in females infected with S. haematobium and its association with the presence of schistosome-derived catechol-estrogens

ST6Gal1 targets the ectodomain of ErbB2 in a site-specific manner and regulates gastric cancer cell sensitivity to trastuzumab

The clinical performance of the therapeutic monoclonal antibody trastuzumab in the treatment of ErbB2-positive unresectable gastric cancer (GC) is severely hampered by the emergence of molecular resistance. Trastuzumab's target epitope is localized within the extracellular domain of the oncogenic cell surface receptor tyrosine kinase (RTK) ErbB2, which is known to undergo extensive N-linked glycosylation. However, the site-specific glycan repertoire of ErbB2, as well as the detailed molecular mechanisms through which specific aberrant glycan signatures functionally impact the malignant features of ErbB2-addicted GC cells, including the acquisition of trastuzumab resistance, remain elusive. Here, we demonstrate that ErbB2 is modified with both alpha 2,6- and alpha 2,3-sialylated glycan structures in GC clinical specimens. In-depth mass spectrometry-based glycomic and glycoproteomic analysis of ErbB2's ectodomain disclosed a site-specific glycosylation profile in GC cells, in which the ST6Gal1 sialyltransferase specifically targets ErbB2 N-glycosylation sites occurring within the receptor's trastuzumab-binding domain. Abrogation of ST6Gal1 expression reshaped the cellular and ErbB2-specific glycomes, expanded the cellular half-life of the ErbB2 receptor, and sensitized ErbB2-dependent GC cells to trastuzumab-induced cytotoxicity through the stabilization of ErbB dimers at the cell membrane, and the decreased activation of both ErbB2 and EGFR RTKs. Overall, our data demonstrates that ST6Gal1-mediated aberrant alpha 2,6-sialylation actively tunes the resistance of ErbB2-driven GC cells to trastuzumab.Proteomic

Efficacy of menthol as an anesthetic for tambaqui (Colossoma macropomum, Characiformes: Characidae)

Anesthetics are important in fish culture to reduce handling stress and mortality. The objective of this work is to investigate menthol as an anesthetic for tambaqui. In the first series of tests, fish were exposed to various concentrations of menthol to evaluate induction time and stress responses. The second series examined the effect of exposure period to menthol at 150 mg/L on recovery time. The third assessed the best dosage for juveniles in larger tambaqui. The best concentration for surgical anesthesia is 150 mg/L. At this concentration the induction time is short, but their recovery time is significantly longer than that for lower concentrations. For biometry procedures, the best concentration is 100 mg/L. At this concentration the induction time is prolonged, but the recovery time is within the desired period. Recovery time for fish exposed to 150 mg/L is equal for 10, 20 or 30 minutes of exposure. The results confirmed that menthol is an adequate anesthetic for tambaqui.Os anestésicos são importantes na piscicultura para reduzir o estresse e a mortalidade no manejo. Este trabalho tem como objetivo determinar a eficácia do mentol para tambaqui durante o manejo. Na primeira série de testes, foi examinado o efeito da concentração de anestésico sobre indução à anestesia e o estresse de tambaqui. Na segunda série de testes, foi avaliada a recuperação dos peixes após a exposição a uma concentração de 150 mg/L de mentol por diferentes tempos. Na terceira série, foi avaliada se a melhor concentração encontrada para juvenil (150 mg/L) também era adequada para peixes maiores. A melhor concentração para uma anestesia cirúrgica foi 150 mg/L, pois o tempo de indução é rápido, porém a recuperação é significativamente mais demorada do que para as menores concentrações testadas. Para uma anestesia, com finalidade de biometria, a melhor concentração foi 100 mg/L. Nesta concentração o tempo de indução à anestesia é prolongado, porém o tempo de recuperação está dentro da faixa considerada adequada. O tempo de recuperação do tambaqui quando exposto a 150 mg/L é significativamente igual para 10, 20 e 30 minutos de anestesia. Os resultados obtidos mostram que o mentol é um anestésico eficiente para o tambaqui

Tear production, intraocular pressure and conjunctival microbiota, cytology and histology of New Zealand rabbits (Oryctolagus cuniculus)

The purpose of this study was to establish reference values for selected ophthalmic diagnostic tests in New Zealand rabbits (Oryctolagus cuniculus). A total of 22 adult male rabbits were used. The ophthalmic tests included evaluation of tear production with Schirmer tear test 1(STT1) and Endodontic absorbent paper point tear test (EAPPTT) using two different commercial brand materials. Applanation tonometry, Culture of the conjunctival bacterial flora, , conjunctival cytology and conjunctival histology were also performed. Mean (±SD) for STT1, EAPPTTa, EAPPTTb and IOP was 7.27±2.51mm/min, 12.43±1.69mm/min, 15.24±2.07mm/min, 12.89±2.80mm Hg, respectively. Staphylococcus epidermidis, Staphylococcus sp. and Bacillus sp. were predominant. The cytological evaluation revealed the presence columnar epithelial cells, superficial squamous keratinized cells, lymphocytes, heterophils, red blood cells, mucus and bacteria. The histological analysis revealed a stratified epithelium, characterized by the presence of columnar epithelial cells with a large number of goblet cells. The reported data can be used for therapeutic or experimental purposes

The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun’s centre, equal to half of Mercury’s perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics