41 research outputs found

    Conjugacy and geometry I : foot of the perpendicular, distance and gram determinant

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    In this note on space geometry, the Gram determinant is used for expressing distances, vectors whose magnitude equals those distances and best approximation points. Three cases are considered: distances from a point to a line and to a plane and distances between two skew lines. (Symbolic) determinants occur in the expressions of the feet of perpendiculars and in the representation of the vectors materializing the distances. Because best approximation problems often require the use of subspaces, in order to solve the general cases of the proposed problems, we make extensive use of the conjugacy principle much present in Mathematics. The main purpose of this paper, focused on the resolution of distance problems in tridimensional geometry, is to provide the acquisition of spatial abilities through the proposed constructive approach. The obtained results, which could be a starting point and give clues for solving more advanced geometry problems, are applicable in several fields of practical sciences, such as the Coordinate Metrology, for instance. Moreover, this paper may be a window for coming across with a diversity of scalar products.info:eu-repo/semantics/publishedVersio

    Sustainable plant polyesters as substrates for optical gas sensors

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    UIDB/04378/2020 PTDC/BII-BIO/28878/2017 PTDC/SAU-SER/30388/2017 SFRH-BD-110467-2015The fast and non-invasive detection of odors and volatile organic compounds (VOCs) by gas sensors and electronic noses is a growing field of interest, mostly due to a large scope of potential applications. Additional drivers for the expansion of the field include the development of alternative and sustainable sensing materials. The discovery that isolated cross-linked polymeric structures of suberin spontaneously self-assemble as a film inspired us to develop new sensing composite materials consisting of suberin and a liquid crystal (LC). Due to their stimuli-responsive and optically active nature, liquid crystals are interesting probes in gas sensing. Herein, we report the isolation and the chemical characterization of two suberin types (from cork and from potato peels) resorting to analyses of gas chromatography–mass spectrometry (GC-MS), solution nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS). The collected data highlighted their compositional and structural differences. Cork suberin showed a higher proportion of longer aliphatic constituents and is more esterified than potato suberin. Accordingly, when casted it formed films with larger surface irregularities and a higher C/O ratio. When either type of suberin was combined with the liquid crystal 5CB, the ensuing hybrid materials showed distinctive morphological and sensing properties towards a set of 12 VOCs (comprising heptane, hexane, chloroform, toluene, dichlormethane, diethylether, ethyl acetate, acetonitrile, acetone, ethanol, methanol, and acetic acid). The optical responses generated by the materials are reversible and reproducible, showing stability for 3 weeks. The individual VOC-sensing responses of the two hybrid materials are discussed taking as basis the chemistry of each suberin type. A support vector machines (SVM) algorithm based on the features of the optical responses was implemented to assess the VOC identification ability of the materials, revealing that the two distinct suberin-based sensors complement each other, since they selectively identify distinct VOCs or VOC groups. It is expected that such new environmentally-friendly gas sensing materials derived from natural diversity can be combined in arrays to enlarge selectivity and sensing capacity.publishersversionpublishe

    Self-reported diabetes in older people: comparison of prevalences and control measures

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    OBJECTIVE The objective of this study was to analyze the prevalence of diabetes in older people and the adopted control measures. METHODS Data regarding older diabetic individuals who participated in the Health Surveys conducted in the Municipality of Sao Paulo, SP, ISA-Capital, in 2003 and 2008, which were cross-sectional studies, were analyzed. Prevalences and confidence intervals were compared between 2003 and 2008, according to sociodemographic variables. The combination of the databases was performed when the confidence intervals overlapped. The Chi-square (level of significance of 5%) and the Pearson’s Chi-square (Rao-Scott) tests were performed. The variables without overlap between the confidence intervals were not tested. RESULTS The age of the older adults was 60-69 years. The majority were women, Caucasian, with an income of between > 0.5 and 2.5 times the minimum salary and low levels of schooling. The prevalence of diabetes was 17.6% (95%CI 14.9;20.6) in 2003 and 20.1% (95%CI 17.3;23.1) in 2008, which indicates a growth over this period (p at the limit of significance). The most prevalent measure adopted by the older adults to control diabetes was hypoglycemic agents, followed by diet. Physical activity was not frequent, despite the significant differences observed between 2003 and 2008 results. The use of public health services to control diabetes was significantly higher in older individuals with lower income and lower levels of education. CONCLUSIONS Diabetes is a complex and challenging disease for patients and the health systems. Measures that encourage health promotion practices are necessary because they presented a smaller proportion than the use of hypoglycemic agents. Public health policies should be implemented, and aimed mainly at older individuals with low income and schooling levels. These changes are essential to improve the health condition of older diabetic patients

    "Sou escravo de oficiais da Marinha": a grande revolta da marujada negra por direitos no período pós-abolição (Rio de Janeiro, 1880-1910)

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    Genotype and phenotype landscape of MEN2 in 554 medullary thyroid cancer patients: the BrasMEN study

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    Multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant genetic disease caused by RET gene germline mutations that is characterized by medullary thyroid carcinoma (MTC) associated with other endocrine tumors. Several reports have demonstrated that the RET mutation profile may vary according to the geographical area. In this study, we collected clinical and molecular data from 554 patients with surgically confirmed MTC from 176 families with MEN2 in 18 different Brazilian centers to compare the type and prevalence of RET mutations with those from other countries. The most frequent mutations, classified by the number of families affected, occur in codon 634, exon 11 (76 families), followed by codon 918, exon 16 (34 families: 26 with M918T and 8 with M918V) and codon 804, exon 14 (22 families: 15 with V804M and 7 with V804L). When compared with other major published series from Europe, there are several similarities and some differences. While the mutations in codons C618, C620, C630, E768 and S891 present a similar prevalence, some mutations have a lower prevalence in Brazil, and others are found mainly in Brazil (G533C and M918V). These results reflect the singular proportion of European, Amerindian and African ancestries in the Brazilian mosaic genome

    Mucopolysaccharidosis I, II, and VI: Brief review and guidelines for treatment

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    Mucopolysaccharidoses (MPS) are rare genetic diseases caused by the deficiency of one of the lysosomal enzymes involved in the glycosaminoglycan (GAG) breakdown pathway. This metabolic block leads to the accumulation of GAG in various organs and tissues of the affected patients, resulting in a multisystemic clinical picture, sometimes including cognitive impairment. Until the beginning of the XXI century, treatment was mainly supportive. Bone marrow transplantation improved the natural course of the disease in some types of MPS, but the morbidity and mortality restricted its use to selected cases. The identification of the genes involved, the new molecular biology tools and the availability of animal models made it possible to develop specific enzyme replacement therapies (ERT) for these diseases. At present, a great number of Brazilian medical centers from all regions of the country have experience with ERT for MPS I, II, and VI, acquired not only through patient treatment but also in clinical trials. Taking the three types of MPS together, over 200 patients have been treated with ERT in our country. This document summarizes the experience of the professionals involved, along with the data available in the international literature, bringing together and harmonizing the information available on the management of these severe and progressive diseases, thus disclosing new prospects for Brazilian patients affected by these conditions

    A produção escrita de alunos com e sem sĂ­ndrome de Down: uma anĂĄlise da coerĂȘncia textual

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    Neste trabalho, analisa-se a coerĂȘncia textual a partir da reescrita do conto de Rapunzel. Baseia-se em uma abordagem psicogenĂ©tica da lĂ­ngua escrita. Participaram desse estudo nove alunos, sendo seis com sĂ­ndrome de Down (Grupo I) e os outros trĂȘs sem deficiĂȘncia (Grupo II). Eles cursavam entre o 2Âș e 8Âș anos do Ensino Fundamental em escolas regulares. O procedimento de produção textual consistiu em um encontro individual, cuja solicitação de produção escrita era precedida pela leitura do conto pela pesquisadora. Os dados indicaram a presença da coerĂȘncia textual nos dois grupos, embora mais frequente nas produçÔes do grupo II, que demonstrava maior competĂȘncia com os elementos de coerĂȘncia textual. O grupo II apresentou estratĂ©gias poderosas para mobilizar os recursos cognitivos que permitiram articular conhecimentos anteriores e focalizĂĄ-los na produção e articulação de suas ideias no texto. O grupo I, na sua maioria, experimentava dificuldades em elaborar um desfecho em estreita relação com as partes que compunham o texto. NĂŁo apresentaram, porĂ©m, dificuldades em definir e manter a personagem principal ao longo de toda a histĂłria escrita, mesmo quando a histĂłria era incoerente se considerarmos outros indicadores. Qualitativamente, os textos dos alunos com sĂ­ndrome de Down se diferenciaram daqueles produzidos pelo grupo II. NĂŁo identificamos, porĂ©m, caracterĂ­sticas que podem representar especificidades na produção escrita dos alunos com essa sĂ­ndrome, visto que alguns alunos com sĂ­ndrome de Down produziram textos apresentando coerĂȘncia

    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ
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