Os gêneros de discurso do texto de biologia dos livros didáticos de ciências

Este trabalho analisa o texto de biologia do livro didático de ciências. A hipótese principal é que esse texto constitui-se em um gênero  de discurso distinto, construído a partir de elementos dos gêneros de discurso científico, didático e cotidiano. Para estudar essa hipótese, buscamos apoio nas concepções de Bakhtin (1953/1997) sobre gêneros de discurso e linguagem social e usamos um conjunto de categorias para caracterizar esses diferentes gêneros de discurso. Essas categorias foram construídas a partir das tipologias textuais de Bronckart (1999) baseadas nas ordens do ‘narrar’ e do ‘expor’; da estrutura analítica utilizada Mortimer e Scott (2002, 2003) para analisar o discurso de sala de aula de ciências; e de alguns elementos gramaticais identificados por Halliday e Martin (1993) nos textos científicos e didáticos. Tendo por base a análise de coleções didáticas de Ciências, do segmento de 5a a 8a série, recomendadas pelo Programa Nacional do Livro Didático  – PNLD/1999 e PNLD/2002, do Ministério de Educação – MEC, foram selecionadas duas coleções, ambas recomendadas nas avaliações do PNLD em 1999 e em 2002 e escolhidas por um número expressivo de professores da rede pública nos dois PNLDs. Foram analisados dois capítulos diferentes dessas coleções, que contemplam temas biológicos distintos – metabolismo e diversidade dos seres vivos. Num primeiro momento, as categorias são explicitadas e exemplificadas por trechos extraídos desses capítulos. A seguir, todos os períodos que constituem os textos desses diferentes capítulos são analisados segundo essas categorias, o que permitiu verificar nossa hipótese de trabalho e fazer inferências sobre a articulação entre os gêneros nos diferentes conteúdos abordados e sobre as particularidades de cada coleção

Perfis de força: velocidade no sprint em jogadores portugueses de futebol e futsal: um estudo piloto transversal

Background: Sprint running is a key factor of performance for team sports as football and futsal. Force-power-velocity relationships and mechanical effectiveness have been recently used to analyse force-velocity (F-V) profiles. The aim of this study was two-fold: (1) to quantify the sprint mechanical F-V profiles in Portuguese football and futsal players; (2) to analyse differences among sexes, competitive levels and sports on sprint mechanical variables in Portuguese football and futsal players. Methods: Four football players (2 mens) and four futsal players (2 mens), aged 26 ± 4.24 years, performed a 3 maximal sprints of 30 m from a standing position with 4 min of rest between successive sprints. Video data was collected with a Go Pro Hero (Full HD 1080p, 30 fps). Force-velocity profile was obtained with time motion data: F0 (N/kg), V0 (m/s), Pmax (W/kg), Sfv, RFmax (%), DRF (%), Vopt (m/s) and max speed (m/s). Results: Men’s players showed a higher V0 (t = -7.12;p<0.001,d=5.04),Vopt (t=-2.90;p≤ 0.05,d=2.05)andmaxspeed(t=-5.09;p≤ 0.05, d = 3.60) than women players. No differences with statistical significance were observed among competitive levels and sports. Conclusion: These results showed that the sprint mechanical F-V profiles is able to distinguish between men and women football and futsal players. No differences among competitive levels could be due to the low competitive level of the sample. Future research should include different competitive level such as elite, sub-elite and recreational.Enqudramento – O sprint é um fator determinante para o desempenho em desportos coletivos como o futebol e o futsal. As relações força-potência-velocidade e eficácia mecânica têm sido recentemente utilizadas para analisar perfis de força-velocidade (F-V). O objetivo deste estudo era duplo: (1) quantificar os perfis biomecânicos F-V do sprint em jogadores de futebol e futsal portugueses; (2) analisar diferenças entre sexos, níveis competitivos e desportos nas variáveis em estudo. Métodos – 4 jogadores de futebol (2 homens) e 4 jogadores de futsal (2 homens), com 26 ± 4,24 anos, realizaram 3 sprints máximos de 30 m a partir de uma posição de pé com 4 min de descanso entre sprints sucessivos. Foram recolhidos dados de vídeo com um Go Pro Hero (Full HD 1080p, 30 fps). O perfil de força- velocidade foi obtido com: F0 (N/kg), V0 (m/s), Pmax (W/kg), Sfv, RFmax (%), DRF (%), Vopt (m/s) e velocidade máxima (m/s). Results – Os jogadores masculinos mostraram umV0 (t=-7,12;p<0,001,d=5,04),Vopt (t=- 2,90; p ≤ 0,05, d = 2,05) e velocidade máxima (t =-5,09;p≤0,05,d=3,60)maisaltadoque nas jogadoras femininas. Não foram observadas diferenças com significado estatístico entre os níveis competitivos e o desporto. Conclusão – Estes resultados mostraram que os perfis mecânicos de sprint (F-V) são capazes de diferenciar entre jogadores masculinos e femininos de futebol e jogadores de futsal. Nenhuma diferença entre os níveis competitivos pode dever-se ao baixo nível competitivo da amostra. A investigação futura deve incluir diferentes níveis competitivos, tais como elite, subelite e recreativo.info:eu-repo/semantics/publishedVersio

Complete atrioventricular block during exercise: New insights from an old test

Exercise stress testing can have a central role in the assessment of cardiovascular disease. Contemporary data, however, has highlighted the added value of imaging modalities over the exercise electrocardiogram in the investigation of coronary artery disease. Given the physiological changes associated with exercise and the possibility to address other parameters such as rhythm changes and the chronotropic response, exercise stress testing with continuous electrocardiographic monitoring can still have an important place in contemporary clinical practice. We report the case of a complete atrioventricular block associated with exercise and discuss the current role of exercise stress testing with continuous electrocardiographic monitoring in this entity

The first observed stellar occultations by the irregular satellite Phoebe (Saturn IX) and improved rotational period

peer reviewedWe report six stellar occultations by Phoebe (Saturn IX), an irregular satellite of Saturn, obtained between mid-2017 and mid-2019. The 2017 July 6 event was the first stellar occultation by an irregular satellite ever observed. The occultation chords were compared to a 3D shape model of the satellite obtained from Cassini observations. The rotation period available in the literature led to a sub-observer point at the moment of the observed occultations where the chords could not fit the 3D model. A procedure was developed to identify the correct sub-observer longitude. It allowed us to obtain the rotation period with improved precision compared to the currently known value from literature. We show that the difference between the observed and the predicted sub-observer longitude suggests two possible solutions for the rotation period. By comparing these values with recently observed rotational light curves and single- chord stellar occultations, we can identify the best solution for Phoebe's rotational period as 9.27365 ± 0.00002 h. From the stellar occultations, we also obtained six geocentric astrometric positions in the ICRS as realized by the Gaia DR2 with uncertainties at the 1-mas level

T-Cell Memory Responses Elicited by Yellow Fever Vaccine are Targeted to Overlapping Epitopes Containing Multiple HLA-I and -II Binding Motifs

The yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulating antibody production and the killing of infected cells. However, little is known about the repertoire of T-cell responses elicited by the YF-17DD vaccine in humans. In this report, a library of 653 partially overlapping 15-mer peptides covering the envelope (Env) and nonstructural (NS) proteins 1 to 5 of the vaccine was utilized to perform a comprehensive analysis of the virus-specific CD4+ and CD8+ T-cell responses. The T-cell responses were screened ex-vivo by IFN-γ ELISPOT assays using blood samples from 220 YF-17DD vaccinees collected two months to four years after immunization. Each peptide was tested in 75 to 208 separate individuals of the cohort. The screening identified sixteen immunodominant antigens that elicited activation of circulating memory T-cells in 10% to 33% of the individuals. Biochemical in-vitro binding assays and immunogenetic and immunogenicity studies indicated that each of the sixteen immunogenic 15-mer peptides contained two or more partially overlapping epitopes that could bind with high affinity to molecules of different HLAs. The prevalence of the immunogenicity of a peptide in the cohort was correlated with the diversity of HLA-II alleles that they could bind. These findings suggest that overlapping of HLA binding motifs within a peptide enhances its T-cell immunogenicity and the prevalence of the response in the population. In summary, the results suggests that in addition to factors of the innate immunity, "promiscuous" T-cell antigens might contribute to the high efficacy of the yellow fever vaccines. © 2013 de Melo et al

Escleroterapia de hemangioma em borda lateral de língua: relato de caso

Os hemangiomas são lesões vasculares benignas que muitas vezes ocorrem na cavidade bucal podendo apresentar crescimento progressivo e sangramentos inesperados de difícil controle, quando expostos a traumas. Diversas formas de tratamento estão descritas na literatura, sendo mais comumente utilizada a cirurgia excisional e a escleroterapia. Objetivo: relatar um caso clínico de hemangioma em língua num paciente adulto portador desta lesão desde o nascimento. Metodologia: paciente do sexo feminino, 53 anos, portador de hemangioma situado na região lateral esquerda da língua, caracterizado pelo crescimento espontâneo e histórico de duas ressecções cirúrgicas com recidivas em um curto intervalo de tempo, foi submetido a procedimentos de escleroterapia através da aplicação intralesional do oleato de monoetanolamina a 5% diluído em glicose a 50% por três ciclos de seis aplicações do quimioterápico, com intervalo de quatro meses entre os ciclos. Resultados: finda as intervenções, o acompanhamento pós-escleroterapia do paciente durante cinco anos revelou êxito do tratamento realizado, uma vez que após este período inexistem sinais clínicos de recidiva. Conclusão: os resultados deste estudo expressam a eficácia da escleroterapia realizada com o uso do oleato de monoetanolamina associado à adoção de um método não invasivo.

Synthesis of Selenium-Quinone Hybrid Compounds with Potential Antitumor Activity via Rh-Catalyzed C-H Bond Activation and Click Reactions

In continuation of our quest for new redox-modulating catalytic antitumor molecules, selenium-containing quinone-based 1,2,3-triazoles were synthesized using rhodium-catalyzed C-H bond activation and click reactions. All compounds were evaluated against five types of cancer cell lines: HL-60 (human promyelocytic leukemia cells), HCT-116 (human colon carcinoma cells), SF295 (human glioblastoma cells), NCIH-460 (human lung cells) and PC3 (human prostate cancer cells). Some compounds showed good activity with IC50 values below 1 µM. The cytotoxic potential of the naphthoquinoidal derivatives was also evaluated in non-tumor cells, exemplified by L929 cells. Overall, these compounds represent promising new lead derivatives and stand for a new class of chalcogenium-containing derivatives with potential antitumor activity

Adenine interaction with and adsorption on Fe-ZSM-5 zeolites: A prebiotic chemistry study using different techniques

Most adsorption experiments are performed under conditions that did not exist on Earth before the life arose on it. Because adsorption is the first step for all other processes (protection against degradation and polymerization), it is important that it is performed under conditions that existed on prebiotic Earth. In this paper, we use an artificial seawater (seawater 4.0 Ga), which contains major cations and anions that could present on the oceans of the prebiotic Earth. In addition, zeolites, with substituted Fe in the framework, and adenine were probably common substances on the prebiotic Earth. Thus, study the interaction between them is an important issue in prebiotic chemistry. There are two main findings described in this paper. Firstly, zeolites with different Si/Fe ratios adsorbed adenine differently. Secondly, XAFS showed that, after treatments with seawater 4.0 Ga and adenine, an increase in the complexity of the system occurred. In general, salts of seawater 4.0 Ga did not affect the adsorption of adenine onto zeolites and adenine adsorbed less onto zeolites with iron isomorphically substituted. The C=C and NH2 groups of adenine interacted with the zeolites. Gypsum, formed from aqueous species dissolved in seawater 4.0 Ga, precipitated onto zeolites. EPR spectra of zeolites showed lines caused by Fe framework and Fe3+ species. TG curves of zeolites showed events caused by loss of water weakly bound to zeolite (in the 30-140 °C range), water bounded to iron species or cations from seawater 4.0 Ga or located in the cavities of zeolites (157-268 °C) and degradation of adenine adsorbed onto zeolites (360-600 °C). Mass loss follows almost the same order as the amount of adenine adsorbed onto zeolites. The XAFS spectrum showed that Fe3+ could be substituted into the framework of the Fe7-ZSM-5 zeolite

Gene Expression Profiling during Early Acute Febrile Stage of Dengue Infection Can Predict the Disease Outcome

Background: We report the detailed development of biomarkers to predict the clinical outcome under dengue infection. Transcriptional signatures from purified peripheral blood mononuclear cells were derived from whole-genome gene-expression microarray data, validated by quantitative PCR and tested in independent samples. Methodology/Principal Findings: The study was performed on patients of a well-characterized dengue cohort from Recife, Brazil. The samples analyzed were collected prospectively from acute febrile dengue patients who evolved with different degrees of disease severity: classic dengue fever or dengue hemorrhagic fever (DHF) samples were compared with similar samples from other non-dengue febrile illnesses. The DHF samples were collected 2-3 days before the presentation of the plasma leakage symptoms. Differentially-expressed genes were selected by univariate statistical tests as well as multivariate classification techniques. The results showed that at early stages of dengue infection, the genes involved in effector mechanisms of innate immune response presented a weaker activation on patients who later developed hemorrhagic fever, whereas the genes involved in apoptosis were expressed in higher levels. Conclusions/Significance: Some of the gene expression signatures displayed estimated accuracy rates of more than 95%, indicating that expression profiling with these signatures may provide a useful means of DHF prognosis at early stages of infection. © 2009 Nascimento et al

Global priority areas for ecosystem restoration

Extensive ecosystem restoration is increasingly seen as being central to conserving biodiversity1 and stabilizing the climate of the Earth2. Although ambitious national and global targets have been set, global priority areas that account for spatial variation in benefits and costs have yet to be identified. Here we develop and apply a multicriteria optimization approach that identifies priority areas for restoration across all terrestrial biomes, and estimates their benefits and costs. We find that restoring 15% of converted lands in priority areas could avoid 60% of expected extinctions while sequestering 299 gigatonnes of CO2—30% of the total CO2 increase in the atmosphere since the Industrial Revolution. The inclusion of several biomes is key to achieving multiple benefits. Cost effectiveness can increase up to 13-fold when spatial allocation is optimized using our multicriteria approach, which highlights the importance of spatial planning. Our results confirm the vast potential contributions of restoration to addressing global challenges, while underscoring the necessity of pursuing these goals synergistically.Fil: Strassburg, Bernardo B. N.. Pontifícia Universidade Católica do Rio de Janeiro; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Iribarrem, Alvaro. Pontifícia Universidade Católica do Rio de Janeiro; BrasilFil: Beyer, Hawthorne L.. The University of Queensland; Australia. University of Queensland; AustraliaFil: Cordeiro, Carlos Leandro. Pontifícia Universidade Católica do Rio de Janeiro; BrasilFil: Crouzeilles, Renato. Universidade Federal do Rio de Janeiro; Brasil. Pontifícia Universidade Católica do Rio de Janeiro; BrasilFil: Jakovac, Catarina C.. Pontifícia Universidade Católica do Rio de Janeiro; BrasilFil: Braga Junqueira, André. Pontifícia Universidade Católica do Rio de Janeiro; BrasilFil: Lacerda, Eduardo. Pontifícia Universidade Católica do Rio de Janeiro; Brasil. Universidade Federal Fluminense; BrasilFil: Latawiec, Agnieszka E.. University of East Anglia; Reino Unido. Pontifícia Universidade Católica do Rio de Janeiro; BrasilFil: Balmford, Andrew. University of Cambridge; Estados UnidosFil: Brooks, Thomas M.. University Of The Philippines Los Banos; Filipinas. Institute For Marine And Antarctic Studies; Australia. International Union For Conservation Of Nature And Natural Resources; SuizaFil: Butchart, Stuart H. M.. University of Cambridge; Estados UnidosFil: Chazdon, Robin L.. University Of The Sunshine Coast; Australia. University of Connecticut; Estados UnidosFil: Erb, Karl-Heinz. Universitat Fur Bodenkultur Wien; AustriaFil: Brancalion, Pedro. Universidade de Sao Paulo; BrasilFil: Buchanan, Graeme. Royal Society For The Protection Of Birds; Reino UnidoFil: Cooper, David. Secretariat Of The Convention On Biological Diversity; CanadáFil: Díaz, Sandra Myrna. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Donald, Paul F.. University of Cambridge; Estados UnidosFil: Kapos, Valerie. United Nations Environment Programme World Conservation Monitoring Centre; Reino UnidoFil: Leclère, David. International Institute For Applied Systems Analysis, Laxenburg; AustriaFil: Miles, Lera. United Nations Environment Programme World Conservation Monitoring Centre; Reino UnidoFil: Obersteiner, Michael. Oxford Social Sciences Division; Reino Unido. International Institute For Applied Systems Analysis, Laxenburg; AustriaFil: Plutzar, Christoph. Universitat Fur Bodenkultur Wien; Austria. Universidad de Viena; AustriaFil: de M. Scaramuzza, Carlos Alberto. International Institute For Sustainability; BrasilFil: Scarano, Fabio R.. Universidade Federal do Rio de Janeiro; BrasilFil: Visconti, Piero. International Institute For Applied Systems Analysis, Laxenburg; Austri