Modernidade e Educação em Darcy Ribeiro: uma reflexão decolonial sobre o sistema educacional brasileiro

Resumo: Este artigo tem o objetivo de explicitar o entrelaçamento entre a modernidade e o processo organização do sistema educacional brasileiro. Para isto, tomamos a trajetória político-intelectual de Darcy Ribeiro (1922-1997) enquanto objeto de análise. A hipótese defendida, é que o posicionamento anti-imperialista de Darcy Ribeiro em suas inciativas educacionais dá a base para a construção de um projeto decolonial. Para isto, realizamos a crítica à ideia de modernidade, e apresentamos o conceito de decolonialidade a partir de Aníbal Quijano, Ramón Grosfoguel e Boaventura de Sousa Santos. Assim, objetivamos tensionar o pensamento darcyniano com a abordagem decolonial. Justificamos esta escolha no fato que Darcy Ribeiro foi um dos atores centrais nas dinâmicas de institucionalização do ensino no Brasil. Nos espaços públicos e acadêmicos, se posicionou criticamente sobre os rumos que a modernidade e educação deveriam tomar nos países latino-americanos, segundo as suas especificidades para atingirem a autonomia sociocultural. Palavras-chave: Darcy Ribeiro; Modernidade; Sistema de Educação; Crítica

Effects of dancing on physical activity levels of children and adolescents : a systematic review

Background: Dancing has been suggested to increase the levels of physical activity of the youth. However, it is not clear what are the physiological characteristics of the dance classes for young people, mainly regarding the levels of moderate to vigorous physical activity (MVPA) during classes. It is also unclear if regular engagement in dance practices can contribute with increases in the amounts of daily/weekly MVPA, recommended by health organizations. Objectives: To conduct a systematic review verifying the amount of time spent at MVPA (primary outcome), by children and adolescents in the following situations: i) During dance classes, and ii) Before and after dance in- terventions. Secondary outcomes included: markers of exercise intensity during class, such as oxygen con- sumption (VO2) and heart rate (HR); VO2peak and lipid profile before and after dance interventions. Methods: Six data sources were accessed (MEDLINE, EMBASE, Cochrane Wiley, PEDRO and SCOPUS). Study selection included different designs (acute, cohort, randomized controlled trials and others). Participants were from 6 to 19 years old, regularly engaged in dance practices. Methodological quality was assessed using the Downs and Black checklist. Two independent reviewers extracted characteristics and results of each study. Results: 3216 articles were retrieved, and 37 included. Studies indicated that dance classes do not achieve 50% of total class time at MVPA. However, there are peaks of HR and VO2 during dance classes, which reach moderate and vigorous intensities. MVPA/daily/weekly did not improve before and after dance interventions for most of the studies, also VO2peak did not. The few results on lipid profile showed improvements only in overweight and obese participants. Limitations: Lack of meta-analysis, because there were not enough articles to be analyzed on any given outcome of interest, neither under the same study design. Conclusions: Results of individual studies indicated that dance classes did not active 50% of the total time at MVPA levels. This may be related to the absence of improvements in daily/weekly MVPA before and after dance interventions. VO2 and HR attained peaks of moderateto vigorous intensity during dance classes, suggesting that the structure of the classes may be manipulated to maintain longer periods at MVPA levels. Lack of data on cardiorespiratory fitness and metabolic outcomes limit conclusions on these parameters. Implications of Keys Finds: Considering there are peaks of HR and VO2 during dance classes, we suggest that the structure of a dance class can be manipulate in order to induce cardiorespiratory and metabolic adaptations. Thus, dancing is a potential strategy to contribute with a healthy life style since the earliest ages. Prospero registration: CRD4202014460

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

The Cloning and Characterization of a Three-Finger Toxin Homolog (NXH8) from the Coralsnake <i>Micrurus corallinus</i> That Interacts with Skeletal Muscle Nicotinic Acetylcholine Receptors

Coralsnakes (Micrurus spp.) are the only elapids found throughout the Americas. They are recognized for their highly neurotoxic venom, which is comprised of a wide variety of toxins, including the stable, low-mass toxins known as three-finger toxins (3FTx). Due to difficulties in venom extraction and availability, research on coralsnake venoms is still very limited when compared to that of other Elapidae snakes like cobras, kraits, and mambas. In this study, two previously described 3FTx from the venom of M. corallinus, NXH1 (3SOC1_MICCO), and NXH8 (3NO48_MICCO) were characterized. Using in silico, in vitro, and ex vivo experiments, the biological activities of these toxins were predicted and evaluated. The results showed that only NXH8 was capable of binding to skeletal muscle cells and modulating the activity of nAChRs in nerve–diaphragm preparations. These effects were antagonized by anti-rNXH8 or antielapidic sera. Sequence analysis revealed that the NXH1 toxin possesses eight cysteine residues and four disulfide bonds, while the NXH8 toxin has a primary structure similar to that of non-conventional 3FTx, with an additional disulfide bond on the first loop. These findings add more information related to the structural diversity present within the 3FTx class, while expanding our understanding of the mechanisms of the toxicity of this coralsnake venom and opening new perspectives for developing more effective therapeutic interventions