When a TeV-scale leptoquark has a sizeable Yukawa coupling, its dominant production mechanism at hadron colliders is the partonic-level lepton-quark fusion. Even though the parton distribution functions for leptons inside the proton are minuscule, they get compensated by the resonant enhancement. We present the first computation of higher order radiative corrections to the resonant leptoquark production cross section at the Large Hadron Collider (LHC). Next-to-leading (NLO) QCD and QED corrections are similar in size but come with the opposite sign. We compute NLO K-factors for a wide range of scalar leptoquark masses, as well as, all possible combinations of quark and lepton flavors and leptoquark charges. Theoretical uncertainties due to the renormalisation and factorisation scale variations and the limited knowledge of parton distribution functions are quantified. We finally discuss how to disentangle the flavor structure of leptoquark interactions by exploiting the interplay between different production channels.

Abstract The aim of this study was to determine the cytogenotoxic effects of methylparaben, ethylparaben and butylparaben using battery of tests in plant cells (Allium cepa assay) and human lymphocytes (chromosome aberration test and alkaline comet assay). Our results for A. cepa assay showed that none of the tested parabens showed an inducing effect on root growth. Mitotic index values decreased with increasing parabens concentration. Ethylparaben (0.10 mg/L) induced a higher number of vagrants and multipolarity, as well as the number of sticky chromosomes (0.50 mg/L), while butylparaben (0.25 and 0.50 mg/L) increased the frequency of sticky chromosomes. Higher frequency of apoptosis and necrosis was observed for ethylparaben (0.50 mg/L) and methylparaben (0.10 and 0.50 mg/L). As for chromosome aberrations test in human lymphocytes, the mitotic index was reduced with an increase in the concentration of all three tested parabens. Differences between methylparaben (0.25 mg/L), ethylparaben (0.10 mg/L) and butylparaben (0.25 mg/L) and controls for acentric fragments, chromatid breaks and polyploidy were observed. Increased frequency of apoptosis was induced by methylparaben and ethylparaben at concentrations of 0.25 and 0.50 mg/L. Alkaline comet assay demonstrated that 0.25 and 0.50 mg/L of ethylparaben and butylparaben have genotoxic potential by increasing the tail intensity against controls. These results suggest that methyl-, ethyl- and butylparaben possess certain geno/cytotoxic potential.

Using X-ray single crystal diffraction, the crystal structures of biologically active benzoxazole derivatives were determined. DFT calculation was performed with standard 6-31G*(d), 6-31G** and 6-31+G* basis set to analyze the molecular geometry and compare with experimentally obtained X-ray crystal data of compounds. The calculated HOMO-LUMO energy gap in compound 2 (2-(2-hydroxynaphtalen-1-yl)-4-methyl-7-isopropyl-1,3-benzoxazol-5-ol) is 3.80 eV and this small gap value indicates that compound 2 is chemically more reactive compared to compounds 1 (4-methyl-2-phenyl-7-isopropyl-1,3-benzoxazol-5-ol) and 3 (2-(4-chlorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazol-5-ol). The crystal structures are stabilized by both intra- and intermolecular hydrogen bonds in which an intermolecular O-H⋅⋅⋅N hydrogen bond generates N3 and O7 chain motif in compounds 1, 2, and 3, respectively. The calculated bond lengths and bond angles of all three compounds are remarkably close to the experimental values obtained by X-ray single crystal diffraction.

There is a great demand for accurate non‐invasive measures to better define the natural history of disease progression or treatment outcome in Duchenne muscular dystrophy (DMD) and to facilitate the inclusion of a large range of participants in DMD clinical trials. This review aims to investigate which MRI sequences and analysis methods have been used and to identify future needs. Medline, Embase, Scopus, Web of Science, Inspec, and Compendex databases were searched up to 2 November 2019, using keywords “magnetic resonance imaging” and “Duchenne muscular dystrophy.” The review showed the trend of using T1w and T2w MRI images for semi‐qualitative inspection of structural alterations of DMD muscle using a diversity of grading scales, with increasing use of T2map, Dixon, and MR spectroscopy (MRS). High‐field (>3T) MRI dominated the studies with animal models. The quantitative MRI techniques have allowed a more precise estimation of local or generalized disease severity. Longitudinal studies assessing the effect of an intervention have also become more prominent, in both clinical and animal model subjects. Quality assessment of the included longitudinal studies was performed using the Newcastle‐Ottawa Quality Assessment Scale adapted to comprise bias in selection, comparability, exposure, and outcome. Additional large clinical trials are needed to consolidate research using MRI as a biomarker in DMD and to validate findings against established gold standards. This future work should use a multiparametric and quantitative MRI acquisition protocol, assess the repeatability of measurements, and correlate findings to histologic parameters.

Deep learning (DL) and the collocation method are merged and used to solve partial differential equations (PDEs) describing structures' deformation. We have considered different types of materials: linear elasticity, hyperelasticity (neo‐Hookean) with large deformation, and von Mises plasticity with isotropic and kinematic hardening. The performance of this deep collocation method (DCM) depends on the architecture of the neural network and the corresponding hyperparameters. The presented DCM is meshfree and avoids any spatial discretization, which is usually needed for the finite element method (FEM). We show that the DCM can capture the response qualitatively and quantitatively, without the need for any data generation using other numerical methods such as the FEM. Data generation usually is the main bottleneck in most data‐driven models. The DL model is trained to learn the model's parameters yielding accurate approximate solutions. Once the model is properly trained, solutions can be obtained almost instantly at any point in the domain, given its spatial coordinates. Therefore, the DCM is potentially a promising standalone technique to solve PDEs involved in the deformation of materials and structural systems as well as other physical phenomena.

O artigo analisa textos de estudantes do setimo ano, do Ensino Fundamental de uma escola publica do campo, de Barreiras – BA. Nessa analise, consideramos o contexto social, economico e cultural a que pertencem esses estudantes. Metodologicamente, trabalhamos etnografia de sala de aula, realizando: observacao, descricao e analise, e participacao colaborativa, com a aplicacao de sequencia didatica, e o uso do texto biografico, subsidiando a producao do texto autobiografico. A luz da teoria dos letramentos multiplos e da leitura sociolinguistica, foi possivel reconhecer a necessidade da observacao do lugar de pertenca do estudante no/do campo e suas distintas praticas de conhecimento de leitura e de escrita, bem como a importância da valorizacao dessa cultura no contexto escolar. Encontramos nos textos escritos, evidentes demarcacoes dos fatores socioculturais de seu autor, com multiplas expressoes e marcas linguisticas que identificam o lugar de pertencimento que, em certos casos, nao sao compreendidas em sala de aula.

Este estudo objetiva discutir a proposta do Programa de Residencia Pedagogica (PRP), relacionado a Politica Nacional de Formacao de Professores, apresentada pelo MEC em 18 de outubro de 2017. A proposta de Residencia Pedagogica foi apresentada no governo de Michel Temer no ano de 2017, teve seu rumo incerto apos uma breve descontinuidade em 2019 e foi retomada com o lancamento de um novo edital no ano de 2020. Destacamos que o atual contexto politico e educacional do Brasil demanda discussoes aprofundadas que busquem problematizar as concepcoes presentes nos projetos de formacao docente em disputa. Intentamos no desenvolvimento desta pesquisa, analisar a proposta do Programa de Residencia Pedagogica, bem como seus possiveis efeitos para a formacao de professores no Brasil. O estudo se organiza em 4 secoes, buscando uma retomada historica da constituicao da formacao docente no pais para a investigacao acerca das concepcoes de formacao docente presentes no PRP. A presente investigacao esta fundamentada na perspectiva metodologica da pesquisa qualitativa, a partir da analise documental e da analise de conteudo. Com este estudo, foi possivel perceber que o PRP vem ao encontro de premissas tecnicistas do fazer docente e demonstra em sua essencia uma visao pragmatica da formacao de professores, entretanto, a autonomia universitaria permitiu algumas iniciativas contra hegemonicas para a organizacao do projeto. PALAVRAS-CHAVE: Formacao de professores; residencia pedagogica; politicas educacionais. Doi: 10.21703/rexe.20201941caporal17

Abstract In spring 2020 both teachers and learners experienced the interruption of education as it had been established for over 150 years and seemed to be unchangeable. The paper focuses on students’ perspectives on how they perceive the changes in learning due to the pandemic educational emergency response based on the results of a survey of students in four countries: Bosnia and Herzegovina, North Macedonia, Poland and Turkey. We aim at discussing the data collected at the end of the 2019-2020 Spring semester. The research focuses on the accessibility of the tools for learning, modes of instruction, as well as interaction patterns. In addition, we present students’ opinions on the difficulties they experienced, the learning strategies they adopted and what aspects of online learning should remain as a regular educational practice after the pandemic period.