612 research outputs found

    Improvements in attention and cardiac autonomic modulation after a 2-weeks sprint interval training program: a fidelity approach

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    This study aimed to: (1) investigate the influence of a 2-weeks sprint interval training (SIT) program on aerobic capacity, cardiac autonomic control, and components of attention in young healthy university students; and (2) to ascertain whether training fidelity would influence these adaptations. One hundred and nine participants were divided into an experimental (EG) and control (CG) groups. The EG performed a SIT program that consisted of 6 sessions of 4 x 30 s "all-out" efforts on a cycle ergometer, interspersed with active rests of 4 min. The criterion for fidelity was achieving >90% of estimated maximum heart rate (HR) during sprint bouts. After analyses, the EG was divided into HIGH (n = 26) and LOW(n = 46) fidelity groups. Components of attention were assessed using the Attention Network Test (ANT). Aerobic capacity (VO(2)max) was estimated while the sum of skinfolds was determined. Autonomic control of HR was assessed by means of HR variability (HRV) and HR complexity at rest and during ANT. Both HIGH and LOW significantly increased aerobic capacity, vagal modulation before and during ANT, and executive control, and decreased body fatness after SIT (p < 0.05). However, only participants from HIGH showed an increase in HR complexity and accuracy in ANT when compared to LOW (p < 0.05). Two weeks of SIT improved executive control, body fatness, aerobic fitness, and autonomic control in university students with better results reported in those individuals who exhibited high fidelity

    Improvements in Attention and Cardiac Autonomic Modulation After a 2-Weeks Sprint Interval Training Program: A Fidelity Approach

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    [EN] This study aimed to: (1) investigate the influence of a 2-weeks sprint interval training (SIT) program on aerobic capacity, cardiac autonomic control, and components of attention in young healthy university students; and (2) to ascertain whether training fidelity would influence these adaptations. One hundred and nine participants were divided into an experimental (EG) and control (CG) groups. The EG performed a SIT program that consisted of 6 sessions of 4 × 30 s “all-out” efforts on a cycle ergometer, interspersed with active rests of 4 min. The criterion for fidelity was achieving >90% of estimated maximum heart rate (HR) during sprint bouts. After analyses, the EG was divided into HIGH (n = 26) and LOW (n = 46) fidelity groups. Components of attention were assessed using the Attention Network Test (ANT). Aerobic capacity (VO2max) was estimated while the sum of skinfolds was determined. Autonomic control of HR was assessed by means of HR variability (HRV) and HR complexity at rest and during ANT. Both HIGH and LOW significantly increased aerobic capacity, vagal modulation before and during ANT, and executive control, and decreased body fatness after SIT (p < 0.05). However, only participants from HIGH showed an increase in HR complexity and accuracy in ANT when compared to LOW (p < 0.05). Two weeks of SIT improved executive control, body fatness, aerobic fitness, and autonomic control in university students with better results reported in those individuals who exhibited high fidelity.AdS, AM, and SD enjoy a PROSUP-CAPES grant. DB enjoys a productivity in research grant from CNPq.CNPq (Brazil) (process number 486116/2013-1) supported this project. AdS, SD, and AM were supported by a PROSUP grant from CAPES (Brazil). SB-F is supported by a doctoral fellowship awarded by ANII (Uruguay). DB was supported by a productivity research grant from CNPq (Brazil). We would like to thank all participants for their collaboration and LEEFS’s laboratory staff (Giseli Kelly de Melo Oliveira Gomes, Alessandra Matida) for their assistance during data collection. The authors declare that the results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation

    Hypermatrix factors for string and membrane junctions

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    The adjoint representations of the Lie algebras of the classical groups SU(n), SO(n), and Sp(n) are, respectively, tensor, antisymmetric, and symmetric products of two vector spaces, and hence are matrix representations. We consider the analogous products of three vector spaces and study when they appear as summands in Lie algebra decompositions. The Z3-grading of the exceptional Lie algebras provide such summands and provides representations of classical groups on hypermatrices. The main natural application is a formal study of three-junctions of strings and membranes. Generalizations are also considered.Comment: 25 pages, 4 figures, presentation improved, minor correction

    A história da ciência (distorcida ou ausente) em livros didáticos: o conteúdo sobre o “experimento de Torricelli” como estudo de caso

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    Esse trabalho apresenta uma pesquisa direcionada à avaliação crítica da História da Ciência presente em livros didáticos brasileiros. Particularmente, o objetivo dessa pesquisa foi contribuir para a compreensão de como os elementos relacionados ao processo de construção histórica do conceito de pressão atmosférica aparecem nos livros didáticos. São discutidos especificamente os resultados da análise realizada de acordo com os seguintes critérios: fundamentos historiográficos atuais; apontamentos da legislação educacional para a inserção didática da História da Ciência, fontes primárias e secundárias da História da Ciência relacionadas ao desenvolvimento do conceito de pressão atmosférica.  Dentre os problemas notados destacam-se o anacronismo, a pseudohistória, visões simplistas sobre a ciência, a ausência de explicações sustentadas por pensadores do passado e uma abordagem (totalmente) descontextualizada do experimento de Torricelli

    Cerebellar Cortical Degeneration in Cattle Poisoned with <i>Solanum</i> spp. in South America: An Epidemiological, Clinicopathological, Pathological, and Toxicological Review

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    Cattle that consume Solanum bonariense L (= Solanum fastigiatum Willd.) or Solanum paniculatum L. develop a typical cerebellar cortical degeneration characterized by periodic episodes of ataxia, hypermetria, hyperesthesia, head and thoracic limb extension, opisthotonus, nystagmus, and falling to the side or backward. Histological lesions include vacuolation, degeneration, and loss of Purkinje cells. Axonal spheroids, microcavitations, and other changes of Wallerian degeneration in cerebellar granular layer and white matter are also observed. Neurotoxic compounds in Solanum spp. causing neurologic dysfunction in ruminants were not definitively elucidated. The same Solanaceae species are extensively used with culinary purposes or for the treatment of liver and gastrointestinal disorders as hangovers in humans. In the present paper, we review the epidemiology, clinical signs, and pathological hallmarks of poisoning by Solanum —S. bonariense L. (=S. fastigiatum Willd.) and S. paniculatum—with emphasis in histopathology, ultrastructural, and lectin- and immuno-histochemical changes in spontaneous and experimentally poisoned cattle in South America. The current knowledge of the pathogenesis of these bovine cerebellar cortical degenerations is discussed, and some advances in botanical and toxicological aspects of these Solanaceae species are presented, taking into account the potential risk of human poisoning.Facultad de Ciencias Veterinaria

    Cerebellar Cortical Degeneration in Cattle Poisoned with <i>Solanum</i> spp. in South America: An Epidemiological, Clinicopathological, Pathological, and Toxicological Review

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    Cattle that consume Solanum bonariense L (= Solanum fastigiatum Willd.) or Solanum paniculatum L. develop a typical cerebellar cortical degeneration characterized by periodic episodes of ataxia, hypermetria, hyperesthesia, head and thoracic limb extension, opisthotonus, nystagmus, and falling to the side or backward. Histological lesions include vacuolation, degeneration, and loss of Purkinje cells. Axonal spheroids, microcavitations, and other changes of Wallerian degeneration in cerebellar granular layer and white matter are also observed. Neurotoxic compounds in Solanum spp. causing neurologic dysfunction in ruminants were not definitively elucidated. The same Solanaceae species are extensively used with culinary purposes or for the treatment of liver and gastrointestinal disorders as hangovers in humans. In the present paper, we review the epidemiology, clinical signs, and pathological hallmarks of poisoning by Solanum —S. bonariense L. (=S. fastigiatum Willd.) and S. paniculatum—with emphasis in histopathology, ultrastructural, and lectin- and immuno-histochemical changes in spontaneous and experimentally poisoned cattle in South America. The current knowledge of the pathogenesis of these bovine cerebellar cortical degenerations is discussed, and some advances in botanical and toxicological aspects of these Solanaceae species are presented, taking into account the potential risk of human poisoning.Facultad de Ciencias Veterinaria

    Evolution of retinoic acid receptors in chordates: insights from three lamprey species, Lampetra fluviatilis, Petromyzon marinus, and Lethenteron japonicum

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    International audienceBackground : Retinoic acid (RA) signaling controls many developmental processes in chordates, from early axis specification to late organogenesis. The functions of RA are chiefly mediated by a subfamily of nuclear hormone receptors, the retinoic acid receptors (RARs), that act as ligand-activated transcription factors. While RARs have been extensively studied in jawed vertebrates (that is, gnathostomes) and invertebrate chordates, very little is known about the repertoire and developmental roles of RARs in cyclostomes, which are extant jawless vertebrates. Here, we present the first extensive study of cyclostome RARs focusing on three different lamprey species: the European freshwater lamprey, Lampetra fluviatilis, the sea lamprey, Petromyzon marinus, and the Japanese lamprey, Lethenteron japonicum.Results : We identified four rar paralogs (rar1, rar2, rar3, and rar4) in each of the three lamprey species, and phylogenetic analyses indicate a complex evolutionary history of lamprey rar genes including the origin of rar1 and rar4 by lineage-specific duplication after the lamprey-hagfish split. We further assessed their expression patterns during embryonic development by in situ hybridization. The results show that lamprey rar genes are generally characterized by dynamic and highly specific expression domains in different embryonic tissues. In particular, lamprey rar genes exhibit combinatorial expression domains in the anterior central nervous system (CNS) and the pharyngeal region.Conclusions : Our results indicate that the genome of lampreys encodes at least four rar genes and suggest that the lamprey rar complement arose from vertebrate-specific whole genome duplications followed by a lamprey-specific duplication event. Moreover, we describe a combinatorial code of lamprey rar expression in both anterior CNS and pharynx resulting from dynamic and highly specific expression patterns during embryonic development. This ‘RAR code’ might function in regionalization and patterning of these two tissues by differentially modulating the expression of downstream effector genes during development
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