The impact of exercise training on the lipid peroxidation metabolomic profile and respiratory infection risk in older adults     

Diana Silva  Eduardo Arend  Silvia M. Rocha  Alisa Rudnitskaya  Luís Delgado  André Moreira 《European Journal of Sport Science》2019,19(3):384-393

Aging is associated with oxidative stress that may increase susceptibility to respiratory infections (RIs). We aimed to assess the impact of exercise training on the risk of RIs in older adults and on a targeted metabolomic profile of stress oxidative lipid peroxidation-related metabolites. Methods: In an 8-month clinical trial, 38 participants over 60 years of age were allocated to an exercise group (EG), in which participants underwent 90-min training sessions three times/week(n?=?20), or a control group (CG), in which participants maintained daily physical activities(n?=?18). Daily respiratory symptoms and RIs number and severity were collected. Serum by-products were assessed by comprehensive two-dimensional gas chromatography coupled to mass spectrometry with time of flight analyzer. Serum metabolomic profiling comprised 76 metabolites (alcohols, aldehydes, alkanes, and ketones). Principal components analysis and ANOVA-simultaneous component analysis were used to evaluate the metabolomic profile change. Results: The odds ratio of RIs for the EG was 2.0 CI 95% [0.2;25]. The incidence of RIs was 47% [23;70] in the EG vs. 44%[12;77] in the CG. The metabolomic profiling showed that alkanes and aldehydes classes differed between the EG and the CG before and after intervention. A calibration model showed a relation between the metabolites from four main classes (ketones, alcohols, alkanes and aldehydes) and the prediction of the number of RIs. Conclusion: Moderate exercise training, in older adults, compared with no exercise in controls, did not show a difference in the risk of RIs. A pattern of lipid peroxidation was associated with the number of RIs.  相似文献   

Helping students build competences in physical education: theoretical proposals and illustrations     

Guillaume Escalié  Nicolas Recoules  Sébastien Chaliès  Pascal Legrain 《Sport, Education and Society》2019,24(4):390-403

In the French education system, the current curriculum for students from the primary to the end of secondary school is structured around the notion of key competence. A competence can be defined as an integrated and stable network of knowledge and know-how, with normative behaviors, procedures and types of reasoning. However, without a theoretical conceptualization of building and mobilization processes, the components of a competence are considered as isolated and not interconnected. In the health and physical education (HPE) setting, too few empirical studies have analyzed how teachers would contribute to the development of student’s competence. The aim of this forward-looking article grounded on an experiential and cultural framework consists in clarifying and illustrating a conceptualization of the dynamics of development of competences among students considering the teacher activity. This theoretical framework seems to offer heuristic possibilities for the examination of teaching and learning practices which contribute to the development of the key competences, particularly when a competence is read as an experience that integrates multiple dimensions. Based on audio-video recording of PE lessons and self-confrontation interviews with the teacher and a student, the results of the present study strengthen the criticism of the definition of competence emphasizing the relevance to adopt a holistic approach corresponding to the articulation of intertwined resources (i.e. motor, methodological and social) students allocate to act in PE groups. Furthermore, the results show that the competence building depends on various roles students have the opportunity to play in PE (i.e. observer, tutor). Finally, our results underline the importance of identifying the specific characteristics of the teacher activity designed to structure the learning environment to train students to acquire new competences transferable in society.  相似文献   

Sultans' Paradise: The Royal Necropolis of Shāla,Rabat     

Péter Tamás Nagy 《Al-Masaq: Islam & the Medieval Mediterranean》2014,26(2):132-146

The following study concerns Shāla, which was the necropolis of the Marīnid rulers from 683/1284 to 752/1351. The Islamic buildings on the site have rarely received scholarly attention, although these edifices – despite their delapidated condition – are among the most important constructed by the dynasty. One of my main aims is to re-establish the buildings' chronological sequence, using the written and archaeological evidence, including publications about the site written in Arabic, which have hardly been considered so far. I also address the meaning and aims behind structure erected for each founder, which, in my view, have been misinterpreted by previous scholarship. In summary, this article attempts to revise our knowledge about the site.  相似文献   

Making news of value: exploiting dissonances in economic journalism     

Tomás Undurraga 《Journal of Cultural Economy》2017,10(6):510-523

This article explores the multiple modes of valuation that pervade newsmaking in economic journalism. It does so by exploring the different ways in which journalists at Valor Econômico, the leading economic newspaper in Brazil, compete and cooperate in the production of news. Valor is a paradigmatic case for discussing valuation practices in newsmaking since its institutional promise is to produce news of value. How, if at all, do Valor journalists embrace the promise of producing news that generates value? Elaborating on Stark’s (2009. The sense of dissonance. Accounts of worth in economic life. Princeton University Press) idea of dissonance, it is contended that different orders of worth collide and cooperate within Valor newsroom. Moreover, journalists engage in a variety of valuation practices through which these orders of worth are shaped, defined, and refined, reflecting different understandings of economy and society, and different conceptions of what journalism is good for. I argue that Valor’s direction intentionally fosters a plural space of value dissonance in order to improve the quality of news reporting. I emphasise, however, that these dissonances are only productive against a larger background of consonance about what actually there is to disagree about. The article is based on a seven-month ethnography of Valor’s newsroom in São Paulo between 2013 and 2015.  相似文献   

Metabolic demand and muscle damage induced by eccentric cycling of knee extensor and flexor muscles     

Luis Peñailillo  Nicolás Guzmán  José Cangas  Alvaro Reyes  Hermann Zbinden-Foncea 《European Journal of Sport Science》2017,17(2):179-187

The aim of this study was to examine the metabolic demand and extent of muscle damage of eccentric cycling targeting knee flexor (FLEX) and knee extensor (EXT) muscles. Methods: Eight sedentary men (23.3?±?0.7?y) underwent two eccentric cycling sessions (EXT and FLEX) of 30?min each, at 60% of the maximum power output. Oxygen consumption (VO₂), heart rate (HR) and rated perceived exertion (RPE) were measured during cycling. Countermovement and squat jumps (CMJ and SJ), muscle flexibility, muscle soreness and pain pressure threshold (PPT) of knee extensor and flexor muscles were measured before, immediately after and 1–4 days after cycling. Results: FLEX showed greater VO₂ (+23%), HR (+14%) and RPE (+18%) than EXT. CMJ and SJ performance decreased similarly after cycling. Muscle soreness increased more after EXT than FLEX and PPT decreased in knee extensor muscles after EXT and decreased in knee flexor muscles after FLEX. Greater loss of muscle flexibility in knee flexor muscles after FLEX was observed. Conclusion: Eccentric cycling of knee flexor muscles is metabolically more demanding than that of knee extensors, however muscle damage induced is similar. Knee flexors experienced greater loss of muscle flexibility possibly due to increased muscle stiffness following eccentric contractions.  相似文献   

Effectiveness and time-course adaptation of resistance training vs. plyometric training in prepubertal soccer players     

Yassine Negra  Helmi Chaabene  Thomas Stggl  Mehrz Hammami  Mohamed Souhaiel Chelly  Youns Hachana 《运动与健康科学(英文)》2020,9(6):620-627

PurposeThis study aimed to assess the effectiveness and time course for improvements in explosive actions through resistance training (RT) vs. plyometric training (PT) in prepubertal soccer players.MethodsThirty-four male subjects were assigned to: a control group (n = 11); an RT group (5 regular soccer training sessions per week, n = 12); a PT group (3 soccer training sessions and 2 RT sessions per week, n = 11). The outcome measures included tests for the assessment of muscle strength (e.g., 1 repetition maximum half-squat test), jump ability (e.g., countermovement jump, squat jump, standing long jump, and multiple 5 bounds test), linear speed (e.g., 20 m sprint test), and change of direction (e.g., Illinois change of direction test).ResultsThe RTG showed an improvement in the half-squat (Δ = 13.2%; d = 1.3, p < 0.001) and countermovement jump (Δ = 9.4%; d = 2.4, p < 0.001) at Week 4, whereas improvements in the 20-m sprint (Δ = 4.2%; d = 1.1, p < 0.01); change of direction (CoD) (Δ = 3.8%; d = 2.1, p < 0.01); multiple 5 bounds (Δ = 5.1%; d = 1.5, p < 0.05); standing long jump (Δ = 7.2%; d = 1.2, p < 0.01); squat jump (Δ = 19.6%; d = 1.5, p < 0.01); were evident at Week 8. The PTG showed improvements in CoD (Δ = 2.1%; d = 1.3, p < 0.05); standing long jump (Δ = 9.3%; d = 1.1, p < 0.01); countermovement jump (Δ = 16.1%; d = 1.2, p < 0.01); and squat jump (Δ = 16.7%; d = 1.4, p < 0.01); at Week 8 whereas improvements in the 20-m sprint (Δ = 4.1%; d = 1.3, p < 0.01); and multiple 5 bounds (Δ = 7.4%; d = 2.4, p < 0.001); were evident only after Week. The RT and PT groups showed improvements in all sprint, CoD, and jump tests (p < 0.05) and in half-squat performance, for which improvement was only shown within the RTG (p < 0.001).ConclusionRT and PT conducted in combination with regular soccer training are safe and feasible interventions for prepubertal soccer players. In addition, these interventions were shown to be effective training tools to improve explosive actions with different time courses of improvements, which manifested earlier in the RTG than in the PTG. These outcomes may help coaches and fitness trainers set out clear and concise goals of training according to the specific time course of improvement difference between RT and PT on proxies of athletic performance of prepubertal soccer players.  相似文献   

Stuart Hall's dialogical interventions     

Johan Fornäs 《Inter-Asia Cultural Studies》2013,14(2):186-190

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Analysis of a varnish applied by Nicéphore Niépce to make a print used for photographic purpose transparent     

Agns Lattuati-Derieux  Jean-Philippe Echard  Sylvie Thao-Heu  Bertrand Lavdrine 《Journal of Cultural Heritage》2010,11(4):1-481

Nicéphore Niépce carried out a lot of meticulous experiments that led him to the invention of photography. In particular, in the 1820s, he obtained heliographs by coating a substrate with a light-sensitive substance, which was then exposed to light under a paper print made translucent with the help of varnish. The objective of the work described here is to determine how Niépce made these paper prints transparent. Did he use his experimental knowledge on photosensitive resins, or did he apply commonly used recipes of his time to make paper transparent? To date, no studies have been carried out on the varnish used by Nicéphore Niépce and no previous research has undertaken analytical investigations on Nicéphore's prints, using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Gas Chromatography/Mass Spectrometry (GC/MS). In this paper, we identify the varnishes used by Nicéphore Niépce on four transparent prints, now belonging to the Nicéphore Niépce museum in Chalon-sur-Saône, France. The varnish he used was based on a diterpenic Pinaceae sp. resin (most probably colophony). The finding is supported by historical knowledge about varnishes.  相似文献   

Characterization and degradation pathways of ancient Korean waxed papers     

Agns Lattuati-Derieux  Cline Egasse  Martine Regert  Yong-Jae Chung  Bertrand Lavdrine 《Journal of Cultural Heritage》2009,10(3):422-427

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A comparison of the reverse and power punches in oriental martial arts   总被引：1，自引：0，他引：1  

Gulledge JK  Dapena J 《Journal of sports sciences》2008,26(2):189-196

In this study, we compared mechanical factors in the reverse and three-inch power punches. Twelve expert male martial artists stood on a force plate, and executed reverse and power punches against a padded target fixed to a wall-mounted force plate. The force plates measured horizontal forces, and subsequently impulses and body centre of mass velocity changes. The motions of four markers attached to the arm were also collected, and were used to compute the horizontal velocities of the knuckle and of the arm centre of mass. The power punch produced smaller velocities immediately before impact than the reverse punch for the whole-body centre of mass (0.14 vs. 0.31 m x s(-1)), for the arm centre of mass (2.86 vs. 4.68 m x s(-1)), and for the knuckle (4.09 vs. 6.43 m x s(-1)). The peak force exerted by the fist was much smaller in the power punch than in the reverse punch (790 vs. 1450 N). However, the linear impulse exerted by the fist during the first 0.20 s of contact was slightly larger in the power punch than in the reverse punch (43.2 vs. 37.7 N x s). The results indicate that the power punch is less potent than the reverse punch, but slightly more effective for throwing the opponent off balance.  相似文献