排序方式： 共有27条查询结果，搜索用时 62 毫秒
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Vivian Maria Arakelian Cássia da Luz Goulart Renata Gonçalves Mendes Nuno Manoel de Sousa Renata Trimer Solange Guizilini 《Journal of sports sciences》2019,37(12):1420-1428
Aim was to identify critical load (CL) in young and elderly apparently healthy male cohorts. To contrast the metabolic, cardiovascular and perceptual responses on CL according to age. We evaluated 12 young (23 ± 3 years) and 10 elderly (70 ± 2 years) apparently healthy active males, who underwent: (1) 1 repetition maximum (1RM) test on a 45° Leg Press; (2) on different days, three high-intensity resistance exercise constant load tests (60%, 75% and 90% 1RM) until fatigue (Tlim). Absolute values of both the CL asymptote and curvature constant (kg) were significantly lower in elderly subjects (P < 0.05). In contrast, elderly subjects demonstrated a significantly higher number of repetitions at CL when compared with young subjects (P < 0.05). As expected, oxygen uptake (VO2) and heart rate (HR) during maximal aerobic exercise testing were significantly reduced in older subjects. However, percent-predicted aerobic capacity were higher in older subjects (P < 0.05). In addition, blood lactate ([La?]) corrected to Tlim and rating of perceived exertion values were greater in younger subjects at all intensities (P < 0.05). These findings, despite reduced force production in older subjects, endurance-related parameters are well preserved according to age-adjusted percent-predicted values in apparently healthy males. 相似文献
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Jorge Arede Pedro Esteves António Paulo Ferreira Jaime Sampaio Nuno Leite 《Journal of sports sciences》2013,31(19):2220-2227
ABSTRACTThe aims of this study were to examine the medium-term effects of previous experiences during early stages of sport development on physical capacities of under-13 (U-13) talented basketball players and, to identify variables that discriminated under-14 (U-14) national team training camp selection. Anthropometrical and physical measurements were collected during a basketball training camp. Previous sport experiences (6–10 years), maturity offset, power outputs for jumping and sprinting were determined. A cluster analysis was used to allocate the subjects according to their different levels of sport experiences (more specialized vs. less specialized) to allow creating a dummy variable for the subsequent analysis of the physical variables. A stepwise discriminant analysis was computed to identify the construct that best classifies selected and non-selected players for U-14 national team training camp. The less specialized group outscored more specialized in all physical parameters, irrespectively of gender. The Abalakov Jump Peak Power and Predicted Adult Height (PAH) could successfully discriminate selected from non-selected players for U-14 national team training camp in boys and PAHin girls. The diversified and non-specific sport stimulus during early ages seem to be determinant to the acquisition and development of fundamental movement skills of talented basketball players. 相似文献
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Nuno Gil 《Research Policy》2007,36(7):980-999
This study defines a project safeguard as the design and physical development work needed to ensure, or enhance, the embedding of a real option in complex products and systems (CoPS). Safeguards operationalize optionlike strategic thinking at implementation. I examine safeguarding investments through an in-depth multiple-case study of 12 options embedded across 5 projects encompassed by an airport expansion programme. This includes options to phase out delivery (stage-option), grow capacity (growth-option), and switch operational regime (switch-option). Passive safeguards only involve design work, whereas active safeguards involve both design and physical execution. The analysis shows how the confluence between the uncertainty of option exercising and the modularity of the relevant functional elements in relation to the CoPS architecture affects the attractiveness of safeguarding. High uncertainty makes safeguarding less attractive as it can lead to sunk costs that may not pay off over the CoPS operating life. Conversely, high modularity increases the attractiveness of safeguarding because (1) safeguards can be limited to marginal investments at the interfaces between the functional elements with other CoPS subsystems, and (2) the stability of modular design rules increases the likelihood that safeguards remain valid over time. Safeguards build options into integrative CoPS. This flexibility and redundancy makes them resilient to change stemming from option exercising if uncertainties resolve favourably in the future. 相似文献
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Pedro Nuno Teixeira Vera Rocha Ricardo Biscaia Margarida Fonseca Cardoso 《Higher Education》2012,63(3):337-352
The expansion of higher education systems has often been associated with the need for increasing diversification, namely at
the program level, based on the pressures to adapt more general programmes to a more diverse student population and multiple
regional, social, and economic needs. This paper explores empirically the question of programme diversity by drawing on the
Portuguese higher education’ experience, which presented massive expansion during the last decades and significant institutional
competition in recent years. The study provides a longitudinal approach and analyzes in detail the evolution of diversification
and specialization of the public and private sectors, as well as the university and polytechnic subsectors. The analysis aims
at helping to illustrate the relevance of analysing diversity from an empirical point of view and its contribution to our
understanding of the complex relationships between competition and diversity in contemporary higher education. 相似文献
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Hosting sporting mega-events involve considerable investment in and significant engagement with local communities. This paper contributes to the burgeoning literature about sporting mega event’s socio-geographical impacts on tourism, employment, urban regeneration, and socio-economic and cultural benefits. Within the context of 2014 FIFA World Cup in Brazil, we assess, utilizing interview data from local communities, the impact of the construction of the 2014 World Cup’s opening venue, ‘Arena Corinthians’ soccer stadium, in Itaquera, as well as other infrastructure developments more widely in the East Zone of São Paulo. The results point to the diversity of opinions among the resident community about the real legacies resulting from this sport mega-event. 相似文献
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Ainara Zornoza-Indart Paula Lopez-Arce Karima Zoghlami Nuno Leal Joaquim Simão 《文物保护研究》2013,58(2):73-89
ABSTRACTCalcarenite stone samples from a historic building (Bizerte, Tunisia) were collected and treated under different environmental conditions with several consolidating products: alkoxysilane (ethyl silicate), a surfactant-templated novel sol–gel, Ca(OH)2, and SiO2 nanoparticles. These were subjected to marine aerosol accelerated aging cycles and studied by several non-destructive tests and techniques to assess the stability of the products. Results show that weathering caused by salt crystallization is not inhibited but it is slowed down due to the enhancement of superficial mechanical properties (surface cohesion and micro-hardness) achieved after one month of treatments application. A high or low relative humidity of the consolidation environment significantly affects the final mechanical and aesthetical physical properties and therefore conditions the durability of the treated substrates, even producing higher damage than observed in the blank specimens, depending on the product. 相似文献
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We propose a conceptual framework to analyze technology adoption in mega infrastructure projects, and assess their potential to innovating large socio-technical systems. Drawing on an in-depth empirical analysis of Heathrow airport's Terminal 5 project, we find that innovation hinges on technology adoption decisions that are governed systematically by two intertwined determinants - assessment of expected profitability and development of absorptive capacity, both of which are distributed across various interdependent actors. On an ad hoc basis, technological decisions are also affected by other factors, namely attitudes toward risk, politics, and (lack of) established standards. We reveal how a schedule-driven project framing creates an underlying boundary condition that constrains the longitudinal process of building a ‘whole collective’ with capacity to absorb new technologies. The innovation potential of mega projects is thus subjected to a fundamental, unifying tension: on the one hand, they offer a one-off opportunity to invest in cutting-edge technologies and innovate socio-technical systems; on the other hand, project stakeholders have limited time to develop capacity to absorb novel technologies and negotiate differences on assessments of profitability and risk. Stakeholders may therefore be compelled to agree to adopt proven technologies upfront to reduce uncertainty and mitigate risks, thus limiting the innovation potential of new infrastructure development. 相似文献