Color characterization of roofing slates from the Iberian Peninsula for restoration purposes     

Beatriz Prieto  Perla Ferrer  Patricia Sanmartín  Victor Cárdenes  Benita Silva 《Journal of Cultural Heritage》2011,12(4):420

Substitution of slate roofing tiles is a conventional operation during building restoration, since tiles are very difficult to restore or clean because of the high degree of alteration they suffer. Criteria for replacement of historical building stones must be based on geological, geotechnical and esthetic parameters, among which color is of great importance. In this sense, this paper constitutes a comprehensive and useful colorimetric study of roofing slates from the Iberian Peninsula, for the purposes of restoration. The color of 50 commercial varieties of roofing slate mined in quarries from the 12 mining districts in the Iberian Peninsula was analyzed with a spectrophotometer device, by considering the CIELAB color space. The results of the study were used to develop a protocol for characterizing the color of roofing slate and to define the color range of roofing slate from the Iberian Peninsula. In addition, the similarities and differences in the color and microstructure of the different commercial varieties of Iberian roofing slate were established and the limit of acceptability of replacement of one type of slate by another was determined. Parameter h_ab was found to be the most important CIELAB color coordinate as regards the formation of homogeneous color groups, and the specular component excluded (SCE) mode was most sensitive as regards detecting color differences between two samples.  相似文献   

Cardiorespiratory and perceptual responses of two interval training and a continuous training protocol in healthy young men     

João Pedro Araújo Naves  Ana Cristina Silva Rebelo  Lucas Raphael Bento E Silva  Maria Sebastiana Silva  Rodrigo Ramirez-Campillo  Robinson Ramírez-Vélez 《European Journal of Sport Science》2019,19(5):653-660

High Intensity Interval Training (HIIT) can be performed with different effort to rest time-configurations, and this can largely influence training responses. The purpose of the study was to compare the acute physiological responses of two HIIT and one moderate intensity continuous training (MICT) protocol in young men. A randomised cross-over study with 10 men [age, 28.3?±?5.5years; weight, 77.3?±?9.3?kg; height, 1.8?±?0.1?m; peak oxygen consumption (VO₂peak), 44?±?11?mL.kg^?1.min^?1]. Participants performed a cardiorespiratory test on a treadmill to assess VO₂peak, velocity associated with VO₂peak (vVO₂peak), peak heart rate (HRpeak) and perceived exertion (RPE). Then participants performed three protocols equated by distance: Short HIIT (29 bouts of 30s at vVO₂peak, interspersed by 30s of passive recovery, 29?min in total), Long HIIT (3 bouts of 4?min at 90% of vVO₂peak, interspersed by 3?min of recovery at 60% of vVO₂peak, 21?min in total) and MICT (21?min at 70% of vVO₂peak). The protocols were performed in a randomised order with ≥48 h between them. VO₂, HRpeak and RPE were compared. VO₂peak in Long HIIT was significantly higher than Short HIIT and MICT (43?±?11 vs 32?±?8 and 37?±?8?mL.kg^?1.min^?1, respectively, P?P?P?2, HR and RPE than Short HIIT and MICT, suggesting a higher demand on the cardiorespiratory system. Short HIIT and MICT presented similar physiologic and perceptual responses, despite Short HIIT being performed at higher velocities.  相似文献   

Aerobic fitness and physical activity are inversely associated with body fat,dyslipidemia and inflammatory mediators in children and adolescents living with HIV     

Luiz Rodrigo Augustemak de Lima  Isabela de Carlos Back  Everson Araújo Nunes  Diego Augusto Santos Silva  Edio Luiz Petroski 《Journal of sports sciences》2019,37(1):50-58

This study aimed to investigate if moderate to vigorous physical activity (MVPA) and aerobic fitness are associated with cardiovascular risk factors in HIV+ children and adolescents. Sixty-five children and adolescents (8 to 15 years) provided minutes of MVPA measured by accelerometers and peak oxygen uptake (peak VO₂) by breath-by-breath respiratory exchange. Cardiovascular risk factors were characterized by body fat, blood pressure, total cholesterol, HDL-c, LDL-c, triglycerides, glucose, insulin, C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α) and carotid intima-media thickness. Results indicated that higher MVPA was associated with lower values of total (β = ?3.566) and trunk body fat (β = ?3.495), total cholesterol (β = ?0.112) and LDL-c (β = ?0.830). Likewise, higher peak VO₂ was associated with lower total (β = ?0.629) and trunk body fat values (β = ?0.592) and levels of CRP (β = ?0.059). The physically active participants had lower total cholesterol (?24.4 mg.dL^?1) and LDL-c (?20.1 mg.dL^?1) compared to participants judged to be insufficiently active. Moreover, participants with satisfactory peak VO? showed lower total (?4.1%) and trunk (?4.3%) body fat, CRP (?2.3 mg.L^?1), IL-6 (?2.4 pg.mL^?1) and TNF-α (?1.0 pg.mL^?1) compared to low peak VO₂ peers. High levels of MVPA and aerobic fitness may prevent developing of cardiovascular risk factors in children and adolescents HIV+.  相似文献   

Effect of a Brazilian Jiu-jitsu-simulated tournament on strength parameters and perceptual responses     

Daniele Detanico  Rodolfo André Dellagrana  Marina Saldanha da Silva Athayde  Rafael Lima Kons  Angel Góes 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):115-126

This study aimed to analyse the effects of a simulated Brazilian jiu-jitsu (BJJ) tournament on vertical jump performance, grip strength test and perceived effort responses. 22 male BJJ athletes participated in a simulated tournament consisting of three 7 min matches separated by 14 min of rest. Kimono grip strength test (KGST), counter movement jump (CMJ) and rate of perceived exertion (RPE) were measured before and after each match, while RPE of specific areas was assessed after three matches. ANOVA for repeated measures was used to compare strength parameters after each match with the level of significance set at 5%. The key results showed a significant decrease of jump height (p = 0.001) and net vertical impulse in the CMJ (p = 0.031), as well as a reduction of the number of reps in the KGST (p < 0.001). A significant increase of RPE was found throughout the matches (p < 0.001). Considering the RPE in specific areas, no differences were observed between the upper and lower body (p = 0.743). We conclude that the BJJ simulated tournament generated a decrease of performance in both upper and lower limbs and provoked a progressive increase in the effort perception over the matches.  相似文献   

Exploring the effects of substituting basketball players in high-level teams     

Miguel-Ángel Gómez  Roberto Silva  Alberto Lorenzo  Rasa Kreivyte  Jaime Sampaio 《Journal of sports sciences》2017,35(3):247-254

Substituting basketball players during competition is a key process to optimise collective performance. Available research on this topic is scarce, probably due to the difficulty in isolating these effects; thus, the aim of this study was to identify the temporal effects of substitutions in basketball (Spanish professional basketball league). The sample was composed of 1118 substitutions gathered from 21 basketball games. The analysed variables were coach-controlled (player and team’s personal fouls, player in and player out roles, player’s in and out minutes on-court and timeout situation); on-court (foul committed, free throws, 2- and 3-point field-goal effectiveness) and situational variables (scoreline, quality of opposition, game location and game quarter). The results showed positive scoring performances after the substitution for all the analyses. During the first quarter, there were significant effects for fouls committed, scoreline and game location after the substitution. The player’s out personal fouls, free-throw effectiveness, player in, minutes on-court player in, timeout situation and 3-point field-goal effectiveness were significant during the second quarter. The team’s personal fouls, game location, and scoreline were identified as important in the third quarter. The fourth quarter did not show significant effects on the independent variables. Current findings allow optimising coaches’ plans and team management of on-court and bench players throughout the game.  相似文献   

Improved children’s motor learning of the basketball free shooting pattern by associating subjective error estimation and extrinsic feedback     

Leandro de Carvalho da Silva  Carla Ferro Pereira-Monfredini 《Journal of sports sciences》2017,35(18):1825-1830

This study aimed at assessing the interaction between subjective error estimation and frequency of extrinsic feedback in the learning of the basketball free shooting pattern by children. 10- to 12-year olds were assigned to 1 of 4 groups combining subjective error estimation and relative frequency of extrinsic feedback (33% × 100%). Analysis of performance was based on quality of movement pattern. Analysis showed superior learning of the group combining error estimation and 100% feedback frequency, both groups receiving feedback on 33% of trials achieved intermediate results, and the group combining no requirement of error estimation and 100% feedback frequency had the poorest learning. Our results show the benefit of subjective error estimation in association with high frequency of extrinsic feedback in children’s motor learning of a sport motor pattern.  相似文献   

Correlations between serum and salivary hormonal concentrations in response to resistance exercise     

Cadore E  Lhullier F  Brentano M  Silva E  Ambrosini M  Spinelli R  Silva R  Kruel L 《Journal of sports sciences》2008,26(10):1067-1072

The aim of present study was to examine the relationships between serum and salivary values of free testosterone, dehydroepiandrosterone, and cortisol before and after a session of resistance exercise. Twenty-eight healthy men (mean age 40 years, s = 4) participated in the present study. Serum and salivary samples were collected at rest and after a multiple-sets resistance exercise protocol, of approximately 25 minutes duration. Concentrations of free testosterone, dehydroepiandrosterone, and cortisol were measured using radioimmunoassay kits. No significant correlation was observed between serum free testosterone and salivary testosterone (r = 0.22 to 0.26, P > 0.05). Serum cortisol was significantly correlated with salivary cortisol before (r = 0.52, P = 0.005) and after (r = 0.62, P = 0.001) the exercise protocol. Serum and salivary concentrations of dehydroepiandrosterone were significantly correlated before (r = 0.68, P < 0.001) and after (r = 0.7, P < 0.001) exercise. The results of the present study suggest that even under exercise conditions, the salivary values of cortisol and dehydroepiandrosterone can reflect the behaviour of these hormones in blood. However, further studies are necessary to verify if salivary testosterone reflects the behaviour of serum free testosterone during resistance exercise.  相似文献   

Screening of Xylanolytic Aspergillus fumigatus for Prebiotic Xylooligosaccharide Production Using Bagasse     

Ana Flavia Azevedo Carvalho  Pedro de Oliva Neto  Paula Zaghetto de Almeida  Juliana Bueno da Silva  Bruna Escaramboni  Glaucia Maria Pastore 《Food Technology and Biotechnology》2015,53(4):428-435

  相似文献   

Environmental Education and Complexity     

Pereira  Brenda Braga  Silva  Luciano Fernandes  dos Santos  Janaina Roberta 《Science & Education》2022,31(1):1-20

Science & Education - The purpose of this study is to identify and analyze meanings that the term complexity assumes in Brazilian theses and dissertations in the field of environmental...  相似文献   

Growth influences biomechanical profile of talented swimmers during the summer break     

Marc F. Moreira  Jorge E. Morais  Daniel A. Marinho  António J. Silva  Tiago M. Barbosa 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(1):62-74

This study aimed to analyse the effect of growth during a summer break on biomechanical profile of talented swimmers. Twenty-five young swimmers (12 boys and 13 girls) undertook several anthropometric and biomechanical tests at the end of the 2011–2012 season (pre-test) and 10 weeks later at the beginning of the 2012–2013 season (post-test). Height, arm span, hand surface area, and foot surface area were collected as anthropometric parameters, while stroke frequency, stroke length, stroke index, propelling efficiency, active drag, and active drag coefficient were considered as biomechanical variables. The mean swimming velocity during an all-out 25 m front crawl effort was used as the performance outcome. After the 10-week break, the swimmers were taller with an increased arm span, hand, and foot areas. Increases in stroke length, stroke index, propelling efficiency, and performance were also observed. Conversely, the stroke frequency, active drag, and drag coefficient remained unchanged. When controlling the effect of growth, no significant variation was determined on the biomechanical variables. The performance presented high associations with biomechanical and anthropometric parameters at pre-test and post-test, respectively. The results show that young talented swimmers still present biomechanical improvements after a 10-week break, which are mainly explained by their normal growth.  相似文献