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351.
Background: We aimed to evaluate the influence of the level of effort during four basic resistance exercises leading to muscular failure on intraocular pressure (IOP) and ocular perfusion (OPP), as well as the role of exercise type and sex. Methods: Twenty-five young adults (12 women) performed 10 repetitions against their 10-RM (repetition maximum) load in the squat, military press, biceps curl and calf raise exercises. IOP was measured before, during and after exercise, whereas OPP was indirectly assessed before and after each exercise. Results: There was a progressive IOP rise during exercise (p?η²?=?0.531), which was dependent on exercise type (p?=?0.020, η²?=?0.125). The squat exercise induced higher IOP increments in comparison to the other exercises (corrected p-values?p-values?=?0.012 and 0.002). OPP exhibited a significant reduction when leading to muscular failure (p?=?0.001, η²?=?0.364), being statistically significant for the squat and military press exercises (corrected p-values?=?0.037 and 0.047). No effect of sex was found for IOP and OPP (p?>?0.05). Conclusions: A single set of resistance training leading to muscular failure causes an instantaneous and progressive IOP rise in healthy young individuals. These IOP rises depend on exercise type (squat?>?military press?=?biceps curl?>?calf raise), but not on participant´s sex. OPP diminished as a consequence of performing resistance training exercise, being statistically significant for the squat and military press exercises. Future studies should include glaucoma patients aiming to corroborate the generalizability of our findings.  相似文献   
352.
Effective force and economy of triathletes and cyclists   总被引:1,自引:0,他引:1  
The effective force applied on the crank, the index of pedalling effectiveness, and the economy of movement at 60, 75, 90, and 105 rev/min cadences were examined in nine cyclists and eight triathletes. Tests were performed on two days. Maximal oxygen uptake was measured and the second ventilatory threshold was estimated on day 1 using a stationary bicycle. On day 2, the four different cadences were tested at about 5% below the second ventilatory threshold. A strain gauge instrumented clip-less pedal mounted on the bicycle enabled us to measure the normal and tangential forces exerted on the pedal, while the pedal and crank angles were monitored with the aid of a video system. Based on this information, the effective force and the index of pedalling effectiveness were calculated. Cyclists produced significantly more effective force and a higher index of pedalling effectiveness at 60 and 75 rev/min and were significantly more economic at all cadences than triathletes. The significant and positive correlation between effective force and economy at all cadences suggests that improvement of the effective force would reflect on economy.  相似文献   
353.
This study shows that the sandstone used in the construction of the Church of San Mateo in Tarifa (Cádiz, Spain) is highly sensitive to processes of decay because of a combination of factors that are intrinsic and extrinsic to the material. The mineralogy, texture and porous system of the sandstone and the proximity of the church to the sea all play a part in these processes. X-ray diffraction reveals that there are interstratified chlorite/smectite clays among the minerals that make up the rock. These mixed layer clays have been shown to undergo hydric expansion. This phenomenon may be accompanied and augmented by the presence of NaCl which acts as an electrolyte in osmotic swelling processes. Two varieties of sandstone were used in the construction of the church, namely grey sandstone and brown sandstone. The latter is more porous and undergoes greater hydric expansion, showing a higher degree of deterioration. Ultrasound analysis has demonstrated that both varieties are anisotropic because they contain bedding planes and are affected by the preferred orientation of the phyllosilicates in the rock. The anisotropic nature of these stones was confirmed by capillary suction tests. The capillary front reaches a relatively low height which means that when water is absorbed, the anisotropic textural properties combined with the presence of chlorite–smectite mixed layers in the sandstone result in mechanical (shear) stress between the first few centimetres of the wet stone and the dry area behind. The latter effect favours the development of flakes, so causing the decay of the ornamental stone and the church façade.  相似文献   
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355.
ABSTRACT

The purpose of this study was to investigate the validity of a smartphone app to measure biomechanical barbell parameters during the snatch. Ten collegiate NCAA division I athletes performed two repetitions each at 40, 50, 60, 70, and 80% of their 1-repetition maximum snatch. Barbell motions were simultaneously recorded with a motion capture system and the smartphone app. The motion capture system recorded the 3-D position of a reflective marker attached to the end of the barbell while the smartphone app was used to record sagittal plane video and track the shape of the weight plate from which the barbell center was derived. Peak forward (PFD) and backward (PBD) displacements and peak vertical displacement (PVD) and velocity (PVV) were calculated from both sets of data. Significant, strong to very strong Pearson’s product-moment correlation coefficients between both systems were noted for all parameters (r = 0.729–0.902, all p < 0.001). Small significant biases between systems were observed for PVD (ES = 0.284, p < 0.001) and PFD (ES=0.340, p < 0.01), while trivial to small, non-significant biases were observed for PBD (ES = 0.143) and PVV (ES = –0.100). Collectively, the results suggest that the app can provide biomechanical data of barbell motions similar to a 3-D motion capture system.  相似文献   
356.
The objectives of this two-part study were to: (a) investigate English learner (EL) accommodation practices on state accountability assessments of reading/English language arts and mathematics in grades 3–8, and (b) conduct a meta-analysis of EL accommodation effectiveness on improving test performance. Across all distinct testing programs, we found that at least one EL test accommodation was provided for both test content areas. The most popular accommodations provided were supplying students with word-to-word dual language dictionaries, reading aloud test directions and items in English, and allowing flexible time/scheduling. However, we found minimal evidence that testing programs provide practitioners with recommendations on how to assign relevant accommodations to EL test takers’ English proficiency level. To evaluate whether accommodations used in practice are supported with evidence of their effectiveness, a meta-analysis was conducted. On average, across 26 studies and 95 effect sizes (N = 11,069), accommodations improved test performance by .16 standard deviations. Both test content and sampling design were found to moderate accommodation effectiveness; however, none of the accommodations investigated were found to have intervention effects that were statistically different from zero. Overall, these results suggest that currently employed EL test accommodations lack evidence of their effectiveness.  相似文献   
357.
358.
A visual culture learning community (VCLC) is an adolescent or young adult group engaged in expression and creation outside of formal institutions and without adult supervision. In the framework of an international, comparative research project executed between 2010 and 2014, members of a variety of eight self‐initiated visual culture groups ranging from manga and cosplay through contemporary art forms, fanart video, graffiti and cosplay in five urban areas (Amsterdam, Budapest, Chicago, Helsinki and Hong Kong) were studied through interview, participant observation and analysis of art works. In this article, collaborative group practices and processes in informal learning environments are presented through results of on‐site observations, interviews and analyses of creations. VCLCs are identified as inspiring, collaborative spaces of peer mentoring that enhance both visual skills and self‐esteem. Authors reveal how identity formation is interrelated with networking and knowledge sharing. Adolescents and young adults become participants of global communities of their creative genres through reinterpretation and individualisation of shared visual repertoires. In conclusion, implications for art education from the VCLC model for creative collaboration are suggested.  相似文献   
359.
Low schooling, high non‐attendance and school dropout rates are critical phenomena within disadvantaged groups, especially among the Gypsy community. For example, in the UK, 10%–25% of Gypsy children do not attend school regularly and have significantly higher levels of overall absence from school (percentage of half‐day sessions missed) than pupils from other ethnic groups. In Portugal, available data on Gypsy children is sparse, yet data from one geographic region of the country reports high school failure (45%) and dropout rates (15%) among this population. The present study assessed the efficacy of a four‐year intervention to promote Gypsy children's behavioural engagement and school success. Gypsy communities were contacted and 30 children participating in the four waves were randomly distributed into control and experimental groups. Every school day throughout four years, 16 children in the experimental group were called at home and invited to go to school. The effectiveness of the intervention was evaluated in four waves (at the end of each of the four school years), assessing behavioural engagement (i.e. school non‐attendance, classroom behaviour) and school achievement (i.e. mathematics achievement, student progression). Findings show the efficacy of the intervention on promoting behaviour engagement and academic success without devaluing Gypsy people's culture.  相似文献   
360.
The Erasmus Programme for higher education students is supposed to play an important socio-economic role within Europe. Erasmus student mobility flows have reached a relevant level of two million since 1987, boosted in recent years by the enlargement of the programme to eastern countries. Thereafter, it seems that flows have staggered. In this context, the article analyses the determinants of Erasmus student mobility establishing relevant hypotheses, which arise from the migration theory and gravity models. A panel data set of bilateral flows for all the participating countries has been used in order to test the factors influencing these student flows. Country size, cost of living, distance, educational background, university quality, the host country language and climate are all found to be significant determinants. Results also reveal that there are other determinants, like a country’s characteristics and time effects, which can affect mobility flows. Based on these findings, some general recommendations are put forward to enhance these flows.  相似文献   
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