Effects of different strength training frequencies during reduced training period on strength and muscle cross-sectional area     

Lucas Duarte Tavares  Eduardo Oliveira de Souza  Carlos Ugrinowitsch  Gilberto Candido Laurentino  Hamilton Roschel  André Yui Aihara 《European Journal of Sport Science》2017,17(6):665-672

This study investigated the effects of different reduced strength training (RST) frequencies on half-squat 1 RM and quadriceps cross-sectional area (QCSA). Thirty-three untrained males (24.7?±?3.9 years; 1.73?±?0.08?m; 74.6?±?8.4?kg) underwent a 16-week experimental period (i.e. eight weeks of strength training [ST] followed by additional eight weeks of RST). During the ST period, the participants performed 3–4 sets of 6–12 RM, three sessions/week in half-squat and knee extension exercises. Following ST, the participants were randomly allocated to one of three groups: reduced strength training with one (RST1) or two sessions per week (RST2), and ceased training (CT). Both RST1 and RST2 groups had their training frequency and total training volume-load (i.e. RST1?=?50.3% and RST2?=?57.1%) reduced, while the CT group stopped training completely. Half-squat 1 RM (RST1?=?27.9%; RST2?=?26.7%; and CT?=?28.4%) and QCSA (RST1?=?6.1%; RST2?=?6.9%; and CT?=?5.8%) increased significantly (p?<?.05) in all groups after eight weeks of ST. No significant changes were observed in 1 RM and QCSA for RST1 and RST2 groups after the RST period, while the CT group demonstrated a decrease in half-squat 1 RM (22.6%) and QCSA (5.4%) when compared to the ST period (p?<?.05). In conclusion, different RST frequencies applied were able to maintain muscle mass and strength performance obtained over the regular ST period. Thus, it appears that RST frequency does not affect the maintenance of muscle mass and strength in untrained males, as long as volume-load is equated between frequencies.  相似文献   

Influence of physical fitness on cognitive and academic performance in adolescents: A systematic review from 2005–2015     

Alberto Ruiz-Ariza  Alberto Grao-Cruces  Nuno Eduardo Marques de Loureiro  Emilio J. Martínez-López 《International review of sport and exercise psychology》2017,10(1):108-133

Background: The aim of this systematic review was to investigate the association of different components of physical fitness on cognitive performance (CP) and academic performance (AP) in adolescents, taking into account potential confounders. Method: Studies were identified in four databases (Pubmed, SportDiscus, Web of Science, and ProQuest) from January 2005 through to January 2015. A total of 21 articles met the inclusion criteria. Results: 8 studies showed association between physical fitness and CP, and 11 studies with AP. Cardiorespiratory fitness, speed-agility, motor coordination, and perceptual-motor skill are the highest measures associated with CP and AP. However, the findings on strength and flexibility are unclear. Finally, 62% of the 21 studies used confounders. The most controlled confounder were socioeconomic status, fatness, pubertal status, sex, and age. Conclusion: Fitness is associated with higher CP and AP. More research is needed in order to understand the causes of the differential effect of physical fitness components on CP and AP.  相似文献   

An Activist Approach to Sport Meets Youth From Socially Vulnerable Backgrounds: Possible Learning Aspirations     

Carla Luguetti  Kimberly L. Oliver  Luiz Eduardo Pinto Basto Tourinho Dantas  David Kirk 《Research quarterly for exercise and sport》2017,88(1):60-71

Purpose: This study was a 2-phase activist research project aimed at co-creating a prototype pedagogical model for working with youth from socially vulnerable backgrounds in a sport context. This article addresses the learning aspirations (learning outcomes) that emerged when we created spaces for youth to develop strategies to manage the risks they face in their community. Method: This study took place in a socially and economically disadvantaged neighborhood in a Brazilian city where we worked with a group of 17 boys aged 13 to 15 years old, 4 coaches, a pedagogic coordinator, and a social worker. During a 6-month period, we collected multiple sources of data including field journal entries/observations (38) and audio records of youth work sessions (18), coaches' work sessions (16), combined coaches and youth work sessions (3), and meetings between the lead and the 2nd author for debriefing and planning sessions (36). Results: By using an activist approach, 4 learning aspirations emerged: becoming responsible/committed, learning from mistakes, valuing each other's knowledge, and communicating with others. Conclusion: Findings suggest there is a need for more sports programs that start from young people's concrete needs and life situations and look to create places for youth to see alternative possibilities and take action.  相似文献   

Swelling damage in clay-rich sandstones used in the church of San Mateo in Tarifa (Spain)   总被引：1，自引：0，他引：1  

Eduardo Sebastin  Giuseppe Cultrone  David Benavente  Lucia Linares Fernandez  Kerstin Elert  Carlos Rodriguez-Navarro 《Journal of Cultural Heritage》2008,9(1):66-76

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   

Hydroethanolic Extract of Grape Peel from Vitis labrusca Winemaking Waste: Antinociceptive and Anti-Inflammatory Activities     

Cristiana F. G. Silva  Victor Fattori  Caroline R. Tonetti  Marcos A. S. Ribeiro  Ricardo L. N. Matos  Jssica B. Carra  Eduardo C. Meurer  Elisa Y. Hirooka  Janice A. Rafael  Sandra R. Georgetti  Marcela M. Baracat  Waldiceu A. Verri  Jr  Nilton S. Arakawa 《Food Technology and Biotechnology》2022,60(1):21

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Extraction of Lipophilic Antioxidants from Native Tomato Using Green Technologies     

Darío R. Gmez-Linton  Arturo Navarro-Ocaa  Silvestre Alavez  Ricardo Lobato-Ortiz  Anglica Romn-Guerrero  Jos Alberto Mendoza-Espinoza  Juan Manuel Villa-Hernndez  Laura J. Prez-Flores 《Food Technology and Biotechnology》2022,60(1):121

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The role of letter knowledge acquisition ability on children's decoding and word identification: Evidence from an artificial orthography     

Joana Acha  Nuria Rodriguez  Manuel Perea 《Journal of Research in Reading》2023,46(4):358-375

Background

Letter knowledge is crucial in the first stages of reading development. It supports learning letter-sound mappings and the identification of the letters that make up words. Previous studies have investigated the longitudinal impact of early letter knowledge on children's further word reading abilities. This study employed an artificial orthography learning paradigm to explore whether the rate of letter learning modulates children's reading and word identification skills.

Methods

In an initial training phase, 8-year-old Spanish children (N = 30) learned nine artificial letters and their corresponding sounds (two vowels and six consonants). The letter learning rate was set according to the number of attempts needed to name at least seven letters (i.e., 80% correct). These ranged from 1 to 4. In a second training phase, children visualized words made up of the trained letters while listening to their pronunciations. Some words included a context-dependent syllable (i.e., leading to grapheme-to-phoneme inconsistency), and others had an inconsistent syllable (i.e., phoneme-to-grapheme inconsistency). The post-test consisted of a reading aloud task and an orthographic-choice task in which the target word was presented with a distractor equal to the target except for the substitution of a letter.

Results

Children showed a high accuracy rate in the post-test tasks, regardless of whether words contained context-dependent or inconsistent syllables. Critically, the letter learning rate predicted both reading aloud and identification accuracy of words in the artificial orthography.

Conclusions

We provide evidence for the vital role of letter knowledge acquisition ability in children's decoding and word identification skills. Training children on this ability facilitates serial letter-sound mapping and word identification skills. Artificial orthography paradigms are optimal for exploring children's potential to achieve specific literacy skills.

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Post-purchase Federal Financial Aid: How (in)Effective is the IRS’s Student Loan Interest Deduction (SLID) in Reaching Lower-Income Taxpayers and Students?     

González Canché  Manuel S. 《Research in higher education》2022,63(6):933-986

Research in Higher Education - Federal financial aid policies for higher education may be classified based on their “for-purchase” and “post-purchase” natures. The former...  相似文献