درخت حوزه‌های تخصصی

To better illuminate the link between scaffolding and visual aids, this quasi-experimental study attempted to scaffold an intact group of 14 intermediate-level Iranian English as a foreign language (EFL) learners through providing graphs with the aim of enhancing their writing ability. Ensuring lack of familiarity with eight unknown words, they were scaffolded through visual images. The scaffolding process included three respective phases of contingency, fading, and transferring. As post-tests for checking the learners’ understanding of and opinion about the graph scaffolding process, a researcher-made questionnaire and a semi-structured interview followed the treatment phase. The results of the questionnaire showed that visual scaffolding aided the learners to better grasp the meaning of the target vocabularies and even some grammatical points in the materials. Moreover, the visual scaffolding helped them to produce the material in different modalities. The results also indicated all the three characteristics of scaffolding were met by the visual scaffolding. Finally, the interview results revealed the learners had favorable attitude toward visual scaffolding and considered the third phase of the scaffolding as the most challenging one. It can be concluded that the findings gave credence to the effectiveness of visual scaffolding in improving EFL students’ writing ability.

This study reports psychometric properties and derivation of norms for a Persian version of the Multiple Intelligence Developmental Assessment Scales (MIDAS) for Adults. After examining and confirming equivalency between English and Persian versions, translated and validated by Saeidi, Ostovar, Shearer, and Asghari Jafarabadi (2015), the scale was administered to a sample (N = 2146), including students, undergraduates, graduates, and adults from different provinces in Iran. The participants were at least 19 years old and above (M = 29.40, SD = 2.26). Out of 2146 samples, 1103 females and 1043 were males. To examine the validity and reliability properties of the scale, exploratory and confirmatory factor analyses, Cronbach Alpha (α) reliability correlation coefficients, and corrected item-total correlations were employed. Exploratory factor analysis using varimax rotation identified eight principal components, which accounted for 67.21% of the variance for 115 items. The internal consistency coefficient (α = .92; ranging from 0.89 to 0.93) was also very high. The confirmatory analysis generally replicated the original conceptualization of the MIDAS. According to the results, the Persian-MIDAS-adults questionnaire has good psychometric properties in the research community and can be safely used as a valid tool to assess MI in Iran.

Introduction: Since people experience fatigue after anterior cruciate ligament injury during exercises, it is important to understand how fatigue affects the biomechanical movement patterns. Therefore, this study aimed to investigate the effect of fatigue on ground reaction force variables during single-leg landing in athletes with a history of an anterior cruciate ligament sprain. Methods: it was a case-control study conducted in the University Laboratory. The sample consisted of 36 male athletes who were divided into three groups: 12 people with Anterior Cruciate Ligament Reconstruction (ACLR), 12 people with Anterior Cruciate Ligament Deficiency (ACLD), and 12 people as the control group. Fatigue was induced via the repetitive sets of double-leg squats (n=8), which were interspersed with the sets of countermovement jumps (n=2) and single-leg landings (n=3) until squats were no longer possible. A 2×2 repeated-measures multivariate analysis of variance was used to detect the main effects of group (ACLD, ACLR, control) and fatigue state (prefatigue, postfatigue) on the ground reaction forces variables. Results: The results showed a significant decrease in the peak vertical force and internal-external ground reaction force in the ACLD group after fatigue. Regardless of the fatigue state, the peak vertical ground reaction force in ACLD and ACLR groups was significantly lower than that in the control group. Conclusion: The athletes with the ACL injury, regardless of the selective treatment type, use compensatory strategies to reduce the contact forces on the lower extremity, compared with healthy athletes.

Introduction: Training at altitude or in a hypoxic environment has gained attention among athletes, coaches, and scientists to enhance sea-level performance. However, the efficacy of “Living-Low, Training-High, Training-Low” (LLTHTL) strategy to escalate the mechanisms associated with enhancing performance in the human athletes is still unknown. The present study aimed to investigate the effect of the LLTHTL on Hypoxia-Inducible Factor-1 alpha (HIF-1α) and peroxisome Proliferator-activated Receptor-Gamma Coactivator-1alpha (PGC-1α) levels in elite endurance runners.  Methods: The study has a crossover design in University laboratory. Eight elite male runners (Mean±SD age: 24.50±3.96 years; Mean±SD height: 179.75±4.62 cm; Mean±SD body mass: 67.37±3.42 kg; Mean±SD body mass index: 20.85±1.11 kg/m²) took part in the research. After 4 weeks of Living-Low (LL), the athletes performed 4 weeks Training-High (TH) and then, 3 weeks training-low (TL). Main Outcome Measures: Anthropometric parameters, time trial (1500 m), PGC-1α, and HIF-1α levels were measured in four different time points: pre-LL, post-LL, post-TH, and post-TL.  Results: There were no significant differences between the 4 time points for body mass and body mass index (P>0.05). The time trial was improved significantly (p <0.001) at post-TH as well as post-TL compared with the pre-LL and post-LL. TH decreased HIF-1α level but did not affect PGC-1α. Besides, TL increased both HIF-1α and PGC-1α.  Conclusion: Training at altitude reduces HIF-1α and training at sea-level increased PGC-1α and HIF-1α levels. Both types of training induced an improvement in the time trial. Athletes and coaches seek advice on the effective training strategy to enhance performance at different altitudes.