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561.
BackgroundCitrulline is one of the non-essential amino acids that is thought to improve exercise performance and reduce post-exercise muscle soreness. We conducted a systematic review and meta-analysis to determine the effect of citrulline supplements on the post-exercise rating of perceived exertion (RPE), muscle soreness, and blood lactate levels.MethodsA random effects model was used to calculate the effect sizes due to the high variability in the study design and study populations of the articles included. A systematic search of PubMed, Web of Science, and ClinicalTrials.gov was performed. Eligibility for study inclusion was limited to studies that were randomized controlled trials involving healthy individuals and that investigated the acute effect of citrulline supplements on RPE, muscle soreness, and blood lactate levels. The supplementation time frame was limited to 2 h before exercise. The types and number of participants, types of exercise tests performed, supplementation protocols for L-citrulline or citrulline malate, and primary (RPE and muscle soreness) and secondary (blood lactate level) study outcomes were extracted from the identified studies.ResultsThe analysis included 13 eligible articles including a total of 206 participants. The most frequent dosage used in the studies was 8 g of citrulline malate. Citrulline supplementation significantly reduced RPE (n = 7, p = 0.03) and muscle soreness 24-h and 48-h after post-exercise (n = 7, p = 0.04; n = 6, p = 0.25, respectively). However, citrulline supplementation did not significantly reduce muscle soreness 72-h post-exercise (n = 4, p = 0.62) or lower blood lactate levels (n = 8, p = 0.17).ConclusionCitrulline supplements significantly reduced post-exercise RPE and muscle soreness without affecting blood lactate levels. 相似文献
562.
In this paper, we study the variation of the thickness of patterned microchannel features in photoresist (PR) by two-step photolithography. The final PR thickness is determined by the thickness and width of the predefined PR pattern in the first-step lithography and the thickness of the spin-coated PR film in the second-step lithography. Thickness variation is demonstrated to be an important consideration within the critical pattern width that the capillary pressure is still dominant for forming the PR film thickness. With this mechanism of two-step photolithography, we demonstrate its ability to form multilevel channel features and its use to fabricate a cross-flow filter with two different pore sizes as a microfluidic application. 相似文献
563.
Carter Glenda Park John C. Copolo Cynthia F. 《Journal of Science Teacher Education》1998,9(2):143-152
Journal of Science Teacher Education - 相似文献
564.
The effects of two instructional strategies, visual display and contextual presentation, were investigated in the acquisition of electronic troubleshooting skills using computer-based instruction. Three types of visual displays (animation, static graphics with motion cues, and static graphics without motion cues) were used to represent structures and functions of electronic circuits and trouble-shooting procedures. The first hypothesis was that animation would be more effective than static graphics, but that static graphics with adequate motional cues representing the dynamic aspects of the task would accomplish results similar to animation. Results supported this hypothesis. The second hypothesis was that context-dependent instruction would be more efficient than context-independent instruction for solving problems in similar contexts, but that context independent instruction would be more effective in solving problems encountered in different contexts. The results supported this hypothesis. A general conclusion of this study is that the use of visual displays and contextual presentation should be based on the learning requirements of the task and the expected roles of the strategy in the learning.When this study was conducted, he was with the U.S. Army Research Institute. The opinions expressed herein are the author's and do not express or imply the views of the U.S. Department of Education or the U.S. Army Research Institute. 相似文献
565.
566.
567.
This study examines the prevalence, contexts, and demographic correlates of monotonic response patterns (MRPs) in online student evaluations. Results of two-level hierarchical generalized linear models show evidence of careless monotonic responses to a survey administered to students enrolled in a university-level foreign language course in the Republic of Korea. All else being equal, freshmen and students in classes with fewer survey participants were more likely to choose monotonic response patterns in course evaluations. Possible factors at work in generating MRPs are identified and discussed. The severity of the MRP problem in online ratings underscores the importance for administrators to consider possible validity threats in student evaluations before using them as tools to inform instructional and administrative decisions. It is also important to design course evaluation surveys in such a way as to minimize careless responses and to identify means to induce more thoughtful responses from college students. 相似文献
568.
Providing effective motivational support is a critical determinant of a successful online distance learning experience for students in higher education. In this study, we examined how students’ academic level and use of 8 motivational regulation strategies influence 3 types of student engagement: behavioral engagement, emotional engagement, and cognitive engagement. A total of 95 undergraduate and graduate students enrolled in online courses in 4-year universities in the United States participated in this study. A series of hierarchical regression analyses of undergraduate and graduate online students (N = 95) showed that behavioral engagement, emotional engagement, and cognitive engagement are predicted by different motivational regulation strategies after controlling for the academic level. Additionally, students’ academic level was found to be a predictor of cognitive engagement but not a predictor of behavioral engagement or emotional engagement. The results suggest that online course instructors, tutors, and designers should provide students with differentiated motivational scaffolding based on their motivational profile in order to promote different aspects of learning engagement. 相似文献
569.
Allison Gruner Gandhi Rachel Slama So Jung Park Patrick Russo Kendra Winner Robin Bzura 《Journal of research on educational effectiveness》2018,11(2):240-266
We used a comparative interrupted time series design to examine the impact of the Massachusetts' Wraparound Zone Initiative on student achievement, attendance, retention, and suspension. This initiative was designed to create coordinated district systems that allow schools to proactively and systematically address students' nonacademic needs. The state education agency awarded grants to seven high-need districts, each of which used the funds to support a select group of schools in implementing strategies that focused on school climate and culture, family engagement, systems to identify and address student needs, and community partnerships. Results from this study showed that students in Wraparound Zone schools performed better on state academic assessments than students in comparison schools, when considering prior achievement trends. Effects were statistically significant in the 3rd year of implementation. The impact on academic achievement was greatest for third- and fourth-grade students, and was particularly strong for English learners. There was no statistically significant overall impact on attendance, retention, or suspension. 相似文献
570.
User acceptance of a digital library system in developing countries: An application of the Technology Acceptance Model 总被引:1,自引:0,他引:1
Namkee Park Raul Roman Seungyoon Lee Jae Eun Chung 《International Journal of Information Management》2009
This study examines the factors that influence people's adoption and use of a digital library system and tests the applicability of the Technology Acceptance Model (TAM) in the context of developing countries. Using data from a survey of 16 institutions in Africa, Asia, and Central/Latin America (N = 1082), a path analysis revealed that perceived ease of use of the library system had a significant impact on perceived usefulness, which ultimately led to behavioral intention to use. In addition, the study examined the similarities and differences in the significant predictors of the digital library acceptance across countries and continents. Further, the current study suggests that external variables that affect perceived ease of use and usefulness need to be considered as important factors in the process of designing, implementing, and operating digital library systems. Such consideration will help decrease the mismatch between system design and local users’ realities, and further facilitate the successful adoption of digital library systems in developing countries. 相似文献