Repeated sprint ability in young basketball players: one vs. two changes of direction (Part 2)     

Giuseppe Attene  Guillaume Laffaye  Anis Chaouachi  Fabio Pizzolato  Gian Mario Migliaccio 《Journal of sports sciences》2015,33(15):1553-1563

The aim of this study was to compare the training effects based on repeated sprint ability (RSA) (with one change of direction) with an intensive repeated sprint ability (IRSA) (with two changes of direction) on jump performance and aerobic fitness. Eighteen male basketball players were assigned to repeated sprint ability and intensive repeated sprint ability training groups (RSAG and IRSAG). RSA, IRSA, squat jump (SJ), countermovement jump (CMJ) and Yo-Yo intermittent recovery level 1 test were assessed before and after four training weeks. The RSA and IRSA trainings consisted of three sets of six sprints (first two weeks) and eight sprints (second two weeks) with 4-min sets recovery and 20-s of sprints recovery. Four weeks of training led to an overall improvement in most of the measures of RSA, but little evidence of any differences between the two training modes. Jump performance was enhanced: CMJ of 7.5% (P < 0.0001) and 3.1% (P = 0.016) in IRSAG and RSAG respectively. While SJ improved of 5.3% (P = 0.003) for IRSAG and 3.4% (P = 0.095) for RSAG. Conversely the Yo-Yo distance increased 21% (P = 0.301) and 34% (P = 0.017) in IRSAG and RSAG respectively. Therefore, short-term repeated sprint training with one/two changes of direction promotes improvements in both RSA and IRSA respectively but the better increase on jump performance shown a few changes on sprint and endurance performances.  相似文献   

Enhancement and reduction of associative retroactive cue interference by training in multiple contexts     

Gonzalo Miguez  Mario A. Laborda  Ralph R. Miller 《Learning & behavior》2014,42(4):318-329

Retroactive cue interference refers to situations in which a target cue X is paired with an outcome in phase 1 and a nontarget cue Z is paired with the same outcome in phase 2, with less subsequent responding to X being seen as a result of the phase 2 training. Two conditioned suppression experiments with rats were conducted to determine whether retroactive cue interference is similarly modulated by a manipulation that influences retroactive outcome interference (e.g., extinction). Both experiments used an ABC renewal-like design in which phase 1 training, phase 2 training, and testing each occurred in different contexts. Experiment 1 found that training the target association in multiple contexts without altering the number of training trials during phase 1 decreased retroactive cue interference (i.e., increased responding consistent with the target association). Experiment 2 found that training the interfering association in multiple contexts without altering the number of interference trials during phase 2 increased retroactive cue interference (i.e., decreased responding consistent with the target association). The possibility of similar mechanisms underlying cue interference and outcome interference is discussed.  相似文献   

STEM Integration in Middle School Life Science: Student Learning and Attitudes     

S. Selcen Guzey  Tamara J. Moore  Michael Harwell  Mario Moreno 《Journal of Science Education and Technology》2016,25(4):550-560

In many countries around the world, there has been an increasing emphasis on improving science education. Recent reform efforts in the USA call for teachers to integrate scientific and engineering practices into science teaching; for example, science teachers are asked to provide learning experiences for students that apply crosscutting concepts (e.g., patterns, scale) and increase understanding of disciplinary core ideas (e.g., physical science, earth science). Engineering practices and engineering design are essential elements of this new vision of science teaching and learning. This paper presents a research study that evaluates the effects of an engineering design-based science curriculum on student learning and attitudes. Three middle school life science teachers and 275 seventh grade students participated in the study. Content assessments and attitude surveys were administered before and after the implementation of the curriculum unit. Statewide mathematics test proficiency scores were included in the data analysis as well. Results provide evidence of the positive effects of implementing the engineering design-based science unit on student attitudes and learning.  相似文献   

Primary and secondary teachers’ conceptions about heritage and heritage education: A comparative analysis     

Jesús Estepa Gimnez  Rosa María vila Ruiz  Mario Ferreras Listn 《Teaching and Teacher Education》2008,24(8):2095-2107

This study describes and analyses the conceptions of primary teachers and secondary teachers of Physics–Chemistry, Biology–Geology and Geography–History with respect to the concept of heritage and its teaching and learning, taking the model of teacher-researcher as the theoretical referent. The data collection instrument used was a questionnaire, designed on the basis of categories that in turn were used for the analysis of the resulting data. The results show a high degree of homogeneity in pedagogic content knowledge, in contrast to the heterogeneity of the conceptions with respect to purely content knowledge.  相似文献   

Improvement of PCR reaction conditions for site-directed mutagenesis of big plasmids     

Bogdan Munteanu  Mario Braun  Kajohn Boonrod 《Journal of Zhejiang University. Science. B》2012,13(4):244-247

QuickChange mutagenesis is the method of choice for site-directed mutagenesis (SDM) of target sequences in a plasmid. It can be applied successfully to small plasmids (up to 10 kb). However, this method cannot efficiently mutate bigger plasmids. Using KOD Hot Start polymerase in combination with high performance liquid chromatography (HPLC) purified primers, we were able to achieve SDM in big plasmids (up to 16 kb) involving not only a single base change but also multiple base changes. Moreover, only six polymerase chain reaction (PCR) cycles and 0.5 μl of polymerase (instead of 18 PCR cycles and 1.0 μl of enzyme in the standard protocol) were sufficient for the reaction.  相似文献   

Race and School Vouchers: Legal,Historical, and Political Contexts     

Mark A. Gooden  Huriya Jabbar  Mario S. Torres  Jr. 《Peabody Journal of Education》2016,91(4):522-536

This article investigates legal and political issues as they relate to school vouchers serving students of color. Specifically, we draw on the empirical, historical, and legal research to examine whether school vouchers will create a more equitable system of education for poor students of color. First, we present a history of vouchers, including how they were used to support segregation. We then discuss how vouchers as a broad opportunity for educational equity for poor children (of color) might present particular challenges in light of, first, the race-neutral approach in contemporary case law and state statutes and, second, the relatively small percentage of U.S. children taking advantage of such programs. Finally, we present empirical results regarding African American families’ support and use of vouchers and a discussion of the racial politics of school vouchers. We argue that unless voucher programs and proponents address race directly, operate on a larger scale, and attend to the broader social justice issues facing urban communities, it will be difficult for such policies to support the greater good for African American children or society as a whole.  相似文献   

Examining entrepreneurial attributes of Latin American female university students     

Marcia Villasana  Rafael Alcaraz-Rodríguez  Mario Moisés Alvarez 《Gender and education》2016,28(1):148-166

The phenomenon of women engaging in entrepreneurship is expanding and becoming acknowledged as a valuable resource that must be institutionally and socially supported. Through entrepreneurship education, female students, as potential entrepreneurs, can develop and strengthen those skills and behaviours identified as characteristic of successful entrepreneurs. This paper explores four attributes associated with entrepreneurship (creativity, problem management, risk management, and self-confidence) of 1838 undergraduate students from 11 universities in Latin America (Mexico, Argentina, Brazil, Chile, Colombia, Costa Rica, El Salvador, Guatemala, and Uruguay) and one in Spain, used as a control group. By comparing the results for the male and female student population, self-confidence appears as an attribute that is present at the same level in both groups; statistically significant differences were reported for the other three attributes (creativity, problem management, and risk management). Entrepreneurship programmes can utilise such information to strengthen in female students those attributes for successful engagement in entrepreneurial activity.  相似文献   

Book reviews     

Roger  Kerstin  D'Souza  Mario O. 《Interchange》1994,25(2):229-236

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College Student Success: A Qualitative Modeling Approach     

Ralph Mario Wirth  Raymond V. Padilla 《Community College Journal of Research & Practice》2013,37(9):688-711

This qualitative study highlighted student perspectives on barriers to success at a community college located in a south Texas city. The study examined barriers to student success, the knowledge that successful students possess to overcome the barriers, and the actions that successful students undertake to overcome the barriers. Padilla's (2004 Padilla , R. V. ( 1999 ). College student retention: Focus on success . Journal of College Student Retention , 1 ( 2 ), 131 – 145 .[Crossref] , [Google Scholar]) theoretical framework and methods for modeling student success provided the conceptual framework for the study. The data analysis resulted in the development of a local student success model and an implementation model for student services at the subject campus.  相似文献   

Determination of the prevalence of anabolic steroids,stimulants, and selected drugs subject to doping controls among elite sport students using analytical chemistry     

Mario Thevis  Michael Sauer  Hans Geyer  Gerd Sigmund  Ute Mareck  Wilhelm Schänzer 《Journal of sports sciences》2013,31(10):1059-1065

Abstract

Drug abuse by adolescents has been investigated in various surveys that reported correlations between age, gender, and activity. However, none of these studies included chemical analyses to help substantiate the statements of participants. In the present study, the urine specimens of 964 students (439 females, 525 males; mean age 22.1 years, s = 1.7), who applied to study sports sciences at university, were assessed for anabolic steroids, stimulants, and selected drugs prohibited in sports. In total, 11.2% of the urine specimens provided contained drugs covered by doping controls. The most frequently detected compound was the major metabolite of tetrahydrocannabinol (9.8%) followed by various stimulants related to amphetamine and cocaine (1.0%). Indications of anabolic steroid use were found in 0.4% of urine samples but originated from contraceptives containing norethisterone. The present study provided unambiguous data on the status quo of drug (ab)use by adolescents hoping for a career related to elite sport or sports sciences. No use of anabolic steroids was detected. However, evidence for stimulants and tetrahydrocannabinol administration was obtained, although not reported by any participant, which highlights the issue of under-reporting in surveys based solely on questionnaires.  相似文献