Effect of time of day on perceived exertion at work rates above and below the ventilatory threshold     

D W Hill  K J Cureton  M A Collins 《Research quarterly for exercise and sport》1989,60(2):127-133

The effect of time of day on ratings of perceived exertion (RPE) at various intensities of cycling exercise, both below and above the ventilatory threshold, was studied in 32 subjects, 18 to 35 years of age. The ventilatory threshold occurred at the same (p greater than .05) mean (+/- SD) work rate in the morning (110.6 +/- 27.0 watts) and in the afternoon (111.9 +/- 23.9 watts) and was perceived as equally strenuous (p greater than .05) in the morning (RPE = 13.8 +/- 2.4) and in the afternoon (RPE = 13.6 +/- 2.8). At intensities below the ventilatory threshold, RPE was the same (p greater than .05) in the morning and in the afternoon; above the ventilatory threshold, RPE was lower (p less than .05) in the morning. We conclude that, during incremental submaximal cycling exercise above the ventilatory threshold, a particular work rate is perceived as less strenuous in the morning than in the afternoon. About 20% of this difference in RPE is explained by lower ventilatory demands in the morning.  相似文献   

Sanitizing the Struggle: Barack Obama,Selma, and Civil Rights Memory     

Theon E. Hill 《Communication quarterly》2017,65(3):354-376

In this article, I examine Barack Obama’s use of collective memory during his 2007 campaign speech in Selma, Alabama. Specifically, I argue that Obama appeals to collective memory to challenge the Black community’s relationship to the past. He reframed the memory of the Civil Rights Movement in a manner favorable to his political aspirations. While this frame was politically expedient, it weakened Black political agency. It robbed the Black community of crucial rhetorical resources used to challenge structural inequalities in society. This article offers insight into the complex relationship between metaphor and collective memory. Specifically, I interrogate the role of metaphor as a crucial site where public memory is formed, disrupted, and rearticulated. Furthermore, I consider the implications of his use of memory for the future of the Black freedom struggle.  相似文献   

Que Luchen por sus Intereses (To Fight for Your Interests): Unearthing Critical Counter-Narratives of Spanish-Speaking Immigrant Parents     

Kevin Roxas  Maria L. Gabriel 《Journal of Latinos & Education》2017,16(3):243-262

This article reports on findings from a year-long research project conducted during the 2012–2013 school year in a PK–12 school district, located in the Mountain West region of the United States, utilizing the Photovoice method. The findings in the project point to the important critical counter-narratives Spanish-speaking immigrant parents present to the larger school community when given the opportunity to have their voices and perspectives heard and recorded in written form. The article provides teachers, counselors, administrators, and support staff in schools and school districts with insight into the hopes and aspirations of Spanish-speaking immigrant parents and highlights educational practices that address issues of equity and access, as seen through the eyes of the participants in the study.  相似文献   

Learning to play: A review and theoretical investigation of the developmental mechanisms and functions of cetacean play     

Heather M. Hill  Sarah Dietrich  Briana Cappiello 《Learning & behavior》2017,45(4):335-354

Play is a behavioral phenomenon most commonly observed in the young of both solitary and social species. Documentation of play in cetaceans varies across species and settings. Cetacean play behavioral repertoires include a broad range of actions, such as the manipulation of diverse objects, blowing bubbles, chasing conspecifics, and swimming in spirals through the water. As is common in research on animal play, cetacean play has been grouped into categories by its form, including locomotor play, object play, and different variations of social play, such as affiliative games, play fighting, and socio-sexual play. Research has primarily focused on recording the topography of cetacean play and the demographics of the individuals engaging in play. However, these classifications are insufficient to address the possible developmental and societal functions of cetacean play behaviors, or the mechanisms with which play behaviors are spread between conspecifics and acquired by young members of cetacean populations. This article applies several developmental and social learning theories in order to organize current knowledge and guide future research.  相似文献   

The Impact of a Professional Development Program on Teachers' Mathematical Knowledge for Teaching,Instruction, and Student Achievement     

Robin Jacob  Heather Hill  Doug Corey 《Journal of research on educational effectiveness》2017,10(2):379-407

In this paper, we describe findings from a three-year evaluation of a well-developed mathematics professional development program that is commercially available on a wide scale. The professional development is designed to improve teachers' mathematical knowledge for teaching and to enable them to elicit more student thinking and reasoning during mathematics lessons. Specifically, it focused on helping teachers (a) learn more mathematics, (b) understand how children learn math, (c) use formative assessment to develop insight into what specific students know and do not know, and (d) develop effective classroom instructional strategies that enable student problem solving. Participants included 105 fourth- and fifth-grade teachers teaching in 19 low-income schools within a single district. Teachers were randomly assigned within schools either to a “business as usual” control group or to receive the professional development. The training consisted of a week-long summer institute and four to six in-service days during the school year. The training was run by full-time trained associates. We find some limited evidence of positive impacts on teachers' mathematical knowledge for teaching, but no effects on instructional practice or student outcomes.  相似文献   

Advancing Diversity in STEM     

Paul L. Hill  Rose A. Shaw  Jan R. Taylor  Brittan L. Hallar 《Innovative Higher Education》2011,36(1):19-27

Although progress has been made, greater efforts are needed to promote faculty diversity at the college and university levels, especially in STEM fields. Thus, it is important to elucidate best practices both for increasing awareness of diversity issues pertaining to higher education and for implementing change. This article focuses on the outcomes of a diversity workshop for college and university faculty hosted by the West Virginia Higher Education Policy Commission, Division of Science and Research. More specifically, it elucidates how participation in the workshop translated into practice at the faculty participants’ home institutions.  相似文献   

Do central examinations lead to greater grading comparability? A study of frame-of-reference effects on the University entrance qualification in Germany     

Marko Neumann  Ulrich Trautwein  Gabriel Nagy 《Studies in Educational Evaluation》2011,37(4):206-217

In Germany, the Abitur grades awarded at the end of upper secondary education are critical in the allocation of sought-after university places. Drawing on a representative sample of 3526 grade 13 Abitur students in the German state of Baden-Württemberg, this article examines whether and to what extent grading is affected by the mean achievement of the school serving as frame of reference (“group-referenced grading”), and to what extent this influence differs for coursework and examination grades in mathematics and English as a foreign language. Overall, the results indicate that the higher level of standardization of the central Abitur examinations makes examination grades less susceptible to frame-of-reference effects than are coursework grades.  相似文献   

Teacher enthusiasm: Dimensionality and context specificity   总被引：1，自引：0，他引：1  

Mareike Kunter  Anne Frenzel  Gabriel Nagy  Jürgen Baumert  Reinhard Pekrun 《Contemporary educational psychology》2011,36(4):289-301

Enthusiasm is considered an important characteristic of effective teachers. However, the conceptualization of the term in the research literature is inconsistent. Whereas most studies use the term “enthusiasm” to describe features of instruction, some have used it to describe a characteristic of teachers. This research seeks to clarify the concept of teacher enthusiasm, examining its dimensionality and context specificity. The study draws on three samples of teachers who were administered questionnaire measures of enthusiasm. In two samples (N = 205 and 332), it was possible to match teacher data with data on the students taught. In another sample (N = 113), additional measures of work-related wellbeing were implemented. Confirmatory multigroup factor analyses showed that two dimensions of teacher enthusiasm can be distinguished, namely enthusiasm for teaching and enthusiasm for the subject. These dimensions differed in their meaning and context specificity. Whereas teaching enthusiasm was systematically linked to occupational wellbeing and to classroom variables, subject enthusiasm related only moderately to other measures of occupational wellbeing and was independent of characteristics of the classes taught.  相似文献   

Whole-body vibration effects on the muscle activity of upper and lower body muscles during the baseball swing in recreational baseball hitters     

Reyes GF  Dickin DC  Crusat NJ  Dolny DG 《Sports biomechanics / International Society of Biomechanics in Sports》2011,10(4):280-293

The purpose of this study was to evaluate the effects of whole-body vibration (WBV) on the muscle recruitment of selected upper and lower body muscles during the baseball swing. Participants were recreationally trained males (n = 16, 22 +/- 2 years, 181.4 +/- 7.4 cm, 84.7 +/- 9.0 kg), with previous baseball experience. Subjects participated in three randomized sessions on separate days, consisting of three sets of five swings offa hitting tee. Exercises (upper and lower body dynamic and static movements) with or without WBVexposure were performed between swing sets. During each swing, the gastrocnemius, biceps femoris, gluteus maximus, pectoralis major, latissimus dorsi, and triceps brachii were evaluated for electromyographic (EMG) activity. EMG values were normalized to EMG measured during maximal voluntary isometric contraction. Statistical analysis revealed no significant differences in EMG activity across the three treatments. In addition, the results displayed a specific muscle recruitment order during the swing, starting with the lower body followed by the upper body muscles. This study was the first to report the recruitment order during the baseball swing. Although acute exposure to WBV did not significantly alter the muscle recruitment, these results may prove useful for practitioners looking to enhance baseball swing performance.  相似文献   

New ways to deal with known preanalytical issues: use of transilluminator instead of tourniquet for easing vein access and eliminating stasis on clinical biochemistry     

Lima-Oliveira G  Lippi G  Salvagno GL  Montagnana M  Manguera CL  Sumita NM  Picheth G  Guidi GC  Scartezini M 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2011,21(2):152-159

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