The relationship between leadership preparation and the level of teachers’ interest in assuming a principalship in Chile     

Sergio Galdames  Alvaro Gonzalez 《School Leadership & Management》2016,36(4):435-451

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What is play fighting and what is it good for?     

Sergio M. Pellis  Vivien C. Pellis 《Learning & behavior》2017,45(4):355-366

Play fighting is a common form of play reported among species of mammals, birds, and some other taxa. The competition present in play fighting revolves around gaining some advantage, such as biting a partner without being bitten. The behavior simulated during play fighting need not be restricted to that present in adult serious fighting, but can involve competitive interactions derived from amicable behavior, such as sex and social grooming, or from nonsocial competition, such as predation. What unifies play fighting, irrespective of the functional behavior being simulated, is that it involves some degree of reciprocity, or turn taking, that requires that the competition be attenuated by cooperation. However, there are several different ways in which cooperation can be inserted into playful interactions, and these vary in use across different species. The moderation of competition with cooperation forces animals to monitor their own actions and those of their partners, and this common feature appears to be one vehicle through which the experience of play fighting in the juvenile period can train animals for greater psychological resilience. The monitoring and contextual adjustment of actions influences the development of executive functions of the brain, which, in turn, leads to the development of more adaptable adults.  相似文献   

Characteristics of Brazilian innovative firms: An empirical analysis based on PINTEC—industrial research on technological innovation     

Sergio Kannebley Jr.  Geciane S. Porto 《Research Policy》2005,34(6):872-893

The present paper reports on an effort to characterize Brazilian innovative firms. The characterization of the firms was based on the data from PINTEC-2000 (Industrial Research on Technological Innovation-2000). A non-parametric statistical procedure was employed which informed, in a decreasing order, that the four major predictors of innovation were exporting orientation, firm size, foreign capital origin, and inter-industry differences. The main determinants of whether firms introduced a new process in the market were foreign or mixed capital origin, sector effect, and export orientation. When the introduction of new products in the market was assessed, the major determinants were export orientation and foreign capital origin.  相似文献   

America's Cup yacht racing: Race analysis and physical characteristics of the athletes     

Vernon Neville  Julian Calefato  Cristina Pérez-Encinas  Enrique Rodilla-Sala  Sergio Rada-Ruiz  Paul Dorochenko 《Journal of sports sciences》2013,31(9):915-923

Abstract

The America's Cup is the oldest competing trophy in sport, yet little is known of the nature and intensity of racing or the physical characteristics of the athletes. In this study, aspects of the physical demands of America's Cup yacht racing were analysed, including the intensity of exercise and activity pattern of “grinding”. Anthropometric data were collected from 92 professional male America's Cup sailors, and fitness data from a top-4 and a lower-7 ranking team during the 32nd America's Cup. Over the 135 races, mean race duration was 82 min (s = 9), with 20 tacks (s = 10) and 8 gybes (s = 3) per race. Grinding bouts were 5.5 s (s = 5.4; range: 2.2–66.3) long, with 143 exercise bouts per race and an exercise-to-rest ratio of 1:6. Mean and peak heart rate was 64% and 92% of maximum for all positions, with bowmen highest (71% and 96%). Grinders were taller, heavier, and stronger than all other positions. Body fat was similar between positions (13%, s = 4). The higher-standard team was stronger and had greater strength endurance, which probably contributed to their quicker manoeuvres. Intensity of exercise was dependent on the similarity of competing boats and the role of the athlete. The short duration and intermittent nature of grinding is indicative of predominantly anaerobic energy provision.  相似文献   

Orienting Scientific Progress     

Martínez  Sergio F. 《Science & Education》2019,28(9-10):1249-1251

Science & Education -  相似文献   

Psychological adjustment in bullies and victims of school violence     

Estefanía Estévez  Sergio Murgui  Gonzalo Musitu 《European Journal of Psychology of Education - EJPE》2009,24(4):473-483

The present study examined psychosocial adjustment in the following four groups of students: victims, bullies, bully/victims and a control group of adolescents not involved in bullying or victimization problems. Psychosocial adjustment was measured considering as indicators: level of self-esteem, depressive symptomatology, perceived stress, feeling of loneliness, and a general measure of satisfaction with life. Participants (N=1319) were aged from 11 to 16 (47% male) and drawn from seven state secondary schools in Valencia (Spain). ANOVAs revealed significant differences among groups, reporting adolescents not involved a general better psychosocial adjustment; they had higher levels of self-esteem and satisfaction with life, and lower levels of depressive symptomatology, perceived stress and feeling of loneliness. The scores for this group were equivalent to those of bullies with respect to self-esteem, depressive symptomatology and loneliness. However, bullies perceived more stress and expressed less satisfaction with life, as did the other two groups, namely victims and bully/victims. Victims reported the strongest feelings of loneliness. Bully/victims seemed to share characteristics with both bullies and victims, though showing more similarities with the latter and a general poor psychosocial profile.  相似文献   

Effects of knowing the task duration on players’ pacing patterns during soccer small-sided games     

Ricardo Ferraz  Bruno Gonçalves  Roland Van Den Tillaar  Sergio Jiménez Sáiz  Jaime Sampaio  Mário C. Marques 《Journal of sports sciences》2018,36(1):116-122

The aim of this study was to identify the influence of prior knowledge of exercise duration on players’ pacing patterns during soccer small-sided games. Twenty semi-professional male soccer players participated in this study. In the first game scenario, players were not informed how long they would be required to play the small-sided game and the activity was terminated after 20 min (Unknown Condition). In the second game scenario, players were told that they would play the small-sided game for 10 min, but immediately after completing the 10-min game, they were asked to complete another 10 min (Partially Condition). In the third game scenario, players were instructed that they would play the small-sided game for 20 min and then they completed the 20-min game (Known Condition). The results presented a tendency of higher values in all performance variables in the [0′–10′] min compared with the [10′–20′] min. As the players’ previous knowledge about the tasks duration increased, the performance between two moments tended to be similar. Considering the entire 20-min game duration, the Partially Condition of the exercise was the most demanding condition. In conclusion, the knowledge of shorter durations of the exercise seems to lead to an increase of exercise duration demand, and longer exercise durations possibly tend to decrease differences between full knowledge and not knowing the exercise duration.  相似文献   

Is the prediction error of a regression model white?     

Sergio Bittanti 《Journal of The Franklin Institute》1983,315(4):239-246

With reference to the classical linear regression problem of Statistics, the whiteness of prediction errors is discussed. Two notions of prediction error are compared. It is shown that, if one tests the regression model on a smaller set of data than that used to estimate the model parameters, the errors will not be white.  相似文献   

Who benefits from school-based management in Mexico?     

Fernando Reimers  Sergio Cárdenas 《Prospects》2007,37(1):37-56

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Choosing letter grade evaluations: The interaction of students’ achievement goals and self-efficacy     

Colin Wayne Leach  Sergio S. Queirolo  Sanford DeVoe  Martin Chemers 《Contemporary educational psychology》2003,28(4):495-509

We examined how achievement (learning and performance) goals and academic self-efficacy predicted three achievement-related outcomes in a college sample. Self-efficacy tended to moderate the effects of (learning and performance) goals on number of courses taken for a letter grade as well as achievement in letter graded and pass/fail courses. Thus, learning goals better predicted choosing letter grades when self-efficacy was high than when it was low. In contrast, performance goals better predicted choosing letter grades when self-efficacy was low than when it was high. Through their prediction of the choice to receive letter grades these interactions predicted achievement in pass/fail courses. In addition, achievement goals and self-efficacy directly predicted achievement in letter graded courses.  相似文献