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This study explores science communication on Twitter by investigating a sample of tweets referring to academic papers in five different scientific fields. The specifications of science communicators on Twitter, the characteristics of those who initiate actions (by tweeting), the extent and quality of reactions (retweeting), individual and group interactions, and the distribution of tweets across types of engagement in the process of science communication (i.e., dissemination, consultation, and evaluation) were explored. A broad array of actors is involved in the communication of science on Twitter, with individual citizens and individual researchers playing an important role. In principle, this is promising for creating direct interaction, which can be difficult through more traditional mass media. The vast majority of communication activities regarding academic papers is undigested dissemination with almost no sign of debate, contestation, or collective reflection. Another general finding of this study is that bot accounts play a major role in the science communication landscape on Twitter. 相似文献
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This study applied expectancy theory to integrate the numerous and disparate explanations that researchers and educators have proposed to account for teacher resistance to implementing cooperative learning as an educational innovation. The cooperative learning implementation questionnaire (CLIQ) contained 48 items grouped under three broad motivational categories: perceived value of the innovation, expectancy of success, and perceived cost. These items accounted for 42.3% of the total variance in self-reported use of cooperative learning among 933 teachers. Expectancy of success issues were most important in differentiating users and non-users, suggesting that increased emphasis on professional development should be used to enhance teachers' beliefs that they can succeed in implementing an innovation in their own context. This may require both follow-up support and adaptation of the innovation. 相似文献
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Dylan Poulsen Michael Defoort Mohamed Djemai 《Journal of The Franklin Institute》2019,356(16):9076-9094
We consider the leader–follower consensus problem for a multi-agent system where information is exchanged only on a non-uniform discrete stochastic time domain. For a second-order multi-agent system subject to intermittent information exchange, we model the tracking error dynamics as a varying linear system on a discrete stochastic time scale, where μ is the graininess operator. Based on a Lyapunov operator and a positive perturbation operator on the space of symmetric matrices, we derive necessary and sufficient conditions to design a decentralized consensus protocol. This protocol allows us to cast the mean-square exponential consensus problem within the framework of dynamic equations on stochastic time scales. We establish some theoretical results which allow for the computation of the control gain matrix which guarantees the mean-square exponential stability with a given decay rate for the error dynamics. To show the effectiveness of the theoretical results, some simulation and experimental results on multi-robot systems have been performed. 相似文献
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The present study investigated the relationships between lexical access, reading fluency, and comprehension. Two components of speed of lexical access were studied: phonological and semantic. Previous studies have mainly investigated these components of lexical access separately. The present study examined both components in naming tasks—with isolated letters (phonological) and pictures (semantic). Seventy-five Grade 5 students were administered measures of letter and picture naming speed, word and nonword reading fluency, and reading comprehension, together with control measures of vocabulary. The results showed that letter naming was a unique predictor of word reading fluency, whereas picture naming was not. Conversely, picture naming speed contributed unique variance to reading comprehension, whereas letter naming did not. The results indicate that phonological and semantic lexical access speed are separable components that are important for different reading subskills. 相似文献
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The emphasis on competitiveness and the knowledge-based economy in European policymaking has resulted in a heightened focus on monitoring and steering the science system, particularly through metric-based instruments. Policymakers’ general aims of fostering excellent research and breakthroughs are shared by researchers as well; however, below the surface is a paradox that is rarely discussed. The political system and the science system understand and pursue these concepts and objectives differently. Through two case studies on high-performing university-based research environments in Denmark and Sweden, this article uncovers the ways in which highly successful researchers often behave in ways that run counter to policy steering attempts. They do this by shielding themselves and their research group from steering pressures originating in the political system. Using Luhmann’s systems theory, the cases demonstrate why the relationship between the science system and the political system needs to be understood as a horizontal rather than a vertical relationship, and using concepts from organizational theory, provides a model and terminology for identifying and analyzing the types of mechanisms and strategic responses that the science system uses to shield itself from political steering pressures. 相似文献
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Henrik S⊘rensen Morten Zacho Erik B. Simonsen Poul Dyhre‐Poulsen Klaus Klausen 《Journal of sports sciences》2013,31(6):483-495
Fast unloaded movements (i.e. striking, throwing and kicking) are typically performed in a proximo‐distal sequence, where initially high proximal segments accelerate while distal segments lag behind, after which proximal segments decelerate while distal segments accelerate. The aims of this study were to examine whether proximal segment deceleration is performed actively by antagonist muscles or is a passive consequence of distal segment movement, and whether distal segment acceleration is enhanced by proximal segment deceleration. Seventeen skilled taekwon‐do practitioners were filmed using a high‐speed camera while performing a high front kick. During kicking, EMG recordings were obtained from five major lower extremity muscles. Based on the kinematic data, inverse dynamics computations were performed yielding muscle moments and motion‐dependent moments. The results indicated that thigh deceleration was caused by motion‐dependent moments arising from lower leg motion and not by active deceleration. This was supported by the EMG recordings. Lower leg acceleration was caused partly by a knee extensor muscle moment and partly by a motion‐dependent moment arising from thigh angular velocity. Thus, lower leg acceleration was not enhanced by thigh deceleration. On the contrary, thigh deceleration, although not desirable, is unavoidable because of lower leg acceleration. 相似文献
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The aim of the present study was through semi-structured interviews to explore udeskole teacher’s perceptions of motivational factors and challenges while teaching regularly outside the classroom on a weekly basis during a year. Six females and two male udeskole teachers participated and answered an interview guide containing five themes about their motivations, student relations, teaching experiences, challenges and recognition. Udeskole was perceived to have substantial potentials to improve both academic learning and life skills and ‘the common third’, i.e. teacher–pupil relations, was mentioned as a value added to the indoor teaching. Health and safety issues were not perceived as barriers. 相似文献
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Kjeld B. Poulsen Søren H. Jensen Elsa Bach John F. Schostak 《Educational Action Research》2013,21(1):75-106
During the past five decades occupational researchers have documented that bus drivers’ health is worse than in almost any other profession. The authors suggest that the reason there has not been any successful attempt to change this situation is because the focus until now on removing statistically associated external risk factors has been too narrow. The article describes a project whose purpose was to improve the health and well‐being of 3500 Copenhagen bus drivers. At the end, more than 200 interventions were implemented. The authors adopted a new approach of combining epidemiological results and qualitative methodologies, creating a broader explanatory foundation for action, linked by repetitive processes of critical reflection, which was central to defining problems, explaining causes, developing sufficiently effective interventions and measuring effects. The project revealed the importance of several new and potentially preventable factors involving such issues as lifestyle, private stressors and inappropriate management. During the project period an evaluative framework was developed to explore and measure the complex effects of multiple interventions. Three years after the interventions were launched, follow‐ups revealed remarkable improvements such as reductions in stress and body pains, an increase in satisfaction, and improvements in management and the drivers’ cabin. This article is the story of a methodological journey, from classical epidemiology to an approach combining the strengths of survey (broad coverage), qualitative methods (in‐depth focus) followed by critical reflections and ending with action research. 相似文献
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