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排序方式: 共有418条查询结果,搜索用时 31 毫秒
91.
Wilfried Admiraal Jantina HuizengaSanne Akkerman Geert ten Dam 《Computers in human behavior》2011,27(3):1185-1194
Generally, high-school students have been characterized as bored and disengaged from the learning process. However, certain educational designs promote excitement and engagement. Game-based learning is assumed to be such a design. In this study, the concept of flow is used as a framework to investigate student engagement in the process of gaming and to explain effects on game performance and student learning outcome. Frequency 1550, a game about medieval Amsterdam merging digital and urban play spaces, has been examined as an exemplar of game-based learning. This 1-day game was played in teams by 216 students of three schools for secondary education in Amsterdam. Generally, these students show flow with their game activities, although they were distracted by solving problems in technology and navigation. Flow was shown to have an effect on their game performance, but not on their learning outcome. Distractive activities and being occupied with competition between teams did show an effect on the learning outcome of students: the fewer students were distracted from the game and the more they were engaged in group competition, the more students learned about the medieval history of Amsterdam. Consequences for the design of game-based learning in secondary education are discussed. 相似文献
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Frederick M. C. van Amstel Vedran Zerjav Timo Hartmann Mascha C. van der Voort Geert P. M. R. Dewulf 《Building Research & Information》2015,43(2):144-159
Space is often designed based on the representations of user activities (i.e. lists, organograms or flowcharts) that streamline user activities in stepwise, oversimplified, representations that may leave insufficient room for future activity development. However, design can anticipate activity development if users are able to represent their own activities while participating in the design process. A case study of a medical imaging centre reveals that once users have such opportunity, their spatial practices are not only taken into account but also expanded. The designers, the users and the researchers created a range of instruments to expand across three units of analysis: operations, actions and activities. As a result, the representations of space proffered by the designers were expanded to a space of representation for the users, where new ways of working were realized. Based on this study, an integrated model for the production of space and the development of activity is proposed. 相似文献
93.
Camilo Benítez-Ávila Andreas Hartmann Geert Dewulf Jörg Henseler 《International Journal of Project Management》2018,36(3):429-443
Defining the nature of the relationship between contractual and relational governance is critical for understanding how to maintain commitment and coordination between private and public organizations in long-term partnerships. In this study, a theoretical model explains Public-Private Partnership (PPP) project performance as the result of a mediation process. Contractual and relational governance elements operate sequentially with relational elements (relational norms and trust), playing a mediating role between contractual elements, project actors' behaviour and final performance. Based on the analysis of a survey of PPP practitioners in The Netherlands, and using Consistent Partial Least Squares Modeling, the study provides empirical support for these mediating effects. The findings are aligned with the idea that both economic incentives and hierarchical relationships formalized in contract agreements require being internalized in working practices by means of informal and socially based mechanisms. The enabling and compensating mechanisms underlying the mediation role of relational governance elements are discussed. Managers can particularly find in relational norms a leverage point for designing collaborative day-to-day practices aimed at reinforcing trust and long-term contractual obligations. 相似文献
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Kris Audenaert Sofie MonbaliuNick Deschuyffeleer Peter Maene Femke Vekeman Geert Haesaert Sarah De SaegerMia Eeckhout 《Food Control》2012,23(2):515-521
Fusarium Head Blight (FHB), caused by a blend of Fusarium species, is a destructive fungal disease of wheat and other small grain cereals. FHB has become an important issue in food and feed industry. Moreover, the majority of FHB pathogens have the ability to synthesize a range of mycotoxins. Although several physical and chemical control measures can be taken to control these fungi in the field, research is needed to provide new techniques for control during storage and transport of cereals. Mounting evidence shows that electrolyzed oxidizing water (EOW) has antimicrobial activity and might be a useful alternative for conventional control measures. The objective of the present work, was to investigate the influence of EOW on outgrowth and germination of Fusarium spp. and deoxynivalenol (DON) production. Both an in vitro and in vivo approach were pursued. In a first approach, a screening of the main FHB causing species was conducted. Secondly, the effect of EOW on Fusarium graminearum and the effect on DON biosynthesis was investigated using a trichothecene knockout mutant. These experiments showed an increase in DON levels upon sub lethal amendments of EOW to F. graminearum spores. In addition, the reactive oxygen species H2O2 was shown to govern this induction.Finally, the work was validated on a laboratory scale via an in vivo assay using wheat grains in which the Fusarium outgrowth was measured. The present work demonstrates that EOW has potential to control Fusarium spp. in wheat grains during transport and storage although sub lethal concentrations can result in increased DON biosynthesis. 相似文献
96.
The aim of this study was to determine the prevalence, major management systems, and fresh cow clinical conditions associated with ketosis in western European dairy herds. A total of 131 dairies were enrolled in Germany, France, Italy, the Netherlands, and the United Kingdom during 2011 to 2012. A milk-based test for ketones (Keto-Test; Sanwa Kagaku Kenkyusho Co. Ltd., Nagoya, Japan; distributed by Elanco Animal Health, Antwerp, Belgium) was used for screening cows between d 7 and 21 after calving and ketosis was defined as a Keto-Test ≥100 µmol/L. Study cows were observed for clinical disease up to 35 d postcalving. Multivariate analysis (generalized estimating equation logistic regression) was performed to determine country, farm, management, feed, and cow factors associated with ketosis and to determine associations between ketosis and fresh cow diseases. Thirty-nine percent of the cows were classified as having ketosis. The herd average of ketosis was 43% in Germany, 53% in France, 31% in Italy, 46% in the Netherlands, and 31% in the United Kingdom. Of the 131 farms, 112 (85%) had 25% or more of their fresh cows resulting as positive for ketosis. Clinical ketosis was not reported in most farms and the highest level of clinical ketosis reported was 23%. The risks of ketosis were significantly lower in Italy and the United Kingdom compared with France, the Netherlands, and Germany. Larger herd size was associated with a decreased risk of ketosis. The farms that fed partially mixed rations had 1.5 times higher odds of ketosis than those that fed total mixed rations. Cows that calved in April to June had the highest odds of ketosis, with about twice as high odds compared with cows that calved in July to September. The cows that calved in January to March tended to have 1.5 times higher risk of ketosis compared with cows that calved in July to September. The odds of ketosis in parity 2 and parity 3 to 7 was significantly higher (1.5 and 2.8 times higher, respectively) than the odds of ketosis in parity 1. The odds of ketosis was significantly smaller in parity 2 compared with parity 3 to 7. Ketosis was associated with significantly higher odds of all common fresh cow conditions: metritis, mastitis, displaced abomasum, clinical ketosis, lameness, and gastrointestinal disorders. Odds of ketosis in cows having had twins or dystocia were not increased, whereas higher odds of ketosis were observed in cows with milk fever or retained placenta. 相似文献
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