Knowledge exchange in clusters: The contingent role of regional inventive concentration     

Alex Vestal  Erwin Danneels 《Research Policy》2018,47(10):1887-1903

Geographic clusters confer advantages to collocated firms, in particular access to local know-how. This article argues that the access to local know-how is contingent on the extent to which inventive activity is concentrated in the cluster. We draw on sociological theories of generalized exchange to argue that contrasting logics of exchange emerge in geographic clusters that have opposing effects on the extent to which firms benefit from collaborating with local organizations and source local knowledge. A longitudinal data set of 1903 firms engaged in nanotechnology research is used to examine the relationship between firm co-authorships on scientific articles with firms and public research organizations (PROs) and firm inventive performance. Results indicate that when cluster-level firm inventive concentration is high, collaborations with local firms are associated with lower inventive performance. We also find that firms source less local knowledge for their own inventions when firm inventive concentration is high. In contrast, concentrated inventive activity among PROs increases the positive relationship between collaborations with local PROs and firm inventive performance. Results also show firms source more knowledge from local PROs when local PRO inventive concentration is high. The findings suggest that inventive concentration both helps and hinders spill-over of cutting-edge knowledge.  相似文献   

Perceived neighborhood environmental characteristics and different types of physical activity among Brazilian adolescents     

Gerfeson Mendonça  Alex Antonio Florindo  Cassiano Ricardo Rech  Delma Katiana Silva de Freitas  José Cazuza de Farias Júnior 《Journal of sports sciences》2018,36(9):1068-1075

Little is known about the association between environmental characteristics and types of physical activity in adolescents in a Latin American context. The aim of this study was to examine the association between perceived neighborhood environmental characteristics and different types of physical activity in 2,874 adolescents from Joao Pessoa, Paraiba State, Northeastern Brazil. The types of activity measured by questionnaire (≥10 min/day) included sports, physical exercises, active commuting and recreational activities. Neighborhood characteristics were measured by a 15-item scale. Multilevel analyses showed that adolescents who reported “having places they liked to go to” (OR = 1.41; 95%CI: 1.10–1.79) and “places with opportunities to practice” (OR = 1.29; 95%CI: 1.01–1.65) were more likely to play sports. “Seeing interesting things while walking” (OR = 1.24; 95%CI: 1.01–1.53) and “Seeing other adolescents engaged in physical activity” (OR = 1.47; 95%CI: 1,05–2,06) were associated with exercises. “Seeing other adolescents engaged in physical activity” (OR = 1.47; 95%CI: 1.18–1.82), “the neighborhood is not violent” (OR = 1.29; 95%CI: 1.04–1.60) and “having places they like to go to” (OR = 1.59; 95%CI: 1.13–2.25) were positively associated and “places with opportunities to practice” (OR = 0.79; 95%CI: 0.63–0.98) inversely related to active commuting. “Seeing other adolescents engaged in physical activities” (OR = 1.31; 95%CI: 1.05–1.63) and “seeing interesting things while walking” (OR = 1.26; 95%CI: 1.02–1.56) were associated with recreational activities. Neighborhood environmental characteristics associated with the physical activity vary with the type of practices adopted by adolescents.  相似文献   

Converting between estimates of moderate-to-vigorous physical activity derived from raw accelerations measured at the wrist and from ActiGraph counts measured at the hip: the Rosetta Stone     

Keith Brazendale  Michael W. Beets  Alex V. Rowlands  Jessica L. Chandler  Stuart J. Fairclough  Lynne M. Boddy 《Journal of sports sciences》2018,36(22):2603-2607

The ability to compare published group-level estimates of objectively measured moderate-to-vigorous physical activity (MVPA) across studies continues to increase in difficulty. The objective of this study was to develop conversion equations and demonstrate their utility to compare estimates of MVPA derived from the wrist and hip. Three studies of youth (N = 232, 9-12yrs, 50% boys) concurrently wore a hip-worn ActiGraph and a wrist-worn GENEActiv for 7-days. ActiGraph hip count data were reduced using four established cutpoints. Wrist accelerations were reduced using the Hildebrand MVPA 200 mg threshold. Conversion equations were developed on a randomly selected subsample of 132 youth. Equations were cross-validated and absolute error, absolute percent error, and modified Bland-Altman plots were evaluated for conversion accuracy. Across equations R²_adj was 0.51–0.56 with individual-level absolute error in minutes ranging from 7 (wrist-to-hip Puyau) to 14.5 minutes (wrist-to-hip Freedson 3MET) and absolute percent differences ranging from 13.9%-24.5%. Group-level cross-validation to convert hip-to-wrist MVPA resulted in average absolute percent errors ranging from 3.1%-4.9%. Conversion of wrist-to-hip MVPA resulted in average absolute percent errors ranging from 3.0%-10.0%. We recommend the use of these equations to compare published estimates of MVPA between the wear-site cut-point combinations presented.  相似文献   

Relationship between academic achievement and healthy school transformations in urban elementary schools in the United States     

Erin E. Centeio  Cheryl L. Somers  E. Whitney G. Moore  Noel Kulik  Alex Garn  Jeffrey Martin 《Physical Education & Sport Pedagogy》2018,23(4):402-417

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Talking Mathematics in School, Edited by M. Lampert & M. Blunk (1998)     

Alex Lawson 《Interchange》2001,32(1):99-110

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Design Education in China: New Proposals to Address Endemic Problems     

Alex Fung Shung‐Yu  Alice Lo Choi Yuet‐Ngor 《The International Journal of Art & Design Education》2001,20(2):171-179

This paper is concerned with identifying the problems that pervade design education and the practice of design in China so that a way forward can be proposed to make improvements that will enable the Chinese design industry to become more competitive after entry into the World Trade Organisation. The authors gathered data from their own experiences and observations in situ, as well as surveys they commissioned. They found that there are numerous endemic, fundamental problems in the practice of design education across the whole education sector. Fortunately, many Chinese design educators and managers of design companies are cognizant of these problems and are motivated to institute changes, even though they are unsure of what these changes should be or how they should be implemented. The authors conclude by making their own recommendations for effecting improvements in design education and professional development.  相似文献   

METRO--the creation of a taxonomy for medical education     

Haig A  Ellaway R  Dozier M  Liu D  McKendree J 《Health information and libraries journal》2004,21(4):211-219

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Peer review research: an invitation to ALPSP members to join Locknet     

Alex Williamson 《Learned Publishing》1995,8(3):139-140

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Careers in publishing and bookselling. Second edition by June Lines Kogan Page, 1994 96 pp. Paperback, £6.99     

Alex Williamson 《Learned Publishing》1995,8(1):67-68

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Serial publications: guidelines for good practice in publishing printed journals and other serial publications PUblished by the UK Serials Group,Witney, Oxfordshire. 1994. 48pp. paperback. £16.00. ISBN 0–906148–10–3     

Alex Williamson 《Learned Publishing》1995,8(3):195-196

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