Whatever works: Uncertainty and technological hybrids in medical innovation

The persistent uncertainty that looms over the search for solutions to health problems offers important conceptual insights for the study of technological change. This paper explores the notion of hybridization, namely the embodiment of multiple competing operational principles within a single medical device, as strategy to deal with the practical shortcomings due to said uncertainty. The history of the development of the hybrid artificial disc affords the elaboration of an alternative view of hybridization and, at the same time, the articulation of a dualism between medical science as area of basic research (e.g. what disease is) and as practical knowledge (e.g. how disease can be tackled).     

The contribution of Project-based-learning to high-achievers’ acquisition of technological knowledge and skills

The main goals of this study were to look after the technological knowledge construction process by high-school high-achievers, and their ability to design and implement solutions for technological problems. More specifically, we examine the contribution of Project-based-learning (PBL), as pedagogical means for supporting the students’ knowledge acquisition and problem-solving process. The findings show a significant increase in formal knowledge as measured by standardized matriculation exams; an expansion in the scope of technological knowledge acquired and implemented, and in the scope of knowledge resources utilized for the projects; a high level of overall performance as regards to the set of design skills studied; a positive change in attitude towards technology and technological studies; the emergence of consistent design styles by individuals and groups along their work in the projects.     

Evaluating impacts of institutional reforms on port efficiency changes: Ownership,corporate structure,and total factor productivity changes of world container ports

This paper evaluates how port institutional reforms influenced efficiency gains between 1991 and 2004. We constructed a panel data for port ownership, corporate structure, and port inputs and outputs for 98 major world ports, and we implemented the Malmquist Productivity Index (MPI) model. The MPI provides efficiency measures for input combinations that allow for obtaining the outputs in the presence of institutional reforms, ownership changes, main agent problems, technological progress, efficient scale growth, and many other reasons for efficiency and the lack of it. The results illustrate that ownership restructuring contributed to total factor productivity gains. The restructuring induced optimized operation of container terminals, especially for large ports, as it allowed specialized private entities to concentrate on terminal operation and cargo handling services.     

When Hosts Become Guests: Return Visits and Diasporic Identities in a Commonwealth Eastern Caribbean Community

The broad intent of this paper is to further contribute to the existing literature that addresses VFR tourism. It suggests that the return visit may ultimately be positioned as a form or type of travel within the larger category of VFR tourism, but a form or type that has built within it a more clear understanding of historic and social contexts and processes. The other broad intent of the paper is to highlight the importance of the relationship between the returning visitor, originating from diasporic communities abroad, and the host community as a stage for the negotiation of identities. The return visit is shown to reflect such underlying processes yet continue to incorporate aspects of individual motivation, which when taken together demonstrate the fluidity of diasporic spaces and transnational identity structures. Using data obtained from ethnographic fieldwork among social networks within the Commonwealth Eastern Caribbean community in Toronto, Canada, it is suggested that return visits are used to retain social histories and contextualise social and cultural backgrounds after migration. The implications for VFR tourism and the relationship between diasporas, transnationalism and tourism are discussed, as is a conceptual model of the return visit.     

Identifying sources of systematic variation in direct price elasticities from revealed preference studies of inter-city freight demand

Freight demand elasticity studies vary significantly in terms of the demand measure, data type, estimation method, commodity type, etc. This wide variation makes it difficult to compare empirical estimates when the differences may arise in part from the methods and data used. In this paper we conduct a comparative analysis to identify systematic sources of influence on direct price elasticity estimates in the context of freight transport, distinguishing between road, rail, and sea transport, using published direct price elasticities from 12 elasticity-derivative studies from five countries. The study focuses on revealed preference elasticities defined by the freight rate for tonnes and tonne kilometres of inter-city freight movements. Systematic sources that explain differences in direct price elasticities include the demand elasticity measure, mode, commodity class, model estimation form, country, and temporal nature of data (e.g., cross-section). Analysts can utilise the model outputs to adjust the empirical evidence from specific studies to control for differences that impact on the behavioural implications of comparative evidence.     

The Role of Information and Influence in Social Networks

A bstract .   This article examines two mechanisms through which social networks are related to job mobility: (1) access to diverse sources of information about job openings and (2) nonredundant sources of influence. Using data on job changing and social networks among television station managers, we assess the extent to which job information and influence variables mediate the relationship between social network structure and getting a better job. Results indicate that there is an association between job mobility and having nonredundant contacts, but our measures of the information and influence mechanisms are not significant mediators. We conclude by reexamining the network-resource model that forms the basis for much of the research on the relationship between social networks and job mobility.