22 research outputs found
Kinetic Characterization and X-ray Structure of a Mutant of Haloalkane Dehalogenase with Higher Catalytic Activity and Modified Substrate Range
Conversion of halogenated aliphatics by haloalkane dehalogenase proceeds via the formation of a covalent alkyl-enzyme intermediate which is subsequently hydrolyzed by water. In the wild type enzyme, the slowest step for both 1,2-dichloroethane and 1,2-dibromoethane conversion is a unimolecular enzyme isomerization preceding rapid halide dissociation. Phenylalanine 172 is located in a helix-loop-helix structure that covers the active site cavity of the enzyme, interacts with the Clβ of 1,2-dichloroethane during catalysis, and could be involved in stabilization of this helix-loop-helix region of the cap domain of the enzyme. To obtain more information about the role of this residue in dehalogenase function, we performed a mutational analysis of position 172 and studied the kinetics and X-ray structure of the Phe172Trp enzyme. The Phe172Trp mutant had a 10-fold higher kcat/Km for 1-chlorohexane and a 2-fold higher kcat for 1,2-dibromoethane than the wild-type enzyme. The X-ray structure of the Phe172Trp enzyme showed a local conformational change in the helix-loop-helix region that covers the active site. This could explain the elevated activity for 1-chlorohexane of the Phe172Trp enzyme, since it allows this large substrate to bind more easily in the active site cavity. Pre-steady-state kinetic analysis showed that the increase in kcat found for 1,2-dibromoethane conversion could be attributed to an increase in the rate of an enzyme isomerization step that preceeds halide release. The observed conformational difference between the helix-loop-helix structures of the wild-type enzyme and the faster mutant suggests that the isomerization required for halide release could be a conformational change that takes place in this region of the cap domain of the dehalogenase. It is proposed that Phe172 is involved in stabilization of the helix-loop-helix structure that covers the active site of the enzyme and creates a rigid hydrophobic cavity for small apolar halogenated alkanes.
A Systemic Assessment of the European Offshore Wind Innovation: Insights from the Netherlands, Denmark, Germany and the United Kingdom
The development and diffusion of offshore wind energy technology is important for European energy policy. However, the large potential does not automatically lead to a large share in future energy systems; neither does an emergent stage of technological development automatically lead to success for companies and the related economic growth and growth in employment. Recent insights in innovation studies suggest that the success chances of technological innovations are, to a large extent, determined by how the surrounding system (the innovation system) is built up and how it functions. Many innovation systems are characterized by flaws that hamper the development and diffusion of innovations. These flaws are often labelled as system problems or system challenges. Intelligent innovation policy therefore evaluates how innovation systems are functioning, tries to create insight into the systems’ challenges and develops policies accordingly. This report assesses the European offshore wind innovation system based on insights from four countries: Denmark, the UK, the Netherlands and Germany. We use the Technological Innovation System (TIS) approach to analyse the state and functioning of the system at the end of 2011. Based on the analysis we identify four types of systemic challenges: (i) actor-related such as deficiency of engineers; (ii) institutional, e.g. non-aligned national regulatory frameworks; (iii) interaction-related like poor transferability of scientific knowledge to specific contexts of application and; (iv) infrastructural such as poor grid infrastructure. We suggest the challenges require a systemic, coordinated policy effort at a European level if the system is expected to contribute to the goals of climate change reduction and stimulation of green growth.JRC.F.6-Energy systems evaluatio
What drives university research performance? An analysis using the CWTS Leiden Ranking data
This paper analyzes the factors underlying university research performance as indicated by the number of highly-cited publications, international co-publications, and university-industry co-publications. The three performance indicators evaluate three possible university missions, respectively: research excellence, internationalization, and innovation. Using a regression analysis, we assess to what extent a university's research performance is influenced by structural variables including size, age, city size, location in a capital city, disciplinary orientation, and country location. Our results show that research performance differences among universities mainly stem from size, disciplinary orientation and country location. This suggests that simple global benchmarking can be misleading; rather, benchmarking is most meaningful between universities of a similar size supplemented with contextual information on a university's specific mission, orientation and national institution
What drives university research performance? An analysis using the CWTS Leiden Ranking data
This paper analyzes the factors underlying university research performance as indicated by the number of highly-cited publications, international co-publications, and university-industry co-publications. The three performance indicators evaluate three possible university missions, respectively: research excellence, internationalization, and innovation. Using a regression analysis, we assess to what extent a university's research performance is influenced by structural variables including size, age, city size, location in a capital city, disciplinary orientation, and country location. Our results show that research performance differences among universities mainly stem from size, disciplinary orientation and country location. This suggests that simple global benchmarking can be misleading; rather, benchmarking is most meaningful between universities of a similar size supplemented with contextual information on a university's specific mission, orientation and national institution
Crowdsourcing ideas : Involving ordinary users in the ideation phase of new product development
The different roles of users in new product development (NPD) have been extensively described. Currently online idea crowdsourcing, via long-term open idea calls, is increasingly being used by companies to collect new product ideas from ordinary users. Such open idea calls can result in thousands of suggested ideas and detecting the ones that a company wants to implement can be problematic. Empirical research in this area is lacking. We therefore investigate which ideator and idea-related characteristics determine whether an idea for NPD is implemented by a crowdsourcing company. To answer this question, we use a cross-sectional research design to analyse publicly available data from an open idea call, run by an internationally active beverage producer. Our results reveal that ideators paying major attention to crowdsourced ideas of others, the idea popularity, as well as its potential innovativeness positively influence whether an idea is implemented by the crowdsourcing company. Counterintuitively, the motivation of an ideator, reflected in the number of ideas suggested, does not influence the likelihood of an idea being implemented
Crowdsourcing ideas : Involving ordinary users in the ideation phase of new product development
The different roles of users in new product development (NPD) have been extensively described. Currently online idea crowdsourcing, via long-term open idea calls, is increasingly being used by companies to collect new product ideas from ordinary users. Such open idea calls can result in thousands of suggested ideas and detecting the ones that a company wants to implement can be problematic. Empirical research in this area is lacking. We therefore investigate which ideator and idea-related characteristics determine whether an idea for NPD is implemented by a crowdsourcing company. To answer this question, we use a cross-sectional research design to analyse publicly available data from an open idea call, run by an internationally active beverage producer. Our results reveal that ideators paying major attention to crowdsourced ideas of others, the idea popularity, as well as its potential innovativeness positively influence whether an idea is implemented by the crowdsourcing company. Counterintuitively, the motivation of an ideator, reflected in the number of ideas suggested, does not influence the likelihood of an idea being implemented
Pathways and harbours for the translocal diffusion of sustainability innovations in Europe
Sustainability challenges require experimenting with various types of sustainability innovations. Local and regional context conditions influence their diffusion. Our research question is: what are pathways for the transfer of sustainability innovations to other locations, and how do local and regional conditions enable this transfer? We use the notion of ‘harbours’ to conceptualise the combination of these conditions. In a comparative case study in four city-regions, analysing 48 experiments, we find that technological innovations travel easier around the globe compared to social innovations. For social innovations, the transferred knowledge has a more tacit character and the innovations are strongly embedded in the local cultural and institutional context. Signifiers may enable their translocal diffusion. Moreover, the results suggest that innovations are ‘translated’ rather than replicated. We find some important local and regional context conditions enabling transfer: cultural conditions, vibrant environments (such as festivals), networks and the presence of enabling regional actors
Pathways and harbours for the translocal diffusion of sustainability innovations in Europe
A review of the European offshore wind innovation system
Offshore wind has the potential of becoming an important pillar of the future European energy system, contributing to policy objectives on climate change, energy security, green growth and social progress. However, the large potential of offshore wind does not automatically lead to a large share in future energy systems; neither does the emergent stage of development of the technology. Recent insights in innovation studies suggest that the success chances of technological innovations are, to a large extent, determined by how the surrounding system - the innovation system - is built up and how it functions. In this paper we assess the offshore wind innovation systems of four countries: Denmark, the UK, the Netherlands and Germany with the objective to provide recommendations for strengthening the overall European offshore wind innovation system. We use the Technological Innovation System (TIS) approach to analyze the system in 2011. Based on the analysis we identify a number of challenges that the European offshore wind sector faces. Some of them include: a serious deficiency of engineers; fragmented policies and poor alignment of national regulatory frameworks;
cost of the technology and limited grid infrastructure. Since the problems hinder the entire system development we call for a systemic policy instrument that would support the innovation system around this technology and contribute to its wider diffusion in Europe.JRC.F.6-Energy systems evaluatio
Pathways and harbours for the translocal diffusion of sustainability innovations in Europe
Sustainability challenges require experimenting with various types of sustainability innovations. Local and regional context conditions influence their diffusion. Our research question is: what are pathways for the transfer of sustainability innovations to other locations, and how do local and regional conditions enable this transfer? We use the notion of ‘harbours’ to conceptualise the combination of these conditions. In a comparative case study in four city-regions, analysing 48 experiments, we find that technological innovations travel easier around the globe compared to social innovations. For social innovations, the transferred knowledge has a more tacit character and the innovations are strongly embedded in the local cultural and institutional context. Signifiers may enable their translocal diffusion. Moreover, the results suggest that innovations are ‘translated’ rather than replicated. We find some important local and regional context conditions enabling transfer: cultural conditions, vibrant environments (such as festivals), networks and the presence of enabling regional actors