Martin Meyer
email: m.s.meyer@sussex.ac.uk

Dirk Libaers
email: libaersd@umkc.edu

Jae-Hwan Park

THE EMERGENCE OF NOVEL SCIENCE-RELATED FIELDS: REGIONAL OR TECHNOLOGICAL PATTERNS? EXPLORATION AND EXPLOITATION IN UK NANOTECHNOLOGY

Keywords: patent analysis, bibliometrics, innovation systems, emerging technologies, nano-districts patent analysis, bibliometrics, innovation systems, emerging technologies, nanodistricts JEL codes: O31, O33, O38, O52

établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

This article addresses the emergence of new technologies in their geographical and cognitive context. Technological innovation patterns can be analysed using a number of levels and units of analysis, each highlighting differing aspects of the boundaries of and the activities and interactions within innovation systems that initiate, import, modify and diffuse novel technologies [START_REF] Freeman | Technology Policy and Economic Performance: Lessons from Japan[END_REF]). An extensive literature has evolved that addresses the emergence of new technologies in their geographical and cognitive context.

The notion of innovation systems has been most prominent in these discussions (e.g. Nelson, 1993;[START_REF] Lundvall | National Systems of Production, Innovation and Competence Building[END_REF]Edquist, 2005a,b). Edquist (2005b: 182) offers a definition of a generic system of innovation as "all important economic, social, political, organizational, institutional, and other factors that influence the development, diffusion and use of innovations."

Every system has a limited extension. The boundaries of the system can be spatial, sectoral, or technological.

Within the overall framework, there have been pronounced differences between approaches as to whether the emergence of technologies occurs predominantly in a spatial (regional, national) (e.g. [START_REF] Freeman | Japan: a New National System of Innovation?[END_REF]Howells,1999;[START_REF] Lundvall | National Systems of Innovation: Towards a Theory of Innovation and Interactive Learning[END_REF][START_REF] Lundvall | National Systems of Production, Innovation and Competence Building[END_REF][START_REF] Cooke | Regional Innovation Systems: The Role of Governance in a Globalized World[END_REF] or rather a cognitive (sectoral, technological) context (e.g. [START_REF] Malerba | Sectoral systems of innovation and production[END_REF][START_REF] Carlsson | On the nature, function, and composition of technological systems[END_REF]Carlsson andJacobsson, 1994, Autio and[START_REF] Autio | Technological systems: structures, dynamism, and sources of change[END_REF].

Recent work by geographers attempts to relate the different spaces and scales of innovation to one another. For instance, Bunnell and Coe 583) stressing the importance of non-local networks of innovators. They argue that "the study of 'spaces of innovation' needs to be more oriented towards exploring the linkages and interrelationships between and across these various spatial levels or scales" (Bunnell and Coe, 2001, 577). Oinas andMalecki (1999, 2002) introduced the notion of 'spatial innovation systems' which is defined as 'overlapping and interlinked national, regional and sectoral innovation systems manifested in different configurations through space'. As Lawton-Smith (2006: 33) puts it, the merit of this approach is highlighting "the co-existence of interdependent factors operating at a particular time shaping geographies of innovation." Oinas and Malecki (1999: 25) suggest that understanding the 'co-functioning of proximity versus distance effects in various sorts of innovation' remains a key challenge. This paper attempts to explore for a newly emerging area, nanoscience and nano-technology, how cognitive, technological aspects relate to geographical factors. Much recent research on the emergence of this field points to strong regional concentration of activities in 'nano-districts' or clusters (e.g., [START_REF] Shapira | Emergence of Nanodistricts in the United States: Path Dependency or New Opportunities?[END_REF][START_REF] Zucker | Socio-economic Impact of Nanoscale Science: Initial Results and Nanobank[END_REF]. But what is the extent to which innovation activity in nanotechnology is networked within the region or across technological paths?

It is fair to state that technological patterns of a novel science & technology discipline such as nanoscience and nanotechnology will occur to a greater or lesser extent in both a spatial-geographic and a cognitive context.

In this paper we examine what context predominates the evolution of nano [START_REF] Bowman | Nanotechnology: Mapping the wild regulatory frontier[END_REF] while other studies explicitly elucidate the spatial patterns of nanotechnology-related knowledge assets at the regional level [START_REF] Shapira | Measures for knowledge-based economic development: Introducing data mining techniques to economic developers in the state of Georgia and the US South[END_REF] or analyze the selection of nanoscience and technology as a key research area for a national R&D program [START_REF] Lee | Selecting the key research areas in the nanotechnology field using technology cluster analysis: A case study based on national R&D programs in South Korea[END_REF].

Research adopting a cognitive approach to examining nanoscience and nanotechnology has been profiled in a series of studies aimed at a better characterization of this novel field in terms of publication and patenting patterns, the collaborative linkages between actors, technological opportunities that are opening up, the interaction between the science and technology realms, the technology transfer mechanisms and the interdisciplinarity of the field. [START_REF] Meyer | Nanotechnology -Interdisciplinarity, patterns of collaboration and differences in application[END_REF][START_REF] Meyer | Hurdles on the way to growth[END_REF][START_REF] Libaers | The role of University Spinout Companies in an Emerging technology: The case of Nanotechnology[END_REF][START_REF] Alencar | Nanopatenting raise issue for managers and countries[END_REF]. The next sections will briefly review and synthesize the intellectual antecedents to the vast and rapidly growing innovation systems literature.

2 Theoretical Background

Geographically bounded Innovation Systems

The observation that technological change is systemic in nature where firms innovate not in a vacuum but in collaboration and interdependence with other organizations has been instrumental in the development of the literature on innovations systems in general, and national and regional innovation [START_REF] Fagerberg | Innovation: A Guide to the Literature[END_REF][START_REF] Powell | Networks of Innovators[END_REF][START_REF] Asheim | Industrial Districts: The Contributions of Marshall and Beyond[END_REF]Howells, 1998). Lundvall and Freeman are widely credited for introducing the concept of a national system of innovation in the late 80's and which has since rapidly diffused in the academic and policy-making world as a useful analytical tool to analyse innovation processes (Edquist, 2005a, b). At the center of national innovation systems and its related alternative specifications are the concepts of innovation and system-wide learning that generate continual social and economic renewal and growth [START_REF] Lundvall | National Systems of Production, Innovation and Competence Building[END_REF].

The boundaries of a national system of innovation coincide with the geographical borders of a sovereign country. These boundaries have important implications for the institutional arrangements within the system which are strongly determined by national policies that pertain to e.g. property rights, funding levels for research, regulatory laws and enforcement etc [START_REF] Edquist | Institutions and Organizations in Systems of Innovation[END_REF]. The system is typically composed of organizational actors in both private and public sectors that perform distinct tasks and in a well-functioning system are connected to each other through formal and informal inter-organizational relationships. A clear division of knowledge production and exploitation can be observed across most national systems of innovation whereby universities and government laboratories perform mostly basic research and some applied research, private firms perform mostly applied research, and posses manufacturing and marketing capabilities needed to commercialize products and services, and finally government agencies creating, enforcing, and amending institutional arrangements. Innovative activity is neither evenly nor randomly distributed across spatial dimensions (for a review of innovation across space see [START_REF] Simmie | Innovation and Space: A Critical Review of the Literature[END_REF]. Perhaps most prominently, [START_REF] Florida | The Rise of the Creative Class[END_REF][START_REF] Florida | People, Place, and Region: The Economic Geography of Talent[END_REF] argues that the distribution of talent, i.e. individuals with high levels of human capital, is an important factor in economic geography that is highly concentrated and strongly associated with high-technology industry location. Or in other words, "talented individuals with high levels of human capital are likely to locate in places that give added strength or support to their productivity and which contain other talented people with whom they can interact and learn from, thereby building on existing knowledge and/or generating new knowledge" (Lawton- Smith, 2006: 33). Some regions seem better able to generate, capture and harness knowledge and the resulting economic benefits critical to economic development than others. Successful technology-based regional development had a transformative effect on areas such as Silicon Valley, Route 128 in Boston, Research Triangle Park, and the Cambridge area in the UK, among many other regions where high concentrations of human capital are available [START_REF] Saxenian | Regional Advantage: Culture and Competition in Silicon Valley and Route 128[END_REF][START_REF] Garnsey | High-technology clustering through spin-out and attraction: The Cambridge Case[END_REF][START_REF] Smith | The geography of talent: entrepreneurship and local economic development in Oxfordshire[END_REF].

Since the early 1980's there has been a revival of interest in the region as a site of economic interaction and innovation, associated with a range of approaches all of which tried to describe dynamic agglomerations and capture, as Bunnel and Coe (2001: 575) put it, the "essence of localized clusters of activity characterized by high-industry interactions involving both tangible and intangible elements". The Regional Systems of Innovation (RSI) approach was introduced by [START_REF] Cooke | Regional innovation systems: competitive regulation in the new Europe[END_REF] and rose to prominence in the late closely resemble those of the NSI approach. However, the RSI approach suggests that the sub-national region is arguably the most appropriate scale for comprehending the dynamics of and organizing policy interventions directed towards integrated innovation systems (see overview in Bunnell and Coe, 2001: 575).

As [START_REF] Oinas | The Evolution of Technologies in Time and Space[END_REF] point out referring to [START_REF] Asheim | Local learning and interactive innovation networks in a global economy[END_REF], the mere presence of a range of industries in a region does not make that region a 'territorially integrated' innovation system. Rather, they argue, it is the potential relatedness between the knowledge and capabilities of firms that may trigger their engagement in innovative interaction [START_REF] Oinas | Identifying contexts of learning in firms and regions[END_REF]. Research by [START_REF] Harrison | Innovative firm behaviour and local milieu: exploring the intersection of agglomeration, firm effects, and technological change[END_REF], [START_REF] Quigley | Urban diversity and economic growth[END_REF] as well as [START_REF] Feldman | Innovation in cities: science-based diversity, specialization and localized competition[END_REF] also indicated that 'diverse locales' -defined as those with relatively large numbers of different industries -are more important for promoting innovative firm behavior than specialised ones. Small firms are seen as the beneficiaries from regional industrial diversity because they cannot create it internally [START_REF] Kelley | Firm size and capabilities, regional agglomeration, and the adoption of new technology[END_REF][START_REF] Oinas | The Evolution of Technologies in Time and Space[END_REF]. In terms of our situation this means that nanotechnology firms of the type university spin-outs, new-technology based firms, etc. might have a preference to locate in areas that are characterized by greater diversity of firms and other relevant innovation actors. i

In their critical appreciation of the RIS approach, Oinas and Malecki (2002: 112) also argue that while diverse regions may be more conducive to regional innovation relative to specialized ones, diversity as 'food for innovation' may not always be locally available in the right form and thus needs to be complemented by interaction with more distant actors. These actors can bring in specialized expertise they gained elsewhere (from their participation in another RIS). Within regions, thus, each sector has its specific connections to extra-regional partners that enhance the innovative potential of these sectors' actors. Similarly, Bunnel and Coe (2001) point to the importance of non-local innovation networks. Translated in our context this implies that we can expect to find links between regions. In an area characterized by many or at least several paths of scientific and technological development, we might expect instances in which innovation actors may have strong non-local links. At times such links might be stronger than local connections. Such regional inter-connectivity might be facilitated by the mobility of highly qualified personnel (HQP) that usually do not operate only in local but rather national or even global labor markets [START_REF] Green | The changing distribution and composition of the highly qualified[END_REF]. Camagni (1991: 134-141) stresses that in industries characterized by high levels of technological change and uncertainty, the beneficial impact of the local milieu has its limits and wider involvement in national and even global networks is imperative for regional actors in order to avoid an erosion in innovative capacity (ibid., pp.139). Camagni's theorizing is supported by empirical results that reveal the importance of reaching beyond the local milieu into other RISs for three reasons: (1) external innovation inputs; (2) inter-firm R&D partnerships; and (3) access to scientific and professional human capital [START_REF] Keeble | Internationalisation processes, networking and local embeddedness in technology-intensive small firms[END_REF][START_REF] Keeble | Collective Learning processes, Networking and 'Institutional Thickness' in the Cambridge region[END_REF]. Innovation patterns differ dramatically across industrial sectors and underlying knowledge and technology paradigms in terms of the sources of innovation, the precise boundaries of the innovation process, the actors involved, and the structure and organization of innovative activities. Broad differences between industrial sectors can be traced to variations in technological regimes [START_REF] Nelson | An Evolutionary Theory of Economic Change[END_REF]. Technological regimes refer to the learning and knowledge context in which firms operate and can be decomposed into three main elements -technological opportunities available to firms and associated appropriability conditions; the degree to which technical knowledge accumulates; and the specific features of the relevant knowledge base. Technological regimes determine the evolutionary processes of variety generation and selection that shape the innovation patterns in a particular sector (Malerba andOrsenigo, 1996, 1997;[START_REF] Carlsson | Innovation Systems: Analytical and Methodological Issues[END_REF]. Malerba (2002: 250) defines a sectoral innovation system as a "system of innovation and production … and the set of agents carrying out market and non-market interactions for the creation, production and sale of products."

Innovation Systems in a Cognitive Context

Malerba notes that a sectoral system has a knowledge base, range of inputs, key technologies, and an existing or potential customer demand for its outputs. As with other innovation system specifications, the actors in the system typically are public and private organizations that have peculiar resource and cognitive endowments and interact through processes of communication, exchange, competition, collaboration, and command. These interactions are shaped by institutions and the sectoral system undergoes change and transformation through co-evolutionary interplay of organizations, actors, and institutions [START_REF] Malerba | Sectoral systems of innovation and production[END_REF].

A fourth variant in the family of innovation system concepts is a technological system of innovation (TSI) which is conceptually distinct from sectoral innovation systems although in practice the delineation is blurred.

Technological systems focus on general purpose technologies (GPT) with widespread applications in many industries [START_REF] Bresnahan | General purpose technologies: 'engines of growth'?[END_REF]. The analysis of TSIs contributes to the understanding of the characteristics which explain the innovation process of a specific technology and its evolution in an environment of different organizations and institutions.

The concept is relevant for the policy maker when creating and supporting industrial settings and policies for new emerging technologies (Research Policy editorial, 2002). [START_REF] Carlsson | On the nature, function, and composition of technological systems[END_REF] define technological systems as "a network of agents interacting in a specific technology area under a particular institutional infrastructure or a set of infrastructure and involved in the generation, diffusion, and utilization of technology." More recently, [START_REF] Carlsson | Technological Systems and Industrial Dynamics[END_REF] 2) describes a TSI as "knowledge and competence networks supporting the development, diffusion and utilization of technology in established or emerging fields of economic activity."

The analysis of technological systems emphasizes the interdependence between micro units (firms, universities, research organizations) and entire sectors of the economy. The macro environment is viewed as a complex network of micro relationships -not only the simple aggregation of various micro units (see also Saviotti and Metcalfe, 1991: 8) [START_REF] Carlsson | Technological systems and economic policy: the diffusion of factory automation in Sweden[END_REF][START_REF] Carlsson | Technological Systems and Industrial Dynamics[END_REF][START_REF] Granberg | On the pursuit of systemic technology policies in an unstable environment: reflections on a Swedish case[END_REF][START_REF] Momma | Developments in New Biotechnology Firms in Germany[END_REF]Meyer, 2001a). It is not surprising that authors explore nanotechnology from a particular technological or sectoral systems perspective (e.g. [START_REF] Miyazaki | Nanotechnology systems of innovationan analysis of industry and academic research activities[END_REF][START_REF] Meyer | Hurdles on the way to growth[END_REF].

Tension or Synthesis: Towards Spatial Innovation Systems

While both geographic and cognitive approaches have more in common than separates them, the notions emphasize certain aspects in different ways. The definition of technological or sectoral systems is close to the definition of national or regional innovation systems. The main difference between these concepts is the system boundaries. The national system of innovation is based on national boundaries. Technological differences or distance, however, determine the boundaries of a technological system. The boundaries of a technological system may not necessarily coincide with national or regional boundaries. They can cross national (or regional) borderlines, or could be very local in nature.

A number of authors from a variety of disciplines have explored the relative differences in emphasis of the different approaches and the boundaries they have drawn. One basic yet non-trivial finding in light of the development of the four different approaches is that neither the geographically bounded nor the 'cognitive' (technological, sectoral) conceptualizations fully "no innovation system is located in one place only. This is why it is not enough to focus on particular RISs in trying to understand technological change. Instead, the development of a technological system takes place via the coterminous evolution of its various components in space and time. It is supported by an interlinked set of social relations in a number of RISs of different levels of socioeconomic development, (semi-)integrated by the requirements of a technological system, resulting in a distinct spatial division of labor in that system. Technological systems are not autonomous of the place-specific RISs where they originate or are transferred because local conditions may be decisive for sustaining creative interaction in making progress in specific technologies." Time, or the respective stage of development, is introduced to mediate the differences in emphasis between the approaches. [START_REF] Klepper | Entry, Exit, Growth and Innovation over the Product Life Cycle[END_REF] argues that technological regimes and their associated innovation patterns change over time as industrial sectors and products progress through their lifecycle. In this sense, the concept of technological systems depends on the degree of technological development. In the early stages of the development of a technology the underlying sciences can provide the frame of the system. In later stages of technological development, however, the presence of similar economic competencies could be used to delineate different technological systems (e.g. Yli-Renko and [START_REF] Yli-Renko | New, Technology-Based Firms[END_REF]. [START_REF] Autio | Technological systems: structures, dynamism, and sources of change[END_REF] hypothesize that the importance of the local context is likely to decrease as Adopting an approach that mediates the 'tension' between the geographically and cognitively bounded perspectives seems appropriate given the technology area to be studied. Based on the review of relevant works so far one can say that in light of the early stage of nanotechnology, the links to sciences will play an important role and that diverse networks of nanotechnology actors appear likely. New and smaller businesses may tend to be located in regions with considerable diversity, which in turn might suggest that the established science hubs in Britain will be centers of major activity. Given various trajectories that are typically explored in an emergent field, such as nanotechnology [START_REF] Kuusi | Technological generalizations and leitbilder -the anticipation of technological opportunities[END_REF][START_REF] Meyer | Nanotechnology: Generalizations in an interdisciplinary field of science and technology[END_REF], it would be surprising if actors would have links within a region exclusively. Non-local links may be important. The following section will explore these aspects further drawing on studies that explored nano-science and technology more specifically.

3 The Empirical Context of Nanotechnology 3.1 'Nanotechnology' as an emerging yet heterogeneous technology Nanotechnology has been selected as the area to be studied as it is often seen as 'the emerging technology' typically associated with considerable economic potential (e.g. [START_REF] Miyazaki | Nanotechnology systems of innovationan analysis of industry and academic research activities[END_REF][START_REF] Wood | The Social and Economic Challenges of Nanotechnology[END_REF].

Currently this area is viewed to be at a stage where it has become a 'going concern' with several hundred businesses worldwide claiming to operate in nanotechnology or one of its subareas (e.g. [START_REF] Maynard | Nanotechnology: A Research Strategy for Adressing Risk. Project on Emerging Technologies[END_REF]. However, it is when one could speak of a well-defined nanotechnology industry. There are still many different approaches as to how one can define nanotechnology (e.g. [START_REF] Malsch | Nanotechnology in Europe: Experts' perceptions and scientific relations between sub-areas[END_REF][START_REF] Malsch | Nanotechnology in Europe: scientific and organizational dynamics[END_REF]Meyer et al., 2001a, b). Attempts to come to a generally acknowledged characterization of nanotechnology have proven futile. As a consequence, actors in the field adopt working definitions for the task at hand.

One of the more broadly accepted definitions is the one proposed by the US National Science and Technology Council (2002) which also informed this study:

Research and technology development at the atomic, molecular or macromolecular levels, in the length scale of approximately 1 -100 nanometer range, to provide a fundamental understanding of phenomena and materials at the nanoscale and to create and use structures, devices and systems that have novel properties and functions because of their small and/or intermediate size. The novel and differentiating properties and functions are developed at a critical length scale of matter typically under 100 nm. Nanotechnology research and development includes manipulation under control of the nanoscale structures and their integration into larger material components, systems and architectures. Within these larger scale assemblies, the control and construction of their structures and components remains at the nanometer scale. In some particular cases, the critical length scale for novel properties and phenomena may be under 1 nm (e.g., manipulation of atoms at ~0.1 nm) or be larger than 100 nm (e.g., nanoparticle reinforced polymers have the unique feature Recent research [START_REF] Meyer | What do we know about innovation in nanotechnology? Some propositions about an emerging field between hype and pathdependency[END_REF] suggests that nanotechnology is often misconstrued as either a field of technology or an area of (broadly) converging technologies while evidence to date suggests rather that nanotechnology be considered a set of inter-related and overlapping but not necessarily merging technologies. Change in nanotechnology tends to be incremental rather than discontinuous, being the result of technological path-dependencies and lockins that are only slowly giving way to more boundary-crossing activities.

Miyazaki and Islam (2007) make a similar point when they speak of the evolutionary character of innovation in nanotechnology. This is likely to affect inter-organizational networking of firms in this area. In an earlier study, one of us [START_REF] Meyer | Hurdles on the way to growth[END_REF](Meyer, , 2001a) ) examined networking activities of firms exploring developments in nanotechnology in the late 1990's. At that time, networking occurred rather within the established networks of the actors' respective industries (or, in the sectoral system of innovation) rather than within a new 'nanotechnology network', with its own individual characteristics. The elements of a nanotechnology innovation system were not in place then (Meyer, 2001a). This study will explore at least to some extent whether this situation has changed. [START_REF] Miyazaki | Nanotechnology systems of innovationan analysis of industry and academic research activities[END_REF] speak of "nanotechnology systems of innovation" when they explore the scientific development of the field focusing on the science pole.

Studies so far seem to suggest that nanotechnology is still quite a 'mixed bag' of technology stressing the diverse and multidisciplinary character and the broad range of application areas (e.g., OECD, 2007, Hullmann, 2007 [START_REF] Miyazaki | Nanotechnology systems of innovationan analysis of industry and academic research activities[END_REF]Islam, 2007, Wong et al. 2007). This might raise doubts as to how much local or regional collaboration between nanotech firms can be expected. If companies located in a geographic area happen not to belong to the same 'line' of nanotechnology, collaboration might be limited or not forthcoming at all. Interestingly, and in spite of the recognized 'mixed bag' character of nano-science and technology, much of the social-science research still looks at it as one generic field. This applies, for instance, to a range of papers recently published in a special issue of Research Policy [START_REF] Bozeman | Understanding the emergence and deployment of "nano[END_REF]. Most papers in this issue are grounded in evolutionary thinking and were inspired by [START_REF] Kuhn | The Structure of Scientific Revolutions[END_REF] concept of the structure of scientific revolutions or the suggestion that both cognitive conditions and industrial structures respond to changes in the nature and maturity of the underlying nanotechnologies [START_REF] Dosi | Technological paradigms and technological trajectories -A suggested interpretation of the determinants and directions of technical change[END_REF][START_REF] Anderson | Technological discontinuities and dominant designs: a cyclical model of technological change[END_REF][START_REF] Afuah | Responding to structural industry changes: a technological evolution perspective[END_REF]. While some papers (e.g. [START_REF] Bonaccorsi | Institutional complementarity and inventive performance in nano science and technology[END_REF] point to different approaches, relatively few papers problematized explicitly the question whether nanotechnology is an appropriate category for analyzing developments. From an evolutionary perspective, one could also argue that nanotechnology is a rather loosely coupled set of technologies that are related to different degrees and may develop quite independently of one another (e.g. [START_REF] Meyer | What do we know about innovation in nanotechnology? Some propositions about an emerging field between hype and pathdependency[END_REF]. This would reinforce the point made above about the possibly limited extent of regional networking. Studies have shown that scientific, technological development and innovation activity is often concentrated within national and regional systems of innovation. For instance, [START_REF] Zitt | Territorial concentration and evolution of science and technology activities in the European Union: a descriptive analysis[END_REF] documented that there is considerable regional specialization in terms of publication and patenting performance. They identified a set of regions that was characterized by high and concurrent performances across the set of science, technology and innovation indicators utilized.

Recent research on the emergence of nanotechnology points to strong regional concentrations of R&D and innovation activity, especially the joint occurrence and concentration of patent and publication activity in nanotechnologies (e.g. [START_REF] Noyons | Mapping Excellence in Science and Technology across Europe[END_REF][START_REF] Heinze | Nanoscience and nanotechnology in Europe: Analysis of publications and patent applications including comparisons with the United States[END_REF][START_REF] Heinze | Die Kopplung von Wissenschaft und Wirtschaft. Das Beispiel der Nanotechnologie[END_REF]. Studies of developments in the US also suggest strong regional concentrations in metropolitan regions [START_REF] Zucker | Socio-economic Impact of Nanoscale Science: Initial Results and Nanobank[END_REF][START_REF] Shapira | Measures for knowledge-based economic development: Introducing data mining techniques to economic developers in the state of Georgia and the US South[END_REF].

Analysts have used more and more the term 'nano-districts' to identify metropolitan areas or regions with high scientific or patenting output (e.g. [START_REF] Shapira | Emergence of Nanodistricts in the United States: Path Dependency or New Opportunities?[END_REF]. While all studies reviewed suggest that regional concentration can be observed, the extent to which this concentration is reinforced by the emergence of local/regional nanotechnology networks is less clear.

Most recently, Zucker et al (2007) presented data that, in their view, supports the cumulative model of knowledge production. They report that regional growth of nano-publication and patenting activity is positively affected both by the size of existing regional stocks of recorded knowledge in all scientific fields and the extent to which tacit knowledge in all fields flows between institutions of different organizational types. iii for instance, in Twente and Grenoble, that actively develop technology platforms in emerging nanoclusters [START_REF] Robinson | Technological agglomeration and the emergence of clusters and networks in nanotechnology[END_REF], one could argue that the tacit dimension of knowledge production in nano-science and technology appears to encourage the convergence of the cognitive and spatial perspectives on knowledge production and exploitation.

Bearing in mind that Zucker et al. (2007) found that the cumulative knowledge stock of articles in non-nanotechnological fields in a given region has a significant positive effect on the rate of production of nano-articles in that region, and a corresponding observation for patenting, one could also argue that the emergence of strong nanotechnology R&D and innovative activity is not necessarily dependent only on the 'nano-actors' in a region but more widely could be related to the broader scientific and technological attractiveness of the region. Translated in our UK context this would mean that nanotechnological activity is likely to be concentrated in areas that are characterized by a high level of scientific and technological activity in general.

Having said this, [START_REF] Shapira | Emergence of Nanodistricts in the United States: Path Dependency or New Opportunities?[END_REF] [START_REF] Miyazaki | Nanotechnology systems of innovationan analysis of industry and academic research activities[END_REF] suggest that the science pole within the 'nanotech system of innovation' is still predominant. In their analysis of nanotechnology patenting, [START_REF] Bonaccorsi | Institutional complementarity and inventive performance in nano science and technology[END_REF] found that hybrid 'author-inventor' patents are the most important contributors to knowledge production underscoring the importance of institutional complementarities (private firms and universities). [START_REF] Meyer | Are patenting scientists the better scholars? An exploratory comparison of inventor-authors with their non-inventing peers in nanoscience and technology[END_REF] reported that, depending on the country, roughly 30-40% of nanotechnology patents are related to inventors who are also active in scholarly publication. All this suggests that for an emergent area, such as nanotechnology, links with science poles can play an important role, even though one can argue that, generally speaking, the role of universities for the attractiveness from a company perspective may be overestimated (see e.g. the overview in Lawton- [START_REF] Lawton-Smith | Universities, Innovation and the Economy[END_REF].

With respect to networks of firms in nanotechnology, studies report that firms can have different approaches towards the field and that players differ also depending on the nanotechnology area studied. Work by Avenel and his colleagues (2007) found firms are following quite different trajectories in the development of their nano-knowledge bases. In this context the authors distinguish between two general approaches: (1) 'hybridization', defined as "as the case in which each item is related to various fields: in effect, hybridization is diversity at the level of individual items." (Avenel et al., 2007: 865); (2) 'juxtaposition', which they characterize as the collection of independent scientific and technological fields within the same knowledge Furthermore, this could suggest a prominent role for academic spinouts and similar businesses. New and smaller businesses may tend to be located in regions with considerable diversity.

2. The diversity and knowledge accumulation argument presented in the innovations systems section was reinforced by empirical work on nanotechnology that suggested regional knowledge stocks in 'nonnano' sciences and technologies affect positively output in nanoscience and technology. This would imply that that nanotechnologyrelated activity is concentrated in geographical areas that are already characterized by a high level of scientific and technological activity; or, in other words, the established science hubs in Britain are likely to be centers of major activity. This concurs with the notion that the availability of highly qualified personnel, or 'talent', is a key factor in 3. Given the multiple paths of exploration and exploitation in an emergent field, it would be surprising if actors would have links within a region exclusively. Non-local links may be important. The nanotechnologyspecific literature suggested that belonging to similar lines, or trajectories, of nanotechnology is a prerequisite for collaboration between nanotechnology firms. If these technology-specific links do not exist, collaboration might be limited or hardly forthcoming while other, non-local links are correspondingly more important. Also, in geographical areas with a larger concentration of activity, it would seem likely to find more than an individual network of nanotechnologyrelated firms that do not overlap or do so only weakly.

4. Finally, empirical research on nanotechnology firms already indicated that larger and smaller firms, incumbents and new entrants approach nanotechnology quite differently and that they may play different roles in further developing particular aspects of the field or integrating different strands of developments. There is also evidence of technology-related differences in 'industry structure'; larger firms seem to be stronger in materials-related areas of nanotechnology than instrumentation and devices. The different roles that these actors play could mean that considerable variety is to occur in terms of the structure and firm membership in UK nanotechnology-related networks. The parallel analysis of science and technology indicators has proven helpful when trying to understand the dynamics between technology and related sciences [START_REF] Schmoch | Indicators and the relationships between science and technology[END_REF]. This study will explore this dynamics specifically for the case of UK nanotechnology applying a multi-method approach drawing on bibliometric, patent and survey analyses.

First, we explore regional concentrations for a range of indicators: scientific publications, patenting output and firm location. In this paper, regional activity is typically explored at the NUTS-1 level. These analyses are complemented with data at the more disaggregated level of towns and cities.

To study the evolution of nano-science and nanotechnology in its spatial and cognitive context we compare the relevant indicators in two distinct five-year time periods i.e. 1999-2003 and 2004-2008. This comparison is extended by firm population data that is based on an earlier study by the authors [START_REF] Libaers | The role of University Spinout Companies in an Emerging technology: The case of Nanotechnology[END_REF] which has been recently update for the purpose of the present study.

In another step, we track collaborative activity for two different datasets. Observations are presented for co-publication and co-invention data. This analysis is complemented by an exploration of inter-organizational collaboration data that was gathered through a survey [START_REF] Libaers | The role of University Spinout Companies in an Emerging technology: The case of Nanotechnology[END_REF].

We present output data in tables and graphs; the results of the collaboration analyses are mostly presented in the form of bibliographic maps. These maps are generated through a multidimensional scaling algorithm that draws on co- occurrence matrices of, in our case, the main locations (regions or towns) associated with either co-publications or patents.

Data Sources

The analyses presented in this paper draw on publication, patent, and firm location data. The publication data is derived from a nano-science database compiled at the ECOOM iv on the basis of data obtained from the Thomson-Reuters Web of Science. We built a publication database that contains more than 100,000 SCI indexed papers topical to the nanosciences [START_REF] Glänzel | Nanotechnology: Analysis of an emerging domain of scientific and technological endeavour[END_REF]. This database encompasses a total of 6,671 papers with UK authors published between 1992 and 2001. We updated this database for the two time periods considered in our study. Below are the numbers of publications with UK-based authors in the area of nanoscience & nanotechnology:

• 7248 papers 1999-2003

• 14059 papers [2004][2005][2006][2007][2008] The patent data utilized is drawn from a database of nanotechnology-related US patents also compiled at ECOOM. This patent database comprises about 4,000 US patents that can be related to the area of nanotechnology. We Glänzel et al. (2003, 14-18). One should note an interesting observation: while there is a doubling in publication activity, patent output has increased only by a third.

The UK nano-firm database was compiled in an earlier project at SPRU/University of Sussex [START_REF] Libaers | The role of University Spinout Companies in an Emerging technology: The case of Nanotechnology[END_REF] (3) Collaboration linkages with other firms, universities, or foreign partners.

For the purposes of this study we utilized in particular data gathered on collaborative links. Respondents were asked to name at least three key organizations they collaborated with. This was cross-referenced with data on firm-type and technological orientation.

Data Analysis: Our mapping approach

This study draws extensively on mapping approaches for an analysis of co-publication and patenting networks. Even though the underlying data is different, the methodological approach remains the same throughout all analyses. The mapping is based on co-occurrence analysis -a well-known approach in bibliometrics and other fields. Here, pairs of collaborators are formed at the respective level of analysis. This could be on the basis of individual authors, inventors or organizations. As we are interested in the geographical dimension, we relate co-publication, co-invention as well firm collaborative data at the level of towns or regions. For instance, let us take publication data as an example. Here co-publication pairs are formed at the level of towns. Authors based in town A and B form a pair A-B, so do authors from C and D (C-D), etc. There is also the case of collaboration within a town or locality. There may be two authors from town A so one could track a pair A-A. Pairings of this sort may be viewed duplicates in bibliometric analysis. For the purposes of our analysis in this study, exploring within-locality pairings is of interest. Therefore, we kept rather than excluded such pairings. In some instances this may mean towns are featured prominently in maps even though they appear not to be (strongly) linked to any other location on the map. This is extremely unlikely to happen in co-publication maps where the output and consequently the number of links are much higher than in e.g. patents. In the patent context, this situation may occur in the case of large public or corporate R&D laboratories that are located in a town/county without university or other research infrastructure.

After establishing pairings, co-occurrence matrices were generated drawing on the Bibexcel bibliometric freeware programme [START_REF] Persson | Bibexcel -A toolbox for bibliometricians[END_REF].

The matrices included integer counts of co-occurrence frequencies between two locations and were imported into a multidimensional scaling (MDS) program for the creation of two-dimensional maps. More specifically, we applied the SYSTAT routine to these matrices to generate maps. We followed the process described by [START_REF] Persson | The intellectual base and research fronts of JASIS 1986-1990[END_REF]. A detailed step-by-step description is available online. vi The approach chosen has been adopted in a number of studies in bibliometric analysis of scholarly communication. vii The maps offer a heuristic perspective on how localities are related to each other through coauthorship in nano-science publication, co-invention and co-classification The mapping routine does not allow an unlimited number of nodes to be included. Only up to 70 nodes can be accommodated by the maps. Often analysts reduce the number of nodes for the benefit of greater clarity. This implies that a threshold has to be set and localities on one (e.g. the science) map would not necessarily appear on another (e.g. patent) map. While this is a limitation, the chosen approach nevertheless offers an overview of the overall structure and pattern in collaboration. The approach focuses attention on the key players in a field and how they are related to another. Strong variation between maps would suggest that there are substantial differences in collaborations between locations. Differences between publication and patent-based maps would indicate that technical collaboration does not necessarily follow the patterns of scientific cooperation, or vice versa.

For patent data we are able to compare networks of inventive collaboration with cognitive networks that relate locations to each other in terms of technological proximity or distance. This comparison draws on patent classification data. We have drawn on the International (IPC) and US patent classification schemes and linked locations with all patent classes (at the 6digit IPC level or equivalent) that were associated with patents that included local residents as inventors. A considerable overlap between network maps would suggest that technological and collaborative links coincide. Our analysis of how co-publication and co-patenting activities are linked in space is driven exclusively by bibliometric maps generated by the BibExcel algorithm. While the same analysis can be performed using statistical analysis

Findings

This section is divided into two main parts. First the regional distribution of publication, patenting and firms is explored. This analysis is then followed by an analysis of collaborative patterns. In the first section, we report on observations that seem to point to strong regional concentration. This finding is not surprising and in line with expectations. In the second section on collaborative activity, we find a less straightforward situation which seems to suggest in particular that networking of firms is neither limited nor particularly focused on the region in which they are located.

Regional Distribution

First data is presented on publication output, then regional distributions on patenting and firm location are introduced. Our overall finding confirms initial expectations. In the case of publication, patent and firm location data we can establish concentration of activity on a small number of UK regions whereas the remainder of activity is spread sparsely across the remainder of the UK. Publication activity is concentrated on the South-East, the East of England, and the Greater London region (as Fig. 1 illustrates). Almost half of all the UK's publication activity in nanotechnology in both five-year time periods is concentrated in these three regions which encompass most of the country's leading universities.

A similar situation can be observed when exploring patenting data.

Patenting activity converges again on the South-East, the East of England, and the Northwest, closely followed by the Greater London area (Fig. 2). Here regions were ranked on the basis of the number of patent assignees based in those regions. The Southeast strengthened its leadership position in patenting in the second five-year time period whereas the North West and the West Midlands witnessed a significant drop in patenting activity in the same time period relative to the first time period. Again, we observe a concentration of high patenting activity in areas with a strong scientific base. indicators concurrently, we note that nano-scale science and technology outputs seem to be related to each other and to nano-firms. Typically regions with strengths in nano-papers and nano-patents account for similar shares in nano-firms. As such, this finding is not unexpected considering earlier work (e.g. Shapira andYoutie, 2008, Zitt et al., 1998) and is consistent with our This section explores the extent of local and regional collaboration in terms of science and technology as well as the inter-organizational collaboration of nanotechnology firms. The maps of scientific and technological collaboration offer mixed results, pointing to links that are based on geographical proximity as well as links to locales comparatively far removed in geographical terms. This is in line with expectations. Our analysis of nanotech firms' collaborative activity points to collaborative groupings that could be explained on the basis of technological proximity rather than regional aspects. We can also identify substantial diversity in regions with larger activity. As expected, these networks do not necessarily overlap at the level of nanotechnology firms.

Co-Publications

The co-publication analysis offers a mixed picture that suggests strong international collaboration in nanosciences linking science hubs in the UK to key overseas centres of scientific activity. The maps in Fig 5 offer an overview of collaborative linkages between different entities at the town/city level. A total of 16,511 (1999-2003) and 46,932 (2004-08) addresses could be identified indicating a very strong growth in the number of both publications and actors between the two time periods as can be seen from the much denser network in the upper map as compared to the one in lower map. The

Co-Inventions

We know from other studies that scholarly collaboration is considerably more frequent than technical collaboration which is often exclusively in-house (e.g. Meyer and Bhattacharya, 2004). As reported, the overall number of patents tracked for the UK in nanotechnology was comparatively small in both time periods. Hardly any co-assignations (i.e., co-ownership) between firms or other organizations could be traced (~3%). We traced 254 addresses for 162 UK-based inventors; a total of 68 patents listed more than one inventor.

Figure 7 presents an overview of collaborations that could be traced at the level of inventor locations. In light of the low overall level of inventive collaborative activity we need to be careful in interpreting the data, especially since there is very little inter-firm activity to be tracked. Comparing these maps with those for UK nano-science collaboration suggests that there are different patterns underlying patenting and publication in nanoscience and technology. Research elsewhere indicated that only a very small fraction of nano-scientists actually engage in patentable inventive activity (e.g. [START_REF] Meyer | Are patenting scientists the better scholars? An exploratory comparison of inventor-authors with their non-inventing peers in nanoscience and technology[END_REF]). In the UK, approximately 0.6% of active nanoscientists are also involved in nanotechnology patenting [START_REF] Meyer | Are patenting scientists the better scholars? An exploratory comparison of inventor-authors with their non-inventing peers in nanoscience and technology[END_REF][START_REF] Meyer | What do we know about innovation in nanotechnology? Some propositions about an emerging field between hype and pathdependency[END_REF]. ix This means that even if these links reflected also scientific collaboration, they would 'disappear' among the much larger numbers of purely scientific collaborations.

Having said this, the share of nano-scientists among inventors is quite high, especially in the UK: we found that around 40% of all nanotechnology inventors were also active in scientific publication. x Bearing this in mind, it is perhaps less surprising to find the main science centers of the UK feature somewhat prominently in terms of co-patenting. Moreover, co-patenting activity in the first time period is significantly more fragmented than in the second time period. Another observation is that co-patenting is frequently an international endeavor. map shows a significant increase in links. In this sense we observe a shift from a fragmented, disjointed pattern to a more extensive, dense pattern of links. To some extent the relatively few links we observed in the earlier period could be seen to reflect collaborative activity between inventors in different locations. We tracked very specific links, mostly only between two or few more locations. One case in point is Bath which is linked to Glenham and Amenia in the US in both co-classification and co-patenting maps. There are other examples (Reading-London, or Southampton-Baton Rouge). Here, only a small group of people work in different locations on very specific technological topics. Also there appear to be relatively few co-classification links between places that are not already linked through strong collaborative activity. Where these links occur, one often finds connections between UK and overseas localities lending support to the notion of the importance of nonlocal links along technological paths.

There is a substantive change in the later period (2004)(2005)(2006)(2007)(2008). Here the cognitive network map is considerably more integrated. While dyadic links remained strong in the earlier map, the later map points to the emergence of cognitive networks. This is reflected also in the co-patenting data where localities are linked to a larger extent in the second period (cf. Figure 7). One could argue that in this sense exploitation of nanotechnology conforms with a technological systems paradigm. The more cognitive links are established between locations the greater the potential for engagement between actors in the related locations. Such a strategy may yield more radical innovations that require the combination of more disparate technological knowledge not necessarily available at the regional or even national level. This potential has understanding of firms' inter-organizational networking activity. Our network analysis is based on a survey in which firms were asked to name their main collaborators, irrespectively whether the partner was a public or private organization. These nominations enabled us to analyze pairs of collaborators.

At times, this allowed us to identify broad collaborative networks of nanotech firms. Our approach allowed us also to distinguish between dedicated nanotechnology firms (from our initial database) and the (not necessarily nanotechnology-focused) organizations they nominated. Some firms partnered also considerably with non-nano/non-UK organizations. The pairs of <<insert Table 4

about here>>

There is considerable diversity amongst the clusters in terms of Another interesting observation relates to clusters within regions that account for a substantial number of nanotech firms. We found that firms within a region appear not to form a large regional nanotech cluster. Instead, groupings of 3-5 firms were identified that belong to three or more (interregional) clusters that can be defined along technological characteristics (see Table 4). To illustrate, the East of England region can point to more than 15 nanotechnology firms -five belong to a network of materials-oriented device producers (cluster 2); another five are electronics-related ventures (cluster 4); and a third group is nanomaterials-oriented (cluster 6). Perhaps, only in the case of cluster 4, one could say that firms from one region are dominant. The South East is the region that accounts for more nanotech firms than any other region in the UK (around 20). However, looking at clusters with more than 5 nanotech firm members, there is no cluster in which its share reaches beyond one-third. This observation is in line with expectations. Both innovation systems literature and earlier empirical work on nanotechnology suggested that there might be considerable non-local links of actors within regions and that there might be knowledge exchange along technological lines.

The clusters are also diverse if one examines them by firm type (see This would suggest that that there is also increased potential to collaborate along non-local technological lines. Both developments may result in some integration. While it is difficult to establish a trend, we observed still considerable variation between localities in terms of the level of local collaborative activity. The trend towards increased breadth in patenting of towns and counties appears more consistent. Towns with a higher patent breadth seem to have a more central position in non-local collaborative networks.

Discussion and Conclusion

This contribution sought to explore the question whether new, sciencerelated technologies, such as nanotechnology, follow a more regional or a more cognitively determined pattern of emergence. This section summarises and discusses the key findings of our study with respect to the four broad We found that there is indeed considerable regional concentration of nanotechnology activities in terms of science, technology and firm location.

Typically regions strong in one of the activities are strong in the other two as well. This corresponds to work by others (e.g. [START_REF] Zitt | Territorial concentration and evolution of science and technology activities in the European Union: a descriptive analysis[END_REF]Zucker et al., 2007). We identified strengths for regions, such as the South-East, the East of England, London, and to a lesser extent the Northwest all of which are strong in science, technology, and innovation activity across the board and not just in nanotechnology. similarities in so far that we also find strong concentrations of explorative and exploitative activity in regional or metropolitan centers [START_REF] Zucker | Socio-economic Impact of Nanoscale Science: Initial Results and Nanobank[END_REF]Youtie and[START_REF] Shapira | Measures for knowledge-based economic development: Introducing data mining techniques to economic developers in the state of Georgia and the US South[END_REF]2008). Having said this, regional concentration does not preclude strong, non-local networks from emerging along technological lines.

Importance of Technology-Specific, Non-Local Links

The spatial innovation systems approach by [START_REF] Oinas | The Evolution of Technologies in Time and Space[END_REF] tries to build a bridge between the regional and technological systems approaches suggesting that a given RIS may require specialized (also technological) expertise from another RIS and thereby connecting locales to the 'travels' technologies make over space and time. Indeed, our findings seem to suggest that the concentration on regions, does not necessarily reflect the nature of the collaborative networks of the firms in the industry.

Here, we found evidence of strong, non-local inter-firm links that could be associated with clusters related to nanomaterials, nanodevices, nanoinstrumentation, or nano-electronics. Correspondingly, we observed that in regional centers with large concentrations of nanotech activity, firms belonged to different networks or clusters rather than a large local/regional collaborative network. In that sense our study offers an extension to other work that identifies concentrations and speaks of clusters or nano-districts, which might be misunderstood as suggesting highly territorially integrated networks. Our research should have clarified that considerable regional concentration of et al, 2007). A similar phenomenon can be observed in Twente, the Netherlands and conceivably around Cambridge and Oxford as we will point out further in this paper.

ii In analogy with [START_REF] Mahdi | Key national factors in the emergence of computational chemistry firms[END_REF], one can define a field as 'novel' if it has essentially evolved within the past 20 years.

iii The authors define cross-institutional collaboration and knowledge flows on the basis of co-authored papers (Zucker et al., 2007: 856, fn. 2).

iv http://www.ecoom.be/ v We have updated the firm population data at the regional level in the autumn of 2009. vii One issue in determining the degree of proximity between nodes is the question of whether or not to normalise the co/occurrence frequencies. While there are good reasons in favour of this approach (see e.g. [START_REF] Leydesdorff | On the normalization and visualization of author cocitation data[END_REF], we chose the standard approach drawing on frequency data without normalising it.

viii The location of the nodes on the maps cannot be modified substantially without obscuring the co-occurrence based networks. For instance, moving overseas localities to one side of the map and domestic ones to the other may offer a clearer picture as to activities within the UK and elsewhere. However, this would essentially run against the underlying idea of presenting nodes in a two dimensional space that reflects the strengths of their relationships to each other.

ix In other countries, such as Germany, the share of nano-inventors amongst nano-scientists is higher (around 1.5%) but still very low.

x For purposes of comparison, the value for Germany is 34% [START_REF] Meyer | Are patenting scientists the better scholars? An exploratory comparison of inventor-authors with their non-inventing peers in nanoscience and technology[END_REF] xi This corresponds to the approach by [START_REF] Gilsing | Network embeddednes and the exploration of novel technologies: Technological distance, betweenness centrality and density[END_REF] who define technological distance as the average of correlations between a focal firm's technology profile and that of each of its collaboration partners, a measure of similarity in technological knowledge and application domains of partners.

xii We used [START_REF] Persson | The intellectual base and research fronts of JASIS 1986-1990[END_REF] clustering algorithm in the Bibexcel bibliometric analysis freeware to analyze collaborative links.

  seek to "defetishize bounded regions as 'containers' of innovation" (p.

  .Extant research examining various social and economic attributes of nanoscience and nanotechnology has for instance highlighted the regulatory framework (which operates in a spatial-geographic context) in which this novel technology might develop

  . It has clear antecedents in the NSI perspective and its elements

  Having said this, the authors argue that one cannot view technological systems entirely detached from their national environments, and, due to the limited transferability of technological knowledge, truly global systems are not likely to emerge.Oinas and Malecki's (2002: 109-110) concept of spatial innovation systems appears to mediate the tension by acknowledging the importance of different configurations: "…key issues in discussing [spatial innovation systems] are (1) the simultaneous and interdependent development of components of technological systems possibly in many places, utilizing spatial division of labor among several [regional innovation systems (RISs)] specialized in different aspects of technologies, possibly in more than one [national innovation system], and (2) the 'travels' that technologies make in space and over time as knowledge flows take place along with the progress made in the frontiers of those components. The key elements in the complex spatial innovation systems are the technological paths themselves, the RISs that participate in creating the technologies or parts of them , the actors whose interaction locally and over space ultimately brings technologies about, as well as their (proximate and more distant ) relations. […] In sum, technologies have their specific, path-dependent time geographies: technologies emerge somewhere, in a place -or sometimes similar technological solutions are invented in more than one place simultaneously …. And the further development of those technologies may take place in a new context and in a new place, where possibly new qualities are added to them.

  Technological development is the result of the intermingling of such technological paths, overlapping in content and possibly also in space."

  novel technological area ii and has not yet reached the stage

  -300 nm as a function of the local bridges or bonds between the nanoparticles and the polymer).

  of co-location of scientific and technology actors,

  work on US nanotechnology reminds us that also new geographic concentrations of nanotechnology research have surfaced which appear to have resulted from concentrated investments in nanotechnology R&D into single institutions. 3.3 Structure and Membership of Nanotechnology Networks Previous work also allows us to develop some suggestions as to how nanotechnology networks might be structured and what members they might have, irrespective of whether they have a predominantly technological or . A range of authors stress the importance of science poles within the overall nanotechnology framework. For instance, Islam and

  .g. either physics or chemistry.Avenel et al (2007: 869) observed differences in the use of these approaches especially with respect to firm size: "New entrants in nanotechnologies -whether high tech start-ups or firms moving into the field -are those which are integrating nanotechnologies through hybridization, while firms which are already performing research in one of the technologies which form nanotechnologies (chemistry, microelectronics, biotechnologies, etc.) develop new programs of research which focus on nanotechnology fields which are new to them. […] Small firms, at least some of them, are achieving very significant levels of diversity through intense hybridization. Big firms, with a few exceptions, also have developed diversified nano-knowledge bases, but their use of hybridization is much more limited. The diversity of their portfolio is the result of the juxtaposition of items focused mainly on one or two established scientific/technological fields. This suggests that small firms are in a better position than big firms to exploit the opportunities created by the emergence of nanotechnologies."[START_REF] Libaers | The role of University Spinout Companies in an Emerging technology: The case of Nanotechnology[END_REF] report rather different compositions depending on the field of nanotechnology. In their study of UK nanotechnology firms, they found that multinationals appear to be the predominant firm type in the nanomaterials, their role was less strong in the case of nano-instrumentation and devices where university spin-outs and new-technology based firms were represented more prominently.Given the different approaches firms seem to follow and technologyrelated differences in 'industry structure', considerable variety is likely to occur the structure and firm membership networks in UK nanotechnology.4 ExpectationsThis section summarizes briefly some expectations that are based on insights from the literature review on the different innovation systems and the empirical background literature on nanotechnology.1. A review of the relevant social-science literature on nanotechnology underlined the important role of the 'science pole' within the broader nanotechnology context. This might be visible in the concentration of technological and innovation-directed activity near centers of science.

  is strongly associated with the location of high-tech industry.

  identified the following number of US patents in nanoscience & nanotechnology assigned to UK-based organizations:• 131 patent 1999-2003• 174 patents[2004][2005][2006][2007][2008] Both patent and publication databases were compiled on the basis of search strategies that evolved from consultation processes with domain experts at national levels. Details on search strategy and data retrieval are described in

  and contains a total of 146 firms active in nanotechnology in the 1999-2003 period v ( The corresponding number of firms for the 2004-2008 period is approximately 116).The firm database was compiled through a combination of publication, patent and other data from reports and online searches. A survey of the nanotechnologyactive firms allowed us to identify the main partners of the nanotechnology firms in the private and public research sector. The sample of firms with nanoscale product offerings very likely approaches the total population of nanofirms in the UK during that period since many sources and commercial databases had been consulted. Just over 10 % of the firms had been contacted for an extensive telephone survey questionnaire and were selected from across different firm types (academic spinouts, new technology based firms, multinational corporations, and corporate spinouts) and subtechnologies (nanomaterials, nanobiodevices, nanoinstruments, nanodevices, and nanoservices).The questionnaire was divided in three main sections that covered: (1) basic corporate data such as year of founding, number of personnel and qualified scientists and engineers, location, primary activities and market segments, annual turnover in the last 3 years, and company funding; (2) Technologies being commercialized, number of patents (co)-owned, and published alone, with other firms, or with universities;

(

  technological distance) in nano-patenting. The closer two nodes (here towns or regions) are to each other the more they are related to each other by cooccurring links. The strength of the links is indicated through the thickness of the lines between them. The size of circles associated with localities indicate the level of activity (e.g., publication or patent outputs). viii Viewing the maps should help clarify how localities are related to each other by collaboration or through cognitive links. While it is difficult to judge or estimate exactly the respective strength of local vs regional, national or international links on the presented maps, a visual inspection should nevertheless offer a strong impression of how localities are linked.

  g. Pearson correlations), the algorithm implicitly performs these statistical computations and graphically displays them to facilitate visual comprehension.

Fig. 3

 3 Fig.3 depicts the distribution of nanotechnology-based firms across the

  In a sense the loci of nanotechnology exploitation are often co-located with the loci of nanoscience exploration highlighting the importance of science poles.

Fig. 4

 4 Fig.4provides a comparative analysis across a ten-year time period of

  within Regional or Technological Context?

  located to one another on a map the stronger the collaborative link between them. Circle size serves as an estimate for the publication output in the different locations. One can observe a number of links between cities and towns that are located relatively closely to another in Fig. 5. For instance, there are comparatively strong links between London and Oxford, Oxford and Cambridge, and Guildford and Brighton. Having said this, there are also examples suggesting the opposite. To illustrate, Glasgow is more closely linked to Cambridge than it is to St Andrews which is geographically closely located to Glasgow. Researchers in Manchester appear to collaborate more intensively with their colleagues in Oxford or London rather than with researchers in Sheffield or Nottingham who are geographically much closer. A similar set of patterns can be observed for the more recent period. Both maps illustrate the strong links of UK researchers with peers in other countries. In terms of collaborative activity, London appears closer to Tsukuba, Moscow or Stuttgart in 1999-2003 than it is to Cambridge. A similar picture can be observed for 2004-2008 where foreign cities, such as Singapore, Shanghai,Toronto, Madrid, and, again, Tsukuba lie between the capital and the university town. On the other hand, one can still trace very regional collaborations. The link between Bristol and Didcot, extended byBath (1999Bath ( - 2003) ) andCardiff (2004Cardiff ( -2008) respectively, is an example.

Figure 6

 6 Figure 6 provides a much clearer picture of domestic collaborative

Figure

  Figure Error! Main Document Only. visualizes co-invention patterns in

  Figure Error! Main Document Only. also points to locations at the fringe

  to carry out cluster analysis which identified a total of 15 clusters.xii These clusters and their membership were inspected manually to determine the respective technological orientation and regional base. Most clusters have a mixed membership of participants from industry and university. Only one exclusive firm cluster (#11) can be identified. We identified 6 mixed clusters with a dominance of firm partners and 8 mixed groupings with a more balanced distribution of participants. We found often very small clusters of 5-10 organizations around 1 or 2 firms. There are also larger clusters with around 15 or more members and at least 5 dedicated nanotechnology members. Table4presents a summary of the data, specifying the cluster size, the number of pure nanotechnology-focused firms, UK-based firms, the number and share of university partners, and the general technological focus of the cluster. Figure9offers an overview of how the clusters are structured in terms of UK regions. Figure10summarises the composition of cluster members by firm type.

  regional and technological orientation as well as firm membership. Only five small clusters with five members or less are based in one region. The other ten clusters with up to 55 members are characterized by a considerable variety of the regions its member firms belong to, underlining the importance of non-local links. While it is possible to identify a relative concentration of nanotech firms on a region within larger clusters, the share of a single region seems not to exceed one-third (with one notable exception).

Fig. 10 )

 10 Fig. 10). Most larger clusters seem to have a broad range of firm types

  of the 'Science Pole' Our findings confirm the importance of the 'science pole' in the nanotechnology framework. This has become clear in a number of ways: (1) the relative importance of university spin-outs and other public researchrelated start-ups in most of the clusters studied (2) the fact that there were hardly any clusters of firms that did not include a university or public research institute, (3) the network maps and cluster data have shown that there is a tendency of firms and non-scientific activity to concentrate around the established science hubs. In that sense, our observations concur with the findings by Zucker et al. (2007). 7.2 Diversity and Knowledge Accumulation: Predominance of 'Science Hubs'

  with US studies, we can observe

  Figures

Figure

  Figure Error! Main Document Only. Collaboration in UK nano-patenting 1999-2003

Figure 9

 9 Figure 9Cluster membership by UK Region (counts of nano-members)

  ,

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  Table 1about here>> <<insert Table 2 about here>> Table 3 illustrates the breadth of technology development at the town level. In the first time period well-established and large science poles/clusters appear to develop a broad range of technologies with the exception of Oxford that in the second time period catches up significantly in terms of breadth of technology development. Compared to the first time period, all large and small 'nano-clusters' expand the breadth of technology development in the second time period, with the exception of Manchester that seems to develop more depth in a narrower range of technologies i.e. specializes in fewer

	technologies.
		<<insert Table 3 about here>>
	6.2.2.	Collaborative Ties of Nano-related Companies
	An analysis of collaborative ties of the 146 UK nanotechnology firms in
	the time period from 1999 to 2003 allowed us to develop a better

Table 1 .

 1 Occurrence of local co-invention links: Patent data for 1999-2003

	Page 71 of 75					Regional Studies
	100%
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	80%
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	20%
	0% 10%	F 1 2 o r 3	4	5	6	7	8 Cluster	9	10	11	12	13	14	15
			E Midlands		E of Engl		London			NE
			NI P SW		NW W Midlands	Scotland Wales		SE York&Humber
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	Figure 10	Cluster membership by firm type
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http://mc.manuscriptcentral.com/cres Email: regional.studies@fm.ru.nl http://mc.manuscriptcentral.com/cres Email: regional.studies@fm.ru.nl

Table 2 .

 2 Occurrence of local co-invention links: Patent data for 2004-2008

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O3 -Technological Change|Research and Development < O -Economic Development, Technological Change, and Growth, O33 -Technological Change: Choices and Consequences|Diffusion Processes < O3 -Technological Change|Research and Development < O -Economic Development, Technological Change, and Growth, O38 -Government Policy < O3 -Technological Change|Research and Development < O -Economic Development, Technological Change, and Growth, O52 -Europe < O5 -Economywide Country Studies < O -Economic Development, Technological Change, and Growth