316 resultados para Chemical industries


Relevância:

20.00% 20.00%

Publicador:

Resumo:

We report on the use of the hydrogen bond accepting properties of neutral nitrone moieties to prepare benzylic-amide-macrocycle-containing [2]rotaxanes in yields as high as 70 %. X-Ray crystallography shows the presence of up to four intercomponent hydrogen bonds between the amide groups of the macrocycle and the two nitrone groups of the thread. Dynamic 1H NMR studies of the rates of macrocycle pirouetting in nonpolar solutions indicate that amide-nitrone hydrogen bonds are particularly strong, ~1.3 and ~0.2 kcal mol-1 stronger than similar amide-ester and amide-amide interactions, respectively. In addition to polarizing the N-O bond through hydrogen bonding, the rotaxane structure affects the chemistry of the nitrone groups in two significant ways: The intercomponent hydrogen bonding activates the nitrone groups to electrochemical reduction, a one electron reduction of the rotaxane being stablized by a remarkable 400 mV (8.1 kcal mol-1) with respect to the same process in the thread; encapsulation, however, protects the same functional groups from chemical reduction with an external reagent (and slows down electron transfer to and from the electroactive groups in cyclicvoltammetry experiments). Mechanical interlocking with a hydrogen bonding molecular sheath thus provides a route to an encapsulated polarized functional group and radical anions of significant kinetic and thermodynamic stability.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This chapter will begin by considering some of the distinctive features of media as creative industries, including their assessment of risk and return on investment, team-based production, the management of creativity, the value chain of production, distribution and circulation, and the significance of intellectual property in their revenue strategies. It will then critically appraise three strategies to capture new markets and revenue streams in the context of the rise of the Internet, digital media and globally networked distribution. The three strategies to be considered are conglomeration, networking and globalization, and the focus will be on the media giants such as News Corporation, Disney and Time-Warner. It will be argued that all three present considerable challenges in their application, and digital media technologies are weakening rather than strengthening their capacity to control the global media environment. The chapter will conclude with consideration of some implications of this analysis for questions of media power.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

It has been argued that the origins of modern creative industries policies can be found in Australia. The Creative Nation national cultural policy statement released by the Labor government headed by the Prime Minister Paul Keating in 1994 sought an original synthesis of arts and media policies that was outwardly looking, identifying the opportunities presented by what were then new digital media technologies, and clearly stated the economic opportunities presented by promotion of what were referred to at the time as the cultural industries. Several commentators have identified the influence that Creative Nation had on the Blair Labour government when it came to power in the United Kingdom in 1997. Faced with the question of how to revitalise the once-mighty industrial cities of the U.K. after the Conservative government, the Department of Culture, Media and Sport drew upon policy documents such as Australia’s Creative Nation, as well as the experience of local governments in these cities, in looking to the cultural sectors to spearhead new jobs growth, as well as re-branding the cities as cultural or creative cities in a post-industrial economic landscape. This growing alignment of culture and economics, that has been a characteristic of creative industries policies as they have developed in Australia, Britain, East Asia and Europe, marks an interesting shift in the traditional focus of arts and cultural policy as compensatory to the economic domain. The first Chair of what would become the Arts Council of Great Britain (now the Arts Council of England) was the famous economist John Maynard Keynes. In the First Annual Report of the Arts Council for 1945-1946, prepared in the latter stages of the Second World War, Keynes proposed that “the day is not far off when the economic problem will take the back seat where it belongs, and the arena of the heart and the head will be occupied or reoccupied, by our real problems — the problems of life and of human relations, of creation and behaviour and religion”. 中文摘要 1994年工黨執政時期澳洲總理基挺(Paul Keating)發表創意的國家(The Creative Nation)的文化政策聲明堪稱是澳洲現代創意產業的起源,該聲明試圖將藝術與媒體政策結合在一起,其目的在面向海外,為新數位媒體技術尋找機會。聲明中明確指出要推動文化產業為經濟帶來機會。「文化政策也是經濟政策。文化創造財富與附加價值,對創新、行銷與設計有重要貢獻,是我們工業的標誌(badge)。我們創意的層次實際上決定了我們適應新經濟imperatives的能力。文化本身就是項重要出口,是其他產品出口的主要附件(essential accompaniment)。文化吸引觀光與學生,也是我們經濟成功之關鍵。」 創意產業的策略是構建藝術、媒體與資訊電信科技的網絡以利文化產業在國家創新政策策略中擁有一席之地。此一策略最早是由1990年代末英國布萊爾(Tony Blair)的新工黨政府所採行,其後歐洲聯盟、澳洲、紐西蘭、新加坡、台灣、南韓與中國。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Delays are an important feature in temporal models of genetic regulation due to slow biochemical processes, such as transcription and translation. In this paper, we show how to model intrinsic noise effects in a delayed setting by either using a delay stochastic simulation algorithm (DSSA) or, for larger and more complex systems, a generalized Binomial τ-leap method (Bτ-DSSA). As a particular application, we apply these ideas to modeling somite segmentation in zebra fish across a number of cells in which two linked oscillatory genes (her1 and her7) are synchronized via Notch signaling between the cells.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Recently the application of the quasi-steady-state approximation (QSSA) to the stochastic simulation algorithm (SSA) was suggested for the purpose of speeding up stochastic simulations of chemical systems that involve both relatively fast and slow chemical reactions [Rao and Arkin, J. Chem. Phys. 118, 4999 (2003)] and further work has led to the nested and slow-scale SSA. Improved numerical efficiency is obtained by respecting the vastly different time scales characterizing the system and then by advancing only the slow reactions exactly, based on a suitable approximation to the fast reactions. We considerably extend these works by applying the QSSA to numerical methods for the direct solution of the chemical master equation (CME) and, in particular, to the finite state projection algorithm [Munsky and Khammash, J. Chem. Phys. 124, 044104 (2006)], in conjunction with Krylov methods. In addition, we point out some important connections to the literature on the (deterministic) total QSSA (tQSSA) and place the stochastic analogue of the QSSA within the more general framework of aggregation of Markov processes. We demonstrate the new methods on four examples: Michaelis–Menten enzyme kinetics, double phosphorylation, the Goldbeter–Koshland switch, and the mitogen activated protein kinase cascade. Overall, we report dramatic improvements by applying the tQSSA to the CME solver.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis explores the proposition that growth and development in the screen and creative industries is not confined to the major capital cities. Lifestyle considerations, combined with advances in digital technology, convergence and greater access to broadband are altering requirements for geographic location, and creative workers are being drawn away from the big metropolises to certain regional areas. Regional screen industry enclaves are emerging outside of London, in the Highlands and Islands of Scotland, in Nova Scotia in Canada and in New Zealand. In the Australian context, the proposition is tested in an area regarded as a ‘special case’ in creative industry expansion: the Northern Rivers region of NSW. A key feature of the ‘specialness’ of this region is the large number of experienced, credited producers who live and operate their businesses within the region. The development of screen and creative industries in the Northern Rivers over the decade 2000 – 2010 has implications for regional regeneration and offers new insights into the rapidly changing screen industry landscape. This development also has implications for creative industry discourse, especially the dominance of the urban in creative industries thought. The research is pioneering in a number of ways. Building on the work conducted for my Masters thesis in 2000, a second study was conducted during the research phase, adapting creative industries theory and mapping methods, which have been largely city and nation-centric, and applying them to a regional context. The study adopted an action research approach as an industry development strategy for screen industries, while at the same time developing fine-grained ground up methods for collecting primary quantitative data on the size and scope of the creative industries. In accordance with the action research framework, the researcher also acted in the dual roles of industry activist and screen industry producer in the region. The central focus of the research has been both to document and contribute to the growth and development of screen and creative industries over the past decade in the Northern Rivers region. These interventions, along with policy developments at both a local and national level, and broader global shifts, have had the effect of repositioning the sector from a marginal one to a priority area considered integral to the future economic and cultural life of the region. The research includes a detailed mapping study undertaken in 2005 with comparisons to an earlier 2000 study and to ABS data for 2001 and 2006 to reveal growth trends. It also includes two case studies of projects that developed from idea to production and completion in the region during the decade in question. The studies reveal the drivers, impediments and policy implications for sustaining the development of screen industries in a regional area. A major finding of the research was the large and increasing number of experienced producers who operate within the region and the leadership role they play in driving the development of the emerging local industry. The two case studies demonstrate the impact of policy decisions on local screen industry producers and their enterprises. A brief overview of research in other regional areas is presented, including two international examples, and what they reveal about regional regeneration. Implications are drawn for creative industries discourse and regional development policy challenges for the future.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Over less than a decade, we have witnessed a seismic shift in the way knowledge is produced and exchanged. This is opening up new opportunities for civic and community engagement, entrepreneurial behaviour, sustainability initiatives and creative practices. It also has the potential to create fresh challenges in areas of privacy, cyber-security and misuse of data and personal information. The field of urban informatics focuses on the use and impacts of digital media technology in urban environments. Urban informatics is a dynamic and cross-disciplinary area of inquiry that encapsulates social media, ubiquitous computing, mobile applications and location-based services. Its insights suggest the emergence of a new economic force with the potential for driving innovation, wealth and prosperity through technological advances, digital media and online networks that affect patterns of both social and economic development. Urban informatics explores the intersections between people, place and technology, and their implications for creativity, innovation and engagement. This paper examines how the key learnings from this field can be used to position creative and cultural institutions such as galleries, libraries, archives and museums (GLAM) to take advantage of the opportunities presented by these changing social and technological developments. This paper introduces the underlying principles, concepts and research areas of urban informatics, against the backdrop of modern knowledge economies. Both theoretical ideas and empirical examples are covered in this paper. The first part discusses three challenges: a. People, and the challenge of creativity: The paper explores the opportunities and challenges of urban informatics that can lead to the design and development of new tools, methods and applications fostering participation, the democratisation of knowledge, and new creative practices. b. Technology, and the challenge of innovation: The paper examines how urban informatics can be applied to support user-led innovation with a view to promoting entrepreneurial ideas and creative industries. c. Place, and the challenge of engagement: The paper discusses the potential to establish place-based applications of urban informatics, using the example of library spaces designed to deliver community and civic engagement strategies. The discussion of these challenges is illustrated by a review of projects as examples drawn from diverse fields such as urban computing, locative media, community activism, and sustainability initiatives. The second part of the paper introduces an empirically grounded case study that responds to these three challenges: The Edge, the Queensland Government’s Digital Culture Centre which is an initiative of the State Library of Queensland to explore the nexus of technology and culture in an urban environment. The paper not only explores the new role of libraries in the knowledge economy, but also how the application of urban informatics in prototype engagement spaces such as The Edge can provide transferable insights that can inform the design and development of responsive and inclusive new library spaces elsewhere. To set the scene and background, the paper begins by drawing the bigger picture and outlining some key characteristics of the knowledge economy and the role that the creative and cultural industries play in it, grasping new opportunities that can contribute to the prosperity of Australia.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Biochemical reactions underlying genetic regulation are often modelled as a continuous-time, discrete-state, Markov process, and the evolution of the associated probability density is described by the so-called chemical master equation (CME). However the CME is typically difficult to solve, since the state-space involved can be very large or even countably infinite. Recently a finite state projection method (FSP) that truncates the state-space was suggested and shown to be effective in an example of a model of the Pap-pili epigenetic switch. However in this example, both the model and the final time at which the solution was computed, were relatively small. Presented here is a Krylov FSP algorithm based on a combination of state-space truncation and inexact matrix-vector product routines. This allows larger-scale models to be studied and solutions for larger final times to be computed in a realistic execution time. Additionally the new method computes the solution at intermediate times at virtually no extra cost, since it is derived from Krylov-type methods for computing matrix exponentials. For the purpose of comparison the new algorithm is applied to the model of the Pap-pili epigenetic switch, where the original FSP was first demonstrated. Also the method is applied to a more sophisticated model of regulated transcription. Numerical results indicate that the new approach is significantly faster and extendable to larger biological models.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Biologists are increasingly conscious of the critical role that noise plays in cellular functions such as genetic regulation, often in connection with fluctuations in small numbers of key regulatory molecules. This has inspired the development of models that capture this fundamentally discrete and stochastic nature of cellular biology - most notably the Gillespie stochastic simulation algorithm (SSA). The SSA simulates a temporally homogeneous, discrete-state, continuous-time Markov process, and of course the corresponding probabilities and numbers of each molecular species must all remain positive. While accurately serving this purpose, the SSA can be computationally inefficient due to very small time stepping so faster approximations such as the Poisson and Binomial τ-leap methods have been suggested. This work places these leap methods in the context of numerical methods for the solution of stochastic differential equations (SDEs) driven by Poisson noise. This allows analogues of Euler-Maruyuma, Milstein and even higher order methods to be developed through the Itô-Taylor expansions as well as similar derivative-free Runge-Kutta approaches. Numerical results demonstrate that these novel methods compare favourably with existing techniques for simulating biochemical reactions by more accurately capturing crucial properties such as the mean and variance than existing methods.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The concept of ‘strategic dalliances’– defined as non-committal relationships that companies can ‘dip in and out of,’ or dally with, while simultaneously maintaining longer-term strategic partnerships with other firms and suppliers – has emerged as a promising strategy by which organizations can create discontinuous innovations. But does this approach work equally well for every sector? Moreover, how can these links be effectively used to foster the process of discontinuous innovation? Toward assessing the role that industry clockspeed plays in the success or failure of strategic dalliances, we provide case study evidence from Twister BV, an upstream oil and gas technology provider, and show that strategic dalliances can be an enabler for the discontinuous innovation process in slow clockspeed industries. Implications for research and practice are discussed, and conclusions from our findings are drawn.