900 resultados para Transport and communications
Resumo:
This thesis explores the drivers of innovation in Irish high-technology businesses and estimates, in particular, the relative importance of interaction with external businesses and other organisations as a source of knowledge for innovation at the business-level. The thesis also examines the extent to which interaction for innovation in these businesses occurs on a local or regional basis. The study uses original survey data of 184 businesses in the Chemical and Pharmaceutical, Information and Communications Technology and Engineering and Electronic Devices sectors. The study considers both product and process innovation at the level of the business and develops new measures of innovation output. For the first time in an Irish study, the incidence and frequency of interaction is measured for each of a range of agents, other group companies, suppliers, customers, competitors, academic-based researchers and innovation-supporting agencies. The geographic proximity between the business and each of the most important of each of each category of agent is measured using average one-way driving distance, which is the first time such a measure has been used in an Irish study of innovation. Utilising econometric estimation techniques, it is found that interaction with customers, suppliers and innovation-supporting agencies is positively associated with innovation in Irish high-technology businesses. Surprisingly, however, interaction with academic-based researchers is found to have a negative effect on innovation output at the business-level. While interaction generally emerges as a positive influence on business innovation, there is little evidence that this occurs at a local or regional level. Furthermore, there is little support for the presence of localisation economies for high-technology sectors, though some tentative evidence of urbanisation economies. This has important implications for Irish regional, enterprise and innovation policy, which has emphasised the development of clusters of internationally competitive businesses. The thesis brings into question the suitability of a cluster-driven network based approach to business development and competitiveness in an Irish context.
Resumo:
Phosphorus (P) is a crucial element for life and therefore for maintaining ecosystem productivity. Its local availability to the terrestrial biosphere results from the interaction between climate, tectonic uplift, atmospheric transport, and biotic cycling. Here we present a mathematical model that describes the terrestrial P-cycle in a simple but comprehensive way. The resulting dynamical system can be solved analytically for steady-state conditions, allowing us to test the sensitivity of the P-availability to the key parameters and processes. Given constant inputs, we find that humid ecosystems exhibit lower P availability due to higher runoff and losses, and that tectonic uplift is a fundamental constraint. In particular, we find that in humid ecosystems the biotic cycling seem essential to maintain long-term P-availability. The time-dependent P dynamics for the Franz Josef and Hawaii chronosequences show how tectonic uplift is an important constraint on ecosystem productivity, while hydroclimatic conditions control the P-losses and speed towards steady-state. The model also helps describe how, with limited uplift and atmospheric input, as in the case of the Amazon Basin, ecosystems must rely on mechanisms that enhance P-availability and retention. Our novel model has a limited number of parameters and can be easily integrated into global climate models to provide a representation of the response of the terrestrial biosphere to global change. © 2010 Author(s).
Resumo:
Bacterial outer membrane vesicles (OMVs) are spherical buds of the outer membrane (OM) containing periplasmic lumenal components. OMVs have been demonstrated to play a critical part in the transmission of virulence factors, immunologically active compounds, and bacterial survival, however vesiculation also appears to be a ubiquitous physiological process for Gram-negative bacteria. Despite their characterized biological roles, especially for pathogens, very little is known about their importance for the originating organism as well as regulation and mechanism of production. Only when we have established their biogenesis can we fully uncover their roles in pathogenesis and bacterial physiology. The overall goal of this research was to characterize bacterial mutants which display altered vesiculation phenotypes using genetic and biochemical techniques, and thereby begin to elucidate the mechanism of vesicle production and regulation. One part of this work elucidated a synthetic genetic growth defect for a strain with reduced OMV production (ΔnlpA, inner membrane lipoprotein with a minor role in methionine transport) and envelope stress (ΔdegP, dual function periplasmic chaperone/ protease responsible for managing proteinaceous waste). This research showed that the growth defect of ΔnlpAΔdegP correlated with reduced OMV production with respect to the hyprevesiculator ΔdegP and the accumulation of protein in the periplasm and DegP substrates in the lumen of OMVs. We further demonstrated that OMVs do not solely act as a stress response pathway to rid the periplasm of otherwise damaging misfolded protein but also of accumulated peptidoglycan (PG) fragments and lipopolysaccharide (LPS), elucidating OMVs as a general stress response pathway critical for bacterial well-being. The second part of this work, focused on the role of PG structure, turnover and covalent crosslinks to the OM in vesiculation. We established a direct link between PG degradation and vesiculation: Mutations in the OM lipoprotein nlpI had been previously established as a very strong hypervesiculation phenotype. In the literature NlpI had been associated with another OM lipoprotein, Spr that was recently identified as a PG hydrolase. The data presented here suggest that NlpI acts as a negative regulator of Spr and that the ΔnlpI hypervesiculation phenotype is a result of rampantly degraded PG by Spr. Additionally, we found that changes in PG structure and turnover correlate with altered vesiculation levels, as well as non-canonical D-amino acids, which are secreted by numerous bacteria on the onset of stationary phase, being a natural factor to increase OMV production. Furthermore, we discovered an inverse relationship between the concentration of Lpp-mediated, covalent crosslinks and the level of OMV production under conditions of modulated PG metabolism and structure. In contrast, situations that lead to periplasmic accumulation (protein, PG fragments, and LPS) and consequent hypervesiculation the overall OM-PG crosslink concentration appears to be unchanged. Form this work, we conclude that multiple pathways lead to OMV production: Lpp concentration-dependent and bulk driven, Lpp concentration-independent.
Resumo:
Musicians living in the Arab Diaspora around the Washington, D.C. metro area are a small group of multi-faceted individuals with significant contributions and intentions to propagate and disseminate their music. Various levels of identity are discussed and analyzed, including self-identity, group/ collective identity, and Arab ethnic identity. The performance and negotiation of Arab ethnic identity is apparent in selected repertoire, instrumentation, musical style, technique and expression, shared conversations about music, worldview on Arabic music and its future. For some musicians, further evidence of self-construction of one's ethnic identity entails choice of name, costume, and venue. Research completed is based on fieldwork, observations, participant-observations, interviews, and communications by phone and email. This thesis introduces concepts of Arabic music, discusses recent literature, reveals findings from case studies on individual Arab musicians and venues, and analyzes Arab identity and ethnicity in relation to particular definitions of identity found in anthropological and ethnomusicological writings. Musical lyrics, translations, transcriptions, quotes, discussions, analyses, as well as charts and diagrams of self-identity analyses are provided as evidence of the performance and negotiation of Arab identity.
Resumo:
BACKGROUND: The bioluminescence technique was used to quantify the local glucose concentration in the tissue surrounding subcutaneously implanted polyurethane material and surrounding glucose sensors. In addition, some implants were coated with a single layer of adipose-derived stromal cells (ASCs) because these cells improve the wound-healing response around biomaterials. METHODS: Control and ASC-coated implants were implanted subcutaneously in rats for 1 or 8 weeks (polyurethane) or for 1 week only (glucose sensors). Tissue biopsies adjacent to the implant were immediately frozen at the time of explant. Cryosections were assayed for glucose concentration profile using the bioluminescence technique. RESULTS: For the polyurethane samples, no significant differences in glucose concentration within 100 μm of the implant surface were found between bare and ASC-coated implants at 1 or 8 weeks. A glucose concentration gradient was demonstrated around the glucose sensors. For all sensors, the minimum glucose concentration of approximately 4 mM was found at the implant surface and increased with distance from the sensor surface until the glucose concentration peaked at approximately 7 mM at 100 μm. Then the glucose concentration decreased to 5.5-6.5 mM more than 100 μmm from the surface. CONCLUSIONS: The ASC attachment to polyurethane and to glucose sensors did not change the glucose profiles in the tissue surrounding the implants. Although most glucose sensors incorporate a diffusion barrier to reduce the gradient of glucose and oxygen in the tissue, it is typically assumed that there is no steep glucose gradient around the sensors. However, a glucose gradient was observed around the sensors. A more complete understanding of glucose transport and concentration gradients around sensors is critical.
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The original concept was to create a 'simulation' which would provide trainee teachers, specializing in Information and Communications Technology (ICT) with the opportunity to explore a primary school environment. Within the simulation, factors affecting the development and implementation of ICT would be modelled so that trainees would be able to develop the skills, knowledge and understanding necessary to identify appropriate strategies to overcome the limitations. To this end, we have developed Allsorts Primary - the prototype of a simulated interactive environment, representing a typical primary school
Resumo:
This paper focuses on urban road pricing as a demand management policy that is often regarded as radical and generally unacceptable. Road pricing often gets delayed or abandoned due to low acceptability. This may be due to the fact that complex interactions and drivers of change affect road transport management and require cooperation within implementation networks. The implementation network is a group of people (referred to as partners and actors) who co-ordinate the introduction of policy tools. The drivers of change include any internal or external influences that have an effect on the time, place, or ‘shape’ of the policy measures being introduced. Demand management measures that focus on 'sustainable transport' usually address a limited set of objectives and are often implemented alone i.e. are not necessarily combined with other policy measures. When combined with other measures, it is not always clear whether the multiple interactions between policy tools and implementation networks have been sufficiently considered. Examples of ongoing implementation of policy package in the UK are the support of road pricing initiatives combined with public transport improvements by the Transport Innovation Fund. The objectives of the paper are twofold. First, we present a review of the UK urban road pricing situation. Second, we contrast the emerging issues against six key implementation factors. The analysis of three existing UK road pricing examples - London, Edinburgh and Durham – shows the importance of combining policy tools. Furthermore, through the above examples and theoretical arguments, we emphasise the additional need of creating and maintaining strong networks when implementing policy packages.
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Rule testing in transport scheduling is a complex and potentially costly business problem. This paper proposes an automated method for the rule-based testing of business rules using the extensible Markup Language for rule representation and transportation. A compiled approach to rule execution is also proposed for performance-critical scheduling systems.
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Since the publication of Hancock's ‘the Petrology of the Chalk’ there have been numerous developments in our appreciation of the palaeoenvironment and stratigraphie correlation of the UK Chalk. This work presents a review of some of the key developments over the last 30 years. Our detailed understanding of Chalk lithostratigraphy and advances in our understanding of chalk sedimentation indicate that large-scale mass transport and re-sedimentation of chalks by low-angle suspension flows is required to explain the observed thickness variations. The provenance of clay minerals and the process of flint and granular phosphate formation are discussed. The growing importance of isotopic studies in high resolution stratigraphy and improving our understanding of the late Cretaceous oceans and climate are emphasized. Developments in lithostratigraphic studies and recent proposals for a new stratigraphie division of the Chalk in the UK are evaluated.
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Over latest decade, Reverse Logistics (RL) has gained more and more attention from both industry and academia. In the past, most research on RL has been focused on automobile, electronic waste, computer, paper, package and package material. There is very little research and practice on drug recycling. Nevertheless, it is vital important to properly dispose expired drug because of hazardous contain which may harm to people and environment. In China, public awareness of the harmfulness of expired drugs is still very low and very few efforts have been made to recycle drugs. Therefore, this research aims to build up a conceptual framework to indentify factors of influencing drug recycling in China, from scratch borrowing from existing literature and industry practices in other recycling areas. This framework helps in designing reverse logistic (RL) network and also can provide a useful reference tool for policymakers at the local and national level. Furthermore, a primary research is planed to validate the framework and RL network.
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Atmospheric inputs of mineral dust supply iron and other trace metals to the remote ocean and can influence the marine carbon cycle due to iron's role as a potentially limiting micronutrient. Dust generation, transport, and deposition are highly heterogeneous, and there are very few remote marine locations where dust concentrations and chemistry (e.g., iron solubility) are routinely monitored. Here we use aerosol and rainwater samples collected during 10 large-scale research cruises to estimate the atmospheric input of iron, aluminum, and manganese to four broad regions of the Atlantic Ocean over two 3 month periods for the years 2001–2005. We estimate total inputs of these metals to our study regions to be 4.2, 17, and 0.27 Gmol in April–June and 4.9, 14, and 0.19 Gmol in September–November, respectively. Inputs were highest in regions of high rainfall (the intertropical convergence zone and South Atlantic storm track), and rainfall contributed higher proportions of total input to wetter regions. By combining input estimates for total and soluble metals for these time periods, we calculated overall percentage solubilities for each metal that account for the contributions from both wet and dry depositions and the relative contributions from different aerosol types. Calculated solubilities were in the range 2.4%–9.1% for iron, 6.1%–15% for aluminum, and 54%–73% for manganese. We discuss sources of uncertainty in our estimates and compare our results to some recent estimates of atmospheric iron input to the Atlantic.
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This report about the Severn Estuary provides an up to date appraisal of the following issues: Transport and fate of sediments; Transport, fate and trends in contaminants; Bioavailability of contaminants; Consequences for biota, and pinpoints the major knowledge gaps.
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Maritime transport and shipping are impacted negatively by biofouling, which can result in increased fuel consumption. Thus, costs for fouling reduction can be considered an investment to reduce fuel consumption. Anti-fouling measures also reduce the rate of introduction of non-indigenous species (NIS). Further mitigation measures to reduce the transport of NIS within ballast water and sediments impose additional costs. The estimated operational cost of NIS mitigation measures may represent between 1.6% and 4% of the annual operational cost for a ship operating on European seas, with the higher proportional costs in small ships. However, fouling by NIS may affect fuel consumption more than fouling by native species due to differences in species’ life-history traits and their resistance to antifouling coatings and pollution. Therefore, it is possible that the cost of NIS mitigation measures could be smaller than the cost from higher fuel consumption arising from fouling by NIS.
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This article reports on the first extensive survey of Approved Social Worker (ASW) activity under the Mental Health (Northern Ireland) Order 1986. The integrated health and social services organizational structure, the adverse effects on individual mental health of the legacy of thirty years of civil conflict and the move from hospital to community care are significant features which have influenced the delivery of mental health social work services locally. The practice and experience of ASWs was surveyed by postal questionnaire and user and carer experience of compulsory hospital admission was investigated by a series of focus groups. The study revealed that two‐thirds of ASWs had experience of acting as an applicant in compulsory hospital admission during the past two years. Nearly half (42 per cent) of these ASWs had reported experience of between one and five admissions and one‐tenth had completed over twenty admissions in the two‐year period. In only a small minority of cases did joint face‐to‐face assessment with the General Practitioner (doctor) take place; nearly half of ASWs reported difficulties in obtaining transport; and only one‐fifth of ASWs had experience of acting as a second approved social worker. Half of ASWs reported experience of guardianship, either as applicant or in making the recommendation. Both service users and carers reported a lack of understanding about the role of the ASW and complained about the lack of alternative resources that ASWs could use to prevent hospital admissions. These findings are discussed and a number of recommendations are proposed for improvements to approved social worker practice.
Resumo:
Much of the interest in promoting sustainable development in planning for the city-region focuses on the apparently inexorable rise in the demand for car travel and the contribution that certain urban forms and land-use relationships can make to reducing energy consumption. Within this context, policy prescription has increasingly favoured a compact city approach with increasing urban residential densities to address the physical separation of daily activities and the resultant dependency on the private car. This paper aims to outline and evaluate recent efforts to integrate land use and transport policy in the Belfast Metropolitan Area in Northern Ireland. Although considerable progress has been made, this paper underlines the extent of existing car dependency in the metropolitan area and prevailing negative attitudes to public transport, and argues that although there is a rhetorical support for the principles of sustainability and the practice of land-use/transportation integration, this is combined with a selective reluctance to embrace local changes in residential environment or in lifestyle preferences which might facilitate such principles.