998 resultados para Réseau local de télécommunications
Resumo:
Modifications of local structure at atomic level could precisely and effectively tune the capacity of materials, enabling enhancement in the catalytic activity. Here we modulate the local atomic structure of a classical but inert transition metal oxide, tungsten trioxide, to be an efficient electrocatalyst for hydrogen evolution in acidic water, which has shown promise as an alternative to platinum. Structural analyses and theoretical calculations together indicate that the origin of the enhanced activity could be attributed to the tailored electronic structure by means of the local atomic structure modulations. We anticipate that suitable structure modulations might be applied on other transition metal oxides to meet the optimal thermodynamic and kinetic requirements, which may pave the way to unlock the potential of other promising candidates as cost-effective electrocatalysts for hydrogen evolution in industry.
Resumo:
This paper addresses the relationship between local and distributed strategies with reference to two recent participatory sound art projects in Belfast and Rio de Janeiro. The local concern for site and place is discussed and juxtaposed with distributed practices, which,by definition question and extend the very notion of site or locale. I refer to examples from ethnomusicology, anthropology and education in which participative horizontal research methodologies lead to a dynamic articulation of local conditions and allow for a reflection on how technology impacts on social interaction and relationships with place. The works of Samuel Araújo, Georgina Born and Brazilian pedagogue Paulo Freire provide a framework of reference in this context.
Resumo:
This paper relates to work supported by the Joseph Rowntree Foundation which examines the way Scottish Local Authorities have approached budget cuts (Asenova, et. al., 2013). Starting with a discussion of notions of social risk, we discuss the heightened challenges faced by local authorities. We note that the literature on public sector innovation predict such pressures would cause local authorities to engage in short term decision making and adopt a static coping approach to risk mitigation which is likely to stifle innovation and obstruct the creation of more coherent and resilient localities. Although we find this to have happened in some areas, we discuss two cases where these challenges have promoted innovative and inclusive approaches to service re-design and delivery.
Resumo:
This paper examines the prospects for sustainable rural tourism within a rural development paradigm. Specifically, an adaptive management approach is proposed as a means of understanding and accommodating the different goals and interests that exist within multi-functional rural areas. This model allows priorities to change in line with particular situations while remaining sensitive to economic, environmental, social and cultural impacts. The proposed Mourne National Park in Northern Ireland, also designated an Area of Outstanding Natural Beauty (AONB), forms the backdrop for this study. Through a critique of a consultation process that was undertaken with the community the question is posed: can a sustainable rural tourism approach achieve meaningful community engagement and thereby reflect the needs of the community? Central to the analysis are the power differentials between the various partners participating in this model of governance. The conclusions consider implications for rural communities, revealing how trusting and meaningful relationships are central to facilitating collaboration, cooperation and adaptation.
Resumo:
Whole genome sequencing (WGS) technology holds great promise as a tool for the forensic epidemiology of bacterial pathogens. It is likely to be particularly useful for studying the transmission dynamics of an observed epidemic involving a largely unsampled 'reservoir' host, as for bovine tuberculosis (bTB) in British and Irish cattle and badgers. BTB is caused by Mycobacterium bovis, a member of the M. tuberculosis complex that also includes the aetiological agent for human TB. In this study, we identified a spatio-temporally linked group of 26 cattle and 4 badgers infected with the same Variable Number Tandem Repeat (VNTR) type of M. bovis. Single-nucleotide polymorphisms (SNPs) between sequences identified differences that were consistent with bacterial lineages being persistent on or near farms for several years, despite multiple clear whole herd tests in the interim. Comparing WGS data to mathematical models showed good correlations between genetic divergence and spatial distance, but poor correspondence to the network of cattle movements or within-herd contacts. Badger isolates showed between zero and four SNP differences from the nearest cattle isolate, providing evidence for recent transmissions between the two hosts. This is the first direct genetic evidence of M. bovis persistence on farms over multiple outbreaks with a continued, ongoing interaction with local badgers. However, despite unprecedented resolution, directionality of transmission cannot be inferred at this stage. Despite the often notoriously long timescales between time of infection and time of sampling for TB, our results suggest that WGS data alone can provide insights into TB epidemiology even where detailed contact data are not available, and that more extensive sampling and analysis will allow for quantification of the extent and direction of transmission between cattle and badgers. © 2012 Biek et al.