1,719 research outputs found

    An information theoretic characterisation of auditory encoding.

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    The entropy metric derived from information theory provides a means to quantify the amount of information transmitted in acoustic streams like speech or music. By systematically varying the entropy of pitch sequences, we sought brain areas where neural activity and energetic demands increase as a function of entropy. Such a relationship is predicted to occur in an efficient encoding mechanism that uses less computational resource when less information is present in the signal: we specifically tested the hypothesis that such a relationship is present in the planum temporale (PT). In two convergent functional MRI studies, we demonstrated this relationship in PT for encoding, while furthermore showing that a distributed fronto-parietal network for retrieval of acoustic information is independent of entropy. The results establish PT as an efficient neural engine that demands less computational resource to encode redundant signals than those with high information content

    The diatom Pseudo-nitzschia (Peragallo) in Irish waters

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    Ph.D. Thesis submitted to the National University of Ireland, Galway.The objectives of this study were to: 1. Determine which Pseudo-nitzschia species are present in Irish waters using light microscopy, scanning and transmission electron microscopy; 2. Investigate the hydrographic conditions that relate to the distribution of the genus Pseudo-nitzschia; 3. Determine which species are capable of producing domoic acid in unialgal cultures; 4. Compare SSU and ITS1 and part of the 5.8S ribosomal DNA sequences of Irish Pseudo-nitzschia isolates with available sequences of Pseudo-nitzschia isolates from other geographic regions; 5. Examine the efficacy of existing oligonucleotide probes to aid identification of Pseudo-nitzschia strains in Irish waters

    Australia’s Alcohol and Other Drug Telephone Information, Referral, and Counselling Services: A Guide to Quality Service Provision.

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    Ann Roche, Keith Evans, Tania Steenson, Ken Pidd, Nicole Lee, Lynette Cusack

    Molecular mechanism of influenza A NS1-mediated TRIM25 recognition and inhibition

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    RIG-I is a viral RNA sensor that induces the production of type I interferon (IFN) in response to infection with a variety of viruses. Modification of RIG-I with K63-linked poly-ubiquitin chains, synthesised by TRIM25, is crucial for activation of the RIG-I/MAVS signalling pathway. TRIM25 activity is targeted by influenza A virus non-structural protein 1 (NS1) to suppress IFN production and prevent an efficient host immune response. Here we present structures of the human TRIM25 coiled-coil-PRYSPRY module and of complexes between the TRIM25 coiled-coil domain and NS1. These structures show that binding of NS1 interferes with the correct positioning of the PRYSPRY domain of TRIM25 required for substrate ubiquitination and provide a mechanistic explanation for how NS1 suppresses RIG-I ubiquitination and hence downstream signalling. In contrast, the formation of unanchored K63-linked poly-ubiquitin chains is unchanged by NS1 binding, indicating that RING dimerisation of TRIM25 is not affected by NS1

    Ocean modelling for aquaculture and fisheries in Irish waters

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    The Marine Institute, Ireland, runs a suite of operational regional and coastal ocean models. Recent developments include several tailored products that focus on the key needs of the Irish aquaculture sector. In this article, an overview of the products and services derived from the models are presented. The authors give an overview of a shellfish model developed in-house and that was designed to predict the growth, the physiological interactions with the ecosystem, and the level of coliform contamination of the blue mussel. As such, this model is applicable in studies on the carrying capacity of embayments, assessment of the impacts of pollution on aquaculture grounds, and the determination of shellfish water classes. Further services include the assimilation of the model-predicted shelf water movement into a new harmful algal bloom alert system used to inform end users of potential toxic shellfish events and high biomass blooms that include fish-killing species. Models are also used to identify potential sites for offshore aquaculture, to inform studies of potential cross-contamination in farms from the dispersal of planktonic sea lice larvae and other pathogens that can infect finfish, and to provide modelled products that underpin the assessment and advisory services on the sustainable exploitation of the resources of marine fisheries. This paper demonstrates that ocean models can provide an invaluable contribution to the sustainable blue growth of aquaculture and fisheries

    'Mindless markers of the nation': The routine flagging of nationhood across the visual environment

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    The visual environment has increasingly been used as a lens with which to understand wider processes of social and economic change with studies employing in-depth qualitative approaches to focus on, for example, gentrification or trans-national networks. This exploratory paper offers an alternative perspective by using a novel method, quantitative photo mapping, to examine the extent to which a particular socio-cultural marker, the nation, is ‘flagged’ across three contrasting sites in Britain. As a multi-national state with an increasingly diverse population, Britain offers a particularly fruitful case study, drawing in debates around devolution, European integration and Commonwealth migration. In contributing to wider debates around banal nationalism, the paper notes the extent to which nations are increasingly articulated through commerce, consumption and market exchange and the overall significance of everyday markers (signs, objects, infrastructure) in naturalising a national view of the world

    Structure, Stresses and Local Dynamics in Glasses

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    The interrelations between short range structural and elastic aspects in glasses and glass forming liquids pose important and yet unresolved questions. In this paper these relations are analyzed for mono-atomic glasses and stressed liquids with a short range repulsive-attractive pair potentials. Strong variations of the local pressure are found even in a zero temperature glass, whereas the largest values of pressure are the same in both glasses and liquids. The coordination number z(J) and the effective first peak radius depend on the local pressures J's. A linear relation was found between components of site stress tensor and the local elastic constants. A linear relation was also found between the trace of the squares of the local frequencies and the local pressures. Those relations hold for glasses at zero temperature and for liquids. We explain this by a relation between the structure and the potential terms. A structural similarity between liquids and solids is manifested by similar dependencies of the coordination number on the pressures.Comment: 7 pages, 11 figure

    Electronic structure of strained InP/GaInP quantum dots

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    We calculate the electronic structure of nm scale InP islands embedded in Ga0.51In0.49PGa_{0.51}In_{0.49}P. The calculations are done in the envelope approximation and include the effects of strain, piezoelectric polarization, and mixing among 6 valence bands. The electrons are confined within the entire island, while the holes are confined to strain induced pockets. One pocket forms a ring at the bottom of the island near the substrate interface, while the other is above the island in the GaInP. The two sets of hole states are decoupled. Polarization dependent dipole matrix elements are calculated for both types of hole states.Comment: Typographical error corrected in strain Hamiltonia

    An activity-centric conceptual framework for assessing and creating positive urban soundscapes

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    The Positive Soundscapes Project is an interdisciplinary investigation of soundscape perception [1]. The project seeks to develop a rounded view of human perception of soundscapes by drawing together methods from the disciplines of engineering sound quality [2], acoustics, psychoacoustics, physiology [3], as well as sound art, acoustic ecology and social science [4]. In the acoustics community, sound in the environment, especially that made by other people has overwhelmingly been considered in negative terms as both intrusive and undesirable. The strong focus of traditional engineering acoustics on reducing noise levels ignores the many possibilities for characterizing positive aspects of the soundscape, whereas art and social science disciplines interpret soundscape perception as a multimodal and multi-dimensional concept. The project team come from a wide range of disciplines and are applying their experiences to investigate soundscapes from different aspects to produce a more nuanced and complete picture of listener response than has so far been achieved. In order for the team behind the project to achieve this, an underpinning framework is required, by which to approach and move the project forward, while aligning thinking from the different disciplines. This paper describes a high-level first iteration of the conceptual framework, which is structured in three parts. The use and potential application of the framework within the Positive Soundscapes Project is then discussed
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