1,501 research outputs found
Oxygen isotope equilibrium in brachiopod shell fibres in the context of biological control
No abstract available
The positive soundscape project : a synthesis of results from many disciplines
This paper takes an overall view of ongoing findings from the Positive Soundscape Project, a large inter-disciplinary soundscapes study which is nearing completion. Qualitative fieldwork (soundwalks and focus groups) and lab-based listening tests have revealed that two key dimensions of the emotional response are calmness and vibrancy. In the lab these factors explain nearly 80% of the variance in listener response. Physiological validation is being sought using fMRI measurements, and these have so far shown significant differences in the response of the brain to affective and neutral soundscapes. A conceptual framework which links the key soundscape components and which could be used for future design is outlined. Metrics are suggested for some perceptual scales and possibilities for soundscape synthesis for design and user engagement are discussed, as are the applications of the results to future research and environmental noise policy
Driving under the influence of an intoxicant in Ireland.
The number of specimens analysed by the MBRS has been increasing for both alcohol and drugs. Blood and urine specimens are analysed for the concentration of alcohol using Headspace Gas Chromatography. Specimens testing positive were forwarded to the State Laboratory for confirmatory analysis by either GC/MS or LC/MS. In 2000, 93 per cent of blood specimens, 91 per cent of urine specimens and 82 per cent of breath specimens were over the limit. In the same year, 57 per cent of blood specimens, 66 per cent of urine specimens and 33 per cent of breath specimens were over twice the limit. Of the 78 specimens tested for the presence of a drug or drugs, 37 were blood specimens and 41 urine specimens. Of these, 34 blood specimens and 37 urine specimens were found to be positive, while seven specimens were negative for the drug or drug classes tested (three blood and four urine specimens). There were 23 specimens found positive for one drug class and 48 for more than one drug.The number of requests for the presence of drugs in RTA blood and urine specimens is increasing annually and the high percentage of positives found in the specimens tested indicates the need for such analyses.
The results showed excellent agreement for drug detection in the blood specimens analysed by the different methods, except for the cannabinoids. The number of specimens in this study is small and care must be exercised in interpreting the results
An activity-centric conceptual framework for assessing and creating positive urban soundscapes
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
Organic carbon sequestration and storage in vegetated coastal habitats along the western coast of the Arabian Gulf
Certain coastal ecosystems such as mangrove, saltmarsh and seagrass habitats have been identified as significant natural carbon sinks, through the sequestration and storage of carbon in their biomass and sediments, collectively known as \u27blue carbon\u27 ecosystems. These ecosystems can often thrive in extreme environments where terrestrial systems otherwise survive at the limit of their existence, such as in arid and desert regions of the globe. To further our understanding of the capability of blue carbon ecosystems to sequester and store carbon in such extreme climates, we measured carbon sediment stocks in 25 sites along the Western Arabian Gulf coast. While seagrass meadows and saltmarsh habitats were widely distributed along the coast, mangrove stands were much reduced as a result of anthropogenic pressures, with 90% of stands having been lost over the last century. Carbon stocks in 1 m deep surface sediments were similar across all three blue carbon habitats, with comparable stocks for saltmarsh (81 ± 22 Mg Corg ha−1), seagrass (76 ± 20 Mg Corg ha−1) and mangroves (76 ± 23 Mg Corg ha−1). We recorded a 38% decrease in carbon stocks between mature established mangrove stands (91 Mg Corg ha−1) and recently planted mangroves (56 Mg Corg ha−1). Mangroves also had the lowest carbon stock per total area owing to their very limited spatial coverage along the coast. The largest stock per total area belonged to seagrass beds as a result of their large spatial coverage within the Gulf. We employed 210Pb dating to determine the sediment accretion rates in each ecosystem and found mangrove habitats to be the most efficient carbon sequesters over the past century, with the highest carbon burial rate of the three ecosystems (19 g Corg m−2 yr−1), followed by seagrass (9 g Corg m−2 yr−1) and saltmarshes (8 g Corg m−2 yr−1). In this work, we describe a comprehensive comparison of sediment stocks in different blue carbon ecosystems within a single marine environment and across a large geographical area, and discuss our results in a global context for other blue carbon ecosystems in the dry tropics
Quantum wires from coupled InAs/GaAs strained quantum dots
The electronic structure of an infinite 1D array of vertically coupled
InAs/GaAs strained quantum dots is calculated using an eight-band
strain-dependent k-dot-p Hamiltonian. The coupled dots form a unique quantum
wire structure in which the miniband widths and effective masses are controlled
by the distance between the islands, d. The miniband structure is calculated as
a function of d, and it is shown that for d>4 nm the miniband is narrower than
the optical phonon energy, while the gap between the first and second minibands
is greater than the optical phonon energy. This leads to decreased optical
phonon scattering, providing improved quantum wire behavior at high
temperatures. These miniband properties are also ideal for Bloch oscillation.Comment: 5 pages revtex, epsf, 8 postscript figure
Structure, Stresses and Local Dynamics in Glasses
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
'Mindless markers of the nation': The routine flagging of nationhood across the visual environment
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
Role of vegetated coastal ecosystems as nitrogen and phosphorous filters and sinks in the coasts of Saudi Arabia
Vegetated coastal ecosystems along the Red Sea and Arabian Gulf coasts of Saudi Arabia thrive in an extremely arid and oligotrophic environment, with high seawater temperatures and salinity. Mangrove, seagrass and saltmarsh ecosystems have been shown to act as efficient sinks of sediment organic carbon, earning these vegetated ecosystems the moniker \u27blue carbon\u27 ecosystems. However, their role as nitrogen and phosphorus (N and P) sinks remains poorly understood. In this study, we examine the capacity of blue carbon ecosystems to trap and store nitrogen and phosphorous in their sediments in the central Red Sea and Arabian Gulf. We estimated the N and P stocks (in 0.2 m thick-sediments) and accumulation rates (for the last century based on 210Pb and for the last millennia based on 14C) in mangrove, seagrass and saltmarsh sediments from eight locations along the coast of Saudi Arabia (81 cores in total). The N and P stocks contained in the top 20 cm sediments ranged from 61 g N m-2 in Red Sea seagrass to 265 g N m-2 in the Gulf saltmarshes and from 70 g P m-2 in Red Sea seagrass meadows and mangroves to 58 g P m-2 in the Gulf saltmarshes. The short-term N and P accumulation rates ranged from 0.09 mg N cm-2 yr-1 in Red Sea seagrass to 0.38 mg N cm-2 yr-1 in Gulf mangrove, and from 0.027 mg P cm-2 yr-1 in the Gulf seagrass to 0.092 mg P cm-2 yr-1 in Red Sea mangroves. Short-term N and P accumulation rates were up to 10-fold higher than long-term accumulation rates, highlighting increasing sequestration of N and P over the past century, likely due to anthropogenic activities such as coastal development and wastewater inputs. © 2020 The Author(s). Published by IOP Publishing Ltd
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