555 research outputs found
Determinants of habitat and site use by turnstones and purple sandpipers in N.E. England, and possible effects of the removal of coastal nutrients
Purple Sandpipers and Turnstones were studied on the coast of south Northumberland, with regard to the possible effects of reductions in sewage inputs into inshore waters along the Northumberland coast as a result of new European legislation. Multivariate analysis of bird density in relation to 33 habitat variables indicated that Purple Sandpiper distribution was positively correlated with the abundance of intertidal musselbeds, but negatively correlated with raptor density. Turnstone density was positively correlated with several intertidal habitats such as bare and barnacle-covered rock, as well as the amount of detached wrack deposited on the strandline. Analysis of stable carbon and nitrogen isotopes in particulate organic matter in inshore waters indicated that sewage contributed up to 60% of the total organic matter in the immediate vicinity of outfalls, and hence probably supported increased intertidal invertebrate densities. Purple Sandpiper numbers were unlikely to be limited by food resources, but birds sought to feed in areas that offered the highest food intake rates, in order to reduce the time spent feeding and therefore minimise the risk of predation by raptors. Social status determined where birds could feed, with larger and older birds excluding subordinates to poorer feeding areas. Social status in Turnstones was determined by sex and age. By feeding on the richest intertidal food resources, dominant individuals (males and adults) minimised the time spent foraging on ephemeral deposits of strandline wrack over high water, which carried a greater risk of predation. Dominant individuals of both species were able to carry less stored fat and hence improved their chances of escaping attacks by raptors. While both species are unlikely to decline in numbers as a direct response to lower food densities, subsequent changes in foraging behaviour and distribution could result in greater mortality
The Late Modernism of Cormac McCarthy (review)
David Holloway\u27s titular phrasing late modernism has an effective ring. It captures the theoretical underpinnings of his recent book, The Late Modernism of Cormac McCarthy, evoking Fredric Jameson\u27s work, on which Holloway heavily relies, while also situating McCarthy precisely where he wants him to be, historically and culturally. According to Holloway, McCarthy\u27s fiction constitutes an important redoubt against the diminishing of modernism\u27s once-valorous stance by forging a productive opposition to what he sees as a final stage in capitalist expansion. At the heart of Holloway\u27s project is his concern to restore an oppositional vitality to literary production, or what he terms a perspective of estrangement (2). Following certain poststructuralist accounts of language\u27s inherent instability and the related impossibilities of narrative, Holloway sees McCarthy as a writer whose singular prose at once foregrounds and incorporates the deathliness of language in his stories of an evacuated yet thoroughly commercialized American West—a topos and a space defined, Holloway suggests, by the ravages of globalization
Rapid-Scan EPR of Immobilized Nitroxides
X-band electron paramagnetic resonance spectra of immobilized nitroxides were obtained by rapid scan at 293 K. Scan widths were 155 G with 13.4 kHz scan frequency for 14N-perdeuterated tempone and for T4 lysozyme doubly spin labeled with an iodoacetamide spirocyclohexyl nitroxide and 100 G with 20.9 kHz scan frequency for 15N-perdeuterated tempone. These wide scans were made possible by modifications to our rapid-scan driver, scan coils made of Litz wire, and the placement of highly conducting aluminum plates on the poles of a Bruker 10 magnet to reduce resistive losses in the magnet pole faces. For the same data acquisition time, the signal-to-noise for the rapid-scan absorption spectra was about an order of magnitude higher than for continuous wave first-derivative spectra recorded with modulation amplitudes that do not broaden the lineshapes
Rapid-Scan EPR of Immobilized Nitroxides
X-band electron paramagnetic resonance spectra of immobilized nitroxides were obtained by rapid scan at 293 K. Scan widths were 155 G with 13.4 kHz scan frequency for 14N-perdeuterated tempone and for T4 lysozyme doubly spin labeled with an iodoacetamide spirocyclohexyl nitroxide and 100 G with 20.9 kHz scan frequency for 15N-perdeuterated tempone. These wide scans were made possible by modifications to our rapid-scan driver, scan coils made of Litz wire, and the placement of highly conducting aluminum plates on the poles of a Bruker 10 magnet to reduce resistive losses in the magnet pole faces. For the same data acquisition time, the signal-to-noise for the rapid-scan absorption spectra was about an order of magnitude higher than for continuous wave first-derivative spectra recorded with modulation amplitudes that do not broaden the lineshapes
Workforce participation among international medical graduates in the National Health Service of England: a retrospective longitudinal study
<p>Abstract</p> <p>Background</p> <p>Balancing medical workforce supply with demand requires good information about factors affecting retention. Overseas qualified doctors comprise 30% of the National Health Service (NHS) workforce in England yet little is known about the impact of country of qualification on length of stay. We aimed to address this need.</p> <p>Methods</p> <p>Using NHS annual census data, we calculated the duration of 'episodes of work' for doctors entering the workforce between 1992 and 2003. Survival analysis was used to examine variations in retention by country of qualification. The extent to which differences in retention could be explained by differences in doctors' age, sex and medical specialty was examined by logistic regression.</p> <p>Results</p> <p>Countries supplying doctors to the NHS could be divided into those with better or worse long-term retention than domestically trained doctors. Countries in the former category were generally located in the Middle East, non-European Economic Area Europe, Northern Africa and Asia, and tended to be poorer with fewer doctors per head of population, but stronger economic growth. A doctor's age and medical specialty, but not sex, influenced patterns of retention.</p> <p>Conclusion</p> <p>Adjusting workforce participation by country of qualification can improve estimates of the number of medical school places needed to balance supply with demand. Developing countries undergoing strong economic growth are likely to be the most important suppliers of long stay medical migrants.</p
Piezo-electric thick films for sensing
Monolithic piezoelectric sensors commonly used for acoustic emission and ultrasonic inspection are non-conforming, bulky, costly and heavy. This means they do not fit well to complex geometries, they can be susceptible to damage, and on larger structures their cost and weight can be prohibitive. An alternative to this is the use of piezo-electric thick films, which comprise of piezo-electric particles suspended in a matrix material. Such materials could provide "paint on" or "printable" sensors and sensor networks that are low profile, easy to mount and very cheap. In this work we explore the potential of piezo-electric thick films to sense and actuate for Acoustic Emission and ultrasonic applications. Sensors were produced by dispersing PZT 5a particles within water based acrylic and epoxy matrix materials with up to 70% fill by weight. The PZT films were applied to steel and their responses to artificial AE sources (Hsu-Nielson) were assessed and three-dimensional laser vibrometry was used to study the frequency response and mode shapes of the sensors under excitation. The results showed that although less sensitive than monolithic piezoelectric transducers, the thick film sensors can excite and detect ultrasonic waves for SHM applications and there is great potential for the development of a low cost, printed sensor network for SHM
Piezo-electric thick films for sensing
Monolithic piezoelectric sensors commonly used for acoustic emission and ultrasonic inspection are non-conforming, bulky, costly and heavy. This means they do not fit well to complex geometries, they can be susceptible to damage, and on larger structures their cost and weight can be prohibitive. An alternative to this is the use of piezo-electric thick films, which comprise of piezo-electric particles suspended in a matrix material. Such materials could provide "paint on" or "printable" sensors and sensor networks that are low profile, easy to mount and very cheap. In this work we explore the potential of piezo-electric thick films to sense and actuate for Acoustic Emission and ultrasonic applications. Sensors were produced by dispersing PZT 5a particles within water based acrylic and epoxy matrix materials with up to 70% fill by weight. The PZT films were applied to steel and their responses to artificial AE sources (Hsu-Nielson) were assessed and three-dimensional laser vibrometry was used to study the frequency response and mode shapes of the sensors under excitation. The results showed that although less sensitive than monolithic piezoelectric transducers, the thick film sensors can excite and detect ultrasonic waves for SHM applications and there is great potential for the development of a low cost, printed sensor network for SHM
Drivers of the changing abundance of European birds at two spatial scales
Detecting biodiversity change and identifying its causes is challenging because biodiversity is multifaceted and temporal data often contain bias. Here, we model temporal change in species' abundance and biomass by using extensive data describing the population sizes and trends of native breeding birds in the United Kingdom (UK) and the European Union (EU). In addition, we explore how species’ population trends vary with species’ traits. We demonstrate significant change in the bird assemblages of the UK and EU, with substantial reductions in overall bird abundance and losses concentrated in a relatively small number of abundant and smaller sized species. In contrast, rarer and larger birds had generally fared better. Simultaneously, overall avian biomass had increased very slightly in the UK and was stable in the EU, indicating a change in community structure. Abundance trends across species were positively correlated with species’ body mass and with trends in climate suitability, and varied with species’ abundance, migration strategy, and niche associations linked to diet. Our work highlights how changes in biodiversity cannot be captured easily by a single number; care is required when measuring and interpreting biodiversity change given that different metrics can provide very different insight
Developing and enhancing biodiversity monitoring programmes: a collaborative assessment of priorities
1.Biodiversity is changing at unprecedented rates, and it is increasingly important that these changes are quantified through monitoring programmes. Previous recommendations for developing or enhancing these programmes focus either on the end goals, that is the intended use of the data, or on how these goals are achieved, for example through volunteer involvement in citizen science, but not both. These recommendations are rarely prioritized.
2.We used a collaborative approach, involving 52 experts in biodiversity monitoring in the UK, to develop a list of attributes of relevance to any biodiversity monitoring programme and to order these attributes by their priority. We also ranked the attributes according to their importance in monitoring biodiversity in the UK. Experts involved included data users, funders, programme organizers and participants in data collection. They covered expertise in a wide range of taxa.
3.We developed a final list of 25 attributes of biodiversity monitoring schemes, ordered from the most elemental (those essential for monitoring schemes; e.g. articulate the objectives and gain sufficient participants) to the most aspirational (e.g. electronic data capture in the field, reporting change annually). This ordered list is a practical framework which can be used to support the development of monitoring programmes.
4.People's ranking of attributes revealed a difference between those who considered attributes with benefits to end users to be most important (e.g. people from governmental organizations) and those who considered attributes with greatest benefit to participants to be most important (e.g. people involved with volunteer biological recording schemes). This reveals a distinction between focussing on aims and the pragmatism in achieving those aims.
5.Synthesis and applications. The ordered list of attributes developed in this study will assist in prioritizing resources to develop biodiversity monitoring programmes (including citizen science). The potential conflict between end users of data and participants in data collection that we discovered should be addressed by involving the diversity of stakeholders at all stages of programme development. This will maximize the chance of successfully achieving the goals of biodiversity monitoring programmes
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