860 resultados para Wakefield, DIck


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Camera traps are used to estimate densities or abundances using capture-recapture and, more recently, random encounter models (REMs). We deploy REMs to describe an invasive-native species replacement process, and to demonstrate their wider application beyond abundance estimation. The Irish hare Lepus timidus hibernicus is a high priority endemic of conservation concern. It is threatened by an expanding population of non-native, European hares L. europaeus, an invasive species of global importance. Camera traps were deployed in thirteen 1 km squares, wherein the ratio of invader to native densities were corroborated by night-driven line transect distance sampling throughout the study area of 1652 km2. Spatial patterns of invasive and native densities between the invader’s core and peripheral ranges, and native allopatry, were comparable between methods. Native densities in the peripheral range were comparable to those in native allopatry using REM, or marginally depressed using Distance Sampling. Numbers of the invader were substantially higher than the native in the core range, irrespective of method, with a 5:1 invader-to-native ratio indicating species replacement. We also describe a post hoc optimization protocol for REM which will inform subsequent (re-)surveys, allowing survey effort (camera hours) to be reduced by up to 57% without compromising the width of confidence intervals associated with density estimates. This approach will form the basis of a more cost-effective means of surveillance and monitoring for both the endemic and invasive species. The European hare undoubtedly represents a significant threat to the endemic Irish hare.

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Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs) of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in “100 of the World's Worst Invasive Alien Species”; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest “attack rates” a, shortest “handling times” h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach.

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Parasites have a variety of behavioural effects on their hosts, which can in turn affect species with which the host interacts. Here we review how these trait-mediated indirect effects of parasites can alter the outcomes of invader-native interactions, illustrating with examples from the literature and with particular regard to the invader-native crustacean systems studied in our laboratories. Parasites may potentially inhibit or exacerbate invasions via their effects on host behaviour, in addition to their direct virulence effects on hosts. In several crustacean systems, we have found that parasites influence both host predation rates on intra- and inter-guild prey and host vulnerability to being preyed upon. These trait effects can theoretically alter invasion impact and patterns of coexistence, as they indirectly affect interactions between predators and prey with the potential for further ramifications to other species in the food web. The fitness consequences of parasite-induced trait-mediated effects are rarely considered in traditional parasitological contexts, but demand attention in the context of ecological communities. We can regard these trait effects as a form of cryptic virulence that only becomes apparent when hosts are examined in the context of the other species with which they interact.

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X-ray backscatter imaging can be used for a wide range of imaging applications, in particular for industrial inspection and portal security. Currently, the application of this imaging technique to the detection of landmines is limited due to the surrounding sand or soil strongly attenuating the 10s to 100s of keV X-rays required for backscatter imaging. Here, we introduce a new approach involving a 140 MeV short-pulse (< 100 fs) electron beam generated by laser wakefield acceleration to probe the sample, which produces Bremsstrahlung X-rays within the sample enabling greater depths to be imaged. A variety of detector and scintillator configurations are examined, with the best time response seen from an absorptive coated BaF2 scintillator with a bandpass filter to remove the slow scintillation emission components. An X-ray backscatter image of an array of different density and atomic number items is demonstrated. The use of a compact laser wakefield accelerator to generate the electron source, combined with the rapid development of more compact, efficient and higher repetition rate high power laser systems will make this system feasible for applications in the field.

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Information and collated statistical analysis on the decline of red squirrels.

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Adult sex ratio (ASR) has critical effects on behavior and life history and has implications for population demography, including the invasiveness of introduced species. ASR exhibits immense variation in nature, yet the scale dependence of this variation is rarely analyzed. In this study, using the generalized multilevel models, we investigated the variation in ASR across multiple nested spatial scales and analyzed the underlying causes for an invasive species, the golden apple snail Pomacea canaliculata. We partitioned the variance in ASR to describe the variations at different scales and then included the explanatory variables at the individual and group levels to analyze the potential causes driving the variation in ASR. We firstly determined there is a significant female-biased ASR for this species when accounting for the spatial and temporal autocorrelations of sampling. We found that, counter to nearly equal distributed variation at plot, habitat and region levels, ASR showed little variation at the town level. Temperature and precipitation at the region level were significantly positively associated with ASR, whereas the individual weight, the density characteristic, and sampling time were not significant factors influencing ASR. Our study suggests that offspring sex ratio of this species may shape the general pattern of ASR in the population level while the environmental variables at the region level translate the unbiased offspring sex ratio to the female-biased ASR. Future research should consider the implications of climate warming on the female-biased ASR of this invasive species and thus on invasion pattern.

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Morphological changes in the retinal vascular network are associated with future risk of many systemic and vascular diseases. However, uncertainty over the presence and nature of some of these associations exists. Analysis of data from large population based studies will help to resolve these uncertainties. The QUARTZ (QUantitative Analysis of Retinal vessel Topology and siZe) retinal image analysis system allows automated processing of large numbers of retinal images. However, an image quality assessment module is needed to achieve full automation. In this paper, we propose such an algorithm, which uses the segmented vessel map to determine the suitability of retinal images for use in the creation of vessel morphometric data suitable for epidemiological studies. This includes an effective 3-dimensional feature set and support vector machine classification. A random subset of 800 retinal images from UK Biobank (a large prospective study of 500,000 middle aged adults; where 68,151 underwent retinal imaging) was used to examine the performance of the image quality algorithm. The algorithm achieved a sensitivity of 95.33% and a specificity of 91.13% for the detection of inadequate images. The strong performance of this image quality algorithm will make rapid automated analysis of vascular morphometry feasible on the entire UK Biobank dataset (and other large retinal datasets), with minimal operator involvement, and at low cost.

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O presente trabalho tem como objectivo estudar as práticas de crossover entre as técnicas vocais que os cantores líricos e de teatro musical utilizam, assim como as técnicas vocais subjacentes às referidas práticas. Descrevem-se as técnicas vocais utilizadas no canto lírico e no teatro musical por pedagogos que fundamentam o seu trabalho com as descobertas da investigação na área da voz, e comparam-se as referidas técnicas para entender quais os pontos comuns e quais os pontos divergentes. Devido à elevada percentagem de pontos comuns às duas técnicas concluiu-se que são muito próximas entre si, o que faz sentido por serem executadas pela mesma estrutura fisiológica. Apresentam-se as entrevistas efectuadas a cantores profissionais de canto lírico e de teatro musical sobre os aspectos fundamentais das técnicas vocais que utilizam e como fazem o crossover entre as mesmas. Dos resultados dos inquéritos concluiu-se que a maioria dos cantores utiliza habitualmente práticas de crossover na sua performance. A segunda conclusão retirada dos resultados do inquérito foi que a execução das referidas práticas é intuitiva na maioria dos casos, e não conscientemente efectuada. Apresenta-se um caso de aplicação em contexto performativo das práticas de crossover: o papel do soprano na cantata cénica "Moby Dick - Aos Peixes". A utilização tecnicamente consciente das práticas de crossover permitiu estabilizar a execução vocal desde o início dos ensaios e obter posteriormente uma performance consistente mas versátil, sem fixar a execução vocal ao longo da carreira do espectáculo. Os apêndices incluem informação anatomofisiológica útil para este estudo, um resumo dos métodos de estudo científico da voz, o questionário utilizado no inquérito, as tabelas dos dados obtidos, a partitura anotada de "Aos Peixes" e o DVD do espectáculo realizado no Centro Cultural de Belém, em Lisboa. ABSTRACT: The present work aims to understand the crossover mecanisms that the classical singers and the musical theatre singers use, and the vocal techniques underlying those practices. This work describes the vocal techniques taught in the lyrical singing and in the musical theatre singing by teachers who base their pedagogy on the findings of scientific investigation of voice and singing. The techniques used in both fields are compared to understand their similarities and diferences. This process led to the conclusion that both techniques are very close, due to the high percentage of common items found, and this makes sense since both techniques are produced by the same physiologic struture: the vocal system. Professional singers from the lyrical and the musical theatre scene were interviewed to explain the basic foundations of their vocal technique and how do they do the crossover between those styles, from a technical point of view. The results of these interviews led to the conclusion that the majority of the singers performs crossover actions in their singing. The second conclusion is that for the majority of singers these crossover actions are intuitive, inspired by the music, the text or the dramatic context, and not informed by technically conscious actions. It is presented a case study of how these crossover methods were used in a staged cantata: the soprano role in "Moby Dick - Aos Peixes". The use of conscious technically informed crossover practice allowed to stabilize the vocal execution right from the beginning of rehearsals and obtain afterwards a performance which was both consistent and versatile, not fixed, during the running of the show. The appendixes include useful anatomical and physiological information, a summary of the methods of the scientific study of voice, the formulary used in the enquiry, the data tables of the field work, the annotated score of "Moby Dick - Aos Peixes" and the DVD from the play filmed at Centro Cultural de Belém, in Lisbon.

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Concert program for Stravinsky Festival, May 10, 1972

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Concert program for A Student Composers' Recital, May 7, 1959

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Este trabalho é motivado por se verificar uma certa confusão sobre a grafia do topónimo em estudo. As diversas grafias do topónimo em estudo utilizadas em manuais escolares, em obras científicas e literárias, em placas toponímicas e em documentos oficiais da Administração Pública, constituem não só confusões toponímicas como também confusões topográficas. Entretanto, apresentamos este trabalho com a finalidade de propor uma medida de uniformização e normalização das diversas grafias utilizadas na administração pública (programa televisivo e radiofónico, jornais, conteúdo escolar, instituições públicas, etc) para se referenciar a região em estudo. Contudo, esta uniformização e normalização visa contribuir para a gestão de informação de qualidade na administração pública da região. O estudo toponímico em questão foi analisado em duas dimensões, histórica e linguística. Na dimensão histórica analisamos os aspectos históricos da região. Na dimensão linguística, analisamos a questão da estrutura morfológica do topónimo em estudo, a sua motivação semântica e a sua classificação toponímica de acordo Dick. Consideramos fundamentais para a análise do topónimo em estudo.

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Pictured here from left to right: Back Row - Les Korchok (Coach), Ken Cripps, Mike McGinnis, Bill Butler, Tim McKillop, Gary Jellum, Fred Kovacs (Manager). Front Row - Jim Leach, Wally Dick, Bob Tatti, Paul Zutautas, Tom Kearney (Trainer). Kneeling - Dave Luff, Dave Brent. Missing - Bill Levesque.