733 research outputs found

    The 1996 U.S. Purse Seine Fishery for Tropical Tunas in the Central-Western Pacific Ocean

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    The U.S. tropical tuna purse seine fleet has fished the central-western Pacific Ocean under the South Pacific Tuna Treaty since 1988. The 1996 fishery was the poorest since the start ofthe Treaty. Fishing effort declined due to the financial collapse of a large fishing enterprise. Catches reached record lows for yellowfin tuna, Thunnus albacares, and skipjack tuna, Katsuwonus pelamis, and continued a declining trend that started in 1995. Catch rates also decreased to the lowest levels since 1991. Whether this declining trend in catch rates is due to reduced availability of fish caused by cyclic ocean environmental changes affecting vulnerability or to reduced abundance from excessive fishing pressure is not yet known and needs to be assessed

    Gaussian Process Kernels for Pattern Discovery and Extrapolation

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    Gaussian processes are rich distributions over functions, which provide a Bayesian nonparametric approach to smoothing and interpolation. We introduce simple closed form kernels that can be used with Gaussian processes to discover patterns and enable extrapolation. These kernels are derived by modeling a spectral density – the Fourier transform of a kernel – with a Gaussian mixture. The proposed kernels support a broad class of stationary covariances, but Gaussian process inference remains simple and analytic. We demonstrate the proposed kernels by discovering patterns and performing long range extrapolation on synthetic examples, as well as atmospheric CO2 trends and airline passenger data. We also show that it is possible to reconstruct several popular standard covariances within our framework.Engineering and Applied Science

    Students as Educators

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    The aim of this study was to evaluate peer assisted learning (PAL) in a pharmacy course context. PAL is interesting for educationalists as the technique offers reciprocity in learning between the student tutor and the student tutee. Both student tutor and student tutee have the ability to learn through the process. 14 students volunteered to be student tutors on a first year pharmacy practice module. The results are discussed from the perspective of both the student tutee and tutor. Although a small pilot study, the results from this project echo the themes of perceived benefits identified in the literature on PAL, most obviously with the three themes of confidence, collaboration, and learning. Challenges to the process are also discussed

    Students' Attitudes Towards Facebook and Online Professionalism: Subject Discipline, Age and Gender Differences.

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    The aim of this study was to investigate the attitudes towards the use of Facebook and online professionalism among students studying three health and social care courses at a UK university. The increasing popularity of social networking sites (SNS) has changed the way people manage information about their personal and professional lives. Previous studies have considered how medical students use Facebook, but there is a paucity of research looking at other professional disciplines; either individually or exploring whether there are inter-professional differences. An anonymous online survey was completed by 595 students at one UK university; pharmacy (n = 91, 15%), social work(n = 166, 28%) and nursing students (n = 338, 57%)across all years of the courses. Significant differences were found with regard to attitudes towards Facebook and online professionalism between the subject disciplines, year of study, age and gender of the students. Findings suggest more education and guidance is needed to provide students with the appropriate knowledge of how to maintain professionalism in an online context

    A Dynamic Comparative Advantage Analysis of Fresh Fruit and Vegetable Trade Between Latin America and the United States

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    In the first of three related papers, the authors analyze the dynamic pattern of comparative advantage in fruit and vegetable trade flows between the United States and Latin America. Their examination of several factors--including market demand, improving investment climates, technological advances, and trade liberalization--indicates a significant potential for the development and expansion of trade flows to meet open windows of opportunity in the United States

    Recruitment to publicly funded trials - are surgical trials really different?

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    Good recruitment is integral to the conduct of a high-quality randomised controlled trial. It has been suggested that recruitment is particularly difficult for evaluations of surgical interventions, a field in which there is a dearth of evidence from randomised comparisons. While there is anecdotal speculation to support the inference that recruitment to surgical trials is more challenging than for medical trials we are unaware of any formal assessment of this. In this paper, we compare recruitment to surgical and medical trials using a cohort of publicly funded trials. Data: Overall recruitment to trials was assessed using of a cohort of publicly funded trials (n = 114). Comparisons were made by using the Recruitment Index, a simple measure of recruitment activity for multicentre randomised controlled trials. Recruitment at the centre level was also investigated through three example surgical trials. Results: The Recruitment Index was found to be higher, though not statistically significantly, in the surgical group (n = 18, median = 38.0 IQR (10.7, 77.4)) versus (n = 81, median = 34.8 IQR (11.7, 98.0)) days per recruit for the medical group (median difference 1.7 (− 19.2, 25.1); p = 0.828). For the trials where the comparison was between a surgical and a medical intervention, the Recruitment Index was substantially higher (n = 6, 68.3 (23.5, 294.8)) versus (n = 93, 34.6 (11.7, 90.0); median difference 25.9 (− 35.5, 221.8); p = 0.291) for the other trials. Conclusions: There was no clear evidence that surgical trials differ from medical trials in terms of recruitment activity. There was, however, support for the inference that medical versus surgical trials are more difficult to recruit to. Formal exploration of the recruitment data through a modelling approach may go some way to tease out where important differences exist.The first author was supported by a Medical Research Council UK Fellowship.Peer reviewedAuthor versio

    Star-Forming or Starbursting? The Ultraviolet Conundrum

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    Compared to starburst galaxies, normal star forming galaxies have been shown to display a much larger dispersion of the dust attenuation at fixed reddening through studies of the IRX-beta diagram (the IR/UV ratio "IRX" versus the UV color "beta"). To investigate the causes of this larger dispersion and attempt to isolate second parameters, we have used GALEX UV, ground-based optical, and Spitzer infrared imaging of 8 nearby galaxies, and examined the properties of individual UV and 24 micron selected star forming regions. We concentrated on star-forming regions, in order to isolate simpler star formation histories than those that characterize whole galaxies. We find that 1) the dispersion is not correlated with the mean age of the stellar populations, 2) a range of dust geometries and dust extinction curves are the most likely causes for the observed dispersion in the IRX-beta diagram 3) together with some potential dilution of the most recent star-forming population by older unrelated bursts, at least in the case of star-forming regions within galaxies, 4) we also recover some general characteristics of the regions, including a tight positive correlation between the amount of dust attenuation and the metal content. Although generalizing our results to whole galaxies may not be immediate, the possibility of a range of dust extinction laws and geometries should be accounted for in the latter systems as well.Comment: 18 pages, 17 figures, accepted for publication in Ap

    Relationship between sociodemographic factors and specialty destination of UK trainee doctors:a national cohort study

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    We are grateful to UKMED for releasing the data for this project. We also are grateful to the following for their support of the application to UKMED for this and other research projects: Dr Sally Curtis (University of Southampton, UK), Dr Sandra Nicholson (Barts and The London School of Medicine and Dentistry, UK). We thank Daniel Smith and Andy Knapton of the General Medical Council of the UK for their support for the application and throughout the project, particularly regarding data linkage and troubleshooting.Peer reviewedPublisher PD
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