3,191 research outputs found

    Cuando la morfología y los marcadores moleculares entran en conflicto: el ejemplo de los anfípodos subterráneos de la región de Pilbara, Australia Occidental

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    Fifteen species of groundwater amphipods in the genus Chydaekata have been described from the Pilbara, Western Australia, each restricted to a single bore. Dewatering at a local mine site was halted while a second survey was undertaken. Newly collected samples were identified using the existing key, and allozyme analysis was used to test species boundaries. Allozymic diversity was not associated with single bores, and only two distinct genetic groups (one of which was very rare), were identified. Based on these results, and the finding that species were found to be more widespread, the Western Australian Environmental Protection Authority recommended that dewatering continue with caution at the site. This study provides an example of the problems associated with incongruent data sets, and the difficulties inherent in working with rare species, namely, interpreting the results of studies based on small samples or incomplete collections.Se han descrito quince especies de anfípodos de aguas subterráneas del género Chydaekata que habitan en la región de Pilbara, Australia Occidental, restringiéndose cada una de ellas a una única perforación. Mientras se elaboraba un segundo estudio, se interrumpió el desagüe que se estaba llevando a cabo en un emplazamiento minero local. Las nuevas muestras recolectadas se identificaron utilizando la clave existente, mientras que para verificar los límites de la especie se recurrió a un análisis alozimático. La diversidad alozimática no se asoció con perforaciones únicas y sólo se identificaron dos grupos genéticos bien diferenciados (uno de los cuales era muy poco común). Basándose en estos resultados y en el hallazgo de que la especie estaba más extendida, el Organismo de Protección Medioambiental de Australia Occidental recomendó que se actuara con cautela al proceder con el desagüe. El presente estudio brinda un ejemplo de los problemas asociados con conjuntos de datos incongruentes, así como las dificultades que conlleva trabajar con especies poco comunes, especialmente en lo que respecta a la interpretación de los resultados de estudios basados en pequeñas muestras o recolecciones incompletas

    Exploring maintenance of physical activity behaviour change among people living with and beyond gastrointestinal cancer: a cross-sectional qualitative study and typology

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    Objectives: In the last decade, there has been a rapid expansion of physical activity (PA) promotion programmes and interventions targeting people living with and beyond cancer (LWBC). The impact that these initiatives have on long-term maintenance of PA remains under-researched. This study sought to explore the experiences of participants in order to characterise those who have and have not successfully sustained increases in PA following participation in a PA intervention after a diagnosis of gastrointestinal (GI) cancer, and identify barriers and facilitators of this behaviour. / Design: Cross-sectional qualitative study. Semi-structured interviews with participants who had previously taken part in a PA programme in the UK, explored current and past PA behaviour and factors that promoted or inhibited regular PA participation. Interviews were audio-recorded, transcribed verbatim and analysed using thematic analysis. Themes and subthemes were identified. Differences between individuals were recognised and a typology of PA engagement was developed. / Participants: Twenty-seven individuals (n=15 male, mean age=66.3 years) with a diagnosis of GI cancer who had participated in one of four interventions designed to encourage PA participation. / Setting: UK. / Results: Seven themes were identified: disease processes, the role of ageing, emotion and psychological well-being, incorporating PA into everyday life, social interaction, support and self-monitoring and competing demands. A typology with three types describing long-term PA engagement was generated: (1) maintained PA, (2) intermittent PA, (3) low activity. Findings indicate that identifying an enjoyable activity that is appropriate to an individual’s level of physical functioning and is highly valued is key to supporting long-term PA engagement. / Conclusion: The typology described here can be used to guide stratified and personalised intervention development and support sustained PA engagement by people LWBC

    On hydrogen bond correlations at high pressures

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    In situ high pressure neutron diffraction measured lengths of O H and H O pairs in hydrogen bonds in substances are shown to follow the correlation between them established from 0.1 MPa data on different chemical compounds. In particular, the conclusion by Nelmes et al that their high pressure data on ice VIII differ from it is not supported. For compounds in which the O H stretching frequencies red shift under pressure, it is shown that wherever structural data is available, they follow the stretching frequency versus H O (or O O) distance correlation. For compounds displaying blue shifts with pressure an analogy appears to exist with improper hydrogen bonds.Comment: 12 pages,4 figure

    Direct slicing of STEP based NURBS models for layered manufacturing

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    Abstract Direct slicing of CAD models to generate process planning instructions for solid freeform fabrication may overcome inherent disadvantages of using stereolithography format in terms of the process accuracy, ease of file management, and incorporation of multiple materials. This paper will present the results of our development of a direct slicing algorithm for layered freeform fabrication. The direct slicing algorithm was based on a neutral, international standard (ISO 10303) STEP-formatted non-uniform rational B-spline (NURBS) geometric representation and is intended to be independent of any commercial CAD software. The following aspects of the development effort will be presented: (1) determination of optimal build direction based upon STEP-based NURBS models; (2) adaptive subdivision of NURBS data for geometric refinement; and (3) ray-casting slice generation into sets of raster patterns. The development also provides for multi-material slicing and will provide an effective tool in heterogeneous slicing processes.

    An adaptogenic role for omega-3 fatty acids in stress; a randomised placebo controlled double blind intervention study (pilot) [ISRCTN22569553]

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    BACKGROUND: There is evidence for an adaptive role of the omega -3 fatty acid, docosahexaenoic acid (DHA) during stress. Mechanisms of action may involve regulation of stress mediators, such as the catecholamines and proinflammatory cytokines. Prevention of stress-induced aggression and hostility were demonstrated in a series of clinical trials. This study investigates whether perceived stress is ameliorated by DHA in stressed university staff. METHODS: Subjects that scored ≥ 17 on the Perceived Stress Scale were randomised into a 6-week pilot intervention study. The diet reactive group was supplemented with 6 g of fish oil containing 1.5 g per day DHA, while the placebo group was supplemented with 6 g a day of olive oil. The groups were compared with each other and a wider cross sectional study population that did not receive either active or placebo intervention. RESULTS: There was a significant reduction in perceived stress in both the fish oil and the placebo group from baseline. There was also a significant between-group difference between the fish oil group and the no-treatment controls in the rate of stress reduction (p < 0.05). However, there was not a significant between-group difference between the fish oil and the placebo group, nor the placebo group and the control group. These results are discussed in the context of several methodological limitations. The significant stress reductions in both the fish oil and the placebo group are considered in view of statistical regression, an effect likely to have been exaggerated by the time course of the study, a large placebo effect and the possibility of an active effect from the placebo. CONCLUSION: There were significant differences (p < 0.05) in the fish oil group compared with no-treatment controls. This effect was not demonstrated in the placebo group. As a pilot study, it was not sufficiently powered to find the difference between the fish oil group and the placebo group significant. Further work needs to be undertaken to conclusively demonstrate these data trends. However, the findings from this research support the literature in finding a protective or 'adaptogenic' role for omega-3 fatty acids in stress

    'Who do "they" cheer for?' Cricket, diaspora, hybridity and divided loyalties amongst British Asians

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    This article explores the relationship between British Asians' sense of nationhood, citizenship, ethnicity and some of their manifestations in relation to sports fandom: specifically in terms of how cricket is used as a means of articulating diasporic British Asian identities. Norman Tebbit's 'cricket test' is at the forefront of this article to tease out the complexities of being British Asian in terms of supporting the English national cricket team. The first part of the article locates Tebbit's 'cricket test' within the wider discourse of multiculturalism. The analysis then moves to focus on the discourse of sports fandom and the concept of 'home team advantage' arguing that sports venues represent significant sites for nationalist and cultural expression due to their connection with national history. The article highlights how supporting 'Anyone but England', thereby rejecting ethnically exclusive notions of 'Englishness' and 'Britishness', continues to be a definer of British Asians' cultural identities. The final section situates these trends within the discourse of hybridity and argues that sporting allegiances are often separate from considerations of national identity and citizenship. Rather than placing British Asians in an either/or situation, viewing British 'Asianness' in hybrid terms enables them to celebrate their traditions and histories, whilst also being proud of their British citizenship. © The Author(s) 2011

    Parsec Scale Properties of Markarian 501

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    We present the results of a high angular resolution study of the BL Lac object Markarian 501 in the radio band. We consider data taken at 14 different epochs, ranging between 1.6 GHz and 22 GHz in frequency, and including new Space VLBI observations obtained on 2001 March 5 and 6 at 1.6 and 5 GHz. We study the kinematics of the parsec-scale jet and estimate its bulk velocity and orientation with respect to the line of sight. Limb brightened structure in the jet is clearly visible in our data and we discuss its possible origin in terms of velocity gradients in the jet. Quasi-simultaneous multi-wavelength observations allow us to map the spectral index distribution and to compare it to the jet morphology. Finally, we estimate the physical parameters of the parsec-scale jet.Comment: accepted for publication in ApJ; 24 pages with 17 figures (fig. 1 and fig. 2 available only as .jpg files

    The purpose of mess in action research: building rigour though a messy turn

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    Mess and rigour might appear to be strange bedfellows. This paper argues that the purpose of mess is to facilitate a turn towards new constructions of knowing that lead to transformation in practice (an action turn). Engaging in action research - research that can disturb both individual and communally held notions of knowledge for practice - will be messy. Investigations into the 'messy area', the interface between the known and the nearly known, between knowledge in use and tacit knowledge as yet to be useful, reveal the 'messy area' as a vital element for seeing, disrupting, analysing, learning, knowing and changing. It is the place where long-held views shaped by professional knowledge, practical judgement, experience and intuition are seen through other lenses. It is here that reframing takes place and new knowing, which has both theoretical and practical significance, arises: a 'messy turn' takes place

    The effect of adherence to spectacle wear on early developing literacy: a longitudinal study based in a large multi-ethnic city, Bradford, UK

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    YesObjectives: To determine the impact of adherence to spectacle wear on visual acuity (VA) and developing literacy following vision screening at age 4–5 years. Design: Longitudinal study nested within the Born in Bradford birth cohort. Setting and participants: Observation of 944 children: 432 had failed vision screening and were referred (treatment group) and 512 randomly selected (comparison group) who had passed (<0.20 logarithm of the minimum angle of resolution (logMAR) in both eyes). Spectacle wear was observed in school for 2 years following screening and classified as adherent (wearing spectacles at each assessment) or non-adherent. Main outcome measures: Annual measures of VA using a crowded logMAR test. Literacy was measured by Woodcock Reading Mastery Tests-Revised subtest: letter identification. Results: The VA of all children improved with increasing age, −0.009 log units per month (95% CI −0.011 to −0.007) (worse eye). The VA of the adherent group improved significantly more than the comparison group, by an additional −0.008 log units per month (95% CI −0.009 to −0.007) (worse eye) and −0.004 log units per month (95% CI −0.005 to −0.003) in the better eye. Literacy was associated with the VA, letter identification (ID) reduced by −0.9 (95% CI −1.15 to −0.64) for every one line (0.10 logMAR) fall in VA (better eye). This association remained after adjustment for socioeconomic and demographic factors (−0.33, 95% CI −0.54 to −0.12). The adherent group consistently demonstrated higher letter-ID scores compared with the non-adherent group, with the greatest effect size (0.11) in year 3. Conclusions: Early literacy is associated with the level of VA; children who adhere to spectacle wear improve their VA and also have the potential to improve literacy. Our results suggest failure to adhere to spectacle wear has implications for the child’s vision and education.AB is funded by a National Institute for Health Research Post- Doctoral Fellowship Award (PDF-2013-06-050). The Born in Bradford study presents independent research commissioned by the National Institute for Health Research Collaboration for Applied Health Research and Care (NIHR CLAHRC) and the Programme Grants for Applied Research funding scheme (RP-PG-0407-10044)
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