173 research outputs found

    Low Loss and Highly Birefringent Hollow-Core Photonic Crystal Fiber

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    Lifespan extension and the doctrine of double effect

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    Recent developments in biogerontology—the study of the biology of ageing—suggest that it may eventually be possible to intervene in the human ageing process. This, in turn, offers the prospect of significantly postponing the onset of age-related diseases. The biogerontological project, however, has met with strong resistance, especially by deontologists. They consider the act of intervening in the ageing process impermissible on the grounds that it would (most probably) bring about an extended maximum lifespan—a state of affairs that they deem intrinsically bad. In a bid to convince their deontological opponents of the permissibility of this act, proponents of biogerontology invoke an argument which is grounded in the doctrine of double effect. Surprisingly, their argument, which we refer to as the ‘double effect argument’, has gone unnoticed. This article exposes and critically evaluates this ‘double effect argument’. To this end, we first review a series of excerpts from the ethical debate on biogerontology in order to substantiate the presence of double effect reasoning. Next, we attempt to determine the role that the ‘double effect argument’ is meant to fulfil within this debate. Finally, we assess whether the act of intervening in ageing actually can be justified using double effect reasoning

    Management of Acute Traumatic Central Cord Syndrome: A Narrative Review.

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    Study Design Narrative review. Objectives To provide an updated overview of the management of acute traumatic central cord syndrome (ATCCS). Methods A comprehensive narrative review of the literature was done to identify evidence-based treatment strategies for patients diagnosed with ATCCS. Results ATCCS is the most commonly encountered subtype of incomplete spinal cord injury and is characterized by worse sensory and motor function in the upper extremities compared with the lower extremities. It is most commonly seen in the setting of trauma such as motor vehicles or falls in elderly patients. The operative management of this injury has been historically variable as it can be seen in the setting of mechanical instability or preexisting cervical stenosis alone. While each patient should be evaluated on an individual basis, based on the current literature, the authors' preferred treatment is to perform early decompression and stabilization in patients that have any instability or significant neurologic deficit. Surgical intervention, in the appropriate patient, is associated with an earlier improvement in neurologic status, shorter hospital stay, and shorter intensive care unit stay. Conclusions While there is limited evidence regarding management of ATCCS, in the presence of mechanical instability or ongoing cord compression, surgical management is the treatment of choice. Further research needs to be conducted regarding treatment strategies and patient outcomes

    Light and gas confinement in hollow-core photonic crystal fibre based photonic microcells

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    We review the recent progress on the understanding of optical guidance mechanisms in hollow-core photonic crystal fibres, and on the quantum and nonlinear optical applications of photonic microcells based on this fibre form. Two classes of hollow-core photonic crystal fibre are identified: one guides via a photonic bandgap and the other guides by virtue of an inhibited coupling between core and cladding mode constituents. For the former fibre type, we explore how the bandgap is formed using a photonic analogue of the tight-binding model and how it is related to the anti-resonant reflection optical waveguide guidance. For the second type of fibre, which can guide over a broad wavelength range, we examine the nature of the inhibited coupling. We describe a technique for the fabrication of photonic microcells that can accommodate vacuum pressures, and we finish by showing the latest results on electromagnetically induced transparency in a rubidium filled hollow-core photonic crystal fibre, the CW-pumped hydrogen Raman laser and the generation of multi-octave spanning stimulated Raman scattering spectral combs

    Is facet joint distraction a cause of postoperative axial neck pain after ACDF surgery?

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    Introduction: Intervertebral distraction in anterior cervical discectomy and fusion (ACDF) has been postulated to injure the degenerative facet joints posteriorly and increase postoperative pain and disability. This study aims to determine if there is a correlation between the amount of facet distraction and postoperative patient reported outcomes. Methods: A retrospective cohort analysis of patients undergoing ACDF for degenerative pathologies was performed. Each patient received lateral cervical spine x-rays at the immediate postoperative time point and were split into groups based on the amount of facet distraction measured on these films: Group A: \u3c 1.5 mm; Group B: 1.5-2.0 mm; and Group C: \u3e 2.0 mm. Patients reported outcome measures were obtained preoperatively and at 1-year postoperatively. Univariate and multivariate analyses were performed to compare outcomes between groups. Results: A total of 229 patients were included with an average follow-up of 19.8 [19.0, 20.7] months with a mean facet joint distraction of 1.7mm. There were 87 patients in Group A, 76 patients in Group B, and 66 patients in Group C. Patients significantly improved across all outcome measures from baseline to postoperatively (p \u3c 0.05). There was no difference between groups at any time point with respect to outcome scores (p \u3e 0.05). Multiple regression analysis did not identify increasing distraction as a predictor of patient outcomes. Conclusions: There were no significant differences between patient outcomes and the amount of facet distraction after ACDF surgery. Multivariate analysis did not find a correlation between facet distraction and overall HRQOL outcome

    BABAR: an R package to simplify the normalisation of common reference design microarray-based transcriptomic datasets

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    Background: The development of DNA microarrays has facilitated the generation of hundreds of thousands of transcriptomic datasets. The use of a common reference microarray design allows existing transcriptomic data to be readily compared and re-analysed in the light of new data, and the combination of this design with large datasets is ideal for 'systems' level analyses. One issue is that these datasets are typically collected over many years and may be heterogeneous in nature, containing different microarray file formats and gene array layouts, dye-swaps, and showing varying scales of log(2)- ratios of expression between microarrays. Excellent software exists for the normalisation and analysis of microarray data but many data have yet to be analysed as existing methods struggle with heterogeneous datasets; options include normalising microarrays on an individual or experimental group basis. Our solution was to develop the Batch Anti-Banana Algorithm in R (BABAR) algorithm and software package which uses cyclic loess to normalise across the complete dataset. We have already used BABAR to analyse the function of Salmonella genes involved in the process of infection of mammalian cells. Results: The only input required by BABAR is unprocessed GenePix or BlueFuse microarray data files. BABAR provides a combination of 'within' and 'between' microarray normalisation steps and diagnostic boxplots. When applied to a real heterogeneous dataset, BABAR normalised the dataset to produce a comparable scaling between the microarrays, with the microarray data in excellent agreement with RT-PCR analysis. When applied to a real non-heterogeneous dataset and a simulated dataset, BABAR's performance in identifying differentially expressed genes showed some benefits over standard techniques. Conclusions: BABAR is an easy-to-use software tool, simplifying the simultaneous normalisation of heterogeneous two-colour common reference design cDNA microarray-based transcriptomic datasets. We show BABAR transforms real and simulated datasets to allow for the correct interpretation of these data, and is the ideal tool to facilitate the identification of differentially expressed genes or network inference analysis from transcriptomic datasets

    The Emergence and Development of Association Football: Influential Sociocultural Factors in Victorian Birmingham

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    This article explores the interdependent, complex sociocultural factors that facilitated the emergence and diffusion of football in Birmingham. The focus is the development of football in the city, against the backdrop of the numerous social changes in Victorian Birmingham. The aim is to fill a gap in the existing literature which seemingly overlooked Birmingham as a significant footballing centre, and the ‘ordinary and everyday’ aspects of the game’s early progression. Among other aspects, particular heed is paid to the working classes’ involvement in football, as previous literature has often focused on the middle classes and their influence on and participation in organized sport. As the agency of the working classes along with their mass participation and central role in the game’s development is unfolded, it is argued that far from being passive cultural beings, the working classes, from the beginnings, actively negotiated the development of their own emergent football culture

    Christianity as Public Religion::A Justification for using a Christian Sociological Approach for Studying the Social Scientific Aspects of Sport

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    The vast majority of social scientific studies of sport have been secular in nature and/or have tended to ignore the importance of studying the religious aspects of sport. In light of this, Shilling and Mellor (2014) have sought to encourage sociologists of sport not to divorce the ‘religious’ and the ‘sacred’ from their studies. In response to this call, the goal of the current essay is to explore how the conception of Christianity as ‘public religion’ can be utilised to help justify the use of a Christian sociological approach for studying the social scientific aspects of sport. After making a case for Christianity as public religion, we conclude that many of the sociological issues inherent in modern sport are an indirect result of its increasing secularisation and argue that this justifies the need for a Christian sociological approach. We encourage researchers to use the Bible, the tools of Christian theology and sociological concepts together, so to inform analyses of modern sport from a Christian perspective

    Diversity Effects on Productivity Are Stronger within than between Trophic Groups in the Arbuscular Mycorrhizal Symbiosis

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    The diversity of plants and arbuscular mycorrhizal fungi (AMF) has been experimentally shown to alter plant and AMF productivity. However, little is known about how plant and AMF diversity interact to shape their respective productivity.We co-manipulated the diversity of both AMF and plant communities in two greenhouse studies to determine whether the productivity of each trophic group is mainly influenced by plant or AMF diversity, respectively, and whether there is any interaction between plant and fungal diversity. In both experiments we compared the productivity of three different plant species monocultures, or their respective 3-species mixtures. Similarly, in both studies these plant treatments were crossed with an AMF diversity gradient that ranged from zero (non-mycorrhizal controls) to a maximum of three and five taxonomically distinct AMF taxa, respectively. We found that within both trophic groups productivity was significantly influenced by taxon identity, and increased with taxon richness. These main effects of AMF and plant diversity on their respective productivities did not depend on each other, even though we detected significant individual taxon effects across trophic groups.Our results indicate that similar ecological processes regulate diversity-productivity relationships within trophic groups. However, productivity-diversity relationships are not necessarily correlated across interacting trophic levels, leading to asymmetries and possible biotic feedbacks. Thus, biotic interactions within and across trophic groups should be considered in predictive models of community assembly
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