330 research outputs found

    Complex functions as lumps of energy

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    We present an application of the basic mathematical concept of complex functions as topological solitons, a most interesting area of research in physics. Such application of complex theory is virtually unknown outside the community of soliton researches.Comment: 8 pages, 1 figure. To appear in "Revista Mexicana de Fisica

    Anisotropic clustering of inertial particles in homogeneous shear flow

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    Recently, clustering of inertial particles in turbulence has been thoroughly analyzed for statistically homogeneous isotropic flows. Phenomenologically, spatial homogeneity of particles configurations is broken by the advection of a range of eddies determined by the Stokes relaxation time of the particles which results in a multi-scale distribution of local concentrations and voids. Much less is known concerning anisotropic flows. Here, by addressing direct numerical simulations (DNS) of a statistically steady particle-laden homogeneous shear flow, we provide evidence that the mean shear preferentially orients particle patterns. By imprinting anisotropy on large scales velocity fluctuations, the shear indirectly affects the geometry of the clusters. Quantitative evaluation is provided by a purposely designed tool, the angular distribution function of particle pairs (ADF), which allows to address the anisotropy content of particles aggregates on a scale by scale basis. The data provide evidence that, depending on the Stokes relaxation time of the particles, anisotropic clustering may occur even in the range of scales where the carrier phase velocity field is already recovering isotropy. The strength of the singularity in the anisotropic component of the ADF quantifies the level of fine scale anisotropy, which may even reach values of more than 30% direction-dependent variation in the probability to find two close-by particles at viscous scale separation.Comment: To appear in Journal Fluid Mechanics 200

    "Oh! What a tangled web we weave": Englishness, communicative leisure, identity work and the cultural web of the English folk morris dance scene

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    In this paper, we consider the relationship between Englishness and the English folk morris dance scene, considering how the latter draws from and reinforces the former. Englishness is considered within the context of the cultural web; a tool more often applied to business management but linked to a sociological viewpoint here. By doing so, we draw the connections between this structured business model and the cultural identity of Englishness. Then, we use the framework of the cultural web and theories of leisure, culture and identity to understand how morris dancers see their role as dancers and ‘communicative leisure’ agents in consciously defending Englishness, English traditions and inventions, the practices and traditions of folk and morris, and the various symbolic communities they inhabit. We argue that most morris dancers in our research become and maintain their leisured identities as dancers because they are attracted to the idea of tradition – even if that tradition is invented and open to change

    International criteria for electrocardiographic interpretation in athletes: Consensus statement.

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    Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly, advanced by a growing body of scientific data and investigations that both examine proposed criteria sets and establish new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington (USA), to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD

    Equivalences between localisations of categories provided by replacements

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    We give a characterisation of functors whose induced functor on the level of localisations is an equivalence and where the isomorphism inverse is induced by some kind of replacements such as projective resolutions or cofibrant replacements

    (Un)becoming women: Indian factory women's counternarratives of gender

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    This paper portrays the life stories of five factory workers in Delhi whose life trajectories run counter to normative femininity. As daughters and wives, they are neglected, abandoned or rejected by their families; they live alone, with their parents past the age that is their natal right, with siblings, or with families and men who are not related to them. I explore the circulation of their counternarratives and how their gender transgressions go public through ordinary forms of talk, such as gossip and rumor. I argue that their move out of the normative is not produced by, but produces, their gender politics; that their agency emerges cognitively from the telling of their stories in tandem with their interlocutors' credulity and uptake; and that the site of gender politics for working class Indian women lies in the informal subaltern publics that are formed by the circulation of their stories. Contrary to the notion of a stable unitary subject that precedes the political, these women's counternarratives demonstrate the subject‐in‐process as a political effect. Their alterity does not exist outside the heteronormative gender order but demarcates the boundaries of its historicity, hinting at both the internal contradictions of existing gender relations and their future possibilities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112196/1/j.1467-954X.2011.02026.x.pd

    Clinical Performance Status and Technical Factors Affecting Outcomes from Percutaneous Transhepatic Biliary Interventions; A Multicentre, Prospective, Observational Cohort Study.

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    Funder: British Society of Interventional RadiologyPURPOSE: The purpose of this study was to evaluate the predictive value of a 'Modified Karnofsky Scoring System' on outcomes and provide real-world data regarding the UK practice of biliary interventions. MATERIALS AND METHODS: A prospective multi-centred cohort study was performed. The pre-procedure modified Karnofsky score, the incidence of sepsis, complications, biochemical improvement and mortality were recorded out to 30 days post procedure. RESULTS: A total of 292 patients (248 with malignant lesions) were suitable for inclusion in the study. The overall 7 and 30 day mortality was 3.1% and 16.1%, respectively. The 30 day sepsis rate was 10.3%. In the modified Karnofsky 'high risk' group the 7 day mortality was 9.7% versus 0% for the 'low risk' group (p = 0.002), whereas the 30 day mortality was 28.8% versus 13.3% (p = 0.003). The incidence of sepsis at 30 days was 19% in the high risk group versus 3.3% at the low risk group (p = 0.001) CONCLUSION: Percutaneous biliary interventions in the UK are safe and effective. Scoring systems such as the Karnofsky or the modified Karnofsky score hold promise in allowing us to identify high risk groups that will need more careful consideration and enhanced patient informed consent but further research with larger studies is warranted in order to identify their true impact on patient selection and outcomes post biliary interventions

    Meta-analysis of individual-patient data from EVAR-1, DREAM, OVER and ACE trials comparing outcomes of endovascular or open repair for abdominal aortic aneurysm over 5 years

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    Background: The erosion of the early mortality advantage of elective endovascular aneurysm repair (EVAR) compared with open repair of abdominal aortic aneurysm remains without a satisfactory explanation. Methods: An individual-patient data meta-analysis of four multicentre randomized trials of EVAR versus open repair was conducted to a prespecified analysis plan, reporting on mortality, aneurysm-related mortality and reintervention. Results: The analysis included 2783 patients, with 14 245 person-years of follow-up (median 5·5 years). Early (0–6 months after randomization) mortality was lower in the EVAR groups (46 of 1393 versus 73 of 1390 deaths; pooled hazard ratio 0·61, 95 per cent c.i. 0·42 to 0·89; P = 0·010), primarily because 30-day operative mortality was lower in the EVAR groups (16 deaths versus 40 for open repair; pooled odds ratio 0·40, 95 per cent c.i. 0·22 to 0·74). Later (within 3 years) the survival curves converged, remaining converged to 8 years. Beyond 3 years, aneurysm-related mortality was significantly higher in the EVAR groups (19 deaths versus 3 for open repair; pooled hazard ratio 5·16, 1·49 to 17·89; P = 0·010). Patients with moderate renal dysfunction or previous coronary artery disease had no early survival advantage under EVAR. Those with peripheral artery disease had lower mortality under open repair (39 deaths versus 62 for EVAR; P = 0·022) in the period from 6 months to 4 years after randomization. Conclusion: The early survival advantage in the EVAR group, and its subsequent erosion, were confirmed. Over 5 years, patients of marginal fitness had no early survival advantage from EVAR compared with open repair. Aneurysm-related mortality and patients with low ankle : brachial pressure index contributed to the erosion of the early survival advantage for the EVAR group. Trial registration numbers: EVAR-1, ISRCTN55703451; DREAM (Dutch Randomized Endovascular Aneurysm Management), NCT00421330; ACE (Anévrysme de l'aorte abdominale, Chirurgie versus Endoprothèse), NCT00224718; OVER (Open Versus Endovascular Repair Trial for Abdominal Aortic Aneurysms), NCT00094575
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