1,853 research outputs found

    Seifert fibered contact three-manifolds via surgery

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    Using contact surgery we define families of contact structures on certain Seifert fibered three-manifolds. We prove that all these contact structures are tight using contact Ozsath-Szabo invariants. We use these examples to show that, given a natural number n, there exists a Seifert fibered three-manifold carrying at least n pairwise non-isomorphic tight, not fillable contact structures.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol4/agt-4-12.abs.htm

    Antonio Gramsci’s impact on critical pedagogy

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    This paper provides an account of Antonio Gramsci’s impact on the area of critical pedagogy. It indicates the Gramscian influence on the thinking of major exponents of the field. It foregrounds Gramsci's ideas and then indicates how they have been taken up by a selection of critical pedagogy exponents who were chosen on the strength of their identification and engagement with Gramsci's ideas, some of them even having written entire essays on Gramsci. The essay concludes with a discussion concerning an aspect of Gramsci's concerns, the question of powerful knowledge, which, in the present author's view, provides a formidable challenge to critical pedagogues.peer-reviewe

    Beyond ‘ignorance’: using the cultural stereotypes of Americans studying in the UK as a resource for learning and teaching about British culture

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    A course introducing British culture is a standard component of many study abroad programmes running in this country that are aimed at international students who will be spending a limited amount of time in the United Kingdom. However, it is not often acknowledged that such students possess a range of strong pre-conceptions about British culture and society prior to their arrival. Conventional teaching strategies assume student ignorance of the subject. However, an alternative approach which makes us of pre-arrival stereotypes can be more productive in terms of engaging students in active processes of comparative analysis of their new and existing knowledge. A case study of American student stereotypes of the British monarchy is presented and it is suggested that these can be used as the basis for refining student understanding of cultural politics in the United Kingdom. International students, therefore, should not be treated as being culturally ignorant of Britain in the sense of having no knowledge or opinions at all. Rather, it should be understood that they possess a culturally mediated state of subjectivity which I refer to as ‘ignorance’ and that this can become a valuable resource for teaching and learning

    Large-scale Star Formation Triggering in the Low-mass Arp 82 System: A Nearby Example of Galaxy Downsizing Based on UV/Optical/Mid-IR Imaging

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    As part of our Spitzer Spirals, Bridges, and Tails project to help understand the effects of galaxy interactions on star formation, we analyze GALEX ultraviolet, SARA optical, and Spitzer infrared images of the interacting galaxy pair Arp 82 (NGC 2535/6) and compare to a numerical simulation of the interaction. We investigate the multiwavelength properties of several individual star forming complexes (clumps). Using optical and UV colors, EW(Halpha), and population synthesis models we constrain the ages of the clumps and find that the median clump age is about 12 Myr. The clumps have masses ranging from a few times 10^6 to 10^9 solar masses. In general, the clumps in the tidal features have similar ages to those in the spiral region, but are less massive. The 8 micron and 24 micron luminosities are used to estimate the far-infrared luminosities and the star formation rates of the clumps. The total clump star formation rate is 2.0+/-0.8 solar masses per year, while the entire Arp 82 system is forming stars at a rate of 4.9+/-2.0 solar masses per year. We find, for the first time, stars in the HI arc to the southeast of the NGC 2535 disk. Population synthesis models indicate that all of the observed populations have young to intermediate ages. We conclude that although the gas disks and some old stars may have formed early-on, the progenitors are late-type or low surface brightness and the evolution of these galaxies was halted until the recent encounter.Comment: Accepted for publication in the AJ, 22 Figures, 5 Table

    Brieskorn manifolds as contact branched covers of spheres

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    We show that Brieskorn manifolds with their standard contact structures are contact branched coverings of spheres. This covering maps a contact open book decomposition of the Brieskorn manifold onto a Milnor open book of the sphere.Comment: 8 pages, 1 figur

    Glycated hemoglobin measurements at three, 12 and 24 months postpartum after gestational diabetes

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    Purpose: To determine the associations between glycated hemoglobin (A1C) values at three, 12 and 24 months postpartum taken during the Families Defeating Diabetes trial. Methods: The Families Defeating Diabetes trial was a randomized 12 month lifestyle intervention delivered in the first year postpartum. Women were reviewed at three, 6 12 and 24 months for body habitus, diet and lifestyle choices. Glycated hemoglobin levels were measured at three, 12 and 24 months. Results: There were 170 randomization participants: 89 interventional (INT); and 81 control (CON). Of these 170 participants, 50 INT and 47 CON completed 12-month follow-up and 26 INT and 24 CON completed 24-month follow-up. Study outcomes did not differ between the cohorts. Combined intraclass correlation coefficients for reliability of repeated results showed substantial reliability: 0.74 (95% CI 0.63, 0.83) between three and 12 month A1C; and 0.72 (95% CI 0.51, 0.85) for three and 24 month A1C. Pearson correlations for three month vs 12 month A1C were r=0.745 (p\u3c0.001) and three month vs 24 month A1C were r=0.718 (p=0.001) Conclusions: The A1C values at three, 12 and 24 months after gestational diabetes mellitus showed substantial reliability by intraclass correlation coefficients analysis as well as significant Pearson correlations. These findings add perspective to timing and use of A1C to document postpartum glucose tolerance for women with recent gestational diabetes mellitus. These findings suggest a role for postpartum A1C testing; however, a longitudinal comparison with OGTT results is required to confirm clinical validity

    Loose Legendrians and the plastikstufe

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    We show that the presence of a plastikstufe induces a certain degree of flexibility in contact manifolds of dimension 2n + 1 gt; 3. More precisely, we prove that every Legendrian knot whose complement contains a "nice" plastikstufe can be destabilized (and, as a consequence, is loose). As an application, it follows in certain situations that two nonisomorphic contact structures become isomorphic after connect-summing with a manifold containing a plastikstufe

    Towards a framework for critical citizenship education

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    Increasingly countries around the world are promoting forms of "critical" citizenship in the planned curricula of schools. However, the intended meaning behind this term varies markedly and can range from a set of creative and technical skills under the label "critical thinking" to a desire to encourage engagement, action and political emancipation, often labelled "critical pedagogy". This paper distinguishes these manifestations of the "critical" and, based on an analysis of the prevailing models of critical pedagogy and citizenship education, develops a conceptual framework for analysing and comparing the nature of critical citizenship

    Differences in risk behaviours and HIV status between primary amphetamines and opioid injectors in Estonia and Russia

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    Background and objective People who inject drugs (PWID) account for over half of new HIV infections in Eastern Europe and central Asia, where opioids continue to be the dominant illicit drugs injected. Stimulants including amphetamines (ATS) have been associated with HIV infection risk in several settings. We sought to examine whether primary ATS injection was associated with greater HIV risk, compared to opioid injection in two European locales with significant HIV epidemics. Methods PWID in Kohtla-JĂ€rve and St. Petersburg were recruited using respondent-driven sampling in 2012–2013. Survey data on demographic characteristics, service use, injecting and sexual risk behaviours and HIV-status (and HCV in Kohtla-JĂ€rve) were compared between primary opioid and ATS injectors using logistic regression models. Results Of 591 injectors recruited in Kohtla-JĂ€rve and 811 in St. Petersburg, 195 (33%) and 27 (4%) primarily injected ATS in each city. In both cities, ATS injectors were younger than opioid injectors, initiated injection later, injected less frequently and were more likely to have been paid for sex. In both cities, PWID had high levels of multiple sex partners. In Kohtla-JĂ€rve, ATS-injectors had lower odds of back-loading and greater odds of polydrug use than opioid-injectors. In St. Petersburg, where over half of PWID reported unsafe sharing practices, ATS-injectors were less likely to report these practices. ATS-injection was negatively associated with being HIV positive in Kohtla-JĂ€rve (aOR = 0.6; 95%CI: 0.5–0.8) and St. Petersburg (aOR = 0.3; 95%CI: 0.1–0.7). ATS-injection was negatively associated with HCV-reactivity in Kohtla-JĂ€rve (aOR = 0.5; 95%CI: 0.3–0.6). Conclusions In both locations, primary ATS injection was associated with lower injecting risk behaviours, lower odds of HIV and being paid for sex compared to opioid injection. Interventions targeting the characteristics and needs of ATS injectors are needed to increase contact with services and reduce sexual and injecting risk. Harm reduction services, including sexual risk reduction, need to be expanded for all PWID in St. Petersburg
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