6,702 research outputs found

    Why is there no queer international theory?

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    Over the last decade, Queer Studies have become Global Queer Studies, generating significant insights into key international political processes. Yet, the transformation from Queer to Global Queer has left the discipline of International Relations largely unaffected, which begs the question: if Queer Studies has gone global, why has the discipline of International Relations not gone somewhat queer? Or, to put it in Martin Wight’s provocative terms, why is there no Queer International Theory? This article claims that the presumed non-existence of Queer International Theory is an effect of how the discipline of International Relations combines homologization, figuration, and gentrification to code various types of theory as failures in order to manage the conduct of international theorizing in all its forms. This means there are generalizable lessons to be drawn from how the discipline categorizes Queer International Theory out of existence to bring a specific understanding of International Relations into existence

    Using Social Media to Promote STEM Education: Matching College Students with Role Models

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    STEM (Science, Technology, Engineering, and Mathematics) fields have become increasingly central to U.S. economic competitiveness and growth. The shortage in the STEM workforce has brought promoting STEM education upfront. The rapid growth of social media usage provides a unique opportunity to predict users' real-life identities and interests from online texts and photos. In this paper, we propose an innovative approach by leveraging social media to promote STEM education: matching Twitter college student users with diverse LinkedIn STEM professionals using a ranking algorithm based on the similarities of their demographics and interests. We share the belief that increasing STEM presence in the form of introducing career role models who share similar interests and demographics will inspire students to develop interests in STEM related fields and emulate their models. Our evaluation on 2,000 real college students demonstrated the accuracy of our ranking algorithm. We also design a novel implementation that recommends matched role models to the students.Comment: 16 pages, 8 figures, accepted by ECML/PKDD 2016, Industrial Trac

    The dispersal of protoplanetary discs - I. A new generation of X-ray photoevaporation models

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    Photoevaporation of planet-forming discs by high-energy radiation from the central star is potentially a crucial mechanism for disc evolution and it may play an important role in the formation and evolution of planetary systems. We present here a new generation of X-ray photoevaporation models for solar-type stars, based on hydrodynamical simulations, which account for stellar irradiation via a significantly improved parametrization of gas temperatures, based on detailed photoionization and radiation transfer calculations. This is the first of a series of papers aiming at providing a library of models which cover the observed parameter space in stellar and disc mass, metallicity, and stellar X-ray properties. We focus here on solar-type stars (0.7 M⊙) with relatively low-mass discs (1 per cent of the stellar mass) and explore the dependence of the wind mass-loss rates on stellar X-ray luminosity. We model primordial discs and transition discs at various stages of evolution. Our two-dimensional hydrodynamical models are then used to derive simple recipes for the mass-loss rates that are suitable for one-dimensional disc evolution and/or planet formation models typically employed for population synthesis studies. Line profiles from typical wind diagnostics ([O I]6300 Å and [Ne II]12.8 μm) are also calculated for our models and found to be roughly in agreement with previous studies. Finally, we perform a population study of transition discs by means of one-dimensional viscous evolution models including our new photoevaporation prescription and find that roughly a half of observed transition discs cavities and accretion rates could be reproduced by our models

    The Effects of Serotonin Receptor Antagonists on Contraction and Relaxation Responses Induced by Electrical Stimulation in the Rat Small Intestine

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    Background: The main source of 5-HT in body is in enterchromafin cells of intestine, different studies mentioned different roles for endogenous 5-HT and receptors involved and it is not clearified the mechanism of action of endogenous 5-HT. Objectives: To study the role of endogenous 5-HT on modulation of contraction and relaxation responses induced by electrical field stimulation (EFS) in different regions of the rat intestine. Materials and Methods: Segments taken from the rat duodenum, jejunum, mid and terminal ileum were vertically mounted, connected to a transducer and exposed to EFS with different frequencies in the absence and presence of various inhibitors of enteric mediators i. e. specific 5-HT receptor antagonists. Results: EFS-induced responses were sensitive to TTX and partly to atropine, indicating a major neuronal involvement and a cholinergic system. Pre-treatment with WAY100635 (a 5-HT1A receptor antagonist) and granisetron up to 10.0 µM, GR113808 (a 5-HT4 receptor antagonist), methysergide and ritanserin up to 1.0 µM, failed to modify responses to EFS inall examined tissues. In the presence of SB258585 1.0 µM (a 5-HT6 receptor antagonist) there was a trend to enhance contraction in the proximal part of the intestine and reduce contraction in the distal part. Pre-treatment with SB269970A 1.0 µM (5-HT7 receptor antagonist) induced a greater contractile response to EFS at 0.4 Hz only in the duodenum. Conclusions: The application of 5-HT1A, 5-HT2, 5-HT3, 5-HT4, 5-HT6 and 5-HT7 receptor antagonists, applied at concentrations lower than 1.0 µM did not modify the EFS-induced contraction and relaxation responses, whichsuggests the unlikely involvement of endogenous 5-HT in mediating responses to EFS in the described test conditions. Keywords: Electric Stimulation Therapy; Serotonin 5-HT1 Receptor Antagonists; Intestine, Smal

    Anatomical and biomechanical evaluation of the tension band technique in patellar fractures

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    Tension band wiring for patellar fractures is common, but some recent reports refer to disadvantages of this approach. Our anatomical and biomechanical study focused on use of tension band techniques in patellar fractures. The anatomy of the patella and tendon insertion was examined with knee magnetic resonance imaging (MRI) and correlated with the technical requirements of the tension band. Tension band wiring over tendinous tissue was simulated and calculated with a cyclic biomechanical test on cow patellae. According to tension band templating on the MRI section, Kirschner wire insertion was needed for the tension band to turn over the tendinous tissue. The tension band became more stable while turning over less tendinous tissue and more adjacent bone surface. Nevertheless, cyclic loading tests indicate that all tension band applications in this study lose their initial stability. Excessive initial compression by the tension band resulted in bending of the Kirschner wire and thus reduction failure. For optimum stabilisation, tension force transfer should be done directly on bone or at least material that protects the tendon would be useful

    Self-Organization, Layered Structure, and Aggregation Enhance Persistence of a Synthetic Biofilm Consortium

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    Microbial consortia constitute a majority of the earth’s biomass, but little is known about how these cooperating communities persist despite competition among community members. Theory suggests that non-random spatial structures contribute to the persistence of mixed communities; when particular structures form, they may provide associated community members with a growth advantage over unassociated members. If true, this has implications for the rise and persistence of multi-cellular organisms. However, this theory is difficult to study because we rarely observe initial instances of non-random physical structure in natural populations. Using two engineered strains of Escherichia coli that constitute a synthetic symbiotic microbial consortium, we fortuitously observed such spatial self-organization. This consortium forms a biofilm and, after several days, adopts a defined layered structure that is associated with two unexpected, measurable growth advantages. First, the consortium cannot successfully colonize a new, downstream environment until it selforganizes in the initial environment; in other words, the structure enhances the ability of the consortium to survive environmental disruptions. Second, when the layered structure forms in downstream environments the consortium accumulates significantly more biomass than it did in the initial environment; in other words, the structure enhances the global productivity of the consortium. We also observed that the layered structure only assembles in downstream environments that are colonized by aggregates from a previous, structured community. These results demonstrate roles for self-organization and aggregation in persistence of multi-cellular communities, and also illustrate a role for the techniques of synthetic biology in elucidating fundamental biological principles

    The United States, PMSCs and the state monopoly on violence: Leading the way towards norm change

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2013 Sage.The proliferation of private military and security companies (PMSCs) in Iraq and Afghanistan has raised many questions regarding the use of armed force by private contractors. This article addresses the question of whether the increased acceptance of PMSCs indicates a transformation of the international norm regarding the state monopoly on the legitimate use of armed force. Drawing on theoretical approaches to the analysis of norm change, the article employs four measures to investigate possible changes in the strength and meaning of this norm: modifications in state behaviour, state responses to norm violation, the promulgation of varying interpretations of the norm in national and international laws and regulations, and changes in norm discourse. Based on an analysis of empirical evidence from the United States of America and its allies, the article concludes that these measures suggest that the USA is leading the way towards a transformation of the international norm of the state monopoly on violence, involving a revised meaning. Although this understanding has not yet been formally implemented in international law, it has allowed a growing number of countries to tolerate, accept or legalize the use of armed force by PMSCs in the international arena.The Alexander von Humboldt Foundation and the Peace Research Institute Frankfurt
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