3,564 research outputs found

    Detection of Exotic Massive Hadrons in Ultra High Energy Cosmic Ray Telescopes

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    We investigate the detection of exotic massive strongly interacting hadrons (uhecrons) in ultra high energy cosmic ray telescopes. The conclusion is that experiments such as the Pierre Auger Observatory have the potential to detect these particles. It is shown that uhecron showers have clear distinctive features when compared to proton and nuclear showers. The simulation of uhecron air showers, and its detection and reconstruction by fluorescence telescopes is described. We determine basic cuts in observables that will separate uhecrons from the cosmic ray bulk, assuming this is composed by protons. If these are composed by heavier nucleus the separation will be much improved. We also discuss photon induced showers. The complementarity between uhecron detection in accelerator experiments is discussed.Comment: 9 page 9 figure

    ‘Everything’s from the inside out with PCOS’:exploring women’s experiences of living with Polycystic Ovary Syndrome (PCOS) and co-morbidities through Skype™ interviews

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    Polycystic ovary syndrome is an endocrine disorder affecting 1 in 10 women. Women with polycystic ovary syndrome can experience co-morbidities, including depressive symptoms. This research explores the experience of living with polycystic ovary syndrome and co-morbidities. Totally, 10 participants with polycystic ovary syndrome took part in Skypeâ„¢ interviews and analysed using thematic analysis. Four themes emerged from the data: change (to life plans and changing nature of condition); support (healthcare professionals, education and relationships); co-morbidities (living with other conditions and depression, self-harm and suicidal ideation) and identity (feminine identity and us and them). The findings highlight the need for screening of women with polycystic ovary syndrome for depressive disorders

    Female Superintendents: Historic Barriers and Prospects for the Future

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    This paper addresses the historic under representation of female superintendents. The primary focus is the legacy of discrimination, in which the barriers to female advancement in a traditionally male field are described. Particular attention is given to three different models of male dominance that have been developed to explain how and/or why women have been excluded from top positions in educational administration. In part two, recognition of the importance of women\u27s contributions to evolving theory in educational administration and a description of the feminine leadership model is offered, wherein women utilize flexible web-like structures, empower others, and prioritize children and learning. In conclusion, future prospects for women in the superintendency are discussed

    Female Superintendents: Historic Barriers and Prospects for the Future

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    This paper addresses the historic under representation of female superintendents. The primary focus is the legacy of discrimination, in which the barriers to female advancement in a traditionally male field are described. Particular attention is given to three different models of male dominance that have been developed to explain how and/or why women have been excluded from top positions in educational administration. In part two, recognition of the importance of women\u27s contributions to evolving theory in educational administration and a description of the feminine leadership model is offered, wherein women utilize flexible web-like structures, empower others, and prioritize children and learning. In conclusion, future prospects for women in the superintendency are discussed

    Varieties of vacua in classical supersymmetric gauge theories

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    We give a simple description of the classical moduli space of vacua for supersymmetric gauge theories with or without a superpotential. The key ingredient in our analysis is the observation that the lagrangian is invariant under the action of the complexified gauge group \Gc. From this point of view the usual DD-flatness conditions are an artifact of Wess--Zumino gauge. By using a gauge that preserves \Gc invariance we show that every constant matter field configuration that extremizes the superpotential is \Gc gauge-equivalent (in a sense that we make precise) to a unique classical vacuum. This result is used to prove that in the absence of a superpotential the classical moduli space is the algebraic variety described by the set of all holomorphic gauge-invariant polynomials. When a superpotential is present, we show that the classical moduli space is a variety defined by imposing additional relations on the holomorphic polynomials. Many of these points are already contained in the existing literature. The main contribution of the present work is that we give a careful and self-contained treatment of limit points and singularities.Comment: 14 pages, LaTeX (uses revtex.sty

    Mapping 6D N = 1 supergravities to F-theory

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    We develop a systematic framework for realizing general anomaly-free chiral 6D supergravity theories in F-theory. We focus on 6D (1, 0) models with one tensor multiplet whose gauge group is a product of simple factors (modulo a finite abelian group) with matter in arbitrary representations. Such theories can be decomposed into blocks associated with the simple factors in the gauge group; each block depends only on the group factor and the matter charged under it. All 6D chiral supergravity models can be constructed by gluing such blocks together in accordance with constraints from anomalies. Associating a geometric structure to each block gives a dictionary for translating a supergravity model into a set of topological data for an F-theory construction. We construct the dictionary of F-theory divisors explicitly for some simple gauge group factors and associated matter representations. Using these building blocks we analyze a variety of models. We identify some 6D supergravity models which do not map to integral F-theory divisors, possibly indicating quantum inconsistency of these 6D theories.Comment: 37 pages, no figures; v2: references added, minor typos corrected; v3: minor corrections to DOF counting in section

    Testing the performance of state-of-the-art dust emission schemes using DO4Models field data

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    Within the framework of the Dust Observations for Models (DO4Models) project, the performance of three commonly used dust emission schemes is investigated in this paper using a box model environment. We constrain the model with field data (surface and dust particle properties as well as meteorological parameters) obtained from a dry lake bed with a crusted surface in Botswana during a 3 month period in 2011. Our box model results suggest that all schemes fail to reproduce the observed horizontal dust flux. They overestimate the magnitude of the flux by several orders of magnitude. The discrepancy is much smaller for the vertical dust emission flux, albeit still overestimated by up to an order of magnitude. The key parameter for this mismatch is the surface crusting which limits the availability of erosive material, even at higher wind speeds. The second-most important parameter is the soil size distribution. Direct dust entrainment was inferred to be important for several dust events, which explains the smaller gap between modelled and measured vertical dust fluxes. We conclude that both features, crusted surfaces and direct entrainment, need to be incorporated into dust emission schemes in order to represent the entire spectra of source processes. We also conclude that soil moisture exerts a key control on the threshold shear velocity and hence the emission threshold of dust in the model. In the field, the state of the crust is the controlling mechanism for dust emission. Although the crust is related to the soil moisture content to some extent, we are not as yet able to deduce a robust correlation between state of crust and soil moisture

    Phosphotyrosine Signaling Analysis in Human Tumors Is Confounded by Systemic Ischemia-Driven Artifacts and Intra-Specimen Heterogeneity

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    Tumor protein phosphorylation analysis may provide insight into intracellular signaling networks underlying tumor behavior, revealing diagnostic, prognostic or therapeutic information. Human tumors collected by The Cancer Genome Atlas program potentially offer the opportunity to characterize activated networks driving tumor progression, in parallel with the genetic and transcriptional landscape already documented for these tumors. However, a critical question is whether cellular signaling networks can be reliably analyzed in surgical specimens, where freezing delays and spatial sampling disparities may potentially obscure physiologic signaling. To quantify the extent of these effects, we analyzed the stability of phosphotyrosine (pTyr) sites in ovarian and colon tumors collected under conditions of controlled ischemia and in the context of defined intratumoral sampling. Cold-ischemia produced a rapid, unpredictable, and widespread impact on tumor pTyr networks within 5 minutes of resection, altering up to 50% of pTyr sites by more than 2-fold. Effects on adhesion and migration, inflammatory response, proliferation, and stress response pathways were recapitulated in both ovarian and colon tumors. In addition, sampling of spatially distinct colon tumor biopsies revealed pTyr differences as dramatic as those associated with ischemic times, despite uniform protein expression profiles. Moreover, intratumoral spatial heterogeneity and pTyr dynamic response to ischemia varied dramatically between tumors collected from different patients. Overall, these findings reveal unforeseen phosphorylation complexity, thereby increasing the difficulty of extracting physiologically relevant pTyr signaling networks from archived tissue specimens. In light of this data, prospective tumor pTyr analysis will require appropriate sampling and collection protocols to preserve in vivo signaling features.National Institutes of Health (U.S.) (Grant U24 CA159988
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