886 research outputs found

    Book Reviews

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    From hypertoric geometry to bordered Floer homology via the m=1 amplituhedron

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    We give a conjectural algebraic description of the Fukaya category of a complexified hyperplane complement, using the algebras defined in arXiv:0905.1335 from the equivariant cohomology of toric varieties. We prove this conjecture for cyclic arrangements by showing that these algebras are isomorphic to algebras appearing in work of Ozsvath-Szabo arXiv:1603.06559 in bordered Heegaard Floer homology arXiv:0810.0687. The proof of our conjecture in the cyclic case extends work of Karp-Williams arXiv:1608.08288 on sign variation and the combinatorics of the m=1 amplituhedron. We then use the algebras associated to cyclic arrangements to construct categorical actions of gl(1|1).Comment: 42 pages, eps figure

    Roles and Attitudes of Males and Females in The Anarchist Punk Community

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    Sexism is a widespread social problem that exists throughout the world today. It persists within the dominant culture, as well as in various subcultures, including the punk subculture (Daugherty 2002; Leblanc 1999; McRobbie 1991; Rosenberg and Garofalo 1998). Nijole Benokraitis and Joe Feagin\u27s (1995) theory of sexism posits that subtle sexism is the unequal and harmful treatment of women that is typically less visible than blatant sex discrimination. This particular type of sexism may often go unnoticed, as society has internalized subtle sexist behaviors. Empirical research on subtle sexism has been conducted in various settings, such as the employment, academic, and military sectors of society (Benokraitis 1997). However, this theory has not been adequately applied to subcultural research. This research investigates whether subtle sexism exists within a group of self-identified anarchist punks who contend their primary tenets/principles dictate that they reject all forms of inequality. Moreover, if sexism does exist within the AP subculture, eradication of this problem within this community may be a daunting task -- as sexism may persist in subtle, invisible, and obstinate ways. This exploratory and descriptive research will utilize interviews of fifty men and women to examine if sexism exists, specifically in a subtle manner, and, if so, to illuminate manifestations of sexism within the anarchist punk community. Additionally, this study engages Benokraitis and Feagin\u27s (1995) sexism theory to a non-traditional, subcultural setting

    Community awareness of green roofs in Sydney

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    There are environmental, economic and social benefits of installing green roofs and walls on city buildings. The environmental benefits are lower building related operational carbon emissions, reductions in the urban heat island, increases in bio-diversity and reductions in storm-water run-off. Economically, the benefits are reduced roof maintenance costs, lower running costs, higher capital and rental values for commercial buildings. Finally the social or community gains are the creation of aesthetically pleasing spaces, landmarksand cultural capital as well as provision of recreational spaces. Furthermore social, psychological and therapeutic gains accrue when the roof or wall is visible to people andis used for social interaction and leisure activities. The perceived drawbacks are perceived greater risk of building leaks, high costs of installation and maintenance, and access and security issues. Whilst the technology to design and install green roofs and walls has existed for hundreds of years the uptake and the demand for green roofs and walls has not been high. Overall, the environmental social and economic gains are not perceived sufficient to create significant demand to set up green roofs and walls. In Sydney Australia, the existing number of green roofs and walls are testimony to this observation. With the aim of addressing the barriers to the uptake of green roofs and walls; it is essential to understand the way in which the key stakeholders; here the community, perceive the technology. With this knowledge it is then feasible to develop an agenda to mitigate any erroneous perceptions that exists. This research reports on a survey with the Sydney community to determine their perceptions of green roofs and walls

    Multiple functional neurosteroid binding sites on GABAA receptors

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    Neurosteroids are endogenous modulators of neuronal excitability and nervous system development and are being developed as anesthetic agents and treatments for psychiatric diseases. While gamma amino-butyric acid Type A (GABAA) receptors are the primary molecular targets of neurosteroid action, the structural details of neurosteroid binding to these proteins remain ill defined. We synthesized neurosteroid analogue photolabeling reagents in which the photolabeling groups were placed at three positions around the neurosteroid ring structure, enabling identification of binding sites and mapping of neurosteroid orientation within these sites. Using middle-down mass spectrometry (MS), we identified three clusters of photolabeled residues representing three distinct neurosteroid binding sites in the human α1β3 GABAA receptor. Novel intrasubunit binding sites were identified within the transmembrane helical bundles of both the α1 (labeled residues α1-N408, Y415) and β3 (labeled residue β3-Y442) subunits, adjacent to the extracellular domains (ECDs). An intersubunit site (labeled residues β3-L294 and G308) in the interface between the β3(+) and α1(-) subunits of the GABAA receptor pentamer was also identified. Computational docking studies of neurosteroid to the three sites predicted critical residues contributing to neurosteroid interaction with the GABAA receptors. Electrophysiological studies of receptors with mutations based on these predictions (α1-V227W, N408A/Y411F, and Q242L) indicate that both the α1 intrasubunit and β3-α1 intersubunit sites are critical for neurosteroid action

    The heats of formation of the haloacetylenes XCCY [X, Y = H, F, Cl]: basis set limit ab initio results and thermochemical analysis

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    The heats of formation of haloacetylenes are evaluated using the recent W1 and W2 ab initio computational thermochemistry methods. These calculations involve CCSD and CCSD(T) coupled cluster methods, basis sets of up to spdfgh quality, extrapolations to the one-particle basis set limit, and contributions of inner-shell correlation, scalar relativistic effects, and (where relevant) first-order spin-orbit coupling. The heats of formation determined using W2 theory are: \hof(HCCH) = 54.48 kcal/mol, \hof(HCCF) = 25.15 kcal/mol, \hof(FCCF) = 1.38 kcal/mol, \hof(HCCCl) = 54.83 kcal/mol, \hof(ClCCCl) = 56.21 kcal/mol, and \hof(FCCCl) = 28.47 kcal/mol. Enthalpies of hydrogenation and destabilization energies relative to acetylene were obtained at the W1 level of theory. So doing we find the following destabilization order for acetylenes: FCCF >> ClCCF >> HCCF >> ClCCCl >> HCCCl >> HCCH. By a combination of W1 theory and isodesmic reactions, we show that the generally accepted heat of formation of 1,2-dichloroethane should be revised to -31.8±\pm0.6 kcal/mol, in excellent agreement with a very recent critically evaluated review. The performance of compound thermochemistry schemes such as G2, G3, G3X and CBS-QB3 theories has been analyzed.Comment: Mol. Phys., in press (E. R. Davidson issue

    A Process for Co-Designing Educational Technology Systems for Refugee Children

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    There is a growing interest in the potential for technology to facilitate emergency education of refugee children. However, designing in this space requires knowledge of the displaced population and the contextual dynamics surrounding it. Design should therefore be informed by both existing research across relevant disciplines, and from the practical experience of those who are on the ground facing the problem in real life. This paper describes a process for designing appropriate technology for these settings. The process draws on literature from emergency education, student engagement and motivation, educational technology, and participatory design. We emphasise a thorough understanding of the problem definition, the nature of the emergency, and of socio-cultural aspects that can inform the design process. We describe how this process was implemented leading to the design of a digital learning space for children living in a refugee camp in Greece. This drew on involving different groups of participants such as social-workers, parents, and children

    Vitamin D deficiency is associated with IL-6 levels and monocyte activation in HIV-infected persons

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    Immune activation plays a key role in HIV pathogenesis. Markers of inflammation have been associated with vitamin D deficiency in the general population. Studies have also demonstrated associations of vitamin D deficiency with increased risk of HIV progression and death. The relationship between persistent inflammation and immune activation during chronic HIV infection and vitamin D deficiency remains unclear.Cryopreserved specimens were analyzed from 663 participants at the time of enrollment from the Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy (SUN Study) from 2004 to 2006. Biomarkers of inflammation, atherosclerosis, and coagulation were measured using enzyme-linked immunosorbent assays (ELISAs) and electrochemiluminescence. 25(OH)D, the stable precursor form of vitamin D, was measured using a radioimmunoassay with levels defined as: normal (≥30ng/mL), insufficient (20-29 ng/mL) and deficient (<20 ng/mL). Monocyte phenotypes were assessed by flow cytometry. Linear and logistic regression models were used to determine statistical associations between biomarkers and vitamin D deficiency.25(OH)D levels were deficient in 251 (38%) participants, insufficient in 222 (34%), and normal in 190 (29%). Patients with vitamin D deficiency, when compared to those with insufficient or normal vitamin D levels, had increased levels of IL-6 (23%; p<0.01), TNF-α (21%, p = 0.03), D-dimer (24%, p = 0.01), higher proportions of CD14dimCD16+ (22%, p<0.01) and CX3CR1+ monocytes (48%; p<0.001) and decreased frequency of CCR2+ monocytes (-3.4%, p<0.001). In fully adjusted models, vitamin D associations with abnormal biomarker levels persisted for IL-6 levels and CX3CR1+ and CCR2+ phenotypes.Vitamin D deficiency is associated with greater inflammation and activated monocyte phenotypes. The role of vitamin D deficiency in persistent immune activation and associated complications during chronic HIV disease should be further evaluated as a possible target for intervention

    Phonon Emission from a 2D Electron Gas: Evidence of Transition to the Hydrodynamic Regime

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    Using as a thermometer the temperature dependent magneto-transport of a two-dimensional electron gas, we find that effective temperature scales with current as Te∼IaT_{\rm e} \sim I^a, where a=0.4±2%a=0.4 \pm 2\% in the {\it Shubnikov de-Haas} regime, and 0.53±2%0.53 \pm 2\% in both the {\it integer and fractional} quantum Hall effect. This implies the phonon energy emission rate changes from the expected P∼T5P\sim T^5 to P∼T4P\sim T^4. We explain this, as well as the dramatic enhancement in phonon emission efficiency using a hydrodynamic model.Comment: 4 pages, 2 Postscript figures uuencoded with TeX file uses psfig macro. Submitted to Phys. Rev. Let

    A selected ion flow tube study of the ion-molecule reactions of monochloroethene, trichloroethene and tetrachloroethene

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    Data for the rate coefficients and product cations of the reactions of a large number of atomic and small molecular cations with monochloroethene, trichloroethene and tetrachloroethene in a selected ion flow tube at 298 K are reported. The recombination energy of the ions range from 6.27 eV (H3_3O+^+) through to 21.56 eV (Ne+^+). Collisional rate coefficients are calculated by modified average dipole orientation theory and compared with experimental values. Thermochemistry and mass balance predict the most feasible neutral products. Together with previously reported results for the three isomers of dichloroethene (J. Phys. Chem. A., 2006, 110, 5760), the fragment ion branching ratios have been compared with those from threshold photoelectron photoion coincidence spectroscopy over the photon energy range 9-22 eV to determine the importance or otherwise of long-range charge transfer. For ions with recombination energy in excess of the ionisation energy of the chloroethene, charge transfer is energetically allowed. The similarity of the branching ratios from the two experiments suggest that long-range charge transfer is dominant. For ions with recombination energy less than the ionisation energy, charge transfer is not allowed; chemical reaction can only occur following formation of an ion-molecule complex, where steric effects are more significant. The products that are now formed and their percentage yield is a complex interplay between the number and position of the chlorine atoms with respect to the C=C bond, where inductive and conjugation effects can be important
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