9,766 research outputs found

    Correlation Functions in ω\omega-Deformed N=6 Supergravity

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    Gauged N=8 supergravity in four dimensions is now known to admit a deformation characterized by a real parameter ω\omega lying in the interval 0ωπ/80\le\omega\le \pi/8. We analyse the fluctuations about its anti-de Sitter vacuum, and show that the full N=8 supersymmetry can be maintained by the boundary conditions only for ω=0\omega=0. For non-vanishing ω\omega, and requiring that there be no propagating spin s>1 fields on the boundary, we show that N=3 is the maximum degree of supersymmetry that can be preserved by the boundary conditions. We then construct in detail the consistent truncation of the N=8 theory to give ω\omega-deformed SO(6) gauged N=6 supergravity, again with ω\omega in the range 0ωπ/80\le\omega\le \pi/8. We show that this theory admits fully N=6 supersymmetry-preserving boundary conditions not only for ω=0\omega=0, but also for ω=π/8\omega=\pi/8. These two theories are related by a U(1) electric-magnetic duality. We observe that the only three-point functions that depend on ω\omega involve the coupling of an SO(6) gauge field with the U(1) gauge field and a scalar or pseudo-scalar field. We compute these correlation functions and compare them with those of the undeformed N=6 theory. We find that the correlation functions in the ω=π/8\omega=\pi/8 theory holographically correspond to amplitudes in the U(N)_k x U(N)_{-k} ABJM model in which the U(1) Noether current is replaced by a dynamical U(1) gauge field. We also show that the ω\omega-deformed N=6 gauged supergravities can be obtained via consistent reductions from the eleven-dimensional or ten-dimensional type IIA supergravities.Comment: 38 pages, one figur

    Review of Cytomegalovirus Anterior Uveitis

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    The Onion Sign in Neovascular Age-Related Macular Degeneration Represents Cholesterol Crystals

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    PURPOSE: To investigate the frequency, natural evolution, and histologic correlates of layered, hyperreflective, subretinal pigment epithelium (sub-RPE) lines, known as the onion sign, in neovascular age-related macular degeneration (AMD). DESIGN: Retrospective observational cohort study and experimental laboratory study. PARTICIPANTS: Two hundred thirty eyes of 150 consecutive patients with neovascular AMD and 40 human donor eyes with histopathologic diagnosis of neovascular AMD. METHODS: Spectral-domain optical coherence tomography (SD OCT), near-infrared reflectance (NIR), color fundus images, and medical charts were reviewed. Donor eyes underwent multimodal ex vivo imaging, including SD OCT, before processing for high-resolution histologic analysis. MAIN OUTCOME MEASURES: Presence of layered, hyperreflective sub-RPE lines, qualitative analysis of their change in appearance over time with SD OCT, histologic correlates of these lines, and associated findings within surrounding tissues. RESULTS: Sixteen of 230 eyes of patients (7.0%) and 2 of 40 donor eyes (5.0%) with neovascular AMD had layered, hyperreflective sub-RPE lines on SD OCT imaging. These appeared as refractile, yellow-gray exudates on color imaging and as hyperreflective lesions on NIR. In all 16 patient eyes, the onion sign persisted in follow-up for up to 5 years, with fluctuations in the abundance of lines and association with intraretinal hyperreflective foci. Patients with the onion sign disproportionately were taking cholesterol-lowering medications (P=0.025). Histologic analysis of 2 donor eyes revealed that the hyperreflective lines correlated with clefts created by extraction of cholesterol crystals during tissue processing. The fluid surrounding the crystals contained lipid, yet was distinct from oily drusen. Intraretinal hyperreflective foci correlated with intraretinal RPE and lipid-filled cells of probable monocytic origin. CONCLUSIONS: Persistent and dynamic, the onion sign represents sub-RPE cholesterol crystal precipitation in an aqueous environment. The frequency of the onion sign in neovascular AMD in a referral practice and a pathology archive is 5% to 7%. Associations include use of cholesterol-lowering medication and intraretinal hyperreflective foci attributable to RPE cells and lipid-filled cells of monocyte origin

    Ferromagnetism in the Infinite-U Hubbard Model

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    We have studied the stability of the ferromagnetic state in the infinite-U Hubbard model on a square lattice by approximate diagonalization of finite lattices using the density matrix renormalization group technique. By studying lattices with up to 5X20 sites, we have found the ferromagnetic state to be stable below the hole density of 22 percent. Beyond 22 percent of hole doping, the total spin of the ground state decreased gradually to zero with increasing hole density.Comment: 13 pages, RevteX 3.0, seven figures appended in uuencoded form, correcting problems with uuencoded figure

    Quantum integrable system with two color components in two dimensions

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    The Davey-Stewartson 1(DS1) system[9] is an integrable model in two dimensions. A quantum DS1 system with 2 colour-components in two dimensions has been formulated. This two-dimensional problem has been reduced to two one-dimensional many-body problems with 2 colour-components. The solutions of the two-dimensional problem under consideration has been constructed from the resulting problems in one dimensions. For latters with the δ\delta -function interactions and being solved by the Bethe ansatz, we introduce symmetrical and antisymmetrical Young operators of the permutation group and obtain the exact solutions for the quantum DS1 system. The application of the solusions is discussed.Comment: 14 pages, LaTeX fil

    Need for achievement moderates the effect of motive-relevant challenge on salivary cortisol changes

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    The hypothalamic–pituitary–adrenal (HPA) axis plays a key role in the physiological response to stress, preparing the organism for appropriate action. While some research has examined universally relevant threats, other research has suggested that individual differences may moderate the relationship between stress and cortisol release, such that some individuals exhibit modified reactivity to personally relevant stressors or challenges. In the present study we investigated whether one individual difference—the implicit need for achievement—moderates the effect of motive-relevant challenge on salivary cortisol. Participants’ salivary cortisol and felt affect were measured before and after engagement in an achievement task. In the positive- and no-feedback conditions, individuals high in implicit achievement motivation demonstrated increased cortisol response to the task, whereas in the negative feedback condition, individuals high in implicit achievement motivation demonstrated a dampened cortisol response. Furthermore, changes in cortisol were accompanied by changes in felt affect in the same direction, specifically hedonic tone. These results suggest that the HPA axis also responds to non-social-evaluative challenge in a personality-contingent manner

    Spectrum of Higher Derivative 6D Chiral Supergravity

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    Gauged off-shell Maxwell-Einstein supergravity in six dimensions with N=(1,0) supersymmetry has a higher derivative extension afforded by a supersymmetrized Riemann squared term. This theory admits a supersymmetric Minkowski x S^2 compactification with a U(1) monopole of unit charge on S^2. We determine the full spectrum of the theory on this background. We also determine the spectrum on a non-supersymmetric version of this compactification in which the monopole charge is different from unity, and we find the peculiar feature that there are massless gravitini in a representation of the S^2 isometry group determined by the monopole charge.Comment: typos correcte

    A New Viscosity Equation For Bin Aqueous Solutions.

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    An equation for the viscosity of binary aqueous solutions has been derived based on the Power law equation and Erying's absolute rate theory. The concentration dependent equation for viscosities of binary aqueous systems is derived using additive contribution from water and solute component. The equation has sufficient degree of freedom to represent the' whole range of concentration. The equation has been applied to 12 nonelectrolyte aqueous systems and 10 electrolyte systems at various temperatures. An average absolute deviation percentage error' (AAD%) of 0.2856% is reported for electrolyte systems: For non-electrolyte systems an average AAD% of 0.7843% is reported. Overall, the equation is found to have yielded an AAD% of 0.5576%

    Transient Analysis of Warm Electron Injection Programming of Double Gate SONOS Memories by means of Full Band Monte Carlo Simulation

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    In this paper we investigate "Warm Electron Injection" as a mechanism for NOR programming of double-gate SONOS memories through 2D full band Monte Carlo simulations. Warm electron injection is characterized by an applied VDS smaller than 3.15 V, so that electrons cannot easily accumulate a kinetic energy larger than the height of the Si/SiO2 barrier. We perform a time-dependent simulation of the program operation where the local gate current density is computed with a continuum-based method and is adiabatically separated from the 2D full Monte Carlo simulation used for obtaining the electron distribution in the phase space. In this way we are able to compute the time evolution of the charge stored in the nitride and of the threshold voltages corresponding to forward and reverse bias. We show that warm electron injection is a viable option for NOR programming in order to reduce power supply, preserve reliability and CMOS logic level compatibility. In addition, it provides a well localized charge, offering interesting perspectives for multi-level and dual bit operation, even in devices with negligible short channel effects

    Predicting Self-Management Behaviors in Familial Hypercholesterolemia Using an Integrated Theoretical Model: the Impact of Beliefs About Illnesses and Beliefs About Behaviors

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    Patients with familial hypercholesterolemia (FH) are at markedly increased risk of coronary artery disease. Regular participation in three self-management behaviors, physical activity, healthy eating, and adherence to medication, can significantly reduce this risk in FH patients. We aimed to predict intentions to engage in these self-management behaviors in FH patients using a multi-theory, integrated model that makes the distinction between beliefs about illness and beliefs about self-management behaviors. Methods: Using a cross-sectional, correlational design, patients (N = 110) diagnosed with FH from a clinic in Perth, Western Australia, self-completed a questionnaire that measured constructs from three health behavior theories: the common sense model of illness representations (serious consequences, timeline, personal control, treatment control, illness coherence, emotional representations); theory of planned behavior (attitudes, subjective norms, perceived behavioral control); and social cognitive theory (self-efficacy). Results: Structural equation models for each self-management behavior revealed consistent and statistically significant effects of attitudes on intentions across the three behaviors. Subjective norms predicted intentions for health eating only and self-efficacy predicted intentions for physical activity only. There were no effects for the perceived behavioral control and common sense model constructs in any model. Conclusions: Attitudes feature prominently in determining intentions to engage in self-management behaviors in FH patients. The prominence of these attitudinal beliefs about self-management behaviors, as opposed to illness beliefs, suggest that addressing these beliefs may be a priority in the management of FH
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