3,101 research outputs found

    An Exploration of Racial/Ethnic Differences in the Association between Perfectionism and Disordered Eating in College Students

    Get PDF
    Perfectionism is a robust risk factor for eating disorders (EDs). Although individually-oriented dimensions of perfectionism are strongly related to eating pathology, less is known about the contribution of parent-oriented dimensions, specifically parental expectations (PE) and parental criticisms (PC). Further, few studies have investigated these effects within racially/ethnically diverse samples. However, PE and PC might be particularly relevant to eating pathology among certain cultural groups, such as those from collectivistic and interdependent societies. This study examined associations among PE, PC, and ED symptoms across racial/ethnic groups. Undergraduates (N=706; 74.8% Female; 48% White, 19.8% Black, 7.1% Latinx, 16% Asian, 9.1% multiracial) completed online surveys assessing perfectionism and ED symptoms. Multiple and logistic regressions examined the association between parent-oriented perfectionism, global eating pathology, loss-of-control (LOC) eating, purging behaviors, and ED risk status (EDE-Q global \u3c 4.0). Analyses were conducted by racial/ethnic group, controlling for gender. Both PE and PC were related to greater ED pathology in students identifying as White (pp=.03), Asian (p=.02), and multiracial (pp=.19). Higher PC was related to a greater likelihood of endorsing LOC eating in White (p=.004) and Black students (p=.05) and purging behaviors in White (p=.004), Asian (p=.04), and multiracial students (p=.03). Greater PC was also associated with ED risk in Asian (p=.03) and multiracial participants (p=.01). Findings indicate that the relations between specific aspects of parent-oriented perfectionism differ among cultural groups and are associated with ED symptoms in college students. PC seemed more relevant to ED pathology than did PE overall. Findings suggest that parent-oriented perfectionism, particularly PC, might be important to include in clinical assessment and treatment with students at-risk of EDs.https://scholarscompass.vcu.edu/gradposters/1039/thumbnail.jp

    Phosphido pincer complexes of platinum: synthesis, structure and reactivity

    Get PDF
    A series of platinum(II) complexes supported by the tridentate bis(phosphine)phosphido ligand bis(2-diisopropylphosphinophenyl)phosphide) [iPr–PPP] have been synthesized and characterized (1–4). X-Ray structural studies of [iPr–PPP]PtCl (1) and [iPr–PPP]PtCH3 (3) complexes show meridional [iPr–PPP] ligands around approximately square-planar platinum centers. Structural data and NMR analysis highlight a strong trans influence for the phosphido phosphorous donor, comparable to that of the anionic aryl carbon of the classic PCP pincer complexes. A series of thermally stable [PPP]Pt(IV) compounds, including [PPP]Pt(CH_3)_2X [X = I (5) and SbF_6 (6)], were also synthesized. The study of the binding affinity of SO_2 and NO to complex 1 has also been addressed

    On ``hyperboloidal'' Cauchy data for vacuum Einstein equations and obstructions to smoothness of ``null infinity''

    Get PDF
    Various works have suggested that the Bondi--Sachs--Penrose decay conditions on the gravitational field at null infinity are not generally representative of asymptotically flat space--times. We have made a detailed analysis of the constraint equations for ``asymptotically hyperboloidal'' initial data and find that log terms arise generically in asymptotic expansions. These terms are absent in the corresponding Bondi--Sachs--Penrose expansions, and can be related to explicit geometric quantities. We have nevertheless shown that there exists a large class of ``non--generic'' solutions of the constraint equations, the evolution of which leads to space--times satisfying the Bondi--Sachs--Penrose smoothness conditions.Comment: 8 pages, revtex styl

    Disordered Flat Phase and Phase Diagram for Restricted Solid on Solid Models of Fcc(110) Surfaces

    Full text link
    We discuss the results of a study of restricted solid-on-solid models for fcc (110) surfaces. These models are simple modifications of the exactly solvable BCSOS model, and are able to describe a (2×1)(2\times 1) missing-row reconstructed surface as well as an unreconstructed surface. They are studied in two different ways. The first is by mapping the problem onto a quantum spin-1/2 one-dimensional hamiltonian of the Heisenberg type, with competing SizSjzS^z_iS^z_j couplings. The second is by standard Monte Carlo simulations. We find phase diagrams with the following features, which we believe to be quite generic: (i) two flat, ordered phases (unreconstructed and missing-row reconstructed); a rough, disordered phase; an intermediate disordered flat (DF) phase, characterized by monoatomic steps, whose physics is shown to be akin to that of a dimer spin state. (ii) a transition line from the (2×1)(2\times 1) reconstructed phase to the DF phase showing exponents which appear to be close, within our numerical accuracy, to the 2D-Ising universality class. (iii) a critical (preroughening) line with variable exponents, separating the unreconstructed phase from the DF phase. Possible signatures and order parameters of the DF phase are investigated.Comment: Revtex (22 pages) + 15 figures (uuencoded file

    Simulation of adsorbate-induced faceting on curved surfaces

    Full text link
    A simple solid-on-solid model, proposed earlier to describe overlayer-induced faceting of bcc(111) surface, is applied to faceting of spherical surfaces covered by adsorbate monolayer. Monte Carlo simulation results show that morphology of faceted surface depends on annealing temperature. At initial stage surface around the [111] pole consists of 3-sided pyramids and step-like facets, then step-like facets dominate and their number decreases with temperature, finally a single big pyramid is formed. It is shown that there is reversible phase transition at which faceted surface transforms to almost spherical one. It is found that temperature of this phase transition is an increasing function of surface curvature. Simulation results show that measurements of high temperature properties performed directly and after fast cooling to low temperature lead to different results.Comment: 8 pages, 10 figure

    A study on the Abruzzo 6 April 2009 earthquake by applying the RST approach to 15 years of AVHRR TIR observations

    Get PDF
    A self adaptive approach (RST, Robust Satellite Technique) has been proposed as a suitable tool for satellite TIR surveys in seismically active regions devoted to detect and monitor thermal anomalies possibly related to earthquake occurrence. In this work, RST approach has been applied to 15 years of AVHRR (Advanced Very High Resolution Radiometer) thermal infrared observations in order to study the 6 April 2009 Abruzzo earthquake. Preliminary results show clear differences in TIR anomalies occurrence during the periods used for validation (15 March–15 April 2009) and the one (15 March–15 April 2008) without earthquakes with <i>M</i><sub>L</sub>≥4.5, used for confutation purposes. Quite clear TIR anomalies appears also to mark main tectonic lineaments during the preparatory phases of others, low magnitude(3.9<<i>M</i><sub>L</sub><4.6) earthquakes, occurred in the area in the same period

    The critical Ising lines of the d=2 Ashkin-Teller model

    Full text link
    The universal critical point ratio QQ is exploited to determine positions of the critical Ising transition lines on the phase diagram of the Ashkin-Teller (AT) model on the square lattice. A leading-order expansion of the ratio QQ in the presence of a non-vanishing thermal field is found from finite-size scaling and the corresponding expression is fitted to the accurate perturbative transfer-matrix data calculations for the L×LL\times L square clusters with L9L\leq 9.Comment: RevTex, 4 pages, two figure

    Equilibrium shapes and faceting for ionic crystals of body-centered-cubic type

    Full text link
    A mean field theory is developed for the calculation of the surface free energy of the staggered BCSOS, (or six vertex) model as function of the surface orientation and of temperature. The model approximately describes surfaces of crystals with nearest neighbor attractions and next nearest neighbor repulsions. The mean field free energy is calculated by expressing the model in terms of interacting directed walks on a lattice. The resulting equilibrium shape is very rich with facet boundaries and boundaries between reconstructed and unreconstructed regions which can be either sharp (first order) or smooth (continuous). In addition there are tricritical points where a smooth boundary changes into a sharp one and triple points where three sharp boundaries meet. Finally our numerical results strongly suggest the existence of conical points, at which tangent planes of a finite range of orientations all intersect each other. The thermal evolution of the equilibrium shape in this model shows strong similarity to that seen experimentally for ionic crystals.Comment: 14 Pages, Revtex and 10 PostScript figures include

    Regularity for eigenfunctions of Schr\"odinger operators

    Full text link
    We prove a regularity result in weighted Sobolev spaces (or Babuska--Kondratiev spaces) for the eigenfunctions of a Schr\"odinger operator. More precisely, let K_{a}^{m}(\mathbb{R}^{3N}) be the weighted Sobolev space obtained by blowing up the set of singular points of the Coulomb type potential V(x) = \sum_{1 \le j \le N} \frac{b_j}{|x_j|} + \sum_{1 \le i < j \le N} \frac{c_{ij}}{|x_i-x_j|}, x in \mathbb{R}^{3N}, b_j, c_{ij} in \mathbb{R}. If u in L^2(\mathbb{R}^{3N}) satisfies (-\Delta + V) u = \lambda u in distribution sense, then u belongs to K_{a}^{m} for all m \in \mathbb{Z}_+ and all a \le 0. Our result extends to the case when b_j and c_{ij} are suitable bounded functions on the blown-up space. In the single-electron, multi-nuclei case, we obtain the same result for all a<3/2.Comment: to appear in Lett. Math. Phy

    A Conformally Invariant Holographic Two-Point Function on the Berger Sphere

    Full text link
    We apply our previous work on Green's functions for the four-dimensional quaternionic Taub-NUT manifold to obtain a scalar two-point function on the homogeneously squashed three-sphere (otherwise known as the Berger sphere), which lies at its conformal infinity. Using basic notions from conformal geometry and the theory of boundary value problems, in particular the Dirichlet-to-Robin operator, we establish that our two-point correlation function is conformally invariant and corresponds to a boundary operator of conformal dimension one. It is plausible that the methods we use could have more general applications in an AdS/CFT context.Comment: 1+49 pages, no figures. v2: Several typos correcte
    corecore