2,597 research outputs found

    Age, Gender, and Socioeconomic Status Differences in Explicit and Implicit Beliefs About Effortlessly Perfect Self-Presentation

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    Feeling pressure to project an image of effortless perfection -- always appearing to perform with self-confidence and ease --- has been portrayed in the media as an increasingly common mental health vulnerability with potentially serious implications for college women. Despite this, almost no empirical research exists on effortlessly perfect self–presentation (EPSP) or demographic differences in it. • Some recent research suggests that perfectionism is on the rise among young people (Curran & Hill, 2017), and that it is more associated with mental health problems among students with high rather than low socioeconomic status (Lyman & Luthar, 2014). However, these studies did not focus specifically on EPSP, which differs from more typical perfectionism in that it prohibits apparent effort or anxiety while striving for perfection. Of the two published studies on EPSP, one did not examine demographic differences (Flett et al., 2016) and the other found higher endorsement of EPSP among men than among women (Travers et al., 2016). • Anonymous interviews we conducted about EPSP in 40 college students (Glazer et al., in prep) yielded very complex, self-contradictory responses suggesting that beliefs about EPSP may be characterized by stigma and ambivalence. For this reason we decided to focus the current study on indirect and implicit measures of EPSP. • In this study, participants completed three new scales about EPSP, along with the two existing measures of this phenomenon, several mental health measures, and demographics questions. They also rated the perceived social status and self-esteem of two target individuals in a within-person experimental design

    Constitutive modeling of the anisotropic behavior of Mullins softened filled rubbers

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    Original constitutive modeling is proposed for filled rubber materials in order to capture the anisotropic softened behavior induced by general non-proportional pre-loading histo-ries. The hyperelastic framework is grounded on a thorough analysis of cyclic experimental data. The strain energy density is based on a directional approach. The model leans on the strain amplification factor concept applied over material directions according to the Mul-lins softening evolution. In order to provide a model versatile that applies for a wide range of materials, the proposed framework does not require to postulate the mathematical forms of the elementary directional strain energy density and of the Mullins softening evo-lution rule. A computational procedure is defined to build both functions incrementally from experimental data obtained during cyclic uniaxial tensile tests. Successful compari-sons between the model and the experiments demonstrate the model abilities. Moreover, the model is shown to accurately predict the non-proportional uniaxial stress-stretch responses for uniaxially and biaxially pre-stretched samples. Finally, the model is effi-ciently tested on several materials and proves to provide a quantitative estimate of the anisotropy induced by the Mullins softening for a wide range of filled rubbers

    An X-ray powder diffractometer at the Daresbury Synchrotron Radiation Source

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    Study of the volume and spin collapse in orthoferrite LuFeO_3 using LDA+U

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    Rare earth (R) orthoferrites RFeO_3 exhibit large volume transitions associated with a spin collapse. We present here ab initio calculations on LuFeO_3. We show that taking into account the strong correlation among the Fe-3d electrons is necessary. Indeed, with the LDA+U method in the Projector Augmented Wave (PAW), we are able to describe the isostructural phase transition at 50 GPa, as well as a volume discontinuity of 6.0% at the transition and the considerable reduction of the magnetic moment on the Fe ions. We further investigate the effect of the variation of U and J and find a linear dependence of the transition pressure on these parameters. We give an interpretation for the non-intuitive effect of J. This emphasizes the need for a correct determination of these parameters especially when the LDA+U is applied to systems (e.g in geophysical investigations) where the transition pressure is a priori unknown

    Octahedral Tilt Instability of ReO_3-type Crystals

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    The octahedron tilt transitions of ABX_3 perovskite-structure materials lead to an anti-polar (or antiferroelectric) arrangement of dipoles, with the low temperature structure having six sublattices polarized along various crystallographic directions. It is shown that an important mechanism driving the transition is long range dipole-dipole forces acting on both displacive and induced parts of the anion dipole. This acts in concert with short range repulsion, allowing a gain of electrostatic (Madelung) energy, both dipole-dipole and charge-charge, because the unit cell shrinks when the hard ionic spheres of the rigid octahedron tilt out of linear alignment.Comment: 4 page with 3 figures included; new version updates references and clarifies the argument

    An updated assessment of the Agulhas sole resource, Austroglossus pectoralis

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    This analysis updates that of Butterworth and Glazer (2014), which considered two hypotheses of decreasing catchability and of decreasing productivity to account for a recent large drop in CPUE. Two further years of data reflect some increase in CPUE. For the most pessimistic scenario (a decrease in productivity, which remains at its current reduced level into the future), projections are somewhat more positive than previously, with recent biomasses estimated higher and projected to decrease more slowly if the 2013 effort level is maintained

    Crystal and magnetic structure of La1x_{1-x}Cax_{x}MnO3_{3} compound $(0.11\leq x\leq 0.175

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    We studied the crystal and magnetic structure of the La1x_{1-x}Cax_{x}MnO3_{3} compound for (0.11x0.175)(0.11\leq x\leq 0.175) using stoichiometric samples. For x<0.13x<0.13 the system's ground state is insulating canted antiferromagnetic. For 0.13x0.1750.13\le x \le 0.175 e below the Jahn Teller transition temperature (TJTT_{\rm JT}) the crystal structure undergoes a monoclinic distortion. The crystal structure can be described with P21/cP 2_1/c space group which permits two Mn sites. The unit cell strain parameter s=2(ac)/(a+c)s=2(a-c)/(a+c) increases for T<TJTT<T_{\rm JT}, taking the maximum value at the Curie point, and then decreases. Below TM/M//60T_{\rm M^/M^{//}}\approx 60 K ss abruptly changes slope and finally approaches T=0 K with nearly zero slope. The change of ss at TM/M//T_{\rm M^/M^{//}} is connected to a characteristic feature in the magnetic measurements. As xx increases towards the ferromagnetic metallic boundary, although ss is reduced appreciably, the monoclinic structure is preserved. The monoclinic structure is discussed with relation to the orbital ordering, which can produce the ferromagnetic insulating ground state. We also studied samples that were prepared in air atmosphere. This category of samples shows ferromagnetic insulating behavior without following the particular variation of the ss parameter. The crystal structure of these samples is related to the so-called O^{*} (c>a>b/2c>a>b/\sqrt{2}) structure

    Hypercholesterolemia is associated with hyperactive cardiac mTORC1 and mTORC2 signaling

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    Nutritional excess and hyperlipidemia increase the heart’s susceptibility to ischemic injury. Mammalian target of rapamycin (mTOR) controls the cellular response to nutritional status and may play a role in ischemic injury. To explore the effect of hypercholesterolemia on cardiac mTOR signaling, we assessed mTOR signaling in hypercholesterolemic swine (HC) that are also susceptible to increased cardiac ischemia-reperfusion injury. Yucatan pigs were fed a high-fat/high-cholesterol diet for 4 weeks to induce hypercholesterolemia, and mTOR signaling was measured by immunoblotting and immunofluorescence in the non-ischemic left ventricular area. Total myocardial mTOR and raptor levels were markedly increased in the HC group compared to the normocholesterolemic group, and directly correlated with serum cholesterol levels. mTOR exhibited intense perinuclear staining in myocytes only in the HC group. Hypercholesterolemia was associated with hyperactive signaling upstream and downstream of both mTOR complexes, including myocardial Akt, S6K1, 4EBP1, S6 and PKC-alpha, increased levels of cardiac hypertrophy markers, and a trend toward lower levels of myocardial autophagy. Hypercholesterolemia can now be added to the growing list of conditions associated with aberrant mTOR signaling. Hypercholesterolemia produces a unique profile of alterations in cardiac mTOR signaling, which is a potential target in cardiac diseases associated with hypercholesterolemia and nutritional excess
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