158 research outputs found

    A functional polymorphism of the MAOA gene is associated with neural responses to induced anger control

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    Aggressiveness is highly heritable. Recent experimental work has linked individual differences in a functional polymorphism of the monoamine oxidase-A gene (MAOA) to anger-driven aggression. Other work has implicated the dorsal ACC (dACC) in cognitive-emotional control and the amygdala in emotional arousal. The present imaging genetics study investigated dACC and amygdala reactivity to induced anger control as a function of MAOA genotype. A research assistant asked 38 healthy male undergraduates to control their anger in response to an insult by a rude experimenter. Men with the low-expression allele showed increased dACC and amygdala activation after the insult, but men with the high-expression allele did not. Both dACC and amygdala activation independently mediated the relationship between MAOA genotype and self-reported anger control. Moreover, following the insult, men with the high-functioning allele showed functional decoupling between the amygdala and dACC, but men with the low-functioning allele did not. These results suggest that heightened dACC and amygdala activation and their connectivity are neuroaffective mechanisms underlying anger control in participants with the low-functioning allele of the MAOA gene

    Labial soft tissue volume evaluation of different techniques for ridge preservation after tooth extraction: a randomized controlled clinical trial

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    OBJECTIVE: To volumetrically evaluate soft tissue changes of different ridge preservation techniques compared to spontaneous healing 6 months after tooth extraction. MATERIALS AND METHODS: In each of 40 patients, one single-rooted tooth was extracted and four treatment modalities were randomly assigned to the following groups (n = 10 each): A) ß-tricalcium-phosphate-particles with a polylactid coating (ß-TCP), B) demineralized bovine bone mineral with 10% collagen covered with a collagen matrix (DBBM-C/CM), C) DBBM with 10% collagen covered with an autogenous soft tissue punch graft (DBBM-C/PG), D) spontaneous healing (control). Impressions were obtained before extraction and 6 months later, casts were digitized and volumetric changes at the buccal soft tissues were determined. One-way anova was performed and pair-wise Wilcoxon rank sum test with Bonferroni-Holm method was applied for comparison of differences between two groups. RESULTS: After 6 months, horizontal contour changes accounted for -1.7 ± 0.7 mm (A), -1.2 ± 0.5 mm (B), -1.2 ± 0.7 mm (C) and -1.8 ± 0.8 mm (D). None of the group comparisons reached statistical significance. CONCLUSIONS: Six months after tooth extraction all groups revealed a horizontal volume change in the buccal soft tissue contour. Application of DBBM-C/CM or DBBM-C/PG reduced the amount of volume resorption compared to ß-TCP or spontaneous healing without reaching statistically significant difference

    Isotope effect in impure high T_c superconductors

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    The influence of various kinds of impurities on the isotope shift exponent \alpha of high temperature superconductors has been studied. In these materials the dopant impurities, like Sr in La_{2-x}Sr_xCuO_4, play different role and usually occupy different sites than impurities like Zn, Fe, Ni {\it etc} intentionally introduced into the system to study its superconducting properties. In the paper the in-plane and out-of-plane impurities present in layered superconductors have been considered. They differently affect the superconducting transition temperature T_c. The relative change of isotope shift coefficient, however, is an universal function of T_c/T_{c0} (T_{c0} reffers to impurity free system) {\it i.e.} for angle independent scattering rate and density of states function it does not depend whether the change of T_c is due to in- or out-of-plane impurities. The role of the anisotropic impurity scattering in changing oxygen isotope coefficient of superconductors with various symmetries of the order parameter is elucidated. The comparison of the calculated and experimental dependence of \alpha/\alpha_0, where \alpha_0 is the clean system isotope shift coefficient, on T_c/T_{c0} is presented for a number of cases studied. The changes of \alpha calculated within stripe model of superconductivity in copper oxides resonably well describe the data on La_{1.8}Sr_{0.2}Cu_{1-x}(Fe,Ni)_xO_4, without any fitting parameters.Comment: 8 pages, 6 figures, Phys. Rev. B67 (2003) accepte

    The too-much-talent effect: Team interdependence determines when more talent is too much or not enough

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    The materials for Studies 1a and 1b have also been made publicly available via Open Science Framework and can be accessed at https://osf.io/y4c82</p

    Sub-surface Oxygen and Surface Oxide Formation at Ag(111): A Density-functional Theory Investigation

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    To help provide insight into the remarkable catalytic behavior of the oxygen/silver system for heterogeneous oxidation reactions, purely sub-surface oxygen, and structures involving both on-surface and sub-surface oxygen, as well as oxide-like structures at the Ag(111) surface have been studied for a wide range of coverages and adsorption sites using density-functional theory. Adsorption on the surface in fcc sites is energetically favorable for low coverages, while for higher coverage a thin surface-oxide structure is energetically favorable. This structure has been proposed to correspond to the experimentally observed (4x4) phase. With increasing O concentrations, thicker oxide-like structures resembling compressed Ag2O(111) surfaces are energetically favored. Due to the relatively low thermal stability of these structures, and the very low sticking probability of O2 at Ag(111), their formation and observation may require the use of atomic oxygen (or ozone, O3) and low temperatures. We also investigate diffusion of O into the sub-surface region at low coverage (0.11 ML), and the effect of surface Ag vacancies in the adsorption of atomic oxygen and ozone-like species. The present studies, together with our earlier investigations of on-surface and surface-substitutional adsorption, provide a comprehensive picture of the behavior and chemical nature of the interaction of oxygen and Ag(111), as well as of the initial stages of oxide formation.Comment: 17 pages including 14 figures, Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

    Screening Low-Income Women of Reproductive Age for Cardiovascular Disease Risk Factors

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    Identifying and treating chronic diseases, their precursors, and other cardiovascular disease (CVD) risk factors during family planning visits may improve long-term health and reproductive outcomes among low-income women. A cross-sectional study design was used to describe the prevalence of chronic diseases (hypertension, high cholesterol, and diabetes), their precursors (pre-hypertension, borderline high cholesterol, and pre-diabetes), and related CVD risk factors (such as obesity, smoking, and physical inactivity) among low-income women of reproductive age

    Safer Sex as the Bolder Choice: Testosterone Is Positively Correlated with Safer Sex Behaviorally Relevant Attitudes in Young Men

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    Introduction.  Higher testosterone (T) is tied to risk‐taking, especially in financial domains but also in health domains relevant to acquiring sexually transmitted infections (STIs). However, safer sex constructs could themselves carry the possibility of “social risk” due to sexual stigma or embarrassment, or could involve boldness or confidence because they could represent status displays of frequent sexual activity. Aim.  To determine how T and behaviorally relevant attitudes about sexual risk‐taking are linked, to better understand biopsychosocial aspects of sexual health related to STIs. Methods.  In 78 first‐year male college students, we examined correlations between salivary T and behaviorally relevant safer sex attitudes assessed via questionnaires. Main Outcome Measures.  T, via saliva; safer sex attitudes, via a composite and the University of California, Los Angeles Multidimensional Condom Attitudes Scale (MCAS). Results.  Higher T was significantly correlated with higher scores on the following: safer sex likelihood composite, r (73) = 0.33, P  = 0.003; the MCAS safer sex resilience, r (32) = 0.36, P  = 0.037; and the MCAS condom purchase comfort, r (32) = 0.37, P  = 0.031. Associations between T and safer sex likelihood and resilience were still robust after controlling for potential confounds, though the association between T and purchase comfort diminished to a trend. Conclusions.  Higher T was positively linked with safer sex attitudes, especially those most closely tied to STI risk avoidance. Thus, future research and interventions for STI prevention should address the possibility that safer sex may be paradoxically perceived as a “bold” or “risky” choice even as it decreases STI risk. van Anders SM, Goldey KL, Conley TD, Snipes DJ, and Patel DA. Safer sex as the bolder choice: Testosterone is positively correlated with safer sex behaviorally relevant attitudes in young men. J Sex Med 2012;9:727–734.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90413/1/j.1743-6109.2011.02544.x.pd
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