9,677 research outputs found

    Amygdala reactivity predicts adolescent antisocial behavior but not callous-unemotional traits.

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    Recent neuroimaging studies have suggested divergent relationships between antisocial behavior (AB) and callous-unemotional (CU) traits and amygdala reactivity to fearful and angry facial expressions in adolescents. However, little work has examined if these findings extend to dimensional measures of behavior in ethnically diverse, non-clinical samples, or if participant sex, ethnicity, pubertal stage, and age moderate associations. We examined links between amygdala reactivity and dimensions of AB and CU traits in 220 Hispanic and non-Hispanic Caucasian adolescents (age 11-15; 49.5% female; 38.2% Hispanic), half of whom had a family history for depression and thus were at relatively elevated risk for late starting, emotionally dysregulated AB. We found that AB was significantly related to increased right amygdala reactivity to angry facial expressions independent of sex, ethnicity, pubertal stage, age, and familial risk status for depression. CU traits were not related to fear- or anger-related amygdala reactivity. The present study further demonstrates that AB is related to increased amygdala reactivity to interpersonal threat cues in adolescents, and that this relationship generalizes across sex, ethnicity, pubertal stage, age, and familial risk status for depression

    Preparation of multiblock copolymers via step-wise addition of l-lactide and trimethylene carbonate.

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    Poly(l-lactide) (PLA) is a bioderived and biodegradable polymer that has limited applications due to its hard and brittle nature. Incorporation of 1,3-trimethylene carbonate into PLA, in a block copolymer fashion, improves the mechanical properties, while retaining the biodegradability of the polymer, and broadens its range of applications. However, the preparation of 1,3-trimethylene carbonate (TMC)/l-lactide (LA) copolymers beyond diblock and triblock structures has not been reported, with explanations focusing mostly on thermodynamic reasons that impede the copolymerization of TMC after lactide. We discuss the preparation of multiblock copolymers via the ring opening polymerization (ROP) of LA and TMC, in a step-wise addition, by a ferrocene-chelating heteroscorpionate zinc complex, {[fc(PPh2)(BH[(3,5-Me)2pz]2)]Zn(μ-OCH2Ph)}2 ([(fcP,B)Zn(μ-OCH2Ph)]2, fc = 1,1'-ferrocenediyl, pz = pyrazole). The synthesis of up to pentablock copolymers, from various combinations of LA and TMC, was accomplished and the physical, thermal, and mechanical properties of the resulting copolymers evaluated

    The optimal polarizations for achieving maximum contrast in radar images

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    There is considerable interest in determining the optimal polarizations that maximize contrast between two scattering classes in polarimetric radar images. A systematic approach is presented for obtaining the optimal polarimetric matched filter, i.e., that filter which produces maximum contrast between two scattering classes. The maximization procedure involves solving an eigenvalue problem where the eigenvector corresponding to the maximum contrast ratio is an optimal polarimetric matched filter. To exhibit the physical significance of this filter, it is transformed into its associated transmitting and receiving polarization states, written in terms of horizontal and vertical vector components. For the special case where the transmitting polarization is fixed, the receiving polarization which maximizes the contrast ratio is also obtained. Polarimetric filtering is then applies to synthetic aperture radar images obtained from the Jet Propulsion Laboratory. It is shown, both numerically and through the use of radar imagery, that maximum image contrast can be realized when data is processed with the optimal polarimeter matched filter

    Measurements with the Chandra X-Ray Observatory's flight contamination monitor

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    NASA's Chandra X-ray Observatory includes a Flight Contamination Monitor (FCM), a system of 16 radioactive calibration sources mounted to the inside of the Observatory's forward contamination cover. The purpose of the FCM is to verify the ground-to-orbit transfer of the Chandra flux scale, through comparison of data acquired during the ground calibration with those obtained in orbit, immediately prior to opening the Observatory's sun-shade door. Here we report results of these measurements, which place limits on the change in mirror--detector system response and, hence, on any accumulation of molecular contamination on the mirrors' iridium-coated surfaces.Comment: 7pages,8figures,for SPIE 4012, paper 7

    Family therapy for schizophrenia: cultural challenges and implementation barriers in the South African context

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    Family therapy is an effective, evidence based intervention for schizophrenia. This literature review explores the impact of culture on family therapy as a treatment model for schizophrenia and examines how cultural beliefs impact on access to care. Although there is a good deal of evidence to suggest that certain principles of family therapy such as empathy and psycho-education are universal, there is a paucity of literature about the role of culture in designing family interventions for people living with schizophrenia in a culturally diverse setting such as South Africa. It is well acknowledged that cultural ideologies influence families’ belief systems of schizophrenia, expected expressed emotion, and levels of stigma in relation to mental illness. Additionally, in adapting models designed for first-world settings, consideration needs to be given to aspects such as language, educational level and accessibility of mental health care facilities. Family therapists are increasingly recognising the need for the study and implementation of evidence based culture-relevant and culture-responsive therapeutic techniques. These techniques need to be cost-effective and will require training, supervision, staff support, and management input in order to become generally available.Keywords: Schizophrenia; Family therapy; South Africa; Cultur

    K+ to pi-mu+mu+ and doubly-charged Higgs

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    The rate for the lepton-number-violating decay K+ to pi- mu+mu+ is calculated in a model which incorporates doubly-charged Higgs bosons. We find that for reasonable values of the parameters the decay branching ratio may be as large as 2E-16. Although this is a discouragingly small number, it is of the same order of magnitude as the rate mediated by massive Majorana neutrinos.Comment: 8 pages, RevTex, Figure1 is P

    Constructing habitus: promoting an international arts trend at the Singapore Arts Festival

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    The Singapore Arts Festival (SAF) is Singapore’s largest government-supported international arts festival. SAF presents the best in international and local arts, in an attempt, to develop what it perceives to be a lack of cultural knowledge of the Singaporean arts-going public. Using Pierre Bourdieu’s key concept of ‘habitus’ together with an analysis of the programming of the festival, this paper will highlight how the festival seeks to create a specific cultural taste in Singaporean art-goers through privileging and promoting works that are internationally marketable to European countries. The paper will conclude that this programming style occurs at the expense of Singaporean artists and hinders the development of the city’s state cultural and artistic development
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