240 research outputs found

    Cross-cultural differences in temperament: Comparing paternal ratings of US and Dutch infants

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    This study conducted longitudinal comparisons of US and Dutch paternal ratings of temperament, measured via the Infant Behaviour Questionnaire-Revised, at 4 months (US n = 99; Dutch n = 127) and 12 months (US n = 66; Dutch n = 112) of age. US fathers rated their infant higher in the broad temperament trait Surgency, and its subscales vocal reactivity, high-intensity pleasure, and activity level. US fathers also rated their infants higher in negative emotionality, and its subscales of sadness, distress to limitations, and fear. Dutch infants received higher ratings in falling reactivity. Though the cultures did not differ in ratings of Orienting/regulatory capacity, US infants were higher on the subscale duration of orienting, and lower in soothability. Significant culture-by-age and culture-by-gender interactions were also noted. Overall, results are largely consistent with those reported for Dutch mothers and speak to considerable differences in early temperament development between cultures viewed as largely similar because of their Western/individualistic orientations

    Model ab initio study of charge carrier solvation and large polaron formation on conjugated carbon chains

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    Using long C_{N}H_{2} conjugated carbon chains with the polyynic structure as prototypical examples of one-dimensional (1D) semiconductors, we discuss self-localization of excess charge carriers into 1D large polarons in the presence of the interaction with a surrounding polar solvent. The solvation mechanism of self-trapping is different from the polaron formation due to coupling with bond-length modulations of the underlying atomic lattice well-known in conjugated polymers. Model ab initio computations employing the hybrid B3LYP density functional in conjunction with the polarizable continuum model are carried out demonstrating the formation of both electron- and hole-polarons. Polarons can emerge entirely due to solvation but even larger degrees of charge localization occur when accompanied by atomic displacements

    Correlated theory of triplet photoinduced absorption in phenylene-vinylene chains

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    In this paper we present results of large-scale correlated calculations of triplet photoinduced absorption (PA) spectrum of oligomers of poly-(para)phenylenevinylene (PPV) containing up to five phenyl rings. In particular, the high-energy features in the triplet PA spectrum of oligo-PPVs are the focus of this study, which, so far, have not been investigated theoretically, or experimentally. The calculations were performed using the Pariser-Parr-Pople (PPP) model Hamiltonian, and many-body effects were taken into account by means of multi-reference singles-doubles configuration interaction procedure (MRSDCI), without neglecting any molecular orbitals. The computed triplet PA spectrum of oligo-PPVs exhibits rich structure consisting of alternating peaks of high and low intensities. The predicted higher energy features of the triplet spectrum can be tested in future experiments. Additionally, theoretical estimates of exciton binding energy are also presented.Comment: To appear in Phys. Rev.

    The Global Temperament Project: Parent-Reported Temperament in Infants, Toddlers and Children from 59 Nations

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    Data from 83,423 parent reports of temperament (Surgency, Negative Affectivity, and Regulatory Capacity) in infants, toddlers and children from 341 samples gathered in 59 countries were used to investigate the relations among culture, gender and temperament. Between-nation differences in temperament were larger than those obtained in similar studies of adult personality, and most pronounced for Negative Affectivity. Nation-level patterns of Negative Affectivity were consistent across infancy, toddlerhood and childhood; and patterns of Regulatory Capacity were consistent between infancy and toddlerhood. Nations that previously reported high Extraversion, high Conscientiousness, and low Neuroticism in adults were found to demonstrate high Surgency in infants and children; and countries reporting low adult Openness and high adult Neuroticism reported high temperamental Negative Affectivity. Negative Affectivity was high in Southern Asia, Western Asia and South America; and low in Northern and Western Europe. Countries in which children were rated as high in Negative Affectivity had cultural orientations reflecting Collectivism, high Power Distance, and Short-Term Orientation. Surgency was high in Southeastern and Southern Asia and Southern Europe, and low in Eastern Asian countries characterized by philosophies of Long-Term Orientation. Low personal income was associated with high Negative Affectivity. Gender differences in temperament were largely consistent in direction with prior studies, revealing higher Regulatory Capacity in females than males and higher Surgency in males than females; with these differences becoming more pronounced at later ages

    C-axis optical properties of high Tc cuprates

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    A review is given of the experimental status of the interlayer coupling energy in the cuprates. A second c-axis plasmon is identified in the double layer compound Y123 for various dopings. The anomalous transport properties along the c-direction and in the planar directions are compared to model calculations based on strongly anisotropic scattering. An excellent description of the optical data at optimal doping is obtained if an anomalously large anisotropy of the scattering rate between cold spots and hot spots is assumed. This raises questions as to the physical meaning of these parameters.Comment: 4 pages, LaTeX, espcrc2.sty, 3 figures in encapsulated postscript forma

    Charge carrier solvation and large polaron formation on a polymer chain revealed in model ab initio computations

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    When an excess charge carrier is added to a semiconducting polymer chain, it is well known that the carrier may self-trap into a polaronic state accompanied by a bond length adjustment pattern. A different mechanism of self-localization is the solvation of charge carriers expected to take place when the polymer chain is immersed in polar media such as common solvents. We use state-of-the-art ab initio computations in conjunction with the Polarizable Continuum Model to unequivocally demonstrate solvation-induced self-consistent charge localization into large-radius one-dimensional (1D) polarons on long CNH2C_{N}H_{2} carbon chains with the polyynic structure. Within the framework used, the solvation results in a much more pronounced charge localization. We believe this mechanism of polaron formation to be of relevance for various 1D semiconductors in polar environments
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