Centrality in children's best friend networks: the role of social behaviour

Centrality is an indicator of an individual's relative importance within a social group. Predictors of centrality in best friendship networks were examined in 146 children (70 boys, 76 girls, Mage= 9.95). Children completed measures of social confidence, social desirability, friendship quality, school liking, and loneliness, and nominated their best friends from within their class at two time points, 3 months apart. Multigroup path analysis revealed gender differences in the antecedents of centrality. Social confidence, social desirability, and friendship quality predicted changes in the indicators of centrality in best friend networks over time. In boys’ social behaviour positively predicted changes in centrality whereas in girls’ social behaviour negatively predicted changes in centrality. Together, these findings suggest that some aspects of social behaviour are influential for centrality in best friend groups

Examining the components of children's peer liking as antecedents of school adjustment

Children’s social interactions with their peers influence their psychosocial adjustment; consequently, the relationship between class-wide peer liking, same-gender peer liking, and school adjustment was explored in two age groups. Peer liking was analysed using the social relations model (SRM). In Study 1, 205 children (103 female and 102 male, Mage = 7.15, SD = 7 months) completed measures of peer liking and school adjustment, and teachers completed the Short-Form TRSSA. In Study 2, 197 children (98 female and 90 male, Mage = 9.87, SD = 5.9 months) completed measures of peer liking and school adjustment. Both studies yielded evidence of reciprocal liking and individual differences in the ratings of liking awarded to, and elicited from, both peer groups. Multigroup path analysis, with groups created according to gender, revealed that elements of liking predicted different aspects of school adjustment with some variation according to age and gender. Together, these findings suggest that the SRM can be used to examine peer liking and underscore the importance of children’s peers for school adjustment

On the birational section conjecture with local conditions

A birationally liftable Galois section s of a hyperbolic curve X/k over a number field k yields an adelic point x(s) in the smooth completion of X. We show that x(s) is X-integral outside a set of places of Dirichlet density 0, or s is cuspidal. The proof relies on $GL_2(F_\ell)$-quotients of $\pi_1(U)$ for some open U of X. If k is totally real or imaginary quadratic, we prove that all birationally adelic, non-cuspidal Galois sections come from rational points as predicted by the section conjecture of anabelian geometry. As an aside we also obtain a strong approximation result for rational points on hyperbolic curves over Q or imaginary quadratic fields.Comment: Theorem C (and Section 7) of the original version have been deleted due to a gap in the proof. This is the journal versio

A prototype and demonstrator of Akogrimo’s architecture: An approach of merging grids, SOA, and the mobile Internet

The trend of merging telecommunication infrastructures with traditional Information Technology (IT) infrastructures is ongoing and important for commercial service providers. The driver behind this development is, on one hand, the strong need for enhanced services and on the other hand, the need of telecommunication operators aiming at value-added service provisioning to a wide variety of customers. In the telecommunications sector, the IP Multimedia Subsystem (IMS) is a promising service platform, which may become a ''standard'' for supporting added-value services on top of the next generation network infrastructure. However, since its range of applicability is bound to SIP- enabled services, IMS extensions are being proposed by ''SIPifying'' applications. In parallel to these developments within the traditional IT sector, the notion of Virtual Organizations (VO) enabling collaborative businesses across organizational boundaries is addressed in the framework of Web Services (WS) standards implementing a Service-oriented Architecture (SOA). Here, concepts for controlled resource and service sharing based on WS and Semantic Technologies have been consolidated. Since the telecommunications sector has become, in the meantime ''mobile'', all concepts brought into this infrastructure must cope with the dynamics mobility brings in. Therefore, within the Akogrimo project the VO concept has been extended towards a Mobile Dynamic Virtual Organization (MDVO) concept, additionally considering key requirements of mobile users and resources. Especial attention is given to ensure the duality of the merge of both, SOA and IMS approaches to holistically support SOA-enabled mobile added-value services and their users. This work describes major results of the Akogrimo project, paying special attention to the overall Akogrimo architecture, the prototype implemented, and the key scenario in which the instantiated Akogrimo architecture shows a very clear picture of applicability, use, and an additional functional evaluation

Fabrication and electrical transport properties of embedded graphite microwires in a diamond matrix

Micrometer width and nanometer thick wires with different shapes were produced \approx 3~\upmum below the surface of a diamond crystal using a microbeam of He$^+$ ions with 1.8~MeV energy. Initial samples are amorphous and after annealing at $T\approx 1475$~K, the wires crystallized into a graphite-like structures, according to confocal Raman spectroscopy measurements. The electrical resistivity at room temperature is only one order of magnitude larger than the in-plane resistivity of highly oriented pyrolytic bulk graphite and shows a small resistivity ratio($\rho(2{\rm K})/\rho(315{\rm K}) \approx 1.275$). A small negative magnetoresistance below $T=200$~K was measured and can be well understood taking spin-dependent scattering processes into account. The used method provides the means to design and produce millimeter to micrometer sized conducting circuits with arbitrary shape embedded in a diamond matrix.Comment: 12 pages, 5 figures, to be published in Journal of Physics D: Applied Physics (Feb. 2017