Social physique anxiety and physical activity in early adolescent girls : the influence of maturation and physical activity motives

This study considered the influence of maturation on social physique anxiety (SPA), the relationship between SPA and current and future physical activity (PA) levels and the influence of motives for physical activity on this relationship in early adolescent girls (n=162; mean age=11.80±0.33 years). Participants completed the Pubertal Development Scale, the modified Social Physique Anxiety Scale and the Motives for Physical Activity Scale at baseline and the Physical Activity Questionnaire for Older Children at baseline and 6 months later. The girls became less active across the 6 months and girls in the early stages of maturation had significantly lower SPA than the girls in the middle and late stages of maturation. SPA was not related to current or future physical activity in the sample as a whole. Cluster analysis identified four groups with different motive profiles and the High Appearance and Fitness group demonstrated a moderate negative relationship between SPA and PA at phase 1, whereas the other groups did not. These findings indicate that SPA may increase with maturation and the relationship between SPA and PA is dependent on reasons for being active. For girls who are motivated to be active primarily by body-related reasons SPA is likely to lead to lower levels of PA

Social Identity Moderates the Effects of Team-Referent Attributions on Collective Efficacy but Not Emotions

Team-referent attributions are associated with collective efficacy and emotions (Allen et al. 2009). However, the contextual factors in which these attributions are formulated have been largely ignored. Therefore, the current research was designed to examine whether social identity could moderate the way individuals think about their team-referent attributions. Across two studies (cross-sectional and longitudinal), the moderating role that social identity has on these relationships was examined. In study 1, athletes (N = 227) on sport teams (K = 30) completed questionnaires assessing social identity, attributions for their team’s most recent performance (team-referent attributions), collective efficacy and emotions. Multilevel linear models revealed that social identity moderated the relationships between team-referent attributions and collective efficacy after team defeat. In Study 2, American football team players (N = 43) completed measures of collective efficacy before each game and social identity and attributions after each game. Multilevel linear models revealed that, after a team victory, social identity moderated the relationships between post-game team-referent attributions and subsequent pre-game collective efficacy. Results also indicated that the relationship between controllability and collective efficacy varied at different levels of social identity across the entire season. The results of these studies extend attribution theory by demonstrating that the relationships between team-referent attributions and collective efficacy might be moderated by social identity. Future studies may look to implement interventions aimed at maximizing collective efficacy through attribution retraining strategies while also encouraging the development of social identit

Thermolectric Materials Based on Intercalated Layered Metallic Systems

A novel thermoelectric material in the form of a unit cell including a first reagent intercalated as a semiconducting layer into a metallic layered host and a method for producing the thermoelectric material are disclosed. The unit cell is characterized by a Seebeck coefficient S of 80-140 μV/K° and an electrical conductivity σ of 103 -104 (Ωcm)-1, as well as a figure of merit Z of about 2×10-3 K-1 at 100° K

Reversible Fluorination of Graphene: towards a Two-Dimensional Wide Bandgap Semiconductor

We report the synthesis and evidence of graphene fluoride, a two-dimensional wide bandgap semiconductor derived from graphene. Graphene fluoride exhibits hexagonal crystalline order and strongly insulating behavior with resistance exceeding 10 G$\Omega$ at room temperature. Electron transport in graphene fluoride is well described by variable-range hopping in two dimensions due to the presence of localized states in the band gap. Graphene obtained through the reduction of graphene fluoride is highly conductive, exhibiting a resistivity of less than 100 k$\Omega$ at room temperature. Our approach provides a new path to reversibly engineer the band structure and conductivity of graphene for electronic and optical applications.Comment: 7 pages, 5 figures, revtex, to appear in PR

Metallic Nanoscale Fibers from Stable Iodine-Doped Carbon Nanotubes

A method of doping involves soaking single-walled carbon nanotubes in molten iodine. Excess physisorbed iodine may then be removed by annealing

\u3ci\u3eIn-Situ\u3c/i\u3e Raman Scattering Studies of Alkali-Doped Single Wall Carbon Nanotubes

Electrochemical doping and in-situ Raman scattering were used to study charge transfer in K- and Li-doped single wall carbon nanotubes (SWNT) as a function of alkali concentration. An 8 cm-1 downshift was observed for the tangential phonon mode of SWNT doped to stoichiometries of KC24 and Li1.25C6. The shift in both systems is reversible upon de-doping despite an irreversible loss of crystallinity. These results indicate that the tangential mode shifts result from electron transfer from alkali dopants to the SWNT, and that these modes are only weakly affected by long-range order within the ropes

Renormalization Group Analysis of a Noisy Kuramoto-Sivashinsky Equation

We have analyzed the Kuramoto-Sivashinsky equation with a stochastic noise term through a dynamic renormalization group calculation. For a system in which the lattice spacing is smaller than the typical wavelength of the linear instability occurring in the system, the large-distance and long-time behavior of this equation is the same as for the Kardar-Parisi-Zhang equation in one and two spatial dimensions. For the $d=2$ case the agreement is only qualitative. On the other hand, when coarse-graining on larger scales the asymptotic flow depends on the initial values of the parameters.Comment: 8 pages, 5 figures, revte