Confirmatory factor analysis of the Test of Performance Strategies (TOPS) among adolescent athletes

The aim of the present study was to examine the factorial validity of the Test of Performance Strategies (TOPS; Thomas et al., 1999) among adolescent athletes using confirmatory factor analysis. The TOPS was designed to assess eight psychological strategies used in competition (i.e. activation, automaticity, emotional control, goal-setting, imagery, negative thinking, relaxation and self-talk,) and eight used in practice (the same strategies except negative thinking is replaced by attentional control). National-level athletes (n = 584) completed the 64-item TOPS during training camps. Fit indices provided partial support for the overall measurement model for the competition items (robust comparative fit index = 0.92, Tucker-Lewis index = 0.88, root mean square error of approximation = 0.05) but minimal support for the training items (robust comparative fit index = 0.86, Tucker-Lewis index = 0.81, root mean square error of approximation = 0.06). For the competition items, the automaticity, goal-setting, relaxation and self-talk scales showed good fit, whereas the activation, emotional control, imagery and negative thinking scales did not. For the practice items, the attentional control, emotional control, goal-setting, imagery and self-talk scales showed good fit, whereas the activation, automaticity and relaxation scales did not. Overall, it appears that the factorial validity of the TOPS for use with adolescents is questionable at present and further development is required

Deleterious Effects of Intermittent Recombinant Parathyroid Hormone on Cartilage Formation in a Rabbit Microfracture Model: a Preliminary Study

Intermittent parathyroid hormone administration can enhance fracture healing in an animal model. Despite the success of exogenous parathyroid hormone on fracture healing and spine fusion, few studies have examined the role of parathyroid hormone on cartilage formation. We determined the effects of intermittent parathyroid hormone on cartilage formation in a rabbit microfracture model of cartilage regeneration. Twelve rabbits were divided into three equal groups: (1) microfracture alone, (2) microfracture + parathyroid hormone daily for 7 days, and (3) microfracture + parathyroid hormone for 28 days. Nonoperated contralateral knees were used as controls. The animals were sacrificed at 3 months and gross and histologic analysis was performed. The microfracture alone group demonstrated the most healing on gross and histologic analysis. Treatment with either 1 or 4 weeks of parathyroid hormone inhibited cartilage formation. Although discouraging from a cartilage repair point of view, this study suggests that the role parathyroid hormone administration has in clinical fracture healing must be examined carefully. Although parathyroid hormone is beneficial to promote healing in spine fusion and midshaft fractures, its deleterious effects on cartilage formation suggests that it may have adverse effects on the outcomes of periarticular fractures such as tibial plateau injuries that require cartilage healing for a successful clinical outcome

The Impact of Non-Equipartition on Cosmological Parameter Estimation from Sunyaev-Zel'dovich Surveys

The collisionless accretion shock at the outer boundary of a galaxy cluster should primarily heat the ions instead of electrons since they carry most of the kinetic energy of the infalling gas. Near the accretion shock, the density of the intracluster medium is very low and the Coulomb collisional timescale is longer than the accretion timescale. Electrons and ions may not achieve equipartition in these regions. Numerical simulations have shown that the Sunyaev-Zel'dovich observables (e.g., the integrated Comptonization parameter Y) for relaxed clusters can be biased by a few percent. The Y-mass relation can be biased if non-equipartition effects are not properly taken into account. Using a set of hydrodynamical simulations, we have calculated three potential systematic biases in the Y-mass relations introduced by non-equipartition effects during the cross-calibration or self-calibration when using the galaxy cluster abundance technique to constraint cosmological parameters. We then use a semi-analytic technique to estimate the non-equipartition effects on the distribution functions of Y (Y functions) determined from the extended Press-Schechter theory. Depending on the calibration method, we find that non-equipartition effects can induce systematic biases on the Y functions, and the values of the cosmological parameters Omega_8, sigma_8, and the dark energy equation of state parameter w can be biased by a few percent. In particular, non-equipartition effects can introduce an apparent evolution in w of a few percent in all of the systematic cases we considered. Techniques are suggested to take into account the non-equipartition effect empirically when using the cluster abundance technique to study precision cosmology. We conclude that systematic uncertainties in the Y-mass relation of even a few percent can introduce a comparable level of biases in cosmological parameter measurements.Comment: 10 pages, 3 figures, accepted for publication in the Astrophysical Journal, abstract abridged slightly. Typos corrected in version

The parabola theorem on continued fractions

Using geometric methods borrowed from the theory of Kleinian groups, we interpret the parabola theorem on continued fractions in terms of sequences of Möbius transformations. This geometric approach allows us to relate the Stern–Stolz series, which features in the parabola theorem, to the dynamics of certain sequences of Möbius transformations acting on three-dimensional hyperbolic space. We also obtain a version of the parabola theorem in several dimensions

Examining the Relationship Between Genetic Counselors’ Attitudes Toward Deaf People and the Genetic Counseling Session

Given the medical and cultural perspectives on deafness it is important to determine if genetic counselors’ attitudes toward deaf people can affect counseling sessions for deafness genes. One hundred fifty-eight genetic counselors recruited through the National Society of Genetic Counselors Listserv completed an online survey assessing attitudes toward deaf people and scenario-specific comfort levels discussing and offering genetic testing for deafness. Respondents with deaf/Deaf friends or who work in prenatal or pediatric settings had more positive attitudes toward deaf people than those without deaf/Deaf friends or those working in ‘other’ settings. More positive attitudes toward deaf people correlated with higher comfort level talking about genetic testing for the two scenarios involving culturally Deaf clients; and correlated with higher comfort level offering genetic testing to culturally Deaf clients wishing to have a deaf child. Attitudes and comfort level were not correlated in the scenarios involving hearing or non-culturally deaf clients. These results suggest that genetic counselors’ attitudes could affect information provision and the decision making process of culturally Deaf clients. Cultural sensitivity workshops in genetic counseling training programs that incorporate personal interactions with culturally Deaf individuals are recommended. Additional suggestions for fostering personal interactions are provided

Arthritis of the base of the thumb

The purpose of this article is to outline the pathophysiology and epidemiology of arthritis of the base of the thumb. The usual presentation and diagnosis will be discussed along with the current conservative treatment options. Surgical treatment options are determined by the stage of the arthritis as well as the demands of the patient. The current standard surgical treatment options will be reviewed along with their results in the literature