Nonlinear refractive index of RECOB (RE = Gd and La) crystals

The Z-scan technique is employed to obtain the nonlinear refractive index (n (2)) of the Ca(4)REO(BO(3))(3) (RECOB, where RE = Gd and La) single crystals using 30 fs laser pulses centered at 780 nm for the two orthogonal orientations determined by the optical axes (X and Z) relative to the direction of propagation of the laser beam (k//Y// crystallographic b-axis). The large values of n (2) indicate that both GdCOB and LaCOB are potential hosts for Yb:RECOB lasers operating in the Kerr-lens mode locking (KLM) regime.

Framing our understanding of learning spaces redesign

Based on the assumption that space is not neutral (Gulson and Symes 2010, Soja 1989, Massey 1994) this paper presents the framework and findings of a literature review into the connections between learning spaces, school organisations, teaching and learning. The literature review identified that there are four temporal dimensions to redesigning built learning spaces: design, transition, consolidation, sustainability/evaluation. But the focus of research and policy has been on the design phase (Tanner 2009). The paper argues the research literature is more aspirational about what redesign of space around flexibility and connectivity but there is as yet lack of coherent evidence on the use of these spaces (Higgins et al 2005). Furthermore, it suggest the need to consider the various actors- the practitioners, learners and spaces- as participative redesign (Fisher 2010, Holloway and Valentine 2000) is ongoing and necessary as schools and teacher become involved over time in serial redesign. This framework guides the analysis of current and future research into learning spaces in Victoria.

Power-law distributions for the citation index of scientific publications and scientists

The number of citations of a scientific publication or of an individual scientist has become an important factor of quality assessment in science. We report a study of the statistical distribution of the citation index of both scientific publications and scientists. We give numerical evidence that Tsallis (power law) statistics explains the entire distribution over eight orders of magnitude (10-4 to 10(4)). Also, we draw Zipf plots in order to analyze the statistical distribution of the citation index of Brazilian and international physicists and chemists. The relatively small group of Brazilian scientists seems more adequate to explain the dynamics of the citation index. In this case, we find that the distribution of the citation index can also be explained by a gradually truncated power law with similar parameters. We finally discuss possible mechanisms behind the citation index of scientists and scientific publications.