The onset of magnetic reconnection in space, astrophysical and laboratory plasmas is reviewed discussing results from theory, numerical simulations and observations. After a brief introduction on magnetic reconnection and approach to the question of onset, we first discuss recent theoretical models and numerical simulations, followed by observations of reconnection and its effects in space and astrophysical plasmas from satellites and ground-based detectors, as well as measurements of reconnection in laboratory plasma experiments. Mechanisms allowing reconnection spanning from collisional resistivity to kinetic effects as well as partial ionization are described, providing a description valid over a wide range of plasma parameters, and therefore applicable in principle to many different astrophysical and laboratory environments. Finally, we summarize the implications of reconnection onset physics for plasma dynamics throughout the Universe and illustrate how capturing the dynamics correctly is important to understanding particle acceleration. The goal of this review is to give a view on the present status of this topic and future interesting investigations, offering a unified approach.

Patients with damage to the cerebellum make reaching movements that are uncoordinated or “ataxic.” One prevailing hypothesis is that the cerebellum functions as an internal model for planning movements, and that damage to the cerebellum results in movements that do not properly account for arm dynamics. An exoskeleton robot was used to record multi-joint reaching movements. Subsequently, joint-torque trajectories were calculated and a gradient descent algorithm found optimal, patient-specific perturbations to actual limb dynamics predicted to reduce directional reaching errors by an average of 41%, elucidating a promising form of robotic intervention and adding support to the internal model hypothesis.

This study examined the psychometric properties of the DSM-oriented scales of the Child Behavior Checklist (Achenbach, Dumenci, & Rescorla, 2003) using confirmatory factor analysis to compare the six-factor structure of the DSM-oriented scales to competing models consistent with developmental theories of symptom differentiation. We tested these models on both clinic-referred (N = 757) and school-based, nonreferred (N = 713) samples of youths in order to assess the generalizability of the factorial structures. Although previous research has supported the fit of the six-factor DSM-oriented structure in a normative sample of youths ages 7 to 18 (Achenbach & Rescorla, 2001), tripartite model research indicates that anxiety and depressive symptomology are less differentiated among children compared to adolescents (Jacques & Mash, 2004). We thus examined the relative fit of a six- and a five-factor model (collapsing anxiety and depression) with younger (ages 7–10) and older (ages 11–18) youth subsamples. The results revealed that the six-factor model fit the best in all samples except among younger nonclinical children. The results extended the generalizability of the rationally derived six-factor structure of the DSM-oriented scales to clinic-referred youths and provided further support to the notion that younger children in nonclinical samples exhibit less differentiated symptoms of anxiety and depression.

Division VIII gathers astronomers engaged in the study of the visible and invisible matter in the Universe at large, from Local Group galaxies via distant galaxies and galaxy clusters to the large-scale structure of the Universe and the cosmic background radiation.

The members of Commission 28 on Galaxies were very busy during this General Assembly, with the Commission involved in two Symposia (IAU Symposium No. 235 Galaxy Evolution across the Hubble Time, IAU Symposium No. 238 Black Holes: from Stars to Galaxies), and two Joint Discussions (JD07 The Universe at z > 6, JD15 New Cosmology Results from the Spitzer Space Telescope). Therefore, the Business Meeting was combined with the Division VIII Business Meeting, which included a short information session on the new Commission 28 Organizing Committee. The triennial report of the Commission for 2003-2005 was also distributed, and is available on the Commission 28 web site.

As documented by the reports of the Presidents of Commission 28 and Commission 47 the fields of extra-galactic research and cosmology have experienced a higher and higher development leading to a vast harvest of results and discoveries. They range from the description of the overall structure of the universe to that of the individual properties of galaxies. The availability of very large telescopes and the coverage of regions of the sky with deep surveys, on the observational side, and the wide use of sophisticated numerical simulations on the theoretical one are starting to produce a satisfactory understanding of the physical processes taking place during the evolution of galaxies. Very often there is an profitable interplay between the subjects of the two Commissions without clearcut boundaries. This makes Division VIII, which is one of the largest of the IAU, counting 1373 members, very well balanced and deserving to remain without modifications for the future.

A satisfactory understanding of the origin of the dependence of galaxy properties on their environment has remained, so far, out of reach. In the light of numerous observational results and substantial theoretical progress obtained for clusters of galaxies in the last few years, a primary goal is to understand how the star formation activity depends on cluster substructure, i.e. on the merging/accretion history of a cluster. In this contribution we present a case in which it is possible to identify the cluster environment, and in particular the intracluster medium and the recent infall history of galaxies onto the cluster, as the cause for an abrupt change in the star formation histories of a subset of galaxies in the Coma cluster.

A main topic at this meeting is how galaxies are affected when they enter for the first time the cluster environment from the outskirts. Most of the times we are forced to infer the environmental effects indirectly, relying on systematic variations of galaxy properties with environment, but there aren't many examples of direct observations able to unveil ongoing transformations, and the corresponding mechanism producing it. We present a case in which it is possible to identify the cluster environment, and in particular the intracluster medium and the recent infall history of galaxies onto the cluster, as the cause for a recent, abrupt change in the evolutionary history of galaxies.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Photometric properties (effective surface brightness, effective radius, radial profile index, axis ratio, color, color gradient) of 328 galaxies in the Coma cluster fainter than $R=15$ mag are examined as a function of the distance from the cluster center. No significant gradient is found for the effective surface brightness, effective radius and radial profile index. The distribution of axis ratios shows a concentration of round galaxies at the cluster center in the magnitude range $16.5 \lt R \lt 18$; most of these are found to be old and to have intermediate metal abundance, suggesting that they are nucleated dwarf ellipticals. On the other hand, we find a significant gradient in color, in the sense that galaxy colours become bluer with increasing distance from the cluster center. We conclude that this color gradient represents a metallicity gradient.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We investigate the environmental dependence of galaxy properties in the local universe based on the data of the Sloan Digital Sky Survey. We focus on how star formation and morphology of galaxies correlate with luminosity, local environment, and global environment. We find that galaxy properties abruptly change at a critical local density of $\log \Sigma_{\rm crit}\sim 0.4\ {\rm galaxies}\ h_{75}^{2}\ \rm Mpc^{-2}$. The ‘break’ at the critical density is found only for faint galaxies ($M^*_r+1 < M_r < M^*_r+2$). Bright galaxies ($M_r < M^*_r+1$) show no break. That is, the star formation-density and the morphology-density relations depend on galaxy luminosity. Next, we focus on global environment, i.e., richness of galaxy groups and clusters. Most galaxies are not forming stars in groups as poor as $\sigma\sim200\rm\ km\ s^{-1}$. This fact suggests that environmental mechanisms that are effective only in rich clusters, such as ram-pressure stripping of cold gas and harassment, have not played a major role in suppressing galaxy star formation. Our results may suggest that evolution of bright galaxies is not strongly related to galaxy systems such as groups and clusters. On the other hand, evolution of faint galaxies may have a close connection.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Adhesion strength in sputter-deposited Cu thin films on various types of barrier layers was investigated by scratch test. The barrier layers were Ta1-xNx with varied nitrogen concentration of 0, 0.2, 0.3, and 0.5. Microstructure observation by TEM indicated that each layer consists of mixed phases of β;-Ta, bcc-TaN0.1, hexagonal-TaN, and fcc-TaN, depending on the nitrogen concentration. A sulfur- containing amorphous phase was also present discontinuously at the Cu/barrier interfaces in all samples. Scratch test showed that delamination occurred at the Cu/barrier interface and that the overall adhesion strength increased with increasing the nitrogen concentration. A good correlation was found between the measured adhesion strength and the composing phases in the barrier layer.

This report covers the period July 1996 to June 1999. It has been prepared by the President of the Commission with contributions from the members of the Organizing Committee and Dr. E.M. Corsini. As discussed in Kyoto and decided by the Organizing Committee, the report is meant to be in the “short” version.

The fields of research covered by Division VIII and its two Commissions have experienced remarkable progress over the last several years. This is due at least in part to the proliferation of major new observational facilities, and the addition of the several 8-m class telescopes presently being completed and new space facilities which will have a huge impact in the years to come. Many of the important recent scientific developments are summarized on the following pages in the reports of Commission 28 and Commission 47. These reports have been prepared in the “short” form, and are intended both to present the major scientific highlights and the most important conference proceedings and reviews for further reading.

Regularly spaced polymer dots are formed on a silicon surface by rubbing a thin polymer plate against the silicon substrate. Typically, the disk-shaped dots are 10 nm in height and 160 nm in diameter, and are separated by 340 nm from each other. It is found that the substrate temperature, the rubbing rate, the polymer viscoelasticity, and wettability against a substrate surface must be within a certain range to produce the aligned dots.