Steps Toward Determinaton of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. V. Variability of the Ultraviolet Continuum and Emission Lines of NGC 3783

We report on the results of intensive ultraviolet spectral monitoring of the Seyfert 1 galaxy NGC 3783. The nucleus of NGC 3783 was observed with the International Ultraviolet Explorer satellite on a regular basis for a total of 7 months, once every 4 days for the first 172 days and once every other day for the final 50 days. Significant variability was observed in both continuum and emission-line fluxes. The light curves for the continuum fluxes exhibited two well-defined local minima or dips, the first lasting ≤20 days and the second ≤ 4 days, with additional episodes of relatively rapid flickering of approximately the same amplitude. As in the case of NGC 5548 (the only other Seyfert galaxy that has been the subject of such an intensive, sustained monitoring effort), the largest continuum variations were seen at the shortest wavelengths, so that the continuum became harder when brighter. The variations in the continuum occurred simultaneously at all wave-lengths (Δt \u3c 2 days). Generally, the amplitude of variability of the emission lines was lower than (or comparable to) that of the continuum. Apart from Mg II (which varied little) and N v (which is relatively weak and badly blended with Ly∝), the light curves of the emission lines are very similar to the continuum light curves, in each case with a small systematic delay or lag. As for NGC 5548, the highest ionization lines seem to respond with shorter lags than the lower ionization lines. The lags found for NGC 3783 are considerably shorter than those obtained for NGC 5548, with values of (formally) ~0 days for He II + O III] , and ~4 days for Ly∝ and C IV. The data further suggest lags of ~4 days for Si IV + O IV] and 8-30 days for Si III] + C III]. Mg II lagged the 1460 Å continuum by ~9 days, although this result depends on the method of measuring the line flux and may in fact be due to variability of the underlying Fe II lines. Correlation analysis further shows that the power density spectrum contains substantial unresolved power over timescales of ≤ 2 days, and that the character of the continuum variability may change with time

Assessment of Gait Symmetry and Gait Normality Using Inertial Sensors : In-Lab and In-Situ Evaluation

Quantitative gait analysis is a powerful tool for the assessment of a number of physical and cognitive conditions. Unfortunately, the costs involved in providing in-lab 3D kinematic analysis to all patients is prohibitive. Inertial sensors such as accelerometers and gyroscopes may complement in-lab analysis by providing cheaper gait analysis systems that can be deployed anywhere. The present study investigates the use of inertial sensors to quantify gait symmetry and gait normality. The system was evaluated in-lab, against 3D kinematic measurements; and also in-situ, against clinical assessments of hip-replacement patients. Results show that the system not only correlates well with kinematic measurements but it also corroborates various quantitative and qualitative measures of recovery and health status of hip-replacement patientsAccelGai

Violence, identity and policing: the case of violence against transgender people

Book synopsis: The call by transgender people for the police to take violence against them more seriously has some familiar attributes. In general it is a violence characterized as hate crime. Transgender activism has highlighted many problems, for example, under-reporting, lack of trust and confidence in policing, lack of police recognition, low detection rates, clear up rates and infrequent judicial determinations of guilt. This activism might be characterized as another instance of identity politics emerging within the field of policing and criminal justice. While we welcome its emergence some scholars have been critical of the impact of identity politics upon policing and criminal justice bodies, suggesting it promotes further social and community divisions. Although we share some of these concerns, in this article we argue that these problems are the effect of particular assumptions about the nature of identity. We offer an analysis of identity politics that seeks to challenge this position, as well as an analysis of empirical data of transgender experiences of violence and insecurity arising out of research undertaken in Sydney, Australia. Our analysis exposes the multiple and simultaneous operation of many different social and cultural divisions at work in the context of transgender identity. We explore the significance of this approach to identity for policing