A Search for Early Optical Emission from Short and Long Duration Gamma-ray Bursts

Gamma-ray bursts of short duration may harbor vital clues to the range of phenomena producing bursts. However, recent progress from the observation of optical counterparts has not benefitted the study of short bursts. We have searched for early optical emission from six gamma-ray bursts using the ROTSE-I telephoto array. Three of these events were of short duration, including GRB 980527 which is among the brightest short bursts yet observed. The data consist of unfiltered CCD optical images taken in response to BATSE triggers delivered via the GCN. For the first time, we have analyzed the entire 16 degree by 16 degree field covered for five of these bursts. In addition, we discuss a search for the optical counterpart to GRB 000201, a well-localized long burst. Single image sensitivities range from 13th to 14th magnitude around 10 s after the initial burst detection, and 14 - 15.8 one hour later. No new optical counterparts were discovered in this analysis suggesting short burst optical and gamma-ray fluxes are uncorrelated.Comment: 8 pages, 2 figures, subm. to ApJ Let

Prompt Optical Observations of Gamma-ray Bursts

The Robotic Optical Transient Search Experiment (ROTSE) seeks to measure simultaneous and early afterglow optical emission from gamma-ray bursts (GRBs). A search for optical counterparts to six GRBs with localization errors of 1 square degree or better produced no detections. The earliest limiting sensitivity is m(ROTSE) > 13.1 at 10.85 seconds (5 second exposure) after the gamma-ray rise, and the best limit is m(ROTSE) > 16.0 at 62 minutes (897 second exposure). These are the most stringent limits obtained for GRB optical counterpart brightness in the first hour after the burst. Consideration of the gamma-ray fluence and peak flux for these bursts and for GRB990123 indicates that there is not a strong positive correlation between optical flux and gamma-ray emission.Comment: 4 pages, 3 figures, submitted to ApJ Letter

Evidence-Based Decision Making When Designing Environments for Physical Activity: The Role of Public Health

© 2016, The Author(s). The important role that the environment plays in health and well-being is widely accepted, as is the impact that the built and natural environment can have on levels of physical activity. As levels of physical activity are a key determinant of health, promoting physical activity through actions to improve the environment is a priority for public health action. The challenge for public health is to ensure that the way the environment is shaped and transformed by a range of professionals, organisations and agencies, maximises health gain in relation to health, including physical activity. This article discusses how the public health profession can and should contribute to generating and disseminating evidence to inform decision-making processes for designing environments to promote physical activity. There are significant challenges to building and applying the evidence base in this area. These include the complex environments in which interventions operate, disciplinary differences in approaches to evidence generation and use, and the fact that public health has little responsibility for environmental change. However, case studies of best practice, presented in the article, offer a snapshot of how challenges can be overcome, to build an accessible evidence base and help to improve the environment for the promotion of physical activity

Correction to “Relaxation Oscillations and Stability”

SCOPUS: ar.jinfo:eu-repo/semantics/publishe