Probing the extragalactic fast transient sky at minute timescales with DECam

Searches for optical transients are usually performed with a cadence of days to weeks, optimised for supernova discovery. The optical fast transient sky is still largely unexplored, with only a few surveys to date having placed meaningful constraints on the detection of extragalactic transients evolving at sub-hour timescales. Here, we present the results of deep searches for dim, minute-timescale extragalactic fast transients using the Dark Energy Camera, a core facility of our all-wavelength and all-messenger Deeper, Wider, Faster programme. We used continuous 20s exposures to systematically probe timescales down to 1.17 minutes at magnitude limits $g > 23$ (AB), detecting hundreds of transient and variable sources. Nine candidates passed our strict criteria on duration and non-stellarity, all of which could be classified as flare stars based on deep multi-band imaging. Searches for fast radio burst and gamma-ray counterparts during simultaneous multi-facility observations yielded no counterparts to the optical transients. Also, no long-term variability was detected with pre-imaging and follow-up observations using the SkyMapper optical telescope. We place upper limits for minute-timescale fast optical transient rates for a range of depths and timescales. Finally, we demonstrate that optical $g$-band light curve behaviour alone cannot discriminate between confirmed extragalactic fast transients such as prompt GRB flashes and Galactic stellar flares.Comment: Published in MNRA

Impacts of Childhood Trauma and How Schools Can Help

Plan BMany children are affected by adverse childhood experiences (ACEs). If left untreated, ACEs can lead to childhood traumatization. The impact of trauma on children’s academic performance and social functioning is significant. Children spend a lot of their time in the school setting growing up. Most students receive mental health services in the school, but there are still many schools that are not trauma-informed. School staff may not be aware of how trauma impacts children in a school setting. As a result, traumatized children are either not identified or are mislabeled with an incorrect diagnosis. Trauma-informed practices may help school staff understand the impacts of trauma, recognize trauma in their students, and support students who have been exposed to trauma. Schools can be a safe and supportive environment where children can get help in times of need. Creating trauma-sensitive schools can benefit all children regardless of their trauma history and enable all children to succeed

Younger and Older Adult Perceptions of Health-Related Risk

Color poster with text, images, charts, and graphs.Older adults (OA) are more likely to experience hypertension, hypercholesterolemia, and cardiovascular disease than are younger adults (YA). Likewise, older persons also often engage in more health preservation efforts (e.g. following a healthy diet and exercising). Although these patterns of behavior may lead to the conclusion that older adults perceive a larger risk toward their health than do younger adults, risk perception varies greatly—especially when predicting personal susceptibility to future illness. The current study used measures of risk perception and participant reports of physical activity to compare younger and older adults’ perception accuracy. We also examined the role of age-based stereotype threat in risk perceptions. If older adults are reminded of their age and their greater susceptibility to future illness due to their age, their mindset may be altered such that they experience an increased perception of disease-related risk compared to those in a control condition. We therefore hypothesize that older adults will report an overall increased perception of disease related risk, increased action self-efficacy, and greater motivation for health preservation than will younger adults, and this difference will be larger following older adults’ exposure to our age-based stereotype threat manipulation.University of Wisconsin--Eau Claire Office of Research and Sponsored Program

How Does Stimulus Difficulty Impact Study Time Allocation in Younger Adults?

Color poster with text and tables.We expect to find relationships between item-specific restudy time and (1) a person’s memory of their past test performance (a recollection of getting an answer correct or incorrect previously); (2) participants’ impressions of item difficulty following an initial study attempt; (3) objective memory accuracy during an initial test (prior to restudy); (4) subjective memory test confidence; (5) objective response times to test stimuli; and (6) subjective response time estimates (i.e., how fast they think they responded to test questions).UW-Eau Claire Blugold Fellowship Program; University of Wisconsin--Eau Claire Office of Research and Sponsored Program

How Do Stimulus Difficulty and Amount of Delay Impact Judgments of Learning Made by Younger and Older Adults?

Color poster with text and charts.Learning is most effective when we monitor our progress and direct our efforts toward unlearned material. The concept of being aware of our learning is referred to as metacognition, and we are interested in what causes a change in judgements of learning (JOLs). Prior research has supported the idea that JOLs are more accurate predictors of learning when there is a delay between study and judgement. Additionally, a delay of at least 30 seconds has been found to increase the accuracy of JOLs. The delayed JOL effect is our primary focus, and in this study we investigated whether there is a change in accuracy between immediate JOLs and JOLs taken after either a 20-, 40-, or 60-second delay. UWEC undergraduates aged 18-25 years and “workers” on Amazon’s Mechanical Turk aged 57 years and older were compared in terms of their performance on a task administered using Qualtrics online survey software. They completed a paired-associate task, wherein individual paired-associates (e.g. APPLECART) were studied. For nonzero delays, study was followed by a distractor task involving the mental rotation of 3-D objects, where participants decided whether two objects were identical when one object may be slightly rotated. The normative difficulty of paired-associates was also manipulated within-subjects; pairs were either normatively easy, moderate, or difficult-to-learn. We hypothesized that JOLs would decrease in response to longer delays and greater difficulty. We also predicted that JOLs would decrease most following a 60-second delay in comparison to no delay and when comparing normatively easy and difficult-to-learn stimuli. Difficulty of stimuli was also expected to impact cued-recall performance more than size of delay. Lastly, we anticipated similar memory monitoring accuracy for younger and older adults in terms of both JOLs and post-test confidence judgements (CJs).University of Wisconsin--Eau Claire Office of Research and Sponsored Program

The BRAVE Program. I. Improved Bulge Stellar Velocity Dispersion Estimates for a Sample of Active Galaxies

We present new bulge stellar velocity dispersion measurements for 10 active galaxies with secure MBH determinations from reverberation mapping. These new velocity dispersion measurements are based on spatially resolved kinematics from integral-field (IFU) spectroscopy. In all but one case, the field of view of the IFU extends beyond the effective radius of the galaxy, and in the case of Mrk 79 it extends to almost one half the effective radius. This combination of spatial resolution and field of view allows for secure determinations of stellar velocity dispersion within the effective radius for all 10 target galaxies. Spatially resolved maps of the first (V) and second (σ∗) moments of the line of sight velocity distribution indicate the presence of kinematic substructure in most cases. In future projects we plan to explore methods of correcting for the effects of kinematic substructure in the derived bulge stellar velocity dispersion measurements. © 2017. The American Astronomical Society. All rights reserve