The Ulysses Supplement to the BATSE 3B Catalog of Cosmic Gamma-Ray Bursts

We present Interplanetary Network localization information for 218 gamma-ray bursts in the 3rd BATSE catalog, obtained by analyzing the arrival times of these bursts at the Ulysses and Compton Gamma-Ray Observatory (CGRO) spacecraft. For any given burst observed by these two spacecraft, arrival time analysis (or "triangulation") results in an annulus of possible arrival directions whose half-width varies between 7 arcseconds and 32 arcminutes, depending on the intensity and time history of the burst, and the distance of the Ulysses spacecraft from Earth. This annulus generally intersects the BATSE error circle, resulting in an average reduction of the error box area of a factor of 30.Comment: Accepted for publication in the Astrophysical Journal Supplemen

Force field feature extraction for ear biometrics

The overall objective in defining feature space is to reduce the dimensionality of the original pattern space, whilst maintaining discriminatory power for classification. To meet this objective in the context of ear biometrics a new force field transformation treats the image as an array of mutually attracting particles that act as the source of a Gaussian force field. Underlying the force field there is a scalar potential energy field, which in the case of an ear takes the form of a smooth surface that resembles a small mountain with a number of peaks joined by ridges. The peaks correspond to potential energy wells and to extend the analogy the ridges correspond to potential energy channels. Since the transform also turns out to be invertible, and since the surface is otherwise smooth, information theory suggests that much of the information is transferred to these features, thus confirming their efficacy. We previously described how field line feature extraction, using an algorithm similar to gradient descent, exploits the directional properties of the force field to automatically locate these channels and wells, which then form the basis of characteristic ear features. We now show how an analysis of the mechanism of this algorithmic approach leads to a closed analytical description based on the divergence of force direction, which reveals that channels and wells are really manifestations of the same phenomenon. We further show that this new operator, with its own distinct advantages, has a striking similarity to the Marr-Hildreth operator, but with the important difference that it is non-linear. As well as addressing faster implementation, invertibility, and brightness sensitivity, the technique is also validated by performing recognition on a database of ears selected from the XM2VTS face database, and by comparing the results with the more established technique of Principal Components Analysis. This confirms not only that ears do indeed appear to have potential as a biometric, but also that the new approach is well suited to their description, being robust especially in the presence of noise, and having the advantage that the ear does not need to be explicitly extracted from the background

No Evidence for Gamma-Ray Burst/Abell Cluster or Gamma- Ray Burst/Radio-Quiet Quasar Correlations

We examine the recent claims that cosmic gamma-ray bursts are associated with either radio-quiet quasars or Abell clusters. These associations were based on positional coincidences between cataloged quasars or Abell clusters, and selected events from the BATSE 3B catalog of gamma-ray bursts. We use a larger sample of gamma-ray bursts with more accurate positions, obtained by the 3rd Interplanetary Network, to re-evaluate these possible associations. We find no evidence for either.Comment: Accepted for publication in the Astrophysical Journa

The Relationship Between Resilience, Coping, and Social Media

This study was designed to explore relationships between measures of resilience, coping strategies, social media usage, and depression. Resilience refers to one\u27s ability to endure and recover from adversity. Many theories about what contributes to the development resilience have been explored without a clear consensus. Taormina (2015) argued that adult personal resilience is comprised of four dimensions - determination, endurance, adapatability, and recuperability. Coping, a construct related to resilience, is the process of regulating emotions, cognition, behavior, physiological responses, and the environment in response to stressful events. Past research indicated those with poorer mental health have the tendency to use maladaptive coping strategies in response to stress and are less resilient. The present study also considered how social media addiction may influence resilience and maladaptive coping. Two-hundred and ten participants were recruited to participate in the study and responded to questions assessing the aforementioned concepts. As predicted, results confirmed that greater resilience was associated with problem-focused and emotion-focused coping strategies compared to avoidant coping strategies. Furthermore, those who reported higher levels of depression were less resilient and engaged in more avoidant coping strategies, while those who employed more problem-focused coping strategies reported less depression. Results also indicated that those who were addicted to social media were more depressed. With regard to coping strategies and social media addiction, those who used mental disengagement and behavioral disengagement as coping strategies reported more problematic social media use. Possible explanations for the results of this study, including limitations and recommendations for the future, and clinical implications of the results are discussed

Planck intermediate results. II. Comparison of Sunyaev-Zeldovich measurements from Planck and from the Arcminute Microkelvin Imager for 11 galaxy clusters

A comparison is presented of Sunyaev-Zeldovich measurements for 11 galaxy clusters as obtained by Planck and by the ground-based interferometer, the Arcminute Microkelvin Imager. Assuming a universal spherically-symmetric Generalised Navarro, Frenk and White (GNFW) model for the cluster gas pressure profile, we jointly constrain the integrated Compton-Y parameter (Y500) and the scale radius (θ500) of each cluster. Our resulting constraints in the Y500 − θ500 2D parameter space derived from the two instruments overlap significantly for eight of the clusters, although, overall, there is a tendency for AMI to find the Sunyaev-Zeldovich signal to be smaller in angular size and fainter than Planck. Significant discrepancies exist for the three remaining clusters in the sample, namely A1413, A1914, and the newly-discovered Planck cluster PLCKESZ G139.59+24.18. The robustness of the analysis of both the Planck and AMI data is demonstrated through the use of detailed simulations, which also discount confusion from residual point (radio) sources and from diffuse astrophysical foregrounds as possible explanations for the discrepancies found. For a subset of our cluster sample, we have investigated the dependence of our results on the assumed pressure profile by repeating the analysis adopting the best-fitting GNFW profile shape which best matches X-ray observations. Adopting the best-fitting profile shape from the X-ray data does not, in general, resolve the discrepancies found in this subset of five clusters. Though based on a small sample, our results suggest that the adopted GNFW model may not be sufficiently flexible to describe clusters universally

Developing a Paradigm for the Measurement of Cortisol

Stress is a set of physical and mental states accompanied by specific physiological responses. The psychophysiological activation of stress centers around the hypothalamic-pituitary-adrenal axis, a group of structures that help the body cope with stress. Cortisol is the principle glucocorticoid secreted by the adrenal cortex and is known as a stress hormone. Cortisol allows the body to stay on high alert during the stress response and recording changes in cortisol can be useful in a variety of research studies. This thesis focused on the utility and pitfalls of cortisol testing and research design. Cortisol can be testing through blood, hair, and saliva, with saliva being considered among the most viable methods due to its versatility. I learned how to use a salivary cortisol ELISA assay kit and used different technologies such as single-channel and multi-channel pipettes, centrifuge, orbital shaker, and the Epoch 2 Microplate Spectrophotometer. I coordinated with my mentor, Dr. Adam Lawson, and Dr. Bradley Kraemer and Dr. Lindsay Calderon from the biology department. There were several challenges with testing cortisol, including the time of the procedure, the lack of in-depth instructions, and having to coordinate outside of the psychology lab. Testing cortisol is difficult, but not impossible. Cortisol testing could be used in experiments, but due to the challenges and time it takes to learn the procedure from the beginning, it is advisable to be done in a lab that already tests cortisol regularly

Cooling of 2 kW H subscript 2-O subscript 2 fuel cell

An extensive research and development program has been carried out to devise an improved method of removing waste heat of reaction from a developmental 2 kW hydrogen-oxygen fuel cell