Searching for γ\gamma-ray signature in WHSP blazars: Fermi-LAT detection of 150 excess signal in the 0.3-500 GeV band

A direct search of $\gamma$-ray emission centered on multi-frequency selected candidates is a valuable complementary approach to the standard search adopted in current $\gamma$-ray Fermi-LAT catalogs. Our candidates are part of the 2WHSP sample, that was assembled with the aim of providing targets for Imaging Atmospheric Cherenkov Telescopes (IACT), and is currently the largest set of high synchrotron peaked (HSP) blazars. We perform a likelihood analysis with the Fermi Science Tools using positions from 400 2WHSP blazars as seeds of tentative $\gamma$-ray sources. This enabled us to detect 150 $\gamma$-ray excess signals that have not yet been reported in previous $\gamma$-ray catalogs (1FGL, 2FGL, and 3FGL). By identifying new sources, we solve a fraction of the extragalactic isotropic $\gamma$-ray background (IGRB) composition, improving the description of the $\gamma$-ray sky. Our analysis considers the 0.3-500 GeV energy band, integrating over 7.2 yrs of Fermi-LAT observation and making use of the Pass 8 data release. Within the 150 2WHSPs that showed excess $\gamma$-ray signature: 85 are high-significance detections with test statistic (TS)$>$25, and 65 are lower-significance detections with TS between 10 to 25. We study the $\gamma$-ray photon spectral index distribution, the likelihood of detection according to the synchrotron peak brightness, and plot the measured $\gamma$-ray LogN-LogS of HSP blazars, also discussing the portion of the IGRB that has been resolved by this work. We report on four cases where we could resolve source confusion and find counterparts for unassociated 3FGL sources with the help of high-energy TS maps together with multi-frequency data. The 150 new $\gamma$-ray sources are named with the acronym 1BIGB for the first version of the Brazil ICRANet Gamma-ray Blazar catalog, in reference to the cooperation agreement supporting this work.Comment: Accepted for publication in A&A: September 01, 201

Social Construction, Knowledge Utilization, and the Politics of Poverty: A Case Study of Washington State’s General Assistance Reform

This paper addresses a gap in welfare reform literature by investigating the social constructions of poor people in state policymaking within the context of diminishing General Assistance (GA) after the Great Recession. Using Social Construction and Policy Design Theoryand thematic content analysis of Washington State’s legislative archives, I found that the negative constructions of GA recipients as deviants with undesired psychological and behavioral problems were associated with the reform direction toward a regulated, punitive model. These constructions, intersecting with the ideologies of personal responsibility and work ethic, contribute to the dismantling of the social safety net for the Washington’s poorest residents

Multi-frequency studies of very high energy peaked blazars

Observations have shown that blazars (a special sub-class of active galactic nuclei) of the high synchrotron peak type (HSPs) play a crucial role in TeV/Very High Energy (VHE) astronomy. To provide a large list of potential VHE emitters, and therefore candidate targets for current and future TeV instruments, we have assembled a catalog including over 2000 confirmed and candidate HSP blazars selected on the basis of multi-frequency data. The catalog, named 3HSP, is currently the largest and most complete sample of HSP blazars, and can be used for detailed statistical properties of the whole HSP population and may shed light on some of the the long-standing issues in the cosmological evolution of blazars. The most recent successful case is a new TeV source, PGC 2402248, was detected by the MAGIC (Major Atmospheric Gamma Imaging Cherenkov Telescopes), applying a 3HSP source as observation seed. Moreover, with a dedicated gamma-ray analysis on the position of bright 3HSP sources using Fermi PASS8 data, we have found 150 new gamma-ray detections recently published in the 1BIGB catalog. To optimise the search for new blazars making full use of all available multi-frequency data we have developed a new software tool, called VOU-Blazars. The tool, based on Virtual Observatory (VO) protocols and developed within the Open Universe initiative, can identify blazars in relatively large regions of the sky, such as gamma-ray and neutrino uncertainty regions. % and rule out bad and uncertain candidates. %With VOU-Blazars, we will find more HSP candidates and figure out the counterpart for VHE sources in a more efficient way. Using radio and gamma-ray flux limited and largest ever subsamples of the 3HSP catalog we explored the statistical and evolution properties of HSP blazars, deriving the radio and gamma-ray LogN-LogS, luminosity function, as well as testing for the presence of cosmological evolution using the V/Vmax test. Our results confirm with unprecedented statistical robustness the presence of negative evolution. The luminosity function and LogN-LogS of HSP blazars imply that there is no preference for high nu peak sources in faint luminous/flux bins, contrary to the predictions of the ``blazar sequence''

Supporting Situation Awareness and Workspace Awareness in Co-located Collaborative Systems Involving Dynamic Data

Co-located technologies can provide digital functionality to support collaborative work for multiple users in the same physical space. For example, digital tabletop computers — large interactive tables that allow users to directly interact with the content — can provide the most up-to-date map information while users can work together face-to-face. Combinations of interactive devices, large and small, can also be used together in a multi-device environment to support collaborative work of large groups. This environment allows individuals to utilize different networked devices. In some co-located group work, integrating automation into the available technologies can provide benefits such as automatically switching between different data views or updating map information based on underlying changes in deployed field agents’ locations. However, dynamic changes in the system state can create confusion for users and lead to low situation awareness. Furthermore, with the large size of a tabletop system or with multiple devices being used in the workspace, users may not be able to observe collaborators’ actions due to physical separations between users. Consequently, workspace awareness — knowledge of collaborators’ up-to-the-moment actions — can be difficult to maintain. As a result, users may be frustrated, and the collaboration may become inefficient or ineffective. The current tabletop applications involving dynamic data focus on interaction and information sharing techniques for collaboration rather than providing situation awareness support. Moreover, the situation awareness literature focuses primarily on single-user applications, whereas, the literature in workspace awareness primarily focuses on remote collaborative work. The aim of this dissertation was in supporting situation awareness of system-automated dynamic changes and workspace awareness of collaborators’ actions. The first study (Timeline Study) presented in this dissertation used tabletop systems to investigate supporting situation awareness of automated changes and workspace awareness, and the second study (Callout Bubble Study) followed up to further investigate workspace awareness support in the context of multi-device classrooms. Digital tabletop computers are increasingly being used for complex domains involving dynamic data, such as coastal surveillance and emergency response. Maintaining situation awareness of these changes driven by the system is crucial for quick and appropriate response when problems arise. However, distractors in the environment can make users miss the changes and negatively impact their situation awareness, e.g., the large size of the table and conversations with team members. As interactive event timelines have been shown to improve response time and decision accuracy after interruptions, in this dissertation they were adapted to the context of collaborative tabletop applications to address the lack of situation awareness due to dynamic changes. A user study was conducted to understand design factors related to the adaption and their impacts on situation awareness and workspace awareness. The Callout Bubble Study investigated workspace awareness support for multi-device classrooms, where students were co-located with their personal devices and were connected through a large shared virtual canvas. This context was chosen due to the environment’s ability to support work in large groups and the increasing prevalence of individual devices in co-located collaborative workspaces. By studying another co-located context, this research also sought to combine the lessons learned and provide a set of more generalized design recommendations for co-located technologies. Existing work on workspace awareness focuses on remote collaboration; however, the co-located users may not need all the information beneficial for remote work. This study aimed to balance awareness and distraction to improve students’ workspace awareness maintenance while minimizing distraction to their learning. A Callout Bubble was designed to augment students’ interactions in the shared online workspace, and a field study was conducted to understand how it impacted the students’ collaboration behaviour. Overall, the research presented in this dissertation aimed to investigate information visualizations for supporting situation awareness and workspace awareness in co-located collaborative environments. The contributions included the design of an interactive event timeline and an investigation of how the control placement (how many timelines and where they should be located) and feedback location (whether to display feedback to the group or to individuals when users interact with timelines) factors affected situation awareness. The empirical results revealed that individual timelines were more effective in facilitating situation awareness maintenance and the timelines were used mainly for perceiving new changes. Furthermore, this dissertation contributed in the design of a workspace awareness cue, Callout Bubble. The field study revealed that Callout Bubbles were effective in improving students’ coordination and self-monitoring behaviours, which in turn reduced teachers’ workloads. The dissertation provided overall design lessons learned for supporting awareness in co-located collaborative environments

A Dynamic User-Centric Mobile Context Model

Context-aware systems can dynamically adapt to user situations to provide smarter services. In general, context refers to the information that can be used to characterize these situations, and context models are deployed to specify contextual information described in context-aware systems. However, even though user context is highly dynamic, existing context models either focus on modeling static views of context or lack appropriate design abstractions to deal with dynamic aspects and interactions involving contextual elements such location, time, user roles, social relationships, and changing preferences. Moreover, virtual environments have not been modelled by most of the existing context models even though online interaction is very common and popular. This thesis presents a dynamic user-centric context model that can be used to model the aspects of context-aware systems that are subject to frequent change. Four case studies are proposed to illustrate the applicability of the approach taken by this thesis, and they are in the domains of mobile e-healthcare, mobile commerce, mobile tourism, and mobile augmented reality gaming. Benefits of the proposed model include avoiding the development of context-aware systems from scratch, enabling future use of model-driven approaches, and reducing implementation effort

Fast Bayesian methods for genetic mapping applicable for high-throughput datasets

QTL mapping is a statistical method for detecting possible gene locations (called Quantitative Trait Loci or QTL) and those genes' effects on the variation in a quantitative phenotype, such as the height of a corn plant, etc. QTL mapping has become an important issue in genetic analysis and has made important contributions to the fields of medicine and agriculture. Traditional QTL mapping methods scan the whole genome and calculate the profile likelihood ratios test statistic at each putative QTL location. The maxima of the test statistics for all putative QTL locations are compared with the genome-wide threshold to identify the QTL. In this thesis, we propose several fast Bayesian methods for QTL mapping, which not only provide direct approximate QTL posterior probabilities at all putative gene locations, but also offer highly interpretable posterior densities for linkage, without the need for Bayes factors in model selection. The applications to simulated data and real data show these methods are highly efficient and more rapid than the alternatives, grid search integration, importance sampling, Markov Chain Monte Carlo (MCMC) sampling or adaptive quadrature. Our results also provide insight into the connection between the profile likelihood ratios test statistic and the posterior probability for linkage. The results of these methods are easy to interpret and have the advantage of producing posterior densities for all model parameters. We infer the presence of QTL at locations with largest posterior probabilities. Because of the high speed and high accuracy of these methods, they are highly suitable for studying high-throughput data sets, e.g. eQTL data sets. The eQTL analysis is a very important application of QTL mapping to a microarray data set, where thousands of transcripts are treated as the phenotypes and provides us insight into the natural variation in gene expression levels. The approach offers highly interpretable direct linkage posterior densities for each transcript, and opens new avenues for research in this area. Biologically attractive priors involving explicit hyperparameters for probabilities of cis-acting and trans-acting QTL are easily incorporated. We also extend the one QTL Bayesian method to multiple QTL. The advantage of this method is the simultaneous detection of multiple QTL and appropriate modelling of their joint effects. Multiple QTL mapping can be computationally intensive, even for our efficient Bayesian approaches. Thus, a fully Bayesian multiple QTL approach for high-throughput datasets remains challenging. We investigate a heuristic for conditional search on the two-location search space that shows promise for identifying the global maximum, and offers the potential for extended approximate Bayesian approaches