Measurement of the Spatial Cross-Correlation Function of Damped Lyman Alpha Systems and Lyman Break Galaxies

We present the first spectroscopic measurement of the spatial cross-correlation function between damped Lyman alpha systems (DLAs) and Lyman break galaxies (LBGs). We obtained deep u'BVRI images of nine QSO fields with 11 known z ~ 3 DLAs and spectroscopically confirmed 211 R < 25.5 photometrically selected z > 2 LBGs. We find strong evidence for an overdensity of LBGs near DLAs versus random, the results of which are similar to that of LBGs near other LBGs. A maximum likelihood cross-correlation analysis found the best fit correlation length value of r_0 = 2.9^(+1.4)_(-1.5) h^(-1)Mpc using a fixed value of gamma = 1.6. The implications of the DLA-LBG clustering amplitude on the average dark matter halo mass of DLAs are discussed.Comment: 12 pages, 2 figures, accepted for publication in Astrophysical Journal Letter

Reviews

Tales Before Narnia: The Roots of Modern Fantasy and Science Fiction. Ed. Douglas A. Anderson. Reviewed by John D. Rateliff. The Magician\u27s Book: A Skeptic\u27s Adventures In Narnia. Laura Miller. Reviewed by Joe R. Christopher. Projecting Tolkien\u27s Musical Worlds: A Study of Musical Affect in Howard Shore\u27s Soundtrack to Lord of the Rings. Matthew Young. Reviewed by Jason Fisher. Esotericism, Art, and Imagination. Eds. Arthur Versluis, Lee Irwin, John Richards, and Melinda Weinstein. Reviewed by Emily E. Auger. The Annotated Wind in the Willows. By Kenneth Grahame; introduction by Brian Jacques; edited with a preface and notes by Annie Gauger. Reviewed by Janet Brennan Croft. The Wind in the Willows: An Annotated Edition. By Kenneth Grahame; edited by Seth Lerer. Reviewed by Janet Brennan Croft. The Illustrators of The Wind in the Willows, 1908-2008. Carolyn Hares-Stryker. Reviewed by Janet Brennan Croft. Truths Breathed Through Silver: The Inklings\u27 Moral and Mythopoeic Legacy. Ed. Jonathan B. Himes Joe R. Christopher, Salwa Khoddam. Reviewed by John D. Rateliff. Tolkien Studies: An Annual Scholarly Review. Volume vi. Edited by Douglas A. Anderson, Michael D.C. Drout, and Verlyn Flieger. Reviewed by Janet Brennan Croft

Reviews

Tolkien and Shakespeare: Essays on Shared Themes and Language. Ed. Janet Brennan Croft. Reviewed by Emily E. Auger. The Evolution of Tolkien\u27s Mythology: A Study of the History of Middle-Earth. Elizabeth A. Whittingham. Reviewed by David Bratman. Charles Williams: Alchemy and Integration. Gavin Ashenden. Reviewed by Joe R. Christopher. The History of The Hobbit. Part One: Mr. Baggins; Part Two: Return to Bag-End. John D. Rateliff. Reviewed by Jason Fisher. Past Watchful Dragons: Fantasy and Faith in the World of C. S. Lewis. Ed. Amy H. Sturgis. Reviewed by John D. Rateliff

Survey for Galaxies Associated with z~3 Damped Lyman alpha Systems II: Galaxy-Absorber Correlation Functions

We use 211 galaxy spectra from our survey for Lyman break galaxies (LBGs) associated with 11 damped Lyman alpha systems (DLAs) to measure the three-dimensional LBG auto-correlation and DLA-LBG cross-correlation functions with the primary goal of inferring the mass of DLAs at z~3. Conventional binning of the data while varying both r_0 and gamma parameters of the fiducial model of the correlation function xi(r)=(r/r_0)^{-gamma} resulted in the best fit values and 1 sigma uncertainties of r_0=2.65+/-0.48, gamma=1.55+/-0.40 for the LBG auto-correlation and r_0=3.32+/-1.25, gamma=1.74+/-0.36 for DLA-LBG cross-correlation function. To circumvent shortcomings found in binning small datasets, we perform a maximum likelihood analysis based on Poisson statistics. The best fit values and 1 sigma confidence levels from this analysis were found to be r_0=2.91(+1.0,-1.0), gamma=1.21(+0.6,-0.3) for the LBG auto-correlation and r_0=2.81(+1.4,-2.0), gamma=2.11(+1.3,-1.4) for the DLA-LBG cross-correlation function. We report a redshift spike of five LBGs with Delta z = 0.015 of the z=2.936 DLA in the PSS0808+5215 field and find that the DLA-LBG clustering signal survives when omitting this field from the analysis. Using the correlation functions measurements and uncertainties, we compute the z~3 LBG galaxy bias b_LBG to be 1.5<b_LBG<3 corresponding to an average halo mass of 10^(9.7)<M_LBG<10^(11.6) M_odot and the z~3 DLA galaxy bias b_DLA to be 1.3<b_DLA<4 corresponding to an average halo mass of 10^(9)<M_LBG<10^(12) M_odot. Lastly, two of the six QSOs discovered in this survey were found to lie within Delta z = 0.0125 of two of the survey DLAs. We estimate the probability of this occurring by chance is 1 in 940 and may indicate a possible relationship between the distribution of QSOs and DLAs at z~3.Comment: 44 pages, 12 figures, accepted to The Astrophysical Journa

IoTSan: Fortifying the Safety of IoT Systems

Today's IoT systems include event-driven smart applications (apps) that interact with sensors and actuators. A problem specific to IoT systems is that buggy apps, unforeseen bad app interactions, or device/communication failures, can cause unsafe and dangerous physical states. Detecting flaws that lead to such states, requires a holistic view of installed apps, component devices, their configurations, and more importantly, how they interact. In this paper, we design IoTSan, a novel practical system that uses model checking as a building block to reveal "interaction-level" flaws by identifying events that can lead the system to unsafe states. In building IoTSan, we design novel techniques tailored to IoT systems, to alleviate the state explosion associated with model checking. IoTSan also automatically translates IoT apps into a format amenable to model checking. Finally, to understand the root cause of a detected vulnerability, we design an attribution mechanism to identify problematic and potentially malicious apps. We evaluate IoTSan on the Samsung SmartThings platform. From 76 manually configured systems, IoTSan detects 147 vulnerabilities. We also evaluate IoTSan with malicious SmartThings apps from a previous effort. IoTSan detects the potential safety violations and also effectively attributes these apps as malicious.Comment: Proc. of the 14th ACM CoNEXT, 201

Reviews

Tolkien, Race and Cultural History: From Fairies to Hobbits. Dimitra Fimi. Reviewed by Jason Fisher. Charles Williams and his Contemporaries. Suzanne Bray and Richard Sturch, eds. Reviewed by Joe R. Christopher. In the Land of Invented Languages: Esperanto Rock Stars, Klingon Poets, Loglan Lovers, and the Mad Dreamers who Tried to Build a Perfect Language. Arika Okrent. Reviewed by Harley J. Sims. Millennial Mythmaking: Essays on the Power of Science Fiction and Fantasy Literature, Films and Games. John Perlich & David Whitt, eds. Reviewed by Priscilla Hobbs Middle-earth Minstrel: Essays on Music in Tolkien. Bradford Lee Eden, ed. Reviewed by Emily A. Moniz. Harry Potter & Imagination: The Way Between Two Worlds. Travis Prinzi. Reviewed by David D. Oberhelman. Fastitocalon: Studies in Fantasticism Ancient to Modern: Immortals and the Undead. Eds. Thomas Honneger and Fanfan Chen. Reviewed by Janet Brennan Croft. Theodor Seuss Geisel [sic]. Donald E. Pease. Reviewed by Joe R. Christopher

Realist evaluation of the use of patient experience data to improve the quality of inpatient mental health care (EURIPIDES) in England : study protocol

Introduction Inpatient mental healthcare continues to be an area of high risk and where patients report negative experiences. To ensure the patient voice is heard, National Health Service (NHS) Trusts are required to collect feedback from patients routinely. We do not know what kinds of feedback are most important or what management processes are needed to translate this into effective action plans. Further, we do not know if this makes any difference to the patients themselves. This study seeks to explore which of the many different approaches to collecting and using patient experience data are the most useful for supporting improvements in inpatient mental healthcare. The overarching aim of the study is to arrive at recommendations for best practice in the collection and use of patient experience data in NHS England adult inpatient mental health settings. We present the protocol for Realist Evaluation of the Use of Patient Experience Data to Improve the Quality of Inpatient Mental Health Care study (EURIPIDES). Methods and analysis The study is composed of five work packages (WPs), including a systematic review of patient experiences (WP1); a telephone survey to assist the selection of case sites (WP2); six in depth case studies involving interviews with service users, carers and staff to enable a realist evaluation of the use of patient experience to improve quality in adult inpatient mental health services (WP3); an economic evaluation of patient experience feedback activity (WP5); and a consensus conference (WP4). We discuss the methodological rationale for the five WPs. Ethics and dissemination This study has received approval from West Midlands/South Birmingham NHS Research Ethics Committee. The outcome of the consensus conference meeting (WP4) will form the basis of the outputs to be disseminated to NHS providers. Dissemination will also take place through publications and presentations at relevant conferences

Using patient experience data to support improvements in inpatient mental health care: the EURIPIDES multimethod study

Background All NHS providers collect data on patient experience, although there is limited evidence about what to measure or how to collect and use data to improve services. We studied inpatient mental health services, as these are important, costly and often unpopular services within which serious incidents occur. Aims To identify which approaches to collecting and using patient experience data are most useful for supporting improvements in inpatient mental health care. Design The study comprised five work packages: a systematic review to identify evidence-based patient experience themes relevant to inpatient mental health care (work package 1); a survey of patient experience leads in NHS mental health trusts in England to describe current approaches to collecting and using patient experience data in inpatient mental health services, and to populate the sampling frame for work package 3 (work package 2); in-depth case studies at sites selected using the work package 2 findings, analysed using a realist approach (work package 3); a consensus conference to agree on recommendations about best practice (work package 4); and health economic modelling to estimate resource requirements and potential benefits arising from the adoption of best practice (work package 5). Using a realist methodology, we analysed and presented our findings using a framework based on four stages of the patient experience data pathway, for which we coined the term CRAICh (collecting and giving, receiving and listening, analysing, and quality improvement and change). The project was supported by a patient and public involvement team that contributed to work package 1 and the development of programme theories (work package 3). Two employed survivor researchers worked on work packages 2, 3 and 4. Setting The study was conducted in 57 NHS providers of inpatient mental health care in England. Participants In work package 2, 47 NHS patient experience leads took part and, in work package 3, 62 service users, 19 carers and 101 NHS staff participated, across six trusts. Forty-four individuals attended the work package 4 consensus conference. Results The patient experience feedback cycle was rarely completed and, even when improvements were implemented, these tended to be environmental rather than cultural. There were few examples of triangulation with patient safety or outcomes data. We identified 18 rules for best practice in collecting and using inpatient mental health experience data, and 154 realist context–mechanism–outcome configurations that underpin and explain these. Limitations The study was cross-sectional in design and we relied on examples of historical service improvement. Our health economic models (in work package 5) were therefore limited in the estimation and modelling of prospective benefits associated with the collection and use of patient experience data. Conclusions Patient experience work is insufficiently embedded in most mental health trusts. More attention to analysis and interpretation of patient experience data is needed, particularly to ways of triangulating these with outcomes and safety data. Future work Further evaluative research is needed to develop and evaluate a locally adapted intervention based on the 18 rules for best practice. Study registration The systematic review (work package 1) is registered as PROSPERO CRD42016033556

A Green Bank Telescope search for narrowband technosignatures between 1.1-1.9 GHz during 12 Kepler planetary transits

A growing avenue for determining the prevalence of life beyond Earth is to search for "technosignatures" from extraterrestrial intelligences/agents. Technosignatures require significant energy to be visible across interstellar space and thus intentional signals might be concentrated in frequency, in time, or in space, to be found in mutually obvious places. Therefore, it could be advantageous to search for technosignatures in parts of parameter space that are mutually-derivable to an observer on Earth and a distant transmitter. In this work, we used the L-band (1.1-1.9 GHz) receiver on the Robert C. Byrd Green Bank Telescope (GBT) to perform the first technosignature search pre-synchronized with exoplanet transits, covering 12 Kepler systems. We used the Breakthrough Listen turboSETI pipeline to flag narrowband hits ($\sim$3 Hz) using a maximum drift rate of $\pm$614.4 Hz/s and a signal-to-noise threshold of 5 - the pipeline returned $\sim 3.4 \times 10^5$ apparently-localized features. Visual inspection by a team of citizen scientists ruled out 99.6% of them. Further analysis found 2 signals-of-interest that warrant follow-up, but no technosignatures. If the signals-of-interest are not re-detected in future work, it will imply that the 12 targets in the search are not producing transit-aligned signals from 1.1-1.9 GHz with transmitter powers $>$60 times that of the former Arecibo radar. This search debuts a range of innovative technosignature techniques: citizen science vetting of potential signals-of-interest, a sensitivity-aware search out to extremely high drift rates, a more flexible method of analyzing on-off cadences, and an extremely low signal-to-noise threshold.Comment: 18 pages, 11 figure