bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comprehensive K2 and Ground-based Study of CRTS J035905.9+175034, an Eclipsing SU UMa System with a Large Mass Ratio
Authors: Littlefield Colin , Garnavich Peter , Kennedy Mark , Szkody Paula , Dai Zhibin
Published: May 2018

CRTS J035905.9+175034 is the first eclipsing SU UMa system for which a superoutburst has been observed by Kepler in the short-cadence mode. The light curve contains one superoutburst, eight normal outbursts (including a precursor to the superoutburst), and several minioutbursts that are present before—but not after—the superoutburst. The superoutburst began with a precursor normal outburst, and shortly after the peak of the precursor, the system developed large-amplitude superhumps that achieved their maximum amplitude after just three superhump cycles. The period excess of the initial superhump period relative to the orbital period implies a mass ratio of 0.281 ± 0.015, placing it marginally above most theoretical predictions of the highest-possible mass ratio for superhump formation. In addition, our analysis of the variations in eclipse width and depth, as well as the hot spot amplitudes, generally provides substantiation of the thermal-tidal instability model. The K2 data, in conjunction with our ground-based time-resolved spectroscopy and photometry from 2014 to 2016, allows us to determine many of the fundamental parameters of this system.
A Multi-year Search for Transits of Proxima Centauri. I. Light Curves Corresponding to Published Ephemerides
Authors: Blank David L. , Feliz Dax , Collins Karen A. , White Graeme L. , Stassun Keivan G. , Curtis Ivan A. , Hart Rhodes , Kielkopf John F. , Nelson Peter , Relles Howard , Stockdale Christopher , Jayawardene Bandupriya , Pennypacker Carlton R. , Shankland Paul , Reichart Daniel E. , Haislip Joshua B. , Kouprianov Vladimir V.
Published: May 2018

Proxima Centauri has become the subject of intense study since the radial-velocity (RV) discovery by Anglada-Escudé et al. of a planet orbiting this nearby M dwarf every ∼11.2 days. If Proxima Centauri b transits its host star, independent confirmation of its existence is possible, and its mass and radius can be measured in units of the stellar host mass and radius. To date, there have been three independent claims of possible transit-like event detections in light curve observations obtained by the MOST satellite (in 2014–15), the Bright Star Survey Telescope telescope in Antarctica (in 2016), and the Las Campanas Observatory (in 2016). The claimed possible detections are tentative, due in part to the variability intrinsic to the host star, and in the case of the ground-based observations, also due to the limited duration of the light curve observations. Here, we present preliminary results from an extensive photometric monitoring campaign of Proxima Centauri, using telescopes around the globe and spanning from 2006 to 2017, comprising a total of 329 observations. Considering our data that coincide directly and/or phased with the previously published tentative transit detections, we are unable to independently verify those claims. We do, however, verify the previously reported ubiquitous and complex variability of the host star. We discuss possible interpretations of the data in light of the previous claims, and we discuss future analyses of these data that could more definitively verify or refute the presence of transits associated with the RV-discovered planet.
The Nucleus of Active Asteroid 311P/(2013 P5) PANSTARRS
Authors: Jewitt David , Weaver Harold , Mutchler Max , Li Jing , Agarwal Jessica , Larson Stephen
Published: May 2018

The unique inner-belt asteroid 311P/PANSTARRS (formerly P/2013 P5) is notable for its sporadic, comet-like ejection of dust in nine distinct epochs spread over ∼250 days in 2013. This curious behavior has been interpreted as the product of localized, equatorward landsliding from the surface of an asteroid rotating at the brink of instability. We obtained new Hubble Space Telescope observations to directly measure the nucleus and to search for evidence of its rapid rotation. We find a nucleus with mid-light absolute magnitude H

V
 = 19.14 ± 0.02, corresponding to an equal-area circle with radius 190 ± 30 m (assuming geometric albedo p

V
 = 0.29). However, instead of providing photometric evidence for rapid nucleus rotation, our data set a lower limit to the light-curve period, P ≥ 5.4 hr. The dominant feature of the light curve is a V-shaped minimum, ∼0.3 mag deep, which is suggestive of an eclipsing binary. Under this interpretation, the time-series data are consistent with a secondary/primary mass ratio, m

s
/m

p
 ∼ 1:6, a ratio of separation/primary radius, r/r

p
 ∼ 4 and an orbit period ∼0.8 days. These properties lie within the range of other asteroid binaries that are thought to be formed by rotational breakup. While the light-curve period is long, centripetal dust ejection is still possible if one or both components rotate rapidly (≲2 hr) and have small light-curve variation because of azimuthal symmetry. Indeed, radar observations of asteroids in critical rotation reveal “muffin-shaped” morphologies, which are closely azimuthally symmetric and which show minimal light curves. Our data are consistent with 311P being a close binary in which one or both components rotates near the centripetal limit. The mass loss in 2013 suggests that breakup occurred recently and could even be on-going. A search for fragments that might have been recently ejected beyond the Hill sphere reveals none larger than effective radius r

e
 ∼ 10 m.
Effective Induction Heating around Strongly Magnetized Stars
Authors: Kislyakova K. G. , Fossati L. , Johnstone C. P. , Noack L. , Lüftinger T. , Zaitsev V. V. , Lammer H.
Published: May 2018

Planets that are embedded in the changing magnetic fields of their host stars can experience significant induction heating in their interiors caused by the planet’s orbital motion. For induction heating to be substantial, the planetary orbit has to be inclined with respect to the stellar rotation and dipole axes. Using WX UMa, for which the rotation and magnetic axes are aligned, as an example, we show that for close-in planets on inclined orbits, induction heating can be stronger than the tidal heating occurring inside Jupiter’s satellite Io; namely, it can generate a surface heat flux exceeding 2 W m−2. An internal heating source of such magnitude can lead to extreme volcanic activity on the planet’s surface, possibly also to internal local magma oceans, and to the formation of a plasma torus around the star aligned with the planetary orbit. A strongly volcanically active planet would eject into space mostly SO2, which would then dissociate into oxygen and sulphur atoms. Young planets would also eject CO2. Oxygen would therefore be the major component of the torus. If the O i column density of the torus exceeds ≈1012 cm−2, the torus could be revealed by detecting absorption signatures at the position of the strong far-ultraviolet O i triplet at about 1304 Å. We estimate that this condition is satisfied if the O i atoms in the torus escape the system at a velocity smaller than 1–10 km s−1. These estimates are valid also for a tidally heated planet.
An Empirical Fitting Method to Type Ia Supernova Light Curves. III. A Three-parameter Relationship: Peak Magnitude, Rise Time, and Photospheric Velocity
Authors: Zheng WeiKang , Kelly Patrick L. , Filippenko Alexei V.
Published: May 2018

We examine the relationship between three parameters of Type Ia supernovae (SNe Ia): peak magnitude, rise time, and photospheric velocity at the time of peak brightness. The peak magnitude is corrected for extinction using an estimate determined from MLCS2k2 fitting. The rise time is measured from the well-observed B-band light curve with the first detection at least 1 mag fainter than the peak magnitude, and the photospheric velocity is measured from the strong absorption feature of Si ii λ6355 at the time of peak brightness. We model the relationship among these three parameters using an expanding fireball with two assumptions: (a) the optical emission is approximately that of a blackbody, and (b) the photospheric temperatures of all SNe Ia are the same at the time of peak brightness. We compare the precision of the distance residuals inferred using this physically motivated model against those from the empirical Phillips relation and the MLCS2k2 method for 47 low-redshift SNe Ia (0.005 < z < 0.04) and find comparable scatter. However, SNe Ia in our sample with higher velocities are inferred to be intrinsically fainter. Eliminating the high-velocity SNe and applying a more stringent extinction cut to obtain a “low-v golden sample” of 22 SNe, we obtain significantly reduced scatter of 0.108 ± 0.018 mag in the new relation, better than those of the Phillips relation and the MLCS2k2 method. For 250 km s−1 of residual peculiar motions, we find 68% and 95% upper limits on the intrinsic scatter of 0.07 and 0.10 mag, respectively.
Fossil Merger of a Population II Star
Authors: Fuhrmann Klaus , Chini Rolf
Published: May 2018

We report on a fossil stellar merger for the subgiant primary of the visual binary HR 3750. The subgiant leads to an age τ ≃ 3.2 Gyr for a mass M
A = 1.39 ± 0.09 M
⊙, in contradiction with its low iron-to-magnesium abundance that classifies it as a Population II (thick-disk) star. Upon the assumption of an ancient source, and since there appears to be no inner Aa–Ab subsystem for HR 3750, the mass of the subgiant primary can only be understood in terms of a merger with a former tertiary component. In a mass conserving scenario, and with M
Aa = 1.03 ± 0.03 M
⊙ as the likely progenitor mass of the primary, the mass of the accreted companion is suggestive of an M dwarf at M
Ab = 0.36 ± 0.03 M
⊙.
The Diffuse Radiation Field at High Galactic Latitudes
Authors: Akshaya M. S. , Murthy Jayant , Ravichandran S. , Henry R. C. , Overduin James
Published: May 2018

We have used GALEX observations of the north and south Galactic poles to study the diffuse ultraviolet background at locations where the Galactic light is expected to be at a minimum. We find offsets of 230–290 photon units in the far-UV (1531 Å) and 480–580 photon units in the near-UV (2361 Å). Of this, approximately 120 photon units can be ascribed to dust-scattered light and another 110 photon units (190 in the near-UV) to extragalactic radiation. The remaining radiation is, as yet, unidentified and amounts to 120–180 photon units in the far-UV and 300–400 photon units in the near-UV. We find that molecular hydrogen fluorescence contributes to the far-UV when the 100 μm surface brightness is greater than 1.08 MJy sr−1.
Demographics of Star-forming Galaxies since z ∼ 2.5. I. The UVJ Diagram in CANDELS
Authors: Fang Jerome J. , Faber S. M. , Koo David C. , Rodríguez-Puebla Aldo , Guo Yicheng , Barro Guillermo , Behroozi Peter , Brammer Gabriel , Chen Zhu , Dekel Avishai , Ferguson Henry C. , Gawiser Eric , Giavalisco Mauro , Kartaltepe Jeyhan , Kocevski Dale D. , Koekemoer Anton M. , McGrath Elizabeth J. , McIntosh Daniel , Newman Jeffrey A. , Pacifici Camilla , Pandya Viraj , Pérez-González Pablo G. , Primack Joel R. , Salmon Brett , Trump Jonathan R. , Weiner Benjamin , Willner S. P. , Acquaviva Viviana , Dahlen Tomas , Finkelstein Steven L. , Finlator Kristian , Fontana Adriano , Galametz Audrey , Grogin Norman A. , Gruetzbauch Ruth , Johnson Seth , Mobasher Bahram , Papovich Casey J. , Pforr Janine , Salvato Mara , Santini P. , van der Wel Arjen , Wiklind Tommy , Wuyts Stijn
Published: May 2018

This is the first in a series of papers examining the demographics of star-forming (SF) galaxies at 0.2 < z < 2.5 in CANDELS. We study 9100 galaxies from GOODS-S and UDS, having published values of redshifts, masses, star formation rates (SFRs), and dust attenuation (A

V
) derived from UV–optical spectral energy distribution fitting. In agreement with previous works, we find that the UVJ colors of a galaxy are closely correlated with its specific star formation rate (SSFR) and A

V
. We define rotated UVJ coordinate axes, termed S
SED and C
SED, that are parallel and perpendicular to the SF sequence and derive a quantitative calibration that predicts SSFR from C
SED with an accuracy of ∼0.2 dex. SFRs from UV–optical fitting and from UV+IR values based on Spitzer/MIPS 24 μm agree well overall, but systematic differences of order 0.2 dex exist at high and low redshifts. A novel plotting scheme conveys the evolution of multiple galaxy properties simultaneously, and dust growth, as well as star formation decline and quenching, exhibit “mass-accelerated evolution” (“downsizing”). A population of transition galaxies below the SF main sequence is identified. These objects are located between SF and quiescent galaxies in UVJ space, and have lower A

V
and smaller radii than galaxies on the main sequence. Their properties are consistent with their being in transit between the two regions. The relative numbers of quenched, transition, and SF galaxies are given as a function of mass and redshift.
The MOSDEF Survey: A Stellar Mass–SFR–Metallicity Relation Exists at z ∼ 2.3∗
Authors: Sanders Ryan L. , Shapley Alice E. , Kriek Mariska , Freeman William R. , Reddy Naveen A. , Siana Brian , Coil Alison L. , Mobasher Bahram , Davé Romeel , Shivaei Irene , Azadi Mojegan , Price Sedona H. , Leung Gene , Fetherholf Tara , Groot Laura de , Zick Tom , Fornasini Francesca M. , Barro Guillermo
Published: May 2018

We investigate the nature of the relation among stellar mass, star formation rate, and gas-phase metallicity (the

–SFR–Z relation) at high redshifts using a sample of 260 star-forming galaxies at z ∼ 2.3 from the MOSDEF survey. We present an analysis of the high-redshift

–SFR–Z relation based on several emission-line ratios for the first time. We show that a

–SFR–Z relation clearly exists at z ∼ 2.3. The strength of this relation is similar to predictions from cosmological hydrodynamical simulations. By performing a direct comparison of stacks of z ∼ 0 and z ∼ 2.3 galaxies, we find that z ∼ 2.3 galaxies have ∼0.1 dex lower metallicity at fixed

and SFR. In the context of chemical evolution models, this evolution of the

–SFR–Z relation suggests an increase with redshift of the mass-loading factor at fixed

, as well as a decrease in the metallicity of infalling gas that is likely due to a lower importance of gas recycling relative to accretion from the intergalactic medium at high redshifts. Performing this analysis simultaneously with multiple metallicity-sensitive line ratios allows us to rule out the evolution in physical conditions (e.g., N/O ratio, ionization parameter, and hardness of the ionizing spectrum) at fixed metallicity as the source of the observed trends with redshift and with SFR at fixed

at z ∼ 2.3. While this study highlights the promise of performing high-order tests of chemical evolution models at high redshifts, detailed quantitative comparisons ultimately await a full understanding of the evolution of metallicity calibrations with redshift.
An L Band Spectrum of the Coldest Brown Dwarf
Authors: Morley Caroline V. , Skemer Andrew J. , Allers Katelyn N. , Marley Mark. S. , Faherty Jacqueline K. , Visscher Channon , Beiler Samuel A. , Miles Brittany E. , Lupu Roxana , Freedman Richard S. , Fortney Jonathan J. , Geballe Thomas R. , Bjoraker Gordon L.
Published: May 2018

The coldest brown dwarf, WISE 0855, is the closest known planetary-mass, free-floating object and has a temperature nearly as cold as the solar system gas giants. Like Jupiter, it is predicted to have an atmosphere rich in methane, water, and ammonia, with clouds of volatile ices. WISE 0855 is faint at near-infrared wavelengths and emits almost all its energy in the mid-infrared. Skemer et al. presented a spectrum of WISE 0855 from 4.5–5.1 μm (M band), revealing water vapor features. Here, we present a spectrum of WISE 0855 in the L band, from 3.4–4.14 μm. We present a set of atmosphere models that include a range of compositions (metallicities and C/O ratios) and water ice clouds. Methane absorption is clearly present in the spectrum. The mid-infrared color can be better matched with a methane abundance that is depleted relative to solar abundance. We find that there is evidence for water ice clouds in the M band spectrum, and we find a lack of phosphine spectral features in both the L and M band spectra. We suggest that a deep continuum opacity source may be obscuring the near-infrared flux, possibly a deep phosphorous-bearing cloud, ammonium dihyrogen phosphate. Observations of WISE 0855 provide critical constraints for cold planetary atmospheres, bridging the temperature range between the long-studied solar system planets and accessible exoplanets. The James Webb Space Telescope will soon revolutionize our understanding of cold brown dwarfs with high-precision spectroscopy across the infrared, allowing us to study their compositions and cloud properties, and to infer their atmospheric dynamics and formation processes.
Spatiotemporal Interpolation Methods for Solar Event Trajectories
Authors: Boubrahimi Soukaina Filali , Aydin Berkay , Schuh Michael A. , Kempton Dustin , Angryk Rafal A. , Ma Ruizhe
Published: May 2018

This paper introduces four spatiotemporal interpolation methods that enrich complex, evolving region trajectories that are reported from a variety of ground-based and space-based solar observatories every day. Our interpolation module takes an existing solar event trajectory as its input and generates an enriched trajectory with any number of additional time–geometry pairs created by the most appropriate method. To this end, we designed four different interpolation techniques: MBR-Interpolation (Minimum Bounding Rectangle Interpolation), CP-Interpolation (Complex Polygon Interpolation), FI-Interpolation (Filament Polygon Interpolation), and Areal-Interpolation, which are presented here in detail. These techniques leverage k-means clustering, centroid shape signature representation, dynamic time warping, linear interpolation, and shape buffering to generate the additional polygons of an enriched trajectory. Using ground-truth objects, interpolation effectiveness is evaluated through a variety of measures based on several important characteristics that include spatial distance, area overlap, and shape (boundary) similarity. To our knowledge, this is the first research effort of this kind that attempts to address the broad problem of spatiotemporal interpolation of solar event trajectories. We conclude with a brief outline of future research directions and opportunities for related work in this area.
Novelty and Foreseeing Research Trends: The Case of Astrophysics and Astronomy
Authors: Varga Attila
Published: May 2018

Metrics based on reference lists of research articles or on keywords have been used to predict citation impact. The concept behind such metrics is that original ideas stem from the reconfiguration of the structure of past knowledge, and therefore atypical combinations in the reference lists, keywords, or classification codes indicate future high-impact research. The current paper serves as an introduction to this line of research for astronomers and also addresses some of the methodological questions in this field of innovation studies. It is still not clear if the choice of particular indexes, such as references to journals, articles, or specific bibliometric classification codes affects the relationship between atypical combinations and citation impact. To understand more aspects of the innovation process, a new metric has been devised to measure to what extent researchers are able to anticipate the changing combinatorial trends of the future. Results show that the variant of the latter anticipation scores that is based on paper combinations is a good predictor of the future citation impact of scholarly works. The study also shows that the effects of tested indexes vary with the aggregation levels that were used to construct them. A detailed analysis of combinatorial novelty in the field reveals that certain sub-fields of astronomy and astrophysics have different roles in the reconfiguration of past knowledge.
Understanding the Lomb–Scargle Periodogram
Authors: VanderPlas Jacob T.
Published: May 2018

The Lomb–Scargle periodogram is a well-known algorithm for detecting and characterizing periodic signals in unevenly sampled data. This paper presents a conceptual introduction to the Lomb–Scargle periodogram and important practical considerations for its use. Rather than a rigorous mathematical treatment, the goal of this paper is to build intuition about what assumptions are implicit in the use of the Lomb–Scargle periodogram and related estimators of periodicity, so as to motivate important practical considerations required in its proper application and interpretation.
High-cadence Imaging and Imaging Spectroscopy at the GREGOR Solar Telescope—A Collaborative Research Environment for High-resolution Solar Physics
Authors: Denker Carsten , Kuckein Christoph , Verma Meetu , Manrique Sergio J. González , Diercke Andrea , Enke Harry , Klar Jochen , Balthasar Horst , Louis Rohan E. , Dineva Ekaterina
Published: May 2018

In high-resolution solar physics, the volume and complexity of photometric, spectroscopic, and polarimetric ground-based data significantly increased in the last decade, reaching data acquisition rates of terabytes per hour. This is driven by the desire to capture fast processes on the Sun and the necessity for short exposure times “freezing” the atmospheric seeing, thus enabling ex post facto image restoration. Consequently, large-format and high-cadence detectors are nowadays used in solar observations to facilitate image restoration. Based on our experience during the “early science” phase with the 1.5 m GREGOR solar telescope (2014–2015) and the subsequent transition to routine observations in 2016, we describe data collection and data management tailored toward image restoration and imaging spectroscopy. We outline our approaches regarding data processing, analysis, and archiving for two of GREGOR’s post-focus instruments (see http://gregor.aip.de), i.e., the GREGOR Fabry–Pérot Interferometer (GFPI) and the newly installed High-Resolution Fast Imager (HiFI). The heterogeneous and complex nature of multidimensional data arising from high-resolution solar observations provides an intriguing but also a challenging example for “big data” in astronomy. The big data challenge has two aspects: (1) establishing a workflow for publishing the data for the whole community and beyond and (2) creating a collaborative research environment (CRE), where computationally intense data and postprocessing tools are colocated and collaborative work is enabled for scientists of multiple institutes. This requires either collaboration with a data center or frameworks and databases capable of dealing with huge data sets based on virtual observatory (VO) and other community standards and procedures.
Activity Analyses for Solar-type Stars Observed with Kepler. II. Magnetic Feature versus Flare Activity
Authors: He Han , Wang Huaning , Zhang Mei , Mehrabi Ahmad , Yan Yan , Yun Duo
Published: May 2018

The light curves of solar-type stars present both periodic fluctuation and flare spikes. The gradual periodic fluctuation is interpreted as the rotational modulation of magnetic features on the stellar surface and is used to deduce magnetic feature activity properties. The flare spikes in light curves are used to derive flare activity properties. In this paper, we analyze the light curve data of three solar-type stars (KIC 6034120, KIC 3118883, and KIC 10528093) observed with Kepler space telescope and investigate the relationship between their magnetic feature activities and flare activities. The analysis shows that: (1) both the magnetic feature activity and the flare activity exhibit long-term variations as the Sun does; (2) unlike the Sun, the long-term variations of magnetic feature activity and flare activity are not in phase with each other; (3) the analysis of star KIC 6034120 suggests that the long-term variations of magnetic feature activity and flare activity have a similar cycle length. Our analysis and results indicate that the magnetic features that dominate rotational modulation and the flares possibly have different source regions, although they may be influenced by the magnetic field generated through a same dynamo process.
OSSOS. VII. 800+ Trans-Neptunian Objects—The Complete Data Release
Authors: Bannister Michele T. , Gladman Brett J. , Kavelaars J. J. , Petit Jean-Marc , Volk Kathryn , Chen 陳英 Ying-Tung 同 , Alexandersen Mike , Gwyn Stephen D. J. , Schwamb Megan E. , Ashton Edward , Benecchi Susan D. , Cabral Nahuel , Dawson Rebekah I. , Delsanti Audrey , Fraser Wesley C. , Granvik Mikael , Greenstreet Sarah , Guilbert-Lepoutre Aurélie , Ip 葉永 Wing-Huen 烜 , Jakubik Marian , Jones R. Lynne , Kaib Nathan A. , Lacerda Pedro , Laerhoven Christa Van , Lawler Samantha , Lehner Matthew J. , Lin 林省 Hsing Wen 文 , Lykawka Patryk Sofia , Marsset Michaël , Murray-Clay Ruth , Pike Rosemary E. , Rousselot Philippe , Shankman Cory , Thirouin Audrey , Vernazza Pierre , Wang 王祥 Shiang-Yu 宇
Published: May 2018

The Outer Solar System Origins Survey (OSSOS), a wide-field imaging program in 2013–2017 with the Canada–France–Hawaii Telescope, surveyed 155 deg2 of sky to depths of m

r
= 24.1–25.2. We present 838 outer solar system discoveries that are entirely free of ephemeris bias. This increases the inventory of trans-Neptunian objects (TNOs) with accurately known orbits by nearly 50%. Each minor planet has 20–60 Gaia/Pan-STARRS-calibrated astrometric measurements made over 2–5 oppositions, which allows accurate classification of their orbits within the trans-Neptunian dynamical populations. The populations orbiting in mean-motion resonance with Neptune are key to understanding Neptune’s early migration. Our 313 resonant TNOs, including 132 plutinos, triple the available characterized sample and include new occupancy of distant resonances out to semimajor axis a ∼ 130 au. OSSOS doubles the known population of the nonresonant Kuiper Belt, providing 436 TNOs in this region, all with exceptionally high-quality orbits of a uncertainty σ

a
 ≤ 0.1%; they show that the belt exists from a ≳ 37 au, with a lower perihelion bound of 35 au. We confirm the presence of a concentrated low-inclination a ≃ 44 au “kernel” population and a dynamically cold population extending beyond the 2:1 resonance. We finely quantify the survey’s observational biases. Our survey simulator provides a straightforward way to impose these biases on models of the trans-Neptunian orbit distributions, allowing statistical comparison to the discoveries. The OSSOS TNOs, unprecedented in their orbital precision for the size of the sample, are ideal for testing concepts of the history of giant planet migration in the solar system.
realfast: Real-time, Commensal Fast Transient Surveys with the Very Large Array
Authors: Law C. J. , Bower G. C. , Burke-Spolaor S. , Butler B. J. , Demorest P. , Halle A. , Khudikyan S. , Lazio T. J. W. , Pokorny M. , Robnett J. , Rupen M. P.
Published: May 2018

Radio interferometers have the ability to precisely localize and better characterize the properties of sources. This ability is having a powerful impact on the study of fast radio transients, where a few milliseconds of data is enough to pinpoint a source at cosmological distances. However, recording interferometric data at millisecond cadence produces a terabyte-per-hour data stream that strains networks, computing systems, and archives. This challenge mirrors that of other domains of science, where the science scope is limited by the computational architecture as much as the physical processes at play. Here, we present a solution to this problem in the context of radio transients: realfast, a commensal, fast transient search system at the Jansky Very Large Array. realfast uses a novel architecture to distribute fast-sampled interferometric data to a 32-node, 64-GPU cluster for real-time imaging and transient detection. By detecting transients in situ, we can trigger the recording of data for those rare, brief instants when the event occurs and reduce the recorded data volume by a factor of 1000. This makes it possible to commensally search a data stream that would otherwise be impossible to record. This system will search for millisecond transients in more than 1000 hr of data per year, potentially localizing several Fast Radio Bursts, pulsars, and other sources of impulsive radio emission. We describe the science scope for realfast, the system design, expected outcomes, and ways in which real-time analysis can help in other fields of astrophysics.
Robust Period Estimation Using Mutual Information for Multiband Light Curves in the Synoptic Survey Era
Authors: Huijse Pablo , Estévez Pablo A. , Förster Francisco , Daniel Scott F. , Connolly Andrew J. , Protopapas Pavlos , Carrasco Rodrigo , Príncipe José C.
Published: May 2018

The Large Synoptic Survey Telescope (LSST) will produce an unprecedented amount of light curves using six optical bands. Robust and efficient methods that can aggregate data from multidimensional sparsely sampled time-series are needed. In this paper we present a new method for light curve period estimation based on quadratic mutual information (QMI). The proposed method does not assume a particular model for the light curve nor its underlying probability density and it is robust to non-Gaussian noise and outliers. By combining the QMI from several bands the true period can be estimated even when no single-band QMI yields the period. Period recovery performance as a function of average magnitude and sample size is measured using 30,000 synthetic multiband light curves of RR Lyrae and Cepheid variables generated by the LSST Operations and Catalog simulators. The results show that aggregating information from several bands is highly beneficial in LSST sparsely sampled time-series, obtaining an absolute increase in period recovery rate up to 50%. We also show that the QMI is more robust to noise and light curve length (sample size) than the multiband generalizations of the Lomb–Scargle and AoV periodograms, recovering the true period in 10%–30% more cases than its competitors. A python package containing efficient Cython implementations of the QMI and other methods is provided.
On the Statistical Properties of Cospectra
Authors: Huppenkothen D. , Bachetti M.
Published: May 2018

In recent years, the cross-spectrum has received considerable attention as a means of characterizing the variability of astronomical sources as a function of wavelength. The cospectrum has only recently been understood as a means of mitigating instrumental effects dependent on temporal frequency in astronomical detectors, as well as a method of characterizing the coherent variability in two wavelength ranges on different timescales. In this paper, we lay out the statistical foundations of the cospectrum, starting with the simplest case of detecting a periodic signal in the presence of white noise, under the assumption that the same source is observed simultaneously in independent detectors in the same energy range. This case is especially relevant for detecting faint X-ray pulsars in detectors heavily affected by instrumental effects, including NuSTAR, Astrosat, and IXPE, which allow for even sampling and where the cospectrum can act as an effective way to mitigate dead time. We show that the statistical distributions of both single and averaged cospectra differ considerably from those for standard periodograms. While a single cospectrum follows a Laplace distribution exactly, averaged cospectra are approximated by a Gaussian distribution only for more than ∼30 averaged segments, dependent on the number of trials. We provide an instructive example of a quasi-periodic oscillation in NuSTAR and show that applying standard periodogram statistics leads to underestimated tail probabilities for period detection. We also demonstrate the application of these distributions to a NuSTAR observation of the X-ray pulsar Hercules X-1.
Enzyme Replacement Therapy: A Review and Its Role in Treating Lysosomal Storage Diseases
Authors: Li Mindy
Published: May 2018

Lysosomal storage diseases (LSDs) are a heterogeneous group of genetic disorders caused by defects in lysosomal function that lead to multiorgan system damage. Due to wide clinical variability within even a single disorder, making a diagnosis can be difficult and identification may be delayed. Enzyme replacement therapy (ERT) was first approved as a treatment for the LSD Gaucher disease in 1991. ERT development for other LSDs followed, and ERT is currently approved for eight LSDs in the United States. ERT may help slow progression and improve clinical symptoms, but it cannot affect neurologic features due to its inability to cross the blood-brain barrier. Additional therapies for LSDs that have been investigated include stem cell transplants, gene therapy, small molecule approaches, and genome editing. Although newer approaches seem promising, there is no “cure” for any LSDs, and management remains focused on early diagnosis and treatment.

[
Pediatr Ann.
2018;47(5):e191–e197.]
Recognizing and Managing Children with a Pediatric Cancer Predisposition Syndrome: A Guide for the Pediatrician
Authors: Coury Stephanie A. , Schneider Katherine A. , Schienda Jaclyn , Tan Wen-Hann
Published: May 2018

It is estimated that at least 8% to 10% of children diagnosed with cancer have an inherited cancer predisposition syndrome. Pediatricians may be called upon to (1) identify children with symptoms suggestive of cancer that require further diagnostic testing, (2) identify children who should be referred to cancer genetics based on their personal and family histories, and (3) provide primary care to children who have an inherited cancer syndrome. This review article provides a list of clinical warning signs suggestive of childhood malignancy, discusses the personal and family history “red flags” suggestive of hereditary cancer, offers checklists to help identify patients who are candidates for cancer genetics evaluation, and describes features of the major pediatric cancer syndromes involving solid tumors and surveillance guidelines. This review aims to provide the pediatrician with the tools needed to recognize, refer, and help manage children at risk for pediatric cancer syndromes.

[
Pediatr Ann.
2018;47(5):e204–e216.]
Neonatal Intestinal Obstruction Syndrome
Authors: Vargas Manuel Gil , Miguel-Sardaneta Mariana L. , Rosas-Téllez Michelle , Pereira-Reyes Dayana , Justo-Janeiro Jaime M.
Published: May 2018

Neonatal intestinal obstruction is caused by an anatomical abnormality that produces bowel movement failure. Intestinal obstruction presents with three classic clinical signs: vomiting, abdominal distention, and failure to pass meconium. Intestinal obstruction is one of the most common causes for admitting a pediatric patient to the pediatric surgery unit in his or her first weeks of postnatal life. Congenital obstruction of the digestive tract in neonates is a common problem, with the most frequent cause being anorectal malformations (41%), followed by esophageal obstruction (24%), and duodenal obstruction (20%).

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Pediatr Ann.
2018;47(5):e220–e225.]
Constipation Management in Pediatric Primary Care
Authors: Khan Leah
Published: May 2018

Constipation is a common and often difficult to manage problem encountered in outpatient primary care. Although we give our patients many different modalities to treat constipation (eg, diet changes, behavior modification, probiotics, medication), there is little evidence to support any of these modalities. We also tend to order unnecessary tests during the diagnostic process. This article tries to clarify the diagnostic process and provide a clear treatment path to be used for functional constipation.

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Pediatr Ann.
2018;47(5):e180–e184.]
Pharmacogenomic Primer for the Pediatrician—What Is Really Important?
Authors: Manzi Shannon
Published: May 2018

Safe prescribing of medications has become increasingly challenging with dozens of new drugs and drug classes added each year. Maximizing the ability to find a medication that will work as intended while minimizing side effects can be difficult, particularly when a patient does not respond as expected. Some of the variability in response may be attributed to the patient's genetics. Pharmacogenomics is the science of examining a patient's genotype in the context of medication selection and dosing. Used correctly, the clinical application of pharmacogenomic data can be useful in decreasing the trial and error approach to medication therapy.

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Pediatr Ann.
2018;47(5):e217–e219.]
Le recours à l’effet différé de la censure par le Conseil constitutionnel : le point de vue de la Cour EDH
Authors: Koskas Michael
Published: May 2018

Une utilisation justifiée et non arbitraire : telles sont les exigences formulées par la Cour européenne des droits de l’homme quant à l’usage par le Conseil constitutionnel de son pouvoir de modulation des effets dans le temps d’une déclaration d’inconstitutionnalité. Par sa décision de rejet Chessa c. France rendue le 1er mars dernier, la Cour offre ainsi une grille d’analyse innovante pour relire à nouveaux frais certaines des décisions rendues par le juge constitutionnel au cours de ces deux dernières années.
Perceptions of City Managers About Open Government Policies
Authors: Criado J. Ignacio , Ruvalcaba-Gomez Edgar Alejandro
Published: May 2018

At this point, the role of the concept Open Government (OG) has been key promoting transparency, participation and collaboration in public administration worldwide. This article presents research about the open government (OG) phenomena in Spanish municipalities over 50,000 inhabitants (146 municipalities), using a questionnaire. Particularly, the research objective of this article is looking at the perceptions of city managers responsible for OG policies in order to understand more about this emergent public policy in the local layer of government. The results are consistent with a notion of OG associated to terms like transparency or access to information, and less to collaboration, co-production, of technologies or electronic government. In addition, the results confirm the intention of city managers to promote transparency or access to information with OG policies, while other possible outcomes (collaboration, managerial improvements or reduction of management costs) are less popular. Finally, the implementation of OG policies remains in its initial stages, whereas they are much expanded in strategic plans or units/departments at the local level of government in Spain.
Secure Digital Voting System Based on Blockchain Technology
Authors: Khan Kashif Mehboob , Arshad Junaid , Khan Muhammad Mubashir
Published: May 2018

Electronic voting or e-voting has been used in varying forms since 1970s with fundamental benefits over paper-based systems such as increased efficiency and reduced errors. However, challenges remain to the achieving of wide spread adoption of such systems, especially with respect to improving their resilience against potential faults. Blockchain is a disruptive technology of the current era and promises to improve the overall resilience of e-voting systems. This article presents an effort to leverage benefits of blockchain such as cryptographic foundations and transparency to achieve an effective scheme for e-voting. The proposed scheme conforms to the fundamental requirements for e-voting schemes and achieves end-to-end verifiability. The article presents details of the proposed e-voting scheme along with its implementation using Multichain platform. The article also presents an in-depth evaluation of the scheme which successfully demonstrates its effectiveness to achieve an end-to-end verifiable e-voting scheme.
Developing Countries E-Government Services Evaluation Identifying and Testing Antecedents of Satisfaction Case of Algeria
Authors: Idoughi Djilali , Abdelhakim Djeddi
Published: May 2018

Because user's satisfaction is considered one of the most important factors in e-government success assessment, this study examines impacts of system quality, information quality, service quality, digital skills, access means, service awareness, trust, and perceived usefulness on expressed satisfaction about e-government services. Using survey, 1453 valid responses were collected from e-government services users across Algeria. The study empirical outcomes shows eight out of nine identified factors have significant impacts on users' satisfaction with e-government services.
Energy Efficient CA based Page Rank Validation Model
Authors: Mitra Arnab , Kundu Anirban
Published: May 2018

Page rank plays an important role in processing of an indexed list for relevant web pages/ clouds by search engines. Validation of computed page rank is significantly important towards the reliability enhancement for a computed page rank. Besides, energy efficiency is a major concern towards environmental sustainability. Detailed analysis on the Cellular Automata based page rank validation model explores that energy efficiency, and low cost physical implementation capability are present in it, and thus it explores its potential competence as a green model in Cloud environment. Experimental results confirm the effectiveness of proposed design.
The Role of the Internet of Things in the Improvement and Expansion of Business
Authors: Hamidi Hodjat , Jahanshahifard Maryam
Published: May 2018

The Internet of Things (IOT) has been examined in several perspectives based on the goals and visions of the present report. First, in this report based on previous studies, the general framework of business models in the Internet of Things has been analyzed, and then the suggested framework is presented. In the following, the business models of the Internet of Things and the impact of Internet of Things on the existing business models are studied. Thus, first of all, recognizing the elements of business models related to the Internet of Things is essential which has been addressed in the report. The results of different studies led to recognition of almost all business models in this field and to stating the most important components of the business models affected by the Internet of Things. The authors are still in the beginning of the process of Internet of Things. Most of the companies are willing to offer and sell the connected products and in near future, the majority of organizations will adopt more complex and ecosystem models. The purpose of this report is to offers social and business ideas to innovators so they can improve business models using the Internet of Things. This report examines the business models and proposed existing frameworks along with the economic energy of Internet of Things according to the successful projects in this scope, and offers the general logic for services or products that can be used as the basis of specific elements and patterns of business models of IOT.
Schistosomiasis Induces Persistent DNA Methylation and Tuberculosis-Specific Immune Changes
Authors: DiNardo Andrew R. , Nishiguchi Tomoki , Mace Emily M. , Rajapakshe Kimal , Mtetwa Godwin , Kay Alexander , Maphalala Gugu , Secor W. Evan , Mejia Rojelio , Orange Jordan S. , Coarfa Cristian , Bhalla Kapil N. , Graviss Edward A. , Mandalakas Anna M. , Makedonas George
Published: May 2018

Epigenetic mechanisms, such as DNA methylation, determine immune cell phenotype. To understand the epigenetic alterations induced by helminth coinfections, we evaluated the longitudinal effect of ascariasis and schistosomiasis infection on CD4+ T cell DNA methylation and the downstream tuberculosis (TB)–specific and bacillus Calmette–Guérin–induced immune phenotype. All experiments were performed on human primary immune cells from a longitudinal cohort of recently TB-exposed children. Compared with age-matched uninfected controls, children with active Schistosoma haematobium and Ascaris lumbricoides infection had 751 differentially DNA-methylated genes, with 72% hypermethylated. Gene ontology pathway analysis identified inhibition of IFN-γ signaling, cellular proliferation, and the Th1 pathway. Targeted real-time quantitative PCR after methyl-specific endonuclease digestion confirmed DNA hypermethylation of the transcription factors BATF3, ID2, STAT5A, IRF5, PPARg, RUNX2, IRF4, and NFATC1 and cytokines or cytokine receptors IFNGR1, TNFS11, RELT (TNF receptor), IL12RB2, and IL12B (p < 0.001; Sidak–Bonferroni). Functional blockage of the IFN-γ signaling pathway was confirmed, with helminth-infected individuals having decreased upregulation of IFN-γ–inducible genes (Mann–Whitney p < 0.05). Hypomethylation of the IL-4 pathway and DNA hypermethylation of the Th1 pathway was confirmed by Ag-specific multidimensional flow cytometry demonstrating decreased TB-specific IFN-γ and TNF and increased IL-4 production by CD4+ T cells (Wilcoxon signed-rank p < 0.05). In S. haematobium–infected individuals, these DNA methylation and immune phenotypic changes persisted at least 6 mo after successful deworming. This work demonstrates that helminth infection induces DNA methylation and immune perturbations that inhibit TB-specific immune control and that the duration of these changes are helminth specific.
IFNAR1 Controls Autocrine Type I IFN Regulation of PD-L1 Expression in Myeloid-Derived Suppressor Cells
Authors: Xiao Wei , Klement John D. , Lu Chunwan , Ibrahim Mohammed L. , Liu Kebin
Published: May 2018

Tumor cells respond to IFN-γ of activated T cells to upregulate programmed death-ligand 1 (PD-L1) in the tumor microenvironment as an adaptive immune resistance mechanism. Tumor cells also express oncogene-driven PD-L1. PD-L1 is also expressed on myeloid-derived suppressor cells (MDSCs). It is known that both type I and II IFNs upregulate PD-L1 expression in MDSCs. However, the molecular mechanism underlying PD-L1 expression in MDSCs is still largely unknown. We report in this article that MDSCs exhibit constitutive STAT1 phosphorylation in vitro without exogenous IFNs, indicating a constitutive active JAK-STAT signaling pathway in mouse MDSCs in vitro. Furthermore, IFN-α and IFN-β but not IFN-γ are endogenously expressed in the MDSC cell line in vitro and in tumor-induced MDSCs in vivo. Neutralizing type I IFN or inhibiting the JAK-STAT signaling pathway significantly decreased constitutive PD-L1 expression in MDSCs in vitro. However, neither IFN-α expression level nor IFN-β expression level is correlated with PD-L1 expression level in MDSCs; instead, the level of IFN receptor type I (IFNAR1) is correlated with PD-L1 expression levels in MDSCs. Consequently, knocking out IFNAR1 in mice diminished PD-L1 expression in tumor-induced MDSCs. Therefore, we determined that 1) PD-L1 expression in MDSCs is activated by type I IFN through an autocrine manner and 2) the expression level of PD-L1 is controlled at least in part by the IFNAR1 level on MDSCs. Our data indicate that MDSCs may maintain their PD-L1 expression via autocrine type I IFN to exert their suppressive activity in the absence of IFN-γ from the suppressed T cells in the tumor microenvironment.