bluuebunny/crossref_metadata_2025_split huggingface dataset:
Full-Sky Maps of the VHF Radio Sky with the Owens Valley Radio Observatory Long Wavelength Array
Authors: Eastwood Michael W. , Hallinan Gregg 
Published: May 2018

Abstract21-cm cosmology is a powerful new probe of the intergalactic medium at redshifts 20 ≳ z ≳ 6 corresponding to the Cosmic Dawn and Epoch of Reionization. Current observations of the highly-redshifted 21-cm transition are limited by the dynamic range they can achieve against foreground sources of low-frequency (<200 MHz) of radio emission. We used the Owens Valley Radio Observatory Long Wavelength Array (OVRO-LWA) to generate a series of new modern high-fidelity sky maps that capture emission on angular scales ranging from tens of degrees to ∼15 arcmin, and frequencies between 36 and 73 MHz. These sky maps were generated from the application of Tikhonov-regularized m-mode analysis imaging, which is a new interferometric imaging technique that is uniquely suited for low-frequency, wide-field, drift-scanning interferometers.
Using low-frequency pulsar observations to study the 3-D structure of the Galactic magnetic field
Authors: Sobey C. ,   the LOFAR and MWA collaborations
Published: May 2018

AbstractThe Galactic magnetic field (GMF) plays a role in many astrophysical processes and is a significant foreground to cosmological signals, such as the Epoch of Reionization (EoR), but is not yet well understood. Dispersion and Faraday rotation measurements (DMs and RMs, respectively) towards a large number of pulsars provide an efficient method to probe the three-dimensional structure of the GMF. Low-frequency polarisation observations with large fractional bandwidth can be used to measure precise DMs and RMs. This is demonstrated by a catalogue of RMs (corrected for ionospheric Faraday rotation) from the Low Frequency Array (LOFAR), with a growing complementary catalogue in the southern hemisphere from the Murchison Widefield Array (MWA). These data further our knowledge of the three-dimensional GMF, particularly towards the Galactic halo. Recently constructed or upgraded pathfinder and precursor telescopes, such as LOFAR and the MWA, have reinvigorated low-frequency science and represent progress towards the construction of the Square Kilometre Array (SKA), which will make significant advancements in studies of astrophysical magnetic fields in the future. A key science driver for the SKA-Low is to study the EoR, for which pulsar and polarisation data can provide valuable insights in terms of Galactic foreground conditions.
Fine structure of Galactic foreground ISM towards high-redshift AGN – utilizing Herschel PACS and SPIRE data
Authors: Perger K. , Pinter S. , Frey S. , Tóth L. V. 
Published: May 2018

AbstractOne of the most certain ways to determine star formation rate in galaxies is based on far infrared (FIR) measurements. To decide the origin of the observed FIR emission, subtracting the Galactic foreground is a crucial step. We utilized Herschel photometric data to determine the hydrogen column densities in three galactic latitude regions, at b = 27°, 50° and −80°. We applied a pixel-by-pixel fit to the spectral energy distribution (SED) for the images aquired from parallel PACS-SPIRE observations in all three sky areas. We determined the column densities with resolutions 45” and 6’, and compared the results with values estimated from the IRAS dust maps. Column densities at 27° and 50° galactic latitudes determined from the Herschel data are in a good agreement with the literature values. However, at the highest galactic latitude we found that the column densities from the Herschel data exceed those derived from the IRAS dust map.
21SSD: a new public 21-cm EoR database
Authors: Eames Evan , Semelin Benoît 
Published: May 2018

AbstractWith current efforts inching closer to detecting the 21-cm signal from the Epoch of Reionization (EoR), proper preparation will require publicly available simulated models of the various forms the signal could take. In this work we present a database of such models, available at 21ssd.obspm.fr. The models are created with a fully-coupled radiative hydrodynamic simulation (LICORICE), and are created at high resolution (10243). We also begin to analyse and explore the possible 21-cm EoR signals (with Power Spectra and Pixel Distribution Functions), and study the effects of thermal noise on our ability to recover the signal out to high redshifts. Finally, we begin to explore the concepts of ‘distance’ between different models, which represents a crucial step towards optimising parameter space sampling, training neural networks, and finally extracting parameter values from observations.
Bayesian component separation: The Planck experience
Authors: Wehus Ingunn Kathrine , Eriksen Hans Kristian 
Published: May 2018

AbstractBayesian component separation techniques have played a central role in the data reduction process of Planck. The most important strength of this approach is its global nature, in which a parametric and physical model is fitted to the data. Such physical modeling allows the user to constrain very general data models, and jointly probe cosmological, astrophysical and instrumental parameters. This approach also supports statistically robust goodness-of-fit tests in terms of data-minus-model residual maps, which are essential for identifying residual systematic effects in the data. The main challenges are high code complexity and computational cost. Whether or not these costs are justified for a given experiment depends on its final uncertainty budget. We therefore predict that the importance of Bayesian component separation techniques is likely to increase with time for intensity mapping experiments, similar to what has happened in the CMB field, as observational techniques mature, and their overall sensitivity improves.
Cosmic evolution of AGN with moderate-to-high radiative luminosity in the COSMOS field
Authors: Ceraj L. , Smolčić V. , Delvecchio I. , Delhaize J. , Novak M. 
Published: May 2018

AbstractWe study the moderate-to-high radiative luminosity active galactic nuclei (HLAGN) within the VLA-COSMOS 3 GHz Large Project. The survey covers 2.6 square degrees centered on the COSMOS field with a 1σ sensitivity of 2.3 μJy/beam across the field. This provides the simultaneously largest and deepest radio continuum survey available to date with exquisite multi-wavelength coverage. The survey yields 10,830 radio sources with signal-to-noise ratios ≥5. A subsample of 1,604 HLAGN is analyzed here. These were selected via a combination of X-ray luminosity and mid-infrared colors. We derive luminosity functions for these AGN and constrain their cosmic evolution out to a redshift of z ∼ 6, for the first time decomposing the star formation and AGN contributions to the radio continuum emission in the AGN. We study the evolution of number density and luminosity density finding a peak at z ∼ 1.5 followed by a decrease out to a redshift z ∼ 6.
Average radio spectral energy distribution of highly star-forming galaxies
Authors: Tisanić K. , Smolčić V. , Delhaize J. , Novak M. , Intema H. , Delvecchio I. , Schinnerer E. , Zamorani G. 
Published: May 2018

AbstractThe infrared-radio correlation (IRRC) offers a way to assess star formation from radio emission. Multiple studies found the IRRC to decrease with increasing redshift. This may in part be due to the lack of knowledge about the possible radio spectral energy distributions (SEDs) of star-forming galaxies. We constrain the radio SED of a complete sample of highly star-forming galaxies (SFR > 100 M⊙/ yr) based on the VLA-COSMOS 1.4 GHz Joint and 3 GHz Large Project catalogs. We reduce archival GMRT 325 MHz and 610 MHz observations, broadening the rest-frame frequency range to 0.3-15 GHz. Employing survival analysis and fitting a double power law SED, we find that the slope steepens from a spectral index of α1 = 0.51±0.04 below 4.5 GHz to α2 = 0.98±0.07 above 4.5 GHz. Our results suggest that the use of a K-correction assuming a single power-law radio SED for star forming galaxies is likely not the root cause of the IRRC trend.
Tracing Cosmic Dawn
Authors: Fialkov Anastasia 
Published: May 2018

AbstractObservational effort is on the way to probe the 21-cm of neutral hydrogen from the epochs of Reionization and Cosmic Dawn. Our current poor knowledge of high redshift astrophysics results in a large uncertainty in the theoretically predicted 21-cm signal. A recent parameter study that is highlighted here explores the variety of 21-cm signals resulting from viable astrophysical scenarios. Model-independent relations between the shape of the signal and the underlying astrophysics are discussed. Finally, I briefly note on possible alternative probes of the high redshift Universe, specifically Fast Radio Bursts.
Understanding the impact of Light cone effect on the EoR/CD 21-cm power spectrum
Authors: Datta Kanan K. , Mondal Rajesh , Ghara Raghunath , Bharadwaj Somnath , Choudhury T. Roy 
Published: May 2018

AbstractRedshifted HI 21-cm signal from the cosmic dawn and epoch of reionization evolve considerably along the LoS. We study the impact of this evolution (so called the light cone effect) on the HI 21-cm power spectrum. It is found that the LC effect has a significant impact on the 3D power spectrum and the change could be up to a factor of few. The LC effect is particularly strong during the cosmic dawn near the ‘peaks’ and ‘dips’ in the power spectrum when plotted with redshift. We also show that the 3D power spectrum, which could fully describe ergodic and periodic signal, losses out some information regarding the second order statistics of the signal as the EoR/CD 21-cm signal is non-ergodic and non-periodic along the line of sight. We show that the multi-frequency angular power spectrum (MAPS)${\mathcal {C}}_{\ell }(\nu _1, \nu _2)$captures all the information regarding the second order statistics of the signal even in the presence of the LC effect.
Prospects of detection of the first sources with SKA using matched filters
Authors: Ghara Raghunath , Choudhury T. Roy , Datta Kanan K. , Mellema Garrelt , Choudhuri Samir , Majumdar Suman , Giri Sambit K. 
Published: May 2018

AbstractThe matched filtering technique is an efficient method to detect H ii bubbles and absorption regions in radio interferometric observations of the redshifted 21-cm signal from the epoch of reionization and the Cosmic Dawn. Here, we present an implementation of this technique to the upcoming observations such as the SKA1-low for a blind search of absorption regions at the Cosmic Dawn. The pipeline explores four dimensional parameter space on the simulated mock visibilities using a MCMC algorithm. The framework is able to efficiently determine the positions and sizes of the absorption/H ii regions in the field of view.
Results from the MWA EoR Experiment
Authors: Webster Rachel L. ,   the MWA EoR Collaboration
Published: May 2018

AbstractThe MWA EoR is one of a small handful of experiments designed to detect the statistical signal from the Epoch of Reionisation. Each of these experiments has reached a level of maturity, where the challenges, in particular of foreground removal, are being more fully understood. Over the past decade, the MWA EoR Collaboration has developed expertise and an understanding of the elements of the telescope array, the end-to-end pipelines, ionospheric conditions, and and the foreground emissions. Sufficient data has been collected to detect the theoretically predicted EoR signal. Limits have been published regularly, however we still several orders of magnitude from a possible detection. This paper outlines recent progress and indicates directions for future efforts.
ACCURACY AND UR-PRIOR CONDITIONALIZATION
Authors: DAS NILANJAN 
Published: May 2018

AbstractRecently, several epistemologists have defended an attractive principle of epistemic rationality, which we shall callUr-Prior Conditionalization. In this essay, I ask whether we can justify this principle by appealing to the epistemic goal of accuracy. I argue that any such accuracy-based argument will be in tension withEvidence Externalism, i.e., the view that agent’s evidence may entail nontrivial propositions about the external world. This is because any such argument will crucially require the assumption that, independently of all empirical evidence, it is rational for an agent to be certain that her evidence will always include truths, and that she will always have perfect introspective access to her own evidence. This assumption is incompatible withEvidence Externalism. I go on to suggest that even if we don’t acceptEvidence Externalism, the prospects for any accuracy-based justification forUr-Prior Conditionalizationare bleak.
Fast and Slow Slip Events Emerge Due to Fault Geometrical Complexity
Authors: Romanet Pierre , Bhat Harsha S. , Jolivet Romain , Madariaga Raúl 
Published: May 2018

AbstractActive faults release elastic strain energy via a whole continuum of modes of slip, ranging from devastating earthquakes to slow slip events (SSEs) and persistent creep. Understanding the mechanisms controlling the occurrence of rapid, dynamic slip radiating seismic waves (i.e., earthquakes) or slow, silent slip (i.e., SSEs) is a fundamental point in the estimation of seismic hazard along subduction zones. Using the numerical implementation of a simple rate‐weakening fault model, we show that the simplest of fault geometrical complexities with uniform rate‐weakening friction properties give rise to both SSEs and fast earthquakes without appealing to complex rheologies or mechanisms. We argue that the spontaneous occurrence, the characteristics and the scaling relationship of SSEs and earthquakes emerge from geometrical complexities. The geometry of active faults should be considered as a complementary mechanism to current numerical models of SSEs and fast earthquakes.
Abnormal Elasticity of Fe‐Bearing Bridgmanite in the Earth's Lower Mantle
Authors: Fu Suyu , Yang Jing , Zhang Yanyao , Okuchi Takuo , McCammon Catherine , Kim Hyo‐Im , Lee Sung Keun , Lin Jung‐Fu 
Published: May 2018

AbstractWe measured the effect of pressure on the compressional and shear wave velocity (VP, VS) as well as density of Fe‐bearing bridgmanite, Mg0.96(1)Fe2+0.036(5)Fe3+0.014(5)Si0.99(1)O3, using impulsive stimulated light scattering, Brillouin light scattering, and X‐ray diffraction, respectively, in diamond anvil cells up to 70 GPa at 300 K. A drastic softening of VP by ~6(±1)% is observed between 42.6 and 58 GPa, while VS increases continuously with increasing pressure. A significant reduction in Poisson's ratio from 0.24 to 0.16 occurs at ~42.6–58 GPa, while VS increases by ~3(±1)% above ~40 GPa compared to MgSiO3‐bridgmanite. Thermoelastic modeling of the experimental results shows that the observed elastic anomaly of Fe‐bearing bridgmanite is consistent with a spin transition of octahedrally coordinated Fe3+ in bridgmanite. These results challenge traditional views that Fe enrichment will reduce seismic velocities, suggesting that seismic heterogeneities in the mid‐lower mantle may be due to a spin transition of Fe in Fe‐bearing bridgmanite.
Targeting MUC1-C suppresses BCL2A1 in triple-negative breast cancer
Authors: Hiraki Masayuki , Maeda Takahiro , Mehrotra Neha , Jin Caining , Alam Maroof , Bouillez Audrey , Hata Tsuyoshi , Tagde Ashujit , Keating Amy , Kharbanda Surender , Singh Harpal , Kufe Donald 
Published: May 2018

AbstractB-cell lymphoma 2-related protein A1 (BCL2A1) is a member of the BCL-2 family of anti-apoptotic proteins that confers resistance to treatment with anti-cancer drugs; however, there are presently no agents that target BCL2A1. The MUC1-C oncoprotein is aberrantly expressed in triple-negative breast cancer (TNBC) cells, induces the epithelial–mesenchymal transition (EMT) and promotes anti-cancer drug resistance. The present study demonstrates that targeting MUC1-C genetically and pharmacologically in TNBC cells results in the downregulation of BCL2A1 expression. The results show that MUC1-C activates the BCL2A1 gene by an NF-κB p65-mediated mechanism, linking this pathway with the induction of EMT. The MCL-1 anti-apoptotic protein is also of importance for the survival of TNBC cells and is an attractive target for drug development. We found that inhibiting MCL-1 with the highly specific MS1 peptide results in the activation of the MUC1-C→NF-κB→BCL2A1 pathway. In addition, selection of TNBC cells for resistance to ABT-737, which inhibits BCL-2, BCL-xL and BCL-W but not MCL-1 or BCL2A1, is associated with the upregulation of MUC1-C and BCL2A1 expression. Targeting MUC1-C in ABT-737-resistant TNBC cells suppresses BCL2A1 and induces death, which is of potential therapeutic importance. These findings indicate that MUC1-C is a target for the treatment of TNBCs unresponsive to agents that inhibit anti-apoptotic members of the BCL-2 family.
Stepwise heating in Stille polycondensation toward no batch-to-batch variations in polymer solar cell performance
Authors: Lee Sang Myeon , Park Kwang Hyun , Jung Seungon , Park Hyesung , Yang Changduk 
Published: May 2018

AbstractFor a given π-conjugated polymer, the batch-to-batch variations in molecular weight (Mw) and polydispersity index (Ð) can lead to inconsistent process-dependent material properties and consequent performance variations in the device application. Using a stepwise-heating protocol in the Stille polycondensation in conjunction with optimized processing, we obtained an ultrahigh-quality PTB7 polymer having high Mw and very narrow Ð. The resulting ultrahigh-quality polymer-based solar cells demonstrate up to 9.97% power conversion efficiencies (PCEs), which is over 24% enhancement from the control devices fabricated with commercially available PTB7. Moreover, we observe almost negligible batch-to-batch variations in the overall PCE values from ultrahigh-quality polymer-based devices. The proposed stepwise polymerization demonstrates a facile and effective strategy for synthesizing high-quality semiconducting polymers that can significantly improve device yield in polymer-based solar cells, an important factor for the commercialization of organic solar cells, by mitigating device-to-device variations.
Cell of origin and mutation pattern define three clinically distinct classes of sebaceous carcinoma
Authors: North Jeffrey P. , Golovato Justin , Vaske Charles J. , Sanborn J. Zachary , Nguyen Andrew , Wu Wei , Goode Benjamin , Stevers Meredith , McMullen Kevin , Perez White Bethany E. , Collisson Eric A. , Bloomer Michele , Solomon David A. , Benz Stephen C. , Cho Raymond J. 
Published: May 2018

AbstractSebaceous carcinomas (SeC) are cutaneous malignancies that, in rare cases, metastasize and prove fatal. Here we report whole-exome sequencing on 32 SeC, revealing distinct mutational classes that explain both cancer ontogeny and clinical course. A UV-damage signature predominates in 10/32 samples, while nine show microsatellite instability (MSI) profiles. UV-damage SeC exhibited poorly differentiated, infiltrative histopathology compared to MSI signature SeC (p = 0.003), features previously associated with dissemination. Moreover, UV-damage SeC transcriptomes and anatomic distribution closely resemble those of cutaneous squamous cell carcinomas (SCC), implicating sun-exposed keratinocytes as a cell of origin. Like SCC, this UV-damage subclass harbors a high somatic mutation burden with >50 mutations per Mb, predicting immunotherapeutic response. In contrast, ocular SeC acquires far fewer mutations without a dominant signature, but show frequent truncations in the ZNF750 epidermal differentiation regulator. Our data exemplify how different mutational processes convergently drive histopathologically related but clinically distinct cancers.
Global genetic differentiation of complex traits shaped by natural selection in humans
Authors: Guo Jing , Wu Yang , Zhu Zhihong , Zheng Zhili , Trzaskowski Maciej , Zeng Jian , Robinson Matthew R. , Visscher Peter M. , Yang Jian 
Published: May 2018

AbstractThere are mean differences in complex traits among global human populations. We hypothesize that part of the phenotypic differentiation is due to natural selection. To address this hypothesis, we assess the differentiation in allele frequencies of trait-associated SNPs among African, Eastern Asian, and European populations for ten complex traits using data of large sample size (up to ~405,000). We show that SNPs associated with height ($$P = 2.46 \times 10^{ - 5}$$
P
=
2.46
×
1

0

-
5

), waist-to-hip ratio ($$P = 2.77 \times 10^{ - 4}$$
P
=
2.77
×
1

0

-
4

), and schizophrenia ($$P = 3.96 \times 10^{ - 5}$$
P
=
3.96
×
1

0

-
5

) are significantly more differentiated among populations than matched “control” SNPs, suggesting that these trait-associated SNPs have undergone natural selection. We further find that SNPs associated with height ($$P = 2.01 \times 10^{ - 6}$$
P
=
2.01
×
1

0

-
6

) and schizophrenia ($$P = 5.16 \times 10^{ - 18}$$
P
=
5.16
×
1

0

-
18

) show significantly higher variance in linkage disequilibrium (LD) scores across populations than control SNPs. Our results support the hypothesis that natural selection has shaped the genetic differentiation of complex traits, such as height and schizophrenia, among worldwide populations.
Parental haplotype-specific single-cell transcriptomics reveal incomplete epigenetic reprogramming in human female germ cells
Authors: Vértesy Ábel , Arindrarto Wibowo , Roost Matthias S. , Reinius Björn , Torrens-Juaneda Vanessa , Bialecka Monika , Moustakas Ioannis , Ariyurek Yavuz , Kuijk Ewart , Mei Hailiang , Sandberg Rickard , van Oudenaarden Alexander , Chuva de Sousa Lopes Susana M. 
Published: May 2018

AbstractIn contrast to mouse, human female germ cells develop asynchronously. Germ cells transition to meiosis, erase genomic imprints, and reactivate the X chromosome. It is unknown if these events all appear asynchronously, and how they relate to each other. Here we combine exome sequencing of human fetal and maternal tissues with single-cell RNA-sequencing of five donors. We reconstruct full parental haplotypes and quantify changes in parental allele-specific expression, genome-wide. First we distinguish primordial germ cells (PGC), pre-meiotic, and meiotic transcriptional stages. Next we demonstrate that germ cells from various stages monoallelically express imprinted genes and confirm this by methylation patterns. Finally, we show that roughly 30% of the PGCs are still reactivating their inactive X chromosome and that this is related to transcriptional stage rather than fetal age. Altogether, we uncover the complexity and cell-to-cell heterogeneity of transcriptional and epigenetic remodeling in female human germ cells.
Self-organizing layers from complex molecular anions
Authors: Warneke Jonas , McBriarty Martin E. , Riechers Shawn L. , China Swarup , Engelhard Mark H. , Aprà Edoardo , Young Robert P. , Washton Nancy M. , Jenne Carsten , Johnson Grant E. , Laskin Julia 
Published: May 2018

AbstractThe formation of traditional ionic materials occurs principally via joint accumulation of both anions and cations. Herein, we describe a previously unreported phenomenon by which macroscopic liquid-like thin layers with tunable self-organization properties form through accumulation of stable complex ions of one polarity on surfaces. Using a series of highly stable molecular anions we demonstrate a strong influence of the internal charge distribution of the molecular ions, which is usually shielded by counterions, on the properties of the layers. Detailed characterization reveals that the intrinsically unstable layers of anions on surfaces are stabilized by simultaneous accumulation of neutral molecules from the background environment. Different phases, self-organization mechanisms and optical properties are observed depending on the molecular properties of the deposited anions, the underlying surface and the coadsorbed neutral molecules. This demonstrates rational control of the macroscopic properties (morphology and size of the formed structures) of the newly discovered anion-based layers.