bluuebunny/crossref_metadata_2025_split huggingface dataset:
Centennial‐Scale SE Pacific Sea Surface Temperature Variability Over the Past 2,300 Years
Authors: Collins James A. , Lamy Frank , Kaiser Jérôme , Ruggieri Nicoletta , Henkel Susann , De Pol‐Holz Ricardo , Garreaud René , Arz Helge W. 
Published: February 2019

AbstractDetailed temperature reconstructions over the past 2,000 years are important for contextualizing modern climate change. The midlatitude SE Pacific is a key region in this regard in terms of understanding the climatic linkages between the tropics and southern high latitudes. Multicentennial timescale temperature variability remains, however, poorly understood, due to a lack of long, high‐temporal‐resolution temperature records from this region and from the southern high latitudes in general. We present a unique alkenone sea surface temperature (SST) record from 44°S on the southern Chilean margin in the SE Pacific spanning the last 2,300 years at decadal resolution. The record displays relatively large changes including a cooling transition from 14 to 12.5 °C between 1,100 and 600 cal yr BP, in line with other Chile margin SST records and coeval with Antarctic cooling. This cooling is attributable to reduced Southern Ocean deep convection, driven by a late Holocene sea‐ice increase in the Weddell Sea associated with increased El‐Niño Southern Oscillation variability. Superimposed on the late Holocene cooling, we observe multicentennial timescale SST variability, including relatively cool SSTs (12.5 °C) from 950 to 500 cal yr BP, corresponding to the Medieval Climate Anomaly, and warmer SSTs (13 °C) from 500 to 200 cal yr BP, corresponding to the Little Ice Age. These oscillations may reflect either multicentennial internal variability of the Southern Ocean deep convection and/or multicentennial variability in the phasing of El‐Niño Southern Oscillation and Southern Annular Mode events.
Tuning the Fröhlich exciton-phonon scattering in monolayer MoS2
Authors: Miller Bastian , Lindlau Jessica , Bommert Max , Neumann Andre , Yamaguchi Hisato , Holleitner Alexander , Högele Alexander , Wurstbauer Ursula 
Published: February 2019

AbstractCharge carriers in semiconducting transition metal dichalcogenides possess a valley degree of freedom that allows for optoelectronic applications based on the momentum of excitons. At elevated temperatures, scattering by phonons limits valley polarization, making a detailed knowledge about strength and nature of the interaction of excitons with phonons essential. In this work, we directly access exciton-phonon coupling in charge tunable single layer MoS2 devices by polarization resolved Raman spectroscopy. We observe a strong defect mediated coupling between the long-range oscillating electric field induced by the longitudinal optical phonon in the dipolar medium and the exciton. This so-called Fröhlich exciton phonon interaction is suppressed by doping. The suppression correlates with a distinct increase of the degree of valley polarization up to 20% even at elevated temperatures of 220 K. Our result demonstrates a promising strategy to increase the degree of valley polarization towards room temperature valleytronic applications.
A large CRISPR-induced bystander mutation causes immune dysregulation
Authors: Simeonov Dimitre R. , Brandt Alexander J. , Chan Alice Y. , Cortez Jessica T. , Li Zhongmei , Woo Jonathan M. , Lee Youjin , Carvalho Claudia M. B. , Indart Alyssa C. , Roth Theodore L. , Zou James , May Andrew P. , Lupski James R. , Anderson Mark S. , Buaas F. William , Rokhsar Daniel S. , Marson Alexander 
Published: February 2019

AbstractA persistent concern with CRISPR-Cas9 gene editing has been the potential to generate mutations at off-target genomic sites. While CRISPR-engineering mice to delete a ~360 bp intronic enhancer, here we discovered a founder line that had marked immune dysregulation caused by a 24 kb tandem duplication of the sequence adjacent to the on-target deletion. Our results suggest unintended repair of on-target genomic cuts can cause pathogenic “bystander” mutations that escape detection by routine targeted genotyping assays.
Unique crystal field splitting and multiband RKKY interactions in Ni-doped EuRbFe4As4
Authors: Xu Chenchao , Chen Qijin , Cao Chao 
Published: February 2019

AbstractThe relationship between magnetism and superconductivity has been one of the most discussed topics in iron-based superconductors. Using first-principles calculations, we have studied the electronic structure of 1144-type iron-based superconductor EuRbFe4As4. We find the crystal field splitting of EuRbFe4As4 is unique, such that the $$d_{z^2}$$

d

z

2

orbitals are closer to the Fermi level $$\epsilon _{\mathrm F}$$

ϵ

F

than the dxy orbitals. The Ruderman−Kittel−Kasuya−Yosida (RKKY) interaction strength is approximately 0.12 meV in pristine EuRbFe4As4. Upon Ni-doping on the Fe site, the RKKY interaction strength is barely changed upon Ni-doping due to the highly anisotropic Fermi surfaces and multiband effect, despite the drastically reduced dzx(y) density of state at $$\epsilon _{\mathrm F}$$

ϵ

F

. Finally, in both pristine and doped compounds, the RKKY interaction is primarily mediated through bands due to Fe-$$d_{z^2}$$

d

z

2

orbitals. Our calculations suggest the RKKY interaction mediated by $$d_{z^2}$$

d

z

2

orbital is probably responsible for the magnetism in EuRbFe4As4 and doesn’t change upon Ni-doping.
Association between ADIPOQ gene variants and knee osteoarthritis in a Chinese population
Authors: Shang Houlai , Hao Yuedong , Hu Wenhao , Hu Xiaohui , Jin Qing 
Published: February 2019

Abstract
A study from Thailand showed no significant association between the adiponectin (ADIPOQ) gene rs1501299 polymorphism and knee osteoarthritis (OA) risk. To investigate this association in a Chinese population, we conducted this case–control study involving 372 knee OA patients and 453 controls. Genotyping via standard PCR and restriction fragment length polymorphism (PCR-RFLP) showed that TT genotype (TT vs. GG: adjusted odds ratio (OR) (95% confidence interval (CI)) = 1.70 (1.01–2.86)) or T allele (T vs. G: adjusted OR (95% CI) = 1.26 (1.02–1.56)) of ADIPOQ gene rs1501299 polymorphism significantly increased the risk of knee OA. Significant associations were also observed in subgroups ≥55 years (TT vs. GG: adjusted OR (95% CI) = 2.21 (1.00–4.86)) and body mass index (BMI) &lt; 25 kg/m2 (TT+GT vs. GG: adjusted OR (95% CI) = 1.53 (1.03–2.29)), but not in the subgroup analysis of sex. In conclusion, the ADIPOQ gene rs1501299 polymorphism intensifies the risk of knee OA in this Chinese Han population. Nevertheless, further studies with larger sample sizes in other populations are warranted to verify this finding.
The XMM-Newton serendipitous survey
Authors: Traulsen I. , Schwope A. D. , Lamer G. , Ballet J. , Carrera F. , Coriat M. , Freyberg M. J. , Michel L. , Motch C. , Rosen S. R. , Webb N. , Ceballos M. T. , Koliopanos F. , Kurpas J. , Page M. J. , Watson M. G. 
Published: February 2019

Context. XMM-Newton has observed the X-ray sky since early 2000. The XMM-Newton Survey Science Centre Consortium has published catalogues of X-ray and ultraviolet sources found serendipitously in the individual observations. This series is now augmented by a catalogue dedicated to X-ray sources detected in spatially overlapping XMM-Newton observations.
Aims. The aim of this catalogue is to explore repeatedly observed sky regions. It thus makes use of the long(er) effective exposure time per sky area and offers the opportunity to investigate long-term flux variability directly through the source-detection process.
Methods. A new standardised strategy for simultaneous source detection on multiple observations was introduced, including an adaptive-smoothing method to describe the image background. It was coded as a new task within the XMM-Newton Science Analysis System and used to compile a catalogue of sources from 434 stacks comprising 1789 overlapping XMM-Newton observations that entered the 3XMM-DR7 catalogue, have a low background and full-frame readout of all EPIC cameras.
Results. The first stacked catalogue is called 3XMM-DR7s. It contains 71 951 unique sources with positions and parameters such as fluxes, hardness ratios, quality estimates, and information on inter-observation variability, directly derived from a simultaneous fit. Source parameters are calculated for the stack and for each contributing observation. About 15% of the sources are new with respect to 3XMM-DR7. Through stacked source detection, the parameters of repeatedly observed sources are determined with higher accuracy than in the individual observations. The method is more sensitive to faint sources and tends to produce fewer spurious detections.
Conclusions. With this first stacked catalogue we demonstrate the feasibility and benefit of the approach. It supplements the large data base of XMM-Newton detections with additional, in particular faint, sources and adds variability information. In the future, the catalogue will be expanded to larger samples and continued within the series of serendipitous XMM-Newton source catalogues.
Tidal deformability and other global parameters of compact stars with strong phase transitions
Authors: Sieniawska M. , Turczański W. , Bejger M. , Zdunik J. L. 
Published: February 2019

Context. Using parametric equations of state (relativistic polytropes and a simple quark bag model) to model dense-matter phase transitions, we study global, measurable astrophysical parameters of compact stars such as their allowed radii and tidal deformabilities. We also investigate the influence of stiffness of matter before the onset of the phase transitions on the parameters of the possible exotic dense phase.
Aims. The aim of our study is to compare the parameter space of the dense matter equation of state permitting phase transitions to a sub-space compatible with current observational constraints such as the maximum observable mass, tidal deformabilities of neutron star mergers, radii of configurations before the onset of the phase transition, and to give predictions for future observations.
Methods. We studied solutions of the Tolman-Oppenheimer-Volkoff equations for a flexible set of parametric equations of state, constructed using a realistic description of neutron-star crust (up to the nuclear saturation density), and relativistic polytropes connected by a density-jump phase transition to a simple bag model description of deconfined quark matter.
Results. In order to be consistent with recent observations of massive neutron stars, a compact star with a strong high-mass phase transition cannot have a radius smaller than 12 km in the range of masses 1.2 − 1.6 M⊙. We also compare tidal deformabilities of stars with weak and strong phase transitions with the results of the GW170817 neutron star merger. Specifically, we study characteristic phase transition features in the Λ1 − Λ2 relation, and estimate the deviations of our results from the approximate formulæ for Λ∼ − R (M1) and Λ-compactness proposed in the literature. We find constraints on the hybrid equations of state to produce stable neutron stars on the twin branch. For the exemplary equations of state most of the high-mass twins occur for the minimum values of the density jump λ = 1.33 − 1.54; corresponding values of the square of the speed of sound are α = 0.7 − 0.37. We compare results with observations of gravitational waves and with the theoretical causal limit and find that the minimum radius of a twin branch is between 9.5 and 10.5 km, and depends on the phase transition baryon density. For these solutions the phase transition occurs below 0.56 fm−3.
A Sino-German λ6 cm polarisation survey of the Galactic plane
Authors: Gao X. Y. , Reich P. , Hou L. G. , Reich W. , Han J. L. 
Published: February 2019

Context. Large-scale radio continuum surveys provide data to get insights into the physical properties of radio sources. H II regions are prominent radio sources produced by thermal emission of ionised gas around young massive stars.
Aims. We identify and analyse H II regions in the Sino-German λ6 cm polarisation survey of the Galactic plane.
Methods. Objects with flat radio continuum spectra together with infrared and/or Hα emission were identified as H II regions. For H II regions with small apparent sizes, we cross-matched the λ6 cm small-diameter source catalogue with the radio H II region catalogue compiled by Paladini and the infrared H II region catalogue based on the WISE data. Effelsberg λ21 cm and λ11 cm continuum survey data were used to determine source spectra. High angular resolution data from the Canadian Galactic Plane Survey and the NRAO VLA Sky Survey were used to solve the confusion when low angular resolution observations were not sufficient. Extended H II regions were identified by eye by overlaying the Paladini and the WISE H II regions onto the λ6 cm survey images for coincidences. The TT-plot method was employed for spectral index verification.
Results. A total of 401 H II regions were identified and their flux densities were determined with the Sino-German λ6 cm survey data. In the surveyed area, 76 pairs of sources are found to be duplicated in the Paladini H II region catalogue, mainly due to the non-distinction of previous observations with different angular resolutions and 78 objects in their catalogue are misclassified as H II regions, being actually planetary nebulae, supernova remnants, or extragalactic sources that have steep spectra. More than 30 H II regions and H II region candidates from our λ6 cm survey data, especially extended ones, do not have counterparts in the WISE H II region catalogue, of which 9 are identified for the first time. Our results imply that some more Galactic H II regions still await to be discovered and the combination of multi-domain observations is important for H II region identification. Based on the newly derived radio continuum spectra and the evidence of infrared emission, the previously identified SNRs G11.1−1.0, G20.4+0.1 and G16.4−0.5 are believed to be H II regions.
Full inversion of solar relativistic electron events measured by the Helios spacecraft
Authors: Pacheco D. , Agueda N. , Aran A. , Heber B. , Lario D. 
Published: February 2019

Context. The Parker Solar Probe and the incoming Solar Orbiter mission will provide measurements of solar energetic particle (SEP) events at close heliocentric distances from the Sun. Up to present, the largest data set of SEP events in the inner heliosphere are the observations by the two Helios spacecraft.Aims. We re-visit a sample of 15 solar relativistic electron events measured by the Helios mission with the goal of better characterising the injection histories of solar energetic particles and their interplanetary transport conditions at heliocentric distances <1 AU.Methods. The measurements provided by the E6 instrument on board Helios provide us with the electron directional distributions in eight different sectors that we use to infer the detailed evolution of the electron pitch-angle distributions. The results of a Monte Carlo interplanetary transport model, combined with a full inversion procedure, were used to fit the observed directional intensities in the 300–800 keV nominal energy channel. Unlike previous studies, we have considered both the energy and angular responses of the detector. This method allowed us to infer the electron release time profile at the source and determine the electron interplanetary transport conditions.Results. We discuss the duration of the release time profiles and the values of the radial mean free path, and compare them with the values reported previously in the literature using earlier approaches. Five of the events show short injection histories (<30 min) at the Sun and ten events show long-lasting (>30 min) injections. The values of mean free path range from 0.02 AU to 0.27 AU.Conclusions. The inferred injection histories match with the radio and soft X-ray emissions found in literature. We find no dependence of the radial mean free path on the radial distance. In addition, we find no apparent relation between the strength of interplanetary scattering and the size of the solar particle release.
IFU investigation of possible Lyman continuum escape from Mrk 71/NGC 2366
Authors: Micheva Genoveva , Christian Herenz Edmund , Roth Martin M. , Östlin Göran , Girichidis Philipp 
Published: February 2019

Context. Mrk 71/NGC 2366 is the closest green pea (GP) analog and candidate Lyman Continuum (LyC) emitter. Recently, 11 LyC-leaking GPs have been detected through direct observations of the ionizing continuum, making this the most abundant class of confirmed LyC-emitters at any redshift. High resolution, multiwavelength studies of GPs can lead to an understanding of the method(s), through which LyC escapes from these galaxies.
Aims. The proximity of Mrk 71/NCG 2366 offers unprecedented detail on the inner workings of a GP analog, and enables us to identify the mechanisms of LyC escape.
Methods. We used 5825–7650 Å integral field unit PMAS observations to study the kinematics and physical conditions in Mrk 71. An electron density map was obtained from the [S II] ratio. A fortuitous second order contamination by the [O II] λ3727 doublet enabled the construction of an electron temperature map. Resolved maps of sound speed, thermal broadening, “true” velocity dispersion, and Mach number were obtained and compared to the high resolution magnetohydrodynamic SImulating the LifeCycle of molecular Clouds (SILCC) simulations.
Results. Two regions of increased velocity dispersion indicative of outflows are detected to the north and south of the super star cluster, knot B, with redshifted and blueshifted velocities, respectively. We confirm the presence of a faint broad kinematical component, which is seemingly decoupled from the outflow regions, and is fainter and narrower than previously reported in the literature. Within uncertainties, the low- and high-ionization gasses move together. Outside of the core of Mrk 71, an increase in Mach numbers is detected, implying a decrease in gas density. Simulations suggest this drop in density can be as high as ∼4 dex, down to almost optically thin levels, which would imply a nonzero LyC escape fraction along the outflows even when assuming all of the detected H I gas is located in front of Mrk 71 in the line of sight.
Conclusions. Our results strongly indicate that kinematical feedback is an important ingredient for LyC leakage in GPs.
Emergence of analogy from relation learning
Authors: Lu Hongjing , Wu Ying Nian , Holyoak Keith J. 
Published: February 2019

Significance
The ability to learn and make inferences based on relations is central to intelligence, underlying the distinctively human ability to reason by analogy across dissimilar situations. We have developed a computational model demonstrating that abstract relations, such as synonymy and antonymy, can be learned efficiently from semantic feature vectors for individual words and can be used to solve simple verbal analogy problems with close to human-level accuracy. The approach illustrates the potential synergy between deep learning from “big data” and supervised learning from “small data.” Core properties of high-level intelligence can emerge from relatively simple computations coupled with rich semantics. The model illustrates how operations on nonrelational inputs can give rise to protosymbolic relational representations.
Quantum experiments and graphs II: Quantum interference, computation, and state generation
Authors: Gu Xuemei , Erhard Manuel , Zeilinger Anton , Krenn Mario 
Published: February 2019

Significance
Graph theory can be used to model and explain different phenomena from physics. In this paper, we show that one can interpret quantum experiments composed of linear optics and probabilistic sources with graph theory. The important understanding is that complex weights in the graph naturally describe the quantum interference. That point of view leads to several results: We uncover a yet unexplored type of multiphoton quantum interference. It can be used to solve questions that are intractable on a classical computer. Also, the connection points toward a general restriction on creating certain classes of quantum states. In general, it gives another perspective on a mature photonic technology and will be significant for future designs of such experiments.
Motor neuron disease-associated loss of nuclear TDP-43 is linked to DNA double-strand break repair defects
Authors: Mitra Joy , Guerrero Erika N. , Hegde Pavana M. , Liachko Nicole F. , Wang Haibo , Vasquez Velmarini , Gao Junling , Pandey Arvind , Taylor J. Paul , Kraemer Brian C. , Wu Ping , Boldogh Istvan , Garruto Ralph M. , Mitra Sankar , Rao K. S. , Hegde Muralidhar L. 
Published: February 2019

SignificanceAmyotrophic lateral sclerosis (ALS) is a devastating, motor neuron degenerative disease without any cure to date. About 95% of ALS patients feature abnormalities in the RNA/DNA binding protein TDP-43, involving its nucleus-cytoplasmic mislocalization in spinal motor neurons. How TDP-43 pathology triggers neuronal apoptosis remains unclear. Here, we report that TDP-43 participates in the DNA damage response and its nuclear clearance in motor neurons causes DNA double-strand break repair defects in ALS. Our findings uncover a link between TDP-43 pathology and impaired DNA repair, and suggest potential avenues for DNA repair-targeted therapies for TDP-43–ALS.
Deep elastic strain engineering of bandgap through machine learning
Authors: Shi Zhe , Tsymbalov Evgenii , Dao Ming , Suresh Subra , Shapeev Alexander , Li Ju 
Published: February 2019

Significance
Deforming a material to a large extent without inelastic relaxation can result in unprecedented properties. However, the optimal deformation state is buried within the vast continua of choices available in the strain space. Here we advance a unique and powerful strategy to circumvent conventional trial-and-error methods, and adopt artificial intelligence techniques for rationally designing the most energy-efficient pathway to achieve a desirable material property such as the electronic bandgap. The broad framework for tailoring any target figure of merit, for any material using machine learning, opens up opportunities to adapt elastic strain engineering of properties and performance in devices and systems in a controllable and efficient manner, for potential applications in microelectronics, optoelectronics, photonics, and energy technologies.
Processability and mechanical properties of surface-modified glass-fibres/phthalonitrile composite and Al–Li alloy fibre-metal-laminates
Authors: Medjahed Aboubakr , Derradji Mehdi , Zegaoui Abdeldjalil , Wu Ruizhi , Li Bingcheng 
Published: February 2019

In this study, newly developed fibre-metal laminates (Al-LiFMLs) were prepared by a lay-up process of a high-performance surface-modified glass fibres/phthalonitrile (GFs/PN) composite and Al–Li alloy. The results showed that varying the composite considerably affected the tensile properties of the Al-LiFMLs, as well as exhibiting enhancements over the properties of both the individual Al–Li alloys and GFs/PN composite constituents. For instance, when the number of composite layers varied from 6 to 14, the ultimate tensile strength of the Al-LiFMLs increased from 315 to 611 MPa. It was revealed that the failure mode displayed a more ductile behaviour (up to 20%) for all the developed Al-LiFMLs affected by the ductile fracture mode of the Al–Li alloy. GRAPHICAL ABSTRACT