bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization with dense array data of seismic sources in the shallow part of the San Jacinto fault zone
Authors: Gradon Chloé , Roux Philippe , Moreau Ludovic , Lecointre Albanne , Ben Zion Yehuda 
Published: August 2020

SUMMARY
We analyse dominant sources identified in a catalogue of more than 156 000 localizations performed using a 26-d data set recorded by a dense array set on the San Jacinto fault near Anza, in California. Events were localized using an array processing technique called Match Field Processing. As for all array processing techniques, the quality of the event position decrease when the events are outside of the array. We thus separate localizations in and outside the array using simple geometrical conditions. We compare the time distribution of the localization to additional data such as meteorological data, day of human activity as well as existing catalogues to determine the nature of the dominant events located using our method. We find that most of the events located outside of the array could be attributed to a surface structure excited by wind. On the other hand, part of the localizations under the array occur during regional earthquakes and could correspond to diffraction on the fault's heterogeneities. The rest of the localizations inside the array could be generated by the fault itself.
Increased levels of plasma nucleotides in patients with rheumatoid arthritis
Authors: Kishikawa Toshihiro , Maeda Yuichi , Nii Takuro , Arase Noriko , Hirata Jun , Suzuki Ken , Yamamoto Kenichi , Masuda Tatsuo , Ogawa Kotaro , Tsuji Shigeyoshi , Matsushita Masato , Matsuoka Hidetoshi , Yoshimura Maiko , Tsunoda Shinichiro , Ohshima Shiro , Narazaki Masashi , Ogata Atsushi , Saeki Yukihiko , Inohara Hidenori , Kumanogoh Atsushi , Takeda Kiyoshi , Okada Yukinori 
Published: August 2020

Abstract
Novel biomarkers of rheumatoid arthritis (RA), in addition to antibodies against cyclic citrullinated peptides, are required. Metabolome analysis is a promising approach to identify metabolite biomarkers for clinical diagnosis. We adopted a comprehensive non-targeted metabolomics approach combining capillary electrophoresis time-of-flight mass spectrometry (TOFMS) and liquid chromatography TOFMS. We constructed metabolomics profiling of 286 plasma samples of a Japanese population [92 RA patients, 13 systemic lupus erythematosus (SLE) patients and 181 healthy controls). RA case–control association tests showed that seven metabolites exhibited significantly increased levels in RA samples compared with controls (P &lt; 1.0 × 10−4; UTP, ethanolamine phosphate, ATP, GDP, ADP, 6-aminohexanoic acid and taurine), whereas one exhibited a decreased level (xanthine). The plasma levels of these eight metabolites were not significantly different between seropositive and seronegative RA patients (P &gt; 0.05; n = 68 and 24, respectively). The four nucleotide levels (UTP, ATP, GDP and ADP) were significantly higher in the non-treatment patients in comparison between patients with and without treatment (P &lt; 0.014; n = 57 and 35, respectively). Furthermore, we found that none of the four nucleotide levels showed significant differences in SLE case–control association tests (P &gt; 0.2; 13 patients with SLE and the 181 shared controls) and psoriatic arthritis (PsA) case–control association tests (P &gt; 0.11; 42 patients with PsA and 38 healthy controls), indicating disease specificity in RA. In conclusion, our large-scale metabolome analysis demonstrated the increased plasma nucleotide levels in RA patients, which could be used as potential clinical biomarkers of RA, especially for seronegative RA.
Carving Out an Empire? How China Strategically Uses Aid to Facilitate Chinese Business Expansion in Africa **
Authors: Harchaoui Tarek M , Maseland Robbert K J , Watkinson Julian A 
Published: August 2020

Abstract:China’s rising investment and aid flows into Africa have raised concerns over its increasing influence, triggering worries about a new scramble for Africa. This paper sorts out the motivations behind the various forms of Chinese aid, arguing that China uses different types of aid strategically to divert the recipient countries’ economic and institutional orientation towards its own interests. Exploiting the AidData set, we show that China’s official development aid (ODA) is positively related to an export bias in favour of China, suggesting that it serves to secure privileged access for Chinese firms to African resources. ODA tends to flow to less democratic regimes, because less accountable governments have more power to offer long-run privileges to their financial supporters. In contrast, we show that other official flows (OOF) are used to increase China’s import share and is positively related to institutional quality, since this has a positive influence on market growth. This suggests that OOF is mainly used to facilitate Chinese access to promising African consumer markets. We conclude that while China employs different aid flows for different economic purposes, it uses all aid flows strategically to advance its interests and create an economic sphere of influence in Africa.
‘Sometime a paradox’, now proof: Yablo is not first order
Authors: Salehi Saeed 
Published: August 2020

Abstract
Interesting as they are by themselves in philosophy and mathematics, paradoxes can be made even more fascinating when turned into proofs and theorems. For example, Russell’s paradox, which overthrew Frege’s logical edifice, is now a classical theorem in set theory, to the effect that no set contains all sets. Paradoxes can be used in proofs of some other theorems—thus Liar’s paradox has been used in the classical proof of Tarski’s theorem on the undefinability of truth in sufficiently rich languages. This paradox (as well as Richard’s paradox) appears implicitly in Gödel’s proof of his celebrated first incompleteness theorem. In this paper, we study Yablo’s paradox from the viewpoint of first- and second-order logics. We prove that a formalization of Yablo’s paradox (which is second order in nature) is non-first-orderizable in the sense of George Boolos (1984).
The Metaphysical Irreversibility of Death
Authors: Nolan Catherine 
Published: August 2020

Abstract
The popularization of the term “clinical death” for the absence of vital signs suggests the possibility of a radical change in our understanding of death. While death used to be considered something that we do not have the power to reverse, contemporary optimism suggests that we may be able to restore life to a dead organism. In this article, I examine how the term “death” is used today to clarify what kind of irreversibility we ought to assign to it. I conclude that the kind of irreversibility closest to our concept of death is one that depends on implicit metaphysical commitments: we generally treat death as though it were metaphysically irreversible, and therefore not reversible by us.
A putative nuclear copper chaperone promotes plant immunity in Arabidopsis
Authors: Chai Long-Xiang , Dong Kai , Liu Song-Yu , Zhang Zhen , Zhang Xiao-Peng , Tong Xin , Zhu Fei-Fan , Zou Jing-Ze , Wang Xian-Bing 
Published: August 2020

Abstract
Copper is essential for many metabolic processes but must be sequestrated by copper chaperones. It is well known that plant copper chaperones regulate various physiological processes. However, the functions of copper chaperones in the plant nucleus remain largely unknown. Here, we identified a putative copper chaperone induced by pathogens (CCP) in Arabidopsis thaliana. CCP harbors a classical MXCXXC copper-binding site (CBS) at its N-terminus and a nuclear localization signal (NLS) at its C-terminus. CCP mainly formed nuclear speckles in the plant nucleus, which requires the NLS and CBS domains. Overexpression of CCP induced PR1 expression and enhanced resistance against Pseudomonas syringae pv. tomato DC3000 compared with Col-0 plants. Conversely, two CRISPR/Cas9-mediated ccp mutants were impaired in plant immunity. Further biochemical analyses revealed that CCP interacted with the transcription factor TGA2 in vivo and in vitro. Moreover, CCP recruits TGA2 to the PR1 promoter sequences in vivo, which induces defense gene expression and plant immunity. Collectively, our results have identified a putative nuclear copper chaperone required for plant immunity and provided evidence for a potential function of copper in the salicylic pathway.
Orbital spin dynamics of a millisecond pulsar around a massive BH with a general mass quadrupole
Authors: Kimpson Tom , Wu Kinwah , Zane Silvia 
Published: August 2020

ABSTRACT
We investigate the spin dynamics of a millisecond pulsar (MSP) in compact orbit around a Kerr-like massive BH with an general mass quadrupole. We use the Mathisson–Papetrou–Dixon formulation to compute the orbital and spin evolution of the MSP, accounting for the non-linear interaction of the pulsar’s energy–momentum tensor on the background space–time metric. We investigate how the MSP spin and BH quadrupole moment manifest in the pulsar spin-orbital dynamics. We discuss the astrophysical observational implications of these spin and orbital dynamics on the timing of a radio pulsar in an extreme mass ratio binary, e.g. a Galactic Centre pulsar. In particular, notable timing variations in the Einstein delay and Roemer delay are observed, along with modifications to the pulsar pulse profile.
Rotational modulation and single g-mode pulsation in the B9pSi star HD 174356?
Authors: Mikulášek Z , Paunzen E , Hümmerich S , Niemczura E , Walczak P , Fraga L , Bernhard K , Janík J , Hubrig S , Järvinen S , Jagelka M , Pintado O I , Krtička J , Prišegen M , Skarka M , Zejda M , Ilyin I , Pribulla T , Kamiński K , Kamińska M K , Tokarek J , Zieliński P 
Published: August 2020

ABSTRACT
Chemically peculiar (CP) stars of the upper main sequence are characterized by specific anomalies in the photospheric abundances of some chemical elements. The group of CP2 stars, which encompasses classical Ap and Bp stars, exhibits strictly periodic light, spectral, and spectropolarimetric variations that can be adequately explained by the model of a rigidly rotating star with persistent surface structures and a stable global magnetic field. Using observations from the Kepler K2 mission, we find that the B9pSi star HD 174356 displays a light curve variable in both amplitude and shape, which is not expected in a CP2 star. Employing archival and new photometric and spectroscopic observations, we carry out a detailed abundance analysis of HD 174356 and discuss its photometric and astrophysical properties in detail. We employ phenomenological modelling to decompose the light curve and the observed radial velocity variability. Our abundance analysis confirms that HD 174356 is a silicon-type CP2 star. No magnetic field stronger than 110 G was found. The star’s light curve can be interpreted as the sum of two independent strictly periodic signals with $P_1=4{_{.}^{\rm d}}043\, 55(5)$ and $P_2=2{_{.}^{\rm d}}111\, 69(3)$. The periods have remained stable over 17 yr of observations. In all spectra, HD 174356 appears to be single-lined. From the simulation of the variability characteristics and investigation of stars in the close angular vicinity, we put forth the hypothesis that the peculiar light variability of HD 174356 arises in a single star and is caused by rotational modulation due to surface abundance patches (P1) and g-mode pulsation (P2).
PS1-STRM: neural network source classification and photometric redshift catalogue for PS1 3π DR1
Authors: Beck Róbert , Szapudi István , Flewelling Heather , Holmberg Conrad , Magnier Eugene , Chambers Kenneth C 
Published: August 2020

ABSTRACT
The Pan-STARRS1 (PS1) 3π survey is a comprehensive optical imaging survey of three quarters of the sky in the grizy broad-band photometric filters. We present the methodology used in assembling the source classification and photometric redshift (photo-z) catalogue for PS1 3π Data Release 1, titled Pan-STARRS1 Source Types and Redshifts with Machine learning (PS1-STRM). For both main data products, we use neural network architectures, trained on a compilation of public spectroscopic measurements that has been cross-matched with PS1 sources. We quantify the parameter space coverage of our training data set, and flag extrapolation using self-organizing maps. We perform a Monte Carlo sampling of the photometry to estimate photo-z uncertainty. The final catalogue contains 2902 054 648 objects. On our validation data set, for non-extrapolated sources, we achieve an overall classification accuracy of $98.1{{\ \rm per\ cent}}$ for galaxies, $97.8{{\ \rm per\ cent}}$ for stars, and $96.6{{\ \rm per\ cent}}$ for quasars. Regarding the galaxy photo-z estimation, we attain an overall bias of 〈Δznorm〉 = 0.0005, a standard deviation of σ(Δznorm) = 0.0322, a median absolute deviation of MAD(Δznorm) = 0.0161, and an outlier fraction of $P\left(|\Delta z_{\mathrm{norm}}|\gt 0.15\right)=1.89{{\ \rm per\ cent}}$. The catalogue will be made available as a high-level science product via the Mikulski Archive for Space Telescopes.
Making massive stars in the Galactic Centre via accretion on to low-mass stars within an accretion disc
Authors: Davies Melvyn B , Lin Doug N C 
Published: August 2020

ABSTRACT
The origin of the population of very massive stars observed within ∼0.4 pc of the supermassive black hole in the Galactic Centre is a mystery. Tidal forces from the black hole would likely inhibit in situ star formation whilst the youth of the massive stars would seem to exclude formation elsewhere followed by transportation (somehow) into the Galactic Centre. Here, we consider a third way to produce these massive stars from the lower mass stars contained in the nuclear stellar cluster which surrounds the supermassive black hole. A passing gas cloud can be tidally shredded by the supermassive black hole forming an accretion disc around the black hole. Stars embedded within this accretion disc will accrete gas from the disc via Bondi–Hoyle accretion, where the accretion rate on to a star, $\dot{M}_\star \propto M_\star ^2$. This super-exponential growth of accretion can lead to a steep increase in stellar masses, reaching the required 40–50 M⊙ in some cases. The mass growth rate depends sensitively on the stellar orbital eccentricities and their inclinations. The evolution of the orbital inclinations and/or their eccentricities as stars are trapped by the disc, and their orbits are circularized, will increase the number of massive stars produced. Thus accretion on to low-mass stars can lead to a top heavy stellar mass function in the Galactic Centre and other galactic nuclei. The massive stars produced will pollute the environment via supernova explosions and potentially produce compact binaries whose mergers may be detectable by the LIGO–VIRGO gravitational waves observatories.
Avoided crossing in gravitational wave spectra from protoneutron star
Authors: Sotani Hajime , Takiwaki Tomoya 
Published: August 2020

ABSTRACT
The ramp up signals of gravitational waves appearing in the numerical simulations could be important signals to estimate parameters of the protoneutron star (PNS) at supernova explosions. To identify the signals with PNS oscillations, we make a linear perturbation analysis and compare the resultant eigenfrequencies with the ramp up signals obtained via the 2D numerical simulations. Then, we find that the ramp up signals correspond well to the g1-mode in the early phase and to the f-mode, to which the g1-mode is exchanged via the avoided crossing. We also confirm that the f- and g1-modes are almost independent of the selection of the PNS surface density in the later phase after core bounce. In addition, we successfully find that the fitting formula of g1- and f-modes, which correspond to the ramp up signals in the numerical simulation, as a function of the PNS average density. That is, via the direct observation of the gravitational waves after supernova explosion, one could extract the time evolution of the PNS average density using our fitting formula.
Analysing the Epoch of Reionization with three-point correlation functions and machine learning techniques
Authors: Jennings W D , Watkinson C A , Abdalla F B 
Published: August 2020

ABSTRACT
Three-point and high-order clustering statistics of the high-redshift 21 cm signal contain valuable information about the Epoch of Reionization (EoR). We present 3PCF-fast, an optimized code for estimating the three-point correlation function (3PCF) of 3D pixelized data such as the outputs from numerical and seminumerical simulations. After testing 3PCF-fast on data with known analytical 3PCF, we use machine learning techniques to recover the mean bubble size and global ionization fraction from correlations in the outputs of the publicly available 21cmfast code. We assume that foregrounds have been perfectly removed and negligible instrumental noise. Using ionization fraction data, our best multilayer perceptron (MLP) model recovers the mean bubble size with a median prediction error of around $10 {{\ \rm per\ cent}}$, or from the 21 cm differential brightness temperature with median prediction error of around $14 {{\ \rm per\ cent}}$. A further two MLP models recover the global ionization fraction with median prediction errors of around $4 {{\ \rm per\ cent}}$ (using ionization fraction data) or around $16 {{\ \rm per\ cent}}$ (using brightness temperature). Our results indicate that clustering in both the ionization fraction field and the brightness temperature field encode useful information about the progress of the EoR in a complementary way to other summary statistics. Using clustering would be particularly useful in regimes where high signal-to-noise ratio prevents direct measurement of bubble size statistics. We compare the quality of MLP models using the power spectrum, and find that using the 3PCF outperforms the power spectrum at predicting both global ionization fraction and mean bubble size.
Shape and spin of minihaloes – II. The effect of streaming velocities
Authors: Druschke Maik , Schauer Anna T P , Glover Simon C O , Klessen Ralf S 
Published: August 2020

ABSTRACT
Models of the decoupling of baryons and photons during the recombination epoch predict the existence of a large-scale velocity offset between baryons and dark matter at later times, the so-called streaming velocity. In this paper, we use high resolution numerical simulations to investigate the impact of this streaming velocity on the spin and shape distributions of high-redshift minihaloes, the formation sites of the earliest generation of stars. We find that the presence of a streaming velocity has a negligible effect on the spin and shape of the dark matter component of the minihaloes. However, it strongly affects the behaviour of the gas component. The most probable spin parameter increases from ∼0.03 in the absence of streaming to ∼0.15 for a run with a streaming velocity of three times σrms, corresponding to 1.4 km s−1 at redshift z = 15. The gas within the minihaloes becomes increasingly less spherical and more oblate as the streaming velocity increases, with dense clumps being found at larger distances from the halo centre. The impact of the streaming velocity is also mass-dependent: less massive objects are influenced more strongly, on account of their shallower potential wells. The number of haloes in which gas cooling and runaway gravitational collapse occurs decreases substantially as the streaming velocity increases. However, the spin and shape distributions of gas that does manage to cool and collapse are insensitive to the value of the streaming velocity and we therefore do not expect the properties of the stars that formed from this collapsed gas to depend on the value of the streaming velocity. The spin and shape of this central gas clump are uncorrelated with the same properties measured on the scale of the halo as a whole.
NEPSC2, the North Ecliptic Pole SCUBA-2 survey: 850-μm map and catalogue of 850-μm-selected sources over 2 deg2
Authors: Shim Hyunjin , Kim Yeonsik , Lee Dongseob , Lee Hyung Mok , Goto Tomo , Matsuhara Hideo , Scott Douglas , Serjeant Stephen , Ao Yiping , Barrufet Laia , Chapman Scott , Clements David L , Conselice Christopher J , Greve Thomas R , Hashimoto Tetsuya , Hwang Ho Seong , Im Myungshin , Jeong Woong-Seob , Jiang Linhua , Kim Minjin , Kim Seong Jin , Kong Albert K H , Koprowski Maciej , Marchetti Lucia , Michałowski Michał J , Parsons Harriet , Pearson Chris , Seo Hyunjong , Toba Yoshiki , White Glenn 
Published: August 2020

ABSTRACT
We present an 850-μm mosaic map and extracted catalogue of submillimetre sources in the extended North Ecliptic Pole (NEP) region over about 2 deg2. The 850-μm map is constructed using newly obtained observations by SCUBA-2 at the East Asian Observatory’s James Clerk Maxwell Telescope, carried out using the observatory’s large programme opportunities. The recent 850-μm survey has extended the submillimetre data coverage by almost a factor of 4 compared to previous surveys, with a depth of $\sigma _\text{rms}\, {=}\, 1.0$–$2.3\, {\rm mJy}\, {\rm beam}^{-1}$. The catalogue contains 549 sources selected above a significance level of 4σ, where the false-detection rate is 10 per cent; a higher threshold of 4.5σ is required in order to achieve a false-detection rate below 3 per cent, which results in 342 sources being selected. Despite the large spatial variation of the noise, the deboosted flux density of sources is comparable to results from the SCUBA-2 Cosmology Legacy Survey, which covered the central 0.6 deg2 of our survey area with better sensitivity. We construct the source counts at 850 μm, finding results in agreement with other 850-μm surveys in cosmological blank fields over S850 = 4–15 mJy. We find a slight excess of bright galaxies ($S_{850}\, {\gt }\, 15$ mJy), which can be considered to be at $z_\text{phot}\, {=}\, 2$–4. The 850-μm data add valuable long-wavelength information to mid-infrared-selected sources from the AKARI NEP-deep and NEP-wide surveys, which will be helpful in preparing for future near-infrared to millimetre wavelength observations in the NEP region. Our 850-μm mosaic map and source catalogue will be made publicly available.
Long-term optical and infrared variability characteristics of Fermi blazars
Authors: Safna P Z , Stalin C S , Rakshit Suvendu , Mathew Blesson 
Published: August 2020

ABSTRACT
We present long-term optical and near-infrared flux variability analysis of 37 blazars detected in the γ-ray band by the Fermi Gamma-Ray Space Telescope. Among them, 30 are flat spectrum radio quasars (FSRQs) and 7 are BL Lac objects (BL Lacs). The photometric data in the optical (BVR) and infrared (JK) bands were from the Small and Moderate Aperture Research Telescope System acquired between 2008–2018. From cross-correlation analysis of the light curves at different wavelengths, we did not find significant time delays between variations at different wavelengths, except for three sources, namely PKS 1144–379, PKS B1424–418, and 3C 273. For the blazars with both B- and J-band data, we found that in a majority of FSRQs and BL Lacs, the amplitude of variability (σm) in the J band is larger than that in B band, consistent with the dominance of the non-thermal jet over the thermal accretion disc component. Considering FSRQs and BL Lacs as a sample, there are indications of σm to increase gradually towards longer wavelengths in both, however, found to be statistically significant only between B and J bands in FSRQs. In the B−J v/s J-colour magnitude diagram, we noticed complicated spectral variability patterns. Most of the objects showed a redder when brighter (RWB) behaviour. Few objects showed a bluer when brighter (BWB) trend, while in some objects both BWB and RWB behaviours were noticed. These results on flux and colour characteristics indicate that the jet emission of FSRQs and BL Lacs is indistinguishable.