bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of model inconsistencies on reconstructions of past mantle flow obtained using the adjoint method
Authors: Colli L , Bunge H-P , Oeser J 
Published: January 2020

SUMMARYThe adjoint method is a powerful technique to compute sensitivities (Fréchet derivatives) with respect to model parameters, allowing one to solve inverse problems where analytical solutions are not available or the cost to determine many times the associated forward problem is prohibitive. In Geodynamics it has been applied to the restoration problem of mantle convection—that is, to reconstruct past mantle flow states with dynamic models by finding optimal flow histories relative to the current model state—so that poorly known mantle flow parameters can be tested against observations gleaned from the geological record. By enabling us to construct time dependent earth models the adjoint method has the potential to link observations from seismology, geology, mineral physics and palaeomagnetism in a dynamically consistent way, greatly enhancing our understanding of the solid Earth system. Synthetic experiments demonstrate for the ideal case of no model error and no data error that the adjoint method restores mantle flow over timescales on the order of a transit time (≈100 Myr). But in reality unavoidable limitations enter the inverse problem in the form of poorly known model parameters and uncertain state estimations, which may result in systematic errors of the reconstructed flow history. Here we use high-resolution, 3-D spherical mantle circulation models to perform a systematic study of synthetic adjoint inversions, where we insert on purpose a mismatch between the model used to generate synthetic data and the model used for carrying out the inversion. By considering a mismatch in rheology, final state and history of surface velocities we find that mismatched model parameters do not inhibit misfit reduction: the adjoint method still produces a flow history that fits the estimated final state. However, the recovered initial state can be a poor approximation of the true initial state, where reconstructed and true flow histories diverge exponentially back in time and where for the more divergent cases the reconstructed initial state includes physically implausible structures, especially in and near the thermal boundary layers. Consequently, a complete reduction of the cost function may not be desirable when the goal is a best fit to the initial condition. When the estimated final state is a noisy low-pass version of the true final state choosing an appropriate misfit function can reduce the generation of artefacts in the initial state. While none of the model mismatches considered in this study, taken singularly, results in a complete failure of the recovered flow history, additional work is needed to assess their combined effects.
Provincializing the International: Communist Print Worlds in Colonial India
Authors: Raza Ali 
Published: January 2020

Abstract
This paper charts communist print worlds in colonial India during the interwar period. Beginning in the early 1920s, self-declared ‘Communist’ and ‘Bolshevik’ publications began surfacing across India. Through the example of the Kirti Kisan Sabha (Workers and Peasants Party: a communist group in the north-western province of Punjab), and its associated publications, this paper will provide a glimpse into the rich, diverse and imaginative print worlds of Indian communism. From 1926 onwards, Kirti publications became a part of a thriving print culture in which a dizzying variety of revolutionary, socialist and communist publications competed and conversed with the equally prolific and rich print worlds of their political and ideological rivals. Removed on the one hand from the ivory towers of party intellectuals, dense treatises and officious theses, and on the other hand from the framing of sedition, rebellion and fanaticism in the colonial archive, Kirti publications show how the global project of communist internationalism became distinctly provincialized and vernacularized in British India.
Validation of the Reveal® 3-D for Peanut Lateral Flow Test: AOAC Performance Tested MethodSM 111901
Authors: Le Quynh-Nhi , Vance Alexis , Bakir Nawal , Almy Dave , Slenk Emily , Roman Brooke , Klass Nicole , Bastin Benjamin , Donofrio Robert 
Published: January 2020

Abstract

Background
Reveal® 3-D for Peanut is an immunochromatographic, lateral flow test for qualitative detection of peanut residue in food manufacturing and food preparation settings. The test can detect low ppm levels of peanut in clean-in-place (CIP) rinses and in swabs from environmental surfaces and can serve as a tool in managing allergen risk.

Objective
The objective of the study was to validate the lateral flow method for detection of peanut in CIP rinses, specifically water, peroxyacetic acid/hydrogen peroxide, and quaternary ammonium compound rinses, and in swabs taken from stainless steel and plastic surfaces.

Methods
CIP rinses spiked with low levels of peanut were tested, as were surfaces inoculated with peanut. Specificity and assay interference were assessed in testing of food commodities with and without added peanut. Assay robustness and test kit stability and consistency testing were also performed.

Results
Results demonstrated that the lateral flow test can detect peanut in CIP rinses in the range of 2–4 ppm and in environmental surface swabs in the range of 3–4 µg/100 cm2. Results of specificity testing with 29 common food items showed lack of cross-reactivity, and potential assay interference only from walnut. Data from stability trials supports expiration dating for the kit of up to 23 months post-manufacture.

Conclusions and Highlights
The lateral flow test is a sensitive, specific, and rapid method for detection of low levels of peanut residue in CIP rinses and environmental samples and can be an important component in a comprehensive allergen risk management program.
Betrayal in War: Rules and Trends on Seeking Collaboration under IHL
Authors: Galvis Martínez Manuel 
Published: January 2020

Abstract
The article analyses the legal regime applicable to military operations seeking to gain the collaboration of enemy elements under International Humanitarian Law (IHL). Apart from addressing the prima facie legality of these practices, the article addresses some trends forming in state practice regarding limitations to its general permission. Throughout the review of academic opinions, treaty provisions, state practice and examples from armed conflicts, the author evaluates the evolution of the legal framework applicable to such tactics and provides some possible interpretations that can guide the developing process of the conduct of hostilities in the near future.
The Many Lines of Defense: The Political Economy of US Defense Acquisition
Authors: Gholz Eugene , Sapolsky Harvey M 
Published: January 2020

AbstractPolitical economy infuses the process that generates military power, notably including weapons acquisition. In the United States, defense acquisition follows a dynamic balance of interests among the private companies that design and build weapons, the military services that use weapons, and the legislators that appropriate money to pay for weapons. That process belies the simplistic conventional wisdoms that explain acquisition as a direct result of strategic need or as dictated by a unified military-industrial complex. A political economy approach that recognizes the complexity of interests—public and private, expert and political—best explains what weapons get built, by whom, where, and when.
Estradiol-inducible AvrRps4 expression reveals distinct properties of TIR-NLR-mediated effector-triggered immunity
Authors: Ngou Bruno Pok Man , Ahn Hee-Kyung , Ding Pingtao , Redkar Amey , Brown Hannah , Ma Yan , Youles Mark , Tomlinson Laurence , Jones Jonathan D G 
Published: January 2020

Abstract
Plant nucleotide-binding domain, leucine-rich repeat receptor (NLR) proteins play important roles in recognition of pathogen-derived effectors. However, the mechanism by which plant NLRs activate immunity is still largely unknown. The paired Arabidopsis NLRs RRS1-R and RPS4, that confer recognition of bacterial effectors AvrRps4 and PopP2, are well studied, but how the RRS1/RPS4 complex activates early immediate downstream responses upon effector detection is still poorly understood. To study RRS1/RPS4 responses without the influence of cell surface receptor immune pathways, we generated an Arabidopsis line with inducible expression of the effector AvrRps4. Induction does not lead to hypersensitive cell death response (HR) but can induce electrolyte leakage, which often correlates with plant cell death. Activation of RRS1 and RPS4 without pathogens cannot activate mitogen-associated protein kinase cascades, but still activates up-regulation of defence genes, and therefore resistance against bacteria.
Linking zonal winds and gravity: the relative importance of dynamic self-gravity
Authors: Wicht Johannes , Dietrich Wieland , Wulff Paula , Christensen Ulrich R 
Published: January 2020

ABSTRACT
Recent precise measurements of Jupiter’s and Saturn’s gravity fields help constraining the properties of the zonal flows in the outer envelopes of these planets. The link is provided by a simplified dynamic equation, which connects zonal flows to related buoyancy perturbations. These can result from density perturbations but also from the gravity perturbations. Whether the latter effect, which we call dynamic self-gravity (DSG), must be included or is negligible has been a matter of intense debate. We show that the second-order differential equation for the gravity perturbations becomes an inhomogeneous Helmholtz equation when assuming a polytrope of index unity for density and pressure. This equation can be solved semi-analytically when using modified spherical Bessel functions for describing the radial dependence. The respective solutions allow us to quantify the impact of the DSG on each gravity harmonic, practically independent of the zonal flow or the details of the planetary interior model. We find that the impact decreases with growing spherical harmonic degree ℓ. For degrees ℓ = 2 to about ℓ = 4, the DSG is a first-order effect and should be taken into account in any attempt of inverting gravity measurements for zonal flow properties. For degrees of about ℓ = 5 to roughly ℓ = 10, the relative impact of DSG is about 10 per cent and thus seems worthwhile to include, in particular since this comes at little extra cost with the method presented here. For yet higher degrees, it seems questionable whether gravity measurements or interior models will ever reach the precision required for disentangling the small DSG effects, which amount to only a few per cent at best.
Searching for optical companions to four binary millisecond pulsars with the Gran Telescopio Canarias
Authors: Kirichenko A Yu , Karpova A V , Zyuzin D A , Zharikov S V , López E A , Shibanov Yu A , Freire P C C , Fonseca E , Cabrera-Lavers A 
Published: January 2020

ABSTRACT
We report on multiband photometric observations of four binary millisecond pulsars with the Gran Telescopio Canarias. The observations led to detection of binary companions to PSRs J1630+3734, J1741+1351, and J2042+0246 in the Sloan g′, r′, and i′ bands. Their magnitudes in the r′ band are ≈24.4, 24.4, and 24.0, respectively. We also set a 3σ upper limit on the brightness of the PSR J0557+1550 companion in the r′ band of ≈25.6 mag. Combining the optical data with the radio timing measurements and white dwarf cooling models, we show that the detected companions are cool low-mass white dwarfs with temperatures and ages in the respective ranges of (4–7) × 103 K and 2–5 Gyr. All the detected white dwarfs are found to likely have either pure hydrogen or mixed helium–hydrogen atmospheres.
mstar – a fast parallelized algorithmically regularized integrator with minimum spanning tree coordinates
Authors: Rantala Antti , Pihajoki Pauli , Mannerkoski Matias , Johansson Peter H , Naab Thorsten 
Published: January 2020

ABSTRACTWe present the novel algorithmically regularized integration method mstar for high-accuracy (|ΔE/E| ≳ 10−14) integrations of N-body systems using minimum spanning tree coordinates. The twofold parallelization of the $\mathcal {O}(N_\mathrm{part}^2)$ force loops and the substep divisions of the extrapolation method allow for a parallel scaling up to NCPU = 0.2 × Npart. The efficient parallel scaling of mstar makes the accurate integration of much larger particle numbers possible compared to the traditional algorithmic regularization chain (ar-chain) methods, e.g. Npart = 5000 particles on 400 CPUs for 1 Gyr in a few weeks of wall-clock time. We present applications of mstar on few particle systems, studying the Kozai mechanism and N-body systems like star clusters with up to Npart = 104 particles. Combined with a tree or fast multipole-based integrator, the high performance of mstar removes a major computational bottleneck in simulations with regularized subsystems. It will enable the next-generation galactic-scale simulations with up to 109 stellar particles (e.g. $m_\star = 100 \, \mathrm{M}_\odot$ for an $M_\star = 10^{11} \, \mathrm{M}_\odot$ galaxy), including accurate collisional dynamics in the vicinity of nuclear supermassive black holes.
Centrifugal acceleration of protons by a supermassive black hole
Authors: Istomin Ya N , Gunya A A 
Published: January 2020

ABSTRACT
Centrifugal acceleration is due to the rotating poloidal magnetic field in the magnetosphere that creates the electric field which is orthogonal to the magnetic field. Charged particles with finite cyclotron radii can move along the electric field and receive energy. Centrifugal acceleration pushes particles to the periphery, where their azimuthal velocity reaches the speed of light. We calculated particle trajectories by numerical and analytical methods. The maximum obtained energies depend on the parameter of the particle magnetization κ, which is the ratio of rotation frequency of magnetic field lines in the magnetosphere ΩF to non-relativistic cyclotron frequency of particles ωc, κ = ΩF/ωc &lt;&lt;1, and on the parameter α which is the ratio of toroidal magnetic field BT to the poloidal one BP, α = BT/BP. It is shown that for small toroidal fields, α &lt; κ1/4, the maximum Lorentz factor γm is only the square root of magnetization, γm = κ−1/2, while for large toroidal fields, α &gt; κ1/4, the energy increases significantly, γm = κ−2/3. However, the maximum possible acceleration, γm = κ−1, is not achieved in the magnetosphere. For a number of active galactic nuclei, such as M87, maximum values of Lorentz factor for accelerated protons are found. Also, for special case of Sgr. A*, estimations of the maximum proton energy and its energy flux are obtained. They are in agreement with experimental data obtained by HESS Cherenkov telescope.
Lessons from a blind study of simulated lenses: image reconstructions do not always reproduce true convergence
Authors: Denzel Philipp , Mukherjee Sampath , Coles Jonathan P , Saha Prasenjit 
Published: January 2020

ABSTRACT
In the coming years, strong gravitational lens discoveries are expected to increase in frequency by two orders of magnitude. Lens-modelling techniques are being developed to prepare for the coming massive influx of new lens data, and blind tests of lens reconstruction with simulated data are needed for validation. In this paper, we present a systematic blind study of a sample of 15 simulated strong gravitational lenses from the EAGLE suite of hydrodynamic simulations. We model these lenses with a free-form technique and evaluate reconstructed mass distributions using criteria based on shape, orientation, and lensed image reconstruction. Especially useful is a lensing analogue of the Roche potential in binary star systems, which we call the lensing Roche potential. This we introduce in order to factor out the well-known problem of steepness or mass-sheet degeneracy. Einstein radii are on average well recovered with a relative error of ${\sim }5{{\ \rm per\ cent}}$ for quads and ${\sim }25{{\ \rm per\ cent}}$ for doubles; the position angle of ellipticity is on average also reproduced well up to ±10°, but the reconstructed mass maps tend to be too round and too shallow. It is also easy to reproduce the lensed images, but optimizing on this criterion does not guarantee better reconstruction of the mass distribution.
The optically selected 1.4-GHz quasar luminosity function below 1 mJy
Authors: Malefahlo Eliab , Santos Mario G , Jarvis Matt J , White Sarah V , Zwart Jonathan T L 
Published: January 2020

ABSTRACT
We present the radio luminosity function (RLF) of optically selected quasars below 1 mJy, constructed by applying a Bayesian-fitting stacking technique to objects well below the nominal radio flux density limit. We test the technique using simulated data, confirming that we can reconstruct the RLF over three orders of magnitude below the typical 5σ detection threshold. We apply our method to 1.4-GHz flux densities from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey, extracted at the positions of optical quasars from the Sloan Digital Sky Survey over seven redshift bins up to z = 2.15, and measure the RLF down to two orders of magnitude below the FIRST detection threshold. In the lowest redshift bin (0.2 &lt; z &lt; 0.45), we find that our measured RLF agrees well with deeper data from the literature. The RLF for the radio-loud quasars flattens below $\log _{10}[L_{1.4}/{\rm W\, Hz}^{-1}] \approx 25.5$ and becomes steeper again below $\log _{10}[L_{1.4}/{\rm W\, Hz}^{-1}] \approx 24.8$, where radio-quiet quasars start to emerge. The radio luminosity where radio-quiet quasars emerge coincides with the luminosity where star-forming galaxies are expected to start dominating the radio source counts. This implies that there could be a significant contribution from star formation in the host galaxies, but additional data are required to investigate this further. The higher redshift bins show a similar behaviour to the lowest z bin, implying that the same physical process may be responsible.
Optimizing gravitational waves follow-up using galaxies stellar mass
Authors: Ducoin J-G , Corre D , Leroy N , Le Floch E 
Published: January 2020

ABSTRACT
We present a new strategy to optimize the electromagnetic follow-up of gravitational wave triggers. This method is based on the widely used galaxy targeting approach where we add the stellar mass of galaxies in order to prioritize the more massive galaxies. We cross-matched the Galaxy List for the Advanced Detector Era (GLADE) galaxy catalogue with the AllWISE catalogue up to 400 Mpc with an efficiency of ∼93 per cent, and derived stellar masses using a mass-to-light ratio using the WISE1 band luminosity. We developed a new grade to rank galaxies combining their 3D localization probability associated with the gravitational wave event with the new stellar mass information. The efficiency of this new approach is illustrated with the GW170817 event, which shows that its host galaxy, NGC 4993, is ranked at the first place using this new method. The catalogue, named MANGROVE, is publicly available and the ranking of galaxies is automatically provided through a dedicated website for each gravitational wave event.
XMM–Newton campaign on ultraluminous X-ray source NGC 1313 X-1: wind versus state variability
Authors: Pinto C , Walton D J , Kara E , Parker M L , Soria R , Kosec P , Middleton M J , Alston W N , Fabian A C , Guainazzi M , Roberts T P , Fuerst F , Earnshaw H P , Sathyaprakash R , Barret D 
Published: January 2020

ABSTRACT
Most ultraluminous X-ray sources (ULXs) are thought to be powered by neutron stars and black holes accreting beyond the Eddington limit. If the compact object is a black hole or a neutron star with a magnetic field ≲1012 G, the accretion disc is expected to thicken and launch powerful winds driven by radiation pressure. Evidence of such winds has been found in ULXs through the high-resolution spectrometers onboardXMM–Newton, but several unknowns remain, such as the geometry and launching mechanism of these winds. In order to better understand ULX winds and their link to the accretion regime, we have undertaken a major campaign with XMM–Newton to study the ULX NGC 1313 X-1, which is known to exhibit strong emission and absorption features from a mildly relativistic wind. The new observations show clear changes in the wind with a significantly weakened fast component (0.2c) and the rise of a new wind phase which is cooler and slower (0.06–0.08c). We also detect for the first time variability in the emission lines which indicates an origin within the accretion disc or in the wind. We describe the variability of the wind in the framework of variable super-Eddington accretion rate and discuss a possible geometry for the accretion disc.
Evidence of spectral evolution on the white dwarf sample from the Gaia mission
Authors: Ourique G , Kepler S O , Romero A D , Klippel T S , Koester D 
Published: January 2020

ABSTRACT
Since the Gaia data release 2, several works have been published describing a bifurcation in the observed white dwarf colour−magnitude diagram for ${G_{\mathrm{BP}}}{}-{G_{\mathrm{RP}}}{} \gt 0$. Some possible explanations in the literature include the existence of a double population with different initial mass functions or two distinct populations, one formed by hydrogen-envelope and one formed by helium-envelope white dwarfs. We propose instead spectral evolution to explain the bifurcation. From a population synthesis approach, we find that spectral evolution occurs for effective temperatures below ${\simeq }11\, 000\, \mathrm{K}$ and masses mainly between $0.64\, \mathrm{M}_\odot$ and $0.74\, \mathrm{M}_\odot$, which correspond to around 16 per cent of all DA white dwarfs. We also find that the Gaia white dwarf colour–magnitude diagram indicates a star formation history that decreases abruptly for objects younger than $1.4\, \mathrm{Gyr}$ and a top-heavy initial mass function for the white dwarf progenitors.
Metallicity has followed local gravitational potential of galaxies since z = 3
Authors: Møller P , Christensen L 
Published: January 2020

ABSTRACT
The MZ relation between stellar mass (M*) and metallicity (Z) of nearby galaxies has been described as both a global and local property, i.e. valid also on sub-galaxy scales. Here, we show that Z has remained a local property, following the gravitational potential, since z = 3. In absorption, the MZ relation has been well studied, and was in place already at z = 5.1. A recent absorption study of gamma-ray burst galaxies revealed a close match to damped Lyα (DLA) galaxies, surprising due to their vastly different impact parameters and leading the authors to suggest that local metallicity follows the local gravitational potential. In this paper, we formulate an observational test of this hypothesis. The test, in essence, forms a prediction that the velocity dispersion of the absorbing gas in galaxy haloes, normalized by the central velocity dispersion, must follow a steep log scale slope of −0.015 dex $\rm kpc^{-1}$ as a function of impact parameter out to at least 20–30 kpc. We then compile an archival data and literature-based sample of galaxies seen in both emission and absorption suitable for the test, and find that current data confirm the hypothesis out to 40–60 kpc. In addition, we show that the distribution of the velocity offsets between zem and zabs favours a model where DLA systems are composed of individual sub-clouds distributed along the entire path through the halo, and disfavours a model where they are one single cloud with a bulk motion and internal sub-structure.