bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy and Safety of Drug-Eluting Beads Transarterial Chemoembolization by CalliSpheres® in 275 Hepatocellular Carcinoma Patients: Results From the Chinese CalliSpheres® Transarterial Chemoembolization in Liver Cancer (CTILC) Study
Authors: Sun Junhui , Zhou Guanhui , Xie Xiaoxi , Gu Wenjiang , Huang Jing , Zhu Dedong , Hu Wenhao , Hou Qinming , Shi Changsheng , Li Tiefeng , Zhang Xin , Ji Wenbin , Ying Shihong , Peng Zhiyi , Zhou Jian , Yu Zhihai , Ji Jiansong , Du Haijun , Guo Xiaohua , Fang Jian , Han Jun , Xu Huanhai , Sun Zhichao , Yu Wenqiang , Shao Guoliang , Wu Xia , Hu Hongjie , Li Ling , Zheng Jiaping , Luo Jun , Chen Yutang , Cao Guohong , Hu Tingyang
Published: September 2019

The purpose of this study was to investigate the efficacy and safety of drug-eluting beads transarterial chemoembolization (DEB-TACE) treatment in Chinese hepatocellular carcinoma (HCC) patients and the prognostic factors for treatment response as well as survival. A total of 275 HCC
patients were included in this prospective study. Treatment response was assessed by modified Response Evaluation Criteria in Solid Tumors (mRECIST), and progression-free survival (PFS) as well as overall survival (OS) were determined. Liver function and adverse events (AEs) were assessed
before and after DEB-TACE operation. Complete response (CR), partial response (PR), and objective response rate (ORR) were 22.9%, 60.7%, and 83.6%, respectively. The mean PFS was 362 (95% CI: 34.9‐375) days, the 6-month PFS rate was 89.4 ± 2.1%, while the mean OS
was 380 (95% CI: 370‐389) days, and the 6-month OS rate was 94.4 ± 1.7%. Multivariate logistic regression revealed that portal vein invasion (p = 0.011) was an independent predictor of worse clinical response. Portal vein invasion (p = 0.040),
previous cTACE treatment (p = 0.030), as well as abnormal serum creatinine level (BCr) (p = 0.017) were independent factors that predicted worse ORR. In terms of survival, higher Barcelona Clinic Liver Cancer (BCLC) stage (p = 0.029)
predicted for worse PFS, and abnormal albumin (ALB) (p = 0.011) and total serum bilirubin (TBIL) (p = 0.009) predicted for worse OS. The number of patients with abnormal albumin, total protein (TP), TBIL, alanine aminotransferase (ALT), and aspartate
aminotransferase (AST) were augmented at 1 week posttreatment and were similar at 1‐3 months compared with baseline. The most common AEs were pain, fever, nausea, and vomiting, and no severe AEs were observed in this study. DEB-TACE was effective and tolerable in treating Chinese HCC
patients, and portal vein invasion, previous cTACE treatment, abnormal BCr, ALB, and TBIL appear to be important factors that predict worse clinical outcome.
The Data Analysis Pipeline for the SDSS-IV MaNGA IFU Galaxy Survey: Emission-line Modeling
Authors: Belfiore Francesco , Westfall Kyle B. , Schaefer Adam , Cappellari Michele , Ji Xihan , Bershady Matthew A. , Tremonti Christy , Law David R. , Yan Renbin , Bundy Kevin , Shetty Shravan , Drory Niv , Thomas Daniel , Emsellem Eric , Sánchez Sebastián F.
Published: September 2019

SDSS-IV MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) is the largest integral-field unit (IFU) spectroscopy survey to date, aiming to observe a statistically representative sample of 10,000 low-redshift galaxies. In this paper, we study the reliability of the emission-line fluxes and kinematic properties derived by the MaNGA Data Analysis Pipeline (DAP). We describe the algorithmic choices made in the DAP with regards to measuring emission-line properties, and the effect of our adopted strategy of simultaneously fitting the continuum and line emission. The effects of random errors are quantified by studying various fit-quality metrics, idealized recovery simulations, and repeat observations. This analysis demonstrates that the emission lines are well fit in the vast majority of the MaNGA data set and the derived fluxes and errors are statistically robust. The systematic uncertainty on emission-line properties introduced by the choice of continuum templates is also discussed. In particular, we test the effect of using different stellar libraries and simple stellar-population models on the derived emission-line fluxes and the effect of introducing different tying prescriptions for the emission-line kinematics. We show that these effects can generate large (>0.2 dex) discrepancies at low signal-to-noise ratio and for lines with low equivalent width (EW); however, the combined effect is noticeable even for Hα EW > 6 Å. We provide suggestions for optimal use of the data provided by SDSS data release 15 and propose refinements on the DAP for future MaNGA data releases.
Li Evolution and the Open Cluster NGC 6819: A Correlation between Li Depletion and Spindown in Dwarfs More Massive Than the F-Dwarf Li-Dip*
Authors: Deliyannis Constantine P. , Anthony-Twarog Barbara J. , Lee-Brown Donald B. , Twarog Bruce A.
Published: September 2019

Spectroscopy of 333 NGC 6819 stars and Gaia astrometry are used to map Li evolution from the giant branch tip to 0.5 mag below the Li dip. Isochrone comparison with [Fe/H] = −0.04, based upon neural network spectroscopic analysis, produces an age of 2.25 (2.4) Gyr for E(B − V) = 0.16 (0.14) and (m − M) = 12.40 (12.29). Despite originating outside the Li dip, only 10% of single subgiants/giants have measurable Li. Above the Li dip, the limiting A(Li) for single stars is 3.2 ± 0.1 but the lower range is comparable to that found within the dip. The F-dwarf Li dip profile agrees with the Hyades/Praesepe, evolved forward. The Li level among stars populating the plateau fainter than the Li dip is A(Li) = 2.83 ± 0.16; the dispersion is larger than expected from spectroscopic error alone. Comparison of Li and V
ROT distributions among turnoff stars in NGC 7789, NGC 2506, NGC 3680, and NGC 6819 indicates that rotational spindown from the main sequence is critical in defining the boundaries of the Li dip. For higher-mass dwarfs, spindown is likewise correlated with Li depletion, creating a second dip, but at higher mass and on a longer timescale. The Li distribution among evolved stars of NGC 6819 is more representative of the older M67, where subgiant and giant stars emerge from within the Li dip, than the younger NGC 7789, where a broad range in V
ROT among the turnoff stars likely produces a range in mass among the giants.
Photoevaporation of Molecular Gas Clumps Illuminated by External Massive Stars: Clump Lifetimes and Metallicity Dependence
Authors: Nakatani Riouhei , Yoshida Naoki
Published: September 2019

We perform a suite of 3D radiation hydrodynamics simulations of photoevaporation of molecular gas clumps illuminated by external massive stars. We study the fate of solar-mass clumps and derive their lifetimes by varying the gas metallicity over a range of

. Our simulations incorporate radiation transfer of far- and extreme-ultraviolet photons and follow atomic/molecular line cooling and dust–gas collisional cooling. Nonequilibrium chemistry is coupled with the radiative transfer and hydrodynamics in a self-consistent manner. We show that radiation-driven shocks compress gas clumps to have a volume that is set by the pressure equilibrium with the hot ambient gas. Radiative cooling enables metal-rich clumps to condense and have small surface areas where photoevaporative flows are launched. For our fiducial setup with an O-type star at a distance of 0.1 pc, the resulting photoevaporation rate is as small as

for metal-rich clumps, but it is larger for metal-poor clumps that have larger surface areas. The clumps are continuously accelerated away from the radiation source by the so-called rocket effect and can travel over ∼1 pc within the lifetime. We also study the photoevaporation of clumps in a photodissociation region. Photoelectric heating is inefficient for metal-poor clumps that contain a smaller amount of grains, and thus they survive for over 105 yr. We conclude that the gas metallicity strongly affects the clump lifetime and thus determines the strength of feedback from massive stars in star-forming regions.
Assessment of the Projection-induced Polarimetry Technique for Constraining the Foreground Spectrum in Global 21 cm Cosmology
Authors: Nhan Bang D. , Bordenave David D. , Bradley Richard F. , Burns Jack O. , Tauscher Keith , Rapetti David , Klima Patricia J.
Published: September 2019

Detecting the cosmological sky-averaged (global) 21 cm signal as a function of observed frequency will provide a powerful tool to study the ionization and thermal history of the intergalactic medium (IGM) in the early universe (∼400 million years after the big bang). The greatest challenge in conventional total-power global 21 cm experiments is the removal of the foreground synchrotron emission (∼103–104 K) to uncover the weak cosmological signal (tens to hundreds of millikelvin), especially because the intrinsic smoothness of the foreground spectrum is corrupted by instrumental effects. Although the EDGES (Experiment to Detect the Global EoR Signature) team has recently reported an absorption profile at 78 MHz in the sky-averaged spectrum, it is necessary to confirm this detection with an independent approach. The projection effect from observing anisotropic foreground source emission with a wide-view antenna pointing at the North Celestial Pole can induce a net polarization, referred to as the projection-induced polarization effect (PIPE). Due to Earth’s rotation, observations centered at the circumpolar region will impose a dynamic sky modulation on the net polarization’s waveforms that is unique to the foreground component. In this study, we review the implementation practicality and underlying instrumental effects of this new polarimetry-based technique with detailed numerical simulations and a test-bed instrument, the Cosmic Twilight Polarimeter. In addition, we explore a singular value decomposition–based analysis approach for separating the foreground and instrumental effects from the background global 21 cm signal using the sky-modulated PIPE.
A Parameter Space Exploration of Galaxy Cluster Mergers. II. Effects of Magnetic Fields
Authors: Brzycki Bryan , ZuHone John
Published: September 2019

The hot intracluster plasma in clusters of galaxies is weakly magnetized. Mergers between clusters produce gas compression and motions that can increase the magnetic field strength. In this work, we perform high-resolution nonradiative magnetohydrodynamics simulations of binary galaxy cluster mergers with magnetic fields, to examine the effects of these motions on the magnetic field configuration and strength, as well as the effect of the field on the gas itself. Our simulations sample a parameter space of initial mass ratios and impact parameters. During the first core passage of mergers, the magnetic energy increases via gas compression. After this, shear flows produce temporary, megaparsec-scale, strong-field “filament” structures. Lastly, magnetic fields grow stronger by turbulence. Field amplification is most effective for low-mass ratio mergers, but mergers with a large impact parameter can increase the magnetic energy more via shearing motions. The amplification of the magnetic field is most effective in between the first two core passages of each cluster merger. After the second core passage, the magnetic energy in this region gradually decreases. In general, the transfer of energy from gas motions to the magnetic field is not significant enough to have a substantial effect on gas mixing and the subsequent increase in entropy, which occurs in cluster cores as a result. In the absence of radiative cooling, this results in an overall decrease of the magnetic field strength in cluster cores. In these regions, the final magnetic field is isotropic, while it can be significantly tangential at larger radii.
A Comparison of the X-Ray Properties of FU Ori-type Stars to Generic Young Stellar Objects
Authors: Kuhn Michael A. , Hillenbrand Lynne A.
Published: September 2019

Like other young stellar objects (YSOs), FU Ori-type stars have been detected as strong X-ray emitters. However, little is known about how the outbursts of these stars affect their X-ray properties. We assemble available X-ray data from XMM-Newton and Chandra observations of 16 FU Ori stars, including a new XMM-Newton observation of Gaia 17bpi during its optical rise phase. Of these stars, six were detected at least once, while 10 were non-detections, for which we calculate upper limits on intrinsic X-ray luminosity (L
X) as a function of plasma temperature (kT) and column density (N
H). The detected FU Ori stars tend to be more X-ray luminous than is typical for non-outbursting YSOs, based on comparison to a sample of low-mass stars in the Orion Nebula Cluster. FU Ori stars with high L
X have been observed both at the onset of their outbursts and decades later. We use the Kaplan–Meier estimator to investigate whether the higher X-ray luminosities for FU Ori stars are characteristic or a result of selection effects, and we find the difference to be statistically significant (p < 0.01) even when non-detections are taken into account. The additional X-ray luminosity of FU Ori stars relative to non-outbursting YSOs cannot be explained by accretion shocks, given the high observed plasma temperatures. This suggests that, for many FU Ori stars, either (1) the outburst leads to a restructuring of the magnetosphere in a way that enhances X-ray emission, or (2) FU Ori outbursts are more likely to occur among YSOs with the highest quiescent X-ray luminosity.
Probing Clumpy Wind Accretion in IGR J18027-2016 with XMM-Newton
Authors: Pradhan Pragati , Bozzo Enrico , Paul Biswajit , Manousakis Antonis , Ferrigno Carlo
Published: September 2019

Supergiant X-ray binaries usually comprise a neutron star accreting from the wind of an OB supergiant companion. They are classified as classical systems and supergiant fast X-ray transients (SFXTs). The different behavior of these subclasses of sources in X-rays, with SFXTs displaying much more pronounced variability, is usually (at least) partly ascribed to different physical properties of the massive star clumpy stellar wind. In the case of SFXTs, a systematic investigation of the effects of clumps on flares/outbursts of these sources has been reported by Bozzo et al. exploiting the capabilities of the instruments on board XMM-Newton to perform a hardness-resolved spectral analysis on timescales as short as a few hundreds of seconds. In this paper, we use six XMM-Newton observations of IGR J18027-2016 to extend the above study to a classical supergiant X-ray binary and compare the findings with those derived in the case of SFXTs. As these observations of IGR J18027-2016 span different orbital phases, we also study its X-ray spectral variability on longer timescales and compare our results with previous publications. Although obtaining measurements of the clump physical properties from X-ray observations of accreting supergiant X-ray binaries has already proven to be challenging, our study shows that similar imprints of clumps are found in the X-ray observations of the SFXTs and at least one classical system, i.e., IGR J18027-2016. This provides interesting perspectives to further extend this study to many XMM-Newton observations already performed in the direction of other classical supergiant X-ray binaries.
Spatially Resolved Signatures of Bidirectional Flows Observed in Inverted-Y Shaped Jets
Authors: Nelson C. J. , Freij N. , Bennett S. , Erdélyi R. , Mathioudakis M.
Published: September 2019

Numerous apparent signatures of magnetic reconnection have been reported in the solar photosphere, including inverted-Y shaped jets. The reconnection at these sites is expected to cause localized bidirectional flows and extended shock waves; however, these signatures are rarely observed as extremely high spatial-resolution data are required. Here, we use Hα imaging data sampled by the Swedish Solar Telescope’s CRisp Imaging SpectroPolarimeter to investigate whether bidirectional flows can be detected within inverted-Y shaped jets near the solar limb. These jets are apparent in the Hα line wings, while no signature of either jet is observed in the Hα line core, implying reconnection took place below the chromospheric canopy. Asymmetries in the Hα line profiles along the legs of the jets indicate the presence of bidirectional flows, consistent with cartoon models of reconnection in chromospheric anemone jets. These asymmetries are present for over two minutes, longer than the lifetimes of Rapid Blue Excursions, and beyond ±1 Å into the wings of the line indicating that flows within the inverted-Y shaped jets are responsible for the imbalance in the profiles, rather than motions in the foreground. Additionally, surges form following the occurrence of the inverted-Y shaped jets. This surge formation is consistent with models, which suggests such events could be caused by the propagation of shock waves from reconnection sites in the photosphere to the upper atmosphere. Overall, our results provide evidence that magnetic reconnection in the photosphere can cause bidirectional flows within inverted-Y shaped jets and could be the driver of surges.
Validating Time–Distance Helioseismic Inversions for Nonseparable Subsurface Profiles of an Average Supergranule
Authors: Dhruv Vedant , Bhattacharya Jishnu , Hanasoge Shravan M.
Published: September 2019

Supergranules are divergent 30 Mm-sized cellular flows observed everywhere at the solar photosphere. Their place in the hierarchy of convective structures and their origin remain poorly understood. Estimating supergranular depth is of particular interest because this may help point to the underlying physics. However, their subsurface velocity profiles have proven difficult to ascertain. Birch et al. suggested that helioseismic inferences would benefit from an ensemble average over multiple realizations of supergranules due to the reduction in realization noise. Bhattacharya et al. used synthetic forward-modeled seismic wave travel times and demonstrated the potential of helioseismic inversions to recover the flow profile of an average supergranule that is separable in the horizontal and vertical directions, although the premise of this calculation has since been challenged by Ferret. In this work we avoid this assumption and carry out a validation test of helioseismic travel-time inversions starting from plausible synthetic nonseparable profiles of an average supergranule. We compute seismic wave travel times and sensitivity kernels by simulating wave propagation through this background. We find that, while the ability to recover the exact profile degrades based on the number of parameters involved, we are nevertheless able to recover the peak depth of our models in a few iterations where the measurements are presumably above the noise cutoff. This represents an important step toward unraveling the physics behind supergranules, as we start appreciating the parameters that we may reliably infer from a time–distance helioseismic inversion.
Constraining the Formation of the Four Terrestrial Planets in the Solar System
Authors: Lykawka Patryk Sofia , Ito 伊 Takashi 藤孝士
Published: September 2019

To reproduce the orbits and masses of the terrestrial planets (analogs) of the solar system, most studies scrutinize simulations for success as a batch. However, there is insufficient discussion in the literature on the likelihood of forming planet analogs simultaneously in the same system (analog system). To address this issue, we performed 540 N-body simulations of protoplanetary disks representative of typical models in the literature. We identified a total of 194 analog systems containing at least three analogs, but only 17 systems simultaneously contained analogs of the four terrestrial planets. From an analysis of our analog systems, we found that, compared to the real planets, truncated disks based on typical outcomes of the Grand Tack model produced analogs of Mercury and Mars that were too dynamically cold and located too close to the Venus and Earth analogs. Additionally, all the Mercury analogs were too massive, while most of the Mars analogs were more massive than Mars. Furthermore, the timing of the Moon-forming impact was too early in these systems, and the amount of additional mass accreted after the event was too great. Therefore, such truncated disks cannot explain the formation of the terrestrial planets. Our results suggest that forming the four terrestrial planets requires disks with the following properties: (1) mass concentrated in narrow core regions between ∼0.7–0.9 au and ∼1.0–1.2 au, (2) an inner region component starting at ∼0.3–0.4 au, (3) a less massive component beginning at ∼1.0–1.2 au, (4) embryos rather than planetesimals carrying most of the disk mass, and (5) Jupiter and Saturn placed on eccentric orbits.
Development of Hydrogen and Helium Proximity Zones around Quasars
Authors: Zheng Wei , Meiksin Avery , Syphers David
Published: September 2019

Increasing evidence suggests that He ii proximity profiles in the quasar spectra at z ∼ 3–4 are sensitive probes of quasar ages. But the development of their H i counterparts is difficult to trace and remains poorly constrained. We compare the UV spectra of 15 He ii quasars with their high-resolution optical counterparts and find a significant correlation between the sizes of He ii and H i proximity zones. The luminous quasar HE2347−4342 displays a null proximity zone in both He ii and H i, suggesting that it is extremely young (age < 0.2 Myr). Three other quasars also display small proximity zones for He ii and H i. There is no evidence that a H i ionization zone expands considerably faster than its He ii counterpart. The results suggest that the expansion of quasar ionizing fronts may be noticeably slower than the speed of light, and raise the possibility of distinguishing young and old quasars from the sizes of their H i proximity zones.
Discovery and Early Evolution of ASASSN-19bt, the First TDE Detected by TESS
Authors: Holoien Thomas W.-S. , Vallely Patrick J. , Auchettl Katie , Stanek K. Z. , Kochanek Christopher S. , French K. Decker , Prieto Jose L. , Shappee Benjamin J. , Brown Jonathan S. , Fausnaugh Michael M. , Dong Subo , Thompson Todd A. , Bose Subhash , Neustadt Jack M. M. , Cacella P. , Brimacombe J. , Kendurkar Malhar R. , Beaton Rachael L. , Boutsia Konstantina , Chomiuk Laura , Connor Thomas , Morrell Nidia , Newman Andrew B. , Rudie Gwen C. , Shishkovksy Laura , Strader Jay
Published: September 2019

We present the discovery and early evolution of ASASSN-19bt, a tidal disruption event (TDE) discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d ≃ 115 Mpc and the first TDE to be detected by TESS. As the TDE is located in the TESS Continuous Viewing Zone, our data set includes 30 minute cadence observations starting on 2018 July 25, and we precisely measure that the TDE begins to brighten ∼8.3 days before its discovery. Our data set also includes 18 epochs of Swift UVOT and XRT observations, 2 epochs of XMM-Newton observations, 13 spectroscopic observations, and ground data from the Las Cumbres Observatory telescope network, spanning from 32 days before peak through 37 days after peak. ASASSN-19bt thus has the most detailed pre-peak data set for any TDE. The TESS light curve indicates that the transient began to brighten on 2019 January 21.6 and that for the first 15 days, its rise was consistent with a flux ∝t
2 power-law model. The optical/UV emission is well fit by a blackbody spectral energy distribution, and ASASSN-19bt exhibits an early spike in its luminosity and temperature roughly 32 rest-frame days before peak and spanning up to 14 days, which has not been seen in other TDEs, possibly because UV observations were not triggered early enough to detect it. It peaked on 2019 March 4.9 at a luminosity of L ≃ 1.3 × 1044 erg s−1 and radiated E ≃ 3.2 × 1050 erg during the 41 day rise to peak. X-ray observations after peak indicate a softening of the hard X-ray emission prior to peak, reminiscent of the hard/soft states in X-ray binaries.
Magnetic Properties of Dust Grains, Effect of Precession, and Radiative Torque Alignment
Authors: Lazarian A. , Hoang Thiem
Published: September 2019

Alignment of dust grains in astrophysical environments results in the polarization of starlight as well as the polarization of radiation emitted by dust. We demonstrate the advances in grain alignment theory that allow the use of linear and circular polarization to probe not only the magnetic field, but also dust composition, the dust environment, etc. We revisit the process of grain alignment by Radiative Torques (RATs) and focus on constraining magnetic susceptibility of grains via observations. We discuss the possibility of observational testing of the magnetic properties of grains as the alignment changes from being in respect to the magnetic field to being in respect to the radiation direction. This both opens a possibility of constraining the uncertain parameters of the RATs theory and provides a new way of measuring magnetic fields in the interstellar medium and circumstellar regions. We provide a detailed discussion of the precession induced both by the magnetic field and the anisotropic radiation and revisit a number of key processes related to magnetic response of the grains. We consider various effects that increase the rate of magnetic relaxation both in silicate and carbonaceous grains. In particular, we find a new relaxation process related to the change of the amplitude of internal magnetization within a wobbling triaxial grain and identify a range of grain sizes in which this effect can dominate the internal alignment of angular momentum within grain axes. We show that these relaxation processes significantly change the dynamics of grains in the presence of RATs. We apply our analysis for observed grain alignment in special environments to put constraints on the enhanced magnetic properties of dust grains in the cloud near supernovae, in cometary coma, and protoplanetary disks.
Quasars Have Fewer Close Companions than Normal Galaxies
Authors: Yue Minghao , Fan Xiaohui , Schindler Jan-Torge , McGreer Ian D. , Huang Yun-Hsin
Published: September 2019

We investigate the distribution of companion galaxies around quasars using Hubble Space Telescope (HST) Advanced Camera for Surveys Wide Field Camera (ACS/WFC) archival images. Our master sample contains 532 quasars that have been observed by HST ACS/WFC, spanning a wide range of luminosity (−31 < M

i
(z = 2) < −23) and redshift (0.3 < z < 3). We search for companions around the quasars with a projected distance of 10 kpc < d < 100 kpc. Point spread function subtraction is performed to enhance the completeness for close companions. The completeness is estimated to be high (>90%) even for the faintest companions of interest. The number of physical companions is estimated by subtracting a background density from the number density of projected companions. We divide all the companions into three groups (faint, intermediate, and bright) according to their fluxes. A control sample of galaxies is constructed to have a similar redshift distribution and stellar mass range as the quasar sample using the data from HST deep fields. We find that quasars and control sample galaxies have similar numbers of faint and bright companions, while quasars show a 3.7σ deficit of intermediate companions compared to galaxies. The numbers of companions in all three groups do not show strong evolution with redshift, and the number of intermediate companions around quasars decreases with quasar luminosity. Assuming that merger-triggered quasars have entered the final coalescence stage during which individual companions are no longer detectable at large separations, our result is consistent with a picture in which a significant fraction of quasars is triggered by mergers.
Impact of Cosmic-Ray Feedback on Accretion and Chemistry in Circumstellar Disks
Authors: Offner Stella S. R. , Gaches Brandt A. L. , Holdship Jonathan R.
Published: September 2019

We use the gas-grain chemistry code uclchem to explore the impact of cosmic-ray feedback on the chemistry of circumstellar disks. We model the attenuation and energy losses of the cosmic rays as they propagate outward from the star and also consider ionization due to stellar radiation and radionuclides. For accretion rates typical of young stars of

M
⊙ yr−1, we show that cosmic rays accelerated by the stellar accretion shock produce an ionization rate at the disk surface ζ ≳ 10−15 s−1, at least an order of magnitude higher than the ionization rate associated with the Galactic cosmic-ray background. The incident cosmic-ray flux enhances the disk ionization at intermediate to high surface densities (Σ > 10 g cm−2), particularly within 10 au of the star. We find that the dominant ions are C+, S+, and Mg+ in the disk surface layers, while the

ion dominates at surface densities above 1.0 g cm−2. We predict the radii and column densities at which the magnetorotational instability (MRI) is active in T Tauri disks and show that ionization by cosmic-ray feedback extends the MRI-active region toward the disk midplane. However, the MRI is only active at the midplane of a minimum-mass solar nebula disk if cosmic rays propagate diffusively (ζ ∝ r
−1) away from the star. The relationship between accretion, which accelerates cosmic rays, the dense accretion columns, which attenuate cosmic rays, and the MRI, which facilitates accretion, creates a cosmic-ray feedback loop that mediates accretion and may produce variable luminosity.
A Prospective New Diagnostic Technique for Distinguishing Eruptive and Noneruptive Active Regions
Authors: Pagano Paolo , Mackay Duncan H. , Yardley Stephanie L.
Published: September 2019

Active regions are the source of the majority of magnetic flux rope ejections that become coronal mass ejections (CMEs). To identify in advance which active regions will produce an ejection is key for both space weather prediction tools and future science missions such as Solar Orbiter. The aim of this study is to develop a new technique to identify which active regions are more likely to generate magnetic flux rope ejections. The new technique will aim to (i) produce timely space weather warnings and (ii) open the way to a qualified selection of observational targets for space-borne instruments. We use a data-driven nonlinear force-free field (NLFFF) model to describe the 3D evolution of the magnetic field of a set of active regions. We determine a metric to distinguish eruptive from noneruptive active regions based on the Lorentz force. Furthermore, using a subset of the observed magnetograms, we run a series of simulations to test whether the time evolution of the metric can be predicted. The identified metric successfully differentiates active regions observed to produce eruptions from the noneruptive ones in our data sample. A meaningful prediction of the metric can be made between 6 and 16 hr in advance. This initial study presents an interesting first step in the prediction of CME onset using only line-of-sight magnetogram observations combined with NLFFF modeling. Future studies will address how to generalize the model such that it can be used in a more operational sense and for a variety of simulation approaches.
Inverse Compton Scattering of the Central Source Photons as an X-Ray Emission Mechanism on Kiloparsec Scales in PKS 1127–145
Authors: Butuzova Marina S. , Pushkarev Alexander B.
Published: September 2019

The beamed inverse Compton/cosmic microwave background model has generally been used for the interpretation of X-ray radiation from kiloparsec-scale jets of core-dominated quasars. Recent Fermi-LAT and HST observations have brought this model into question. We examine the assumption that X-rays from the kiloparsec-scale jet of the quasar PKS 1127−145 are produced by inverse Compton scattering of the central source emission. In this context, we show that both similarity and distinction between the observed radio and X-ray spectral indices for some of the jet knots can be explained under a single power-law electron energy distribution. We derive that the viewing angle of the kiloparsec-scale jet is about 35° and the jet has a moderate relativistic speed of ≈0.8c. The predicted gamma-ray flux of the jet is found to be a few orders of magnitude lower than the minimum flux level measured by Fermi-LAT, further supporting our scenario.
A Global Two-scale Helicity Proxy from π-ambiguous Solar Magnetic Fields
Authors: Brandenburg Axel
Published: September 2019

If the α effect plays a role in the generation of the Sun’s magnetic field, the field should show evidence of magnetic helicity of opposite signs at large and small length scales. Measuring this faces two challenges: (i) in weak-field regions, horizontal field measurements are unreliable because of the π ambiguity, and (ii) one needs a truly global approach to computing helicity spectra in the case where one expects a sign reversal across the equator at all wavenumbers. Here we develop such a method using spin-2 spherical harmonics to decompose the linear polarization in terms of the parity-even and parity-odd E and B polarizations, respectively. Using simple one- and two-dimensional models, we show that the product of the spectral decompositions of E and B, taken at spherical harmonic degrees that are shifted by one, can act as a proxy of the global magnetic helicity with a sign that represents that in the northern hemisphere. We then apply this method to the analysis of solar synoptic vector magnetograms, from which we extract a pseudo-polarization corresponding to a “π-ambiguated” magnetic field, i.e., a magnetic field vector that has no arrow. We find a negative sign of the global EB helicity proxy at spherical harmonic degrees of around 6. This could indicate a positive magnetic helicity at large length scales, but the spectrum fails to capture clear evidence of the well-known negative magnetic helicity at smaller scales. This method might also be applicable to stellar and Galactic polarization data.
The Habitability of GJ 357D: Possible Climate and Observability
Authors: Kaltenegger L. , Madden J. , Lin Z. , Rugheimer S. , Segura A. , Luque R. , Pallé E. , Espinoza N.
Published: September 2019

The GJ 357 system harbors three planets orbiting a bright, nearby M2.5V star at 9.44 pc. The innermost planet, GJ 357b (TOI-562.01), is a hot transiting Earth-sized planet with Earth-like density, which receives about 12 times the irradiation Earth receives from the Sun, and was detected using data from TESS. Radial velocities discovered two more planets in the system at 9.12 (GJ 357 c) and 55.6 days (GJ 357 d), with minimum masses of 3.59 ± 0.50 and 6.1 ± 1 Earth masses, and an irradiation of 4.4 and 0.38 Earth’s irradiation, respectively. GJ 357 d receives slightly less stellar irradiation than Mars does in our own solar system, which puts it in the Habitable Zone (HZ) for its host star. GJ 357 d could not have been detected with TESS and whether it transits remains an open question. Here we model possible conditions within which GJ357 d could sustain surface habitability and present planetary models as well as synthetic transmission, reflection, and emission spectra for a range of models for GJ 357 d from water worlds to Earth-like models. With Earth-analog outgassing rates, GJ 357 d would be a frozen rocky world; however, with an increased CO2 level, as would be expected if a geological cycles regulates CO2 concentration like on Earth, the planet models show temperate surface conditions. If we can detect a transit of GJ 357 d, it would become the closest transiting, potentially habitable planet in the solar neighborhood. Even if GJ 357 d does not transit, the brightness of its star makes this planet, in the HZ of a close-by M star, a prime target for observations with Extremely Large telescopes as well as future space missions.
Économie des conflits : revue de la littérature et guide à l’intention des acteurs de l’aide extérieure
Authors: Rohner Dominic
Published: September 2019

Cet essai est une analyse documentaire dont l’objectif est de donner une vue d’ensemble des récents travaux de recherche en matière d’économie des conflits, traitant les principales conséquences et causes profondes des guerres civiles. Déjà abondante, la littérature dans ce domaine est en plein essor : partant de ce constat, notre analyse ne peut être que sélective. Nous mettrons l’accent tout particulièrement sur le potentiel d’applications pratiques des résultats par les acteurs de l’aide extérieure internationale. Plus précisément, nous examinerons les outils de prévision à la pointe des technologies, permettant une meilleure protection des activités courantes. En outre, nous étudierons des résultats empiriques récents portant sur des politiques publiques et sur des programmes et initiatives spécifiques de développement, susceptibles, ou non, de contribuer à la réduction des conflits.
Écoles paysannes et rendement du cacao au Cameroun
Authors: Kamdem Cyrille Bergaly
Published: September 2019

L’objectif de cet article est d’évaluer l’effet des écoles paysannes sur la production du cacao dans les régions du Centre et du Sud-Ouest du Cameroun, au moyen de la méthode quasi- expérimentale. Cette méthode utilise les techniques des modèles « propensity score matching » (PSM) et « endogenous switching regression » (ESR). Les données utilisées proviennent des enquêtes de l’International Institute of Tropical Agriculture (IITA) réalisées en 2009 auprès de 201 producteurs de cacao dans les régions du Centre-Est et du Sud-Ouest du Cameroun. Les résultats montrent que les écoles paysannes ont un effet positif et statistiquement significatif sur le rendement du cacao par hectare. Cet effet est estimé à une augmentation de 17 % et 29 % du rendement par hectare lorsqu’on utilise la technique des cinq voisins les plus proches et la technique du kernel, respectivement. Il est recommandé d’améliorer la qualité de la formation dans les écoles paysannes afin d’accroître leur impact sur le rendement du cacao. Il est également recommandé de promouvoir les écoles paysannes dans les villages où il n’y en a pas afin d’augmenter substantiellement le niveau national de la production du cacao, qui est l’un des principaux objectifs de la politique agricole du Cameroun. La politique de renforcement des écoles paysannes doit prendre en compte les organisations paysannes, les vulgarisateurs et les agriculteurs expérimentés en tant qu’acteurs principaux de la mise en œuvre du modèle des écoles paysannes. L’évaluation de l’impact montre que l’amélioration des compétences des agriculteurs augmenterait considérablement la production du cacao. Notre cadre d’analyse intéresse les décideurs politiques car il peut leur permettre d’identifier les conditions d’amélioration du rendement du cacao à travers les écoles paysannes et de concevoir des stratégies de motivation efficaces.
Impact de l’expérimentation de coopération entre médecin généraliste et infirmière Asalée sur l’activité des médecins
Authors: Loussouarn Christophe , Franc Carine , Videau Yann , Mousquès Julien
Published: September 2019

Dans de nombreux pays, les politiques et réformes ont explicitement encouragé l’intégration des organisations de soins primaires et la coopération pluri-professionnelle afin d’améliorer l’efficience productive et allocative de l’offre de soins et lutter contre l’inégale répartition géographique des médecins. En France, la Direction de la Sécurité sociale et une association dénommée Asalée (« Action de santé libérale en équipe », depuis 2004) ont mis en place une expérimentation destinée à favoriser l’intégration verticale et le travail en équipe entre médecins généralistes et infirmières par la mise en place de nouveaux modes de rémunération et la formation d’infirmières sélectionnées. Cet article évalue l’extension de cette expérimentation sur la période 2010-2016 en étudiant l’influence de cette coopération, mais aussi de l’organisation et des incitations financières à l’œuvre, sur l’activité des médecins généralistes appréhendée à partir de trois indicateurs : le nombre de jours travaillés, de patients rencontrés (en file active et, parmi eux, ceux inscrits médecin traitant) et d’actes (consultations au cabinet et visites à domicile). Nous contrôlons autant que possible des biais d’endogénéité et de sélection en recourant à un design cas-témoins, selon une méthode d’appariement exact, et des méthodes d’estimation en différence de différences sur données de panel. Dans ce cadre, nous montrons un effet positif du dispositif mais relativement modeste sur le nombre de jours travaillés par les médecins (+1,2 %) et un effet plus marqué sur le nombre de patients rencontrés (+7,55 %) et inscrits médecin traitant (+6,87 %). En revanche, aucun effet significatif n’est mis en évidence sur le nombre de consultations et visites. Codes JEL : C31, C33, I11, J22, L23
Healthcare Quality, Patients’ Satisfaction, and Hospital Incentives in France
Authors: Lescher Myriam , Sirven Nicolas
Published: September 2019

Les autorités sanitaires françaises ont récemment produit et mis à disposition du public un large éventail de mesures de la qualité des soins hospitaliers, régulièrement mises à jour ( www.scopesante.fr ). La théorie économique appliquée aux marchés des soins de santé prédit que les coûts de surveillance engagés par les autorités de santé au bénéfice du patient (le principal) pour signaler la qualité des hôpitaux (les agents) devraient inciter ces derniers à améliorer les indicateurs de qualité et de sécurité des soins (IQSS). Cependant, les patients se réfèrent rarement à l’information clinique, technique de qualité des soins afin de discriminer les hôpitaux; et sont davantage enclins à utiliser des évaluations subjectives (telles que le bouche-à-oreille) dont la satisfaction des patients peut être un indicateur indirect. A l’aide d’un échantillon unique de données concernant 2 323 hôpitaux en France métropolitaine et en surmontant les problèmes de sélection inhérents à notre échantillon, nous trouvons une forte corrélation entre une mesure standardisée de la satisfaction des patients, e-satis , et diverses mesures des IQSS. Nos résultats suggèrent que, puisque les patients utilisent un signal qui transmet des informations sur la qualité, les hôpitaux pourraient être incités à améliorer la qualité des soins. Codes JEL: I18, L25, C34
L’influence des accidents de la route sur les trajectoires professionnelles des personnels en fin de carrière, à partir de la cohorte Gazel
Authors: Sanchez Marc-Antoine , Barnay Thomas , Marsaudon Antoine , Rochaix Lise
Published: September 2019

L’objectif de cet article est d’évaluer l’effet des accidents de la route sur les trajectoires professionnelles des employés de court et moyen terme d’EDF-GDF en fin de carrière, à partir de la cohorte Gazel sur la période 2002-2014. Cette étude permet d’identifier les stratégies d’adaptation de l’entreprise et de l’accidenté, qui conduisent à modifier la trajectoire professionnelle à la suite d’un tel choc exogène. Elle permet d’apprécier les marges de manœuvre dont disposent réellement les acteurs, dans un contexte marqué par la volonté de réformer les retraites, tout particulièrement pour les régimes spéciaux, comme c’est le cas pour EDF-GDF. La base Gazel permet de caractériser les différents types d’accidents de la route afin de distinguer leurs impacts sur les changements de trajectoires professionnelles des individus en fin de carrière. La méthode des doubles différences avec appariement par score de propension est utilisée. Au total, 4066 individus ont été victimes d’accidents de la route sur la période d’étude. En moyenne plus âgées, les victimes sont issues de catégories socio-professionnelles plus défavorisées et les hommes sont surreprésentés. Les résultats suggèrent une sortie plus précoce du marché du travail possible grâce à des mécanismes de reclassement qui permettraient d’ouvrir des droits à un départ anticipé du marché. Par ailleurs, les victimes d’accidents de la route subissent moins de changements de trajectoire à la suite d’un accident de la route sans impact sur la santé. Classification JEL : J26, J24, J32, I10
Development of a Gerontology Graduate Certificate in Post-Acute and Long-Term Care
Authors: Dassel Kara B. , Flattes Valerie , Eaton Jacqueline , Towsley Gail , Moyers Landon , Edelman Linda
Published: September 2019

Nurse practitioners (NPs) can provide safe, effective, quality care to older adults in post-acute and long-term care (PALTC) settings. However, there is a paucity of exposure to PALTC settings in most NP educational programs. Therefore, the current authors developed an elective graduate certificate in gerontology with an emphasis in PALTC for NP students. The graduate certificate curriculum was developed by faculty with expertise in nursing and gerontology education. The PALTC certificate comprises 15 credit hours of online didactic courses, 80 leadership hours, 200 clinical hours, and a scholarly project dedicated to PALTC. Completion of a graduate certificate in PALTC is a novel model for preparing NP students for practice in PALTC settings. The current article serves as a framework for other programs to reference as they develop individualized graduate certificate PALTC programs in their academic institutions. [
Journal of Gerontological Nursing, 45
(10), 47–52.]
Missionários, índios e sociedade colonial no nordeste da Bahia: Natuba, séculos XVII e XVIII
Authors: Sales Souza Evergton
Published: September 2019

El artículo examina aspectos de la conquista y población del noreste de Bahía, centrando la atención en el papel del indio en la ocupación colonial de nuevos espacios. Se toma la aldea de Natuba como la principal referencia para el estudio del contexto de la violencia que marca el avance de la sociedad colonial en la región. Tras estudiar el problema de la demarcación de tierras, que afectaba a indios, misioneros, gobierno y colonos, se muestra cómo la aldea misionera tendía a ser un espacio menos inestable, porque permitía a los indígenas avanzar por una senda de reconfiguración propicia a mantener su identidad, bajo la influencia de la tradición católica vivida en el noreste de Bahía.

[pt] O artigo estuda aspectos da conquista e povoamento do nordeste da Bahia, privilegiando o olhar sobre o lugar dos índios na ocupação colonial de novos espaços. A aldeia de Natuba foi tomada como a principal referência para o estudo do contexto de violência que marca o avanço da sociedade colonial na região. Após examinar o problema da demarcação de terras, que envolve índios, missionários, governo e colonos, mostra-se como a aldeia missionária tendeu a ser um espaço menos instável, permitindo aos indígenas trilharem um caminho de reconfigurações que ajudou a manter sua identidade e influenciar o catolicismo vivido no nordeste baiano.
La fundación del Juzgado Privativo de Tierras y Aguas de la Real Audiencia de México, 1692-1735
Authors: Carrera Quezada Sergio Eduardo
Published: September 2019

El presente texto aborda el conjunto de disposiciones jurídicas promulgadas por los monarcas españoles que impulsaron la fundación de instancias gubernamentales comisionadas para la regularización de la propiedad agraria en la América colonial a finales del siglo XVII y comienzos del XVIII. Se dan a conocer los decretos y edictos de los ministros del Juzgado Privativo de Tierras de la Real Audiencia de México para analizar la operatividad de esta dependencia y de las actividades de sus comisionados en las jurisdicciones novohispanas. Asimismo, se subraya la importancia de las composiciones de tierras y ventas de baldíos en la historia rural de México, dado que fueron procedimientos que, por un lado, apuntalaron el derecho a la propiedad absoluta, y por el otro, incidieron en la propiedad comunal de los pueblos de indios y en su configuración territorial.