bluuebunny/crossref_metadata_2025_split huggingface dataset:
La distribution des éléments alcalins Li, Na, K, Rb, dans les minéraux essentiels des granites et granodiorites du sud de la Corse
Authors: Carron Jean-Paul , Lagache Martine 
Published: April 2019

The partition of major and minor alkali elements between the main minerals of 15 biotite-granites and 15 amphibole-biotite-granodiorites agrees with an equilibrium state due to ion exchange mechanisms. According to experimental data, the Na and K distribution between coexisting feldspars indicates an equili¬ brium temperature of 550° C for the granites, and 475° C for the granodiorites. For trace elements, weight partition coefficients have been calculated between K-feldspars (F), plagioclases (P), biotites (B) and amphiboles (A) : for lithium D[B/A] = 10 and D[P/F] = 4.3 ; for rubidium D[F/P] = 12 (the last two coefficients are established for all samples taken together). The rubidium partition between biotites and K feldspars, defined by the ratios Rb/(K + Na) for each mineral, makes it possible to split the two rock types, and to attribute to them temperatures differing by approximately 50° C. Most results for Li and Rb are explained by comparing their ionic radii with the size of suitable sites in the various minerals.
The Splashback Radius of Planck SZ Clusters*
Authors: Zürcher Dominik , More Surhud 
Published: April 2019

Abstract
We present evidence for the existence of the splashback radius in galaxy clusters selected using the Sunyaev–Zeldovich effect, a sample unaffected by systematics related to cluster finding in the optical wavelength range. We show that the deprojected cross-correlation of galaxy clusters found in the Planck survey with galaxies detected photometrically in the Pan-STARRS survey shows a sharp steepening feature (a logarithmic slope steeper than −3), which we associate with the splashback radius. We infer the 3D splashback radius for the SZ cluster sample to be

, where the cluster sample has an average halo mass of M
500c
= 3.0 × 1014

at an average redshift of z = 0.18. The inferred value of the splashback radius appears marginally consistent with the expected location for dark matter halos in the standard cold dark matter paradigm. However, given the limited precision of our measurements, we cannot conclusively confirm or rule out the smaller splashback radius measured so far in the literature for optically selected galaxy clusters. We show that the splashback radius does not depend on the galaxy magnitude for galaxies fainter than

and is present at a consistent location in galaxy populations divided by color. The presence of the splashback radius in the star-forming galaxy population could potentially be used to put lower limits on the quenching timescales for galaxies. We can marginally rule out the contamination of the star-forming galaxy sample by quenched galaxies, but the results would need further verification with deeper data sets.
X-Ray and Optical Monitoring of State Transitions in MAXI J1820+070
Authors: Shidatsu Megumi , Nakahira Satoshi , Murata Katsuhiro L. , Adachi Ryo , Kawai Nobuyuki , Ueda Yoshihiro , Negoro Hitoshi 
Published: April 2019

Abstract
We report results from the X-ray and optical monitoring of the black hole candidate MAXI J1820+070 (=ASSASN-18ey) over the entire period of its outburst from 2018 March to October. In this outburst, the source exhibited two sets of “fast rise and slow decay”-type long-term flux variations. We found that the 1–100 keV luminosities at two peaks were almost the same, although a significant spectral softening was only seen in the second flux rise. This confirms that the state transition from the low/hard state to the high/soft state is not determined by the mass accretion rate alone. The X-ray spectrum was reproduced with the disk blackbody emission and its Comptonization, and the long-term spectral variations seen in this outburst were consistent with a disk truncation model. The Comptonization component, with a photon index of 1.5–1.9 and electron temperature of ≳40 keV, was dominant during the low/hard state periods, and its contribution rapidly decreased (increased) during the spectral softening (hardening). During the high/soft-state period, in which the X-ray spectrum became dominated by the disk blackbody component, the inner disk radius was almost constant, suggesting that the standard disk was present down to the innermost stable circular orbit. The long-term evolution of optical and X-ray luminosities and their correlation suggest that the jets substantially contributed to the optical emission in the low/hard state, while they are quenched and the outer disk emission dominated the optical flux in the intermediate state and the high/soft state.
A Data-constrained Magnetohydrodynamic Simulation of Successive Events of Blowout Jet and C-class Flare in NOAA AR 12615
Authors: Nayak Sushree S. , Bhattacharyya R. , Prasad A. , Hu Qiang , Kumar Sanjay , Joshi B. 
Published: April 2019

Abstract
Magnetohydrodynamic simulation is carried out for the NOAA AR 12615 in the time span t ∈ {05:48, 06:18} UT on 2016 December 5; covering events of a blowout jet and a C1.2 flare. The events are selected based on the small interval between their occurrences, which provides us with an opportunity to explore two energetically different events of magnetic reconnection (MR) within the run time of a single magnetohydrodynamic (MHD) simulation. The simulation is initiated with magnetic field extrapolated from the vector magnetogram provided by the Helioseismic Magnetic Imager/Solar Dynamics Observatory, using a non-force-free approximation. The extrapolated Lorentz force is found to decay at a rate faster than the volume current density, making the higher corona to be effectively force-free while the Lorentz force affects only the lower corona and the photosphere—a desirable feature that agrees with the contemporary understanding. For the simulation, the plasma is idealized to be incompressible, thermally homogeneous and having perfect electrical conductivity. The results affirm MRs near a set of two three-dimensional (3D) magnetic nulls to be responsible for initiating the jet. Moreover, a flux rope located near the nulls contributes to the jet by changing its magnetic field lines from an anchored to an open topology. The scenario agrees with the standard mini-filament breakout model for blowout jets and provides its first demonstration from a 3D data-constrained MHD simulation where the computational output is reconciled with magnetogram(s) only once. The generation of flare ribbons is attributed to reconnections at a 3D null and a quasi-separatrix layer (QSL), highlighting the importance of topological complexity in flare initiation.
The Role of a Magnetic Topology Skeleton in a Solar Active Region
Authors: Guo Juan , Wang Huaning , Wang Jingxiu , Zhu Xiaoshuai , Dai Xinghua , Huang Xin , He Han , Yan Yan , Zhao Hui 
Published: April 2019

Abstract
We investigate the 3D magnetic topology in the active region NOAA 11719 nine hours before and after a flare–coronal mass ejection (CME) event on 2013 April 11. The extrapolated 3D coronal magnetic field is computed employing a boundary integrated model, and a complex magnetic topology skeleton comprising five fairly robust null points and their relevant structures are revealed with a mathematical method based on a Poincaré index of isolated 3D null points. Comparative analyses show that the magnetic topology skeleton in this active region determines geometries of post-flare loops and flare ribbons, and characterizes the initial stage of the CME. The present work demonstrates that the magnetic topology skeleton plays an important role in the process of the flare–CME eruption.
The Flare Catalog and the Flare Activity in the Kepler Mission
Authors: Yang Huiqin , Liu Jifeng 
Published: April 2019

Abstract
We present a flare catalog of the Kepler mission using the long-cadence data of Data Release 25. This catalog comprises 3420 flare stars and 162,262 flare events. A comparison shows that the flare catalogs of previous studies are seriously polluted by various false-positive signals and artifacts. The incidence of flare stars rises with decreasing temperature, which accords with the theoretical analysis. The flare frequency distributions (FFDs) from F-type stars to M-type stars obey a power-law relation with α ∼ 2, indicating that they have the same mechanism on generating flares. The remarkable incidence and the deviation of FFDs on A-type flare stars imply that they generate flares in a different way. The activity–rotation relation is consistent with previous studies at low temperature bands, whereas it becomes dispersive with increasing temperature. Combined with the Gyrochronology, we find that the mixing of stars of two different dynamos gives rise to the dispersion. We thereby propose a scenario on understanding the activity–rotation relation across the Hertzsprung-Russell diagram. Based on the scenario and the correspondence of dynamo with regard to activity and rotation, we suggest a new expression on the activity–rotation relation, in which the segmentation is on the basis of the dynamo rather than the rotation period. The rotation distribution of flare stars shows that about 70% of flare stars rotate faster than 10 days and the rate approaches 95% at 30 days. Based on the incidence and the rotation distribution of flare stars, we estimate that a superflare with energy ∼1034 erg occurs on the Sun at least once in 5500 yr.
CAFE-R: A Code That Solves the Special Relativistic Radiation Hydrodynamics Equations
Authors: Rivera-Paleo F. J. , Guzmán F. S. 
Published: April 2019

Abstract
We present a 3D special relativistic radiation hydrodynamics code. It uses the radiative inversion scheme with the M1 closure relation for the radiation equations, which allows the treatment of a wide range of optical depth, temperature, and opacity. The radiation field is treated in the graybody approximation. We present the standard 1D and 2D tests that include both optically thin and thick scenarios, as well as hydrodynamical and radiation-pressure-dominated configurations. As an application in 3D, we show the evolution of a jet driven by radiation hydrodynamics with a helical perturbation. The code is expected to allow the exploration of scenarios in high-energy astrophysics where the radiation is important, like sources of gamma-ray bursts.
Origin of the Excess of High-energy Retrograde Stars in the Galactic Halo
Authors: Matsuno Tadafumi , Aoki Wako , Suda Takuma 
Published: April 2019

Abstract
We report on the very low α-element abundances of a group of metal-poor stars with high orbital energy and with large retrograde motion in the Milky Way halo, whose excess has been reported recently from metallicity and kinematics. We constructed a sample of halo stars with measured abundances and precise kinematics, including ∼880 stars with [Fe/H] < −0.7, by crossmatching the Stellar Abundances for Galactic Archaeology database to the second data release of Gaia. Three regions in the energy-angular momentum space have been selected: the innermost halo, Gaia Enceladus/Sausage, and the high-energy retrograde halo. While the innermost halo and Gaia Enceladus regions have chemical abundances consistent with high- and low-α populations in the halo, respectively, chemical abundances of stars in the high-energy retrograde halo are different from the two populations; their [X/Fe], where X represents Na, Mg, and Ca, are even lower than those in Gaia Enceladus. These abundances, as well as their low mean metallicity, provide a new support for the idea that the retrograde component is dominated by an accreted dwarf galaxy which has a longer star formation timescale and is less massive than Gaia Enceladus/Sausage.
Deletion of Biliverdin Reductase A in Myeloid Cells Promotes Chemokine Expression and Chemotaxis in Part via a Complement C5a­–C5aR1 Pathway
Authors: Bisht Kavita , Canesin Giacomo , Cheytan Tasneem , Li Mailin , Nemeth Zsuzsanna , Csizmadia Eva , Woodruff Trent M. , Stec David E. , Bulmer Andrew C. , Otterbein Leo E. , Wegiel Barbara 
Published: April 2019

AbstractBiliverdin reductase (BVR)-A is a pleotropic enzyme converting biliverdin to bilirubin and a signaling molecule that has cytoprotective and immunomodulatory effects. We recently showed that biliverdin inhibits the expression of complement activation fragment 5a receptor one (C5aR1) in RAW 264.7 macrophages. In this study, we investigated the role of BVR-A in determining macrophage inflammatory phenotype and function via regulation of C5aR1. We assessed expression of C5aR1, M1-like macrophage markers, including chemokines (RANTES, IP-10), as well as chemotaxis in response to LPS and C5a in bone marrow–derived macrophages from BVRfl/fl and LysM-Cre:BVRfl/fl mice (conditional deletion of BVR-A in myeloid cells). In response to LPS, macrophages isolated from LysM-Cre:BVRfl/fl showed significantly elevated levels of C5aR1 as well as chemokines (RANTES, IP10) but not proinflammatory markers, such as iNOS and TNF. An increase in C5aR1 expression was also observed in peritoneal macrophages and several tissues from LysM-Cre:BVRfl/fl mice in a model of endotoxemia. In addition, knockdown of BVR-A resulted in enhanced macrophage chemotaxis toward C5a. Part of the effects of BVR-A deletion on chemotaxis and RANTES expression were blocked in the presence of a C5aR1 neutralizing Ab, confirming the role of C5a–C5aR1 signaling in mediating the effects of BVR. In summary, BVR-A plays an important role in regulating macrophage chemotaxis in response to C5a via modulation of C5aR1 expression. In addition, macrophages lacking BVR-A are characterized by the expression of M1 polarization–associated chemokines, the levels of which depend in part on C5aR1 signaling.
TLR2 Plays a Pivotal Role in Mediating Mucosal Serotonin Production in the Gut
Authors: Wang Huaqing , Kwon Yun Han , Dewan Varun , Vahedi Fatemeh , Syed Saad , Fontes Michelle E. , Ashkar Ali A. , Surette Michael G. , Khan Waliul I. 
Published: April 2019

Abstract
Serotonin (5-hydroxytryptamine [5-HT]) is a key enteric signaling molecule that mediates various physiological processes in the gut. Enterochromaffin (EC) cells in the mucosal layer of the gut are the main source of 5-HT in the body and are situated in close proximity to the gut microbiota. In this study, we identify a pivotal role of TLR2 in 5-HT production in the gut. Antibiotic treatment reduces EC cell numbers and 5-HT levels in naive C57BL/6 mice, which is associated with downregulation of TLR2 expression but not TLR1 or TLR4. TLR2-deficient (Tlr2−/−) and Myd88−/− mice express lower EC cell numbers and 5-HT levels, whereas treatment with TLR2/1 agonist upregulates 5-HT production in irradiated C57BL/6 mice, which are reconstituted with Tlr2−/− bone marrow cells, and in germ-free mice. Human EC cell line (BON-1 cells) release higher 5-HT upon TLR2/1 agonist via NF-κB pathway. Tlr2−/− mice and anti-TLR2 Ab–treated mice infected with enteric parasite, Trichuris muris, exhibited attenuated 5-HT production, compared with infected wild-type mice. Moreover, excretory-secretory products from T. muris induce higher 5-HT production in BON-1 cells via TLR2 in a dose-dependent manner, whereby the effect of excretory-secretory products is abrogated by TLR2 antagonist. These findings not only suggest an important role of TLR2 in mucosal 5-HT production in the gut by resident microbiota as well as by a nematode parasite but also provide, to our knowledge, novel information on the potential benefits of targeting TLR2 in various gut disorders that exhibit aberrant 5-HT signaling.
Primary intracranial leiomyoma - A case report and literature review
Authors: Jehendran Mary Varunya , Monish V , Aswathappa Suresh , Ramprakash H V 
Published: April 2019

AbstractPrimary intracranial leiomyoma is a rare tumour of mesenchymal origin, with less than 30 cases reported in literature including two cases from the Indian subcontinent. In this article, we describe a case of primary intracranial leiomyoma in an immunocompromised patient with a brief review of literature.
Upper limb peripheral neuropathy in sickle cell anemia: MR neurography appearances
Authors: Poh Feng , Hlis Rocco , Chhabra Avneesh 
Published: April 2019

AbstractSickle cell anemia is an inherited disorder with many systemic complications. Peripheral neuropathy related to this disorder has been sparsely reported. We report an interesting case of upper limb peripheral neuropathy from sickle cell disease with emphasis on MR neurography appearances and electrophysiology correlation.
Role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in restaging and prognosis of recurrent melanoma after curative surgery
Authors: Malik Dharmender , Sood Ashwani , Mittal Bhagwant Rai , Basher Rajender Kumar , Bhattacharya Anish , Singh Gurpreet 
Published: April 2019

AbstractMalignant melanoma is a highly aggressive tumor and surgical resection is the primary treatment. However, the chances of recurrence are quite high despite complete resection. The aim of study was to evaluate the 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography–computed tomography (PET/CT) in detection of recurrent melanoma after curative surgery and its prognostic value. Fifty-four melanoma patients (32 women) with prior primary lesion resection were evaluated with 18F-FDG PET/CT for clinically suspicious recurrent disease. The diagnostic accuracy of 18F-FDG PET/CT (visual interpretation as well as semi-quantitative parameter) was determined on the basis of subsequent imaging and clinical follow-up. Melanoma-specific survival and risk of progression (hazard ratio [HR]) were assessed using Kaplan–Meier method and Cox regression analysis.18F-FDG PET/CT detected recurrent diseases in 36 (66%) patients including distant metastases in 13 patients and second synchronous malignancy in 2 patients. Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT were 91.2%, 80.0%, 88.6%, and 84.2%, respectively, with area under the curve of 0.86 (95% confidence interval: 0.74–0.97; P < 0.05). Positive 18F-FDG PET/CT study was associated with a significantly shorter overall survival than negative study (30.8 ± 4.6 vs. 64.5 ± 6.9 months, P < 0.05). Apart from positive 18F-FDG PET/CT scan, maximum standardized uptake value (SUVmax) >2.7 and combination of both were independently associated with an increased risk of disease progression (HR = 7.72, 21.58, and 11.37, respectively; P < 0.05).18F-FDG PET/CT showed enhanced diagnostic performance in patients with suspicious recurrent malignant melanoma leading to appropriate management. FDG positivity along with SUVmax >2.7 provides important prognostic value in predicting the survival outcomes and assessing the risk of disease progression.
Prostate-specific antigen and risk of bone metastases in west Africans with prostate cancer
Authors: Amoako Yaw Ampem , Hammond Emmanuel Nii Boye , Assasie-Gyimah Awo , Laryea Dennis Odai , Ankrah Alfred , Amoah George 
Published: April 2019

AbstractWe aimed to assess the relationship between bone scintigraphy findings and prostate-specific antigen (PSA) and Gleason score in a group of treatment naïve West Africans with prostate cancer. The age, PSA, and Gleason scores of 363 patients with prostate cancer were collected. Patients were risk stratified using the D'Amico criteria. Logistic regression was performed to assess the relationship between bone scan results and PSA and Gleason score. Receiver operating characteristics (ROC) analysis was used to determine the diagnostic reliability of the bone scan findings. Ninety of the 96 patients with metastases had high risk, and only 6 had low-to-intermediate risk disease (P = 0.0001). PSA (odds ratio [OR] 2.4 [95% confidence interval [CI] 1.5–3.8], P = 0.001) and GS (OR 2.2 [95% CI 1.5–3.1], P = 0.001) were independently predictive of the presence of metastases. ROC analysis revealed that PSA predicted the presence of metastases with an area under the curve of 0.72, and using a cut-off value of ≥20 predicted metastases with a sensitivity of 86.5% and specificity of 41.2%. A Gleason score of ≥7 had an 89.6% sensitivity and 34.8% specificity for bone metastases. Using a Gleason cutoff of ≥8, the sensitivity and specificity for predicting bone metastases were 54.2% and 71.5%, respectively. The area under the Gleason score ROC curve was 0.68. PSA and Gleason score are independent predictors of the presence of bone metastases in West Africans with prostate cancer.
18F-fluorodeoxyglucose positron emission tomography/computed tomography in extensive bland portal vein thrombosis from retroperitoneal adenocarcinoma
Authors: Chausse Guillaume , Abikhzer Gad , Probst Stephan , Laufer Jerome 
Published: April 2019

AbstractA 73-year-old woman undergoing hormone therapy for previously treated localized breast cancer presented at oncology follow-up 4 years after mastectomy/radiation therapy with weight loss, night sweats, and abdominal pain. Contrast computed tomography (CT) abdomen revealed a soft-tissue mass posterior to the pancreas, several enlarged retroperitoneal lymph nodes, and a dilated portal vein. On 18F-fluorodeoxyglucose positron emission tomography/CT, metabolic activity extended along the portal vein, outlining most of the liver venous system. This “tree-like” appearance was diagnostic of recent portal vein thrombosis by vascular compression from the retroperitoneal mass. Biopsy of the mass later confirmed undifferentiated adenocarcinoma without breast cancer marker expression.
GD en GD (Gramática Digital en Geometría Descriptiva)
Authors: González Uriel Ana , García Ríos Ismael , Gómez Sánchez Mª Isabel 
Published: April 2019

<p>Actualmente, en el área EGA está extensamente asentada la integración de programas informáticos de dibujo en la docencia de Geometría Descriptiva, o Geometría y Dibujo. En este contexto, se plantea la introducción de aplicaciones de programación visual que permiten incidir en los procesos de generación y trazado de curvas y superficies y en las relaciones entre elementos geométricos. Se exploran las posibilidades que brindan estas aplicaciones respecto a los contenidos propios del currículo de la materia. Se ofrece una serie de ejemplos que los autores han desarrollado, y se reflexiona sobre los problemas y ventajas encontrados tras analizar los resultados de su inclusión en un curso ordinario. </p>
El coeficiente beta (β) como medida del riesgo sistemático: Una demostración de que el valor del riesgo sistemático del mercado es igual a uno
Authors: Brenes González Humberto Antonio 
Published: April 2019

El coeficiente beta, es una medida del riesgo sistemático o no diversificable que afecta al conjunto de empresas de un mercado, es por ello, que su estimación es importante a la hora de realizar inversiones, puesto que dicho riesgo, debe ser asumido por los inversionistas. El objetivo del presente trabajo, es demostrar que el riesgo sistemático del mercado tiene un valor igual a uno, esto a partir de distintas técnicas tales como: cálculo del coeficiente beta a través de una regresión lineal, por medio del análisis de varianzas y covarianzas y por medio de gráficos y cálculo de la pendiente a través del programa Microsoft Excel. Para realizar la demostración, se utilizó las cotizaciones del índice de mercado Standar & Poor´s 500, durante el período del 1 de septiembre de 2013 al 1 de septiembre de 2018. El valor del coeficiente beta por medio de las técnicas utilizadas, dio como resultado un valor igual a uno, quedando así demostrado que el beta del mercado tiene un valor igual a uno.