bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of sweet spots in tight sandstone reservoirs based on anisotropic frequency-dependent AVO inversion
Authors: Qin Xilin , Gui Zhixian , Yang Fei , Liu Yuanyuan , Jin Wei , Xiong Jian 
Published: September 2021

Abstract
The frequency-dependent amplitude-versus-offset (FAVO) method has become a practical method for fluid detection in sand reservoirs. At present, most FAVO inversions are based on the assumption that reservoirs are isotropy, but the application effect is not satisfactory for fractured reservoirs. Hence, we analyse the frequency variation characteristics of anisotropy parameters in tight sandstone reservoirs based on a new petrophysical model, and propose a stepwise anisotropic FAVO inversion method to extract frequency-dependent attributes from prestack seismic field data. First, we combine the improved Brie's law with the fine-fracture model to analyse frequency-dependent characteristics of velocities and Thomsen anisotropy parameters at different gas saturations and fracture densities. Then, we derive an anisotropic FAVO inversion algorithm based on Rüger's approximation formula and propose a stepwise anisotropic FAVO inversion method to obtain the dispersions of anisotropy parameters. Finally, we propose a method that combines the inversion spectral decomposition with the stepwise anisotropy FAVO inversion and apply it to tight sand reservoirs in the Xinchang area. We use P-wave velocity dispersion and anisotropy parameter ε dispersion to optimise favourable areas. Numerical analysis results show that velocity dispersion of the P-wave is sensitive to fracture density, which can be used for fracture prediction in fractured reservoirs. In contrast, anisotropic parameter dispersion is sensitive to gas saturation and can be used for fluid detection. The seismic data inversion results show that velocity dispersion of the P-wave and anisotropic parameter dispersion are sensitive to fractured reservoirs in the second member of Xujiahe Group, which is consistent with logging interpretation results.
Reference Gene Selection for Analyzing the Transcription Patterns of Two Fatty Acyl-CoA Reductase Genes From Paracoccus marginatus (Hemiptera: Pseudococcidae)
Authors: Liang Xiao , Chen Qing , Wu Chunling , Liu Ying , Han Zhiling , Wu Mufeng 
Published: September 2021

Abstract
Paracoccus marginatus (Hemiptera: Pseudococcidae), known as the papaya mealybug, could cause considerable yield loss of several plants. To date, there is no molecular-based study of P. marginatus. Fatty acyl-CoA reductases (FARs) are key enzymes involved in wax synthesis. In the present study, we cloned and characterized coding sequences (CDS) of two FAR genes from P. marginatus. The results showed that PmFAR1 and PmFAR2 CDS were 1,590 and 1,497 bp in length, respectively, and sequence analysis indicated that these two genes both had the conservative motifs belonging to FAR_C superfamily. Furthermore, seven candidate reference genes were analyzed for their expression stability by using common algorithms including comparative ΔCq method, geNorm, NormFinder, BestKeeper, and RefFinder. Eventually, β-actin and GAPDH were the best reference genes in evaluating the expression of those two FAR genes. We found that PmFAR1 and PmFAR2 showed distinct expression patterns in different life stages. Moreover, the transcription of PmFAR1 and PmFAR2 in P. marginatus fed on resistant cassava cultivars was significantly lower compared with those fed on susceptible ones, indicating the potential function of FAR genes in cassava resistance to P. marginatus. The present study might help in better understanding the molecular mechanism of cassava resistance to mealybug.
Clinical efficacy and safety of different doses of intrathecal methotrexate in the treatment of leptomeningeal carcinomatosis: a prospective and single-arm study
Authors: Hou Lan , Han Weixin , Jin Jie , Chen Xin , Zou Yueli , Yan Litian , He Junying , Bu Hui 
Published: September 2021

Abstract

Objective
To investigate the clinical efficacy and safety of different doses of intrathecal methotrexate in the treatment of leptomeningeal carcinomatosis.

Methods
53 patients admitted to the Second Hospital of Hebei Medical University with leptomeningeal carcinomatosis were recruited. They were divided into two groups: 15-mg-group received 15 mg methotrexate intrathecally, while the other received 10 mg methotrexate. All patients were followed up to 31 December 2020 or until death. Primary endpoint was the response rate. Secondary endpoints were survival and safety. Treatment-related adverse events were recorded.

Results
The intrathecal chemotherapy was regularly maintained in 42 cases. Most primary cancers were lung (60.4%), stomach (18.9%) or breast (5.7%). The clinical response rate was higher in the 15 mg group than the 10 mg group (62.5 vs. 34.5%, P = 0.042). In the 15 mg group, two cases showed myelosuppression and one case showed seizures. In the 10 mg group, one patient appeared fever, three patients appeared myelosuppression and one showed leukoencephalopathy. However, there were no serious irreversible adverse reactions in neither of the two groups. In terms of survival, the median survival was 15.7 weeks in the 15 mg group and 27.1 weeks in the 10 mg group (P = 0.116). Multivariate analysis showed that only targeted therapy improved the survival (P &lt; 0.0001, HR = 5.386).

Conclusion
Increased dose of methotrexate did not prolong the overall survival, but it was more effective in relieving clinical symptoms with no increased adverse reactions. Targeted therapy might improve the survival.
Bioengineered Models to Study Microenvironmental Regulation of Glioblastoma Metabolism
Authors: Chen Joseph , Lee Hyunchul , Schmitt Philipp , Choy Caleb J , Miller Donald M , Williams Brian J , Bearer Elaine L , Frieboes Hermann B 
Published: September 2021

Abstract
Despite extensive research and aggressive therapies, glioblastoma (GBM) remains a central nervous system malignancy with poor prognosis. The varied histopathology of GBM suggests a landscape of differing microenvironments and clonal expansions, which may influence metabolism, driving tumor progression. Indeed, GBM metabolic plasticity in response to differing nutrient supply within these microenvironments has emerged as a key driver of aggressiveness. Additionally, emergent biophysical and biochemical interactions in the tumor microenvironment (TME) are offering new perspectives on GBM metabolism. Perivascular and hypoxic niches exert crucial roles in tumor maintenance and progression, facilitating metabolic relationships between stromal and tumor cells. Alterations in extracellular matrix and its biophysical characteristics, such as rigidity and topography, regulate GBM metabolism through mechanotransductive mechanisms. This review highlights insights gained from deployment of bioengineering models, including engineered cell culture and mathematical models, to study the microenvironmental regulation of GBM metabolism. Bioengineered approaches building upon histopathology measurements may uncover potential therapeutic strategies that target both TME-dependent mechanotransductive and biomolecular drivers of metabolism to tackle this challenging disease. Longer term, a concerted effort integrating in vitro and in silico models predictive of patient therapy response may offer a powerful advance toward tailoring of treatment to patient-specific GBM characteristics.
Fine and hyperfine excitation of nitric oxide by collision with para-H2 at low temperature
Authors: Ben Khalifa M , Loreau J 
Published: September 2021

ABSTRACT
Nitric oxide is an open-shell molecule abundantly detected in the interstellar medium. A precise modelling of its radiative and collisional processes opens the path to a precise estimate of its abundance. We present here the first rate coefficients for fine and hyperfine (de-)excitation of NO by collisions with the most ubiquitous collision partner in the interstellar medium, para-H2 hydrogen molecules, using a recently developed accurate interaction potential. We report quantum scattering calculations for transitions involving the first 74 fine levels and the corresponding 442 hyperfine levels belonging to both F1 and F2 spin–orbit manifolds. To do so, we have calculated cross-sections by means of the quantum mechanical close-coupling approach up to 1000 cm−1 of total energy and rate coefficients from 5 to 100 K. Propensity rules are discussed and the new NO–H2 rates are compared to those available in the literature, based on scaled NO–He rates. Large differences are observed between the two sets of rate coefficients, and this comparison shows that the new collision rates must be used in interpreting NO emission lines. We also examined the effect of these new rates on the NO excitation in cold clouds by performing radiative transfer calculations of the excitation and brightness temperatures for the two NO lines at 150.176 and 250.4368 GHz. This shows that the local thermodynamic equilibrium is not fulfilled for this species for typical conditions. We expect the use of the rates presented in this study to improve the constraints on the abundance of NO.
The impact of winds on the spectral appearance of red supergiants
Authors: Davies Ben , Plez Bertrand 
Published: September 2021

ABSTRACT
The rate at which mass is lost during the red supergiant (RSG) evolutionary stage may strongly influence how the star appears. Though there have been many studies discussing how RSGs appear in the mid- and far-infrared (IR) as a function of their mass-loss rate, to date, there have been no such investigations at optical and near-IR wavelengths. In a preliminary study, we construct model atmospheres for RSGs that include a wind, and use these models to compute synthetic spectra from the optical to the mid-IR. The inclusion of a wind has two important effects. First, higher mass-loss rates result in stronger absorption in the TiO bands, causing the star to appear as a later spectral type despite its effective temperature remaining constant. This explains the observed relation between spectral type, evolutionary stage, and mid-IR excess, as well as the mismatch between temperatures derived from the optical and IR. Secondly, the wind mimics many observed characteristics of a ‘MOLsphere’, potentially providing an explanation for the extended molecular zone inferred to exist around nearby RSGs. Thirdly, we show that wind fluctuations can explain the spectral variability of Betelgeuse during its recent dimming, without the need for dust.
The GALAH+ survey: a new library of observed stellar spectra improves radial velocities and hints at motions within M67
Authors: Zwitter Tomaž , Kos Janez , Buder Sven , Čotar Klemen , Asplund Martin , Bland-Hawthorn Joss , Casey Andrew R , De Silva Gayandhi M , D’Orazi Valentina , Freeman Ken C , Hayden Michael R , Lewis Geraint F , Lin Jane , Lind Karin , Martell Sarah L , Schlesinger Katharine J , Sharma Sanjib , Simpson Jeffrey D , Stello Dennis , Zucker Daniel B , Beeson Kevin L , de Grijs Richard , Nordlander Thomas , Ting (丁源森) Yuan-Sen , Traven Gregor , Vogrinčič Rok , Watson Fred , Wittenmyer Rob 
Published: September 2021

ABSTRACT
GALAH+ is a magnitude-limited survey of high-resolution stellar spectra obtained by the HERMES spectrograph at the Australian Astronomical Observatory. Its third data release provides reduced spectra with new derivations of stellar parameters and abundances of 30 chemical elements for 584 015 dwarfs and giants, 88 per cent of them in the Gaia magnitude range 11 &lt; G &lt; 14. Here, we use these improved values of stellar parameters to build a library of observed spectra which is useful to study variations of individual spectral lines with stellar parameters. This and other improvements are used to derive radial velocities with uncertainties which are generally within 0.1 km s−1 or ∼25 per cent smaller than in the previous release. Median differences in radial velocities measured here and by the Gaia DR2 or APOGEE DR16 surveys are smaller than 30 m s−1, a larger offset is present only for Gaia measurements of giant stars. We identify 4483 stars with intrinsically variable velocities and 225 stars for which the velocity stays constant over ≥3 visits spanning more than a year. The combination of radial velocities from GALAH+ with distances and sky plane motions from Gaia enables studies of dynamics within streams and clusters. For example, we estimate that the open cluster M67 has a total mass of ∼3300 M⊙ and its outer parts seem to be expanding, though astrometry with a larger time-span than currently available from Gaia eDR3 is needed to judge if the latter result is real.
An ALMA study of hub-filament systems – I. On the clump mass concentration within the most massive cores
Authors: Anderson Michael , Peretto Nicolas , Ragan Sarah E , Rigby Andrew J , Avison Adam , Duarte-Cabral Ana , Fuller Gary A , Shirley Yancy L , Traficante Alessio , Williams Gwenllian M 
Published: September 2021

ABSTRACT
The physical processes behind the transfer of mass from parsec-scale clumps to massive star-forming cores remain elusive. We investigate the relation between the clump morphology and the mass fraction that ends up in its most massive core (MMC) as a function of infrared brightness, i.e. a clump evolutionary tracer. Using Atacama Large Millimeter/submillimeter Array (ALMA) 12 m and Atacama Compact Array, we surveyed six infrared dark hubs in 2.9 mm continuum at ∼3 arcsec resolution. To put our sample into context, we also re-analysed published ALMA data from a sample of 29 high-mass surface density ATLASGAL sources. We characterize the size, mass, morphology, and infrared brightness of the clumps using Herschel and Spitzer data. Within the six newly observed hubs, we identify 67 cores, and find that the MMCs have masses between 15 and 911 M⊙ within a radius of 0.018–0.156 pc. The MMC of each hub contains 3–24 per cent of the clump mass (fMMC), becoming 5–36 per cent once core masses are normalized to the median core radius. Across the 35 clumps, we find no significant difference in the median fMMC values of hub and non-hub systems, likely the consequence of a sample bias. However, we find that fMMC is ∼7.9 times larger for infrared dark clumps compared to infrared bright ones. This factor increases up to ∼14.5 when comparing our sample of six infrared dark hubs to infrared bright clumps. We speculate that hub-filament systems efficiently concentrate mass within their MMC early on during its evolution. As clumps evolve, they grow in mass, but such growth does not lead to the formation of more massive MMCs.
The SnRK2.10 kinase mitigates the adverse effects of salinity by protecting photosynthetic machinery
Authors: Mazur Radosław , Maszkowska Justyna , Anielska-Mazur Anna , Garstka Maciej , Polkowska-Kowalczyk Lidia , Czajkowska Anna , Zmienko Agnieszka , Dobrowolska Grazyna , Kulik Anna 
Published: September 2021

AbstractSNF1-Related protein kinases Type 2 (SnRK2) are plant-specific enzymes widely distributed across the plant kingdom. They are key players controlling abscisic acid (ABA)-dependent and ABA-independent signaling pathways in the plant response to osmotic stress. Here we established that SnRK2.4 and SnRK2.10, ABA-nonactivated kinases, are activated in Arabidopsis thaliana rosettes during the early response to salt stress and contribute to leaf growth retardation under prolonged salinity but act by maintaining different salt-triggered mechanisms. Under salinity, snrk2.10 insertion mutants were impaired in the reconstruction and rearrangement of damaged core and antenna protein complexes in photosystem II (PSII), which led to stronger non-photochemical quenching, lower maximal quantum yield of PSII, and lower adaptation of the photosynthetic apparatus to high light intensity. The observed effects were likely caused by disturbed accumulation and phosphorylation status of the main PSII core and antenna proteins. Finally, we found a higher accumulation of reactive oxygen species (ROS) in the snrk2.10 mutant leaves under a few-day-long exposure to salinity which also could contribute to the stronger damage of the photosynthetic apparatus and cause other deleterious effects affecting plant growth. We found that the snrk2.4 mutant plants did not display substantial changes in photosynthesis. Overall, our results indicate that SnRK2.10 is activated in leaves shortly after plant exposure to salinity and contributes to salt stress tolerance by maintaining efficient photosynthesis and preventing oxidative damage.
Formulation of a shell–cluster overlap integral with the Gaussian expansion method
Authors: Nakamoto R , Ueda E , Ito M , Shimizu N 
Published: September 2021

Abstract
We formulate a computational method to evaluate the overlap integral of the shell-model and cluster-model wave functions. The framework is applied to the system of the core plus two neutrons, and the magnitude of the overlap of the shell-model configuration (core + $n$ + $n$) and the di-neutron cluster one (core + $2n$) is explored. We have found that the magnitude of the overlap integral is prominently enhanced when two neutrons occupy shell-model orbits with low orbital angular momenta, such as $s$- and $p$-wave orbits. The shell–cluster overlap is calculated in systems with $jj$-closed cores plus two neutrons, and the enhancement due to occupation of the $s$ or $p$ orbit also occurs in the systematic calculation. The effect of the configuration interaction on the shell–cluster overlap integrals is also discussed.
Crowded Trades and Tail Risk
Authors: Brown Gregory W , Howard Philip , Lundblad Christian T 
Published: September 2021

Abstract
Hedge fund positions are an important component of crowded trades. These vehicles are particularly active, take highly concentrated positions, and utilize leverage and short sales. Using a database of hedge fund holdings, we measure the degree of security-level crowdedness. The difference between the average returns on portfolios sorted by high versus low crowdedness portfolios is sizable, and the variation in the realized portfolio returns is distinct from other traditional risk factors. Further, hedge fund exposures to crowdedness are often significant, and they help to explain downside “tail risk,” as funds with higher exposures experience relatively larger drawdowns during periods of industry distress.
Authors have furnished an Internet Appendix, which is available on the Oxford University Press Web site next to the link to the final published paper online.
Short-Termism Spillovers from the Financial Industry
Authors: Bird Andrew , Ertan Aytekin , Karolyi Stephen A , Ruchti Thomas G 
Published: September 2021

Abstract
To meet short-term benchmarks, lenders may alter their monitoring behavior, providing a channel for short-termism to spill over to their borrowers. We find that short-termist lenders are significantly more likely to enforce covenant breaches. This behavior is pronounced when performance benchmarks are precise or salient, and when managers have high pay-performance sensitivity, but not when they face strong shareholder governance. Affected borrowers are more likely to switch lenders, pay higher spreads on renegotiated loans, and reduce investment. Our findings suggest that bank managers trade off relationship capital for income-boosting fees and term changes from covenant enforcement to meet earnings benchmarks.
Localized versus systemic granulomatosis with polyangiitis: data from the French Vasculitis Study Group Registry
Authors: Iudici Michele , Pagnoux Christian , Courvoisier Delphine S , Cohen Pascal , Néel Antoine , Aouba Achille , Lifermann François , Ruivard Marc , Aumaître Olivier , Bonnotte Bernard , Maurier François , Le Gallou Thomas , Hachulla Eric , Karras Alexandre , Khouatra Chahéra , Jourde-Chiche Noémie , Viallard Jean-François , Blanchard-Delaunay Claire , Godmer Pascal , Le Quellec Alain , Quéméneur Thomas , de Moreuil Claire , Régent Alexis , Terrier Benjamin , Mouthon Luc , Guillevin Loïc , Puéchal Xavier ,   the French Vasculitis Study Group
Published: September 2021

Abstract

Objective
To describe the main features at diagnosis and evolution over time of patients with localized granulomatosis with polyangiitis (L-GPA) compared with those of systemic GPA (S-GPA).

Methods
EULAR definitions of L-GPA, i.e. upper and/or lower respiratory tract involvement, and S-GPA were applied to patients from the French Vasculitis Study Group Registry. L-GPA and S-GPA patients’ characteristics at diagnosis and long-term outcomes were analysed and compared.

Results
Among the 795 Registry patients, 79 (10%) had L-GPA. Their main clinical manifestations were rhinitis, lung nodules, sinusitis and otitis. L-GPA vs S-GPA patients at diagnosis, respectively, were younger, more frequently had saddle nose deformity or subglottic stenosis and were less often PR3-ANCA–positive. L-GPA vs S-GPA induction therapy less frequently included CYC but more often a combination of MTX and glucocorticoids; 64% of MTX-treated patients experienced disease progression within 18 months post-diagnosis. L- and S-GPA patients’ estimated relapse-free–survival probabilities, relapse rates and refractory disease rates at each time point were comparable, but L-GPA patients had more frequent ENT and lung relapses, and higher overall survival rates (P&lt;0.02). Over a median follow-up of 3.5 years, 18 (22.8%) L-GPA progressed to S-GPA, either as a relapse after a period in remission or more frequently in the context of refractory disease. L-GPA patients experienced more ENT-related damage.

Conclusions
The relapse risks of L-GPA and S-GPA were similar, but relapse patterns differed and L-GPA overall survival rate was higher. About one-quarter of L-GPA patients developed S-GPA over time, but without end-stage organ involvement.