bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analytic solution for the electrostatic potential of the solar wind
Authors: Osuna Alcalaya Pedro , Zouganelis Ioannis , Rodríguez Pacheco Javier 
Published: July 2021

Context. Some kinetic models of the solar wind, such as the exospheric ones, make certain assumptions about the solar plasma, which for modelling purposes is generally considered collisionless and quasi-neutral. They also assume specific distribution functions for the electron and proton populations from which the fundamental properties of the plasma, including the density, are calculated using the moment integrals. Imposing the quasi-neutrality condition leads to the presence of an ambipolar electrostatic field, which is responsible for the acceleration of the wind. Usually, the calculation of the moment integrals is complicated by the fact that most kinetic models assume different trajectories for the solar wind components, separating the integrals into chunks corresponding to the pitch angles defining the trajectories. Hence, up to now all these integrals and therefore the plasma fundamental quantities have been calculated numerically.
Aims. A new model is presented that makes use of similar assumptions to other kinetic collisionless models but does not need to impose the separation of the populations in different trajectories for the calculation of the integrals. As a consequence, an analytic solution for the electrostatic potential of the solar wind valid for all distances is found.
Methods. A kinetic collisionless approach was used to characterise the solar wind plasma. A single equation for the electrostatic potential function was found assuming certain distribution functions (Maxwellian or non-thermal such as Kappa), which include an unknown electrostatic potential, calculating the density integral for those distribution functions and making those densities equal for electrons and protons.
Results. An analytic solution for the electrostatic potential as a function of radial distance is found (for the first time for all distances) and shown to produce a non-monotonic total potential, which is compatible with other models like the exospheric ones whose electrostatic potential drives the acceleration of the solar wind. This expression can now be used, in a straightforward way, to provide insight into the importance of the electron distribution functions to shape the electrostatic potential of thermal solar-like outflows.
Spectro-imagery of an active tornado-like prominence: Formation and evolution
Authors: Barczynski Krzysztof , Schmieder Brigitte , Peat Aaron W. , Labrosse Nicolas , Mein Pierre , Mein Nicole 
Published: July 2021

Context. The dynamical nature of fine structures in prominences remains an open issue, including rotating flows in tornado prominences. While the Atmospheric Imaging Assembly imager aboard the Solar Dynamics Observatory allowed us to follow the global structure of a tornado-like prominence for five hours, the Interface Region Imaging Spectrograph, and the Multichannel Subtractive Double Pass spectrograph permitted to obtain plasma diagnostics of its fine structures.
Aims. We aim to address two questions. Firstly, is the observed plasma rotation conceptually acceptable in a flux rope magnetic support configuration with dips? Secondly, how is the plasma density distributed in the tornado-like prominence?
Methods. We calculated line-of-sight velocities and non-thermal line widths using Gaussian fitting for Mg II lines and the bisector method for Hα line. We determined the electron density from Mg II line integrated intensities and profile fitting methods using 1D non-LTE radiative transfer theory models.
Results. The global structure of the prominence observed in Hα, and Mg II h, and k line fits with a magnetic field structure configuration with dips. Coherent Doppler shifts in redshifted and blueshifted areas observed in both lines were detected along rapidly-changing vertical and horizontal structures. However, the tornado at the top of the prominence consists of multiple fine threads with opposite flows, suggesting counter-streaming flows rather than rotation. Surprisingly we found that the electron density at the top of the prominence could be larger (1011 cm−3) than in the inner part of the prominence.
Conclusions. We suggest that the tornado is in a formation state with cooling of hot plasma in a first phase, and following that, a phase of leakage of the formed blobs with large transverse flows of material along long loops extended away from the UV prominence top. The existence of such long magnetic field lines on both sides of the prominence would stop the tornado-like prominence from really turning around its axis.
Predictive Ability of a Clinical-Genetic Risk Score for Venous Thromboembolism in Northern and Southern European Populations
Authors: Salas Eduardo , Farm Maria , Pich Sara , Onelöv Liselotte , Guillen Kevin , Ortega Israel , Antovic Jovan P. , Soria Jose Manuel 
Published: July 2021

AbstractVenous thromboembolism (VTE) is a complex, multifactorial problem, the development of which depends on a combination of genetic and acqfiguired risk factors. In a Spanish population, the Thrombo inCode score (or TiC score), which combines clinical and genetic risk components, was recently proven better at determining the risk of VTE than the commonly used model involving the analysis of two genetic variants associated with thrombophilia: the Factor V Leiden (F5 rs6025) and the G20210A prothrombin (F2 rs1799963).The aim of the present case–control study was to validate the VTE risk predictive capacity of the TiC score in a Northern European population (from Sweden).The study included 173 subjects with VTE and 196 controls. All were analyzed for the genetic risk variants included in the TiC gene panel. Standard measures —receiver operating characteristic (ROC) area under the curve (AUC), sensitivity, specificity, and odds ratio (OR)—were calculated.The TiC score returned an AUC value of 0.673, a sensitivity of 72.25%, a specificity of 60.62%, and an OR of 4.11. These AUC, sensitivity, and OR values are all greater than those associated with the currently used combination of genetic variants. A TiC version adjusted for the allelic frequencies of the Swedish population significantly improved its AUC value (0.783).In summary, the TiC score returned more reliable risk estimates for the studied Northern European population than did the analysis of the Factor V Leiden and the G20210A genetic variations in combination. Thus, the TiC score can be reliably used with European populations, despite differences in allelic frequencies.
Chudley–McCullough Syndrome: Case Report and the Role of Neuroimaging to Suggest the Diagnosis
Authors: Freitas Leonardo Furtado , Barros Gabriel Santaterra , Barletta Enrico Affonso , de Araújo Coimbra Pablo Picasso , Lourenço Charles Marques , Ferreira Paula Mendes 
Published: July 2021

AbstractChudley–McCullough syndrome (CMS) is an autosomal recessive condition first described in 1997. The most striking features of this syndrome include sensorineural hearing loss, craniofacial disproportion, and brain abnormalities such as agenesis of the corpus callosum, polymicrogyria, ventriculomegaly, and changes in cerebellar architecture. We described the case of a 2-year-old male child patient with CMS confirmed by genetic testing (GPSM2 gene mutation), who presented with global developmental delays and characteristic neuroimaging features including arachnoid cysts, agenesis of the corpus callosum, cerebellar dysplasia, and frontal heterotopia. Early recognition of this rare clinical syndrome may reduce the diagnostic odyssey and ultimately improve the quality of life for affected children. This report will focus on unique clinical and radiographic features of CMS.
Steroids Significantly Decrease Postoperative Postural Hypotension in Total Knee Replacement
Authors: Cheng Gloria H. M. , Tan Gabriel K. Y. , Kamarudin Muhammad F. B. , Lee Bryan W. W. , Mei Yap Yan , Tan Kelvin G. 
Published: July 2021

AbstractTotal knee replacement (TKR) is one of the most common orthopaedic procedures performed, and enhanced recovery after surgery (ERAS) has been developed and incorporated into inpatient surgical pathways to improve patient outcomes. Under ERAS recommendations, multimodal prophylaxis has been used to help manage postoperative nausea and vomiting (PONV) following TKR. Dexamethasone is one of the commonly used for this and the anti-inflammatory properties could depress vagal activity, reducing postural hypotension (PH). The hypothesis of this study is that postoperative dexamethasone use is associated with lower rates of early postoperative PH following TKR surgery. In our institution, patients who undergo elective primary TKR are admitted on the day of surgery and follow a standardized ERAS protocol. Data on patients who underwent elective primary TKR under a single adult reconstruction team from September 2017 to March 2020 were reviewed and analyzed. A review of demographic characteristics, surgical data, postoperative medications, and postoperative notes was performed. Binary logistic regression was used to assess the effect of the use of dexamethasone on PH, with an adjusted odds ratio (OR) calculated after accounting for potential confounders. Of the 149 patients were included in the study, 78 had dexamethasone postoperatively, and 71 did not. Patients who had received dexamethasone were statistically less likely to suffer from PH (OR = 0.31, p = 0.03) and less likely to develop PONV (OR = 0.21, p = 0.006). Patients who had received dexamethasone were more likely able to participate in early physiotherapy (OR = 2.42, p = 0.14), and this result was statistically insignificant. The use of postoperative intravenous dexamethasone is significantly associated with lower rates of postoperative PH after TKR. However, more studies are required to assess the optimal dosing amount and frequency, as well as to assess other factors which can enhance early postoperative patient mobilization as part of our goals for ERAS. This therapeutic study reflects level of evidence III.
High-efficiency single-pixel imaging using discrete Hartley transform
Authors: Ma Mengchao , Sun Qianzhen , Gao Xicheng , Wang Guan , Deng Huaxia , Zhang Yi , Guan Qingtian , Zhong Xiang 
Published: July 2021

Single-pixel imaging technology is popular with invisible wavelengths and low light environments. However, the time-consuming steps hindered the development of single-pixel imaging technology. To improve imaging efficiency, a high-efficiency one-step single-pixel imaging method based on the discrete Hartley transform is proposed. The proposed method does not require a large number of fringe patterns and only requires a real-number calculation. The number of fringe patterns required for the proposed method is only half of that required for the four-step phase-shift Fourier method at the same sampling rate. Although a one-step method, it also uses the idea of differential measurements and adds upsampling processing strategies, which simultaneously improve the signal-to-noise ratio of the recovered image. The simulation shows that the peak signal-to-noise ratio and structural similarity index of the recovered target scene exceed 20 dB and 80%, respectively, when the sampling rate is 30%. Only 20 164 patterns are needed to reconstruct a (256 × 256)-pixel image. After defocusing the gray stripe pattern into a binary pattern, it only takes milliseconds to project these patterns into the target. It can be seen that the experimental results of the proposed method are significantly better than those of the two-step phase-shift method under dramatical noise interference. With the rapid development of advanced equipment, this method will represent significant progress in the real-time reconstruction of single-pixel imaging.
Collaborative assessments in Mandarin conversation
Authors: Fang Di 
Published: July 2021

AbstractThe co-production of a sentence is a phenomenon that is widely observed in talk-in-interaction across languages. However, with a few notable exceptions, there is still much room for the investigation of how the co-production of sentences is put to the service of specific actions and activities in different language communities. This paper, using 10 hours of video-recorded data, examines the co-production of assessments (“collaborative assessments”) in Mandarin conversation. It is found that speakers can use syntactic, prosodic, and bodily-visual devices to realize assessment collaboration, and that the functions of collaborative assessment include (1) helping provide a candidate assessment term and facilitating the assessment; (2) articulating/specifying ‘vague’ assessments; (3) helping complete the foreshadowing of a negative assessment term; and (4) co-participation in the assessment activity. This paper also discusses the design features of co-completion and subsequent responses on the basis of the continuum of speakers’ epistemic authority and agency in collaborative assessment sequences and concludes with some implications of this study for grammar as practice.
Real-potential-driven anti-

PT

-symmetry breaking in non-Hermitian Su–Schrieffer–Heeger model
Authors: Zhao Xuedong , Xing Yan , Qi Lu , Liu Shutian , Zhang Shou , Wang Hong-Fu 
Published: July 2021

Abstract
Non-Hermitian Hamiltonians with anti-

PT

symmetry show distinct discrepancies compared to

PT

-symmetric systems. Here we investigate the non-Hermitian Su–Schrieffer–Heeger (SSH) model and reveal the interplay between anti-

PT

symmetry and different topological phases, in which the anti-

PT

symmetry is triggered by introducing real chemical potential and imaginary nearest-neighbor hopping. Three types of anti-

PT

-symmetric SSH models with different on-site configurations are investigated, and the effect of each on-site configuration on the energy spectrum of system is analyzed and discussed. We find that the type of on-site configuration affects the energy spectrum of the same topological region significantly and each on-site configuration has distinguishable impacts on the energy spectra of different topological regions. Moreover, the spontaneous anti-

PT

-symmetry-breaking transitions undergone in both of the topologically trivial and nontrivial regions are also clarified. Furthermore, we address the corresponding eigenstates of some specific eigenvalues and some interesting localized phenomena are observed. Our results enrich the study of non-Hermitian topological phases and broaden the understanding of anti-

PT

-symmetric systems.
Conservative constraints on the effective theory of dark matter-nucleon interactions from IceCube: the impact of operator interference
Authors: Brenner Anja , Ibarra Alejandro , Rappelt Andreas 
Published: July 2021

Abstract
We present a method to derive conservative upper limits on
the coupling constants of the effective theory of dark
matter-nucleon interactions, taking into account the interference
among operators. The method can be applied in any basis, and can be
easily particularized to any UV complete model. To illustrate our
method, we use the IceCube constraints on an exotic neutrino flux
from dark matter annihilations in the Sun to derive conservative
upper limits on the dark matter-nucleon coupling constants of the
effective theory, as well as to derive conservative upper limits on
the dark matter-proton and dark matter-neutron scattering
cross-sections.
Cosmic no-hair theorems for viscous contracting Universes
Authors: Ganguly Chandrima 
Published: July 2021

Abstract
A cosmic no-hair theorem for all initially contracting, spatially homogeneous, orthogonal Bianchi Cosmologies is derived - which shows that all such Universes asymptote to a spatially flat, isotropic Universe with the inclusion of a shear viscous stress. This establishes a new mechanism of isotropisation in a contracting Universe, which does not take recourse to an ekpyrosis-like mechanism using an effective ultra-stiff equation of state fluid, that is, one in which the pressure is much greater than the energy density.
Improved sensitivity of the DRIFT-IId directional dark matter experiment using machine learning
Authors: Battat J.B.R. , Eldridge C. , Ezeribe A.C. , Gaunt O.P. , Gauvreau J.-L. , Marcelo Gregorio R.R. , Habich E.K.K. , Hall K.E. , Harton J.L. , Ingabire I. , Lafler R. , Loomba D. , Lynch W.A. , Paling S.M. , Pan A.Y. , Scarff A. , Schuckman II F.G. , Snowden-Ifft D.P. , Spooner N.J.C. , Toth C. , Xu A.A. 
Published: July 2021

Abstract
We demonstrate a new type of analysis for the DRIFT-IId
directional dark matter detector using a machine learning algorithm
called a Random Forest Classifier. The analysis labels events as
signal or background based on a series of selection parameters,
rather than solely applying hard cuts. The analysis efficiency is
shown to be comparable to our previous result at high energy but
with increased efficiency at lower energies. This leads to a
projected sensitivity enhancement of one order of magnitude below a
WIMP mass of 15 GeV c-2 and a projected sensitivity limit that
reaches down to a WIMP mass of 9 GeV c-2, which is a first for
a directionally sensitive dark matter detector.
MIKE: a new computational tool for investigating radiation, optical and physical properties of prototyped shielding materials
Authors: Hussein K.I. , Alqahtani M.S. , Algarni H. , Zahran H. , Yaha I.S. , Grelowska I. , Reben M. , Yousef E.S. 
Published: July 2021

Abstract
The development of new, advanced shielding materials has attracted great interest among scientists and engineers. Recently, various shielding materials have been developed, which could replace the toxic, heavy, and costly conventional shielding materials. In this paper, we present our new computational software, MIKE, to assist researchers in the process of calculating and analyzing different radiation shielding parameters, such as the linear attenuation coefficient, mass attenuation coefficient, and half-value layer. The shielding parameter equations were coded using MATLAB. Additionally, the computational tool can be used to calculate the physical and optical properties of the selected composition, such as the average molar weight, molar volume, and molar electronic polarizability. Moreover, this tool allows the user to analyze the shielding parameters and the transmission factors for a selected material against a wide range of ionizing radiation energies. The newly developed computational software has been compared with existing radiation-shielding codes, including Phy-X/PSD and WinXcom, in addition to the available experimental data in the literature. The computed values produced using the MIKE software show good agreement with values calculated using the available competitor software programs (WinXcom, Phy-X/PSD, and the Monte Carlo method) with percentage differences of less than 0.2%. Our user-friendly computational software could help researchers evaluate whether various shielding materials meet the requirements of radiation applications, such as diagnostic and therapy applications including mammography, general radiography, computed tomography (CT), nuclear medicine, and high-energy photons used in radiotherapy applications.
Landscape-scale characterization of Arctic tundra vegetation composition, structure, and function with a multi-sensor unoccupied aerial system
Authors: Yang Dedi , Morrison Bailey D , Hantson Wouter , Breen Amy L , McMahon Andrew , Li Qianyu , Salmon Verity G , Hayes Daniel J , Serbin Shawn P 
Published: July 2021

Abstract
The Arctic is experiencing some of the most rapid climate change on Earth, with strong impacts on tundra ecosystems that are characterized by high land-surface and vegetation heterogeneity. Previous studies have explored this complexity using satellite remote sensing, however these typically coarse spatial resolution data have generally missed sub-pixel heterogeneity, leaving critical gaps in our understanding of tundra vegetation dynamics from the community to landscape scales. To address these gaps, we collected very high-resolution (1–5 cm) optical, structural, and thermal data at three low-Arctic tundra sites on the Seward Peninsula, Alaska, using a multi-sensor unoccupied aerial system (UAS). We examined the application of these data to studying tundra vegetation dynamics, by quantifying (a) canopy height and thermoregulation (leaf–air temperature) of representative plant functional types (PFTs), (b) fine-scale patterns of vegetation composition across landscapes, and (c) impacts of fine-scale vegetation composition on landscape-scale variation of canopy height and thermoregulation. Our results show that deciduous tall shrubs (those that can potentially grow >2 m) had a strong cooling effect, with canopy temperatures significantly lower than local air temperatures and other PFTs. Increased cover of tall shrubs also had the potential to reduce the cover of low-stature PFTs across the landscape, potentially associated with their closed canopy (i.e. increased light competition) and strong thermoregulation. To understand the connections between fine-scale vegetation composition and large-scale ecosystem processes, we produced a random forest model which showed that fine-scale PFT composition accounted for 86.8% and 74.2% of the landscape-scale variation in canopy height and thermoregulation, respectively. These findings highlight the importance of spatially detailed characterization of tundra PFTs to improve our ecological understanding and model representation of tundra vegetation, also transcend our study to show the need for continued collection of similar datasets to better understand the impacts of surface heterogeneity on the mapping and modeling of tundra ecosystem dynamics, as well as assist with conservation management and biodiversity monitoring strategies.
Labrador Slope Water connects the subarctic with the Gulf Stream
Authors: New A L , Smeed D A , Czaja A , Blaker A T , Mecking J V , Mathews J P , Sanchez-Franks A 
Published: July 2021

AbstractLabrador Slope Water (LSLW) is a relatively fresh and cool water mass that originates from the Labrador Current in the subarctic and is known to occur in the Eastern Slope Sea on the US-Canadian shelf-slope north of the Gulf Stream. It has potential densities of 27.4–27.65 kg m−3. Using ocean observations, we show here that the LSLW penetrates as a boundary current deeply into the Western Slope Sea (west of 66°W) as a salinity minimum between 400 and 600 m, bringing it into close proximity with the Gulf Stream. The LSLW at Line W (near 69°W) also spreads across, and brings fresher and thicker waters to, the Slope Sea north of the Gulf Stream. A high-resolution ocean model simulation shows that the spreading of the LSLW occurs throughout the entire Slope Sea through the extrusion of fine-scale filaments from the boundary current following interaction with Gulf Stream meanders and eddies. At Line W, the LSLW is also found to be fresher and thicker between 2003 and 2008, when the Atlantic Meridional Overturning Circulation (AMOC) at 26°N is higher (by 3 Sv), and the Shelf Slope Front is further south (by 0.7°), compared to AMOC low conditions in 2009–2014. The thicker LSLW causes lighter isopycnals to rise over the shelf slope, and through increasing the lateral density gradient contributes an additional 1.3 Sv to the Gulf Stream transport. These changes to the LSLW and the Shelf Slope Front are likely to result from an enhanced flow of the Labrador Current into the Slope Sea, caused by changes in the wind stress in the subpolar gyre. The transport of the LSLW (as opposed to the deeper Labrador Sea Water) thereby offers a potential new mechanism for decadal variability in the Atlantic climate system, through connecting changes in the subarctic with subsequent variability in the Gulf Stream and AMOC.