bluuebunny/crossref_metadata_2025 huggingface dataset:
Densification of single-walled carbon nanotube films: Mesoscopic distinct element method simulations and experimental validation
Authors: Drozdov Grigorii , Ostanin Igor , Xu Hao , Wang Yuezhou , Dumitrică Traian , Grebenko Artem , Tsapenko Alexey P. , Gladush Yuriy , Ermolaev Georgy , Volkov Valentyn S. , Eibl Sebastian , Rüde Ulrich , Nasibulin Albert G.
Published: November 2020

Nanometer-thin single-walled carbon nanotube (CNT) films collected from the aerosol chemical deposition reactors have gathered attention for their promising applications. Densification of these pristine films provides an important way to manipulate mechanical, electronic, and optical properties. To elucidate the underlying microstructural level restructuring, which is ultimately responsible for the change in properties, we perform large scale vector-based mesoscopic distinct element method simulations in conjunction with electron microscopy and spectroscopic ellipsometry characterization of pristine and densified films by drop-cast volatile liquid processing. Matching with the microscopy observations, pristine CNT films with a finite thickness are modeled as self-assembled CNT networks comprising entangled dendritic bundles with branches extending down to individual CNTs. Simulations of these films under uniaxial compression uncover a soft deformation regime extending up to an ∼75% strain. When removing the loads, the pre-compressed samples evolve into homogeneously densified films with thickness values depending on both the pre-compression level and the sample microstructure. The significant reduction in thickness is attributed to the underlying structural changes occurring at the 100 nm scale, including the zipping of the thinnest dendritic branches.
On the connection between Lagrangian and Eulerian metrics for recurrent particulate flows
Authors: Lichtenegger T. , Miethlinger T.
Published: November 2020

Data analysis and recently developed data-assisted simulations of particulate flows often require assessing the similarity of their spatial structure at different times. To that end, various metrics have been defined in the literature, either of Eulerian, field-based or of Lagrangian, particle-position-based nature. We demonstrate the equivalence of a broad class of these distance functions for sufficiently recurrent states analytically and numerically on simulation data of a small-scale, flat fluidized bed consisting of Np = 50 000 grains. The investigated Eulerian and Lagrangian metrics led to consistent dynamic properties. Both identified a correlation dimension of about Dcorr ≲ 20, which is orders of magnitude smaller than the number of microscopic degrees of freedom. Similarly, the prediction time massively exceeded the mean free duration between particle collisions. Both observations were caused by the formation of mesoscopic structures. Complementary simulations of a fully 3D bed showed that the agreement of the metrics also holds for more complex motion. To calculate Lagrangian distances, we employed the Hungarian algorithm with complexity O(Np3) for which we investigated different approximations leading to significant speed ups. In particular, we tracked randomly selected subsets of grains down to 10% of their total number and evaluated their mutual distance with only minor deviations from results of the full system. Our study clearly demonstrates that fundamental dynamic properties of granular matter are widely independent from the type of distance function used to investigate them. The final choice may be made based upon performance considerations or any specific information provided by different kinds of metrics.
Effect of dynamic ions on band structure of plasmon excitations
Authors: Akbari-Moghanjoughi M.
Published: November 2020

In this paper, we develop a new method to study the plasmon energy band structure in multispecies plasmas. Using this method, we investigate a plasmon dispersion band structure of various quasineutral plasma systems with arbitrary degree of electron degeneracy. The linearized Schrödinger–Poisson model is used to derive an appropriate coupled pseudoforce system from which the energy dispersion structure is calculated. It is shown that the introduction of ion dynamics, as opposed to static ion assumption in the jellium model with a wide plasmon bandgap, can significantly modify the plasmon dispersion character leading to a new low-level energy band caused by the electron–ion interactions. The investigation on the effect of ion charge-state and chemical potential of electrons on the plasmonic band structure indicates some interesting features and reveals the fundamental role played by ions in the phonon assisted plasmon excitations in different kinds of plasma systems. Moreover, our study confirms that ion charge screening has a significant impact on plasmon excitations in multispecies plasmas. The plasmon band structure in pair-ion or electron–positron plasmas indicates the unique role of positive charges on collective excitations. Current research helps us to better understand the underlying mechanisms of collective interactions in charged environment and the important role played by heavy charged particles on elementary plasmon excitations, which have important applications in plasmonic devices. The method developed in this research may also be extended to study magnetized quantum plasmas as well as to investigate surface plasmon–polariton interactions in nanometallic structures.
Quantum-confinement-induced periodic surface states in two-dimensional metal-organic frameworks
Authors: Zhou Chun-Sheng , Liu Xiang-Rui , Feng Yue , Shao Xiji , Zeng Meng , Wang Kedong , Feng Min , Liu Chang
Published: November 2020

Recently, a series of single-layer metal–organic frameworks (MOFs) was theoretically predicted to be two-dimensional organic topological materials. However, the experimental evidence of their nontrivial topological states has not been found. Here, combining the use of angle-resolved photoemission spectroscopy and scanning tunneling microscopy, we report the electronic structure studies on a single-layer Cu-coordinated 2,4,6-tri(4-pyridyl)-1,3,5-triazine (Cu-T4PT) MOF supported by a Cu(111) substrate and identify periodic surface states with the period of the Cu-T4PT reciprocal lattice. These periodic surface states, which have identical features to the Cu(111) Shockley surface states, can be attributed to the quantum confinement of the surface states of the underlying Cu(111) substrate by the network lattices of the Cu-T4PT MOF. Our work indicates that the surface states of the metal substrate can be tailored in a controlled manner by the network structures of MOFs with different periodic lattices. The lack of intrinsic bands and the possible topological properties of the single-layer Cu-T4PT MOF may be attributed to the strong electronic coupling between the Cu-T4PT MOF and the Cu(111) substrates. In order to exploit organic topological materials predicted in MOFs, it is necessary to grow them on weak van der Waals interaction substrates in the future.
Non-isothermal mixing characteristics in the extreme near-field of turbulent jets in hot crossflow: Effects of jet exit turbulence and velocity profile
Authors: Dayton James W. , Poettgen Benjamin K. , Cetegen Baki M.
Published: November 2020

The non-reacting and reacting jets-in-crossflow (JICF) are important flow configurations for effective mixing and combustion in practical applications. Many studies in the literature examine the overall mixing characteristics of isothermal, unconfined, non-reacting JICF. This experimental study expands on our recently published work that examined mixing characteristics in the near-field of a non-reacting jet in a hot vitiated crossflow (1500 K) for the jet-to-crossflow density ratio between 3.2 and 7.8 issuing from a round jet with a fully developed turbulent pipe flow exit profile. In this study, effects of the changing jet exit velocity profile to top-hat as well as exit turbulence levels (28% and 40%) with parabolic profiles are examined. Temperature measurements were made using laser Rayleigh scattering. The jet trajectory, centerline concentration decay based on adiabatic mixing assumption, Favre-averaged scalar dissipation, and mixing time scales were compared with the previous study results. Center-plane mixing metrics indicated that top-hat and pipe flow jets behave similarly, with better near-field mixing at lower momentum flux ratios and higher density ratios. The elevated turbulence cases have a higher near-field mixing efficiency with rates that are nearly independent of momentum flux ratios above 9.3 at a constant density ratio. Scalar dissipation analysis showed that the elevated turbulence jets differ from the nominal turbulence top-hat and pipe exit jet cases with a lack of strong peaks and slightly higher upstream crossflow magnitudes. Reducing the density ratio resulted in a decrease in the windward and leeward dissipation region size and magnitude.
Symmetry breaking of Worthington jets by gradients in liquid pool depth
Authors: Lee Yeawan , Shin Seungwon , Choi Geunhyeok , Jeon Hyejun , Kim Youngdo , Kim Hyoungsoo
Published: November 2020

We investigate the impact of a vertically falling droplet onto a non-uniform liquid depth having a linear slope of the bottom substrate. Here, we report that the resulting jet direction is inclined to the shallow liquid depth after the droplet impact, which is found to be markedly distinct from a vertically falling droplet onto a uniform liquid bath. From experimental and numerical results, we observe that initially the cavity grows almost axisymmetrically, and then, when it retracts, asymmetric capillary waves exhibit. The asymmetric cavity reversal leads to the inclined jet ejection that is related to pressure distribution and velocity of the interface. For the systematic study, we explore the jet dynamics by varying the surface tension, the droplet size, the droplet impact speed, the inclination angle of the bottom substrate, and the depth of the liquid bath. Finally, we provide a simple scaling model to predict the inclination angle of the resulting jet after the drop impact on the inclined liquid pool.
High-extinction electron pulses by laser-triggered emission from a Schottky emitter
Authors: Israel Yonatan , Bowman Adam J. , Klopfer Brannon B. , Koppell Stewart A. , Kasevich Mark A.
Published: November 2020

We study electron emission from a Schottky tip induced by nanosecond laser pulses. Prompt sub-nanosecond emission is observed at low laser power, with moderate voltage bias applied to the tip. We show that electron pulses demonstrate high extinction with electron emission after the pulse suppressed by up to 92 dB. Photoemission is shown to be highly nonlinear with laser intensity while maintaining nearly linear field emission, as probed by the laser polarization dependence. We suggest the emission is described by a photo-assisted thermally enhanced field emission process.
Microscopic fluid dynamics of a wire screen bound to a slit resonator excited by acoustic waves
Authors: Chen C. , Li X. D.
Published: November 2020

The microscopic fluid dynamics of a wire screen bound to a slit resonator excited by incident sound waves of different intensity are investigated numerically. The microscopic flow features help in understanding the acoustic behavior. A normal impedance-tube model is used in this investigation, and the wire mesh is modeled as an array of eight identical tiny circular cylinders arranged in parallel. Tonal waves of different sound pressure levels and frequencies are introduced from the termination of the tube through a non-reflecting boundary condition. Direct numerical simulations are carried out to solve for the flow and acoustic fields simultaneously, and the velocity and vorticity fields around the resonator are resolved. Upon closer inspection, the tiny cylinders suppress the vortex shedding from the slit excited by high-intensity incident sound waves, thereby retarding the nonlinear acoustic behavior of the slit. Furthermore, the wire mesh contributes greatly to the absorption of acoustic energy through scrubbing loss and flow separation. The acoustic impedance and absorption coefficient are derived using a two-microphone method. The numerical results show that the wire mesh increases the resistance of the resonator significantly while hardly affecting its reactance.
Indium antimonide—Constraints on practicality as a magneto-optical platform for topological surface plasmon polaritons
Authors: Pakniyat S. , Liang Y. , Xiang Y. , Cen C. , Chen J. , Hanson G. W.
Published: November 2020

Magnetic-field-biased indium antimonide (InSb) is one of the most widely discussed materials for supporting nonreciprocal surface plasmon polaritons (SPPs), which have recently been shown to be topological. In this work, we provide a critical assessment of InSb as a magneto-optical SPP platform and show that it is only viable under a narrow set of conditions.
Pure spin current phenomena
Authors: Huang S. Y. , Qu D. , Chuang T. C. , Chiang C. C. , Lin W. , Chien C. L.
Published: November 2020

Spintronic phenomena and devices have evolved from exploiting spin-polarized current to pure spin current. A pure spin current can more efficiently deliver spin angular momentum with fewer or no charge carriers, enabling spin–orbit torque switching in ferromagnets. The prospects of antiferromagnetic spintronics, especially electrical switching, remain perplexing and controversial. We describe some recent advances, outstanding issues, challenges, and prospects of pure spin current.
On existence and uniqueness of a carrying simplex in Kolmogorov differential systems
Authors: Hou Zhanyuan
Published: November 2020

This paper deals with global asymptotic behaviour of the dynamics for N-dimensional competitive Kolmogorov differential systems of equations

d

x

i

d
t

=

x

i

f

i

(

x

)

,

1
⩽
i
⩽
N
,

x
∈

R

+

N

. A theory based on monotone dynamical systems was well established by Hirsch (1988 Nonlinearity
1 51–71). One of his theorems is outstanding and states the existence of a co-dimension 1 compact invariant submanifold Σ that attracts all the nontrivial orbits under certain assumptions and, in practice, under the condition that the system is totally competitive (all N
2 entries of the Jacobian matrix Df are negative). The submanifold Σ has been called carrying simplex since then and the theorem has been well accepted with many hundreds of citations. In this paper, we point out that the requirement of total competition is too restrictive and too strong; we prove the existence and uniqueness of a carry simplex under the assumption of strong internal competition only (i.e. N diagonal entries of Df are negative), a much weaker condition than total competition. Thus, we improve the theorem significantly by dramatic cost reduction from requiring N
2 to N negative entries of Df. As an example of applications of the main result, the existence and global attraction (repulsion) of a heteroclinic limit cycle for three-dimensional systems is discussed and two concrete examples are given to demonstrate the existence of such heteroclinic cycles.
On the crystallization kinetics of multicomponent nano-chalcogenide Se79-xTe15In6Pbx(x = 0, 1, 2, 4, 6, 8 and 10) alloys
Authors: Anjali  , Patial Balbir Singh , Bhardwaj Suresh , Awasthi A M , Thakur Nagesh
Published: November 2020

Nanotechnology continuously rises due to its potential applications. To control nano-materials design and microstructure, it is very essential to understand nucleation and crystalline growth in these materials. In this research contribution, crystallization kinetics and thermal behaviour of nano-crystalline Se79-xTe15In6Pbx(x = 0, 1, 2, 4, 6, 8 and 10 at. wt%) chalcogenide alloys is analyzed through differential scanning calorimetry (DSC) process under non-isothermal conditions at four different heating rates; 5, 10, 15 and 20 °C min−1. The examined Se-Te-In-Pb nano-chalcogenide system is prepared through melt-quenching process. Characteristic temperatures namely glass transition temperature (Tg), onset crystallization temperature (To), peak temperature of crystallization (Tp) and melting temperature (Tm) show dependence on heating rate and composition. The various kinetic parameters such as activation energy of glass transition (Eg), activation energy of crystallization (Ec), reduced glass transition temperature (Trg), Hruby number (Kgl), thermal stability parameters (SandH’) and fragility index (Fi) are analyzed for investigated Se-Te-In-Pb nano-crystalline system. Different empirical approaches are applied to determine the apparent glass transition activation energy (Eg) and crystallization activation energy (Ec).
The Mackey bijection for complex reductive groups and continuous fields of reduced group C*-algebras
Authors: Higson Nigel , Román Angel
Published: November 2020

The purpose of this paper is to make a further contribution to the Mackey bijection for a complex reductive groupGG, between the tempered dual ofGGand the unitary dual of the associated Cartan motion group. We shall construct an embedding of theC∗C^*-algebra of the motion group into the reducedC∗C^*-algebra ofGG, and use it to characterize the continuous field of reduced groupC∗C^*-algebras that is associated to the Mackey bijection. We shall also obtain a new characterization of the Mackey bijection using the same embedding.
Number of Concussions Does Not Affect Treatment Response to Cognitive Rehabilitation Interventions Following Mild TBI in Military Service Members
Authors: Ord Anna S , Shura Robert D , Curtiss Glenn , Armistead-Jehle Patrick , Vanderploeg Rodney D , Bowles Amy O , Kennedy Jan E , Tate David F , Cooper Douglas B
Published: November 2020

Objective

The study objective was to determine whether number of concussions would affect symptom improvement following cognitive rehabilitation (CR) interventions.

Method

Service members (N = 126) with concussion history completed a 6-week randomized control trial of CR interventions. Participants were stratified based on self-reported lifetime concussion frequency. Outcome measures included the Paced Auditory Serial Addition Test (PASAT), the Global Severity Index (GSI) from the Symptom Checklist-90-Revised, and the Key Behaviors Change Inventory (KBCI).

Results

Mixed-model analyses of variance revealed a significant main effect for time on cognitive, psychological, and neurobehavioral functioning. A significant main effect for the number of concussions was observed for GSI and KBCI, but not PASAT. Interactions between the number of concussions and time were not significant for any of the outcome variables.

Conclusions

Over the 6-week interval, improvements were found for all participants across all outcome measures. Number of concussions did not affect improvements over time.
Democratic Culture and the Development of Artificial Intelligence in the USA and China
Authors: Abungu Cecil Yongo
Published: November 2020

Advancement in artificial intelligence has gradually become a pressing concern for the world’s leading nations, especially the USA and China. In this article, the author confronts an argument made and alluded to in certain quarters: that when considered next to China’s, the US democratic culture leaves it disadvantaged in the development of artificial intelligence insofar as it stands in the way of decisive and coordinated action. The author deploys a variety of case study situations to analyse the claim and eventually finds that the apparent disadvantage is, at worst, inexistent and, at best, negligible. Instead, it is argued that the differences in democratic culture between the two countries may, in fact, be responsible for the still-leading innovation within artificial intelligence development in the USA. Through demonstrating the faults of this disadvantage thesis, the final aim of this article is to call on US law- and policy-makers to retain faith in their democratic culture.
Sodium intake, life expectancy, and all-cause mortality
Authors: Messerli Franz H , Hofstetter Louis , Syrogiannouli Lamprini , Rexhaj Emrush , Siontis George C M , Seiler Christian , Bangalore Sripal
Published: November 2020

Aims 

Since dietary sodium intake has been identified as a risk factor for cardiovascular disease and premature death, a high sodium intake can be expected to curtail life span. We tested this hypothesis by analysing the relationship between sodium intake and life expectancy as well as survival in 181 countries worldwide.

Methods and results 

We correlated age-standardized estimates of country-specific average sodium consumption with healthy life expectancy at birth and at age of 60 years, death due to non-communicable diseases and all-cause mortality for the year of 2010, after adjusting for potential confounders such as gross domestic product per capita and body mass index. We considered global health estimates as provided by World Health Organization. Among the 181 countries included in this analysis, we found a positive correlation between sodium intake and healthy life expectancy at birth (β = 2.6 years/g of daily sodium intake, R  2 = 0.66, P < 0.001), as well as healthy life expectancy at age 60 (β = 0.3 years/g of daily sodium intake, R  2 = 0.60, P = 0.048) but not for death due to non-communicable diseases (β = 17 events/g of daily sodium intake, R  2 = 0.43, P = 0.100). Conversely, all-cause mortality correlated inversely with sodium intake (β = −131 events/g of daily sodium intake, R  2 = 0.60, P < 0.001). In a sensitivity analysis restricted to 46 countries in the highest income class, sodium intake continued to correlate positively with healthy life expectancy at birth (β = 3.4 years/g of daily sodium intake, R  2 = 0.53, P < 0.001) and inversely with all-cause mortality (β = −168 events/g of daily sodium intake, R  2 = 0.50, P < 0.001).

Conclusion 

Our observation of sodium intake correlating positively with life expectancy and inversely with all-cause mortality worldwide and in high-income countries argues against dietary sodium intake being a culprit of curtailing life span or a risk factor for premature death. These data are observational and should not be used as a base for nutritional interventions.
Polyscore of autonomic parameters for risk stratification of the elderly general population: the Polyscore study
Authors: Steger Alexander , Dommasch Michael , Müller Alexander , Sinnecker Daniel , Huster Katharina M , Gotzler Teresa , Gotzler Othmar , Hapfelmeier Alexander , Ulm Kurt , Barthel Petra , Hnatkova Katerina , Laugwitz Karl-Ludwig , Malik Marek , Schmidt Georg
Published: November 2020

Aims

Present society is constantly ageing and elderly frequently suffer from conditions that are difficult and/or costly to treat if detected late. Effective screening of the elderly is therefore needed so that those requiring detailed clinical work-up are identified early. We present a prospective validation of a screening strategy based on a Polyscore of seven predominantly autonomic, non-invasive risk markers.

Methods and results

Within a population-based survey in Germany (INVADE study), participants aged ≥60 years were enrolled between August 2013 and February 2015. Seven prospectively defined Polyscore components were obtained during 30-min continuous recordings of electrocardiogram, blood pressure, and respiration. Out of 1956 subjects, 168 were excluded due to atrial fibrillation, implanted pacemaker, or unsuitable recordings. All-cause mortality over a median 4-year follow-up was prospectively defined as the primary endpoint. The Polyscore divided the investigated population (n = 1788, median age: 72 years, females: 58%) into three predefined groups with low (n = 1405, 78.6%), intermediate (n = 326, 18.2%), and high risk (n = 57, 3.2%). During the follow-up, 82 (4.6%) participants died. Mortality in the Polyscore-defined risk groups was 3.4%, 7.4%, and 17.5%, respectively (P < 0.0001). The Polyscore-based mortality prediction was independent of Framingham score, diabetes, chronic kidney disease, and major stroke and/or myocardial infarction history. It was particularly effective in those aged <75 years (n = 1145).

Conclusion

The Polyscore-based mortality risk assessment from short-term non-invasive recordings is effective in the elderly general population, especially those aged 60–74 years. Implementation of a comprehensive Polyscore screening of this age group is proposed to advance preventive medical care.
Hybrid local and teleseismic P-wave tomography in North Tanzania: role of inherited structures and magmatism on continental rifting
Authors: Clutier A , Gautier S , Tiberi C
Published: November 2020

While local earthquake tomography is typically used to image the crust, this technique has restricted depth penetration due to short receiver-source distances. Regional tomography however aims to image the upper mantle from teleseismic events but suffers from poor resolution from 0 down to 40 km depth. We present here a hybrid method that combines the two approaches taking advantage of the short-wavelength resolution within the crust to better constrain the ray path at depth, and thus to improve the lithospheric imaging. Using this new method enhances the continuity or disruption of mantle anomalies towards the surface. Such hybrid tomographic images of crust-to-upper mantle structures are then critical to understand the relation and interplay between the thermal and mechanical lithospheric processes and the role in the localization of the deformation at the surface. We apply our approach to the North Tanzanian Divergence (NTD), where those processes interact with a cold cratonic lithosphere. Our new tomographic images clearly demonstrate the impact of deep-seated processes on surface features. First, strong lateral velocity anomalies and clustered seismicity in the crust are consistent with the surface geology of the NTD (rifted basins, volcanoes and border faults). Then, at a lithospheric scale, the velocity distribution highlights the major role of inherited structures in guiding the rift opening. In particular, our study suggests a strong influence of the Masai cratonic block, south of the NTD, in the rift evolution. The transition from the north–south axial valley into three diverging rift arms (Eyasi, Natron-Manyara and Pangani) is likely due to the change in rheology and to the presence of magma along inherited sutures between the craton and the mobile belts.
Impaired IFN-γ-dependent STAT3 Activation Is Associated With Dysregulation of Regulatory and Inflammatory Signaling in Monocytes of Ulcerative Colitis Patients
Authors: Cordes Friederike , Lenker Eva , Weinhage Toni , Spille Lea J , Bettenworth Dominik , Varga Georg , Schmidt Hartmut H , Foell Dirk
Published: November 2020

Background

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) inhibitor tofacitinib has been recently approved for the treatment of ulcerative colitis (UC) but not Crohn’s disease (CD). Systematic analysis of the JAK/STAT pathway in inflammatory bowel disease is still missing. The aim of this study was to investigate JAK/STAT activation and adjacent signaling in monocytes of patients with inflammatory bowel diseases, which are key players in inflammatory responses.

Methods

Blood samples of active UC (n = 28) and CD patients (n = 28) and healthy controls (n = 22) were collected for primary monocyte investigation. STAT phosphorylation (pSTAT), cytokine secretion, and surface marker expression ± prior tofacitinib blockade in addition to Th-17 and regulatory T cell induction in cocultures were analyzed upon interferon (IFN)-γ timulation.

Results

Baseline frequencies of pSTAT1+ and pSTAT3+ monocytes were significantly higher in UC, whereas IFN-γ-associated crosstalk induction of pSTAT3+ monocytes was missing in UC-derived monocytes compared with controls and CD. This coincided with decreased interleukin (IL)-10 and cluster of differentiation (CD)39 levels, diminished regulatory T cell (Treg) induction, and increased IL-12 and IL-23 secretion compared with controls, which was not observed in CD monocytes. Tofacitinib induced stronger inhibition of inflammatory cytokine release (IL-6, TNFα, IL-12, IL-23) in UC compared with CD monocytes.

Conclusions

In UC monocytes, IFN-γ-associated activation of the JAK/STAT pathway is impaired with an imbalance between STAT1 and STAT3, coinciding with stronger induction of inflammatory monocytes by IFN-γ compared with controls or CD. The fact that tofacitinib had stronger regulatory impact on UC than on CD monocytes further underlines a stronger inflammatory involvement of the JAK/STAT pathway in UC pathogenesis, which might result from missing STAT3 activation to counteract STAT1-induced inflammation.
Measuring stellar atmosphere parameters using follow-up polarimetric microlensing observations
Authors: Khalouei Elahe , Sajadian Sedighe , Rahvar Sohrab
Published: November 2020

We present an analysis of potential follow-up polarimetric microlensing observations to study the stellar atmospheres of distant stars. First, we produce synthetic microlensing events using the Galactic model, stellar population and interstellar dust toward the Galactic bulge. We simulate the polarization microlensing light curves and pass them through the instrument specifications of the FOcal Reducer and low dispersion Spectrograph (FORS2) polarimeter at the Very Large Telescope (VLT), and then analyse them. We find that the accuracy of the VLT allows us to constrain the atmospheres of cool red giant branch (RGB) stars. Assuming that about 3000 microlensing events are detected per year by the Optical Gravitational Lensing Experiment (OGLE) telescope, we expect to detect almost 20, 10, 8 and 5 polarization microlensing events for the following four criteria: being three consecutive polarimetric data points above the baseline with 1σ, 2σ, 3σ and 4σ, respectively, in the polarimetric light curves. We generalize the covariance matrix formulation and present the combination of polarimetric and icinformation that leads us to measure the scattering optical depth of the atmosphere and the inner radius of the stellar envelope of RGB stars. These two parameters could determine the dust opacity of the atmosphere of cool RGB source stars and the radius where dust can be formed.
Kinematic complexity around NGC 419: resolving the proper motion of the cluster, the Small Magellanic Cloud, and the Magellanic bridge
Authors: Massari Davide , Raso Silvia , Libralato Mattia , Bellini Andrea
Published: November 2020

We present Hubble Space Telescope proper motions in the direction of the star cluster NGC 419 in the Small Magellanic Cloud. Because of the high precision of our measurements, for the first time it is possible to resolve the complex kinematics of the stellar populations located in the field, even along the tangential direction. In fact, the proper motions we measured allow us to separate cluster stars, which move on average with ($\mu _{\alpha }\cos \delta ^{\rm NGC\, 419}, \mu _{\delta }^{\rm NGC\, 419}$) = (+0.878 ± 0.055, −1.246 ± 0.048) mas yr−1, from those of the Small Magellanic Cloud and those belonging to a third kinematic feature that we recognize as part of the Magellanic Bridge. Resolving such a kinematic complexity enables the construction of decontaminated colour–magnitude diagrams, as well as the measurement of the absolute proper motion of the three separate components. Our study therefore sets the first steps towards the possibility of dynamically investigating the Magellanic system by exploiting the resolved kinematics of its stellar clusters.
The structure of hydrodynamic γ-ray burst jets
Authors: Gottlieb Ore , Nakar Ehud , Bromberg Omer
Published: November 2020

After being launched, gamma-ray burst (GRB) jets propagate through dense media prior to their breakout. The jet-medium interaction results in the formation of a complex structured outflow, often referred to as a ‘structured jet’. The underlying physics of the jet-medium interaction that sets the post-breakout jet morphology has never been explored systematically. Here, we use a suite of 3D simulations to follow the evolution of hydrodynamic long and short gamma-ray bursts (lGRBs and sGRBs) jets after breakout to study the post-breakout structure induced by the interaction. Our simulations feature Rayleigh–Taylor fingers that grow from the cocoon into the jet, mix cocoon with jet material and destabilize the jet. The mixing gives rise to a previously unidentified region sheathing the jet from the cocoon, which we denote the jet–cocoon interface (JCI). lGRBs undergo strong mixing, resulting in most of the jet energy to drift into the JCI, while in sGRBs weaker mixing is possible, leading to a comparable amount of energy in the two components. Remarkably, the jet structure (jet-core plus JCI) can be characterized by simple universal angular power-law distributions, with power-law indices that depend solely on the mixing level. This result supports the commonly used power-law angular distribution, and disfavours Gaussian jets. At larger angles, where the cocoon dominates, the structure is more complex. The mixing shapes the prompt emission light curve and implies that typical lGRB afterglows are different from those of sGRBs. Our predictions can be used to infer jet characteristics from prompt and afterglow observations.
The distinct stellar-to-halo mass relations of satellite and central galaxies: insights from the IllustrisTNG simulations
Authors: Engler Christoph , Pillepich Annalisa , Joshi Gandhali D , Nelson Dylan , Pasquali Anna , Grebel Eva K , Lisker Thorsten , Zinger Elad , Donnari Martina , Marinacci Federico , Vogelsberger Mark , Hernquist Lars
Published: November 2020

We study the stellar-to-halo mass relation (SHMR) for central and satellite galaxies with total dynamical masses above $10^{10.5}\, \rm {M}_\odot$ using the suite of cosmological magnetohydrodynamical simulations IllustrisTNG. In particular, we quantify environmental effects on satellite populations from TNG50, TNG100, and TNG300 located within the virial radius of group- and cluster-like hosts with total masses of $10^{12\!-\!15.2}\, \rm {M}_\odot$. At fixed stellar mass, the satellite SHMR exhibits a distinct shift towards lower dynamical mass compared to the SHMR of centrals. Conversely, at fixed dynamical mass, satellite galaxies appear to have larger stellar-to-total mass fractions than centrals by up to a factor of a few. The systematic deviation from the central SHMR is larger for satellites in more massive hosts, at smaller cluster-centric distances, with earlier infall times, and that inhabits higher local density environments; moreover, it is in place already at early times (z ≲ 2). Systematic environmental effects might contribute to the perceived galaxy-to-galaxy variation in the measured SHMR when galaxies cannot be separated into satellites and centrals. The SHMR of satellites exhibits a larger scatter than centrals (by up to ∼0.8 dex), over the whole range of dynamical mass. The shift of the satellite SHMR results mostly from tidal stripping of their dark matter, which affects satellites in an outside-in fashion: The departure of the satellite SHMR from the centrals’ relation diminishes for measurements of dynamical mass in progressively smaller apertures. Finally, we provide a family of fitting functions for the SHMR predicted by IllustrisTNG.
Lnc2Cancer 3.0: an updated resource for experimentally supported lncRNA/circRNA cancer associations and web tools based on RNA-seq and scRNA-seq data
Authors: Gao Yue , Shang Shipeng , Guo Shuang , Li Xin , Zhou Hanxiao , Liu Hongjia , Sun Yue , Wang Junwei , Wang Peng , Zhi Hui , Li Xia , Ning Shangwei , Zhang Yunpeng
Published: November 2020

An updated Lnc2Cancer 3.0 (http://www.bio-bigdata.net/lnc2cancer or http://bio-bigdata.hrbmu.edu.cn/lnc2cancer) database, which includes comprehensive data on experimentally supported long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) associated with human cancers. In addition, web tools for analyzing lncRNA expression by high-throughput RNA sequencing (RNA-seq) and single-cell RNA-seq (scRNA-seq) are described. Lnc2Cancer 3.0 was updated with several new features, including (i) Increased cancer-associated lncRNA entries over the previous version. The current release includes 9254 lncRNA-cancer associations, with 2659 lncRNAs and 216 cancer subtypes. (ii) Newly adding 1049 experimentally supported circRNA-cancer associations, with 743 circRNAs and 70 cancer subtypes. (iii) Experimentally supported regulatory mechanisms of cancer-related lncRNAs and circRNAs, involving microRNAs, transcription factors (TF), genetic variants, methylation and enhancers were included. (iv) Appending experimentally supported biological functions of cancer-related lncRNAs and circRNAs including cell growth, apoptosis, autophagy, epithelial mesenchymal transformation (EMT), immunity and coding ability. (v) Experimentally supported clinical relevance of cancer-related lncRNAs and circRNAs in metastasis, recurrence, circulation, drug resistance, and prognosis was included. Additionally, two flexible online tools, including RNA-seq and scRNA-seq web tools, were developed to enable fast and customizable analysis and visualization of lncRNAs in cancers. Lnc2Cancer 3.0 is a valuable resource for elucidating the associations between lncRNA, circRNA and cancer.
Plasma exchange in ANCA-associated vasculitis: the pro position
Authors: Kronbichler Andreas , Shin Jae Il , Wang Chia-Shi , Szpirt Wladimir M , Segelmark Mårten , Tesar Vladimir
Published: November 2020

Plasma exchange (PLEX) is capable of removing significant amounts of circulating antibodies. In anti-neutrophil cytoplasmic antibody-associated vasculitis, PLEX was reserved for patients with severe presentation forms such as rapidly progressive glomerulonephritis and pulmonary haemorrhage. The Plasma Exchange and Glucocorticoids in Severe ANCA-Associated Vasculitis (PEXIVAS) trial included all comers with a glomerular filtration rate <50 mL/min/1.73 m2 and thus aimed to answer the question of whether PLEX is an option for patients with no relevant kidney function impairment or not. PEXIVAS revealed that after a follow-up of almost 3 years, routine administration of PLEX does not provide an additional benefit to reduce the rate of a composite comprising end-stage kidney disease or death. In the absence of histological parameters, it is tempting to speculate whether PLEX is effective or not in those with a potential for renal recovery. A subset of patients presented with alveolar haemorrhage, and there was a trend towards a better outcome of such cases receiving PLEX. This would be in line with observational studies reporting a recovery of alveolar haemorrhage following extracorporeal treatment. In this PRO part of the debate, we highlight the shortcomings of the PEXIVAS trial and stimulate further research paths, which in our eyes are necessary before abandoning PLEX from the therapeutic armamentarium.
A Nine-Dimensional Algebra which is not a Block of a Finite Group
Authors: Linckelmann Markus , Murphy William
Published: November 2020

We rule out a certain nine-dimensional algebra over an algebraically closed field to be the basic algebra of a block of a finite group, thereby completing the classification of basic algebras of dimension at most 12 of blocks of finite group algebras.
Learning from House Prices: Amplification and Business Fluctuations
Authors: Chahrour Ryan , Gaballo Gaetano
Published: November 2020

We formalize the idea that house price changes may drive rational waves of optimism and pessimism in the economy. In our model, a house price increase caused by aggregate disturbances may be misinterpreted as a sign of higher local permanent income, leading households to demand more consumption and housing. Higher demand reinforces the initial price increase in an amplification loop that drives comovement in output, labour, residential investment, land prices, and house prices even in response to aggregate supply shocks. The qualitative implications of our otherwise frictionless model are consistent with observed business cycles and it can explain the economic impact of apparently autonomous changes in sentiment without resorting to non-fundamental shocks or nominal rigidity.
Novel Technical Factors Affecting Proximal Humerus Fixation Stability
Authors: Laflamme G-Yves , Moisan Philippe , Chapleau Julien , Goulet Julien , Leduc Stéphane , Benoit Benoit , Rouleau Dominique M.
Published: November 2020

Objectives:

Intra-articular screw cut-out is a common complication after proximal humerus fracture (PHF) fixation using a locking plate. This study investigates novel technical factors associated with mechanical failures and complications in PHF fixation.

Design:

A retrospective radiological study.

Setting:

Level 1 trauma center.

Patients/Participants:

Clinical and radiological data from consecutive PHF patients treated between January 2007 and December 2013 were reviewed.

Intervention:

Open reduction and internal fixation with the Synthes Philos locking plate.

Main Outcome Measurements:

Postoperative radiographs were assessed for quality of initial reduction, humeral head offset, screw length, number and position, restoration of medial calcar support or the presence of calcar screws, and intra-articular screw perforations. Using SliceOMatic software, we validated a method to accurately identify screws of 45 mm or longer on AP radiographs. Follow-up radiographs were reviewed for complications.

Results:

Among 110 patients included [mean age 60 years, 78 women (71%), follow-up 2.5 years] and the following factors were associated with a worse outcome. (1) Screws >45 mm in proximal rows [Odds Ratio (OR) = 5.3 for screw cut-out); (2) lateral translation of the humeral diaphysis over 6 mm (OR = 2.7 for loss of reduction); (3) lack in medial support by bone contact (OR = 4.9 for screw cut-out); (4) varus reduction increased the risk of complications (OR = 4.3).

Conclusion:

The importance of reduction and calcar support in PHF fixation is critical. This study highlights some technical factors to which the surgeon must pay attention: avoid varus reduction, maximize medial support, avoid screws longer than 45 mm in the proximal rows, and restore the humeral offset within 6 mm or less.

Level of evidence:

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Level of Evidence:

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Young Intertrochanteric Femur Fractures Are Associated With Fewer Complications than Young Femoral Neck Fractures
Authors: DeKeyser Graham J. , Wilson Jacob M. , Kellam Patrick J. , Spencer Corey , Haller Justin M. , Rothberg David L. , Wagner Eric R. , Higgins Thomas F. , Marchand Lucas S.
Published: November 2020

Objective:

To compare the complication profile of femoral neck (FN) and intertrochanteric (IT) femur fractures in young patients.

Design:

A retrospective database review.

Setting:

Large, national private insurer claims database with longitudinal follow-up.

Patients:

Individuals undergoing surgical fixation of IT or FN fractures from 2010 to 2017 were identified. Patients were included if they were 18–50 years of age and had 1-year postoperative follow-up. Those with comorbid conditions of chronic kidney disease, congestive heart failure, diabetes, or coronary artery disease were excluded from the primary analysis.

Main Outcome Measures:

Complication data, including a diagnosis of nonunion, malunion, avascular necrosis (AVN), or need for revision surgery at 1-year follow-up, were compared. In addition, medical complication data at 90 days postoperatively were evaluated.

Results:

In total, 808 patients were identified: 392 (48.5%) patients with IT femur fractures and 416 (51.5%) patients with FN fractures. On multivariate analysis, FN fractures had nearly twice the risk of nonunion compared with IT femur fractures (odds ratio = 1.89; confidence interval, 1.09–3.30). IT femur fractures had a 5.4% rate of nonunion, a 3.6% rate of revision surgery, a 1% rate of AVN, and a 0.8% rate of conversion into total hip arthroplasty. By contrast, FN fractures had significantly higher rates of nonunion (10.3%; P = 0.009), revision surgery (9.4%; P = 0.001), AVN (5.8%; P < 0.001), and conversion to total hip arthroplasty (6%; P < 0.001).

Conclusion:

The results of this study demonstrate that IT fractures in young patients have superior outcomes when compared with their intracapsular counterparts. This is the only series of its kind to evaluate the complication profile of young IT femur fractures on a large scale. This information will be helpful in counseling patients in the perioperative setting.

Level of Evidence:

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Long noncoding RNA PCED1B-AS1 promotes erythroid differentiation coordinating with GATA1 and chromatin remodeling
Authors: Zhu Junwei , Ren Yunxiao , Han Yuanyuan , Jin Tingting , Li Yanming , Ruan Xiuyan , Qu Hongzhu , Huang Shengwen , Zhang Zhaojun , Fang Xiangdong
Published: November 2020

Erythropoiesis is a complex and sophisticated multi-stage process regulated by a variety of factors, including the transcription factor GATA1 and non-coding RNA. GATA1 is regarded as an essential transcriptional regulator promoting transcription of erythroid-specific genes—such as long non-coding RNAs (lncRNA). Here, we comprehensively screened lncRNAs that were potentially regulated by GATA1 in erythroid cells. We identified a novel lncRNA—PCED1B-AS1—and verified its role in promoting erythroid differentiation of K562 erythroid cells. We also predicted a model in which PCED1B-AS1 participates in erythroid differentiation via dynamic chromatin remodeling involving GATA1. The relationship between lncRNA and chromatin in the process of erythroid differentiation remains to be revealed, and in our study we have carried out preliminary explorations.
T cell metabolism in graft-versus-host disease
Authors: Zou Yujing , Chen Benny J.
Published: November 2020

Graft-versus-host disease (GVHD) is a major source of morbidity and mortality following allogeneic hematopoietic stem cell transplant (allo-HSCT), one of the most effective approaches to treat hematopoietic malignancies.
1
However, current prophylaxis regimens and treatments that reduce the detrimental effect of acute GVHD can be offset by increased incidence in opportunistic infections and relapse of the primary malignancy.
2
In addition, the majority of the approaches that inhibit T cell responses are non-specific, resulting in the inhibition of both alloreactive T cells and protective T cells from the donor. Therefore, there is an increase in the demand to develop novel approaches that selectively target alloreactive T cells. One potential means to address this issue is to take advantage of the unique metabolic profile of activated T cells.
Dynamic regulation of GATA2 in fate determination in hematopoiesis: possible approach to hPSC-derived hematopoietic stem/progenitor cells
Authors: Zhou Ya , Mao Bin , Chen Yijin , Xue Yuan , Chen Bo , Zhang Yonggang , Ma Feng
Published: November 2020

GATA2, a principal member of the GATA family, plays important roles in the generation and maintenance of hematopoietic stem/progenitor cells. Among the three mRNA transcripts, the distal first exon of GATA2 (IS exon) is specific for hematopoietic and neuronal cells. GATA2 mutants with abnormal expression are often present in acute myeloid leukemia-related familial diseases and myelodysplastic syndrome, indicating the crucial significance of GATA2 in the proper maintenance of blood system functions. This article offers an overview of the regulation dynamics and function of GATA2 in the generation, proliferation, and function of hematopoietic stem cells in both mouse and human models. We acknowledge the current progress in the cell fate determination mechanism by dynamic GATA2 expression. The gene modification approaches for inspecting the role of GATA2 in definitive hematopoiesis demonstrate the potential for acquiring hPSC-derived hematopoietic stem cells via manipulated GATA2 regulation.