bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Gd-rich precipitates on the martensitic transformation, magnetocaloric effect, and mechanical properties of Ni–Mn–In Heusler alloys—A comparative study
Authors: Scheibel Franziska , Liu Wei , Pfeuffer Lukas , Shayanfar Navid , Taubel Andreas , Skokov Konstantin P. , Riegg Stefan , Wu Yuye , Gutfleisch Oliver
Published: February 2023

A multi-stimuli cooling cycle can be used to increase the cyclic caloric performance of multicaloric materials like Ni–Mn–In Heusler alloys. However, the use of uniaxial compressive stress as an additional external stimulus to a magnetic field requires good mechanical stability. Improvement in mechanical stability and strength by doping has been shown in several studies. However, doping is always accompanied by grain refinement and a change in transition temperature. This raises the question of the extent to which mechanical strength is related to grain refinement, transition temperature, or precipitates. This study shows a direct comparison between a single-phase Ni–Mn–In and a two-phase Gd-doped Ni–Mn–In alloy with the same transition temperature and grain size. It is shown that the excellent magnetocaloric properties of the Ni–Mn–In matrix are maintained with doping. The isothermal entropy change and adiabatic temperature change are reduced by only 15% in the two-phase Ni–Mn–In Heusler alloy compared to the single-phase alloy, which results from a slight increase in thermal hysteresis and the width of the transition. Due to the same grain size and transition temperature, this effect can be directly related to the precipitates. The introduction of Gd precipitates leads to a 100% improvement in mechanical strength, which is significantly lower than the improvement observed for Ni–Mn–In alloys with grain refinement and Gd precipitates. This reveals that a significant contribution to the improved mechanical stability in Gd-doped Heusler alloys is related to grain refinement.
Spatial organization of lysosomal exocytosis relies on membrane tension gradients
Authors: Lachuer Hugo , Le Laurent , Lévêque-Fort Sandrine , Goud Bruno , Schauer Kristine
Published: February 2023

Lysosomal exocytosis is involved in many key cellular processes but its spatiotemporal regulation is poorly known. Using total internal reflection fluorescence microscopy (TIRFM) and spatial statistics, we observed that lysosomal exocytosis is not random at the adhesive part of the plasma membrane of RPE1 cells but clustered at different scales. Although the rate of exocytosis is regulated by the actin cytoskeleton, neither interfering with actin or microtubule dynamics by drug treatments alters its spatial organization. Exocytosis events partially co-appear at focal adhesions (FAs) and their clustering is reduced upon removal of FAs. Changes in membrane tension following a hypo-osmotic shock or treatment with methyl-β-cyclodextrin were found to increase clustering. To investigate the link between FAs and membrane tension, cells were cultured on adhesive ring-shaped micropatterns, which allow to control the spatial organization of FAs. By using a combination of TIRFM and fluorescence lifetime imaging microscopy (FLIM), we revealed the existence of a radial gradient in membrane tension. By changing the diameter of micropatterned substrates, we further showed that this gradient as well as the extent of exocytosis clustering can be controlled. Together, our data indicate that the spatial clustering of lysosomal exocytosis relies on membrane tension patterning controlled by the spatial organization of FAs.
Data assimilation in operator algebras
Authors: Freeman David , Giannakis Dimitrios , Mintz Brian , Ourmazd Abbas , Slawinska Joanna
Published: February 2023

We develop an algebraic framework for sequential data assimilation of partially observed dynamical systems. In this framework, Bayesian data assimilation is embedded in a nonabelian operator algebra, which provides a representation of observables by multiplication operators and probability densities by density operators (quantum states). In the algebraic approach, the forecast step of data assimilation is represented by a quantum operation induced by the Koopman operator of the dynamical system. Moreover, the analysis step is described by a quantum effect, which generalizes the Bayesian observational update rule. Projecting this formulation to finite-dimensional matrix algebras leads to computational schemes that are i) automatically positivity-preserving and ii) amenable to consistent data-driven approximation using kernel methods for machine learning. Moreover, these methods are natural candidates for implementation on quantum computers. Applications to the Lorenz 96 multiscale system and the El Niño Southern Oscillation in a climate model show promising results in terms of forecast skill and uncertainty quantification.
Discovery of a rapidly evolving yeast defense factor,
KTD1
, against the secreted killer toxin K28
Authors: Andreev Ilya , Laidlaw Kamilla M. E. , Giovanetti Simone M. , Urtecho Guillaume , Shriner Daniel , Bloom Joshua S. , MacDonald Chris , Sadhu Meru J.
Published: February 2023

Secreted protein toxins are widely used weapons in conflicts between organisms. Elucidating how organisms genetically adapt to defend themselves against these toxins is fundamental to understanding the coevolutionary dynamics of competing organisms. Within yeast communities, “killer” toxins are secreted to kill nearby sensitive yeast, providing a fitness advantage in competitive growth environments. Natural yeast isolates vary in their sensitivity to these toxins, but to date, no polymorphic genetic factors contributing to defense have been identified. We investigated the variation in resistance to the killer toxin K28 across diverse natural isolates of the
Saccharomyces cerevisiae
population. Using large-scale linkage mapping, we discovered a novel defense factor, which we named
KTD1
. We identified many
KTD1
alleles, which provided different levels of K28 resistance.
KTD1
is a member of the DUP240 gene family of unknown function, which is rapidly evolving in a region spanning its two encoded transmembrane helices. We found that this domain is critical to
KTD1
’s protective ability. Our findings implicate
KTD1
as a key polymorphic factor in the defense against K28 toxin.
Anomalous Metallic State Driven by Magnetic Field at the LaAlO3/KTaO3 (111) Interface
Authors: Zhang Zi-Tao , Qiao Yu-Jie , Shao Ting-Na , Zhao Qiang , Chen Xing-Yu , Chen Mei-Hui , Zhu Fang-Hui , Dou Rui-Fen , Liu Hai-Wen , Xiong Chang-Min , Nie Jia-Cai
Published: February 2023

The origin of the quantum superconductor to metal transition at zero temperature in two-dimensional superconductors is still an open problem, which has caused intensely discussion. Here, we report the observation of a quantum superconductor-to-metal transition in LaAlO3/KTaO3 (111) interface, driven by magnetic field. When a small magnetic field perpendicular to the film plane is applied, the residual saturated resistance is observed, indicating the emergence of an anomalous metallic state associated with a failed superconductor. The dependence of saturated resistance on magnetic field at low temperature indicates that the observed metal state is a Bose metal state. From our findings, magnetic field regulating LaAlO3/KTaO3 (111) interface emerges as a platform to scrutinize the details of the anomalous metallic state in a controllable way.
Structure-controlled valley splitting and anomalous valley Hall effect in Janus VSe2/VSeX (X = S, Te) heterojunctions
Authors: Li C L , Wang N B , Hu G C , Yuan X B , Ren J F , Zhao X W
Published: February 2023

Ferrovalley materials possess spontaneous valley splitting and anomalous valley Hall effect (AVHE) characteristics, making this an ideal platform for valleytronic information devices. The efficient regulation of valley splitting and the anomalous Hall current is critical for the realization of information coding. In this work, to realize the regulation of valley properties, Janus VSe2/VSeX (X = S, Te) heterojunctions are investigated using first-principles calculations. Spontaneous valley splitting and the AVHE can be achieved in VSe2/VSeX. In addition, the asymmetrical structure, different stacking configurations of heterojunctions, and the intrinsic polarity of the Janus VSeX monolayer can regulate the band alignments, i.e. type-Ⅰ, -Ⅱ, and -Ⅲ band alignments can be realized, and they are accompanied with the switch between semiconductor and metal phases. Moreover, the structure-controlled valley states and AVHE are obtained. When altering the Janus VSeS and VSeTe, the K and K′ valleys possess contrary characteristics: opposite spin signs and valley splitting occurred. Accordingly, we design a low-power-consumption switch to achieve multistate storage without external field regulation. The results can provide an alternative avenue for spintronics and valleytronics devices.
Possible enhancement of the superconducting

Tc

due to sharp Kohn-like soft phonon anomalies
Authors: Jiang Cunyuan , Beneduce Enrico , Baggioli Matteo , Setty Chandan , Zaccone Alessio
Published: February 2023

Phonon softening is a ubiquitous phenomenon in condensed matter systems which is often associated with charge density wave (CDW) instabilities and anharmonicity. The interplay between phonon softening, CDW and superconductivity is a topic of intense debate. In this work, the effects of anomalous soft phonon instabilities on superconductivity are studied based on a recently developed theoretical framework that accounts for phonon damping and softening within the Migdal–Eliashberg theory. Model calculations show that the phonon softening in the form of a sharp dip in the phonon dispersion relation, either acoustic or optical (including the case of Kohn-type anomalies typically associated with CDW), can cause a manifold increase of the electron–phonon coupling constant λ. This, under certain conditions, which are consistent with the concept of optimal frequency introduced by Bergmann and Rainer, can produce a large increase of the superconducting transition temperature

T

c

. In summary, our results suggest the possibility of reaching high-temperature superconductivity by exploiting soft phonon anomalies restricted in momentum space.
Emergence of Rashba-/Dresselhaus effects in Ruddlesden–Popper halide perovskites with octahedral rotations
Authors: Krach Sonja , Forero-Correa Nicolás , Biega Raisa-Ioana , Reyes-Lillo Sebastian E , Leppert Linn
Published: February 2023

Ruddlesden–Popper halide perovskites are highly versatile quasi-two-dimensional energy materials with a wide range of tunable optoelectronic properties. Here we use the all-inorganic Cs

n
+
1

Pb
n
X

3
n
+
1

Ruddlesden–Popper perovskites with X = I, Br, and Cl to systematically model the effect of octahedral tilting distortions on the energy landscape, band gaps, macroscopic polarization, and the emergence of Rashba-/Dresselhaus splitting in these materials. We construct all unique n = 1 and n = 2 structures following from octahedral tilts and use first-principles density functional theory to calculate total energies, polarizations and band structures, backed up by band gap calculations using the GW approach. Our results provide design rules for tailoring structural distortions and band-structure properties in all-inorganic Ruddlesden–Popper perovskites through the interplay of the amplitude, direction, and chemical character of the antiferrodistortive distortion modes contributing to each octahedral tilt pattern. Our work emphasizes that, in contrast to three-dimensional perovskites, polar structures may arise from a combination of octahedral tilts, and Rashba-/Dresselhaus splitting in this class of materials is determined by the direction and Pb-I orbital contribution of the polar distortion mode.
Harvesting microwave energy using pyroelectricity of nanostructured graphene/zirconium-doped hafnium oxide ferroelectric heterostructures
Authors: Dragoman Mircea , Aldrigo Martino , Dinescu Adrian , Vasilache Dan , Iordanescu Sergiu , Dragoman Daniela , Laudadio Emiliano , Pavoni Eleonora
Published: February 2023

In this work, we present the design, atomistic/circuit/electromagnetic simulations, and the experimental results for graphene monolayer/zirconium-doped hafnium oxide (HfZrO) ultra-thin ferroelectric-based field effect transistors fabricated at the wafer scale, regarding the pyroelectricity generation directly from microwave signals, at room temperature and below it, namely at 218 K and at 100 K. The transistors work like energy harvesters, i.e. they collect low-power microwave energy and transform it into DC voltages with a maximum amplitude between 20 and 30 mV. The same devices function as microwave detectors in the band 1–10.4 GHz and at very low input power levels not exceeding 80 μW when they are biased by using a drain voltage, with average responsivity values in the range 200–400 mV mW−1.
Highly efficient and stable near-infrared photodetectors enabled from passivated tin–lead hybrid perovskites
Authors: Zhao Ru , Huang Junyi , Liu Meiyue , Tan Furui , Zhang Putao , Chen Zeng , Yao Xiang , Li Shengjun
Published: February 2023

Tin–lead perovskite-based photodetectors have a wide light-absorption wavelength range, which spans 1000 nm. However, the preparation of the mixed tin–lead perovskite films faces two great obstacles, namely easy oxidation of Sn2+to Sn4+and fast crystallization from tin–lead perovskite precursor solutions, thus further resulting in poor morphology and high density of defects in tin–lead perovskite films. In this study, we demonstrated a high-performance of near-infrared photodetectors prepared from a stable low-bandgap (MAPbI3)0.5(FASnI3)0.5film modified with 2-fluorophenethylammonium iodide (2-F-PEAI). The addition engineering can efficiently improve the crystallization of (MAPbI3)0.5(FASnI3)0.5films through the coordination binding between Pb2+and N atom in 2-F-PEAI, and resulting in a uniform and dense (MAPbI3)0.5(FASnI3)0.5film. Moreover, 2-F-PEAI suppressed Sn2+oxidation and effectively passivated defects in the (MAPbI3)0.5(FASnI3)0.5film, thereby significantly reducing the dark current in the PDs. Consequently, the near-infrared photodetectors showed a high responsivity with a specific detectivity of over 1012Jones at 800 to near-1000 nm. Additionally, the stability of PDs incorporated with 2-F-PEAI has been significantly improved under air conditions, and the device with the 2-F-PEAI ratio of 400:1 retained 80% of its initial efficiency after 450 h storage in air without encapsulation. Finally, 5 × 5 cm2photodetector arrays were fabricated to demonstrate the potential utility of the Sn–Pb perovskite photodetector in optical imaging and optoelectronic applications.
Fabrication of sandwich structures of Ag/analyte/MoO3 sea urchins for SERS detection of methylene blue dye molecules
Authors: B Ramya Prabhu , Varier Meenakshi M , John Neena S
Published: February 2023

A substrate for surface-enhanced Raman spectroscopy (SERS) in a sandwich configuration, noble metal/analyte/defect-rich metal oxide, is demonstrated for the detection of methylene blue(MB). The sandwich structure (Ag/MB/SUMoO3) is fabricated by physical vapour deposition of Ag nanoparticles over the MB analytes that are adsorbed on sea urchin MoO3 (SUMoO3). SUMoO3 are grown on a glass substrate by chemical bath deposition. The morphology of the fabricated sandwich structures shows serrated spikes of MoO3 from the core region decorated with strings of silver nanoparticles. The silver-decoration and the oxygen defects of SUMoO3 promote absorption in the visible region and facilitate charge transfer between MB and SUMoO3, which are beneficial for achieving superior SERS properties in this configuration compared to the contribution from individual components alone. The sandwich structure is able to detect the MB molecule up to 100 nM with an enhancement factor of 8.1 × 106. The relative standard deviation of SERS intensity for the 1618 cm−1 peak of MB across the substrate is 29.2%. The configuration offers stability to SERS substrate under ambient conditions. The combined effect of charge transfer, surface plasmon resonance, and MB resonance results in the improved SERS detection of MB molecules with the Ag/MB/SUMoO3 sandwich structure.
On variable stiffness of flexible parallel electroadhesive structures
Authors: Yuan Yingze , Li Fengfeng , Guo Jianglong , Liu Liwu , Liu Yanju , Leng Jinsong
Published: February 2023

Electrostatic layer jamming represents a lightweight, low energy consumption, electrically tunable, and cost-effective variable stiffness structure. Flexible parallel electroadhesive structures are the simplest form of electrostatic layer jamming. There is a lack of comprehensive and experimentally validated theoretical variable stiffness models of flexible parallel electroadhesive structures. Here we present the first variable stiffness model of flexible parallel electroadhesive structures under three-point bending, cantilever beam bending subjected to tip concentrated forces, and cantilever beam bending subjected to uniformly distributed forces, using the Euler–Bernoulli beam theory and considering friction and slip between layers by integrating the Maxwell stress tensor into the model. We find that: (1) three-point bending and cantilever beam bending under tip concentrated forces only have pre-slip and full-slip, whereas cantilever beam bending under uniformly distributed forces has an additional partial-slip which can be used for stiffness modulation; (2) the stiffness during the pre-slip stage is four times larger than the stiffness in the full-slip stage; and (3) increasing the voltage, dielectric permittivity, and coefficient of friction can elongate the pre-slip stage, thus enhancing the structural load capability. A customized three-point bending and a cantilever beam bending experimental setup were developed and the experimental deflection–force curve agreed relatively well with the theoretical one. The model, which considered electrode thickness and Young’s modulus, and the results presented in this work are useful insights for understanding the variable stiffness mechanism of electroadhesive layer jamming and are helpful for their structural optimization towards practical applications.
A parasitic-inertia piezoelectric actuator with isosceles trapezoidal flexible mechanism base on parasitic motion exploration and asymmetrical installation
Authors: Gao Jingwen , Chen Weizheng , Dong Chenxu , Tian Hailong , Li Jianping
Published: February 2023

Parasitic-inertia piezoelectric actuators have been widely studied for their ability to achieve both high positioning accuracy and large working strokes. However, backward motion results in parasitic-inertia piezoelectric actuators with the disadvantages of low efficiency and abrasion of driving foot. In this study, a parasitic-inertia piezoelectric actuator with an isosceles trapezoidal flexible mechanism is diegned and optimized to reduce backward motion considering the influence of parasitic motion proportion. It applies the asymmetrical installation of the piezoelectric stack to increase parasitic motion hence the reducing of backward motion. This study discusses the structure and working process of piezoelectric actuators and optimizes the design of flexible mechanism structure parameters with matrix displacement method and finite element method. A prototype of an parasitic-inertia piezoelectric actuator was manufactured, and a series of experiments were conducted. From the experiment, the piezoelectric actuator obtained a minimum backward motion percentage α = 18.36% and forward motion time percentage β = 95.9% at the frequency f = 1 Hz and the voltage U = 80 V. At U = 120 V, f = 500 Hz, the maximum motion speed of the actuator is 916 μm s−1; At U = 20 V and f = 1 Hz, the minimum positioning resolution of the actuator is 0.69 μm. At U = 120 V, f = 1 Hz, the maximum vertical load force is 1600 g, and the maximum parallel load force is 50 g. It has shown that the proposed isosceles trapezoidal flexible mechanism is feasible and can significantly reduce backward motion at the appropriate voltage. The mentioned characteristics of isosceles trapezoidal flexible mechanism can significantly alleviate the abrasion of driving foot, improve working efficiency. Also, it is vital for the miniaturization and practical application of parasitic-inertia piezoelectric actuators.
Spontaneous change of symmetry in a magnetoactive elastomer beam at its critical bending induced by a magnetic field
Authors: Kalita V M , Dzhezherya Yu I , Cherepov S V , Skirta Yu B , Bodnaruk A V , Ryabchenko S M
Published: February 2023

The features of the critical bending deformation and magnetization of a magnetoactive elastomer (MAE) beam with a fixed end in a transverse uniform magnetic field have been studied. After the beam reaches a critical bending, the symmetry of the beam shape and the symmetry of the MAE magnetic state change spontaneously. At the critical point, a continuous transition from the highly symmetric magnetic state in the unbent MAE beam to the low symmetric magnetic state in the bent MAE beam (this is the angular state with the effective magnetization inclined to the field) takes place. The beam bending occurs due to the gain in the magnetic energy of the beam. The formation of an angular magnetic state in it has a magnetoelastic origin and is characterized by the critical behavior of the mutually related bending and longitudinal effective magnetization of the MAE, but it is the magnetization that plays the role of order parameter. Furthermore, there is no longitudinal magnetization in the absence of bending and, vice versa, there is no bending in the absence of longitudinal magnetization. The influence of a low remanent magnetization, which eliminates the uncertainty in the bending direction, on the critical bending has been analyzed. The role of the magnetorheological effect, which affects the critical field magnitude and leads to the appearance of field-induced bending hysteresis near the critical point, has also been elucidated.
Calculation and measurement of coupling loss in a no-insulation ReBCO racetrack coil exposed to AC magnetic field
Authors: Otten Simon , ter Harmsel Jeroen , Dhallé Marc , Ten Kate Herman
Published: February 2023

No-insulation coils are self-protecting and can therefore generally be operated at higher current densities. However, the electrical turn-to-turn connections may cause additional AC loss when charging the coil or when it is exposed to a time-dependent magnetic field. In this work, we study the case of a no-insulation ReBCO tape racetrack coil exposed to a uniform AC field applied parallel to the tape surface. We show that an anisotropic continuum model allows to formulate analytical approximations for coupling loss in the low- and high-frequency limits. For intermediate frequencies, the continuum model needs to be evaluated numerically. The model was validated with representative measurements of AC loss in the coils, measured calorimetrically as well as magnetically using pick-up coils. The validation experiment confirms the predicted frequency dependence of the coupling loss, which is

P
∝

f
2

at low frequencies and

P
∝

f

at high frequencies, due to the skin effect. The transition between low- and high-frequency regimes occurs around a characteristic frequency

f

c

that is directly related to the characteristic time constant

τ
=
1

/

2
π

f

c

associated with the current decay in (dis)charge experiments.
Magnetized homann flow comprising GO and Co3O4 nanoparticles past a biaxially stretching surface
Authors: Sarfraz Mahnoor , Khan Masood
Published: February 2023

The usage of hybrid nanofluid due to their outstanding thermal conductivity has become a fascinating topic in research. This study considers the suspension of graphene oxide and cobalt oxide in ethylene glycol on a biaxially, planarly, and perpendicularly stretching surface. The influence of heat Cattaneo-Christov double diffusion with generation/absorption, Joule heating, and shapes of nanoparticles is scrutinized. The similarity conversions are assumed, which determine dimensionless ordinary equations. The collocation method, bvp4c routine is utilized to determine the numerical and asymptotic behavior of the problem. Because of better thermal and electrical conductivity of nanoparticles under consideration, this research can be used for energy storage, electronics, catalytic supports, and cooling of a system. The thermophysical properties are scrutinized via the Hamilton-Crosser model of nanofluids, which is significant as it provides a quantitative understanding of the heat transfer behavior of nanofluids, enabling the design and optimization of nanofluid-based heat transfer systems. Due to the magnetic field, temperature distribution is increased; however, velocities diminish. Moreover, energy transport is maximum for spherical-shaped nanoparticles, while it is lowest for blade-shaped nanoparticles. By incrementing volume fraction, the intermolecular motion amongst the particles becomes disorderly and erratic, which enhances the flow and thermal transport. The wall stress parameter along the x-axis is augmented due to an increment in the stretching parameter, while the opposite trend is seen for the wall stress parameter along the y-axis.
Edge turbulence transport during ELM suppression with n = 4 resonant magnetic perturbation on EAST
Authors: Liu S.C. , Liang Y. , Li L.T. , Tang T.F. , Wu X.H. , Yan N. , Shi T.H. , Li G.S. , Ye K.X. , Meng L.Y. , Ding R. , Sun Y. , Jia M. , Ma Q. , Zang Q. , Li X. , Wang S.X. , Wang M.R. , Zhao H.L. , Wei J.L. , Zhang T. , Jin Y.F. , Liao L. , Wei W.Y. , Li Y. , Chen R. , Hu G.H. , Zhao N. , Liu X.J. , Ming T.F. , Han X. , Zhang W.B. , Wang L. , Qian J.P. , Zeng L. , Li G.Q. , Xu G.S. , Gong X.Z. , Gao X.
Published: February 2023

The edge turbulence characteristics and the induced radial transport have been investigated in edge localized mode (ELM) suppression by using the

n
=

4 resonant magnetic perturbation coils on EAST, with

q

95

=

3.6 and the electron collisionality

ν

e

∗

≈

0.5. During ELM suppression, the edge turbulence is enhanced dramatically, as measured by the reciprocating probe and the poloidal correlation reflectometry. In the near SOL, the low frequency turbulence (<30 kHz) has a large fluctuation level and propagates along the ion diamagnetic drift direction with a speed of 0.35 km s−1 in the plasma frame; an

n
=
1

electromagnetic mode around 120 kHz with a small

k

θ

(∼0.15 cm−1) appears when the ELM is suppressed; weak broadband turbulence between 40–120 kHz propagates in the electron diamagnetic drift direction with a velocity of 3.4 km s−1 in the plasma frame. During the ELM suppression, the radial turbulent particle flux, calculated in both the time and frequency domains, is much higher (can be up to five times) than that in the inter-ELM phase. Furthermore, the low frequency turbulence (<30 kHz) dominates the cross-field particle transport. The 120 kHz electromagnetic mode also contributes to outward particle flux, which is relatively small. A set of CGYRO simulations are performed to illustrate the nature of the 120 kHz electromagnetic mode and the low frequency turbulence, suggesting that the former is the micro-tearing mode and the latter is the ion temperature gradient mode. The bispectral analysis suggests a strong three-wave coupling between the low frequency and high frequency turbulence (>250 kHz), which could be beneficial to form the observed turbulent transport. The estimated upstream cross-field particle flux is consistent with the total particle flux deposited on divertor targets, demonstrating that the enhanced radial turbulent particle transport is an important mechanism for particle exhaust in ELM suppression.
Accounting for spatial economic interactions at local and meso scales in integrated assessment model (IAM) frameworks: challenges and recent progress
Authors: Cultice Brian , Irwin Elena , Jones Mackenzie
Published: February 2023

The scientific and policy needs to assess and manage climate change impacts have spawned new coupled, multi-scale integrated assessment model (IAM) frameworks that link global climate and economic processes with high-resolution data and models of human-environmental systems at local and meso scales (Fisher-Vanden and Weyant 2020 Annu. Rev. Resour. Econ.
12 471–87). A central challenge is in accounting for the fundamental interdependence of people, firms, and economic activities across space at multiple scales. This requires modeling approaches that can incorporate the relevant spatial details at each scale while also ensure consistency with spatially varying feedbacks and interactions across scales—a condition economists refer to as spatial equilibrium. In this paper, we provide an overview of how economists think about and model spatial interactions, particularly those at the local level. We describe challenges and recent progress in accounting for greater spatial heterogeneity at individual (field, agent) scales and incorporating heterogeneous spatial interactions and dynamics into consistent IAM frameworks. We conclude that the most notable progress is in advancing global IAMs with spatial heterogeneity and dynamics embedded in spatial equilibrium frameworks and that less progress has been made in incorporating features of spatial equilibrium into highly detailed multi-scale IAMs.
Quantifying factory-scale CO2/CH4 emission based on mobile measurements and EMISSION-PARTITION model: cases in China
Authors: Shi Tianqi , Han Ge , Ma Xin , Mao Huiqin , Chen Cuihong , Han Zeyu , Pei Zhipeng , Zhang Haowei , Li Siwei , Gong Wei
Published: February 2023

Development of the measurement-based carbon accounting means is of great importance to supplement the traditional inventory compilation. Mobile CO2/CH4 measurement provides a flexible way to inspect plant-scale CO2/CH4 emissions without the need to notify factories. In 2021, our team used a vehicle-based monitor system to conduct field campaigns in two cities and one industrial park in China, totaling 1143 km. Furthermore, we designed a model based on sample concentrations to evaluate CO2/CH4 emissions, EMISSION-PARTITION, which can be used to determine global optimal emission intensity and related dispersion parameters via intelligent algorithm (particle swarm optimization) and interior point penalty function. We evaluated the performance of EMISSION-PARTITION in chemical, coal washing, and waste incineration plants. The correlations between measured samples and rebuilt simulated ones were larger than 0.76, and RMSE was less than 11.7 mg m−3, even with much fewer samples (25). This study demonstrated the wide applications of a vehicle-based monitoring system in detecting greenhouse gas emission sources.
Single and double toral band Fatou components in meromorphic dynamics
Authors: Hawkins Jane , Koss Lorelei
Published: February 2023

We analyze the existence and types of unbounded Fatou components for elliptic functions and other meromorphic functions with doubly periodic Julia sets. We show that apart from Herman rings and Siegel disks, all types of dynamics can occur in these domains, which are called toral bands. We show that toral bands are not necessarily periodic, and we give results about the number of distinct residue classes of critical points in each toral band.
Convergence of the MAC scheme for the incompressible Navier-Stokes equations with variable density and viscosity
Authors: Batteux L. , Gallouët T. , Herbin R. , Latché J. , Poullet P.
Published: February 2023

The present paper addresses the convergence of the implicit Marker-and-Cell scheme for time-dependent Navier–Stokes equations with variable density and density-dependent viscosity and forcing term. A priori estimates on the unknowns are obtained, and thanks to a topological degree argument, they lead to the existence of an approximate solution at each time step. Then, by compactness arguments relying on these same estimates, we obtain the convergence (up to the extraction of a subsequence), when the space and time steps tend to zero, of the numerical solutions to a limit; this latter is shown to be a weak solution to the continuous problem by passing to the limit in the scheme.
Topology of the Stokes phenomenon
Authors: Boalch P.
Published: February 2023

Several intrinsic topological ways to encode connections on vector bundles on smooth complex algebraic curves will be described. In particular the notion of Stokes decompositions will be formalised, as a convenient intermediate category between the Stokes filtrations and the Stokes local systems/wild monodromy representations. The main result establishes a new simple characterisation of the Stokes decompositions.

\begin{equation*} \ \ \ \includegraphics [width=0.6\textwidth ]{fission} \end{equation*}
Canonical maps and integrability in 𝑇𝑇̄ deformed 2d CFTs
Authors: Jorjadze George , Theisen Stefan
Published: February 2023

We study

T

T
¯

T\bar T

deformations of 2d CFTs with periodic boundary conditions. We relate these systems to string models on

R

×

S

1

×

M

\mathbb {R}\times {S}^1\times {\mathcal M}

, where

M

\mathcal M

is the target space of a 2d CFT. The string model in the light cone gauge is identified with the corresponding 2d CFT and in the static gauge it reproduces its

T

T
¯

T\bar T

deformed system. This relates the deformed system and the initial one by a worldsheet coordinate transformation, which becomes a time dependent canonical map in the Hamiltonian treatment. The deformed Hamiltonian defines the string energy and we express it in terms of the chiral Hamiltonians of the initial 2d CFT. This allows exact quantization of the deformed system, if the spectrum of the initial 2d CFT is known. The generalization to non-conformal 2d field theories is also discussed.
Spin Calogero-Moser models on symmetric spaces
Authors: Reshetikhin Nicolai
Published: February 2023

In this paper we construct and prove superintegrability of spin Calogero-Moser type systems on symplectic leaves of

K
1

∖

T
∗

G

/

K
2

K_1\backslash T^*G/K_2

where

K
1

,
 

K
2

⊂
G

K_1,\space K_2\subset G

are subgroups. We call them two-sided spin Calogero-Moser systems. One important type of such systems correspond to

K
1

=

K
2

=
K

K_1=K_2=K

where

K
K

is a subgroup of fixed points of Chevalley involution

θ
:
G
→
G

\theta : G\to G

. The other important series of examples come from pair

G
⊂
G
×
G

G\subset G\times G

with the diagonal embedding. We explicitly describe examples of such systems corresponding to symplectic leaves of rank one when

G
=
S

L
n

G=SL_n

.
On Schur problem and Kostka numbers
Authors: Coquereaux Robert , Zuber Jean-Bernard
Published: February 2023

We reconsider the two related problems: distribution of the diagonal elements of a Hermitian

n
×
n

n\times n

matrix of known eigenvalues (Schur) and determination of multiplicities of weights in a given irreducible representation of

S
U
(
n
)

SU(n)

(Kostka). It is well known that the former yields a semi-classical picture of the latter. We present explicit expressions for low values of

n
n

that complement those given in the literature \cite{GLS,BGR}, recall some exact (non asymptotic) relation between the two problems, comment on the limiting procedure whereby Kostka numbers are obtained from Littlewood–Richardson coefficients, and finally extend these considerations to the case of the

B
2

B_2

algebra, with a few novel conjectures.
A Note On Some Minimally Supersymmetric Models In Two Dimensions
Authors: Gaiotto Davide , Johnson-Freyd Theo , Witten Edward
Published: February 2023

We explore the dynamics of a simple class of two-dimensional models with

(
0
,
1
)

(0,1)

supersymmetry, namely sigma-models with target

S

3

\mathsf {S}^3

and the minimal possible set of fields. For any nonzero value of the Wess–Zumino coupling

k
k

, we describe a superconformal fixed point to which we conjecture that the model flows in the infrared. For

k
=
0

k=0

, we conjecture that the model spontaneously breaks supersymmetry. We further explore the question of whether this model can be continuously connected to one that spontaneously breaks supersymmetry by “flowing up and down the renormalization group trajectories,” in a sense that we describe. We show that this is possible if

k
k

is a multiple of 24, or equivalently if the target space with its

B
B

-field is the boundary of a “string manifold.” The mathematical theory of “topological modular forms” suggests that this condition is necessary as well as sufficient.
Aspects of 𝑝-adic geometry related to entanglement entropy
Authors: Marcolli Matilde
Published: February 2023

The replica argument for the computation of entanglement entropy is based on Rényi entropies computed over cyclic branched coverings of a Riemann surface. The recent development of a

p
p

-adic approach to AdS/CFT holography suggests that this computational method should have an analog in

p
p

-adic geometry. The purpose of this survey paper is to outline some aspects of

p
p

-adic geometry that are naturally related to the problem of formulating an analog of the usual replica argument for entanglement entropy in the context of

p
p

-adic holography.
Higher dietary protein intake is associated with sarcopenia in older British twins
Authors: Ni Lochlainn Mary , Bowyer Ruth C E , Welch Ailsa A , Whelan Kevin , Steves Claire J
Published: February 2023

Background

Sarcopenia, characterised by an accelerated loss of skeletal muscle mass and function, is associated with negative outcomes. This study aimed to evaluate factors associated with skeletal muscle strength, mass and sarcopenia, particularly protein intake, and to assess whether shared twin characteristics are important.

Methods

This study utilised cross-sectional data from a study of community-dwelling twins aged ≥60 years. Multivariable logistic regression and between- and within-twin pair regression modelling were used.

Results

Participants (n = 3,302) were 89% female (n = 2,923), aged a mean of 72.1 (±7.3) years and composed of 858 (55%) monozygotic, 709 (45%) dizygotic twin pairs and 168 individual lone twins. Using optimal protein intake as the reference group (1.0–1.3 g/kg/day), there was no significant association between protein intake (neither high nor low) and low muscle strength, or between low protein intake and sarcopenia (odds ratio (OR) 0.7; 95% confidence interval (CI) 0.39–1.25; P = 0.229) in unadjusted models. High protein intake (>1.3 g/kg/day) was associated with low muscle mass (OR 1.76; 95% CI 1.39–2.24; P < 0.0001), while low protein intake was protective (OR 0.52; 95% CI 0.40–0.67; P < 0.0001). High protein intake was associated with sarcopenia (OR 2.04; 95% CI 1.21–3.44; P = 0.008), and this was robust to adjustment for demographic, anthropometric and dietary factors. The association between muscle strength and weight, body mass index, healthy eating index, protein intake and alpha diversity was not significantly influenced by shared twin factors, indicating greater amenability to interventions.

Conclusions

High protein intake is associated with sarcopenia in a cohort of healthy older twins.
Design and Implementation of the All of Us Research Program COVID-19 Participant Experience (COPE) Survey
Authors: Schulkey Claire E , Litwin Tamara R , Ellsworth Genevieve , Sansbury Heather , Ahmedani Brian K , Choi Karmel W , Cronin Robert M , Kloth Yasmin , Ashbeck Alan W , Sutherland Scott , Mapes Brandy M , Begale Mark , Bhat Geeta , King Paula , Marginean Kayla , Wolfe Keri Ann , Kouame Aymone , Raquel Carmina , Ratsimbazafy Francis , Bornemeier Zach , Neumeier Kyle , Baskir Rubin , Gebo Kelly A , Denny Joshua , Smoller Jordan W , Garriock Holly A
Published: February 2023

In response to the rapidly evolving coronavirus disease 2019 (COVID-19) pandemic, the All of Us Research Program longitudinal cohort study developed the COVID-19 Participant Experience (COPE) survey to better understand the pandemic experiences and health impacts of COVID-19 on diverse populations within the United States. Six survey versions were deployed between May 2020 and March 2021, covering mental health, loneliness, activity, substance use, and discrimination, as well as COVID-19 symptoms, testing, treatment, and vaccination. A total of 104,910 All of Us Research Program participants, of whom over 73% were from communities traditionally underrepresented in biomedical research, completed 275,201 surveys; 9,693 completed all 6 surveys. Response rates varied widely among demographic groups and were lower among participants from certain racial and ethnic minority populations, participants with low income or educational attainment, and participants with a Spanish language preference. Survey modifications improved participant response rates between the first and last surveys (13.9% to 16.1%, P < 0.001). This paper describes a data set with longitudinal COVID-19 survey data in a large, diverse population that will enable researchers to address important questions related to the pandemic, a data set that is of additional scientific value when combined with the program’s other data sources.
A Bayesian Approach for Estimating the Survivor Average Causal Effect When Outcomes Are Truncated by Death in Cluster-Randomized Trials
Authors: Tong Guangyu , Li Fan , Chen Xinyuan , Hirani Shashivadan P , Newman Stanton P , Wang Wei , Harhay Michael O
Published: February 2023

Many studies encounter clustering due to multicenter enrollment and nonmortality outcomes, such as quality of life, that are truncated due to death—that is, missing not at random and nonignorable. Traditional missing-data methods and target causal estimands are suboptimal for statistical inference in the presence of these combined issues, which are especially common in multicenter studies and cluster-randomized trials (CRTs) carried out among the elderly or seriously ill. Using principal stratification, we developed a Bayesian estimator that jointly identifies the always-survivor principal stratum in a clustered/hierarchical data setting and estimates the average treatment effect among them (i.e., the survivor average causal effect (SACE)). In simulations, we observed low bias and good coverage with our method. In a motivating CRT, the SACE and the estimate from complete-case analysis differed in magnitude, but both were small, and neither was incompatible with a null effect. However, the SACE estimate has a clear causal interpretation. The option to assess the rigorously defined SACE estimand in studies with informative truncation and clustering can provide additional insight into an important subset of study participants. Based on the simulation study and CRT reanalysis, we provide practical recommendations for using the SACE in CRTs and software code to support future research.
Does COVID-19 Vaccination Disturb Menstrual Cycling?
Authors: Weinberg Clarice R
Published: February 2023

Coronavirus disease 2019 (COVID-19) vaccines have been reported to have a short-term effect on the menstrual cycle, delaying the onset of the next menses. However, the analytical methods that have been used to study this are subject to a statistical phenomenon called “length-biased sampling” that calls the results into question. Those data are important and should be reanalyzed in an unbiased way.
Africa and the making of Classical literature: on decolonizing Greco-Roman literature syllabi
Authors: Giusti Elena
Published: February 2023

This article presents the author’s development and teaching of a year-long module on Africa in Greco-Roman literature and its receptions, and the challenges of imagining a decolonized pedagogy in Classics, and specifically in the subfield of Greco-Roman literature. It argues that the equivalence of curriculum ‘diversification’ with ‘decolonization’ can be pernicious in its tokenizing effects, and that a committed practice of decolonizing pedagogy cannot be limited to studying Africa in Greco-Roman texts, but should involve serious engagement with postcolonial and critical race theorists, as much as African authors and authors from the African diaspora engaging meaningfully with the Greco-Roman traditions.
Storying early Alexandria: occluded histories, colonial fantasies
Authors: Blouin Katherine
Published: February 2023

There is something very affective, and also formulaic, about the story of the foundation of Alexandria. What makes it so enduring? What is it really about? And whose story is this? This paper explores the European historiographical tradition regarding the landscape and occupation of the site of Alexandria prior to and at the time of the city’s foundation. The number of publications on ancient Alexandria from its foundation in 331 bce to the Arab conquest of 642 ce is immense. Yet what interests me here is neither ancient Alexandria nor its early occupation per se, but rather the story European(ized) scholars have been telling about it, and how this story relates to land, people, and power. As such, it is a study in intellectual history.
An anti-amyloid therapy works for Alzheimer’s disease: why has it taken so long and what is next?
Authors: Hardy John , Mummery Catherine
Published: February 2023

Hardy and Mummery discuss the recent positive findings in the clinical trial of lecanemab in early Alzheimer’s disease, and the implications for the amyloid hypothesis. They argue that the results mark a turning point for the Alzheimer’s field, but that taking anti-amyloid therapies into clinical practice will be challenging.
Resting-state neural correlates of visual Gestalt experience
Authors: Wilding Marilena , Ischebeck Anja , Zaretskaya Natalia
Published: February 2023

Subjective perceptual experience is influenced not only by bottom-up sensory information and experience-based top-down processes, but also by an individual’s current brain state. Specifically, a previous study found increased prestimulus insula and intraparietal sulcus (IPS) activity before participants perceived an illusory Gestalt (global) compared with the non-illusory (local) interpretation of a bistable stimulus. That study provided only a snapshot of the brain state that favors the illusory interpretation. In the current study, we tested whether areas that differentiate between the illusory and non-illusory perception, immediately before stimulus onset, are also associated with an individual’s general tendency to perceive it, which remains stable over time. We examined individual differences in task-free functional connectivity of insula and IPS and related them to differences in the individuals’ duration of the two stimulus interpretations. We found stronger connectivity of the IPS with areas of the default mode and visual networks to be associated with shorter local perceptual phases, i.e. a faster switch to an illusory percept, and an opposite effect for insula connectivity with the early visual cortex. Our findings suggest an important role of IPS and insula interactions with nodes of key intrinsic networks in forming a perceptual tendency toward illusory Gestalt perception.