bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast electrothermal coupling calculation method for supporting digital twin construction of electrical equipment
Authors: Zhu Xiaosong , Wang Youyuan , Meng Ruixiao , Long Shi , Wu Shaowen
Published: October 2022

The failure of electrical equipment directly or indirectly caused by overheating has become one of the main reasons for equipment accidents. The real‐time condition monitoring method of electrical equipment based on digital twin (DT) has received extensive attention and is considered as a technology with great engineering values and excellent application prospects. However, the current calculation of DT mostly relies on the traditional finite element method (CFEM). This method becomes less computationally efficient as the size of the DT increases, especially for electrical equipment with high complexity. It is difficult to meet the requirements real‐time calculation in DT. Therefore, starting from the algorithm optimization and parallel architecture, based on the weighted residual method and stabilised conforming nodal integration, a novel discrete method of electrothermal coupling equation is proposed and the data storage structure of the algorithm from the bottom layer is redesigned, and the corresponding GPU and multi‐core CPU parallel framework are proposed. Finally, taking the high voltage bushing as an example, the correctness of the method in this paper is verified by the CFEM code and commercial software ABAQUS. Under the same grid and accuracy requirement, the calculation time is shortened by at least five times than ABAQUS. And the method is easy to extend to other types of multi‐physics calculations.
Insulation degradation and fracture cracks of mechanical impacted thermal‐ageing oil‐impregnated papers
Authors: Chi Minghe , Xia Ruochun , Guan Yi , Sun Weifeng , Liu Ji , Chen Qingguo
Published: October 2022

In order to elucidate mechanical impacts affecting the insulation strength of thermal‐ageing oil‐impregnated pressboards, we perform mechanical degradation experiments of impacting forces that are represented as the winding‐suffered stresses on thermal‐ageing oil‐paper insulation in transient short‐circuit of transformer. Water content, degree of polymerisation (DP), partial discharge inception voltage and AC breakdown field strength are tested and analysed for diverse thermal‐ageing levels. An analytical model of mechanical degradation is established by relating dielectric breakdown strength to mechanical impact. Mechanical impacts result in less water content in thermal‐aging oil‐impregnated pressboards while causing reduction and increment of DP, respectively, in mildly and severely aged oil‐impregnated pressboards. Partial discharge inception voltage and dielectric breakdown strength vary significantly with the numbers of impact cycles, showing a maximum value under low‐intensity impact and decreasing monotonously under high‐intensity impact. High‐intensity mechanical impacts will evidently exacerbate the thermal deterioration process of oil‐impregnated pressboards, which is primarily attributed to cellulose fibre fractures in pressboard cracks produced by equivalent tensile stress of mechanical impacts. It is acceptable for mildly aged oil‐impregnated pressboards to suffer low‐intensity mechanical impacts that will alleviate insulation degradation by restraining partial discharge in smaller oil‐gaps and prolonging breakdown discharge pathways along impact‐caused cracks.
Accretion variability in RU Lup
Authors: Stock C. , McGinnis P. , Caratti o Garatti A. , Natta A. , Ray T. P.
Published: October 2022

Context. The process of accretion in classical T Tauri stars (CTTSs) has been observed to vary on different timescales. Studying this variability is vital to understanding a star’s evolution and provides insight into the complex processes at work within, including sources of the veiling present. Understanding the dichotomy between continuum veiling and emission line veiling is integral to accurately measuring the amount of veiling present in stellar spectra.

Aims. Here, 15 roughly consecutive nights of optical spectroscopic data from the spectropolarimeter ESPaDOnS are utilised to characterise the short-term accretion activity in the CTTS, RU Lup, and investigate its relationship with the veiling in the Li I 6707 Å absorption line.

Methods. The accretion-tracing H I Balmer series emission lines were studied and used to obtain the accretion luminosity (Lacc) and mass accretion rate (Ṁacc) for each night, which vary by a factor of ∼2 between the brightest and dimmest nights. We also measured the veiling using multiple photospheric absorption lines (Na I 5688 Å, Mn I 6021 Å, and Li I 6707 Å) for each night.

Results. We find the Li I 6707 Å line provides measurements of veiling that produce a strong, positive correlation with Lacc in the star. When corrected for Li depletion, the average veiling measured in the Li I 6707 Å line is rLi I, avg ∼ 3.25 ± 0.20, which is consistent with the other photospheric lines studied (ravg ∼ 3.28 ± 0.65).

Conclusions. We measured short timescale variability in the accretion luminosity and mass accretion rate that are intrinsic and not due to geometric effects. As the forbidden line emission we observe ([O I] 6300 Å and [S II] 6730 Å) remains remarkably constant over our epochs, it is clear that the variations in the mass accretion rate are too short to have an effect on these outflow tracers. Upon comparing the changes in veiling and accretion luminosity, we find a strong, positive correlation. This study provides an example of how this correlation can be used as a tool to determine whether a measured variability is due to extinction or an intrinsic change in accretion. As the determination of veiling is an independent process from measuring Lacc, their relationship allows further exploration of accretion phenomena in young stars.
Jetted narrow-line Seyfert 1 galaxies breaking the jet paradigm: A comprehensive study of host-galaxy morphologies
Authors: Varglund I. , Järvelä E. , Lähteenmäki A. , Berton M. , Ciroi S. , Congiu E.
Published: October 2022

Narrow-line Seyfert 1 (NLS1) galaxies are unevolved active galactic nuclei (AGNs) that exist predominantly in spiral galaxies. However, mostly due to the small number of sources studied, it has been under debate whether also the hosts of jetted NLS1 galaxies, a particular subclass of these sources hosting a relativistic jet, are disk-like or elliptical, as the hosts of more powerful jetted AGNs. We studied the host morphologies of 14 NLS1 galaxies, 11 of which have been detected at 37 GHz, indicating that these sources harbour relativistic jets. TheJ- andKs-band data used in this study were obtained with the Nordic Optical Telescope (NOT). We performed the photometric decomposition of the host galaxy using the band that gave a better fit and additionally created colour maps of all sources that had both aJ- and aKs-band observation. We were able to successfully model 12 sources, nine of which most likely have disk-like morphologies. Of the remaining sources, one source could possibly be hosted either in a disk-like or a dwarf galaxy, and in two cases the results are inconclusive. Only one of our sources shows clear signs of interaction, but the colour maps of most of our sources hint at ample dust in the nuclei, possibly indicating earlier minor mergers, which can go unnoticed due to the limited resolution of these observations. Our results further support disk-like galaxies as the predominant host type of jetted NLS1 galaxies. Most importantly, with the number of modelled hosts of jetted NLS1s now exceeding 50, with only a few elliptical hosts, it seems to be safe to conclude that also disk-like galaxies are able to launch and maintain relativistic jets, and that the traditional jet paradigm stating that only massive elliptical galaxies are capable of hosting relativistic jets is severely outdated.
Volume-limited sample of low-mass red giant stars, the progenitors of hot subdwarf stars
Authors: Uzundag Murat , Jones Matías I. , Vučković Maja , Vos Joris , Bobrick Alexey , Paladini Claudia
Published: October 2022

Context. Current theory predicts that hot subdwarf binaries are produced from evolved low-mass binaries that have undergone mass transfer and drastic mass loss during either a common-envelope phase or a stable Roche-lobe overflow while on the red giant branch (RGB).

Aims. We perform a spectroscopic survey to find binary systems that include low-mass red giants near the tip of the RGB, which are predicted to be the direct progenitors of subdwarf B (sdB) stars. We aim to obtain a homogeneous sample to search for the observational evidence of correlations between the key parameters governing the formation of sdB stars and constrain the physics of stable mass transfer.

Methods. Based on data from the Gaia mission and several ground-based, multiband photometry surveys, we compiled a sample of low-mass red giant branch (RGB) candidates. The candidates were selected according to their Gaia data release 2 (DR2) color, absolute magnitude, and proper motion cuts. In this work, we concentrated on the southern hemisphere targets and conducted a spectroscopic survey of 88 red giant stars to search for the long-period RGB plus main-sequence binary systems within 200 pc. Combining radial velocity (RV) measurements from ground-based observations with CORALIE and RV measurements from Gaia DR2 and from the early data release 3 (eDR3) as well as the astrometric excess noise and renormalized unit weight error measurements from Gaia DR3, we defined a robust binary classification method. In addition, we searched for known binary systems in the literature and in Gaia DR3.

Results. We select a total of 211 RGB candidates in the southern hemisphere within 200 pc based on the Gaia DR2 color-magnitude diagram. Among them, a total of 33 red giants were reported as binary systems with orbital periods between 100 and 900 days, some of which are expected to be the direct progenitors of wide binary sdB stars. In addition, we classified 37 new main-sequence plus RGB binary candidates, whose orbital parameters will be measured with future spectroscopic follow-up.

Conclusions. Using high-quality astrometric measurements provided by the Gaia mission coupled with high-resolution spectroscopy from the ground, we provide a powerful method for searching for low-mass red giant stars in long-period binary systems.
Preliminary evaluation of interferometry measurements of the flow field in the vicinity of a self-excited single profile
Authors: Procházka Pavel , Vlček Václav , Šidlof Petr
Published: October 2022

This paper deals with the interferometry measurement of the flow field in the vicinity of the surface of the self-excited single profile NACA 0015 in subsonic air flow. The pressure and velocity on the profile surface, the total forces and total moments acting on the profile are evaluated in the range of the Mach number Ma = 0.18-0.45 and the Reynolds number Re = (3-6)·105 . Since the interferogram processing was conducted with simplified assumptions of the isentropic changes of the flow field, the results have a limited accuracy especially in the case with flow separation. Results were not compared with the direct pressure measurement on the profile surface. The optical measurement method enabled the forces and moments to be evaluated separately for the suction and pressure surface of the airfoil.
Overshot water wheel efficiency measurements for low heads and low flowrates
Authors: Štigler Jaroslav
Published: October 2022

Utilizing of low renewable energy sources is an actual topic nowadays. This paper is focused on the locations with the low hydro-energy potential. It means locations with a head about 1m and flow rates about tens of litres per second. Hydro turbines for such parameters belong to the pico-turbines. It is not easy to design the hydro-turbine for such parameters with an acceptable efficiency. One of the possibilities is to use a water wheel. It is possible to find in a literature that the efficiency of overshot water wheels achieves 85%. This is the very good efficiency. It is not so easy to find some experimental data which proves this statement. Aims of this work are to design a simple manufactured overshot water wheel, measure the hydraulic efficiency of this wheel for wide range of parameters, finding an effect of the leading edge adjusting and the effect of the channel outflow edge position on the water wheel efficiency.
Comparison of the RAFSI and PIV method in multi-criteria decision making: application to turning processes
Authors: Trung Do Duc , Thinh Hoang Xuan , Ha Le Dang
Published: October 2022

Multi-criteria decision-making (MCDM) methods are used in many fields so as to rank alternatives and find the best one. However, rank reversal after adding or removing an alternative can occur in using some of the methods. In this study, two methods RAFSI and PIV were compared for application of making multi-criteria decisions. They are known to be capable of avoiding rank reversal problems. Sixteen 9XC steel turning tests were performed for the experiment. Tool holder length, spindle speed, feed rate and depth of cut are parameters that vary in each test. Three criteria for evaluating the turning process consist of MRR, RE and Ra. Four methods including MEREC, ROC, RS and EQUAL were used for determining weights of the criteria. The blend of two multi-criteria decision making methods (RAFSI and PIV) with four weight-determining methods resulted in eight ranking options. This is a new approach of the study. A positive outcome was reached that all eight ranking options identified the same best test. The best experiment must ensure to have maximum MRR and minimum RE and Ra simultaneously. A detailed discussion of the ranking results in each case was also carried out. Finally, the directions and issues that need to be studied further were pointed out in this paper as well.
Zervikaler Rückenmarksinfarkt beim Hund – Welche
Maßnahmen sind zu empfehlen?
Authors: Challande-Kathmann Iris
Published: October 2022

Hunde mit einem zervikalen Rückenmarksinfarkt zeigen oft dramatische
neurologische Ausfälle bis hin zum Verlust der Steh- und
Gehfähigkeit. Frühzeitig eingesetzte physiotherapeutische
Maßnahmen erhöhen die Chance, dass diese Patienten ihr
Gehvermögen wiedererlangen.
The origin of edge-enhanced second harmonic generation in monolayer MoS2 flakes
Authors: Lai Man-Hong , Chen Wei-Liang , Lo Chao-Yuan , Yu Jia-Ru , Tang Po-Wen , Chen Chi , Chang Yu-Ming
Published: October 2022

The sensitiveness of second-harmonic generation (SHG) signal to crystal lattice orientation and crystal symmetry makes it a powerful tool for structural characterization of low dimensional transition metal dichalcogenide (TMD) materials. In this paper, we report the strain-induced SHG enhancement at the edge of the monolayer MoS2 flakes. By performing raster mapping of SHG intensity, the images show an enhanced SHG intensity at the flake edge with cubic-power dependence. The AFM analysis of the MoS2 flake edge with enhanced SHG, indeed, detected a topographic height change as compared to the center region. Micro-Raman spectroscopy analysis shows a blue shift in A1g phonon mode at the flake edge. This edge-enhanced SHG may be attributed to the intrinsic strain effect induced during the chemical vapor deposition growth condition, which modulates the nonlinear susceptibility. The micro-Raman spectroscopy implies that the flake edge has a compressed and stiffened structure in an out-of-plane direction. This work brings out the awareness of the residual strain effect on 2D TMD device performance, and the adequate characterization of the strained structure by SHG intensity mapping.
Transition state search and geometry relaxation throughout chemical compound space with quantum machine learning
Authors: Heinen Stefan , von Rudorff Guido Falk , von Lilienfeld O. Anatole
Published: October 2022

We use energies and forces predicted within response operator based quantum machine learning (OQML) to perform geometry optimization and transition state search calculations with legacy optimizers but without the need for subsequent re-optimization with quantum chemistry methods. For randomly sampled initial coordinates of small organic query molecules, we report systematic improvement of equilibrium and transition state geometry output as training set sizes increase. Out-of-sample SN2 reactant complexes and transition state geometries have been predicted using the LBFGS and the QST2 algorithms with an root-mean-square deviation (RMSD) of 0.16 and 0.4 Å—after training on up to 200 reactant complex relaxations and transition state search trajectories from the QMrxn20 dataset, respectively. For geometry optimizations, we have also considered relaxation paths up to 5’595 constitutional isomers with sum formula C7H10O2 from the QM9-database. Using the resulting OQML models with an LBFGS optimizer reproduces the minimum geometry with an RMSD of 0.14 Å, only using ∼6000 training points obtained from normal mode sampling along the optimization paths of the training compounds without the need for active learning. For converged equilibrium and transition state geometries, subsequent vibrational normal mode frequency analysis indicates deviation from MP2 reference results by on average 14 and 26 cm−1, respectively. While the numerical cost for OQML predictions is negligible in comparison to density functional theory or MP2, the number of steps until convergence is typically larger in either case. The success rate for reaching convergence, however, improves systematically with training set size, underscoring OQML’s potential for universal applicability.
Fluorine-passivated In2O3 thin film transistors with improved electrical performance via low-temperature CF4/N2O plasma
Authors: Zhang Jie , Charnas Adam , Lin Zehao , Zheng Dongqi , Zhang Zhuocheng , Liao Pai-Ying , Zemlyanov Dmitry , Ye Peide D.
Published: October 2022

In this Letter, we report the electrical performance improvement of indium oxide (In2O3) thin film transistors (TFTs) via a low-temperature CF4/N2O plasma treatment. It is found that the fluorination via CF4/N2O plasma can reduce the excessive electrons in the In2O3 channel more effectively compared to the oxidative annealing, providing the same low off-currents at a lower temperature of 200 °C, while the hydrogenation could not give rise to the off-current reduction. The fluorinated In2O3 TFTs with a channel thickness of 3.5 nm, a HfO2 dielectric thickness of 3.5 nm, and a channel length ranging from 80 nm to 1 μm demonstrate markedly improved electrical performances, including a high field effect mobility of 72.8 cm2/V s, a more positive threshold voltage, a higher on/off current ratio of ∼106, a smaller subthreshold swing below 200 mV/dec, and a higher stability to both negative and positive gate biases. X-ray photoelectron spectroscopy (XPS) confirms the fluorine incorporation in In2O3/HfO2 heterojunction upon CF4/N2O plasma, speculatively passivating the oxygen vacancies and explaining TFT performance enhancement. This study suggests that the anion doping such as fluorine incorporation could be an effective method to improve the performance of oxide semiconductor TFTs with ultrathin channel and dielectric.
Thermoelectric properties of hole-doped CuRhO2 thin films
Authors: Cheng W. P. , He Y. D. , Wei R. H. , Hu L. , Song W. H. , Zhu X. B. , Sun Y. P.
Published: October 2022

Design and realization of high-efficiency p-type thermoelectric materials with excellent performance are the demand for integrated thermoelectric components. Compared with single crystal bulk materials, thermoelectric thin films are more suitable for the miniaturization of thermoelectric devices. Here, c-axis oriented CuRh1−xMgxO2 (x = 0, 0.05, and 0.1) thin films were prepared and the thermoelectric properties are reported. The power factor of a p-type 10% Mg-doped CuRhO2 thin film shows a large value of 535.7 μW K–2 m-1 at 300 K. The results suggest that the hole-doped CuRhO2 thin films can be regarded as potential p-type thermoelectric oxide and will pave an avenue to develop Rh-based thermoelectric thin films.
Predictive modeling of drop impact force on concave targets
Authors: Dickerson Andrew K. , Alam MD Erfanul , Buckelew Jacob , Boyum Nicholas , Turgut Damla
Published: October 2022

Impacting drops are ubiquitous and the corresponding impact force is their most studied dynamic quantity. However, impact forces arising from collisions with curved surfaces are understudied. In this study, we impact small cups with falling drops across drop Reynolds number 2975–12 800, isolating five dominant parameters influencing impact force: drop height and diameter, surface curvature and wettability, and impact eccentricity. These parameters are effectively continuous in their domain and have stochastic variability. The unpredictable dynamics of the system incentivize the implementation of tools that can unearth relationships between parameters and make predictions about impact force for parameter values for which there is not explicit experimental data. We predict force due to the impacting drop in a concave target using an ensemble learning algorithm comprised of four base algorithms: a random forest regressor, k-nearest neighbor, a gradient boosting regressor, and a multi-layer perceptron. We train and test our algorithm with original experimental data comprising 387 total trials using four cup radii with two wetting conditions each. Our approach permits the determination of relative importance of the input features in producing impact force and force predictions which can be compared to scaling relations modified from those for flat targets. Algorithmic predictions indicate that deformation of the drop and surface wettability, often neglected in scaling for impact force on flat surfaces, are important for concave targets. Finally, our approach provides another opportunity for the application of machine learning to characterize complex systems' fluid mechanics for which experimental variables are numerous and vary independently.
van der Waals ferroelectrics: Progress and an outlook for future research directions
Authors: Parker Jacob , Gu Yi
Published: October 2022

The recent discovery of van der Waals (vdW) ferroelectric materials has inspired their incorporation into numerous nonvolatile technologies and shown potential promise for various device applications. Here in this perspective, we evaluate the recent developments in the field of vdW ferroelectric devices, with discussions focusing on vdW heterostructure ferroelectric field-effect transistors and vdW ferroelectric memristor technologies. Additionally, we discuss some of the many open questions that persist in these technologies and possible pathways research can take to answer these questions and further advance the understanding of vdW ferroelectric materials.
Effects of solid–liquid interaction and mixture concentration on wettability of nano-droplets: Molecular dynamics simulations
Authors: Xu Jinzhu , Jia Li , Dang Chao , Liu Xinyuan , Ding Yi
Published: October 2022

The wetting of droplets plays a critical role in engineering applications. Intensive study on nano-droplets is of great significance in revealing the wetting characteristics of droplets. The wetting behavior of ethanol/water mixture nano-droplets on a smooth substrate was investigated through molecular dynamics simulation in this paper. Five nano-droplets of the ethanol/water mixture with different mass fractions placed on a copper surface with different surface energies were simulated to equilibrium at 298.15 K. The contract angle, wetting limit (the minimum and the maximum surface tension of droplets make the surface completely wetted or completely non-wetted by the droplet), and density distribution at the solid–liquid interface of the nano-droplet were analyzed. The effects of ethanol concentration and solid–liquid interaction (corresponding to the droplet’s surface tension and the substrate’s surface energy, respectively) on droplet wettability were intensely discussed. Results revealed that the contact angle of nano-droplets decreased with the increase in ethanol concentration and the interaction between droplets and the substrate. In addition, the critical and ultimate surface tension increased with the increase in the substrate surface energy. The peak density values of the droplets were proportional to the interaction between the droplets and substrate and not related to the droplet concentration. The research also indicated that solid substrates with different surface energies and droplets with various components affected the contact angle of droplets in different ways: the former not only increased the surface tension of droplets at the solid–liquid interface but also increased the separation energy of solids and droplets, while the latter only had a great influence on the surface tension of droplets at the solid–liquid interface.
Decoding the correlation between initial polarity and strain property of BNT-based ceramics
Authors: Lv Xiang , Liu Xinyu , Wu Jiagang
Published: October 2022

Although a large electric-induced strain has been obtained in sodium bismuth titanate (Bi0.5Na0.5TiO3, BNT)-based ceramics using chemical modifications, the effect of initial BNT-based ceramic's polarity on modulating strain properties was rarely reported. Herein, we comparatively studied the effect of tantalum (Ta) doping on two BNT-based ceramics with different ferroelectric polarities, namely, (Bi0.5Na0.5)0.935Ba0.065TiO3–0.7%Bi2FeCrO6 and (Bi0.98Gd0.02)0.5Na0.5TiO3. The former locates at the morphotropic phase boundary (MPB), whereas the latter is close to pristine BNT ceramics. An effective critical point, located at the crossover between ferroelectric and relaxor, is constructed in the former ceramic and significantly enhances strain properties, whereas a useless one is found in the latter ceramic due to the retention of a non-ergodic relaxor and has merely limited ability to promote strain properties. Our results demonstrate that the ferroelectric polarity of the initial BNT-based ceramic matrix also plays an important role in pursuing high strain properties.
Baboon perspectives on the ecology and behavior of early human ancestors
Authors: King Glenn E.
Published: October 2022

For more than 70 y researchers have looked to baboons (monkeys of the genus
Papio
) as a source of hypotheses about the ecology and behavior of early hominins (early human ancestors and their close relatives). This approach has undergone a resurgence in the last decade as a result of rapidly increasing knowledge from experimental and field studies of baboons and from archeological and paleontological studies of hominins. The result is a rich array of analogies, scenarios, and other stimuli to thought about the ecology and behavior of early hominins. The main intent here is to illustrate baboon perspectives on early hominins, with emphasis on recent developments. This begins with a discussion of baboons and hominins as we know them currently and explains the reasons for drawing comparisons between them. These include occupation of diverse environments, combination of arboreal and terrestrial capabilities, relatively large body size, and sexual dimorphism. The remainder of the paper illustrates the main points with a small number of examples drawn from diverse areas of interest: diet (grasses and fish), danger (leopards and crocodiles), social organization (troops and multilevel societies), social relationships (male–male, male–female, female–female), communication (possible foundations of language), cognition (use of social information, comparison of self to others), and bipedalism (a speculative developmental hypothesis about the neurological basis). The conclusion is optimistic about the future of baboon perspectives on early hominins.
How was the Earth–Moon system formed? New insights from the geodynamo
Authors: Cattaneo Fausto , Hughes David W.
Published: October 2022

The most widely accepted scenario for the formation of the Earth–Moon system involves a dramatic impact between the proto-Earth and some other cosmic body. Many features of the present-day Earth–Moon system provide constraints on the nature of this impact. Any model of the history of the Earth must account for the physical, geochemical, petrological, and dynamical evidence. These constraints notwithstanding, there are several radically different impact models that could in principle account for all the evidence. Thus, in the absence of further constraints, we may never know for sure how the Earth–Moon system was formed. Here, we put forward the idea that additional constraints are indeed provided by the fact that the Earth is strongly magnetized. It is universally accepted that the Earth’s magnetic field is maintained by a dynamo operating in the outer liquid core. However, because of the rapid rotation of the Earth, this dynamo has the peculiar property that it can maintain a strong field but cannot amplify a weak one. Therefore, the Earth must have been magnetized at a very early epoch, either preimpact or as a result of the impact itself. Either way, any realistic model of the formation of the Earth–Moon system must include magnetic field evolution. This requirement may ultimately constrain the models sufficiently to discriminate between the various candidates.
Human neutrophil development and functionality are enabled in a humanized mouse model
Authors: Zheng Yunjiang , Sefik Esen , Astle John , Karatepe Kutay , Öz Hasan H. , Solis Angel G. , Jackson Ruaidhrí , Luo Hongbo R. , Bruscia Emanuela M. , Halene Stephanie , Shan Liang , Flavell Richard A.
Published: October 2022

Mice with a functional human immune system serve as an invaluable tool to study the development and function of the human immune system in vivo. A major technological limitation of all current humanized mouse models is the lack of mature and functional human neutrophils in circulation and tissues. To overcome this, we generated a humanized mouse model named MISTRGGR, in which the mouse granulocyte colony-stimulating factor (G-CSF) was replaced with human G-CSF and the mouse G-CSF receptor gene was deleted in existing MISTRG mice. By targeting the G-CSF cytokine-receptor axis, we dramatically improved the reconstitution of mature circulating and tissue-infiltrating human neutrophils in MISTRGGR mice. Moreover, these functional human neutrophils in MISTRGGR are recruited upon inflammatory and infectious challenges and help reduce bacterial burden. MISTRGGR mice represent a unique mouse model that finally permits the study of human neutrophils in health and disease.
A model of autonomous interactions between hippocampus and neocortex driving sleep-dependent memory consolidation
Authors: Singh Dhairyya , Norman Kenneth A. , Schapiro Anna C.
Published: October 2022

How do we build up our knowledge of the world over time? Many theories of memory formation and consolidation have posited that the hippocampus stores new information, then “teaches” this information to the neocortex over time, especially during sleep. But it is unclear, mechanistically, how this actually works—How are these systems able to interact during periods with virtually no environmental input to accomplish useful learning and shifts in representation? We provide a framework for thinking about this question, with neural network model simulations serving as demonstrations. The model is composed of hippocampus and neocortical areas, which replay memories and interact with one another completely autonomously during simulated sleep. Oscillations are leveraged to support error-driven learning that leads to useful changes in memory representation and behavior. The model has a non–rapid eye movement (NREM) sleep stage, where dynamics between the hippocampus and neocortex are tightly coupled, with the hippocampus helping neocortex to reinstate high-fidelity versions of new attractors, and a REM sleep stage, where neocortex is able to more freely explore existing attractors. We find that alternating between NREM and REM sleep stages, which alternately focuses the model’s replay on recent and remote information, facilitates graceful continual learning. We thus provide an account of how the hippocampus and neocortex can interact without any external input during sleep to drive useful new cortical learning and to protect old knowledge as new information is integrated.
Sleep preferentially consolidates negative aspects of human memory: Well-powered evidence from two large online experiments
Authors: Denis Dan , Sanders Kristin E. G. , Kensinger Elizabeth A. , Payne Jessica D.
Published: October 2022

Research suggests that sleep benefits memory. Moreover, it is often claimed that sleep selectively benefits memory for emotionally salient information over neutral information. However, not all scientists are convinced by this relationship [e.g., J. M. Siegel.
Curr. Sleep Med. Rep.
, 7, 15–18 (2021)]. One criticism of the overall sleep and memory literature—like other literature—is that many studies are underpowered and lacking in generalizability [M. J. Cordi, B. Rasch.
Curr. Opin. Neurobiol.
, 67, 1–7 (2021)], thus leaving the evidence mixed and confusing to interpret. Because large replication studies are sorely needed, we recruited over 250 participants spanning various age ranges and backgrounds in an effort to confirm sleep’s preferential emotional memory consolidation benefit using a well-established task. We found that sleep selectively benefits memory for negative emotional objects at the expense of their paired neutral backgrounds, confirming our prior work and clearly demonstrating a role for sleep in emotional memory formation. In a second experiment also using a large sample, we examined whether this effect generalized to positive emotional memory. We found that while participants demonstrated better memory for positive objects compared to their neutral backgrounds, sleep did not modulate this effect. This research provides strong support for a sleep-specific benefit on memory consolidation for specifically negative information and more broadly affirms the benefit of sleep for cognition.
Sea ice fluctuations in the Baffin Bay and the Labrador Sea during glacial abrupt climate changes
Authors: Scoto Federico , Sadatzki Henrik , Maffezzoli Niccolò , Barbante Carlo , Gagliardi Alessandro , Varin Cristiano , Vallelonga Paul , Gkinis Vasileios , Dahl-Jensen Dorthe , Kjær Helle Astrid , Burgay François , Saiz-Lopez Alfonso , Stein Ruediger , Spolaor Andrea
Published: October 2022

Sea ice decline in the North Atlantic and Nordic Seas has been proposed to contribute to the repeated abrupt atmospheric warmings recorded in Greenland ice cores during the last glacial period, known as Dansgaard-Oeschger (D-O) events. However, the understanding of how sea ice changes were coupled with abrupt climate changes during D-O events has remained incomplete due to a lack of suitable high-resolution sea ice proxy records from northwestern North Atlantic regions. Here, we present a subdecadal-scale bromine enrichment (Br
enr
) record from the NEEM ice core (Northwest Greenland) and sediment core biomarker records to reconstruct the variability of seasonal sea ice in the Baffin Bay and Labrador Sea over a suite of D-O events between 34 and 42 ka. Our results reveal repeated shifts between stable, multiyear sea ice (MYSI) conditions during cold stadials and unstable, seasonal sea ice conditions during warmer interstadials. The shift from stadial to interstadial sea ice conditions occurred rapidly and synchronously with the atmospheric warming over Greenland, while the amplitude of high-frequency sea ice fluctuations increased through interstadials. Our findings suggest that the rapid replacement of widespread MYSI with seasonal sea ice amplified the abrupt climate warming over the course of D-O events and highlight the role of feedbacks associated with late-interstadial seasonal sea ice expansion in driving the North Atlantic ocean–climate system back to stadial conditions.
Mammalian octopus cells are direction selective to frequency sweeps by excitatory synaptic sequence detection
Authors: Lu Hsin-Wei , Smith Philip H. , Joris Philip X.
Published: October 2022

Octopus cells are remarkable projection neurons of the mammalian cochlear nucleus, with extremely fast membranes and wide-frequency tuning. They are considered prime examples of coincidence detectors but are poorly characterized in vivo. We discover that octopus cells are selective to frequency sweep direction, a feature that is absent in their auditory nerve inputs. In vivo intracellular recordings reveal that direction selectivity does not derive from across-frequency coincidence detection but hinges on the amplitudes and activation sequence of auditory nerve inputs tuned to clusters of hot spot frequencies. A simple biophysical octopus cell model excited with real nerve spike trains recreates direction selectivity through interaction of intrinsic membrane conductances with the activation sequence of clustered excitatory inputs. We conclude that octopus cells are sequence detectors, sensitive to temporal patterns across cochlear frequency channels. The detection of sequences rather than coincidences is a much simpler but powerful operation to extract temporal information.
Predicting network dynamics without requiring the knowledge of the interaction graph
Authors: Prasse Bastian , Van Mieghem Piet
Published: October 2022

A network consists of two interdependent parts: the network topology or graph, consisting of the links between nodes and the network dynamics, specified by some governing equations. A crucial challenge is the prediction of dynamics on networks, such as forecasting the spread of an infectious disease on a human contact network. Unfortunately, an accurate prediction of the dynamics seems hardly feasible, because the network is often complicated and unknown. In this work, given past observations of the dynamics on a fixed graph, we show the contrary: Even without knowing the network topology, we can predict the dynamics. Specifically, for a general class of deterministic governing equations, we propose a two-step prediction algorithm. First, we obtain a surrogate network by fitting past observations of every nodal state to the dynamical model. Second, we iterate the governing equations on the surrogate network to predict the dynamics. Surprisingly, even though there is no similarity between the surrogate topology and the true topology, the predictions are accurate, for a considerable prediction time horizon, for a broad range of observation times, and in the presence of a reasonable noise level. The true topology is not needed for predicting dynamics on networks, since the dynamics evolve in a subspace of astonishingly low dimension compared to the size and heterogeneity of the graph. Our results constitute a fresh perspective on the broad field of nonlinear dynamics on complex networks.
Location-specific strategies for eliminating US national racial-ethnic PM2.5 exposure inequality
Authors: Wang Yuzhou , Apte Joshua S. , Hill Jason D. , Ivey Cesunica E. , Patterson Regan F. , Robinson Allen L. , Tessum Christopher W. , Marshall Julian D.
Published: October 2022

Air pollution levels in the United States have decreased dramatically over the past decades, yet national racial-ethnic exposure disparities persist. For ambient fine particulate matter (

PM

2.5

), we investigate three emission-reduction approaches and compare their optimal ability to address two goals: 1) reduce the overall population average exposure (“overall average”) and 2) reduce the difference in the average exposure for the most exposed racial-ethnic group versus for the overall population (“national inequalities”). We show that national inequalities in exposure can be eliminated with minor emission reductions (optimal: ~1% of total emissions) if they target specific locations. In contrast, achieving that outcome using existing regulatory strategies would require eliminating essentially all emissions (if targeting specific economic sectors) or is not possible (if requiring urban regions to meet concentration standards). Lastly, we do not find a trade-off between the two goals (i.e., reducing overall average and reducing national inequalities); rather, the approach that does the best for reducing national inequalities (i.e., location-specific strategies) also does as well as or better than the other two approaches (i.e., sector-specific and meeting concentration standards) for reducing overall averages. Overall, our findings suggest that incorporating location-specific emissions reductions into the US air quality regulatory framework 1) is crucial for eliminating long-standing national average exposure disparities by race-ethnicity and 2) can benefit overall average exposures as much as or more than the sector-specific and concentration-standards approaches.
Metabolome-wide association study on
ABCA7
indicates a role of ceramide metabolism in Alzheimer’s disease
Authors: Dehghan Abbas , Pinto Rui Climaco , Karaman Ibrahim , Huang Jian , Durainayagam Brenan R. , Ghanbari Mohsen , Nazeer Areesha , Zhong Qi , Liggi Sonia , Whiley Luke , Mustafa Rima , Kivipelto Miia , Solomon Alina , Ngandu Tiia , Kanekiyo Takahisa , Aikawa Tomonori , Radulescu Carola I. , Barnes Samuel J. , Graça Gonçalo , Chekmeneva Elena , Camuzeaux Stephane , Lewis Matthew R. , Kaluarachchi Manuja R. , Ikram M. Arfan , Holmes Elaine , Tzoulaki Ioanna , Matthews Paul M. , Griffin Julian L. , Elliott Paul
Published: October 2022

Genome-wide association studies (GWASs) have identified genetic loci associated with the risk of Alzheimer’s disease (AD), but the molecular mechanisms by which they confer risk are largely unknown. We conducted a metabolome-wide association study (MWAS) of AD-associated loci from GWASs using untargeted metabolic profiling (metabolomics) by ultraperformance liquid chromatography–mass spectrometry (UPLC-MS). We identified an association of lactosylceramides (LacCer) with AD-related single-nucleotide polymorphisms (SNPs) in
ABCA7
(
P
= 5.0 × 10
−5
to 1.3 × 10
−44
). We showed that plasma LacCer concentrations are associated with cognitive performance and genetically modified levels of LacCer are associated with AD risk. We then showed that concentrations of sphingomyelins, ceramides, and hexosylceramides were altered in brain tissue from
Abca7
knockout mice, compared with wild type (WT) (
P
= 0.049–1.4 × 10
−5
), but not in a mouse model of amyloidosis. Furthermore, activation of microglia increases intracellular concentrations of hexosylceramides in part through induction in the expression of sphingosine kinase, an enzyme with a high control coefficient for sphingolipid and ceramide synthesis. Our work suggests that the risk for AD arising from functional variations in
ABCA7
is mediated at least in part through ceramides. Modulation of their metabolism or downstream signaling may offer new therapeutic opportunities for AD.
Large-effect loci mediate rapid adaptation of salmon body size after river regulation
Authors: Jensen Arne J. , Hagen Ingerid J. , Czorlich Yann , Bolstad Geir H. , Bremset Gunnbjørn , Finstad Bengt , Hindar Kjetil , Skaala Øystein , Karlsson Sten
Published: October 2022

Understanding the potential of natural populations to adapt to altered environments is becoming increasingly relevant in evolutionary research. Currently, our understanding of adaptation to human alteration of the environment is hampered by lack of knowledge on the genetic basis of traits, lack of time series, and little or no information on changes in optimal trait values. Here, we used time series data spanning nearly a century to investigate how the body mass of Atlantic salmon (Salmo salar) adapts to river regulation. We found that the change in body mass followed the change in waterflow, both decreasing to ∼1/3 of their original values. Allele frequency changes at two loci in the regions ofvgll3andsix6predicted more than 80% of the observed body mass reduction. Modeling the adaptive dynamics revealed that the population mean lagged behind its optimum before catching up approximately six salmon generations after the initial waterflow reduction. Our results demonstrate rapid adaptation mediated by large-effect loci and provide insight into the temporal dynamics of evolutionary rescue following human disturbance.
Reconstructing biblical military campaigns using geomagnetic field data
Authors: Vaknin Yoav , Shaar Ron , Lipschits Oded , Mazar Amihai , Maeir Aren M. , Garfinkel Yosef , Freud Liora , Faust Avraham , Tappy Ron E. , Kreimerman Igor , Ganor Saar , Covello-Paran Karen , Sergi Omer , Herzog Zeev , Arav Rami , Lederman Zvi , Münger Stefan , Fantalkin Alexander , Gitin Seymour , Ben-Yosef Erez
Published: October 2022

The Hebrew Bible and other ancient Near Eastern texts describe Egyptian, Aramean, Assyrian, and Babylonian military campaigns to the Southern Levant during the 10th to sixth centuries BCE. Indeed, many destruction layers dated to this period have been unearthed in archaeological excavations. Several of these layers are securely linked to specific campaigns and are widely accepted as chronological anchors. However, the dating of many other destruction layers is often debated, challenging the ability to accurately reconstruct the different military campaigns and raising questions regarding the historicity of the biblical narrative. Here, we present a synchronization of the historically dated chronological anchors and other destruction layers and artifacts using the direction and/or intensity of the ancient geomagnetic field recorded in mud bricks from 20 burnt destruction layers and in two ceramic assemblages. During the period in question, the geomagnetic field in this region was extremely anomalous with rapid changes and high-intensity values, including spikes of more than twice the intensity of today’s field. The data are useful in the effort to pinpoint these short-term variations on the timescale, and they resolve chronological debates regarding the campaigns against the kingdoms of Israel and Judah, the relationship between the two kingdoms, and their administrations.
Observation of high-order imaginary Poynting momentum optomechanics in structured light
Authors: Zhou Yuan , Xu Xiaohao , Zhang Yanan , Li Manman , Yan Shaohui , Nieto-Vesperinas Manuel , Li Baojun , Qiu Cheng-Wei , Yao Baoli
Published: October 2022

The imaginary Poynting momentum (IPM) of light has been captivated as an unusual origin of optical forces. However, the IPM force is predicted only for dipolar magnetoelectric particles that are hardly used in optical manipulation experiments. Here, we report a whole family of high-order IPM forces for not only magnetoelectric but also generic Mie particles, assisted with their excited higher multipoles within. Such optomechanical manifestations derive from a nonlocal contribution of the IPM to the optical force, which can be remarkable even when the incident IPM is small. We observe the high-order optomechanics in a structured light beam, which, despite carrying no angular momentum, is able to set normal microparticles into continuous rotation. Our results provide unambiguous evidence of the ponderomotive nature of the IPM, expand the classification of optical forces, and open new possibilities for levitated optomechanics and micromanipulations.