bluuebunny/crossref_metadata_2025 huggingface dataset:
Laboratory Evaluation of Antithrombin, Protein C, and Protein S
Authors: Marlar Richard A.
Published: March 2023

Thrombophilia is a complex disease process, clinically manifesting in various forms of venous thromboembolism. Although both genetic and acquired (or environmental) risks factors have been reported, the presence of a genetic defect (antithrombin [AT], protein C [PC], protein S [PS]) is considered three of the major contributing factors of thrombophilia. The presence of each of these risk factors can be established by clinical laboratory analysis; however, the clinical provider and laboratory personnel must understand the testing limitations and shortcomings associated with the assays for these factors to be able to ensure an accurate diagnosis. This article will describe the major pre-analytical, analytical, and post-analytical issues associated with the various types of assays and discuss evidence-based algorithms for analyzing AT, PC, and PS in plasma.
A Brief History of Hemostasis and Thrombosis at the Mayo Clinic
Authors: Chen Dong , Pruthi Rajiv
Published: March 2023

Coagulation is a crucial biological mechanism in human bodies to prevent blood loss. Abnormal coagulation can cause bleeding diathesis or thrombosis, common pathologic conditions in our clinical practice. Many individuals and organizations have dedicated their efforts in the past decades to understanding the biological and pathological mechanisms of coagulation and developing laboratory testing tools and treatment options to help patients with bleeding or thrombotic conditions. Since 1926, the Mayo Clinic coagulation group has made significant contributions to the clinical and laboratory practice, basic and translational research on various hemostatic and thrombotic disorders, and the education and collaboration to share and advance our knowledge in coagulation through a highly integrated team and practice model. We would like to use this review to share our history and inspire medical professionals and trainees to join the efforts to advance our understanding of coagulation pathophysiology and improve our care for patients with coagulation disorders.
When action is not least for systems with action-dependent Lagrangians
Authors: Ryan Joseph
Published: March 2023

The dynamics of some non-conservative and dissipative systems can be derived by calculating the first variation of an action-dependent action according to the variational principle of Herglotz. This is directly analogous to the variational principle of Hamilton commonly used to derive the dynamics of conservative systems. In a similar fashion, just as the second variation of a conservative system’s action can be used to infer whether that system’s possible trajectories are dynamically stable, so too can the second variation of the action-dependent action be used to infer whether the possible trajectories of non-conservative and dissipative systems are dynamically stable. In this paper, I show, generalizing earlier analyses of the second variation of the action for conservative systems, how to calculate the second variation of the action-dependent action and how to apply it to two physically important systems: a time-independent harmonic oscillator and a time-dependent harmonic oscillator.
A pre-time-zero spatiotemporal microscopy technique for the ultrasensitive determination of the thermal diffusivity of thin films
Authors: Varghese Sebin , Mehew Jake Dudley , Block Alexander , Reig David Saleta , Woźniak Paweł , Farris Roberta , Zanolli Zeila , Ordejón Pablo , Verstraete Matthieu J. , van Hulst Niek F. , Tielrooij Klaas-Jan
Published: March 2023

Diffusion is one of the most ubiquitous transport phenomena in nature. Experimentally, it can be tracked by following point spreading in space and time. Here, we introduce a spatiotemporal pump–probe microscopy technique that exploits the residual spatial temperature profile obtained through the transient reflectivity when probe pulses arrive before pump pulses. This corresponds to an effective pump–probe time delay of 13 ns, determined by the repetition rate of our laser system (76 MHz). This pre-time-zero technique enables probing the diffusion of long-lived excitations created by previous pump pulses with nanometer accuracy and is particularly powerful for following in-plane heat diffusion in thin films. The particular advantage of this technique is that it enables quantifying thermal transport without requiring any material input parameters or strong heating. We demonstrate the direct determination of the thermal diffusivities of films with a thickness of around 15 nm, consisting of the layered materials MoSe2 (0.18 cm2/s), WSe2 (0.20 cm2/s), MoS2 (0.35 cm2/s), and WS2 (0.59 cm2/s). This technique paves the way for observing nanoscale thermal transport phenomena and tracking diffusion of a broad range of species.
Simplified intensity- and phase-modulated transmitter for modulator-free decoy-state quantum key distribution
Authors: Lo Y. S. , Woodward R. I. , Walk N. , Lucamarini M. , De Marco I. , Paraïso T. K. , Pittaluga M. , Roger T. , Sanzaro M. , Yuan Z. L. , Shields A. J.
Published: March 2023

Quantum key distribution (QKD) allows secret key exchange between two users with unconditional security. For QKD to be widely deployed, low cost and compactness are crucial requirements alongside high performance. Currently, the majority of QKD systems demonstrated rely on bulk intensity and phase modulators to generate optical pulses with precisely defined amplitude and relative phase difference—i.e., to encode information as signal states and decoy states. However, these modulators are expensive and bulky, thereby limiting the compactness of QKD systems. Here, we present and experimentally demonstrate a novel optical transmitter design to overcome this disadvantage by generating intensity- and phase-tunable pulses at GHz clock speeds. Our design removes the need for bulk modulators by employing directly modulated lasers in combination with optical injection locking and coherent interference. This scheme is, therefore, well suited to miniaturization and photonic integration, and we implement a proof-of-principle QKD demonstration to highlight potential applications.
Hybrid stochastic synapses enabled by scaled ferroelectric field-effect transistors
Authors: Islam A. N. M. Nafiul , Saha Arnob , Jiang Zhouhang , Ni Kai , Sengupta Abhronil
Published: March 2023

Achieving brain-like density and performance in neuromorphic computers necessitates scaling down the size of nanodevices emulating neuro-synaptic functionalities. However, scaling nanodevices results in reduction of programming resolution and emergence of stochastic non-idealities. While prior work has mainly focused on binary transitions, in this work, we leverage the stochastic switching of a three-state ferroelectric field-effect transistor to implement a long-term and short-term two-tier stochastic synaptic memory with a single device. Experimental measurements are performed on a scaled 28 nm high-k metal gate technology-based device to develop a probabilistic model of the hybrid stochastic synapse. In addition to the advantage of ultra-low programming energies afforded by scaling, our hardware–algorithm co-design analysis reveals the efficacy of the two-tier memory in comparison to binary stochastic synapses in on-chip learning tasks—paving the way for algorithms exploiting multi-state devices with probabilistic transitions beyond deterministic ones.
Hard-breakable Ohmic contact in 2D CrSi2N4-metal heterostructures: A DFT study
Authors: Zhang Yukai , Chen Jiayou , Dou Chuanjun , Jiang Yumeng , Zhu Xiangjiu , Li Xinying , Han Donglai , Chen Enliang , Qu Xin , Yang Shuo
Published: March 2023

The interface barrier in van der Waals heterostructures (vdWHs) determines the charge-transfer efficiency and, thus, affects the performance of electronic devices. In this work, we propose two novel 2H–CrSi2N4 and 1T–CrSi2N4 monolayers that can form Ohmic contact heterostructures with other monolayers, including graphene, Ti2C, NbS2, and Ti3C2, based on first-principle calculations. First, we studied 2H–CrSi2N4 and 1T–CrSi2N4 contact with the widely used graphene, and the calculation results show that these heterostructures can form Ohmic contact with zero potential barriers, a desirable property to achieve high-performance electronic devices. Interestingly, this kind of Ohmic contact can be well maintained under electric fields, indicating a great potential for practical applications. On the other hand, 2H–CrSi2N4 and 1T–CrSi2N4 also form Ohmic-contact heterostructures with the Ti2C, NbS2, and Ti3C2 monolayers via vdW interaction. These interesting phenomena of vdWHs can provide enlightenment for designing high-efficiency electronic devices.
Geometric part error and material property profile separation technique of the additively manufactured and post-processed rods
Authors: Kim Jungsub , Chun Heebum , Nguyen Phuc , Li-Jung Tai Bruce , Lee Chabum
Published: March 2023

This paper presents novel surface profilometry for both geometric part error and metallurgical material property distribution measurements of the additively manufactured and post-processed rods. The measurement system, the so-called fiber optic-eddy current sensor, consists of a fiber optic displacement sensor and an eddy current sensor. The electromagnetic coil was wrapped around the probe of the fiber optic displacement sensor. The fiber optic displacement sensor was used to measure the surface profile, and the eddy current sensor was used to measure the change in permeability of the rod under varying electromagnetic excitation conditions. The permeability of the material changes upon exposure to mechanical forces, such as compression or extension and high temperatures. The geometric part error and material property profiles of the rods were successfully extracted by using a reversal method that is conventionally used for spindle error separation. The fiber optic displacement sensor and the eddy current sensor developed in this study have a resolution of 0.286 µm and 0.00359 μr, respectively. The proposed method was applied not only to characterize the rods but also to characterize composite rods.
Effects of the triangular hollow tubes structure and carbon coating on the lithium storage performances of Co3O4/NiO microspheres
Authors: Zhu Guozhen , Yang Qihao , Che Renchao
Published: March 2023

Co3O4/NiO@C (CNOT@C) microspheres were synthesized via a facile solvothermal method and annealing treatment under an argon atmosphere. A high initial reversible specific capacity of 1469.7 mA h g−1 of CNOT@C was attained due to its high specific surface area from its unique triangular hollow tube morphology. These triangular hollow tubes relieved volume expansion from repeated cycling processes, with CNOT@C attaining a high reversible specific capacity of 694.9 mA h g−1 after 1000 cycles at 6000 mA g−1. Furthermore, excellent rate performance of CNOT@C was achieved due to its carbon layer coating, exhibiting a reversible specific capacity of 429.8 mA h g−1 at 10 000 mA g−1.
Silicon photonic integrated circuit for high-resolution multimode fiber imaging system
Authors: Hu Gaolei , Zhong Keyi , Qin Yue , Tsang Hon Ki
Published: March 2023

We propose and demonstrate a silicon photonic integrated circuit (PIC) for exciting different spatial modes launched into a multimode-fiber (MMF) speckle imaging system. The PIC consists of a 45-channel optical phased array and an array of nanoantennas to bridge the PIC and MMF. The nanoantenna array can excite a wide range of spatial modes in the MMF with a mode-group dependent loss of less than 3 dB. A high spatial resolution, which approaches the theoretical limit determined by the number of modes in the MMF, is realized by using the proposed PIC. An equivalent resolution of 1.75 µm is experimentally attained across a field of view of 105 µm. Two different algorithms for image reconstruction are compared. The algorithm based on truncated singular value decomposition is computationally efficient and suitable for real-time image reconstruction, whereas the algorithm based on total-variation regularization produces higher imaging quality. The number of resolvable points is derived to be ∼3000, which is more than the square of the number of phase shifters. These results represent the highest spatial resolution yet demonstrated in a PIC-based MMF imaging system.
Automatic drift compensation for nanoscale imaging using feature point matching
Authors: Diao Zhuo , Ueda Keiichi , Hou Linfeng , Yamashita Hayato , Custance Oscar , Abe Masayuki
Published: March 2023

An implementation of drift compensation for imaging at the nanoscale is presented. The method is based on computer vision techniques and hence applicable to any microscope that generates images through a computer interface. The algorithm extracts and matches pairs of feature points from consecutive images to compute and compensate for probe–sample misalignments over time. The protocol also applies selection rules that enable it to withstand significant changes in image contrast. We demonstrate our fully automatic implementation by continuously imaging the same area of a Si(100) surface at the atomic scale with scanning probe microscopy over a period of 25 h at room temperature, showing that the method is robust even under the presence of non-linear drift or spontaneous changes of the probe apex. We apply our method to study the movement of pairs of tin atoms confined within a half-unit cell of the Si(111)-(7 × 7) surface and estimate the energy barrier for their diffusion at room temperature.
Temporally programmed switching of functional states in polyaniline film
Authors: Sonu K. P. , Dhiman Shikha , Garg Abhishek , Selvakumar D. , George Subi J. , Eswaramoorthy Muthusamy
Published: March 2023

Polyaniline films are under extensive consideration for applications in sensors, memory devices, displays, biomedicals, etc., owing to their unique optical and electronic functional states that are switchable in response to external stimuli. The application arena of these materials could be enhanced by creating active, adaptive, and autonomous systems with preprogramable spatiotemporal control over the functional states. Here, we present a simple approach to achieve autonomous temporal regulation of polyaniline films’ optical and electrical states by integrating enzyme-catalyzed biochemical reaction. The enzymatic reaction produces a feedback-induced transient pH profile, and correspondingly, the functional states of polyaniline films give rise to a similar switching profile, whose lifetime could be preprogrammed via enzyme concentration. This autonomous, temporally regulated polymer film system represents an advancement to the existing switchable materials that operate at equilibrium.
Physical mechanism of material flow and temperature distribution in keyhole plasma arc welding at initial unstable stage
Authors: Liu Jingbo , Jiang Fan , Xu Bin , Zhang Guokai , Chen Shujun
Published: March 2023

The initial unstable stage associated with keyhole plasma arc welding affects the stability and quality heavily, especially in the non-vertical welding position, which is difficult to control and restricts the process development and application. This work clarifies the temperature distribution and flow behavior of the process from the digging keyhole stage to the keyhole stable movement stage via an infrared thermography system and high-speed camera system. The experimental results showed that the molten metal on the rear side of the keyhole gradually accumulates and solidifies on the exit side and rear wall of the keyhole. When enough molten metal accumulates on the keyhole rear sidewall, it closes under the action of surface tension. The angle (86°–90°) of the keyhole rear sidewall formation can be used to determine whether the keyhole rear side is closed and reached the keyhole stable movement stage. Simultaneously, the influence of the shifting direction of gravity on the temperature distribution, flow behavior, and solidification morphology of the keyhole weld pool was investigated, which further revealed the initial unstable stage of the welding process. In the flat position, at this stage, the high-temperature area within the keyhole rear sidewall surface gradually accumulates close to the exit side of the weld pool. More molten metal flows to the keyhole exit side by gravity and shear forces, which causes a separation area on the keyhole rear side that is nearer to the exit side of the weld pool. This makes it harder to close the keyhole wall when it is in a flat position during the initial unstable stage. Furthermore, the temperature distribution and flow behavior of the keyhole rear side can be used as another factor to characterize the flow state of the weld pool in all positions and stages of welding.
Fast conformational clustering of extensive molecular dynamics simulation data
Authors: Hunkler Simon , Diederichs Kay , Kukharenko Oleksandra , Peter Christine
Published: March 2023

We present an unsupervised data processing workflow that is specifically designed to obtain a fast conformational clustering of long molecular dynamics simulation trajectories. In this approach, we combine two dimensionality reduction algorithms (cc_analysis and encodermap) with a density-based spatial clustering algorithm (hierarchical density-based spatial clustering of applications with noise). The proposed scheme benefits from the strengths of the three algorithms while avoiding most of the drawbacks of the individual methods. Here, the cc_analysis algorithm is applied for the first time to molecular simulation data. The encodermap algorithm complements cc_analysis by providing an efficient way to process and assign large amounts of data to clusters. The main goal of the procedure is to maximize the number of assigned frames of a given trajectory while keeping a clear conformational identity of the clusters that are found. In practice, we achieve this by using an iterative clustering approach and a tunable root-mean-square-deviation-based criterion in the final cluster assignment. This allows us to find clusters of different densities and different degrees of structural identity. With the help of four protein systems, we illustrate the capability and performance of this clustering workflow: wild-type and thermostable mutant of the Trp-cage protein (TC5b and TC10b), NTL9, and Protein B. Each of these test systems poses their individual challenges to the scheme, which, in total, give a nice overview of the advantages and potential difficulties that can arise when using the proposed method.
Enhancement of interfacial spin transparency in Py/NiO/Pt heterostructure
Authors: Dong Jing , Cheng Chen , Wei Jinwu , Xu Hongjun , Zhang Yu , Wang Yuqiang , Zhu Zengwei , Li Liang , Wu Hao , Yu Guoqiang , Han Xiufeng
Published: March 2023

This work reports the enhancement of damping-like and field-like spin–orbit torque (SOT) efficiencies and interfacial spin transparency (Tin) in the Py/NiO/Pt heterostructure. The SOT efficiencies and Tin are characterized by combining the spin–torque ferromagnetic resonance (ST-FMR) and the spin-pumping (SP) techniques. The inevitable inverse spin Hall voltage contamination induced by SP in the ST-FMR spectrum is extracted and subtracted by combining additional SP measurements, which allows obtaining accurate SOT efficiencies and Tin. The damping-like and field-like SOT efficiencies vary with the NiO insertion layer thickness, which is a result of the change of Tin. The maximum Tin reaches ∼0.82 for a 0.6 nm-thick NiO layer. This work shows that NiO insertion is an effective method for enhancing Tin and, hence, the SOT efficiency.
Improved tri-training method for identifying user abnormal behavior based on adaptive golden jackal algorithm
Authors: Wang Kun , Gao Jinggeng , Kang Xiaohua , Li Huan
Published: March 2023

Identification of abnormal user behavior helps reduce non-technical losses and regulatory operating costs for power marketing departments. Therefore, this paper proposes an adaptive golden jackal algorithm optimization improved tri-training method to identify user abnormal behavior. First, this paper constructs multiple weak learners based on the abnormal behavior data of users, combined with the method of sampling and putting back, and uses the filtering method to select the tri-training base model. Second, aiming at the problem that the traditional optimization algorithm has a slow convergence speed and is easy to fall into local optimization, the adaptive golden jackal algorithm is used to realize the parameter optimization of tri-training. Based on the electricity consumption data of a certain place in the past five years, it is found that the model can provide stable identification results: accuracy = 0.987, f1-score = 0.973.
Magnetic field detection using spin-torque nano-oscillator combined with magnetic flux concentrator
Authors: Tonini Denis , Wu Kai , Saha Renata , Wang Jian-Ping
Published: March 2023

Spin-torque nano-oscillators (STNO) are studied in terms of the Landau–Lifshitz–Gilbert (LLG) equation. The effect on the limit of detectivity of an STNO concerning externally applied magnetic fields is studied with micromagnetic models by placing adjacent magnetic flux concentrators (MFCs) at different distances from the nanopillar to analyze the effect on the induced auto-oscillations and magnetization dynamics. Perpendicular STNO structures allow for different detectivities with respect to externally applied magnetic fields depending on the distance from the MFCs to the nanopillar. The optimal design of an STNO combined with MFCs is proposed to improve the limit of detectivity, where the STNO consists of two out-of-plane (OP) ferromagnetic (FM) layers separated by a MgO insulating nonmagnetic (NM) thin film, and the MFCs positioned in the vicinity of the STNO are made of permalloy. The time evolution of the free-layer magnetization is governed by the Landau–Lifshitz–Gilbert (LLG) equation. The auto-oscillations induced within the free-layer averaged magnetization are provoked by externally applied magnetic fields. In addition, the DC current-driven auto-oscillations in the STNO structure are studied as a function of the externally applied magnetic field strength, with and without MFCs. The suppression of the DC current-driven auto-oscillations is observed due to the damping effect generated by the MFCs positioned at varying distances with respect to the STNO. By placing MFCs adjacent to the STNO, the lowest detectable magnetic field strength is enhanced from 10 (μT) to 10 (nT). Therefore, it is concluded that MFCs improve the sensitivity of STNO to externally applied magnetic fields thanks to the damped magnetization dynamics. The results presented in this work could inspire the optimal design of STNO and MFC-based ultra-low magnetic field sensors based on nanoscale oscillators and spintronic diodes.
The ecology of human-caused mortality for a protected large carnivore
Authors: Benson John F. , Dougherty Kyle D. , Beier Paul , Boyce Walter M. , Cristescu Bogdan , Gammons Daniel J. , Garcelon David K. , Higley J. Mark , Martins Quinton E. , Nisi Anna C. , Riley Seth P. D. , Sikich Jeff A. , Stephenson Thomas R. , Vickers T. Winston , Wengert Greta M. , Wilmers Christopher C. , Wittmer Heiko U. , Dellinger Justin A.
Published: March 2023

Mitigating human-caused mortality for large carnivores is a pressing global challenge for wildlife conservation. However, mortality is almost exclusively studied at local (within-population) scales creating a mismatch between our understanding of risk and the spatial extent most relevant to conservation and management of wide-ranging species. Here, we quantified mortality for 590 radio-collared mountain lions statewide across their distribution in California to identify drivers of human-caused mortality and investigate whether human-caused mortality is additive or compensatory. Human-caused mortality, primarily from conflict management and vehicles, exceeded natural mortality despite mountain lions being protected from hunting. Our data indicate that human-caused mortality is additive to natural mortality as population-level survival decreased as a function of increasing human-caused mortality and natural mortality did not decrease with increased human-caused mortality. Mortality risk increased for mountain lions closer to rural development and decreased in areas with higher proportions of citizens voting to support environmental initiatives. Thus, the presence of human infrastructure and variation in the mindset of humans sharing landscapes with mountain lions appear to be primary drivers of risk. We show that human-caused mortality can reduce population-level survival of large carnivores across large spatial scales, even when they are protected from hunting.
Empirical Determination of the Pion Mass Distribution
Authors: Xu Y.-Z. , Raya K. , Cui Z.-F. , Roberts C. D. , Rodríguez-Quintero J.
Published: March 2023

Existing pion+nucleus Drell-Yan and electron+pion scattering data are used to develop ensembles of model-independent representations of the pion generalized parton distribution (GPD). Therewith, one arrives at a data-driven prediction for the pion mass distribution form factor,

θ
2
π

. Compared with the pion elastic electromagnetic form factor,

θ
2
π

is harder: the ratio of the radii derived from these two form factors is

r
π

θ
2

/

r
π

=
0.79
(
3
)

. Our data-driven predictions for the pion GPD, related form factors and distributions should serve as valuable constraints on theories of pion structure.
A gravitationally induced decoherence model using Ashtekar variables
Authors: Fahn Max Joseph , Giesel Kristina , Kobler Michael
Published: March 2023

We consider the coupling of a scalar field to linearised gravity and derive a relativistic gravitationally induced decoherence model using Ashtekar variables. The model is formulated at the gauge invariant level using suitable geometrical clocks in the relational formalism, broadening existing gauge invariant formulations of decoherence models. For the construction of the Dirac observables we extend the known observable map by a kind of dual map where the role of clocks and constraints is interchanged. We also discuss a second choice of geometrical clocks existing in the ADM literature. Then we apply a reduced phase space quantisation on Fock space and derive the final master equation choosing a Gibbs state for the gravitational environment and using the projection operator technique. The resulting master equation is not automatically of Lindblad type, a starting point sometimes assumed for phenomenological models, but still involves a residual time dependence at the level of the effective operators in the master equation due to the form of the correlation functions that we express in terms of thermal Wightman functions. Furthermore, we discuss why in the model analysed here the application of a second Markov approximation in order to obtain a set of time independent effective system operators is less straightforward than in some of the quantum mechanical models.
Lorentzian wormholes in an emergent universe
Authors: Sengupta Rikpratik , Ghosh Shounak , Paul B C , Kalam M
Published: March 2023

A non-singular emergent universe (EU) scenario within the realm of standard Relativistic physics requires a generalization of the equation of state (EoS) connecting the pressure and energy density. This generalized EoS is capable of describing a composition of exotic matter, dark energy and cosmological dust matter. Since the EU scenario is known to violate the null energy condition (NEC), we investigate the possibility of presence of static, spherically symmetric and traversable Lorentzian wormholes in an EU. The obtained shape function is found to satisfy the criteria for wormhole formation, besides the violation of the NEC at the wormhole throat and ensuring traversability such that tidal forces are within desirable limits. Also, the wormhole is found to be stable through linear stability analysis. Most importantly, the numerical value of the EU parameter B as estimated by our wormhole model is in agreement with and lies within the range of values as constrained by observational data in a cosmological context. Also, the negative sign of the second EU parameter A as obtained from our wormhole model is in agreement with the one required for describing an EU, which further indicates on the existence of such wormholes in an EU without accounting for any additional exotic matter field or any modification to the gravitational sector.
The Rüchardt experiment revisited: using simple theory, accurate measurement and python based data analysis
Authors: Shearwood Chris , Sloan Peter A
Published: March 2023

This project uses the Rüchardt experiment to determine the ratio of specific heats and hence the number of degrees of freedom f of different gases by measuring the frequency of damped simple harmonic motion where the gas provides the Hooke's law like spring of a cylinder–piston system. This project links mechanics, electromagnetism, thermodynamics, statistical mechanics and quantum mechanics making it an excellent synoptic experiment for a year 2 undergraduate student and we detail our implementation of this team-based learning project. We present, for the Rüchardt experiment, simple derivations of the main relationships that govern the experiment, a detailed data analysis of the physics of the apparatus and the experimental data. We find f(He) = 3.48 ± 0.14, f(N2) = 4.92 ± 0.24, f(Air) = 4.96 ± 0.25, f(CO2) = 6.46 ± 0.39 at room temperature and atmospheric pressure. The results for CO2 requires a statistical analysis of its vibrational modes. These results show that the expected results can be measured using fairly simple apparatus, coupled with careful analysis of large data sets.
Coexistence of logarithmic and SdH quantum oscillations in ferromagnetic Cr-doped tellurium single crystals
Authors: Zhang Shu-Juan , Chen Lei , Li Shuang-Shuang , Zhang Ying , Yan Jian-Min , Tang Fang , Fang Yong , Fei Lin-Feng , Zhao Weiyao , Karel Julie , Chai Yang , Zheng Ren-Kui
Published: March 2023

We report the synthesis of transition-metal-doped ferromagnetic elemental single-crystal semiconductors with quantum oscillations using the physical vapor transport method. The 7.7 atom% Cr-doped Te crystals (Cr:Te) show ferromagnetism, butterfly-like negative magnetoresistance in the low temperature (<3.8 K) and low field (<0.15 T) region, and high Hall mobility, e.g. 1320 cm2 V−1 s−1 at 30 K and 350 cm2 V−1 s−1 at 300 K, implying that Cr:Te crystals are ferromagnetic elemental semiconductors. When B // [001] // I, the maximum negative MR is ∼−27% at T = 20 K and B = 8 T. In the low temperature semiconducting region, Cr:Te crystals show strong discrete scale invariance dominated logarithmic quantum oscillations when the direction of the magnetic field B is parallel to the [100] crystallographic direction (B // [100]) and show Landau quantization dominated Shubnikov-de Haas oscillations for B // [210] direction, which suggests the broken rotation symmetry of the Fermi pockets in the Cr:Te crystals. The findings of coexistence of multiple quantum oscillations and ferromagnetism in such an elemental quantum material may inspire more study of narrow bandgap semiconductors with ferromagnetism and quantum phenomena.
Fused solar-blind UV/VIS Bi-spectral sensing and imaging with vertically stacking ZnGa2O4/MAPbI3 structure
Authors: Liu Jiaxin , Ni Mingzhu , Zou Jikuang , Gu Wanzhong , Xu Xiaobao , Zou Yousheng
Published: March 2023

Various spectral bands provide different types of information, and information enhancement could be achieved by selective fusion of different spectral bands. The fused solar-blind Ultraviolet (UV)/Visible (VIS) bi-spectral sensing and imaging can provide the precise location of UV targets in virtue of VIS background, which has been increasingly promoted. However, most reported UV/VIS bi-spectral photodetectors (PDs) only have one single channel towards a broadband spectrum of both UV and VIS light, which cannot distinguish two kinds of signals, hindering the image fusion of bi-spectral signals. This work demonstrates the solar-blind UV/VIS bi-spectral PD based on vertically stacking perovskite of MAPbI3 and ternary oxide of ZnGa2O4 with independent and distinct response toward solar-blind UV and VIS light in a single pixel. The PD exhibits excellent sensing properties with an I
on/I
off ratio of >107 and 102, detectivity of >1010 and 108 Jones, and response decay time of 90 μs and 16 ms for VIS and UV channels, respectively. The successful fusion of VIS and UV images suggests that our bi-spectral PD can be applied in the accurate identification of corona discharge and fire detection.
LCR transients in theory and practice
Authors: Atkin Keith
Published: March 2023

In this paper I shall demonstrate how the transient behaviour of an LCR series circuit may be taught from both mathematical and laboratory perspectives. The mathematical analysis uses a straightforward step-wise approach without recourse to advanced calculus. Experimentally, the practical problem of electrical noise which arises during switching is solved by very simple means.
Riemann–Hilbert problems and N-soliton solutions of the nonlocal reverse space-time Chen–Lee–Liu equation
Authors: Liu Tongshuai , Xia Tiecheng
Published: March 2023

In this paper, the N-soliton solutions to the nonlocal reverse space-time Chen–Lee–Liu equation have been derived. Under the nonlocal symmetry reduction to the matrix spectral problem, the nonlocal reverse space-time Chen–Lee–Liu equation can be obtained. Based on the spectral problem, the specific matrix Riemann–Hilbert problem is constructed for this nonlocal equation. Through solving this associated Riemann–Hilbert problem, the N-soliton solutions to this nonlocal equation can be obtained in the case of the jump matrix as an identity matrix.
Low carrier recombination in polysiloxane gel electrolyte for high-performance DSSC
Authors: Usman Ida , Arsyad Waode Sukmawati , Herman Herman , Hidayat Rahmat
Published: March 2023

Previous research on quasi-solid-state DSSC (QSS-DSSC) that utilized polysiloxane-based polymer gel electrolytes (PGE) showed that the functional performance of the cells was highly affected by electrolyte infiltration into the TiO2 nano-porous layers. This study evaluated the efficiency enhancement in siloxane-based cells by introducing a TiCl4 pre-treatment process twice. We compared the impedance spectrum of PGE-based DSSC without (type-1 PGE) and with (type-2 PGE) with the addition of propylene carbonate, measured under dark and light illumination. The impedance spectra of both cells showed different characteristics at different condition measurements, especially in the high-frequency region. Unlike the type-2 PGE-based DSSC, the type-1 PGE-based DSSC did not show the transmission line characteristic, which indicated less charge carrier diffusion inside the TiO2 nano-porous layer. Under light illumination, the interfacial charge transfer between electrons inside TiO2 layers with the electrolyte (Rct), and the electron lifetime inside TiO2 layers before it is recombined (τ
r), became smaller for type-2 PGE-based DSSC and larger for type-1 PGE-based DSSC. This indicated that the recombination rate increased as the PGE became more vicious. This result supports the photovoltaic characteristics that yield current density and efficiency values of 16 mA cm−2 and 5.37% for type-2 PGE-based DSSC, 13.4 mA cm−2, and 4.72% for type-1 PGE-based DSSC. The challenge for further improvement in DSSC that employs PGE is to elevate the wetting capability of the gel inside the TiO2 layer without additional solvent since additional solvent eventually can reduce ionic concentration and consequently increase the Rct value as shown in the analysis of the impedance spectrum of TiO2 layer without dye.
Chronic basal forebrain activation improves spatial memory, boosts neurotrophin receptor expression, and lowers BACE1 and Aβ42 levels in the cerebral cortex in mice
Authors: Kumro Jacob , Tripathi Ashutosh , Lei Yun , Sword Jeremy , Callahan Patrick , Terry Alvin , Lu Xin-yun , Kirov Sergei A , Pillai Anilkumar , Blake David T
Published: March 2023

The etiology of Alzheimer’s dementia has been hypothesized in terms of basal forebrain cholinergic decline, and in terms of reflecting beta-amyloid neuropathology. To study these different biological elements, we activated the basal forebrain in 5xFAD Alzheimer’s model mice and littermates. Mice received 5 months of 1 h per day intermittent stimulation of the basal forebrain, which includes cholinergic projections to the cortical mantle. Then, mice were behaviorally tested followed by tissue analysis. The 5xFAD mice performed worse in water-maze testing than littermates. Stimulated groups learned the water maze better than unstimulated groups. Stimulated groups had 2–3-fold increases in frontal cortex immunoblot measures of the neurotrophin receptors for nerve growth factor and brain-derived neurotrophic factor, and a more than 50% decrease in the expression of amyloid cleavage enzyme BACE1. Stimulation also led to lower Aβ42 in 5xFAD mice. These data support a causal relationship between basal forebrain activation and both neurotrophin activation and reduced Aβ42 generation and accumulation. The observation that basal forebrain activation suppresses Aβ42 accumulation, combined with the known high-affinity antagonism of nicotinic receptors by Aβ42, documents bidirectional antagonism between acetylcholine and Aβ42.
Perspective changes in human listeners are aligned with the contextual transformation of the word embedding space
Authors: Tikochinski Refael , Goldstein Ariel , Yeshurun Yaara , Hasson Uri , Reichart Roi
Published: March 2023

Word embedding representations have been shown to be effective in predicting human neural responses to lingual stimuli. While these representations are sensitive to the textual context, they lack the extratextual sources of context such as prior knowledge, thoughts, and beliefs, all of which constitute the listener’s perspective. In this study, we propose conceptualizing the listeners’ perspective as a source that induces changes in the embedding space. We relied on functional magnetic resonance imaging data collected by Yeshurun Y, Swanson S, Simony E, Chen J, Lazaridi C, Honey CJ, Hasson U. Same story, different story: the neural representation of interpretive frameworks. Psychol Sci. 2017:28(3):307–319, in which two groups of human listeners (n = 40) were listening to the same story but with different perspectives. Using a dedicated fine-tuning process, we created two modified versions of a word embedding space, corresponding to the two groups of listeners. We found that each transformed space was better fitted with neural responses of the corresponding group, and that the spatial distances between these spaces reflect both interpretational differences between the perspectives and the group-level neural differences. Together, our results demonstrate how aligning a continuous embedding space to a specific context can provide a novel way of modeling listeners’ intrinsic perspectives.
The Money War: democracy, taxes and inflation in the U.S. Civil War
Authors: Ron Ariel , Valeonti Sofia
Published: March 2023

Both sides in the U.S. Civil War financed military spending by issuing new fiat currencies. The Union ‘greenback’ underwent moderate inflation (by wartime standards), but the Confederate ‘greyback’ suffered hyperinflation. Existing explanations for these price movements typically treat only one of the two cases and adopt either a quantity theory or rational expectations approach. We compare Union and Confederate policies directly and highlight the importance of taxation for assuring the value of inconvertible money. Combining monetary and fiscal history literatures, we find that tax policies were determined by long-term development of democratic governing institutions. Higher levels of democracy in the North, as compared to the slaveholding South, meant greater tax policy legitimacy and administrative competence. The Union drew on this legacy to back its money effectively, while the Confederacy failed to do so. We contribute to credit theories of money by drawing attention to the political determinants of effective fiscal policy.
Henrik Ibsen, Emperor Julian, and the crisis of faith in modernity
Authors: Boswell Brad , Crawford Matthew R , Stavrakopoulou Anna
Published: March 2023

Although it is one of his lesser known and performed plays, Henrik Ibsen considered Emperor and Galilean to be his Hovedverk—his ‘main’ or ‘pivotal’ work—in which he finally presented his positive worldview. It remains comparatively little studied in scholarship, though one scholar has recently argued that it is the key to unlocking his entire corpus. The present study builds upon past scholarship uncovering the works Ibsen drew upon in writing the play but goes beyond the mere question of its historical sources and accuracy to consider Ibsen’s purpose for including the specific and precise pieces of historical texture he chose in the particular order and configuration he devised. In short, we aim to identify the creative purposes for his curating of the historical details he took from his sources. What emerges from our analysis is that, even when Ibsen is following the sources, his protagonist stands out as a strikingly modern figure, more at home in the nineteenth century than the fourth. Ibsen portrays his Julian struggling with doubt and uncertainty of a distinctly modern caste; he puts in his mouth criticisms of Christianity that stem from modernity rather than the historical figure; and he suggests that, just as Christianity had to prove victorious over paganism in late antiquity, so Christianity itself must be superseded in the modern era, though perhaps some aspects of it are worth preserving in the yet-to-arrive third empire.
FAIR Island: real-world examples of place-based open science
Authors: Robinson Erin , Buys Matthew , Chodacki John , Garzas Kristian , Monfort Steven , Nancarrow Catherine , Praetzellis Maria , Riley Brian , Wimalaratne Sarala , Davies Neil
Published: March 2023

The relationship between people, place, and data presents challenges and opportunities for science and society. While there has been general enthusiasm for and work toward Findable, Accessible, Interoperable, and Reusable (FAIR) data for open science, only more recently have these data-centric principles been extended into dimensions important to people and place—notably, the CARE Principles for Indigenous Data Governance, which affect collective benefit, authority to control, responsibility, and ethics. The FAIR Island project seeks to translate these ideals into practice, leveraging the institutional infrastructure provided by scientific field stations. Starting with field stations in French Polynesia as key use cases that are exceptionally well connected to international research networks, FAIR Island builds interoperability between different components of critical research infrastructure, helping connect these to societal benefit areas. The goal is not only to increase reuse of scientific data and the awareness of work happening at the field stations but more generally to accelerate place-based research for sustainable development. FAIR Island works reflexively, aiming to scale horizontally through networks of field stations and to serve as a model for other sites of intensive long-term scientific study.
Characterization and simulation of metagenomic nanopore sequencing data with Meta-NanoSim
Authors: Yang Chen , Lo Theodora , Nip Ka Ming , Hafezqorani Saber , Warren René L , Birol Inanc
Published: March 2023

Background

Nanopore sequencing is crucial to metagenomic studies as its kilobase-long reads can contribute to resolving genomic structural differences among microbes. However, sequencing platform-specific challenges, including high base-call error rate, nonuniform read lengths, and the presence of chimeric artifacts, necessitate specifically designed analytical algorithms. The use of simulated datasets with characteristics that are true to the sequencing platform under evaluation is a cost-effective way to assess the performance of bioinformatics tools with the ground truth in a controlled environment.

Results

Here, we present Meta-NanoSim, a fast and versatile utility that characterizes and simulates the unique properties of nanopore metagenomic reads. It improves upon state-of-the-art methods on microbial abundance estimation through a base-level quantification algorithm. Meta-NanoSim can simulate complex microbial communities composed of both linear and circular genomes and can stream reference genomes from online servers directly. Simulated datasets showed high congruence with experimental data in terms of read length, error profiles, and abundance levels. We demonstrate that Meta-NanoSim simulated data can facilitate the development of metagenomic algorithms and guide experimental design through a metagenome assembly benchmarking task.

Conclusions

The Meta-NanoSim characterization module investigates read features, including chimeric information and abundance levels, while the simulation module simulates large and complex multisample microbial communities with different abundance profiles. All trained models and the software are freely accessible at GitHub: https://github.com/bcgsc/NanoSim.
A hierarchical model of the relative efficiency of two trawl survey protocols, with application to flatfish off the coast of Newfoundland
Authors: Cadigan N G , Walsh S J , Benoît H P , Regular P M , Wheeland L J
Published: March 2023

We present a hierarchical model for survey comparative fishing (CF) experiments (x) to utilize data from several species (s) and x to provide improved estimates of the relative efficiency of one survey protocol compared to another. This model is applied to four flatfish s and two x conducted by Fisheries and Oceans Canada (DFO) in 1995 and 1996. We used a monotone increasing function for relative efficiency, and included spatial effects to account for this important source of variation that was not considered in previous analyses of these data. We provide detailed analyses of the anticipated impacts of the various changes in the DFO survey protocols to better understand the reliability of the results. We show that there were important differences in relative efficiency among s, x, and spatial regions, which, combined with low sample sizes and low catch rates, contributed to poor precision in the estimates of relative efficiency. We conclude that stock assessment models in the future should have a goal of using unconverted survey indices, but also include information on the relative efficiency of trawl survey protocols as prior distributions. This will more adequately account for this important source of uncertainty.