bluuebunny/crossref_metadata_2025 huggingface dataset:
Breakup dynamics of a neutron-halo projectile on heavy target at deep sub-barrier energies
Authors: Mukeru B , Sithole T , Tomio Lauro
Published: July 2024

By studying the total fusion and breakup cross-sections in the interaction of the neutron-halo 11Be projectile on the lead target 208Pb, it is shown that, even for the neutron-halo projectile, the breakup channel remains the most dominant reaction channel at sub-barrier energies, following a characteristic behavior that was also previously verified for the case of the proton-halo projectile 8B. This feature is found to emanate from the enhancement of the breakup cross-section, due to the continuum–continuum couplings (CCC) coming exclusively from its Coulomb component. We further speculate that the enhancement of the Coulomb breakup cross-section at sub-barrier incident energies by the CCC could be associated with the projectile breaking up on the outgoing trajectory, provided these couplings can be proven to delay the breakup process.
Threshold temperature of superfluorescence generation in CuCl quantum dots under resonant excitation of excitons and resonant two-photon excitation of biexcitons
Authors: Kawamura Kohei , Yoshida Tomoharu , Ishihara Jun , Ishikawa Akira , Miyajima Kensuke
Published: July 2024

We studied the threshold temperature of superfluorescence (SF) generation with regard to biexcitons in CuCl quantum dots (QDs) under resonant two-photon excitation of biexcitons and resonant excitation of excitons to demonstrate the influence of initial population densities in the QDs on SF generation. As a result, the threshold temperature under the resonant excitation of excitons was higher than that under the two-photon excitation of biexcitons. This indicates that the high density of excited dots facilitates the rapid establishment of coherence among the dots, overcoming disadvantages of incomplete population inversion and formation process of biexcitons. We performed a theoretical calculation of the time profiles of the biexcitonic emission based on semiconductor luminescence equations. The experimentally obtained temperature dependence of the time profiles was qualitatively reproduced by calculating their dependence on the dephasing rate. In addition, we estimated the temperature dependence of the phase relaxation time of the biexcitons in the CuCl QDs by analyzing the temperature dependence of SF.
An investigation of shaft voltage in synchronous generators under SAGE and variable load condition
Authors: Sun Kai , He Yu-Ling , Wu Xue-wei , Luo Hao-ran , Jiao Ling-yu , Gerada David
Published: July 2024

Synchronous generators are widely used in power generation systems. Static air-gap eccentricity (SAGE) often occurs in synchronous generators due to the component wear over prolonged operation. This paper presents a comprehensive mathematical model specifically tailored for SAGE fault, incorporating for the influence of stator slotting. The study thoroughly examines the impacts of both eccentricity and varying loads on the shaft voltage using the developed model. Furthermore, a novel method for detecting SAGE is introduced, leveraging the mathematical model of shaft voltage. This detection method proves effective for identifying eccentricity in synchronous generators across different load conditions by reasonably combining shaft voltage and phase current. The mathematical model of shaft voltage and the proposed detection method are validated through three-dimensional finite-element calculations and experimental studies. The work is helpful to manage and predict the shaft voltage. This paper contributes to the prevention of shaft voltage damage and real-time monitoring of the SAGE fault in synchronous generators.
Sparse reservoir computing with vertically coupled vortex spin-torque oscillators for time series prediction
Authors: Shen Haobo , Xu Lie , Jin Menghao , Li Hai , Yu Changqiu , Liu Bo , Zhou Tiejun
Published: July 2024

Spin torque nano-oscillators possessing fast nonlinear dynamics and short-term memory functions are potentially able to achieve energy-efficient neuromorphic computing. In this study, we introduce an activation-state controllable spin neuron unit composed of vertically coupled vortex spin torque oscillators and a V–I source circuit is proposed and used to build an energy-efficient sparse reservoir computing (RC) system to solve nonlinear dynamic system prediction task. Based on micromagnetic and electronic circuit simulation, the Mackey–Glass chaotic time series and the real motor vibration signal series can be predicted by the RC system with merely 20 and 100 spin neuron units, respectively. Further study shows that the proposed sparse reservoir system could reduce energy consumption without significantly compromising performance, and a minimal response from inactivated neurons is crucial for maintaining the system’s performance. The accuracy and signal processing speed show the potential of the proposed sparse RC system for high-performance and low-energy neuromorphic computing.
Atmospheric neutron-induced single event burnout characterization of 4.5 kV Si IGBTs with spallation neutron irradiation
Authors: Peng Chao , Yang Liu , Lei Zhifeng , Zhou Yuebin , Ma Teng , Yuan Zhiyong , Zhang Zhangang , He Yujuan , Huang Yun
Published: July 2024

The atmospheric neutron-induced single event burnout (SEB) is observed for 4.5 kV Si IGBTs with trench gate structure by conducting spallation neutron source irradiation. The SEB is manifested as a random failure and is strongly related to the bias voltage. The SEB failure rates of two different Si IGBTs at different bias voltages are calculated based on the experimental results. It shows that the failure rates increase exponentially with bias voltages. For two different kinds of IGBTs, the atmospheric neutron-induced failure rate at an altitude of 4000 m is 0.855 FIT and 4.39 FIT, respectively, when biased at 60% of the rated voltage. When the bias voltage is increased to 64% of the rated voltage, the corresponding failure rates are increased to 24.7 FIT and 47.6 FIT. Furthermore, the SEB mechanisms for Si IGBTs are investigated by TCAD simulations.
Performance of surge-induced synchronized switch harvesting on inductor as an efficient technique under strong electromechanical coupling and low amplitudes of vibration
Authors: Onoda Junjiro , Minesugi Kenji
Published: July 2024

The process of harvesting energy from ambient sources is key for various applications. This study examined the performance of two representative techniques from the surge-induced synchronized switch harvesting on inductor (S3HI) family under strong electromechanical coupling and compared this performance with that of some established techniques. S3HI techniques exploit the surge voltage to overcome the voltage barrier of diodes for rectifiers and storage capacitor voltages. One of their features, revealed in a previous study on weakly coupled systems, is that they can harvest substantial energy from low-level vibrations. This feature is desirable for certain use cases. This study aimed to clarify whether this feature is applicable even when the coupling is strong. The performance of various established techniques and two representatives from the S3HI group was studied by formulating an approximate analytical solution and performing numerical simulations and experiments. The theoretical results were confirmed to be consistent, and the discrepancy between experimental and theoretical results was minor. These results clearly demonstrate that the techniques from the S3HI family can effectively harvest substantial energy from small-amplitude vibrations, even when the coupling is strong. Moreover, the performance advantage of S3HI methods is even greater when the coupling is strong.
A nonlinear piezoelectric shunt absorber with tunable piecewise linear negative capacitance
Authors: Zhang Lin , Li Ming , Sun Xiaoming , Cheng Wei
Published: July 2024

In recent years, extensive research has been devoted to nonlinear piezoelectric shunt circuits for mitigating structural vibrations. However, existing studies have primarily concentrated on polynomial nonlinearity, particularly cubic nonlinearity. This paper develops a tunable non-smooth piezoelectric shunt absorber to suppress structural vibrations under harmonic excitation. We enhance the conventional resonant circuit by introducing a piecewise linear negative capacitor, which is implemented using a pair of diodes and voltage sources. The stationary response of the non-smooth system is derived using the complexification–averaging method. The effects of critical voltage and excitation intensity on the damping performance are investigated subsequently. Furthermore, we apply an adaptive control method based on the gradient descent algorithm with adaptive moment estimation (Adam) to the nonlinear circuit, improving its damping performance and enabling adaptation to changes in excitation intensity. Experimental results validate the effectiveness of the proposed adaptive nonlinear circuit, demonstrating superior stationary performance compared to linear resonant shunt circuits across a broad bandwidth of frequencies, especially at off-resonant frequencies.
Development and testing of a discrete coil magnetostrictive actuator
Authors: Wang Yanwen , Zhu Yuchuan , Chen Long , Ling Jie , Zhang Mingming
Published: July 2024

Active combustion control (ACC) technology is an effective measure for suppressing the combustion oscillation of aero-engines. The magnetostrictive actuator is the most suitable choice for the ACC actuator due to its excellent high-frequency characteristics and high-temperature resistance. In order for the magnetostrictive actuator to produce high-frequency displacement, the constant current driver must have sufficient power, which results in a larger mass of the driver. A solution is to use multi-channel and low-power constant current driver. Therefore, the coil of the magnetostrictive actuator is axially dispersed and driven by two four-channel servo amplifiers. The driver’s mass is significantly reduced while maintaining the same electromagnetic conversion effect. In addition, an analytical model of a discrete coil magnetostrictive actuator is established, and a series of experiments are conducted. The maximum hysteresis error of output displacement at 200 Hz is reduced by 15.2%. Furthermore, under PID closed-loop control, the root mean square (RMS) error is less than 2% when tracking a 10 Hz sinusoidal displacement with coil switching drive.
Applicability of measurement-based quantum computation towards physically-driven variational quantum eigensolver
Authors: Qin Zheng , Li Xiufan , Zhou Yang , Zhang Shikun , Li Rui , Du Chunxiao , Xiao Zhisong
Published: July 2024

Variational quantum algorithms are considered one of the most promising methods for obtaining near-term quantum advantages; however, most of these algorithms are only expressed in the conventional quantum circuit scheme. The roadblock to developing quantum algorithms with the measurement-based quantum computation (MBQC) scheme is resource cost. Recently, we discovered that the realization of multi-qubit rotation operations only requires a constant number of single-qubit measurements with the MBQC scheme, providing a potential advantage in terms of resource cost. The structure of the Hamiltonian variational ansatz aligns well with this characteristic. Thus, we propose an efficient measurement-based quantum algorithm for quantum many-body system simulation tasks, called measurement-based Hamiltonian variational ansatz (MBHVA). We then demonstrate its effectiveness, efficiency, and advantages with the two-dimensional Heisenberg model and the Fermi–Hubbard chain. Numerical experiments show that MBHVA can have similar performance as circuit-based ansatz, and is expected to reduce operation counts during execution compared to quantum circuits, bringing the advantage of running time. We conclude that the MBQC scheme is potentially feasible for achieving near-term quantum advantages in the noisy intermediate-scale quantum era, especially in the presence of large multi-qubit rotation operations.
Multiphase cooperation for multilevel strain accommodation in a single-crystalline BiFeO3 thin film
Authors: Choi Wooseon , Park Bumsu , Hwang Jaejin , Han Gyeongtak , Yang Sang-Hyeok , Lee Hyeon Jun , Lee Sung Su , Jo Ji Young , Borisevich Albina Y. , Jeong Hu Young , Oh Sang Ho , Lee Jaekwang , Kim Young-Min
Published: July 2024

The functionalities and diverse metastable phases of multiferroic BiFeO3 (BFO) thin films depend on the misfit strain. Although mixed phase-induced strain relaxation in multiphase BFO thin films is well known, it is unclear whether a single-crystalline BFO thin film can accommodate misfit strain without the involvement of its polymorphs. Thus, understanding the strain relaxation behavior is key to elucidating the lattice strain–property relationship. In this study, a correlative strain analysis based on dark-field inline electron holography (DIH) and quantitative scanning transmission electron microscopy (STEM) was performed to reveal the structural mechanism for strain accommodation of a single-crystalline BFO thin film. The nanoscale DIH strain analysis results indicated a random combination of multiple strain states that acted as a primary strain relief, forming irregularly strained nanodomains. The STEM-based bond length measurement of the corresponding strained nanodomains revealed a unique strain accommodation behavior achieved by a statistical combination of multiple modes of distorted structures on the unit-cell scale. The globally integrated strain for each nanodomain was estimated to be close to −1.5%, irrespective of the nanoscale strain states, which was consistent with the fully strained BFO film on the SrTiO3 substrate. Density functional theory calculations suggested that strain accommodation by the combination of metastable phases was energetically favored compared to single-phase-mediated relaxation. This discovery allows a comprehensive understanding of strain accommodation behavior in ferroelectric oxide films, such as BFO, with various low-symmetry polymorphs.
Anisotropic pressure effect on central EOS of PSR J0740+6620 in the light of dimensionless TOV equation*
Authors: Yang 杨 Zhihao 致浩 , Wen 文 Dehua 德华
Published: July 2024

It is generally agreed upon that the pressure inside a neutron star is isotropic. However, a strong magnetic field or superfluidity suggests that the pressure anisotropy may be a more realistic model. We derived the dimensionless TOV equation for anisotropic neutron stars based on two popular models, namely, the BL and H models, to investigate the effect of anisotropy. Similar to the isotropic case, the maximum mass

and its corresponding radius

can also be expressed linearly by a combination of radial central pressure

and central energy density

, which is insensitive to the equation of state (EOS). We also found that the obtained central EOS would change with different values of

(

), which controls the magnitude of the difference between the transverse pressure and radial pressure. Combining with observational data of PSR J0740+6620 and comparing to the extracted EOS based on an isotropic neutron star, it is shown that in the BL model, for

= 0.4, the extracted central energy density

changed from 546 − 1056 MeV/fm3 to 510 − 1005 MeV/fm3, and the extracted radial central pressure

changed from 87 − 310 MeV/fm3 to 76 − 271 MeV/fm3. For

= 2, the extracted

and

changed to 412 − 822 MeV/fm3 and 50 − 165 MeV/fm3, respectively. In the H model, for

= 0.4, the extracted

changed to 626 − 1164 MeV/fm3, and the extracted

changed to 104 − 409 MeV/fm3. For

= 2, the extracted

decreased to 894 − 995 MeV/fm3, and the extracted

changed to 220 − 301 MeV/fm3.
Testing Bell inequality through
at CEPC*
Authors: Ma 马 Kai 凯 , Li 李 Tong 佟
Published: July 2024

The decay of Higgs boson into two spin-1/2 particles provides an ideal system to reveal quantum entanglement and Bell-nonlocality. Future

colliders can improve the measurement accuracy of the spin correlation of tau lepton pairs from Higgs boson decay. We show the testability of Bell inequality through

at Circular Electron Positron Collider (CEPC). Two realistic methods of testing Bell inequality are investigated, i.e., Törnqvist's method and Clauser-Home-Shimony-Holt (CHSH) inequality. In the simulation, we consider the detector effects of CEPC including uncertainties for tracks and jets from Z boson in the production of

. Necessary reconstruction approaches are described to measure quantum entanglement between

and

. Finally, we show the sensitivity of CEPC to Bell inequality violation for the two methods.
Chromomagnetic dipole moments of light quarks in the bestest little Higgs model
Authors: Cisneros-Pérez T. , Cruz-Albaro E. , Ojeda-Castañeda A. Y. , Solís-Núñez S. E.
Published: July 2024

In this study, we investigated the anomalous Chromomagnetic Dipole Moment (CMDM), denoted as

, of light quarks

within the framework of the Bestest Little Higgs Model (BLHM) as an extension of the Standard Model (SM). Our investigation encompassed novel interactions among the light quarks, heavy quark B, and heavy bosons

, incorporating the extended Cabibbo-Kobayashi-Maskawa (CKM) matrix characteristic of the BLHM. We thoroughly explored the permissible parameter space, yielding a spectrum of CMDM values ranging from

to

.
X-Ray Source Classification Using Machine Learning: A Study with EP-WXT Pathfinder LEIA
Authors: Zuo Xiaoxiong , Tao Yihan , Liu Yuan , Xu Yunfei , Zhang Wenda , Pan Haiwu , Sun Hui , Zhang Zhen , Cui Chenzhou , Yuan Weimin
Published: July 2024

X-ray observations play a crucial role in time-domain astronomy. The Einstein Probe (EP), a recently launched X-ray astronomical satellite, emerges as a forefront player in the field of time-domain astronomy and high-energy astrophysics. With a focus on systematic surveys in the soft X-ray band, EP aims to discover high-energy transients and monitor variable sources in the universe. To achieve these objectives, a quick and reliable classification of observed sources is essential. In this study, we developed a machine learning classifier for autonomous source classification using data from the EP-WXT Pathfinder—Lobster Eye Imager for Astronomy (LEIA) and EP-WXT simulations. The proposed Random Forest classifier, built on selected features derived from light curves, energy spectra, and location information, achieves an accuracy of approximately 95% on EP simulation data and 98% on LEIA observational data. The classifier is integrated into the LEIA data processing pipeline, serving as a tool for manual validation and rapid classification during observations. This paper presents an efficient method for the classification of X-ray sources based on single observations, along with implications of most effective features for the task. This work facilitates rapid source classification for the EP mission and also provides valuable insights into feature selection and classification techniques for enhancing the efficiency and accuracy of X-ray source classification that can be adapted to other X-ray telescope data.
The Unruh–DeWitt model and its joint interacting Hilbert space
Authors: Tjoa Erickson , Gray Finnian
Published: July 2024

In this work we make the connection between the Unruh–DeWitt (UDW) particle detector model applied to quantum field theory in curved spacetimes and the rigorous construction of the spin-boson (SB) model. With some modifications, we show that existing results about the existence of a SB ground state can be adapted to the UDW model. In the most relevant scenario involving massless scalar fields in (3+1)-dimensional globally hyperbolic spacetimes, where the UDW model describes a simplified model of light–matter interaction, we argue that common choices of the spacetime smearing functions regulate the ultraviolet behaviour of the model but can still exhibit infrared (IR) divergences. In particular, this implies the well-known expectation that the joint interacting Hilbert space of the model cannot be described by the tensor product of a two-dimensional complex Hilbert space and the Fock space of the vacuum representation. We discuss the conditions under which this problem does not arise and the relevance of the operator-algebraic approach for better understanding of particle detector models and their applications.Our work clarifies the connection between obstructions due to Haag’s theorem and IR bosons in the SB models, and paves the way for more rigorous study of entanglement and communication in the UDW framework involving multiple detectors.
Strongly quasi-mixing properties for one-dimensional diffusion processes with killing
*
Authors: Liao Saixia , Zhang Hanjun , Li Huasheng
Published: July 2024

In this paper, we establish sufficient conditions for the existence of strongly (uniformly and exponentially) quasi-mixing limits of one-dimensional diffusion processes with killing. As a by-product, these conditions also ensure that the considered processes have strong quasi-ergodicity, strong fractional quasi-ergodicity and uniform mean-ratio quasi-ergodicity. Moreover, the quasi-ergodic speeds of these three quasi-ergodicities are also characterized.
Five narrow bands terahertz metamaterial absorber based on metal and Dirac semi-metal for high sensitivity refractive index sensing
Authors: Liu Yulong , Xiao Zhongyin , Cai Xianshun , Zheng Qi
Published: July 2024

A five narrow bands terahertz metamaterial absorber based on metal and Dirac semi-metal for high sensitivity refractive index sensing is designed in this paper. The absorber is a traditional sandwich structure. And the most remarkable difference is that two hybrid materials (metal and Dirac semi-metal) are used in the top layer. The numerical results show five absorption peaks can be achieved at 5.527, 5.759, 7.247, 9.257 and 10.186 THz, among which the perfect absorption achieve at 5.759, 7.247 and 10.186 THz, respectively. The physical mechanism of the proposed absorber is analyzed qualitatively and quantitatively by electric field distributions and couple-mode theory. In addition, the sensing application of the proposed absorber is also studied. The sensitivity of the sensing band can reach up to 3.89 THz/RIU by computation. Finally, we design a specific application scenario to ensure the accuracy of the absorber in application through calculation. We believe that the absorber we designed will shine brilliantly in the fields of thermal imaging, thermal radiation and photothermal detection.
Dynamic pricing strategy for efficient electric vehicle charging and discharging in microgrids using multi-objective jaya algorithm
Authors: Sharma Swati , Ali Ikbal
Published: July 2024

The rising demand for electric vehicle (EV) charging is spurring their increased integration into microgrids. With significant advancements, EVs have become widely adopted and integrated into various settings for charging/discharging. EVs integrated with the microgrids possess the capability to serve as variable loads and the various energy suppliers present it as a dual opportunity. However, a primary challenge in EV deployment lies in efficiently managing charging stations (CSs) to minimize waiting times for users and reduce charging costs for EV owners. In addressing these challenges require consideration of dynamic pricing mechanisms and the diverse characteristics of EVs to achieve optimal scheduling. A novel approach that combines dynamic pricing strategies with optimized scheduling for effective EV charging operations using multi-objective Jaya algorithm. To evaluate its performance, we conducted a numerical experiment using real-time data and the Nissan Leaf model EV. The results demonstrate that our multi-objective Jaya-based approach outperforms existing methods by achieving a remarkable cost saving rate of 16.013% and an average profit of ₹ 243.6331 per kilowatt-hour with a network convergence time of 112 s. Also, our proposed algorithm provides a correlation between minimized EV charging costs and maximized EV aggregator profits. These findings validate the effectiveness and practical applicability of our proposed EV scheduling algorithm in real-world scenarios.
Comparison of Si and SiC MOSFETs responses to electrical stress and the observation of parameter recovery in SiC MOSFET by stress superposition
Authors: Wang Xinyu , Awadelkarim Osama O
Published: July 2024

In this study we examined the effects of room temperature DC and AC electrical stress on Si and SiC n-channel metal-oxide-semiconductor field effect transistors (MOSFETs). Measurement of threshold voltage, transconductance, subthreshold swing, charge pumping, and gate oxide breakdown are used to compare the impact of stress on Si MOSFETs and SiC MOSFETS, as well as to understand the processes of carrier injection and trapping at oxide and interface defects. DC stress is observed to promote negative charge buildup in the gate oxide and interface in Si MOSFETs. However, in SiC MOSFETs the net charge buildup sign alternates between negative and positive as the DC stress polarity is changed from positive to negative, respectively. For the same stress level, relative degradation in parameters of SiC MOSFETs are significantly smaller than those in Si MOSFETs, where in the latter interface state density, conductance, and subthreshold swing have degraded by up to 400%.The change of charge buildup sign explains our observation that degradation in SiC MOSFETs subjected to AC bipolar stress is insignificantly small, whereas AC stressing of Si MOSFETs is observed to be much more severe. Also, the superposition of alternating DC stress polarity eliminates the stress induced degradation in SiC MOSFETs thus enabling a straightforward process for parameter reconfiguration and recovery.
Towards robust data-driven automated recovery of symbolic conservation laws from limited data
Authors: Oellerich Tracey , Emelianenko Maria
Published: July 2024

Conservation laws are an inherent feature in many systems modeling real world phenomena, in particular, those modeling biological and chemical systems. If the form of the underlying dynamical system is known, linear algebra and algebraic geometry methods can be used to identify the conservation laws. Our work focuses on using data-driven methods to identify the conservation law(s) in the absence of the knowledge of system dynamics. We develop a robust data-driven computational framework that automates the process of identifying the number and type of the conservation law(s) while keeping the amount of required data to a minimum. We demonstrate that due to relative stability of singular vectors to noise we are able to reconstruct correct conservation laws without the need for excessive parameter tuning. While we focus primarily on biological examples, the framework proposed herein is suitable for a variety of data science applications and can be coupled with other machine learning approaches.
Enhancing the rationale of convolutional neural networks for glitch classification in gravitational wave detectors: a visual explanation
Authors: Koyama Naoki , Sakai Yusuke , Sasaoka Seiya , Dominguez Diego , Somiya Kentaro , Omae Yuto , Terada Yoshikazu , Meyer-Conde Marco , Takahashi Hirotaka
Published: July 2024

In the pursuit of detecting gravitational waves, ground-based interferometers (e.g. LIGO, Virgo, and KAGRA) face a significant challenge: achieving the extremely high sensitivity required to detect fluctuations at distances significantly smaller than the diameter of an atomic nucleus. Cutting-edge materials and innovative engineering techniques have been employed to enhance the stability and precision of the interferometer apparatus over the years. These efforts are crucial for reducing the noise that masks the subtle gravitational wave signals. Various sources of interference, such as seismic activity, thermal fluctuations, and other environmental factors, contribute to the total noise spectra characteristic of the detector. Therefore, addressing these sources is essential to enhance the interferometer apparatus’s stability and precision. Recent research has emphasised the importance of classifying non-stationary and non-Gaussian glitches, employing sophisticated algorithms and machine learning methods to distinguish genuine gravitational wave signals from instrumental artefacts. The time-frequency-amplitude representation of these transient disturbances exhibits a wide range of new shapes, variability, and features, reflecting the evolution of interferometer technology. In this study, we developed a convolutional neural network model to classify glitches using spectrogram images from the Gravity Spy O1 dataset. We employed score-class activation mapping and the uniform manifold approximation and projection algorithm to visualise and understand the classification decisions made by our model. We assessed the model’s validity and investigated the causes of misclassification from these results.
Capturing the ghost in the machine: a process for development and validation of measures of phenomenal consciousness in delirium
Authors: Eeles Eamonn , Tran David Duc , Ward Sarah , Teodorczuk Andrew , Ray Julian , Miller Tim , Dissanayaka Nadeeka N
Published: July 2024

Background

Delirium has conventionally been considered a disorder of consciousness. Alertness and arousal are used as surrogates in clinical practice but are insufficient for the purposes of a more dimensional assessment of consciousness. We present a process of development and validation of candidate measures of phenomenal consciousness that could be applied to the diagnosis of delirium.

Methods

First, a narrative review of available instruments in the fields of phenomenal consciousness, including prereflective consciousness, the phenomenal-sensed experience and reflective thought, was undertaken. Eligibility of tools in the context of applicability to delirium was based upon objectivity in test interpretation and the requirement for tester administration. Second, where there was a gap in suitable cognitive tools, new items were derived using the silent generation technique. A process of face and construct validity using a diverse panel of experts was performed, and readability was evaluated.

Results

814 articles were screened from the literature review. Fourteen candidate tools were reported from the three domains of phenomenal consciousness. One of these met the eligibility criteria for a delirium assessment. Fifty-seven new tests of phenomenal consciousness were identified. After a process of item reduction, a total of 26 individual tests were identified. After content validity, 22 of the 26 items were retained. The scale average content validity index was 0.89. The agreement between raters was between 80% and 97%. 100% of responses for face validity were rated as positive. Flesch Reading Ease Score was 91.6 (very easy to read).

Conclusions

Candidate measures of phenomenal consciousness are described, and early validity studies are promising.
Spatiotemporal patterns of excess mortality from non-COVID causes of death in the United States, March to December 2020
Authors: Zalla Lauren C , Lesko Catherine R
Published: July 2024

To estimate the burden of excess mortality from 17 underlying causes of death between March and December 2020 in the United States and to compare trends in excess deaths from non-COVID causes vs from COVID-19. Using time-series models, we estimated monthly counts of all-cause and cause-specific excess deaths. We stratified by geographic region and compared temporal trends in excess deaths from non-COVID causes to trends in deaths attributed to COVID-19. Of approximately 500 000 excess deaths, 70% were attributed to COVID-19. We observed increases in several underlying causes of death, ranging from a 3% increase in kidney disease deaths to a 24% increase in homicides, as well as decreases in deaths from cancer (–0.3%), influenza and pneumonia (–2%), chronic lower respiratory disease (–3%), and suicide (–7%). Trends in excess deaths from cardiovascular disease, diabetes, and Alzheimer disease closely mirrored trends in deaths from COVID-19. Trends in excess liver disease, homicide, suicide, and motor vehicle accident deaths were negatively correlated with trends in deaths from COVID-19. There was wide regional variation in excess death rates for some causes of death, including a disproportionate increase in homicide and motor vehicle accident deaths in the Great Lakes and a sustained reduction in cancer deaths in the Mideast and New England. Increases in cardiovascular disease, diabetes, and Alzheimer disease deaths from March to December 2020 likely reflect health care system disruptions or acute complications of COVID-19. Excess deaths from homicide and liver disease are more likely to reflect social and economic effects of the emerging pandemic or other separate causes.
Preconception and first trimester exposure to pesticides and associations with stillbirth
Authors: Furlong Melissa A , Paul Kimberly C , Parra Kimberly L , Fournier Alfred J , Ellsworth Peter C , Cockburn Myles G , Arellano Avelino F , Bedrick Edward J , Beamer Paloma I , Ritz Beate
Published: July 2024

Associations of pesticide exposures during preconception with stillbirth have not been well explored. We linked Arizona pesticide use records with birth certificates from 2006 to 2020 and estimated associations of living within 500 m of any pyrethroid, organophosphate (OP), or carbamate pesticide applications during a 90-day preconception window or the first trimester, with stillbirth. We considered a binary measure of exposure (any exposure), as well as log-pounds and log-acres applied within 500 m, in a negative control exposure framework with log-binomial regression. We included 1 237 750 births, 2290 stillbirths, and 27 pesticides. During preconception, any exposure to pesticides was associated with stillbirth, including cyfluthrin (risk ratio [RR] = 1.97; 95% CI, 1.17-3.32); zeta-cypermethrin (RR = 1.81; 95% CI, 1.20-2.74); OPs as a class (RR = 1.60; 95% CI, 1.16-2.19); malathion (RR = 2.02; 95% CI, 1.26-3.24); carbaryl (RR = 6.39; 95% CI, 2.07-19.74); and propamocarb hydrochloride (RR = 7.72; 95% CI, 1.10-54.20). During the first trimester, fenpropathrin (RR = 4.36; 95% CI, 1.09-17.50); permethrin (RR = 1.57; 95% CI, 1.02-2.42); OPs as a class (RR = 1.50; 95% CI, 1.11-2.01); acephate (RR = 2.31; 95% CI, 1.22-4.40); and formetanate hydrochloride (RR = 7.22; 95% CI, 1.03-50.58) were associated with stillbirth. Interpretations were consistent when using continuous measures of pounds or acres of exposure. Pesticide exposures during preconception and first trimester may be associated with stillbirth.

This article is part of a Special Collection on Environmental Epidemiology.
Feasibility of respirable crystalline silica exposure reduction in small-scale tanzanite mining in Tanzania
Authors: Nota Manti Michael , Mbuligwe Stephen E , Kassenga Gabriel R , Gottesfeld Perry
Published: July 2024

Introduction

Respirable crystalline silica (RCS) exposures in tanzanite gem mining have been linked to tuberculosis and silicosis among miners. We conducted a plot study to assess RCS exposures and to introduce safer mining practices in one small-scale underground tanzanite mine.

Materials and methods

Personal and area air samples for RCS were collected during tanzanite mining operations before and after improved work practices employed to reduce exposures and analyzed using X-ray diffraction. Area samples were collected at the rest area, located approximately 300 m underground and 100 m from other work activities. Improved practices included the use of wet drilling methods and drilling with new bits.

Results

A total of 33 personal and 4 area air samples were collected. Pre-intervention, mean exposures for all operations, drilling operations, non-drilling activities, and area samples were 122 mg/m3, 247 mg/m3, 34.3 mg/m3, and 1.95 mg/m3, respectively which exceeded the U.S. OSHA Permissible Exposure Limit (PEL) by 2,440 times for all operations, by 4,946 times for drilling operations, by 686 times for non-drilling activities and 39 times for area samples collected at an underground rest area. The post-intervention results showed a 99% reduction of RCS exposures for wet drilling operations, 98.5% reduction for non-drilling activities, and 36% reduction for area samples. Despite improvements, post-intervention RCS exposures during drilling had a mean of 2.08 mg/m3 or more than 41 times the OSHA PEL.

Conclusions

We successfully piloted a program to work with small-scale tanzanite miners to reduce RCS exposures and raise awareness about the occupational health risks of RCS, though additional measures are recommended to further reduce RCS exposures. Similar programs should be taken to scale throughout underground mining sites in Tanzania and other countries.
Customized antisense oligonucleotide-based therapy for neurofilament-associated Charcot–Marie–Tooth disease
Authors: Medina Jessica , Rebelo Adriana , Danzi Matt C , Jacobs Elizabeth H , Xu Isaac R L , Ahrens Kathleen P , Chen Sitong , Raposo Jacquelyn , Yanick Christopher , Zuchner Stephan , Saporta Mario A
Published: July 2024

DNA-based therapeutics have emerged as a revolutionary approach for addressing the treatment gap in rare inherited conditions by targeting the fundamental genetic causes of disease. Charcot–Marie–Tooth (CMT) disease, a group of inherited neuropathies, represents one of the most prevalent Mendelian disease groups in neurology and is characterized by diverse genetic aetiology. Axonal forms of CMT, known as CMT2, are caused by dominant mutations in >30 different genes that lead to degeneration of lower motor neuron axons. Recent advances in antisense oligonucleotide therapeutics have shown promise in targeting neurodegenerative disorders.

Here, we elucidate pathomechanistic changes contributing to variant specific molecular phenotypes in CMT2E, caused by a single nucleotide substitution (p.N98S) in the neurofilament light chain gene (NEFL). We used a patient-derived induced pluripotent stem cell-induced motor neuron model that recapitulates several cellular and biomarker phenotypes associated with CMT2E. Using an antisense oligonucleotide treatment strategy targeting a heterozygous gain-of-function variant, we aimed to resolve molecular phenotypic changes observed in the CMT2E p.N98S subtype. To determine the therapeutic potential of antisense oligonucleotide, we applied our treatment strategy in induced pluripotent stem cell-derived motor neurons and used both established and new biomarkers of peripheral nervous system axonal degeneration.

Our findings demonstrated a significant decrease in clinically relevant biomarkers of axonal degeneration, presenting the first clinically viable genetic therapeutic for CMT2E. Similar strategies could be used to develop precision medicine approaches for otherwise untreatable gain-of-function inherited disorders.
Task and stimulus coding in the multiple-demand network
Authors: Shashidhara Sneha , Assem Moataz , Glasser Matthew F , Duncan John
Published: July 2024

In the human brain, a multiple-demand (MD) network plays a key role in cognitive control, with core components in lateral frontal, dorsomedial frontal and lateral parietal cortex, and multivariate activity patterns that discriminate the contents of many cognitive activities. In prefrontal cortex of the behaving monkey, different cognitive operations are associated with very different patterns of neural activity, while details of a particular stimulus are encoded as small variations on these basic patterns (Sigala et al, 2008). Here, using the advanced fMRI methods of the Human Connectome Project and their 360-region cortical parcellation, we searched for a similar result in MD activation patterns. In each parcel, we compared multivertex patterns for every combination of three tasks (working memory, task-switching, and stop-signal) and two stimulus classes (faces and buildings). Though both task and stimulus category were discriminated in every cortical parcel, the strength of discrimination varied strongly across parcels. The different cognitive operations of the three tasks were strongly discriminated in MD regions. Stimulus categories, in contrast, were most strongly discriminated in a large region of primary and higher visual cortex, and intriguingly, in both parietal and frontal lobe regions adjacent to core MD regions. In the monkey, frontal neurons show a strong pattern of nonlinear mixed selectivity, with activity reflecting specific conjunctions of task events. In our data, however, there was limited evidence for mixed selectivity; throughout the brain, discriminations of task and stimulus combined largely linearly, with a small nonlinear component. In MD regions, human fMRI data recapitulate some but not all aspects of electrophysiological data from nonhuman primates.
The integration of migrants in the German labour market: evidence over 50 years
Authors: Berbée Paul , Stuhler Jan
Published: July 2024

Germany has become the second-most important destination for migrants worldwide. Using all waves from the microcensus, we study their labour market integration over the last 50 years and highlight differences to the US case. Although the employment gaps between immigrant and native men decline after arrival, they remain large for most cohorts; the average gap after one decade is 10 percentage points. Conversely, income gaps tend to widen post-arrival. Compositional differences explain how those gaps vary across groups, and why they worsened over time; after accounting for composition, integration outcomes show no systematic trend. Still, economic conditions do matter, and employment collapsed in some cohorts after structural shocks hit the German labour market in the early 1990s. Lastly, we examine the integration of recent arrivals during the European refugee ‘crisis’ and the Russo-Ukrainian war.
Pan-Genome Provides Insights into Vibrio Evolution and Adaptation to Deep-Sea Hydrothermal Vents
Authors: Bosi Emanuele , Taviani Elisa , Avesani Alessia , Doni Lapo , Auguste Manon , Oliveri Caterina , Leonessi Martina , Martinez-Urtaza Jaime , Vetriani Costantino , Vezzulli Luigi
Published: July 2024

This study delves into the genomic features of 10 Vibrio strains collected from deep-sea hydrothermal vents in the Pacific Ocean, providing insights into their evolutionary history and ecological adaptations. Through sequencing and pan-genome analysis involving 141 Vibrio species, we found that deep-sea strains exhibit larger genomes with unique gene distributions, suggesting adaptation to the vent environment. The phylogenomic reconstruction of the investigated isolates revealed the presence of 2 main clades: The first is monophyletic, consisting exclusively of Vibrio alginolyticus, while the second forms a monophyletic clade comprising both Vibrio antiquarius and Vibrio diabolicus species, which were previously isolated from deep-sea vents. All strains carry virulence and antibiotic resistance genes related to those found in human pathogenic Vibrio species which may play a wider ecological role other than host infection in these environments. In addition, functional genomic analysis identified genes potentially related to deep-sea survival and stress response, alongside candidate genes encoding for novel antimicrobial agents. Ultimately, the pan-genome we generated represents a valuable resource for future studies investigating the taxonomy, evolution, and ecology of Vibrio species.
Regional variation in length of stay for stroke inpatient rehabilitation in traditional Medicare and Medicare Advantage
Authors: Luo Dian , Ouayogodé Mariétou H , Mullahy John , Cao Ying (Jessica)
Published: July 2024

Regional variation in health care use threatens efficient and equitable resource allocation. Within the Medicare program, variation in care delivery may differ between centrally administered traditional Medicare (TM) and privately managed Medicare Advantage (MA) plans, which rely on different strategies to control care utilization. As MA enrollment grows, it is particularly important for program design and long-term health care equity to understand regional variation between TM and MA plans. This study examined regional variation in length of stay (LOS) for stroke inpatient rehabilitation between TM and MA plans in 2019 and how that changed in 2020, the first year of the COVID-19 pandemic. Results showed that MA plans had larger across-region variations than TM (SD = 0.26 vs 0.24 days; 11% relative difference). In 2020, across-region variation for MA further increased, but the trend for TM stayed relatively stable. Market competition among all inpatient rehabilitation facilities (IRFs) within a region was associated with a moderate increase in within-region variation of LOS (elasticity = 0.46). Policies reducing administrative variation across MA plans or increasing regional market competition among IRFs can mitigate regional variation in health care use.
Transgender persons’ view on previous fertility decision-making and current infertility: a qualitative study
Authors: Asseler J D , de Nie I , van Rooij F B , Steensma T D , Mosterd D , Verhoeven M O , Goddijn M , Huirne J A F , van Mello N M
Published: July 2024

STUDY QUESTION

How do adult transgender and gender diverse (TGD) people, who are infertile due to prior gender-affirming treatment, view their current infertility and their reproductive decisions made in the past?

SUMMARY ANSWER

In a time where sterilization was mandatory, transgender adolescents prioritized gender-affirming treatment over their future fertility and would make the same choice today despite emotional challenges related to infertility experienced by some.

WHAT IS KNOWN ALREADY

Under transgender law in the Netherlands, sterilization was required for legal gender recognition until 2014, resulting in permanent infertility. The long-term consequences of this iatrogenic infertility in transgender adolescents who have now reached adulthood remain underexplored.

STUDY DESIGN, SIZE, DURATION

Qualitative study design based on 21 in-depth one-on-one semi-structured interviews.

PARTICIPANTS/MATERIALS, SETTING, METHODS

TGD people in a stage of life where family planning may be a current topic were eligible for participation. They all received gender-affirming treatment in adolescence prior to the legislation change in 2014. A purposeful sampling technique was used from participants of another ongoing study. Eleven people assigned female at birth and ten people assigned male at birth were included. Interview transcripts were thematically analysed using a modified version of Braun and Clarke’s six steps theory.

MAIN RESULTS AND THE ROLE OF CHANCE

Six main themes were generated: (i) personal considerations regarding fertility and fertility preservation in the past; (ii) external considerations regarding fertility and fertility preservation in the past; (iii) current vision on past considerations and decisions; (iv) Current experiences and coping with infertility; (v) future family building; (vi) advice regarding fertility and fertility preservation decision-making.

LIMITATIONS, REASONS FOR CAUTION

Selection, recall, and choice supportive bias may play a role in interpreting our results.

WIDER IMPLICATIONS OF THE FINDINGS

This study highlights the importance of tailored counselling and comprehensive information on fertility preservation for transgender individuals, especially adolescents, undergoing gender-affirming treatment.

STUDY FUNDING/COMPETING INTEREST(S)

N/A.

TRIAL REGISTRATION NUMBER

N/A.