bluuebunny/crossref_metadata_2025 huggingface dataset:
A compact flexible sub-nanosecond framing photographic system
Authors: Li Xin-yan , Yuan Peng , Wu Li-xuan , Gao Fan , Zheng Jian
Published: December 2023

A novel high-speed multi-frame photographic system is presented in this paper. The system demonstrates exceptional compactness and flexibility, requiring only the introduction of a cavity comprising multiple beam-splitters in the optical path to enable multi-frame imaging of sub-nanosecond events. The number and temporal delay of frames can be easily adjusted by adjusting the distance and angle between beam-splitters. These capabilities are demonstrated by observing the laser ablation process, highlighting the great potential for application in capturing ultrafast time-evolving events such as optical breakdown, the evolution of laser-produced plasmas, and the propagation of shock waves.
A model for the contraction kinetics of cytoskeletal gel slabs
Authors: Ferraresso Matteo , Shojaeifard Mohammad , Kong Albert , Bacca Mattia
Published: December 2023

Cytoskeletal gels are engineered prototypes that mimic the contractile behavior of a cell in vitro. They are composed of an active polymer matrix and a liquid solvent. Their contraction kinetics is governed by two dynamic phenomena: mechanotransduction (molecular motor activation) and solvent diffusion. In this paper, we solve the transient problem for the simple case of a thin gel slab in uniaxial contraction under two extreme conditions: motor-limited or slow motor (SM) activation regime, and diffusion-limited or fast motor (FM) activation regime. The former occurs when diffusion is much faster than mechanotransduction, while the latter occurs in the opposite case. We observe that in the SM regime, the contraction time scales as t/t0∼(λ/λ0)−3, with t0 being the nominal contraction time, and λ and λ0 being the final and initial stretches of the slab. t0 is proportional to 1/w˙, where w˙ is the average mechanical power generated by the molecular motors per unit reference (dry polymer) volume. In the FM regime, the contraction time scales as t/t1∼(1−λ/λ0)2, with t1 being the nominal contraction time, here proportional to the ratio L2/D, where L is the reference (dry polymer) thickness, and D is the diffusivity of the solvent in the gel. The transition between the SM and FM regimes is defined by a characteristic power density w˙∗, where w˙≪w˙∗ gives the SM regime and w˙≫w˙∗ gives the FM regime. Intuitively, w˙∗ is proportional to D/L2, where, at a given power density w˙, a thinner gel slab (smaller L) or including smaller solvent molecules (higher D) is more likely to be in the SM regime given that solvent diffusion will occur faster than motor activation.
Derivation and rogue waves of the fractional nonlinear Schrödinger equation for the Rossby waves
Authors: Geng Jingxuan , Fu Lei , Dong Huanhe , Ren Yanwei
Published: December 2023

The Cartesian coordinate system is not sufficient to study wave propagation on the coastline or in the sea where the terrain is extremely complicated, so it is necessary to study it in an unconventional coordinate system, fractals. In this paper, from the governing equations of fluid, the fractional nonlinear Schrödinger equation is derived to describe the evolution of Rossby waves in fractal by using multi-scale analysis and perturbation method. Based on the equation, the rogue-wave solution is obtained by the integral preserving transformation to explain some serious threats at sea.
Analysis and modeling of reverse-biased gate leakage current in AlGaN/GaN high electron mobility transistors
Authors: Rai Narendra , Sarkar Ritam , Mahajan Ashutosh , Laha Apurba , Saha Dipankar , Ganguly Swaroop
Published: December 2023

We have analyzed and modeled the reverse-biased gate leakage current in a Schottky-gate AlGaN/GaN high electron mobility transistor. While the Poole–Frenkel emission current along conductive threading dislocations dominates at low negative gate bias, the trap-assisted tunneling of thermally energized electrons and the thermal emission of electrons from threading dislocations aided by dislocation-related states at multiple energy levels within the AlGaN bandgap are dominant at moderate to large reverse bias. Additionally, deep trap levels of high density localized near the gate/AlGaN interface cause significant leakage at 473 K at low to moderate reverse bias, which could be specific to the device we have analyzed. We extracted about 1012 cm−2 traps near the AlGaN/GaN interface from the difference of the barrier layer electric field profile obtained from the experimental high-frequency capacitance–gate voltage and the one needed for final matching. The thermionic- and the thermionic field-emission currents are considerably low; the latter, however, dominates in the defect-free case. Finally, the simulation framework we developed here helped us identify various conduction mechanisms contributing to the reverse-biased gate leakage and the density and electronic structure of the responsible defects.
Two-color polarization spectroscopy measurements of Zeeman state-to-state collision induced transitions of nitric oxide in binary gas mixtures
Authors: Chang Ziqiao , Satija Aman , Lucht Robert P.
Published: December 2023

We investigated collision induced transitions in the (0, 0) band of the A2Σ+–X2Π electronic transition of nitric oxide (NO) using two-color polarization spectroscopy (TCPS). Two sets of TCPS spectra for 1% NO, diluted in different buffer gases at 295 K and 1 atm, were obtained with the pump beam tuned to the R11(11.5) and OP12(1.5) transitions. The buffer gases were He, Ar, and N2. The probe was scanned while the pump beam was tuned to the line center. Theoretical TCPS spectra, calculated by solving the density matrix formulation of the time-dependent Schrödinger wave equation, were compared with the experimental spectra. A collision model based on the modified exponential-gap law was used to model the rotational level-to-rotational level collision dynamics. A model for collisional transfer from an initial to a final Zeeman state was developed based on the difference in cosine of the rotational quantum number J projection angle with the z-axis for the two Zeeman states. Rotational energy transfer rates and Zeeman state collisional dynamics were varied to obtain good agreement between theory and experiment for the two different TCPS pump transitions and for the three different buffer gases. One key finding, in agreement with quasi-classical trajectory calculations, is that the spin-rotation changing transition rate in the A2Σ+ level of NO is almost zero for rotational quantum numbers ≥8. It was necessary to set this rate to near zero to obtain agreement with the TCPS spectra.
Microphysiological systems as reliable drug discovery and evaluation tools: Evolution from innovation to maturity
Authors: Moon Hye-Ran , Surianarayanan Nishanth , Singh Tarun , Han Bumsoo
Published: December 2023

Microphysiological systems (MPSs), also known as organ-on-chip or disease-on-chip, have recently emerged to reconstitute the in vivo cellular microenvironment of various organs and diseases on in vitro platforms. These microfluidics-based platforms are developed to provide reliable drug discovery and regulatory evaluation testbeds. Despite recent emergences and advances of various MPS platforms, their adoption of drug discovery and evaluation processes still lags. This delay is mainly due to a lack of rigorous standards with reproducibility and reliability, and practical difficulties to be adopted in pharmaceutical research and industry settings. This review discusses the current and potential use of MPS platforms in drug discovery processes while considering the context of several key steps during drug discovery processes, including target identification and validation, preclinical evaluation, and clinical trials. Opportunities and challenges are also discussed for the broader dissemination and adoption of MPSs in various drug discovery and regulatory evaluation steps. Addressing these challenges will transform long and expensive drug discovery and evaluation processes into more efficient discovery, screening, and approval of innovative drugs.
Ion correlation-driven like-charge attraction in multivalent salt solutions
Authors: Agrawal Nikhil R. , Kaur Ravtej , Carraro Carlo , Wang Rui
Published: December 2023

The electrostatic double layer force is key to determining the stability and self-assembly of charged colloids and many other soft matter systems. Fully understanding the attractive force between two like-charged surfaces remains a great challenge. Here, we apply the modified Gaussian renormalized fluctuation theory to study ion correlation-driven like-charge attraction in multivalent salt solutions. The effects of spatially varying ion correlations on the structure of overlapping double layers and their free energy are self-consistently accounted for. In the presence of multivalent salts, increasing surface charge or counterion valency leads to a short-range attraction. We demonstrate that although both overcharging and like-charge attraction are outcomes of ion correlation, there is no causal relationship between them. Our theory also captures the non-monotonic dependence of like-charge attraction on multivalent salt concentration. The reduction of attraction at high salt concentrations could be a contributing factor toward the reentrant stability of charged colloidal suspensions. Our theoretical predictions are consistent with the observations reported in experiments and simulations.
Influence of elastic anisotropy on the shapes of ellipsoidal blisters and stress field around the blisters in solid materials
Authors: Ishii Akio
Published: December 2023

To address the embrittlement challenges posed by gas blisters in anisotropic materials, the stable shape of constant-pressure blisters in anisotropic materials (hexagonal, tetragonal, and rhombohedral) was energetically investigated based on continuum theory (micromechanics), considering the blister as Eshelby’s ellipsoidal inclusion. The non-negligible change in the blister shape was confirmed in terms of the anisotropic factor η ≡ C3333/C1111. Although the spherical shape of the blister is preferable for isotropic and cubic materials (η = 1), the x3 normal penny and capsule shapes were theoretically confirmed to be the most stable ones for η > 1 and η < 1, respectively. The penny and capsule shape blisters generate larger stress fields around themselves than the sphere shape blisters, thus inducing crack formation. The embrittlement due to the gas (typically hydrogen or helium) inside the blister for the anisotropic materials was more significant than isotropic and cubic embrittlement.
Direct-write printed magnetic-controlled soft robots for non-contact applications
Authors: Chen Xiaojun , Xu Yueyu , Lin Xitong , Zheng Ruoxian , Mo Deyun , Lian Haishan , Li Xin , Cui Zaifu
Published: December 2023

Magnetic soft robots have attracted extensive attention in the fields of biomimetic wireless cable robots, flexible electronic devices, targeted drug delivery, and minimally invasive surgery due to their advantages of remote non-contact control, fast response, good performance, and easy miniaturization. However, the current manufacturing methods and material systems restrict the uniformity, simplicity, and motion capabilities of the magnetic contour of soft robots. Here, we utilized a self-made magnetic composite material ink to direct-write printing magnetic soft robots for non-contact applications. The introduction of a polydimethylsiloxane solution mixed with a neodymium iron boron (NdFeB) magnetic powder/silicone rubber material has modified the rheological properties of the printing ink, resulting in the improved structural integrity and fidelity of the printed samples. The morphology and quality of the magnetic structure are controlled by optimizing the printing process parameters, such as solution ratio, printing layer height, and printing speed. Experimental results showed that the magnetic induction intensity of the dumbbell sample with 50 wt. % NdFeB was 4.57 mT, the fracture elongation was 175%, the mechanical strength was 0.8483 MPa, and the five-cycle fatigue tensile stress–strain curve had a high coincidence. As a demonstration, we printed a controllable magnetic clock and a biomimetic magnetic-controlled flower, showcasing the potential applications in non-contact fields, such as smart healthcare and rescue.
Applicability of a central force water model to study adsorption in disordered hydrophobic matrices—replica Ornstein–Zernike theory
Authors: Hribar-Lee B.
Published: December 2023

A simple central force water model to study adsorption in random Lennard-Jones-like matrices has been studied using the replica Ornstein–Zernike integral equation theory in hypernetted-chain (HNC) approximation and in HNC+bridge approximation. The structure of water in obstacle matrices of different sizes was studied, showing that the model appropriately accounts for the hydrophobic hydration. By calculating the chemical potential of water in the model adsorbent, we have constructed the adsorption isotherm. Except for the cases of highly dispersed matrices, water gets excluded from the crowded hydrophobic environment, as expected experimentally.
A novel analysis of Cole–Hopf transformations in different dimensions, solitons, and rogue waves for a (2 + 1)-dimensional shallow water wave equation of ion-acoustic waves in plasmas
Authors: Kumar Sachin , Mohan Brij
Published: December 2023

This work investigates a (2 + 1)-dimensional shallow water wave equation of ion-acoustic waves in plasma physics. It comprehensively analyzes Cole–Hopf transformations concerning dimensions x, y, and t and obtains the dispersion for a phase variable of this equation. We show that the soliton solutions are independent of the different logarithmic transformations for the investigated equation. We also explore the linear equations in the auxiliary function f present in Cole–Hopf transformations. We study this equation's first- and second-order rogue waves using a generalized N-rogue wave expression from the N-soliton Hirota technique. We generate the rogue waves by applying a symbolic technique with β and γ as center parameters. We create rogue wave solutions for first- and second-order using direct computation for appropriate choices of several constants in the equation and center parameters. We obtain a trilinear equation by transforming variables ξ and y via logarithmic transformation for u in the function F. We harness the computational power of the symbolic tool Mathematica to demonstrate the graphics of the soliton and center-controlled rogue wave solutions with suitable choices of parameters. The outcomes of this study transcend the confines of plasma physics, shedding light on the interaction dynamics of ion-acoustic solitons in three-dimensional space. The equation's implications resonate across diverse scientific domains, encompassing classical shallow water theory, fluid dynamics, optical fibers, nonlinear dynamics, and many other nonlinear fields.
Disconnection flow–mediated grain rotation
Authors: Qiu Caihao , Salvalaglio Marco , Srolovitz David J. , Han Jian
Published: December 2023

Grain rotation is commonly observed during the evolution of microstructures in polycrystalline materials of different kinds, including metals, ceramics, and colloidal crystals. It is widely accepted that interface migration in these systems is mediated by the motion of line defects with step and dislocation character, i.e., disconnections. We propose a crystallography-respecting continuum model for arbitrarily curved grain boundaries or heterophase interfaces, accounting for the disconnections’ role in grain rotation. Numerical simulations demonstrate that changes in grain orientations, as well as interface morphology and internal stress field, are associated with disconnection flow. Our predictions agree with molecular dynamics simulation results for pure capillarity-driven evolution of grain boundaries and are interpreted through an extended Cahn–Taylor model.
Utilizing the L-curve criterion for the inverse magnetostatic problem of Hall drift current estimation
Authors: Ren Ziying , Zhou Liwei , Wei Liqiu , Hu Yanlin , Han Liang , Li Hong , Ding Yongjie
Published: December 2023

Aiming at achieving the in-orbit diagnostic of Hall drift current, this study focuses on estimation through the indirect measurement methodology using a magnetic sensor array. It elaborates on the application of a pseudo-seminorm defined for the Hall drift current solution to address the inverse magnetostatic problems, which are formulated with a two-dimensional Tikhonov regularization constraint, and thereby offering a systematic approach to select regularization parameters. Our investigation discusses factors influencing the formation of the L-curve and the accuracy of the resultant solution obtained via the L-curve criterion. The results reveal that the formation of the defined pseudo-seminorm of the Hall drift current solution in the semi-logarithmic coordinate system is independent of the number of calibrating current elements or the number of magnetic sensors. This effectively resolves the issue of failing to generate an L-curve during regularization parameter selection. Furthermore, the study indicates that expanding the number of calibrating current elements—essentially increasing the unknown variables in the inverse magnetostatic equations—contributes to a significant enhancement in the accuracy of Hall drift current solutions. It also has extensibility to be applied to other areas where the contactless current measuring is required.
Construction of a digital twin model for vertical storage tank deformation assessment using terrestrial laser scanning technology
Authors: Wu Yujian , Yang Gang , Sun Jiangang , Cui Lifu , Wang Mengzhu
Published: December 2023

The foundational settlement and deformation of vertical storage tanks are crucial factors influencing their safe operation. To enable rapid deformation assessment of storage tanks, this paper combines point cloud data acquired through terrestrial laser scanning with relevant data processing algorithms to construct a digital twin (DT) model. This achieves high-precision automated detection of tank deformation, facilitating the digital transformation of deformation assessment and offering an integrated detection strategy. First, Euclidean distance clustering is applied to the point cloud, and the point density within clusters is statistically analyzed using a Gaussian distribution. This results in a collection of point clusters within one standard deviation, effectively filtering out outliers and noise points, which facilitates the rapid global registration of the point cloud. Second, in order to quickly segment tank point clouds in the scene, back propagation neural network classification learning based on principal component analysis information is used. The point cloud model is combined with the fitting information of slices to generate a DT model, whose deformation can be evaluated through comparison with appropriate storage tank specifications, taking radial deformation, tank inclination, and foundation settlement as indicators.
Self-powered semitransparent WS2/LaVO3 vertical-heterostructure photodetectors by employing interfacial hexagonal boron nitride
Authors: Kim Da Hee , Shin Dong Hee , Lee Hosun
Published: December 2023

Two-dimensional (2D) semiconductor and LaVO3 materials with high absorption coefficients in the visible light region are attractive structures for high-performance photodetector (PD) applications. Insulating 2D hexagonal boron nitride (h-BN) with a large band gap and excellent transmittance is a very attractive material as an interface between 2D/semiconductor heterostructures. We first introduce WS2/h-BN/LaVO3 semitransparent PD. The photo-current/dark current ratio of the device exhibits a delta-function characteristic of 4 × 105 at 0 V, meaning ‘self-powered’. The WS2/h-BN/LaVO3 PD shows up to 0.27 A W−1 responsivity (R) and 4.6 × 1010 cm Hz1/2 W−1 detectivity (D*) at 730 nm. Especially, it was confirmed that the D* performance improved by about 5 times compared to the WS2/LaVO3 device at zero bias. Additionally, it is suggested that the PD maintains 87% of its initial R for 2000 h under the atmosphere with a temperature of 25 °C and humidity of 30%. Based on the above results, we suggest that the WS2/h-BN/LaVO3 heterojunction is promising as a self-powered optoelectronic device.
Estimating forest extent across Mexico
Authors: Braden Dustin , Mondal Pinki , Park Taejin , Alanís de la Rosa José Armando , Aldrete Leal Metzli Ileana , Cuenca Lara Rubi Angélica , Mayorga Saucedo Rafael , Paz Fernando , Salas-Aguilar Victor Manuel , Soriano-Luna María de Los Ángeles , Vargas Rodrigo
Published: December 2023

Information on forest extent and tree cover is required to evaluate the status of natural resources, conservation practices, and environmental policies. The challenge is that different forest definitions, remote sensing-based (RSB) products, and data availability can lead to discrepancies in reporting total forest area. Consequently, errors in forest extent can be propagated into forest biomass and carbon estimates. Here, we present a simple approach to compare forest extent estimates from seven regional and global land or tree cover RSB products at 30 m resolution across Mexico. We found substantial differences in forest extent estimates for Mexico, ranging from 387 607 km2 to 675 239 km2. These differences were dependent on the RSB product and forest definition used. Next, we compared these RSB products with two independent forest inventory datasets at national (n = 26 220 plots) and local scales (n = 754 plots). The greatest accuracy among RSB products and forest inventory data was within the tropical moist forest (range 82%–95%), and the smallest was within the subtropical desert (range <10%–80%) and subtropical steppe ecological zones (range <10%–60%). We developed a forest extent agreement map by combining seven RSB products and identifying a consensus in their estimates. We found a forest area of 288 749 km2 with high forest extent agreement, and 340 661 km2 with medium forest extent agreement. The high-to-medium forest extent agreement of 629 410 km2 is comparable to the official national estimate of 656 920 km2. We found a high forest extent agreement across the Yucatan Peninsula and mountain areas in the Sierra Madre Oriental and Sierra Madre Occidental. The tropical dry forest and subtropical mountain system represent the two ecological zones with the highest areas of disagreement among RSB products. These findings show discrepancies in forest extent estimates across ecological zones in Mexico, where additional ground data and research are needed. Dataset available at https://doi.org/10.3334/ORNLDAAC/2320.
Plasma current tomography for HL-2A based on Bayesian inference
Authors: LIU 刘 Zijie 自结 , WANG 王 Tianbo 天博 , WU 吴 Muquan 木泉 , LUO 罗 Zhengping 正平 , WANG 王 Shuo 硕 , SUN 孙 Tengfei 腾飞 , XIAO 肖 Bingjia 炳甲 , LI 李 Jiangang 建刚
Published: December 2023

An accurate plasma current profile has irreplaceable value for the steady-state operation of the plasma. In this study, plasma current tomography based on Bayesian inference is applied to an HL-2A device and used to reconstruct the plasma current profile. Two different Bayesian probability priors are tried, namely the Conditional AutoRegressive (CAR) prior and the Advanced Squared Exponential (ASE) kernel prior. Compared to the CAR prior, the ASE kernel prior adopts non-stationary hyperparameters and introduces the current profile of the reference discharge into the hyperparameters, which can make the shape of the current profile more flexible in space. The results indicate that the ASE prior couples more information, reduces the probability of unreasonable solutions, and achieves higher reconstruction accuracy.
SpliceWiz: interactive analysis and visualization of alternative splicing in R
Authors: Wong Alex C H , Wong Justin J-L , Rasko John E J , Schmitz Ulf
Published: December 2023

Alternative splicing (AS) is a crucial mechanism for regulating gene expression and isoform diversity in eukaryotes. However, the analysis and visualization of AS events from RNA sequencing data remains challenging. Most tools require a certain level of computer literacy and the available means of visualizing AS events, such as coverage and sashimi plots, have limitations and can be misleading. To address these issues, we present SpliceWiz, an R package with an interactive Shiny interface that allows easy and efficient AS analysis and visualization at scale. A novel normalization algorithm is implemented to aggregate splicing levels within sample groups, thereby allowing group differences in splicing levels to be accurately visualized. The tool also offers downstream gene ontology enrichment analysis, highlighting ASEs belonging to functional pathways of interest. SpliceWiz is optimized for speed and efficiency and introduces a new file format for coverage data storage that is more efficient than BigWig. Alignment files are processed orders of magnitude faster than other R-based AS analysis tools and on par with command-line tools. Overall, SpliceWiz streamlines AS analysis, enabling reliable identification of functionally relevant AS events for further characterization. SpliceWiz is a Bioconductor package and is also available on GitHub (https://github.com/alexchwong/SpliceWiz).
Wind power potential over northern South America using ERA5-Land global reanalysis
Authors: Arregocés Heli A , Bonivento Guillermo J , Rojano Roberto
Published: December 2023

The northernmost region of South America has great potential for wind energy production and is a strategic area for the energy transition. We analysed data from ERA5-Land global reanalysis from 1980 to 2020 to determine the wind power potential in this area. Our aim was to identify areas with a high potential for wind energy that could be used to supply energy in case of drought in the region or increases in fuel prices. We compared data from 19 meteorological stations located in Colombia with ERA5-Land reanalysis data to generate reliable information for the feasibility and operation of wind farms. According to our analysis, the Colombian Caribbean and Coastal Plain have monthly average wind speeds at 90 m ranging from 4.85 to 10.34 m/s and 3.79 to 6.62 m/s, respectively. Based on wind power density calculations, these regions have the highest wind power density in our study, with a monthly average of between 250 and 399 W/m2. The Caribbean Region had a 69% increase in wind power density from January to July compared with the annual average. The wind power density in the plains increased from January to March, while the Mountain Region had higher anomalies from May to October. The Alta Guajira and Paraguaná Peninsula have great potential to generate wind energy due to their privileged geographical location. Although ERA5 offers valuable information about wind availability in time and space, it cannot represent the influence of local effects on wind patterns for the Mountain Region.
Life satisfaction and L2 engagement in adolescents
Authors: Li Chengchen , Wei Li , Cai Jinting
Published: December 2023

The study examined how L2 engagement is associated with students’ general life satisfaction, a core element of well-being. A total of 1,109 seventh-grade EFL learners from a rural secondary school in China completed a measure of life satisfaction (family satisfaction, environment satisfaction, academic satisfaction, school satisfaction, freedom satisfaction, and friendship satisfaction) and a measure of foreign language engagement (cognitive engagement, emotional engagement, behavioural engagement, and social engagement). Path analysis shows that life satisfaction generally predicted L2 engagement positively. Variations were found in the associations between six life satisfaction dimensions and four L2 engagement dimensions. A positive psychology lens is adopted to interpret the findings and make concrete suggestions about how to enhance learner engagement. The findings imply that a proactive preventative stance on bolstering engagement could be encouraged such as fostering learners’ positive perceptions and beliefs of self, family, school, environment, study, and friends.
Conventional biventricular pacing is still preferred to conduction system pacing for atrioventricular block in patients with reduced ejection fraction and narrow QRS
Authors: Glikson Michael , Jastrzebski Marek , Gold Michael R , Ellenbogen Kenneth , Burri Haran
Published: December 2023

It is well established that right ventricular pacing is detrimental in patients with reduced cardiac function who require ventricular pacing (VP), and alternatives nowadays are comprised of biventricular pacing (BiVP) and conduction system pacing (CSP). The latter modality is of particular interest in patients with a narrow baseline QRS as it completely avoids, or minimizes, ventricular desynchronization associated with VP. In this article, experts debate whether BiVP or CSP should be used to treat these patients.
Polygenic response of sex chromosomes to sexual antagonism
Authors: Muralidhar Pavitra , Coop Graham
Published: December 2023

Sexual antagonism occurs when males and females differ in their phenotypic fitness optima but are constrained in their evolution to these optima because of their shared genome. The sex chromosomes, which have distinct evolutionary “interests” relative to the autosomes, are theorized to play an important role in sexually antagonistic conflict. However, the evolutionary responses of sex chromosomes and autosomes have usually been considered independently, that is, via contrasting the response of a gene located on either an X chromosome or an autosome. Here, we study the coevolutionary response of the X chromosome and autosomes to sexually antagonistic selection acting on a polygenic phenotype. We model a phenotype initially under stabilizing selection around a single optimum, followed by a sudden divergence of the male and female optima. We find that, in the absence of dosage compensation, the X chromosome promotes evolution toward the female optimum, inducing coevolutionary male-biased responses on the autosomes. Dosage compensation obscures the female-biased interests of the X, causing it to contribute equally to male and female phenotypic change. We further demonstrate that fluctuations in an adaptive landscape can generate prolonged intragenomic conflict and accentuate the differential responses of the X and autosomes to this conflict.
Prompt GRB polarization from non-axisymmetric jets
Authors: Gill Ramandeep , Granot Jonathan
Published: December 2023

Time-resolved linear polarization (Π) measurements of the prompt gamma-ray burst emission can reveal its dominant radiation mechanism. A widely considered mechanism is synchrotron radiation, for which linear polarization can be used to probe the jet’s magnetic-field structure, and in turn its composition. In axisymmetric jet models, the polarization angle (PA) can only change by 90°, as Π temporarily vanishes. However, some time-resolved measurements find a continuously changing PA, which requires the flow to be non-axisymmetric in at least one out of its emissivity, bulk Lorentz factor, or magnetic field. Here, we consider synchrotron emission in non-axisymmetric jets, from an ultrarelativistic thin shell, comprising multiple radially expanding mini-jets (MJs) or emissivity patches within the global jet, that yield a continuously changing PA. We explore a wide variety of possibilities with emission consisting of a single pulse or multiple overlapping pulses, presenting time-resolved and integrated polarization from different magnetic field configurations and jet angular structures. We find that emission from multiple incoherent MJs/patches reduces the net polarization due to partial cancellation in the Stokes plane. When these contain a large-scale ordered field in the plane transverse to the radial direction, Π always starts near maximal and then declines over the single pulse or shows multiple highly polarized peaks due to multiple pulses. Observing $\Pi \lesssim 40~{{\ \rm per\ cent}}$ (15  per cent) integrated over one (several) pulse(s) will instead favour a shock-produced small-scale field either ordered in the radial direction or tangled in the plane transverse to it.
Lethal perturbation of an Escherichia coli regulatory network is triggered by a restriction-modification system's regulator and can be mitigated by excision of the cryptic prophage Rac
Authors: Gucwa Katarzyna , Wons Ewa , Wisniewska Aleksandra , Jakalski Marcin , Dubiak Zuzanna , Kozlowski Lukasz Pawel , Mruk Iwona
Published: December 2023

Bacterial gene regulatory networks orchestrate responses to environmental challenges. Horizontal gene transfer can bring in genes with regulatory potential, such as new transcription factors (TFs), and this can disrupt existing networks. Serious regulatory perturbations may even result in cell death. Here, we show the impact on Escherichia coli of importing a promiscuous TF that has adventitious transcriptional effects within the cryptic Rac prophage. A cascade of regulatory network perturbations occurred on a global level. The TF, a C regulatory protein, normally controls a Type II restriction-modification system, but in E. coli K-12 interferes with expression of the RacR repressor gene, resulting in de-repression of the normally-silent Rac ydaT gene. YdaT is a prophage-encoded TF with pleiotropic effects on E. coli physiology. In turn, YdaT alters expression of a variety of bacterial regulons normally controlled by the RcsA TF, resulting in deficient lipopolysaccharide biosynthesis and cell division. At the same time, insufficient RacR repressor results in Rac DNA excision, halting Rac gene expression due to loss of the replication-defective Rac prophage. Overall, Rac induction appears to counteract the lethal toxicity of YdaT. We show here that E. coli rewires its regulatory network, so as to minimize the adverse regulatory effects of the imported C TF. This complex set of interactions may reflect the ability of bacteria to protect themselves by having robust mechanisms to maintain their regulatory networks, and/or suggest that regulatory C proteins from mobile operons are under selection to manipulate their host's regulatory networks for their own benefit.
Effect of digital monitoring and counselling on self-management ability in patients with rheumatoid arthritis: a randomised controlled trial
Authors: Li Linda C , Xie Hui , Feehan Lynne M , Shaw Chris , Lu Na , Ramachandran Smruthi , Wang Ellen , Therrien Stephanie , Mucha Julia , Hoens Alison M , English Kelly , Davidson Eileen , Liu-Ambrose Teresa , Backman Catherine L , Esdaile John M , Miller Kimberly J , Lacaille Diane
Published: December 2023

Objectives

To assess a remote physiotherapist (PT) counselling intervention using self-monitoring tools for improving self-management ability, physical activity participation and health outcomes in people with rheumatoid arthritis (RA).

Methods

Eligible participants were randomly assigned to receive group education, a Fitbit®, a self-monitoring app, and PT counselling phone calls (Immediate Group). The Delayed Group received a monthly e-newsletter until week 26, and then the intervention. The primary outcome was Patient Activation Measure (PAM-13). Participants were assessed at baseline, 27 weeks (the primary end point) and 53 weeks. Secondary outcomes included disease activity, pain, fatigue, depression, sitting/walking habits, daily physical activity time and daily awake sedentary time. Generalized Linear Mixed-effect Models (GLMMs) were used to assess the effect of the intervention on the change of each outcome measure from the initiation to 27 weeks after the intervention.

Results

Analysis included 131 participants (91.6% women; 80.2% completed during the COVID-19 pandemic). The mean change of PAM-13 at 27 weeks was 4.6 (Standard Deviation [SD] = 14.7) in the Immediate Group vs −1.6 (SD = 12.5) in the Delayed Group. The mean change in Delayed Group at 53 weeks (after the 26-week intervention) was 3.6 (SD = 14.6). Overall, the intervention improved PAM-13 at 27 weeks post-intervention from the GLMM analysis (adjusted coefficient: 5.3; 95% CI: 2.0, 8.7; P ≤ 0.001). Favourable intervention effects were also found in disease activity, fatigue, depression and self-reported walking habit.

Conclusion

Remote counselling paired with self-monitoring tools improved self-management ability in people with RA. Findings of secondary outcomes indicate that the intervention had a positive effect on symptom management.
LSD1 Regulates Neurogenesis in Human Neural Stem Cells Through the Repression of Human-Enriched Extracellular Matrix and Cell Adhesion Genes
Authors: Channakkar Asha S , D’Souza Leora , Kumar Aparajita , Kalia Kishan , Prabhu Srilekha , Phalnikar Kruttika , Reddy Puli Chandramouli , Muralidharan Bhavana
Published: December 2023

Neurogenesis begins with neural stem cells undergoing symmetric proliferative divisions to expand and then switching to asymmetric differentiative divisions to generate neurons in the developing brain. Chromatin regulation plays a critical role in this switch. Histone lysine-specific demethylase LSD1 demethylates H3K4me1/2 and H3K9me1/2 but the mechanisms of its global regulatory functions in human neuronal development remain unclear. We performed genome-wide ChIP-seq of LSD1 occupancy, RNA-seq, and Histone ChIP-seq upon LSD1 inhibition to identify its repressive role in human neural stem cells. Novel downstream effectors of LSD1 were identified, including the Notch signaling pathway genes and human-neural progenitor-enriched extracellular matrix (ECM) pathway/cell adhesion genes, which were upregulated upon LSD1 inhibition. LSD1 inhibition led to decreased neurogenesis, and overexpression of downstream effectors mimicked this effect. Histone ChIP-seq analysis revealed that active and enhancer markers H3K4me2, H3K4me1, and H3K9me1 were upregulated upon LSD1 inhibition, while the repressive H3K9me2 mark remained mostly unchanged. Our work identifies the human-neural progenitor-enriched ECM pathway/cell adhesion genes and Notch signaling pathway genes as novel downstream effectors of LSD1, regulating neuronal differentiation in human neural stem cells.
Human Umbilical Cord Mesenchymal Stromal Cell-Derived Exosomes Alleviate Hypoxia-Induced Pulmonary Arterial Hypertension in Mice Via Macrophages
Authors: Liu Hong , Zhang Qingqing , Liu Chuanchuan , Zhang Yuwei , Wang Yuxiang , Huang Pan , Ma Lan , Ge Rili
Published: December 2023

Pulmonary hypertension (PH) is an intractable, severe, and progressive cardiopulmonary disease. Recent findings suggest that human umbilical cord mesenchymal stromal cells (HUCMSCs) and HUCMSC-derived exosomes (HUCMSC-Exos) possess potential therapeutic value for PH. However, whether they have beneficial effects on hypoxic pulmonary hypertension (HPH) is unclear. Exos are released into the extracellular environment by the fusion of intracellular multivesicular bodies with the cell membrane, and they play an important role in cellular communication. Exos ameliorate immune inflammation levels, alter macrophage phenotypes, regulate mitochondrial metabolic function, and inhibit pulmonary vascular remodeling, thereby improving PH. Macrophages are important sources of cytokines and other transmitters and can promote the release of cytokines, vasoactive molecules, and reactive oxygen species, all of which are associated with pulmonary vascular remodeling. Therefore, the aim of this study was to investigate whether HUCMSC-Exos could improve the lung inflammatory microenvironment and inhibit pulmonary vascular remodeling by targeting macrophages and identifying the underlying mechanisms. The results showed that HUCMSC-Exos promoted M2 macrophage polarization, decreased pro-inflammatory factors, increased IL-10 levels, and inhibited IL-33/ST2 axis expression, thereby inhibiting hypoxia-induced proliferation of pulmonary artery smooth muscle cells and ameliorating HPH.
Split-tendon Docking Technique for Tibialis Anterior Allograft Reconstruction
Authors: Elgie Cameron , Glazebrook Mark A. , Walls Andrew , Arora Gaurav
Published: December 2023

Tibialis anterior ruptures present unique surgical challenges due to frequently delayed diagnosis, often necessitating tendon reconstruction. The Pulvertaft weave has been a mainstay for tendon coaptation in graft reconstruction, but the bulky nature of that construct is a disadvantage in areas with limited soft tissue, such as the foot and ankle. Here we introduce the “split-tendon docking” technique as an alternative, aiming to maintain the strength of the tendon coaptation while reducing its profile. Preoperative evaluation is discussed, including clinical and imaging assessments. The technique is described, including the approach, graft preparation, and docking technique. Complications and postoperative care are considered. While the technique requires further use and validation, it presents a promising, lower-profile alternative for foot and ankle tendon coaptation.

Level of Evidence:

Diagnostic Level 5. See Instructions for Authors for a complete description of levels of evidence.
Dermatopathology Trends in African Americans: A Retrospective Analysis of Biopsies
Authors: Stan Merida Stormy , Gamal Ahmed , Honda Kord
Published: December 2023

In a retrospective analysis of biopsies from January 1, 2019 to December 31, 2020, at University Hospitals Cleveland Medical Center, we aimed to determine the frequency of dermatologic conditions biopsied in African Americans (AA). Given that AAs constitute 13.4% of the US population, understanding the skin disease profile within this significant demographic is crucial. From a total of 1701 biopsies collected from 1442 AA patients, benign neoplasms emerged as the most common diagnosis, accounting for 26.7%, predominantly in females. Notably, cutaneous T-cell lymphoma was the most frequently biopsied malignancy, whereas pigmentary disorders were the least common at 1.4%. The study highlighted the higher occurrence of squamous cell carcinoma compared with basal cell carcinoma in AA, contrasting trends in other racial demographics. Moreover, recognizing the unique presentations of skin disorders in different racial backgrounds is essential, especially because disparities have been reported in skin of color training among dermatology residency programs. Understanding these racial differences in skin diseases can assist clinicians in refining their diagnostic approach. Future research could further explore the potential gaps between clinical expectations and histologic findings, improving diagnostic accuracy.
The Clinical Learning Environment: Past, Present, and Future
Authors: Casey Donald E.
Published: December 2023

In this issue of AJMQ, Graduate Medical Education leaders from a large nationally renowned academic medical center describe in detail the “Residents and Fellows Leading Interprofessional Continuous Improvement Teams” program with a focus on the collaboration within their health system in alignment with Clinical Learning Environment review since its inception. In addition, the authors share key outcomes of the program using the reach, effectiveness, adoption, implementation, maintenance framework, additional structural (eg, timeline) and outcome (eg, scholarship) measures for further context within Graduate Medical Education and Undergraduate Medical Education, and describe elements which supported the program’s success and lessons learned.
Mortality Among Individuals Diagnosed With Chronic Beryllium Disease and Beryllium Sensitization
Authors: TenHarmsel Hailey , Wang Ling , Dumas Constantine , Rosenman Kenneth D.
Published: December 2023

Objective

The aim of the study is to investigate the cause of death among individuals diagnosed with chronic beryllium disease (CBD) or beryllium sensitization (BeS).

Methods

Vital status, cause of death, and standardized mortality ratios for the underlying cause of death were determined for a cohort of 354 individuals with CBD and 290 individuals with BeS.

Results

Among 216 deceased individuals, 153 had CBD and 63 had BeS. Nonmalignant respiratory deaths and other causes of death were significantly increased among those with CBD. No cause of death was significantly increased for BeS. Mortality from lung cancer was not increased.

Conclusions

Individuals with CBD had an overall increased mortality risk due to increased respiratory mortality regardless of their duration of exposure to beryllium. Individuals with BeS did not have increased respiratory mortality. No increased risk of lung cancer was seen among this cohort.
Flexible CO2 Laser in Therapeutic Bronchoscopy
Authors: Ortiz-Jaimes Gabriel , Mullon John , Nelson Darlene , Reisenauer Janani , Midthun David , Edell Eric , Anderson Dagny , Vargas-Brochero Maria , Petrossian Robert , Kern Ryan
Published: December 2023

Background:

CO2 Laser (CO2L) technology deployable through flexible endoscopes now allows for their use throughout the airway, although published data are limited.

Methods:

Retrospective analysis of CO2L bronchoscopic procedures, excluding glottic and subglottic interventions. Procedural success was defined as >50% visual reduction in airway obstruction in the area treated or resolution of the procedural indication.

Results:

Seventy-two procedures were performed on 36 patients. Nonmalignant indications comprised 66%: stent-associated granulation tissue (28%), granulomatosis with polyangiitis lesions (23%), and lung transplant-related granulation tissue (16%) were the most common. Bronchoscopic access was flexible only in 81% and primarily rigid (combined with flexible) in 18%. The site of intervention was the trachea at 19%, the mainstem at 56%, and lobar/segmental airways at 45%. Procedural success was 89%. CO2L was used exclusively in 19%; in 81%, additional techniques were required, most commonly balloon dilation (59%), cryo-debulking (23%), and rigid dilation (16%). Malignant indications had a nonsignificant trend toward requiring adjuvant techniques (P=0.05). Seventy-six percent of the patients required more than 1 procedure. CO2L exclusive cases had no statistically different needs for subsequent therapeutic bronchoscopies (P=0.10) or time to reintervention (109 vs. 41 days, P=0.07), and reintervention-free survival was similar (P=0.10) and difficult to predict. The complication rate attributable to CO2L was 2.7%.

Conclusion:

CO2L is a safe and useful tool when precise cutting and vaporization are desired. Its use in multi-modality approaches has high levels of success in adequately selected lesions, adding an ablative potential to dilation techniques. Vasculitis-associated scars/webs and granulation tissue (including stent-associated) appear to be ideal targets.
Generative AI Backstories for Simulation Preparation
Authors: Reed Janet M. , Dodson Tracy M.
Published: December 2023

Background:

Developing engaging presimulation learning materials that provide contextualized patient information is needed to best prepare students for nursing simulation. One emerging strategy that can be used by educators to create visual images for storytelling is generative artificial intelligence (AI).

Purpose:

The purpose of this pilot study was to determine how the use of generative AI–created patient backstories as a presimulation strategy might affect student engagement and learning in nursing simulation.

Methods:

A qualitative cross-sectional survey with content analysis was completed with undergraduate nursing students following an acute care simulation.

Results:

Student surveys point to positive pedagogical outcomes of using AI image generation as a strategy to prepare for simulation such as decreased anxiety in simulation, increased preparatory knowledge, and increased emotional connection with the patient's story.

Conclusions:

Images created with generative AI hold promise for future research and transforming nursing education.