bluuebunny/crossref_metadata_2025 huggingface dataset:
Sapphire crystal growth and solid–liquid interface structure: An investigation by molecular dynamic simulation and Czochralski growth
Authors: Liu Feng , Chen Kunfeng , Peng Chao , Xue Dongfeng
Published: May 2023

Sapphire has increasing demand toward optoelectrical devices like LED; its big challenge is to find reasonable growth mechanisms for high quality large size single crystals. In this paper, we proposed both theoretical and experimental studies to clarify multiscale behaviors within the Al2O3 growth system. Molecular dynamics simulation for sapphire crystal growth along c-, a-, and m-axes, and solid–liquid interface structure, and grown 2″ sapphire via the Czochralski method along the c-axis, were reported herein. Our studies show that α-Al2O3 growth behaviors along different crystal directions are different, which is different from the amorphous Al2O3 phase transition at the various α-Al2O3 planes. α-Al2O3 crystal growth in the c-axis system may be a complex process involving solid–liquid and solid–solid transformations, rather than a single solid–liquid transformation that happened in the systems growing along the a- and m-axes. Within the time scale of simulation, the crystals cannot be grown by the lattice period of the seed crystal along the c-axis and transform into γ-Al2O3 rather than α-Al2O3, while it is opposite along the a- and m-axes. This may be the microscopic reason why it is difficult to grow sapphire along the c-axis in the experiment. An abrupt change in the interfacial structure is the key reason to inhibit the transformation of liquid Al2O3 into α-Al2O3 along the c-axis.
Optical and electrical investigation of plasma generated by high-energy self-stabilized spark ignition system
Authors: Janda Mário , Korytchenko Kostyantyn , Shypul Olga , Krivosheev Serhiy , Yeresko Oleksandr , Kasimov Anatoly
Published: May 2023

Spark discharge plasma is commonly used for ignition in internal combustion engines. The environmental performance of internal combustion engines with forced ignition is improved when operating under lean mixture conditions. High-energy ignition systems are needed to ensure reliable ignition of lean mixtures. The ignition of a combustible mixture is influenced by several plasma parameters, such as the temperature of its various components, the size of the plasma, and the deposited energy. It is, therefore, beneficial to know these parameters. Here, we present optical and electrical investigation of plasma generated in ambient air by a novel high-energy self-stabilized spark ignition system. The electrical investigation showed two high current pulses, with the current amplitude of ∼40 and ∼150 A. The energy is deposited to the spark gap mainly during the second current pulse, and it is increasing from 213 to 541 mJ with the increasing gap size from 3 to 13 mm. The energy efficiency increases with the gap as well, from around 23% to 58%. Time-resolved emission spectra enabled us to estimate the evolution of the gas temperature, electron excitation temperature, and electron density in the generated plasma. It was found that the highest electron density, 3–4 × 1017 cm−3, correlates with the maximum of the second pulse current. We observed a specific plasma evolution between the two current pulses, with an increase in temperature from 4500 to 7500 K and a contraction of the plasma channel diameter from 3.3 to 0.5 mm.
A millikelvin precision temperature control system designed for a low cost, portable and variable temperature blackbody from 298.15 to 693.15 K
Authors: Liang Peizhao , Hu Tieli , Xu Jinxin , Xu Qiyue , Ding Jiong
Published: May 2023

Millikelvin precision portable variable temperature blackbody from 298.15 to 693.15 K is very important in the on-site calibration of infrared measuring instruments. The stability of the blackbody temperature directly affects the calibration quality. However, the temperature measurement and control system is the key component to guarantee the stability of the blackbody temperature. In this article, a measurement and control system of the low-cost and portable blackbody was designed and verified. A Pt100 platinum resistance thermometer was employed to measure the temperature of the blackbody radiation source. Based on the round-robin structure and current reversing technology, the precision of the temperature measurement achieved a sub-millikelvin level. To overcome the drawbacks that traditional proportional integral derivative (PID) controller would lead to large overshoot and long adjustment time during the temperature control of the large thermal inertia blackbody, a feedforward and segmented PID controller was introduced to improve the dynamic performance of the blackbody radiation source. The experimental results showed that the precision of the temperature measurement at 0.5 Hz was better than 0.5 mK and the temperature stability within 10 min was better than 3 mK in the temperature range from 298.15 to 693.15 K. Hence, the millikelvin precision measurement and control system has a strong prospect for practical application in high-performance blackbody development.
Two-dimensional dynamics of a mobile elliptical cylinder in an upward flow
Authors: Akinpelu David , Schoegl Ingmar , Minocha Nitin , Nandakumar Krishnaswamy
Published: May 2023

The fully resolved dynamics of an elliptical particle suspended in an upward flow in an expanding channel, with successively increasing degrees of freedom of motion from a completely fixed state to an eventually fluidized state, are examined using particle resolved direct numerical simulation. The signed distance function immersed boundary method (sdfibm), implemented in OpenFOAM, is validated against results from COMSOL for the case of a pinned ellipse. The aspect ratio of the ellipse (defined as the ratio of the major to the minor axis (γ=Ra/Rb) is held constant at 2, while the minor axis is kept as Rb=0.15 (with respect to the inlet width, Wi = 1). A particle Reynolds number defined as Rep=(2Ra)Vmax/ν (where Vmax = 1 is the centerline velocity) is varied up to 300. The simulations exhibit rich dynamical behavior with stable, steady solutions up to Rep around 67, above which vortex shedding begins, with the ellipse responding with its oscillatory motion in response to the stresses and torques acting on it by the fluid. For the case of free translation in the x direction, multiple oscillatory states are found, where the particle is confined in the left or right half of the flow domain, depending on the initial placement of the particle. The forces on the particle get progressively complicated as the degree of freedom of movement of the ellipse increases, indicating that traditional drag correlations with fixed particles may not be valid in situations when they have mobility if one desires higher fidelity in coarse-grained models.
Numerical examination of wall properties for the magnetohydrodynamics stagnation point flow of micro-rotating fluid subject to weak concentration
Authors: Khan Abdul Samad , Idrees Muhammad , Khan Noor Ul Samad
Published: May 2023

In this investigation, stagnation point flow of non-Newtonian fluid is considered under the impact of magnetohydrodynamics, porous medium, and mixed convection effects. Additionally, angular momentum and energy transport constitutive equations are also taken into account in order to explore the fluid micro-rotational effects. The fluid motion develops by virtue of linear stretching and slip factors. Furthermore, the energy transport equation is raised with the effect of viscous dissipation and heat source phenomena. Mathematical formulations lead to a set of ordinary differential equations by introducing similarity variables. The proposed model has been solved numerically using fourth-order Runge–Kutta method with shooting technique. Influence of pertinent flow parameters for the case of weak concentration of micro-elements on velocity, temperature, skin friction, and local heat flux at the surface is computed and discussed. Different ranges are chosen for the flow parameters, for example; magnetic field variation is taken [0, 0.9], micro-rotation [0,1], stretching ratio [0,0.2], surface condition [0,1], the Prandtl number [3, 12], and the Eckert number [3, 11]. The fluid velocity slows down when the magnetic number varies from 0.0 to 0.5 in the presence of weak concentration (m = 0.5) of micro-elements. In addition, the maximum increasing percentage of skin friction is obtained when the porosity parameter varies from 0.0 to 0.6. The maximum decreasing percentage of the Nusselt number is obtained when the thermal slip parameter varies from 0.0 to 0.8. The current study has multiple fascinating applications in polymeric solutions, bio-medical functions like magnetic drug targeting, heat conduction in tissues, surface roughness, and squeeze film lubrication problems between conical bearings.
Ionization dynamics of sub-micrometer-sized clusters in intense ultrafast laser pulses
Authors: Gao Xiaohui
Published: May 2023

Sub-micrometer-sized targets are found in intense laser–cluster interaction experiments and laser-based material processing. Here, we investigate the internal field localization due to Mie scattering and its effect on ionization dynamics in sub-micrometer-sized clusters using Mie calculation and particle-in-cell simulations. As a result of intertwined processes of pulse propagation and ionization, sub-micrometer nanofocusing dominates at lower intensity and gives rise to an ionization hotspot at the rear of the targets while plasma shielding wins over at a higher intensity, stopping further rear side ionization. As ionization is often the precursor of other processes, understanding the ionization dynamics of ultrafast laser pulses with wavelength-sized nanostructure can be relevant for intense laser-cluster experiments and femtosecond laser micro-/nanomachining.
Numerical characterization of a discharge-based compact soft x-ray source operation in CO2 and Ar:He mixture
Authors: Samokhvalov A. A. , Sergushichev K. A. , Eliseev S. I. , Smirnov A. A. , Bronzov T. P. , Timshina M. V. , Burtsev V. A.
Published: May 2023

This paper presents numerical characterization of a recently developed compact soft x-ray source based on a nanosecond electric discharge in a gas-filled capillary. When operated in CO2 and Ar:He mixture, the source is capable of producing line radiation in wavelength ranges corresponding to the carbon (4.5–5.0 nm) and water (2.3–4.4 nm) transparency windows. Experimentally obtained trends in emission properties are analyzed using a two-temperature magnetohydrodynamic model, which utilizes mean ion approximation for calculation of basic properties of multicomponent plasma. Spatiotemporal distributions of plasma parameters were obtained for a range of gas pressures corresponding to the studied experimental conditions of the soft x-ray source. Peak values of electron density and electron temperature were analyzed and used to interpret the experimentally obtained trends in dependence of the source operation on inlet gas pressure.
Determination of short-range order in TiVNbHf(Al)
Authors: Xu Michael , Wei Shaolou , Tasan C. Cem , LeBeau James M.
Published: May 2023

The presence of short-range chemical order can be a key factor in determining the mechanical behavior of metals, but directly and unambiguously determining its distribution in complex concentrated alloy systems can be challenging. Here, we directly identify and quantify chemical order in the globally single phase BCC-TiVNbHf(Al) system using aberration corrected scanning transmission electron microscopy (STEM) paired with spatial statistics methods. To overcome the difficulties of short-range order (SRO) quantification with STEM when the components of an alloy exhibit large atomic number differences and near equiatomic ratios, “null hypothesis” tests are used to separate experiment from a random chemical distribution. Experiment is found to deviate from both the case of an ideal random solid solution and a fully ordered structure with statistical significance. We also identify local chemical order in TiVNbHf and confirm and quantify the enhancement of SRO with the addition of Al. These results provide insight into local chemical order in the promising TiVNbHf(Al) refractory alloys while highlighting the utility of spatial statistics in characterizing nanoscale SRO in compositionally complex systems.
Effect of size and spacing on the wake characteristics of two spheres placed in tandem
Authors: Kumar Abhishek , Tiwari Shaligram , Das S. P.
Published: May 2023

In the present study, the flow past two spheres placed in a tandem arrangement is investigated numerically using open source field operation and manipulation (OpenFOAM) at a fixed Reynolds number (Re) of 300, where the Reynolds number is defined based on the diameter (D) of the downstream sphere (DS) and the freestream velocity at the inlet. Keeping size of the DS constant, the diameter of the upstream sphere (US) has been varied, so that the diameter ratio, DR (ratio of the diameters upstream and downstream spheres), takes the values of 0.4, 0.6, 0.8, 1.0, and 1.5. The spacing between the spheres (S) is also varied from 1D to 5D. Iso-Q surfaces show that both upstream and downstream wakes undergo various transitions with changes in the values of DR and S. For US, transition from steady symmetric to planar symmetric occurs at DR = 0.6 and S = 1, which corresponds to a local Re of 180. For DR = 0.8, steady to unsteady transition occurs at S = 2, whereas for all other values of S, the wake remains steady. For DR > 0.8 and S > 1, both upstream and downstream wakes are found to be unsteady. Hilbert analysis revealed that unsteady wakes are periodic for DR values of 0.4, 0.8, and 1.0 and are aperiodic for DR = 1.5. In addition, the extent of wake nonlinearity has also been quantified in terms of degree of stationarity. The drag force on both the spheres increases with an increase in spacing between the spheres.
Assessment of the shear stress transport dynamic ℓ2−ω delayed detached eddy simulation in Bachalo–Johnson flow with shock-induced separation
Authors: Qu Lipeng , Bader Shujaut H. , Yin Zifei
Published: May 2023

Driven by the need for simulating compressible flows, Germano identity-based [Z. Yin and P. A. Durbin, “An adaptive DES model that allows wall-resolved eddy simulation,” Int. J. Heat Fluid Flow 62, 499–509 (2016)] and Vreman operator-based [Bader et al., “A hybrid model for turbulence and transition, with a locally varying coefficient,” Flow, Turbul. Combust. 108, 935–954 (2022)] dynamic ℓ2−ω delayed detached eddy simulation (DDES) formulations are constructed on the k−ω shear stress transport (SST) model. The Bachalo–Johnson transonic axisymmetric bump is simulated to assess the models’ capability in handling the compressible boundary layers under pressure gradient and transonic shock–boundary layer interaction. The new dynamic ℓ2−ω DDES formulation based on k−ω SST overcomes the issues of freestream sensitivity and inaccurate compressible boundary layer profile observed in the original k−ω (88) based model. The new SST-based dynamic model using the Vreman operator to compute the model coefficient (Vreman-dynamic model) has superior performance against Germano identity-based model due to its capability of suppressing the subgrid viscosity during the initial development of a separating shear layer. The Vreman-dynamic model predicts a reattachment location similar to the zonal improved-DDES/direct numerical simulation approach by Spalart et al. [“Large-eddy and direct numerical simulations of the bachalo-johnson flow with shock-induced separation,” Flow, Turbul. Combust. 99, 865–885 (2017)] on a much coarser mesh demonstrating its potential for application in industrial flows.
Self-consistent integrated modeling of combined hybrid discharge-laser produced plasma devices for extreme ultraviolet metrology
Authors: Sizyuk Valeryi , Hassanein Ahmed , Melsheimer Florian , Juschkin Larissa , Sizyuk Tatyana
Published: May 2023

Discharge- and laser-produced plasma (DLPP) devices are being used as light sources for extreme ultraviolet (EUV) generation. A key challenge for both, DPP and LPP, is achieving sufficient brightness to support the throughput requirements of nanometrology tools. To simulate the environment of a hybrid DLPP device and optimize the EUV output, we have developed an integrated HEIGHTS-DLPP computer simulation package. The package integrates simulation of two evolving plasmas (DPP and LPP) and includes modeling of a set of integrated self-consistent processes: external power source and plasma energy balance, plasma resistive magnetohydrodynamics, plasma heat conduction, detailed radiation transport (RT), and laser absorption and refraction. We simulated and optimized DLPP devices using Xe gas as a target material. We synchronized the external circuit parameters, chamber gas parameters, and laser beam temporal and spatial profiles to achieve maximum EUV output. The full 3D Monte Carlo scheme was integrated for detailed RT and EUV output calculations in Xe using more than 3600 spectral groups. The modeling results are in good agreement with Julich Forschungszentrum experimental data. Theoretical models, developed and integrated into the HEIGHTS package, showed wide capabilities and flexibility. The models and package can be used for optimization of the experimental parameters and settings, investigation of DLPP devices with complex design, analyzing the impact of integrated spatial effects and working timeline arrangement on the final EUV output, and EUV source size, shape, and angular distribution.
Complexity factor parameterization for traversable wormholes
Authors: Bhattacharya Subhra , Nalui Subhasis
Published: May 2023

It is known that static traversable wormholes in Einstein gravity are supported by matter that violates null energy conditions (NEC). Essentially, such wormholes will be characterized by a central throat with anisotropic matter lining the throat that violates NEC. This, in turn, provides viable geometry for the wormhole to sustain. In 2018, Herrera [Phys. Rev. D 97, 044010 (2018)] introduced a new classification for spherically symmetric bodies called “complexity factor.” It was proposed that a spherically symmetric non-trivial geometry can be classified as complex or non-complex based on the nature of the inhomogeneity and anisotropy of the stress–energy tensors with only homogeneous and isotropic matter distribution leading to null complexity. Mathematically, there was also another way of obtaining zero complexity geometry. In this context, since static traversable wormholes, by default, are characterized by anisotropic and inhomogeneous matter stress tensors, the question we answer is whether it is possible to obtain zero complexity class of wormholes supported by exotic matter.
Influence of channel bend angle on the turbulent statistics in sharply bent channel flows
Authors: Sharma Abhishek , Lakkaraju Rajaram , Atta Arnab
Published: May 2023

Turbulence in wall-bounded flows shows a wide range of regimes, where the interaction between scales significantly occur. Reynolds number is used to characterize the dynamics of fluid corresponding to single phase channel flows. Meanwhile, different flow behavior exists in curved channels even at fixed Reynolds number, where the curvature varies as shown by Brethouwer [“Turbulent flow in curved channels,” J. Fluid Mech. 931, A21 (2022)]. In the present study, we show how wall-bounded turbulent flow behaves on sharply bending the channel by investigating the time averaged velocity profiles at the straight section, at the bend, and in the inclined section. The well-known logarithmic behavior of the time averaged normalized velocity profile is retained, where the von Kármán and the additive constants assume altered values depending on the sharp bend inclination. The near-wall fluctuations at the bend are enhanced, which is due to diffusion of counter-rotating vortices leading to increased turbulent activity. In terms of spatial structure of the random fluctuating field, the two-point correlation statistics suggest that multiple high speed and low speed streak pairs are generated, and there are multiple streamwise vortices of different sizes when bend inclination is increased. Budgets of turbulent kinetic energy are presented for various inclinations of the bend at different sections of the bend channel, which depicts that turbulent kinetic energy is modulated at the bend.
White matter plasticity following cataract surgery in congenitally blind patients
Authors: Pedersini Caterina A. , Miller Nathaniel P. , Gandhi Tapan K. , Gilad-Gutnick Sharon , Mahajan Vidur , Sinha Pawan , Rokers Bas
Published: May 2023

The visual system develops abnormally when visual input is absent or degraded during a critical period early in life. Restoration of the visual input later in life is generally thought to have limited benefit because the visual system will lack sufficient plasticity to adapt to and utilize the information from the eyes. Recent evidence, however, shows that congenitally blind adolescents can recover both low-level and higher-level visual function following surgery. In this study, we assessed behavioral performance in both a visual acuity and a face perception task alongside longitudinal structural white matter changes in terms of fractional anisotropy (FA) and mean diffusivity (MD). We studied congenitally blind patients with dense bilateral cataracts, who received cataract surgery at different stages of adolescence. Our goal was to differentiate between age- and surgery-related changes in both behavioral performance and structural measures to identify neural correlates which might contribute to recovery of visual function. We observed surgery-related long-term increases of structural integrity of late-visual pathways connecting the occipital regions with ipsilateral fronto-parieto-temporal regions or homotopic contralateral areas. Comparison to a group of age-matched healthy participants indicated that these improvements went beyond the expected changes in FA and MD based on maturation alone. Finally, we found that the extent of behavioral improvement in face perception was mediated by changes in structural integrity in late visual pathways. Our results suggest that sufficient plasticity remains in adolescence to partially overcome abnormal visual development and help localize the sites of neural change underlying sight recovery.
Humans plan for the near future to walk economically on uneven terrain
Authors: Darici Osman , Kuo Arthur D.
Published: May 2023

Humans experience small fluctuations in their gait when walking on uneven terrain. The fluctuations deviate from the steady, energy-minimizing pattern for level walking and have no obvious organization. But humans often look ahead when they walk, and could potentially plan anticipatory fluctuations for the terrain. Such planning is only sensible if it serves some an objective purpose, such as maintaining constant speed or reducing energy expenditure, that is also attainable within finite planning capacity. Here, we show that humans do plan and perform optimal control strategies on uneven terrain. Rather than maintaining constant speed, they make purposeful, anticipatory speed adjustments that are consistent with minimizing energy expenditure. A simple optimal control model predicts economical speed fluctuations that agree well with experiments with humans (N = 12) walking on seven different terrain profiles (correlated with model 

ρ
=
0.55
±
0.11

 ,

P
<
0.05

all terrains). Participants made repeatable speed fluctuations starting about six to eight steps ahead of each terrain feature (up to ±7.5 cm height difference each step, up to 16 consecutive features). Nearer features matter more, because energy is dissipated with each succeeding step’s collision with ground, preventing momentum from persisting indefinitely. A finite horizon of continuous look-ahead and motor working space thus suffice to practically optimize for any length of terrain. Humans reason about walking in the near future to plan complex optimal control sequences.
Modeling human skeletal development using human pluripotent stem cells
Authors: Lamandé Shireen R. , Ng Elizabeth S. , Cameron Trevor L. , Kung Louise H. W. , Sampurno Lisa , Rowley Lynn , Lilianty Jinia , Patria Yudha Nur , Stenta Tayla , Hanssen Eric , Bell Katrina M. , Saxena Ritika , Stok Kathryn S. , Stanley Edouard G. , Elefanty Andrew G. , Bateman John F.
Published: May 2023

Chondrocytes and osteoblasts differentiated from induced pluripotent stem cells (iPSCs) will provide insights into skeletal development and genetic skeletal disorders and will generate cells for regenerative medicine applications. Here, we describe a method that directs iPSC-derived sclerotome to chondroprogenitors in 3D pellet culture then to articular chondrocytes or, alternatively, along the growth plate cartilage pathway to become hypertrophic chondrocytes that can transition to osteoblasts. Osteogenic organoids deposit and mineralize a collagen I extracellular matrix (ECM), mirroring in vivo endochondral bone formation. We have identified gene expression signatures at key developmental stages including chondrocyte maturation, hypertrophy, and transition to osteoblasts and show that this system can be used to model genetic cartilage and bone disorders.
Switch-like compaction of poly(ADP-ribose) upon cation binding
Authors: Badiee Mohsen , Kenet Adam L. , Ganser Laura R. , Paul Tapas , Myong Sua , Leung Anthony K. L.
Published: May 2023

Poly(ADP-ribose) (PAR) is a homopolymer of adenosine diphosphate ribose that is added to proteins as a posttranslational modification to regulate numerous cellular processes. PAR also serves as a scaffold for protein binding in macromolecular complexes, including biomolecular condensates. It remains unclear how PAR achieves specific molecular recognition. Here, we use single-molecule fluorescence resonance energy transfer (smFRET) to evaluate PAR flexibility under different cation conditions. We demonstrate that, compared to RNA and DNA, PAR has a longer persistence length and undergoes a sharper transition from extended to compact states in physiologically relevant concentrations of various cations (Na
+
, Mg
2+
, Ca
2+
, and spermine
4+
). We show that the degree of PAR compaction depends on the concentration and valency of cations. Furthermore, the intrinsically disordered protein FUS also served as a macromolecular cation to compact PAR. Taken together, our study reveals the inherent stiffness of PAR molecules, which undergo switch-like compaction in response to cation binding. This study indicates that a cationic environment may drive recognition specificity of PAR.
CRISPR editing of CCR5 and HIV-1 facilitates viral elimination in antiretroviral drug-suppressed virus-infected humanized mice
Authors: Dash Prasanta K. , Chen Chen , Kaminski Rafal , Su Hang , Mancuso Pietro , Sillman Brady , Zhang Chen , Liao Shuren , Sravanam Sruthi , Liu Hong , Waight Emiko , Guo Lili , Mathews Saumi , Sariyer Rahsan , Mosley R. Lee , Poluektova Larisa Y. , Caocci Maurizio , Amini Shohreh , Gorantla Santhi , Burdo Tricia H. , Edagwa Benson , Gendelman Howard E. , Khalili Kamel
Published: May 2023

Treatment of HIV-1
ADA
-infected CD34+ NSG-humanized mice with long-acting ester prodrugs of cabotegravir, lamivudine, and abacavir in combination with native rilpivirine was followed by dual CRISPR-Cas9 C-C chemokine receptor type five (CCR5) and HIV-1 proviral DNA gene editing. This led to sequential viral suppression, restoration of absolute human CD4
+
T cell numbers, then elimination of replication-competent virus in 58% of infected mice. Dual CRISPR therapies enabled the excision of integrated proviral DNA in infected human cells contained within live infected animals. Highly sensitive nucleic acid nested and droplet digital PCR, RNAscope, and viral outgrowth assays affirmed viral elimination. HIV-1 was not detected in the blood, spleen, lung, kidney, liver, gut, bone marrow, and brain of virus-free animals. Progeny virus from adoptively transferred and CRISPR-treated virus-free mice was neither detected nor recovered. Residual HIV-1 DNA fragments were easily seen in untreated and viral-rebounded animals. No evidence of off-target toxicities was recorded in any of the treated animals. Importantly, the dual CRISPR therapy demonstrated statistically significant improvements in HIV-1 cure percentages compared to single treatments. Taken together, these observations underscore a pivotal role of combinatorial CRISPR gene editing in achieving the elimination of HIV-1 infection.
Learning rules of engagement for social exchange within and between groups
Authors: Rojek-Giffin Michael , Lebreton Maël , Daunizeau Jean , Fariña Andrea , Gross Jörg , De Dreu Carsten K. W.
Published: May 2023

Globalizing economies and long-distance trade rely on individuals from different cultural groups to negotiate agreement on what to give and take. In such settings, individuals often lack insight into what interaction partners deem fair and appropriate, potentially seeding misunderstandings, frustration, and conflict. Here, we examine how individuals decipher distinct rules of engagement and adapt their behavior to reach agreements with partners from other cultural groups. Modeling individuals as Bayesian learners with inequality aversion reveals that individuals, in repeated ultimatum bargaining with responders sampled from different groups, can be more generous than needed. While this allows them to reach agreements, it also gives rise to biased beliefs about what is required to reach agreement with members from distinct groups. Preregistered behavioral (
N
= 420) and neuroimaging experiments (
N
= 49) support model predictions: Seeking equitable agreements can lead to overly generous behavior toward partners from different groups alongside incorrect beliefs about prevailing norms of what is appropriate in groups and cultures other than one’s own.
Engineering transmembrane signal transduction in synthetic membranes using two-component systems
Authors: Peruzzi Justin A. , Galvez Nina R. , Kamat Neha P.
Published: May 2023

Cells use signal transduction across their membranes to sense and respond to a wide array of chemical and physical signals. Creating synthetic systems which can harness cellular signaling modalities promises to provide a powerful platform for biosensing and therapeutic applications. As a first step toward this goal, we investigated how bacterial two-component systems (TCSs) can be leveraged to enable transmembrane-signaling with synthetic membranes. Specifically, we demonstrate that a bacterial two-component nitrate-sensing system (NarX-NarL) can be reproduced outside of a cell using synthetic membranes and cell-free protein expression systems. We find that performance and sensitivity of the TCS can be tuned by altering the biophysical properties of the membrane in which the histidine kinase (NarX) is integrated. Through protein engineering efforts, we modify the sensing domain of NarX to generate sensors capable of detecting an array of ligands. Finally, we demonstrate that these systems can sense ligands in relevant sample environments. By leveraging membrane and protein design, this work helps reveal how transmembrane sensing can be recapitulated outside of the cell, adding to the arsenal of deployable cell-free systems primed for real world biosensing.
A cytosolic bifunctional geranyl/farnesyl diphosphate synthase provides MVA-derived GPP for geraniol biosynthesis in rose flowers
Authors: Conart Corentin , Bomzan Dikki Pedenla , Huang Xing-Qi , Bassard Jean-Etienne , Paramita Saretta N. , Saint-Marcoux Denis , Rius-Bony Aurélie , Hivert Gal , Anchisi Anthony , Schaller Hubert , Hamama Latifa , Magnard Jean-Louis , Lipko Agata , Swiezewska Ewa , Jame Patrick , Riveill Geneviève , Hibrand-Saint Oyant Laurence , Rohmer Michel , Lewinsohn Efraim , Dudareva Natalia , Baudino Sylvie , Caissard Jean-Claude , Boachon Benoît
Published: May 2023

Geraniol derived from essential oils of various plant species is widely used in the cosmetic and perfume industries. It is also an essential trait of the pleasant smell of rose flowers. In contrast to other monoterpenes which are produced in plastids via the methyl erythritol phosphate pathway, geraniol biosynthesis in roses relies on cytosolic NUDX1 hydrolase which dephosphorylates geranyl diphosphate (GPP). However, the metabolic origin of cytosolic GPP remains unknown. By feeding
Rosa chinensis
“Old Blush” flowers with pathway-specific precursors and inhibitors, combined with metabolic profiling and functional characterization of enzymes in vitro and in planta, we show that geraniol is synthesized through the cytosolic mevalonate (MVA) pathway by a bifunctional geranyl/farnesyl diphosphate synthase, RcG/FPPS1, producing both GPP and farnesyl diphosphate (FPP). The downregulation and overexpression of
RcG/FPPS1
in rose petals affected not only geraniol and germacrene D emissions but also dihydro-β-ionol, the latter due to metabolic cross talk of RcG/FPPS1-dependent isoprenoid intermediates trafficking from the cytosol to plastids. Phylogenetic analysis together with functional characterization of G/FPPS orthologs revealed that the G/FPPS activity is conserved among
Rosaceae
species. Site-directed mutagenesis and molecular dynamic simulations enabled to identify two conserved amino acids that evolved from ancestral FPPSs and contribute to GPP/FPP product specificity. Overall, this study elucidates the origin of the cytosolic GPP for NUDX1-dependent geraniol production, provides insights into the emergence of the RcG/FPPS1 GPPS activity from the ancestral FPPSs, and shows that RcG/FPPS1 plays a key role in the biosynthesis of volatile terpenoid compounds in rose flowers.
Metabolic homeostasis and growth in abiotic cells
Authors: Akbari Amir , Palsson Bernhard O.
Published: May 2023

Metabolism constitutes the core chemistry of life. How it began on the early Earth and whether it had a cellular origin are still uncertain. A leading hypothesis for life’s origins postulates that metabolism arose from geochemical CO
2
-fixing pathways, driven by inorganic catalysts and energy sources, long before enzymes or genes existed. The acetyl-CoA pathway and the reductive tricarboxylic acid cycle are considered ancient reaction networks that hold relics of early carbon-fixing pathways. Although transition metals can promote many steps of these pathways, whether they form a functional metabolic network in abiotic cells has not been demonstrated. Here, we formulate a nonenzymatic carbon-fixing network from these pathways and determine its functional feasibility in abiotic cells by imposing fundamental physicochemical constraints. Using first principles, we show that abiotic cells can sustain a steady carbon-fixing cycle that performs a systemic function over a relatively narrow range of conditions. Furthermore, we find that in all feasible steady states, the operation of the cycle elevates the osmotic pressure, leading to volume expansion. These results suggest that achieving homeostatic metabolic states under prebiotic conditions was possible, but challenging, and volume growth was a fundamental property of early metabolism.
0.3% Tacrolimus gel and 0.5% Tacrolimus cream show efficacy in mild to moderate plaque psoriasis: Results of a randomized, open-label, observer-blinded study
Authors: Ortonne JP , Van de Kerkhof PC , Prinz JC , Bieber T , Lahfa M , Rubins A , Wozel G , Lorette G.
Published: May 2023

The efficacy and safety of 0.3% tacrolimus gel and 0.5% tacrolimus cream compared with calcipotriol ointment were evaluated in adults (n = 124) with mild to moderate plaque psoriasis. Treatment was twice daily for a maximum of 12 weeks. Clinical efficacy was assessed by the percentage change in the local psoriasis severity index of a target lesion between baseline and week 12. By week 12, the median percentage changes in local psoriasis severity index of the target lesions in the tacrolimus gel, tacrolimus cream and calcipotriol groups were 55.6%, 50.0% and 58.6%, respectively (no statistically significant differences). Clinical improvement was observed after one week and increased throughout the study. Tacrolimus-treated patients experienced more application site skin burning (tacrolimus gel and cream both 31.0% versus 7.5% for calcipotriol; p = 0.011). Skin burning was mostly mild in intensity and decreased substantially after 1 week of treatment. There were no differences in the nature and incidence of infections and no clinically relevant changes in laboratory values.
Systemic absorption of topical tacrolimus in Pyoderma gangrenosum
Authors: Pitarch G , Torrijos A , Mahiques L , Sánchez-Carazo JL , Fortea JM.
Published: May 2023

This article does not have an abstract.
Summary
Authors: Listed No authors
Published: May 2023

This article does not have an abstract.
1. Introduction: Immunotherapy for Dermatological Conditions
Authors: Rigel B  , Berman B
Published: May 2023

This article does not have an abstract.
SARS-CoV-2 Serology Across Scales: A Framework for Unbiased Estimation of Cumulative Incidence Incorporating Antibody Kinetics and Epidemic Recency
Authors: Takahashi Saki , Peluso Michael J , Hakim Jill , Turcios Keirstinne , Janson Owen , Routledge Isobel , Busch Michael P , Hoh Rebecca , Tai Viva , Kelly J Daniel , Martin Jeffrey N , Deeks Steven G , Henrich Timothy J , Greenhouse Bryan , Rodríguez-Barraquer Isabel
Published: April 2023

Serosurveys are a key resource for measuring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) population exposure. A growing body of evidence suggests that asymptomatic and mild infections (together making up over 95% of all infections) are associated with lower antibody titers than severe infections. Antibody levels also peak a few weeks after infection and decay gradually. We developed a statistical approach to produce estimates of cumulative incidence from raw seroprevalence survey results that account for these sources of spectrum bias. We incorporate data on antibody responses on multiple assays from a postinfection longitudinal cohort, along with epidemic time series to account for the timing of a serosurvey relative to how recently individuals may have been infected. We applied this method to produce estimates of cumulative incidence from 5 large-scale SARS-CoV-2 serosurveys across different settings and study designs. We identified substantial differences between raw seroprevalence and cumulative incidence of over 2-fold in the results of some surveys, and we provide a tool for practitioners to generate cumulative incidence estimates with preset or custom parameter values. While unprecedented efforts have been launched to generate SARS-CoV-2 seroprevalence estimates over this past year, interpretation of results from these studies requires properly accounting for both population-level epidemiologic context and individual-level immune dynamics.
Global Epidemiology and Mechanisms of Resistance of Acinetobacter baumannii-calcoaceticus Complex
Authors: Castanheira Mariana , Mendes Rodrigo E , Gales Ana C
Published: May 2023

Acinetobacter baumannii-calcoaceticus complex is the most commonly identified species in the genus Acinetobacter and it accounts for a large percentage of nosocomial infections, including bacteremia, pneumonia, and infections of the skin and urinary tract. A few key clones of A. baumannii-calcoaceticus are currently responsible for the dissemination of these organisms worldwide. Unfortunately, multidrug resistance is a common trait among these clones due to their unrivalled adaptive nature. A. baumannii-calcoaceticus isolates can accumulate resistance traits by a plethora of mechanisms, including horizontal gene transfer, natural transformation, acquisition of mutations, and mobilization of genetic elements that modulate expression of intrinsic and acquired genes.
Exploring the size of Andean condor foraging groups along an altitudinal and latitudinal gradient in the Tropical Andes: Ecological and conservation implications
Authors: Méndez Diego , Vargas Félix Hernán , Sarasola José Hernán , Olea Pedro P
Published: April 2023

Patterns of variation in the size of vulture foraging groups, and their ecological causes and consequences, remain little explored despite strong links with the carrion recycling service that this key functional group provides. We documented the group size-frequency pattern of Andean condors Vultur gryphus gathered to feed on 42 equine carcasses experimentally placed in Bolivia, between 2012 and 2019, along an elevation range of 1,300–4,500 m asl. Based on the location (altitude and latitude) of the foraging groups, we examined the relationship between their size and species’ population parameters (size and trend), habitat conditions, and livestock carcass availability and predictability. Condors utilized a high frequency (93%) of carcasses forming groups that ranged from 1 to 80 individuals (mean = 25, median = 18) and shaped a “lazy-J curve” typical pattern of size-frequency distribution whereby few groups (5, 12%) were large (> 55 individuals) and most (21, 50%) were relatively small (<19 individuals). Group size related to altitude in that most larger groups formed at lower sites (below c. 3,000 m asl), likely following an altitudinal gradient whereby larger groups are more likely to form around larger carcasses (i.e., cattle), which are more likely to occur at lower elevations. Regardless of population size, group size could be an adaptive response of condors via local enhancement for improving individual scavenging efficiency. Many information gaps on this topic still exist, thus we provide a set of questions to address them, especially amidst the unrestricted impacts of human activities that condition vulture survival globally.
On Philip Kitcher's The Main Enterprise of the World: Rethinking Education
Authors: White John
Published: May 2023

This is a long review of a long book, the longest to my knowledge on what educational aims and the curriculum that flows from them should be. The first half of the review is devoted to a brief summary of each of the eleven chapters. The second half raises some critical points. These cover remarks about R.S. Peters' alleged traditionalism; the salience of climate change considerations among educational aims; the claim that the arts, like the sciences, make progress; seeing the elements of morality as a toolbox. The longest critical discussion is about Kitcher's notion of human fulfillment and whether he is right in his view that we should see it in terms of a successful life-plan aimed at furthering ‘the human project’.
Development of a Modern-Style Trench-Arc-Backarc System in the Proto-Tethys Ocean (Qilian Orogenic Belt, NW China)
Authors: Qiao Jinran , Dong Jie , Song Shuguang , Allen Mark B , Wang Chao , Xia Xiaohong , Su Li
Published: April 2023

The development of trench-arc-backarc (TABA) systems is uniquely associated with modern-style plate tectonics on Earth. The Qilian orogenic belt in NW China records the evolution history of the Proto-Tethys Ocean at the transition time from the Proterozoic to Phanerozoic. This paper presents systematic studies of petrography, U–Pb chronology and geochemistry on various rocks from a middle-ocean ridge (MOR)-type ophiolite belt, active continental margin and back-arc basin in the Qilian orogenic belt to address the development of a modern-style TABA system. Arc magmas include felsic intrusions with ages of 531 to 477 Ma and felsic-mafic arc volcanic rocks with ages of 506 to 439 Ma, showing distinctive features of typical magmatic rocks formed at an Andean-type continental margin. The back-arc basin is recorded by a 490- to 448-Ma suprasubduction zone (SSZ)-type ophiolite with boninite, and Silurian turbidite flysch formation. We establish a three-stage tectonic history from the initiation of subduction to the formation of a mature Japan-Sea-type back-arc basin at the active continental margin in the Early Paleozoic era. (1) Northward subduction of Proto-Tethys Ocean initiated and the Andean-type continental arc developed at ~530 to 500 Ma with continual crustal thickening; (2) a tectonic transition occurred from an Andean-type active continental margin to a West Pacific-type active continental margin at ~500 to 490 Ma with rapid thinning of crust to ~35 km; and (3) mature ocean basins and back-arc-basin (BAB) ophiolites were formed in the back-arc extensional environment at ~490 to 450 Ma.
Death of a Simulated Patient
Authors: Murphy Glenn , Sweeney Amy
Published: May 2023

Dosage calculation errors impact patient safety. A creative teaching strategy for undergraduate nursing students in the nursing skills laboratory incorporated a simulated patient who had died. The patient received three incorrect medication dosages. The objective of the learning activity was for students to calculate the medication dosages and determine which error most likely resulted in the patient’s death. Students were highly engaged in this activity. Faculty observed student learning in the cognitive and affective domains. This innovative teaching strategy encouraged students to evaluate dosage calculations in a safe learning environment.
Socioeconomic Inequality in Hearing Impairment Among Working-Age Australians: Evidence From a Cross-Sectional and Longitudinal Analyses
Authors: Nure Alam Mohammad , Dawes Piers , Sinha Kompal
Published: May 2023

Objectives:

The objective of this study was to analyze the spatial and temporal association between socioeconomic gradient in hearing impairment among working-age Australians.

Design:

We modeled the cross-sectional and longitudinal associations between individual- and area-level socioeconomic status (SES) and hearing impairment among working-age Australians using longitudinal data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey for 10,719 working-age adults aged between 15 and 64 years surveyed between 2008 and 2018. Associations between self-reported hearing impairment and education, income, employment status, and area-level SES were estimated using a multivariate logistic regression model and Cox proportional hazards regression, controlling for age, sex, and a range of other sociodemographic factors.

Results:

Among 10,719 participants, the prevalence of hearing impairment was higher among individuals with lower income, occupational status and socioeconomic disadvantage. The odds ratio (OR) of those with the lowest income quintile versus highest income quintile (OR = 2.10, 95% confidence interval [CI] = 1.40 to 3.14); for blue-collar occupation versus white-collar (OR = 1.92, 95% CI = 1.39 to 2.66) and most disadvantaged area quintile versus most advantaged area quintile (OR = 1.76, 95% CI = 1.10 to 2.83) were associated with higher odds of prevalence of hearing impairment. For the 10,046 participants without hearing loss at baseline, income quintile 1 versus quintile 5 (hazard ratio [HR] = 1.44, 95% CI = 1.33 to 1.56), ≤ year 11 versus ≥ bachelor’s degree (HR = 2.15, 95% CI = 1.98-2.34) blue-collar occupation versus white collar (HR = 1.15, 95% CI = 1.07 to 1.25) and most disadvantaged area quintile versus most advantaged quintile (HR = 1.49, 95% CI = 1.37 to 1.63) was positively associated with incident hearing impairment.

Conclusions:

Lower individual-level and area-level SES was associated with an increased risk of prevalence and incidence of hearing impairment among working-age Australians. These findings are particularly concerning since working-age Australians are mostly not eligible for socially subsidized hearing-related health care in Australia. This lack of access to affordable hearing services could exacerbate the negative consequences of hearing impairment and increase social inequality.