bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcomes of a Five-Year Formal Ophthalmology Residency Mentorship Program
Authors: Yang Sen , Glass Sarah T , Clements John L , Reznick Leah G , Faridi Ambar
Published: August 2022

Objective This article describes a formal ophthalmology residency mentorship program, identifies its strengths and weaknesses over 5 years of implementation, and proposes strategies to improve qualitative outcomes of the mentorship program.

Design Cross-sectional anonymous online survey.

Subjects All current and former mentees and mentors at the Casey Eye Institute (CEI) residency program from 2016 to 2021.

Methods All eligible participants were contacted via email to complete a survey to describe and analyze their experiences with the CEI's formal residency mentorship program.

Results Of the 65 surveyed participants, 82% preferred in-person meetings and met up from 2 to 3 times (44%) to 4 to 6 times (38.5%) annually at 15 minutes to 1 hour (48%) or 1 to 2 hours (42%) duration. Sixty-two percent of meetings were initiated by mentors, 8% by mentees, and 32% shared responsibilities equally. Participants also identified the three most important qualities for successful mentor-mentee relationship as personality (33.6%), communication styles (29.2%), and extracurricular interests/hobbies (16.8%). Mentees valued career advising, networking, and wellness support over academic and research mentorship. Subjective outcomes showed 25% of the mentee and 43% of the mentors agreed the mentorship program was a valuable experience. Comparably, 14% of the mentees and 38% of the mentors prioritized the relationship. There was a strong correlation between participants who prioritized the relationship and acknowledged it as a valuable experience (p < 0.01). Eighteen percent of the mentees and 43% of the mentors found the relationship effective and met their expectations. Twenty-one percent of the mentees and 38% of the mentors believed they had the tools and skills necessary to be effective in their respective roles.

Conclusion Our survey identified that weaknesses of the mentorship program include ineffective communications, inadequate preparation in their respective roles, and lack of priority focus on the relationship. We propose strategies to strengthen our program through creating workshops to clarify roles and responsibilities, emphasizing accountability with a contract statement, and implementing a new matching algorithm to customize participants' experience. Additional studies from other residencies with formal mentorship programs are warranted to identify, strategize, and foster high-quality mentorship.
The politics and imaginary of ‘autonomous vehicles’: a participatory journey
Authors: Van Wynsberghe Axelle , Guimarães Pereira Ângela
Published: August 2022

The Connected and Automated Vehicles (CAVs) pilot project set out to explore the alternative mobility imaginaries of participants. These imaginaries challenged the automated vision of the future presented by vehicle and technology companies. This paper takes a post-normal science and digital anthropology approach to the question of automated technology and the role that citizens have in shaping mobility future(s). Through narrative analysis, interviews with stakeholders, and Futures Making Ateliers, this citizen engagement journey deconstructs the technological promises of CAVs, as well as their plausibility and desirability from the point of view of the participants of the participatory journey. Our findings suggest that the technology is solving a different problem than the mobility problem as articulated in policy documents. By investigating the matters of concern of participants, the problem of mobility was redefined in their own terms, and alternative futures were explored. We use the concept of MacGuffin as means to explore the wider relevance of CAVs in mobility futures.
Disease extinction for susceptible–infected–susceptible models on dynamic graphs and hypergraphs
Authors: John Higham Desmond , de Kergorlay Henry-Louis
Published: August 2022

We consider stochastic, individual-level susceptible–infected–susceptible models for the spread of disease, opinion, or information on dynamic graphs and hypergraphs. We set up “snapshot” models where the interactions at any time are independently and identically sampled from an underlying distribution that represents a typical scenario. In the hypergraph case, this corresponds to a new Gilbert-style random hypergraph model. After justifying this modeling regime, we present useful mean field approximations. With an emphasis on the derivation of spectral conditions that determine long-time extinction, we give computational simulations and accompanying theoretical analysis for the exact models and their mean field approximations.
The extreme mechanics of viscoelastic metamaterials
Authors: Dykstra David M. J. , Janbaz Shahram , Coulais Corentin
Published: August 2022

Mechanical metamaterials made of flexible building blocks can exhibit a plethora of extreme mechanical responses, such as negative elastic constants, shape-changes, programmability, and memory. To date, dissipation has largely remained overlooked for such flexible metamaterials. As a matter of fact, extensive care has often been devoted in the constitutive materials’ choice to avoid strong dissipative effects. However, in an increasing number of scenarios, where metamaterials are loaded dynamically, dissipation cannot be ignored. In this Research Update, we show that the interplay between mechanical instabilities and viscoelasticity can be crucial and that they can be harnessed to obtain new functionalities. We first show that this interplay is key to understanding the dynamical behavior of flexible dissipative metamaterials that use buckling and snapping as functional mechanisms. We further discuss the new opportunities that spatial patterning of viscoelastic properties offer for the design of mechanical metamaterials with properties that depend on the loading rate.
Fabrication of high-quality PMMA/SiOx spaced planar microcavities for strong coupling of light with monolayer WS2 excitons
Authors: Yun Tinghe , Estrecho Eliezer , Truscott Andrew G. , Ostrovskaya Elena A. , Wurdack Matthias J.
Published: August 2022

Exciton polaritons in atomically thin transition metal dichalcogenide crystals (monolayer TMDCs) have emerged as a promising candidate to enable topological transport, ultra-efficient laser technologies, and collective quantum phenomena such as polariton condensation and superfluidity at room temperature. However, integrating monolayer TMDCs into high-quality planar microcavities to achieve the required strong coupling between the cavity photons and the TMDC excitons (bound electron–hole pairs) has proven challenging. Previous approaches to integration had to compromise between various adverse effects on the strength of light–matter interactions in the monolayer, the cavity photon lifetime, and the lateral size of the microcavity. Here, we demonstrate a scalable approach to fabricate high-quality planar microcavities with an integrated monolayer WS2 layer-by-layer by using polymethyl methacrylate/silicon oxide (PMMA/SiOx) as a cavity spacer. Because the exciton oscillator strength is well protected against the required processing steps by the PMMA layer, the microcavities investigated in this work, which have quality factors of above 103, can operate in the strong light–matter coupling regime at room temperature. This is an important step toward fabricating wafer-scale and patterned microcavities for engineering the exciton-polariton potential landscape, which is essential for enabling many proposed technologies.
A regularized high-order moment model to capture non-Maxwellian electron energy distribution function effects in partially ionized plasmas
Authors: Alvarez Laguna A. , Esteves B. , Bourdon A. , Chabert P.
Published: August 2022

A model for electrons in partially ionized plasmas that self-consistently captures non-Maxwellian electron energy distribution function (EEDF) effects is presented. The model is based on the solution of scalar and vectorial velocity moments up to the contracted fourth-order moment. The set of fluid (macroscopic) equations is obtained with Grad's method and exact expressions for the collision production terms are derived, considering the electron–electron, electron–gas, and electron–ion elastic collisions as well as for electron–gas excitation and ionization collisions. A regularization of the equations is proposed in order to avoid spurious discontinuities, existing in the original Grad's moment model, by using a generalized Chapman–Enskog expansion that exploits the disparity of mass between the electrons and the heavy particles (ions and atoms) as well as the disparity of plasma and gas densities, typical of gas discharges. The transport model includes non-local effects due to spatial gradients in the EEDF as well as the impact of the EEDF in the calculation of the elastic and inelastic collision rates. Solutions of the moment model under spatially homogeneous conditions are compared to direct simulation Monte Carlo and a two-term Boltzmann solver under conditions that are representative of high plasma density discharges at low-pressure. The moment model is able to self-consistently capture the evolution of the EEDF, in good quantitative agreement with the kinetic solutions. The calculation of transport coefficients and collision rates of an argon plasma in thermal non-equilibrium under the effect of an electric field is in good agreement with the solutions of a two-term Boltzmann solver, largely improving models with a simplified Bhatnagar–Gross–Krook collisional operator.
High-sensitivity stereo coded aperture gamma camera for three-dimensional localization of radioactive hotspots
Authors: Liu Yantao , Shuai Lei , Li Daowu , Liu Shuangquan , Wang Yingjie , Zhou Wei , Huang Huan , Wang Xiaoming , Hu Xuanhou , Liang Xiuzuo , Zhuang Kai , Li Ting , Yu Yue , Li Xin , Ding Yi , Zhao Yan , Zhang Yiwen , Zhang Zhiming , Wei Cunfeng , Ai Xianyun , Zhang Jipeng , Xiao Xiong , Wei Long
Published: August 2022

This work presents a novel stereo coded aperture gamma camera based on four detection modules placed within four quadrants. Each module includes 48 × 48 strips of Bi4Ge3O12 scintillators, 24 × 24 pieces of silicon photomultipliers (SiPMs), and a set of data acquisition circuits. All signals from the SiPMs are individually extracted and finally simplified into 144 outputs to calculate the positions and energies of gamma-rays. Two masks of modified uniformly redundant arrays are fixed in the front of the top-right and bottom-left modules and two anti-masks are fixed in the top-left and bottom-right modules to achieve simultaneous imaging without dual measure. Once the projections of radioactive sources are determined, their source-to-detector distances can be estimated by our new multocular ranging algorithm. A series of lab and field experiments, including flood histogram and energy spectrum testing, field-of-view and angular resolution testing, real-time imaging, long-distance imaging, and ranging ability testing, with different radioactive sources, such as 137Cs, 22Na, 241Am, 60Co, 133Ba, and 75Se, have been completed to evaluate the comprehensive ability of the stereo gamma camera. The results show that the stereo gamma camera has a strong ability for the three-dimensional localization of radioactive sources over long distances with a high image sensitivity. So far, the stereo gamma camera has been successfully used in practical nuclear security and safety tasks although the angular resolution and the ranging algorithm robustness should be more optimized in the future.
Adiabatic conversion between gigahertz quasi-Rayleigh and quasi-Love modes for phononic integrated circuits
Authors: Wang Bao-Zhen , Xu Xin-Biao , Zhang Yan-Lei , Wang Weiting , Sun Luyan , Guo Guang-Can , Zou Chang-Ling
Published: August 2022

Unsuspended phononic integrated circuits have been proposed for on-chip acoustic information processing. Limited by the operation mechanism of a conventional interdigital transducer, the excitation of the quasi-Love mode in GaN-on-sapphire is inefficient, and thus, a high-efficiency Rayleigh-to-Love mode converter is of great significance for future integrated phononic devices. Here, we propose a high-efficiency and robust phononic mode converter based on an adiabatic conversion mechanism. Utilizing the anisotropic elastic property of the substrate, the adiabatic mode converter is realized by a simple tapered phononic waveguide. A conversion efficiency exceeding 96% with a 3 dB bandwidth of 1.44 GHz can be realized for phononic waveguides working at GHz frequency band, and excellent tolerance to the fabrication errors is also numerically validated. The device that we proposed can be useful in both classical and quantum phononic information processing, and the adiabatic mechanism could be generalized to other phononic device designs.
Retardation of freezing of precooled, impinged water droplets on glass surfaces with microgrooves and silane coating
Authors: Yonezawa Sho , Kasahara Kazuya , Waku Tomonori , Hagiwara Yoshimichi
Published: August 2022

Freezing impinged water droplets on glass surfaces cause serious problems such as reduced visibility of traffic lights and surveillance cameras. Droplets in the air associated with these issues are often at subzero temperatures. However, experimental results on the freezing of precooled impinged droplets are limited. In this study, we measured the freezing of precooled and impinged water droplets on cold glass surfaces. Two types of lattice-patterned microscale grooves were formed on glass surfaces to reduce the contact area of droplets and growth of frosts, which contributed to droplet freezing. In addition, the surfaces were coated with a silane coupling agent to further reduce the contact area. We analyzed the images of droplets captured using a high-speed video camera. The results of the linear relationships between the frozen droplet height, freezing front velocity, and freezing time (for the impinged droplets) indicated that the grooves and coating were effective in retarding the freezing of impinged droplets. This retardation was more evident for frost-free glass surfaces, and it was less evident for precooled droplets. Moreover, a simple heat transfer analysis was conducted to effectively estimate the overall heat flux and freezing front velocity. The sublimation of frost (adjacent to the impinged droplets) and supercool elimination of the precooled droplets significantly contributed to the heat flux and caused an increase in the freezing front velocity.
In situ observation of the magnetization configuration and reversal in cylindrical nanowires
Authors: Brajuskovic Vuk , McCray Arthur , Zhang Yuepeng , Phatak Charudatta
Published: August 2022

Curvilinear magnetic structures often have unique magnetic behavior compared to their rectilinear counterparts. This is due to the unique curvilinear boundary conditions as well as the curvature induced Dzyaloshinskii–Moriya-like interaction and the curvature induced anisotropy. The effects of a curvilinear geometry are best studied in 3D structures, where the curvature can have a significant spatial extent. Of these 3D structures, the simplest structure to study is the cylindrical nanowire. Here, we have simulated the magnetization reversal in cylindrical NiFe nanowires and present in situ Lorentz TEM images to support the findings of the simulations. We studied the domain formation and reversal of nanowires with two distinct diameters that give rise to a different reversal behavior. We have, thus, found that the zero-field magnetization configuration in these wires can take on a double helix type of configuration. The reversal in these structures then proceeds through the winding and unwinding of these helical configurations rather than through domain wall propagation.
La0.7Na0.3−xKxMnO3 (x = 0.2): A thermistor film that exhibits high-sensitivity at room temperature
Authors: Jin Shuaizhao , Zhu Xiaokun , Yan Yixin , Yu Xiaohan , Guan Xiaoli , Gu Xin , Wu Kaikai , Zhao Liming , Liu Xiang
Published: August 2022

A high-sensitivity thermistor La0.7Na0.3−xKxMnO3 (x = 0.2) film with a perovskite structure was fabricated and studied. The results show that the film displayed excellent adaptation and clear interfaces with the SrTiO3 substrate. Under the combination of Jahn–Teller effect and double exchange mechanism, the temperature coefficient of resistivity (TCR) of the La0.7Na0.1K0.2MnO3 film reached 10.86% K−1 at 296.98 K. Compared with the conventional VO2 and nickel–manganite-based film materials, the La0.7Na0.1K0.2MnO3 film with high TCR values at room temperature exhibited tunable metal–insulation transition temperature and more sensitive thermal properties. Consequently, the La0.7Na0.1K0.2MnO3 film can substantially improve the detection sensitivity of uncooled infrared bolometers as thermistor materials.
Dynamics study on the effect of memristive autapse distribution on Hopfield neural network
Authors: Shen Hui , Yu Fei , Kong Xinxin , Mokbel Abdulmajeed Abdullah Mohammed , Wang Chunhua , Cai Shuo
Published: August 2022

As the shortest feedback loop of the nervous system, autapse plays an important role in the mode conversion of neurodynamics. In particular, memristive autapses can not only facilitate the adjustment of the dynamical behavior but also enhance the complexity of the nervous system, in view of the fact that the dynamics of the Hopfield neural network has not been investigated and studied in detail from the perspective of memristive autapse. Based on the traditional Hopfield neural network, this paper uses a locally active memristor to replace the ordinary resistive autapse so as to construct a 2n-dimensional memristive autaptic Hopfield neural network model. The boundedness of the model is proved by introducing the Lyapunov function and the stability of the equilibrium point is analyzed by deriving the Jacobian matrix. In addition, four scenarios are established on a small Hopfield neural network with three neurons, and the influence of the distribution of memristive autapses on the dynamics of this small Hopfield neural network is described by numerical simulation tools. Finally, the Hopfield neural network model in these four situations is designed and implemented on field-programmable gate array by using the fourth-order Runge–Kutta method, which effectively verifies the numerical simulation results.
Characterization of the hardened single line of sight camera at the National Ignition Facility
Authors: Trosseille C. , Garafalo A. M. , Dayton M. S. , Durand C. E. , Funsten B. T. , Hilsabeck T. J. , Imhoff E. , Morioka S. B. , Piston K. W. , Raymond A. E. , Welton A. C. , Claus L. , Sanchez M. , Hares J. D. , Chung T. M. , Carpenter A. C. , Nagel S. R.
Published: August 2022

The hardened single line of sight camera has been recently characterized in preparation for its deployment on the National Ignition Facility. The latest creation based on the pulse-dilation technology leads to many new features and improvements over the previous-generation cameras to provide better quality measurements of inertial confinement fusion experiments, including during high neutron yield implosions. Here, we present the characterization data that illustrate the main performance features of this instrument, such as extended dynamic range and adjustable internal magnification, leading to improved spatial resolution.
α-RuCl3 and other Kitaev materials
Authors: Kim Subin , Yuan Bo , Kim Young-June
Published: August 2022

Quantum spin liquids have been drawing much attention in recent years as a platform to develop future quantum technologies, such as topological quantum computing. In particular, Kitaev’s honeycomb model has provided a blueprint to realize a quantum spin liquid that has Majorana fermions as its elementary excitation. While numerous theoretical studies have shown intriguing properties of quantum spin liquids, an experimental realization remains elusive. The recent observation of the quantized thermal Hall effect in α-RuCl3 has brought us tantalizingly close to an experimental realization of Kitaev quantum spin liquids. However, various groups report conflicting results, indicating that the Kitaev quantum spin liquid phase might be very fragile and its properties strongly depend on the sample. Here, we present a short overview of the rise of α-RuCl3 as a prime candidate material for realizing Kitaev quantum spin liquids. There are already many excellent review papers on this topic, so the emphasis will be on the materials aspect, comparing different crystal growth methods and crystal morphologies. We also discuss current research attempts to find other candidate materials to realize Kitaev quantum spin liquids, mostly focused on 3d transition-metal compounds, such as transition-metal halides and layered cobalt compounds.
Peculiarity of topological Hall effect in Mn2Sb0.9Bi0.1 ferrimagnet
Authors: Zhang Zhirui , Xu Yang , Ma Shengcan , Chen Changcai , Luo Xiaohua , Fang Chunsheng , Liu Chaofei , Sun Haocheng , Zhang Guanghua , Zhong Zhenchen
Published: August 2022

The substituted Mn2Sb-based ferrimagnetic (FIM) alloys by other elements have attracted much attention recently due to excellent magneto-functional properties. However, almost all investigations have been concentrated on the first-order phase transition between antiferromagnetic and FIM state. In this work, a large topological Hall effect (THE) associated with the spin reorientation transition is observed in the Mn2Sb0.9Bi0.1 alloy. Strikingly, the sign reversal of topological Hall resistivity (ρxyT) is found before and after the SRT temperature TSR ∼260 K. Above the TSR, a positive ρxyT is observed, e.g., ∼0.52 μΩ cm at 320 K. By reducing temperature to 275 K, the ρxyT value decreases to ∼0.42 μΩ cm. It is interesting that, however, the negative ρxyT value is found below the TSR, e.g., ∼−0.66 μΩ cm at 175 K. The physical mechanism about this peculiar THE is discussed in Bi-doped Mn2Sb-based alloys.
Distinct spreading patterns induced by coexisting channels in information spreading dynamics
Authors: Wu Jiao , Xu Kesheng , Zhang Xiyun , Zheng Muhua
Published: August 2022

In modern society, new communication channels and social platforms remarkably change the way of people receiving and sharing information, but the influences of these channels on information spreading dynamics have not been fully explored, especially in the aspects of outbreak patterns. To this end, based on a susceptible–accepted–recovered model, we examined the outbreak patterns of information spreading in a two-layered network with two coexisting channels: the intra-links within a layer and the inter-links across layers. Depending on the inter-layer coupling strength, i.e., average node degree and transmission probability between the two layers, we observed three different spreading patterns: (i) a localized outbreak with weak inter-layer coupling, (ii) two peaks with a time-delay outbreak appear for an intermediate coupling, and (iii) a synchronized outbreak for a strong coupling. Moreover, we showed that even though the average degree between the two layers is small, a large transmission probability still can compensate and promote the information spread from one layer to another, indicating by that the critical average degree decreases as a power law with transmission probability between the two layers. Additionally, we found that a large gap closed to the critical inter-layer average degree appears in the phase space of theoretical analysis, which indicates the emergence of a global large-scope outbreak. Our findings may, therefore, be of significance for understanding the outbreak behaviors of information spreading in real world.
Nanoscale color control of perovskite solar cells using Fano resonances of aluminum arsenide nanoarrays
Authors: Zhang Jie , Zhang Cheng , Wang Yanping , Zhang Yinan , Sun Mingyu , Chen Xi , Gu Min
Published: August 2022

Colorful perovskite solar cells have been widely explored in building-integrated photovoltaics for esthetic requirements. However, a principle to control both light reflection peak wavelengths and widths on the nanoscale has not been carried out, which is critical to realize pure colors controllably, thus impeding large-scale application severely. In this paper, we presented a simulation pathway for the nanoscale color control through Fano resonances interaction in aluminum arsenide nanocylinder clusters, which are embedded in the glass above indium tin oxide layers of perovskite solar cells. The Fano resonances are controlled through the adjustment of periods, diameters, and heights of the aluminum arsenide nanocylinder clusters, and thus, the solar cells exhibit extremely narrow reflection peaks. The full widths at half-maximum are measured from 8 to 15 nm, and the tuning resolution of the reflection peak position can reach 1 nm only through the adjustment of the nanocylinder heights. Compared to a blank solar cell, slight optical absorption reductions of 3.41%, 6.31%, and 6.43% are demonstrated in blue, green, and red colored Fano structure integrated perovskite solar cells, respectively. We have also verified that the solar cell’s colors are independent of the incident light angles, satisfying the requirement of building decoration. The results pave a promising strategy with the potential applicability of colorful perovskite solar cells in building-integrated photovoltaics.
Control of quasi-equilibrium state of annular flow through reinforcement learning
Authors: Chen Yi , Duan Li , Kang Qi
Published: August 2022

Stability control of the convection flow field has always been a focal issue. The annular flow discussed in this work is a typical research model of microgravity fluid physics, which is extracted from the industrial crystal growth by the Czochralski method. It is believed that the instability of thermal convection is the key factor affecting the quality of crystal growth. Combining the reinforcement learning algorithm with the neural network, this paper proposes a control policy that makes forced convection compete with thermocapillary convection by changing the dynamic boundary conditions of the system. This control policy is successfully applied to the control of the quasi-equilibrium state of annular flow, and the global stability of the flow field is well maintained. It first experimentally makes the annular flow field under low and medium Ma numbers achieve a quasi-equilibrium state, which is different from that before the onset of flow oscillations. Then, a simulation environment is created to imitate the experimental conditions. After training in the simulation environment, with the self-optimized algorithm, the machine learning approach can successfully maintain the simulation environment in a quasi-equilibrium state for a long period of time. Finally, the learning method is validated in the experimental environment, and a quasi-equilibrium state control policy is completely optimized by using the same optimization policy and similar neural network structure. This work demonstrates that the model can understand the physical environment and the author's control objectives through reinforcement learning. It is an important application of reinforcement learning in the real world and a clear demonstration of the research value of microgravity fluid physics.
Inertially amplified seismic metamaterial with an ultra-low-frequency bandgap
Authors: Zeng Yi , Cao Liyun , Wan Sheng , Guo Tong , An Shuowei , Wang Yan-Feng , Du Qiu-Jiao , Vincent Brice , Wang Yue-Sheng , Assouar Badreddine
Published: August 2022

In last two decades, it has been theoretically and experimentally demonstrated that seismic metamaterials are capable of isolating seismic surface waves. Inertial amplification mechanisms with small mass have been proposed to design metamaterials to isolate elastic waves in rods, beams, and plates at low frequencies. In this Letter, we propose an alternative type of seismic metamaterial providing an ultra-low-frequency bandgap induced by inertial amplification. A unique kind of inertially amplified metamaterial is first conceived and designed. Its bandgap characteristics for flexural waves are then numerically and experimentally demonstrated. Finally, the embedded inertial amplification mechanism is introduced on a soil substrate to design a seismic metamaterial capable of strongly attenuating seismic surface waves around a frequency of 4 Hz. This work provides a promising alternative way to conceive seismic metamaterials to steer and control surface waves.
Mechanisms for undesired nucleation on H-terminated Si and dimethylamino-trimethylsilane passivated SiO2 during TiO2 area-selective atomic layer deposition
Authors: Nye Rachel A. , Song Seung Keun , Van Dongen Kaat , Delabie Annelies , Parsons Gregory N.
Published: August 2022

During TiO2 atomic layer deposition (ALD) using TiCl4 and H2O at ∼150 °C, nucleation proceeds rapidly on hydroxylated SiO2 but is inherently delayed on passivated surfaces such as H-terminated silicon (Si-H) and trimethylsilyl-passivated SiO2 (SiO2-TMS) formed using dimethylamino-trimethylsilane (DMA-TMS) as a small molecule inhibitor. In this work, we explore details of TiO2 nucleation on both Si-H and SiO2-TMS and show that the mechanisms leading to unwanted nuclei depend strongly on the passivation mechanism. Initial growth is observed as a function of ALD cycles using scanning electron microscopy to obtain average particle size, density, and overall surface coverage fraction. Also, average film thickness vs cycle is estimated using ellipsometry or Rutherford backscattering spectrometry. Data are compared to an analytical model that considers that either nucleation sites are present on the starting non-growth surface or sites are generated during the ALD process. On the Si-H surface, data and modeling indicate that nucleation occurs predominantly from a fixed number of nucleation sites present on the starting growth surface that start to immediately grow. However, on TMS-passivated SiO2, nucleation sites are predominantly generated during the growth process so that the density of nucleation sites increases as growth proceeds. Results indicate that nucleation sites are created when adsorbed ALD reactants become kinetically trapped on the SiO2-TMS surface. This demonstrates that mechanisms associated with unwanted nucleation during area-selective deposition (ASD) can depend on details of the surface passivation scheme, thereby providing insight to help to improve ASD strategies for advanced applications.
Exploiting breakdown in nonhost effector–target interactions to boost host disease resistance
Authors: McLellan Hazel , Harvey Sarah E. , Steinbrenner Jens , Armstrong Miles R. , He Qin , Clewes Rachel , Pritchard Leighton , Wang Wei , Wang Shumei , Nussbaumer Thomas , Dohai Bushra , Luo Qingquan , Kumari Priyanka , Duan Hui , Roberts Ana , Boevink Petra C. , Neumann Christina , Champouret Nicolas , Hein Ingo , Falter-Braun Pascal , Beynon Jim , Denby Katherine , Birch Paul R. J.
Published: August 2022

Plants are resistant to most microbial species due to nonhost resistance (NHR), providing broad-spectrum and durable immunity. However, the molecular components contributing to NHR are poorly characterised. We address the question of whether failure of pathogen effectors to manipulate nonhost plants plays a critical role in NHR. RxLR (Arg-any amino acid-Leu-Arg) effectors from two oomycete pathogens,
Phytophthora infestans and Hyaloperonospora arabidopsidis
, enhanced pathogen infection when expressed in host plants (
Nicotiana benthamiana
and Arabidopsis, respectively) but the same effectors performed poorly in distantly related nonhost pathosystems. Putative target proteins in the host plant potato were identified for 64
P
. infestans RxLR effectors using yeast 2-hybrid (Y2H) screens. Candidate orthologues of these target proteins in the distantly related non-host plant Arabidopsis were identified and screened using matrix Y2H for interaction with RxLR effectors from both
P
. infestans and
H
.
arabidopsidis
. Few
P
. infestans effector-target protein interactions were conserved from potato to candidate Arabidopsis target orthologues (cAtOrths). However, there was an enrichment of
H
.
arabidopsidis
RxLR effectors interacting with cAtOrths. We expressed the cAtOrth AtPUB33, which unlike its potato orthologue did not interact with
P
.
infestans
effector PiSFI3, in potato and Nicotiana benthamiana. Expression of AtPUB33 significantly reduced
P
.
infestans
colonization in both host plants. Our results provide evidence that failure of pathogen effectors to interact with and/or correctly manipulate target proteins in distantly related non-host plants contributes to NHR. Moreover, exploiting this breakdown in effector-nonhost target interaction, transferring effector target orthologues from non-host to host plants is a strategy to reduce disease.
Blocking CHOP-dependent TXNIP shuttling to mitochondria attenuates albuminuria and mitigates kidney injury in nephrotic syndrome
Authors: Park Sun-Ji , Kim Yeawon , Li Chuang , Suh Junwoo , Sivapackiam Jothilingam , Goncalves Tassia M. , Jarad George , Zhao Guoyan , Urano Fumihiko , Sharma Vijay , Chen Ying Maggie
Published: August 2022

Albuminuria is a hallmark of glomerular disease of various etiologies. It is not only a symptom of glomerular disease but also a cause leading to glomerulosclerosis, interstitial fibrosis, and eventually, a decline in kidney function. The molecular mechanism underlying albuminuria-induced kidney injury remains poorly defined. In our genetic model of nephrotic syndrome (NS), we have identified CHOP (C/EBP homologous protein)-TXNIP (thioredoxin-interacting protein) as critical molecular linkers between albuminuria-induced ER dysfunction and mitochondria dyshomeostasis. TXNIP is a ubiquitously expressed redox protein that binds to and inhibits antioxidant enzyme, cytosolic thioredoxin 1 (Trx1), and mitochondrial Trx2. However, very little is known about the regulation and function of TXNIP in NS. By utilizing
Chop
−/−
and
Txnip
−/−
mice as well as
68
Ga-Galuminox, our molecular imaging probe for detection of mitochondrial reactive oxygen species (ROS) in vivo, we demonstrate that CHOP up-regulation induced by albuminuria drives TXNIP shuttling from nucleus to mitochondria, where it is required for the induction of mitochondrial ROS. The increased ROS accumulation in mitochondria oxidizes Trx2, thus liberating TXNIP to associate with mitochondrial nod-like receptor protein 3 (NLRP3) to activate inflammasome, as well as releasing mitochondrial apoptosis signal-regulating kinase 1 (ASK1) to induce mitochondria-dependent apoptosis. Importantly, inhibition of TXNIP translocation and mitochondrial ROS overproduction by CHOP deletion suppresses NLRP3 inflammasome activation and p-ASK1–dependent mitochondria apoptosis in NS. Thus, targeting TXNIP represents a promising therapeutic strategy for the treatment of NS.
School choice increases racial segregation even when parents do not care about race
Authors: Ukanwa Kalinda , Jones Aziza C. , Turner Broderick L.
Published: August 2022

This research examines how school choice impacts school segregation. Specifically, this work demonstrates that even if parents do not take the racial demographics of schools into account, preference differences between Black and White parents for other school attributes can still result in segregation. These preference differences stem from motivational differences in pursuit of social status. Given that the de facto US racial hierarchy assigns Black people to a lower social status, Black parents are more motivated to seek schools that signal that they can improve their children’s status. Simulations of parental school decisions at scale show that preference differences under an unmitigated school-choice policy lead to more segregated schools, impacting more than half a million US children for every 3-percentage-point increase in school-choice availability. In contrast, if Black and White parents have similar preferences, unmitigated school choice would reduce racial segregation. This research may inform public policy concerning school choice and school segregation.
A class of identifiable phylogenetic birth–death models
Authors: Legried Brandon , Terhorst Jonathan
Published: August 2022

In a striking result, Louca and Pennell [S. Louca, M. W. Pennell, Nature 580, 502–505 (2020)] recently proved that a large class of phylogenetic birth–death models is statistically unidentifiable from lineage-through-time (LTT) data: Any pair of sufficiently smooth birth and death rate functions is “congruent” to an infinite collection of other rate functions, all of which have the same likelihood for any LTT vector of any dimension. As Louca and Pennell argue, this fact has distressing implications for the thousands of studies that have utilized birth–death models to study evolution. In this paper, we qualify their finding by proving that an alternative and widely used class of birth–death models is indeed identifiable. Specifically, we show that piecewise constant birth–death models can, in principle, be consistently estimated and distinguished from one another, given a sufficiently large extant timetree and some knowledge of the present-day population. Subject to mild regularity conditions, we further show that any unidentifiable birth–death model class can be arbitrarily closely approximated by a class of identifiable models. The sampling requirements needed for our results to hold are explicit and are expected to be satisfied in many contexts such as the phylodynamic analysis of a global pandemic.
The amino acid sensor GCN2 controls red blood cell clearance and iron metabolism through regulation of liver macrophages
Authors: Toboz Phoenix , Amiri Mehdi , Tabatabaei Negar , Dufour Catherine R. , Kim Seung Hyeon , Fillebeen Carine , Ayemoba Charles E. , Khoutorsky Arkady , Nairz Manfred , Shao Lijian , Pajcini Kostandin V. , Kim Ki-Wook , Giguère Vincent , Oliveira Regiana L. , Constante Marco , Santos Manuela M. , Morales Carlos R. , Pantopoulos Kostas , Sonenberg Nahum , Pinho Sandra , Tahmasebi Soroush
Published: August 2022

GCN2 (general control nonderepressible 2) is a serine/threonine-protein kinase that controls messenger RNA translation in response to amino acid availability and ribosome stalling. Here, we show that GCN2 controls erythrocyte clearance and iron recycling during stress. Our data highlight the importance of liver macrophages as the primary cell type mediating these effects. During different stress conditions, such as hemolysis, amino acid deficiency or hypoxia,GCN2knockout (GCN2−/−) mice displayed resistance to anemia compared with wild-type (GCN2+/+) mice.GCN2−/−liver macrophages exhibited defective erythrophagocytosis and lysosome maturation. Molecular analysis ofGCN2−/−cells demonstrated that the ATF4-NRF2 pathway is a critical downstream mediator of GCN2 in regulating red blood cell clearance and iron recycling.
Stroke-associated intergenic variants modulate a human FOXF2 transcriptional enhancer
Authors: Ryu Jae-Ryeon , Ahuja Suchit , Arnold Corey R. , Potts Kyle G. , Mishra Aniket , Yang Qiong , Sargurupremraj Muralidharan , Mahoney Douglas J. , Seshadri Sudha , Debette Stéphanie , Childs Sarah J.
Published: August 2022

SNPs associated with human stroke risk have been identified in the intergenic region between Forkhead family transcription factors
FOXF2
and
FOXQ1
, but we lack a mechanism for the association. FoxF2 is expressed in vascular mural pericytes and is important for maintaining pericyte number and stabilizing small vessels in zebrafish. The stroke-associated SNPs are located in a previously unknown transcriptional enhancer for
FOXF2
, functional in human cells and zebrafish. We identify critical enhancer regions for
FOXF2
gene expression, including binding sites occupied by transcription factors ETS1, RBPJ, and CTCF. rs74564934, a stroke-associated SNP adjacent to the ETS1 binding site, decreases enhancer function, as does mutation of RPBJ sites. rs74564934 is significantly associated with the increased risk of any stroke, ischemic stroke, small vessel stroke, and elevated white matter hyperintensity burden in humans.
Foxf2
has a conserved function cross-species and is expressed in vascular mural pericytes of the vessel wall. Thus, stroke-associated SNPs modulate enhancer activity and expression of a regulator of vascular stabilization,
FOXF2
, thereby modulating stroke risk.
Maternal IL-33 critically regulates tissue remodeling and type 2 immune responses in the uterus during early pregnancy in mice
Authors: Valero-Pacheco Nuriban , Tang Eric K. , Massri Noura , Loia Rachel , Chemerinski Anat , Wu Tracy , Begum Salma , El-Naccache Darine W. , Gause William C. , Arora Ripla , Douglas Nataki C. , Beaulieu Aimee M.
Published: August 2022

The pregnant uterus is an immunologically rich organ, with dynamic changes in the inflammatory milieu and immune cell function underlying key stages of pregnancy. Recent studies have implicated dysregulated expression of the interleukin-1 (IL-1) family cytokine, IL-33, and its receptor, ST2, in poor pregnancy outcomes in women, including recurrent pregnancy loss, preeclampsia, and preterm labor. How IL-33 supports pregnancy progression in vivo is not well understood. Here, we demonstrate that maternal IL-33 signaling critically regulates uterine tissue remodeling and immune cell function during early pregnancy in mice. IL-33–deficient dams exhibit defects in implantation chamber formation and decidualization, and abnormal vascular remodeling during early pregnancy. These defects coincide with delays in early embryogenesis, increased resorptions, and impaired fetal and placental growth by late pregnancy. At a cellular level, myometrial fibroblasts, and decidual endothelial and stromal cells, are the main IL-33+cell types in the uterus during decidualization and early placentation, whereas ST2 is expressed by uterine immune populations associated with type 2 immune responses, including ILC2s, Tregs, CD4+T cells, M2- and cDC2-like myeloid cells, and mast cells. Early pregnancy defects in IL-33–deficient dams are associated with impaired type 2 cytokine responses by uterine lymphocytes and fewer Arginase-1+macrophages in the uterine microenvironment. Collectively, our data highlight a regulatory network, involving crosstalk between IL-33–producing nonimmune cells and ST2+immune cells at the maternal–fetal interface, that critically supports pregnancy progression in mice. This work has the potential to advance our understanding of how IL-33 signaling may support optimal pregnancy outcomes in women.
Evidence for massive methane hydrate destabilization during the penultimate interglacial warming
Authors: Weldeab Syee , Schneider Ralph R. , Yu Jimin , Kylander-Clark Andrew
Published: August 2022

The stability of widespread methane hydrates in shallow subsurface sediments of the marine continental margins is sensitive to temperature increases experienced by upper intermediate waters. Destabilization of methane hydrates and ensuing release of methane would produce climatic feedbacks amplifying and accelerating global warming. Hence, improved assessment of ongoing intermediate water warming is crucially important, especially that resulting from a weakening of Atlantic meridional overturning circulation (AMOC). Our study provides an independent paleoclimatic perspective by reconstructing the thermal structure and imprint of methane oxidation throughout a water column of 1,300 m. We studied a sediment sequence from the eastern equatorial Atlantic (Gulf of Guinea), a region containing abundant shallow subsurface methane hydrates. We focused on the early part of the penultimate interglacial and present a hitherto undocumented and remarkably large intermediate water warming of 6.8 °C in response to a brief episode of meltwater-induced, modest AMOC weakening centered at 126,000 to 125,000 y ago. The warming of intermediate waters to 14 °C significantly exceeds the stability field of methane hydrates. In conjunction with this warming, our study reveals an anomalously low δ13C spike throughout the entire water column, recorded as primary signatures in single and pooled shells of multitaxa foraminifers. This extremely negative δ13C excursion was almost certainly the result of massive destabilization of methane hydrates. This study documents and connects a sequence of climatic events and climatic feedback processes associated with and triggered by the penultimate climate warming that can serve as a paleoanalog for modern ongoing warming.
Logic-enabled textiles
Authors: Rajappan Anoop , Jumet Barclay , Shveda Rachel A. , Decker Colter J. , Liu Zhen , Yap Te Faye , Sanchez Vanessa , Preston Daniel J.
Published: August 2022

Textiles hold great promise as a soft yet durable material for building comfortable robotic wearables and assistive devices at low cost. Nevertheless, the development of smart wearables composed entirely of textiles has been hindered by the lack of a viable sheet-based logic architecture that can be implemented using conventional fabric materials and textile manufacturing processes. Here, we develop a fully textile platform for embedding pneumatic digital logic in wearable devices. Our logic-enabled textiles support combinational and sequential logic functions, onboard memory storage, user interaction, and direct interfacing with pneumatic actuators. In addition, they are designed to be lightweight, easily integrable into regular clothing, made using scalable fabrication techniques, and durable enough to withstand everyday use. We demonstrate a textile computer capable of input-driven digital logic for controlling untethered wearable robots that assist users with functional limitations. Our logic platform will facilitate the emergence of future wearables powered by embedded fluidic logic that fully leverage the innate advantages of their textile construction.