114333 research outputs found
Sort by
Spectroscopic Evidence of Edge-Localized States in an Antiferromagnet Topological Insulator NdBi
No full textMaterials exhibiting non-trivial topology and magnetism hold the promise of hosting 1D chiral edge states, which can carry dissipationless currents and, when proximitized to a superconductor, develop Majorana modes. However, persistent materials challenges arising from magnetic and electronic disorder have hindered the realization and measurement of these states, and limited the observation of the Quantum Anomalous Hall effect to low temperatures. Here we study the topological antiferromagnet NdBi, which belongs to a new class of magnetic topological materials, i.e., rare earth monopnictides. These binary topological compounds with intrinsic magnetism are not plagued by the same materials issues and may potentially offer a new platform for hosting 1D edge states. By combining spin-polarized scanning tunneling microscopy (STM) with quasiparticle interference, we successfully identify distinct signatures of the ferromagnetic (FM) and antiferromagnetic (AFM) terminations. Crucially, we demonstrate that step edges on ferromagnetic surfaces, which serve as magnetic domain walls, host well-defined 1D edge modes that vanish above the Néel temperature. Our findings position NdBi as a promising platform for further explorations of 1D chiral edge modes and future realizations of Majorana states in proximitized rare-earth mono-pnictides.This article is published as Almoalem, Avior, Rebecca Chan, Brinda Kuthanazhi, Juan Schmidt, Jose A. Moreno, Hermann Suderow, Paul Canfield, Taylor L. Hughes, and Vidya Madhavan. "Spectroscopic Evidence of Edge‐Localized States in an Antiferromagnet Topological Insulator NdBi." Advanced Science (2026): e22116. doi: https://doi.org/10.1002/advs.202522116.STM studies at UIUC were supported by the Air Force Office of Scientific Research (AFOSR) under Grant Number. FA9550-23-1-0635. VM acknowledges support from Gordon and Betty More Foundation’s EPiQS Initiative through grant GBMF4860 and the Quantum Materials Program at CIFAR, where she is a Fellow. A.A. acknowledges support from the US National Science Foundation (NSF) Grant Number 2201516 under the Accelnet program of the Office of International Science and Engineering (OISE). T.L.H. thanks ARO MURI W911NF2020166 for support. Work done at Ames National Laboratory was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Materials Sciences and Engineering. Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. J.A.M. and H.S. acknowledge support by the Spanish Research State Agency (PID2020-114071RB-I00, PID2023- 150148OB-I00, and CEX2023-001316-M) and the Comunidad de Madrid (TEC-2024/TEC-380)
FHOD3 and DIAPH3 control cell migration and differentially shift the balance of parallel and perpendicular stress fibers
No full textCell morphology, dictated by the filamentous actin (F-actin) cytoskeleton, is fundamental to cell migration during wound healing and cancer metastasis. Cell morphology is shaped by the extracellular matrix (ECM), which provides mechanical cues in the form of ECM stiffness. These mechanical cues regulate the assembly of the F-actin cytoskeleton which in turn controls cell morphology and cell migration. Formins are key regulators of linear F-actin, assembling it into stress fibers, yet the specific roles of individual formins in controlling distinct stress fiber subpopulations to control cell morphology and migration remain poorly defined. Here, we characterize formin expression across different cell types and leverage the inherent expression and cell morphology differences to identify FHOD3 and DIAPH3 as strongly correlated with cell elongation. We demonstrate that these formins regulate complementary but distinct stress fiber networks. In contractile, but less motile cells, FHOD3 knock-down shifts the balance towards stress fibers oriented perpendicular to the long axis of the cell. In contrast, DIAPH3 knock-down shifts the balance towards stress fibers oriented parallel to the long axis of the cell. However, in less contractile and highly motile cells, knockdown of either formin significantly impairs cell migration speed, suggesting both F-actin fiber networks are necessary for cell migration. Our work establishes a model where FHOD3 and DIAPH3 function through non-overlapping mechanisms to control the F-actin architecture that governs cell shape and motility.This is a preprint from Namanda, Fred Rogers, Azarnoosh Foroozandehfar, and Ian Christopher Schneider. "FHOD3 and DIAPH3 control cell migration and differentially shift the balance of parallel and perpendicular stress fibers." bioRxiv (2026): 2026-02. doi: https://doi.org/10.64898/2026.02.13.703290.National Institutes of Health, GM143302
Functional characterization of cysteine-rich receptor-like kinases in regulating plasmodesmata and plant immunity
No full textPlasmodesmata (PD) are membrane-lined channels that connect plant cells and regulate the movement of signals, metabolites, and proteins essential for development and stress responses. Chapter 1 reviews PD structure, callose-mediated control of permeability, and the diverse proteins that regulate PD function. It also highlights advances in proximity labeling, such as TurboID, which have expanded the identification of PD-associated proteins and improved understanding of PD dynamics during growth and defense.
Chapter 2 builds on this foundation by examining how PD contributes to plant immunity. Using TurboID-based proximity labeling, over 200 potential interactors of PDLP5 were identified during bacterial infection, including cysteine-rich receptor-like kinases (CRKs) and NADPH oxidases (RBOHs). Structural modeling and functional analyses suggest that CRK13 modulates RBOH activity, influencing extracellular ROS production and PD permeability. crk13 mutants exhibit enhanced resistance to Pst DC3000, indicating a regulatory connection between PD signaling, ROS dynamics, and immune responses
Feasibility Informed Advantage Weighted Regression for Persistent Safety in Offline Reinforcement Learning
No full textSafe offline reinforcement learning aims to learn policies that maximize cumulative rewards while adhering to safety constraints, using only offline data for training. A key challenge is balancing safety and performance, particularly when the policy encounters out-of-distribution (OOD) states and actions, which can lead to safety violations or overly conservative behavior during deployment. To address these challenges, we introduce Feasibility Informed Advantage Weighted Actor-Critic (FAWAC), a method that prioritizes persistent safety in constrained Markov decision processes (CMDPs). FAWAC formulates policy optimization with feasibility conditions derived specifically for offline datasets, enabling safe policy updates in non-parametric policy space, followed by projection into parametric space for constrained actor training. By incorporating a cost-advantage term into Advantage Weighted Regression (AWR), FAWAC ensures that the safety constraints are respected while maximizing performance. Additionally, we propose a strategy to address a more challenging class of problems that involves tempting datasets where trajectories are predominantly high-rewarded but unsafe. Empirical evaluations on standard benchmarks demonstrate that FAWAC achieves strong results, effectively balancing safety and performance in learning policies from the static datasets.This proceeding is published as Koirala, Prajwal, Zhanhong Jiang, Soumik Sarkar, and Cody Fleming. "Feasibility Informed Advantage Weighted Regression for Persistent Safety in Offline Reinforcement Learning." In 2025 IEEE 64th Conference on Decision and Control (CDC), pp. 5837-5844. IEEE, 2025. doi: https://doi.org/10.1109/CDC57313.2025.11313011
Model reference control for grid forming inverters
No full textThe growing integration of renewable energy resource-based generation introduces power electronics-based interfaces between generation and the grid in place of traditional synchronous generators. Approaches to renewable energy integration can be categorized into grid-forming (GFM) vs. grid-following (GFL) inverters. This paper proposes a novel model reference-control framework for grid-forming inverters where the control is designed so that the overall system acts as traditional
synchronous generation system would act. The paper proposes an imitation-based learning algorithm to emulate the operation of a traditionally controlled synchronous generator. A simplified two-bus test system is used to validate the controller’s grid-forming capability
Integrating the Equitable Design Toolkit into user experience (UX) and design education
No full textBecause the use of digital technology has become commonplace in modern society, its influence has become pervasive. Consequently, it is necessary for designers to acknowledge their social and ethical responsibilities as they help create and shape these technologies. As individuals share personal information through and become dependent upon their digital devices, the designers’ choices have become increasingly important, as they impact how and who can participate fully in society. Influenced by their perspectives and biases, designers play a critical role in determining who can engage with the digital world and who may be marginalized. This challenge resulted by the growing diversity and unpredictability of user interactions with new technologies, often leaving underrepresented users needing access to essential services and further widening the digital divide. In this context, the connection between technology and human experience must be considered in design processes to foster inclusivity and equity and to ensure devices and the tools they provide are usable by a broad user base.
User experience (UX) design, driven by rapidly evolving information and communication technologies, demands a shift toward inclusive design practices that consider the complexities of users’ identities, such as race, gender, socioeconomic status, and disability. Traditional design pedagogy, rooted in outdated curricula, is ineffective in preparing students for these contemporary challenges. Current educational models, still influenced by the Bauhaus movement, need to focus more on human-centered design.
Today, many classroom design projects rely on hypothetical users, often shaped by generalized or stereotypical assumptions. Consequently, the current design studio curriculum does not adequately teach students about the real-world diversity and inequity related to design. The Equitable Design Toolkit was developed to provide structured, hands-on methods for incorporating intersectionality into the design process, allowing students to engage more meaningfully with equity-focused thinking. It supports a shift from designing for imagined users to designing with an awareness of real, complex human identities.
This study explores the integration of an intersectionality framework into design education to address ethical and social responsibilities while enhancing inclusivity. It introduces the Equitable Design Toolkit with various activities for students to test their biases, understand the impact of biased designs, and develop personas using intersectionality. The research was conducted in two parts within graphic design classes: (1) a pilot study to test the toolkit’s usability and functionality with eight students (n=8), and (2) a main study examining the toolkit’s impact on design outcomes and decisions made by fourteen students (n=14) over eight weeks.
The main study was divided into two phases: the first focused on designing habit-forming interactions, and the second incorporated the Discover design process with implementation of Equitable Design Toolkit into the design process to redesign outcomes from the first phase. The study employed the Scholarship of Teaching and Learning and qualitative research methods, including case studies, project progress, reflection statements, and exit surveys.
The findings indicate that integrating intersectionality into the design curriculum using a toolkit effectively promotes the development of more inclusive, ethical, and equitable systems and interactions. This approach not only addresses the biases and assumptions inherent in traditional design practices but also empowers students to consider the diverse identities and experiences of their users. By actively engaging with biases and intersectionality, students are better equipped to recognize and mitigate the societal impact of their design.
Moreover, the Equitable Design Toolkit is an effective pedagogical tool for creating a sustainable curriculum. It provides educators with the resources and methodologies needed to teach students about the importance of inclusive and ethical design. Through practical activities and reflective exercises, students learn to prioritize social values in their work, fostering a deeper understanding of their role as designers in shaping society. This approach ensures that future designers are skilled and committed to advancing social justice and equity through professional practice
Modern maize hybrids have improved tolerance to drought stress and increased yield potential
No full textThis study quantifies the effect of breeding and water supply on maize (Zea mays L.) yields, yield components, grain quality, and water use efficiency in Bayer legacy maize hybrids. Thirty-eight hybrids released from 1980 to 2020 were grown under three irrigation levels (non-irrigated, partially, and fully irrigated) in a 3-year experiment in Nebraska. Results indicate a significant grain yield increase across all irrigation treatments, with an average genetic gain of 111 kg/ha/year. New hybrids without irrigation produced as much yield as old hybrids with irrigation. Kernel number and weight increased with the year of hybrid release, with the kernel number being the primary driver of yield increase. This coincided with a reduced anthesis-silking interval (delta of 3 days between old and new hybrids). Grain protein concentration decreased by 1% from 1980 to 2020 following a dilution curve. Starch concentration increased by the same amount (∼1%), while oil concentration remained unchanged. Water use efficiency, defined as grain yield per water supply unit (growing season rain and irrigation), increased by 28% in the 40-year period. We concluded that maize breeding for high yields has indirectly affected several plant traits, including water use efficiency improvement, which is very encouraging for the future of crop production in the face of increased weather variability and climate change. Furthermore, we concluded that yield increase is the result of increasing both yield potential and drought stress tolerance. Present results can assist decision-making regarding water management of modern hybrids and enhance our crop physiology knowledge.This article is published as Danalatos, Gerasimos JN, Emily E. Wright, Mark Reiman, Slobodan Trifunovic, Brian Olson, Michael J. Castellano, and Sotirios V. Archontoulis. "Modern maize hybrids have improved tolerance to drought stress and increased yield potential." Agronomy Journal 118, no. 1 (2026): e70294. https://doi.org/10.1002/agj2.70294Foundation for Food and Agriculture Research; Bayer CropScienc
Improving authentication for wireless healthcare sensors
No full textWireless Body Area Networks (WBANs) enable continuous health monitoring through wearable and implantable sensors, promising significant improvements in personalized healthcare delivery. However, these networks face critical security and privacy challenges, stemming from their resource-constrained devices, the sensitivity of transmitted medical data, and emerging threats such as quantum computing. Existing cryptographic methods often impose unsustainable computational and energy demands, while widely adopted standards like Bluetooth Low Energy (BLE) suffer from well-known security vulnerabilities.
This thesis addresses these challenges by advancing both device authentication and message integrity mechanisms tailored for WBANs. At the physical layer, we explore the transition from classical cryptographic methods to Physical Layer Authentication (PLA) techniques that exploit the intrinsic properties of wireless channels and hardware imperfections. We propose AI-enhanced PLA models, including novel applications of Complex-Valued Neural Networks (CVNNs) and transformer-based architectures, demonstrating their superior ability to capture the amplitude and phase information inherent in RF signals. Our contributions include the design, collection, and analysis of a dedicated BLE-WBAN RF dataset, recorded under realistic body-area conditions to support robust machine learning models for device fingerprinting and anomaly detection.
Beyond authentication, we investigate the challenge of message integrity in short-packet healthcare transmissions, where conventional Message Authentication Codes (MACs) introduce prohibitive overhead. We propose innovative overhead-reducing schemes, including a Two-Dimensional Compound MAC (2D MAC) approach that aggregates integrity checks across time and space to reduce per-message overhead without sacrificing security. Building on this, the OPTIMAC framework formulates integrity-check scheduling as an optimization problem, balancing authenticated throughput and security in adversarial, lossy environments.
Experimental validation includes simulations of IEEE 802.15.6-based authentication, real-world BLE recordings, and WiFi-based UDP streaming subject to jamming attacks. Results demonstrate the feasibility and effectiveness of our proposed schemes, achieving robust authentication and integrity verification under realistic constraints. This work advances the state-of-the-art in secure WBAN communication by integrating physical-layer security, advanced machine learning, and optimized integrity-checking mechanisms, offering practical pathways for secure and energy-efficient healthcare sensor networks
Distribution, habitat associations, and trapping efficiency of crayfish communities in shallow lentic systems of the Prairie Pothole Region of Iowa
No full textAnthropogenic effects on shallow lentic systems of the Prairie Pothole Region (PPR), such as draining, pollution, climate change, and invasive species, are major threats to aquatic species, including crayfish. Crayfish are critical for freshwater food webs and act as habitat engineers through their diets and burrowing behavior. However, crayfish are declining, facing similar anthropogenic effects as the aquatic systems of the PPR. Nearly a third of crayfish species lack data critical for creating effective management plans; yet many regions lack historical data on crayfish distribution, habitat associations, and species status. There is a vital need to limit these knowledge gaps to protect native crayfish against threats, including the introduction of invasive crayfish. Invasive crayfish are a major factor in the decline of native crayfish as they out-compete native crayfish for food and shelter. As invasive crayfish expand their range, it is important to understand how they influence native crayfish and identify their habitat associations in novel environments to prevent the spread to other systems.
Rusty Crayfish (Faxonius rusticus) is an invasive species that has caused damage to ecosystems across the United States and Canada by disrupting aquatic food webs and outcompeting native crayfish. In 2018, Rusty Crayfish were found in Storm Lake, a shallow glacial lake in northwestern Iowa. Storm Lake is on the western front of the Rusty Crayfish invasion region and has undergone a variety of enhancement projects, making it a novel system for examining the habitat associations of Rusty Crayfish and native crayfish. We evaluated the habitat associations of Rusty and Virile crayfish (Faxonius virilis) within Storm Lake, focusing on habitat created or altered by enhancement projects, and explored the temporal variation in crayfish capture. We deployed 707 baited Gee’s minnow traps across three habitat regions based on water depth. We captured 112 crayfish; 65 Rusty Crayfish and 47 Virile Crayfish. Rusty Crayfish were strongly associated with cobble presence created by shoreline armoring, and Virile Crayfish were associated with macrophyte presence. Capture probability also varied by Julian day, with the highest capture probability for Rusty Crayfish in June and Virile Crayfish in August. Collectively, our results suggest niche partitioning could be occurring in Storm Lake as Rusty Crayfish outcompete Virile Crayfish for cobble habitat. Seasonal capture probabilities differed by species, which could be important to consider when sampling or monitoring Rusty Crayfish in other lentic systems of the PPR.
In addition to our sampling at Storm Lake, we wanted to address knowledge gaps on crayfish distribution, trapping efficiency, and habitat associations in other shallow lentic systems of the PPR in Iowa. We sampled 42 glacial lakes and wetlands using baited Gee’s minnow traps, capturing 780 crayfish (752 Calico Crayfish Faxonius immunis; 28 Virile Crayfish) at 25 sites. At each site, we collected waterbody-level environmental data on aquatic habitat, nearshore land cover, and fish community data. We used non-metric multidimensional scaling (NMDS) in conjunction with a multi-response permutation procedure (MRPP) to determine how habitat and fish communities are associated with crayfish presence. We also grouped sites using hierarchical clustering based on the waterbody-level environmental data. Finally, we used an 11-year crayfish dataset from Iowa’s multiple species inventory and monitoring (MSIM) program to explore how drought and Julian day influence crayfish capture probability using generalized linear mixed-effect models. Our results suggest Calico Crayfish presence was positively associated with shallow wetlands with emergent vegetation, silt substrate, and fewer fish species, while Virile Crayfish presence was positively associated with larger systems characterized by open water and various sport and non-sport fishes. Hierarchical clustering identified two groups of lentic systems: wetlands, where crayfish trapping efficiency was higher, and shallow lakes, where crayfish trapping efficiency was lower. Crayfish capture probability increased from 0.03 on Julian day 109, peaked at 0.10 on Julian day 198, and then declined to 0.02 by Julian day 289. These results provide new data on crayfish distributions, habitat use, and trapping efficiency that can help managers better monitor and manage crayfish populations in lentic habitats across the PPR, where distribution records are often sparse
Bridging atomic and mesoscopic length scales with Replica Scanning Tunneling Microscopy: Visualizing the intra-unit cell pair density modulation of superconducting FeSe at micron length scale
No full textScanning Tunneling Microscopy (STM) is a cornerstone technique for visualizing the electronic density of states with atomic resolution (typically below 0.1 nm). While the field of view of most STM setups extends up to a few microns, obtaining atomic resolution over these large areas is often impractical and excessively time-consuming. This is due to the need to acquire maps with a point number reaching 107 or more with a full current or conductance vs voltage curve at each point. The standard procedure is to make large scale maps and then select small regions to zoom-in for high-resolution atomic scale analysis. However, this approach fails to address a question which is often critical: Does a specific atomic-scale modulation of the electronic density of states persist over much larger, mesoscopic length scales? Here we present a new method: Replica STM (R-STM), that overcomes this limitation, allowing the study of atomic-scale phenomena up to micron length scales. We obtained new large-area STM tunneling conductance maps in UTe2 and FeSe, spanning areas over 200 nm in size. In these large scale maps we discovered signals with wavelengths significantly exceeding interatomic distances. We show that these large-wavelength signals are replicas of the underlying atomic-scale density of states modulations. R-STM leverages these replica signals to efficiently track atomic-scale features over large areas. Using this novel technique, we show that the pair density modulation discovered recently in FeSe persists with the same characteristic wavelength up to hundreds of nm length scales. R-STM provides a powerful and practical new capability for STM to compare atomic scale with micrometer scale phenomena. The proof of principle of R-STM can be extended to any other scanning probe microscopy experiment where a periodic signal is traced as a function of position.This is a preprint from Velasco, Miguel Águeda, Jose D. Bermúdez-Pérez, Pablo García Talavera, Raquel Sánchez-Barquilla, Jose Antonio Moreno, Juan Schmidt, Sergey L. Bud'ko et al. "Bridging atomic and mesoscopic length scales with Replica Scanning Tunneling Microscopy: Visualizing the intra-unit cell pair density modulation of superconducting FeSe at micron length scale." arXiv preprint arXiv:2602.19678 (2026). doi: https://doi.org/10.48550/arXiv.2602.19678.This work was supported by the Spanish Research State Agency (PID2020-114071RB-I00, PID2023-150148OB-I00, TED2021-130546BI00 and CEX2023001316-M), Comunidad de Madrid through project TEC-2024/TEC-380 “Mag4TIC” and PhD thesis support (PIPF-2023/TEC-30853 and PIPF-2023/TEC- 30683), and the EU through grant agreement No 871106. We acknowledge the
QUASURF project (SI4/PJI/2024-00199) funded by the Comunidad de Madrid through the agreement to promote and encourage research and technology transfer at the Universidad Aut´onoma de Madrid. We acknowledge collaborations through EU program Cost CA21144 (www.superqumap.eu). We also acknowledge SEGAINVEX for support in design and for construction of the electronics of the STM