Distinct Behavior Research Articles

Distinct Activation Mechanisms of CXCR4 and ACKR3 Revealed by Single-Molecule Analysis of their Conformational Landscapes.

The canonical chemokine receptor CXCR4 and atypical receptor ACKR3 both respond to CXCL12 but induce different effector responses to regulate cell migration. While CXCR4 couples to G proteins and directly promotes cell migration, ACKR3 is G protein-independent and scavenges CXCL12 to regulate extracellular chemokine levels and maintain CXCR4 responsiveness, thereby indirectly influencing migration. The receptors also have distinct activation requirements. CXCR4 only responds to wild-type CXCL12 and is sensitive to mutation of the chemokine. By contrast, ACKR3 recruits GPCR kinases (GRKs) and β-arrestins and promiscuously responds to CXCL12, CXCL12 variants, other peptides and proteins, and is relatively insensitive to mutation. To investigate the role of conformational dynamics in the distinct pharmacological behaviors of CXCR4 and ACKR3, we employed single-molecule FRET to track discrete conformational states of the receptors in real-time. The data revealed that apo-CXCR4 preferentially populates a high-FRET inactive state, while apo-ACKR3 shows little conformational preference and high transition probabilities among multiple inactive, intermediate and active conformations, consistent with its propensity for activation. Multiple active-like ACKR3 conformations are populated in response to agonists, compared to the single CXCR4 active-state. This and the markedly different conformational landscapes of the receptors suggest that activation of ACKR3 may be achieved by a broader distribution of conformational states than CXCR4. Much of the conformational heterogeneity of ACKR3 is linked to a single residue that differs between ACKR3 and CXCR4. The dynamic properties of ACKR3 may underly its inability to form productive interactions with G proteins that would drive canonical GPCR signaling.

Rapid detection of capture and emission processes in surface and buffer traps: Understanding dynamic degradation in GaN power devices

This study utilized a rapid detection technique, Isothermal Capture Transient Spectroscopy (ICTS), to identify and evaluate defects related to GaN device surface and buffer traps, and investigated the mechanisms by which they affect the dynamic performance of GaN based devices. Interface states and dielectric bulk traps were analyzed, unveiling distinctive device behavior under positive gate pulse-biased ICTS. The observed S-shaped threshold voltage (VTH) instability and dynamic gate-drain capacitance (CGD) issues were directly associated with these interface states and bulk traps. Negative gate pulse-biased ICTS revealed the presence of logarithmic electron trapping originating from extended electron traps, and spatial wide distributed hole traps within the GaN buffer layer, significantly impacting the dynamic on-resistance (RON) during off-state stress of the devices. The rapid assessment capabilities of this method provide a valuable tool for optimizing GaN epitaxy and manufacturing processes.

Binder Parameter in a Generalized Two-dimensional XY Model

We performed Monte Carlo simulation for a two-dimensional generalized XY model and calculated the magnetic and nematic Binder parameters. The phase diagram is re-examined based on these Binder parameters, demonstrating their power in studying generalized XY models. The Binder parameter has distinctive behaviors, resulting in different types of phase transition. More importantly, the magnetic Binder parameter gives more insights into the tricritical region where the Kosterlitz-Thouless, Ising, and 1/2 Kosterlitz-Thouless (KT) transition lines meet. It shows signatures for the intermediate region starting from the tricritical point, where the transition line is neither the same physics as the Ising transition below nor the KT transition far above the tricritical point.

Bacterial hemophilin homologs and their specific type eleven secretor proteins have conserved roles in heme capture and are diversifying as a family.

Cellular life relies on enzymes that require metals, which must be acquired from extracellular sources. Bacteria utilize surface and secreted proteins to acquire such valuable nutrients from their environment. These include the cargo proteins of the type eleven secretion system (T11SS), which have been connected to host specificity, metal homeostasis, and nutritional immunity evasion. This Sec-dependent, Gram-negative secretion system is encoded by organisms throughout the phylum Proteobacteria, including human pathogens Neisseria meningitidis, Proteus mirabilis, Acinetobacter baumannii, and Haemophilus influenzae. Experimentally verified T11SS-dependent cargo include transferrin-binding protein B (TbpB), the hemophilin homologs heme receptor protein C (HrpC), hemophilin A (HphA), the immune evasion protein factor-H binding protein (fHbp), and the host symbiosis factor nematode intestinal localization protein C (NilC). Here, we examined the specificity of T11SS systems for their cognate cargo proteins using taxonomically distributed homolog pairs of T11SS and hemophilin cargo and explored the ligand binding ability of those hemophilin cargo homologs. In vivo expression in Escherichia coli of hemophilin homologs revealed that each is secreted in a specific manner by its cognate T11SS protein. Sequence analysis and structural modeling suggest that all hemophilin homologs share an N-terminal ligand-binding domain with the same topology as the ligand-binding domains of the Haemophilus haemolyticus heme binding protein (Hpl) and HphA. We term this signature feature of this group of proteins the hemophilin ligand-binding domain. Network analysis of hemophilin homologs revealed five subclusters and representatives from four of these showed variable heme-binding activities, which, combined with sequence-structure variation, suggests that hemophilins are diversifying in function.IMPORTANCEThe secreted protein hemophilin and its homologs contribute to the survival of several bacterial symbionts within their respective host environments. Here, we compared taxonomically diverse hemophilin homologs and their paired Type 11 secretion systems (T11SS) to determine if heme binding and T11SS secretion are conserved characteristics of this family. We establish the existence of divergent hemophilin sub-families and describe structural features that contribute to distinct ligand-binding behaviors. Furthermore, we demonstrate that T11SS are specific for their cognate hemophilin family cargo proteins. Our work establishes that hemophilin homolog-T11SS pairs are diverging from each other, potentially evolving into novel ligand acquisition systems that provide competitive benefits in host niches.

Environmental Governance and Gender Inclusivity: Analyzing the Interplay of PM2.5 and Women’s Representation in Political Leadership in the European Union

This research addresses a critical gap in the literature by establishing a direct correlation between particle pollution from fine particulates (PM2.5) and women’s political participation. It offers a nuanced understanding of gender dynamics in governance and their impact on environmental outcomes. Focusing on 27 European Union (EU) countries from 2013 to 2021, econometric techniques unveil common trends, underscoring cross-sectional dependence. This study reveals distinct gender behaviors in combating pollution, with women in parliaments and regional assemblies notably contributing to pollutant reduction. However, the negative impact of women’s engagement in politics on PM2.5 intensifies the lower part of the representation hierarchy. Policymakers are urged to create conditions fostering women’s political participation, advocating for gender quotas to address underrepresentation. The research emphasizes the interconnectedness of gender, politics, and environmental issues, urging heightened awareness among policymakers. Limitations include a confined scope and duration, requiring cross-validation beyond the EU. Future research pathways involve exploring the intricate connections between gender, politics, and environmental initiatives, seeking thresholds for impactful women’s representation. In contributing to Sustainable Development Goals (SDGs), this study aligns with SDG 5 (gender equality), SDG 3 (good health and well-being), SDG 7 (affordable and clean energy), SDG 11 (sustainable cities and communities), SDG 16 (peace, justice, and strong institutions), and SDG 17 (partnerships for the goals).

Deep learning of movement behavior profiles and their association with markers of cardiometabolic health

BackgroundTraditionally, existing studies assessing the health associations of accelerometer-measured movement behaviors have been performed with few averaged values, mainly representing the duration of physical activities and sedentary behaviors. Such averaged values cannot naturally capture the complex interplay between the duration, timing, and patterns of accumulation of movement behaviors, that altogether may be codependently related to health outcomes in adults. In this study, we introduce a novel approach to visually represent recorded movement behaviors as images using original accelerometer outputs. Subsequently, we utilize these images for cluster analysis employing deep convolutional autoencoders.MethodsOur method involves converting minute-by-minute accelerometer outputs (activity counts) into a 2D image format, capturing the entire spectrum of movement behaviors performed by each participant. By utilizing convolutional autoencoders, we enable the learning of these image-based representations. Subsequently, we apply the K-means algorithm to cluster these learned representations. We used data from 1812 adult (20–65 years) participants in the National Health and Nutrition Examination Survey (NHANES, 2003–2006 cycles) study who worn a hip-worn accelerometer for 7 seven consecutive days and provided valid accelerometer data.ResultsDeep convolutional autoencoders were able to learn the image representation, encompassing the entire spectrum of movement behaviors. The images were encoded into 32 latent variables, and cluster analysis based on these learned representations for the movement behavior images resulted in the identification of four distinct movement behavior profiles characterized by varying levels, timing, and patterns of accumulation of movement behaviors. After adjusting for potential covariates, the movement behavior profile characterized as “Early-morning movers” and the profile characterized as “Highest activity” both had lower levels of insulin (P < 0.01 for both), triglycerides (P < 0.05 and P < 0.01, respectively), HOMA-IR (P < 0.01 for both), and plasma glucose (P < 0.05 and P < 0.1, respectively) compared to the “Lowest activity” profile. No significant differences were observed for the “Least sedentary movers” profile compared to the “Lowest activity” profile.ConclusionsDeep learning of movement behavior profiles revealed that, in addition to duration and patterns of movement behaviors, the timing of physical activity may also be crucial for gaining additional health benefits.

β-sheets mediate the conformational change and allosteric signal transmission between the AsLOV2 termini.

Avena sativa phototropin 1 light-oxygen-voltage 2 domain (AsLOV2) is a model protein of Per-Arnt-Sim (PAS) superfamily, characterized by conformational changes in response to external environmental stimuli. This conformational change begins with the unfolding of the N-terminal A'α helix in the dark state followed by the unfolding of the C-terminal Jα helix. The light state is characterized by the unfolded termini and the subsequent modifications in hydrogen bond patterns. In this photoreceptor, β-sheets are identified as crucial components for mediating allosteric signal transmission between the two termini. Through combined experimental and computational investigations, the Hβ and Iβ strands are recognized as the most critical and influential β-sheets in AsLOV2's allosteric mechanism. To elucidate the role of these β-sheets, we introduced 13 distinct mutations (F490L, N492A, L493A, F494L, H495L, L496F, Q497A, R500A, F509L, Q513A, L514A, D515V, and T517V) and conducted comprehensive molecular dynamics simulations. In-depth hydrogen bond analyses emphasized the role of two hydrogen bonds, Asn482-Leu453 and Gln479-Val520, in the observed distinct behaviors of L493A, L496F, Q497A, and D515V mutants. This illustrates the role of β-sheets in the transmission of the allosteric signal upon the photoactivation of the light state.

Interconnected CoNi-Se Hollow Flakes through Reduced Graphene Oxide Sheets as a Cathode Material for Hybrid Supercapacitors.

Achieving a high energy density and long-cycle stability in energy storage devices demands competent electrochemical performance, often contingent on the innovative structural design of materials under investigation. This study explores the potential of transition metal selenide (TMSe), known for its remarkable activity, electronic conductivity, and stability in energy storage and conversion applications. The innovation lies in constructing hollow structures of binary metal selenide (CoNi-Se) at the surface of reduced graphene oxide (rGO) arranged in a three-dimensional (3D) morphology (CoNi-Se/rGO). The 3D interconnected rGO architecture works as a microcurrent collector, while porous CoNi-Se sheets originate the active redox centers. Electrochemical analysis of CoNi-Se/rGO based-electrode reveals a distinct faradic behavior, thereby resulting in a specific capacitance of 2957 F g-1 (1478.5 C g-1), surpassing the bare CoNi-Se with a value of 2149 F g-1 (1074.5 C g-1) at a current density of 1 A g-1. Both materials exhibit exceptional high-rate capabilities, retaining 83% of capacitance at 10 A g-1 compared to 1 A g-1. In a two-electrode coin cell system, the device achieves a high energy density of 73 Wh kg-1 at a power density of 1500 W kg-1, stating an impressive 90.4% capacitance retention even after enduring 20,000 cycles. This study underscores the CoNi-Se/rGO composite's promise as a superior electrode material for high-performance energy storage applications.

Viscoelastic Response in Hydrous Polymers: The Role of Hydrogen Bonds and Microstructure.

Water responsive polymers represent a remarkable group of soft materials, acting as a laboratory for diverse water responsive physical phenomena and cutting-edge biology-electronics interfaces. We report on peculiarly distinctive viscoelastic behaviors of the biobased water responsive polymer cellulose 10-undecenoyl ester, while biobased regenerated cellulose displays stronger hydroplastic behaviors. We discovered a novel hydrous deformation mechanism involving the stretching of hydrogen bonds mediated by hydroxyl groups and water molecules, serving as a crucial factor in accommodating deformations. In parallel, the microstructure of cellulose 10-undecenoyl ester with unique coexisting nanoparticles and a continuous phase of entangled chains is mechanically resilient in the anhydrous state but enhances structural stiffness in the hydrous state. This variation arises from a different hydration level within the hydrous microstructure. Such a fundamental discovery offers valuable insights into the connection between the microscopic physical properties that can be influenced by water and the corresponding viscoelastic responses, extending its applicability to a wide range of hygroscopic materials.

Parasomnia induced by lemborexant: a case report.

Lemborexant, an orexin receptor antagonist, is effective not only for sleep disorders but also for preventing and treating delirium. To date, no complex sleep-related behaviors due to lemborexant have been reported. Herein, we present the case of a 69-year-old male patient who was hospitalized for oral floor and tongue cancer and developed delirium after surgery; however, upon lemborexant dosage increase, used to treat insomnia, he developed abnormal nocturnal behavior. This symptom rapidly improved when lemborexant was discontinued. Distinguishing parasomnia from delirium is important because the treatment of these two conditions differs. Although rapid eye movement sleep behavior or sleepwalking was the cause of this parasomnia, a definitive diagnosis could not be established. If qualitatively distinct abnormal behavior is observed compared to delirium after increasing lemborexant dosage, the possibility of parasomnia should be considered.

Parametric Semidefinite Programming: Geometry of the Trajectory of Solutions

In many applications, solutions of convex optimization problems are updated on-line, as functions of time. In this paper, we consider parametric semidefinite programs, which are linear optimization problems in the semidefinite cone whose coefficients (input data) depend on a time parameter. We are interested in the geometry of the solution (output data) trajectory, defined as the set of solutions depending on the parameter. We propose an exhaustive description of the geometry of the solution trajectory. As our main result, we show that only six distinct behaviors can be observed at a neighborhood of a given point along the solution trajectory. Each possible behavior is then illustrated by an example. Funding: This work was supported by OP RDE [Grant CZ.02.1.01/0.0/0.0/16_019/0000765].

Left-right Myosin-Is, Myosin1C, and Myosin1D exhibit distinct single molecule behaviors on the plasma membrane of Drosophila macrophages.

Left-right (LR) asymmetry is crucial for animal development, particularly in Drosophila where LR-asymmetric morphogenesis of organs hinges on cellular-level chirality, termed cell chirality. In this species, two class I myosins, Myosin1D (Myo1D), and Myosin1C (Myo1C), respectively determine dextral (wild type) and sinistral (mirror image) cell chirality. Previous studies demonstrated Myo1D's ability to propel F-actin in leftward circles during in vitro gliding assays, suggesting its mechanochemical role in defining dextral chirality. Conversely, Myo1C propels F-actin without exhibiting LR-directional preference in this assay, suggesting at other properties governing sinistral chirality. Given the interaction of Myo1D and Myo1C with the membrane, we hypothesized that differences in their membrane behaviors might be critical in dictating their dextral or sinistral activities. In this study, employing single-molecule imaging analyses, we investigated the dynamic behaviors of Myo1D and Myo1C on the plasma membrane. Our findings revealed that Myo1C exhibits a significantly greater proportion of slow-diffusing population compared to Myo1D. Importantly, this characteristic was contingent upon both head and tail domains of Myo1C. The distinct diffusion patterns of Myo1D and Myo1C did not exert mutual influence on each other. This divergence in membrane diffusion between Myo1D and Myo1C may be crucial for dictating cell and organ chirality.

Seismic scattering regimes from multiscale entropy and frequency correlations

SUMMARY Seismic-wave scattering is observed, to variable degrees, on Earth, its moon and Mars. Current scattering models and data processing typically rely on two end-member phenomena: weak, single- or multiple-scattering events (ballistic) on the one hand, or intense scattering such that the wavefield retains no path information or bearing on its origin (diffuse).This study explores the existence of scattering behaviour intermediate between these end-members, as well as the properties of heterogeneous media that facilitate a transition between them. We apply multiscale entropy and frequency-correlation analysis to seismic coda, and observe a distinct transitional behaviour is present within a part of the investigated parameter space. Analysis of terrestrial, lunar and Martian seismograms further demonstrate the applicability of these new methods across a wide range of scattering behaviours, while also highlighting their shortcomings. Results from the planetary data indicate partially non-diffuse behaviour and low complexity within specific bandwidths of lunar wavefields, potentially contradicting the current paradigm that lunar wavefields are diffuse, and require continued study. Furthermore, Martian seismograms are shown to possess greater statistical entropy than lunar seismograms and diffuse energy properties, yet still display distinct phase arrivals, suggesting substantial scattering and transitional scattering behaviour on Mars. The robust, comparative nature of multiscale entropy and frequency-correlation analysis, applied to idealised simulation as well as three separate planetary bodies, provides a promising framework for future exploration of scattered wavefields across ballistic, transitional and diffuse regimes, that complements existing methods.

Motivators and barriers to plant-based product consumption across Aotearoa New Zealand flexitarians

Limited knowledge exists concerning Aotearoa New Zealand (A-NZ) flexitarians and their respective motivators and barriers towards consumption of novel plant-based products (PBPs) heralded as aids for dietary meat reduction. This study aimed to determine if A-NZ flexitarians, who have tried novel PBPs, can be segmented based on different motivators and barriers to meat reduction and PBP consumption, if the consumer profile of the different segments varies according to identified gender, generation group, neophobia and meat and PBP consumption frequency. It also aimed to identify sensory characteristics novel PBPs need to possess to be attractive to A-NZ flexitarians and if these vary across segments. PBP-consuming flexitarians (n = 584), stratified according to age (Millennial/Gen X), identified gender and meat consumption frequency, completed an online survey regarding a) their level of agreement regarding statements related to factors driving PBP consumption and flexitarianism in general, and b) their satisfaction with the sensory experience of consuming current PBPs. ‘Tastes good’ was the top-rated factor for selecting PBPs for all consumers, but most were dissatisfied with the sensory characteristics of current PBPs. K-means cluster analysis identified three flexitarian segments based on similarities and differences in key motivations and barriers to consume PBPs. Attitudes and behaviours related to nutrition/health, and social status attained from eating both PBPs and meat products, accounted for most variation across the respondents. Overall, higher food neophobia was associated with higher PBP consumption, suggesting that neophobia itself is not necessarily a barrier to PBP consumption in A-NZ flexitarians. Improving the sensory profiles of PBPs whilst delivering nutritional requirements presented as key considerations for future product development and research. This research highlights the importance of understanding the distinct values, attitudes and behaviours of different flexitarian groups as opposed to generalised research aimed at flexitarians per se.

Bending strain–induced changes in perpendicular magnetic properties of Pt/Co/Pt films on flexible substrates

We studied the irreversible changes in the perpendicular magnetic properties of Pt(2.2 nm)/Co(0.8 nm)/Pt(2.2 nm) films deposited on a flexible polyethylene terephthalate substrate with bending deformation. The changes in the magnetic properties of the Pt/Co/Pt film with deformation were analyzed using magneto-optical Kerr-effect microscopy. The film was bent in one direction using cylindrical rods or semicylindrical grooves of different radii and then restored to the initial flat state. No significant changes in the magnetic properties due to bending strain were observed below a critical bending curvature. However, for bending curvatures above +0.25 mm−1 or below −0.14 mm−1, the magnetic domain shape changed from circular to elongated ellipses, perpendicular to the bending direction, and the coercivity of the film increased by 10%–30%. Furthermore, the domain wall motion exhibited a distinct anisotropic behavior, with ∼12-fold difference in the velocity of domain wall motion in different directions. Conclusively, the magnetic properties of the Pt/Co/Pt film fabricated on a flexible substrate exhibited irreversible changes beyond a critical deformation of +2.44% or −1.37%.

Airflow Triggered Water Film Self-Sculpturing on Femtosecond Laser-Induced Heterogeneously Wetted Micro/Nanostructured Surfaces.

Liquid manipulation is essential for daily life and modern industry, and it is widely used in various fields, including seawater desalination, microfluidic robots, and biomedical engineering. Nevertheless, the current research focuses on the manipulation of individual droplets. There are a few projects for water film management. Here, we proposed a facile method of wind-triggered water film self-sculpturing based on a heterogeneous wettability surface, which is achieved by the femtosecond laser direct writing technology and femtosecond laser deposition. Under the conditions of various airflow velocities and water film thicknesses, three distinct behaviors of the water film were analyzed. As a result, when the water film thickness is lower than 4.9 mm, the self-sculpture process will occur until the whole superhydrophobic surface dewetting. Four potential applications are demonstrated, including encryption, oil containers, reconfigurable patterning, and self-splitting devices. This work provides a new approach for manipulating a water film of fluid control engineering.

Deciphering Hydrogen Embrittlement Mechanisms in Ti6Al4V Alloy: Role of Solute Hydrogen and Hydride Phase.

Ti6Al4V (Ti64) is a versatile material, finding applications in a wide range of industries due to its unique properties. However, hydrogen embrittlement (HE) poses a challenge in hydrogen-rich environments, leading to a notable reduction in strength and ductility. This study investigates the complex interplay of solute hydrogen (SH) and hydride phase (HP) formation in Ti64 by employing two different current densities during the charging process. Nanoindentation measurements reveal distinct micro-mechanical behavior in base metal, SH, and HP, providing crucial insights into HE mechanisms affecting macro-mechanical behavior. The fractography and microstructural analysis elucidate the role of SH and HP in hydrogen-assisted cracking behaviors. The presence of SH heightens intergranular cracking tendencies. In contrast, the increased volume of HP provides sites for crack initiation and propagation, resulting in a two-layer brittle fracture pattern. The current study contributes to a comprehensive understanding of HE in Ti6Al4V, essential for developing hydrogen-resistant materials.

Incorporation of self-healing of UHPC in structural design approaches through healable crack width threshold and kinetics: The case study of H2020 project ReSHEALience database

Ultra-high-performance concrete (UHPC) stands out as a crucial construction material, boasting outstanding mechanical properties and exceptional durability in its uncracked state. The distinctive strain-hardening tensile behavior of UHPC necessitates a consideration of material and structural durability in the cracked state, prompting a rethinking of structural concepts and design approaches. Consequently, various competing mechanisms, including material deterioration, self-sealing, and self-healing capabilities, require meticulous assessment. The autogenous nature of the self-healing capacity of the material, crafted with compositions tailored to specific mechanical properties, further underscores this evaluation. This study elucidates above concepts by compiling and analyzing an extensive database of crack closure data obtained and processed through image processing techniques. This research specifically delves into appraising the self-sealing capacity of UHPC under structural service conditions, encompassing challenges such as chloride and sulfate attacks. Additionally, it endeavors to distinguish the crack healing kinetics of diverse UHPC mix designs, calibrating them across varying crack widths (0–20, 20–50, 50–100, 100–300 μm) and diverse healing environments. These findings assume significance in establishing the "healable width threshold" and the "self-healing coefficients of the crack healing kinetics law" under "structural service conditions".

Stability and dynamics of self-bound state of spin–orbit coupled spin-1 Bose–Einstein condensates

We study self-bound state of spin–orbit (SO) coupled spin-1 BECs under the action of the SO coupling and the density-dependent and spin-dependent interactions. The phase transition conditions from the magnetized phase to the unmagnetized phase are analytically obtained in the self-bound state, and the physical mechanism of the phase transition is revealed. The distinct properties of self-bound state in different ground states are discussed in detail, and static and moving self-bound states are obtained. Then, the stability of the self-bound state is studied, and the unstable threshold caused by the competition among SO coupling, Raman coupling, spin-dependent interaction and density-dependent interaction is obtained analytically and confirmed numerically. Furthermore, the dynamical transition of self-bound state from moving type to static type is studied numerically. Due to the spin momentum locking and the drive of spin dynamics, the self-bound states exhibit distinct dynamical behaviors in different ground state phases. Our study provides theoretical evidence for a deep understanding of the stability and the dynamic of self-bound states in SO coupled spin-1 BECs.

The wind tunnel test research on the aerodynamic stability of wind turbine airfoils

The issue of nonlinear aerodynamic stability of blades is a significant technological bottleneck in the development of large-scale wind turbines. In order to explore the influencing parameters and mechanisms of the nonlinear aerodynamic stability of large-scale wind turbine blades, the flexible blade was simplified into a two-dimensional rigid blade segment with elastic supports, which formed the pitch single-degree-of-freedom aeroelastic wind tunnel test system. Through wind tunnel vibration and pressure measurement synchronization tests, the torsional vibration characteristics and the flow field development mechanism of the airfoil under different wind speeds and attack angles were studied in detail. The wind tunnel tests revealed two distinct torsional aeroelastic behaviors: the static equilibrium state with negligible amplitude and high vibrational randomness, and the stall flutter state with larger amplitude, which was changed according to sinusoidal law substantially. The stall flutter state was confined within a specific wind speed range, and its stability boundary, which included the critical initiation wind speed and the critical cessation wind speed, all varied linearly with the installation attack angle. The growth rate of the critical cessation wind speed with the installation attack angle was significantly higher than that of the critical initiation wind speed, making the wind speed range for the occurrence of stall flutter also linearly larger. Additionally, the frequency of the stall flutter was significantly higher than the natural frequency of the model, and it exhibited a positive correlation with the critical initiation wind speed. The flow state around the airfoil during stall flutter was primarily distinguished from its static counterpart by the presence of leading-edge vortices. The formation and shedding of these leading-edge vortices would significantly influence the characteristics of stall flutter.