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High-spatial-resolution wearable tactile arrays have drawn interest from both industry and research, thanks to their capacity for delivering detailed tactile sensations. However, investigations of human tactile perception with high resolution tactile displays remain limited, primarily due to the high costs of multi-channel control systems and the complex fabrication required for fingertip-sized actuators. In this work, we introduce the Soft Haptic Display (SHD) toolkit, designed to enable students and researchers from diverse technical backgrounds to explore high-density tactile feedback in extended reality (XR), robotic teleoperation, braille displays, navigation aid, MR-compatible somatosensory stimulation, and remote palpation. The toolkit provides a rapid prototyping approach and real-time wireless control for a low-cost, 4×4 soft wearable fingertip tactile display with a spatial resolution of 4 mm. We characterized the display’s performance with a maximum vertical displacement of 1.8 mm, a rise time of 0.25 second, and a maximum refresh rate of 8 Hz. All materials and code are open-sourced to foster broader human tactile perception research of high-resolution haptic displays. 

This paper investigates the relationship between teacher and student discourse patterns, measured by accountable talk moves (Michaels & O’Connor, 2015) and the quality of mathematics instruction as measured by the Mathematical Quality of Instruction (MQI) rubric. This study uses a large public dataset of human coded MQI lesson transcripts and validated AI coding for talk moves to explore how different talk moves predict instructional quality. Results indicate that certain talk moves at certain frequencies, especially those relating to accountability to the learning community and rigorous thinking, positively correlate with higher MQI scores. Thus the nature and frequency of nuanced discourse patterns are crucial for high-quality mathematics instruction, while simple metrics like the amount of student talk have little impact. 

(1) Background: The safe execution of heavy machinery operations and high-risk construction tasks requires operators to manage multiple tasks, with a constant awareness of coworkers and hazards. With high demands on visual and auditory resources, vibrotactile feedback systems offer a solution to enhance awareness without overburdening vision or hearing. (2) Aim: This study evaluates the impact of vibrotactile feedback regarding proximity to hazards on multitasking performance and cognitive workload in order to support hazard awareness in a controlled task environment. (3) Method: Twenty-four participants performed a joystick-controlled navigation task and a concurrent mental spatial rotation task. Proximity to hazards in the navigation task was conveyed via different encodings of vibrotactile feedback: No Vibration, Intensity-Modulation, Pulse Duration, and Pulse Spacing. Performance metrics, including obstacle collisions, target hits, contact time, and accuracy, were assessed alongside perceived workload. (4) Results: Intensity-Modulated feedback reduced obstacle collisions and proximity time, while lowering workload, compared to No Vibration. No significant effects were found on spatial rotation accuracy, indicating that vibrotactile feedback effectively guides navigation and supports spatial awareness. (5) Conclusions: This study highlights the potential of vibrotactile feedback to improve navigation performance and hazard awareness, offering valuable insights into multimodal safety systems in high-demand environments. 

Medical palpation is a task that traditionally requires a skilled practitioner to assess and diagnose a patient through direct touch and manipulation of their body. In regions with a shortage of such professionals, robotic hands or sensorized gloves could potentially capture the necessary haptic information during palpation exams and relay it to medical doctors for diagnosis. From an engineering perspective, a comprehensive understanding of the relevant motions and forces is essential for designing haptic technologies capable of fully capturing this information. This study focuses on thyroid examination palpation, aiming to analyze the hand motions and forces applied to the patient’s skin during the procedure. We identified key palpation techniques through video recordings and interviews and measured the force characteristics during palpation performed by both non-medical participants and medical professionals. Our findings revealed five primary palpation hand motions and characterized the multi-dimensional interaction forces involved in these motions. These insights provide critical design guidelines for developing haptic sensing and display technologies optimized for remote thyroid nodule palpation and diagnosis. 

ABSTRACT Extracellular matrix stiffness is enhanced in cancer and fibrosis; however, there is limited knowledge on how matrix mechanics modulate expression and signaling of the methyltransferase G9a. Here, we show that matrix stiffness and transforming growth factor (TGF)‐β1 signaling together regulate G9a expression and the levels of the histone mark H3K9me2. Suppressing the activity and expression of G9a attenuates TGFβ1‐induced alpha smooth muscle actin (αSMA) and N‐cadherin expression and cell morphology changes in mammary epithelial cells cultured on stiff substrata. Knockdown of G9a increases the expression of large tumor suppressor kinase 2 (LATS2) and decreases the nuclear localization of yes associated protein (YAP). Furthermore, inhibition of LATS promotes an increase in YAP nuclear localization and αSMA expression, while inhibition of YAP attenuates αSMA expression. Overall, our findings indicate that a G9a‐LATS‐YAP signaling cascade regulates mammary epithelial cell response to matrix stiffness and TGFβ1. 

Active, exploratory touch supports human perception of a broad set of invisible physical surface properties. When traditionally hands-on tasks, such as medical palpation of soft tissue, are translated to virtual settings, haptic perception is throttled by technological limitations, and much of the richness of active exploration can be lost. The current research seeks to restore some of this richness with advanced methods of passively conveying haptic data alongside synchronized visual feeds. A robotic platform presented haptic stimulation modeled after the relative motion between a hypothetical physician's hands and artificial tissue samples during palpation. Performance in discriminating the sizes of hidden “tumors” in these samples was compared across display conditions which included haptic feedback and either: 1) synchronized video of the participant's hand, recorded during active exploration; 2) synchronized video of another person's hand; 3) no accompanying video. The addition of visual feedback did not improve task performance, which was similar whether receiving relative motion recorded from one's own hand or someone else's. While future research should explore additional strategies to improve task performance, this initial attempt to translate active haptic sensations to passive presentations indicates that visuo-haptic feedback can induce reliable haptic perceptions of motion in a stationary passive hand. 

Engineering student writers must document their reference sources in their theses, papers, proposals, reports, and related documents that they prepare. This is generally done in Microsoft Word or in a LaTeX software package and typically done in the IEEE citation style which is widely used in engineering and technology. In this work, we identify 25 primary reference types and 21 secondary reference types that are used in present-day engineering writing. Because all 46 of these engineering reference types are typically not available in commercial reference management software, we have generated customization files for the widely used EndNote reference management software package that enable referencing to be done using either Cite-While-You-Write (CWYW) for Word users or using BibTeX for LaTeX users. These customization files and instructions on how to install and use them, herein called the Georgia Tech Engineering Reference Management System (GTERMS), are made available on an open-access free-to-use basis. 

Transient absorption spectroscopy (TAS) is among the most common ultrafast photochemical experiments, but its interpretation remains challenging. In this work, we present an efficient and robust method for simulating TAS signals from first principles. Excited-state absorption and stimulated emission (SE) signals are computed using time-dependent complete active space configuration interaction (TD-CASCI) simulations, leveraging the robustness of time-domain simulation to minimize electronic structure failure. We demonstrate our approach by simulating the TAS signal of 1′-hydroxy-2′-acetonapthone (HAN) from ab initio multiple spawning nonadiabatic molecular dynamics simulations. Our results are compared to gas-phase TAS data recorded from both jet-cooled (T ∼ 40 K) and hot (∼403 K) molecules via cavity-enhanced TAS (CE-TAS). Decomposition of the computed spectrum allows us to assign a rise in the SE signal to excited-state proton transfer and the ultimate decay of the signal to relaxation through a twisted conical intersection. The total cost of computing the observable signal (∼1700 graphics processing unit hours for ∼4 ns of electron dynamics) was markedly less than that of performing the ab initio multiple spawning calculations used to compute the underlying nonadiabatic dynamics. 

The phosphoregulation of proteins with multiple phosphorylation sites is governed by biochemical reaction networks that can exhibit multistable behavior. However, the behavior of such networks is typically studied in a single reaction volume, while cells are spatially organized into compartments that can exchange proteins. In this work, we use stochastic simulations to study the impact of compartmentalization on a two-site phosphorylation network. We characterize steady states and fluctuation-driven transitions between them as a function of the rate of protein exchange between two compartments. Surprisingly, the average time spent in a state before stochastically switching to another depends nonmonotonically on the protein exchange rate, with the most frequent switching occurring at intermediate exchange rates. At sufficiently small exchange rates, the state of the system and mean switching time are controlled largely by fluctuations in the balance of enzymes in each compartment. This leads to negatively correlated states in the compartments. For large exchange rates, the two compartments behave as a single effective compartment. However, when the compartmental volumes are unequal, the behavior differs from a single compartment with the same total volume. These results demonstrate that exchange of proteins between distinct compartments can regulate the emergent behavior of a common signaling motif.