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Tension activation of mechanosensitive two-pore domain K+ channels TRAAK, TREK-1, and TREK-2.
Get PDFTRAAK, TREK-1, and TREK-2 are mechanosensitive two-pore domain K+ (K2P) channels that contribute to action potential propagation, sensory transduction, and muscle contraction. While structural and functional studies have led to models that explain their mechanosensitivity, we lack a quantitative understanding of channel activation by membrane tension. Here, we define the tension response of mechanosensitive K2Ps using patch-clamp recording and imaging. All are low-threshold mechanosensitive channels (T10%/50% 0.6-2.7 / 4.4-6.4 mN/m) with distinct response profiles. TRAAK is most sensitive, TREK-1 intermediate, and TREK-2 least sensitive. TRAAK and TREK-1 are activated broadly over a range encompassing nearly all physiologically relevant tensions. TREK-2, in contrast, activates over a narrower range like mechanosensitive channels Piezo1, MscS, and MscL. We further show that low-frequency, low-intensity focused ultrasound increases membrane tension to activate TRAAK and MscS. This work provides insight into tension gating of mechanosensitive K2Ps relevant to understanding their physiological roles and potential applications for ultrasonic neuromodulation
STRESS AND COPING MECHANISMS OF NON-TRADITIONAL INTERNATIONAL DOCTORAL STUDENTS
Get PDFHigher education institutions are battling with the shrinking enrollment rate of students and the various college alternatives (Drozdowski, 2022); however, it has been evidenced in the literature that these issues can be augmented with international student enrollments and adult learners (Donaldson, 2022). Pursuing a doctoral degree is a tedious move (Devonport & Lane, 2014), and leaving one’s comfort zone to study in a different land for non-traditional international students can be exhausting due to the responsibilities at hand. Thus, this qualitative study examines the stressors experienced by non-traditional international doctoral students, the coping mechanisms utilized in the cause of these stressors, and their perception of doctoral stress. The study participants consisted of four non-traditional international students. The findings generated two major themes of stressors namely: personal stressors and academic stressors, alongside two sub-categories of coping strategies which include personal and institutional coping strategies. Overall, participants perceive doctoral stress as a temporal phase of life
UTILIZING STUDENTS’ TECHNOLOGICAL KNOWLEDGE TO DEVELOP CRITICAL READING SKILLS AND DIGITAL LITERACY IDENTITIES
Get PDFThis study aims to explore how teachers can purposefully integrate and connect students’ digital literacy funds of knowledge into in-school digital literacy meaning making to enhance critical reading and thinking, and how it supports students’ development of their digital literacy identity. The theories that guided this thesis were from New London Group, Freire, Gee, Knobel, and Lankshear. This was a qualitative research study that collected data from surveys, interviews, observations, and student work samples. Over the course of the study, students participated in a controlled choice research unit. Throughout the study, students received specific instruction on how to use multiliteracies and digital tools in order to create a final digital product. During the study, students gathered information from various sources, such as informational books, internet sites, videos, and graphic sources to answer the six posed research questions, and they collaborated with one another to share ideas, information, and understanding on the research questions. At the end of the study, students showed an increase in collaborative skills, critical reading skills, and technological knowledge. This study is relevant to primary elementary teachers because it shows that students need explicit instruction with digital tools even though they use technology everyday, and students need opportunities to become digital creators of content to share their ideas and understanding
Estimation of Vehicle Traffic Parameters Using an Optical Distance Sensor for Use in Smart City Road Infrastructure
Get PDFIn recent decades, the dynamics of road vehicle traffic have significantly evolved, compelling traffic engineers to develop innovative traffic monitoring solutions, especially for dense road networks. Traditional methods for measuring traffic volume along road sections may no longer suffice for modern traffic control systems. This is particularly true for induction loops, a widely used method since the last century. In contrast, measuring techniques using microwaves or visible light offer better accuracy but are often hindered by the high cost of sensors. This paper presents new techniques for measuring traffic flow and other parameters that adapt to changing traffic dynamics using low-cost optical distance sensors. Our study demonstrates that the integration of multiple monitoring approaches enhances measurement accuracy, contingent on the dynamics and specific characteristics of the traffic. The results indicate that cheap optical distance sensors are particularly well suited for use in smart city road networks
TendrilBot: Modular soft robot with versatile radial grasping and locomotion capabilities
Get PDFThis paper introduces TendrilBot, a novel modular soft robot designed for versatile manipulation, stiffness modulation, and locomotion tasks. Built upon previously developed modular units, the TendrilBot consists of multiple actuators connected linearly in linear, cylindrical, or helix configurations. Cylindrical configurations (single row or stacked) enable the robot to wrap around objects for grasping and manipulation in a single row or stacked configuration when interconnected with the magnets on sides of the units. Additionally, such configurations further facilitate internal grasping within hollow tubes or objects holding them with its reconfigurable shape. Both wrapping and internal grasping are experimentally validated to demonstrate radial stiffness modulation and squeezing capabilities. By further rearranging these modular units, TendrilBot can transform into a robotic arm with four or more degrees of freedom, significantly enhancing its manipulative capabilities. In addition, two types of locomotion are demonstrated. When connected in a linear configuration, TendrilBot exhibits locomotion through a sinusoidal motion pattern, similar to sidewinding. When connected in a circular configuration, TendrilBot can achieve locomotion via rolling with steering capabilities, utilizing its cylindrical or helical shape, respectively. Presented are detailed design configurations and characterization of TendrilBot functionalities and capabilities. In addition, we developed a data-driven model that can accurately capture bending of the modular soft actuators, which was validated by the experimental results. Comparison with other similar modular soft robots is provided and discussed. Extensive experimental validations are performed to showcase TendrilBot\u27s potential for diverse applications in the field of modular soft robotics
Inactivation of bacteria using synergistic hydrogen peroxide with split-dose nanosecond pulsed electric field exposures.
Get PDFThe use of pulsed electric fields (PEF) as a nonthermal technology for the decontamination of foods is of growing interest. This study aimed to enhance the inactivation of Escherichia coli, Listeria innocua, and Salmonella enterica in Gomori buffer using a combination of nsPEF and hydrogen peroxide (H2O2). Three sub-MIC concentrations (0.1, 0.3, and 0.5%) of H2O2 and various contact times ranging from 5-45 min were tested. PEF exposures as both single (1000 pulse) and split-dose (500+500 pulse) trains were delivered via square-wave, monopolar, 600 ns pulses at 21 kV/cm and 10 Hz. We demonstrate that \u3e5 log CFU/mL reduction can be attained from combination PEF/H2O2 treatments with a 15 min contact time for E. coli (0.1%) and a 30 min contact time for L. innocua and S. enterica (0.5%), despite ineffective results from either individual treatment alone. A 5 log reduction in microbial population is generally the lowest acceptable level in consideration of food safety and represents inactivation of 99.999% of bacteria. Split-dose PEF exposures enhance lethality for several tested conditions, indicating greater susceptibility to PEF after oxidative damage has occurred
Broad and diverse roles of sphingosine-1-phosphate/sphingosine-1-phosphate receptors in the prostate.
Get PDFBenign prostatic hyperplasia (BPH) is a common condition in aging males, but its underlying pathogenesis remains unclear. Sphingosine-1-phosphate (S1P) and its receptors (S1PRs) play important roles in various diseases, while less studied in prostate. Current study attempts to clarify the expression and functional activities of S1P/S1PRs in the prostate. We discovered that S1P/S1PRs were richly expressed in the prostate, with S1PR1/2/3 localized in the epithelial/stromal compartments, while S1PR4/5 were less expressed. In vitro, S1P/S1PR1/S1PR3 promoted cell proliferation via AKT and ERK1/2 pathways, S1P/S1PR2/S1PR3 enhanced contraction of WPMY-1 cells and human prostate via RhoA/ROCK pathway, while S1P/S1PR1/S1PR2/S1PR3 alleviated the inflammation response via STAT3 pathway. In vivo, S1P and S1PR1/3 agonists (SEW2871, CYM5541) led to prostate enlargement in rats, while S1PR1/3 antagonists (W-146, TY-52156) suppressed testosterone-induced BPH. Overall, this study suggests that S1P/S1PRs play a critical role in the development of BPH and may be a promising therapeutic target for BPH treatment
Multi-Agent Reinforcement Learning for Smart Community Energy Management
Get PDFThis paper investigates a Local Strategy-Driven Multi-Agent Deep Deterministic Policy Gradient (LSD-MADDPG) method for demand-side energy management systems (EMS) in smart communities. LSD-MADDPG modifies the conventional MADDPG framework by limiting data sharing during centralized training to only discretized strategic information. During execution, it relies solely on local information, eliminating post-training data exchange. This approach addresses critical challenges commonly faced by EMS solutions serving dynamic, increasing-scale communities, such as communication delays, single-point failures, scalability, and nonstationary environments. By leveraging and sharing only strategic information among agents, LSD-MADDPG optimizes decision-making while enhancing training efficiency and safeguarding data privacy—a critical concern in the community EMS. The proposed LSD-MADDPG has proven to be capable of reducing energy costs and flattening the community demand curve by coordinating indoor temperature control and electric vehicle charging schedules across multiple buildings. Comparative case studies reveal that LSD-MADDPG excels in both cooperative and competitive settings by ensuring fair alignment between individual buildings’ energy management actions and community-wide goals, highlighting its potential for advancing future smart community energy management
Roots and Refuge: A Critical Exploration of Nature in Black Visual Narratives
Get PDFThis article examined the underrepresentation of Black characters in children’s picture books, particularly in natural settings, and its effect on Black children’s relationship with nature. Through an analysis of four contemporary picture books, the study revealed how visual depictions challenge these exclusions and expand narratives about Black engagement with the natural world. Utilizing visual semiotics and the theory of Black Aliveness, this research underscores the transformative power of illustrations by Black artists in enriching children’s literature and advancing joy
Integrating Physiological Measures within a Music Therapy Research Course: Program Description and Initial Evaluation
Get PDFApplying research to practice is an essential competency, and some educators have turned to course-based undergraduate research experiences (CUREs) to support music therapy students in developing these skills. We provided a bounded CURE involving a research question requiring data from three different biosensors. We collected program evaluation outcomes where respondents reported increased interest and confidence in reading and doing research as well as personal investment in the project. Respondents also indicated that, as a result of taking this course, they were more likely to take part in research projects in the future and they were interested in pursuing master’s level research. The students also reported that using the sensors in the course supported their learning. We discuss the role of the research assistant, including her deepened understanding of research concepts through her work with the data collection and preparation stages. We plan to continue implementing CUREs with biosensors in future runs of the course, and with larger class sizes we aim to publish data from our projects, while also examining students’ experiences