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Modulation of Redox-Sensitive Cardiac Ion Channels
No full textRedox regulation is crucial for the cardiac action potential, coordinating the sodium-driven depolarization, calcium-mediated plateau formation, and potassium-dependent repolarization processes required for proper heart function. Under physiological conditions, low-level reactive oxygen species (ROS), generated by mitochondria and membrane oxidases, adjust ion channel function and support excitation–contraction coupling. However, when ROS accumulate, they modify a variety of important channel proteins in cardiomyocytes, which commonly results in reducing potassium currents, enhancing sodium and calcium influx, and enhancing intracellular calcium release. These redox-driven alterations disrupt the cardiac rhythm, promote after-depolarizations, impair contractile force, and accelerate the development of heart diseases. Experimental models demonstrate that oxidizing agents reduce repolarizing currents, whereas reducing systems restore normal channel activity. Similarly, oxidative modifications of calcium-handling proteins amplify sarcoplasmic reticulum release and diastolic calcium leak. Understanding the precise redox-dependent modifications of cardiac ion channels would guide new possibilities for targeted therapies aimed at restoring electrophysiological homeostasis under oxidative stress, potentially alleviating myocardial infarction and cardiovascular dysfunction
Making the Most of Artificial Intelligence and Large Language Models to Support Collection Development in Health Sciences Libraries
Get PDFThis project investigated the potential of generative AI models in aiding health sciences librarians with collection development. Researchers at Chapman University’s Harry and Diane Rinker Health Science campus evaluated four generative AI models—ChatGPT 4.0, Google Gemini, Perplexity, and Microsoft Copilot—over six months starting in March 2024. Two prompts were used: one to generate recent eBook titles in specific health sciences fields and another to identify subject gaps in the existing collection. The first prompt revealed inconsistencies across models, with Copilot and Perplexity providing sources but also inaccuracies. The second prompt yielded more useful results, with all models offering helpful analysis and accurate Library of Congress call numbers. The findings suggest that Large Language Models (LLMs) are not yet reliable as primary tools for collection development due to inaccuracies and hallucinations. However, they can serve as supplementary tools for analyzing subject coverage and identifying gaps in health sciences collections
Empirically Validating a Computational Model of Automatic Behavior Shaping
Get PDFBackground
Mobile sensing technology allows automated behavior shaping routines to be incorporated into health behavior interventions and other settings. In previous work, a computational model was built to investigate how to best arrange automatic behavior shaping procedures, but the degree to which this model reflects actual human behavior is not known. Purpose
To translate a previously developed computational model of automatic behavior shaping into an experimental setting. Methods
Participants (n = 54) operated a computer mouse and attempted to locate a hidden, randomly-placed target circle on a blank computer screen and clicks within some threshold distance of the target circle were reinforced by a pleasant auditory tone. As the trial progressed, the threshold distance narrowed according to a shaping function until eventually only clicks within the target circle were reinforced. Accumulated Area Under Trajectory Curves and Time Until 10 Consecutive Target Clicks were used to quantify the probability of the target behavior. Linear mixed effects models were used to assess differential outcomes for concave up, concave down, and linear shaping functions. Results
In congruence with the computational model, concave-up functions most effectively shaped participants’ behavior, with linear and then concave-down shaping functions producing the next best outcomes. Conclusion
Concave-up shaping routines most effectively generated target behavior, which should be confirmed in health behavior trials. The automatic shaping routines that this study helps develop can be applied in a number of domains, including exercise intensity and duration, tobacco/cannabis smoking, caloric intake, and screen time
Bibliography for Love Data Week 2025
Get PDFA bibliography created to support a display about research data and Love Data Week during January/February 2025 at the Leatherby Libraries at Chapman University
Technical Note: What Exercises are Appropriate for Managing Back Pain in Persons with Lower Limb Amputation?
Get PDFIndividuals with lower extremity amputation (LLA) have high rates of low back pain (LBP) and related disability. The purpose of this technical note is to discuss considerations and provide initial recommendations about what exercises may be appropriate for management of LBP in persons with LLA. Five commonly prescribed motor control and strengthening exercises (cat-camel, curl-up, bird dog, side bridge, and Roman chair extensor exercise) were examined for use in the LLA population. Each exercise seemed to be safe and appropriate for use in persons with LLA yet required additional considerations for use in this population. For example, some of the exercises, such as the bird dog, pose challenges to balance. Thus, more detailed up-front instruction, closer monitoring, and adequate support are recommended to facilitate usefulness and success. This technical note provides initial guidance for clinical decision-making about implementation of commonly prescribed exercises in the general non-amputee patient population with the LLA population. While future research is needed, implementation of appropriate exercise interventions has the potential to decrease disability, hasten recovery, and improve resiliency in persons with LLA suffering from LBP
Antibacterial and Antifungal Activities of Linear and Cyclic Peptides Containing Arginine, Tryptophan, and Diphenylalanine
Get PDFBackground. We have previously reported peptides composed of sequential arginine (R) residues paired with tryptophan (W) or 3,3-diphenyl-L-alanine residues (Dip), such as cyclic peptides [R4W4] and [R4(Dip)3], as antibacterial agents. Results. Herein, we report antibacterial and antifungal activities of five linear peptides, namely ((DipR)4(WR)), ((DipR)3(WR)2), ((DipR)2(WR)3), ((DipR)(WR)4), and (DipR)4R, and five cyclic peptides [(DipR)4(WR)], [(DipR)3(WR)2], [(DipR)2(WR)3], [(DipR)(WR)4], and [DipR]5, containing alternate positively charged R and hydrophobic W and Dip residues against fungal, Gram-positive, and Gram-negative bacterial pathogens. The minimum inhibitory concentrations (MICs) of all peptides were determined by the micro-broth dilution method against Methicillin-Resistant Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis, Streptococcus pneumoniae, and Bacillus subtilis. Fungal organisms were Candida albicans, Candida parapsilosis, and Aspergillus fumigatus. [DipR]5 and ((DipR)2(WR)3) showed MIC values of 0.39–25 µM and 0.78–12.5 µM against Gram-positive and Gram-negative bacteria strains, respectively. The highest activity was observed against S. pneumoniae with MIC values of 0.39–0.78 µM among tested compounds. [DipR]5 demonstrated MIC values of 6.6 µM against C. parapsilosis and 1.6 µM against A. fumigatus, whereas fluconazole showed MIC values of 3.3 µM and \u3e209 µM, respectively. Conclusions. These findings highlight the potential of these peptides as broad-spectrum antimicrobial agents
Proximal Remote Sensing: An Essential Tool for Bridging the Gap Between High-resolution Ecosystem Monitoring and Global Ecology
Get PDFA new proliferation of optical instruments that can be attached to towers over or within ecosystems, or ‘proximal’ remote sensing, enables a comprehensive characterization of terrestrial ecosystem structure, function, and fluxes of energy, water, and carbon. Proximal remote sensing can bridge the gap between individual plants, site-level eddy-covariance fluxes, and airborne and spaceborne remote sensing by providing continuous data at a high-spatiotemporal resolution. Here, we review recent advances in proximal remote sensing for improving our mechanistic understanding of plant and ecosystem processes, model development, and validation of current and upcoming satellite missions. We provide current best practices for data availability and metadata for proximal remote sensing: spectral reflectance, solar-induced fluorescence, thermal infrared radiation, microwave backscatter, and LiDAR. Our paper outlines the steps necessary for making these data streams more widespread, accessible, interoperable, and information-rich, enabling us to address key ecological questions unanswerable from space-based observations alone and, ultimately, to demonstrate the feasibility of these technologies to address critical questions in local and global ecology
You Want Me to Teach What?: Building Confidence with Instructors as a New Subject Liaison
Get PDFBeing assigned to a subject area which does not match your degree is a common challenge that many new and experienced librarians face, either in a new position or when asked to take on additional responsibilities. When you do not have extensive knowledge in a subject, where do you begin and how do you reach out to instructors and their department as a new subject liaison? This session will focus on learning the basics of a newly assigned subject area and building relationships with instructors. It will include tips for learning your new subject and teaching information literacy for that subject. It will also introduce best practices for developing and maintaining connections with departments, instructors, and students
Quantitative Characterization and Prediction of the Binding Determinants and Immune Escape Hotspots for Groups of Broadly Neutralizing Antibodies Against Omicron Variants: Atomistic Modeling of the SARS-CoV-2 Spike Complexes with Antibodies
Get PDFA growing body of experimental and computational studies suggests that the cross-neutralization antibody activity against Omicron variants may be driven by the balance and tradeoff between multiple energetic factors and interaction contributions of the evolving escape hotspots involved in antigenic drift and convergent evolution. However, the dynamic and energetic details quantifying the balance and contribution of these factors, particularly the balancing nature of specific interactions formed by antibodies with epitope residues, remain largely uncharacterized. In this study, we performed molecular dynamics simulations, an ensemble-based deep mutational scanning of SARS-CoV-2 spike residues, and binding free energy computations for two distinct groups of broadly neutralizing antibodies: the E1 group (BD55-3152, BD55-3546, and BD5-5840) and the F3 group (BD55-3372, BD55-4637, and BD55-5514). Using these approaches, we examined the energetic determinants by which broadly potent antibodies can largely evade immune resistance. Our analysis revealed the emergence of a small number of immune escape positions for E1 group antibodies that correspond to the R346 and K444 positions in which the strong van der Waals and interactions act synchronously, leading to the large binding contribution. According to our results, the E1 and F3 groups of Abs effectively exploit binding hotspot clusters of hydrophobic sites that are critical for spike functions along with the selective complementary targeting of positively charged sites that are important for ACE2 binding. Together with targeting conserved epitopes, these groups of antibodies can lead expand the breadth and resilience of neutralization to the antigenic shifts associated with viral evolution. The results of this study and the energetic analysis demonstrate excellent qualitative agreement between the predicted binding hotspots and critical mutations with respect to the latest experiments on average antibody escape scores. We argue that the E1 and F3 groups of antibodies targeting binding epitopes may leverage strong hydrophobic interactions with the binding epitope hotspots that are critical for the spike stability and ACE2 binding, while escape mutations tend to emerge in sites associated with synergistically strong hydrophobic and electrostatic interactions
Bibliography for Greek Mythology Display
Get PDFA bibliography created to support a display about Greek mythology in March 2025 at the Leatherby Libraries at Chapman University