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Abstract We propose and unify classes of different models for information propagation over graphs. In a first class, propagation is modelled as a wave, which emanates from a set ofknownnodes at an initial time, to all otherunknownnodes at later times with an ordering determined by the arrival time of the information wave front. A second class of models is based on the notion of a travel time along paths between nodes. The time of information propagation from an initialknownset of nodes to a node is defined as the minimum of a generalised travel time over subsets of all admissible paths. A final class is given by imposing a local equation of an eikonal form at eachunknownnode, with boundary conditions at theknownnodes. The solution value of the local equation at a node is coupled to those of neighbouring nodes with lower values. We provide precise formulations of the model classes and prove equivalences between them. Finally, we apply the front propagation models on graphs to semi-supervised learning via label propagation and information propagation on trust networks. 

In most undergraduate programs, immunology is relegated to a few weeks of microbiology or human anatomy courses, or rarely offered as a dedicated topics course. As such, we feel it is essential to consider new approaches to introduce undergraduate students to immunological concepts. Recent work by the ImmunoReach network uncovered gaps in connecting concepts of metabolism and evolution in undergraduate immunology education. With these ideas in mind, we developed a comparative immunology lesson within an upper-division Animal Physiology course, in which students explore how differences in body size change both the metabolic rates and immune cell concentrations. Students who completed this activity improved their scores on scaling questions included in a class exam by more than 29% over students who only received a lecture on the course material. Pre- and post-quizzes demonstrate that the activity increased scores on questions about scaling (>17%) and immune concepts (>100%). By requiring students to apply concepts of scaling, a fundamental concept in biology and physiology, to a system not typically considered in animal physiology courses, this activity enhanced students' understanding of that topic, as well as introducing them to immune cell types. It also introduced pointillist comparative methods, just now being integrated into immune studies, thereby introducing students to leading-edge research in immunology and a new way of thinking about the immune system. We believe this approach can not only fill gaps within undergraduate immunology courses but also incorporate immunology into curricula where immunology is not a viable stand-alone course. 

The palladium-catalyzed sp-sp2 C−C bond forming the Sonogashira reaction has been both extensively studied mechanistically and widely used in organic synthesis. Herein, we describe an investigation into how a palladium(II) complex with arylazoformamide (AAF) ligands mediates these transformations. When mixed, two AAFs coordinate in a κ1-fashion with an equivalent of PdCl2, creating complexes of the form PdCl2(AAF)2. Under typical and optimized copper(I)-cocatalyzed Sonogashira conditions, using phenylacetylene and iodobenzene as reagents, these complexes (precatalysts) reduce to Pd(0) and afford the coupled diphenylacetylene product in high yields (i.e., 99%). A substrate scope explored the substitution on both rings, yielding 18 examples with yields varying from 38 to 99%. Mechanistically, from DFT studies, a formal Pd(I) open-shell singlet complex is suggested, along with an explanation of the need for DBU when employing CuI in toluene. Further DFT exploration provides insight into the copper-free Sonogashira reaction when utilizing Pd(AAF)2 complexes. 

The mechanical impedance of the human lower-limb joints during locomotion encodes our understanding of how the neuromotor system regulates the behavior of these tasks. Impedance is also a key component of several strategies for translating this behavior to robots, powered prosthetic limbs, and people empowered by exoskeletons. However, due to difficulty in making accurate measurements, there is little empirical evidence for the impedance behaviors of joints other than the ankle during active walking tasks. In this letter we propose a measurement system based on a highly backdrivable quasi-direct-drive actuator and a carefully calibrated actuator torque model. Bench-top validation with known mechanical impedance human-substitutes, confirms the viability of this system as an impedance measurement tool. A pilot study with two subjects utilizing a custom knee-exoskeleton apparatus confirms the feasibility of this system for human walking experiments. 

This study investigates the role of video vantage, “Encounterer“ and “Observer”, in shaping perceptions of robot social intelligence. Using videos depicting robots navigating hall-ways and employing gaze cues, results revealed that the Observer vantage consistently yielded higher ratings for perceived social intelligence compared to the Encounterer vantage. These findings underscore the impact of vantage on interpreting robot behaviors and highlight the need for careful design of video-based HRI studies to ensure accurate and generalizable insights for real-world applications.