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Experimental data and code for "Consensus formation and change are enhanced by neutrality"
No full textThis dataset contains raw and processed data on a number of experiments on marching locust nymphs in a ring-shaped arena. With sufficiently large densities the locusts exhibit coherent motion and directional switching. The code accompanying that data is for processing the raw data, analysing the processed data and simulating both spatial and non-spatial models of the data. This dataset also contains raw and processed data on a number of experiments into consensus formation in which human participants played an iterated voting game. The code accompanying the data is for processing the raw data, analysing the processed data and simulating mathematical models of the process. This dataset also contains code to simulate a model of nucleosome modification. The model describes the modifications of nucleosomes by recruitment of modifying and unmodifying enzymes from their neighbours or in a ‘recruitment-independent’ (spontaneous) manner. In the model, nucleosomes can be acetylated (A), unmodified (U) or methylated (M), hence A and M represent active states, while U is a neutral state. Effective collective decision-making in human and animal groups requires robust mechanisms for consensus formation and change, typically via feedback loops in which individuals adapt their behaviour and opinions based on their perception of others. Such processes have been observed in the onset of motion in insect swarms and is believed to manifest across scales from nucleosomes to entire societies. However, levels of participation can be highly variable over time, with individuals sometimes adopting neutral positions such as moving to the back of a group or abstaining from a vote. In this work we present a new theoretical and experimental analysis showing that neutrality has two important and hitherto unreported benefits to collective decision making. First, it enables the robust formation of consensus in groups of individuals applying simple linear reasoning, updating their state after consideration of at most one other individual at a time. Second, we find that neutral actors can facilitate efficient consensus change by reducing the effective population size during transitions. These findings are derived from a new general mathematical model of collective binary decision problems, and validated against experiments with insect and human populations. Our results provide a parsimonious explanation of how groups of animals and humans quickly reach and overturn consensus, suggesting efficient solutions to collective decision-making problems
A comparison of cost-sharing models in horizontal cooperative routing
Full text linkWe develop and compare several cost-sharing models for cooperative vehicle routing problems formulated under various objectives and constraints. Our study is motivated by a real-world case involving smallholder farmers in the Province of Quebec. We examine the issues of fairness and stability in cooperative routing, and we show that coalitions served by single routes are sufficient to impose stability conditions. To evaluate equity, we use the Gini coefficient to measure the dispersion of individual savings. Hence we can analyze the trade-offs between fairness and stability. We demonstrate that widely used fairness proxies do not necessarily yield equitable outcomes. We test our methodology on randomly generated instances and on a Quebec-based case study
Compression of Currents and Varifolds
Full text linkWe derive an algorithm for compression of the currents and varifolds representations of shapes, using the Nystrom approximation in Reproducing Kernel Hilbert Spaces. Our method is faster than existing compression techniques, and comes with theoretical guarantees on the rate of convergence of the compressed approximation, as a function of the smoothness of the associated shape representation. The obtained compression are shown to be useful for down-line tasks such as nonlinear shape registration in the Large Deformation Metric Mapping (LDDMM) framework, even for very high compression ratios. The performance of our algorithm is demonstrated on large-scale shape data from modern geometry processing datasets, and is shown to be fast and scalable with rapid error decay
Synergistic Fe–O–Ni bridged sites in layered double hydroxides boost electrocatalytic oxidation of glycerol to formate coupled with hydrogen evolution
Full text linkElectrochemical glycerol oxidation (GOR) to formate emerges as a highly promising and cost-effective approach for biomass valorization. However, the formate yield and selectivity are predominantly hindered by the slow kinetics in successive dehydrogenation and C–C bond cleavage of glycerol. Herein, we demonstrate an enhanced electrochemical GOR over Fe–O–Ni bridged sites in layered double hydroxides (LDHs), which couples charge transfer with adsorption/activation of *OH/glycerol. Engineered from a facile electrochemical deposition approach, NiFe-LDH is successfully constructed on Ni-foam. This catalyst with Fe–O–Ni bridged sites delivers formate selectivity of 92.26 % and yield of 67.76 mol m–2 h–1, outperforming most of the reported GOR electrocatalysts in the literature. The Fe–O–Ni bridged sites facilitate the electron transfer from Ni to Fe and boost the redox reaction between Ni3+ and glycerol while synergistically enhancing the adsorption and activation of *OH and glycerol, which improves dynamics in successive dehydrogenation and C-C cleavage of glycerol. Moreover, the membrane electrode assembly (MEA) flow cell employing NiFe-LDH@NF as both anode and cathode exhibits a current density of 100 mA cm–2 for a stable 120 h, demonstrating potential applications for electrooxidation of glycerol to formate coupled with H2 production. This study pioneers a new strategy of designing highly efficient electrocatalysts for advancing biomass valorization and sustainable energy conversion.</p
Overlapping Effects of Music Training on Multisensory and Emotion Processing:A Systematic Review
Full text linkEvidence suggests musicians have enhanced audio-visual and emotion recognition abilities. However, these two lines of research have generally been separated in the literature, despite these processes being similarly altered in certain populations (e.g., autism, schizophrenia). The current systematic review presents a comprehensive picture of the effect of music training on behavioural and neural changes in audio-visual and emotion recognition processes, to better understand where they might overlap or share any similarities. It additionally assessed the impact of different music training factors (i.e., training onset, length, type of musical instrument and the type of research task). Finally, this review aimed to produce a clearer understanding of whether the effects of music training extend beyond the music and sound domain. Following PRISMA guidelines, 64 papers were identified, of which 41 examined audio-visual processing, 20 investigated emotion processing, and three examined both processes. The available evidence revealed a consistent musician advantage for some audio-visual processes (e.g., audio-visual temporal correspondence), with some evidence that this advantage extended beyond the music domain. Consistent musician advantages were also found for processing basic emotions from speech prosody, with some evidence that this extended to complex emotions. A share brain network for these effects was identified comprising the anterior cingulate cortex and superior frontal gyrus. Together, our findings suggest that audio-visual and emotion recognition processes share a number of similarities in how music training can shape them. Further research should directly explore the combined effect of music training on multisensory and emotion recognition to inform effective music interventions aimed at enhancing these processes
Fluid Dynamics of Rotors Through Dynamic Transition
Full text linkUrban Air Mobility requires vehicles (UAMs) that operate in close proximity to buildings, particularly in take-off and landing phases. Such operation results in the aircraft encountering significant unsteadiness in the form of large amplitude gusts. Control in these transitional areas of flight is paramount to safety, and therefore rotor performance during transition must be understood. To this end, the Bath University Low-speed eVTOL Test-Rig (BULLET) has been significantly upgraded to deliver transition rates up to 10pi/9 rad/s, designed to probe the dynamic behavior of rotors through dynamic transitions and gust encounters. To the authors' knowledge these represent the fastest experimental transitions in the literature. Coupled with stereoscopic Particle Image Velocimetry, this study presents for the first time flow visualization of a rotor undergoing dynamic motion. The inflow PIV indicates an asymmetry of blade loading during transition, which is magnified by rapid transition despite the net thrust remaining unchanged. Blade angle of attack distributions are observed varying by up to 0.5deg. However, force decomposition demonstrates a lack of any unsteady overall thrust response from the rotor in response to the dynamic motion. This is corroborated by PIV analysis of both the wake and inflow to the rotor disc which show no introduction of unsteady effects
A review on energy harvesting for sustainable IoT monitoring systems
Full text linkAutonomous condition monitoring is essential for advancing intelligent systems in both industrial and domestic Internet of Things (IoT) applications. However, continuous long-term condition monitoring is challenged by the limited energy availability for wireless sensor nodes (WSNs). Therefore, energy harvesting offers a promising approach by converting ambient or host energy into electrical power to sustain WSN operation. To bridge the gap between energy harvesting and condition monitoring, this review provides an overview and synthesis of recent advances in energy harvesting technologies tailored for condition monitoring applications. State-of-the-art developments in energy harvesting are categorized into six domains: healthcare, ocean, machinery, grid, railway, and infrastructure. The characteristics of these energy sources and their domain-specific monitoring requirements are analyzed. Furthermore, this review examines harvesting transducers, structural designs, and optimization methods employed in energy harvesters. Finally, the review discusses current challenges and future prospects for energy-autonomous condition monitoring systems, aiming to support the deployment of sustainable IoT sensing solutions.</p
Compression of Currents and Varifolds
Full text linkWe derive an algorithm for compression of the currents and varifolds representations of shapes, using the Nystrom approximation in Reproducing Kernel Hilbert Spaces. Our method is faster than existing compression techniques, and comes with theoretical guarantees on the rate of convergence of the compressed approximation, as a function of the smoothness of the associated shape representation. The obtained compression are shown to be useful for down-line tasks such as nonlinear shape registration in the Large Deformation Metric Mapping (LDDMM) framework, even for very high compression ratios. The performance of our algorithm is demonstrated on large-scale shape data from modern geometry processing datasets, and is shown to be fast and scalable with rapid error decay
Adsorption performance and mechanism analysis of hydrotalcite derived CaFe-bimetal materials for highly efficient Cd<sup>2+</sup> removal process from kinetic and isotherm aspects
Full text linkThe removal of toxic and soluble Cd2+ is facing challenges in developing low-cost materials with retention stability and high capacity. To solve this problem, the CaFe-bimetal hydrotalcite (LDH) and its oxide (LDO) were adopted due to their integrated excellent ion exchange and isomorphic substitution property. The influencing factors, including Ca/Fe mole ratio, calcination temperature, the initial Cd2+ concentration and the adjustable ion kinds, were considered to obtain better adsorption performance. Similar ion size of Ca2+ and Cd2+ and the calcined LDOs with expanded channels promoted the Ca2+ dissolution and the mass transfer of Cd2+ entering into the laminate, and thus the isomorphic substitution sufficiently improved the high efficiency of Cd2+ removal of about 1079 mg/g in 20 min with Ca4Fe1-LDO-300. Based on the characterization and DFT results, LDOs exposed more active sites and enhanced the isomorphic substitution of Cd2+ for Ca2+ process. The thermodynamic and kinetic results revealed that the abundant –OH sites in hydrotalcite were beneficial for Cd2+ removal through surface adsorption, electrostatic attraction, and other interactions. The obtained adsorption mechanism offers guidance for the highly efficient Cd2+ removal in an aqueous solution system.</p
The Impact of Inter-Departmental Distance on Joint Sales in Retail Stores
Full text linkWe find that inter-departmental distance between two departments in a store can significantly impact joint (combined) sales of that pair. Using data from blueprints and sales across 64 stores for 52 weeks, along with an experimental study to test our theorizing, we find a curvilinear (inverted U-shaped) relationship between inter-departmental distance and joint sales. Specifically, close departments are perceived to be substitutes, decreasing the likelihood of buying products from both departments. As distance increases, departments are perceived as somewhat related but different, increasing their diversity and the likelihood of buying from both departments. As distance between departments becomes large and products are seen as unrelated, the likelihood of buying from both departments decreases. This relationship is moderated when departments have non-identical layouts and when there are larger variety differentials across departments. Accordingly, we determine an optimal store layout using BARON solver by maximizing total store revenue. Our results suggest an increase in weekly revenue of about 4.08% for supermarkets (range of -.67% to 9.50%) and 3.20% for hypermarkets (range of .82% to 8.5%). While strategic locations of departments can help retailers increase overall sales, prior empirical work has not studied the impact of distance between departments at the store level
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