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Biohybrid systems in which robotic lures interact with animals have become compelling tools for probing and identifying the mechanisms underlying collective animal behavior. One key challenge lies in the transfer of social interaction models from simulations to reality, using robotics to validate the modeling hypotheses. This challenge arises in bridging what we term the 'biomimicry gap', which is caused by imperfect robotic replicas, communication cues and physics constraints not incorporated in the simulations, that may elicit unrealistic behavioral responses in animals. In this work, we used a biomimetic lure of a rummy-nose tetra fish (Hemigrammus rhodostomus) and a neural network (NN) model for generating biomimetic social interactions. Through experiments with a biohybrid pair comprising a fish and the robotic lure, a pair of real fish, and simulations of pairs of fish, we demonstrate that our biohybrid system generates social interactions mirroring those of genuine fish pairs. Our analyses highlight that: 1) the lure and NN maintain minimal deviation in real-world interactions compared to simulations and fish-only experiments, 2) our NN controls the robot efficiently in real-time, and 3) a comprehensive validation is crucial to bridge the biomimicry gap, ensuring realistic biohybrid systems.
Despite 15 years of extensive investigation, the fabrication and study of nanofluidic devices that incorporate a single carbon nanotube (CNT) still represents a remarkable experimental challenge. In this study, we present the fabrication of nanofluidic devices that integrate an individual single-walled CNT (SWCNT), showcasing a notable reduction in noise by 1 -3 orders of magnitude compared to conventional devices. This achievement was made possible by employing high dielectric constant materials for both the substrate and the CNT-covering layer. Furthermore, we provide a detailed account of the crucial factors contributing to the successful fabrication of SWCNT-based nanofluidic devices that are reliably leak-free, plug-free, and long-lived. Key considerations include the quality of the substrate-layer interface, the nanotube opening, and the effective removal of photoresist residues and trapped microbubbles. We demonstrate that these devices, characterized by a high signal-tonoise ratio, enable spectral noise analysis of ionic transport through an individual SWCNT, thus showing that SWCNTs obey Hooge's law in 1/ f at low frequencies. Beyond advancing our fundamental understanding of ion transport in SWCNTs, these ultralow-noise measurements open avenues for leveraging SWCNTs in nanopore sensing applications for single-molecule detection, offering high sensitivity and identification capabilities.
Stigmergy is a generic coordination mechanism widely used by animal societies, in which traces left by individuals in the environment guide and stimulate the subsequent actions of the same or different individuals. In the human context, with the digitization of society, new forms of stigmergic processes have emerged through the development of online services that extensively exploit the digital traces left by their users, in particular, using rating-based recommendation systems. Therefore, understanding the impact of these digital traces on both individual and collective decision-making is essential. This study pursues two main objectives. First, I investigate and modelize the interactions of groups of individuals with their digital traces, and determine how they can exploit these traces to cooperate in an information search task. Subsequently, the research explores the impact of intragroup and intergroup competition on the dynamics of cooperation in the framework of this information search task. To answer these questions, we have developed the online multiplayer Stigmer game, on which we base 16 series of experiments under varying conditions. In this game, groups of individuals leave and exploit digital traces in an information search task that implements a 5-star rating system. This system is similar to recommendation systems used by many online marketplaces and platforms, where users can evaluate products, services, or sellers. In the game, all individuals interact with a grid of hidden values, searching for cells with the highest values, and using only indirect information provided in the form of colored traces resulting from their collective ratings. This controlled environment allows for a thorough and quantitative analysis of individual and collective behaviors, and offers the possibility of manipulating and studying the combined impact of intragroup and intergroup competition on cooperation. The experimental and modeling results indicate that the type and intensity of competition determine how individuals interpret and use digital traces, and impact the reliability of the information delivered via these traces. This study reveals that individuals can be classified into three behavioral profiles that differ in their degree of cooperation: collaborators, neutrals, and defectors. When there is no competition, digital traces spontaneously induce cooperation among individuals, highlighting the potential for stigmergic processes to foster collaboration in human groups. Likewise, competition between two groups also promotes cooperative behavior among group members who aim to outperform the members of the other group. However, intragroup competition can prompt deceptive behaviors, as individuals may manipulate their ratings to gain a competitive advantage over the other group members. In this situation, the presence of misinformation reinforces the use of private information over social information in the decision-making process. Finally, situations that combine both intragroup and intergroup competition display varying levels of cooperation between individuals, that we explain. This research establishes the foundations for understanding stigmergic interactions in digital environments, shedding light on the relationships between competition, cooperation, deception, and decision-making. The insights gained may contribute to the development of sustainable and cooperative personalized decision-making algorithms and artificial collective intelligence systems grounded in stigmergy.
These lecture notes, adapted from the habilitation thesis of the author, survey in a first part various exact results obtained in the past few decades about KPZ fluctuations in one dimension, with a special focus on finite volume effects describing the relaxation to its stationary state of a finite system starting from a given initial condition. The second part is more specifically devoted to an approach allowing to express in a simple way the statistics of the current in the totally asymmetric simple exclusion process in terms of a contour integral on a compact Riemann surface, whose infinite genus limit leads to KPZ fluctuations in finite volume.
In this work, we construct galactic halos in order to fit the rotation curves (RCs) of a sample of low surface brightness (LSB) galaxies. These halos are made of Fuzzy Dark Matter (FDM) with a multimode expansion of non-spherical modes that in average contribute to the appropriate density profile consisting of a core and an envelope needed to fit the rotation curves. These halos are constructed assuming a solitonic core at the center and two types of envelopes, Navarro-Frenk-White and Pseudo-Isothermal density profiles. The resulting FDM configurations are then evolved in order to show how the average density changes in time due to the secular dynamical evolution, along with a condensation process that lead to the growth of the solitonic core.
Subjets
Quantum chromodynamics axion
Cosmological constant
Collective motion
Smoluchowski equation
Random walker
Brownian motion
Fermi gas
Chemotaxis
Density
Dark matter theory
Competition
Axion star
Asymptotic behavior
Energy density
Dissipation
Gravitation
Fermions
Formation
Halo
Cosmological model
Current fluctuations
Denaturation
9862Gq
Energy internal
Collective behaviour
9530Sf
Structure
Bose–Einstein condensates
Gravitation self-force
Marcheur aléatoire
Pressure
Chemotaxie
Smoluchowski-Poisson
Black hole
Effect relativistic
Diffusion
Quantum mechanics
TASEP
Bethe ansatz
Dark energy
Collisionless stellar-systems
Equation of state
Axion
Electromagnetic
Stability
Dark matter density
Collective behavior
Bose-Einstein
9536+x
Numerical calculations
Computational modeling
Gas Chaplygin
Thermodynamics
Collective intelligence
Galaxy
Nonrelativistic
Hydrodynamics
Dark matter
Collapse
Physique statistique
Distributed Control
Entropy
Rotation
Feedback
Dark matter halo
Catastrophe theory
Gravitational collapse
Field theory scalar
Keller-Segel
Fokker-Planck
9535+d
Mass density
Mouvement brownien
Scalar field
Dark matter fuzzy
Effondrement gravitationnel
Einstein
Turbulence
Scattering length
Critical phenomena
DNA
Atmosphere
Nanofiltration
Expansion acceleration
Fermion
Cosmology
Energy high
Phase separation
Statistical mechanics
Evaporation
Kinetic theory
Gravitation collapse
Condensation Bose-Einstein
Transition vitreuse
Dark matter condensation
9880-k
Computational modelling
Wave function
Euler-Maclaurin
General relativity