An unsupervised map of excitatory neuron dendritic morphology in the mouse visual cortex.

Neurons in the neocortex exhibit astonishing morphological diversity, which is critical for properly wiring neural circuits and giving neurons their functional properties. However, the organizational principles underlying this morphological diversity remain an open question. Here, we took a data-driven approach using graph-based machine learning methods to obtain a low-dimensional morphological "bar code" describing more than 30,000 excitatory neurons in mouse visual areas V1, AL, and RL that were reconstructed from the millimeter scale MICrONS serial-section electron microscopy volume.

Power-law adaptation in the presynaptic vesicle cycle.

After synaptic transmission, fused synaptic vesicles are recycled, enabling the synapse to recover its capacity for renewed release. The recovery steps, which range from endocytosis to vesicle docking and priming, have been studied individually, but it is not clear what their impact on the overall dynamics of synaptic recycling is, and how they influence signal transmission. Here we model the dynamics of vesicle recycling and find that the multiple timescales of the recycling steps are reflected in synaptic recovery.

Combined effects of electrode morphology and electrolyte composition on single H gas bubble detachment during hydrogen evolution reaction.

During the hydrogen evolution reaction, H gas bubbles form on the electrode surface, significantly affecting electrochemical processes, particularly at high current densities. While promoting bubble detachment has been shown to enhance the current density, the mechanisms governing gas bubble detachment at the electrochemical interface remain poorly understood. In this study, we investigated the interplay between electrode surface morphology and electrolyte composition on single H gas bubble detachment during hydrogen evolution reaction (HER).

Portable multi-ionic reverse electrodialysis for continuous power supply and controllable drug release.

Bioinspired ionic power devices have been investigated due to their high biocompatibility and potential for sustainable energy conversion through ion concentration gradients. However, recent research into portable ionic power devices has primarily focused on hydrogel-based stacking elements, such as ion-selective gels and ionic reservoirs, to enhance productivity. However, this approach results in ionic resource consumption for the operating time.

-inspired powerless micropump: long-term, high-flow operation and energy-generation application.

Powerless micropumps are in increasing demand for applications requiring portability, simplicity, and long-term operation. However, several existing passive pumps have limitations such as sustained high flow rates and extended operational periods. Inspired by the unique structural characteristics of , this study aims to develop a biomimetic micropump capable of long-term and high-flow operation.

A general framework for interpretable neural learning based on local information-theoretic goal functions.

Despite the impressive performance of biological and artificial networks, an intuitive understanding of how their local learning dynamics contribute to network-level task solutions remains a challenge to this date. Efforts to bring learning to a more local scale indeed lead to valuable insights, however, a general constructive approach to describe local learning goals that is both interpretable and adaptable across diverse tasks is still missing. We have previously formulated a local information processing goal that is highly adaptable and interpretable for a model neuron with compartmental structure.

Frozen by Heating: Temperature Controlled Dynamic States in Droplet Microswimmers.

Self-propelling active matter relies on the conversion of energy from the undirected, nanoscopic scale to directed, macroscopic motion. One of the challenges in the design of synthetic active matter lies in the control of dynamic states, or motility gaits. Here, an experimental system of self-propelling droplets with thermally controllable and reversible dynamic states is presented, from unsteady over meandering to persistent to arrested motion.

On the shape of air bubbles trapped in ice.

Water usually contains dissolved gases, and because freezing is a purifying process these gases must be expelled for ice to form. Bubbles appear at the freezing front and are then trapped in ice, making pores. These pores come in a range of sizes from microns to millimeters and their shapes are peculiar; never spherical but elongated, and usually fore-aft asymmetric.

Analytical solution for the hydrodynamic resistance of a disk in a compressible fluid layer with odd viscosity on a rigid substrate.

Chiral active fluids can exhibit odd viscosity, a property that breaks the time-reversal and parity symmetries. Here, we examine the hydrodynamic flows of a rigid disk moving in a compressible 2D fluid layer with odd viscosity, supported by a thin lubrication layer of a conventional fluid. Using the 2D Green's function in Fourier space, we derive an exact analytical solution for the flow around a disk of arbitrary size, as well as its resistance matrix.

Thermal-solutal-induced bistability of evaporating multicomponent liquid thin films.

Volatile multicomponent liquid films show rich dynamics, due to the complex interplay of gradients in temperature and in solute concentrations. Here, we study the evaporation dynamics of a tricomponent liquid film, consisting of water, ethanol, and trans-anethole oil (known as "ouzo"). With the preferential evaporation of ethanol, cellular convective structures are observed both in the thermal patterns and in the nucleated oil droplet patterns.

Swarm coherence mechanism for jellyfish.

We present a model of active Brownian particles for the process of jellyfish swarm formation. The motivation for our analysis is the phenomenon of jellyfish blooming in natural habitats and clustering of jellyfish in laboratory tanks which follow from an interplay of physical and behavioral mechanisms. We reach the conclusion that phase separation at low jellyfish density is induced by behavioral reactions to environmental conditions.

Unexplored aspects of spiral wave dynamics in the Barkley model within an extended parameter range.

The Barkley model has been widely used to simulate diverse reaction-diffusion systems exhibiting various self-organization processes, including creation of spiral waves. Depending on the given parameters, this model is capable of simulating monostable, bistable, or oscillatory dynamics that are often observed in nature. This study is concentrated on the general features of spiral wave dynamics in the extended parameter range of the Barkley model, including both monostable and bistable dynamics.

Metabolic activity controls the emergence of coherent flows in microbial suspensions.

Photosynthetic microbes have evolved and successfully adapted to the ever-changing environmental conditions in complex microhabitats throughout almost all ecosystems on Earth. In the absence of light, they can sustain their biological functionalities through aerobic respiration, and even in anoxic conditions through anaerobic metabolic activity. For a suspension of photosynthetic microbes in an anaerobic environment, individual cellular motility is directly controlled by its photosynthetic activity, i.

The concepts of irreversibility and reversibility in research on anthropogenic environmental changes.

The concept of "irreversibility" and its counterpart "reversibility" have become prominent in environmental and ecological research on human-induced changes, thresholds, climate tipping points, ecosystem degradation, and losses in the cryosphere and biosphere. Through a systematic literature review, we show that in these research fields, these notions are not only descriptive terms, but can have different semantic functions and normative aspects. The results suggest that, in the context of environmental and ecological research the concepts of irreversibility and reversibility have taken on additional usages in comparison to their contexts in theoretical thermodynamics and mechanics.

Sonogenetics is a novel antiarrhythmic mechanism.

Arrhythmia of the heart is a dangerous and potentially fatal condition. The current widely used treatment is the implantable cardioverter defibrillator (ICD), but it is invasive and affects the patient's quality of life. The sonogenetic mechanism proposed here focuses ultrasound on a cardiac tissue, controls endogenous stretch-activated Piezo1 ion channels on the focal region's cardiomyocyte sarcolemma, and restores normal heart rhythm.

Spike frequency adaptation in primate lateral prefrontal cortex neurons results from interplay between intrinsic properties and circuit dynamics.

Cortical neurons in brain slices display intrinsic spike frequency adaptation (I-SFA) to constant current inputs, while extracellular recordings show extrinsic SFA (E-SFA) during sustained visual stimulation. Inferring how I-SFA contributes to E-SFA during behavior is challenging due to the isolated nature of slice recordings. To address this, we recorded macaque lateral prefrontal cortex (LPFC) neurons in vivo during a visually guided saccade task and in vitro in brain slices.

Experimental identification of topological defects in 2D colloidal glass.

Topological defects are singularities within a field that cannot be removed by continuous transformations. The definition of these irregularities requires an ordered reference configuration, calling into question whether they exist in disordered materials, such as glasses. However, recent work suggests that well-defined topological defects emerge in the dynamics of glasses, even if they are not evident in the static configuration.

Emergent polar order in nonpolar mixtures with nonreciprocal interactions.

Phenomenological rules that govern the collective behavior of complex physical systems are powerful tools because they can make concrete predictions about their universality class based on generic considerations, such as symmetries, conservation laws, and dimensionality. While in most cases such considerations are manifestly ingrained in the constituents, novel phenomenology can emerge when composite units associated with emergent symmetries dominate the behavior of the system. We study a generic class of active matter systems with nonreciprocal interactions and demonstrate the existence of true long-range polar order in two dimensions and above, both at the linear level and by including all relevant nonlinearities in the Renormalization Group sense.

Photon-Scanning Approach to Control Spiral Wave Dynamics in the Heart.

Self-organizing spiral electrical waves are produced in the heart during fatal cardiac arrhythmias. Controlling these waves is therefore an essential step in managing the disease. Here we present an effective method for controlling cardiac spiral waves using optogenetics.

Local and Global Variability in Developing Human T-Cell Repertoires.

The adaptive immune response relies on T cells that combine phenotypic specialization with diversity of T-cell receptors (TCRs) to recognize a wide range of pathogens. TCRs are acquired and selected during T-cell maturation in the thymus. Characterizing TCR repertoires across individuals and T-cell maturation stages is important for better understanding adaptive immune responses and for developing new diagnostics and therapies.

Statistical properties of microphase and bubbly phase-separated active fluids.

In phase-separated active fluids, the Ostwald process can go into reverse, leading to either microphase separation or bubbly phase separation. We show that the latter is formed of two macroscopic regions that are occupied by the homogeneous fluid and by the microphase separated one. Within the microphase-separated fluid, the relative rate of the Ostwald process, coalescence, and nucleation determines whether the size distribution of mesoscopic domains is narrowly peaked or displays a broad range of sizes before attaining a cutoff independent of system size.

Influence of conduction heterogeneities on transient spatiotemporal chaos in cardiac excitable media.

Life-threatening cardiac arrhythmias such as ventricular fibrillation are often based on chaotic spiral or scroll wave dynamics which can be self-terminating. In this work, we investigate the influence of conduction heterogeneities on the duration of such chaotic transients in generic models of excitable cardiac media. We observe that low and medium densities of heterogeneities extend the average transient lifetime, while at high densities very long transients, potentially persistent chaos, and periodic attractors occur.