Mastodawn

Liquid Gold — Soap Bubble Network in Warm Light

Soap and water. A warm light below. And suddenly — liquid gold. A dense network of soap bubbles fills a circular vessel, each thin film wall catching the amber light and turning translucent, glowing, alive. The pattern that forms is not random — it follows the same mathematical laws that govern honeycomb, biological cells, and the large-scale structure of the universe itself. This is not just soap foam. This is nature solving a geometry problem. And the answer is beautiful.

#soap, #bubble, #macro, #abstract, #gold, #yellow, #texture, #pattern, #foam, #closeup, #fineart, #science, #cell, #biology, #geometry, #warm, #light, #glowing, #circular, #nature, #experimental, #creative, #surreal, #artphoto, #minimal, #network, #honeycomb, #translucent, #stunning, #unique

Jocelyn Etienne – research 1d ago

#PhD opening in Lab #Interdisciplinaire de #Physique, #Grenoble, in collaboration with @JonFouchard (Dev2A, Paris Sorbonne)

The objective is to investigate the #mechanics of fibrous #tissue, and specifically the #cell-driven short time active response, based on kinetic models of statistical #physics, and in connection with experiments where suspended microtissues are subjected to large strain.

https://liphy-annuaire.univ-grenoble-alpes.fr/pages_personnelles/jocelyn_etienne/collagen/collagen_2026.html

#Liphy #interdisciplinary #Physics #Biophysics #PhDoffer #PhDprogram

Rxiv mechanobio 2d ago

📰 "A homogenization approach for spatial cytokine distributions in immune-cell communication"
https://www.biorxiv.org/content/10.64898/2026.03.31.715485v1?rss=1 #Dynamics #Cell

A homogenization approach for spatial cytokine distributions in immune-cell communication

Cytokine-mediated communication is a central mechanism by which immune cells coordinate activation, differentiation and proliferation. While mechanistic reaction-diffusion models provide detailed descriptions of cytokine secretion and uptake at the cellular scale, their computational cost limits their applicability to large and densely packed cell populations. Previously employed approximations of cytokine diffusion fields rely on assumptions that neglect the influence of cellular geometry and volume exclusion. In this work, we study a macroscopic description of cytokine diffusion and reaction dynamics based on homogenization techniques, rigorously linking microscopic reaction-diffusion formulations to effective continuum models. The resulting homogenized equations replace discrete responder cells with a continuous density, while retaining essential features of cellular uptake and excluded-volume effects. Further, we show that in regimes with approximate radial symmetry, classical Yukawa-type solutions emerge as limiting cases of the homogenized model, provided appropriate correction factors are included. Overall, our approach allows efficient multiscale modeling of cytokine signaling in complex immune-cell environments. ### Competing Interest Statement The authors have declared no competing interest. Deutsche Forschungsgemeinschaft, https://ror.org/018mejw64 Germany's Excellence Strategy

bioRxiv

Rxiv mechanobio 2d ago

📰 "Aurora kinase A enables collective invasion and metastasis by endowing a leader cell phenotype and stabilizing Eplin-mediated cohesion with follower cells"
https://www.biorxiv.org/content/10.64898/2026.03.31.715024v1?rss=1 #Dynamics #Cell

Aurora kinase A enables collective invasion and metastasis by endowing a leader cell phenotype and stabilizing Eplin-mediated cohesion with follower cells

The metastatic process initiates with collective cell invasion into surrounding tissues and axillary nodes, and subsequent colonization at a distant site. Previously, we found collective invasion is augmented during the G2 cell cycle phase, facilitated through Aurora kinase A (AURKA)-mediated centrosome polarization in the leader cell. Here, we identify cell cycle-associated gene signatures as overrepresented in axilla and liver metastatic sites, with AURKA expression strongly correlated with breast cancer metastasis signatures, and pan-cancer patient survival. Then, we show GFP-AURKA expression endows breast epithelia cells with the ability to form metastatic outgrowths within immune-incompetent chicken embryos. Multi-parametric imaging of wound closure assays reveals phenotypes enabled by, and dependent upon AURKA expression. We discover leader cells express AURKA and acquire front-polarized centrosomes, which differentiates them from other cells in the migrating group. Ectopic expression of GFP-AURKA induces a leader cell phenotype. Conversely, inhibition of AURKA activity alters actin dynamics, promotes turnover of cell contacts, and reduces coordination within migrating groups. Specifically, AURKA interacts with the actin regulator EPLIN, and AURKA inhibition localizes EPLIN to lamellipodia and away from E-cadherin-positive contacts. Inhibiting these necessary roles for AURKA may provide a critical barrier against the metastatic spread of human breast carcinoma cells. ### Competing Interest Statement The authors have declared no competing interest. Canadian Institutes of Health Research, CIHR F-19 03865, TFRI PPG F22-00533, CIHR F22-03789, CIHR F24-00975

bioRxiv

Rxiv mechanobio 2d ago

📰 "Stiff matrix-induced KRTAP2-3 expression suppresses ciliogenesis via actin tension-driven chromatin remodeling"
https://doi.org/doi:10.1038/s41419-026-08678-1
https://pubmed.ncbi.nlm.nih.gov/41922305/
#Mechanotransduction #Matrix #Cell

Rxiv mechanobio 2d ago

📰 "Caspase-3/Drice as a critical regulator of actin dynamics through its dual control of small RhoGTPase family and Gelsolin in the Malpighian tubules of Drosophila"
https://doi.org/doi:10.1038/s41420-026-03061-7
https://pubmed.ncbi.nlm.nih.gov/41922321/
#Morphogenesis #Dynamics #Actin #Cell

Rxiv mechanobio 2d ago

📰 "Design and performance of a large-area scintillator-based chamber for the MID subsystem of ALICE 3"
https://arxiv.org/abs/2604.00176 #Physics.Ins-Det #Mechanical #Hep-Ex #Cell

Design and performance of a large-area scintillator-based chamber for the MID subsystem of ALICE 3

This paper reports on the design and construction of a chamber for the muon identifier detector (MID) of the ALICE 3 upgrade project. The chamber consists of two sensitive layers separated by a 1 cm air gap. Each layer holds 24 scintillator bars ($1\times4\times100$ cm$^3$) manufactured by FNAL-NICADD. The bars are equipped with Kuraray wavelength shifting fibers and the readout is provided by a silicon photomultiplier from Hamamatsu. The bars in the second layer are orthogonal to the bars in the first layer, thus providing an overlapping cell size of 4$\times$4 cm$^{2}$. The bar assembly as well as the design of the mechanical structure is described. The design of the chamber is close to that considered in the ALICE 3 letter of intent. The chamber was tested at the CERN T10 beamline using 3 GeV/$c$ pion-enriched and muon beams. The chamber was placed behind an iron absorber, with different absorber lengths considered in the test. The muon identification is performed using a Machine Learning algorithm, which was trained and tested using muon (signal) and pion (background) data (50% of the available statistics). The trained ML algorithm was applied to muon data, yielding a muon efficiency above 99% for the OR condition (detection in either layer 1 or 2). The implementation in the pion-beam data gives the fake-muon efficiency as a function of the absorber length that is well described by an exponential function with a slope parameter of 18.79 cm. The next steps towards finalizing the optimization are outlined.

arXiv.org

Rxiv mechanobio 2d ago

📰 "Predictability is dynamically constructed by topological collective modes in deterministic systems"
https://arxiv.org/abs/2604.01088 #Cond-Mat.Stat-Mech #Physics.Bio-Ph #Dynamics #Nlin.Ps #Cell

Predictability is dynamically constructed by topological collective modes in deterministic systems

Deterministic many-body systems governed by simple interactions can self-organize into macroscopic patterns, and the determinants of long-time behavior are assumed to be encoded in the initial configuration. Here we show that predictability can instead be constructed dynamically rather than being accessible in the initial configuration. We study a generalized cellular automaton of secrete-and-sense cells that self-organizes from disorder into static configurations, rectilinear waves, or spiral waves. Although dynamics are deterministic, the final outcome cannot be reliably inferred from the initial state alone. Treating cell states as a discrete phase field, we uncover emergent topological modes - charged vortices connected by strings that form non-contractible loops. Tracking their dynamics reveals that predictive signatures of macroscopic fate appear only late in the trajectory: vortex annihilation becomes readable through loop loss, whereas vortex persistence remains unreadable until spiral waves form abruptly. These results show how predictability can be dynamically constructed in deterministic nonequilibrium systems.

arXiv.org

Rxiv mechanobio 2d ago

📰 "Contact-Dependent Ion Gating Explains Directional Asymmetry in the Bacterial Flagellar Motor"
https://arxiv.org/abs/2604.00470 #Physics.Bio-Ph #Mechanical #Q-Bio.Bm #Cell

Contact-Dependent Ion Gating Explains Directional Asymmetry in the Bacterial Flagellar Motor

The bacterial flagellar motor (BFM) is a rotary molecular machine driven by the ion electrochemical potential across the cell membrane. Recent cryo-EM structures reveal a cogwheel-like architecture in which multiple stators engage a large rotor. A longstanding puzzle is the directional asymmetry of its torque-speed relation: concave in counterclockwise (CCW) rotation but nearly linear in clockwise (CW) rotation. Here, we develop a stochastic mechanochemical model that explicitly incorporates rotor-stator coupling and detailed ion translocation kinetics. By integrating physiological torque-speed data with recent measurements of rotor-stator relative motion, we show that under physiological conditions the motor operates in a tight engagement regime, rendering the torque-speed relation largely insensitive to the specific form of mechanical interactions. This finding rules out differences in rotor-stator mechanics as the origin of CW-CCW asymmetry. Guided by cryo-EM structures, we propose a contact-dependent gating mechanism in which the MotA-FliG interaction modulates the ion release rate of the MotB subunit proximal to the FliG ring. Molecular dynamics simulations indicate tighter MotA-FliG contact in the CW motor, implying a reduced ion release rate compared to CCW. Our model demonstrates that differential gating strength accounts for the observed asymmetry: stronger gating in CCW shortens torque-free waiting phases, enhances torque generation, and produces a concave torque-speed curve, whereas weaker gating in CW yields lower torque and a linear relation. This structure-based framework quantitatively links molecular asymmetry to motor function and identifies specific interfaces for targeted perturbation and mutational studies.

arXiv.org

Rxiv mechanobio 2d ago

📰 "Integrated quantitative imaging and biomechanical modeling of early gastrulation in C. elegans"
https://www.biorxiv.org/content/10.64898/2026.03.30.715391v1?rss=1 #Mechanics #Cell

Integrated quantitative imaging and biomechanical modeling of early gastrulation in C. elegans

The stereotyped internalization of two endodermal precursors during early Caenorhabditis elegans gastrulation enables quantitative dissection of cell ingression mechanics. Experimental work has shown that apical constriction drives Ea and Ep ingression, and several molecular features involved have been identified. Yet, no integrative mechanical analysis has assessed how these elements collectively produce the observed behavior. To address this, we combined biomechanical simulations with a comprehensive dataset of 3D-segmented cell meshes, some with cortical protein distributions, to analyze the mechanics of ingression in its in-vivo context. Our analysis shows the process starts shortly after birth of the ingressing cells. A cortical flow drives the formation of an E-cadherin-rich structure at the apical Ea-Ep interface, which contributes to localizing the buildup of apical tension. Simulations show that medioapical actomyosin contraction can reproduce the observed ingression movements and suggest force transmission to neighboring cells via a friction-based "molecular clutch" at the apical ring of contact. A series of concurrent cell divisions facilitates ingression, and their stereotyped planar orientation also contributes. Furthermore, we observe an embryo-wide movement of cells during gastrulation. This movement resembles a flow, suggesting that local force generation leads to global rearrangements via internal pressure changes. Finally, at the end of ingression, detailed microscopy shows that neighboring cells actively close the gastrulation cleft by forming a rosette-like configuration and extending actin-rich protrusions. In conclusion, our integrated mechanical description of gastrulation shows that successful ingression is driven by apical constriction and supported by localized friction-based force transmission, coordinated stereotyped cell divisions, and the resulting global tiss ### Competing Interest Statement The authors have declared no competing interest. Research Foundation - Flanders, 11I2921N, 1194222N, 11L0923N, 11D9923N, G008423N KU Leuven, C14/24/109

bioRxiv