Raindrop impact on the ocean has been proposed as a mechanism for microplastic transfer from seawater to the atmosphere, yet the interfacial dynamics governing particle ejection from floating microplastics remain largely unexplored. We investigate droplet impact onto microparticle monolayers (rafts) spanning a wide range of sizes, contrasting densities, and wettabilities, under raindrop-relevant impact conditions. Particle rafts strongly influence splash dynamics, cavity collapse, and Worthington jet formation. Splash onset is controlled by particle-induced roughness and capillary adhesion: deeply immersed particles stabilise the spreading lamella, producing only microdroplets, whereas weakly immersed particles destabilise the rim, promoting fingering and splashing. Following impact, raft characteristics govern wave-swell dynamics, separating into elastic and rigid regimes. Superhydrophobic rafts enable particle ejection upon impact and form particle-armoured Worthington jets that fragment into liquid marbles, providing an efficient aerosolisation pathway. In contrast, less hydrophobic rafts show limited detachment upon impact but still support Worthington jet-mediated transport. Despite these differences, splash thresholds and Worthington jet heights collapse under a simple geometric-inertial-capillary scaling. These results show how particulate monolayers modify canonical droplet-impact and identify the interfacial conditions under which rainfall transfers microplastics from ocean to atmosphere, and inform related droplet-granular processes such as soil erosion, and impacts on sandy substrates.
To form new sprouts during angiogenesis, endothelial cells coordinate migration through biophysical and biomechanical signaling with each other and the micro-environment. In zebrafish embryos, a key example of this process is intersegmental vessel (ISV) formation, where endothelial tip cells sprout dorsally from the dorsal aorta, elongate between somites, and connect to form the dorsal longitudinal anastomotic vessel (DLAV). While various factors coordinate ISV pathfinding, such as vascular endothelial growth factor (VEGF), semaphorin signaling, and integrin-mediated adhesion, the role of extracellular matrix (ECM) mechanics and distribution remains incompletely understood. Here, we combined in vivo timelapse imaging with mathematical modeling to study how ECM components influence endothelial migration. Experimentally, morpholino single knockdowns of laminin or fibronectin slowed ISV elongation but most vessels eventually reached the DLAV. To analyze potential effects of ECM mechanics on sprout progression, we developed a hybrid mathematical model of ISV elongation. The model combines a mass-spring based representation of a network of ECM fibers with an experimentally validated Cellular Potts Model of endothelial cell behavior that described cell elongation and migration, integrin-based mechanosensitive adhesion formation, and chemical signaling through VEGFs and semaphorins. For baseline parameters, this model predicts that the ECM helps to confine the extending sprout to the intersegmental space. After reducing the stiffness of the ECM network, ISVs sprouted more slowly than in baseline conditions, consistent with our experimental observation. After further reduction of ECM stiffness, the model predicted increased fusion of ISVs, a behavior reminiscent of the behavior of endothelial cells in many in vitro models and in our previous in silico models. Guided by these data and predictions, we hypothesized that ECM in the intersomitic space guides endothelial self-organization during ISV pathfinding. In agreement with this hypothesis and model predictions, combined knockdown of laminin and fibronectin produced network-like endothelial arrangements and errant pathfinding of ISVs. Importantly, re-expression of fibronectin using chimeric fibronectin mRNA substantially restored ISV organization in the triple knockdown backgrounds, supporting that the severe disorganization reflects specific loss of fibronectin-dependent function rather than nonspecific injection effects. Altogether, our results suggest a model of guided self-organization for ISV formation, in which the ECM and chemical guidance cues including semaphorins confine self-organized endothelial network formation to the intersegmental space. ### Competing Interest Statement The authors have declared no competing interest. NWO, VICI 865.17.004
- https://raar.info/2026/03/rencontre-publique-avec-robert-hirsch-la-gauche-et-l-antisemitisme-une-histoire-compliquee/ (Rencontre publique avec Robert Hirsch, "La gauche et l’antisémitisme : une histoire compliquée" )
Pistes pour ramener la gauche sur la voie de la lutte contre l’antisémitisme.
Rencontre publique:
📍 au Maltais Rouge (40 rue de Malte à Paris) et par Zoom
📆 le 26 mars 2026 à 19h
✍️ Pour participer, inscrivez-vous par mail à: [email protected] et précisez si vous venez sur place ou assistez en visio
# Texte d'appel à rejoindre le RAAR au format PDF: https://raar.info/wp-content/uploads/2026/03/pourquoi_adherer_au_RAAR_2026_03_26.pdf
# Bulletin d'adhésion au RAAR : https://raar.info/wp-content/uploads/2026/03/bulletin_adhesion_2026.pdf
# Texte d’appel à rejoindre le RAAR
Nous sommes nombreux à nous sentir trop souvent accablés, tristes et impuissants face au chaos du monde.
La haine, toutes les haines, qu’elles soient racistes, homophobes, sexistes explose de toutes parts et l’antisémitisme, cette mère des haines, est devenu l’un des signes de l’effondrement du monde.
En 2021 nous avons créé le RAAR (Réseau d’Actions contre l’Antisémitisme et tous les Racismes).
Cette volonté partait d’un constat, hélas largement vérifié depuis ; la lutte contre l’antisémitisme était dramatiquement délaissée à gauche…
Nous avons souhaité nous organiser pour lutter ensemble, dénoncer l’antisémitisme partout où il sévit et réintégrer la lutte contre l’antisémitisme dans la lutte contre tous les racismes au sein du camp de l’émancipation.
Et ce combat, crucial pour la gauche, nous le menons à partir de nos valeurs communes et de notre commune humanité ; la lutte contre l’injustice et toutes les formes de racisme.
Depuis les choses ont empiré, particulièrement depuis le 7 octobre 2023.
L’antisémitisme est de plus en plus présent, il n’est pas « résiduel » et n’est jamais excusable par le contexte, il s’étale et vocifère, telle une obsession qui vise, rappelons-le, 0,2 % de la population mondiale…
Nous avons besoin de vous, de vos talents, de vos révoltes, de vos réflexions pour mener ensemble ce combat et amplifier une voix résolument humaniste et solidaire contre l’antisémitisme et tous les racismes.
Nous ne sommes et n’avons pas pour vocation de nous constituer en parti ou organisation politique.
Nous considérons les divergences comme des richesses et souhaitons bannir entre nous la violence, les anathèmes et suspicions qui trop souvent hélas empoisonnent les débats.
Notre seul « programme commun » pourrait tenir en une phrase : on ne lutte pas contre l’antisémitisme avec des racistes et on ne lutte pas contre le racisme avec des antisémites.
Le 26 mars 2026, nous organisons une réunion autour de la question de « la gauche et l’antisémitisme : une histoire compliquée » avec l’historien et militant Robert Hirsch, auteur de deux passionnants ouvrages sur la question.
Après la réunion, que nous espérons riche et conviviale, nous partagerons le verre de l’amitié.
Rejoins-nous dans ce combat commun pour réagir, interpeller, partager nos colères, mais aussi notre force collective et, pourquoi pas, la joie d’être ensemble…
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#Antifascisme #Antisémitisme #Effondrement #Gauche #Haine #Racisme #Webinaire #RejoignezLeRAAR #Adhesion
11-Mar-2026
#Mussel #adhesion meets conductivity: new #bioglue for #bioelectronic #implants
Over the past two decades, anti-CD20 monoclonal antibodies have become a cornerstone in the management of B cell malignancies and autoimmune diseases, including multiple sclerosis (MS). Although their ability to induce profound depletion of peripheral B cells is well established, the broader spectrum of their immunomodulatory actions remains incompletely understood. This gap is clinically relevant, as treatment responses in MS do not consistently correlate with peripheral B cell counts. Moreover, tissue-resident B cells, particularly those within the central nervous system (CNS) and secondary lymphoid organs, as well as long-lived plasma cells, are largely unaffected by anti-CD20 therapy. These observations underscore the need to elucidate additional mechanisms contributing to therapeutic efficacy, including effects in antibody-mediated disorders such as neuromyelitis optica spectrum disorder (NMOSD). In this review, we focus on preclinical and clinical evidence concerning the effects of anti-CD20 therapies on soluble immunological mediators—cytokines, chemokines, and adhesion molecules—across MS. Emerging data suggest anti-CD20 treatments may restore the balance between pro-inflammatory and regulatory pathways, indirectly modulating other immune cell populations. However, available studies are constrained by small sample sizes, heterogeneous methods, and variable patient populations. Future systematic investigations are needed to clarify mechanisms of action, guide rational combination therapies, improve understanding of treatment response and side effects, and deepen insights into the underlying disease itself.
Rxiv mechanobio
RAAR contre l'antisémitisme..
michael