# gst: like the slender body theory, the effect of curvature on the diffusion of colloidal bananas.

<< Anisotropic colloidal particles exhibit complex dynamics which play a crucial role in their functionality, transport, and phase behavior.  >>️

AA << investigate the two-dimensional diffusion of smoothly curved colloidal rods—also known as colloidal bananas—as a function of their opening angle α >>️

<< the experimental results are consistent with slender body theory, indicating that the dynamical behavior of the particles arises primarily from their local drag anisotropy. These results highlight the impact of curvature on the Brownian motion of elongated colloidal particles, which must be taken into account when seeking to understand the behavior of curved colloidal particles. >>️

Justin-Aurel Ulbrich, Carla Fernández-Rico, et al. Effect of curvature on the diffusion of colloidal bananas. Phys. Rev. E 107, L042602. April 21, 2023.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.107.L042602

Img: https://twitter.com/PhysRevE/status/1650782974722338816

Also: gst, particle, in https://www.inkgmr.net/kwrds.html

Keywords: gst, colloids, particles, behavior

# evol: gentle bonobos vs. aggressive chimps ...

<< Among the great apes, the chimpanzees and the bonobos are the most genetically related to us as we share about 98.7% of our DNA with them. >>️

<< So where exactly do humans stand? We seem to have incorporated the traits of both species, resulting in a tension between our aggressive and harmonious proclivities. Our tendency for conflict mirrors the competitiveness of chimpanzees, and yet the bonobos teach us that we have it in us to be altruistic and that society can be organised in more peaceful ways. This selflessness underlies the large-scale cooperation that has helped Homo sapiens share ideas, form nations, explore the universe and outlast other early humans such as Homo erectus. >>️

Jose Yong. Bonobos and chimps: what our closest relatives tell us about humans. theconversation.com. April 4, 2023. 

https://theconversation.com/bonobos-and-chimps-what-our-closest-relatives-tell-us-about-humans-202265

Img: https://images.theconversation.com/files/519318/original/file-20230404-897-1b84fi.png

Also: 'evolution', 'chimps', 'behav' in https://www.inkgmr.net/kwrds.html

Keywords: evolution, chimps, bonobos,  chimpanzees, behavior

# gst: emergent organization and polarization due to active fluctuations.

AA << introduce and study a model of active Brownian motion with multiplicative noise describing fluctuations in the self-propulsion or activity. (They) find that the standard picture of density accumulation in slow regions is qualitatively modified by active fluctuations, as stationary density profiles are generally not determined only by the mean self-propulsion speed landscape. As a result, activity gradients generically correlate the particle self-propulsion speed and orientation, leading to emergent polarization at interfaces pointing either towards dense or dilute regions depending on the amount of noise in the system.  >>

️

Benoit Mahault, Prakhar Godara, Ramin Golestanian. Emergent organization and polarization due to active fluctuations. Phys. Rev. Research 5, L022012. April 12, 2023. 

https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.5.L022012

Also: 'particle', 'fluctuations', 'noise', 'self-assembly' in https://www.inkgmr.net/kwrds.html

Keywords: gst, particle, organization, polarization, fluctuations, noise, self-propulsion, self-assembly 

# gst: when droplets are capable of self-propulsion as if they were surfing on a self-generated wave.

<< active droplets can move autonomously or oscillate between confining walls (..). Those behaviors could provide a clue about how life emerged from inanimate material. >>️

<< in the past decades, it has become clear that weak physical interactions among biomolecules are a crucial part of the answer. Such interactions allow some molecules to stay together transiently while avoiding others, which can lead to the spontaneous formation of droplets whose composition differs from their surroundings. Although biochemist Alexander Oparin suggested such ideas a century ago (..), experimental corroboration arrived only recently >>️

<< The key contribution of Demarchi and his collaborators is to demonstrate that droplet drift can enhance the heterogeneity of substrate and product. The resulting positive feedback allows droplets to move continuously as if they were surfing on a self-generated wave. >>️

David Zwicker. Droplets Come to Life. Physics 16, 45. Mar 20, 2023. 

https://physics.aps.org/articles/v16/45

AA << find that condensates move toward the center of a confining domain when this feedback is weak. Above a feedback threshold, they exhibit self-propulsion, leading to oscillatory dynamics. Moreover, catalysis-driven enzyme fluxes can lead to interrupted coarsening, resulting in equidistant condensate positioning, and to condensate division. >>

️

Leonardo Demarchi, Andriy Goychuk, et al. Enzyme-Enriched Condensates Show Self-Propulsion, Positioning, and Coexistence. Phys. Rev. Lett. 130, 128401. Mar 20, 2023.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.130.128401

Also

'drop', 'droplet', 'droploid', 'transition' in 

https://www.inkgmr.net/kwrds.html

Keywords: gst, drop, droplet, waves, transition, liquid-liquid phase transition, nonequilibrium systems

# gst: the physiological emergence and evolution of cell-spanning vortices (inside Drosophila oocytes).

<< Life in complex systems, such as cities and organisms, comes to a standstill when global coordination of mass, energy, and information flows is disrupted. Global coordination is no less important in single cells, especially in large oocytes and newly formed embryos, which commonly use fast fluid flows for dynamic reorganization of their cytoplasm. Here, (AA) combine theory, computing, and imaging to investigate such flows in the Drosophila oocyte, where streaming has been proposed to spontaneously arise from hydrodynamic interactions among cortically anchored microtubules loaded with cargo-carrying molecular motors. >>️

Sayantan Dutta, Reza Farhadifar, et al. Self-organized intracellular twisters. arXiv: 2304.02112v2 [physics.bio-ph].  Apr 6, 2023. 

https://arxiv.org/abs/2304.02112

Also

keyword 'vortex' in FonT

https://flashontrack.blogspot.com/search?q=vortex

keyword 'vortice' in Notes

(quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=vortice

Keywords: gst, fluid dynamics, vortex, vortices, vortexes, vorticity,

# gst: even a single bubble can produce creative musical outcomes

<< Producing original and arranging existing musical outcomes is an art that takes years of learning and practice to master. Yet, despite the constant advances in the field of AI-powered musical creativity, production of quality musical outcomes remains a prerogative of the humans. Here we demonstrate that a single bubble in water can be used to produce creative musical outcomes, when it nonlinearly oscillates under an acoustic pressure signal that encodes a piece of classical music. >>️

Ivan S. Maksymov. Musical creativity enabled by nonlinear oscillations of a bubble in water. arXiv:2304.00822v1 [cs.SD]. Apr 3, 2023. 

https://arxiv.org/abs/2304.00822

keyword "bubble" in FonT

https://flashontrack.blogspot.com/search?q=bubble

Keywords: gst, ai, fluid dynamics, bubble, sound, music, audio processing

# gst: packing in slender structures, the geometry of squeezed elastic beams

<< The behavior of a collection of squeezed elastic beams is determined by geometry, not by complex forces. >>️

Dan Garisto. How Order Emerges in Bendy Beam Bunches. Physics 16, 54. Apr 3, 2023.

https://physics.aps.org/articles/v16/54

<< A collection of thin structures buckle, bend, and bump into each other when confined. This contact can lead to the formation of patterns: hair will self-organize in curls; DNA strands will layer into cell nuclei; paper, when crumpled, will fold in on itself, forming a maze of interleaved sheets. This pattern formation changes how densely the structures can pack, as well as the mechanical properties of the system. >>️

<< Here (AA) study the emergence of order in a canonical example of packing in slender structures, i.e., a system of parallel confined elastic beams. >>️

They << find that the compressive stiffness and stored bending energy of this metamaterial are directly proportional to the number of beams that are geometrically frustrated at any given point.  >>

️

Arman Guerra, Anja C. Slim, et al. Self-Ordering of Buckling, Bending, and Bumping Beams. Phys. Rev. Lett. 130, 148201. Apr 3, 2023.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.130.148201

Also

keyword 'self-assembly' in FonT

https://flashontrack.blogspot.com/search?q=self-assembly

keyword 'elastic' in FonT

https://flashontrack.blogspot.com/search?q=elastic

keyword 'elastico' in Notes

(quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=elastico

Keywords: gst, self-assembly, beams, buckling, bending, bumping, elasticity