# gst: controlled creation of point defects in 3D colloidal crystals

<< Crystal defects crucially influence the properties of crystalline materials and have been extensively studied. Even for the simplest type of defect—the point defect—however, basic properties such as their diffusive behavior, and their interactions, remain elusive on the atomic scale. >>️

Here AA << demonstrate in situ control over the creation of isolated point defects in a three-dimensional (3D) colloidal crystal allowing insight on a single-particle level. >>

AA << experimental model system provides a unique opportunity to shed light on the interplay between point defects, on the mechanisms of their diffusion, on their interactions, and on collective dynamics. >>️

Max P. M. Schelling, Janne-Mieke Meijer. Controlled creation of point defects in three-dimensional colloidal crystals. Phys. Rev. E 109, L062601. Jun 4, 2024.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.L062601

Also: colloids, defect, error, transition,  in https://www.inkgmr.net/kwrds.html 

Keywords: gst, colloids, defect, error, transition

# gst: periodic defect braiding in active nematics confined to a cardioid.

AA' paper << examines self-mixing in active nematics, a class of fluids in which mobile topological defects drive chaotic flows in a system comprised of biological filaments and molecular motors. (They) present experiments that demonstrate how geometrical confinement can influence the braiding dynamics of the defects. >>️

<< Notably, (AA) show that confinement in cardioid-shaped wells leads to realization of the golden braid, a maximally efficient mixing state of exactly three defects with no defect creation or annihilation. >>

<< Increasing the size of the confining cardioid produces a transition from the golden braid, to the fully chaotic active turbulent state. >>️️

Fereshteh L. Memarian, Derek Hammar, et al. Controlling Chaos: Periodic Defect Braiding in Active Nematics Confined to a Cardioid. Phys. Rev. Lett. 132, 228301. May 28, 2024. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.228301

https://x.com/PhysRevLett/status/1796622457303876000

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

Keywords: gst, chaos, turbulence, active nematics, cardioid

# brain: a body-brain circuit regulates the body's inflammatory responses

<< The body-brain axis is emerging as a principal conductor of organismal physiology. It senses and controls organ function, metabolism and nutritional state. >>

Here AA << show that a peripheral immune insult powerfully activates the body-brain axis to regulate immune responses. (They) demonstrate that pro- and anti-inflammatory cytokines communicate with distinct populations of vagal neurons to inform the brain of an emerging inflammatory response. In turn, the brain tightly modulates the course of the peripheral immune response. >>

<< Genetic silencing of this body-to-brain circuit produced unregulated and out-of-control inflammatory responses. By contrast, activating, rather than silencing, this circuit affords exceptional neural control of immune responses. >>️

Jin, H., Li, M., Jeong, E. et al. A body–brain circuit that regulates body inflammatory responses. Nature. May 1, 2024. 

https://doi.org/10.1038/s41586-024-07469-y

Also: brain, pnei, in https://www.inkgmr.net/kwrds.html 

Keywords: brain, pnei

# gst: approaching 'size doppelgangers'

<< NASA visualization scientist Kimberly Arcand has constructed a photo essay comparing microscopic images of biological phenomena, such as this mouse retina, to macroscopic images from celestial phenomena such as Saturn’s north pole. These “size doppelgangers”, she writes, allow people to “begin to explore the true scale of science”. >>

Sara Reardon. Nature Briefing: Translational Research. May 22, 2024. 

https://us17.campaign-archive.com/?e=f87c45d7b6&u=2c6057c528fdc6f73fa196d9d&id=c09c87d1c6

Bryan William Jones, Robert E. Marc. Micro Macro blog. Univ of Utah / NASA/JPL-Caltech/SSI/Hampton University

https://chandra.si.edu/micro/

img (left): Mouse Eye

https://images.nigms.nih.gov/Pages/DetailPage.aspx?imageID2=3641 

img (right): Saturn's North Pole

https://saturn.jpl.nasa.gov/science/saturn/hexagon-in-motion

Also: keywords 'analogy", 'similarity', in FonT

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

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

Keywords: gst, analogy, similarity, ai (artificial intell), size doppelgangers

# gst: exotic geometries, a Janus trefoil knot, which rotates as it swims forwards.

AA << present an asymptotic theory for solving the dynamics of slender autophoretic loops and knots. >>️

They << elucidate the behavior of many exotic active particle geometries, such as a bumpy uniformly active torus that spins and a Janus trefoil knot, which rotates as it swims forwards. >>️

Panayiota Katsamba, Matthew D. Butler, et al. Slender phoretic loops and knots. Phys. Rev. Fluids 9, 054201. May 10, 2024. 

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.9.054201

Also: keywords janus, knots, particle, in FonT

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

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

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

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

Keywords: janus, loops & knots, particles

# game: apropos of Parrondo's game, how a flexible parasite can outsmart its hosts for evolutionary dominance.

<< Antagonistic coevolution between hosts and parasites substantially impacts community structure, with parasites displaying fluctuating selection or arms race dynamics during coevolution. The traditional matching alleles (MA) and gene-for-gene (GFG) models have been used to describe the dynamics and interaction of host-parasite coevolution, with these models assuming that parasites adopt a single strategy when competing with other parasites. >>

AA << present a nonlinear dynamic population model that challenges this assumption, showing how a parasite that is disadvantaged under either the MA or the GFG model can win the competition by switching between the two losing strategies based on an external environmental cue, internal processes, or stochastic decision-making. >>

<< This counterintuitive outcome is analogous to Parrondo's paradox, a game-theoretic concept that shows how alternating between two losing strategies can result in a winning outcome. >>

Tao Wen, Eugene V. Koonin, Kang Hao Cheong. How flexible parasites can outsmart their hosts for evolutionary dominance. Phys. Rev. Research 6, 023104. Apr 30, 2024.

https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.6.023104 

Also: game, Parrondo, evolution, in https://www.inkgmr.net/kwrds.html 

Keywords: game, Parrondo, evolution

FonT: from my point of view, if well modulated, the two paired strategies "Stochastic Tit-For-Tat" and "Parrondo" are deadly, regardless of the aims of the objectives (cooperative purposes, parasitism, etc)

# gst: relativistic chaotic scattering, scaling laws for trapped trajectories.

AA << study different types of phase space structures which appear in the context of relativistic chaotic scattering. By using the relativistic version of the Hénon-Heiles Hamiltonian, (They) numerically study the topology of different kind of exit basins and compare it with the case of low velocities in which the Newtonian version of the system is valid. >>

<< In all cases, fractal structures are present, and the escaping dynamics is characterized. In every case a scaling law is numerically obtained in which the percentage of the trapped trajectories as a function of the relativistic parameter β and the energy is obtained. >>

Their << work could be useful in the context of charged particles which eventually can be trapped in the magnetosphere, where the analysis of these structures can be relevant. >>️

Fernando Blesa, Juan D. Bernal, et al. Relativistic chaotic scattering: Unveiling scaling laws for trapped trajectories. Phys. Rev. E 109, 044204. Apr 5, 2024.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.044204

Also: chaos, chaotic, escape, particle, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, chaos, chaotic, escape, escape trajectories