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sabato 22 aprile 2023

# 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. 

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.

Also

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

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




sabato 15 aprile 2023

# 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. 

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keyword 'vortex' in FonT

keyword 'vortice' in Notes
(quasi-stochastic poetry)

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


venerdì 14 aprile 2023

# 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. 

keyword "bubble" in FonT

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



venerdì 7 aprile 2023

# 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.

<< 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.

Also

keyword 'self-assembly' in FonT

keyword 'elastic' in FonT

keyword 'elastico' in Notes
(quasi-stochastic poetry)

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





venerdì 31 marzo 2023

# gst: influence of disorder on the spreading and entanglement properties of coined quantum walks.


AA << investigate the influence of disorder on the spreading and entanglement properties of coined quantum walks. Specifically, (AA) consider quantum walks on the line and explore the effects of quenched disorder in the coin operations. (They) find that coin disorder alters the usual ballistic transport properties of coined quantum walks considerably and yields an extremely slow dynamics with strong evidence for localization behavior. (They) investigate this slow dynamics by comparing different properties of the walker occupation probability with the standard Hadamard walk. (They) find that the walker distribution, and a number of properties associated with it, are significantly altered by the coin disorder. Special focus is given to the influence of coin disorder on entanglement properties. (AA) observe that generically, coin disorder decreases the coin-walker entanglement. The behavior of the entanglement properties further supports the premise that coin disorder induces localization in coined quantum walks. >>

Louie Hong Yao, Sascha Wald. Coined Quantum Walks on the Line: Disorder, Entanglement and Localization. arXiv: 2303.15978v1 [quant-ph]. doi: 10.48550/ arXiv.2303.15978. 28 Mar 28, 2023.

Also

Voli a casaccio. Notes. Oct 01, 2006. 
(quasi-stochastic poetry)

keyword 'disorder' in FonT

keyword 'disordine' in Notes 
(quasi-stochastic poetry)

keyword 'walk' | 'walking' in FonT


keyword 'passo lieve' | 'walk' | 'walking' in Notes
(quasi-stochastic poetry)



Keywords: gst, disorder, quantum physics, walk, walking, coined quantum walks



sabato 25 marzo 2023

# life: apropos of AI chatbots, a hypothetical nightmare (for professional writers).


<< Nearly half of white-collar professionals have tried using ChatGPT to help with their work, according to a recent survey of more than 10,000 people at blue chips such as Google, JP Morgan and McKinsey. That’s staggering, considering the AI chatbot was only released to the public in November. It’s potentially very exciting for the future of work, but it also brings serious risks. >>️

<< Jobs involving significant amounts of writing will inevitably be affected most, such as journalists, academic researchers and policy analysts. >>️

<< For example Mihir Shukla, CEO and founder of California-based software company Automation Anywhere, thinks that “anywhere from 15% to 70% of all the work we do in front of the computer could be automated”. On the other hand a recent McKinsey report suggests that only about 9% of people will have to change careers. Even so, that’s a lot of people. Lower to mid-level employees are likely to be the ones most affected. >>

<< Employers have historically used labour-saving devices to maximise productivity, making people work harder, not smarter or better. Computers and emails, for example, have made work never-ending for many people. >>️

<< There are additionally concerns about the human cost of creating AI chatbots. Kenyan workers, for instance, were paid between US$1 and US$2 (80 pence to £1.60) per hour to train OpenAI’s GPT-3 model, on which ChatGPT is based. Their brief was to make it less toxic by labelling thousands of samples of potentially offensive text so that the platform could learn to detect violent, racist and sexist language. This was so traumatic for the workers that the contractor nearly brought the project to an early end. Unfortunately, there’s likely to be much more of this kind of work to come. >>️

<< Finally, AI chatbots raise fascinating intellectual property issues. >>️
Peter Bloom, Pasi Ahonen. ChatGPT: how to prevent it becoming a nightmare for professional writers. The Conversation. Mar 1, 2023. 


Also 

<< Earlier this week, I was chatting with a policy professor in Washington, DC, who told me that students and colleagues alike are asking about GPT-4 and generative AI: What should they be reading? How much attention should they be paying?
She wanted to know if I had any suggestions, and asked what I thought all the new advances meant for lawmakers. I’ve spent a few days thinking, reading, and chatting with the experts about this, and my answer morphed into this newsletter. So here goes! >>️

Tate Ryan-Mosley. MIT - The Technocrat. Mar 24, 2023. 

Also

AI (co)creators of storytelling ... they don't cry during sad stories, but they could tell when you will. FonT. Dec 2, 2018. 

keyword 'ai' | 'bot' in FonT


keyword 'ia' | 'ai' | 'robota' in Notes
(quasi-stochastic poetry)



Keywords: life, ai, ia, artificial intelligence, bot, robota, chatbot, GPT-3, GPT-4, chatGPT, chatBARD, chatERNIE, chatFIREFLY, chatCLAUDE



giovedì 23 marzo 2023

# gst: apropos of weakly coupled oscillators, a new approach to depict about their spontaneous stochastic activities

<<  Many systems in physics, chemistry and biology exhibit oscillations with a pronounced random component. Such stochastic oscillations can emerge via different mechanisms, for example linear dynamics of a stable focus with fluctuations, limit-cycle systems perturbed by noise, or excitable systems in which random inputs lead to a train of pulses. Despite their diverse origins, the phenomenology of random oscillations can be strikingly similar. >>


<< Here (AA) introduce a nonlinear transformation of stochastic oscillators to a new complex-valued function Q∗1(x) that greatly simplifies and unifies the mathematical description of the oscillator's spontaneous activity, its response to an external time-dependent perturbation, and the correlation statistics of different oscillators that are weakly coupled. >>

AA << approach makes qualitatively different stochastic oscillators comparable, provides simple characteristics for the coherence of the random oscillation, and gives a framework for the description of weakly coupled oscillators. >>️

Alberto Pérez-Cervera, Boris Gutkin, et al. A Universal Description of Stochastic Oscillators. arXiv: 2303.03198v1 [nlin.AO]. Feb 27, 2023. 

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'oscillations' in FonT

Keywords: gst, oscillations, random oscillations, weakly coupled oscillators