lunedì 30 maggio 2022

# gst: intentional defects to trap confined acoustic modes that are protected from perturbation

AA << has discovered how to exploit certain defects to protect confined energy in acoustics systems. Their experimental approach provides a versatile platform to create at-will defects for further theoretical validation and to improve control of waves in other systems, such as light >>

<< We set to understand whether topological defects, such as disclinations, can be created to trap highly confined acoustic modes that are protected from perturbation, (..) Our core insight was that, if we consider the point group symmetry of the disclination, a pair of disclinations modes are prevented from pairing away from zero frequency. This protection mechanism results from the interplay of the symmetry-protected topological phase of the crystalline lattice and the topological charge and symmetry of the disclination. >> Wladimir A. Benalcazar.

<< This is the first work experimentally validating that such protected states exist in the disclination core, >> Yun Jing. 
️
Ashley J. Wennersherron. Researchers find imperfections provide protection for system symmetry. Penn State College of Engineering. May 20, 2022.


Sarah Wells. Symmetrical Binding for Topological States. Physics 15, s56. Apr 26, 2022. 


Yuanchen Deng, Wladimir A. Benalcazar, et al. Observation of Degenerate Zero-Energy Topological States at Disclinations in an Acoustic Lattice. Phys. Rev. Lett. 128, 174301. Apr 26, 2022. 


Also

keyword 'acoustic' in FonT


Keywords: gst, acoustics, acoustic metamaterials, symmetry, system symmetry, imperfection, defect, topological defects, disclination






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sabato 28 maggio 2022

# gst: surface geometry for pattern dynamics, how a static model on a flat surface can propagate over a curved one

<< Pattern dynamics on curved surfaces are found everywhere in nature. The geometry of surfaces have been shown to influence dynamics and play a functional role, yet a comprehensive understanding is still elusive. >>

AA << report for the first time that a static Turing pattern on a flat surface can propagate on a curved surface, as opposed to previous studies, where the pattern is presupposed to be static irrespective of the surface geometry. To understand such significant changes on curved surfaces, (AA) investigate reaction-diffusion systems on axisymmetric curved surfaces. (..) both the symmetries of the surface and pattern participate in the initiation of pattern propagation. >>️

Ryosuke Nishide, Shuji Ishihara. Pattern Propagation Driven by Surface Curvature. arXiv:2205.08064v1 [nlin.PS]. May 17, 2022. 


Keywords: gst, pattern formation, curved surface, transition, geometry














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sabato 21 maggio 2022

# gst: apropos of transitions, two aspects of intermittency


<< intermittency produces significant probability of rare events that may locally accelerate the collision rates by a large factor in comparison with estimates using typical events. >>

<< Increasing intermittency of turbulence destroys the theory not via stronger bursts, but rather via increase of characteristic sizes of regions of calm and quiescent flow. ([AA️] remind that these two aspects of intermittency go together: increase of regions of calm flow and at the same time increased probability of strong bursts ([8] U. Frisch, Turbulence: The Legacy of A. N. Kolmogorov, (Cambridge University Press, New York, 1995).). >>

Itzhak Fouxon, Seulgi Lee, Changhoon Lee. Intermittency and collisions of fast sedimenting droplets in turbulence.  arXiv:2205.06972v1 [physics.flu-dyn]. May 14, 2022. 


Also

keyword 'intermittency' in FonT


keyword 'intermittenza|e' | 'intermittente|i' in Notes (quasi-stochastic poetry)





Keywords: gst, intermittency, collision, drop, droplet, turbulence


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mercoledì 18 maggio 2022

# brain: jazzy perceptions inside, there’s more to all the noise; even in the dark, neurons of the visual cortex chat

<< Scientists are now rethinking how they study and conceive of perception. >>

<< At every moment, neurons whisper, shout, sputter and sing, filling the brain with a dizzying cacophony of voices. Yet many of those voices don’t seem to be saying anything meaningful at all. They register as habitual echoes of noise, not signal; as static, not discourse. >>️

<< But over the past decade, that view has changed. (..) There’s more to all the noise, scientists realized, than they had assumed. >>️

<< Now, by analyzing both the neural activity and the behavior of mice in unprecedented detail, researchers have revealed a surprising explanation for much of that variability: Throughout the brain, even in low-level sensory areas like the visual cortex, neurons encode information about far more than their immediately relevant task. They also babble about whatever other behaviors the animal happens to be engaging in, even trivial ones — the twitch of a whisker, the flick of a hind leg. Those simple gestures aren’t just present in the neural activity. They dominate it. >>️

<< Our brains aren’t just thinking in our heads. Our brains are interacting with our bodies and the way that we move through the world. >> Cris Niell. 

<< Wait — maybe the brain isn’t noisy. Maybe it’s actually much more precise than we thought, >> David McCormick️.️

Jordana Cepelewicz. ‘Noise’ in the Brain Encodes Surprisingly Important Signals. Quantamag. Nov 7, 2019. 


Salkoff DB, Zagha E, McCarthy E, McCormick DA. Movement and Performance Explain Widespread Cortical Activity in a Visual Detection Task. Cereb Cortex. 2020 Jan 10;30(1):421-437. doi: 10.1093/ cercor/bhz206. 


Also

keyword 'perception' in FonT


keyword 'percezione' | 'percezioni' in Notes (quasi-stochastic poetry)



keyword 'error' | 'fuzzy' | 'noise'  in FonT 




keywords 'errore' | 'errori' in Notes (quasi-stochastic poetry)



keyword 'jazz' in FonT


keyword 'jazz' in Notes (quasi-stochastic poetry):


Keywords: brain, perception, visual cortex, noise









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martedì 17 maggio 2022

# esobio: the Benjamin's hypothesis: looking for Dyson spheres around white dwarfs.

<< Dyson spheres (DSR) are the stuff of highly advanced civilizations, commonly thought of as artificial spheres surrounding an entire star.  (..) any of these configurations would have one unique, tell-tale sign—they would change that star's infrared signature. >> 

Benjamin Zuckerman's << theory focuses on scanning white dwarves for anomalous infrared signatures that might indicate that an artificial construct surrounds them. But why white dwarves? Other than being reasonably ubiquitous, they have the distinction of being the end state of stars like our own. >>️

WISE and Spitzer << watched white dwarves with masses around what we would expect our own sun to turn into. They even noticed some incidences of anomalous infrared signatures. However, the researchers thought dust was the most likely cause of those anomalies, and there was no evidence of any DSR. (..) But the absence of evidence is not evidence of absence—it just helps to constrain the likelihood. (..) According to Dr. Zuckerman, with the observations we have already made, we can do a statistical calculation that less than 3% of habitable planets that orbit stars that eventually turn into white dwarves build a DSR around them. Granted, current estimates put the number of habitable planets around G-type stars that might ultimately evolve into white dwarves at 300 million—so there could still be upward of 9 million civilizations that have built a DSR around their white dwarf home star. But for now, the Fermi paradox still holds, and science continues to collect data that will either further constrain the estimates of the number of advanced technological civilizations in our galaxy or prove that we're not alone once and for all. >>️️

Andy Tomaswick. If there are Dyson spheres around white dwarfs, we should be able to detect them. Universe Today. May 10, 2022. 



Benjamin Zuckerman. Infrared and Optical Detectability of Dyson Spheres at White Dwarf Stars.  Monthly Notices of the Royal Astronomical Society.  stac1113. doi: 10.1093/ mnras/stac1113. April 28, 2022. 


Also

keyword 'esobio' | 'exobio' in FonT



Keywords: esobio, exobio, Dyson, Dyson sphere 








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venerdì 13 maggio 2022

# evol: spontaneous, immediate asymmetry, the chiral twist


<< When holding a right hand in front of a mirror, one can see a reflected image of a left hand and vice versa. In 1848, Louis Pasteur discovered that organic molecules are much like our hands: they come in mirror-image pairs of left- and right-handed variants. Nowadays, we know that this handedness or chirality (from the Greek word for "hand") is a hallmark of organic molecules. >>

<< Organic molecules are rich in carbon atoms, which form bonds to create either a right or a left "nano-hand." Yet, puzzlingly, life almost always selects to exclusively use one of the two mirror-image twins—a phenomenon called homochirality. For example, terrestrial life is based on left-handed amino acids and right-handed sugars. >>️️

<< A model now proposes a novel explanation for the emergence of homochirality in life—a longstanding puzzle about the origin of life on Earth. >>️

<< Homochirality emerges spontaneously in prebiotic chemical networks that adapt to optimize energy harvesting from the environment. Previously, it was believed that chiral symmetry breaking requires multiple loops of auto-catalysis, which increasingly produces one enantiomer of a molecule while inhibiting the formation of the other. However, the IBS team's results showed that the underlying mechanism of symmetry breaking is very general, as it can occur in large reaction systems with many random molecules and does not require sophisticated network architectures. It was found that this sharp transition to homochirality stems from the self-configuration of the reaction network in order to achieve more efficient harvesting of energy from the environment. >>️

Learning chemical networks give life a chiral twist. Institute for Basic Science. Apr 26, 2022. 


William D. Pineros, Tsvi Tlusty. Spontaneous chiral symmetry breaking in a random driven chemical system. Nat Commun 13, 2244. doi: 10.1038/ s41467-022-29952-8. Apr 26, 2022.


Also



Keywords: evolution, gst, randomness, self-assembly, self-configuration, break symmetry, asymmetry, chiral, chirality  




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mercoledì 11 maggio 2022

# life: be careful ... by Potus Joe.

<< attenzione a non farvi male quando uscite >> by Potus Joe Biden. (traduzione dal filmato, TGLa7. Maggio 10, 2022 20:24. https://tg.la7.it )

Chissà cosa realmente intendeva dire  Potus Joe Biden alla fine del colloquio preliminare con Mario Draghi 

Ai tempi della sua nomina a VPotus (2009, Potus Barak Obama), si diceva che Mr Joe Biden era da sempre incline alle 'gaffe' ...

Chissà perchè, ho sempre avuto qualche dubbio sulle sue presunte 'gaffe'.

keywords: Potus, Joe Biden, Mario Draghi




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martedì 10 maggio 2022

# brain: waiting for 'magic strings', psilocybin is a 'relatively safe' drug.

<< Psilocybin-containing mushrooms are used for recreational, spiritual, self-development and therapeutic purposes. However, physiologically relatively nontoxic, adverse reactions are occasionally reported. >>

The << study investigated the 12-month prevalence and nature of magic mushroom-related adverse reactions resulting in emergency medical treatment seeking in a global sample of (9.233) people reporting magic mushroom use. >>️
️
️ << The results confirm psilocybin mushrooms are a relatively safe drug, with serious incidents rare and short lasting. Providing harm-reduction information likely plays a key role in preventing adverse effects. More research is needed to examine the detailed circumstances and predictors of adverse reactions including rarer physiological reactions. >>️

Emma I Kopra, Jason A Ferris, et al. Adverse experiences resulting in emergency medical treatment seeking following the use of magic mushrooms. Journal of Psychopharmacology. 1-9. doi: 10.1177/ 02698811221084063. 
Apr 7, 2022.


<< Psilocybin is currently being investigated in clinical trials for mental health conditions across the world, including in our department, (..) It is important to draw a distinction between the use of psilocybin in clinical or research settings and recreational magic mushroom use, with partly overlapping yet distinct safety considerations and risk profiles. >> Emma Kopra. 

Beth Ellwood. Large survey suggests psilocybin is a “relatively safe” drug, with serious reactions being rare and short-lived. May 4, 2022. 


Also

keyword 'magic string' in FonT


keyword 'psychedelic' in FonT


Keywords: brain, drugs, magic string, magic mushrooms, psilocybin, psychedelic


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