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sabato 16 dicembre 2023

# gst: correlated noise and critical dimensions.

<< In equilibrium, the Mermin-Wagner theorem prohibits the continuous symmetry breaking for all dimensions d≤2. In this work, (AA) discuss that this limitation can be circumvented in nonequilibrium systems driven by the spatiotemporally long-range anticorrelated noise. >>

<< results suggest that the critical dimensions increase when the noise is positively correlated in space and time and decrease when anticorrelated. (AA)  also report that the spherical model with the correlated noise shows the hyperuniformity and giant number fluctuation even well above the critical point. >>️

Harukuni Ikeda. Correlated noise and critical dimensions. Phys. Rev. E 108, 064119. Dec 13, 2023.

Also: noise, fluctuations, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, noise, fluctuations


giovedì 14 dicembre 2023

# gst: pulsating active matter.

<< the mechanical pulsation of locally synchronized particles is a generic route to propagate deformation waves. >>
AA << consider a model of dense repulsive particles whose activity drives periodic change in size of each individual. >>️

They << show that the competition between repulsion and synchronization triggers an instability which promotes a wealth of dynamical patterns, ranging from spiral waves to defect turbulence. >>️

Yiwei Zhang, Etienne Fodor. Pulsating Active Matter. Phys. Rev. Lett. 131, 238302. Dec 8, 2023. 

Also: waves, particle, transition, instability, turbulence, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, waves, particle, transition, instability, turbulence


lunedì 11 dicembre 2023

# gst: scanning inside a granular raft

<< Rheology of macroscopic particle-laden interfaces, called “granular rafts,” has been experimentally studied in the simple shear configuration.  >>️

<< Close to the walls of the rheometer cell, one can observe regions of large local shear rate while in the middle of the cell a quasistatic zone exists. >>

<< Measuring the probability density functions of the instantaneous local shear rate, (AA) provide evidence of a balance between positive and negative instantaneous local shear rate. This behavior is the signature of a quasistatic region inside the granular raft. >>️
J. Lalieu, A. Seguin, G. Gauthier. Rheology of granular rafts. Phys. Rev. E 107, 064901. June 29, 2023.

Also: Bavand Keshavarz, Michela Geri. Mandelbrot granular raft. Phys. Rev. Fluids 8, 110506. Nov 16, 2023.

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

Also: << l'invasiva scorribanda /
sull' oramai alla deriva lacerata randa. >>️ in: Schismi da vibrati di tangone. Notes. March 23, 2005. (quasi-stochastic poetry)

Keywords: gst, raft, particle, grain, granular raft, life


sabato 9 dicembre 2023

# gst: buckling instability of sticky bubbles.


<< A slender object undergoing an axial compression will buckle to alleviate the stress. Typically the morphology of the deformed object depends on the bending stiffness for solids, or the viscoelastic properties for liquid threads. >>️

AA << study a chain of uniform sticky air bubbles in an aqueous bath that rise due to buoyancy. A buckling instability of the bubble chain, with a characteristic wavelength, is observed in the absence of a bending stiffness. If a chain of bubbles is produced faster than it is able to rise, the dominance of viscous drag over buoyancy results in a compressive stress that is alleviated by buckling the bubble chain. >>
Carmen L. Lee, Kari Dalnoki-Veress. Buckling instability in a chain of sticky bubbles. arXiv: 2311.15452v1 [cond-mat.soft]. Nov 26, 2023.

Also: bubble, instability, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, bubble, instability, buckling instability


giovedì 7 dicembre 2023

# art: nature as a bizarre artist, the self-sculpted Sphinx.


<< There is evidence that the Great Sphinx was a natural landform before its surface features were chiseled by the ancient Egyptians. Is this controversial theory plausible? >>

AA << carried out experiments on the fluid mechanical erosion of clay. Based on accounts of the nonuniform composition of the Sphinx, we tested the effect of hard inclusions within hillocks of softer clay. The flow of a water tunnel mimics the prevailing winds of Giza, and three-dimensional optical scanning records the history and evolution of the shape as it erodes. >>

<< These results show what ancient peoples may have encountered in the deserts of Egypt and why they envisioned a fantastic creature. >>️
Samuel Boury, Scott Weady, Leif Ristroph. Sculpting the Sphinx. Phys. Rev. Fluids 8, 110503. Nov 16, 2023.


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

Keywords: art, sculpt, Sphinx, erosion, fluid mechanical erosion, brain, mind, perceptions.




venerdì 1 dicembre 2023

# life: POTUS race 2024, Native voters could make a difference


<< There are predicted to be at least 5 million Native and Alaska Native-identifying voters in the U.S. in both rural and urban communities, according to the U.S. Census Bureau — although estimates are expected to be an undercount. >>️

<< Native Americans are incredibly influential and have the ability to really swing those elections on the margins, >> Jacqueline De Leon.

<< Hanging in the balance is control of House, Senate and the Oval Office in 2024. In a country in which turnout can make or break campaigns, organizers said courting Native voters can dictate a candidate's success. (..) Organizers argue Native voters are increasingly a coalition to watch, even if parties have not fully recognized them yet. (..) Here are some of the states where Native voters could have a significant impact on 2024 races for Congress, the Senate and for president. >>️️

Ximena Bustillo. Sometimes overlooked by campaigns, Native voters could decide major elections in 2024. NPR. Nov 21, 2023. 




Also: margine, in Notes (quasi-stochastic poetry) https://inkpi.blogspot.com/search?q=margine

Keywords: potus, potus race, Native, Native voters, life, transition, edge, margin


giovedì 30 novembre 2023

# gene: bacteria and archaea CRISPR everywhere in nature

<< Single-celled bacteria and archaea use CRISPR systems to defend themselves against viruses known as bacteriophages. (..) Until now, researchers had identified six types of CRISPR system, designated I–VI. >>

AA << developed an algorithm called FLSHclust, which analyses genetic sequences in public databases. (..) By looking at the predicted function of the clusters, the researchers found around 130,000 genes associated in some way with CRISPR, 188 of which had never been seen before, >>️️

<< It’s a treasure trove for biochemists, >> Lennart Randau.

Sara Reardon. ‘Treasure trove’ of new CRISPR systems holds promise for genome editing. Nature. doi: 10.1038/ d41586-023-03697-w. Nov 23, 2023. 

Han Altae-Tran, Soumya Kannan, Feng Zhang, et al. Uncovering the functional diversity of rare CRISPR-Cas systems with deep terascale clustering. 
Science, Vol 382, Issue 6673. doi: 10.1126/ science.adi1910. Nov 23, 2023. 


Keywords: genome, gene, crispr, crispr system, ai, artificial intelligence