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mercoledì 3 marzo 2021

# gst: labyrinth chaos: revisiting the elegant, chaotic and hyperchaotic walks

<< Labyrinth chaos was discovered by Otto Rossler and Rene' Thomas in their endeavour to identify the necessary mathematical conditions for the appearance of chaotic and hyperchaotic motion in continuous flows. Here, (AA) celebrate their discovery by considering a single labyrinth walks system and an array of coupled labyrinth chaos systems that exhibit complex, chaotic behaviour, reminiscent of chimera-like states, a peculiar synchronisation phenomenon. >>

 << As all Rossler’s pioneering contributions, labyrinth chaos still holds promise for very interesting further developments. Its simplicity and elegance, both in terms of symmetries, topology and feedback-circuit structure, makes it a good candidate to compare it with other nonlinear, cyclically coupled systems, such as the Arabesques, the Lotka-Voltera system and its variants, and the Arnold-Beltrami-Childress  model. >> 

Vasileios Basios, Chris G. Antonopoulos, Anouchah Latifi. Labyrinth chaos: Revisiting the elegant, chaotic and hyperchaotic walks. arXiv: 2011.11009v1. Nov 22, 2020.






sabato 27 febbraio 2021

# life: even when you play classic (e.g. Montezuma's Revenge), bots win.

<< A team of researchers (..) has developed a set of learning algorithms that proved to be better at playing classic video games than human players or other AI systems. >>

They << explain how their algorithms differ from others and why they believe they have applications in robotics, language processing and even designing new drugs. >>

<< Reinforcement learning algorithms learn how to do things by synthesizing information provided in a large dataset- they recognize patterns and use them to make guesses about new data. (..) But, (..) such algorithms tend to run into trouble when they encounter data that does not fit with other data in the dataset. (AA) have overcome this problem by adding an algorithm that remembers all the paths a previous algorithm has taken as it has tried to solve a problem. When it finds a data point that does not appear to be correct, it goes back to its memory map and tries another route. In terms of playing video games, it retains screen grabs as it plays and when it finds itself losing, goes back to another point in the game and tries another approach. The algorithm also groups together images that look similar to figure out what point in time it should return to if things go awry. >>

<< They then used their system to play 55 Atari games that, over time, have become benchmarks for testing AI systems. The new system beat other AI systems 85.5 percent of the time. It did particularly well at Montezuma's Revenge, scoring higher than any other AI system and beating the record for a human. >>

Bob Yirka. Reinforcement learning algorithms score higher than humans, other AI systems at classic video games. Feb 25, 2021.


Ecoffet A, Huizinga J, et al. First return, then explore. Nature 590, 580–586. doi: 10.1038/ s41586-020-03157-9. Feb 25, 2021.


Also

keyword 'AI' | 'bot' in FonT



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










giovedì 25 febbraio 2021

# life: apropos of tricks, 'torpor', a survival strategy not as rare as previously thought

<< Life is hard for small animals in the wild, but they have many solutions to the challenges of their environment. One of the most fascinating of these strategies is torpor. Not, to be confused with sleep or Sunday afternoon lethargy, torpor is a complex response to the costs of living. >>

<<  Once thought to occur only in birds and mammals in the Northern Hemisphere where winters are more pronounced, (AA) now know torpor is widespread in small Australian mammals, and has also been observed in many small Australian bird species. >>

<<  The question people often ask about torpor, is "can humans do it?" Interestingly, some small primates have been observed using torpor. While it is technically possible to induce torpor in humans chemically, torpor is a very complex physiological process, and there are many aspects of it scientists still don't fully understand. >>

Chris Wacker. Torpor: a neat survival trick once thought rare in Australian animals is actually widespread. The Conversation. Dec 29, 2020. 



Also

Hrvatin S., Sun S., Wilcox OF et al. Neurons that regulate mouse torpor. Nature 583, 115–121. doi: 10.1038/ s41586-020-2387-5. Jun 11, 2020.


Takahashi TM, Sunagawa GA, et al. A discrete neuronal circuit induces a hibernation-like state in rodents. Nature 583, 109–114. doi: 10.1038/ s41586-020-2163-6. Jun 11, 2020.






mercoledì 24 febbraio 2021

# gst: apropos of 'transitions', slow dynamics of complex connected networks can control the rate of demixing

<< A space- spanning network structure is a basic morphology in phase separation of soft and biomatter, alongside a droplet one. Despite its fundamental and industrial importance, the physical principle underlying such network- forming phase separation remains elusive. >>

AA << find that phase- separation dynamics is controlled by mechanical relaxation of the network- forming dense phase, whose limiting process is permeation flow of the solvent for colloidal suspensions and heat transport for pure fluids. This universal coarsening law would contribute to the fundamental physical understanding of network-forming phase separation. >>

Michio Tateno, Hajime Tanaka. Power-law coarsening in network-forming phase separation governed by mechanical relaxation. Nat Commun 12, 912. doi: 10.1038/  s41467-020-20734-8. Feb 10,  2021.

Discovery of a new law of phase separation. University of Tokyo. Feb 10, 2021. 


Also

keyword 'transition' in FonT


keyword 'transition' | 'transizion*' in Notes (quasi-stochastic poetry)







martedì 23 febbraio 2021

# gst: a slow motion can triggers strong, fast-slip (many miles away)

<< At a glacier near the South Pole, earth scientists have found evidence of a quiet, slow-motion fault slip that triggers strong, fast-slip earthquakes many miles away,  >>

<< During an earthquake, a fast slip happens when energy builds up underground and is released quickly along a fault. Blocks of earth rapidly slide against one another. However, at an Antarctic glacier called Whillans Ice Plain, (they) show that "slow slips" precede dozens of large magnitude 7 earthquakes. >>

<< We found that there is almost always a precursory 'slow slip' before an earthquake, >> Grace Barcheck.

<< these slow-slip precursors- occurring as far as 20 miles away from the epicenter- are directly involved in starting the earthquake. >>

<< These slow slips are remarkably common, (..) and they migrate toward where the fast earthquake slip starts. >>

<< Within a period of two months in 2014, the group captured 75 earthquakes at the bottom of the Antarctic glacier. Data from GPS stations indicated that 73- or 96% - of the 75 earthquakes showed a period of precursory slow motion. >>

Blaine Friedlander. Slow motion precursors give earthquakes the fast slip. Cornell University. Feb 16, 2021.

G. Barcheck, E. Brodsky, et al. Migratory earthquake precursors are dominant on an ice stream fault. Science Advances. Vol. 7, no. 6, eabd0105. doi: 10.1126/ sciadv.abd0105. Feb 5, 2021.





venerdì 19 febbraio 2021

# life: to eat each other's wings within mating pairs (among wood-feeding cockroaches Salganea taiwanensis)

 << The behavior of eating their mates or a part of their mate's body has been studied in sexual cannibalism or nuptial feeding. In these behaviors, only one sex eats the other unilaterally. Within mating pairs of a wood‐feeding cockroach (Salganea taiwanensis), males and females eat the mate's wings each other, which is the first “mutual” case in these behaviors. Because the evolution of sexual cannibalism and nuptial feeding has been explained based on unilaterality, this mutual eating should have a new significance of reproduction. >> 

Haruka Osaki, Eiiti Kasuya. Mutual wing-eating between female and male within mating pairs in wood‐feeding cockroach. doi: 10.1111/eth.13133. Jan 25, 2021.


Bob Yirka. Wood-eating cockroach couples take turns eating each other's wings after mating. Feb 15, 2021.


Also

the beetle Carabaeus lamarcki, dancer and sky analyzer. May 14, 2016.


2022 - si risvegliano stercorari. Notes. June 17, 2006. (quasi-stochastic poetry)


keyword 'cockroach' in FonT







martedì 9 febbraio 2021

# zoo; apropos of extreme dwarf entities, the nano-chameleon (Brookesia nana)

<< An international team, (..) has discovered a minuscule new species of chameleon.  (..) They have named the new species Brookesia nana. >>

 << At a body length of just 13.5 mm and a total length of just 22 mm including the tail, the male nano-chameleon is the smallest known male of all 'higher vertebrates' >> Frank Glaw.

<< Unfortunately, the habitat of the Nano-Chameleon is under heavy pressure from deforestation, but the area has recently been designated as a protected area, and hopefully that will enable this tiny new chameleon to survive, >> Oliver Hawlitschek.

Meet the nano-chameleon, a new contender for the title of world's smallest reptile. Staatliche Naturwissenschaftliche Sammlungen Bayerns. Feb 01, 2021. 


Glaw, F., Kohler, J., Hawlitschek, O. et al. Extreme miniaturization of a new amniote vertebrate and insights into the evolution of genital size in chameleons. Sci Rep 11, 2522. doi: 10.1038/ s41598-020-80955-1. Jan 28,  2021.