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martedì 31 dicembre 2019

# brain: the memory switch p75NTR

<< many molecular and environmental factors have been studied to understand how synaptic plasticity is modulated. Sleep, as an evolutionary conserved biological function, has shown to be a critical player for the consolidation and filtering of synaptic circuitry underlying memory traces. Although sleep disturbances do not alter normal memory consolidation, they may reflect fundamental circuit malfunctions that can play a significant role in exacerbating diseases, such as autism and Alzheimer's disease. (..) This paper will review the role of the p75NTR (p75 neurotrophic receptor), critically discuss the impact and implications of this research as the bridge for sleep research and neurological diseases.>>

Shen Ning, Mehdi Jorfi. p75NTR as a Molecular Memory Switch.  arXiv: 1912.11449v1 [q-bio.NC]. Dec 24, 2019.

https://arxiv.org/abs/1912.11449

lunedì 30 dicembre 2019

# pharma: a 'magical' (engineered) Escherichia coli to produce psychedelic psilocybin

<< Psilocybin, the prodrug of the psychoactive molecule psilocin, has demonstrated promising results in clinical trials for the treatment of addiction, depression, and post-traumatic stress disorder.  >>

AA << present the development of a modular biosynthetic production platform in the model microbe, Escherichia coli. (..) This is the highest psilocybin titer achieved to date from a recombinant organism and a significant step towards demonstrating the feasibility of industrial production of biologically-derived psilocybin. >>

Alexandra M.Adams, Nicholas A.Kaplan, et al. In vivo production of psilocybin in E. coli. Metabolic Engineering. Volume 56, pages 111-9. doi: 10.1016/j.ymben.2019.09.009. Sep 21, 2019.

https://www.sciencedirect.com/science/article/pii/S109671761930309X

Tanya Lewis. E. coli Could Produce a Popular Psychedelic for Therapeutic Use. Scientists engineered the bacterium to produce psilocybin. SCIAM. 322, 1, 16. Jan 2020.

https://www.scientificamerican.com/article/e-coli-could-produce-a-popular-psychedelic-for-therapeutic-use/

Also

keyword 'magic' in FonT

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

sabato 28 dicembre 2019

# gst: scrambling does not necessitate chaos.

<< Focusing on semiclassical systems, (AA) show that the parametrically long exponential growth of out-of-time order correlators (OTOCs), also known as scrambling, does not necessitate chaos. Indeed, scrambling can simply result from the presence of unstable fixed points in phase space, even in an integrable model. >>

Tianrui Xu, Thomas Scaffidi, Xiangyu Cao. Does scrambling equal chaos? arXiv:1912.11063v1 [cond-mat.stat-mech] Dec 23, 2019.

https://arxiv.org/abs/1912.11063

venerdì 27 dicembre 2019

# phys: three forms of ambiguity in the definition of entanglement


<< A more general definition (of entanglement) was published by Thaller, (B. Thaller, Advanced Visual Quantum Mechanics, (Springer 2005) p218) "A state of a compound system is called entangled if it cannot be written as a single tensor product of subsystem states. A state in the product form is called unentangled or separable."  >>

The paper << discusses experiments with single-particle systems, some of whose states appear to be entangled. (..) Three forms of ambiguity are discussed. The choice of state-space and its dimensions is a matter of taste. There is not an a-priori natural partitioning of the state-space. The observables are not necessarily experimentally accessible and only determined by theory-laden extrapolation from experimental results. >>

Robert Shaw. Single-particle entanglement and three forms of ambiguity. arXiv:1912.11349v1 [physics.hist-ph]. Dec 22, 2019

https://arxiv.org/abs/1912.11349

martedì 24 dicembre 2019

# life: squeezing jaraca' (Bothrops jararaca)

<< Dozens of poisonous snake species, including the jararaca, thrive in Brazil's hot and humid climate. >>

<< Venom is extracted from each snake once a month in a delicate and potentially dangerous process. >>

Brazil milks deadly snakes for their life-saving venom.  Dec 10, 2019.

https://m.phys.org/news/2019-12-brazil-deadly-snakes-life-saving-venom.html

lunedì 23 dicembre 2019

# behav: backward walking, navigational uncertainties (among Cataglyphis velox)

<< Current opinion in insect navigation assumes that animals need to align with the goal direction to recognise familiar views and approach it. Yet, ants sometimes drag heavy food items backward to the nest and it is still unclear to what extent they rely on visual memories while doing so. >>

<< ants do indeed recognise and use the learnt visual scenery to guide their path while walking backward. In addition, the results show that backward homing ants estimate their directional certainty by combining visual familiarity with other cues such as their path integrator and the time spent backward. >>

Sebastian Schwarz, Leo Clement, et al.  How do backward walking ants (Cataglyphis velox) cope with navigational uncertainty? doi: 10.1101/2019.12.16.877704. Dec 17, 2019.

https://www.biorxiv.org/content/10.1101/2019.12.16.877704v1


sabato 21 dicembre 2019

# life: a case of extreme swing (3): he's impeachable/ impeached, or (maybe) not

<< Now that the House of Representatives has voted to impeach President Donald Trump, what is the constitutional status of the two articles of impeachment? Must they be transmitted to the Senate to trigger a trial, or could they be held back by the House until the Senate decides what the trial will look like, as Speaker Nancy Pelosi has hinted?  The Constitution doesn’t say how fast the articles must go to the Senate. Some modest delay is not inconsistent with the Constitution, or how both chambers usually work. >>

<< Strictly speaking, "impeachment" occurred – and occurs - when the articles of impeachment are presented to the Senate for trial. And at that point, the Senate is obliged by the Constitution to hold a trial. >>

Noah Feldman. Trump Isn’t Impeached Until the House Tells the Senate
According to the Constitution, impeachment is a process, not a vote.  Dec 19,  2019. 

https://www.bloomberg.com/view/articles/2019-12-19/trump-impeachment-delay-could-be-serious-problem-for-democrats

Also

"extreme swing" in FonT

https://flashontrack.blogspot.com/search?q=extreme+swing



mercoledì 18 dicembre 2019

# gst: the complex dynamics of a transition

<< The transition state is a central concept of chemistry (..) Everything we think about in reactions really hinges on the structure of the transition state, which we cannot directly observe. >> Robert Field.

<< there are two different mechanisms competing for transition states, >>

<< there are additional reaction mechanisms beyond those two, >>

Chemists glimpse the fleeting 'transition state' of a reaction. 
Massachusetts Institute of Technology. Dec 16, 2019.

https://m.phys.org/news/2019-12-chemists-glimpse-fleeting-transition-state.html

lunedì 16 dicembre 2019

# gst: a hexagonal pattern of six cyclones (Jupiter, by NASA)

<< In this annotated infrared image, six cyclones form a hexagonal pattern around a central cyclone at Jupiter's south pole. The image was generated from data collected by NJASA’s Juno spacecraft on Nov. 4, 2019 >>

Tony Greicius. NASA's Juno Navigators Enable Jupiter Cyclone Discovery.  Dec. 13, 2019. 

https://www.nasa.gov/feature/jpl/nasas-juno-navigators-enable-jupiter-cyclone-discovery

A New Cyclone Joins the Jovian Fray.  NASA. Dec 12, 2019. 

https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA23558

sabato 14 dicembre 2019

# life: oops! trust in (British) politics

<< In previous British elections, to say that trust was the main issue would have meant simply that trust is the trump card – whichever leader or party could secure most trust would win. Now, the emerging question about trust is whether it even matters anymore. >>

<< Even many Labour voters don’t rate their leader as trustworthy. Neil Hall/EPA >>

<< These are moral judgements of the utmost significance. So it suggests that British democracy is in some moral jeopardy, when the leaders of the two major parties, the only likely candidates for the premiership, were rated so low on trustworthiness by the public, including supporters of their own party. For example, according to one YouGov poll, 53% of respondents thought Johnson untrustworthy, while for Corbyn the figure was 57%. (..) These figures suggest not only seriously depleted trust but also a substantial readiness amongst voters to separate trustworthiness from electability.  (..) A lack of trustable people creates insecurity, and in this anxious environment some people will want to convince themselves, whatever the evidence, that they have found a trustworthy leader.  (..) On that front, the most significant outcome may not be the seats won by the competing parties, but the national profile as expressed in the popular vote, and what it tells us about whether trust matters. >>

Barry Richards. We should look closely at Britain’s decision to elect a man so renowned for his untrustworthiness. 
Bournemouth University. Dec 13, 2019. 

https://theconversation.com/we-should-look-closely-at-britains-decision-to-elect-a-man-so-renowned-for-his-untrustworthiness-128733

<< Johnson is regularly accused of hiding who he really is, but maybe that’s not actually the case at all. He has left enough clues along the way for us to build a picture of the man he is – and the British public has decided they are fine with it. >>

Laura Hood. Boris Johnson’s big election victory: academics on what it means for the UK and Brexit. Dec13, 2019.

https://theconversation.com/boris-johnsons-big-election-victory-academics-on-what-it-means-for-the-uk-and-brexit-128850

venerdì 13 dicembre 2019

# life: JARexit Flight Dynamics ...

keyword "JARexit" in FonT

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

"1878-onda ricorsiva"

https://inkpi.blogspot.com/2005/09/1878-onda-ricorsiva.html

Also

harmonica flight, by Michael Stipe ("Bad Day", time 10:15)  in: R.E.M. - June 3 2005 - Rockpalast - Rock am Ring - Nürburg Germany  

https://youtu.be/rD9BSKNcn0g

mercoledì 11 dicembre 2019

# behav: a great white shark at rest

<< Great white sharks are known for racing past the Mid-Atlantic states to get someplace else, so experts pay attention in rare cases when one not only stops, but stays put.
That's happening now along the Virginia-North Carolina border with a 10-foot, 3-inch male tracked by OCEARCH.
"It's interesting watching white shark Shaw since unlike other sharks on the Tracker, he has been hanging out off the Virginia coast for over a month," OCEARCH posted Tuesday on Facebook. >>

Mark Price. Experts puzzled as 10-foot great white shark stays a month in one spot off East Coast.  Dec 10, 2019.

https://m.phys.org/news/2019-12-experts-puzzled-foot-great-white.html

Ocearch. Dec 4, 2019

https://m.facebook.com/OCEARCH/posts/10162443074005167

Also

The long (and slow) life of Greenland shark (Somniosus microcephalus). Aug 16, 2016. 

https://flashontrack.blogspot.com/2016/08/s-ageing-long-and-slow-life-of.html

martedì 10 dicembre 2019

# game: apropos of perpetual hack, to bypass 'lizard' brains with a Tit-for-Tat approach

<< In (..) lizard brain, (..) "cheating" was really just "retaliation." >>

<< Where do we go from here?
Is there a way to break this cycle? >>

<<  For no matter how viscerally satisfying and rational it may appear to operate in a never-ending tit-for-tat spiral, in the long run, cooperation pays >>  

Niels Rosenquist.  How Tit-for-Tat Game Theory Hacked Politics. Jun 10, 2019. 

https://thebulwark.com/how-tit-for-tat-game-theory-has-hacked-politics/

FonT

a "catapulting" approach to bypass "lizard" brains: 

1668 - ramificata tinnula (di carmina fluitantia). Jun 9, 2005.

https://inkpi.blogspot.com/2005/06/1668-ramificata-tinnula-di-carmina.html

More

keyword "tit-for-tat" in FonT:

https://flashontrack.blogspot.com/search?q=tit-for-tat

keyword "tit-for-tat" in Notes:

https://inkpi.blogspot.com/search?q=tit-for-tat


sabato 7 dicembre 2019

# gst: apropos of clogging and jamming, they are not really jammed, they move steadily, if slowly, downwards

<< The first study of the way logs become pinned in rivers reveals that those seemingly trapped in a logjam move steadily, if slowly, downriver. >>

<< One of the lesser-known consequences of forest fires is logjams—river channels clogged with wood. The mechanism is straightforward. Forest fires create vast areas of dead wood. During the winter, heavy snow leads to avalanches that push thousands of the burned logs to the bottom of river valleys, where they enter the water. When the logs stretch across the river, from bank to bank, the river can no longer flow. It is this formation that has long captured the public imagination: the word "logjam" has come to mean a situation in which movement, physical or otherwise, is impossible. >>

Logjams aren’t really jammed at all, say geoscientists. Tech Rev - Emerging Technology from the arXiv. Nov 19, 2019

https://www.technologyreview.com/s/614724/logjams-arent-really-jammed-at-all-say-geoscientists/

Nakul S. Deshpande, Benjamin T. Crosby. Logjams are not jammed: measurements of log motions in Big Creek, Idaho. arXiv:1911.01518v1 [physics.geo-ph]. Nov 4, 2019.

https://arxiv.org/abs/1911.01518



giovedì 5 dicembre 2019

# brain AI bots: a hypothetical model for exploratory bots, the pulsating perceptions of mantis shrimps

AA << examined the neuronal organization of mantis shrimp, which are among the top predatory animals of coral reefs and other shallow warm water environments. >>

They << discovered a region of the mantis shrimp brain they called the reniform ("kidney-shaped") body. The discovery sheds new light on how the crustaceans may process and integrate visual information with other sensory input. >>

<< Mantis shrimp sport the most complex visual system of any living animal. They are unique in that they have a pair of eyes that move independently of each other, each with stereoscopic vision and possessing a band of photoreceptors that can distinguish up to 12 different wavelengths as well as linear and circular polarized light.  >>

<< One of the study's crucial findings was that neural connections link the reniform bodies to centers called mushroom bodies, iconic structures of arthropod brains that are required for olfactory learning and memory. >>

<< The fact that we were now able to demonstrate that the reniform body is also connected to the mushroom body and provides information to it, suggests that olfactory processing may take place in the context of already established visual memories, >> Nicholas Strausfeld.

How mantis shrimp make sense of the world. University of Arizona.  Nov 25, 2019. 

https://m.phys.org/news/2019-11-mantis-shrimp-world.html

Hanne Halkinrud Thoen, Gabriella Hannah Wolff, et al. The reniform body: An integrative lateral protocerebral neuropil complex of Eumalacostraca identified in Stomatopoda and Brachyura. Journal of Comparative Neurology. doi: 10.1002/cne.24788. Oct 16, 2019.

https://onlinelibrary.wiley.com/doi/abs/10.1002/cne.24788

FonT

these neural models could be reproduced for "compassionate" (or even "bonobos") bots, but NEVER for "nfulaw" purposes, please

keyword  "nfulaw" in FonT

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

venerdì 29 novembre 2019

# gst: a bizarre extension of the Jelly Roll approach, the morphogenesis of the leaves (plant Utricularia gibba)

AA << discovered that simple shifts in gene activity in the leaf bud provide a flexible mechanism for how leaves of all shapes and sizes are made. >>

<< We've discovered a general principle by which leaves from flat sheets to needle-like and curved shapes are formed,  (..) We found that the complex leaf shapes of carnivorous plants evolved from species with flat leaves through simple shifts in gene activity in the leaf bud. What surprised us is that how such a simple mechanism could underlie such a wide diversity of leaf shapes.  (..) If you want to understand why water boils at 100°C, look for situations in which it doesn't, like the top of Mount Everest where it boils at 70°C. From that we learn the general principle that boiling point depends on air pressure. Similarly, if you want to understand why most leaves are flat, you might study exceptions, like the leaves of some carnivorous plants which form pitchers to trap prey, >> Enrico Coen.

Nature's secret recipe for making leaves. John Innes Centre. Nov 21, 2019. 

https://m.phys.org/news/2019-11-nature-secret-recipe.html

Christopher D. Whitewoods, Beatriz Goncalves, et al. Evolution of carnivorous traps from planar leaves through simple shifts in gene expression. Science. eaay5433 doi: 10.1126/science.aay5433. Nov 21, 2019

https://science.sciencemag.org/content/early/2019/11/20/science.aay5433


Also

keyword "Jelly Roll" in Notes:

https://inkpi.blogspot.com/search?q=jelly+roll

keyword "Jazz" in Notes:

https://inkpi.blogspot.com/search?q=jazz

keyword "Jelly Roll" in FonT

https://flashontrack.blogspot.com/search?q=jelly+roll


mercoledì 27 novembre 2019

# phys: the qu-wave of the natural antibiotic gramicidin

<< One of the great counterintuitive puzzles of quantum mechanics is wave-particle duality. This is the phenomenon in which objects behave both like particles and like waves. >>

AA << for the first time, have demonstrated quantum interference in molecules of gramicidin, a natural antibiotic made up of 15 amino acids. Their work paves the way for the study of the quantum properties of  biomolecules and sets the scene for experiments that exploit the quantum nature of enzymes, DNA, and perhaps one day simple life forms such as viruses. >>

A natural biomolecule has been measured acting like a quantum wave for the first time. Mit Tech Rew - Emerging Technology from the arXiv. Nov 9, 2019. 

https://www.technologyreview.com/s/614688/a-natural-biomolecule-has-been-measured-acting-in-a-quantum-wave-for-the-first-time/

Armin Shayeghi, Philipp Rieser, et al. Matter-wave interference of a native polypeptide. arXiv:1910.14538v1 [quant-ph]. Oct 31, 2019.

https://arxiv.org/abs/1910.14538

Also

keyword "quantum" in FonT

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

lunedì 25 novembre 2019

# gst: apropos of elusive interference effects (at the nanoscale)

AA << investigate and characterize a subspace of the weak coupling regime between quasidiscrete and quasicontinuum localized surface plasmon resonances where infrared plasmonic Fano antiresonances appear.  >>

Kevin C. Smith, Agust Olafsson, et al.  Direct Observation of Infrared Plasmonic Fano Antiresonances by a Nanoscale Electron Probe. Phys. Rev. Lett. 123, 177401. 21 Oct 21,  2019. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.177401

<< In 1961, atomic physicist Ugo Fano theorized that electrons harbor another and unexpected talent: They can interfere with themselves as they simultaneously take two different quantum-mechanical paths. On one path, they jump within the atom between discrete energy states. On the other path, they jump off the atom into the continuum of free space. >>

<< Fano described a complicated-and even counterintuitive-type of energy transfer that can occur in these systems, (..) It's like having two children on neighboring swings that are weakly coupled to each other: You push one child, but that swing isn't the one that moves. Instead, the other child's swing moves due to this interference. It's a one-way energy transfer. >> David Masiello.

Team uses golden 'lollipop' to observe elusive interference effect at the nanoscale. University of Washington. 
 Nov 8, 2019.

https://m.phys.org/news/2019-11-team-golden-lollipop-elusive-effect.html


venerdì 22 novembre 2019

# life: an anti-flood approach, techno- humans ask beavers for help

<< The National Trust has announced plans to release Eurasian beavers at two sites in the south of England next spring to help with flood management and to improve biodiversity. >>

National Trust announces first beaver reintroductions. Press Release. Nov 20, 2019. 

https://www.nationaltrust.org.uk/press-release/national-trust-announces-first-beaver-reintroductions

Beavers brought in to beat flooding in Britain. Nov 20, 2019.

https://m.phys.org/news/2019-11-beavers-brought-britain.html

Also

Facing a cross-border crimes. FonT.   May 9, 2017. 

https://flashontrack.blogspot.com/2017/05/n-soc-facing-cross-border-crimes.html




giovedì 21 novembre 2019

# brain: the flexible mental maps of flies

<< In the Drosophila brain, 'compass'  neurons track the orientation of the body and head (the fly’s heading) during navigation >>

<<  a visual cue can evoke synaptic inhibition in compass neurons and that R (ring) neurons mediate this inhibition. Each compass neuron is inhibited only by specific visual cue positions, indicating that many potential connections from R neurons onto compass neurons are actually weak or silent. (..) the pattern of visually evoked inhibition can reorganize over minutes as the fly explores an altered virtual-reality environment. >>

Yvette E. Fisher, Jenny Lu, et al. Sensorimotor experience remaps visual input to a heading-direction network.  Nature. doi: 10.1038/s41586-019-1772-4. Nov 20, 2019. 

https://www.nature.com/articles/s41586-019-1772-4

To navigate, flies make flexible mental maps of the world. Howard Hughes Medical Institute. Nov 20, 2019.

https://m.phys.org/news/2019-11-flies-flexible-mental-world.html

Also

<<  Considerando invece l' immagine classica della "mosca nella bottiglia", >>  in: 2066 - voli a casaccio. Notes. Oct 01, 2006. 

https://inkpi.blogspot.com/2006/10/2066-voli-casaccio.html


martedì 19 novembre 2019

# gst: measuring biological noise of gene expression

<< Essential genes are often expressed with high variability during the development of cells. Scientists call this phenomenon "biological noise" and suspect that it is also decisive for the fate of cells, i.e. the developmental pathway a cell takes. Max Planck researcher Dominic Grun now presents a method based on single-cell data to quantify this variability in gene expression.  >>

Dominic Grun << hopes to gain a better understanding of the extent to which noise regulates development or is even necessary for the differentiation of cells. >>

How gene expression noise shapes cell fate. Max Planck Society. Nov 18, 2019. 

https://m.phys.org/news/2019-11-gene-noise-cell-fate.html   

Grun D. Revealing dynamics of gene expression variability in cell state space. Nat Methods (2019) doi:10.1038/s41592-019-0632-3. Nov 18, 2019.

https://www.nature.com/articles/s41592-019-0632-3

Also

keyword 'noise' in Notes:

https://inkpi.blogspot.com/search?q=noise

keyword 'noise' in FonT:

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



venerdì 15 novembre 2019

# gst: interface mobility enhances the bounce effect of bubbles

<< Theoretically, when a bubble reaches the surface of a pure liquid, the thin film of liquid between the bubble and the air above should quickly drain away, allowing the bubble to coalesce with the air. The same would be expected when two bubbles meet within the liquid or when two droplets of oil come together in water.  >>

<< Counterintuitively, bubbles or droplets reaching the highly mobile fluorocarbon liquid-air interface bounced off of the interface much more strongly than from the immobilized interface. The reason is that there is less friction on the mobile interface and thus less energy is lost during the bounce. "To our knowledge, our studies and simulations are the first to demonstrate an enhanced bounce effect due to interface mobility," >> Ivan U. Vakarelski.

When bubbles bounce back.  King Abdullah University of Science and Technology. Nov 13, 2019.

https://m.phys.org/news/2019-11-when-bubbles-bounce-back.html

Ivan U. Vakarelski, Fan Yang, et al. 
Mobile-surface bubbles and droplets coalesce faster but bounce stronger. Science Advances  25 Oct 2019:
Vol. 5, no. 10, eaaw4292 DOI: 10.1126/sciadv.aaw4292 

https://advances.sciencemag.org/content/5/10/eaaw4292

martedì 12 novembre 2019

# gst: marginally outer trapped surfaces (during a binary Black Hole merger)

<< do MOTSs (marginally outer trapped surfaces, or marginal surfaces) merge in a BBH (binary black hole ) coalescence, and if so, how, exactly? >>

<< It is an underappreciated fact that event horizons are not really very useful for studying astrophysical properties of black hole mergers, (..) What is much more useful are surfaces which go under the boring name of marginally outer trapped surfaces (..). This uninteresting name hides their importance in understanding black holes. >>

Ingrid Fadelli. Numerical evidence for the merger of MOTSs inside a binary black hole. Nov 1, 2019

https://m.phys.org/news/2019-11-numerical-evidence-merger-motss-binary.html

Daniel Pook-Kolb, Ofek Birnholtz, et al. 
Interior of a Binary Black Hole Merger. Phys. Rev. Lett. 123, 171102 Oct 21, 2019. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.171102


sabato 9 novembre 2019

# gst: apropos of turbulences close to a wall, the repetitive structure of a vortex

<< At the boundary where a fluid flows over a fixed structure, a turbulent boundary layer is created where the fluid interacts with the wall, creating eddies in the current. These eddies may seem to be random on first glance, but they actually create distinct patterns, with countless tiny eddies close to the wall; fewer but larger eddies located a little farther out; and even fewer, but still larger, eddies beyond those. >>

<< "We knew that, underlying these very complicated structures, there had to be a very simple pattern. We just didn't know what that pattern was until now," says McKeon, who next plans to dig deeper into the model to quantify just how many eddies should be included to create an accurate representation of the whole. >>

Engineers exploit the repeating structure of turbulence to create a more complete model of the phenomenon. California Institute of Technology. Nov 6, 2019.

https://m.phys.org/news/2019-11-exploit-turbulence-phenomenon.html

Beverley J. McKeon. Self-similar hierarchies and attached eddies. Phys. Rev. Fluids 4, 082601(R). Aug 26, 2019.

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.4.082601

giovedì 7 novembre 2019

# gst: multiple singularities by optical vortices (a 30y review)

<< Vortices are common phenomena that widely exist in nature, from quantum vortices in liquid nitrogen to ocean circulation and typhoon vortices and even spiral galaxies in the Milky Way. Vortices also exist in optics, the concept of which was first proposed by theoretical physicist Pierre Coullet and colleagues [Opt. Commun. 73, 403 (1989)] thirty years ago. Hitherto, owing to their amazing structures, optical vortices have engendered tremendous advanced applications such as optical tweezers, quantum entanglement, and nonlinear optics, throughout every branch of modern optics. >>

Commemorating 30 years of optical vortices: A comprehensive review. 
Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences. Nov 4, 2019.

https://m.phys.org/news/2019-11-commemorating-years-optical-vortices-comprehensive.html

Yijie Shen, Xuejiao Wang, et al. Optical vortices 30 years on: OAM manipulation from topological charge to multiple singularities. Light: Science & Applications volume 8, Article number: 90. Oct 2, 2019.

https://www.nature.com/articles/s41377-019-0194-2


mercoledì 6 novembre 2019

# behav: 'run and tumble' behavior (among bacteria)

<< Bacteria in groundwater move in surprising ways. They can passively ride flowing groundwater, or they can actively move on their own in what scientists call "run and tumble" behavior.  >>

AA << noted a distinct run (movement in one direction) followed by a tumble (a sudden, random change in direction). By calculating the length and timing of these movements, they could develop a simple Continuous Time Random Walk (CTRW) model to predict how the bacteria would move. When compared to current models for bacterial remediation, the CTRW model was better at predicting bacterial transport in many circumstances. The CTRW model is the first step in developing and testing new reactive transport models that incorporate bacterial transport behavior.  >>

Rishi Parashar. Calculating 'run and tumble' behavior of bacteria in groundwater. Environmental Molecular Sciences Laboratory. Oct 31, 2019. 

https://m.phys.org/news/2019-10-behavior-bacteria-groundwater.html  

Xueke Yang, Rishi Parashar, et al. On Modeling Ensemble Transport of Metal Reducing Motile Bacteria. Scientific Reports volume 9, Article number: 14638. Oct 10, 2019. 

https://www.nature.com/articles/s41598-019-51271-0

martedì 5 novembre 2019

# behav: adaptive synchronizations; the tendency to anticipate during auditory rhythms

<< Dancing and playing music require people to coordinate actions with auditory rhythms. In laboratory perception-action coordination tasks, people are asked to synchronize taps with a metronome. When synchronizing with a metronome, people tend to anticipate stimulus onsets, tapping slightly before the stimulus. The anticipation tendency increases with longer stimulus periods of up to 3500ms, but is less pronounced in trained individuals like musicians compared to non-musicians.  >>

Iran R. Roman, Auriel Washburn, et al.  Delayed feedback embedded in perception-action coordination cycles results in anticipation behavior during synchronized rhythmic action: A dynamical systems approach. PLoS Comput Biol 15(10): e1007371. doi: 10.1371/journal.pcbi.1007371. Oct 31, 2019.

https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1007371

Delayed neural communication may underlie anticipatory behaviors. Public Library of Science. Oct 31, 2019.

https://m.phys.org/news/2019-10-neural-underlie-anticipatory-behaviors.html

sabato 2 novembre 2019

# evol: apropos of our origin, the KhoeSan trunk of the human tree

<< Where was the evolutionary birthplace of modern humans? The East African Great Rift Valley has long been the favoured contender – until today. (AA) new research has used DNA to trace humanity’s earliest footsteps to a prehistoric wetland called Makgadikgadi-Okavango, south of the Great Zambezi River. >>

<< KhoeSan have the most diverse mitogenomes of anyone on Earth, which suggests their DNA most closely resembles that of our shared common ancestors. If we all sit on branches of the human family tree, then KhoeSan are the tree's trunk. >>

Vanessa Hayes. Humanity’s birthplace: why everyone alive today can call northern Botswana home. University of Sydney. Oct 28, 2019.

https://theconversation.com/humanitys-birthplace-why-everyone-alive-today-can-call-northern-botswana-home-125814

Eva K. F. Chan, Axel Timmermann, et al.  Human origins in a southern African palaeo-wetland and first migrations. Nature (2019) doi:10.1038/s41586-019-1714-1. Oct 28, 2019.

https://www.nature.com/articles/s41586-019-1714-1    


giovedì 31 ottobre 2019

# gst: spontaneous spin-sliding of volatile drops

<< When a volatile solvent droplet is deposited on a freely floating swellable sheet, it can spontaneously become lobed, asymmetric, and either spin, slide or move via a combination of the two.  This process of symmetry-breaking is a consequence of the solvent droplet swelling the membrane and its inhomogeneous evaporation from the membrane, coupled with the hydrodynamics within the droplet. By tuning the membrane thickness and the droplet size, (AA) find a critical threshold that determines the transition from a quiescent spherical cap state to a self-piloted motile state.>>

Aditi Chakrabarti, Gary P. T. Choi, L. Mahadevan. Spontaneous spin-sliding of volatile drops on swelling sheets. arXiv:1910.07064v1 [cond-mat.soft]  Oct 15, 2019. 

https://arxiv.org/abs/1910.07064   

mercoledì 30 ottobre 2019

# gst: the three-body problem approach using deep neural networks

AA << show that an ensemble of solutions obtained using an arbitrarily precise numerical integrator can be used to train a deep artificial neural network (..) that, over a bounded time interval, provides accurate solutions at fixed computational cost and up to 100 million times faster than a state-of-the-art solver. >>

Philip G. Breen, Christopher N. Foley,  et al. Newton vs the machine: solving the chaotic three-body problem using deep neural networks. arXiv: 1910.07291v1 [astro-ph.GA] Oct 16, 2019

https://arxiv.org/abs/1910.07291

A neural net solves the three-body problem 100 million times faster. By Emerging Technology from the arXiv. 
Oct 26, 2019. 

https://www.technologyreview.com/s/614597/a-neural-net-solves-the-three-body-problem-100-million-times-faster/

Also

keyword "three" in FonT    

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

keyword "three" in Notes      

https://inkpi.blogspot.com/search?q=three


lunedì 28 ottobre 2019

# brain: to test schizophrenia in human hair.

<< MPST gene expression (which leads to hydrogen sulphide production) was higher in postmortem brains from people with schizophrenia than in those from unaffected people. MPST protein levels in these brains also correlated well with the severity of premortem symptoms.  >>

AA << examined hair follicles from more than 150 people with schizophrenia and found that expression of MPST mRNA was much higher than people without schizophrenia. Even though the results were not perfect-indicating that sulfide stress does not account for all cases of schizophrenia-MPST levels in hair could be a good biomarker for schizophrenia before other symptoms appear. >>

<< Nobody has ever thought about a causal link between hydrogen sulfide and schizophrenia, (..) Once we discovered this, we had to figure out how it happens and if these findings in mice would hold true for people with schizophrenia. >> Takeo Toshikawa.

Biomarker for schizophrenia can be detected in human hair. Riken. Oct 28, 2019.

https://medicalxpress.com/news/2019-10-biomarker-schizophrenia-human-hair.html

Masayuki Ide, Tetsuo Ohnishi, et al. 
Excess hydrogen sulfide and polysulfides production underlies a schizophrenia pathophysiology. EMBO Mol Med (2019) e10695. doi: 10.15252/emmm.201910695. Oct 28, 2019.

https://www.embopress.org/doi/full/10.15252/emmm.201910695   


sabato 26 ottobre 2019

# astro: (they) accidentally snap a picture of the beast - lurking in dust - for the first time

<< Astronomers accidentally discovered the footprints of a monster galaxy in the early universe that has never been seen before. Like a cosmic Yeti, the scientific community generally regarded these galaxies as folklore, given the lack of evidence of their existence, but astronomers in the United States and Australia managed to snap a picture of the beast for the first time. >>

<< An open question is exactly how many of them there are. >>

Cosmic Yeti from the dawn of the universe found lurking in dust. University of Arizona. Oct 22, 2019.

https://m.phys.org/news/2019-10-cosmic-yeti-dawn-universe-lurking.html

Christina C. Williams, Ivo Labbe, et al. 
Discovery of a Dark, Massive, ALMA-only Galaxy at z ~ 5–6 in a Tiny 3 mm Survey. The Astrophysical Journal, Volume 884, Number 2. Oct 22, 2019.

https://iopscience.iop.org/article/10.3847/1538-4357/ab44aa   

martedì 22 ottobre 2019

# gst: the transition from quiescent spherical cap states to self-piloted motile states of volatile droplets

<< When a volatile solvent droplet is deposited on a freely floating swellable sheet, it can spontaneously become lobed, asymmetric, and either spin, slide or move via a combination of the two. This process of symmetry-breaking is a consequence of the solvent droplet swelling the membrane and its inhomogeneous evaporation from the membrane, coupled with the hydrodynamics within the droplet. By tuning the membrane thickness and the droplet size, (AA) find a critical threshold that determines the transition from a quiescent spherical cap state to a self-piloted motile state. Simple scaling laws determine the angular and linear velocities of the droplets, and a 1D analog experiment confirms the relative roles of evaporation, swelling and viscoelastic dissipation.  >>

Aditi Chakrabarti, Gary P. T. Choi, L. Mahadevan. Spontaneous spin-sliding of volatile drops on swelling sheets. 
arXiv:1910.07064v1 [cond-mat.soft]. Oct 15, 2019

https://arxiv.org/abs/1910.07064   

Also

keyword 'droplet' in FonT  

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

sabato 19 ottobre 2019

# brain: the 'loosely balanced state' of cerebral cortex

<< Many studies have shown that the excitation and inhibition received by cortical neurons remain roughly balanced across many conditions. A key question for understanding the dynamical regime of cortex is the nature of this balancing. (..) loose balance, but not tight balance, can yield many nonlinear population behaviors seen in sensory cortical neurons, allow the presence of correlated variability, and yield decrease of that variability with increasing external stimulus drive as observed across multiple cortical areas. >>  

<< at least sensory, and perhaps all of, cortex operates in a regime in which the inhibition and excitation neurons receive are loosely balanced. This along with the supralinear input/output function of individual neurons and simple assumptions on connectivity explains a large set of cortical response properties. A key outstanding question is the computational function or functions of this loosely balanced state and the response properties it creates >>

Yashar Ahmadian, Kenneth D. Miller.  What is the dynamical regime of cerebral cortex?  arXiv:1908.10101v2 [q-bio.NC] Aug 28, 2019.   

https://arxiv.org/abs/1908.10101  

giovedì 17 ottobre 2019

# gst: fingerprints of reality (2): the stormquake

AA << find that during large storms such as hurricanes and Nor'easters the interaction of long‐period ocean waves with shallow seafloor features located near the edge of continental shelves, known as ocean banks, excites coherent transcontinental Rayleigh wave packets in the 20 to 50 s period band. These "stormquakes" migrate coincident with the storms, but are effectively spatiotemporally focused seismic point sources with equivalent earthquake magnitudes that can be greater than 3.5. >>

Wenyuan Fan, Jeffrey J. McGuire, et al. Stormquakes. Geophysical Research Letters. Oct 14, 2019.    https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL084217  

Strong storms generating earthquake-like seismic activity. Florida State University. Oct 15, 2019.    https://m.phys.org/news/2019-10-strong-storms-earthquake-like-seismic.html 

Also  

fingerprints of reality: water drops that vibrate, flames that oscillate, and viscous fluids that form rivulets ...

mercoledì 16 ottobre 2019

# gst: counterintuitively, even complex processes can be hidden inside flat power spectra

<< Power spectral densities are a common, convenient, and powerful way to analyze signals. So much so that they are now broadly deployed across the sciences and engineering - from quantum physics to cosmology, and from crystallography to neuroscience to speech recognition. The features they reveal not only identify prominent signal-frequencies but also hint at mechanisms that generate correlation and lead to resonance. Despite their near-centuries-long run of successes in signal analysis, here (AA) show that flat power spectra can be generated by highly complex processes, effectively hiding all inherent structure in complex signals.  >>

P. M. Riechers, J. P. Crutchfield.  Fraudulent White Noise: Flat power spectra belie arbitrarily complex processes.   arXiv:1908.11405v1 [cond-mat.stat-mech] Aug 29, 2019.   https://arxiv.org/abs/1908.11405

martedì 15 ottobre 2019

# ai: the future where machines will test hypotheses on their own

<< Brian Nord imagines a future where machines test hypotheses on their own  (..) Nord has begun applying AI to problems in astronomy, such as identifying unusual astronomical objects known as gravitational lenses. (..)  He spoke to Physics about his recent projects and how he thinks AI, also known as machine learning, will change the way researchers do science. >>

Sophia Chen. Paving A Path for AI in Physics Research.  Physics 12, 108. Oct 3, 2019.    https://physics.aps.org/articles/v12/108  

Also

oops! artificial intelligence will kill self-employment. Oct 4, 2019.   https://flashontrack.blogspot.com/2019/10/ai-life-oops-artificial-intelligence.html

keyword "ai" in FonT:     https://flashontrack.blogspot.com/search?q=ai

lunedì 14 ottobre 2019

# gst: chaotic dynamics modulate complex systems, even in the presence of extrinsic and intrinsic noise

AA << find that chaotic dynamics modulates gene expression and up-regulates certain families of low-affinity genes, even in the presence of extrinsic and intrinsic noise. Furthermore, this leads to an increase in the production of protein complexes and the efficiency of their assembly. Finally, (AA) show how chaotic dynamics creates a heterogeneous population of cell states, and describe how this can be beneficial in multi-toxic environments. >>

Mathias L. Heltberg, Sandeep Krishna, Mogens H. Jensen. On chaotic dynamics in transcription factors and the associated effects in differential gene regulation.  Nature Comm. volume 10, Article number: 71 Jan 8, 2019.   https://www.nature.com/articles/s41467-018-07932-1  

<< Chaos in bodily regulation can optimize our immune system according to a recent discovery made by researchers at the University of Copenhagen's Niels Bohr Institute. The discovery may prove to be of great significance for avoiding serious diseases such as cancer and diabetes.  >>

Chaos in the body tunes up your immune system. Niels Bohr Institute.
Jan 16, 2019.   https://m.medicalxpress.com/news/2019-01-chaos-body-tunes-immune.html

Also

'l'immaginifico "tracciante ... che svagola nella macina ...'    in:  2149 - onda di predazione (to knock seals off the ice). Notes. Dec 17, 2007.    https://inkpi.blogspot.com/2007/12/2149-onda-di-predazione-to-knock-seals.html

Also

never boring with chaos and tit-for-tat theories. F.on.T. Jun 12, 2016.  https://flashontrack.blogspot.com/2016/06/s-gst-never-boring-with-chaos-and-tit.html

sabato 12 ottobre 2019

# gst: exploring the lifespan of a liquid droplet

<< Current theories state that the droplet's diameter-squared decreases in proportion to time (classical law); however, this period only accounts for a small portion of the drop's evolution. As the diameter approaches the unobservable micro- and nano-scale, molecular dynamics have to be used as virtual experiments and these show a crossover to a new behaviour, with the diameter now reducing in proportion to time (nano-scale law). >>

<< It is fascinating that intuition based on everyday observations are a hindrance when attempting to understand nanoscale flows, so that, as in this research, one has to lean on theory to enlighten us. >>  James Sprittles.

The lifespan of an evaporating liquid drop. University of Warwick. Oct 10, 2019.     https://m.phys.org/news/2019-10-lifespan-evaporating-liquid.html

Rana A.S., Lockerby D.A., Sprittles J.E.  Lifetime of a Nanodroplet: Kinetic Effects and Regime Transitions. Phys. Rev. Lett. 123, 154501 Oct 9, 2019.     https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.154501   

venerdì 11 ottobre 2019

# gst: retooling viruses

<< New research reveals that the way viruses were perceived in terms of their architecture will need to be retooled, because they are actually structured in many more patterns than previously understood. The findings could have significant impact on how they are classified, our understanding of how they form, evolve and infect hosts, and strategies to identify ways to design vaccines to target them. >>

Why viruses like Herpes and Zika will need to be reclassified, and its biotech impact. San Diego State University. Sep 27, 2019.    https://www.eurekalert.org/pub_releases/2019-09/sdsu-wvl092519.php  

<<  improved imaging techniques have revealed increasing numbers of viral outliers >>

<< The polyhedral layouts describing the quasiequivalent capsid structures in CK-theory (Caspar, D. L. & Klug, A. theory) also occur in other areas of science, (..) The conceptual framework for the classification of icosahedral and octahedral polyhedral layouts presented here is therefore of interest for a wide range of scientific disciplines beyond virology. >>

Reidun Twarock, Antoni Luque.  Structural puzzles in virology solved with an overarching icosahedral design principle. Nature Comm. volume 10, Article number: 4414 Sep 27, 2019.   https://www.nature.com/articles/s41467-019-12367-3  

martedì 8 ottobre 2019

# gst: a cylindrical solitonlike that collapses into a spherical shape, and, along the filaments, central cores of matter exhibit fuzzies

In AA simulation, << the dark matter filaments show coherent interference patterns on the boson de Broglie scale and develop cylindrical solitonlike cores, which are unstable under gravity and collapse into kiloparsec-scale spherical solitons. Features of the dark matter distribution are largely unaffected by the baryonic feedback. On the contrary, the distributions of gas and stars, which do form along the entire filament, exhibit central cores imprinted by dark matter-a smoking gun signature of FDM ("fuzzy" dark matter). >>

Philip Mocz, Anastasia Fialkov, et al. First Star-Forming Structures in Fuzzy Cosmic Filaments. Phys. Rev. Lett. 123, 141301. Oct 2, 2019.     https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.141301  

Jennifer Chu. This is how a 'fuzzy' universe may have looked. Massachusetts Institute of Technology. Oct 3, 2019       https://m.phys.org/news/2019-10-fuzzy-dark-disrupts-conventional.html   

FonT

intrigante qui come una simulazione di evoluzione cosmologica - filamenti strutturati a cilindro mutanti (collassanti) in strutture sferoidali (ma non a generica fluttuante frittella) formanti, nei filamenti di gas,  serie (sciami?) di kernel a dinamiche fuzzy - possa far immaginare generici contesti altri ...

sabato 5 ottobre 2019

# evol: echolocation, a prime example of convergent evolution

<< Echolocation is a prime example of convergent evolution, the independent gain of similar features in species of different lineages. >>

<< Distantly related species entering similar biological niches often adapt by evolving similar morphological and physiological characters. How much genomic molecular convergence (particularly of highly constrained coding sequence) contributes to convergent phenotypic evolution, such as echolocation in bats and whales, is a long-standing fundamental question.  >>

AA << find that the gene set most overrepresented (q-value = 2.2e-3) with convergent substitutions in echolocators, affecting 18 genes, regulates development of the cochlear ganglion, a structure with empirically supported relevance to echolocation. >>

Amir Marcovitz, Yatish Turakhia, et al. A functional enrichment test for molecular convergent evolution finds a clear protein-coding signal in echolocating bats and whales.
PNAS doi: 10.1073/pnas.1818532116   Sep 30, 2019    https://www.pnas.org/content/early/2019/09/27/1818532116 

Krista Conger. Scientists uncover genetic similarities among species that use sound to navigate. Stanford University Medical Center. Oct 4, 2019.   https://m.phys.org/news/2019-10-scientists-uncover-genetic-similarities-species.html

venerdì 4 ottobre 2019

# ai life: oops! artificial intelligence will kill self-employment

<< People who are self-employed in some of the lowest paid and most popular jobs are at the greatest risk of being displaced by artificial intelligence (AI), according to new research from the School of Management. Recently published by the Center for Research on Self-Employment, the study found that with both self-employment and AI investment on the rise, independent sales people, drivers, and agriculture and construction workers are in the greatest danger of having their jobs computerized because the work is routine and low in technical expertise. >>

Kevin Manne. How artificial intelligence will impact self-employment. University at Buffalo.  Oct 1, 2019.  

https://m.phys.org/news/2019-10-artificial-intelligence-impact-self-employment.html  

http://www.buffalo.edu/ubnow/stories/2019/10/ai-self-employment.html    

FonT

tutto cio' in prima approx; in seconda e terza approx anche tutte le altre professioni saranno 'coperte' da intelligenza artificiale, anche quelle ad elevata professionalita', e' solo questione di tempo. Paradossalmente non poche professioni che necessitano  elevato livello cognitivo (e accademico) potrebbero essere 'duplicate' da autonome AI anche prima di altre considerate di livello inferiore ...

giovedì 3 ottobre 2019

# gst: a kick-like behaviour may emerge from a crossed over superexponential self-interacting oscillator dynamics

<< Opposite to standard oscillators such as the (an-)harmonic oscillator the SSO (superexponential self-interacting oscillator) combines both scattering and confined periodic motion with an exponentially varying nonlinearity. The SSO potential exhibits a transition point with a hierarchy of singularities of logarithmic and power law character leaving their fingerprints in the agglomeration of its phase space curves. The period of the SSO consequently undergoes a crossover from decreasing linear to a nonlinearly increasing behaviour when passing the transition energy. (AA) explore its dynamics and show that the crossover involves a kick-like behaviour. >>

Peter Schmelcher. Superexponential Self-Interacting Oscillator.  arXiv: 1909.09792v1 [physics.class-ph] Sep 21, 2019.   https://arxiv.org/abs/1909.09792 

mercoledì 2 ottobre 2019

# gst: approaching the automorphism groupoid of a groupoid

AA << construct two groupoids from morphisms of groupoids, with one from a categorical viewpoint and the other from a geometric viewpoint. (AA) show that for each pair of groupoids, the two kinds of groupoids of morphisms are equivalent. Then (AA) study the automorphism groupoid of a groupoid. >>

Bohui Chen, Cheng-YongDu, et al. The groupoid structure of groupoid morphisms. J of Geometry and Physics Vol 145 doi: 10.1016/j.geomphys.2019.103486  Aug 12,  2019.     https://www.sciencedirect.com/science/article/pii/S0393044019301676

Also

"groupoid" in: https://en.m.wikipedia.org/wiki/Groupoid  

martedì 1 ottobre 2019

# game: mutual cooperation without non-cooperative actions

AA << have developed a model that consists of all possible strategies using a one-period memory of past actions. This model enables us to analyze a "melting pot" of strategies, wherein several strategies interact and compete with each other. (AA) results revealed that one strategy, in which one escapes if a partner defects or cooperates if a partner becomes a loner, dominates and maintains cooperation in an alternating prisoner's dilemma game. >>

H. Yamamoto, I. Okada, et al.
Effect of voluntary participation on an alternating and a simultaneous prisoner's dilemma.  Phys. Rev. E 100, 032304 Sep 11,  2019.    https://journals.aps.org/pre/abstract/10.1103/PhysRevE.100.032304   

The Prisoner's Dilemma: Exploring a strategy that leads to mutual cooperation without non-cooperative actions. Rissho University. Sep 23, 2019.   https://m.phys.org/news/2019-09-prisoner-dilemma-exploring-strategy-mutual.html   

Also

keyword "game" in "FonT"   https://flashontrack.blogspot.com/search?q=game

giovedì 26 settembre 2019

# life: the generation of multiple bubbles mediated by gerrymandering could self trapped in deadlock

AA << analysis provides an account of the vulnerabilities of collective decision-making to systematic distortion by restricted information flow. >>

The analysis << also highlights a group-level social dilemma: information gerrymandering can enable one party to sway decisions in its favour, but when multiple parties engage in gerrymandering the group loses its ability to reach consensus and remains trapped in deadlock. >>

Alexander J. Stewart, Mohsen Mosleh, et al. Information gerrymandering and undemocratic decisions. Nature. volume 573, pages 117–121 Sep 4,  2019.     https://www.nature.com/articles/s41586-019-1507-6    

Alexander J. Stewart, Joshua B. Plotkin. Here’s what happens when political bubbles collide. Sep 4, 2019.     https://theconversation.com/heres-what-happens-when-political-bubbles-collide-121856  

Also

keyword "bubble" in: FonT  https://flashontrack.blogspot.com/search?q=bubble

Also

<< dell' ombre a bolle di neurodiscoide di ghiozzo >> in: 1813b - alea in psichedelico catino.  https://inkpi.blogspot.com/2005/03/1813b-alea-in-psichedelico-catino.html

martedì 24 settembre 2019

# gst: apropos of weak bonds, hydrophobic cohesion to stabilize the double helix of DNA

<< The main stabilizer of the DNA double helix is not the base-pair hydrogen bonds but coin-pile stacking of base pairs, whose hydrophobic cohesion, requiring abundant water, indirectly makes the DNA interior dry so that hydrogen bonds can exert full recognition power. (..) (AA) speculate that hydrophobic catalysis is a general phenomenon in DNA enzymes. >>

<< The forces that stabilize the DNA double helix are a prerequisite for the secure storage of genetic information but their modest strength is also necessary for the efficient processes of replication, transcription, recombination, and repair systems-wherein thermal fluctuations, or "breathing," play an important role >>

Bobo Feng, Robert P. Sosa, et al. Hydrophobic catalysis and a potential biological role of DNA unstacking induced by environment effects. PNAS.  116 (35) 17169-17174; Aug 27, 2019.  doi: 10.1073/ pnas.1909122116.    https://www.pnas.org/content/116/35/17169

DNA is held together by hydrophobic forces. Chalmers University of Technology. Sep 23, 2019.     https://m.phys.org/news/2019-09-dna-held-hydrophobic.html   

lunedì 23 settembre 2019

# gst: the hypothesis of a first order phase transition (a type of abrupt phase transition) to originate black holes observed by LIGO/Virgo in binary mergers.

<<  To summarize, motivated by the ~10 M* (mass similar to that of the sun) black holes observed by LIGO/Virgo in binary mergers, (AA) entertained the possibility that the quark-gluon confinement phase transition was first order due to the effect of 6 light quarks. The larger number of light quarks, compared to the standard case, pushes the transition temperature below ∼100 MeV. The first order nature of the transition significantly improves the likelihood of forming primordial black holes and its lower temperature suggests that these black holes can potentially be as heavy as ∼10 M*, compared to ∼M* for the standard QCD transition. >>

Hooman Davoudiasl.  LIGO/Virgo Black Holes from a First Order Quark Confinement Phase Transition. Phys. Rev. Lett. 123, 101102. Sep 6, 2019.   https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.101102  

Ingrid Fadelli. Theory proposes that LIGO/Virgo black holes originate from a first order phase transition. Sep 23, 2019.    https://m.phys.org/news/2019-09-theory-ligovirgo-black-holes-phase.html  

QCD = quantum chromodynamic  
https://en.m.wikipedia.org/wiki/Standard_Model

sabato 21 settembre 2019

# gst: dealing with bistability (through hyperbolic paraboloid origami)

<< Origami offers an avenue to program three-dimensional shapes via scale-independent and non-destructive fabrication. >>

Using theoretical model, << which connects geometry to mechanics, (AA) prove that a folded hypar origami exhibits bistability between two symmetric configurations. Further, (AA) tessellate the hypar origami and harness its bistability to encode multi-stable metasurfaces with programmable non-Euclidean geometries. >>

Ke Liu, Tomohiro Tachi, Glaucio H. Paulino. Invariant and smooth limit of discrete geometry folded from bistable origami leading to multistable metasurfaces. Nature Comm. volume 10, Article number: 4238, 17 Sep 17, 2019.    https://www.nature.com/articles/s41467-019-11935-x  

Josh Brown. Hyperbolic paraboloid origami harnesses bistability to enable new applications. Georgia Institute of Technology. Sep 17, 2019.    https://m.techxplore.com/news/2019-09-hyperbolic-paraboloid-origami-harnesses-bistability.html 

domenica 15 settembre 2019

# astro: test the 'no-hair' hypothesis on coalescent black holes (at the ~ 10% or ~ 20% levels)

<< Agreement between the postinspiral measurements of mass and spin and those using the full waveform supports the hypothesis that the GW150914 merger produced a Kerr black hole, as predicted by general relativity, and provides a test of the no-hair theorem at the ∼10% level. An independent measurement of the frequency of the first overtone yields agreement with the no-hair hypothesis at the ∼20% level.  >>

Maximiliano Isi, Matthew Giesler, et al. Testing the No-Hair Theorem with GW150914. Phys. Rev. Lett. 123, 111102. Sep 12, 2019.    https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.111102

Synopsis: Hunting for Hair on Coalescing Black Holes. A fresh look at data from the first detected black-hole merger supports the “no hair” theorem.  Sep 12, 2019.   https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.123.111102

'No-hair' theorem   https://en.m.wikipedia.org/wiki/No-hair_theorem

Kerr black hole   https://en.m.wikipedia.org/wiki/Rotating_black_hole

sabato 14 settembre 2019

# gst: nano entities that are both twisted and untwisted at the same time

<< Scientists who study the nanoscale-with molecules and materials 10,000 smaller than a pinhead-need to be able to test the way that some molecules twist, known as their chirality, because mirror image molecules with the same structure can have very different properties. >>

<< Recently, a new class of nanoscale materials have been developed to help distinguish the chirality of molecules. These so-called 'nanomaterials' usually consist of tiny twisted metal wires, that are chiral themselves. However, it has become very hard to distinguish the twist of the nanomaterials from the twist of the molecules they are supposed to help study. >>

To solve this problem AA << created a nanomaterial that is both twisted and it is not. This nanomaterial has equal number of opposite twists—meaning they cancel each other out.  >>

<< Using a mathematical analysis of the material's symmetry properties, the team discovered a few special cases, which can bring the 'hidden' twist to light and allow very sensitive detection of chirality in molecules. >>

Chris Melvin. Scientists create a nanomaterial that is both twisted and untwisted at the same time. University of Bath. Sep 13, 2019   https://m.phys.org/news/2019-09-scientists-nanomaterial-untwisted.html  

Christian Kuppe,  Xuezhi Zheng, et al. Measuring optical activity in the far-field from a racemic nanomaterial: diffraction spectroscopy from plasmonic nanogratings. Nanoscale Horizons.  Issue 5, 2019.  doi: 10.1039/C9NH00067D.   https://pubs.rsc.org/en/content/articlelanding/2019/NH/C9NH00067D

mercoledì 11 settembre 2019

# gst: apropos to try numerically to discover states with desired response properties in chaotic (i.e. normal - ab.normal) systems, by Hridesh, Deng, Jean-Jacques, Jeremy.

  <<
Systems with many stable configurations abound in nature, both in living and inanimate matter. Their inherent nonlinearity and sensitivity to small perturbations make them challenging to study, particularly in the presence of external driving, which can alter the relative stability of different attractors. Under such circumstances, one may ask whether any clear relationship holds between the specific pattern of external driving and the particular attractor states selected by a driven multistable system. To gain insight into this question, (AA)  numerically study driven disordered mechanical networks of bistable springs which possess a vast number of stable configurations arising from the two stable rest lengths of each spring, thereby capturing the essential physical properties of a broad class of multistable systems.  (AA) find that the attractor states of driven disordered multistable mechanical networks are fine-tuned with respect to the pattern of external forcing to have low work absorption from it. Furthermore,  (AA)  find that these drive-specific attractor states are even more stable than expected for a given level of work absorption.  (AA)  results suggest that the driven exploration of the vast configuration space of these systems is biased towards states with exceptional relationship to the driving environment, and could therefore be used to 'discover' states with desired response properties in systems with a vast landscape of diverse configurations.
  >>

Hridesh Kedia, Deng Pan, et al. Drive-specific adaptation in disordered mechanical networks of bistable springs. arXiv:1908.09332v1 [nlin.AO] Aug 25, 2019.    https://arxiv.org/abs/1908.09332 

Also

keyword "three" in: FonT    https://flashontrack.blogspot.com/search?q=three

keyword "three" in: Notes      https://inkpi.blogspot.com/search?q=three

sabato 7 settembre 2019

# gst: leading to an order-disorder transition to design of decentralized swarm systems.

<< Adaptive collective behavior underpinned by specialized optimization strategies is ubiquitous in the natural world. (AA) develop a minimal model of agents that explore their environment by means of sampling trajectories. (..) (They) find that, as cognitive agents build and update their internal, cognitive representation of the causal structure of their environment, complex patterns emerge in the system (..) Exchange of information among the agents leads to an order-disorder transition. As a result of the spontaneous breaking of translational symmetry, a Goldstone mode emerges, which points at a collective mechanism of information transfer >>

Hannes Hornischer, Stephan Herminghaus, Marco G. Mazza. Structural transition in the collective behavior of cognitive agents. Scientific Reports. volume 9, Article number: 12477 (2019).   https://www.nature.com/articles/s41598-019-48638-8 

Nature's most beautiful performances could inspire the next generation of artificial intelligence. Loughborough University. Sep 6, 2019.    https://m.techxplore.com/news/2019-09-nature-beautiful-artificial-intelligence.html  

venerdì 6 settembre 2019

# gst: apropos of swirling granular media, a geometric frustration; will these entities turn left or right?

<< Granular material in a swirled container exhibits a curious transition as the number of particles is increased: At low densities, the particle cluster rotates in the same direction as the swirling motion of the container, while at high densities it rotates in the opposite direction.  >>

AA << show that the transition to counterrotation is friction dependent. At high particle densities, frictional effects result in geometric frustration, which prevents particles from cooperatively rolling and spinning. Consequently, the particle cluster rolls like a rigid body with no-slip conditions on the container wall, which necessarily counterrotates around its own axis. Numerical simulations verify that both wall-disk friction and disk-disk friction are critical for inducing counterrotation. >>

Lisa M. Lee, John Paul Ryan, et al. Geometric frustration induces the transition between rotation and counterrotation in swirled granular media. Phys. Rev. E 100, 012903. July 8, 2019.     https://journals.aps.org/pre/abstract/10.1103/PhysRevE.100.012903  

Leah Burrows. Solving the pancake problem. Harvard University. Aug 30, 2019.    https://m.phys.org/news/2019-08-pancake-problem.html  

giovedì 5 settembre 2019

# game: exploitation; a theoretical scenario in which victims (chaotically?) will cooperate

<< A new analysis of the famous game-theory puzzle finds that even when the players seem equal, one can learn to profit at the other’s expense-and the victim will cooperate. >>

Prisoner’s dilemma shows exploitation is a basic property of human society. Emerging Technology from the arXiv. May 30, 2019.

https://www.technologyreview.com/s/613585/prisoners-dilemma-shows-how-exploitation-is-a-basic-property-of-human-society/  

Yuma Fujimoto, Kunihiko Kaneko.  Emergence of Exploitation as Symmetry Breaking in Iterated Prisoner's Dilemma. arXiv: 1905.06602v1 [math.OC] May 16, 2019.

https://arxiv.org/abs/1905.06602  

lunedì 2 settembre 2019

# geo gst: even small flank failures can cause large tsunamis

<< Volcanogenic tsunamis are one of the deadliest volcanic phenomena. >>

<< Small flank failures causing large tsunamis represent a vastly underappreciated geohazards-current tsunami monitoring systems do not monitor for this kind of volcanic activity, instead focusing on large earthquakes or proxies related to unusual increases in magma intrusion.  >>

<< This collapse was captured in unprecedented detail by satellite remote sensing, providing an opportunity to understand the collapse of the volcano (Anak Krakatau volcano,  Indonesia) in a way that has not previously been possible at any volcanic island in the world. >>

Reconstructing the Anak Krakatau flank collapse that caused the December 2018 Indonesian tsunami. Geological Society of America. Aug 30, 2019.   https://m.phys.org/news/2019-08-reconstructing-anak-krakatau-flank-collapse.html   

<< the volume of material initially lost from the volcano flank failure (..) was relatively small (~0.1 km3) compared to the overall changes observed during the entire eruption, but it was nonetheless able to generate rapid tsunami waves with devastating impacts. The flank failure also changed the eruption style and the upper volcanic plumbing system, with the subsequent explosive eruptions destroying the summit and then partially rebuilding the lost flank.  >>

Rebecca Williams, Pete Rowley, Matthew C. Garthwaite. Reconstructing the Anak Krakatau flank collapse that caused the December 2018 Indonesian tsunami. Geology. doi.org/10.1130/G46517.1. Aug 30, 2019.    https://pubs.geoscienceworld.org/gsa/geology/article-abstract/573356/reconstructing-the-anak-krakatau-flank-collapse

giovedì 29 agosto 2019

# bot: here you can imagine a scenery where tiny bots jump & wing-flapping

AA << have recently designed two insect-scale microbots, one that jumps and another that flaps its artificial wings. These robot designs, (..) mimic real biological behaviors observed in insects. >>

Ingrid Fadelli. New designs for jumping and wing-flapping microrobots. Phys.org. Aug 28, 2019.    https://m.techxplore.com/news/2019-08-wing-flapping-microrobots.html 

Palak Bhushan, Claire Tomlin. An Insect-scale Untethered Laser-powered Jumping Microrobot.  arXiv:1908.03282v1 [cs.RO]  Aug 8,  2019.    https://arxiv.org/abs/1908.03282  

Palak Bhushan, Claire Tomlin. Design of the first sub-milligram flapping wing aerial vehicle.  arXiv:1908.03203v1 [cs.RO] Aug 9, 2019.   https://arxiv.org/abs/1908.03203  

mercoledì 28 agosto 2019

# gst: the creation of giant bubbles is underappreciated in sci res

<< In the pantheon of scientific achievement, the creation of giant soap bubbles is sadly underappreciated. >>

<< "How are such large films created, and how do they remain stable?" ask Frazier (Stephen Frazier) and co. >>

The chemistry behind how you make a record-breaking giant soap bubble.
The art of creating giant bubbles is more mysterious than it seems, but researchers are at last teasing apart the chemistry of thin soapy films. Emerging Technology from the arXiv.  Aug 24, 2019.  
https://www.technologyreview.com/s/614181/the-chemistry-behind-how-you-make-a-record-breaking-giant-soap-bubble/      

https://twitter.com/techreview/status/1166167505246871552

Stephen Frazier, Xinyi Jiang, Justin C. Burton. How to make a giant bubble.
arXiv:1908.00537v1 [physics.flu-dyn] Aug 1, 2019. 

https://arxiv.org/abs/1908.00537

FonT

a proposito di generica "creation of giant bubbles", una entita' AI, anche di "media forza", opportunamente orientata per le pulsioni sperimentali, ci giochera' alla grande, io penso ...

Anomalous formation of molecules after vapor deposition. FonT. Dec 31, 2015.   

https://flashontrack.blogspot.com/2015/12/rmx-s-gst-anomalous-formation-of.html

lunedì 26 agosto 2019

# gst: the hypothesis to optimize multiplicative noise to enhance a signal-to-noise ratio

AA << study simple integrate-and-fire type models with multiplicative noise and consider the transmission of a weak and slow signal, >>

<< The specific question of interest is whether and how the state-dependence of the noise can be optimized with respect to information transmission >>

<< also in a biophysically more relevant situation, multiplicative noise can enhance the signal-to-noise ratio (..) results shed light on a so far unexplored aspect of stochastic signal transmission in neural systems. >>

Jonathan Bauermann Benjamin Lindner. Multiplicative noise is beneficial for the transmission of sensory signals in simple neuron models. Biosystems. Volume 178, Apr 2019, Pages 25-31. doi: 10.1016/ j.biosystems.2019.02.002

https://www.sciencedirect.com/science/article/pii/S0303264718303861

sabato 24 agosto 2019

# gst: active drops: from steady to chaotic self-propulsion

<< Individual chemically active drops suspended in a surfactant solution were observed to self-propel spontaneously with straight, helical, or chaotic trajectories. (..) strong advection (e.g., large droplet size) may destabilize a steadily self-propelling drop; once destabilized, the droplet spontaneously stops and a symmetric extensile flow emerges. If advection is strengthened even further in comparison with molecular diffusion, the droplet may perform chaotic oscillations. >>

Matvey Morozov, Sebastien Michelin. Nonlinear dynamics of a chemically-active drop: From steady to chaotic self-propulsion. J. Chem. Phys. 150, 044110 (2019). doi: 10.1063/1.5080539. Jan 31, 2019.  https://aip.scitation.org/doi/10.1063/1.5080539



venerdì 23 agosto 2019

# evol: when the dinosaurs died, lichens thrived ...

AA << results imply that multiple historical events during the transition from Mesozoic to Cenozoic eras, including the K-Pg mass extinction event, impacted the evolutionary dynamics in lichen-forming fungi. >>

Jen-Pan Huang, Ekaphan Kraichak, et al.   Accelerated diversifications in three diverse families of morphologically complex lichen-forming fungi link to major historical events. Scientific Reports.  volume 9, Article number: 8518 (2019).   https://www.nature.com/articles/s41598-019-44881-1  

<< We thought that lichens would be affected negatively, but in the three groups we looked at, they seized the chance and diversified rapidly, (..) Some lichens grow sophisticated 3D structures like plant leaves, and these ones filled the niches of plants that died out. >> Jen-Pang Huang.

When the dinosaurs died, lichens thrived. Mass extinction hurt land plants, but DNA shows that some fungus/plant combo organisms rose up. Field Museum, Academia Sinica, Taipei.  - ScienceDaily. Jun 28, 2019.   https://www.sciencedaily.com/releases/2019/06/190628120432.htm

K-Pg mass extinction event   https://en.m.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event

mercoledì 21 agosto 2019

# gst: tracking tiny particles

<< Kymographs are graphical representations of spatial position over time, which are often used in biology to visualise the motion of fluorescent particles, molecules, vesicles, or organelles moving along a predictable path. >>

AA << developed KymoButler, a Deep Learning-based software to automatically track dynamic processes in kymographs. (They) demonstrate that KymoButler performs as well as expert manual data analysis on kymographs with complex particle trajectories from a variety of different biological systems. >>

Maximilian AH Jakobs, Andrea Dimitracopoulos, Kristian Franze.  KymoButler, a deep learning software for automated kymograph analysis.
eLife. doi: 10.7554/eLife.42288.  Aug 13, 2019.  https://elifesciences.org/articles/42288

<< We hope our tool will prove useful for others involved in analysing small particle movements, whichever field they may work in, >> Kristian Franze

Machine learning tool improves tracking of tiny moving particles. eLife. Aug 13, 2019.   https://m.techxplore.com/news/2019-08-machine-tool-tracking-tiny-particles.html 

mercoledì 14 agosto 2019

# game: inject irrationality into a game scenario; when a player will be their own worst enemy

<< in game theory, a game is defined as any type of scenario where there's an interaction between different decision-makers, or players, each of whom has well-defined preferences. >>

<< previous analyses assume the decision-makers always do what is best for them-they are fully rational-which is not always realistic. >>

<< So SFI Professor David Wolpert and economist Justin Grana, a former SFI postdoctoral scholar, wanted to inject some humanity into the players. They analyzed games with players who were subject to error, or "boundedly rational." >>

<< Our analysis shows that in many of these situations, a player will be their own worst enemy; >> David Wolpert.

Jenna Marshall. How much would you pay to change a game before playing it? Santa Fe Institute. Aug13, 2019.    https://m.phys.org/news/2019-08-game.html  

David Wolpert, Justin Grana. How Much Would You Pay to Change a Game before Playing It? Entropy 2019, 21, 686. doi: 10.3390/ e21070686. July 13, 2019.   https://www.mdpi.com/1099-4300/21/7/686  

martedì 13 agosto 2019

# gst: early seismic waves could allow to glimpse the power of the main temblor

AA << explore databases of earthquake source time functions and find that they are composed of distinct peaks that (..) call subevents (..) the main event magnitude can be estimated after observing only the first few subevents. >>

Philippe Danre, Jiuxun Yin, et al. Earthquakes Within Earthquakes: Patterns in Rupture Complexity. Geophysical Research Letters. Volume 46, Issue 13. doi: 10.1029/ 2019GL083093. Jun 25, 2019.   https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL083093

Anna Fiorentino. Early seismic waves hold the clue to the power of the main temblor. Harvard University. Aug 8, 2019.  https://m.phys.org/news/2019-08-early-seismic-clue-power-main.html  

lunedì 12 agosto 2019

# gst: an approach to delay solitary states within complex networks

AA << present a technique to engineer solitary states by means of delayed links in a network of neural oscillators and in coupled chaotic maps. Solitary states are intriguing partial synchronization patterns, where a synchronized cluster coexists with solitary nodes displaced from this cluster and distributed randomly over the network. >>

<< It is shown that the extent of displacement and the position of solitary elements can be completely controlled by the choice (values) and positions (locations) of the incorporated delays, reshaping the delay engineered solitary states in the network. >>

Leonhard Schulen, Saptarshi Ghosh, et al. Delay engineered solitary states in complex networks. arXiv:1908.01295v1 [nlin.AO] Aug 4, 2019.

https://arxiv.org/abs/1908.01295

sabato 10 agosto 2019

# behav: the sophisticated dance of the sulphur-crested cockatoo (Cacatua galerita eleonora)

<< Spontaneous movement to music occurs in every human culture and is a foundation of dance. This response to music is absent in most species (including monkeys), yet it occurs in parrots, perhaps because they (like humans, and unlike monkeys) are vocal learners whose brains contain strong auditory–motor connections, conferring sophisticated audiomotor processing abilities. >>

AA << report that a sulphur-crested cockatoo (Cacatua galerita eleonora) responds to music with remarkably diverse spontaneous movements employing a variety of body parts, and suggest why parrots share this response with humans.  >>

R. Joanne Jao Keehn, John R. Iversen, et al. Spontaneity and diversity of movement to music are not uniquely human. Current Biology. Volume 29, Issue 13, PR621-R622. doi: 10.1016/j.cub.2019.05.035. Jul 08, 2019.   https://www.cell.com/current-biology/fulltext/S0960-9822(19)30604-9  

Ed Yong. Not a Human, but a Dancer. What Snowball the parrot’s spontaneous moves teach us about ourselves. Jul 8, 2019   https://www.theatlantic.com/science/archive/2019/07/what-snowball-dancing-parrot-tells-us-about-dance/593428/   

Also

"Dance", in "Notes"

https://inkpi.blogspot.com/search?q=dance

"Dance", in "FonT"

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

venerdì 9 agosto 2019

# life: a case of extreme swing (2): "and we will or (vice versa) we won’t"

<< "This is formal impeachment proceedings," Nadler (Jerry Nadler) said in a CNN interview. "We are investigating all the evidence, gathering the evidence. And we will [at the] conclusion of this - hopefully by the end of the year - vote to vote articles of impeachment to the House floor. Or we won’t. That’s a decision that we’ll have to make. But that’s exactly the process we’re in right now." >>

Andrew Desiderio. Nadler: "This is formal impeachment proceedings". Politico. Aug 8, 2019    https://www.politico.com/story/2019/08/08/nadler-this-is-formal-impeachment-proceedings-1454360   

Also

a case of extreme swing: clearly "He is not not" or vice versa "He is yes yes" . FonT. May 30, 2019.    https://flashontrack.blogspot.com/2019/05/life-case-of-extreme-swing-clearly-is.html

giovedì 8 agosto 2019

# behav: acceptance into non-natal groups of Barbary macaques, showing concern and consolation

Such observations << challenges concerns that only infants and young juveniles may be accepted into non-natal groups, suggesting that even older confiscated juveniles could be candidates for release. This also adds to the literature on behavioural responses to distressed and injured individuals, demonstrating the capacity of wild monkeys to exhibit affiliative behaviours even towards unfamiliar distressed conspecifics, providing a rare example of potential consolation of an unknown individual.  >>

Liz A. D. Campbell. Fostering of a wild, injured, juvenile by a neighbouring group: implications for rehabilitation and release of Barbary macaques confiscated from illegal trade. Primates.  Volume 60, Issue 4, pp 339–345. Jul 2019.    https://link.springer.com/article/10.1007%2Fs10329-019-00729-w   

Unprecedented display of concern and 'consolation' toward an unknown monkey offers hope for endangered macaques. University of Oxford. Jul 10, 2019.   https://m.phys.org/news/2019-07-unprecedented-consolation-unknown-monkey-endangered.html  

mercoledì 7 agosto 2019

# game: 'pulsing' Parrondo to jump (and win) between two losing games

<< Parrondo’s paradox, in which losing strategies can be combined to produce winning outcomes, has received much attention in mathematics and the physical sciences; >>

<< In this review paper, the authors examine a large range of recent developments of Parrondo’s paradox in biology, across ecology and evolution, genetics, social and behavioral systems, cellular processes, and disease. >>

Kang Hao Cheong, Jin Ming Koh, Michael C. Jones. Paradoxical Survival: Examining the Parrondo Effect across Biology. BioEssays. Volume 41, Issue 6. doi: 10.1002/bies.201900027. May 27,  2019.   https://onlinelibrary.wiley.com/doi/abs/10.1002/bies.201900027  

Paradoxical Survival: Examining the Parrondo effect across biology. Singapore University of Technology and Design. Aug 5, 2019.   https://www.sciencedaily.com/releases/2019/08/190805134043.htm 

Also

"Parrondo" in: "Notes" & "FonT"

https://inkpi.blogspot.com/search?q=parrondo

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

venerdì 2 agosto 2019

# gst: dissolve into randomness, the kinetics

AA << have developed mathematical tools that send that shot across the bow-they determine when randomness emerges in any stochastic (random) system, answering a long-standing question: When does randomness set in during a random walk? >>

<< We are trying to describe an effect as exactly as possible irrespective of the cause. >> Rajan K. Chakrabarty

<< physicists normally solve problems by mathematically describing a cause and effect and marrying the two for a solution. But this new tool cares nothing about the cause, only about mathematically capturing the effect. >>

Tony Fitzpatrick. New tools reveal prelude to chaos. Washington University in St. Louis. Jun 6, 2018

https://m.phys.org/news/2018-06-tools-reveal-prelude-chaos.html  

Pai Liu, William R. Heinson, et al. Establishing the kinetics of ballistic-to-diffusive transition using directional statistics. Phys. Rev. E 97, 042102. Apr 4, 2018.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.97.042102  

giovedì 1 agosto 2019

# ecol: a umbrella coordination; the Stratospheric Controlled Perturbation Experiment (SCoPEx)

<<  Researchers plan to spray sunlight-reflecting particles into the stratosphere, an approach that could ultimately be used to quickly lower the planet’s temperature. >>

<< The idea is simple: spray a bunch of particles into the stratosphere, and they will cool the planet by reflecting some of the Sun’s rays back into space. >>

<< The first phase - a US$3-million test involving two flights of a steerable balloon 20 kilometres above the southwest United States — could launch as early as the first half of 2019. Once in place, the experiment would release small plumes of calcium carbonate, each of around 100 grams, roughly equivalent to the amount found in an average bottle of off-the-shelf antacid. The balloon would then turn around to observe how the particles disperse. >>

<< The SCoPEx team’s initial stratospheric experiments will focus on calcium carbonate, which is expected to absorb less heat than sulfates and to have less impact on ozone. But textbook answers - and even Dai’s (Zhen Dai) tabletop device - can’t capture the full picture. “We actually don’t know what it would do, because it doesn’t exist in the stratosphere,” Keutsch (Frank Keutsch) says. “That sets up a red flag.” >>

Jeff Tollefson. First sun-dimming experiment will test a way to cool Earth. Nature. Nov 27, 2018; Correction Nov 30, 2018.   https://www.nature.com/articles/d41586-018-07533-4  

<< SCoPEx is a scientific experiment to advance understanding of stratospheric aerosols that could be relevant to solar geoengineering. >>

SCoPEx. Stratospheric Controlled Perturbation Experiment. Keutsch Research Group. Harvard University. 12 Oxford Street. Cambridge, MA 02138   https://projects.iq.harvard.edu/keutschgroup/scopex

mercoledì 31 luglio 2019

# web: multitudes under hypothetical conditioning; trolls and bots in social media.

<< Trolls and bots have a huge and often unrecognized influence on social media. They are used to influence conversations for commercial or political reasons. They allow small hidden groups of people to promote information supporting their agenda and a large scale. They can push their content to the top of people’s news feeds, search results, and shopping carts. Some say they can even influence presidential elections. >>

<< Trolls are dangerous online because it’s not always obvious when you are being influenced by them or engaging with them. >>

<< Bots are computer programs posing as people. They can amplify the effect of trolls by engaging or liking their content en masse, or by posting their own content in an automated fashion. They will get more sophisticated and harder to detect in the future. Bots can now create entire paragraphs of text in response to text posts or comments. >>

Jason Skowronski. Trolls and bots are disrupting social media - here’s how AI can stop them (Part 1). Jul 30, 2019.   https://towardsdatascience.com/trolls-and-bots-are-disrupting-social-media-heres-how-ai-can-stop-them-d9b969336a06   

Jason Skowronski. Identifying trolls and bots on Reddit with machine learning (Part 2). Jul 30, 2019.  https://towardsdatascience.com/identifying-trolls-and-bots-on-reddit-with-machine-learning-709da5970af1 

Also

Notes. 2151 - a voting machine (to explain precisely). Jan 15, 2008.   https://inkpi.blogspot.com/2008/01/2151-voting-machine-to-explain.html