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sabato 26 agosto 2017

# gst: modeling around the edge of a crack

<< It is said that a weak link determines the strength of the entire chain. Likewise, defects or small cracks in a solid material may ultimately determine the strength of that material – how well it will withstand various forces >>

<< What, exactly, happens right around the edge of the crack, in the area in which those large stresses are concentrated? >>

The Breaking Point. What happens at the moving edge of crack? Aug 23, 2017

https://wis-wander.weizmann.ac.il/chemistry/breaking-point

https://www.sciencedaily.com/releases/2017/08/170823094054.htm

AA << show that cracks undergo an oscillatory instability controlled by small-scale, near crack-tip, elastic nonlinearity. This instability occurs above an ultrahigh critical velocity and features an intrinsic wavelength proportional to the ratio of the fracture energy to the elastic modulus (..) This ratio emerges as a fundamental scaling length assumed to play no role in the classical theory of cracks, but shown here to strongly influence crack dynamics >>

Chih-Hung Chen, Eran Bouchbinder & Alain Karma. Instability in dynamic fracture and the failure of the classical theory of cracks. Nature Physics doi: 10.1038/nphys4237 Publ. Aug 21, 2017

https://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys4237.html

venerdì 25 agosto 2017

# trade: the national cryptocurrency 'estcoin' by Kaspar, the begin?

<< In a Tuesday blog post, Kaspar Korjus, the managing director of the e-Residency program, said this experience gave Estonia an edge over other countries that are considering the introduction of national cryptocurrencies. Indeed, the estcoin could become bound up with the rest of the e-Residency ecosystem >>

David Meyer. This Country May Launch Its Own Virtual Currency. Aug 23, 2017

http://amp.timeinc.net/fortune/2017/08/22/estonia-estcoin-digital-currency/

Estonia could offer ‘estcoins’ to e-residents. The proposal to issue crypto tokens would make the Republic of Estonia the first country with an Initial Coin Offering (ICO). Aug 22, 2017

https://medium.com/e-residency-blog/estonia-could-offer-estcoins-to-e-residents-a3a5a5d3c894

also:

# e-ai: an intriguing hypothesis: cheating that system will become near impossible

http://flashontrack.blogspot.it/2017/06/e-ai-intriguing-hypothesis-cheating.html

giovedì 24 agosto 2017

# ecol: reprogrammed by a virus

AA << work demonstrates how a virus can amend host–viral dynamics by modulating acquisition of nutrients from the environment >>

AA << data show that a virus can acquire genes encoding nutrient transporters from a host genome and that expression of the viral gene can alter the nutrient uptake behavior of host cells >>

AA << results have implications for understanding how viruses manipulate the physiology and ecology of phytoplankton, influence marine nutrient cycles, and act as vectors for horizontal gene transfer >>

Adam Moniera, Aurelie Chambouvet, et al. Host-derived viral transporter protein for nitrogen uptake in infected marine phytoplankton. PNAS doi: 10.1073/pnas.1708097114

http://m.pnas.org/content/early/2017/08/17/1708097114

<< A virus which infects ocean plankton can reprogramme cells and change the way they absorb nutrients - potentially changing how carbon is stored in the ocean >>

Virus reprograms ocean plankton.
Aug 21, 2017

https://m.phys.org/news/2017-08-virus-reprograms-ocean-plankton.html

martedì 22 agosto 2017

# gst: concerning turbulences, turbulence researchers & lovers ...

<< Charles Doering, a mathematical physicist at the University of Michigan in Ann Arbor, says he hopes that the approach might ultimately point the way to a model of turbulence that is simpler to use than the Navier–Stokes equations, and works in all situations. That is the “grand dream”, he says >>

Davide Castelvecchi. Mysteries of turbulence unravelled. Simulations follow how swirls in a fluid transfer and dissipate energy. Aug 21, 2017 Corrected: Aug 22, 2017

http://www.nature.com/news/mysteries-of-turbulence-unravelled-1.22474

FonT

"a model of turbulence that is simpler to use (..) and works in all situations"; una intelligenza artificiale, anche genericamente  di "media forza" sara' senz'altro in totale accordo con Charles Doering.

lunedì 21 agosto 2017

# gene: 99 loci to drive general cognitive function

AA << combined cognitive and genetic data from the CHARGE and COGENT consortia, and UK Biobank (total N=280,360; age range = 16 to 102) >>

AA << found 9,714 genome-wide significant SNPs  [Single Nucleotide Polymorphism] (P<5 x 10-8) in 99 independent loci >>

<< Among many novel genes associated with general cognitive function were SGCZ, ATXN1, MAPT, AUTS2, and P2RY6 >>

Gail Davies, Max Lam, et al. Ninety-nine independent genetic loci influencing general cognitive function include genes associated with brain health and structure (N = 280,360). biorxiv. doi: 10.1101/176511 Aug18, 2017.

http://www.biorxiv.org/content/early/2017/08/18/176511

FonT

il sistema a 3 palle in fisica (three-body problem) qui genericamente estensibile a 99 ...

three-body problem:

Jon Cartwright. Physicists  Discover a Whopping 13 New  Solutions to Three-Body  Problem. Mar. 8, 2013

http://www.sciencemag.org/news/2013/03/physicists-discover-whopping-13-new-solutions-three-body-problem

Institute  of  Physics  Belgrade. Three-body gallery

http://suki.ipb.ac.rs/3body/

sabato 19 agosto 2017

# phyto: feel sounds to spot water

AA << used the model plant Pisum sativum to investigate the mechanism by which roots sense and locate water >>

AA << found that roots were able to locate a water source by sensing the vibrations generated by water moving inside pipes, even in the absence of substrate moisture. When both moisture and acoustic cues were available, roots preferentially used moisture in the soil over acoustic vibrations, suggesting that acoustic gradients enable roots to broadly detect a water source at a distance, while moisture gradients help them to reach their target more accurately >>

AA << results also showed that the presence of noise affected the abilities of roots to perceive and respond correctly to the surrounding soundscape >>

Monica Gagliano, Mavra Grimonprez, et al. Tuned in: plant roots use sound to locate water. Oecologia. Volume 184, Issue 1, pp 151–160. May 2017

https://link.springer.com/article/10.1007%2Fs00442-017-3862-z

venerdì 18 agosto 2017

# websec: everyone is a target (N3v$r M1^d!), by Kevin

<< At the end of the day, Cardwell [Kevin Cardwell] notes that "no product will make you secure." What's important is setting up a process of defenses because he says, "everyone is a target." >>

Leah Becerra. How to protect your data from cyberattacks. The Kansas City Star. May 25, 2017

https://m.phys.org/news/2017-05-cyberattacks.html

also

<< “Much of what I did I now regret,” Burr [Bill Burr], who is now retired, told the Wall Street Journal. “In the end, it was probably too complicated for a lot of folks to understand very well, and the truth is, it was barking up the wrong tree.” >>

James Titcomb. Password guru who told the world to make them complicated admits: I got it completely wrong. 8 Aug 8, 2017

http://www.telegraph.co.uk/technology/2017/08/08/man-wrote-password-bible-admits-advice-completely-wrong/

Robert McMillan. The Man Who Wrote Those Password Rules Has a New Tip: N3v$r M1^d! Aug. 7, 2017

https://www.wsj.com/articles/the-man-who-wrote-those-password-rules-has-a-new-tip-n3v-r-m1-d-1502124118

https://pages.nist.gov/800-63-3/