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giovedì 13 giugno 2019

# gst: "diffusing wave paradox",  synthetic microswimmers can mimic the behavior of Amoeba

<< Amoeba are unusual creatures that form when a dispersed population of cells spontaneously comes together and reorganizes itself into a multicellular macroscopic organism. To do this, a few leader cells emit chemical pulses that cause the other individual cells to move in the direction opposite to that of the traveling pulses (the "diffusing wave paradox," ), leading to the formation of dense clusters. >>

<< In experiments, the researchers used spherical particles that are half-coated by a carbon cap and placed in a viscous liquid. When illuminated by light, the particles propel themselves forward with the cap in front. >>

<< At low pulse speeds, the particles have enough time to reorient themselves, if needed, so that their caps are facing in the same direction as that of the traveling pulses. This orientation ensures that the particles travel in the same direction as the pulses. >>

<< At high pulse speeds, on the other hand, the pulses come too quickly for the particles to reorient themselves before the next one comes. This is because the speed of the particles' rotation is limited by the friction of the viscous liquid. So if the particles' caps are initially facing the oncoming pulses, the particles will move counter to the direction of the traveling pulses, resembling the behavior of amoeba in the diffusing wave paradox. >>

Lisa Zyga. Diffusing wave paradox may be used to design micro-robotics. Jun 12, 2019.

https://m.phys.org/news/2019-06-diffusing-paradox-micro-robotics.html

Celia Lozano, Clemens Bechinger. Diffusing wave paradox of phototactic particles in traveling light pulses. Nature Communications 10, Article number: 2495.  Jun 7, 2019.

https://www.nature.com/articles/s41467-019-10535-z

mercoledì 12 giugno 2019

# brain: humans could be uniquely sensitive to pitch

<< our brains may be uniquely sensitive to pitch, the harmonic sounds we hear when listening to speech or music. >>

<< The results raise the possibility that these sounds, which are embedded in speech and music, may have shaped the basic organization of the human brain. >> Bevil Conway

Our brains appear uniquely tuned for musical pitch. National Institutes of Health. Jun 10, 2019.

https://m.medicalxpress.com/news/2019-06-brains-uniquely-tuned-musical-pitch.html

Sam V. Norman-Haignere, Nancy Kanwisher, et al. Divergence in the functional organization of human and macaque auditory cortex revealed by fMRI responses to harmonic tones.
Nature Neuroscience. Jun 10, 2019

https://www.nature.com/articles/s41593-019-0410-7

martedì 11 giugno 2019

# gst: apropos of bubbles, how simple foams collapse

<< When a bubble breaks, (AA) found that a collapse event propagates via impact with the receding film and tiny scattered droplets breaking other bubbles. >>

<< A key finding was that changing the viscosity of the fluid did not lead to a significant change in the number of bubbles broken. Methods to stabilize foams commonly rely on changing the viscosity, yet the team's findings clearly show how both the number of bubbles collapsed and the velocity of the receding film are unaffected. >>

Two distinct physical mechanisms identified for how simple foams collapse. Tokyo Metropolitan University. June 10, 2019.

https://m.phys.org/news/2019-06-distinct-physical-mechanisms-simple-foams.html

Naoya Yanagisawa, Rei Kurita. In-situ observation of collective bubble collapse dynamics in a quasi-two-dimensional foam. Scientific Reports 9, Article number: 5152. March 26, 2019

https://www.nature.com/articles/s41598-019-41486-6

lunedì 10 giugno 2019

# hack: oops! breaking the 2048-bit RSA encryption in 8h (back to the "Pizzinu" docs?)

<< A new study shows that quantum technology will catch up with today’s encryption standards much sooner than expected. That should worry anybody who needs to store data securely for 25 years or so. >>

How a quantum computer could break 2048-bit RSA encryption in 8 hours. Emerging Technology from the arXiv May 30, 2019.

https://www.technologyreview.com/s/613596/how-a-quantum-computer-could-break-2048-bit-rsa-encryption-in-8-hours

<< When factoring 2048 bit RSA integers, our construction's spacetime volume is a hundredfold less than comparable estimates from earlier works. >>

Craig Gidney, Martin Ekera. How to factor 2048 bit RSA integers in 8 hours using 20 million noisy qubits.  arXiv:1905.09749v1 [quant-ph]

https://arxiv.org/abs/1905.09749

"pizzinu"

http://www.treccani.it/vocabolario/pizzino

Also

Crackin' as a snap. FonT. Dec 6, 2015

https://flashontrack.blogspot.com/2015/12/s-phys-tech-bot-crackin-as-snap.html

sabato 8 giugno 2019

# gst: triggering earthquakes, even the slightest stress can set off a tremor

<< A new study reveals the inner workings of tidally triggered earthquakes, and finds that even the slightest stress can set off a tremor. >>

Solved: How tides can trigger earthquakes. Earth Institute At  Columbia University. Jun 7, 2019.

https://www.eurekalert.org/pub_releases/2019-06/eiac-sht060519.php

<< The strong tidal triggering of mid-ocean ridge earthquakes has remained unexplained because the earthquakes occur preferentially during low tide, when normal faulting earthquakes should be inhibited. >>

AA << show that the axial magma chamber inflates/deflates in response to tidal stresses, producing Coulomb stresses on the faults that are opposite in sign to those produced by the tides. When the magma chamber’s bulk modulus is sufficiently low, the phase of tidal triggering is inverted. >>

Christopher H. Scholz, Yen Joe Tan, Fabien Albino. The mechanism of tidal triggering of earthquakes at mid-ocean ridges. Nature Communications 10, Article number: 2526 June 7, 2019.

https://www.nature.com/articles/s41467-019-10605-2

venerdì 7 giugno 2019

# life: repositioning to align to continue to hire aggressively; AI will change 100% of jobs.

<< We are continuing to reposition our team to align with our focus on the high-value segments of the IT market, and we also continue to hire aggressively in critical new areas that deliver value for our clients and IBM, >>

<< IBM has more than 340,000 employees, according to its last proxy statement, which means the cuts would affect around 1,700 employees. >>

Jordan Novet. IBM is laying off more than 1,000 employees. Jun 6, 2019.

https://www.cnbc.com/2019/06/06/ibm-layoffs-affect-more-than-1000-employees.html  

<< IBM CEO Ginni Rometty sits down with CNBC's Jon Fortt to discuss her push to reshape the company's jobs, and how A.I. will affect the workforce in the future. >>

IBM's Ginni Rometty: AI will change 100 percent of jobs. 12:00 PM ET  Apr 3, 2019.

https://www.cnbc.com/video/2019/04/03/ibms-ginni-rometty-ai-will-change-100-percent-of-jobs.html

giovedì 6 giugno 2019

# aibot: apropos of "Buddha Bots" ...

an << interesting insight into how people perceive blessing robots compared to other robots for more conventional purposes. >>

<< Robots are continuing to enter all sorts of social spaces and we wanted to critically investigate fringe uses, such as in religious contexts, >> Diana Loffler

Ingrid Fadelli. Investigating the implications of social robots in religious contexts. Jun 5, 2019.

https://m.techxplore.com/news/2019-06-implications-social-robots-religious-contexts.html

Diana Loffler, Jorn Hurtienne, Ilona Nord. Blessing Robot BlessU2: A Discursive Design Study to Understand the Implications of Social Robots in Religious Contexts. Int J of Soc Robotics. doi: 10.1007/s12369-019-00558-3. May 22, 2019.

https://link.springer.com/article/10.1007%2Fs12369-019-00558-3

Also

onda di blues. Nov 29, 2004.

https://inkpi.blogspot.com/2004/11/1664-onda-di-blues.html