sabato 23 settembre 2017

# chem: strange transitions: tying a crystal into a knot

<< Single crystals are typically brittle, inelastic materials. Such mechanical responses limit their use in practical applications, particularly in flexible electronics and optical devices >>

AA << describe single crystals of a well-known coordination compound—copper(II) acetylacetonate—that are flexible enough to be reversibly tied into a knot >>

Anna Worthy, Arnaud Grosjean, et al. Atomic resolution of structural changes in elastic crystals of copper(II) acetylacetonate. Nature Chemistry. doi: 10.1038/nchem.2848. Aug 28, 2017

<< crystals exhibit traditional characteristics of not only hard matter, but soft matter like nylon >> John McMurtrie

<< Under strain the molecules in the crystal reversibly rotate and reorganise to allow the compression and expansion required for elasticity and still maintain the integrity of the crystal structure >> Jack Clegg

Bendable crystals tie current thinking in knots. Aug 29, 2017.

venerdì 22 settembre 2017

# gst: chaotic networks inside a chaotic world, a 2015 review by Jennifer

<<  Networks grow as individual nodes connect to one another. By tweaking the rules that govern when nodes connect, researchers can shape the network’s properties >>

Jennifer Ouellette. The New Laws of Explosive Networks. Researchers are uncovering the hidden laws that reveal how the Internet grows, how viruses spread, and how financial bubbles burst. Jul 14, 2015.


<< The most celebrated part of this account, however, is at 2.216–93, where Lucretius [Titus Lucretius Carus] maintains that not only to explain how atomic collisions can occur in the first place, but also to account for the evident fact of free will in the animal kingdom, it is necessary to postulate a minimal indeterminacy in the motions of atoms, an unpredictable ‘swerve’ (clinamen) ‘at no fixed place or time’. Otherwise we would all be automata, our motions determined by infinitely extended and unbreakable causal chains >>

Lucretius. 4.Physics. Stanford Encyclopedia of Philosophy. First published Wed Aug 4, 2004; substantive revision Sat Aug 10, 2013

giovedì 21 settembre 2017

# qubit-ai: inside the qubit AI neural “black boxes”

<< Neural networks’ powers of prediction have fueled the recent AI boom, but it can be hard to explain how they reach their decisions. A new technique aimed at uncovering the inner workings of language processing networks is just the latest effort to shed some light on these “black boxes.” >>

<< Going a step further, some researchers are trying to create AI able to explain its decisions to lay people, not just experts >>

Edd Gent. Machines Are Getting Smarter—Now They Should Explain Themselves. Sep 19, 2017


"but it can be hard to explain how they [AI machines] reach their decisions"

An easy prediction: "Qubit AI  Machines" will never fully explain themselves.

mercoledì 20 settembre 2017

# game: low-cooperativity feedbacks in burst size could be preferable for noisy proteins

AA << consider a specific kind of negative feedback, which makes bursts smaller in the excess of protein >>

<< Increasing the strength of the feedback may lead to dramatically different outcomes depending on a key parameter, the noise load >>

<< for noise loads smaller than critical, the coefficient of variation remains bounded with increasing feedback strength; contrastingly, if the noise load is larger than critical, the coefficient of variation diverges to infinity in the limit of ever greater feedback strengths >>

<< Interestingly, high-cooperativity feedbacks have lower critical noise loads, implying that low-cooperativity feedbacks in burst size can be preferable for noisy proteins >>

Pavol Bokes, Abhyudai Singh, Yen Ting Lin. High Cooperativity In Negative Feedback Can Amplify Noisy Gene Expression. biorxiv sysbio. doi: 10.1101/125914  April 10, 2017.

lunedì 18 settembre 2017

# soc: pulsatile self-destructive choices, by Oliver and Julia

<< Let’s all be thankful that FiveThirtyEight readers don’t control America’s nuclear arsenal >>

Last week AA << published an article on the game theory of nuclear standoffs. That article included an interactive game ... >>

Oliver Roeder, Julia Wolfe. Thank God You People Don’t Have The Nuclear Codes. Sep. 14, 2017.

<< Shall we play a game? >>

Oliver Roeder. How To Win A Nuclear Standoff. President Trump and Kim Jong Un’s saber-rattling is dangerous, but not irrational. Sep. 6, 2017

domenica 17 settembre 2017

# acad: ig-nobel 2017; not so evanescent but intriguing: contact with a live crocodile actually could affects a person's willingness to gamble

<< ECONOMICS PRIZE [AUSTRALIA, USA] — Matthew Rockloff and Nancy Greer, for their experiments to see how contact with a live crocodile affects a person's willingness to gamble.
REFERENCE: "Never Smile at a Crocodile: Betting on Electronic Gaming Machines is Intensified by Reptile-Induced Arousal," Matthew J. Rockloff and Nancy Greer, Journal of Gambling Studies, vol. 26, no. 4, December 2010, pp. 571-81. WHO ATTENDED THE CEREMONY: Matthew Rockloff and Nancy Greer >>

Mark Pratt. Research on big ears, crocodile gambling wins Ig Nobels. Sep 14, 2017

<< Tourists at the Koorana Saltwater Crocodile Farm in Coowonga, Queensland, Australia (..) were randomly assigned to play a laptop-simulated Electronic Gaming Machine (EGM) either: (1) prior to entry, or (2) after having held a 1-m saltwater-crocodile >>

<< At-risk gamblers with few self-reported negative emotions placed higher average bets at the EGM after having held the crocodile when compared to the control >>

<< high arousal can intensify gambling in at-risk players, but only if this feeling state is not perceived as a negative emotion >>

Matthew J. Rockloff, Nancy Greer. Never Smile at a Crocodile: Betting on Electronic Gaming Machines is Intensified by Reptile-Induced Arousal. Journal of Gambling Studies.  2010;  Vol 26, Issue 4, pp 571–581. Jan 6, 2010.

sabato 16 settembre 2017

# age: autophagy inactivation (e.g. in neurons) to reverse the effects of age (50% extension of life) in the whole old body (post-reproductive C. elegans)

AA << identified that the inactivation of genes governing the early stages of autophagy up until the stage of vesicle nucleation, such as bec-1, strongly extend both life span and health span >>

AA << demonstrate that the improvements in health and longevity are mediated through the neurons, resulting in reduced neurodegeneration and sarcopenia >>

AA << propose that autophagy switches from advantageous to harmful in the context of an age-associated dysfunction >>

Thomas Wilhelm, Jonathan Byrne, et al.  Neuronal inhibition of the autophagy nucleation complex extends life span in post-reproductive C. elegans. Genes & Dev. Sep 7, 2017 doi: 10.1101/gad.301648

<< By inactivating autophagy in the neurons of old worms they were not only able to prolong the worms life but they increased the total health of the worms dramatically >>

Why we did not evolve to live forever: Unveiling the mystery of  why we age.  Breakthrough in  understanding the origin of the  ageing process. Sep 07,  2017

Why we did not evolve to live forever: Unveiling the mystery of why we age. Sep 15, 2017.