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venerdì 13 maggio 2022
# evol: spontaneous, immediate asymmetry, the chiral twist
venerdì 9 aprile 2021
# gst: this arrangement may not be completely random; you might observe ordered structures (also) into amorphous (metallic glasses) solids
martedì 6 ottobre 2020
# zoo: Tatupa, a random genus name for fixing a rare species of tropical Heteroptera with long antennas
lunedì 14 agosto 2023
# gst: rich behaviors from stochastic walking with variable long jumps.
venerdì 12 agosto 2022
# gst: like steering a marble through a tilting labyrinth, randomness seems to quickly deliver specific outcomes.
domenica 28 maggio 2017
# gst-chem: growth by random fluctuations in a curvy fractal structure
<< The weaker interaction causes the molecules to slide past each other and dislocate during crystal growth, resulting in an unusual, irregular crystal. According to Guoquing Zhang, ‘at room temperature, there is a high probability that crystal growth will be dictated by random fluctuations, resulting in a curvy fractal structure’ >>
Thomas Foley. Fractal crystals win fashion design contest. 14 May 2017
https://www.chemistryworld.com/news/fractal-crystals-win-fashion-design-contest/3007277.article
<< The crystals of 1-(4-methoxyphenyl)-3-(pyridin-2-yl)propane-1,3-dione exhibited rarely seen curved fractal structures under an optical microscope. Weak intermolecular interactions may result in dislocation during crystal growth and thus the irregular crystalline structures. The micrographs of the crystals were exploited for their artistic value and were transferred onto fabrics for application in fashion design. >>
Zongzheng Qian, Dongxue Li, et al. Curved fractal structures of pyridine-substituted β-diketone crystals. CrystEngComm. 2017, 19, 2283-2287. doi: 10.1039/C7CE00462A
http://pubs.rsc.org/en/Content/ArticleLanding/2017/CE/C7CE00462A#!divAbstract
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
domenica 7 febbraio 2016
# rmx-s-gst: similar to the "Brazil Nut effect", a everyday example
<< If you shake a can of mixed nuts before opening it, you can count on finding the walnuts on top and the peanuts at the bottom. This is an everyday example of the “spontaneous”, demixing of heterogeneously sized particles, popularly known as the Brazil Nut effect. The phenomenon is observed in all granular systems consisting of particles of unequal sizes, where the imposition of an undirected force results in random active movements of its constituents. >>
http://www.en.uni-muenchen.de/news/newsarchiv/2016/frey_sortieren.html
Weber, Simon N., Weber, Christoph A., Frey, Erwin. Binary Mixtures of Particles with Different Diffusivities Demix. Physical Review Letters. 10.1103/PhysRevLett.116.058301
giovedì 26 ottobre 2017
# gene: point code cracking machines (without detectable byproducts)
DNA cracking machine
<< The spontaneous deamination of cytosine is a major source of C•G to T•A transitions, which account for half of known human pathogenic point mutations. The ability to efficiently convert target A•T base pairs to G•C could therefore advance the study and treatment of genetic diseases >>
AA << report adenine base editors (ABEs) that mediate conversion of A•T to G•C in genomic DNA >>
<< ABEs advance genome editing by enabling the direct, programmable introduction of all four transition mutations without double-stranded DNA cleavage >>
Nicole M. Gaudelli, Alexis C. Komor, et al. Programmable base editing of A•T to G•C in genomic DNA without DNA cleavage. Nature 2017 doi: 10.1038/nature24644 Oct 25, 2017
https://www.nature.com/nature/journal/vaap/ncurrent/full/nature24644.html
<< there are virtually no detectable byproducts such as random insertions, deletions, translocations, or other base-to-base conversions >>
Researchers extend power of gene editing by developing a new class of DNA base editors. Oct 25, 2017
https://m.phys.org/news/2017-10-enzyme-rewrites-genome.html
RNA cracking machine
<< RNA Editing for Programmable A to I Replacement (REPAIR), which has no strict sequence constraints, can be used to edit full-length transcripts containing pathogenic mutations >>
David B. T. Cox, Jonathan S. Gootenberg, et al. RNA editing with CRISPR-Cas13. Science. Oct 25, 2017:eaaq0180 doi: 10.1126/science.aaq0180
http://science.sciencemag.org/content/early/2017/10/24/science.aaq0180
Researchers engineer CRISPR to edit single RNA letters in human cells. Oct 25, 2017
https://m.phys.org/news/2017-10-crispr-rna-letters-human-cells.html
Lauran Neergaard. Scientists working toward reversible kind of gene editing. Oct. 25, 2017
https://m.phys.org/news/2017-10-scientists-reversible-kind-gene.html
also:
lunedì 13 marzo 2017
# s-gst: breaking a kind of time- symmetry to draw stabilities
<< Time crystals are hypothetical structures that pulse without requiring any energy — like a ticking clock that never needs winding >>
<< In 2012, Wilczek [Frank Wilczek] [..] wondered why symmetry never broke spontaneously in time and whether it would be possible to create something in which it did >>
<< These systems draw stability from random interactions that would normally disrupt other kinds of matter >>
Elizabeth Gibney. The quest to crystallize time. Bizarre forms of matter called time crystals were supposed to be physically impossible. Now they’re not. Nature. Vol. 543, Pages: 164–166 164-166 09 March 2017 doi :10.1038/543164a
http://www.nature.com/news/the-quest-to-crystallize-time-1.21595
martedì 17 agosto 2021
# brain: like a Zazen entity, mice can spontaneously self-modulate cortical dopamine impulses to reward.
lunedì 16 gennaio 2023
# gst: diffusivity of ordered and freely evolving bubbly suspensions.
lunedì 29 gennaio 2018
# chem: extreme superconductive in random atomic-scale mixture
<< High-entropy alloys (HEAs) are a new class of materials that are composed of multiple transition-metal elements in equimolar or near-equimolar ratios >>
<< many HEAs have been found in disordered solid-solution phases with body-centered-cubic, hexagonal closest-packed, and face-centered-cubic crystal structures >>
<< In many respects, HEAs display novel properties, including ultrahigh fracture toughness at cryogenic temperatures, excellent specific strength, and superior mechanical performance at high temperatures. In addition to their promising mechanical properties, some HEAs also exhibit interesting electronic properties: [TaNb]1−x(ZrHfTi)x HEAs were found to display superconductivity, for example >>
AA << report high-pressure studies on the superconducting HEA (TaNb)0.67(HfZrTi)0.33, [..] this alloy exhibits extraordinarily robust superconductivity - its zero-resistance superconducting state is still achieved even at a pressure of 190.6 GPa, or almost 2 megabars (1 Mbar = 1011 pascal), a pressure like that within the outer core of the earth. >>
Jing Guo, Honghong Wang, et al. Robust zero resistance in a superconducting high-entropy alloy at pressures up to 190 GPa. PNAS 2017; 114 (50) 13144-7. doi: 10.1073/pnas.1716981114.
http://www.pnas.org/content/114/50/13144
Laura Mgrdichian. A material that superconducts continuously up to extreme pressures. Jan 17, 2018
https://m.phys.org/news/2018-01-material-superconducts-extreme-pressures.html
lunedì 29 febbraio 2016
# rmx-s-behav: echoes from the Cambrian explosion
<< these early arthropods displayed such sophisticated predatory behavior >>
Jeff Sossamon, Feb. 16, 2016
http://munews.missouri.edu/news-releases/2016/0216-500-million-year-old-fossils-show-how-extinct-organisms-attacked-their-prey/
<< What she found was that the trilobite traces intersected the worm burrows more often than would be expected by random chance. The fossils also show evidence that suggests the trilobites were selective in hunting their prey, preferring smaller worms, and that trilobites attacked their prey at low angles more frequently than expected, improving their chances of grabbing onto and handling their prey >>
Jordan Yount, Friday, January 29, 2016.
https://coas.missouri.edu/news/early-trilobite-gets-worm
Tara Selly, John Warren Huntley, et al. Ichnofossil record of selective predation by Cambrian trilobites. Palaeogeography, Palaeoclimatology, Palaeoecology. 15 Feb. 2016, Vol.444:28–38, doi:10.1016/j.palaeo.2015.11.033