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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