# gst: a simple signal to drive complex dynamics

<< a developmental signaling pattern can be erased and replaced with a synthetic, patterned stimulus. (..) unlike pharmacological or genetic perturbations, light can be applied and removed quickly, focused with high spatial precision, or shaped into arbitrary spatial patterns. (AA) found that a simple all-or-none blue light stimulus, delivered to the embryonic termini, is sufficient to convert a lethal loss-of-function phenotype to rescue the full Drosophila life cycle: embryogenesis; larval development; pupation; adulthood; and fecundity. >>

<<  Such optical control over development could be used to probe cell and tissue-level regulation, engineer tissue organization, and correct developmental defects. >>

Heath E. Johnson, Nareg J.V. Djabrayan, et al. Optogenetic Rescue of a Patterning Mutant. Current Biology. 30, 1-11. doi: 10.1016/ j.cub.2020.06.059. Jul 23, 2020. 

https://www.sciencedirect.com/science/article/abs/pii/S0960982220309118

Complex developmental patterns are under the control of surprisingly simple signals. Princeton University. Jul 23, 2020.

https://phys.org/news/2020-07-complex-developmental-patterns-surprisingly-simple.html   

Also

keyword 'signal' in FonT

https://flashontrack.blogspot.com/search?q=signal

keyword 'signal' in Notes (quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=signal

# life: high traffic, busy skies; every 6 months the Agency will publish news about TicTac Entities, UFOs, UAPs, ...

<< The Pentagon’s secretive UFO unit is going to make some of its findings public, The New York Times reported. And one consultant to the agency (Eric W. Davis, Astrophysicist) has briefed Defense Department officials of some highly unusual discoveries ― including items retrieved from “off-world vehicles not made on this Earth,” the newspaper said. >>

<< The military’s encounters with possible UFOs have come under intense interest since several videos were leaked in 2017 showing encounters with fast-moving objects including one given the nickname “Tic Tac” because it looked like one of the candies. This object, still not publicly identified, dropped from 60,000 feet to just 50 feet in a matter of seconds: “The part that drew our attention was how it wasn’t behaving within the normal laws of physics,” >> Chad Underwood, pilot. 

Ed Mazza. Explosive UFO Report In NYT Mentions ‘Off-World Vehicles Not Made On This Earth’. A Pentagon consultant made the revelation to The New York Times. Jul 24, 2020

https://m.huffpost.com/us/entry/us_5f1a5815c5b6296fbf404a07

<< It's not every day one reads a New York Times article containing the phrase “off-world vehicles not made on this earth". When I investigated UFOs for the UK government in the Nineties, I could only dream of such mainstream respectability for this subject. >> Nick Pope. 07:33 Jul 24, 2020. 

https://twitter.com/nickpopemod/status/1286534963597172736

Also

keyword 'ufo' in FonT:

https://flashontrack.blogspot.com/search?q=ufo

keyword 'ufo' in Notes (quasi-stochastic poetry):

https://inkpi.blogspot.com/search?q=ufo

# physics: SQUID, a probe at the boundary between 'quantum' and 'classic' worlds

<< A new device that relies on flowing clouds of ultracold atoms promises potential tests of the intersection between the weirdness of the quantum world and the familiarity of the macroscopic world we experience every day. The atomtronic Superconducting QUantum Interference Device (SQUID) is also potentially useful for ultrasensitive rotation measurements and as a component in quantum computers. >>

AA << created the device by trapping cold atoms in a sheet of laser light. A second laser intersecting the sheet "painted" patterns that guided the atoms into two semicircles separated by small gaps known as Josephson Junctions. When the SQUID is rotated and the Josephson Junctions are moved toward each other, the populations of atoms in the semicircles change as a result of quantum mechanical interference of currents through Josephson Junctions. By counting the atoms in each section of the semicircle, the researchers can very precisely determine the rate the system is rotating.>>

James Riordon. Atomtronic device could probe boundary between quantum, everyday worlds. Los Alamos National Laboratory. July 17, 2020.

https://phys.org/news/2020-07-atomtronic-device-probe-boundary-quantum.html

C. Ryu, E. C. Samson, M. G. Boshier. Quantum interference of currents in an atomtronic SQUID. Nat Commun 11, 3338. doi: 10.1038/ s41467-020-17185-6. Jul 3, 2020.

https://www.nature.com/articles/s41467-020-17185-6

# gst: weird matter, the 'ballistic resonance' paradox; amplitude of mechanical vibrations can grow without external influence

AA << discovered a new physical phenomenon of 'ballistic resonance', where mechanical oscillations can be excited only due to internal thermal resources of the system. >>

<< The discovered phenomenon describes that the process of heat equilibration leads to mechanical vibrations with an amplitude that grows with time. The effect is called ballistic resonance. >>

<< Over the past few years, our scientific group has been looking into the mechanisms of heat propagation at the micro and nano levels. We found out that at these levels, heat doesn't spread in the way we expected it to: for example, heat can flow from cold to hot. This behavior of nanosystems leads to new physical effects, such as ballistic resonance, >> Vitaly Kuzkin.

Scientists have discovered a new physical paradox. Peter the Great Saint-Petersburg Polytechnic University. Jul 13, 2020.

https://phys.org/news/2020-07-scientists-physical-paradox.html

<< coupling between macroscopic dynamics and quasiballistic heat transport gives rise to mechanical vibrations with growing amplitude. This phenomenon is referred to as ballistic resonance. At large times, these mechanical vibrations decay monotonically >>

Vitaly A. Kuzkin, Anton M. Krivtsov. 

Ballistic resonance and thermalization in the Fermi-Pasta-Ulam-Tsingou chain at finite temperature. Phys. Rev. E 101, 042209. Apr 16, 2020.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.101.042209

# gst: apropos of 'strange states', the modulation of PdGa crystals from conventional to 'exotic' behaviors

<< In topological materials, electrons can display behavior that is fundamentally different from that in 'conventional' matter, and the magnitude of many such 'exotic' phenomena is directly proportional to an entity known as the Chern number. New experiments establish for the first time that the theoretically predicted maximum Chern number can be reached—and controlled—in a real material. >>

<<  in the topological semimetal palladium gallium (PdGa) one of the most common classifiers of topological phenomena, the Chern number, can reach the maximum value that is allowed in any metallic crystal. That this is possible in a real material has never been shown before. (..)  the team has established ways to control the sign of the Chern number, which might bring new opportunities for exploring, and exploiting, topological phenomena. >>

Cherned up to the maximum. Paul Scherrer Institute. Jul 9, 2020.

https://phys.org/news/2020-07-cherned-maximum.html   

<< Here, (AA) show that the chiral crystal palladium gallium (PdGa) displays multifold band crossings, which are connected by exactly four surface Fermi arcs, thus proving that they carry the maximal Chern number magnitude of 4. By comparing two enantiomers, (They) observe a reversal of their Fermi-arc velocities, which demonstrates that the handedness of chiral crystals can be used to control the sign of their Chern numbers. >>

Niels B. M. Schroter, Samuel Stolz, et al. Observation and control of maximal Chern numbers in a chiral topological semimetal.  Science. Vol. 369, Issue 6500, pp. 179-183. doi: 10.1126/ science.aaz3480. Jul 10, 2020.

https://science.sciencemag.org/content/369/6500/179    

Also

D.J. Thouless, F. D.M. Haldane, J. M.Kosterlitz  << opened the door on an unknown world where matter can assume strange states. >> Oct 4, 2016

https://www.nobelprize.org/prizes/physics/2016/press-release/

# life: perform very large flights without flapping (among Andean condors)

<< Andean condors, at 10kg or more, are among the world’s heaviest flying birds. Once birds get this big, the energetic costs of flapping are so high they instead rely on currents of rising air to travel long distances. >>

AA << results showed that on average, condors fly for three hours a day, but they flap for less than two minutes of this - just 1% of their flight time. One bird even flew for more than five hours without a single flap, covering 172km. Surprisingly, the amount they flapped hardly changed whether they were in the Andes or the steppe, or whether it was windy or not. >>

<< Nonetheless, even in weak thermal conditions, which may occur in winter, (their) results suggest condors may flap for only around two seconds per km. This remarkably low investment in flapping flight is on a par with albatrosses. In fact, albatrosses appear to flap more than condors – between (1% and 15% of their flight time outside take-off) >>

<< What is particularly striking about our findings is that all the birds we studied were immature. There was some suggestion that flight performance improved with age, but the demonstration that all birds flap so rarely shows that it is possible for even young condors to invest little energy in flying. >>

Emily Shepard. We tagged Andean condors to find out how huge birds fly without flapping. Jul 13, 2020. 

https://theconversation.com/we-tagged-andean-condors-to-find-out-how-huge-birds-fly-without-flapping-142472

H. J. Williams, E. L. C. Shepard, et al

 Physical limits of flight performance in the heaviest soaring bird.  PNAS. doi: 10.1073/ pnas.1907360117. Jul 13, 2020

https://www.pnas.org/content/early/2020/07/09/1907360117

# evol: iterative hacking mechanics; a large group of viruses can assemble human-virus codes to produce novel chimeric (UFO) proteins

<< Like a scene out of "Invasion of the Body Snatchers," a virus infects a host and converts it into a factory for making more copies of itself. Now researchers have shown that a large group of viruses, including the influenza viruses and other serious pathogens, steal genetic signals from their hosts to expand their own genomes. >>

AA << looked at a large group of viruses known as segmented negative-strand RNA viruses (sNSVs), which include widespread and serious pathogens of humans, domesticated animals and plants, including the influenza viruses and Lassa virus (..) by stealing genetic signals from their hosts, viruses can produce a wealth of previously undetected proteins. The researchers labeled them as UFO (Upstream Frankenstein Open reading frame) proteins, as they are encoded by stitching together the host and viral sequences. There was no knowledge of the existence of these kinds of proteins prior to this study. >>

Viruses can steal our genetic code to create new human-virus genes. The Mount Sinai Hospital. Jun 18, 2020.

https://phys.org/news/2020-06-viruses-genetic-code-human-virus-genes.html

Jessica Sook Yuin Ho, Matthew Angel, et al. Hybrid Gene Origination Creates Human-Virus Chimeric Proteins during Infection. Cell. Vol 181, Issue 7, P1502-1517.e23. doi: 10.1016/ j.cell.2020.05.035. June 25, 2020. 

https://www.cell.com/cell/fulltext/S0092-8674(20)30630-9