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sabato 27 aprile 2019

# phys: to move (momentarily) in and out of existence by extracting something from nothing

<< According to Einstein, nothing can travel faster than light in vacuum. Because of this, it is usually assumed that the Cherenkov emission cannot occur in vacuum. But according to quantum theory, the vacuum itself is packed full of "virtual particles", which move momentarily in and out of existence. These ghostly particles are usually not observable but, in the presence of extremely strong electric and magnetic fields, they can turn the vacuum into an optical medium where the speed of light is slowed down so that high velocity charged particles can emit Cherenkov gamma rays. This is totally unexpected in a vacuum. >>

Extracting something from nothing: A bright glow from empty space.
University of Strathclyde. Apr 25, 2019.

https://www.eurekalert.org/pub_releases/2019-04/uos-esf042519.php

Alexander J. Macleod, Adam Noble, Dino A. Jaroszynski. Cherenkov Radiation from the Quantum Vacuum.  Phys. Rev. Lett. 122, 161601 Apr 24,  2019.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.161601

venerdì 26 aprile 2019

# age: apropos of flatworm regeneration (2)

AA << have developed a computational model of planarian (flatworm) regeneration that explains how fragments of planaria determine which end should form a tail and which should form a head. >>

Scientists unlock new role for nervous system in regeneration. Tufts  University. Apr 25, 2019.

https://www.eurekalert.org/pub_releases/2019-04/tu-sun042519.php

<< Uniquely, [AA] model explains the various head-tail patterning outcomes of a wide range of molecular and physiological manipulations. Testing the novel predictions of this model revealed the nervous system as an instructive regulator of axial patterning. >>

Alexis Pietak, Johanna Bischof, et al.  Neural control of body-plan axis in regenerating planaria. PLoS Comput Biol 15(4): e1006904. Apr 16, 2019. doi:10.1371/journal.pcbi.1006904

https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1006904

Also

# age: apropos of flatworm regeneration. Apr 2, 2019

https://flashontrack.blogspot.com/2019/04/age-apropos-of-flatworm-regeneration.html

mercoledì 24 aprile 2019

# behav: to change moral decisions (between 'guilt aversion’ and 'inequity aversion) depending on the context.

AA << find markedly different neural substrates for the strategies of "guilt aversion’ and 'inequity aversion", even under conditions where the two strategies produce the same choices.  >>

AA << also identify a new strategy, 'moral opportunism', in which participants adaptively switch between guilt and inequity aversion, with a corresponding switch observed in their neural activation patterns. These findings provide a valuable view into understanding how different individuals may utilize different moral principles. >>

Jeroen M. van Baar, Luke J. Chang,  Alan G. Sanfey. The computational and neural substrates of moral strategies in social decision-making.  Nature Communications. volume 10, Article number: 1483 (2019)

https://www.nature.com/articles/s41467-019-09161-6

How do we make moral decisions?
New study shows how your moral behavior may change depending on the context. Dartmouth College. Apr 18, 2019.

https://www.eurekalert.org/pub_releases/2019-04/dc-hdw041819.php

martedì 23 aprile 2019

# zen brain: imagine a movement, in total rest, to train and change brains

AA << use NFB [neurofeedback by fMRI] to train healthy individuals to reinforce brain patterns related to motor execution while performing a motor imagery task, with no overt movement.  (..) After 1 h of NFB training, participants displayed increased fractional anisotropy (FA) in the sensorimotor segment of corpus callosum and increased functional connectivity of the sensorimotor resting state network. >>

<< this is the first demonstration of white matter FA changes following a very short training schedule (<1 h). >>

T. Marins,  E.C. Rodrigues, et al. Structural and functional connectivity changes in response to short-term neurofeedback training with motor imagery.  NeuroImage. doi: org/10.1016/j.neuroimage.2019.03.027.  Mar 18, 2019.

https://www.sciencedirect.com/science/article/pii/S1053811919302046

Train your brain, change your brain. Scientists developed a technique for brain training capable to induce changes of neural networks in less than one hour.  D'Or Instit. for Research and Education. Apr 14, 2019.

https://www.eurekalert.org/pub_releases/2019-04/difr-tyb041119.php

sabato 20 aprile 2019

# phys: cloud-to-ground lightning often strikes twice (or more)

<< Lightning is a dangerous yet poorly understood natural phenomenon. Lightning forms a network of plasma channels propagating away from the initiation point with both positively and negatively charged ends-called positive and negative leaders. >>

<< Negative leaders propagate in discrete steps, (..) Positive leaders propagate more continuously and thus emit very little high-frequency radiation. >>

<< It has been inferred that positive leaders can become transiently disconnected from negative leaders, which may lead to current pulses that both reconnect positive leaders to negative leaders, and cause multiple cloud-to-ground lightning events. >>

<< The disconnection process is thought to be due to negative differential resistance ... >>

AA << find small plasma structures-which (they) call 'needles'- (..) that appear to drain charge from the leader, and are probably the reason why positive leaders disconnect from negative ones, and why cloud-to-ground lightning connects to the ground multiple. >>

B. M. Hare, O. Scholten, et al. Needle-like structures discovered on positively charged lightning branches. Nature. volume 568, pages360–363 (2019) Apr 17, 2019.

https://www.nature.com/articles/s41586-019-1086-6

Why lightning often strikes twice. New study reveals needle-like structures in positively charged lightning leaders. Univ. of Groningen Apr 17, 2019

https://www.eurekalert.org/pub_releases/2019-04/uog-wlo041619.php

venerdì 19 aprile 2019

# tech: The U.S. Navy's patent for a "terrestrial UFO" (titled 'unconventional spacecraft propulsion systems')

<< A craft using an inertial mass reduction device comprises of an inner resonant cavity wall, an outer resonant cavity, and microwave emitters. The electrically charged outer resonant cavity wall and the electrically insulated inner resonant cavity wall form a resonant cavity. The microwave emitters create high frequency electromagnetic waves throughout the resonant cavity causing the resonant cavity to vibrate in an accelerated mode and create a local polarized vacuum outside the outer resonant cavity wall.
>>

Salvatore Cezar Pais. Craft using an inertial mass reduction device. - B64G1/409 Unconventional spacecraft propulsion systems. Current Assignee: US Secretary of Navy. US10144532B2. Dec 04, 2018.

https://patents.google.com/patent/US10144532B2/en

Nick Pope (@nickpopemod)

https://twitter.com/nickpopemod/status/1118969379629101056

Jasper Hamill. The US Navy has been granted a patent for an advanced aircraft which resembles a flying saucer UFO. Apr 18, 2019.

https://metro.co.uk/2019/04/18/us-navy-secretly-designed-super-fast-futuristic-aircraft-resembling-ufo-documents-reveal-9246755

Also

# esobio: #ufo, this phenomenon was a lot more than nuts and bolts machines ...  FonT. Jun 29, 2018

https://flashontrack.blogspot.com/2018/06/esobio-ufo-this-phenomenon-was-lot-more.html

giovedì 18 aprile 2019

# chem: HeH+, the beginning of chemistry

In the planetary nebula  NGC 7027 <<  SOFIA (Stratospheric Observatory for Infrared Astronomy) detected helium hydride, a combination of helium (..) and hydrogen (..), which was the first type of molecule to ever form in the early universe. This is the first time helium hydride has been found in the modern universe. >>

<< It was the beginning of chemistry, >> David Neufeld.

Marlowe Hood. Elusive molecule, first in Universe, detected in space. April 17, 2019.

https://m.phys.org/news/2019-04-elusive-molecule-universe-space.html 

Rolf Gusten, Helmut Wiesemeyer, et al. Astrophysical detection of the helium hydride ion HeH+. Nature, volume 568, pages 357–359 (2019)

https://www.nature.com/articles/s41586-019-1090-x