# gst: density fluctuations may exist in an amorphous matrix

<< Silicon does not have to be crystalline, but can also be produced as an amorphous thin film. In such amorphous films, the atomic structure is disordered like in a liquid or glass. If additional hydrogen is incorporated during the production of these thin layers, so-called a-Si:H layers are formed. >>

<< With this study, we show that the a-Si:H is by no means a homogeneously amorphous material. The amorphous matrix is interspersed with nanometre-sized areas of varying local density, from cavities to areas of extremely high order, >> Klaus Lips

<< We find a nanoscopic order in the disorder of the a-Si:H layers by X-ray scattering measurements (..) We were then able to determine the distribution of the hydrogen atoms in the amorphous network by neutron scattering (..) We were able to discover nanometer-sized voids, which are created by slightly more than 10 missing atoms. These voids arrange themselves into clusters with a recurrent distance of about 1.6 nanometres to each other, >> Eike Gericke

Density fluctuations in amorphous silicon discovered. Helmholtz Association of German Research Centres. Oct 29, 2020. 

https://phys.org/news/2020-10-density-fluctuations-amorphous-silicon.html

Eike Gericke, Jimmy Melskens, et al. Quantification of Nanoscale Density Fluctuations in Hydrogenated Amorphous Silicon. Phys. Rev. Lett. 125, 185501. Oct 29,  2020. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.185501

# life: exchange of nomadic music in the sea, male fin whales swap songs

<< Until now, scientists believed the male fin whale sings just one song pattern, which is unique to the males in his particular group—but new research has blown this theory out of the water. This study, (..) suggests that these endangered deep-sea giants actually sing multiple different songs, which may spread to different parts of the ocean through migrating individuals. >>

Male fin whales surprise scientists by swapping songs. Frontiers. Oct 29, 2020. 

https://phys.org/news/2020-10-male-fin-whales-scientists-swapping.html  

Tyler A. Helble, Regina A. Guazzo, et al.  Fin Whale Song Patterns Shift Over Time in the Central North Pacific. Front. Mar. Sci. doi: 10.3389/ fmars.2020.587110. Oct 29, 2020. 

https://www.frontiersin.org/articles/10.3389/fmars.2020.587110/full    

# gst: stitch together at both ends to selective formation of classes of bicyclic medium-sized ring compounds

AA << have discovered catalyst-controlled divergent reactions to synthesize three different classes of medium-sized bicyclic compounds from the same starting materials  >>

<< Intermolecular higher-order cycloaddition, in which two starting materials are 'stitched' together at both ends, provides great potential to build complex cyclic compounds from simple building blocks. Unfortunately, such transformations to prepare medium-sized rings are often plagued with competitive reaction pathways and low levels of site- and stereo-selectivity >>

<< The most significant aspect of this chemistry was that not one, but three different classes of bicyclic medium-sized ring compounds were obtained with high efficiency and stereo-selectivity from the same set of starting molecules.  >>

Divergent synthesis of bicyclic medium-sized ring structures. National University of Singapore. Oct 26, 2020.

https://phys.org/news/2020-10-divergent-synthesis-bicyclic-medium-sized.html

Li-Cheng Yang, Ya-Nong Wang, et al. Stereoselective access to [5.5.0] and [4.4.1] bicyclic compounds through Pd-catalysed divergent higher-order cycloadditions. Nat. Chem. 12, 860–868. doi: 10.1038/ s41557-020-0503-7. July 27, 2020. 

https://www.nature.com/articles/s41557-020-0503-7

# life: aprops of 1or2 achoo! from Wuhan (SARS-CoV-2), a mask build of 'nanofibers randomly land on a collector to create a sort of non-woven mesh'

<< Recently, students from BYU’s College of Engineering teamed up with Nanos Foundation to develop a nanofiber membrane that can be sandwiched between the cloth pieces in a homemade mask. While today’s typical cloth mask might block fewer than 50% of virus particles, the membrane — which can be made using simple, inexpensive materials — will be able to block 90 to 99% of particles, increasing effectiveness while preserving breathability. The membranes are made through a process called “electrospinning,” which involves dissolving a polymer plastic in a solution and then using an electrical current to move a droplet of the polymer downward through a needle. As the droplet accelerates, it stretches into a very small fiber that retains a static charge. >>

<< Those nanofibers randomly land on a collector to create a sort of non-woven mesh, >> Katie Varela.

Christie Allen. With innovative nanofiber membranes, cloth masks’  efficacy goes up to 99%. Oct 21, 2020.

https://news.byu.edu/intellect/with-new-byu-created-nanofiber-membranes-cloth-masks-efficacy-goes-up-to-99 

https://phys.org/news/2020-10-nanofiber-membranes-masks-efficacy.html   

Also

keyword 'virus' in FonT: 

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

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

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

# astro: the effect of Yarkovsky acceleration to direct the asteroid Apophis (towards us, hypothetically)

<< A University of Hawai Institute for Astronomy (IfA) astronomer has revealed critical new findings linked to a large asteroid expected to pass extremely close to Earth. Dave Tholen and collaborators have announced the detection of Yarkovsky acceleration on the near-Earth asteroid Apophis. This acceleration arises from an extremely weak force on an object due to non-uniform thermal radiation. This force is particularly important for the asteroid Apophis, as it affects the probability of an Earth impact in 2068. >>

Massive asteroid subject of new findings. Oct 26, 2020. 

https://www.hawaii.edu/news/2020/10/26/new-massive-asteroid-findings

"2068" –Massive Asteroid Apophis on Path for Earth Impact. Oct 27, 2020.

https://dailygalaxy.com/2020/10/2068-massive-asteroid-apophis-on-path-for-earth-impact

Also

il ciottolo Apophis. Notes. May 05, 2006 (quasi-stochastic poetry). 

https://inkpi.blogspot.com/2006/05/2001-il-ciottolo-apophis.html

A wicked list in the dino-killing range; waiting for new entries. FonT. Jun 29, 2017. 

https://flashontrack.blogspot.com/2017/06/s-astro-wicked-list-in-dino-killing.html

A few hints of our presence. Notes. Oct 13, 2006 (quasi-stochastic poetry)

https://inkpi.blogspot.com/2006/10/2073-few-hints-of-our-presence.html

# life: deliver care remotely; can we trust AI Doctors?

<< Machine learning is taking medical diagnosis by storm. From eye disease, breast and other cancers, to more amorphous neurological disorders, AI is routinely matching physician performance, if not beating them outright.  Yet how much can we take those results at face value? When it comes to life and death decisions, when can we put our full trust in enigmatic algorithms—“black boxes” that even their creators cannot fully explain or understand? The problem gets more complex as medical AI crosses multiple disciplines and developers, including both academic and industry powerhouses such as Google, Amazon, or Apple, with disparate incentives. >>

<< This week, the two sides battled it out in a heated duel in one of the most prestigious science journals, Nature. >>

Shelly Fan. Can We Trust AI Doctors? Google Health and Academics Battle It Out. Oct 20, 2020. 

https://singularityhub.com/2020/10/20/can-we-trust-ai-doctors-google-health-and-academics-battle-it-out

Benjamin Haibe-Kains, George Alexandru Adam, et al. Transparency and reproducibility in artificial intelligence. Nature 586, E14–E16.  doi: 10.1038/ s41586-020-2766-y. Oct 15, 2020

https://www.nature.com/articles/s41586-020-2766-y

Emre Sezgin, Yungui Huang, et al. Readiness for voice assistants to support healthcare delivery during a health crisis and pandemic. npj Digit. Med. 3, 122. doi: 10.1038/ s41746-020-00332-0. Sep 16, 2020.

https://www.nature.com/articles/s41746-020-00332-0

# gst: NikS, a small RNA molecule uses a sort of 'bet-hedging' strategy to survive and infect

<< More than half of the world's population carries the bacterium Helicobacter pylori in their stomach mucosa. It often causes no problems throughout life, but sometimes it can cause inflammation, and in some cases, it can even lead to the development of stomach cancer. Helicobacter pylori uses several 'virulence' factors that allow it to survive in the stomach and can lead to the development of disease. (AA) report that multiple of these factors are centrally regulated by a small RNA molecule called NikS.  >>

<< The fact that Helicobacter pylori can colonize such a hostile environment as the stomach so successfully is also due to a special genetic strategy: Like other pathogens, H. pylori uses a strategy known as phase variation to adapt as flexibly as possible to changes in its environment. Phase variation means that the bacteria constantly switch expression of a gene at random through genetic mutations, meaning that some bacteria in a population will always be ready to express the important gene when it becomes important—a sort of 'bet-hedging' strategy. >>

Robert Emmerich. Small RNA as a central player in infections. University of Würzburg. Oct 15, 2020. 

https://phys.org/news/2020-10-small-rna-central-player-infections.html   

Sara K. Eisenbart, Mona Alzheimer, et al. A Repeat-Associated Small RNA Controls the Major Virulence Factors of Helicobacter pylori. Mol Cell. vol 80, issue 2, P210-226.E7. doi: 10.1016/ j.molcel.2020.09.009. Oct 15, 2020. 

https://www.cell.com/molecular-cell/fulltext/S1097-2765(20)30617-1