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martedì 3 novembre 2020

# life: the 'built-in float' of an ancient marine predator

<< About 240 million years ago, when reptiles ruled the ocean, a small lizard-like predator floated near the bottom of the edges in shallow water, picking off prey with fang-like teeth. >>

<< Our analysis of two well-preserved skeletons reveals a reptile with a broad, pachyostotic body (denser boned) and a very short, flattened tail. A long tail can be used to flick through the water, generating thrust, but the new species we've identified was probably better suited to hanging out near the bottom in shallow sea, using its short, flattened tail for balance, like an underwater float, allowing it to preserve energy while searching for prey, >> Qing-Hua Shang.

<< Perhaps this small, slow-swimming marine reptile had to be vigilante for large predators as it floated in the shallows, as well as being a predator itself, >> Xiao-Chun Wu.

Taylor & Francis. Ancient marine predator had a built-in float. Oct 28, 2020. 


Qing-Hua Shang, Xiao-Chun Wu, Chun Li. A New Ladinian Nothosauroid (Sauropterygia) from Fuyuan, Yunnan Province, China. Journal of Vertebrate Paleontology. doi: 10.1080/ 02724634.2020.1789651. Oct 29, 2020.





lunedì 2 novembre 2020

# 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. 



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



domenica 1 novembre 2020

# 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. 


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. 



venerdì 30 ottobre 2020

# 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.


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. 





giovedì 29 ottobre 2020

# 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.



Also

keyword 'virus' in FonT


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




mercoledì 28 ottobre 2020

# 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. 


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


Also

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


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



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





martedì 27 ottobre 2020

# 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. 


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


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.