# tech: it repels everything with some beneficial exceptions

<< Researchers at McMaster University have solved a vexing problem by engineering surface coatings that can repel everything, such as bacteria, viruses and living cells, but can be modified to permit beneficial exceptions. >>

Researchers design "smart" surfaces to repel everything but targeted beneficial exceptions. McMaster University. Oct 24, 2018

https://phys.org/news/2018-10-smart-surfaces-repel-beneficial-exceptions.html

Tohid Didar. Researchers design "smart" surfaces, creating promise for safer implants and more accurate diagnostic tests. Oct 24, 2018.

https://www.eng.mcmaster.ca/news/researchers-design-smart-surfaces-creating-promise-safer-implants-and-more-accurate-diagnostic

# brain: sometimes to see it is necessary to rewire

<< Life-changing moments are also brain-changing moments: everything from a first kiss to a last goodbye modifies cells within the skull. The capacity to learn and remember, however, extends beyond the profound experiences that we lament or treasure. In fact, a new study (..)  suggests that even when we're not consciously forming new memories, our brains can change in important ways, altering how we interpret and interact with the world. >>

Charles D. Gilbert. To see what's right in front of you, your brain may need some rewiring. Rockefeller University. Oct 24, 2018.

https://m.medicalxpress.com/news/2018-10-front-brain-rewiring.html

AA << found that during the course of perceptual learning axon collaterals in primary visual cortex (V1) undergo sprouting and pruning, suggesting how V1 is engaged in encoding learned information. >>

Timo van Kerkoerle, Sally A. Marik, et al. Axonal plasticity associated with perceptual learning in adult macaque primary visual cortex. PNAS Oct 9, 2018 115 (41) 10464-9 doi: 10.1073/pnas.1812932115

http://www.pnas.org/content/115/41/10464

# brain: somatic stem cell proliferation could be modulated by autonomic nervous system

this << study (..) demonstrates, for the first time, that stem cell proliferation is directly controlled by the autonomic nervous system (ANS). >>

<< To demonstrate that stem cell behavior was changing as a result of ANS stimulation, the researchers grew intestinal epithelial cells in the lab and exposed them to high levels of two neurotransmitters, norepinephrine and acetylcholine. Norepinephrine is a major neurotransmitter of the sympathetic nervous system, or "fight or flight" branch of the ANS, while acetylcholine is produced by the parasympathetic nervous system, or "rest and digest" branch. >>

Scientists find stem cell proliferation is controlled directly by nervous system. University of Illinois at Urbana-Champaign. Oct 17, 2018.

https://m.phys.org/news/2018-10-scientists-stem-cell-proliferation-nervous.html

Elizabeth A. Davis, Megan J. Dailey. A direct effect of the autonomic nervous system on somatic stem cell proliferation?  Am J Physiol. doi: 10.1152/ajpregu.00266.2018. Oct 10, 2018.

https://www.physiology.org/doi/abs/10.1152/ajpregu.00266.2018

# gst: a new type of vortex in the flight of a dandelion

<< Wind-dispersed plants have evolved ingenious ways to lift their seeds >>

AA << visualized the flow around dandelion seeds, uncovering an extraordinary type of vortex. This vortex is a ring of recirculating fluid, which is detached owing to the flow passing through the pappus. >>

<< The discovery of the separated vortex ring provides evidence of the existence of a new class of fluid behaviour around fluid-immersed bodies that may underlie locomotion, weight reduction and particle retention in biological and manmade structures. >>

Cathal Cummins, Madeleine Seale, et al. A separated vortex ring underlies the flight of the dandelion. Nature 2018; 562: 414–8. doi: 10.1038/s41586-018-0604-2.

https://www.nature.com/articles/s41586-018-0604-2

<< When dandelion seeds fly, a ring-shaped air bubble forms as air moves through the bristles, enhancing the drag that slows their descent. >>

Dandelion seeds reveal newly discovered form of natural flight. University of Edinburgh. Oct 17, 2018.

https://m.phys.org/news/2018-10-dandelion-seeds-reveal-newly-natural.html

# chem: to explore the structure of small molecules

<< In the many scientific endeavors that  are driven by organic chemistry, unambiguous identification of small molecules is of paramount importance (..) the  unambiguous determination of a small molecule’s structure  requires  X-ray  and/or neutron  diffraction  studies.  In practice, however,  X-ray crystallography is rarely applied in routine organic chemistry due to  intrinsic limitations  of both  the analytes and the technique. >>

AA << report the use of the CryoEM (cryo-electron microscopy) method MicroED (micro-electron diffraction) to provide routine and unambiguous structural determination of small organic molecules. >>

Christopher G. Jones, Michael W. Martynowycz, et al. The CryoEM Method MicroED as a Powerful Tool for Small Molecule Structure Determination. ChemRxiv Oct 17, 2018 doi: 10.26434/chemrxiv.7215332.v1

https://chemrxiv.org/articles/The_CryoEM_Method_MicroED_as_a_Powerful_Tool_for_Small_Molecule_Structure_Determination/7215332

https://twitter.com/ChemRxiv/status/1052562398295539712

# astro: wormhole, a theoretical view of its quasinormal modes

AA << demonstrated how to describe the shape of any symmetrical wormhole - a black hole that theoretically can be a kind of a portal between any two points in space and time - based on its wave spectrum >>

Physicist describes the shape of a wormhole.  RUDN University. Oct 17, 2018.

https://m.phys.org/news/2018-10-physicist-wormhole.html

R.A.Konoplya. How to tell the shape of a wormhole by its quasinormal modes. Physics Letters B. Volume 784 Sep 10, 2018 Pages 43-49  doi: 10.1016/j.physletb.2018.07.025

https://www.sciencedirect.com/science/article/pii/S037026931830563X

# gst: when a 'ricequake' repeat perpetually and propagate

<< puffed rice and milk can serve as a stand-in to simulate collapsing ice shelves and rockfill dams. >>

<< Intrigued by their findings, the researchers created what they call a "crushing wave model," which they believe could prove useful for describing the behavior of much larger collapse events. >>

Bob Yirka. Using puffed rice to simulate collapsing ice shelves and rockfill dams. Oct 15, 2018.

https://m.phys.org/news/2018-10-puffed-rice-simulate-collapsing-ice.html

<< These "ricequakes" repeat perpetually during the experiments and propagate upward through the material. >>

Itai Einav, Francois Guillard. Tracking time with ricequakes in partially soaked brittle porous media. Science Advances  Oct 12, 2018. Vol. 4, no. 10, eaat6961. doi: 10.1126/sciadv.aat6961.

http://advances.sciencemag.org/content/4/10/eaat6961