# s-ecol: asymmetric cooperation during symbiosis (among Polynucleobacteria)

<< Relationships where two organisms depend on each other, known as symbiosis, evoke images of partnership and cooperation. But a new study in Nature Ecology and Evolution shows that, when it comes to certain microorganisms, symbiotic partners are actually being held "hostage" >>

Hostage situation or harmony? Researchers rethink symbiosis. July 27, 2017

https://m.phys.org/news/2017-07-hostage-situation-harmony-rethink-symbiosis.html

Vittorio Boscaro, Martin Kolisko, et al.  Parallel genome reduction in symbionts descended from closely related free-living bacteria. Nature Ecology & Evolution 1, 1160–1167 (2017) doi: 10.1038/s41559-017-0237-0 Publ. July 21,  2017

https://www.nature.com/articles/s41559-017-0237-0

# s-game: equilibrium, a chimeric target

<< In 1950, John Nash — the mathematician later featured in the book and film “A Beautiful Mind” — wrote a two-page paper that transformed the theory of economics. His crucial, yet utterly simple, idea was that any competitive game has a notion of equilibrium: a collection of strategies, one for each player, such that no player can win more by unilaterally switching to a different strategy >>

<< Nash’s equilibrium concept, which earned him a Nobel Prize in economics in 1994, offers a unified framework for understanding strategic behavior not only in economics but also in psychology, evolutionary biology and a host of other fields. Its influence on economic theory “is comparable to that of the discovery of the DNA double helix in the biological sciences,” wrote Roger Myerson of the University of Chicago, another economics Nobelist >>

In a paper posted online last September AA << proved that no method of adapting strategies in response to previous games — no matter how commonsensical, creative or clever — will converge efficiently to even an approximate Nash equilibrium for every possible game. It’s “a very sweeping negative result,” Roughgarden (Tim Roughgarden) said >>

Erica Klarreich. In Game Theory, No Clear Path to Equilibrium. July 18, 2017.

https://www.quantamagazine.org/in-game-theory-no-clear-path-to-equilibrium-20170718/

Yakov Babichenko, Aviad Rubinstein. Communication complexity of approximate Nash equilibria. arXiv:1608.06580 Sep. 13,  2016

https://arxiv.org/abs/1608.06580

# s-pnei: brain-like activities; syntesis and release of dopamine by T-cells

<< a proportion of human TFH  [follicular helper T] cells contain dense-core granules marked by chromogranin B, which are normally found in neuronal presynaptic terminals storing catecholamines such as dopamine.  TFH cells produce high amounts of dopamine and release it upon cognate interaction with B cells >>

<< faster dopamine-induced T–B-cell interactions increase total germinal centre output and accelerate it by days >>

Ilenia Papa, David Saliba, et al. TFH-derived dopamine accelerates productive synapses in germinal centres. Nature 547, 318–323 (July 20, 2017) doi: 10.1038/nature23013

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature23013.html

Kate Prestt. Discovery of brain-like activity in immune system promises better disease treatments. July 13, 2017

http://www.anu.edu.au/news/all-news/discovery-of-brain-like-activity-in-immune-system-promises-better-disease-treatments

# s-astro: a macro "switch-like" dynamics

AA << propose  that  a  “switch-like”  magnetosphere  exists  at Uranus  in  both  equinox  and  solstice  seasons,  where  the  planetary rotation  drives  the  interchange  between  an  open  magnetosphere  and  a closed  magnetosphere  each  Uranus  day >>

Xin Cao , Carol Paty. Diurnal  and  seasonal  variability  of  Uranus's magnetosphere. Journal  of  Geophysical  Research:  Space  Physics. Vol. 122,  Issue  6, June  2017 Pages  6318–6331 Publ. June 27, 2017 doi:  10.1002/2017JA024063

http://onlinelibrary.wiley.com/doi/10.1002/2017JA024063/full

<< Stay weird, Uranus. We wouldn’t have you any other way >>

Rae Paoletta. Uranus Is Even Freakier Than We Thought. June 23, 2017.

http://gizmodo.com/uranus-is-even-freakier-than-we-thought-1796378503

# s-chem: self-assembled also into cuboids

<< Phospholipid liposomes are archetypical self-assembled structures. To minimize the surface tension, the vesicles typically are spherical >>

<< A 1,2-diamidophospholipid is presented that self-assembles into a cuboid structure. Owing to intermolecular hydrogen bonding, the bilayer membranes form an exceptionally tight subgel packing, leading to a maximization of flat structural elements and a minimization of any edges. These conditions are optimized in the geometrical structure of a cube >>

Frederik  Neuhaus, Dennis  Mueller, et al. Vesicle  Origami:  Cuboid  Phospholipid  Vesicles  Formed  by Template-Free  Self-Assembly. Angewandte  Chemie  International  Edition.  Vol. 56,  Issue 23, June  1,  2017. Pages  6515–6518. doi: 10.1002/anie.201701634

http://onlinelibrary.wiley.com/doi/10.1002/anie.201701634/abstract

Phosphorus-containing lipid  molecule self-assembles into a cuboid structure. June  5,  2017

https://m.phys.org/news/2017-06-phosphorus-containing-lipid-molecule-self-assembles-cuboid.html

# s-astro: the “mudball” model; a terrestrial muddiness from carbonaceous asteroids

<< Scientists have long held the belief that planets – including Earth – were built from rocky asteroids, but new research challenges that view >>

Planets like earth may have had muddy origins. July 14, 2017

https://m.phys.org/news/2017-07-planets-earth-muddy.html

<< It would have been a mud, rather than a rock >>

Philip A. Bland, Bryan J. Travis. Giant convecting mud balls of the early solar system. Science  Advances 14 Jul 2017: Vol.  3,  no.  7,  e1602514 doi: 10.1126/sciadv.1602514

http://advances.sciencemag.org/content/3/7/e1602514

# s-lang: jazz session during a bird song

<< Music is thought to engage its listeners by driving feelings of surprise, tension, and relief through a dynamic mixture of predictable and unpredictable patterns, a property summarized (..) [by AA] as "expressiveness" >>

<< birds render their songs more expressive by subtly modifying note timing patterns, similar to musical operations like accelerando or ritardando >>

AA << findings bear consequences for neuronal models of vocal sequence generation in birds, as they require non-local rules to generate rhythm >>

Tina C Roeske, Damian Kelty-Stephen, Sebastian Wallot. Birds have swing: Multifractal analysis reveals expressive rhythm in birdsong. BioRxiv June 29, 2017 doi: 10.1101/157594

http://www.biorxiv.org/content/early/2017/06/29/157594

<< A veery thrush, ready to join the band >>

Michael Le Page. Swinging birds play with rhythm like jazz musicians. July 14, 2017

https://www.newscientist.com/article/2140543-swinging-birds-play-with-rhythm-like-jazz-musicians/

Lang Elliott. Veery Thrush. June 1, 2010

https://m.youtube.com/watch?v=cK1gaTqBRRk