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sabato 8 settembre 2018

# gst: even repulsive interactions generate solitons

<< Solitons are nonspreading wave packets that exist in a wide range of real-world systems, including water waves, sound, DNA, optics, and so on. >>

<< Two or more solitons can bind together to form a soliton molecule with dynamics similar to matter molecules, such as vibration, synthesis, and dissociation. >>

<< Formation processes for three types of soliton molecules were studied: ground-, excited-state, and a new one termed an intermittent-vibration soliton molecule. While it is generally believed that attractive interactions of solitons are responsible for the formation of soliton molecules, the authors found that soliton interactions are not limited to attractive interactions. Counterintuitively, even repulsive interactions can lead to the formation of soliton molecules, >>

John Wallace. Investigation with a femtosecond fiber laser finds new type of soliton ‘molecule’. Aug 01, 2018.

https://www.laserfocusworld.com/articles/print/volume-54/issue-08/newsbreaks/investigation-with-a-femtosecond-fiber-laser-finds-new-type-of-soliton-molecule.html

<< For closely‐separated bound solitons, soliton interactions display wide diversities in repeated measurements, including soliton attraction, repelling, collision, vibration, and annihilation. For well‐separated bound solitons, repulsive interactions dominate the soliton interactions. >>

Junsong Peng, Heping Zeng. Build‐Up of Dissipative Optical Soliton Molecules via Diverse Soliton Interactions. Laser & Photonics Reviews 2018, 12, 1800009.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/lpor.201800009 

Also "soliton" in:

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

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

lunedì 3 settembre 2018

# gst: a chaos-inducing approach against superbugs evolution

<< The CHAOS [Controlled Hindrance of Adaptation of OrganismS] method takes advantage of this effect, pulling multiple genetic levers in order to build up stress on the bacterial cell and eventually trigger a cascading failure, leaving the bug more vulnerable to current treatments. The technique does not alter the bug's DNA itself, only the expression of individual genes, similar to the way a coded message is rendered useless without the proper decryption. >>

<< We now have a way to cut off the evolutionary pathways of some of the nastiest bugs and potentially prevent future bugs from emerging at all, >> Peter Otoupal

Chaos-inducing genetic approach stymies antibiotic-resistant superbugs. University of Colorado at Boulder. Sept 3, 2018.

https://m.phys.org/news/2018-09-chaos-inducing-genetic-approach-stymies-antibiotic-resistant.html 

<< While individual perturbations improved fitness during antibiotic exposure, multiplexed perturbations caused large fitness loss in a significant epistatic fashion. >>

Peter B. Otoupal, William T. Cordell, et al. Multiplexed deactivated CRISPR-Cas9 gene expression perturbations deter bacterial adaptation by inducing negative epistasis. Comm  Biol 1 (129) Sept 3, 2018

https://www.nature.com/articles/s42003-018-0135-2

giovedì 30 agosto 2018

# evol-ethno: the fuzzy dispersal and interaction dynamics of ancient (early) nomads (2)

AA << present the genome of 'Denisova 11', a bone fragment from Denisova Cave (Russia)3 and show that it comes from an individual who had a Neanderthal mother and a Denisovan father. >>

<< The finding of a first-generation Neanderthal–Denisovan offspring among the small number of archaic specimens sequenced to date suggests that mixing between Late Pleistocene hominin groups was common when they met. >>

Viviane Slon, Fabrizio Mafessoni, et al. The genome of the offspring of a Neanderthal mother and a Denisovan father. Nature. Aug 22, 2018. doi: 10.1038/s41586-018-0455-x

https://www.nature.com/articles/s41586-018-0455-x

Marlowe Hood. Neandertal mother, Denisovan father-Newly-sequenced genome sheds light on interactions between ancient hominins. Aug 22, 2018.

https://m.phys.org/news/2018-08-neandertal-mother-denisovan-fathernewly-sequenced-genome.html

Also

the fuzzy dispersal and interaction dynamics of ancient (early) nomads. Dec 11, 2017.

https://flashontrack.blogspot.com/2017/12/evol-ethno-fuzzy-dispersals-and.html

mercoledì 29 agosto 2018

# astro: when an unlucky star ventures close enough to a black hole, it spaghettifies ...

<< To be disrupted, an unlucky star must venture close enough to a black hole that gravitational tides exceed the internal gravity that binds the star together. In other words, the difference in the black hole's gravitational pull on the near and far sides of the star, along with the inertial pull as the star swings around the black hole, stretches the star out into a stream. "Basically it spaghettifies," >> James Guillochon

Joshua Sokol. Star-Swallowing Black Holes Reveal Secrets in Exotic Light Shows. August 8, 2018.

https://www.quantamagazine.org/star-swallowing-black-holes-reveal-secrets-in-exotic-light-shows-20180808/

martedì 28 agosto 2018

# behav: strange "sunk cost" behaviors: to repeat the wrong choice

<< In a temporal context, a sensitivity to sunk costs arises when an individual resists ending an activity, even if it seems unproductive, because of the time already invested. In two parallel foraging tasks [AA] found that mice, rats, and humans show similar sensitivities to sunk costs in their decision-making. >>

Brian M. Sweis, Samantha V. Abram, et al. Sensitivity to "sunk costs" in mice, rats, and humans. Science  Jul 13, 2018; 361 (6398): 178-81 doi: 10.1126/science.aar8644

http://science.sciencemag.org/content/361/6398/178

Krystle Barbour. Sticking with the wrong choice. University of Minnesota Medical School. July 13, 2018.

https://m.phys.org/news/2018-07-wrong-choice.html

lunedì 27 agosto 2018

# drugs: proteins found in tick saliva (Rhipicephalus and Amblyomma) to treat a potentially fatal form of heart disease

<< Tick saliva contains proteins [evasins] that suppress chemokine-driven inflammation by binding and neutralizing multiple chemokines simultaneously, helping them to suck blood for several weeks without eliciting inflammation. >>

Kamayani Singh, Graham Davies, et al.  Yeast surface display identifies a family of evasins from ticks with novel polyvalent CC chemokine - binding activities. Scientific Reports. Jun 27, 2017; 7 (4267).

https://www.nature.com/articles/s41598-017-04378-1

AA << has identified several new tick evasins and shown that one of them, P991_AMBCA, from the cayenne tick found in the Americas, can bind to and block the effect of chemokines which cause inflammation in myocarditis, heart attack and stroke. >>

From bug to drug - tick saliva could be key to treating heart disease. University of Oxford. Jun 27, 2017.

https://m.phys.org/news/2017-06-bug-drugtick-saliva-key-heart.html

Also: "saliva" in:

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

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

sabato 25 agosto 2018

# drugs: from a slug (A. subfuscus) mucus: strong adhesives for wet surfaces

<< Adhesives that can bond strongly to biological tissues would have broad applications ranging from tissue repair and drug delivery to wound dressings and biomedical devices. However, existing tissue adhesives are far from ideal. >>

<< Achieving high adhesion energy requires the synergy of two effects. First, the adhesive should form strong bonds with the substrate. Second, materials inside either the adhesive or the substrate (or both) should dissipate energy by hysteresis. Tissue adhesives must also show compatibility with body fluids, as well as with cells and tissues. >>

AA << report the design of a family of tough adhesives for biological applications to meet those requirements. The design is inspired by a defensive mucus secreted by slugs (Arion subfuscus) that strongly adheres to wet surfaces. >>

J Li, AD Celiz, et al. Tough adhesives for diverse wet surfaces. Science  Jul 28, 2017; 357 (6349): 378-81. doi: 10.1126/science.aah6362

http://science.sciencemag.org/content/357/6349/378 

Sticky when wet: Strong adhesive for wound healing. Slug-inspired, flexible medical bio-glue sticks to wet surfaces without toxicity. Wyss Institute for Biologically Inspired Engineering at Harvard. July 27, 2017.

https://www.sciencedaily.com/releases/2017/07/170727141508.htm