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mercoledì 31 luglio 2019

# web: multitudes under hypothetical conditioning; trolls and bots in social media.

<< Trolls and bots have a huge and often unrecognized influence on social media. They are used to influence conversations for commercial or political reasons. They allow small hidden groups of people to promote information supporting their agenda and a large scale. They can push their content to the top of people’s news feeds, search results, and shopping carts. Some say they can even influence presidential elections. >>

<< Trolls are dangerous online because it’s not always obvious when you are being influenced by them or engaging with them. >>

<< Bots are computer programs posing as people. They can amplify the effect of trolls by engaging or liking their content en masse, or by posting their own content in an automated fashion. They will get more sophisticated and harder to detect in the future. Bots can now create entire paragraphs of text in response to text posts or comments. >>

Jason Skowronski. Trolls and bots are disrupting social media - here’s how AI can stop them (Part 1). Jul 30, 2019.   https://towardsdatascience.com/trolls-and-bots-are-disrupting-social-media-heres-how-ai-can-stop-them-d9b969336a06   

Jason Skowronski. Identifying trolls and bots on Reddit with machine learning (Part 2). Jul 30, 2019.  https://towardsdatascience.com/identifying-trolls-and-bots-on-reddit-with-machine-learning-709da5970af1 

Also

Notes. 2151 - a voting machine (to explain precisely). Jan 15, 2008.   https://inkpi.blogspot.com/2008/01/2151-voting-machine-to-explain.html

martedì 30 luglio 2019

# chem: acoustic levitation techniques to perform chemistry in floating droplets

<<  Beauchamp (Jack Beauchamp) is doing work in what he calls "lab-in-a-drop" chemistry, in which chemical reactions are performed within a drop of liquid suspended in midair through acoustic levitation. >>

Performing chemistry in floating droplets. California Institute of Technology. Jul 29, 2019.

https://m.phys.org/news/2019-07-chemistry-droplets.html  

Chaonan Mu, Jie Wang, et al. Mass Spectrometric Study of Acoustically Levitated Droplets Illuminates Molecular‐Level Mechanism of Photodynamic Therapy for Cancer involving Lipid Oxidation. Angewandte Chemie International Edition. Volume 58, Issue 24. doi: 10.1002/anie.201902815. Apr 23, 2019.

https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201902815 

mercoledì 24 luglio 2019

# gst: the intermittent dance of liquid droplets

<< Liquid droplets bouncing on a vibrating liquid surface can execute a surprising cycle, alternating between moving and standing still. >>

Focus: Video—Stop and Go Droplets.
July 12, 2019• Physics 12, 80.    https://physics.aps.org/articles/v12/80    

Rahil N. Valani, Anja C. Slim, and Tapio Simula. Superwalking Droplets.
Phys. Rev. Lett. 123, 024503 – Published 12 July 2019.   https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.024503  

Also

"droplets". In FonT.   https://flashontrack.blogspot.com/search?q=droplets

martedì 23 luglio 2019

# gene: parental 'memory' could be inherited across generations (2); the happiness project.

<< In public talks and interviews, Mansuy (Isabelle Mansuy) says she's careful not to promise too much. As confident as she is in her mouse model, she says, there's lots more work to be done. "I don't think the field is moving too fast,"  Mansuy says. "I think it's moving too slow." >>

Andrew Curry. Parents’ emotional trauma may change their children’s biology. Studies in mice show how. Science. doi: 10.1126/science.aay7690. Jul. 18, 2019.    https://www.sciencemag.org/news/2019/07/parents-emotional-trauma-may-change-their-children-s-biology-studies-mice-show-how  

Andrew Curry. A painful legacy. Science. Vol. 365, Issue 6450, pp. 212-215. doi: 10.1126/science.365.6450.212. Jul 19, 2019.     https://science.sciencemag.org/content/365/6450/212

Jocelyn Kaiser. The Epigenetics Heretic. Science  Vol. 343, Issue 6169, pp. 361-363. doi: 10.1126/science.343.6169.361.  Jan 24, 2014.    https://science.sciencemag.org/content/343/6169/361   

David Grimm. The happiness project. Science. Vol. 359, Issue 6376, pp. 624-627. doi: 10.1126/science.359.6376.624. Feb 09, 2018.    https://science.sciencemag.org/content/359/6376/624  

Also

parental 'memory' could be inherited across generations. FonT. Jul 22, 2019.  http://flashontrack.blogspot.com/2019/07/gene-parental-could-be-inherited-across.html

'magic string'.  In: FonT.    https://flashontrack.blogspot.com/search?q=magic+string

lunedì 22 luglio 2019

# gene: parental 'memory' could be inherited across generations

AA << tested the possibility that environmentally triggered modifications could allow 'memory' of parental experiences to be inherited. In Drosophila melanogaster, exposure to predatory wasps leads to inheritance of a predisposition for ethanol-rich food for five generations.  Inhibition of Neuropeptide-F (NPF) activates germline caspases required for transgenerational ethanol preference. Further, inheritance of low NPF expression in specific regions of F1 brains is required for the transmission of this food preference >>

<< Given the conserved signaling functions of NPF and its mammalian NPY homolog in drug and alcohol disorders, these observations raise the intriguing possibility of NPY-related transgenerational effects in humans. >>

Julianna Bozler, Balint Z Kacsoh, Giovanni Bosco. Transgenerational inheritance of ethanol preference is caused by maternal NPF repression.
eLife doi: 10.7554/eLife.45391.001. Jul 9, 2019.

https://elifesciences.org/articles/45391

Study finds that parental 'memory' is inherited across generations. The Geisel School of Medicine at Dartmouth. Jul 9, 2019.

https://m.phys.org/news/2019-07-parental-memory-inherited.html   

Also

"Neuropeptide-F"

https://www.ncbi.nlm.nih.gov/mesh/?term=Neuropeptide-F

http://flybase.org/reports/FBgn0027109.html 

https://www.wikigenes.org/e/gene/e/42018.html

domenica 21 luglio 2019

# brain: to trace transitions from consciousness to unconscious subliminal perception

AA << study the transition in the functional networks that characterize the human brains’ conscious-state to an unconscious subliminal state of perception >>

<< the most inner core (i.e., the most connected kernel) of the conscious-state functional network corresponds to areas which remain functionally active when the brain transitions from the conscious-state to the subliminal-state. That is, the inner core of the conscious network coincides with the subliminal-state. >>

<< This finding imposes constraints to theoretical models of consciousness, in that the location of the core of the functional brain network is in the unconscious part of the brain rather than in the conscious state as previously thought. >>

Francesca Arese Lucini, Gino Del Ferraro, et al. How the Brain Transitions from Conscious to Subliminal Perception. Neuroscience. Volume 411, Jul 15, 2019, Pages 280-290.

https://www.sciencedirect.com/science/article/abs/pii/S0306452219302052

<< The k-core of the conscious state is reduced to three active regions of the brain, the fusiform gyrus (left and right) and the precentral gyrus. These regions are the only active in the subliminal state. >>

Physicists use mathematics to trace neuro transitions. City College of New York. Jul 18, 2019.

https://m.medicalxpress.com/news/2019-07-physicists-mathematics-neuro-transitions.html  

venerdì 19 luglio 2019

# life: simmetrico, purtuttavia caotico

<< La Bce starebbe mettendo in dubbio l'efficacia del target di inflazione stabilito per l'Eurozona. Un target che, così come è noto, è "inferiore, ma vicino alla soglia del 2%". Ora, per far sì che gli stimoli monetari rimangano operativi per un periodo di tempo più lungo, Mario Draghi & Co - stando a quanto riporta Bloomberg - starebbero valutando la possibilità di adottare un approccio più "simmetrico", ovvero stabilire un target di inflazione che sia "non solo inferiore, ma vicino alla soglia del 2%", come quello attuale, ma anche "superiore e vicino alla soglia del 2%". >>

Laura Naka Antonelli. Bce medita modifiche a target inflazione attuale 'al di sotto, ma vicino al 2%'. Jul 18, 2019

https://www.finanza.com/Finanza/Notizie_Mondo/Altri_paesi_Europa/notizia/Bce_medita_modifiche_a_target_inflazione_attuale__al_di_sott-508928  

giovedì 18 luglio 2019

# bot: 3D-printed micro-bristle-bot, vibrobot (expected everywhere ...)

<< A bristle-bot or vibrobot is a multi-legged robot made of bristles and an oscillating actuator that generates vibrations. This work presents the first demonstration of a micro-bristle-bot, with 3D-printed legs, fabricated by two-photon polymerization lithography. The presented miniaturized bristle-bot has a weight of only 5 mg, in the size of 2 mm × 1.87 mm × 0.8 mm, and can achieve a speed up to 4 times the body length per second.  >>

<< The presented micro-bristle-bots show a resonant frequency around 6.3 kHz, which can be tailored based on their geometry. This feature allows for addressing individual micro-bristle-bots with various geometries based on their unique resonance frequency. >>

DeaGyu Kim, Zhijian Hao, et al. A 5mg micro-bristle-bot fabricated by two-photon lithography. Journal of Micromechanics and Microengineering. Jul 9, 2019.

https://iopscience.iop.org/article/10.1088/1361-6439/ab309b  

John Toon. Tiny vibration-powered robots the size of the world's smallest ant. Georgia Institute of Technology. Jul 17, 2019.

https://m.techxplore.com/news/2019-07-tiny-vibration-powered-robots-size-world.html  

mercoledì 17 luglio 2019

# phys: synchronizing nano 'Pendulums'

AA << report synchronization of the mechanical dynamics of a pair of optomechanical crystal cavities that, (..) are intercoupled with a mechanical link and support independent optical modes. In this regime they oscillate in antiphase, >>

AA << also show how to temporarily disable synchronization of the coupled system >>

Colombano MF, Arregui G, et al. Synchronization of Optomechanical Nanobeams by Mechanical Interaction. Phys. Rev. Lett. 123, 017402. July 1, 2019.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.017402  

Katherine Wright. Synopsis: Synchronizing Nanosized "Pendulums". Jul 1, 2019.

https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.123.017402 

sabato 13 luglio 2019

# gst: a floating vortex of fluff, the flight of the dandelion

<< A fluff-topped dandelion seed can float through the air for more than a kilometer before it drifts to the ground. In experiments last year, researchers revealed that the white filaments in the fluff-known collectively as a pappus-create a ring-shaped wake behind the seed that is associated with low pressure and acts to keep it aloft. >>

AA << have theoretically modeled the airflow around the pappus, reproducing the experimentally measured wake and showing that it provides the seed with steady flight capabilities. >>

Katherine Wright. Dandelion Fluff Perfected for Flight. July 2, 2019

https://physics.aps.org/synopsis-for/10.1103/PhysRevFluids.4.071901

Ledda PG, Siconolfi L, et al. Flow dynamics of a dandelion pappus: A linear stability approach. Phys. Rev. Fluids 4, 071901(R) July 2, 2019.

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.4.071901

giovedì 11 luglio 2019

# game: inside an irregular 'rock-paper-scissors' game; 'uneveness nomads' will survive, probably ...

AA << study a class of the stochastic May-Leonard models, with three species dominating each other in a cyclic nonhierarchical way, according to the rock-paper-scissors game. (They) introduce an unevenness in the system, by considering that one of the species is weaker because of a lower selection probability. >>

To << investigate the coexistence probability (..) the surviving species depends on the level of unevenness of the model and the mobility of individuals. >>

Menezes J., Moura B., Pereira TA. Uneven rock-paper-scissors models: Patterns and coexistence. EPL -  Europhysics Letters, Volume 126, Number 1. May 22, 2019.

https://iopscience.iop.org/article/10.1209/0295-5075/126/18003/meta   

Lisa Zyga. The rock-paper-scissors game and coexistence. Phys.org.
Jul 4, 2019

https://m.phys.org/news/2019-07-rock-paper-scissors-game-coexistence.html   

martedì 9 luglio 2019

# acad: apropos of pulsating, nomadic entities; to generate and manage 'theories and vagrant thoughts', by Isaac

<< Presumably, the process of creativity, whatever it is, is essentially the same in all its branches and varieties, so that the evolution of a new art form, a new gadget, a new scientific principle, all involve common factors. We are most interested in the “creation” of a new scientific principle or a new application of an old one, but we can be general here. >>

Isaac Asimov Asks, "How Do People Get New Ideas?". A 1959 Essay by Isaac Asimov on Creativity. Oct 20, 2014.

https://www.technologyreview.com/s/531911/isaac-asimov-asks-how-do-people-get-new-ideas/amp/

https://twitter.com/techreview/status/1147256914016964608

lunedì 8 luglio 2019

# phys: optical vortex to probe magnetism in matter

<< A light "corkscrew" is sensitive to the local magnetic field direction, so it can be used to probe magnetism in a material. >>

<< Circularly polarized light can act as a powerful probe of magnetism in matter. By measuring differences in the transmission of light beams polarized in different directions as they pass through a material, physicists can unravel atomic-level details of the material’s magnetic properties. >>

Synopsis: Optical Vortices Can Probe Magnetism. Jun 12, 2019.

https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.122.237401

A. A. Sirenko, P. Marsik, et al. Terahertz Vortex Beam as a Spectroscopic Probe of Magnetic Excitations. Phys. Rev. Lett. 122, 237401. Jun 12, 2019.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.237401

sabato 6 luglio 2019

# brain: short-term exercise enhances brain function

<< Exercise is cheap, and you don't necessarily need a fancy gym membership or have to run 10 miles a day, >> Gary Westbrook

AA << designed a study in mice that specifically measured the brain's response to single bouts of exercise in otherwise sedentary mice that were placed for short periods on running wheels. The mice ran a few kilometers in two hours. >>

<< short-term bursts of exercise- the human equivalent of a weekly game of pickup basketball, or 4,000 steps- promoted an increase in synapses in the hippocampus. Scientists made the key discovery by analyzing genes that were increased in single neurons activated during exercise. >>

<< One particular gene stood out: Mtss1L. This gene had been largely ignored in prior studies in the brain. >>

Study reveals a short bout of exercise enhances brain function. Oregon Health & Science University.  Jul 3, 2019.

https://m.medicalxpress.com/news/2019-07-reveals-short-bout-brain-function.html   

AA << results link short-term effects of exercise to activity-dependent expression of Mtss1L, which propose as a novel effector of activity- dependent rearrangement of synapses. >>

Christina Chatzi, Yingyu Zhang, et al.  Exercise-induced enhancement of synaptic function triggered by the inverse BAR protein, Mtss1L.  eLife 2019; 8: e45920. doi: 10.7554/eLife.45920. Jun 24, 2019

https://elifesciences.org/articles/45920 

venerdì 5 luglio 2019

# cells: liver tissue as a 'liquid-crystal' structure

<< analysis of the spatial organization of cell polarity revealed that hepatocytes are not randomly oriented but follow a long-range liquid crystal order. >>

New modeling technique discovers surprising 'liquid-crystal' organization of liver tissue. Max Planck Society.  Jul 3, 2019.

https://m.medicalxpress.com/news/2019-07-technique-liquid-crystal-liver-tissue.html   

Hernan Morales-Navarrete, Hidenori Nonaka, et al.  Liquid-crystal organization of liver tissue. eLife. doi: 10.7554/eLife.44860. Jun 17, 2019.

https://elifesciences.org/articles/44860

giovedì 4 luglio 2019

# gst: when two like-charged spherical metal nanoparticles with unequal charges counterintuitively will attract one another.

<< When it comes to electric charge, there is one overriding theme: opposites attract, and like charges repel. But in a new study, physicists have made the surprising discovery that two spherical like-charged metal nanoparticles with unequal charges can attract one another in a dilute electrolyte solution. The reason, in short, is that the more strongly charged nanoparticle polarizes the metal core of the weakly charged nanoparticle, which alters the interaction between the nanoparticles. >>

<< Our paper elucidates a very counterintuitive behavior which was previously thought to be impossible, >>  Yan Levin.

Lisa Zyga. A counterintuitive case in which like charges attract. Phys.org. Jul 2, 2019.

https://m.phys.org/news/2019-07-counterintuitive-case.html   

Alexandre P. dos Santos, Yan Levin. Like-Charge Attraction between Metal Nanoparticles in a 1∶ 1 Electrolyte Solution.  Phys. Rev. Lett. 122, 248005. June 21, 2019.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.248005  

martedì 2 luglio 2019

# gst: apropos of freezing bubbles ...

<< Droplets or puddles tend to freeze from the propagation of a single freeze front. In contrast, videographers have shown that as soap bubbles freeze, a plethora of growing ice crystals can swirl around in a beautiful effect visually reminiscent of a snow globe. >>

AA << characterize the physics of soap bubbles freezing on an icy substrate and reveal two distinct modes of freezing. The first mode, occurring for isothermally supercooled bubbles, generates a strong Marangoni flow that entrains ice crystals to produce the aforementioned snow globe effect. The second mode occurs when using a cold stage in a warm ambient, resulting in a bottom-up freeze front that eventually halts due to poor conduction along the bubble.  >>

S. Farzad Ahmadi, Saurabh Nath, et al. How soap bubbles freeze. Nature Communications. volume 10, Article number: 2531. Jun 18, 2019.

https://www.nature.com/articles/s41467-019-10021-6   

Rosaire Bushey. Freezing bubbles viral video inspired research now published. Virginia Tech. Jun 19, 2019.

https://m.phys.org/news/2019-06-viral-video-published.html  

lunedì 1 luglio 2019

# brain: naturally-occurring psychedelic DMT, a 'magic string' endogenously synthesized

AA << results show for the first time that the rat brain is capable of synthesizing and releasing DMT [N,N-dimethyltryptamine] at concentrations comparable to known monoamine neurotransmitters and raise the possibility that this phenomenon may occur similarly in human brains. >>

Jon G. Dean, Tiecheng Liu, et al.  Biosynthesis and Extracellular Concentrations of N,N- dimethyltryptamine (DMT) in Mammalian Brain. Scientific Reports. volume 9, Article number: 9333 (2019).  Jun 27, 2019.

https://www.nature.com/articles/s41598-019-45812-w

'Mystical' psychedelic compound found in normal brains. University of Michigan. Jun 27, 2019.

https://m.medicalxpress.com/news/2019-06-mystical-psychedelic-compound-brains.html  

Also

'magic strings', in: FonT

https://flashontrack.blogspot.com/search?q=magic+strings