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mercoledì 16 ottobre 2019

# gst: counterintuitively, even complex processes can be hidden inside flat power spectra

<< Power spectral densities are a common, convenient, and powerful way to analyze signals. So much so that they are now broadly deployed across the sciences and engineering - from quantum physics to cosmology, and from crystallography to neuroscience to speech recognition. The features they reveal not only identify prominent signal-frequencies but also hint at mechanisms that generate correlation and lead to resonance. Despite their near-centuries-long run of successes in signal analysis, here (AA) show that flat power spectra can be generated by highly complex processes, effectively hiding all inherent structure in complex signals.  >>

P. M. Riechers, J. P. Crutchfield.  Fraudulent White Noise: Flat power spectra belie arbitrarily complex processes.   arXiv:1908.11405v1 [cond-mat.stat-mech] Aug 29, 2019.   https://arxiv.org/abs/1908.11405

martedì 15 ottobre 2019

# ai: the future where machines will test hypotheses on their own

<< Brian Nord imagines a future where machines test hypotheses on their own  (..) Nord has begun applying AI to problems in astronomy, such as identifying unusual astronomical objects known as gravitational lenses. (..)  He spoke to Physics about his recent projects and how he thinks AI, also known as machine learning, will change the way researchers do science. >>

Sophia Chen. Paving A Path for AI in Physics Research.  Physics 12, 108. Oct 3, 2019.    https://physics.aps.org/articles/v12/108  

Also

oops! artificial intelligence will kill self-employment. Oct 4, 2019.   https://flashontrack.blogspot.com/2019/10/ai-life-oops-artificial-intelligence.html

keyword "ai" in FonT:     https://flashontrack.blogspot.com/search?q=ai

lunedì 14 ottobre 2019

# gst: chaotic dynamics modulate complex systems, even in the presence of extrinsic and intrinsic noise

AA << find that chaotic dynamics modulates gene expression and up-regulates certain families of low-affinity genes, even in the presence of extrinsic and intrinsic noise. Furthermore, this leads to an increase in the production of protein complexes and the efficiency of their assembly. Finally, (AA) show how chaotic dynamics creates a heterogeneous population of cell states, and describe how this can be beneficial in multi-toxic environments. >>

Mathias L. Heltberg, Sandeep Krishna, Mogens H. Jensen. On chaotic dynamics in transcription factors and the associated effects in differential gene regulation.  Nature Comm. volume 10, Article number: 71 Jan 8, 2019.   https://www.nature.com/articles/s41467-018-07932-1  

<< Chaos in bodily regulation can optimize our immune system according to a recent discovery made by researchers at the University of Copenhagen's Niels Bohr Institute. The discovery may prove to be of great significance for avoiding serious diseases such as cancer and diabetes.  >>

Chaos in the body tunes up your immune system. Niels Bohr Institute.
Jan 16, 2019.   https://m.medicalxpress.com/news/2019-01-chaos-body-tunes-immune.html

Also

'l'immaginifico "tracciante ... che svagola nella macina ...'    in:  2149 - onda di predazione (to knock seals off the ice). Notes. Dec 17, 2007.    https://inkpi.blogspot.com/2007/12/2149-onda-di-predazione-to-knock-seals.html

Also

never boring with chaos and tit-for-tat theories. F.on.T. Jun 12, 2016.  https://flashontrack.blogspot.com/2016/06/s-gst-never-boring-with-chaos-and-tit.html

sabato 12 ottobre 2019

# gst: exploring the lifespan of a liquid droplet

<< Current theories state that the droplet's diameter-squared decreases in proportion to time (classical law); however, this period only accounts for a small portion of the drop's evolution. As the diameter approaches the unobservable micro- and nano-scale, molecular dynamics have to be used as virtual experiments and these show a crossover to a new behaviour, with the diameter now reducing in proportion to time (nano-scale law). >>

<< It is fascinating that intuition based on everyday observations are a hindrance when attempting to understand nanoscale flows, so that, as in this research, one has to lean on theory to enlighten us. >>  James Sprittles.

The lifespan of an evaporating liquid drop. University of Warwick. Oct 10, 2019.     https://m.phys.org/news/2019-10-lifespan-evaporating-liquid.html

Rana A.S., Lockerby D.A., Sprittles J.E.  Lifetime of a Nanodroplet: Kinetic Effects and Regime Transitions. Phys. Rev. Lett. 123, 154501 Oct 9, 2019.     https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.154501   

venerdì 11 ottobre 2019

# gst: retooling viruses

<< New research reveals that the way viruses were perceived in terms of their architecture will need to be retooled, because they are actually structured in many more patterns than previously understood. The findings could have significant impact on how they are classified, our understanding of how they form, evolve and infect hosts, and strategies to identify ways to design vaccines to target them. >>

Why viruses like Herpes and Zika will need to be reclassified, and its biotech impact. San Diego State University. Sep 27, 2019.    https://www.eurekalert.org/pub_releases/2019-09/sdsu-wvl092519.php  

<<  improved imaging techniques have revealed increasing numbers of viral outliers >>

<< The polyhedral layouts describing the quasiequivalent capsid structures in CK-theory (Caspar, D. L. & Klug, A. theory) also occur in other areas of science, (..) The conceptual framework for the classification of icosahedral and octahedral polyhedral layouts presented here is therefore of interest for a wide range of scientific disciplines beyond virology. >>

Reidun Twarock, Antoni Luque.  Structural puzzles in virology solved with an overarching icosahedral design principle. Nature Comm. volume 10, Article number: 4414 Sep 27, 2019.   https://www.nature.com/articles/s41467-019-12367-3  

martedì 8 ottobre 2019

# gst: a cylindrical solitonlike that collapses into a spherical shape, and, along the filaments, central cores of matter exhibit fuzzies

In AA simulation, << the dark matter filaments show coherent interference patterns on the boson de Broglie scale and develop cylindrical solitonlike cores, which are unstable under gravity and collapse into kiloparsec-scale spherical solitons. Features of the dark matter distribution are largely unaffected by the baryonic feedback. On the contrary, the distributions of gas and stars, which do form along the entire filament, exhibit central cores imprinted by dark matter-a smoking gun signature of FDM ("fuzzy" dark matter). >>

Philip Mocz, Anastasia Fialkov, et al. First Star-Forming Structures in Fuzzy Cosmic Filaments. Phys. Rev. Lett. 123, 141301. Oct 2, 2019.     https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.141301  

Jennifer Chu. This is how a 'fuzzy' universe may have looked. Massachusetts Institute of Technology. Oct 3, 2019       https://m.phys.org/news/2019-10-fuzzy-dark-disrupts-conventional.html   

FonT

intrigante qui come una simulazione di evoluzione cosmologica - filamenti strutturati a cilindro mutanti (collassanti) in strutture sferoidali (ma non a generica fluttuante frittella) formanti, nei filamenti di gas,  serie (sciami?) di kernel a dinamiche fuzzy - possa far immaginare generici contesti altri ...

sabato 5 ottobre 2019

# evol: echolocation, a prime example of convergent evolution

<< Echolocation is a prime example of convergent evolution, the independent gain of similar features in species of different lineages. >>

<< Distantly related species entering similar biological niches often adapt by evolving similar morphological and physiological characters. How much genomic molecular convergence (particularly of highly constrained coding sequence) contributes to convergent phenotypic evolution, such as echolocation in bats and whales, is a long-standing fundamental question.  >>

AA << find that the gene set most overrepresented (q-value = 2.2e-3) with convergent substitutions in echolocators, affecting 18 genes, regulates development of the cochlear ganglion, a structure with empirically supported relevance to echolocation. >>

Amir Marcovitz, Yatish Turakhia, et al. A functional enrichment test for molecular convergent evolution finds a clear protein-coding signal in echolocating bats and whales.
PNAS doi: 10.1073/pnas.1818532116   Sep 30, 2019    https://www.pnas.org/content/early/2019/09/27/1818532116 

Krista Conger. Scientists uncover genetic similarities among species that use sound to navigate. Stanford University Medical Center. Oct 4, 2019.   https://m.phys.org/news/2019-10-scientists-uncover-genetic-similarities-species.html