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sabato 25 luglio 2020
# gst: a simple signal to drive complex dynamics
martedì 27 marzo 2018
# brain: strong signals to connect to consciousness
<< Unexpectedly, our model reveals that only when the signal is strong enough, above a threshold level, the signal reaches a large set of areas of the brain region called the prefrontal cortex, which plays a critical role in high-level cognition >> Madhura Joglekar.
James Devitt. From Signal Propagation to Consciousness: A Potential Connection Discovered. Neuroscience News. Mar 22, 2018.
http://neurosciencenews.com/consciousness-signal-propagation-8674/amp/
Madhura R. Joglekar, Jorge F. Mejias, et al. Inter-areal Balanced Amplification Enhances Signal Propagation in a Large-Scale Circuit Model of the Primate Cortex. Neuron.
doi: 10.1016/j.neuron.2018.02.031.
Mar 22, 2018.
lunedì 26 agosto 2019
# gst: the hypothesis to optimize multiplicative noise to enhance a signal-to-noise ratio
AA << study simple integrate-and-fire type models with multiplicative noise and consider the transmission of a weak and slow signal, >>
<< The specific question of interest is whether and how the state-dependence of the noise can be optimized with respect to information transmission >>
<< also in a biophysically more relevant situation, multiplicative noise can enhance the signal-to-noise ratio (..) results shed light on a so far unexplored aspect of stochastic signal transmission in neural systems. >>
Jonathan Bauermann Benjamin Lindner. Multiplicative noise is beneficial for the transmission of sensory signals in simple neuron models. Biosystems. Volume 178, Apr 2019, Pages 25-31. doi: 10.1016/ j.biosystems.2019.02.002
https://www.sciencedirect.com/science/article/pii/S0303264718303861
mercoledì 30 giugno 2021
# gst: weird Nature; randomly arranged nanowire networks seem to behave, at the edge of chaos, like cortical neuronal cultures
mercoledì 9 settembre 2020
# gst: to reach detectability of a weak signal, they add background noise
martedì 19 aprile 2016
# s-psych: in the first moments ... to establish a rank asymmetry
<< You may not win friends, but a new study finds that you can influence people simply by lowering the pitch of your voice in the first moments of a conversation. >>
<< (..) people whose voices went down in pitch early on in an interaction were more likely to be seen as dominant and influential than those whose vocal pitch went up early in conversation. Those viewed as dominant also were more likely to convince others to go along with their ideas than those seen as less dominant. >>
<< “What excites me about this research is that we now know a little bit more about how humans use their voices to signal status,” said (..) Joey Cheng >>
Diana Yates. Psychology professor Joey Cheng and her colleagues found that changes in vocal pitch coincided with dominance, but not prestige, in small groups working together on a task. Apr 18, 2016 9:30 AM
https://news.illinois.edu/blog/view/6367/352099
<< Similar to the nonverbal signals shown by many non human animals during aggressive conflicts, humans display a broad range of behavioral signals to advertise and augment their apparent size, strength, and fighting prowess when competing for social dominance. Favored by natural selection, these signals communicate the displayer’s capacity and willingness to inflict harm, and increase responders’ likelihood of detecting and establishing a rank asymmetry, and thus avoiding costly physical conflicts. >>
<< Together [ from Study 1 and Study 2], findings suggest that humans use transient vocal changes to track, signal, and coordinate status relationships. >>
Cheng, Joey T., Tracy, Jessica L., et al. Listen, follow me: Dynamic vocal signals of dominance predict emergent social rank in humans. Journal of Experimental Psychology: General, Vol 145(5), May 2016, 536-547.
lunedì 2 gennaio 2017
# s-astro: exploring the sea of ‘noise’ to understand intricacies
<< Rather than trying to filter out the signal “noise” from stars around which exoplanets are orbiting, (AA) studied all of the signal information together to understand the intricacies within its structure >>
Jim Shelton. Searching a sea of ‘noise’ to find exoplanets — using only data as a guide. Dec. 20, 2016
http://news.yale.edu/2016/12/20/searching-sea-noise-find-exoplanets-using-only-data-guide
Sahil Agarwal, Fabio Del Sordo and John S. Wettlaufer. Exoplanetary Detection by multifractal spectral analysis. Publ. 2016 Dec. 20, 2016. The Astronomical Journal, Volume 153, Number 1; doi 10.3847/1538-3881/153/1/12
http://iopscience.iop.org/article/10.3847/1538-3881/153/1/12
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
lunedì 7 agosto 2017
# s-evol: a noise effect inside: new species pulsating by chance instead of ...
<< W. Andrew Barr, a visiting assistant professor of anthropology, published a report that says it's possible the pulse of new species could have occurred by chance and might not be directly related to climate change >>
Researcher's paper challenges the claim that the genus Homo originated in response to environmental changes. Aug 4, 2017
https://m.phys.org/news/2017-08-paper-genus-homo-response-environmental.html
W. Andrew Barr. Signal or noise? A null model method for evaluating the significance of turnover pulses. Paleobiology 2017 doi: 10.1017/pab.2017.21 Publ. online: 31 July 2017
also
<< "Nell' Arte tutto e', o dovrebbe essere, un esperimento". Gill Evans. >>
2127 - enigmistiche tonalita'. March 23, 2007
http://inkpi.blogspot.it/2007/03/2127-enigmistiche-tonalita.html
sabato 5 giugno 2021
#life: reliability, deception and lies of a signal (among the Siberian jay Perisoreus infaustus)
lunedì 18 giugno 2018
# geo: low frequency sounds that resemble the shape of the tornillo seismic waves
AA << characterize and interpret a new type of infrasound signal originating from the summit of Volcán Cotopaxi (Ecuador) >>
<< This infrasound waveform is a slowly decaying sinusoid with exceptional low‐frequency (..) and high quality factor (..) and resembles the shape of tornillo seismic waveforms. >>
Johnson JB, Ruiz MC, et al. Infrasound Tornillos Produced by Volcán Cotopaxi's Deep Crater. Geophysical Research Letters. doi: 10.1029/2018GL077766. Jun 13, 2018.
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL077766
Volcano music could help scientists monitor eruptions. American Geophysical Union. Jun 15, 2018.
https://m.phys.org/news/2018-06-volcano-music-scientists-eruptions.html
domenica 15 maggio 2016
# s-gene: extensive, quantitative perturbation approach to trace "the poetry" of gene regulatory networks
<< DNA content of our genomes resembles a complex biological language, composed of coding regions and regulatory regions. Although protein-coding regions in DNA could be compared to a traffic signal – utilizing a simple stop or go message – the regulatory regions in DNA are more like poetry. “The regulatory sites in DNA operate like a light switch to turn a gene on and off. In animals, it’s extremely complex,” said David Arnosti (..) “There might be hundreds of protein factors in the cell that bind to the gene and impact activity. And there might be hundreds of binding places.” He compares the “language” used in these regulatory sites to poetry. “It may be Emily Dickinson, or Shakespeare or Allen Ginsberg; but all are using ‘words’ to evoke thoughts and emotions, to control the message” >>
Val Osowski, Layne Cameron. DO GENES EXPRESS THEMSELVES THROUGH POETRY? A new study from Michigan State University makes inroads in learning to “read” the genome, a key goal of modern biology. Published: May 9, 2016
http://msutoday.msu.edu/news/2016/do-genes-express-themselves-through-poetry/
To understand transcription factor interactions on enhancers << (..) an extensive, quantitative perturbation analysis targeting the dorsal-ventral patterning gene regulatory network (GRN) controlled by Drosophila NF-κB homolog Dorsal [was used to test] the effects of cooperativity, repression, and factor potency >>
Rupinder Sayal, Jacqueline M Dresch, et al. Quantitative perturbation-based analysis of gene expression predicts enhancer activity in early Drosophila embryo. eLife 2016;5:e08445. Published May 6, 2016
mercoledì 3 giugno 2020
# behav: persistent neuronal firing during flight in flies, like a pulsating gambler who has to decide quickly
mercoledì 13 luglio 2016
# s-nanotech: displayed by an electronic tattoo
<< A new temporary "electronic tattoo" (..) that can measure the activity of muscle and nerve cells (..) is poised to revolutionize medicine, rehabilitation, and even business and marketing research. >>
<< The tattoo consists of a carbon electrode, an adhesive surface that attaches to the skin, and a nanotechnology-based conductive polymer coating that enhances the electrode's performance. It records a strong, steady signal for hours on end without irritating the skin. >>
<< The electrode (..) may improve the therapeutic restorationof damaged nerves and tissue -- and may even lead to new insights into our emotional life. >>
Nanotechnology 'tattoo' can map emotionsand monitor muscle activity. Jul 11, 2016.
http://www.nanowerk.com/nanotechnology-news/newsid=43905.php
domenica 24 dicembre 2017
# behav: a form of modified oxytocin (a molecule of love), with less adverse effects
<< Oxytocin is clinically used to induce labor, and there is interest in using this peptide to treat social disorders. However, oxytocin triggers adverse cardiovascular side effects >>
AA << generated ligands based on oxytocin with subtle modifications >>
this new molecular form << reduced social fear in mice and induced contractile activity in human myometrial strips without affecting cultured cardiomyocytes >>
Markus Muttenthaler, Asa Andersson, et al. Subtle modifications to oxytocin produce ligands that retain potency and improved selectivity across species. Sci. Signal. 2017; 10 (508): eaan3398. 10.1126/scisignal.aan3398. Dec 05, 2017.
http://stke.sciencemag.org/content/10/508/eaan3398
Scientists create molecule of love with less complications. Dec 12, 2017.
https://m.phys.org/news/2017-12-scientists-molecule-complications.html
lunedì 15 marzo 2021
# gst: an atomic imaging of a (slow) crack
giovedì 24 dicembre 2015
# s-trade-behav: "harbinger of failure" (human) scanners
<< (..) customers, termed “Harbingers of failure,” who systematically purchase new products that flop. Their early adoption of a new product is a strong signal that a product will fail—the more they buy, the less likely the product will succeed >>
Eric Anderson, Song Lin, et al. Harbingers of Failure. Journal of Marketing Research, 2015; 52 (5): 580 DOI: 10.1509/jmr.13.0415
http://journals.ama.org/doi/10.1509/jmr.13.0415
http://news.mit.edu/2015/harbinger-failure-consumers-unpopular-products-1223
mercoledì 18 maggio 2022
# brain: jazzy perceptions inside, there’s more to all the noise; even in the dark, neurons of the visual cortex chat
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
venerdì 17 maggio 2019
# sec: adversarial audio attacks; small sound perturbations to hack a Machine Learning model and remedies
<< Adversarial audio attacks can be considered as a small perturbation unperceptive to human ears that is intentionally added to the audio signal and causes a machine learning model to make mistakes. >>
Mohammad Esmaeilpour, Patrick Cardinal, Alessandro Lameiras Koerich. A Robust Approach for Securing Audio Classification Against Adversarial Attacks. arXiv:1904.10990 [cs.LG] Apr 24, 2019.
https://arxiv.org/abs/1904.10990
Ingrid Fadelli. An approach for securing audio classification against adversarial attacks. May 7, 2019.
https://m.techxplore.com/news/2019-05-approach-audio-classification-adversarial.html