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sabato 30 maggio 2020

# gst: apropos of unexpected Hopfion tangles

<< a certain geometrical structure of knots, which scientists call a Hopfion, manifests itself in unexpected corners of the universe, ranging from particle physics, to biology, to cosmology. >>

<< In a recent theoretical study, (..) (AA) discovered the presence of the Hopfion structure in nano-sized particles of ferroelectrics. >>

<< The Hopfion is a very abstract mathematical concept, (..) but the structure shows up in hydrodynamics, electrodynamics and even in the packing of DNA and RNA molecules in biological systems and viruses. >> Valerii Vinokur

<< When we visualized the polarization, we saw the Hopfion structure emerge, (..) We thought, wow, there is a whole world inside of these nanoparticles. >> Igor Luk'yanchuck.

Savannah Mitchem. Novel insight reveals topological tangle in unexpected corner of the universe. Argonne National Laboratory. May 26, 2020.


Luk’yanchuk I., Tikhonov Y., et al. Hopfions emerge in ferroelectrics
 Nat Commun 11, 2433. doi: 10.1038/ s41467-020-16258-w. May 15, 2020.


giovedì 28 maggio 2020

# math; a weird phenomenon, the Banach-Tarski paradox, how to create two balls by reassembling one in 3-D space.

<< A famous geometrical theorem called the Banach-Tarski paradox says that if you have a ball in 3-D space and split it into a few specific pieces, there is a way to reassemble the parts so that you create two balls. (..) When the two new balls are created, they will both be the same size as the first ball. >>  Thomas Britz. 

Sherry Landow. The mystique of mathematics: 5 beautiful math phenomena. University of New South Wales. May 20, 2020.


Banach–Tarski paradox



mercoledì 27 maggio 2020

# life: how social media could act to dehumanize the 'dehumanizable' ...

<< Fundamentally, we wanted to examine how online platforms can normalize hatred and contribute to dehumanization, (..) We found that the language used in these Facebook interactions hewed very closely to three stages we see in Terrell Northrup's theory of intractable conflict (..) One stage is the threat (..) A second stage is distortion (..) A third stage is rigidification >> Jessica Jameson.

Matt Shipman. How social media platforms can contribute to dehumanizing people. North Carolina State University. May 20, 2020


Tal Orian Harel, Jessica Katz Jameson, Ifat Maoz. The Normalization of Hatred: Identity, Affective Polarization, and Dehumanization on Facebook in the Context of Intractable Political Conflict. Social Media + Society. doi: 10.1177/ 2056305120913983. May 12, 2020


Also

keyword 'facebook' in FonT:


martedì 26 maggio 2020

# gst: predict stability in a collapsing ring

<< it is possible to predict the stability of a collapsing ring by counting its kinks. (..) (AA) group describes experiments they conducted that involved placing an elastic ring over a soap film and recording what happens when the ring collapses. >>

Bob Yirka. Counting kinks in a collapsing ring to predict stability. May 20, 2020.


Finn Box, Ousmane Kodio, et al. Dynamic Buckling of an Elastic Ring in a Soap Film. Phys. Rev. Lett. 124, 198003. 13 May 13, 2020.



sabato 23 maggio 2020

# evol: apropos of a big mystery; Neanderthal may have been surrounded and terminated (killed) by Sapiens competition (and/or probably by Sapiens multitudes, their viruses, their chatter, ...)

<< Climate scientists from the IBS Center for Climate Physics discover that, contrary to previously held beliefs, Neanderthal extinction was neither caused by abrupt glacial climate shifts, nor by interbreeding with Homo sapiens. According to new supercomputer model simulations, only competition between Neanderthals and Homo sapiens can explain the rapid demise of Neanderthals around 43 to 38 thousand years ago. >>

Supercomputer model simulations reveal cause of Neanderthal extinction. Institute for Basic Science. May 20, 2020.


<< Anatomically Modern Humans are the sole survivor of a group of hominins that inhabited our planet during the last ice age and that included, among others, Homo neanderthalensis, Homo denisova, and Homo erectus. Whether previous hominin extinctions were triggered by external factors, such as abrupt climate change, volcanic eruptions or whether competition and interbreeding played major roles in their demise still remains unresolved. (..)  a realistic extinction of the Neanderthal population can only be simulated when Homo sapiens is chosen to be considerably more effective in exploiting scarce glacial food resources as compared to Neanderthals. >>

Axel Timmermann. Quantifying the potential causes of Neanderthal extinction: Abrupt climate change versus competition and interbreeding. Quaternary Science Reviews. 
Volume 238, 15 June 2020, 106331. May 15, 2020. 


Also

keyword 'Neanderthal' in FonT



giovedì 21 maggio 2020

# pharma: drawing 'magic strings' for GPCRs

<< Psychedelics such as LSD and magic mushrooms have proven highly effective in treating depression and post-traumatic stress disorders, but medical use of these drugs is limited by the hallucinations they cause. >>

<< What if we could redesign drugs to keep their benefits while eliminating their unwanted side effects? >> Ron O.  Dror. 

<< Dror's team describes discoveries that could be used to minimize or eliminate side effects in a broad class of drugs that target G protein-coupled receptors, or GPCRs. GPCRs are proteins found in all human cells. LSD and other psychedelics are molecules that attach to GPCRs, as are about a third of all prescription drugs, including antihistamines, beta blockers and opioids. So important is this molecular mechanism that Stanford professor Brian Kobilka shared the 2012 Nobel Prize in Chemistry for his role in discovering how GPCRs work. >>

Tom Abate. What if we could design powerful drugs without unwanted side effects? Stanford University.  May 19, 2020.


The << work could provide a framework for the rational design of drugs that are more effective and have fewer side effects. >>

Carl-Mikael Suomivuori, Naomi R. Latorraca, et al. Molecular mechanism of biased signaling in a prototypical G protein–coupled receptor. Science. 
Vol. 367, Issue 6480, pp. 881-887
doi: 10.1126/ science.aaz0326. Feb 21, 2020.


Also

keyword 'magic' in FonT


keyword 'GPCR'  in Wikipedia


mercoledì 20 maggio 2020

# gst: as a Lorenz's butterfly, even small disturbances can trigger catastrophic storms

<< meteorologists still have questions about how hurricanes develop. Now, Florida State University researchers have found that even the smallest changes in atmospheric conditions could trigger a hurricane, >>

Researchers find even small disturbances can trigger catastrophic storms. Florida State University. May 13, 2020.


Jacob D. Carstens,  Allison A. Wing. Tropical Cyclogenesis From Self‐Aggregated Convection in Numerical Simulations of Rotating Radiative‐Convective Equilibrium. Journal of Advances in Modeling Earth Systems. Vol 12, Issue 5. doi: 10.1029/ 2019MS002020. Apr 24, 2020.


Also

Edward Lorenz. Deterministic nonperiodic flow. Journal of Atmospheric Sciences. Vol.20 130—141. 1963. in:  Lynn M. Resler. Edward N Lorenz’s 1963 paper, “Deterministic nonperiodic flow”, in Journal of the Atmospheric Sciences, Vol 20, pages 130–141: Its history and relevance to physical geography. Progress in Physical Geography: Earth and Environment. Vol 40 issue 1,  175-180. doi: 10.1177/ 0309133315623099. Jan 21, 2016. 


sabato 16 maggio 2020

# behav: nomadic impulse, they return to Death Valley

<< More than a century after railroads, ranchers and hunters vanquished their ancestors, pronghorn antelope are returning to this unforgiving expanse of desert along the California-Nevada border. >>

<< the American pronghorn, North America's land speed champion, may be extending its migratory range into the Mojave Desert once again from cooler seas of sage nearly 100 miles to the north and east. >>

Louis Sahagun. Desert mystery: Why have pronghorn antelope returned to Death Valley? May 13, 2020.


venerdì 15 maggio 2020

# behav: the smart sleep of flies (Drosophila melanogaster)

<< Flies that cannot take to the air respond by sleeping more as they learn to adapt to their flightlessness, (..) The findings, (..) suggest that sleep may be an evolutionary tool that helps animals adapt to challenging new situations. >>

<< Fruit flies' sleep looks a lot like people's. Baby flies need a lot of sleep, but as they get older, their need for sleep diminishes. Flies become more alert with caffeine and drowsier with antihistamines. And if you keep a fly awake one day, it will sleep more the next. >>

Flies sleep when need arises to adapt to new situations. Washington University School of Medicine. May 8, 2020.


K. Melnattur, B. Zhang, P. J. Shaw. Disrupting flight increases sleep and identifies a novel sleep-promoting pathway in Drosophila. Sci Adv 
Vol. 6, no. 19, eaaz2166. doi: 10.1126/sciadv.aaz2166. May 8, 2020.


Also

keyword 'Drosophila' in FonT


keyword 'mosca' in Notes (quasi- stochastic poetry)


giovedì 14 maggio 2020

# ecol: when a predator could help his prey to adapt to an uncertain future (among the fly Iteomyia salicisverruca) ...

<< The loss of biodiversity is rewiring the web of life; however, it is uncertain how this will affect the ability of remaining populations to evolve and adapt to future environments. >>

AA << conducted a field experiment that either maintained a natural community of predators or removed all but one of the predators that was able to impose selection on a common prey. (They) found that the loss of predators acted to constrain prey evolution toward a particular combination of traits. Moreover, (they) found that the loss of predators could make it more difficult for prey to adapt to uncertain future environments. Taken together, (these) results suggest that the simplification of the web of life may constrain the adaptive potential of remaining populations. >>

Matthew A. Barbour, Christopher J. Greyson‐Gaito, et al. Loss of consumers constrains phenotypic evolution in the resulting food web. Evolution Letters. doi: 10.1002/ evl3.170. Apr 20, 2020. 


<< Thinking about the big picture, our study hints at a potential insidious side effect of extinctions, (..) The extinction of natural enemies may compromise the ability of remaining species to adapt and persist in an uncertain and changing world. If this is true, this would put many ecosystems at even greater risk than we currently realize. >> Matthew A. Barbour.

Predators help prey adapt to an uncertain future. University of Zurich. 
 May 4, 2020




mercoledì 13 maggio 2020

# gst: the generation of solitary waves to move and direct a pulse-drive bot

<< The unique properties of nonlinear waves have been recently exploited to enable a wide range of applications, including impact mitigation, asymmetric transmission, switching, and focusing. (..) (AA) demonstrate that the propagation of nonlinear waves can be as well harnessed to make flexible structures crawl. By combining experimental and theoretical methods, (they) show that such pulse-driven locomotion reaches a maximum efficiency when the initiated pulses are solitons and that (their) simple machine can move on a wide range of surfaces and even steer. >>

<< nonlinear waves (..) demonstrates that they offer a new platform to make flexible machines to move. >>

Bolei Deng, Liyuan Chen, et al. Pulse-driven robot: Motion via solitary waves. Science Advances. Vol. 6, no. 18, eaaz1166. doi: 10.1126/ sciadv.aaz1166. May 1, 2020. 


Pulse-driven robot: Motion via solitary waves. Thamarasee Jeewandara. May 8, 2020.


giovedì 7 maggio 2020

# gst: shape-shifting dynamics; tiny evolutionary changes have turned a tongue into a fast elastic recoil mech (in salamanders)

<< relatively minor changes in the musculoskeletal morphology of the tongue apparatus and in the timing of muscle activation have, through evolutionary time, transformed a muscle-powered system with modest performance and high thermal sensitivity into a spring-powered system with extreme performance and thermal robustness, in parallel in both major groups of this largest family of salamanders. High performance and thermal robustness evolve together, indicating they are both properties of the same elastic-recoil, "bow-and-arrow" mechanism. Similar evolutionary patterns may be found in other ectothermic animals with extreme performance. >>

Stephen M. Deban, Jeffrey A. Scales, et al. Evolution of a high-performance and functionally robust musculoskeletal system in salamanders. PNAS. doi: 10.1073/pnas.1921807117. Apr 27, 2020.


Bob Yirka. Minor evolutionary changes helped transform the salamander tongue into a fast elastic recoil mechanism. Apr 28, 2020.


Also

keyword 'tiny' in FonT



sabato 2 maggio 2020

# life: At this point ... are you a pseudo naked mole-rat? Well, it would be useful ...

<< African naked mole-rats are sometimes referred to as animal superheroes. They resist cancer, tolerate pain, and live a remarkably long time. They're also known for their ability to handle high levels of carbon dioxide and can go for several minutes without oxygen. >>

AA << may have found the mole-rats' kryptonite: they need high levels of carbon dioxide to function. (..) the mole-rats don't just tolerate high levels of carbon dioxide in their crowded nests; it appears that they actually require it. When they reach the hot surface and start heat-induced hyperventilation in the fresh air, it sends them into seizures. >>

AA << found that this curious need for carbon dioxide is explained by the presence of a missense mutation in a gene that encodes the major neuronal chloride transporter known as KCC2. >>

Similarly, families of people << with a genetic predisposition for febrile seizures carry the very same genetic change. >>

<< The identification of the genetic polymorphism in the naked mole-rat KCC2 was a surprise, (..) Aside from a small subset of humans, naked mole-rats are now the only other mammals known to harbor this variant. >> Martin Puskarjov.

Naked mole-rats need carbon dioxide to avoid seizures and here's why. Cell Press. Apr 30, 2020. 


Michael Zions, Edward F. Meehan, et al. Nest Carbon Dioxide Masks GABA-Dependent Seizure Susceptibility in the Naked Mole-Rat. Curr Biol. doi: 10.1016/j.cub.2020.03.071. Apr 30, 2020.


Also 

the 'naked mole-rats paradox'

Scientists explain why naked mole-rats' longevity contradicts accepted aging theory. Missouri University of Science and Technology. Feb 10, 2020.


Wenyun Zuo, Xiaolong Tang, Chen Hou. Why Naked Mole-Rats Have High Oxidative Damage but Live a Long Life: A Simple Explanation Based on the Oxidative Stress Theory of Aging. 
Adv Geriatr Med Res. 2(1): e200006. doi: 10.20900/agmr20200006. Jan 7, 2020. 


Also

keyword 'naked' in FonT