Wednesday, January 13, 2021

Origamibots and Trefoil Knots - Messengers of the Future


Quantum origami and light knots, we just can't get enough.

image credit: Microphoto of a human hair by Robert Vierthaler for the the Nikon Small World 2020 competition.

Origami microbots - Centuries-old artform guides cutting-edge advances in tiny machines
Aug 2020, phys.org

Origamibots.

They change shape depending on what they need to do. It's more efficient, and they can now be made smaller, faster, and more precise. It also sounds like it's covered in a thin layer of gold, then polymer, and this allows heat to be applied and to travel across the surface of the microbot, controlling its folds with hots and colds. 

via University of Michigan, Yi Zhu et al, Elastically and Plastically Foldable Electrothermal Micro‐Origami for Controllable and Rapid Shape Morphing, Advanced Functional Materials (2020). DOI: 10.1002/adfm.202003741

This is a Kressling pattern, courtesy of NOVA

Building mechanical memory boards using origami
Aug 2020, phys.org

It's an origami mechanical memory board. It's called a Kresling-inspired mechanical switch, or KIMS. Kressling pattern origami are ones that can flip between two shapes, depending on how you configure them, and this one is configured by vibrating a platform on which it rests. The vibration activates a mechanical switch.
 
This is just fucking crazy. Imagine making origami metamaterial that have properties like an electric circuit. It would be like a 3D computer where the transistors are an integral part if the structure, instead of being in a central location, they're all over, like cells in a body.

Framed Trefoil Knot, University of Ottawa

Classified knots - Researchers create optical framed knots to encode information
Oct 2020, phys.org

More origami people. Made of lights, of course.

Optical framed knots distributing secret cryptographic keys, providing a platform for topological quantum computations, they say.

Framed knots are when you take a strip of paper and try to tie a knot with it, kind of like M.C.Escher's mobius strip.

It has to do with light beams, structured light beams, using beam-shaping techniques that can actually shape the light beam to have knots in it? Cryptographic code knots sounds like a great idea.

Hugo Larocque et al, Optical framed knots as information carriers, Nature Communications (2020). DOI: 10.1038/s41467-020-18792-z

Face Rec and Image Tech


Deepfake used to attack activist couple shows new disinformation frontier
Experts in deceptive imagery used state-of-the-art forensic analysis programs to determine that Taylor’s profile photo is a hyper-realistic forgery - a “deepfake.”
Something about the Ventriloquist's Dummy and the dangers of impersonating an influential leader.



Image cloaking tool thwarts facial recognition programs
Aug 2020. phys.org

Reverse camoufaluge? Fill the pool with dirty data; it's a simple approach. This technique is named Fawkes after the V for Vendetta guy, also known as the Anonymous Mask from the online shadow activist group circa 2010.

"What we are doing is using the cloaked photo in essence like a Trojan Horse, to corrupt unauthorized models to learn the wrong thing about what makes you look like you and not someone else," Fawkes co-creator Ben Zhao, a computer science professor at the University of Chicago, said.

"Our original goal was to serve as a preventative measure for Internet users to inoculate themselves against the possibility of some third-party, unauthorized model," the team recently stated in a FAQ sheet.


Deepfake detection tool unveiled by Microsoft
Sep 2020, BBC News
"The only really widespread use we've seen so far is in non-consensual pornography against women," commented Nina Schick, author of the book Deep Fakes and the Infocalypse.

"But synthetic media is expected to become ubiquitous in about three to five years, so we need to develop these tools going forward

Synthetic media and fingerprinted news - Microsoft has teamed up with the BBC, among other media organisations, to support Project Origin, an initiative to "mark" online content in a way that makes it possible to spot automatically any manipulation of the material.

New photon-counting camera captures 3-D images with record speed and resolution
Apr 2020, phys.org

24,000 fps:
The camera's speed makes it possible to measure the time a photon hits the sensor very precisely. This information can be used to calculate how long it takes individual photons to travel the distance from a source to the camera, known as time-of-flight. Combining time-of-flight information with the ability to capture a million pixels simultaneously enables extremely high-speed reconstruction of 3-D images.

In Bits and Pieces


For those of you who can't wait to be fully cybernetic; we're almost there.

And the above image is a microphoto of the microvasculatire of the optic nerve by Dr. Dong An for the Nikon Small World 2020 competition.


Nanotechnology applied to medicine - The first liquid retina prosthesis
Jul 2020, phy.org

Artificial Liquid Retinal Prosthesis: Already on the second generation of artificial retinas, this one is biomimetic:
Compared to other existing approaches, the new liquid nature of the prosthesis ensures fast and less traumatic surgery that consists of microinjections of nanoparticles directly under the retina, where they remain trapped and replace the degenerated photoreceptors; this method also ensures increased effectiveness.
And another microphoto of retinal blood vessels by Dr. Nicolás Cuenca and Isabel Ortuño-Lizarán, also for the the Nikon Small World 2020 competition.

Using light instead of electricity in cochlear implants
Aug 2020, phys.org

And here, a next-generation cochlear prosthesis. 

Nanodiamonds and Quantum Crystals


Team finds path to nanodiamond from graphene
Oct 2020, phys.org

Not sure what's more exciting the pic or nanodiomands in general. (image: Diamane, credit to Pavel Sorokin)

They call it diamane, but nanodiamond sounds good enough no?

A "pinpoint" of pressure on a thick sandwich of graphene layers can propagate a crystallizing chemical reaction. Normally, to make diamonds, you need a lot more pressure than a pinpoint. But being nano- and all, we throw out all the rules, and can now make single-crystal diamond film. 


Researchers building a harder diamond, called pentadiamonds
Jul 2020, phys.org

Pentadiamonds.

Also, the "diamond anvil cell" is a high-pressure device used in geology, engineering, materials science experiments, and heavy metal band names.


Crystal wars - Research may lead to more efficient crystal engineering methods
Jul 2020, phys.org

Just here for the crystals:
A team of researchers at the University of Tokyo and Fudan University has studied the process of crystallization when more than one structural arrangement is possible. By reducing the noise from random fluctuations, they found that transient precursors of the various crystalline orderings coexist and compete with each other. This work may help lead to more efficient crystal engineering methods.
Crystal engineering.


First sighting of mysterious Majorana fermion on a common metal
Apr 2020, phys.org
Majorana fermions require growing very precise crystals of semiconducting material and it is very challenging to turn these into high-quality superconductors.

Physicists at MIT and elsewhere have observed evidence of Majorana fermions—particles that are theorized to also be their own antiparticle—on the surface of a common metal: gold. This is the first sighting of Majorana fermions on a platform that can potentially be scaled up. 

"The next push will be to take these objects and make them into qubits, which would be huge progress toward practical quantum computing," adds co-author Patrick Lee, the William and Emma Rogers Professor of Physics at MIT.

Quantum simulation of quantum crystals
Aug 2020, phys.org

Quantums crystals and BECs.

They're artificial and highly fragile systems, but a place where we can play with atoms.


Scientists make insta-bling at room temperature
Nov 2020, phys.org

Diamonds muthafu**

Tuesday, January 12, 2021

Thermodynamic Hallucinations


What's up with that? 

Just looking for headlines absent from the search results. 
As of today's date, this should be number one (of one). 

Totally unrelated image via the Nikon Small World competition: Actin, by Dr. Andrew Moore and Dr. Dvir Gur
 

Sunday, January 10, 2021

Exobiological Skin Shell Sensors and Remote Control Metabolism Engineering



Just trying to come up with a catchy title for a quick list of developments in color application technology, but also biomimicry, wearables, and radioactive fungi. We're finishing off with some recent bits in the endless stream of synthetic biology advancements that will eventually define the 21st century.

Images courtesy of Nikon's Small World Challenge, best microscopy photos you can get!

The first one is a snail tongue by Dr. Igor Siwanowicz, and has nothing to do with the articles below.


Blue dye from red beets - Chemists devise a new pigment option
Apr 2020, phys.org

Non-toxic and Blue dye do not belong in the same sentence, historically. But now, a new class of dyes called pseudo-natural dyes use the same molecules that come from bright red beets (betalains), and they change the carbon-nitrogen chemical bond to a carbon-carbon bond. These new molecules are called quasibetalains, and they're blue.

On a sidenote, I do not recognize the opening statement in the above link, which says that blue is the most liked color the world over. In my art room, in the box of color pencils, and in the box of markers, both followed the same pattern every year for every class: the red pencils are the first to go, followed by blue; it gets fuzzy after that, but they all end up with nothing but brown, orange and yellow, and in that order. After all, brown is the entropic heat death of the rainbow, kind of an anti-color. 

B. C. Freitas-Dörr et al. A metal-free blue chromophore derived from plant pigments, Science Advances (2020). DOI: 10.1126/sciadv.aaz0421
http://dx.doi.org/10.1126/sciadv.aaz0421


Red light for stress - A color-changing organic crystal
May 2020, phys.org

Here we've got some organic crystals that change color based on pressure, but that can also return to their original shape. And that's called superelastochromism.

The idea here is to use them as sensors to show you where a building is getting out of whack. But there's a whole lot more you can imagine doing with these.

via the University of Tokyo: Toshiki Mutai et al, A superelastochromic crystal, Nature Communications (2020). DOI: 10.1038/s41467-020-15663-5


Liquid crystals create easy-to-read, color-changing sensors
Jul 2020, phys.org

Similar thing here; they're pushing and pulling liquid crystals to manipulate their color. The thing is, these don't just change color based on pressure, but even temperature. The walls in your room could change if the temperature shifts too quickly, for example. 
 
Then again, if you're wearing this, it could show you inflammation in your body. 

via the University of Chicago: "Prolate and oblate chiral liquid crystal spheroids". Juan de Pablo et al. Science Advances (2020). DOI: 10.1126/sciadv.aba6728 

Mohamed Ghassen Nouira makes purple dye.

Passion for purple revives ancient dye in Tunisia
Aug 2020, phys.org

Emperors hate him. This guy figures out how to take special snails and make purple dye out of them, just like how they used to do. Imperial clothiers and dye-makers knew how to do this centuries ago, and the art was lost to the time in between us and them. 

And that wasn't a mistake. The process of making Tyrian Purple was a secret, kind of like how we try to keep people from making believable hundred dollar bills. 

Think about it, if you, a Carthaginian hustlepimp, could make your own purple robe and deceive the court into thinking you were royalty, kind of like an ancient Borat, you could cause a ruckus. And we can't have a ruckus in the upper reaches of the royal elites. 

More importantly, empires made their fortunes selling this dye to other empires. Can't have some guy in his garage creeping into your marketshare. 

100,000 grams (100kg) of shelled murex yields 1 gram of Tyrian Purple, and goes for $2,400 - $4,000 per gram, and takes about a week's worth of work.

Sidenote, if you search the words "royal elite" it reeks of fake shit and dupery, which I think is funny because it's a redundant term that would only be used by people who don't really know what either word means.


Testing Chernobyl fungi as a radiation shield for astronauts
Aug 2020, phys.org

Bioshell.

They want to coat spaceships in a shell of superfungus to protect from radiation. They didn't create these fungi by engineering them in a lab; they found them. 

And where are on earth are you going to find an organism that metabolizes radioactive isotopes? Yes, thank you Chernobyl.

Graham K. Shunk et al. A Self-Replicating Radiation-Shield for Human Deep-Space Exploration: Radiotrophic Fungi can Attenuate Ionizing Radiation aboard the International Space Station, bioRxiv (2020). DOI: 10.1101/2020.07.16.205534. http://dx.doi.org/10.1101/2020.07.16.205534

Beetle leg - Aigars Jukna

Low-cost, fly footpad-like adhesive structure capable of repeated attachment/detachment
Aug 2020, phys.org

The design is based on fly feet, fine, that's pretty standard biomimicry. But the way they learned how to manufacutre the thing is by looking at how the fly itself makes flies, in the pupa. That's next level biomimicry. And it allows you to repeatedly stick and unstick  without losing any of its stickiness.

Ken-ichi Kimura et al, Framework with cytoskeletal actin filaments forming insect footpad hairs inspires biomimetic adhesive device design, Communications Biology (2020). DOI: 10.1038/s42003-020-0995-0


Florida mosquitoes - 750 million genetically modified insects to be released
Aug 2020, BBC News

I'm not sure where this belongs on this list, but modified mosquitoes were approved by federal regulators, fuck yeah.


Development of photovoltaics that can be applied like paint for real-life application
Sep 2020, phys.org

It's a solar cell solution that can coat surfaces. Eventually it will coat your body, so that you can live forever.

So Hyun Park et al, Developement of highly efficient large area organic photovoltaic module: Effects of nonfullerene acceptor, Nano Energy (2020). DOI: 10.1016/j.nanoen.2020.105147


Evergreen needles act as air quality monitors
Sep 2020, phys.org

Biosensors that measure the magnetism of the particulate matter that accumulates on the needles. Pretty smart.

Grant Rea‐Downing et al, Evergreen needle magnetization as a proxy for particulate matter pollution in urban environments, GeoHealth (2020). DOI: 10.1029/2020GH000286

Bindweed Epidermis - Michael Gibson

Electronic skin promises cheap and recyclable alternative to wearable devices
Nov 2020, phys.org

Man.

"Stretchy and fully-recyclable circuit board that's inspired by, and sticks onto, human skin."

via University of Colorado Boulder:  "Heterogeneous integration of rigid, soft, and liquid materials for self-healable, recyclable, and reconfigurable wearable electronics" Science Advances (2020). DOI: 10.1126/sciadv.abd0202


Engineers print wearable sensors directly on skin without heat
Oct 2020, phys.org

Direct printing for on-body sensors, usually hindered by the bonding process on skin. You can't sinter skin. So they add an "aid layer", basically a protective insulator for the skin that bonds at room temperature. And room temperature.


Artificial skin heals wounds and makes robots sweat
Jun 2020, phys.org

It's about time these robots take over. This is a skin (or "smart coating" when we're trying not to make it sound like the robots will become human and take over) that control fluid flow across its membrane via radio, or UV. And it's made of liquid-crystal molecules, like LCD.

Nylon Stockings - Alexander Klepnev

Thanks to flexoskeletons, these insect-inspired robots are faster and cheaper to make
Apr 2020, phys.org

Just flexoskeletons.


Machine learning takes on synthetic biology - algorithms can bioengineer cells for you
Sep 2020, phys.org

This one is about creating virtual laboratories that produce probable outcomes. They used to say, if you can't build it, you can't know it. But now, we just let the computer figure it out. 

Anyway, they specifically say engineering microbiomes. That's a bit new, because although engineering cells has now penetrated the consumer market (fake meat), engineering the entire ecosystem is a new frontier.

Nature Communications. A machine learning Automated Recommendation Tool for synthetic biology. Tijana Radivojević. (2020). DOI: 10.1038/s41467-020-18008-4

Unopened Flower Bud - Charles B. Krebs


Chemists expand genetic code of E. coli to produce 21st amino acid, giving it new abilities
Aug 2020, phys.org

Bodymods and beyond.

They've created a new amino acid, a "noncanonical amino acid" which kind of means not a real amino acid. It's called 5-hydroxyl-tryptophan (5HTP), and it's now the 21st amino acid. Kind of like how the ampersand was the 27th letter in the alphabet for a while.

They put the code for this protein into a "blank" space of the E. coli's genetic code. This means that the bacteria is now a factory that we designed to produce a molecule. It's a living factory. We're all living factories, bioreactors. But we don't make anything we want with our bodies. In this case, we've reverse-engineered the "making" process itself. The is called biohacking. 

Yuda Chen et al, Creation of Bacterial Cells with 5-Hydroxytryptophan as a 21st Amino Acid Building Block, Chem (2020). DOI: 10.1016/j.chempr.2020.07.013


Researchers develop a yeast-based platform to boost production of rare natural molecules
Aug 2020, phys.org

Again, biofarms of the future.


Engineers reprogram yeast cells to become microscopic drug factories
Sep 2020, phys.org

"Metabolic engineering" is another term for this. They're reprogramming yeast cells at the genetic level to convert sugars and amino acids into drugs. (And someting about the name has me thinking these are hallucinogenic drugs?)

Biosynthesis of medicinal tropane alkaloids in yeast, Nature (2020). DOI: 10.1038/s41586-020-2650-9 

Duckweed Root Decay - Dr. Robert Markus

Soil-powered fuel cell promises cheap, sustainable water purification
Oct 2020, phys.org

Soil microbial fuel cells (SMFCs)


Lowering atmospheric CO2 in large-scale renewable energy electrochemical process
Jun 2020, phys.org

This plus synthetic biology aka the biological revolution, or the 5th(?) industrial revolution, and I say that in 100 years, we'll be taking more CO2 out of the air than what we put in. 
Researchers at the National Renewable Energy Laboratory (NREL) have been focusing on improving electrochemical routes to convert CO2, which would otherwise be released into the atmosphere, into a range of value-added products.

the research team created a high rate of formate production and product selectivity, the latter of which is critical to reduce the need for further costly separations processes downstream. The formate could then be fed to biological organisms or coupled with enzymes, resulting in robust interactions between the formate and enzymes that yield high-density chemicals or fuels, such as ethylene or ethanol, respectively.

The program's larger goal is to use highly efficient electrons at industry scale to convert a waste compound such as CO2 into a multitude of more useful industry-relevant, energy-dense fuels or chemicals, such as polyethylene, which has a large global market.

Google conducts largest chemical simulation on a quantum computer to date
Aug 2020, phys.org

Stuff like this scares the shit out of me, although it's hard to articulate why. Probably because quantum chemical simulator is another word for reality generator, and I just don't think we're ready to activate the mass transference device yet.

Hartree-Fock on a superconducting qubit quantum computer, Science  28 Aug 2020: Vol. 369, Issue 6507, pp. 1084-1089, DOI: 10.1126/science.abb9811


IBM announces AI based chemistry lab - RoboRXN
Sep 2020, phys.org

Same as above.

Automating chemical synthesis with RoboRXN. https://www.ibm.com/blogs/research/2020/08/roborxn-automating-chemical-synthesis/

More Snail Tongue - Dr. Igor Siwanowicz

Remote control of blood sugar - Electromagnetic fields treat diabetes in animal models
Oct 2020, phys.org

And lastly; completely fucking bonkers.

Exposing diabetic mice to a combination of static electric and magnetic fields for a few hours per day normalizes two major hallmarks of type 2 diabetes. And it works by remote control, and it can be applied in your sleep to normalize your blood sugar for the rest of the day.

EMF therapy. Sounds like absolute and total bullshit. Remote control blood sugar.

And this makes it even better; "The initial finding was pure serendipity." One scientist borrowed another scientist's mice; he was working on EMF exposure, and she was working on bloodsugar. Using his mice in her experiment, she found something strange going on. Now we think the EMFs prolong activation of superoxide molecules in the liver, rebalancing the body's response to insulin.

Later, they even treated human liver cells with EMFs, for six hours, and found that the surrogate marker for insulin sensitivity improved.

Calvin S. Carter et al, Exposure to Static Magnetic and Electric Fields Treats Type 2 Diabetes, Cell Metabolism (2020). DOI: 10.1016/j.cmet.2020.09.012

Sunday, August 16, 2020

Sociothermodynamics and Predictive Analytics

 

Investigating dynamics of democratic elections using physics theory

Feb 2020, phys.org

 

Sometimes, physics theories and models can be used to study seemingly unrelated phenomena, such as social behaviors or social dynamics.

 

While human beings are not exactly similar to individual physical particles, theories or techniques that physicists use to analyze "behavioral patterns" in atoms or electrons may aid the general understanding of large-scale social behaviors, as long as these behaviors do not depend on small-scale details.

 

Based on this idea, some researchers use physics theories to investigate social behaviors that take place during democratic elections, for example.

 

The very idea of a quantifiable social network was unknown to the average person prior to the year 2000. (Check out Barabasi's Links for a reminder of what the world was like at that time.) Now, the idea is clear as day, with the trademark "nodes-and-links" emblazoned into the retina of any 21st century citizen. We all understand what a social network is, and being that a social network is the marriage of sociology and network science, we can all understand these models and their implications.

 

Below is a list of articles related to sociothermodynamics, although I tend to use this term as a synonym for predictive analytics as well, so there are other articles about using all kinds of big data (like semantic analysis) to make sense out of the sloppy sociobiological mess that we spread all over the planet. And speaking of spreading all over, the last article uses biological data from slime molds to describe human social behavior.

 

 

The physics that drives periodic economic downturns

Mar 2020, phys.org

 

There exist universal mechanisms that give rise to laws governing the growth of economics.

 

The way spilled milk spreads across the floor can explain why economic downturns regularly occur, as a natural feature of physics, rooted in the time-dependent movement of spreading over an area. Growth of the innumerable spreading phenomena over time follows the shape of an "S curve" otherwise known as the sigmoid function.

 

A bottle of milk spilled on the floor will have a small initial footprint, followed by a rapid finger-shaped expansion across the kitchen's tiles, followed by a final phase of slow creep.

 

This same history of slow, fast, slow can be seen in chemical reactions, population growth, the adoption of new technology and even the spreading of new ideas.

-Adrian Bejan et al, Energy theory of periodic economic growth, International Journal of Energy Research (2020). DOI: 10.1002/er.5267

 

 

Secularism and tolerance of minority groups predicts future prosperity of countries

Feb 2020, phys.org

 

Changes in culture generally come before any improvements in wealth, education and democracy, rather than the other way around.

 

Promoting democracy, whether through economic exchange or regime change, will only succeed if combined with promoting openness and tolerance of minority groups.

 

(In the 20th Century) places which had the greatest improvement also tended to have pre-existing secular and tolerant cultures.

 

 

Study of 62 countries finds people react similarly to everyday situations

June 2020, phys.org

 

The world is a much more similar and unified place than we once thought.

 

[Because at the right scale, we are all just particles banging around on the surface of the planet.]

 

This project is unprecedented. Very few international studies look at relationships between more than two countries, let alone 62," Lee, a doctoral researcher in the lab of UCR Distinguished Professor David Funder, and the lead author of the paper.

 

 

Facebook users change their language before an emergency hospital visit - study

Mar 2020, phys.org

 

Researchers from the Perelman School of Medicine at the University of Pennsylvania and Stony Brook University's Computer Science Department compared patients' Facebook posts to their medical records, which showed that a shift to more formal language and/or descriptions of physical pain, among other changes, reliably preceded hospital visits.

 

 

Wikipedia visits to disease outbreak pages show impact of news media on public attention

Mar 2020, phys.org

 

During the 2016 Zika outbreak, news exposure appears to have had a far bigger impact than local disease risk on the number of times people visited Zika-related Wikipedia pages in the U.S.

 

Previous research has explored how public opinion responds to media exposure during an emerging outbreak, but has mostly relied on surveys rather than observational data.

 

The analysis showed that Zika-related Wikipedia page view counts during the outbreak were highly synchronized with mentions of the virus in web and national TV news at both the national and state level.

 

 

What do 'Bohemian Rhapsody,' 'Macbeth,' and a list of Facebook friends all have in common?

June 2020, phys.org

 

I almost forgot to mention -- network science is rapidly evolving into a useful tool for understanding our world, and there's a possibility that it can go even further than physics in modeling human dynamics; I saw earlier this year a that network science could do a better job than physics of describing what happens inside the sun. [The link to that study is probably on this weblog somewhere].

 

New research published in Nature Physics uses tools from network science to explain how complex communication networks can efficiently convey large amounts of information to the human brain. Conducted by postdoc Christopher Lynn, graduate students Ari Kahn and Lia Papadopoulos, and professor Danielle S. Bassett, the study found that different types of networks, including those found in works of literature, musical pieces, and social connections, have a similar underlying structure that allows them to share information rapidly and efficiently.

 

The researchers evaluated 40 real-world communication networks to see what features were crucial for communicating information. They looked at works of English literature, including the canon of Shakespeare and Jane Austen's "Pride and Prejudice," along with musical pieces such as Mozart's Sonata No 11 and Queen's "Bohemian Rhapsody." They also studied networks of social relationships, including co-authorship networks in science and Facebook friend connections.

 

After looking at this diverse group of networks, the researchers found that the large-scale structure of a network was essential to that network's ability to convey information. What was surprising was just how similar this structure was across the different networks, whether the network was representing noun transitions in a work of literature or melodic progressions in a piece of music.

 

What makes these networks both information-rich and efficient is a balance between two key network features known as "community" structure and "heterogeneous" structure. Community structure occurs when nodes clump together and form clusters that evoke related concepts. Saying the word "dog" might bring to mind "ball," "Frisbee," or "bone," for example. Such community structure helps make networks more efficient because a person can anticipate what word or idea might come next.

 

But if a person can anticipate what comes next, there won't be much information conveyed because information is directly related to surprise. To provide information, networks have to have a "heterogeneous" mixture of both well-connected and sparsely connected nodes. Take the works of Shakespeare as an example. While "the" and "and" are used 28,944 and 27,317 times, respectively, there are also 12,493 word forms that only occur once. "At a hub like, 'the,' you can't anticipate where you are about to go," says Lynn. "It turns out that these hub nodes are really important for generating surprisal or, equivalently, information."

 

 

Evolution selects for 'loners' that hang back from collective behavior-at least in slime molds

Mar 2020, phys.org

 

Testing whether loners are random or a predictable quantity, possibly subject to natural or cultural selection:

 

Target system: cellular slime mold Dictyostelium discoideum

 

Evolution could indeed select for loner behavior in slime molds. Loners are both an ecological and an evolutionary insurance plan, a way to diversify a genetic portfolio to ensure the survival of the social, collective behavior:

 

Slime molds, when they are threatened by starvation, the tiny amoebae coalesce into slug-like creatures that then aggregate into a large, swaying tower that grows upward with a burgeoning slimy top—until that top sticks to an unwitting passing insect, the starvation-resistant spores hitchhiking out into the world, while all the individuals making up the base and stalk die.

 

But what caught Tarnita's eye were the slime mold loners, the amoebae that resist the biochemical call to form the tower.

 

Here and there, some scattered cells on the plate just didn't seem to react at all to this aggregation process.

 

They tested the loners to see if they were flawed in some way, but they couldn't find anything wrong with them.

 

It could make sense for some fraction of the slime mold population to remain behind in order to take advantage of any resources that might return in the environment while the rest of the cells are aggregating.

 

30% chose the loner life over collective action.

 

The proportion of solitary cells in the social amoeba Dictyostelium discoideum is not simply determined by each cell individually tossing a coin. It results instead from interactions between the [organism] and the environment.

 

The decision not to become part of the collective is, in fact, taken collectively. All the cells kind of talk to each other chemically: 'Oh, you're going? I guess I'm staying.' There's communication involved in becoming a loner.

-"Eco-evolutionary significance of 'loners'" by Fernando W. Rossine, Ricardo Martinez-Garcia, Allyson E. Sgro, Thomas Gregor and Corina E. Tarnita, appears in the Mar. 18 issue of the journal PLoS Biology.

 

Image source: Fernando Fornies Gracia, infrared photography

 

Other Infrared Photos