Starling flocks, schools of fish, and clouds of insects all agree.
- Scientists discover that active particles take a pass on Newton's Second Law.
- Active particles exist in a "swirlonic" state of matter.
- Swirlonic behavior explains some of the more dazzling natural phenomena such as starling swarms and shape-shifting schools of fish.
Lawbreakers<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTcwMzc5NS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3NTExNzM4Nn0.HI6HiDo4WitAWTCUr1KPULnvRHCGoZcxvaI9viBM2v4/img.jpg?width=980" id="4f3ec" class="rm-shortcode" data-rm-shortcode-id="1a5d7f236b8371c99d7a4414160ff74d" data-rm-shortcode-name="rebelmouse-image" data-width="1000" data-height="967" />
Credit: Wikimedia Commons/Big Think<p>According to <a href="https://www.physicsclassroom.com/class/newtlaws/Lesson-3/Newton-s-Second-Law" target="_blank">Newton's Second Law</a>, the acceleration of an object depends on both the force acting upon it and the object's mass. Its acceleration increases in accordance with the force being exerted, and as its mass increases, the object's acceleration decreases. These things don't happen with swirlons.</p><p>It appears that the Second Law relates only to passive, non-living objects at small and large scales. Swirlons, however, are comprised of active, living matter that moves courtesy of its own internal force. In this context, individual starlings are analogous to self-propelled particles within the larger swirlonic object, their flock.</p>
Spotting swirlonic motion<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTcwMzgyMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3MDM2MDgzMX0.KrEacUm8yaSsZciDVItiO_UTqzbDYd_y0Gj2qXxNbFg/img.jpg?width=980" id="ce03e" class="rm-shortcode" data-rm-shortcode-id="b9f876eede09e4952b8d32a80c44f80a" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: Johnny Chen/Unsplash<p>The scientists at Leicester, led by mathematician <a href="https://www2.le.ac.uk/departments/mathematics/extranet/staff-material/staff-profiles/nb144" target="_blank">Nikolai Brilliantov</a>, came upon swirlonic matter as they developed computer models of self-propelled particles similar to simple bacteria or nanoparticles. They were interested in better understanding the movement of human crowds evacuating a crowded space, and these particles served as human stand-ins.</p><p>The word "swirlonic" comes from the circular direction in which the scientists witnessed their particles milling about in clusters that operated together as larger quasi-particles.</p><p>"We were completely baffled," <a href="https://le.ac.uk/news/2021/february/swirlonic" target="_blank">says</a> Brilliantov, "to witness how these quasi-particles swirl within active matter, behaving like individual super-particles with surprising properties including not moving with acceleration when force is applied, and coalescing upon collision to form swirlons of a larger mass."</p><p>Brilliantov tells <a href="https://www.livescience.com/swirlonic-matter-unusual-behavor.html" target="_blank" rel="noopener noreferrer">Live Science</a>, "[They] just move with a constant velocity, which is absolutely surprising."</p><p>It's not the first time such behavior has been seen, but the first time it's been identified as a distinct state of matter. Says Brilliantov, "These patterns have previously been observed for animals at different evolution stages, ranging from plant-animal worms and insects to fish, but rather as singular structures, not as a phase which borders other phases, resembling gaseous and liquid phases of 'normal' matter."</p><p>The researchers also saw that swirlonic particles operate on a sort of "one for all, all for one" basis. With passive particles such as water, different individual particles can exist in different states: some may evaporate into gas as others remain as liquid. The models of active particles, on the other hand, stuck together in the same state as either a liquid, solid, or gas.</p>
Moving forward, and back, or up, or down together<p>Brilliantov and his colleagues hope to explore swirlons further, moving beyond their simulation into real-world investigations and experiments.</p><p>The researchers are also developing more sophisticated models that mimic the behavior of swirlonic animals such as starlings, fish, and insects. In these models, the active particles will have information-processing capabilities that allow them to make movement decisions as living creatures presumably do. They hope these models will reveal some of the secrets behind flocking, schooling, and swarming.</p><p>Another future possibility is creating man-made active particles that can self-assemble. Other Leicester experts agree that this is reason alone to continue researching swirlons.</p><p>In any event, says study co-author <a href="https://www2.le.ac.uk/departments/mathematics/extranet/staff-material/staff-profiles/it37" target="_blank">Ivan Tyukin</a>, "It is always exciting to consider deepening our understanding of novel phenomena and their guiding physical principles. What we know to date is so much less than what there is to know. The phenomenon of the 'swirlon' is part of the tip of the iceberg of hidden knowledge. It leaves us with the eternal question: 'what else don't we know'?"</p>
After 20 months, scientists find lab-dish brain cells matured at a similar rate to those of an actual infant.
- Scientists have found that cultures of embryonic brain cells mature at the same rate as a 20-month-old infant's.
- Researchers have looked to such cell structures, called "organoids," as potential models for understanding the human body's biological mechanisms.
- Their study validates the use of lab-dish organoids for research.
What organoids really are and aren't<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTY4MzgzOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1OTEzMjc5Mn0.R1KWf66xU7CYlT3CPthA2J-xJKjZP0h0W4vx2Quxiq8/img.jpg?width=980" id="60c18" class="rm-shortcode" data-rm-shortcode-id="a496d5eb7684457c09d0139882876a8f" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="1080" />
A brain organoid
Credit: NIH Image Gallery/Wikimedia<p>Organoids are tissue cultures comprised of human embryonic stem cells. They start off as induced pluripotent stem cells (IPS) drawn from skin cells or blood cells before being reprogrammed to revert to an embryonic stem-cell-like state. From there, they can be exposed to chemicals that cause them to behave like a specific type of human cell.</p><p>In the case of this study, the chemicals caused them to become cerebral organoids, self-organized 3D cell structures that behave similarly to natural human brain cells. They don't grow to become full mini-brains.</p>
The promise of organoids<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTY4Mzg0MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzMDEzODg0Nn0.AmSwbhi7wxpv1vKOX4jqOhB-pEqJNyFQzu2mhzHWTvc/img.jpg?width=980" id="92a7b" class="rm-shortcode" data-rm-shortcode-id="3746da47064a9d07ca33ddf44c5c1880" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: David Matos/Unsplash<p>The hope for organoids has been that they would provide researchers a way of observing human biological process in a benign, non-invasive way. Insights regarding the manner in which human cells and organs develop a disease, progress through its stages, and respond, or not, to medication, without involving actual human subjects or animal analogues could revolutionize research.</p><p>In the case of brain organoids, researchers have been hoping they can somehow be used to reveal the secrets of neurological and neurodevelopmental disorders, including epilepsy, autism and schizophrenia.</p><p>That organoids <em>could</em> be useful—though that doesn't mean that they <em>would</em> be—as a result of their permanently remaining embryonic cells. This study is a first indicator that organoids' larger promise can actually be fulfilled. </p>
An answer scientists have been hoping for<p>"This is novel," says Geschwind. "Until now, nobody has grown and characterized these organoids for this amount of time, nor shown they will recapitulate human brain development in a laboratory environment for the most part."</p><p>Now, says first author <a href="https://geschwindlab.dgsom.ucla.edu/pages/aaron-gordon" target="_blank">Aaron Gordon</a>, "We show that these 3D brain organoids follow an internal clock, which progresses in a laboratory environment in parallel to what occurs inside a living organism. This is a remarkable finding — we show that they reach post-natal maturity around 280 days in culture, and after that begin to model aspects of the infant brain, including known physiological changes in neurotransmitter signaling."</p><p>With the study verifying a 20-month maturation process, it remains to be seen how long, or how far, maturation in organoids goes. Can their cells continue to mature for years? Decades?</p><p>Even without an answer to that question, the study, says Geschwind, "represents an important milestone by showing which aspects of human brain development are modeled with the highest fidelity and which specific genes are behaving well in vitro and when best to model them. Equally important, we provide a framework based on unbiased genomic analyses for assessing how well in vitro models model in vivo development and function."</p><p>With IPS cells able to take on the roles of so many types of cells in the human body, and the new knowledge that they do in fact mature beyond their embryonic stage, researchers can feel more confident of insights into biological mechanisms organoids seem to reveal. And researchers can now better equipped to solve some of the human body's vexing mysteries.</p>
A large new study puts caffeine-drinking moms on alert.
- A study finds that the brains of children born to mothers who consumed coffee during pregnancy are different.
- Neuroregulating caffeine easily crosses the placental barrier.
- The observed differences may be associated with behavioral issues.
A large study of nine- and ten-year-old brains<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTY3NzIyOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1MDk5MjQ0N30.UCu1Ygfi_rmO-xLpW-KOgCX-MJ3bfqjzfIVg4Kmcr9w/img.jpg?width=980" id="d2e15" class="rm-shortcode" data-rm-shortcode-id="c96aa86f8dbe08aa8536502ac1769497" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: myboys.me/Adobe Stock<p>For the study, researchers analyzed brain scans of 9,000 nine and ten-year-olds. Based on their mothers' recollections of their coffee consumption during pregnancy, the researchers found that children of coffee drinkers had clear changes in the manner in which white brain matter tracks were organized. These are the pathways that interconnect brain regions.</p><p>According to Foxe, "These are sort of small effects, and it's not causing horrendous psychiatric conditions, but it is causing minimal but noticeable behavioral issues that should make us consider long-term effects of caffeine intake during pregnancy."</p><p>Christensen says that what makes this finding noteworthy is that "we have a biological pathway that looks different when you consume caffeine through pregnancy."</p><p>Of children with such pathway differences, Christensen says, "Previous studies have shown that children perform differently on IQ tests, or they have different psychopathology, but that could also be related to demographics, so it's hard to parse that out until you have something like a biomarker. This gives us a place to start future research to try to learn exactly when the change is occurring in the brain."</p><p>The study doesn't claim to have determined exactly <em>when</em> during development these changes occur, or if caffeine has more of an effect during one trimester or another.</p><p>Foxe cautions, "It is important to point out this is a retrospective study. We are relying on mothers to remember how much caffeine they took in while they were pregnant."</p><p>So as if being pregnant wasn't difficult enough, it sounds like the most conservative and safe course of action for expectant mothers is to forgo those revitalizing cups of Joe and switch to decaf or some other un-caffeinated form of liquid comfort. We apologize on behalf of science.</p>
A study says nature's candy can be a valuable supplement to sunblock.
- The skin of study participants who consumed lots of grapes developed an increased resistance to UV light.
- Grapes contain polyphenols, good stuff for repairing skin and fighting inflammation.
- After their grape adventure, biopsies revealed less skin-cell damage from UV light.
The study<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTY2MTgyMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNDMxNjEwNX0.ZN4iBw442Ivwcdy3aw1GqOO2NTLUhukEhtDKfv3p4OU/img.jpg?width=980" id="702c7" class="rm-shortcode" data-rm-shortcode-id="1f388f9531613b90c49e8de5e6411e9f" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="954" />
Credit: Maciej Serafinowicz/Unsplash/Big Think<p>For the study, published in the <a href="https://www.jaad.org/article/S0190-9622(21)00183-3/pdf" target="_blank">Journal of the American Academy of Dermatology</a>, the researchers fed 19 healthy volunteers a powder of freeze-dried grapes for 14 days. This is the equivalent of 2.25 cups of grapes per day.</p><p>The participants' sensitivity to UV light was assessed before the trial period, and again afterward. Each individual's skin was assigned a Minimal Erythema Dose (MED) value — the threshold beyond which UVC radiation causes visible reddening to skin after 24 hours. After the test period, the amount of UV light required to redden each participant's skin was 74.8 percent greater than it had been before. This is the first study demonstrating this effect.</p><p>Biopsies also revealed fewer skin-cell deaths and fewer inflammatory markers. These slow down healing and may be linked to skin cancer.</p><p>The enhanced resistance to UV light came courtesy of an increase of <a href="https://en.wikipedia.org/wiki/Polyphenol" target="_blank">polyphenols</a> in their skin. Polyphenols are a naturally occurring family of compounds found in grapes, berries, and other fruits. They're also in products derived from them, such as wine, chocolate, tea, and legumes.</p><p>"Study results indicate that oral consumption of grapes has systemic beneficial effects in healthy adults," says Oak, citing prior research showing that polyphenols repair UV-ray damage, and that they can also reduce <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5055983/" target="_blank">inflammation</a>.</p><p>The researchers also found that a topical application of a grapeseed extract containing the polyphenol proanthocyanidins inhibited the formation of sunburn cells.</p>
Avoiding skin cancer?<p>An estimated one in five Americans develops skin cancer by age 70, with most cases being linked to sun exposure, including 90 percent of nonmelanoma skin cancers and 86 percent of melanomas.</p><p>The study finds early indications that grape consumption may also help a person avoid skin cancer, though these findings are just preliminary, cautions Oak, and require further investigation before a definitive conclusion may be drawn.</p><p>Principle investigator Craig Elmets, also of UAB, <a href="https://www.grapesfromcalifornia.com/wp-content/uploads/2021/02/20210204-nr-grape-consumption-may-protect-against-uv-damage-to-skin.pdf" target="_blank" rel="noopener noreferrer">tells</a> the California Table Grape Commission, "We saw a significant photoprotective effect with grape consumption and we were able to identify molecular pathways by which that benefit occurs — through repair of DNA damage and downregulation of proinflammatory pathways. Grapes may act as an edible sunscreen, offering an additional layer of protection in addition to topical sunscreen products."</p>
Introducing the Deep Space Food Challenge.
The way to an astronaut's heart<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTU5Mjg4My9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0MTkwODAwOH0.5z68HGX5Zup_y_PZfTfTnlibo3B2jKha-gjAT6jF9-w/img.jpg?width=980" id="7a63a" class="rm-shortcode" data-rm-shortcode-id="98e1e8efc2a98052faa9678a62d5f0fe" data-rm-shortcode-name="rebelmouse-image" data-width="520" data-height="402" />
An image showing the different challenges a viable space-food system solution must overcome.