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JWST's Puzzling Early Galaxies Don't Break Cosmology—But They Do Bend Astrophysics - Jonathan O'Callaghan on Scientific American
🔭 2024 Feb 9

Ever since it opened its giant infrared eye on the cosmos after its December 2021 launch, the James Webb Space Telescope (JWST) has found a shocking surfeit of bright galaxies that stretch back to the very early universe. Imagine visiting a foreign land and finding that many of its toddlers weighed as much as teenagers. You might have questions, too: Is the cause of such large children something in the water, or might it instead be that your grasp of human growth is fundamentally flawed? Scientists dubbed these relatively older systems ultramassive galaxies and kept scratching their heads: neither set of galaxies could be wholly explained by our current models.

Investigating some of these early galaxies, several studies now point more toward an astrophysical explanation for the unexpected girth—such as earlier-forming black holes or bursts of star formation—rather than some physics-shattering result.

Today in the journal Physical Review Letters, Nashwan Sabti of Johns Hopkins University (JHU) and his colleagues have proposed a solution for JWST's ultramassive galaxies. Existing data from Hubble's UV observations allowed the researchers to better gauge the rates of star formation—the change in stellar mass over time—versus the stellar mass itself from JWST, which primarily observes in infrared. Comparing those two pieces of information, Sabti and his colleagues found that the galaxies were growing exactly as expected in accordance with our cosmological model of the universe: the Lambda Cold Dark Matter (Lambda-CDM) model.

Boylan-Kolchin says the paper makes a “great point” in comparing Hubble and JWST data from this period of the universe. He isn't completely convinced just yet, however. “I don't think the case is airtight,” he says. “The loophole is: you're not necessarily observing the same galaxies with JWST and Hubble. Galaxies can be luminous [in infrared] for JWST but invisible for Hubble. If the most massive ones happen to be in that [infrared] regime, then maybe Hubble wouldn't be seeing them.”

Dead flies could be used to make biodegradable plastic, scientists say - Helena Horton on The Guardian
🪰 2023 Aug 14

The larvae of black soldier flies are farmed for their proteins and other nutritious compounds to be used in/as(?) animal feed, and they break down waste so they're being bred for that, too. However, adult flies are discarded after their short life span. Karen Wooley's team at Texas A&M Univerity has been trying to use these carcasses to make useful materials from a waste product.

Fly-sourced chitin (a sugar-based polymer) powder seemed purer than that from crustaceans, and avoids concerns over some seafood allergies.

From the fly products, the team created a hydrogel that can absorb 47 times its weight in water in just one minute. This product could be used in cropland soil to capture flood water and then slowly release moisture during droughts.

Wooley said: “Here in Texas, we're constantly either in a flood or drought situation, so I've been trying to think of how we can make a superabsorbent hydrogel that could address this.”

Naps Not Needed to Make New Memories
Karen Hopkin speaks with Marion Inostroza and Jan Born
on Scientific American's 60-Second Science 🐀 2022 Oct 14
From the authors of this study:

Rats who stayed awake were actually better at remembering the original object than their fully rested counterparts-but only when the item was presented in a new location. Rats who'd gotten some shut-eye after their initial study sesh seemed thrown by the change in venue and showed no signs of recognizing the familiar objects when they appeared out of context.

No one in physics dares say so, but the race to invent new particles is pointless
by Sabine Hossenfelder on The Guardian🔍 2022 Sep 26

Imagine you go to a zoology conference. The first speaker talks about her 3D model of a 12-legged purple spider that lives in the Arctic. There's no evidence it exists, she admits, but it's a testable hypothesis, and she argues that a mission should be sent off to search the Arctic for spiders.

The second speaker has a model for a flying earthworm, but it flies only in caves. There's no evidence for that either, but he petitions to search the world's caves. The third one has a model for octopuses on Mars. It's testable, he stresses.

Kudos to zoologists, I've never heard of such a conference. But almost every particle physics conference has sessions just like this, except they do it with more maths.

Why stinky sweat is good for you - Michealeen Doucleff on NPR's All Things Considered 🦠 2022 Aug 25

Staphylococcus hominins, one of the 200 or so bacteria on some people's skin, produces an onion smell after eating the sweat it finds on the body. It also kills MRSA(!!!) by punching holes in its cell membrane. As the water evaporates, sweat antibiotics increase in concentration. So it kind of leaves a little coating on your skin. Onion-smelling sweat is antibiotic juice. Don't worry about washing it off; the good stuff is deep in your pores.

New Evidence Points to Supports Theory of the Moon Once Being Part of Earth - Jonathan O'Callaghan on Wired Science 🔬 2022 Aug 17

The current moon formation theory is called giant impact hypothesis: our planet was hit, with giant impact, by Theia, who was blown to pieces and sent a huge chunk of Earth careening into space. That material continued to swirl around the planet and some of it stuck together to form the moon.

The new evidence: six lunar meteorites recovered by NASA from Antarctica in the early 2000s were found to contain helium and neon trapped in tiny glass beads, which were formed in volcanic eruptions on the lunar surface as magma was pulled up from the moon's interior. These noble (unreactive) gases appear to have originated on Earth, and were likely inherited by the moon during its formation.

Lunar rocks show a striking similarity to Earth rocks, albeit with some differences. One difference is a lighter version of chlorine, pointing to a dramatic event early in the history of our two worlds that separated some material. Most scientists now agree this event was a gigantic collision.

Had these gases instead been transported across space into the moon by solar winds, we'd expect there to be much much lower quantities present in the meteorites analyzed.

The next step is to understand how Earth got its noble gases.

Science Finally Has a Good Idea about Why We Stutter
Karen Hopkin speaks with Marion Frank Guenther
on Scientific American's 60-Second Science 🗣 2022 Apr 13

Hopkins: The basal ganglia, structures tucked beneath the brain's cerebral cortex, play a critical role in initiating a variety of motor activities. Guenther: They basically monitor our thoughts sensations and actions and they determine which actions we should perform next.

Guenther seems to have created a model of the human brain and speech system. Fiddling with the controls on his simulation shows that stuttering is affected by issues in the initiation sequence, rather than the carry-out sequence- so it's probably the basal ganglia's fault. This is being presented as a discovery. Guenther would like to combine his model with imaging studies that show the basal ganglia in action.

Hopkins: The ultimate goal is to come up with precisely targeted treatments… like drugs that tweak the activity of the basal ganglia without inducing serious side effects… Guenther: Or possibly even implanted electrodes that modulate activity in particular parts of the basal ganglia circuit.

On the evolutionary trail of MRSA
from Evo in the News on Understanding Evolution 🦔 2022 February
We've known that hedgehogs harbor antibiotic resistant bacteria since the 1960s. But the new research [...] traced these different lineages back in time and found that some groups of the antibiotic resistant bacteria were infecting hedgehogs long before methicillin was even discovered, let alone prescribed to treat infections.
The researchers hypothesize that the culprit is a fungus called Trichophyton erinacei, which often lives on the skin of hedgehogs. It also happens to produce its own antibiotics.
Each time the fungus evolved an advantage over the bacteria, it created an environment in which any bacterium that happened to be able to resist that new fungal weapon left behind more descendants - and vice versa. The weapons that the two sides wound up with through this arms race seem to be two antibiotics (on the fungal side) and the mecC antibiotic resistance gene (on the bacterial side).
Neutrinos’ identity shift snares physics Nobel
Andrew Grant and Thomas Sumner
on Science News 🪅 2015 Oct 06

Nicknamed 'ghost particles,' the elusive neutrinos have been around since the beginning of the universe, appearing in three 'flavors' named for the particle they produce upon interacting with matter: electrons, muons, and taus. The sun serves as a massive nuclear reactor emitting torrents of electron neutrinos, but experiments detected roughly a third as many electron neutrinos radiating from the sun as expected. Some researchers began to suspect that the solar neutrinos were oscillating, or switching flavors, en route to Earth.

Takaaki Kajita and Arthur McDonald spearheaded giant underground experiments that revealed that individual neutrinos do oscillate from one flavor into another, and that they have mass.

Kajita and his Super-Kamiokande collaborators focused on detecting muon neutrinos that are produced in the atmosphere when incoming charged particles from space collide with air molecules. The researchers counted up the rare flashes due to neutrino interactions and charted where each neutrino had come from. More muon neutrinos came from above than below, even though they pass unaffected through the Earth. In 1998, the team concluded that the neutrinos from below had enough time during their trek through Earth's interior to change flavors, while the ones from above did not (SN: 6/13/98, p. 374). While Super-Kamiokande produced compelling evidence for neutrino oscillation, the experiment couldn't prove that the total number of neutrinos, regardless of flavor, was consistent.
In 2001 and 2002, McDonald's team confirmed the scarcity of electron neutrinos from the sun but showed that the shortage disappeared if one took into account neutrinos of all flavors (SN: 6/23/01, p. 388).

These discoveries led to more research on the three neutrino flavors. A few recent experiments suggest that the oscillation rate of neutrinos may differ from the oscillation rate of anti-neutrinos, which could help explain why the universe is dominated by matter, even though it probably started out with equal parts matter and anti-matter.

Acrobatic Octopus Arm Could Be Model for Flexible Robots
by Brandon Keim
from Wired🐙 2009 Sep 17

Unlike us, specific regions of an octopus' motor cortex don't correspond to specific parts of its body. Instead, each region controls different parts at different times. Their motor neural network seems as flexible as their bodies — a phenomenon that expands the range of neurophysiological possibility, and could refine the design of arm-flexing robots.

How octopuses control their arms has been a focus of [University of Jerusalem neurobiologist Benny] Hochner's work for more than a decade. In earlier studies, he helped show that seemingly complex movements are actually combinations of individually simple motions. Hochner also found that many of the movements are guided peripherally, rather than by the brain, as if each arm had its own spinal cord.

An octopus brain sends a general prompt, and the arm computes the specifics: It's much simpler than running all those calculations in the brain itself. And all this is especially interesting to roboticists who want to build machines with flexible appendages, ideal for rescue bots working in disaster areas or surgical machines weaving through a body.

"The networks are embedded in one another. The system is remodeled according to stimulation. It's more dynamic, rather than strictly organized," said Hochner.

Hochner suspects that other neurological programs, stored elsewhere in the octopuses' bodies — perhaps at the base of each arm — act as gates, blocking signals from the brain or allowing them to pass.