Enlarge / A phlebotomist draws blood meant for antibody testing. (credit: Frederic J. Brown / Getty Images )

We've tended to treat the RNA-based vaccines from Moderna and Pfizer/BioNTech as functionally equivalent. They take an identical approach to producing immunity and have a very similar set of ingredients. Clinical trial data suggested they had very similar efficacy—both in the area of 95 percent.

So it was a bit of a surprise to have a paper released yesterday indicating that the two produce an antibody response that's easy to distinguish, with Moderna inducing antibody levels that were more than double that seen among people who received the Pfizer/BioNTech shot. While it's important not to infer too much from a single study, this one was large enough that the results are likely to be reliable. If so, the results serve as a caution that we might not want to base too many of our expectations on relatively crude measures of antibody levels.

The new study

The work itself was remarkably simple. A Belgian medical center was vaccinating its staff and asked for volunteers willing to give blood samples. Samples were taken both prior to vaccination and six to 10 weeks after, with the levels of antibody specific to the SARS-CoV-2 spike protein tested at both points. About 700 participants received the Moderna vaccine, while roughly 950 took the one from Pfizer/BioNTech.

Enlarge / An interdisciplinary team of roboticists, engineers and biologists modeled the mechanics of the mantis shrimp’s punch and built a robot that mimics the movement. (credit: Second Bay Studios and Roy Caldwell/Harvard SEAS)

The mantis shrimp boasts one of the most powerful, ultrafast punches in nature—it's on par with the force generated by a .22 caliber bullet. This makes the creature an attractive object of study for scientists eager to learn more about the relevant biomechanics. Among other uses, it could lead to small robots capable of equally fast, powerful movements. Now a team of Harvard University researchers have come up with a new biomechanical model for the mantis shrimp's mighty appendage, and they built a tiny robot to mimic that movement, according to a recent paper published in the Proceedings of the National Academy of Sciences (PNAS).

“We are fascinated by so many remarkable behaviors we see in nature, in particular when these behaviors meet or exceed what can be achieved by human-made devices,” said senior author Robert Wood, a roboticist at Harvard University's John A. Paulson School of Engineering and Applied Sciences (SEAS). “The speed and force of mantis shrimp strikes, for example, are a consequence of a complex underlying mechanism. By constructing a robotic model of a mantis shrimp striking appendage, we are able to study these mechanisms in unprecedented detail.”

Wood's research group made headlines several years ago when they constructed RoboBee , a tiny robot capable of partially untethered flight. The ultimate goal of that initiative is to build a swarm of tiny interconnected robots capable of sustained untethered flight—a significant technological challenge, given the insect-sized scale, which changes the various forces at play. In 2019, Wood's group announced their achievement of the lightest insect-scale robot so far to have achieved sustained, untethered flight—an improved version called the RoboBee X-Wing. (Kenny Breuer, writing in Nature, described it as a "a tour de force of system design and engineering.")

Enlarge / A cartoon of the process that translates the genetic code in DNA into a protein. (credit: BSIP / Getty Images )

All living things on Earth use a version of the same genetic code. Every cell makes proteins using the same 20 amino acids. Ribosomes, the protein-making machinery within cells, read the genetic code from a messenger RNA molecule to determine which amino acid to put next into the particular protein they are building.

This code is universal, which is why the ribosomes in our cells can read a piece of viral messenger RNA and make a functional viral protein from it. There are plenty of other amino acids, though. While life does not generally use them, scientists have been incorporating these into proteins. Now, researchers have figured out a way to greatly expand the genetic code, allowing widespread incorporation of these non-biological amino acids. They accomplish this by running a second set of everything—proteins and RNAs—needed to translate the genetic code.

A system apart

Non-canonical amino acids can serve a number of functions. They can act as labels so a researcher’s particular protein of interest can more easily be tracked within cells. They can help to regulate a protein’s function, allowing researchers to activate and inactivate it at a specific time and place of their choosing and then observe the downstream effects. If enough of these non-canonical amino acids are strung together, the resulting proteins would constitute an entirely new class of biopolymers that might carry out functions that traditional proteins cannot—for research, therapeutic, or other purposes.

Enlarge / The stuff we call "laughter" from hyenas? It's not. (credit: Getty Images )

Among humans, laughter can signify a lot of different things, from intimacy to discomfort. Among animals, however, laughter usually signifies something along the lines of “this is playtime—I’m not actually going for your throat.”

According to new research from the University of California, Los Angeles, there are likely at least 65 different creatures, including humans, that make these vocalizations. They’re most commonly found in primates, but they have also been noted in distant relatives like birds. It’s not clear whether this is because laughter has arisen several times over the course of evolution or if it’s more widespread and we just haven’t noticed.

Laughter in the library stacks

To reach this number, Sasha Winkler, a PhD student in UCLA’s anthropology department, searched high and low for any mention of animals making noises during play sessions. Some of the articles she found were quite old—one paper on mink dates back to 1931—so she ended up dusting off some aged tomes in the university’s library.

Enlarge (credit: David Aubrey )

Since its advent in 2005, a technique called optogenetics has made it vastly easier to link neural activity with behavior and to understand how neurons and brain regions are connected to each other. Neuroscientists just pick the (animal) neurons they’re interested in, genetically engineer them to express a light-responsive protein, and then stimulate them with the right type of light. This technique can be used to inhibit or excite a select subset of neurons in living, breathing, moving animals, illuminating which neural networks dictate the animals' behaviors and decisions.

Taking advantage of work done in miniaturizing the optogenetic hardware, researchers have now used optogenetics to alter the activity in parts of the brain that influence social interactions in mice. And they’ve exerted a disturbing level of control over the way the mice interact.

Going small

A big limitation for early optogenetic studies was that the wires and optical fibers required to get light into an animal’s brain also get in the animals’ way, impeding their movements and potentially skewing results. Newer implantable wireless devices were developed about five years ago, but they can only be placed near certain brain regions. They're also too tiny to accommodate many circuit components and receiver antennas, and they have to be programmed beforehand. Pity the poor would-be mind controllers who have to deal with such limited tools.

Enlarge / An artist's schematic of the system. (credit: Nature)

Elon Musk's Neuralink has been making waves on the technology side of neural implants, but it hasn't yet shown how we might actually use implants. For now, demonstrating the promise of implants remains in the hands of the academic community.

This week, the academic community provided a rather impressive example of the promise of neural implants. Using an implant, a paralyzed individual managed to type out roughly 90 characters per minute simply by imagining that he was writing those characters out by hand.

Dreaming is doing

Previous attempts at providing typing capabilities to paralyzed people via implants have involved giving subjects a virtual keyboard and letting them maneuver a cursor with their mind. The process is effective but slow, and it requires the user's full attention, as the subject has to track the progress of the cursor and determine when to perform the equivalent of a key press. It also requires the user to spend the time to learn how to control the system.

Enlarge / A common cuttlefish, Sepia officianalis , in the Marine Resources Center at the Marine Biological Laboratory, Woods Hole, MA. A new study finds the cuttlefish can delay gratification—a key feature of the famous "marshmallow test." (credit: Alexandra Schnell)

Certain species show a remarkable ability to delay gratification, notably great apes, corvids, and parrots, while other species do not (such as rodents, chickens, and pigeons.) Add the cuttlefish to the former category.

Scientists administered an adapted version of the Stanford marshmallow test to cuttlefish and found the cephalopods could delay gratification—that is, wait a bit for preferred prey rather than settling for a less desirable prey. Cuttlefish also performed better in a subsequent learning test, according to a new paper published in the journal Proceedings of the Royal Society B. It's the first time such a link between self-control and intelligence has been found in a non-mammalian species.

As we've previously reported , the late Walter Mischel's landmark behavioral study involved 600 kids between the ages of four and six, all culled from Stanford University's Bing Nursery School. He would give each child a marshmallow and give them the option of eating it immediately if they chose. But if they could wait 15 minutes, they would get a second marshmallow as a reward. Then Mischel would leave the room, and a hidden video camera would tape what happened next.

Enlarge / The massive trunk of a kauri tree can remain intact for tens of thousands of years. (credit: W. Bulach / Wikimedia )

The Earth's magnetic field helps protect life from energetic particles that would otherwise arrive from space. Mars now lacks a strong magnetic field, and the conditions on its surface are considered so damaging to life that any microbes that might inhabit the planet are thought to be safely beneath the surface. On Earth, the magnetic field ensures that life can flourish on the surface.

Except that's not always true. The Earth's magnetic field varies, with the poles moving and sometimes swapping places and the field sometimes weakening or effectively vanishing. Yet a look at these events has revealed nothing especially interesting—no obvious connections to extinctions, no major ecological upsets.

A paper published yesterday in Science provides an impressively precise dating for a past magnetic field flip by using rings of trees that have been dead for tens of thousands of years. And it shows the flip was associated with changes in climate. But the paper then goes on to attempt to tie the flip to everything from a minor extinction event to the explosion of cave art by our ancestors. In the end, the work is a mix of solid science, provocative hypothesizing, and unconstrained speculation.