作者： chenchen

From Babbling to Birdsong: What Finches Can Teach Us About Vocal Learning

Imagine listening to Puccini’s “O Mio Babbino Caro,” as performed by a two-month-old baby, or Bizet’s “Habanera” crooned by a toddler. In some sense, that is what you hear when a baby finch practices its singing. Recently, scientists have studied how juvenile finches learn their songs, and their findings could teach us a thing or two about the way our own learning works.

Learning to speak is very much like learning to play a violin or a piano. It involves properly controlling the complex muscles that enable speech. In fact, humans and birds share a similar process. Just as a baby learns to say “Mama” or “Dada” by mirroring their parents’ baby talk, juvenile songbirds reproduce their parents’ song — but it’s more like a skipping CD stringing together single notes instead of the full track. Humans and songbirds are more impressionable when they’re young, and their neuroplasticity decreases in transition from adolescence to adulthood. Observing this change in birds could help scientists develop treatments for strokes and other conditions that affect speech and movement.

Michael Brainard, a professor of physiology and psychiatry at the University of California San Francisco, conducted experiments on juvenile Bengalese finches to explore the neurological circuitry behind vocal learning. By observing the finches learning songs from computerized teachers, he was able to stitch together the neural networks that coordinate cognitive and motor control during singing. He discovered that suppressing a region of the brain responsible for motor control, known as the basal ganglia, made the juvenile finches sing a duller tune, as if the glissandos and fortissimos had been taken out of the score. At the same time, variations in pitch were subdued, making the song more monotone. “It looks like this part of the brain is introducing variability — constantly doing things a little differently and then discovering ‘Okay, that sounded really good. I’ll do it that way again,’” Dr. Brainard said. Basically, the juvenile finches’ ability to use trial and error in learning had been eliminated. Whether it’s learning to ride a bike or cook pasta, trial and error helps us get better at certain tasks over time. “You need to try something different to optimize your performance,” Dr. Brainard explained.

Because birds and humans share so many parallels in vocal learning, scientists believe insights into the finch basal ganglia function could be relevant in understanding the way our own basal ganglia works during human speech learning and other types of motor skill performance, especially in diseases. Many illnesses, like Parkinson’s and Huntington’s disease, both directly involve the basal ganglia. “We think it’s probably no accident that the same circuit performing a function and introducing variability in birds might also be a circuit that contributes to abnormalities and movement variability,” said Dr. Brainard. “We can discover general principles that will contribute broadly to understanding how normal learning systems work, and ultimately how to correct function when it goes awry.”

Works Cited

Brainard, Michael S., and Allison J. Doupe. “Translating Birdsong: Songbirds as a Model for Basic and Applied Medical Research.” U.S. National Library of Medicine, 8 July 2013.

Kao, Mini, and Michael S. Brainard. “Lesions of an Avian Basal Ganglia Circuit Prevent Context-Dependent Changes to Song Variability.” Journal of Neurophysiology, U.S. National Library of Medicine, 24 May 2006.

Grunbaum, Mara. “Astonishing Animals That Illuminate Human Health.” University of California San Francisco, 25 Feb. 2021.

Mets, David G, and Michael S. Brainard. “An Automated Approach to the Quantitation of Vocalizations and Vocal Learning in the Songbird.” PLoS Computational Biology, Public Library of Science, 31 Aug. 2018.

Requarth, Tim and Meehan Crist. “From the Mouths of Babes and Birds.” The New York Times, 30 June 2013.

The Peacock Mantis Shrimp: The Ant-Man of Atlantis

Fifty miles per hour. A force of 8,000 G’s. All deployed in under two milliseconds. You’re not looking at a modern-day bullet, but the fastest punch in the animal kingdom.

Dubbed by scientists as “nature’s underwater marvel,” the peacock mantis shrimp has the ability to pierce its prey’s skull and completely cavitate the water around it. However, as fascinating as that sounds, the question still remains: How can this four-inch creature deliver forces 1,000 times its own weight?

In typical fashion, nature doesn’t like to reveal all its secrets, but scientists around the world have managed to attribute this mystery to one factor: its structure. While most man-made materials have their atoms layered on top of each other in an orderly fashion, this shrimp’s club takes a page out of nature’s cookbook by layering its fibers in small varying degrees, forming a spiral-like helicoid structure, capable of withstanding over 2,000 Newtons of force!

Split into three main layers, its club is purpose-built to pack a powerful punch every time. The first layer is composed of a mineral known as hydroxyapatite, the same one found in your hair and teeth; however, in this case, it’s in a more crystalline form, owing to a much harder surface. The second layer is composed of a much softer form of the same mineral albeit with each layer being rotated slightly, forming the helicoid structure that scientists have now come to recognize. The third consists of layers of chitin that prevent the club from expanding upon impact.

But what if we were to implement this into the mainstream market? While scientists and engineers have known about this phenomena for more than half a decade, the research originally conducted by the University of California, Riverside, in 2014 is just starting to trickle down into various corporations. The most complex architecture used in the aerospace industry today revolves around layering sheets of carbon-fiber at zero degrees, 45 right, 45 left and then 90 degrees. However, if we were to layer the same material using a helicoid configuration, the results would be borderline revolutionary!

This would delay internal failure by over 74 percent, increase impact resistance by over 50 percent and improve load-bearing by over 92 percent. Now, you don’t need to be a rocket scientist to understand that those figures can reform entire industries.

However, while figures are one thing, real-life performance is a whole different situation, and it doesn’t fall short. This extraordinary structure allows for much lighter, stronger and cheaper composites, which, when implemented into vehicles, allows them to emit less carbon dioxide and carry a smaller carbon footprint. And while our world is hanging onto life support, this could be the very turning point at which we can make a significant change.

As scientists continue to pluck from the fruits of nature, this discovery merely marks the beginning of a whole new wave of materials to come. From hummingbirds to geckos, we are finally turning a new leaf, falling toward the mystic arts of nature rather than trying to cast away its spells.

Works Cited

Kim, Meeri. “Shrimp’s Shell-Smashing Punch Hands Researchers a Lead on Tougher Materials.” The Guardian, 9 May 2014.

Kwok, Roberta. “This Shrimp Packs A Punch.” Science News, 27 March 2013.

News Channel 3 Staff. “The Mantis Shrimp Changing Composites.” News Channel 3, 19 Nov. 2019.

Scharping, Nathaniel. “How Mantis Shrimp Punch So Hard Without Hurting Themselves.” Discover, 16 Jan. 2018.

Science Daily Staff. “Mantis Shrimp Stronger Than Airplanes.” Science Daily, 22 April 2014.

Treacy, Siobhan. “Materials for Aerospace and Sports Inspired by the Mantis Shrimp’s Club.” Engineering360, 16 Jan. 2018.

Origami in Space Engineering: Rediscovering the Meaning of Discovery

Rocket science is a discipline so notoriously difficult that the phrase “It’s not rocket science” is used to mark how easy something is. In space, scientists have to inhabit the uninhabitable with the bare essentials that a rocket can carry. So it can be hard to believe that a skill taught in kindergarten could be the next big discovery in the most difficult discipline in science.

Origami, the ancient art of paper folding, transforms the potential of a piece of material without changing its volume or weight. Folds maximize the functionality of a material, as seen when a piece of construction paper transforms into a standing crane or a jumping frog. In space engineering, origami is applied as a method of organizing luggage for space travel, increasing flexibility of spatial structures, and improving the accuracy of robotic motion.

NASA’s Jet Propulsion Laboratory has the lead in origami space engineering. Origami, with its folds, compresses materials and packs them in the smallest of volumes. In the words of Robert Salazar, an intern at the laboratory, “origami offers the potential to take a vast structure and get it to fit within the rocket,” therefore “greatly magnifying what we are capable of building in space.”

Not only is origami used for compression, but it’s also used for robotic exploration. Starshade, an occulter in NASA’s Exoplanet Exploration Program, the New Worlds Mission, prevents starlight from interfering with exoplanet pictures that the telescope takes. Its unfolding resembles a flower blooming; the petals spread out from the “stem,” which disconnects from the occulter and transforms into an independent telescope. Jeremy Kasdin, the principal investigator, expects that the mission will “allow us to directly image Earth-size, rocky exoplanets.” Origami makes this expansion possible without investing the energy and resources to have a human astronaut manually perform the mission.

As seen in the Starshade occulter, origami is one of the simplest and most elegant sets of directions scientists can relay to robots. While robots can perform actions humans are incapable of, human instincts cannot be programmed into them. However, the mechanical nature of material folding makes directions far more accurate and precise for robots to understand. Origami serves as a common language robots can easily interpret in space. Self-folding robots, developed by Samuel Felton, an assistant professor at Northeastern University, and his team, are one of the first adopters of this language. Electricity passes through the circuit board like blood running through veins, and the robot walks away after bending its body parts. Dr. Felton believes such robots could be deployed in space missions in the far future.

Origami space engineering teaches us that difficult problems often have simple solutions. Science celebrates discoveries and breaking new ground. Less spotlight is shone on rediscoveries; what we already possess can be given a new lease on life if we believe in its potential. In space, the final frontier, origami engineering serves as a humble reminder for scientists that a kind gaze at our individual potential can unleash the ultimate frontier within all of us.

Works Cited

Callahan, Molly. “New Professor Creates Self-Folding, Origami Robots.” News@Northeastern, 24 Oct. 2016.

Chang, Kenneth. “Origami Inspires Rise of Self-Folding Robot.” The New York Times, 7 Aug. 2014.

Good, Andrew. “What Looks Good on Paper May Look Good in Space.” Jet Propulsion Laboratory, 22 Sept. 2017.

Lee, Elizabeth. “Ancient Origami Art Becomes Engineers’ Dream in Space.” Voice of America, 26 Oct. 2017.

Rodriguez, Joshua. “Flower Power: NASA Reveals Spring Starshade Animation.” Exoplanet Exploration, 24 Sept. 2020.

A Rising Star: These Star-Shaped Polymers May Be Our Last Defense Against Superbugs

The horror starts with a single cut on your finger. Suddenly, your vulnerable insides are continuous with the wide expanse of the universe, and millions of bacteria swarm in. Your immune system puts up a valiant effort, but the bacteria simply multiply too quickly. Like a hydra, one defeated foe is replaced with two more. And as we watch helplessly, the invisible enemy destroys us from the inside. Blood pressure plummets, and multiple organs start shutting down. This is not a fear of the distant past — 700,000 people die annually from antibiotic-resistant bacterial infections. According to World Health Organization estimates, that number could jump to 10 million by 2050, overtaking the number of cancer deaths.

Bacterial infections are nothing new — they have been a persistent scourge for almost all of human history. But since the first antibiotic was discovered in 1928, killer bacteria have been consigned to the past. Nowadays, bacterial infections seem trivial — just pop a few antibiotics and you’re fine. But our heavy reliance on antibiotics may have taken a toll. Bacteria are living creatures, and they can evolve. As time passes, more and more bacteria are evolving to become resistant to our antibiotics. These antibiotic-resistant bacteria are known as “superbugs,” and we currently have almost no way to defeat them.

So with our antibiotics neutralized, what do we turn to? Luckily, a team from the Melbourne School of Engineering may have developed a new weapon. Named “structurally nanoengineered antimicrobial peptide polymers” (SNAPPs, for short), these star-shaped polymers target antibiotic-resistant bacteria and tear them apart.

As Shu Lam, one of the lead scientists, explained, “Bacteria need to divide and grow, but when our star is attached to the membrane, it interferes with these processes. This puts a lot of stress on the bacteria and it initiates a process to kill itself from stress.” The team found that the star polymers were effective against all Gram-negative bacteria they tested, including several antibiotic-resistant bacteria. The star polymers were also nontoxic to human cells and relatively cheap to produce, making them a good candidate for an antimicrobial drug.

But what if bacteria become resistant to these star polymers too? Scientists have found that this is unlikely to happen. Even after 600 generations, bacteria showed almost no resistance to the star polymers. The team believes that this is because the polymers kill bacteria through multiple pathways, while most antibiotics only kill with a single pathway. SNAPPs can “rip apart” the bacteria cell wall, cause uncontrolled movement of ions in and out of the bacteria cell membrane, and initiate a biochemical pathway that makes the bacteria kill itself. This multipronged approach makes it extremely difficult for bacteria to develop resistance to this new weapon.

There is still much work to be done — these star polymers have yet to be tested on humans and will require years of research and development before they can be widely available. But when the waning sun finally sets on the era of effective antibiotics, these polymers may be the star that lights our way.

Works Cited

Dwyer, Vincent. “Australian Scientists May Have Just Saved Us From Antibiotic-Resistant Superbugs.” Vice, 12 Sept. 2016.

Jacobs, Andrew. “U.N. Issues Urgent Warning On The Growing Peril Of Drug-Resistant Infections.” The New York Times, 29 April 2019.

Jacobs, Andrew. “W.H.O. Warns That Pipeline For New Antibiotics Is Running Dry.” The New York Times, 17 Jan. 2020.

Lam, Shu J., Neil M. O’Brien-Simpson, Namfon Pantarat, Adrian Sulistio, et al. “Combating Multidrug-Resistant Gram-Negative Bacteria With Structurally Nanoengineered Antimicrobial Peptide Polymers.” Nature Microbiology, 12 Sept. 2016.

Science News Staff. “Killing Superbugs With Star-Shaped Polymers, Not Antibiotics.” Science News, 13 Sept. 2016.

Seppa, Nathan. “Drug Resistance Has Gone Global, W.H.O. Says.” Science News, 30 April 2014.

Unleash the Tests: The Four-Legged Future of Covid-19 Testing

She’s got pointy ears, a long snout and four strong legs. Meet your new Covid-19 test.

For years dogs have been used to detect bombs and drugs at airports, but our canine friends can also detect certain diseases, such as cancer and Parkinson’s disease, years before the onset of symptoms.

How can they do this? A dog’s nose has between 125 and 300 million scent glands, compared to a human nose, which only has about five million. As a result, a dog’s sense of smell can be up to 100,000 times more sensitive than a human’s. If there were a juicy steak 10 miles away, your dog’s nose could find it. So, when diseases cause people to emit slightly different odors, dogs can detect them.

With Covid-19 occupying the minds of scientists around the world, it was only a matter of time before researchers put dogs to the test to see if they could sniff out the novel coronavirus. Lucky for us, they can. Indeed, researchers have started to train dogs to detect Covid-19 in human sweat samples, and many countries are looking to dogs for cheap, reliable and rapid testing.

It is believed that dogs can recognize a scent produced by volatile organic compounds generated by catabolites, substances produced during replication of the Covid-19 virus. Catabolites exit the body in the form of sweat, which then carries a scent that dogs can detect and be trained to identify.

Dogs in recent trials could pick up the scent of Covid-19 in asymptomatic carriers, and many could even detect Covid-19 earlier than a PCR test could. As Cynthia Otto, the director of the Penn Vet Working Dog Center at the University of Pennsylvania School of Veterinary Medicine, explained to me in an interview: “PCR identifies the RNA associated with the virus. It requires sufficient virus to capture that signal. The dogs pick up the odor of the person’s response to infection. That response could be activated before the virus is in sufficient numbers in the sample collected.”

Another drawback of PCR testing is its speed, often taking several days to get results back. In contrast, dogs could screen hundreds of people in a matter of minutes in busy places such as airports and sports stadiums. Beyond their speed, dogs are also accurate, with the ability to identify positive samples about 95 percent of the time and with a false negativity rate of around one percent in trials. Dr. Otto worries, however, that “If a dog is trained but inadvertently does not actually recognize Covid, then use of this dog would result in false negatives, which would provide inaccurate information and could result in greater spread.”

For this reason, Dr. Otto suggests that “Dogs potentially could be used for screening, rather than diagnosis,” which would allow for “rapid identification of people who need further testing.”

Either way, there is great potential for dogs to help control the pandemic. These inexpensive and quick canine testers could help us get back to a pre-Covid normal.

Works Cited

Hunt, Katie. “Dogs Can be Trained to Detect Covid-19 by Sniffing Human Sweat, Study Suggests.” CNN, 10 Dec. 2020.

Lee, Jack. “New Coronavirus Tests Promise to be Faster, Cheaper and Easier.” Science News, 31 Aug. 2020.

McNeil Jr., Donald. “Dogs Can Detect Malaria. How Useful Is That?” The New York Times, 25 Nov. 2018.

Moysich, Kirsten. “Can Dogs Smell Cancer?” Rosewell Park Cancer Center. 25 Aug. 2020.

Otto, Cynthia. Personal Interview.

Peltier, Elian. “The Nose Needed for This Coronavirus Test Isn’t Yours. It’s a Dog’s.” The New York Times, 23 Sept. 2020.