from the world's big
Nanosensor can alert a smartphone when plants are stressed
Carbon nanotubes embedded in leaves detect chemical signals that are produced when a plant is damaged.
These sensors can be embedded in plant leaves, where they report on hydrogen peroxide signaling waves.
Plants use hydrogen peroxide to communicate within their leaves, sending out a distress signal that stimulates leaf cells to produce compounds that will help them repair damage or fend off predators such as insects. The new sensors can use these hydrogen peroxide signals to distinguish between different types of stress, as well as between different species of plants.
"Plants have a very sophisticated form of internal communication, which we can now observe for the first time. That means that in real-time, we can see a living plant's response, communicating the specific type of stress that it's experiencing," says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT.
This kind of sensor could be used to study how plants respond to different types of stress, potentially helping agricultural scientists develop new strategies to improve crop yields. The researchers demonstrated their approach in eight different plant species, including spinach, strawberry plants, and arugula, and they believe it could work in many more.
Strano is the senior author of the study, which appears today in Nature Plants. MIT graduate student Tedrick Thomas Salim Lew is the lead author of the paper.
Over the past several years, Strano's lab has been exploring the potential for engineering "nanobionic plants" — plants that incorporate nanomaterials that give the plants new functions, such as emitting light or detecting water shortages. In the new study, he set out to incorporate sensors that would report back on the plants' health status.
Strano had previously developed carbon nanotube sensors that can detect various molecules, including hydrogen peroxide. About three years ago, Lew began working on trying to incorporate these sensors into plant leaves. Studies in Arabidopsis thaliana, often used for molecular studies of plants, had suggested that plants might use hydrogen peroxide as a signaling molecule, but its exact role was unclear.
Lew used a method called lipid exchange envelope penetration (LEEP) to incorporate the sensors into plant leaves. LEEP, which Strano's lab developed several years ago, allows for the design of nanoparticles that can penetrate plant cell membranes. As Lew was working on embedding the carbon nanotube sensors, he made a serendipitous discovery.
"I was training myself to get familiarized with the technique, and in the process of the training I accidentally inflicted a wound on the plant. Then I saw this evolution of the hydrogen peroxide signal," he says.
He saw that after a leaf was injured, hydrogen peroxide was released from the wound site and generated a wave that spread along the leaf, similar to the way that neurons transmit electrical impulses in our brains. As a plant cell releases hydrogen peroxide, it triggers calcium release within adjacent cells, which stimulates those cells to release more hydrogen peroxide.
"Like dominos successively falling, this makes a wave that can propagate much further than a hydrogen peroxide puff alone would," Strano says. "The wave itself is powered by the cells that receive and propagate it."
This flood of hydrogen peroxide stimulates plant cells to produce molecules called secondary metabolites, such as flavonoids or carotenoids, which help them to repair the damage. Some plants also produce other secondary metabolites that can be secreted to fend off predators. These metabolites are often the source of the food flavors that we desire in our edible plants, and they are only produced under stress.
A key advantage of the new sensing technique is that it can be used in many different plant species. Traditionally, plant biologists have done much of their molecular biology research in certain plants that are amenable to genetic manipulation, including Arabidopsis thaliana and tobacco plants. However, the new MIT approach is applicable to potentially any plant.
"In this study, we were able to quickly compare eight plant species, and you would not be able to do that with the old tools," Strano says.
The researchers tested strawberry plants, spinach, arugula, lettuce, watercress, and sorrel, and found that different species appear to produce different waveforms — the distinctive shape produced by mapping the concentration of hydrogen peroxide over time. They hypothesize that each plant's response is related to its ability to counteract the damage. Each species also appears to respond differently to different types of stress, including mechanical injury, infection, and heat or light damage.
"This waveform holds a lot of information for each species, and even more exciting is that the type of stress on a given plant is encoded in this waveform," Strano says. "You can look at the real time response that a plant experiences in almost any new environment."
The near-infrared fluorescence produced by the sensors can be imaged using a small infrared camera connected to a Raspberry Pi, a $35 credit-card-sized computer similar to the computer inside a smartphone. "Very inexpensive instrumentation can be used to capture the signal," Strano says.
Applications for this technology include screening different species of plants for their ability to resist mechanical damage, light, heat, and other forms of stress, Strano says. It could also be used to study how different species respond to pathogens, such as the bacteria that cause citrus greening and the fungus that causes coffee rust.
"One of the things I'm interested in doing is understanding why some types of plants exhibit certain immunity to these pathogens and others don't," he says.
Strano and his colleagues in the Disruptive and Sustainable Technology for Agricultural Precision interdisciplinary research group at the Singapore-MIT Alliance for Research and Technology (SMART), MIT's research enterprise in Singapore, are also interested in studying is how plants respond to different growing conditions in urban farms.
One problem they hope to address is shade avoidance, which is seen in many species of plants when they are grown at high density. Such plants turn on a stress response that diverts their resources into growing taller, instead of putting energy into producing crops. This lowers the overall crop yield, so agricultural researchers are interested in engineering plants so that don't turn on that response.
"Our sensor allows us to intercept that stress signal and to understand exactly the conditions and the mechanism that are happening upstream and downstream in the plant that gives rise to the shade avoidance," Strano says.
The research was funded by the National Research Foundation of Singapore, the Singapore Agency for Science, Technology, and Research (A*STAR), and the U.S. Department of Energy Computational Science Graduate Fellowship Program.
- Plants have awareness and intelligence, argue scientists - Big Think ›
- “Forest Bathing”: Stress-Reducer, Immune-Booster, and Artistic ... ›
Emotional intelligence is a skill sought by many employers. Here's how to raise yours.
- Daniel Goleman's 1995 book Emotional Intelligence catapulted the term into widespread use in the business world.
- One study found that EQ (emotional intelligence) is the top predictor of performance and accounts for 58% of success across all job types.
- EQ has been found to increase annual pay by around $29,000 and be present in 90% of top performers.
Researchers hope the technology will further our understanding of the brain, but lawmakers may not be ready for the ethical challenges.
- Researchers at the Yale School of Medicine successfully restored some functions to pig brains that had been dead for hours.
- They hope the technology will advance our understanding of the brain, potentially developing new treatments for debilitating diseases and disorders.
- The research raises many ethical questions and puts to the test our current understanding of death.
What's dead may never die, it seems<p>The researchers did not hail from House Greyjoy — "What is dead may never die" — but came largely from the Yale School of Medicine. They connected 32 pig brains to a system called Brain<em>Ex</em>. Brain<em>Ex </em>is an artificial perfusion system — that is, a system that takes over the functions normally regulated by the organ. The pigs had been killed four hours earlier at a U.S. Department of Agriculture slaughterhouse; their brains completely removed from the skulls.</p><p>Brain<em>Ex</em> pumped an experiment solution into the brain that essentially mimic blood flow. It brought oxygen and nutrients to the tissues, giving brain cells the resources to begin many normal functions. The cells began consuming and metabolizing sugars. The brains' immune systems kicked in. Neuron samples could carry an electrical signal. Some brain cells even responded to drugs.</p><p>The researchers have managed to keep some brains alive for up to 36 hours, and currently do not know if Brain<em>Ex</em> can have sustained the brains longer. "It is conceivable we are just preventing the inevitable, and the brain won't be able to recover," said Nenad Sestan, Yale neuroscientist and the lead researcher.</p><p>As a control, other brains received either a fake solution or no solution at all. None revived brain activity and deteriorated as normal.</p><p>The researchers hope the technology can enhance our ability to study the brain and its cellular functions. One of the main avenues of such studies would be brain disorders and diseases. This could point the way to developing new of treatments for the likes of brain injuries, Alzheimer's, Huntington's, and neurodegenerative conditions.</p><p>"This is an extraordinary and very promising breakthrough for neuroscience. It immediately offers a much better model for studying the human brain, which is extraordinarily important, given the vast amount of human suffering from diseases of the mind [and] brain," Nita Farahany, the bioethicists at the Duke University School of Law who wrote the study's commentary, told <em><a href="https://www.nationalgeographic.com/science/2019/04/pig-brains-partially-revived-what-it-means-for-medicine-death-ethics/" target="_blank">National Geographic</a>.</em></p>
An ethical gray matter<p>Before anyone gets an <em>Island of Dr. Moreau</em> vibe, it's worth noting that the brains did not approach neural activity anywhere near consciousness.</p><p>The Brain<em>Ex</em> solution contained chemicals that prevented neurons from firing. To be extra cautious, the researchers also monitored the brains for any such activity and were prepared to administer an anesthetic should they have seen signs of consciousness. </p><p>Even so, the research signals a massive debate to come regarding medical ethics and our definition of death. </p><p>Most countries define death, clinically speaking, as the irreversible loss of brain or circulatory function. This definition was already at odds with some folk- and value-centric understandings, but where do we go if it becomes possible to reverse clinical death with artificial perfusion?</p><p>"This is wild," Jonathan Moreno, a bioethicist at the University of Pennsylvania, told <a href="https://www.nytimes.com/2019/04/17/science/brain-dead-pigs.html" target="_blank">the <em>New York Times</em></a>. "If ever there was an issue that merited big public deliberation on the ethics of science and medicine, this is one."</p><p>One possible consequence involves organ donations. Some European countries require emergency responders to use a process that preserves organs when they cannot resuscitate a person. They continue to pump blood throughout the body, but use a "thoracic aortic occlusion balloon" to prevent that blood from reaching the brain.</p><p>The system is already controversial because it raises concerns about what caused the patient's death. But what happens when brain death becomes readily reversible? Stuart Younger, a bioethicist at Case Western Reserve University, <a href="https://www.nature.com/articles/d41586-019-01216-4#ref-CR2" target="_blank">told <em>Nature</em></a> that if Brain<em>Ex</em> were to become widely available, it could shrink the pool of eligible donors.</p><p>"There's a potential conflict here between the interests of potential donors — who might not even be donors — and people who are waiting for organs," he said.</p><p>It will be a while before such experiments go anywhere near human subjects. A more immediate ethical question relates to how such experiments harm animal subjects.</p><p>Ethical review boards evaluate research protocols and can reject any that causes undue pain, suffering, or distress. Since dead animals feel no pain, suffer no trauma, they are typically approved as subjects. But how do such boards make a judgement regarding the suffering of a "cellularly active" brain? <a href="https://bigthink.com/philip-perry/after-death-youre-aware-that-youve-died-scientists-claim" target="_blank">The distress of a partially alive brain</a>? </p><p>The dilemma is unprecedented.</p>
Setting new boundaries<p>Another science fiction story that comes to mind when discussing this story is, of course, <em>Frankenstein</em>. As Farahany told <em>National Geographic</em>: "It is definitely has [sic] a good science-fiction element to it, and it is restoring cellular function where we previously thought impossible. But to have <em>Frankenstein</em>, you need some degree of consciousness, some 'there' there. [The researchers] did not recover any form of consciousness in this study, and it is still unclear if we ever could. But we are one step closer to that possibility."</p><p>She's right. The researchers undertook their research for the betterment of humanity, and we may one day reap some unimaginable medical benefits from it. The ethical questions, however, remain as unsettling as the stories they remind us of.</p>
A study published Friday tested how well 14 commonly available face masks blocked the emission of respiratory droplets as people were speaking.
- The study tested the efficacy of popular types of face masks, including N95 respirators, bandanas, cotton-polypropylene masks, gaiters, and others.
- The results showed that N95 respirators were most effective, while wearing a neck fleece (aka gaiter) actually produced more respiratory droplets than wearing no mask at all.
- Certain types of homemade masks seem to be effective at blocking the spread of COVID-19.
Fischer et al.<p>A smartphone camera recorded video of the participants, and a computer algorithm counted the number of droplets they emitted. To establish a control trial, the participants spoke into the box both with and without a mask. And to make sure that the droplets weren't in fact dust from the masks, the team conducted more tests by "repeatedly puffing air from a bulb through the masks."</p>
Fischer et al.<p>The results, published Friday in <a href="https://advances.sciencemag.org/content/early/2020/08/07/sciadv.abd3083" target="_blank">Science Advances</a>, showed that some masks are pretty much useless. In particular, neck fleeces (also called gaiters) actually produced more respiratory droplets compared to the control trial — likely because the fabric breaks down big droplets into smaller ones.</p><p>The top three most effective masks were N95 respirators, surgical masks, and polypropylene-cotton masks. Bandanas performed the worst, but were slightly better than wearing no mask at all.</p>
Fischer et al.<p>Research on mask efficacy is still emerging. But the new results seem to generally align with <a href="https://newsroom.wakehealth.edu/News-Releases/2020/04/Testing-Shows-Type-of-Cloth-Used-in-Homemade-Masks-Makes-a-Difference" target="_blank" rel="noopener noreferrer dofollow">prior tests</a>. For example, a study from June published in <a href="https://aip.scitation.org/doi/10.1063/5.0016018" target="_blank" rel="noopener noreferrer dofollow">Physics of Fluid</a> found that bandanas (followed by folded handkerchiefs) were least effective at blocking respiratory droplets. That same study also found, as <a href="https://newsroom.wakehealth.edu/News-Releases/2020/04/Testing-Shows-Type-of-Cloth-Used-in-Homemade-Masks-Makes-a-Difference" target="_blank" rel="noopener noreferrer dofollow">others have</a>, that masks made from multiple layers of quilter's fabric were especially effective at blocking droplets.</p><p>The researchers hope other institutions will conduct similar experiments so the public can see how well different masks can block the spread of COVID-19.</p><p style="margin-left: 20px;">"This is a very powerful visual tool to raise awareness that a very simple masks, like these homemade cotton masks, do really well to stop the majority of these respiratory droplets," Fischer told CNN. "Companies and manufacturers can set this up and test their mask designs before producing them, which would also be very useful."</p>
Sharing QAnon disinformation is harming the children devotees purport to help.
- The conspiracy theory, QAnon, is doing more harm than good in the battle to end child trafficking.
- Foster youth expert, Regan Williams, says there are 25-29k missing children every year, not 800k, as marketed by QAnon.
- Real ways to help abused children include donating to nonprofits, taking educational workshops, and becoming a foster parent.
Real ways you can help stop child trafficking<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="21fc2dc85391501eec28c4bf46d7db15"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/AXL0q9jNZGU?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Williams is the founder and CEO of <a href="http://www.seenandheard.org/" target="_blank">Seen and Heard</a>, a Los Angeles-based nonprofit that helps foster youth develop character through the performing arts. She's been involved with foster youth for years; I <a href="https://bigthink.com/politics-current-affairs/child-sex-trafficking" target="_self">wrote about her work</a> in child trafficking just over a year ago. Tragically, since that time, the situation for these children has only gotten worse, in large part because of QAnon.</p><p>Williams says child trafficking is an easy cause to rally people together. Fear is also a powerful unifying force, one that QAnon believers are already primed for via the news they consume. Almost every parent cares about their children, making them the ideal target to solidify groups. </p><p>The real problem, she says, is that the youth she works with are falling for these conspiracy theories. Trauma is a particularly powerful tool for indoctrination. If you're a teenager that's been abducted or abused, your trust level is already extremely low. Then you read about a global cabal of powerful men (and a few women) secretly abusing children, and the narrative seems ready-made for your personal history.</p><p>When Williams tried to "lovingly and kindly correct" the youth she was working with after learning about the Wayfair conspiracy, the girls' response was, "well, who owns the media?" </p><p style="margin-left: 20px;">"She goes from this small little thing to a QAnon talking point. I've been thinking about why she would believe such a preposterous idea—and there are others; it's not just one student, and they're in in deep. I think that when something horrific happens to you as a child, it's a lot easier to distance yourself from the immediate reality that it was an uncle or a parent or a sibling that hurt you. By detaching from that immediate person, they project it onto Bill Gates or Chrissy Teigen. Then it's not so personal, it's global." </p>
A man wear a shirt with the words Q Anon as he attends a rally for President Donald Trump at the Make America Great Again Rally being held in the Florida State Fair Grounds Expo Hall on July 31, 2018 in Tampa, Florida.
Photo by Joe Raedle/Getty Images<p>As Williams mentions, there are over 30,000 kids in foster care in the Los Angeles area alone. It's easy to fall through the cracks. The systems in place aren't perfect; they're certainly underfunded. When you're in a system trying to support you yet isn't capable of doing so, viewing the world as imperfect, and even harmful, becomes the lens through which you see reality. Again, this makes for a perfect indoctrination tool.</p><p>One popular QAnon talking point is that 800,000 children are missing. As Williams says, child trafficking experts "don't buy this for a minute." The number makes for a good meme but a poor representation of the problem. </p><p>To source better data, Williams turns to the <a href="https://www.missingkids.org/" target="_blank">National Center for Missing and Exploited Children</a> (NCMEC) and the <a href="https://www.fbi.gov/services/cjis/ncic" target="_blank" rel="noopener noreferrer dofollow">National Crime Information Center</a> (NCIC). An important factor when reading data: if a teacher <em>and</em> a caregiver report a missing child to NCIC, that counts as two children, not one, which accounts for some of the fluctuations in numbers. In total, between 25,000 and 29,000 kids go missing every year. Importantly, 94 percent of those children are recovered within four to six weeks. </p><p style="margin-left: 20px;">"They're not documenting the recovery rate. It's not like these numbers are perpetually hanging out there. So this 800,000 number is just ludicrous." </p><p>Williams compares what's going on to Black Lives Matter. Blacking out your Instagram profile picture is performative. It signals that you actually care, which is great, but if you're not supporting Black-owned businesses, for example, there are no teeth to your activism. </p><p>Of course, blacking out your profile doesn't cause the real-world harm the QAnon virus does. Sharing misinformation is ultimately harmful to the children in need of help. Williams offers the resources below—ranging from donations to nonprofits to educational trainings to becoming a foster parent—for people that actually want to do something to help victims of sexual and physical abuse. They might not make a great Twitter meme, but in the actual world, this support makes all the difference. </p><p><strong>To report abuse/neglect, call the child abuse hotline: 800.540.4000 (LA county) / 800.422.4453 (National)</strong></p><ul><li>Support anti-trafficking organizations by donating to <a rel="noopener noreferrer dofollow" href="http://savinginnocence.org/" target="_blank">Saving Innocence</a>, which runs the continuum of care from rescue to recovery, <a href="http://gozoe.org/" target="_blank" rel="noopener noreferrer dofollow">Zoe</a>, a reputable faith-based organization, and <a rel="noopener noreferrer dofollow" href="https://withtwowings.org/" target="_blank">Two Wings</a>, which helps to rehabilitate female survivors</li><li><a rel="noopener noreferrer dofollow" href="http://www.nolabrantleyspeaks.org/" target="_blank">Nola Brantley</a> offers in-person and online trainings to help combat the commercial sexual exploitation of children</li><li><a rel="noopener noreferrer dofollow" href="http://instagram.com/imrebeccabender" target="_blank">Rebecca Bender</a> is a trafficking survivor that runs "Myth Busters," which combats conspiracy theory disinformation</li><li>The <a href="https://www.instagram.com/missingkids/" target="_blank" rel="noopener noreferrer dofollow">National Center</a> of Missing and Exploited Children</li><li>Operation <a href="https://www.instagram.com/ourrescue/" target="_blank" rel="noopener noreferrer dofollow">Underground Railroad </a></li><li><a href="https://www.instagram.com/defendinnocence/" target="_blank" rel="noopener noreferrer dofollow">Defend Innocence</a> offers tips for parents and caregivers to keep kids safe</li></ul><p><span></span>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a>, <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank">Facebook</a> and <a href="https://derekberes.substack.com/" target="_blank">Substack</a>. His next book is</em> "<em>Hero's Dose: The Case For Psychedelics in Ritual and Therapy."</em></p>