from the world's big
Tardigrades' kryptonite? Climate change.
Not so indestructible after all.
- Tardigrades, also known as water bears, are microscopic creatures best known for their ability to withstand a variety of extreme conditions, such as high heat, extreme cold, high pressure, and even the vacuum of space.
- However, new research shows that the famously durable creatures aren't so robust against the long-term heat of climate change.
- The findings underscore how fundamentally humans have affected life at every level.
The water bear — those minuscule, nigh-indestructible, spacefaring, radiation-proof, eight-footed, weirdly adorable creatures that hang out in mosses and lichens the world over. Turns out these microscopic supermen may not be as impervious as we thought. In fact, new research suggests that there is a kryptonite for tardigrades: climate change.
What are tardigrades?
For the unfamiliar, tardigrades — commonly referred to as water bears — are 0.5 mm-long (0.02 inches) creatures with four pairs of legs who have garnered internet fame for their extreme durability and their half-cute, half-terrifying appearance. They are extremophiles, capable of withstanding incredible heat, cold, and pressure. For instance, they can survive for a few minutes at 151°C (304°F) and a few days at -200°C (-328°F), they can withstand the vacuum of space and greater pressures than those found in the Marianas Trench, they can survive dehydration for decades, and they can handle 1,000 times more radiation than what would prove fatal to other animals.
In part, this incredible durability comes from their ability to enter into a state known as cryptobiosis. In this state, their metabolism decreases to 0.01 percent of normal levels, and they form a protein in their cells in place of water that protects their DNA in a glassy coating.
For these reasons, scientists believe that tardigrades may be capable of spreading life to different planets. If an asteroid were to strike Earth, shooting chunks of land out into space with a few hitchhiking tardigrades, the plucky creatures would hunker down, enter cryptobiosis, and endure the highly irradiated vacuum of space while they waited for their ride to crash into a planet suitable for life.
An Achilles' heel
A) An image of a tardigrade in its active state, and B) an image in its cryptobiotic state. During desiccation, an active state tardigrade contracts its body longitudinally and withdraw its legs to enter cryptobiosis.
Neves et al., 2020
Unfortunately, however, tardigrades do seem to have a fatal weakness. "We had found their Achilles' heel," researcher Ricardo Neves told Newsweek. "Tardigrades are definitely not the almost indestructible organism as advertised in so many popular science websites."
As it turns out, tardigrades are unable to survive sustained high temperatures. Even though they can endure a few minutes at 151°C, long-term exposure to far less than that blistering temperature killed half of the water bears in the researchers' sample.
Specifically, these scientists collected tardigrades from roof gutters in Denmark, the country where the study was conducted, and exposed them to temperatures of 37.1°C (98°F) for 24 hours. Half of the sample perished, a worrying result considering that the highest temperature recorded in Denmark is 36.4°C. Since global temperatures are rising, more and more tardigrade populations could be put at risk.
The researchers also tested out whether a more gradual heating process would improve survivability — after all, the environment doesn't just suddenly jump from mild to boiling. Unfortunately, improvements were marginal in this case — half of the tardigrade sample had died once temperatures reached 37.6°C.
What about their famous ability to enter cryptobiosis? When the tardigrades were first dried out to coax them into entering this state, they fared a bit better. In this case, half of the sample was able to survive 24 hours at 63.1°C (145.6°F). It's important to note, too, that this study examined the tardigrade species Ramazzottius varieornatus, which is known to be one of the hardier varieties of water bear.
"Before our study," said Neves, "tardigrades were regarded as the only organism on Earth to survive a cataclysmic event, but now we know this is not true. [While tardigrades are] among the most resilient organisms inhabiting our planet, it is now clear that they are vulnerable to high temperatures. Therefore, it seems that even tardigrades will have a hard time handling rising temperatures due to global warming."
Still sturdier than us
Still, it looks like tardigrades will certainly outlast us regardless. Most humans would die from hyperthermia within 10 minutes of exposure to temperatures in the 60°C range, compared to cryptobiotic tardigrades' 24 hours. Considering that climate change will increase drought conditions and gradually raise temperatures, it seems likely that they'll adapt to these new conditions — it's not a stretch of the imagination to think that they might enter cryptobiosis as a kind of heatwave hibernation, waiting until a bit of rain falls or temperatures drop.
As the globe heats up and humanity abandons the hottest regions of Earth, it seems likely that only the hardiest species will remain behind. Cockroaches, D. radiodurans, and tardigrades will likely inhabit the places we once did until it gets too hot for them, too.
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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>
Starting and running a business takes more than a good idea and the desire to not have a boss.
- Anyone can start a business and be an entrepreneur, but the reality is that most businesses will fail. Building something successful from the ground up takes hard work, passion, intelligence, and a network of people who are equally as smart and passionate as you are. It also requires the ability to accept and learn from your failures.
- In this video, entrepreneurs in various industries including 3D printing, fashion, hygiene, capital investments, aerospace, and biotechnology share what they've learned over the years about relationships, setting and attaining goals, growth, and what happens when things don't go according to plan.
- "People who start businesses for the exit, most of them will fail because there's just no true passion behind it," says Miki Agrawal, co-founder of THINX and TUSHY. A key point of Agrawal's advice is that if you can't see yourself in something for 10 years, you shouldn't do it.
After a decade of failed attempts, scientists successfully bounced photons off of a reflector aboard the Lunar Reconnaissance Orbiter, some 240,000 miles from Earth.
- Laser experiments can reveal precisely how far away an object is from Earth.
- For years scientists have been bouncing light off of reflectors on the lunar surface that were installed during the Apollo era, but these reflectors have become less efficient over time.
- The recent success could reveal the cause of the degradation, and also lead to new discoveries about the Moon's evolution.
A close-up photograph of the laser reflecting panel deployed by Apollo 14 astronauts on the Moon in 1971.
NASA<p>The technology isn't quite new. During the Apollo era, astronauts installed on the lunar surface five reflecting panels, each containing at least 100 mirrors that reflect back to whichever direction it's coming from. By bouncing light off these panels, scientists have been able to learn, for example, that the Moon is drifting away from Earth at a rate of about 1.5 inches per year.<br></p><p style="margin-left: 20px;">"Now that we've been collecting data for 50 years, we can see trends that we wouldn't have been able to see otherwise," Erwan Mazarico, a planetary scientist from NASA's Goddard Space Flight Center in Greenbelt, Maryland, <a href="https://www.nasa.gov/feature/goddard/2020/laser-beams-reflected-between-earth-and-moon-boost-science" target="_blank" rel="dofollow">said</a>. "Laser-ranging science is a long game."</p>
NASA's Lunar Reconnaissance Orbiter (LRO)
NASA<p>But the long game poses a problem: Over time, the panels on the Moon have become less efficient at bouncing light back to Earth. Some scientists suspect it's because dust, kicked up by micrometeorites, has settled on the surface of the panels, causing them to overheat. And if that's the case, scientists need to know for sure.</p><p>That's where the recent LRO laser experiment comes in. If scientists find discrepancies between the data sent back by the LRO reflector and those on the lunar surface, it could reveal what's causing the lunar reflectors to become less efficient. They could then account for these discrepancies in their models.</p>