from the world's big
How astronomy makes neuroscience even cooler: brains, gold, and neutron stars
Love being an intelligent, mobile, conscious being? Thank colliding neutron stars. They created all the gold in the universe, including the gold atoms that your brain can't function without.
Dr. Michelle Thaller is an astronomer who studies binary stars and the life cycles of stars. She is Assistant Director of Science Communication at NASA. She went to college at Harvard University, completed a post-doctoral research fellowship at the California Institute of Technology (Caltech) in Pasadena, Calif. then started working for the Jet Propulsion Laboratory's (JPL) Spitzer Space Telescope. After a hugely successful mission, she moved on to NASA's Goddard Space Flight Center (GSFC), in the Washington D.C. area. In her off-hours often puts on about 30lbs of Elizabethan garb and performs intricate Renaissance dances. For more information, visit NASA.
Michelle Thaller: To me it’s amazing some of the things that we actually do know. There’s plenty of things that are conjecture or theories but there’s a lot of stuff that we have real observations and real knowledge of. And amazingly, to me, one of the things is: where did all the atoms in our body come from? And it is actually a real fact, not a theory, that when you look back at how the universe looked about, say, 13 billion years ago, the chemistry was very, very different. We can actually see so far away out into space that the light we’re looking at took billions and billions of years to get to us even at the speed of light. And the farthest away we can see is to a time that was about 400,000 years after the Big Bang. That’s pretty impressive. That’s about 13.5 billion years ago. And when you look back that far the only thing you see is very hot hydrogen gas, a little bit of helium, a tiny bit of lithium, but that’s it. That’s not a theory. That’s actually an observation. And as you look at galaxies very far away in space and therefore very far back in time, you can actually watch the chemistry change. You watch different atoms get built up. And the only thing in the universe that we know that can make a large atom—by large I mean something like oxygen or carbon or calcium or anything that makes up our bodies—is actually the very core of a star. That’s where nuclear fusion reactions ram hydrogen together. The hydrogen was formed during the Big Bang. You take these hydrogen atoms, you smash them together and you build larger and large atoms until you build something like the carbon that makes up most of my body.
And so we’ve known for a while that the only way you get these large atoms is stars. But even with something as powerful as the core of a star there were some atoms that were a little bit more slippery; we couldn’t quite figure out how you get the energy needed to make something really big like a gold atom. That should take even higher temperatures, even more energy than what you typically find in the core of a massive star. So what is even more violent than an exploding mass of star, which makes a lot of heavy elements of the universe? One of the things we discovered recently is that two dead cores of stars called neutron stars can actually spiral together and collide. And when they collide instead of a normal death of an exploding star you basically have something like that on steroids. You have an explosion that’s so big and so violent people have really seen nothing like it since the Big Bang. Sometimes they call this a hyper nova, sometimes they call it gamma ray burst because of the burst of high energy radiation that comes out. But wonderfully we’ve been observing more and more of these colliding neutron stars and they are just pumping out gold atoms, platinum atoms and, interestingly enough, bismuth—but these very, very large, difficult-to-form atoms. And there’s so much gold created in one of these explosions that if you just look at the rate, you know, how many of these explosions do we observe—amazingly we observe about one a day—and how much gold is created in one of those? And you can actually account for the entire abundance of gold in the universe just from that one thing, those colliding neutron stars.
So the gold you have, I mean yes, you have gold in your jewelry. That’s really cool. I’ve got a gold ring. But interestingly enough our neurons don’t work without a tiny, little bit of gold to help our brain actually charge the neurons in our brain. We need a little bit of gold and a little bit of copper. So your brain wouldn’t work without a little bit of gold, a couple of gold atoms in the neurons. So the reason we’re here thinking and moving and actually existing the way we do is intimately connected to these colliding dead stars, these colliding neutron stars that most likely created all of the gold in this room.
Did you know you have gold in your brain? Inside every neuron, there are just a few atoms of gold that keep the neuron charged, which is what keeps you thinking, moving, and frankly existing. What could be cooler than that? Well, NASA's assistant director of science communication Michelle Thaller adds a layer of astronomy on top of that amazing neuroscience. It turns out that when we look far into outer space, essentially back through time, we can see that all the gold in the known universe was created and spewed out in cosmically violent neutron star collisions—that includes the atoms of gold that are now inside your brain. Crazy, right? That's what Carl Sagan meant when he wrote that "we are made of star-stuff."
Duke University researchers might have solved a half-century old problem.
- Duke University researchers created a hydrogel that appears to be as strong and flexible as human cartilage.
- The blend of three polymers provides enough flexibility and durability to mimic the knee.
- The next step is to test this hydrogel in sheep; human use can take at least three years.
Duke researchers have developed the first gel-based synthetic cartilage with the strength of the real thing. A quarter-sized disc of the material can withstand the weight of a 100-pound kettlebell without tearing or losing its shape.
Photo: Feichen Yang.<p>That's the word from a team in the Department of Chemistry and Department of Mechanical Engineering and Materials Science at Duke University. Their <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202003451" target="_blank">new paper</a>, published in the journal,<em> Advanced Functional Materials</em>, details this exciting evolution of this frustrating joint.<br></p><p>Researchers have sought materials strong and versatile enough to repair a knee since at least the seventies. This new hydrogel, comprised of three polymers, might be it. When two of the polymers are stretched, a third keeps the entire structure intact. When pulled 100,000 times, the cartilage held up as well as materials used in bone implants. The team also rubbed the hydrogel against natural cartilage a million times and found it to be as wear-resistant as the real thing. </p><p>The hydrogel has the appearance of Jell-O and is comprised of 60 percent water. Co-author, Feichen Yang, <a href="https://today.duke.edu/2020/06/lab-first-cartilage-mimicking-gel-strong-enough-knees" target="_blank">says</a> this network of polymers is particularly durable: "Only this combination of all three components is both flexible and stiff and therefore strong." </p><p> As with any new material, a lot of testing must be conducted. They don't foresee this hydrogel being implanted into human bodies for at least three years. The next step is to test it out in sheep. </p><p>Still, this is an exciting step forward in the rehabilitation of one of our trickiest joints. Given the potential reward, the wait is worth it. </p><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>
An algorithm may allow doctors to assess PTSD candidates for early intervention after traumatic ER visits.
- 10-15% of people visiting emergency rooms eventually develop symptoms of long-lasting PTSD.
- Early treatment is available but there's been no way to tell who needs it.
- Using clinical data already being collected, machine learning can identify who's at risk.
The psychological scars a traumatic experience can leave behind may have a more profound effect on a person than the original traumatic experience. Long after an acute emergency is resolved, victims of post-traumatic stress disorder (PTSD) continue to suffer its consequences.
In the U.S. some 30 million patients are annually treated in emergency departments (EDs) for a range of traumatic injuries. Add to that urgent admissions to the ED with the onset of COVID-19 symptoms. Health experts predict that some 10 percent to 15 percent of these people will develop long-lasting PTSD within a year of the initial incident. While there are interventions that can help individuals avoid PTSD, there's been no reliable way to identify those most likely to need it.
That may now have changed. A multi-disciplinary team of researchers has developed a method for predicting who is most likely to develop PTSD after a traumatic emergency-room experience. Their study is published in the journal Nature Medicine.
70 data points and machine learning
Image source: Creators Collective/Unsplash
Study lead author Katharina Schultebraucks of Columbia University's Department Vagelos College of Physicians and Surgeons says:
"For many trauma patients, the ED visit is often their sole contact with the health care system. The time immediately after a traumatic injury is a critical window for identifying people at risk for PTSD and arranging appropriate follow-up treatment. The earlier we can treat those at risk, the better the likely outcomes."
The new PTSD test uses machine learning and 70 clinical data points plus a clinical stress-level assessment to develop a PTSD score for an individual that identifies their risk of acquiring the condition.
Among the 70 data points are stress hormone levels, inflammatory signals, high blood pressure, and an anxiety-level assessment. Says Schultebraucks, "We selected measures that are routinely collected in the ED and logged in the electronic medical record, plus answers to a few short questions about the psychological stress response. The idea was to create a tool that would be universally available and would add little burden to ED personnel."
Researchers used data from adult trauma survivors in Atlanta, Georgia (377 individuals) and New York City (221 individuals) to test their system.
Of this cohort, 90 percent of those predicted to be at high risk developed long-lasting PTSD symptoms within a year of the initial traumatic event — just 5 percent of people who never developed PTSD symptoms had been erroneously identified as being at risk.
On the other side of the coin, 29 percent of individuals were 'false negatives," tagged by the algorithm as not being at risk of PTSD, but then developing symptoms.
Image source: Külli Kittus/Unsplash
Schultebraucks looks forward to more testing as the researchers continue to refine their algorithm and to instill confidence in the approach among ED clinicians: "Because previous models for predicting PTSD risk have not been validated in independent samples like our model, they haven't been adopted in clinical practice." She expects that, "Testing and validation of our model in larger samples will be necessary for the algorithm to be ready-to-use in the general population."
"Currently only 7% of level-1 trauma centers routinely screen for PTSD," notes Schultebraucks. "We hope that the algorithm will provide ED clinicians with a rapid, automatic readout that they could use for discharge planning and the prevention of PTSD." She envisions the algorithm being implemented in the future as a feature of electronic medical records.
The researchers also plan to test their algorithm at predicting PTSD in people whose traumatic experiences come in the form of health events such as heart attacks and strokes, as opposed to visits to the emergency department.
What would it be like to experience the 4th dimension?
Physicists have understood at least theoretically, that there may be higher dimensions, besides our normal three. The first clue came in 1905 when Einstein developed his theory of special relativity. Of course, by dimensions we’re talking about length, width, and height. Generally speaking, when we talk about a fourth dimension, it’s considered space-time. But here, physicists mean a spatial dimension beyond the normal three, not a parallel universe, as such dimensions are mistaken for in popular sci-fi shows.
Vaccines find more success in development than any other kind of drug, but have been relatively neglected in recent decades.
Vaccines are more likely to get through clinical trials than any other type of drug — but have been given relatively little pharmaceutical industry support during the last two decades, according to a new study by MIT scholars.