Chronic traumatic encephalopathy: Causes, Symptoms and Treatment


Post 8534

Chronic traumatic encephalopathy: Causes, Symptoms and Treatment

Chronic traumatic encephalopathy: Causes, Symptoms and Treatment

There’s still a lot that scientists don’t know about the links between football and concussions and chronic traumatic encephalopathy (CTE).

Credit: Amy Myers/Shutterstock

Chronic traumatic encephalopathy (CTE) is a degenerative brain disease that kills brain cells. Though it has been linked to brain trauma and certain proteins in the brain, little is known about this disease.

CTE is thought to be caused by repetitive brain trauma. It is often found in those who are more likely to get head injuries. In fact, it was once called punch-drunk syndrome or dementia pugilistica. A 1928 study in the Journal of the American Medical Association (JAMA) was the first to describe the condition, which occurred among boxers, according to the Brain Injury Research Institute.

Indeed, boxing and other sports where head injuries are common — wrestling, cheerleading, basketball, soccer, ice hockey, rugby, field hockey, volleyball, lacrosse and football — are often culprits. A 2017 study published in JAMA on 200 deceased football players found that 90 percent of the players had CTE. Of these players, 71 percent of the players had severe CTE.

Other people who may acquire CTE include those who have been physically abused, have epilepsy or who’ve had traumatic injuries in the military. A 2012 study published in the journal Science Translational Medicine found the disease in the brains of four deceased U.S. military veterans.

“Our study, for the first time, shows military personnel that have experienced blast exposure exhibit CTE that’s basically indistinguishable from [the CTE in] the athletes we’ve looked at,” said study researcher Patric Stanton, a cell biology professor at New York Medical College in Valhalla, New York.

How chronic traumatic encephalopathy works isn’t completely understood. Experts think that when the brain is injured repetitively, it wastes away, according to the Mayo Clinic. Researchers also think that after a brain injury, a protein called tau forms clumps in the brain, thus killing brain cells, according to the Concussion Legacy Foundation. And, though uncommon, the protein beta-amyloid has also been found in people with CTE.

The damage of CTE often mimics that of Alzheimer’s disease. The difference is that the tau protein builds up in the wrinkles of the brain in those affected with CTE, while in those affected with Alzheimer’s, the protein is more spread out in the brain.

Currently, CTE can be diagnosed only after a person has died, because an examination of the person’s brain is required to make the diagnosis. Because that type of examination can’t be performed until the patient is dead, it is hard to know the exact symptoms of the disease. Recently, though, scientists found a new marker for CTE that could help doctors diagnose the condition while a person is still alive.

The symptoms of CTE generally do not show up until years or decades after the brain trauma, according to the Boston University Research CTE Center. This can also make it very hard to link symptoms to CTE.

According to the Mayo Clinic, symptoms of CTE may include the following:

  • Difficulty planning and carrying out tasks
  • Difficulty thinking
  • Substance abuse
  • Depression or apathy
  • Short-term memory loss
  • Impulsive behavior
  • Emotional instability
  • Suicidal thoughts or behavior
  • Aggression
  • Irritability
  • Trouble swallowing (dysphagia)
  • Motor impairment, such as difficulty walking, tremors, loss of muscle movement, weakness or rigidity
  • Speech and language difficulties
  • Vision and focusing problems
  • Dementia
  • Trouble with sense of smell

Images of the brains of people who had CTE clearly show holes in the brain.

Because CTE is diagnosed after death, there is really no way yet of diagnosing and treating a person who has this disease. Medical professionals may try neurological, or brain imaging, tests to determine if there has been injury to the brain, but there is no standard way to diagnose CTE in the living.

Prevention seems to be the best course of action. Traumatic brain injury(TBI), or concussions, causes 1.4 million deaths, hospitalizations and emergency department visits each year, according to the Centers for Disease Control and Prevention (CDC). In addition, 1.6 million to 3.8 million sports-and-recreation-related TBIs occur each year.

Dr. Kory Gill, an assistant professor at the Texas A&M Health Science Center College of Medicine and a team physician for Texas A&M University Athletics, told Live Science, “Become familiar with the signs/symptoms of concussions, and if you think you or a teammate has a concussion, speak up.”

Gill also pointed out that a law passed in 2009 — the Zackery Lystedt Law— requires school districts and nonprofit organizations using school facilities to adopt policies for the management of concussion and head injury in youth sports.

Additional resources

Advertisements

How to build a Dyson sphere in five (relatively) easy steps


Post 8533

How to build a Dyson sphere in five (relatively) easy steps

We are closer to being able to build a Dyson Sphere than we think. By enveloping the sun in a massive sphere of artificial habitats and solar panels, a Dyson Sphere would provide us with more energy than we would ever know what to do with while dramatically increasing our living space. Implausible you say? Something for our distant descendants to consider? Think again. We could conceivably get going on the project in about 25 to 50 years, with completion of the first phase requiring only a few decades.

Given that our resources here on Earth are starting to dwindle, and combined with the problem of increasing demand for more energy and living space, this would seem to a good long-term plan for our species.

Now, before I tell you how we could do such a thing, it’s worth doing a quick review of what is meant by a “Dyson sphere”.

Dyson Spheres, Swarms, and Bubbles

The Dyson sphere, also referred to as a Dyson shell, is the brainchild of the physicist and astronomer Freeman Dyson. In 1959 he put out a two page paper titled, “Search for Artificial Stellar Sources of Infrared Radiation” in which he described a way for an advanced civilization to utilize all of the energy radiated by their sun. This hypothetical megastructure, as envisaged by Dyson, would be the size of a planetary orbit and consist of a shell of solar collectors (or habitats) around the star. With this model, all (or at least a significant amount) of the energy would hit a receiving surface where it can be used. He speculated that such structures would be the logical consequence of the long-term survival and escalating energy needs of a technological civilization.

Needless to say, the amount of energy that could be extracted in this way is mind-boggling. According to Anders Sandberg, an expert on exploratory engineering, a Dyson sphere in our solar system with a radius of one AU would have a surface area of at least 2.72×10^17 km2, which is around 600 million times the surface area of the Earth. The sun has an energy output of around 4×10^26 W, of which most would be available to do useful work.

I should note at this point that a Dyson sphere may not be what you think it is. Science fiction often portrays it as a solid shell enclosing the sun, usually with an inhabitable surface on the inside. Such a structure would be a physical impossibility as the tensile strength would be far too immense and it would be susceptible to severe drift.

Dyson’s original proposal simply assumed there would be enough solar collectors around the sun to absorb the starlight, not that they would form a continuous shell. Rather, the shell would consist of independently orbiting structures, around a million kilometres thick and containing more than 1×10^5 objects. Consequently, a “Dyson sphere” could consist of solar captors in any number of possible configurations. In a Dyson swarm model, there would be a myriad of solar panels situated in various orbits. It’s generally agreed that this would be the best approach. Another plausible idea is that of the Dyson bubble in which solar sails, as well as solar panels, would be put into place and balanced by gravity and the solar wind pushing against it.

For the purposes of this discussion, I’m going to propose that we build a Dyson swarm (sometimes referred to as a type I Dyson sphere), which will consist of a large number of independent constructs orbiting in a dense formation around the sun. The advantage of this approach is that such a structure could be built incrementally. Moreover, various forms of wireless energy transfer could be used to transmit energy between its components and the Earth.

Megascale construction

So, how would we go about the largest construction project ever undertaken by humanity?

As noted, a Dyson swarm can be built gradually. And in fact, this is the approach we should take. The primary challenges of this approach, however, is that we will need advanced materials (which we still do not possess, but will likely develop in the coming decades thanks to nanotechnology), and autonomous robots to mine for materials and build the panels in space.

Now, assuming that we will be able to overcome these challenges in the next half-decade or so-which is not too implausible- how could we start the construction of a Dyson sphere?

Oxford University physicist Stuart Armstrong has devised a rather ingenious and startling simple plan for doing so-one which he claims is almost within humanity’s collective skill-set. Armstrong’s plan sees five primary stages of construction, which when used in a cyclical manner, would result in increasingly efficient, and even exponentially growing, construction rates such that the entire project could be completed within a few decades.

Broken down into five basic steps, the construction cycle looks like this:

1. Get energy
2. Mine Mercury
3. Get materials into orbit
4. Make solar collectors
5. Extract energy

The idea is to build the entire swarm in iterative steps and not all at once. We would only need to build a small section of the Dyson sphere to provide the energy requirements for the rest of the project. Thus, construction efficiency will increase over time as the project progresses. “We could do it now,” says Armstrong. It’s just a question of materials and automation.

And yes, you read that right: we’re going to have to mine materials from Mercury. Actually, we’ll likely have to take the whole planet apart. The Dyson sphere will require a horrendous amount of material-so much so, in fact, that, should we want to completely envelope the sun, we are going to have to disassemble not just Mercury, but Venus, some of the outer planets, and any nearby asteroids as well.

Why Mercury first? According to Armstrong, we need a convenient source of material close to the sun. Moreover, it has a good base of elements for our needs. Mercury has a mass of 3.3×10^23 kg. Slightly more than half of its mass is usable, namely iron and oxygen, which can be used as a reasonable construction material (i.e. hematite). So, the useful mass of Mercury is 1.7×10^23 kg, which, once mined, transported into space, and converted into solar captors, would create a total surface area of 245g/m2. This Phase 1 swarm would be placed in orbit around Mercury and would provide a reasonable amount of reflective surface area for energy extraction.

There are five fundamental, but fairly conservative, assumptions that Armstrong relies upon for this plan. First, he assumes it will take ten years to process and position the extracted material. Second, that 51.9% of Mercury’s mass is in fact usable. Third, that there will be 1/10 efficiency for moving material off planet (with the remainder going into breaking chemical bonds and mining). Fourth, that we’ll get about 1/3 efficiency out of the solar panels. And lastly, that the first section of the Dyson sphere will consist of a modest 1 km2 surface area.

And here’s where it gets interesting: Construction efficiency will at this point start to improve at an exponential rate.

Consequently, Armstrong suggests that we break the project down into what he calls “ten year surges.” Basically, we should take the first ten years to build the first array, and then, using the energy from that initial swarm, fuel the rest of the project. Using such a schema, Mercury could be completely dismantled in about four ten-year cycles. In other words, we could create a Dyson swarm that consists of more than half of the mass of Mercury in forty years! And should we wish to continue, if would only take about a year to disassemble Venus.

And assuming we go all the way and envelope the entire sun, we would eventually have access to 3.8×10^26 Watts of energy.

Dysonian existence

Once Phase 1 construction is complete (i.e. the Mercury phase), we could use this energy for other purposes, like megascale supercomputing, building mass drivers for interstellar exploration, or for continuing to build and maintain the Dyson sphere.

Interestingly, Armstrong would seem to suggest that this might be enough energy to serve us. But other thinkers, like Sandberg, suggest that we should keep going. But in order for us to do so we would have to deconstruct more planets. Sandberg contends that both the inner and outer solar system contains enough usable material for various forms of Dyson spheres with a complete 1 AU radius (which would be around 42 kg/m2 of the sphere). Clearly, should we wish to truly attain Kardashev II status, this would be the way to go.

And why go all the way? Well, it’s very possible that our appetite for computational power will become quite insatiable. It’s hard to predict what a post-Singularity or post-biological civilization would do with so much computation power. Some ideas include ancestor simulations, or even creating virtual universes within universes. In addition, an advanced civilization may simply want to create as many positive individual experiences as possible (a kind of utilitarian imperative). Regardless, digital existence appears to be in our future, so computation will eventually become our most valuable and sought after resource.

That said, whether we build a small array or one that envelopes the entire sun, it seems clear that the idea of constructing a Dyson sphere should no longer be relegated to science fiction or our dreams of the deep future. Like other speculative projects, like the space elevator or terraforming Mars, we should seriously consider putting this alongside our other near-term plans for space exploration and work.

And given the progressively worsening condition of Earth and our ever-growing demand for living space and resources, we may have no other choice.

This post originally appeared on Sentient Developments.

Top illustration by Oh Jihoon.

Why We Should Look For Alien Megastructures Around Pulsars


Post 8532

Why We Should Look For Alien Megastructures Around Pulsars

Image: NASA

Some day in the far future, it’s possible our descendants will kick it up a notch and wrap the entire Sun in a massive solar-collecting shell known as a Dyson Sphere. It’s also possible that some advanced alien civilizations have already gone this route, which is why some SETI folks are on the lookout for these hypothetical objects. But a new study proposes that aliens are more likely to build megastructures around pulsars than stars—and importantly, we should be able to detect these objects from Earth using current technology.

When Freeman Dyson came up with his mind-altering idea back in 1959, he wasn’t imagining an energy solution for future humans. Instead, he was thinking about aliens, and the kinds of things we should be looking for to finally prove they actually exist. Today, the search for alien megastructures is referred to as Dysonian SETI, and we haven’t found anything yet (though we’ve had some false signals).

Conceptually, Dyson’s hypothetical sphere makes a lot of sense, particularly for advanced civilizations with a huge appetite for energy. By constructing a thin spherical shell around its sun, a civilization could capture oodles of solar energy that would otherwise bleed uselessly into space.

Graduating to a Type 2 Kardashev civilization sounds all good and well, but constructing—and maintaining—a megastructure of this scale won’t be easy. The shell itself would be located around one AU from the host star (that’s the average distance the Earth orbits the Sun). Consequently, the amount of material required to build a Dyson Sphere would be literally astronomical, andsome experts have speculated that, if we were to ever build a Dyson Sphere, we’d have to dismantle Mercury, and possibly even Venus and the Asteroid Belt. Unfortunately, this could disrupt the delicate gravitational balance within the Solar System, leading to downstream consequences like planet-on-planet collisions. Other challenges exist as well, such as maintaining the shape and position of the shell, and repairing the endless damage wrought to the structure by incoming asteroids and comets.

It’s for these and other reasons that Zaza Osmanov, an astronomer from the Free University of Tbilisi, believes that Dyson Spheres aren’t the way to go. Ina paper he published last year in the International Journal of Astrobiology, Osmanov said that Dyson Spheres are “unrealistically massive and cannot be considered seriously,” and that aliens (or future humans for that matter) are more likely to build Dyson Rings—a stripped down version of a Dyson Sphere. What’s more, he said aliens weren’t likely to construct these solar-collecting rings around stars, but pulsars instead. Now, in a follow-up study to this first paper, Osmanov is arguing that we should be able to detect these structures from Earth.

Osmanov’s idea is actually kind of awesome. Pulsars are rapidly rotating neutron stars or white dwarfs that emit a concentrated beam of electromagnetic radiation. From our vantage point on Earth, we can only see pulsars if their beams are pointing directly at us. Pulsars have short and highly regular rotational periods, which is why they blink. (Fun fact: When the first pulsar was discovered in 1967, astronomers thought they had stumbled upon an alien intelligence—they even named it LGM, which stands for Little Green Men.)

According to Osmanov, advanced alien civilizations are likely to exploit this high-power celestial phenomenon. Extending Dyson’s concept to pulsars, he says a ring of solar panels could be constructed around a slowly-rotating pulsar (spinning around about once every half second, so not that slow) at a distance of around nine million miles, or roughly one-third of the distance between Mercury and our Sun. He estimates that the Dyson Ring would be exposed to temperatures of around 117 degrees C (242 degrees F), which would make the object visible to observers on Earth in the infrared (IR) band.

Consequently, and assuming these objects actually exist, Osmanov says we could detect these Dyson rings from Earth using existing telescopes, such as the Very Large Telescope Interferometer (VLTI), the Wide-field Infrared Survey Explorer (WISE), and in future, the James Webb Space Telescope. “The search of infrared rings is quite promising for distances up to [652 lightyears], where one will be able to monitor potentially 64 [known] pulsars by using the IR instruments,” he writes in the study. “Observation of distant pulsars [up to 3,262 lightyears]… will significantly increase the total number of potential objects to [around] 1,600, but at this moment the UV instruments cannot provide such a level of sensitivity.”

Artist’s impression of a Dyson Ring. (Image: Wikimedia)

“This is pretty cool,” Milan M. Ćirković, an astronomer and astrobiologist at the Astronomical Observatory of Belgrade, told Gizmodo. “I do agree that they are detectable in principle… and this study is worthy of attention just for that. Whether [the construction of Dyson Rings around pulsars] is likely to happen depends on too many issues, including perhaps the most intriguing one, namely what other [kinds]… of megastructures could we expect from a Type 2 civilization that has capacity and will to build pulsar rings.”

Anders Sandberg, a senior research fellow at Oxford University’s Future of Humanity Institute, likes Osmanov’s idea, but he’s still a big believer in good ol’ fashion Dyson spheres.

“For stars, a Dyson swarm [a variation of the Dyson sphere] can pick up most of the energy because the star shines evenly in all directions,” Sandberg told Gizmodo. “For a pulsar there is not much light, but indeed a big electromagnetic field with a lot of directionality one can capture and use using much smaller rings. Osmanov is right in that this requires less material, but it is not clear why this would matter much. One could build a thin yet energy-collecting Dyson swarm out of a few large asteroids in the solar system. If you have self-replicating [robotic] technology, scale is not a problem, and if you lack it you will struggle to build even a Dyson ring.”

Sandberg also says that Dysonian superstructures don’t have to be located in a star system’s habitable zone, and that we should look for alien megastructures in other regions of space as well.

“But it makes sense to look at pulsars to see if there is something there: They are rare enough to stand out—and it has been suggested that SETI should look near them for this very reason—and they might have accessible energy sources useful in ways normal Dyson swarms aren’t,” he said.

So what the hell are we waiting for? Time for someone with access to an IR-scanning telescope to hone in on on this rather small set of candidate objects. Who knows, the celestial phenomena we once thought were signs of alien intelligence may in fact be home to ET—and possibly a glimpse into our very own future.

[International Journal of Astrobiology]