One Third of Humanity May Host a Mind-Altering Parasite
Humans can contract the parasite by ingesting anything contaminated with cat feces.
This article originally appeared in the Newton blog at RealClearScience. You can read the original here.
In the opening scenes of Star Trek II: The Wrath of Khan, two Starfleet officers find themselves in quite a perilous situation. Captured by a group of renegades bent on revenge against Captain James T. Kirk, the duo is forced to host slimy, grotesque parasitic worms that crawl into their ears and roost in their brains. There, the parasites exert control over the two officers, bending their minds to the will of the renegades.
To the best of our knowledge, insidious parasites like these only exist in science fiction. However, there is an organism on Earth -- a single-celled protozoan to be specific -- that bears a striking resemblance. And alarmingly, it may infest as much as a third of humanity (including 45% of the French)!
That parasite is Toxoplasma gondii. Commonly found in domestic cats, it sexually reproduces only within feline intestines. Humans can contract the parasite by ingesting anything contaminated with cat feces. Once infected, individuals may succumb to mild, flu-like symptoms for a couple weeks, but little more. Often no symptoms manifest at all. The parasite's apparent harmless nature cloaks its presence. Soon after finding its way into a human host, it weasels its way into the brain. There, "sheltered from the full fury of the immune system," it can remain in what's called a tissue cyst for decades, not reproducing, just persisting. But in this form, researchers are finding that it can produce some subtle and startling changes in the host's behavior.
Biologist Jaroslav Flegr, one of the leading researchers on T. gondii has discerned some very peculiar findings when comparing people with the infection to those without it. Kathleen Mcauliffe reported on this last year in The Atlantic:
...males who had the parasite were more introverted, suspicious, oblivious to other people's opinions of them, and inclined to disregard rules. Infected women, on the other hand, presented in exactly the opposite way: they were more outgoing, trusting, image-conscious, and rule-abiding than uninfected women.
Additionally, people infected with T. gondii display slightly impaired motor skills, undertake more risks, and get into more automotive accidents. Furthermore, 38 studies have linked the parasite with schizophrenia, a fact which fascinates neurologist and Yale assistant professor Steven Novella.
"Some drugs which are typically used to treat schizophrenia actually have anti-toxo effects," Novella said on a recent episode of The Skeptic's Guide to the Universe. "So they may work because they're actually counteracting toxoplasma, itself."
How T. gondii subtly reprograms the brain is still not well understood. Studying the parasite outside of the body, researchers have found that it profoundly affects gene expression in host cells, as well as molecules involved in signal transduction pathways. If neurons in the brain are influenced in the same manner, that could possibly give rise to the behavior-altering effects.
Worldwide, as many as 1 in 3 people have T. gondii in their brains. Scary, I know. But hold off on any urges to cull the cat population. Indoor cats pose little to no threat to their owners, and the prevalence of infection is only about 1 in 10 in the United States (and currently declining). However, that's still a significant amount, a preponderance that makes you wonder how much of an effect these microscopic, mind-altering parasites really have on human interactions and everyday life as we know it.
(Image: Toxoplasmosis via Shutterstock)
It's just the current cycle that involves opiates, but methamphetamine, cocaine, and others have caused the trajectory of overdoses to head the same direction
- It appears that overdoses are increasing exponentially, no matter the drug itself
- If the study bears out, it means that even reducing opiates will not slow the trajectory.
- The causes of these trends remain obscure, but near the end of the write-up about the study, a hint might be apparent
Through computationally intensive computer simulations, researchers have discovered that "nuclear pasta," found in the crusts of neutron stars, is the strongest material in the universe.
- The strongest material in the universe may be the whimsically named "nuclear pasta."
- You can find this substance in the crust of neutron stars.
- This amazing material is super-dense, and is 10 billion times harder to break than steel.
Superman is known as the "Man of Steel" for his strength and indestructibility. But the discovery of a new material that's 10 billion times harder to break than steel begs the question—is it time for a new superhero known as "Nuclear Pasta"? That's the name of the substance that a team of researchers thinks is the strongest known material in the universe.
Unlike humans, when stars reach a certain age, they do not just wither and die, but they explode, collapsing into a mass of neurons. The resulting space entity, known as a neutron star, is incredibly dense. So much so that previous research showed that the surface of a such a star would feature amazingly strong material. The new research, which involved the largest-ever computer simulations of a neutron star's crust, proposes that "nuclear pasta," the material just under the surface, is actually stronger.
The competition between forces from protons and neutrons inside a neutron star create super-dense shapes that look like long cylinders or flat planes, referred to as "spaghetti" and "lasagna," respectively. That's also where we get the overall name of nuclear pasta.
Caplan & Horowitz/arXiv
Diagrams illustrating the different types of so-called nuclear pasta.
The researchers' computer simulations needed 2 million hours of processor time before completion, which would be, according to a press release from McGill University, "the equivalent of 250 years on a laptop with a single good GPU." Fortunately, the researchers had access to a supercomputer, although it still took a couple of years. The scientists' simulations consisted of stretching and deforming the nuclear pasta to see how it behaved and what it would take to break it.
While they were able to discover just how strong nuclear pasta seems to be, no one is holding their breath that we'll be sending out missions to mine this substance any time soon. Instead, the discovery has other significant applications.
One of the study's co-authors, Matthew Caplan, a postdoctoral research fellow at McGill University, said the neutron stars would be "a hundred trillion times denser than anything on earth." Understanding what's inside them would be valuable for astronomers because now only the outer layer of such starts can be observed.
"A lot of interesting physics is going on here under extreme conditions and so understanding the physical properties of a neutron star is a way for scientists to test their theories and models," Caplan added. "With this result, many problems need to be revisited. How large a mountain can you build on a neutron star before the crust breaks and it collapses? What will it look like? And most importantly, how can astronomers observe it?"
Another possibility worth studying is that, due to its instability, nuclear pasta might generate gravitational waves. It may be possible to observe them at some point here on Earth by utilizing very sensitive equipment.
The team of scientists also included A. S. Schneider from California Institute of Technology and C. J. Horowitz from Indiana University.
Check out the study "The elasticity of nuclear pasta," published in Physical Review Letters.
Scientists think constructing a miles-long wall along an ice shelf in Antarctica could help protect the world's largest glacier from melting.
- Rising ocean levels are a serious threat to coastal regions around the globe.
- Scientists have proposed large-scale geoengineering projects that would prevent ice shelves from melting.
- The most successful solution proposed would be a miles-long, incredibly tall underwater wall at the edge of the ice shelves.
The world's oceans will rise significantly over the next century if the massive ice shelves connected to Antarctica begin to fail as a result of global warming.
To prevent or hold off such a catastrophe, a team of scientists recently proposed a radical plan: build underwater walls that would either support the ice or protect it from warm waters.
In a paper published in The Cryosphere, Michael Wolovick and John Moore from Princeton and the Beijing Normal University, respectively, outlined several "targeted geoengineering" solutions that could help prevent the melting of western Antarctica's Florida-sized Thwaites Glacier, whose melting waters are projected to be the largest source of sea-level rise in the foreseeable future.
An "unthinkable" engineering project
"If [glacial geoengineering] works there then we would expect it to work on less challenging glaciers as well," the authors wrote in the study.
One approach involves using sand or gravel to build artificial mounds on the seafloor that would help support the glacier and hopefully allow it to regrow. In another strategy, an underwater wall would be built to prevent warm waters from eating away at the glacier's base.
The most effective design, according to the team's computer simulations, would be a miles-long and very tall wall, or "artificial sill," that serves as a "continuous barrier" across the length of the glacier, providing it both physical support and protection from warm waters. Although the study authors suggested this option is currently beyond any engineering feat humans have attempted, it was shown to be the most effective solution in preventing the glacier from collapsing.
Source: Wolovick et al.
An example of the proposed geoengineering project. By blocking off the warm water that would otherwise eat away at the glacier's base, further sea level rise might be preventable.
But other, more feasible options could also be effective. For example, building a smaller wall that blocks about 50% of warm water from reaching the glacier would have about a 70% chance of preventing a runaway collapse, while constructing a series of isolated, 1,000-foot-tall columns on the seafloor as supports had about a 30% chance of success.
Still, the authors note that the frigid waters of the Antarctica present unprecedently challenging conditions for such an ambitious geoengineering project. They were also sure to caution that their encouraging results shouldn't be seen as reasons to neglect other measures that would cut global emissions or otherwise combat climate change.
"There are dishonest elements of society that will try to use our research to argue against the necessity of emissions' reductions. Our research does not in any way support that interpretation," they wrote.
"The more carbon we emit, the less likely it becomes that the ice sheets will survive in the long term at anything close to their present volume."
A 2015 report from the National Academies of Sciences, Engineering, and Medicine illustrates the potentially devastating effects of ice-shelf melting in western Antarctica.
"As the oceans and atmosphere warm, melting of ice shelves in key areas around the edges of the Antarctic ice sheet could trigger a runaway collapse process known as Marine Ice Sheet Instability. If this were to occur, the collapse of the West Antarctic Ice Sheet (WAIS) could potentially contribute 2 to 4 meters (6.5 to 13 feet) of global sea level rise within just a few centuries."
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