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This week: Physicists conducted a biological study, engineers built a waste-recycling suit for astronauts (and worm riders), and astronomers identified the first known intermediate-mass black hole, and it’s right here in our own galactic backyard.

Water pumping

Observing that human muscle tissue is about 70% water, physicists at the University of Michigan created a theoretical model for the role of water in muscle contraction and reported that the velocity of fluid through the muscle fiber determines the rate of muscle contraction. But they also discovered a strange type of elasticity, which, in accordance with the Snakes in the Plane principle, they call strange elasticity. This allows the muscles to generate energy through three-dimensional deformations, as seen by the perpendicular bulging of the muscles when they are flexed lengthwise, often while posing in the mirror and pointing out the price of admission to the gun show.

UM physicist Suraj Shankar says, “Our results suggest that even such basic questions as how fast a muscle can contract or how many ways a muscle can generate energy have new and unexpected answers when one takes a more integrated and holistic view of muscle as a complex and hierarchically organized material, not just a bag of molecules, is more than the sum of its parts.”

Space walk without rhythm

Ideally, astronauts should enjoy spacewalks as observers of the unfolding majesty of the universe without the undignified and humiliating requirement to wear adult diapers. The unsanitary reality of life in space is that human biological demands are relegating our evolution into transdimensional, floating star children and astronauts who wear all diapers. Another drawback is that EVA urination bypasses the recycling system on board the International Space Station and represents waste in a resource-poor environment.

Cornell University researchers, inspired by the waste-recycling suits worn by the Fremen in the movies “Dune 1” and “Dune 2: The Squeak,” have developed a downsuit that could solve both problems for future astronauts. It includes a vacuum-based external catheter that directs urination to a combined reverse osmosis unit and provides a continuous supply of drinking water. This is a simplified description of a much more technical part of the kit, which you can read about here.

Parasite Eve

Toxoplasma gondii is a parasite that causes a potentially behavior-altering, incurable condition called toxoplasmosis. It reproduces in cats and eventually seeks to infect rodents to make them more susceptible to the approach of cats. There is no vaccine for toxoplasmosis, in part because the biological mechanisms of the infection are poorly understood, so a team at the University of Wisconsin-Madison conducted an optical imaging study to better understand it. They used a non-invasive technology called optical metabolic imaging to monitor metabolic activity in cells in real time.

They report that over the course of infection, host cells became more oxidized and the lifetime of NAD(P)H increased—this extra energy fuels the parasite during replication. They also discovered a dynamic in the interaction of T gondii with the host cell surface, to which they applied the vaguely disgusting name “kiss and spit.”

Scientist Gina Gallego-Lopez says, “One cell may be infected while the cells around it are not; it seems that the parasite ‘kisses’ these cells and then injects some proteins – a kiss and a spit,” she says. “To our surprise, we were able to see similar changes as full infection. So it appears that a simple ‘kiss’ from the parasite is sufficient to induce changes in the host cell.”

A new black hole has just fallen

Omega Centauri is a globular cluster located in the Milky Way galaxy, 17,090 light-years from the Sun and visible in the southern sky. A gravitationally bound bundle of 10 million stars, it is the most massive globular cluster in our galaxy. Scientists believe it is the surviving core of another galaxy that has been captured by the Milky Way and stripped of its outer stellar populations. For years, astronomers have speculated that if it is in fact the core of a galaxy, Omega Centauri may contain a central black hole.

Now researchers from the Max Planck Institute for Astronomy have confirmed this suspicion with a detailed study of stellar trajectories in the cluster. Researchers have compiled a huge catalog of the motions of the stars in Omega Centauri, calculating the velocities of 1.4 million stars from 500 Hubble images. Eventually, they zeroed in on seven fast-moving stars in the central region that showed velocities and motions that could only be explained by an invisible gravitational body.

Here’s the cool part: This black hole represents the missing link between stellar-mass black holes and supermassive black holes—an intermediate-mass black hole that has been predicted but never observed before. The reason it is so much smaller than the black holes typically found in the cores of galaxies is that Omega Centauri itself is frozen in time—with its stable population of stellar cores and no external population of stars, the black hole it cannot feed and increase its mass.

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