For more than two decades, researchers have explored using DNA as a chemical computer. Until now though, DNA computers have only been capable of solving whatever mathematical problem they were built to tackle. Now though, researchers have demonstrated a more general-purpose DNA computer that can run a variety of chemical "programs." From
Caltech:
"Think of them as nano apps," says Damien Woods, professor of computer science at Maynooth University near Dublin, Ireland, and one of two lead authors of the study. "The ability to run any type of software program without having to change the hardware is what allowed computers to become so useful. We are implementing that idea in molecules, essentially embedding an algorithm within chemistry to control chemical processes."
The system works by self-assembly: small, specially designed DNA strands stick together to build a logic circuit while simultaneously executing the circuit algorithm. Starting with the original six bits that represent the input, the system adds row after row of molecules—progressively running the algorithm. Modern digital electronic computers use electricity flowing through circuits to manipulate information; here, the rows of DNA strands sticking together perform the computation. The end result is a test tube filled with billions of completed algorithms, each one resembling a knitted scarf of DNA, representing a readout of the computation. The pattern on each "scarf" gives you the solution to the algorithm that you were running. The system can be reprogrammed to run a different algorithm by simply selecting a different subset of strands from the roughly 700 that constitute the system.
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For many years, we've been following the research on phages, viruses that kill bacteria, once a staple of Soviet medicine and now touted as a possible answer to the worrying rise of antibiotic-resistant strains of bacteria.
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Bob Goldstein, a professor of cell biology at the University of North Carolina at Chapel Hill, is also a talented graphic designer who creates fantastic "Gig Posters for Scientists" who lecture at the university. These days, Bob and his son do their own screenprinting too! Above:
12.5x19 inch hand screenprinted gig poster for distinguished scientist visiting UNC Chapel Hill. This one's got lights... LED lights are powered by 3V lithium-ion button cell batteries that were taped to the back of each poster. Image is based on results reported in this cool paper that showed that doublet microtubules are 2-lane highways. Locomotive image modified from this photo by priceman141, caboose modified from this photo by Roy Winkelman via ClipPix.
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On Monday, we reported that for the first time, a plant seed had germinated on the moon, an early experiment to test whether food could someday be grown on the moon to feed residents of a lunar base. The cotton sprout was inside a canister on China's Chang’e 4 lander that touched down on the far side of the moon earlier this month. Now, word that the first lunar plant has died. The little seedling froze to death during the lunar night. From GBTimes:
Liu Hanlong, head of the experiment at Chongqing University, said at a Chongqing government press conference on Tuesday that the temperature inside the 1-litre-capacity canister had reached -52 degrees Celsius and the experiment had ended.
According to Liu, the experiment did not carry a battery and could not continue environmental control during the lunar nighttime. The lack of battery was possibly due to mass constraints for the mission and the lander's own power demands...
"Although it is a biological payload for popularising science, it laid a foundation and technological support for our next step, that is, to build a lunar base for living," (Chongqing University professor and designer of the experiment) Xie (Genxin) said.
Previously:
• China launching lunar spacecraft to test growing plants on the dark side of the Moon
• First images from China's probe that just landed on the dark side of the moon
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The California turret spider build tiny towers on the forest floor that extend underground into a burrow. At night, they climb up into the tower and await their dinner -- beetles, moths, and other insects. Video above. From KQED's Deep Look:
While remaining hidden inside their turret, they’re able to sense the vibrations created by their prey’s footsteps.
That’s when the turret spider strikes, busting out of the hollow tower like an eight legged jack-in-the-box. With lightning speed the spider swings its fangs down like daggers, injecting venom into its prey before dragging it down into the burrow.
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A cotton seed has germinated on the moon. The sprout is inside a canister on China's Chang’e 4 lander that touched down on the far side of the moon earlier this month. From The Guardian:
Plants have been grown previously on the International Space Station, but this is the first time a seed has sprouted on the moon. The ability to grow plants in space is seen as crucial for long-term space missions and establishing human outposts elsewhere in the solar system, such as Mars.
Harvesting food in space, ideally using locally extracted water, would mean astronauts could survive for far longer without returning to Earth for supplies...
Scientists from Chongqing University, who designed the “mini lunar biosphere” experiment, sent an 18cm bucket-like container holding air, water and soil.
Inside are cotton, arabidopsis – a small, flowering plant of the mustard family – and potato seeds, as well as fruit-fly eggs and yeast.
Images sent back by the probe show a cotton plant has grown well, but so far none of the other plants had sprouted, the university said.
Imaging the marketing opportunity for a cannabis company to sell space weed!
Previously:
• China launching lunar spacecraft to test growing plants on the dark side of the Moon
• First images from China's probe that just landed on the dark side of the moon
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Known as a "living fossil," the coelacanth is an order of fish thought to have been extinct for 65 million years until one was caught in 1938 in a fisherman's net off the coast of South Africa and identified by museum curator Marjorie Courtenay-Latimer. This wonderful paper animation tells the story of the curious creature and its rediscovery.
(hhmi BioInteractive via The Kid Should See This)
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D. Allan Drummond is a a professor of biochemistry, microbiology, and human genetics who has a penchant for trilobites, the marine arthropods that first appeared more than 500 million years ago and went extinct 245 million years ago for unknown reasons. Drummond creates 3D renderings of his trilobite fossils and then has them cast in bronze. Now, Drummond has added insects to his practice, modeling jumping spiders, praying mantises, and stag beetles.
Seattle's reborn Roq La Rue Gallery is presenting Drummond's first show of his work until January 6: D. Allan Drummond: "Curiosity"
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Why do humans have so little hair, at least compared to all other primates? At Smithsonian, Jason Daley shares the latest genetic research on the biological factors that result in humans' minimal body hair and its unusual distribution. Daley also surveys the fascinating current theories about why we evolved into the only naked apes. From Smithsonian:
One popular idea that has gone in and out of favor since it was proposed is called the aquatic ape theory. The hypothesis suggests that human ancestors lived on the savannahs of Africa, gathering and hunting prey. But during the dry season, they would move to oases and lakesides and wade into shallow waters to collect aquatic tubers, shellfish or other food sources. The hypothesis suggests that, since hair is not a very good insulator in water, our species traded in most of our fur for a layer of fat. The hypothesis even suggests we might have developed bipedalism to become more effective waders. But this idea, which has been around for decades, hasn’t received much support from the fossil record and isn’t taken seriously by most researchers.
A more widely accepted theory is that, when human ancestors moved from the cool shady forests into the savannah, they needed better thermoregulation. Losing all that fur made it possible for hominins to hunt during the day in the hot grasslands without overheating. An increase in sweat glands, many more than other primates, also kept early humans on the cool side. The development of fire and clothing meant that humans could keep cool during the day and cozy up at night.
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Leon Hong writes, "I made this science-y animation for my wife Elaine Hsiao's research — with the hopes that people will learn something new about how all the microbes that live in and on us affect our brains and behavior."
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Researchers at Flinders University knocked out a gene known as RCAN1 in mice, hypothesizing that this would increase "non-shivering thermogenesis," which "expends calories as heat rather than storing them as fat" -- the mice were fed a high-calorie diet and did not gain weight.
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In 1977, just a few months after Voyager 1 and 2 began their grand tour of the solar system, Carl Sagan gave the esteemed Christmas Lectures at the Royal Institution of Great Britain. You can watch them below via YouTube or at the Read the rest
Researchers have spent decades exploring methods to 3D print organs for transplant but progress is slow due to the complex structure of, say, a kidney or pancreas. Precise Bio, a startup founded by scientists from Wake Forest Institute for Regenerative Medicine, claim that the first real success will come from 3D-printed corneas. They've already conducted animal studies and are building a roadmap toward human trials. From
IEEE Spectrum:
Corneas could be the first mainstream application of bioprinting, (Precise Bio CEO Aryeh) Batt says, in part because they have a layered structure that’s a good match for the technology. Each layer consists of different types of cells and fibers, which the printer could lay down in sequence, and these layers don’t contain blood vessels or nerves. What’s more, putting a new kind of transplant in the eye is inherently safer than implanting one deep in the body, since physicians could easily check for signs of trouble and could remove the tissue if anything seemed wrong.
There’s certainly a need for more corneas in the world, says Kevin Corcoran, president and CEO of the Eye Bank Association of America. In 2017, his members supplied nearly 51,000 transplantable corneas to patients in the United States, and also sent more than 26,000 abroad. Internationally, “there is a tremendous amount of unmet demand,” he says. “It’s estimated that 10 million people suffer from corneal blindness globally, primarily because they lack access to effective and affordable treatment.”
Part of Precise Bio’s proprietary approach is its printer, which uses a technique called laser-induced forward transfer to propel droplets of bioinks onto a surface.
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What animals have night vision and how the hell can they see in the dark anyway? (Nat Geo WILD via The Kid Should See This)
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As a result of noisy ship engines and the racket of ocean mining, bottlenose dolphins have slowly reducing the complexity and changing the frequency of their calls. According to new research from the University of Maryland Center for Environmental Science and published in the journal
Biology Letters, "the noise-induced simplification of dolphin whistles may reduce the information content in these acoustic signals and decrease effective communication, parent–offspring proximity or group cohesion." From
YaleEnvironment360:
“It’s kind of like trying to answer a question in a noisy bar and after repeated attempts to be heard, you just give the shortest answer possible,” Bailey said. “Dolphins simplified their calls to counter the masking effects of vessel noise.”
Dolphins are highly social animals and use their calls to stay together as a group, talk as they feed, and call out their names when they meet new members of their species. Each animal has a distinctive whistle, which typically uses complex sound patterns with variations in pitch and frequency.
photo: US Navy
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Blood is complicated: it changes texture, color and thickness depending on where it's flowing from and how fast. Though you can make a convincing fake blood with water, food coloring, flour and corn syrup, getting the proportions right depends on a scientific understanding of the context in which your fake blood is appearing.
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