The soft, pale foot of a six-inch long razor clam burrows through sand at an impressive rate of four body lengths per minute (video). When scientists put muscles in the razor clam to the strength test though, they found that its foot was only 1/10 as strong as it would need to be to dig so fast. What gives? The sand, literally.
Instead of relying on brute force, the burrowing razor clam turns the sediment around itself into quicksand, according to a study published in the Journal of Experimental Biology. And as Hollywood has taught us well, it’s easy to sink in quicksand.* The razor clam pulls its shell up, creating a vacuum that sucks water into the space surrounding its body. Quicksand is just sand with enough water between all its particles so that it no longer holds any weight, making it easy for the razor clam to tunnel down. Although most (big) pools of quicksand are created by earthquakes or flowing water, the razor clam’s small scale strategy is quite effective. In fact, the little buggers are so fast that recreational clam digging actually takes some practice.
*The human body is actually too buoyant to sink beyond the armpits in quicksand. So no, you can’t die of drowning in quicksand but you can get stuck and die of dehydration. Comforting thought, right?
Gallus gallus, the undomesticated ancestor of modern chickens
Chickens, the surviving descendants of once-mighty therapod dinosaurs, have come to dominate American dinner tables, where its meat is consumed at a rate of 80 pounds per person per year. How the wild grub-eating Gallus Gallus was tamed and commodified into frozen breaded cutlets is actually quite an epic story, one that involves (possibly) saving Greek civilization from Persians, the rise and fall of the Roman Empire, and continues today with KFC’s remarkable invasion of China.
Jerry Adler and Andrew Lawler have written a cover story for Smithsonian magazine on the taming of the chicken that delivers these tidbits and gives plenty more food for thought. It was the Egyptians, for example, who first figured out how to artificially incubate eggs, so they could be hatched without the presence of hens—a method so important that their methods were kept secret for centuries:
The enemy of my enemy is my friend—especially if I’m a frog and my enemies are competing parasites. A recent study in PNAS found that frogs populations exposed to a more diverse set of flukes actually had lower rates of infection, with fewer frogs in the group afflicted with tiny hitchhikers.
Researchers at the University of Colorado-Boulder bred Pacific chorus frogs in a lab and put their tadpoles in different tanks with anywhere from one to six different types of flukes. On average, 40% of the frogs that came into contact with only a single fluke species developed infections, while 34% of frogs exposed to four flukes and 23% of frogs exposed to six flukes were infected (the numbers for two, three flukes followed a roughly similar trend). Additionally, some of the fluke species make frogs sicker than others, and oddly enough, the frogs exposed to a greater variety of flukes had a lower proportion of infections from these dangerous species.
This beautiful golden earring, decorated with figures of goats, was one of a trove of jewelry pieces that were wrapped in cloth and stuffed into a jar discovered by archaeologists at the Tel Meggido dig in Israel. When the team flushed the jar’s interior with water, earrings, a ring, and carnelian beads came tumbling out.
They aren’t sure why the jewelry was in the jar, but they posit that it could have been hidden there by the inhabitants of the home where the jar was found for safekeeping. The layer of soil where the find occurred dates from the 11th century BCE, a period when Meggido was under Egyptian rule, and the team believes the jewelry is either of Egyptian origin or inspired by Egyptian designs.
Let’s face it, ketchup bottles suck. When you get down to an almost empty the bottle, plastic ones burp and splat all over your clothes, and glass ones have you awkwardly whacking the “57″ on the Heinz bottle. That’s why this video of ketchup sliding effortlessly with a tip wrist is so impressive—even surreal.
This little bit of magic is the effect of LiquiGlide, a superslippery coating developed by physicists at MIT. The lab headed by Kripa Varanasi initially began researching coatings that could prevent clogs in deep sea oil pipes and ice from sticking to airplane wings. Other research groups have also come up with nonstick coatings that follow the same broad principle: the coating is actually a thin layer of liquid, which allows things to slip right off.
Most of us assume that by the time food arrives at the grocery store, it’s been checked for any chemicals that might harm us. That’s not necessarily the case: food manufacturers and federal employees test for some known culprits in some foods, but the search isn’t exhaustive, especially when it comes to imported items. Recently, scientists working with ABC News checked to see whether imported farmed shrimp bought from grocery stores had any potentially dangerous antibiotic residue, left over from the antibiotic-filled ponds in which they are raised. It turns out, a few of them did.
It’s easy to see how overwatering our crops would deplete the groundwater supply and cause land nearby to sink, but could it cause sea level to rise on a global scale? Yes, according to a model published in Nature Geosciences, that attributes 42% of the sea-level rise over the past half century to groundwater use.
Ninety percent of readily available freshwater is underground, and water used for drinking or crop irrigation must, of course, be brought above ground. That water then evaporates or flows into rivers, entering the water cycle and eventually the oceans, making them deeper.
DNA is a great way to store information—just ask your cells. Its molecules are stable, and billions of base pairs coil neatly into a few microns in a cell nucleus. While it’s easy for a cell to read information from DNA, a cell can’t rewrite new data into its DNA sequence.
But now synthetic biologists at Stanford have managed to pull off that very trick. To do so, they had to abandon the genetic code of ATCG and get a DNA sequence to act like bits—pieces of binary information—in a computer. The memory system uses two enzymes that can cut out and reintegrate a sequence of DNA in a live cell. Crucially, the attachment sites are designed so that the DNA sequence can be flipped every time it is put back in. The sequence oriented one way would represent 1, and its inversion is 0.
And early this morning, after an aborted launch attempt on Sunday, SpaceX’s first rocket left Earth, carrying a capsule bound for the space station. You can watch the unmanned vehicle take off in the video above, and you can hear in the excitement in the NASA launch commentator’s voice as the fiery ship takes off through the night.
The story caused a sensation, as media discussed what could make rocks catch on fire. By Friday, California environmental health officials had an answer, or at least part of one: two of the rocks were covered in phosphorus, an element that’s known for igniting into a fierce white flame when it’s exposed to air. Near as they can tell, as long as the rocks were wet with seawater, the phosphorus didn’t ignite, but after they’d dried out in the woman’s pockets over the course of the day, the phosphorus reacted explosively.
But how did the rocks get covered with phosphorus? Though the substance is mined and used in fertilizers, it isn’t very common in in the natural world in its explosive form, called white phosphorus. White phosphorous does, however, have a long history of production by militaries, who use it in flares. Unexploded military flares, presumably dropped by aircraft, have been known to wash up on beaches: Just last year flares washed up on a beach a half-hour’s drive from San Onofre. NBC reported that those flares were from military exercises going on off the coast.
The NIH National Children’s Study was launched in 2000 with much fanfare and an important mission: to follow a hundred thousand of American children from birth to age 21 and collect data on the environmental, chemical, physical, and psychosocial factors affecting them, with an eye towards understanding diseases that start in childhood, including autism, diabetes and asthma.
Now, however, the study has been deemed too expensive to continue in the same form—so far, only about 4,000 children have been enrolled, at a cost of a billion dollars. While it makes sense to look into bringing the costs down, one of the NIH’s money-saving strategies is in danger of compromising the study’s statistical usefulness: instead of continuing to recruit children from all over the country, the NIH is proposing working with health maintenance organizations, or HMOs, to gather the remaining data. This move would mean that children in rural areas, which tend not to be served by HMOs, would be excluded, and the mountains of data the study is poised to gather would not be complete. Already, two advisory board members have resigned in protest of this proposed policy.
Given all the time and money have already been invested in the study, these changes are a big deal. To find out more about the National Children’s Study controversy, and learn about what’s happening next, check out Nature News‘ thorough coverage.
That sphere was only 860 miles in diameter, fitting comfortably between Salt Lake City and Topeka, Kansas, on a map. It was striking, especially considering that the water available for humans use in our daily lives is only a very small fraction of that; the vast majority of the Earth’s water is saltwater, and most of the freshwater is tied up in glaciers.
How big would a sphere of just the freshwater available to humans be? Reader Jay Kimball of 8020Vision, his interest piqued, went ahead and made such a graphic:
That sphere—the sphere representing the freshwater available to humans—has a diameter of just 170 miles. Head to his blog to see the math.
Last week, a video of this mysterious blob floating 5000 feet under the sea was all over the Internet. Was it a whale placenta? A jellyfish? After some collective ooing and aahing, folks on the interwebs put their thinking hats on. Craig McClain at Deep Sea News dug through the literature and found a 1988 paper describing just such a jellyfish, calling it Deepstaria reticulum.
Now the Monterey Bay Aquarium Research Institute has posted a stunning video of Deepstaria jellyfish. Watch it to learn more about Deepstaria—and to look at pretty images. Win win for a Friday afternoon.
A recent study suggesting a link between coffee drinking and longer lives has prompted a flurry of coverage—some snarky, some cautious, but mostly celebratory. (We see you there, reaching for another cup of coffee.)
The study published at the prestigious New England Journal of Medicine is about as good as observational epidemiology studies go, but it’s limited by virtue of being observational. Last month on our Crux blog, Gary Taubes wrote a hard-hitting piece about the problems with observational studies. A major limitation of surveying people about their lifestyle habits is that correlation does not imply causation. It can’t prove coffee drinking actually led to living longer. There are always confounding variables. Read the rest of this entry »
FA=high-fat, ab libitum (eat-at-will) diet, FT=high-fat, time-restricted diet, NA=normal ab libitum (eat-at-will) diet, NT=normal diet, time-restricted
Diets tell you what you eat, but a new study suggests when you eat matters too. Of two groups of mice who were fed the same high-fat diet, the mice who could eat around the clock were much heavier than those who had food restricted to eight hours per day, in a new study published in Cell Metabolism.
Researchers in the study gave the mice a special high-fat chow, 61% of whose calories come from fat (compared to just 13% in normal feed). The mice who chowed down all day and night became, unsurprisingly, obese, but the ones who ate the same amount of hi-fat food in only eight hours per day did not. Their body weight was comparable to mice fed an equivalent amount of calories on normal feed.
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