Two American men and an Israeli woman have won the Nobel Prize for chemistry for work that probed the structure of the ribosome, the cell’s protein factory. Venkatraman Ramakrishnan, Thomas Steitz, and Ada Yonath worked separately to understand one of life’s core processes: the method by which ribosomes translate genetic code into proteins, the building blocks of all organisms.
Their work revealed what ribosomes, which produce proteins that control the chemistry in all living organisms, look like and how they function at the atomic level. The Laureates also created three-dimensional models that show how different antibiotics bind to the ribosome, research that has been used to develop new anti-infective medicines [Bloomberg].
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Scientists have used nanotechnology in some bizarre applications—nanotube speakers and glue are just two examples. Now carbon nanotubes may have a use as fertilizer, according to a new study. Plant biologist Mariya Khodakovskaya and nanotechnologist Alexandru Biris … planted tomato seeds in a growth medium that contained carbon nanotubes. They found that the seeds germinated sooner and seedlings grew faster than those in a non-treated medium [New Scientist]. After 12 days, 72 percent of the treated seeds had germinated compared with 30 percent of the untreated group. After four weeks, the nanotube-supplemented seeds were twice as tall and had twice the biomass. However, the root systems in both groups were roughly the same.
Similar findings have been reported previously, but until now nobody understood how nanotubes sped and enhanced plant growth. The new study, which recently appeared in the journal ACS Nano, proposes that nanotubes poke holes in the seeds, which allows water to seep in and speeds up germination. However, some researchers are skeptical that a complex process like germination can be enhanced simply by poking holes in the seed’s coating, and at least one researcher is suggesting that the nanotubes cause a hormonal imbalance in the plants.
Before nanotubes could become a commercial fertilizer, their effect on the environment would have to be studied, with close attention to how nanotubes move through the food chain. Some single-walled nanotubes are toxic to some insects; testing on mice has found multi-layer nanotubes (like the kind used in the study) have carcinogenic effects similar to those of asbestos [Popular Science].
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Image: flickr / wit
A team of researchers recently discovered that Tamiflu, the leading flu-fighting drug, is accumulating in rivers downstream from sewage-treatment plants in Kyoto. How is this possible? Tamiflu’s active ingredient, oseltamivir phosphate, is excreted in the urine of people taking the medication. Concerns are now building that birds, which are natural influenza carriers, are being exposed to waterborne residues of Tamiflu’s active form and might develop and spread drug-resistant strains of seasonal and avian flu [Science News]. The resistant virus strains would be of the conventional seasonal or avian flu variety, not the H1N1 swine flu strain that is currently pandemic in humans. Seasonal flu, however, kills thousands of people each year.
Study coauthor Gopal Ghosh explains that the team took measurements during normal flu season, and found concentrations that seem “high enough to lead to antiviral resistance in waterfowl” [Science News]. Computer models show that oseltamivir phosphate will survive sewage treatment, but it should break down when exposed to sunlight and its concentrations should decrease by half every three weeks. The high concentrations were found during a period where 1,738 flu cases were reported in Kyoto, according to the study, published in the journal Environmental Health Perspectives. In the United States, Tamiflu is only recommended for the very sick or those with compromised immune system, while Japan has a more liberal policy.
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Image: flickr / law_keven
In a landmark concession that will likely lead to the largest dam-removal effort in U.S. history, an electrical utility company has agreed to destroy four dams on the Klamath River to help migrating salmon and steelhead. The dams won’t be decommissioned until 2020 and there are still regulatory hoops to jump through, but fishermen and environmentalists are delighted by the development. “We’re about to make changes to the Klamath Basin that will be observable from space,” said Craig Tucker of the Karuk tribe, which traditionally fished for salmon [Los Angeles Times].
The Klamath River, which winds through Southern Oregon and eventually reaches California’s Pacific coast, was once home to one of the most vibrant salmon runs in the West. But since the first dam was erected in 1908, the region has been host to a nasty battle over water rights, with wildlife and commercial fishers ultimately bearing the worst scars as regulators were forced to repeatedly close salmon fishing along 700 miles of the Oregon-California coast [Greenwire]. The removal of the dams’ will open 300 miles of river to the salmon.
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Image: flickr / patrickmccully
Could the Chicago Field Museum’s mighty Tyrannosaurus Rex, a dino named Sue, have been toppled by a lowly parasite? According to a recent study in the journal PLoS ONE, a microbe commonly found in pigeons may be responsible for holes in the dinosaur’s mandible, holes that were previously thought to be bite marks. Paleontologists compared a similar infection in a modern predatory bird to the T-Rex holes and found surprising similarities.
The researchers think the parasite, a protozoan named Trichomonas gallinae, settled in the back of Sue’s throat, and in nine other Tyrannosaurs … studied with similar holes. The parasite caused inflammation that eventually damaged the jawbone [Los Angeles Times], first forming lesions and then eroding the bone away. The inflammation would have choked off the dino’s esophagus, they say, eventually starving the T. Rex to death.
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Scientists have located a biological dimmer switch in a species of electric fish that uses electricity during everything from swimming to mating. The switch comes in handy when they don’t need to be electrified; during the day, the fish turn their current down to save energy for other activities, according to a new study in PLoS Biology. That means that the South American river fish, Sternopygus macrurus, is a natural practitioner of energy efficiency. It can reshape the charged-molecule channels in its electricity-producing cells to tone down its electrical signature within a matter of minutes [Wired.com].
Scientists found the dimmer switch in the membranes of cells called electrocytes within this electric organ. The switch takes the form of sodium channels that the fish can insert and remove from the electrocyte membranes. More sodium channels mean a stronger electric impulse [LiveScience]. Because the energy is expensive to produce for the fish, they do what the rest of us do when energy gets expensive–turn it off. The fish keep sodium channels on stand-by in the electric cells so they can switch the electricity back on in a moments notice if something spooks them.
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Image: flickr / walknboston
Organisms evolve to fit the world around them–but if the changes don’t work out, can a creature reverse the process? Say, for example, an insect originally eats a wide variety of tree leaves, but then evolves to live exclusively on the leaves from one type of tree that is abundant in its habitat; if that tree goes extinct, can the bug reverse course? A new study in Nature sheds some light on such questions, which have perplexed evolutionary biologists for many decades.
More than a century ago, the French–born Belgian palaeontologist Louis Dollo proposed that evolution cannot retrace its steps to restore a lost trait — an idea that has remained controversial [Nature News]. So researchers set out to test “Dollo’s Law” on the molecular level, studying a protein called the glucocorticoid receptor, which binds to the hormone cortisol to regulate the stress response. Study coauthor Joseph Thornton says that at least in this protein’s case, new mutations make it practically impossible for evolution to reverse direction. “They burn the bridge that evolution just crossed” [The New York Times], he says.
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The tiny island nation of Palau has taken a big step to protect the ocean’s endangered sharks, by designating all of its territorial waters a shark sanctuary within which all commercial shark fishing is prohibited. Palau’s president, Johnson Toriboing, announced the plan at a meeting of the UN General Assembly last Friday. Sharks are increasingly under threat as the demand for shark-fin soup—a delicacy in many Asian countries—has risen worldwide. “The need to save the ocean and save sharks far outweighs the need to enjoy bowls of soup,” Toriboing said [National Geographic News].
Palau consists of about 200 small islands in the Pacific Ocean to the east of the Philippines; its expansive marine territory spans 230,000 square miles, an area about the size of Texas. About 130 species of rare sharks either make their homes or pass through these waters, including hammerheads, leopard sharks, and reef sharks, as well as the related stingrays.
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One day, the most advanced ships may not have steel hulls that slice cleanly through the water, but instead may sort of ooze along, leaving a wake of slime and microbes. Researchers are trying to design a ship that continuously exudes slime to form a coating around its hull that steadily wears away, taking hangers-on like barnacles with it.
Barnacles and the other sea creatures that accumulate on boats’ undersides create drag, and therefore reduce speed and energy-efficiency. The problem is an expensive one, as it requires vessels to be brought into dry dock every couple of years to remove plants and animals from the hull. It has been made worse by the banning last year of antifouling paints based on tributyltin, which is toxic to marine life [New Scientist].
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A feathered dinosaur unearthed in a Chinese quarry has added another solid piece of evidence to the theory that birds descended from dinosaurs. The newly uncovered fossil of the species Anchiornis huxleyi dates from the Late Jurassic period, 151-161 million years ago, and therefore predates the earliest known bird, the Archaeopteryx. Paleontologists say this represents the final proof that dinosaurs were ancestral to birds. “Drawing the tree of life, it’s fairly obvious that feathers arose before Archaeopteryx appears in the fossil record” [BBC News], says paleontologist Michael Benton.
The creature, described in a paper [pdf] in Nature, was covered in the short feathers known as “dino-fuzz,” and had longer feathers on both its forelimbs and its back legs that formed primitive wings. The four-winged dinosaurs also had feathers on their feet and wing-like attachments on the arms and legs. But they could probably only glide, as their plumage was insufficient for powered flight [Nature News].
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Image: Zhao Chuang, Xing Lida. An artist’s rendering of Anchiornis huxleyi.
Even European eels enjoy a trip to the Bahamas, for mating season of course. The eel travels thousands of miles to the Sargasso Sea, in the Atlantic Ocean near the Bahamas, just to get a little action. Scientists wanted to see what the little eels were up to on their trek, so they equipped a few with satellite tags and tracked their journey, which surfaced in Science this week. The tags allowed researchers to follow 22 eels for the first 1,300 kilometers of their trek from the coast of Ireland to mating grounds near the Bahamas. Understanding the details of the eels’ journey may help to protect this critically endangered species, a favorite of sushi eaters [Science News].
The tags recorded location, speed, depth and direction of the eels for 6 months, before popping off and floating to the ocean’s surface to beam their data back to the laboratory. The researchers found the eels swim too slowly to get to the Sargasso Sea by the April spawning period. The researchers suggest this means the eels may gain speed and travel efficiency by entering the ocean currents that begin west of Africa and continue as part of the subtropical gyre system that flows to the Caribbean [BBC News]. The data also show that the eels swim in shallow, warm water at night and dive to depths of 3,200 feet during the day swims. Since the eels do not feed on their trip, scientists think swimming in warm water boosts metabolism, while the cold water helps slow sexual development until they reach the Sargasso Sea.
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Image: flickr / wwarby
A new experiment has shed light on how the monarch butterfly executes its impressive 2,000-mile migration every fall, and all it took was a lick of paint.
Researchers already knew that the butterflies use the sun to guide them to the exact same wintering spot in central Mexico. But because the sun is a moving target, changing position throughout the day, biologists have long speculated that in addition to having a “sun compass” in their brains, butterflies must use some kind of 24-hour clock to guide their migration [Wired.com]. In a new study, published in Science, researchers determined that the butterflies have a second circadian clock in their antennae, which sense light.
The researchers conducted the test by holding the butterfly wings gently and dipping their antennas in enamel paint. The ones with black paint were unable to orient to the south, they found, while butterflies whose antennas were coated with clear paint had no trouble navigating [AP]. This proved that the antennae had to be able to sense light for the butterflies’ navigation system to operate, and also showed that the butterflies weren’t navigating by scent, as both kinds of paint interfered with the insects‘ sense of smell.
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Image: Monarch Watch / Chip Taylor
Oil and gas companies looking for deposits offshore have touted their equipment as environmentally friendly. However, new research suggests that blue whales are having a hard time hearing each other over the seismic blasting that the search entails. Research has discovered that whales forced to compete with the seismic testing work, which involves bouncing sound waves off the sea bed, markedly increase the number of times they repeat the same calls [The Times].
The study, published in Biology Letters, was conducted in Canada’s St. Lawrence Estuary, and is the first report of whales increasing their calls in response to underwater noise. Researchers believe that the whales are repeating the calls simply because other whales can’t hear them, and they’re having trouble gathering to feed and mate.
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In an ironic twist, the weaponry of the fire ants that have invaded the American South is also their potential downfall. Entomologists have found that the fire ants’ venom contains chemical compounds that attract their natural foes, the parasitic phorid flies that turn ants into zombies before decapitating them.
The invasive red fire ants first came from South America by boat, and from their original disembarkation point in Mobile, Alabama, they have spread across the South, from Texas to Maryland. Their painful stings and their habit of shorting out electrical equipment make them a serious pest to humans, and biologists have been attempting to control their numbers by importing and distributing the parasitic phorid flies. But until now, researchers didn’t know how the flies homed in on the ants. So researcher Henry Fadamiro hooked electrodes up to the antennae of flies to investigate which of several stimuli prompted nerves to fire. By exposing the antennae to extracts from different ant glands and body parts, the researchers determined that juice from the venom glands got antennae buzzing [Science News].
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What’s worse than having one gigantic-but-relatively-docile python species invading Florida? Finding out that an extremely aggressive python species is moving in as well, and learning that the two species could theoretically interbreed to create a hybrid monster.
Florida wildlife officials have been concerned for some time about the 20-foot-long Burmese pythons that are thought to have been released by irresponsible pet owners and have established a thriving colony in Everglades National Park. But over the past year, four African rock pythons have also been sighted or captured in Miami-Dade county, giving biologists new cause for concern. Says herpetologist Kenneth Krysko: “They are just mean, vicious snakes…. You couldn’t get a worse python to become established. A Burmese python is just a docile snake. These things will lunge at you” [Miami Herald].
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