80beats

Zebra Stripes: Fashion Statement or Fly Repellant?

Veronique Greenwood — Fri, 10 Feb 2012 17:35:19 +0000

Why’d the zebra evolve its stripes? Perhaps because stripes seem to keep off horseflies, a new study suggests. There’s good evolutionary reason to escape the ravages of horseflies, at least for horses and their relatives; though flies are just annoying pests from the human perspective, horsefly-bitten horses can grow skinny and have trouble producing milk for their young. And as soon as baby-making is affected by something in the environment, adaptation isn’t far behind.

Other research has shown that horseflies prefer to land on black horses instead of white, which got Gabor Horvath, author of the recent study, thinking about how they’d react to black-and-white specimens, such as zebras. Of course, actual zebras can be hard to experiment on, as The Economist notes in an article on the research:

[Real zebras] insist on moving around and swishing their tails. The team therefore conducted their study using inanimate objects. Some were painted uniformly dark or uniformly light, and some had stripes of various widths. Some were plastic trays filled with salad oil (to trap any insect that landed). Some were glue-covered boards. And some were actual models of zebra. They put these objects in a field infested ...

Study: Americas + Europe + Asia Will Form Amasia, a Supercontinent in the Arctic

Sarah Zhang — Thu, 09 Feb 2012 21:08:15 +0000

Geological analysis suggest the current-day continents we know and love will drift together, forming a new supercontinent like ones that existed many millions of years ago. What’s not certain is where that supercontinent will be. The authors of a new Nature study suggest that the next supercontinent, dubbed Amasia, will join together up in the Arctic. Antarctica, though, would stay by its lonesome in the south.

The Yale scientists analyzed the formation of two earlier supercontinents, Rodinia and Pangaea, and found that the continents had rotated 90 degrees between one supercontinent and the next one. They calculated these rotations based on the alignment of magnetic material in ancient rocks. Before lava solidifies into rock, the tiny shards of magnetic material point to align with the Earth’s North Pole at the time—a magnetic snapshot of the past that can tell us how continents have since rotated. Rotate 90 degrees away from the last supercontinent, Pangaea, and that puts Amasia near the North Pole. However, this contradicts previous models proposing that Amasia will be either exactly where Pangaea was or directly 180 degrees across from it.

Of course, none of us will be around to ...

Video: Coral’s Dramatic Yet Slo-Mo Emergence From the Sea Floor

Sarah Zhang — Thu, 09 Feb 2012 19:05:20 +0000

It’s just a pile of sand–no wait, is that a tentacle wriggling in the corner? These time-lapse videos taken by researchers at the University of Queensland show that mushroom corals unearth themselves by slowly inflating and then deflating over 10 to 20 hours. See a second coral attempt the same after the jump.

It’s a Shark-Eating Shark–Eating–Shark World

Veronique Greenwood — Thu, 09 Feb 2012 17:02:08 +0000

Om nom nom…oh, you caught me in the middle of dinner!

While conducting a survey of fish in an area of the Great Barrier Reef, scientists stumbled upon this little tableau: a tasselled wobbegong, or “carpet shark,” in the midst of devouring a brown-banded bamboo shark. (Either that, or they’re just sharing a very intense kiss.) The carpet shark, which hides in the sand and springs out at its prey, has never been photographed eating another shark before, though scientists could tell from poking around in their stomach contents that their distant cousins were sometimes on the menu. Carpet sharks seem to be slow eaters, though: the team hung around for a full 30 minutes to see if it would suck in more of the bamboo shark, but to no avail.

Maybe it just has stage fright.

Images courtesy of Tom Mannering and the journal Coral Reefs

Solar Panels Sometimes Pit Global Warming Against Local Ecosystems

Sarah Zhang — Thu, 09 Feb 2012 15:22:08 +0000

Joshua trees in the Mojave Desert

Solar energy has been enjoying its day in the sun with massive federal subsidies, but the energy taken from sunlight also has a dark side. Building these plants in the American West destroys large swathes of the desert ecosystem. Cacti must be mowed down and local wildlife displaced to make room for the giant mirrors that will essentially carpet the desert. The LA Times has a great feature on the Ivanpah project in the Mojave that began construction in October 2010.

Far from an empty stretch of sand, the Mojave supports diverse wildlife. No one knows exactly how the new solar power plant will affect the tortoises, eagles, and Joshua trees that currently inhabit the area. Is it okay to sacrifice the desert in the fight against larger climate change? The situation has put environmental groups in a bind, as Times reporter Julie Cart explains:

The national office of the Sierra Club has had to quash local chapters’ opposition to some solar projects, sending out a 42-page directive making it clear that the club’s national policy goals superseded the objections of a local group. Animosity bubbled over after a local Southern California chapter was ...

Woman Receives First 3D-Printed Jawbone Transplant

Veronique Greenwood — Wed, 08 Feb 2012 16:48:50 +0000

An 83-year-old woman operated on last summer was the first person to receive an entire 3D-printed jaw transplant, her Belgian doctors announced Monday. The woman’s own lower jaw was riddled with infection, and given her age, and the fact that reconstructive surgery would have been a long and painful process, her doctors decided to have a new jaw specially manufactured for her. The replacement jaw is made out of titanium, assembled in thousands of layers by a 3D printer. It took 4 hours of surgery to get the jaw in place, but that’s just a fifth of how long a reconstructive surgery session would have been. She will receive follow-up surgery later this month to have permanent dentures attached to the jaw.

The new jaw is about 30% heavier than her old jaw was, but the doctors say she’ll get used to it. Someday, though, patients may be able to get replacement bones printed in more bone-like material: scientists are working on getting 3D printers to accept calcium-based substances as ink.

Image courtesy of LayerWise

It’s a Small and Wonderful World: Stunning Images of Science Under the Microscope

Sarah Zhang — Wed, 08 Feb 2012 16:43:08 +0000

Looking down a microscope always reminds us how much we can’t see with the naked eye. The winners of the 2011 International Science and Engineering Visualization Challenge provide a tantalizing glimpse into the micro- and nanoscopic world.

This image of a thin slice of a mouse’s eye, above, was dyed so that different tissues show up as different colors. Muscles are pale yellow, for example, and the sclera is green.

No, this isn’t a cliff—it’s far too tiny. Each layer of titanium carbide—an exceptionally hard material used in energy storage devices, solar cells, and the like—in the stack pictured here is only 5 atoms thin.

These honeycombed stalks are carbon nanotubules illustrated by graphic artist Joel Brehm. Carbon nanotubules have unique thermal and electric properties that give them potential roles in everything from detecting cancer to powering hydrogen cars.

You might know these better as the little white hairs on young cucumbers. But under 800x magnification, these tiny outgrowths, called trichomes, look almost creature-like. In fact, these ...

In Flies, a Prion-Like Protein Helps Maintain Long-Term Memories

Sarah Zhang — Wed, 08 Feb 2012 13:08:56 +0000

What’s the News: When prions or amyloids make the news, it’s usually because they cause mad cow disease or Alzheimer’s—prions, after all, cause any proteins they touch to become as misfolded as they are, and amyloids, which are large clumps of wadded-together proteins, can jam the workings of cells.

But a new study in Cell suggests that a prion-like protein that forms amyloids has a normal, vital function in the brain. Far from being a memory destroyer, this protein, called CPEB, is necessary for long-term memory in fruit flies.

How the Heck:

To see where the protein resides in the brain, the researchers added a fluorescent tag to the fruit fly version of CPEB, which is called Orb2A. They observed that Orb2A formed amyloids at synapses, the junctions between neurons—a promising sign that it could be involved in memory. To see whether Orb2A was actually necessary for memory, the researchers created fly mutants with a defective version of Orb2A. A single amino acid was changed, but that was enough to prevent the formation of amyloids. It was also enough to disrupt the flies’ long-term memory, the team found. As a test of memory, flies had been ...

Watch Ants Sip Grenadine, Spheres of Algae Spin, and Other Small-Scale Spectacles in These Movies

Valerie Ross — Tue, 07 Feb 2012 20:20:11 +0000

The many-times-magnified photos of the Nikon Small World photomicrography contest entrance us year after year, with mesmerizing close-ups of nature’s microscopic marvels. Now, in the first Small World in Motion movie competition, we get to see the world’s wee wonders in action. The three winning films and eleven honorable mentions chronicle circulating blood, budding yeast, gestating eggs, and more.

First Place: This time-lapse video, at 10x magnification, traces the path of ink injected into an artery of a three-day-old chick embryo. As the ink spreads through the chick’s vascular system, the branching blood vessels and beating heart become clearly visible.

Second Place: Mitochondria (in blue), the power plants of animal cells, move through the nerve cells (in green) of a transgenic zebrafish. This film, at 40x magnification, is the first time mitochondria have been watched shuttling through nerve cells in a living vertebrate, says its creator Dominik Paquet.

Third Place: A daphnia, a type of small crustacean, turns its compound eye towards a tiny sphere of Volvox algae, at 50x magnification. The scientist who made the video found these organisms in water from his garden pond.

Honorable Mention: An ant colony devours a drop of grenadine in this time-lapse video.

Watch the rest of the runners ...

The Engineer Who Has “Saved More Lives Than Any Single Person in the History of Aviation”

Sarah Zhang — Tue, 07 Feb 2012 17:52:02 +0000

The number one cause of plane crashes used to be controlled flight into terrain (pdf), accidents where pilots unintentionally collide with an obstacle. A pilot unable to see through fog, for example, could fly straight into a mountain, crashing an otherwise perfectly functional plane. Such accidents killed over 9000 people—until aviation engineer Don Bateman’s crash-avoidance technology changed all that.

Bateman invented the original Ground Proximity Warning System (GPWS) in the 1970s. Using information from the altimeter. airspeed indicator, and other devices already standard in planes, the original GPWS warned pilots with increasing urgency—first “Caution—Terrain,” then “Pull up! Pull up!”—if the plane was due to crash. Bateman, now 79 years old, still works at Honeywell and he’s still perfecting the GPWS. The modern warning system integrates GPS locations of potential obstacles. In a profile of Bateman for the Seattle Times, Bob Voss, chief executive of the Flight Safety Foundation, says, “It’s accepted within the industry that Don Bateman has probably saved more lives than any single person in the history of aviation.”

Bateman traces his interest in improving flight safety to a horrific plane crash he witnessed as a 8-year-old boy growing up in Canada. He snuck out of school with ...

Audio: Ancient Katydid Sings From Beyond the Grave

Veronique Greenwood — Tue, 07 Feb 2012 17:46:51 +0000

Above, the fossilized teeth running along the katydid’s left and right wings
that researchers used to reconstruct the creature’s call.

Well-preserved fossils can tell paleontologists myriad things, such as what color feathers dinosaurs had, how ancient spiders evolved, and what kind of microbes were around 3 billion years ago. The latest such revelation is rather whimsical, as well as being scientifically interesting. Scientists have been able to reconstruct the chirping of a Jurassic ancestor of modern katydids by examining the wings of an exquisitely preserved fossil specimen.

Katydids create their song by scraping one wing across the other, running a hard ridge of tiny teeth, like those on a comb, across the ridge on the opposite wing. The research team examined the size and shape of the teeth on the wings of Archaboilus musicus, as the Jurassic specimen is called, to come up with an estimate of the frequency of the sound that such scraping would have produced. They found that the resulting chirping would have fallen at 6.4 kilohertz, within the range of normal human hearing.

So, if you ever get the chance to travel back 165 million years, keep your ...

How Can You Tell If You’ve Hit an Antarctic Lake?

Veronique Greenwood — Tue, 07 Feb 2012 15:47:55 +0000

The outline of Lake Vostok beneath the ice, as seen from space.

Last week, as Russian scientists neared the end of two decades of drilling to reach Lake Vostok, an ancient Antarctic lake buried beneath miles of ice that hasn’t seen light in 20 million years, people around the world waited with bated breath for news. Yesterday the Russian state-run news agency announced that on Sunday, the drill had reached water, apparently the lake surface. Today, the project leader clarified that they need to verify that the water the drill struck was actually Lake Vostok. New Scientist has a tidy explanation of why it’s not necessarily obvious if you’ve hit a massive underground lake:

[Hitting water] suggests the lake has been breached, but the team are now checking the level of water in the borehole and readings from pressure sensors to confirm that the water did come from the lake and not a pocket of water in the ice above the lake. Ice temperatures rise as you go deeper into the ice sheet, and approach melting point just above the lake, so the fact that the team hit liquid water doesn’t necessarily mean they’ve reached the ...

What’s Causing the Bizarre Plague of Tics in Upstate New York?

Veronique Greenwood — Mon, 06 Feb 2012 21:18:27 +0000

About three months ago, otherwise healthy girls at a high school in LeRoy, NY, started stuttering, jerking, and making odd noises, among other symptoms similar to Tourette’s syndrome, a neurological disorder. The number of people affected has grown now to more than a dozen, though a more specific count is difficult to nail down, and seems to include one boy and one 36-year-old woman in addition to the teenage girls.

What could be causing these symptoms? Health officials have inspected the girls’ school and found no environmental contaminants. A variety of other causes, including the Gardasil vaccine and strep throat, have been investigated as causes of the uncontrollable tics (neither of those panned out, as in each case only some of the girls had had the shots or been sick). The pattern of cases doesn’t suggest an infectious cause. The current best guess comes from a pediatric neurologist who has examined eight of the girls and has given a diagnosis of conversion disorder, which is defined as the development of tics, paralysis, or a variety of other neurology-related symptoms as a result of stress.

Conversion disorder can sometimes be controversial, since it traces its roots back ...

The Visionary Programmer Behind Those Viral Taiwanese News Animations

Sarah Zhang — Mon, 06 Feb 2012 19:19:49 +0000

At the pace of 30 videos a day, Next Media Animation is churning out “All the news that’s fit to animate.” The Taiwanese media company is (in)famous for hilarious and hilariously inappropriate news videos reenacting Tiger Woods’ car crash and TSA’s new full body scanners. It’s the day after the Super Bowl and their video featuring Eli Manning, God, and a “geriatric Lady Gaga Impersonator” (aka Madonna) has already been up for hours. How does it happen so fast? The answer is a huge team of animators but also one particular programming whiz. Eliza Strickland at IEEE Spectrum has a profile of Kevin Wang, the guy who makes it all possible:

On Wang’s first day as director of NMA’s multimedia lab, he had no employees, no hardware, and no office. The assignment: Reduce the animation production cycle from 2 weeks to 2 hours so that on-the-fly animations could be ripped from the headlines and published on the company’s websites before the news got stale. Accomplishing this, Wang realized, would require a completely new approach to computer animation, using a combination of tricks and shortcuts that no one had tried before.

The process Wang came up with starts with motion-capture technology: Live actors re-create a scene, ...

New Solar Cell Pulls Electricity Out of Chopped-up Plants

Sarah Zhang — Mon, 06 Feb 2012 15:08:39 +0000

For years, solar energy researchers have tried to imitate the success of photosynthesis by building devices like an artificial leaf and a solar cell that hijacks chemistry of photosynthetic bacteria. Now researchers at MIT have come up with an innovative technique that also happens to be very cheap: all you need is some “stabilizing powder” and plant waste. Mowed your lawn lately?

The stabilizing powder is a mix of safe, easily attainable chemicals that preserves photosystem I, a protein complex that captures light energy in plant cells. (In contrast, the newest photovoltaic cells in solar panels require metals that are rare or toxic.) The powder is mixed with plant matter such as grass clippings and crushed, and the resulting green goo is spread onto glass or metal substrate. Hook up wires to capture the electric current and that’s your solar panel.

The efficiency of these solar panels is only 0.1%, compared to the 15 to 18% efficiency of solar panels out in the market right now. Lead researcher Andrew Mershin says the technology still needs to improve 10-fold to become practical. After all, being able to power only one lightbulb with a whole house covered in solar ...

Massage Doesn’t Just Feel Good—It Changes Gene Expression and Reduces Inflammation

Sarah Zhang — Fri, 03 Feb 2012 14:52:38 +0000

What’s the News: If you’ve ever been told been that a massage is good for “releasing toxins”—or to sound more scientific, “lactic acid”—from your muscles, then you’ve been told wrong. Turns out muscle cells do like a good massage, but it has nothing to do with lactic acid.

In the first study on the cellular effects of massage post-exercise, researchers found that massage bolsters chemical signals reducing inflammation and promoting repair of muscle cells.

How the Heck:

Strenuous exercise actually tears your muscle fibers; that’s why an intense workout can leave you sore for days. (Don’t worry—it’s normal and it generally heals fine.) The researchers wanted to study how massage affects this muscle damage, so they made 11 healthy young men cycle to the point of exhaustion. Then, finally, relief! Sort of. One leg on each man was randomly chosen for a 10-minute massage. Unfortunately more pain was then in store for these volunteers. A tissue sample was taken from the quadriceps muscle (often known simply as “quad”) of each leg 10 minutes and 2.5 hours after the massage. Researchers looked at the level of different mRNA, or messenger RNA, transcripts in these tissue samples. mRNA carries the ...

Alzheimer’s Spreads Like a Virus From Neuron to Neuron, Studies Show

Valerie Ross — Fri, 03 Feb 2012 13:30:21 +0000

A protein tangle in an Alzheimer’s-afflicted neuron

Exactly how Alzheimer’s disease proliferates through the brain, overtaking one region after another, has eluded scientists. As the disease progresses, tau—a malformed protein that forms snarls and tangles inside neurons—shows up in more and more brain areas. Researchers have wondered whether tau, and the disease, are working their way out from a single area of origin or mounting numerous, distinct attacks on vulnerable parts of the brain. Two new studies in mice provide strong support for the first idea: Tau see ms to pass from affected cells to their neighbors, spreading much the same way a virus or bacteria infection would.

The studies—one recently published in PLoS ONE, the other forthcoming in Neuron—used mice genetically engineered to produce abnormal human tau protein in the entorhinal cortex, the tiny bit of brain tissue where Alzheimer’s first appears in most patients. Since those cells, but not others, were equipped to produce human tau, any tau that showed up elsewhere in the brain could be traced back to the entorhinal cortex. The researchers watched and waited, and found that the tau proteins spread through neural circuits out ...

Does a Chinese Boy Really Have “Cat Eyes” That See in the Dark?

Sarah Zhang — Thu, 02 Feb 2012 23:23:09 +0000

The strangest thing about this Chinese boy’s light blue eyes is not their color. It’s the purported fact that he can see in the dark. His eyes are just like cat eyes, glowing blue-green when you shine a light in them, says this clip from China’s state-run English TV channel. The boy can catch crickets in the dark without a flashlight and even completes a writing test in a pitch-black stairwell. True, or too good to be?

Natalie Wolchover at Life’s Little Mysteries has rounded up some experts and their collective reaction seems to be, “Hmm…” (It doesn’t help that this video has been posted on YouTube under the name, “Alien Hybrid or Starchild Discovered in China? 2012.”) One possibility they consider is whether the boy has a mutation that produced something like a tapetum lucidum, an extra layer of tissue that helps cats see in the dark. James Reynolds, a pediatric ophthalmologist at State University of New York in Buffalo, puts a stop to that idea:

[T]here is no single genetic mutation that could produce a fully formed and functioning tapetum lucidum, Reynolds explained; such an ability would require multiple mutations, which wouldn’t occur all at once. Evolution happens incrementally, ...

How Spider Silk’s Molecular Make-up Lets It Morph

Veronique Greenwood — Thu, 02 Feb 2012 21:06:48 +0000

What’s the News: The surprising strength of spider silk has fascinated scientists (and everyone else) for years: it’s stronger than steel, yet incredibly flexible. A new paper gives some delicious details that explain how, exactly, spider silk has such superpowers.

Go With the Flow, Then Stay Strong: The strand of silk that a spider hangs from can stretch to double its usual length. But then, after that virtuosic show of elasticity, it turns rigid.

The reason for that, this team found previously, is that on the molecular level, spider silk is made of scrunched-up proteins that are pulled straight as the silk stretches. But once they’ve been fully unfurled, the proteins lock into a new, stiff pattern called a beta-sheet nanocrystal. For a spider, having the molecules snap to stiffness after stretching is probably analogous to a rock climber arresting a rappel by clipping the end of her rope in place.

Breezy Bulkheads: In their current study using real-life spider webs and computer models, the team found that when a gentle force like a breeze is broadly applied to a spider web, the whole thing stretches and elongates. But yank or push more forcefully on one part ...

Hacking the Microbiome for Fun and Profit: Can Killing Just One Mouth Bacterium Stop Cavities?

Veronique Greenwood — Thu, 02 Feb 2012 17:32:11 +0000

What’s the News: The bacterial hordes that call your mouth home—and yes, even if you brush rigorously, you’ve got ‘em—are generally a pretty benign bunch. Mostly they just mooch around, snagging tastes of whatever you’re eating, but Streptococcus mutans, the bad boy that causes cavities, releases tooth-corroding acid whenever you eat sugar. Even mouthwash that kills everything it touches can’t save you from the ravages of S. mutans in the long term; it just grows back, along with the rest of your bacteria.

Scientists who study the mouth microbiome, however, think that a mouthwash that kills S. mutans and leaves the rest of the bacteria to take over S. mutans‘s real estate could spell the end of cavities. In a small clinical study last year, one team found that one application of the mouthwash knocked down S. mutans levels, and that harmless bacteria grew back in its place. If the mouthwash pans out, it could join the ranks of an emerging new type of treatment: better living through hacking the microbiome.

How the Heck:

The team, whose work is funded by toothpaste manufacturer Colgate-Palmolive, had designed a molecule called C16G2 that had been proven to kill ...

An Ambitious Frontier for Flying Drones: Saturn’s Earth-Like Moon, Titan

Sarah Zhang — Thu, 02 Feb 2012 15:27:36 +0000

Artist’s rendering of AVIATR flying on Titan.

Saturn’s moon Titan is a lot like Earth: it has rain, seasons, volcanoes, and maybe even life. Well, it’s not exactly like Earth: the rain is liquid methane, the volcanoes spew ice, and any life would be based on methane. But still, it’s an interesting and relatively Earth-like place, considering the other planets and moons in our solar system. And University of Idaho physicist Jason Barnes says he has a perfect way to explore this moon: with a flying drone.

Why use a flying machine rather than the rovers that worked so well on Mars? With 1/7 the gravity but 4 times the atmospheric density of Earth, flying through Titan is 28 times easier than on our own planet. In fact, it’s the easiest place to fly in our entire solar system. Drones on Titan can be heavier while requiring less fuel. With these facts in hand, University of Idaho physicist Jason Barnes has proposed AVIATR, otherwise known as the Aerial Vehicle for In-situ and Airborne Titan Reconnaissance.

As proposed, AVIATR would fly through Titan for a year on its radioactive power source plutonium-238, previously used on ...

Scientists to Breach Buried Antarctic Lake, Untouched for Millions of Years

Veronique Greenwood — Wed, 01 Feb 2012 18:01:50 +0000

The outline of Lake Vostok beneath the ice, as seen from space.

After two decades of drilling through miles of Antarctic ice, Russian scientists are about to breach an underground lake that has not been exposed to the surface in more than 20 million years. Lake Vostok, as the body of water is called, is part of a chain of more than 200 lakes hidden beneath the ice, some of which were formed when Australia and Antarctica were still connected. Vostok will be the first one of all to be opened when the drill hits water next week.

Scientists believe that there may be life in the lake, as ice removed from the Vostok borehole has been found to contain bacteria. And since the subterranean lakes, kept liquid by heat from the Earth’s core, are similar to those found on moons Enceladus and Europa, scientists are excited to see what such inhabitants might be like. But the Russian team’s somewhat sloppy drilling methods have got a number of people worried about preserving the pristine lake from contamination, as Marc Kaufman reports in a great feature for the Washington Post.

The lake is known to have quite a bit ...

Chemotherapy in Parents May Make Offspring’s DNA Unstable & Riddled With Mutations

Sarah Zhang — Wed, 01 Feb 2012 14:02:56 +0000

Chemotherapy is poison that happens to kill cancer cells faster than it kills healthy cells; that it wreaks havoc on the bodies of patients is unsurprising. But chemo may also affect their unborn children. According to a new study in PNAS, the offspring of mice treated with chemotherapy have higher rates of mutation, even though the offspring themselves were never exposed to the drugs.

The results suggest that these mutations arise from genome destabilization caused by exposure to chemo, rather than just mutated sperm from the treated father. Male mice in the study were exposed to one of three common anticancer drugs—cyclophosphamide, mitomycin C, or procarbazine—and then allowed to mate with untreated females. After sequencing a small piece of DNA from the offspring, the researchers found that mice with treated fathers had mutation rates up to twice that of mice with untreated fathers. Notably, these mutations were present in DNA inherited from both the treated father and untreated mother.

What this likely means, according to the researchers, is that chemotherapy induces epigenetic changes in the sperm. Epigenetic changes don’t affect the underlying DNA sequence, but they alter chemical tags that control how genes are expressed. This ...

Getting Big Takes Time…Millions and Millions of Generations, Say Biologists

Veronique Greenwood — Tue, 31 Jan 2012 20:21:05 +0000

Creatures as large as elephants are unusual; it takes a long time to evolve such size.

How long does it take for a mammal as small as a mouse to evolve into something as large as an elephant? A really, really long time, a recent study has found: about 24 million generations, at minimum.

To get that number, researchers looked at the evolution of body mass over the last 70 million years, after the dinosaurs went extinct and surviving animals expanded into the ecological niches they left behind. That estimate is far longer than earlier estimates, which, extrapolating from bursts of super-fast evolution in mice, range from just 200,000 to 2 million generations. Such speedy evolution, in actuality, is probably not sustainable over the long term—hence the lengthy new estimate.

Getting smaller, on the other hand, is a much shorter process, happening up to 30 times faster. Evolving to a smaller size might be easier because smaller animals reach reproductive maturity more quickly, the researchers suggest. Or it could reflect the greater availability of ecological niches for tiny organisms: a scrap of grassland can feed a fieldmouse, but an elephant needs acres. Certain physical constraints—the pull of ...

How Do Females Keep Sperm Fresh for Years?

Veronique Greenwood — Tue, 31 Jan 2012 16:04:34 +0000

The researchers chose to examine the sperm of crickets, because, as with humans, you can get samples of it without having the male come into contact with a female first.

What’s the News: You might already know that sperm, which can survive for only a few hours when exposed to the outside world, can live for several days in women after ejaculation. But did you know that an ant queen can fertilize her eggs with sperm she’s stored for up to 30 years? And that organisms as diverse as birds, reptiles, and insects can hang onto sperm and keep it fresh for days, weeks, or months?

Scientists studying this ability have been trying to figure out how females do it, and in a recent paper, researchers put forth evidence showing that the ladies may be arresting the aging process, by slowing down sperms’ metabolism.

How the Heck:

The researchers, who hail from the University of Tuebingen in Germany and University of Sheffield in the UK, decided to test one of the current models of cellular aging with sperm. This model proposes that the reason cells age is that as they go about their daily business ...

Why Google Thinks You Are (a) Male and (b) Old

Veronique Greenwood — Mon, 30 Jan 2012 17:54:16 +0000

A funny thing happened after Google’s new privacy policy was announced last week. When people started checking what Google knows about them on Ad Preferences Manager—that’s the profile of you they build by watching your movements on the Web, so they can tailor ads accordingly—young women began reporting that actually, Google had aged them quite a bit. And had thought they were dudes. One young lady of our acquaintance is believed by the Ad Preferences genie to be a “65+” male. Why?

Well, as Kashmir Hill at Forbes points out, the way Ad Preferences works is by placing a cookie on the computer you happen to be using at the moment. The cookie records the sites you visit, each of which has certain user demographic information, like percentage of male and female visitors, age range, etc. ascribed to it by Google (though where they get that information, and how accurate it is, is not clear). Then Ad Preferences combines all the demographics of those sites to get your special blend of age, gender, interest in power tools, etc. Your Ad Preferences profile is not based on your Google profile—what you search, what you ...

New Plan Proposes Protecting New Orleans By Restoring the Delta

Veronique Greenwood — Sat, 28 Jan 2012 13:29:40 +0000

In this graphic from the restoration authority, the land that will
be lost to erosion if the plan isn’t undertaken is shown in red.

Six years after Hurricane Katrina devastated New Orleans and the Louisiana coast, the state’s Coastal Protection and Restoration Authority has finally released a draft of a plan to try to keep it from happening again. How? By restoring the wetlands along the Mississippi River Delta, which we have more or less systematically destroyed but used to act as buffers between storm surge waves and inland cities.

Previous plans had relied on mainly on building levees and seawalls, so it’s striking that this plan, which would unroll over the course of 50 years at a cost of $50 billion, focuses on wetland restoration, writes Mark Fischetti, who has been covering this issue for Scientific American for years. Here’s how it would work:

Along the outer edge of the torn-up coast, furthest from New Orleans, former barrier islands that have been worn to thin wisps of land would be broadened with sandy sediment, mostly dredged from the ocean bottom and conveyed through pipelines. Natural ridges of land along the coast would be strengthened ...

Thousands of Infrastructure Computer Systems are Online, Unprotected

Veronique Greenwood — Thu, 26 Jan 2012 21:04:55 +0000

We’ve written before about hapless business owners practically handing hackers customers’ information by failing to observe basic computer security (Subway, we’re looking at you). But this is a security fail on a whole different level. A researcher has just revealed that about ten thousand systems controlling water plants, sewage plants, and other infrastructure are online, mostly unprotected and findable with a simple search.

Manufacturers of such industrial control systems, which can be used to direct everything from a high school’s lighting to power plants, have taken comfort in the fact that they aren’t supposed to be connected to the web, and thus protecting them from hackers isn’t necessary, said Eireann Leverett, the computer science grad student who presented these findings at the S4 conference (we learned of them from Kim Zetter at Wired’s Threat Level). But for whatever reason, in many cases the computers running the control software are in fact networked. Using a search that lets you identify Internet-connected devices, previous researchers have shown that you can find such computers, which is worrisome enough. But this single grad student, working full time for three months and part time for three months, ...

Your Laptop is Not Your Mind, Says Judge

Veronique Greenwood — Thu, 26 Jan 2012 18:05:03 +0000

If you think of your personal computer as almost an extension of yourself, a recent federal court ruling in Colorado sounds a little disturbing. The court has ordered that a woman decrypt files on her laptop so they can be used by prosecutors against her. The woman, who is being tried for mortgage fraud, argued that this is a violation of her Fifth Amendment right to keep from testifying against herself, but the court sees the matter differently. Timothy Lee at Ars Technica’s explanation of the problem gets to the heart of it:

In previous cases, judges have drawn a distinction between forcing a defendant to reveal her password and forcing her to decrypt encrypted data without disclosing the password. The courts have held that the former forces the defendant to reveal the contents of her mind, which raises Fifth Amendment issues. But Judge Robert Blackburn has now ruled that forcing a defendant to decrypt a laptop so that its contents can be inspected is little different from producing any other kind of document.

For some, being forced to decrypt your computer and handing over your password to investigators so they can decrypt it might not seem that different—what’s hidden by ...

How Vultures Eat Human Bodies

Veronique Greenwood — Wed, 25 Jan 2012 20:03:55 +0000

Vultures eating a gazelle.

By now, you’re probably familiar with the Body Farm at University of Tennessee. It’s one of the places where bodies donated to science go to rot while being closely observed by appreciative forensic scientists, and we say that with the greatest respect: if not for the brave few who gave their mortal remains to be studied, we would have a much harder time telling when and how people found in fields, woods, and other unusual locales died. Now, scientists working at another Body Farm-like facility, Texas State University’s Forensic Anthropology Research Facility, have performed a fascinating study to see exactly what happens when a human body is eaten by vultures.

Their findings imply that vultures can take much longer—37 days instead of 24 hours—to find a body than the carcass of a pig left in the wilderness, which is what previous studies in the Texas facility have used. On the other hand, vultures can also pick clean, or skeletonize, a body much faster than we’d thought: it took just 5 hours instead of the expected 24. The scientists also tracked where the vultures spread the body parts that they didn’t ...

Discovering Long-Lost Relatives Through Commercial DNA Tests

Veronique Greenwood — Tue, 24 Jan 2012 17:16:41 +0000

Family reunion time!

Digging around in your DNA is getting cheaper and easier all the time. For only $207, you can now subscribe to 23andMe’s genotyping service, for instance, which gives you information about your genetic background, potential disease susceptibilities, and other traits. And as the numbers of people in such companies’ databases climb into the hundreds of thousands, it has become possible for software to connect customers who share so much DNA, they may well be relatives. For adoptees who don’t have access to their adoption records and are curious about biological family, there’s never been a better time to go searching. The New York Times follows the story of one 42-year-old woman who, after learning she was adopted, finds her third cousin through a DNA service, and details the relationship that they form as she deals with the revelation that she is not, after all, the daughter of her adoptive parents.

About five weeks after shipping off two tiny vials of her cells from a swab of her cheek, Mrs. Vaughan received an e-mail informing her that her bloodlines extended to France, Romania and West Africa. She was also given the names and ...

The National Parks That No Longer Are

Valerie Ross — Tue, 24 Jan 2012 16:16:28 +0000

With their majestic peaks, imposing canyons, and lofty designation, America’s national parks seem inviolate, places of natural grandeur far from the vagaries of money or politics. But over the years, 26 sites have lost their national park status. In a slideshow at National Geographic, Brian Handwerk explores why.

A few parks were less-than-ideal candidates to begin with (the National Park Service running the Kennedy Center? huh?). But more often than not, the decision to jettison a park from the list came down to economics: Several parks, like Montana’s Lewis and Clark Caverns, above, were too remote to attract enough visitors; the caverns are now part of the state’s park system. Other ex-parks, however, are no longer open to the public: a Palm Beach retreat that proved too expensive for the government to maintain was bought by Donald Trump—and made into a swanky, exclusive club.

Read the rest at National Geographic.

Image courtesy of Montana State Parks

Ancient Tulip-like Creatures Discovered in the Burgess Shale

Veronique Greenwood — Fri, 20 Jan 2012 20:22:14 +0000

Tulips in the rocks.

Artist’s conception of what the living creatures would have looked like.

The Burgess Shale fossil beds in the Canadian Rockies are famous for showing us some of the creepiest evolutionary dead-ends to ever grace the planet. They conjure up underwater scenes of many-legged spiky creatures scuttling beneath gigantic spider shrimp, but a recent find in the Burgess Shale suggests a more pastoral landscape: fields of waving tulip-shaped creatures, each about 8 inches high.

These newly discovered filter feeders, named Siphusauctum gregarium by their discoverers, have been found in clumps of over 65, and appear to have fed by sucking water through their bodies and extracting food particles.

Images courtesy of Royal Ontario Museum and Marianne Collins.

[via ScienceDaily]

A Possible Treatment for a Deadly Food Poisoning Toxin

Veronique Greenwood — Fri, 20 Jan 2012 18:03:21 +0000

Shiga toxin is nasty stuff. If you are infected with a Shiga-producing bacterium, like Shigella dysenteriae or some E. coli strains, there is no clear treatment: if you are given antibiotics, your infected cells will explode, spraying the toxin all over neighboring cells and exacerbating your symptoms. Each year, 150 million people are infected with Shiga-producing bacteria, which cause dysentery and food poisoning, and a million of those die. The lack of effective treatment for such Shiga toxicosis infections is one of the main reasons this year’s outbreak of E. coli poisoning in Europe was so deadly, with more than 3,700 people infected and 45 dead. But now scientists studying how the toxin makes its way around the cell have discovered that treating mice with the metal element manganese makes them resistant to Shiga poisoning. Since manganese’s chemistry is already well understood and it’s readily available, the possibility of using it as a treatment is exciting.

Here’s how manganese blocks Shiga’s spread, according to the group’s experiments in cultured human cells:

Normally, bacterial toxins trying to gain access to your cells are intercepted and sent to be destroyed by sacs of enzymes called lysosomes. Shiga, however, hitches ...

Study: When Doctors Predict How Long You Have to Live, They’re Pretty Much Guessing

Valerie Ross — Thu, 19 Jan 2012 17:43:17 +0000

A recent column by Dr. Pauline Chen at the New York Times explores a surprising oversight in modern healthcare: Doctors don’t really have a clue how to predict how long a patient will live. In the absence of a widely accepted, systematic method of prognosis, they’re kind of making it up—an informed guess, with the benefit of education and experience, but a guess nonetheless.

Prognosis was once a diligently studied, widely practiced part of a physician’s job, Chen writes. But as treatments improved, and keeping patients alive longer became ever more possible, the unpleasant but necessary skill of predicting when patients might die fell by the wayside. A recent study, she reports, revealed just how much:

Prognosis was rarely, if ever, alluded to in the most popular medical textbooks and on clinical Web sites used by practicing physicians. Even the widely used medical database PubMed, maintained by the National Library of Medicine, had no specific indexing category for prognosis, making finding any published study on the subject like searching for a book in a library before the Dewey Decimal System.

Any individual prognosis, of course, may prove to be wrong, however reliable the ...

Cracking Open the Neanderthal Personality

Valerie Ross — Thu, 19 Jan 2012 15:05:22 +0000

Over the past few years, several studies have illuminated some of what happened during the brief period when modern humans and Neanderthals overlapped in Europe, with genetic analyses showing that the two groups interbred tens of thousands of years ago (though not frequently) and ancient remains suggesting that modern humans fought and—more controversially—ate their prominent-browed contemporaries.

It seems that humans and Neanderthals made occasional love and intermittent war, but what were those interludes of interaction actually like? What was going on inside those distinctive crania? It’s a tricky question to answer—behavior doesn’t fossilize—but anthropologist Thomas Wynn and psychologist Frederick L. Coolidge combine genetic and anthropological evidence with a healthy dose of well-informed speculation to offer an intriguing picture of how Neanderthals may have lived, thought, felt, and acted.

Wynn & Coolidge have a new book out on the subject, and they share a condensed version of their theory at New Scientist, offering answers to such questions as whether Neanderthals had a sense of humor (slapstick yes, subtleties no) and how their cognitive abilities compared to ours (less creativity and short-term memory, more learning by observation). And as for whether ...

Research on Quebec’s Rare Brain Disease Could Help Unravel the Common Ones

Valerie Ross — Tue, 17 Jan 2012 19:56:15 +0000

Artist’s rendering of a mitochondrian, the energy-producing
cellular structure affected by ARSACS

Scientists have pinpointed the cause of a rare, fatal neurodegenerative disorder called ARSACS, or autosomal recessive spastic ataxia of Charlevoix-Saguenay. The disease is due to defects in neuron’s mitochondria, the bit of biological machinery that generates energy for the cell—a structure known to be affected in Parkinson’s, Alzheimer’s, and other neurological diseases, as well.

ARSACS was first observed in the descendants of a small group of 17th century French settlers who made their homes near the Charlevoix and Saguenay rivers in what is now Quebec, and has since been seen worldwide. But its incidence remains unusually high in that particular French Canadian community, with 1 in 1,500 to 2,000 people developing ARSACS and 1 in 23 people unaffected genetic carriers of the disease.

The first symptoms of ARSACS appear in early childhood, often as a two- or three-year-old learns to walk, a skill that—because t he disease primarily affects the cerebellum, the brain’s motor control center—those suffering from ARSACS never master. As the disease progresses, it leads to muscle weakness, slurred speech, and difficulty coordinating or controlling movement. People with ARSACS ...

Tuberculosis Resistant to All Known TB Drugs Surfaces in India

Veronique Greenwood — Sat, 14 Jan 2012 14:03:16 +0000

When tuberculosis kills lung tissue, it can produce gaping
holes like in the lung on the right.

For a long time, tuberculosis was a gruesome and incurable disease. Antibiotics changed that, but over the last century, as the drugs have been incorrectly used, the tuberculosis bacterium has been developing resistance to them. Multi-drug resistant tuberculosis, which requires a cocktail of many drugs to treat it, has become common. Now Indian doctors have reported in a medical journal that a strain that is resistant to all known drugs for tuberculosis has appeared in Mumbai. Twelve patients so far have been diagnosed with the strain, and it’s likely that they are just the tip of the iceberg in terms of those infected.

At the Superbug blog, Maryn McKenna explains that this is the third time on record that totally drug-resistant TB (TDR-TB) has appeared. The most recent cases were in Iran in 2009, but the earliest cases were in Italy in 2003, in two middle-class Italian women:

They were both diagnosed by local doctors and treated with repeated rounds of the normal TB drugs — three rounds each — before someone recognized that something unusual was ...

In the Milky Way, There Are As Many Planets As Stars

Veronique Greenwood — Thu, 12 Jan 2012 17:49:48 +0000

There are at least as many planets in the galaxy as there are stars. And even that is probably a vast underestimate.

That’s the latest bombshell from astronomers looking for planets beyond our solar system. Phil Plait at Bad Astronomy will have a post on this soon, but for now, here’s a little quote salad for you:

“Planets are like bunnies; you don’t just get one, you get a bunch,” said Seth Shostak, a senior astronomer at the SETI Institute who was not involved in this research. “So really, the number of planets in the Milky Way is probably like five or 10 times the number of stars. That’s something like a trillion planets.” (via PopSci)

“We think about one-sixth of stars should have a Jupiter-like planet, half have a Neptune-sized planet, and two-thirds should have an Earth,” said Kailash Sahu, an author of the Nature paper in which this observation was published. (via Wired)

“Kepler [a space telescope devoted to the search for planets] has already been finding that small planets are actually quite ubiquitous around stars,” says Scott Gaudi of Ohio State University, who did not contribute to the new research. “That bodes ...

Why This Winter is So Crazily Warm

Veronique Greenwood — Thu, 12 Jan 2012 13:12:52 +0000

Spring! Not.

Across the US, this winter has been unusually balmy, with precious little snow, or even rain, and with trees taking the warmth as a cue to send out new leaves in January. Temperature data support those impressions: in the first week of the year, temperatures were 40 degrees F higher than average in some parts of the Midwest, Discovery News reports, and snow cover is at 19 percent across the country, compared to an average of 50 percent at this time of year. In notoriously chilly Fargo, North Dakota, the January 4 high temperature of 55 broke the record for the warmest January day on record, and the country has seen close to no rain or snow in this first week of 2012, writes Wunderground meteorologist Jeff Masters. “It has been remarkable to look at the radar display day after day and see virtually no echoes,” he writes, referring to the radar echoes reflected back by storms. “It is very likely that this has been the driest first week of January in U.S. recorded history.”

Why this freaky weather? The answer is, basically, an extremely unusual jet stream over the ...