Posts Tagged ‘science’

Talking cars

Posted: February 14, 2009 in science
Tags: , ,

How often people might have dreamt of having talking cars after watching Bond movies?
Well, they could soon be a reality, for scientists have reportedly developed a radio-based technology that allows cars to “talk” to each other, analyzing potential accidents and advising the driver.
A team in Australia has developed the radio technology which will provide warnings to drivers of potential intersection crashes, rear-end collisions and lane drift. Moreover, it could be available in everyday vehicles as soon as 2012, means within three years!
According to scientists, the technology will also enable traffic flow management and optimize selection of route for drivers, reducing the costs of traffic congestion as well as greenhouse emissions.
Reports say that scientist Prof Alex Grant of UniSA Institute for Telecommunications Research says the radio technology combines GPS and Wi-Fi like communications to enable vehicles to talk to each other effectively. On board processing units assess the risk of an accident and provide advice to the driver. This technology equips vehicles with the ability to see around corners and to predict and avoid dangerous situations.

Advertisements

Skin specialist at home

Posted: February 8, 2009 in beauty, science
Tags: , , ,

Though it looks like a thorny cactus, aloe vera belongs to the family of onion/lily. Distinguished by its thick fleshy lance-shaped leaves, this green plant is supposed to have mystical properties. Its botanical name is Aloe barbadensis miller. People even call it as the fragrant desert lily.

aloe_veraa

If we go by an Egyptian lore, then the gel from the aloe vera leaves was the secret ingredient that Cleopatra used for her skin and not the much-touted milk. In fact, the Egyptians use aloe vera for their embalming process since times immemorial.

The juice of the plant is sold across the world in health stores in the form of capsules and gels. The gel has 20 amino acids which the body needs as supplement for its wear and tear.

According to sources, eight of these amino acids have to be ingested and are not produced by the body itself. The gel oozes from the leaf when it is cut. As a beauty aid, the gel is used in lotions and creams for its moisturising and soothing effect. It is also used to treat burns and wounds. It has effectively been used internationally for radiation burns also. The natural gel is, in fact, the most effective and provides faster relief since the polysaccarides are destroyed during processing when heat is applied and enzymes are added in order to stabilise it. The gel also has amazing anti-bacterial, anti-fungal and anti-inflammatory properties. It is said to aid the immune system, cure constipation and also has its positive effect on the texture of the skin. The local practioners of Ayurvedic medicine use the yellow sap of the aloe as a cure for constipation. T aloe vera gel can also be used to ward off mosquitoes/insect bites by applying it on the skin, besides relieving sunburns and minor kitchen burns.

Use of the gel on the skin restores its elasticity to a great extent by its immense moisturising effect and rejuvenates the skin. When the flesh of the aloe is applied to the scalp, it deters hair loss and decreases dandruff.

Bee dance

Posted: January 7, 2009 in science
Tags: , , , , ,

Food Dance Gets New Life When Bees Get Cocaine

Honey beeBy PAM BELLUCK
Published: January 5, 2009 NYT

Buzz has a whole new meaning now that scientists are giving bees cocaine.
To learn more about the biochemistry of addiction, scientists in Australia dropped liquefied freebase cocaine on bees’ backs, so it entered the circulatory system and brain.

The scientists found that bees react much like humans do: cocaine alters their judgment, stimulates their behavior and makes them exaggeratedly enthusiastic about things that might not otherwise excite them.

What’s more, bees exhibit withdrawal symptoms. When a coked-up bee has to stop cold turkey, its score on a standard test of bee performance (learning to associate an odor with sugary syrup) plummets.

“What we have in the bee is a wonderfully simple system to see how brains react to a drug of abuse,” said Andrew B. Barron, a senior lecturer at Macquarie University in Australia and a co-leader in the bees-on-cocaine studies. “It may be that when we know that, we’ll be able to stop a brain reacting to a drug of abuse, and then we may be able to discover new ways to prevent abuse in humans.”

The research, published in The Journal of Experimental Biology, advances the knowledge of reward systems in insects, and aims to “use the honeybee as a model to study the molecular basis of addiction,” said Gene E. Robinson, director of the neuroscience program at the University of Illinois at Urbana-Champaign and a co-author with Dr. Barron, and Ryszard Maleszka and Paul G. Helliwell at Australian National University.

The researchers looked at honeybees whose job is finding food — flying to flowers, discovering nectar, and if their discovery is important enough, doing a waggle dance on a special “dance floor” to help hive mates learn the location.

“Many times they don’t dance,” Professor Robinson said. “They only dance if the food is of sufficient quality and if they assess the colony needs the food.”

On cocaine the bees “danced more frequently and more vigorously for the same quality food,” Dr. Barron said. “They were about twice as likely to dance” as undrugged bees, and they circled “about 25 percent faster.”

The bees did not dance at the wrong time or place. Cocaine only made them more excited about the food they found. That’s like “when a human takes cocaine at a low dose,” Dr. Barron said. “They find many stimuli, but particularly, rewarding stimuli, to be more rewarding than they actually are.”

Now, scientists are studying whether bees begin to crave cocaine and need more for the same effect, like humans.

The testing occurred in Australia, and, Dr. Barron said, “my dean got extremely twitchy about holding cocaine on campus. It’s in a safe bolted to a concrete floor within a locked cupboard in a locked room in a locked building with a combination code not known even to me. A technician from the ethics department has to walk across campus to supervise the release of the cocaine.”

That, Dr. Barron said, for a bee-size supply of “one gram, which has lasted me two years. One gram, a human would go through in one night. I’m not like the local drug lord.”

squirrel

Posted: January 7, 2009 in science
Tags: , , , , ,

 

 

 

British Gray Suqirrel

British Gray Suqirrel

Saving a Squirrel by Eating One

By MARLENA SPIELER
Published: January 6, 2009 NYT

 RARE roast beef splashed with meaty jus, pork enrobed in luscious crackling fat, perhaps a juicy, plump chicken … these are feasts that come to mind when one thinks of quintessential British food. Lately, however, a new meat is gracing the British table: squirrel.

Though squirrel has appeared occasionally in British cookery, history doesn’t deem it a dining favorite. Even during World War II and the period of austerity that followed, the Ministry of Food valiantly promoted the joys of squirrel soup and pie. British carnivores replied, “No, thank you.”

These days, however, in farmers’ markets, butcher shops, village pubs and elegant restaurants, squirrel is selling as fast as gamekeepers and hunters can bring it in.

“Part of the interest is curiosity and novelty,” said Barry Shaw of Shaw Meats, who sells squirrel meat at the Wirral Farmers Market near Liverpool. “It’s a great conversation starter for dinner parties.”

While some have difficulty with the cuteness versus deliciousness ratio — that adorable little face, those itty-bitty claws — many feel that eating squirrel is a way to do something good for the environment while enjoying a unique gastronomical experience.

With literally millions of squirrels rampaging throughout England, Scotland and Wales at any given time, squirrels need to be controlled by culls. This means that hunters, gamekeepers, trappers and the Forestry Commission (the British equivalent of forest rangers) provide a regular supply of the meat to British butchers, restaurants, pâté and pasty makers and so forth.

The situation is more than simply a matter of having too many squirrels. In fact, there is a war raging in Squirreltown: invading interlopers (gray squirrels introduced from North America over the past century or more) are crowding out a British icon, the indigenous red squirrel immortalized by Beatrix Potter and cherished by generations since. The grays take over the reds’ habitat, eat voraciously and harbor a virus named squirrel parapox (harmless to humans) that does not harm grays but can devastate reds. (Reports indicate, though, that the reds are developing resistance.)

“When the grays show up, it puts the reds out of business,” said Rufus Carter, managing director of the Patchwork Traditional Food Company, a company based in Wales that plans to offer squirrel and hazelnut pâté on its British Web site, patchwork-pate.co.uk.

Enter the “Save Our Squirrels” campaign begun in 2006 to rescue Britain’s red squirrels by piquing the nation’s appetite for their marauding North American cousins. With a rallying motto of “Save a red, eat a gray!” the campaign created a market for culled squirrel meat.

British bon vivants suddenly couldn’t get enough squirrel. Television chefs were preparing it, cookbooks were extolling it, farmers’ markets were selling out of it and restaurants in many places were offering it on the menu.

Meanwhile gamekeepers, hunters and trappers were happy to know that the meat was being eaten, not wasted. “My lads don’t like to kill an animal if it’s not going to be eaten,” Mr. Shaw said of the hunters who bring him game.

Many enjoy squirrel, however, simply because they like its taste. Mr. Carter said he didn’t know what he was eating when he tried it. But, he said, “at first bite, I thought it delicious.” Patchwork will send squirrel pâté, by the way, in return for a donation to “Save Our Squirrels” — but only within Britain.

Mark Holdstock, a writer and broadcaster specializing in countryside matters, is less enthusiastic, having recently eaten squirrel on the air on “Farming Today,” BBC Radio 4’s iconic program devoted to rural issues. “It’s fair to say I didn’t dislike it,” he said.

Nichola Fletcher, a food writer and co-owner of a venison farm, held a squirrel tasting for Britain’s Guild of Food Writers, finding “their lovely flavor tasted of the nuts they nibbled.” At a later event, however, she found the flavor disappointing, with “a greasy texture and unpleasant taste,” presumably reflecting these squirrels’ diet.

Though squirrel has been promoted as a low-fat food, Ms. Fletcher said that in her experience, “the quality and amount of fat varied from no visible fat to about 30 percent, depending on the season, their age and, especially, diet.”

Fergus Henderson, the chef and co-owner of St. John restaurant in London, offers squirrel on the menu “seasonally.” Though the meat is available all year long, it is in the spring, when hunting season is over, that country folk can focus their attentions on controlling the squirrel population. That’s when squirrel appears on St. John’s menu.

Mr. Henderson, who cooks with both poetry and passion, sometimes prepares his squirrels “to recreate the bosky woods they come from,” braising them with bacon, “pig’s trotter, porcini and whole peeled shallots to recreate the forest floor.” He serves it with wilted watercress “to evoke the treetops.”

Other chefs may be less lyrical, but they are no less enthusiastic. The Famous Wild Boar Hotel in Britain’s Lake District serves squirrel Peking-duck style; at Matfen Hall, a grand country house hotel, it is layered with hazelnuts into a terrine; in Cornwall, it can be found baked into the iconic meat pie known as a pasty.

If you want to grab your shotgun, make sure you have very good aim — squirrels must be shot in the head; a body shot renders them impossible to skin or eat. (You want to get rid of the head in any event, as squirrel brains have been linked to variant Creutzfeldt-Jakob disease, the human form of mad cow disease.)

Skinning a squirrel is “difficult and unpleasant,” the food writer Leslie Mackley said, adding, “You have to fight to rip the skin from the flesh.”

A. H. Griffiths, who sells squirrel for the equivalent of about $3 per squirrel at the butcher shop in Shropshire that bears his name, added that it is “best left to the professionals.”

“Each squirrel skinned makes the next one easier,” he added. “When you’ve skinned as many as I have, you find the best way.”

Mr. Griffiths is a fan of the meat, likening it to a slightly oily rabbit. “We started selling squirrel a few years ago, after the owner of our local pub bragged about winning a squirrel-eating contest,” he said. Then, he said, the owner “caught a squirrel, casseroled it up, and we liked it so much Griffiths has been selling it ever since.”

One might think that because of easy availability, squirrel would be the perfect meal-stretcher for these economically challenged times, but it takes a lot of work to get the meat off even the plumpest squirrel. (One would make a good main course.) Combined with the aforementioned difficulty in skinning, Mr. Carter said, many otherwise enthusiastic hunters, gamekeepers and chefs “can’t be bothered with it.”

red squirrel

red squirrel

insects

Posted: January 7, 2009 in science
Tags: , ,

A Large-Size Focus on Life Lived Small

insectsinsects2By NATALIE ANGIER
Published: January 5, 2009 NYT

NEW ORLEANS — Zack Lemann opened the thick acrylic terrarium marked “Dung Beetles” and began poking around in the dirt and, uh, beetle food with the delicate vigor of a practiced surgeon. A moment later he emerged with a piece of live jewelry balanced on his fingertip: Phanaeus vindex, the rainbow scarab. “Isn’t it a beauty?” Mr. Lemann said proudly. “Purple, green and gold — as close to Mardi Gras colors as you can get.”

Its party armor isn’t the only trait that suits Phanaeus to its bayou setting. For the ancient Egyptians, the sacred scarab symbolized resurrection and self-invention, the power to tunnel out from the tar-pit grip of the earth and back into the agile light of morning, and who better to counsel rebirth in the wake of inundation and obliteration than a civilization built on the floodplains of the Nile?

Here at the boisterous new Audubon Insectarium, a $25 million private nonprofit venture located on the shank of the French Quarter, metaphors and messages are easy to find, coin and liberally mix. Let’s start with the mixing of the large and the small. Opened just half a year ago, the Insectarium is the largest museum in the nation devoted solely to insects and their arthropod relations. It is also the first major attraction to open in New Orleans since Hurricane Katrina howled through the city in 2005. “We want to let the nation know that we’re coming back as a city,” said Mr. Lemann, a staff entomologist who helped design many of the exhibits. “We’re not just coming back, we’re looking forward as well.”

The museum is also large with special effects, most notably a so-called 4-D movie theater where audience members are treated to a multisensory experience as they watch an insect-themed cartoon with voiceovers by Jay Leno, Joan Rivers and other celebrities, all while sitting in special $2,000 chairs that prickle and poke them, insect-style, and are spritzed with samples of insectile perfumes. And if at the end of the 4-D foray anybody can remember what the movie was about, I will happily spring for lunch at the museum’s Bug Appétit cafe, where the boyishly enthusiastic and slightly pushy Mr. Lemann shamed me into sampling the insect cuisine, like the “crispy Cajun crickets,” which consists of fried, spiced crickets, and the “waxworm chutney,” which consists not of worms but of plump white caterpillars that parasitize beehives. “The hardest part is convincing people to try eating insects in the first place,” Mr. Lemann said. The second hardest part is persuading people who don’t have a pet lizard to take home some leftovers.

Despite the museum’s large size and larger expectations, however, its true focus is on life lived small, on the insects that surround us and define the world we humans happen to inhabit. It can be easy to ignore insects or consider them insignificant, as exemplified by the museum visitor who, on hearing that all the work in an ant colony was performed by females, said to her son: “You see, honey? It’s just like in the real world.” The “real world”? You mean the one in which, for every one of us, there are maybe 1.5 billion of them, and for every pound of human there are maybe 200 pounds of insect? In the real world, insects account for nearly 90 percent of all living species, and there are as many varieties of beetles alone as there are plants. “Insects won’t inherit the Earth,” the renowned Cornell entomologist Thomas Eisner has said. “They own it now.”

Through a mix of live animal displays and artful arrangements of posthumous specimens, the museum emphasizes the spectacular abundance and diversity of the insect class, and how everything that can be done is being done somewhere in their ranks.

Insects are defined by a few salient features — the six segmented legs, the three body parts of head, thorax and abdomen, the exoskeleton that lends them their crunch — yum yum. But given 440 million years of evolution, very short generation times and extremely large litters, oh what an obscenity of riches can be wrought from the basic Insecta ingredients. You end up with the Costa Rican fairyfly, a parasitic wasp that is smaller than a single-celled paramecium, and with the Borneo walking stick, which at 22 inches is nearly as long as a human arm. You have flies that resemble wasps and metalmark moths that mimic jumping spiders and diving beetles that look like cute little turtles as they swim through the water but are voracious predators capable of devouring little turtles. If you can watch the walking leaf insects as they creep through the leaves of their display and not be agog at the precision of their evolved camouflage, with those fake leaf veins and those fake leaf cutouts that mimic the chewings of herbivorous insects past, then, sorry, you are already garden mulch.

And there is so much skulduggery among insects, so many iterations of the flea-upon-flea strategy. For example, in one species of velvet ant — which looks like a large, furry ant but is really a wasp — the female waits for the offspring of another parasitic wasp to fatten up on the host insect it has invaded and, just before the pupa is about to emerge from that hollowed host shell, lays her eggs in the pupa to begin their own evisceration. Dragonflies are brilliant aerial hunters, but robber flies can catch both dragonflies and their prey in midflight.

The Insectarium celebrates the essential roles that insects play, from the breezily lovable honeybees and butterflies that fertilize our crops to the less photogenic crews that clean up our filth. One mesmerizing time-lapse movie clip at the museum shows the industrious recycling of a rat corpse, as a fly lays her eggs in its blinded eye, and maggots boil out and reduce the carrion to a memory of fur, and, finally, fresh green shoots spring up from the fertilized ground. Insects remind us that the wheel of life keeps on spinning. Come sorrow and loss, breached levees and broken trust, there’s always a new year, another party, a bittersweet song.

holocaust

Posted: January 3, 2009 in science
Tags: , ,

From a Place of Fire and Weeping, Lessons on Memory, Aging and Hope
By MARC E. AGRONIN, M.D.
Published: December 22, 2008 NYT

Place of fire,

place of weeping,

place of madness

— Zelda, “Place of Fire”

The forest still stands, but the people are gone. Only a stone memorial guards their place, surrounded by tall grasses that hide bits of ash and bone deep beneath their roots.

On this spot on Feb. 4, 1942, more than 920 Jewish men, women and children from the town of Rakov in what is now Belarus were rounded up by the Nazis and herded into the synagogue. Several shrieking children were stabbed with bayonets and thrown over the heads of the weeping Jews just before the doors and windows were sealed and the building was doused with kerosene.

An unspeakable scene of wailing ensued as the once vibrant Jewish community was annihilated in the fire. My patient, now 98, still weeps when he describes witnessing this horror from a hidden perch in a tree. He gasps audibly when he recalls watching his father being pummeled by a Nazi soldier before he was thrust into the doomed crowd.

When this survivor first told me his story, I was speechless. He held tight to my arm, and I imagined myself as the branches of the tree that supported him during this trauma. I was now a witness.

As his psychiatrist I am obliged to ease his suffering, but no medicine of mine can touch such a memory. I have tried hard to understand how he and others managed to mentally survive such traumatic experiences. These aging Holocaust survivors, in particular, have taught me what I have come to call “lessons from fire.”

Lesson 1 is the most difficult for a doctor. Sometimes the perpetual sadness of many older survivors is not to be healed but shared. Over time, as memories fade and the voices of lost loved ones grow quieter, all that remains is a closely guarded sadness, persisting as a substitute for the losses. Any attempt to ease this emotion may be a threat to painful but beloved remnants of memory. What some survivors seek is not medicine or therapy: it is the attentive presence of a doctor and others to serve as the next generation of witnesses.

Lesson 2 brings a paradox. Surviving a grueling trauma does not inoculate one against the stresses of aging. A patient once told me that the small daily indignities she faced in the nursing home felt worse than her experiences in a Siberian labor camp. I realized that she could not bear feeling like a victim again, even in small measure.

Lesson 3 gives me hope. One patient, a survivor of Auschwitz, recently lost her husband of 60 years. She came to me severely depressed, with thoughts of suicide.

I asked her, “How did you have any hope in the camp, knowing that each day could be your last?” She smiled briefly and told me a story (I reconstruct her words from memory):

“My dear doctor, I believe in God, and he was with me in the camp. But I also had several young women from my town with me in the barracks.

“When we had to stand at attention for hours, we stood together, propping up one another when weak. When we dug ditches we did it together, one holding and moving the arms and shovel for another who didn’t have strength that day. We were desperate, but never alone.”

I referred her to a social club we created for older people with mild memory problems, and one day I crept into the room during a discussion group and hid behind a corner to listen.

One women spoke disparagingly of her memory. “I am losing my mind,” she said. “It is so painful.”

Then I heard my patient respond in a resolute voice: “You must have hope. We are all in the same boat here, together.”

As I listened I could feel tears welling in my eyes, but I kept myself hidden, afraid to let the group see their doctor weeping. From my hiding place I witnessed a beloved patient begin to heal herself.

These lessons from fire are not the only points of clinical knowledge that one needs to work with aging victims of trauma, but they’re a good start. When facing the last generation of Holocaust survivors, I offer my presence as a doctor and I feel strengthened by their words.

“Faith — I still have faith,” I hear a survivor say. “Doctor, hope for me!” another commands. These are the primal gifts of life that we share.

Marc E. Agronin is a geriatric psychiatrist in Miami.

tsunami

Posted: January 2, 2009 in science
Tags: , , , ,

Meteorite Strikes, Setting Off a Tsunami: Did It Happen Here?

By KENNETH CHANG
Published: December 29, 2008 NYT

The tsunami washed over Fire Island and, to the west, waves perhaps as high as 20 feet spilled into Lower Manhattan. The furious onrush of water left sediment a foot and a half deep on the Jersey Shore, and debris cascaded far up the Hudson River.

No, there’s no need to rush to higher ground, commandeer a rowboat in Central Park or empty the closet to grab the rubber boots. This disaster occurred about 2,300 years ago, though how bad it was, or even if it was a tsunami, remains in dispute.

But several geologists have collected evidence indicating that something very big and unusual occurred in waters near the New York area around 300 B.C., give or take a century. And Dallas Abbott, a research scientist at Columbia University’s Lamont-Doherty Earth Observatory, is asserting that a meteorite, landing somewhere in the Atlantic, generated the tsunami.

Someone at the tip of Lower Manhattan then would probably have seen “something coming in,” Dr. Abbott said. “Then you would hear a big bang, maybe a series of bangs, something that sounded like gunfire or cannons. It would be a really, really loud noise. And then you would be knocked to the ground by the air blast. And then you would be inundated by the tsunami.”

While not nearly as severe as the tsunami that killed more than 180,000 people in South and Southeast Asia in 2004, “it would have been a bad day to end all bad days,” she said, “in all senses.”

Although American Indians had long been living in and around the area that became New York, Dr. Abbott said there was no archeological evidence of a tsunami or known legends of, say, a terrible flood. She has built her case with diamonds, very tiny ones.

At a meeting of the American Geophysical Union in San Francisco earlier this month, Dr. Abbott reported finding minute carbon spheres and smaller-than-dust diamonds in sediment layers, which she said were the distinctive calling cards of a meteorite’s impact.

“I think it’s pretty convincing,” Dr. Abbott said. “We always find the impact ejecta in the tsunami layer, never outside.”

A few years ago, the geologist Steven Goodbred, then at the State University of New York at Stony Brook, was not looking for tsunamis or meteorites when he first examined sediment cores taken along the South Shore of Long Island. Dr. Goodbred was interested in the history of oysters in that area. But in the very first core, he saw a strange layer several inches thick containing fist-size gravel.

“We started joking immediately, ‘It’s a tsunami,’ ” recalled Dr. Goodbred, now a professor at Vanderbilt University in Nashville.

Subsequent cores, taken in Great South Bay, also contained that layer, deposited about 2,300 years ago. When Dr. Goodbred presented his findings at a conference a couple of years ago, he failed to convince other scientists. They said the layer was more likely caused by a big storm, not a tsunami.

“Even if it was a storm, it was the mother of all storms,” Dr. Goodbred said, pointing out that the devastating hurricane that passed directly over Long Island in 1938 generated less than an inch of sediment.

Then Dr. Goodbred met other scientists who had found similar sediment layers nearby. Cecilia McHugh, a professor at Queens College, had seen a sediment layer a foot and a half thick at Sandy Hook in New Jersey. That, too, was laid down about 2,300 years ago. And Frank Nitsche, another research scientist at Lamont-Doherty, had discovered a layer of wood debris in sediment cores from the upstate reaches of the Hudson River.

Then Dr. Abbott joined the project and found possible evidence of a meteorite.

But the arguments of a meteor causing a New York tsunami are still regarded skeptically by many, if not most, geologists. For one, no one has found any craters.

The evidence hinges most strongly on the tiny diamonds, presumably formed by the ultra-high pressures of impact.

The carbon atoms inside some of the diamonds are lined up in a hexagonal crystal structure instead of the usual cubic crystals. The hexagonal diamonds have been found only within meteorites and at impact craters, said Allen West, a geologist who performed the diamond analysis for Dr. Abbott’s New York sediments.

But unless researchers find a crater in the ocean floor, an Indian legend telling of a day of fire and water or many more thick sediment deposits, convincing other scientists of what they believe happened 2,300 years ago will continue to be an uphill battle.

crabs

Posted: January 2, 2009 in science
Tags: , , ,

To Find Way Home, Some Crabs Find It’s All in the Stride

By HENRY FOUNTAIN
Published: December 29, 2008 NYT

Most animals have the ability to return home from a foraging trip, even if home is nowhere in sight. They do this at least partly through path integration — using information about direction and distance to return to a starting point. (Sailors and others refer to this as dead reckoning.)

But how animals measure distance is largely a mystery. The honeybee has been shown to use the flow of the passing landscape across its field of vision. Some other animals may be able to gauge linear acceleration and use that to determine distance.

Now Michael L. Walls and John E. Layne of the University of Cincinnati provide direct evidence of yet another method. In a report in Current Biology, they show that the fiddler crab Uca pugilator uses its stride to gauge distance.

The researchers devised an experiment in which they put a slippery sheet of acetate in the path of a crab heading toward its burrow. Crabs took the same number of steps as if they were on a normal surface, but since they made no progress with some of the steps they ended up short of their burrow. Since the crabs were not moving, Dr. Layne said, this shows that they were using leg movements as a cue to gauge distance, rather than acceleration or the movement of the landscape across their vision.

The researchers found that this stride integration was quite flexible. With both slipping crabs and those that encountered no slippery patches, they found that the number of strides depended both on the distance to the burrow and the length of the stride, which could vary. “Our theory after doing this is that they don’t count steps at all,” Dr. Layne said. “They just add them up no matter how big or small they are.”

He added that the crab’s behavior must involve neuronal signals either to or from the legs.