Posts Tagged ‘senses’

Radar May Keep Bats Away From Wind Turbines’ Blades

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batsWind power may prove to be a promising source of clean energy, but it can also be deadly to bats. Not only can the animals be sliced by the blades of wind turbines, but the sudden drop in air pressure around the turbines can also cause bats’ lungs to explode. An electromagnetic field emitted near the turbines, however, may help bats steer clear of them, according to a new study published in the Public Library of Science One.

Bat casualties near wind turbines have proven to be significant: In 2004, over the course of six weeks, roughly 1,764 and 2,900 bats were killed at two wind farms in Pennsylvania and West Virginia, respectively [LiveScience]. If wind power continues to become increasingly prevalent, so too might the turbines become a growing threat to bat populations. “Given the growing number of wind turbines worldwide, this is going to be an increasing problem, no question about that,” said [co-author] Paul Racey [LiveScience].

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July 21st, 2009 Tags: , , , , , , ,
by Allison Bond in Environment, Living World | 1 Comment » | RSS feed | Trackback >

Tiger Moths Jam Bats’ Sonar Like a Helicopter in Enemy Territory

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bat mothBats may have a clever way of catching prey, but it turns out the tiger moth has some tricks of its own to avoid becoming a bat’s next meal. According to a study published in Science, the tiger moth disrupts the sound waves the bat uses home in on prey by emitting its own ultrasound blasts.

Researchers knew that the tiger moth emitted ultrasound waves, but they weren’t sure why. Previous studies indicated the moth’s sounds might serve to startle the bats, or warn them that the insects were unpalatable. The new research, however, tested both of these theories. The scientists had so-called big brown bats hunt tiger moths in a chamber fitted with ultrasonic recording equipment and high-speed infrared video. If the moth sound is used to startle bats, then in the chamber the bats should be disrupted on first attack, then learn to ignore the ultrasonic click, the team figured. That didn’t happen. If the moths’ clicks are warnings that the insects taste bad, then the bats should hear the click, bite the moth—and never do so again whenever they hear the sound. That didn’t happen either [National Geographic News].

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July 20th, 2009 Tags: , , , , ,
by Allison Bond in Living World | 1 Comment » | RSS feed | Trackback >

Clubbers More Likely to Give Cigarettes If You Ask Their Right Ears

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dance clubA noisy Italian disco may not seem like a conducive location for scientific experiments, but for a couple of researchers investigating hearing and language processing it was perfect. The undercover scientists studied clubbers who were trying to talk while the music was pumping, and found that they showed a decided preference for speaking into each other’s right ears. What’s more, when the researchers approached clubbers with a request for a cigarette, they found the unwitting test subjects were much more likely to comply if the petition was made in the right ear.

Previous lab studies have also suggested that humans tend to have a preference for listening to verbal input with their right ears and that given stimulus in both ears, they’ll privilege the syllables that went into the right ear. Brain scientists hypothesize that the right ear auditory stream receives precedence in the left hemisphere of the brain, where the bulk of linguistic processing is carried out [Wired.com]. Researchers say this bias holds true for both lefties and righties.

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June 24th, 2009 Tags: , , ,
by Eliza Strickland in Mind & Brain | 1 Comment » | RSS feed | Trackback >

To the Brain, Tools Are Temporary Body Parts

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tool useWhen a person pick up a rake or a croquet mallet or any other tool, their mental image of their body expands subtly, according to a new study. To move our bodies around in space, the brain builds what’s called a “body schema,” a representation of all our various parts. And this so-called schema is frequently updated to keep up with our ever-changing bodies [Scientific American]. This new study, published in Current Biology, found that using a tool for even a brief amount of time caused volunteers to update their body schema, and to consider the tool a part of their bodies.

Lead researcher Alessandro Farnè first asked volunteers to point at and grab wooden blocks with their hands, then had them perform the same motions with a grabber tool, and finally returned to the hands-only gestures. The researchers recorded all of these tasks using a high-resolution three-dimensional motion-tracking system, so that they could compare in detail the movements performed in each task. They found that after using the grabber, the volunteers approached the blocks with slightly lower acceleration and velocity, although their accuracy was not affected. “They behave like their arm is longer,” says Farnè. “They aren’t clumsy, but they are slower and more determined” [Nature News].

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June 23rd, 2009 Tags: ,
by Eliza Strickland in Mind & Brain | 5 Comments » | RSS feed | Trackback >

A Near-Extinct Blue Butterfly Flourishes Again, Thanks to a Red Ant

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blue butterflyIn a rare conservation success, a beautiful butterfly species that was headed for extinction has been brought back from the brink, thanks to careful biological observations of the insect’s life cycle. The mysterious disappearance of the Large Blue Butterfly across most of northern Europe was originally put down to its popularity among insect collectors [Telegraph]. Then biologist Jeremy Thomas spent six summers in the 1970s studying the very last colony of large blue butterflies in the United Kingdom, and determined that the butterflies were dependent on one species of red ant for their survival–and those ants were losing their habitat.

The butterflies lay their eggs on flowering thyme plants, and the hatched caterpillars fall to the ground and begin to impersonate immature red ants. They secrete chemicals and even make noises that make the red ants believe they are wayward grubs. The ants then mistakenly carry the caterpillars to their underground homes and keep looking after them even though the adopted intruders gobble ant grubs for 10 months before forming a chrysalis and flying away as adult butterflies [Reuters].

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June 16th, 2009 Tags: , , , , , , ,
by Eliza Strickland in Environment, Living World | 9 Comments » | RSS feed | Trackback >

One Myth About Fingerprints Debunked: They Don’t Help People Keep a Grip

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fingerprintWhat are fingerprints good for, besides aiding police investigations? That’s the question that biomechanics researcher Roland Ennos recently set out to answer. This notion that human fingerprints (and presumably footprints) evolved because they act like tire or boot tread–increasing the friction against a smooth surface so we don’t slip or drop stuff–is a 100-year-old urban myth that, apparently, had never been put to the test [NPR].

To test the impact of fingerprints, Ennos rigged a machine that measured the amount of friction generated by a fingertip (belonging to study coauthor Peter Warman) when it was pressed against a piece of acrylic glass. Warman gradually increased the pressure, going from a light touch on the glass to a tight grip, but the corresponding friction didn’t increase as much as the researchers expected. Soon they realised that the skin was not behaving like a normal solid, where friction is proportional to the strength of the contact. Instead, it was behaving like rubber, where the friction is proportional to the contact area between the two surfaces [BBC News].

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June 15th, 2009 Tags: , , ,
by Eliza Strickland in Health & Medicine, Human Origins | 8 Comments » | RSS feed | Trackback >

The Original Bat-Signals: Bats Can Recognize Individual Voices

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batScientists have long been impressed with bats’ echolocation calls, the brief bursts of sound that bounce off surrounding objects and allow the bats to navigate in the dark. But now researchers have found a new level of sophistication in those cries. A new study of greater mouse-eared bats proves that bats can distinguish between the calls of different individual bats. Researchers say this could explain how they remain in a group when flying at high speeds in darkness, and how they avoid interference with one another’s echo-location calls [The Guardian].

In the study, published in the journal PLoS Computational Biology, lead researcher Yossi Yovel played the recordings of bat cries back to his test subjects. “Each bat was assigned two others it had to distinguish between,” Dr Yovel explained. “So we trained bat A on a platform, playing a sound from bat B on one side and from bat C on the other. He had crawl to where the ‘correct’ sound was coming from” [BBC News]. For a correct answer, the bat was rewarded with a mealworm.

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June 8th, 2009 Tags: , , ,
by Eliza Strickland in Living World | 3 Comments » | RSS feed | Trackback >

Can Sight Be Restored With Stem Cells Grown on Contact Lenses?

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eyeThree patients with severe damage to the corneas of their eyes have achieved dramatic improvements in their vision thanks to contact lenses coated with their own stem cells. While the study was extremely small and the results are quite preliminary, the unequivocal improvement seen in the three patients has given doctors hope that the treatment may work for many patients with damaged corneas. Two of the three patients were legally blind in the treated eye; they can now read big letters on the eye chart. The third could read the top few rows of the chart but is now able to pass the vision test for a driving license [The Australian].

The cornea is the transparent layer that covers the eye – but it can lose transparency, damaging sight. In the most serious cases, people can need cornea grafts or transplants. Corneal disease can be caused by genetic disorders, surgery, burns, infections or chemotherapy. In this study, all three patients had damage to the epithelium – the layer of cells covering the front of the cornea [BBC News].

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May 28th, 2009 Tags: , , ,
by Eliza Strickland in Health & Medicine | 10 Comments » | RSS feed | Trackback >

Chemistry Experiment Produces the Ultimate Wine Taster

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wine barrelsUsing a fancy piece of chemistry equipment to study the chemical composition of wine, European researchers have one-upped the sophisticated palates of wine connoisseurs. The researchers used ultra high resolution mass spectrometry to sort through all the chemical compounds present in wines that had been aged in oak barrels, and found that for each wine, they could determine which French forest the oak was cut from. No other approach – analytical or sensory – has been able to significantly discriminate wines according to the species or the origin of the oak used for the barrels before, they say [Chemistry World].

The findings could prove useful to wine connoisseurs and historians, the researchers said, concluding that their findings produced “chemical representations of the way such noble nectar can shape, on the (tongue) of the wine taster, some of the outlines of the scene of its birth” [AP]. Similar analyses could also be used to detect wine fraud, the researchers noted.

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May 27th, 2009 Tags: , , , , ,
by Eliza Strickland in Environment, Living World, Technology | 3 Comments » | RSS feed | Trackback >

Non-Slip Cells on Flower Petals Help Bees Get a Grip

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snapdragon cellsSpecialized cells found only on flower petals have the same basic function as nonslip mats that prevent people from slipping in the shower, a new study has determined. The bumpy cells, called conical cells, help bees come in for a landing on the flower petals and find their footing, so they can get down to the important business of pollination.

Conical cells had been something of a botanical mystery, with most researchers assuming they played a visual role. One hypothesis held that by modifying the spectral properties of the petal, the cells enabled the plant to appear brighter to pollinators [The Scientist]. In the study, will be published in a forthcoming issue of Current Biology, researchers showed that the conical cells’ main function is to provide friction, and that bees can detect them by touch. The first experiment used two kinds white snapdragons that looked identical to both human and bee eyes, but one was a mutant with flat cells instead of conical. The bees initially went to both flower types, but after 20 visits they chose the blossoms with conical cells more than 80 percent of the time.

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May 14th, 2009 Tags: , , ,
by Eliza Strickland in Living World | No Comments » | RSS feed | Trackback >

Ant’s Chemical Signal Tells Nest Mates: “I’m Not Dead Yet”

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ant deathEach adult Argentine ant has two chemical fragrances that send out critical messages to other ants in its colony, in what is literally a matter of life and death. Normal, still-breathing adult workers carry chemicals signaling “Dead ant — haul to burial pile” on their outer covering, proposes [entomologist] Dong-Hwan Choe…. What prevents awkward mistakes about who’s really dead are two additional compounds also found on the covering of living ants, Choe suggests. These compounds temporarily inhibit responses to the death cues by signaling, “Wait — still alive so far,” Choe and his colleagues report [Science News].

Choe’s study, which was published in the Proceedings of the National Academy of Sciences, set out to examine the corpse-ridding behavior, or necrophoresis, that is common to many ants and other social insects, and helps maintain good sanitation in the colony…. The prevailing theory of necrophoresis had been that ants were responding to fatty acids and other chemical cues from the decomposing corpse. But the researchers noticed that ants would haul a corpse away within an hour after death — before much decomposition began [The New York Times].

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May 5th, 2009 Tags: , , ,
by Eliza Strickland in Living World | No Comments » | RSS feed | Trackback >

Watching YouTube Videos of Dancing Birds for the Sake of Science

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It may be the first example of a serious scientific study being launched by a viral video. Neuroscientist Aniruddh Patel was astonished when someone e-mailed him a link to a YouTube video of a sulfur-crested cockatoo named Snowball dancing to the Backstreet Boys.”I said, you know, this is much more than just a cute pet trick. This is potentially scientifically very important,” recalls Patel [NPR].

Researchers had previously assumed that only humans move in time to a beat, but Snowball appeared to bob and rock to the rhythm just like any dancer. But Patel still wondered if the tail-shaking cockatoo had simply learned one dance routine that happened to synchronize to the Backstreet Boys song. For his study, published in Current Biology, Patel made slowed down and sped up versions of the song, and played them back to the bird while Snowball’s owner videotaped the reaction.  They found that Snowball did adjust his moves to match the tempo. At slower speeds the bird swayed rhythmically from side to side, and when the beats came fast and furious, the bird erupted into rapid head-bobbing.

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May 1st, 2009 Tags: , ,
by Eliza Strickland in Living World, Mind & Brain | 6 Comments » | RSS feed | Trackback >

Sniffing Out Sickness: Mouse Noses Respond to the Urine of Diseased Mice

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mouse noseResearchers may have determined the method by which some animals can literally sniff out a sick individual–and hence avoid it to protect their own health. A team of scientists has identified a type of smell receptor in mice that seems to respond to disease-related molecules produced by bacteria, viruses, or as the result of inflammation [New Scientist].

Scientists have previously identified a number of mouse smell receptors, cell-surface proteins in the animals’ noses that pick up everything from the fragrance of food to the scent of fear…. Neurogeneticist Ivan Rodriguez of the University of Geneva in Switzerland and colleagues wondered whether there might be additional such receptors that respond to a disease “scent,” perhaps by detecting chemicals associated with bacteria and inflammation [ScienceNOW Daily News]. After scanning the mouse genome for genes in the olfactory system, they detected genes for five new smell receptors that seemed to be likely candidates. The receptors are part of a known family of proteins that are involved in immune response; other proteins in the same family detect chemicals given off by pathogens in an animal’s own blood.

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April 27th, 2009 Tags: , , , ,
by Eliza Strickland in Living World, Mind & Brain | No Comments » | RSS feed | Trackback >

Nocturnal Mammals Use Special DNA Lenses to See in the Dark

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racoonsA group of geneticists has peered into the eyes of nocturnal animals, and say they may have found the secret to these animals’ keen night vision: light-sensing cells with unusually structured DNA that turns each cell’s nucleus into a tiny lens.

The researchers were examining mice’s rod cells, the cells in the retina of the eye that operate under low light. Usually, they say, active genes are clustered in the center of each cell’s nucleus for convenient access to cellular machinery. But rod cells in the mouse retina shove active genes to the outside of the nucleus, the researchers found. The center of the nucleus is instead occupied by densely-packed inactive DNA called heterochromatin. Mice put this type of DNA front and center in their rod cells. “Everything that must be inside is outside, and everything that should be outside is inside,” [lead researcher Boris] Joffe says. “It was an absolutely heretic finding” [Science News].

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April 17th, 2009 Tags: , ,
by Eliza Strickland in Living World | 7 Comments » | RSS feed | Trackback >

In a Sensory Hack, What You Touch Affects What You See

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fingertipScientists have found that manipulating a person’s sense of touch can confuse their sense of sight, an intriguing finding that suggests that touch and vision are integrated in the human brain…. For decades, instructors in medical schools have taught students that the senses —including vision, touch and sound — are interpreted in different, discrete parts of the brain, says Michael Beauchamp of the University of Texas Medical School at Houston. “Now it turns out what we’re teaching them is wrong,” he says. “There’s a lot more cross talk between the modalities” [Science News]. 

In the experiment, which will be published in an upcoming Current Biology, researchers used a postage stamp-sized device that used tiny pins to stroke the test subject’s finger in either an upward or downward direction. When subjects watched a stationary stripe on a computer screen after a machine stroked their fingertips, the motion of the stroking created the illusion that the stripe was moving [ScienceNOW Daily News].

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April 10th, 2009 Tags: , ,
by Eliza Strickland in Mind & Brain | 4 Comments » | RSS feed | Trackback >