agnieszka biskup — writer & editor

Sex among the arachnids isn’t particularly romantic to the human eye: female spiders routinely attempt to munch on their mates during or after copulation. And it makes sense: The females need the extra nutrition for their offspring-to-be. Most males try to escape this dire fate, but not the male of the species Argiope aurantia. This orb-weaving spider invariably dies spontaneously during copulation, according to a study published last week in the Royal Society’s Biology Letters. Experiments by Matthias Foellmer and Daphne Fairbairn at the University of California at Riverside show that death is triggered immediately upon insertion of the second of the male spider’s two sex organs, resulting in a seizure that stops his heart within minutes. The researchers speculate that the male’s dead body acts as a temporary chastity belt, preventing the female from mating again and giving his sperm time to fertilize her eggs. The female is completely innocent in her Romeo’s death and she still gets to eat his dead body, with no guilt involved.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 7/01/2003.

People feel pain differently, and brain scans prove it, Robert Coghill of Wake Forest University and his colleagues reported last week in the online edition of the Proceedings of the National Academy of Sciences. In their experiment, the researchers put a heating pad on volunteers’ legs to heat their skin to an uncomfortable 120 degrees Fahrenheit as they scanned the subjects’ brains. They then asked them to rate the pain on a scale from one to 10. The least-sensitive subject rated the pain a “one,” and the most sensitive, “almost nine.” The people who reported higher levels of pain showed increased activation in the primary somatosensory cortex and the anterior cingulate cortex, regions of the brain involved in the perception and processing of pain, whereas those who said the pain was minimal showed little activation of those areas. Coghill, in a press release, stated: “These findings confirm that self-reports of pain intensity are highly correlated to brain activation and that self-reports should guide treatment of pain.”

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 7/01/2003.

The sky’s not the limit for lightning discoveries: In the past few years, scientists have observed new high-altitude electrical phenomena called sprites, elves, and blue jets. Now Han-Tzong Su of National Cheng Kung University of Taiwan and his colleagues report in the June 25 Nature that they’ve observed another new type of lightning — “gigantic jets.” The researchers used low-light cameras to capture images of the gargantuan electrical discharges shooting upward from the tops of thunderclouds over the South China Sea. The jets ascend to the ionosphere — the charged portion of the upper atmosphere — to form vast 50-mile-tall shapes resembling carrots or trees that last less than a second. By feeding negative charge from the thundercloud to the ionosphere, the researchers believe such jets may have a strong influence on what they call “Earth’s global electric circuit.”

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 7/01/2003.

Are you a night owl late for your day job again? Tell your boss to blame your genes. British researchers from the University of Surrey report in Sleep, the journal of the American Academy of Sleep Medicine and the Sleep Research Society, that they have found a link between a person’s preference for nights or days and a gene called Per3. The gene is involved in regulating the body’s internal clock and comes in two forms, long and short. The researchers took cell samples from people’s cheeks and analyzed their DNA and then compared the results to questionnaires given earlier that helped identify the subjects as morning or evening people. Early risers were more likely to have the long version of the gene, whereas night owls were more likely to sport the shorter.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 6/24/2003.

Researchers from the Nara Institute of Science and Technology of Japan are growing decaffeinated coffee plants. Shinjiro Ogita and colleagues report in the June 19 Nature that they have genetically modified coffee plants to repress a key caffeine-making gene, thereby reducing the caffeine content of the engineered plants by up to 70 percent. Coffee is currently decaffeinated in expensive industrial processes that use solvents to get rid of the stimulant — as well as much of the flavor, according to connoisseurs. The modified plants are only a year old and have not produced beans, but the researchers believe that their plants will produce decaf that tastes more like the real thing.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 6/24/2003.

Just like bats (and submarines), dolphins send out sonar signals to navigate as well as home in on prey. They emit high-pitched sounds and then process the echoes that are bounced back from distant objects to obtain a picture of their world. But the problem is, as they get closer to their target, the echo comes back not only faster, but louder, so loud that it could become literally deafening. Bats can decrease the sensitivity of their hearing by flexing their inner-ear muscles to cope with the problem, but dolphin ears are less adaptable. So, how do dolphins keep from going deaf? Whitlow Au and Kelly Benoit-Bird from the University of Hawaii’s Institute of Marine Biology may have solved the mystery. In the June 19 Nature, they report that instead of turning down their receivers, like bats, dolphins can adjust the volume of their sonar clicks as they approach a target.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 6/24/2003.

Hairy humans just aren’t sexy, report British researchers in the Royal Society’s Biology Letters last week. That’s the reason why humans are hairless, instead of furry like almost all other mammals. The old theory of human hairlessness supposes that we lost our body hair to keep cool in hot climates, but Mark Pagel of the University of Reading and Walter Bodmer of Oxford University challenge that assumption. They believe humans became hairless to reduce the amount of disease-carrying parasites that live in fur and to enhance sexual attractiveness. Because humans could respond to their environment by producing shelters and clothing, hairlessness was both possible and desirable since clothing and shelters can be cleaned more easily than fur when infested with bugs. Pagel stated in a press release: “Hairlessness would have allowed humans to convincingly ‘advertise’ their reduced susceptibility to parasitic infection and this trait therefore became desirable in a mate.”

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 6/17/2003.

Art historians know that in 1889 Vincent van Gogh painted one of his masterpieces, “Moonrise,” but they were never able to pinpoint the exact moment portrayed in the painting. (Never let it be said that art historians are less obsessed than scientists in their quest for precise measurements.) Enter astronomer Donald Olson of Southwest Texas State University and his colleagues. As they report in the July issue of Sky & Telescope magazine, the team traveled to Saint-Remy-de-Provence in France to identify the landmarks in the painting. They then consulted topographical and lunar maps, aerial photographs, weather records, and van Gogh’s letters to help them calculate the precise time and date of the painted scene: 9:08 p.m. on July 13, 1889. Our long international nightmare of ignorance is finally over.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 6/17/2003.

Male dragonflies appear to be extraordinarily wily when in pursuit of rivals in their territories: they can fly in such a way that they appear completely motionless to their foes, a technique known as motion camouflage. Akiko Mizutani of Australian National University in Canberra and her colleagues used stereo cameras to precisely capture dragonfly flight maneuvers in three dimensions and then reconstructed dragonfly-eye views of pursuers. Their results, published in the June 5 Nature, show that a male dragonfly can adjust its position relative to a rival so perfectly that its image always appears on the same spot on the rival’s retina. This fools the rival into thinking his pursuer isn’t moving, and can help the pursuer perform sneak attacks. The researchers admit they’re not sure how the dragonflies do the trick, which requires highly accurate flight control and positional sensing.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 6/17/2003.

You don’t usually want to get too close to a colony of seabirds, unless you really enjoy the smell of bird excrement. But perhaps smelling a crested auklet colony wouldn’t be so bad — the highly social Alaskan seabirds (right) give off the citrusy scent of tangerines during their breeding season. And that odor may be more than just a pleasant-smelling anomaly. Julie Hagelin of Swarthmore College and her team reported in the Proceedings of the Royal Society last month that the auklets may use that scent as a communication device. Though odors are a common form of communication in other vertebrate animals, this is the first study to show that birds might use it, too. Continue reading →