Chapter 16. None
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Nishad Karim African penguins communicate feelings such as hunger, anger and loneliness through six distinctive vocal calls, according to scientists who have observed the birds' behaviour in captivity. The calls of the "jackass" penguin were identified by researchers at the University of Turin, Italy. Four are exclusive to adults and two are exclusive to juveniles and chicks. The study, led by Dr Livio Favaro, found that adult penguins produce distinctive short calls to express their isolation from groups or their mates, known as "contact" calls, or to show aggression during fights or confrontations, known as "agonistic" calls. They also observed an "ecstatic display song", sung by single birds during the mating season and the "mutual display song", a custom duet sung by nesting partners to each other. Juveniles and chicks produce calls relating to hunger. "There are two begging calls; the first one is where chicks utter 'begging peeps', short cheeps when they want food from adults, and the second one we've called 'begging moan', which is uttered by juveniles when they're out of the nest, but still need food from adults," said Favaro. The team made simultaneous video and audio recordings of 48 captive African penguins at the zoo Zoom Torino, over a 104 non-consecutive days. They then compared the audio recordings with the video footage of the birds' behaviour. Additional techniques, including visual inspection of spectrographs, produced statistical and quantifiable results. The research is published in the journal PLOS One. © 2014 Guardian News and Media Limited
by Bethany Brookshire The deep ocean has spawned a new record: the longest egg-brooding period. In April 2007, Bruce Robison of the Monterey Bay Aquarium Research Institute in Moss Landing, Calif., and colleagues sent a remote-operated vehicle down 1,397 meters (4,583 feet) into the Monterey Submarine Canyon. There they saw a deep-sea octopus (Graneledone boreopacifica) making its way toward a stony outcrop. One month later, the scientists spotted the same octopus, which they dubbed ‘Octomom,’ on the rock with a clutch of 155 to 165 eggs. The researchers returned to the site 18 times in total. Each time, there she was with her developing eggs. Most female octopuses lay only one clutch of eggs, staying with the eggs constantly and slowly starving to death while protecting them from predators and keeping them clean. When the eggs hatch, the female dies. The scientists report July 30 in PLOS ONE that the octopus was observed on her eggs for 53 months, until September 2011, the longest brooding period of any known animal. B. Robison et al. Deep-sea octopus (Graneledone boreopacifica) conducts the longest-known egg-brooding period of any animal. PLOS ONE. Published online July 30, 2014. doi: 10.1371/journal.pone.0103437 © Society for Science & the Public 2000 - 2013.
Keyword: Sexual Behavior
Link ID: 19904 - Posted: 07.31.2014
By BRENT STAPLES The federal law that makes possession of marijuana a crime has its origins in legislation that was passed in an atmosphere of hysteria during the 1930s and that was firmly rooted in prejudices against Mexican immigrants and African-Americans, who were associated with marijuana use at the time. This racially freighted history lives on in current federal policy, which is so driven by myth and propaganda that it is almost impervious to reason. The cannabis plant, also known as hemp, was widely grown in the United States for use in fabric during the mid-19th century. The practice of smoking it appeared in Texas border towns around 1900, brought by Mexican immigrants who cultivated cannabis as an intoxicant and for medicinal purposes as they had done at home. Within 15 years or so, it was plentiful along the Texas border and was advertised openly at grocery markets and drugstores, some of which shipped small packets by mail to customers in other states. The law enforcement view of marijuana was indelibly shaped by the fact that it was initially connected to brown people from Mexico and subsequently with black and poor communities in this country. Police in Texas border towns demonized the plant in racial terms as the drug of “immoral” populations who were promptly labeled “fiends.” As the legal scholars Richard Bonnie and Charles Whitebread explain in their authoritative history, “The Marihuana Conviction,” the drug’s popularity among minorities and other groups practically ensured that it would be classified as a “narcotic,” attributed with addictive qualities it did not have, and set alongside far more dangerous drugs like heroin and morphine. © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19903 - Posted: 07.31.2014
By Sandra G. Boodman At first the rash didn’t bother her, said Julia Omiatek, recalling the itchy red bumps that suddenly appeared one day on her palm, near the base of her first and third fingers. It was January 2013 — the dead of winter in Columbus, Ohio — so when the area reddened and cracked a few weeks later, she assumed her problem was simply dry skin and slathered on some cream. Omiatek, then 35, had little time to ponder the origin of her problem. An occupational therapist who works with adult patients, she was also raising two children younger than 3. A few weeks later when her lips swelled and the rash appeared on her face, she decided it was time to consult her dermatologist. Skin problems were nothing new; Omiatek was so allergic to nickel that her mother had had to sew cloth inside her onesies to prevent the metal snaps from touching her skin and causing a painful irritation. Over the years she had learned to avoid nickel and contend with occasional, inexplicable rashes that seemed to clear up when she used Elidel, a prescription cream that treats eczema. But this time the perpetually itchy rash didn’t go away, no matter what she did. Over the course of 11 months, she saw four doctors, three of whom said they didn’t know what was causing the stubborn eruption that eluded numerous tests. The fourth specialist took one look at her hand and figured it out. “The location was a tip-off,” said Matthew Zirwas, an assistant professor of dermatology at the Ohio State University Wexner Medical Center who specializes in treating unexplained rashes. Omiatek’s case was considerably less severe than that of many of the approximately 300 other patients he has treated for the same problem.
Keyword: Pain & Touch
Link ID: 19900 - Posted: 07.30.2014
Posted by Celeste Biever | The four females and one male are onboard a satellite as part of an experiment to investigate sexual activity and reproduction in microgravity carried out by Russia’s space agency. Roscosmos launched the lizards using a six-tonne Foton-M4 rocket on 19 July. But the fate of the tiny cosmonauts became uncertain when their satellite briefly lost contact with ground control on Thursday 24 July. Luckily, technicians managed to restore control on Saturday, and Roscosmos announced on its website that since then it has communicated with the satellite 17 times.”Contact is established, the prescribed commands have been conducted according to plan,” said Roscosmos chief Oleg Ostapenko. Keeping the geckos company are Drosophila fruit flies, as well as mushrooms, plant seeds and various microorganisms that are also being studied. There is also a special vacuum furnace on board, which is being used to analyse the melting and solidification of metal alloys in microgravity. Foton-M4 is set to carry out experiments over two months, and involves a “study of the effect of microgravity on sexual behaviour, the body of adult animals and embryonic development”, according to the website of the Institute of Medico-Biological Problems of the Russian Academy of Sciences, which has developed the project along with Roscosmos. Specific aims of the Gecko-F4 mission include: Create the conditions for sexual activity, copulation and reproduction of geckos in orbit Film the geckos’ sex acts and potential egg-laying and maximise the likelihood that any eggs survive Detect possible structural and metabolic changes in the animals, as well as any eggs and foetuses © 2014 Macmillan Publishers Limited.
Keyword: Sexual Behavior
Link ID: 19896 - Posted: 07.30.2014
By Erik Schechter The folks who brought us the giant, smartphone-controlled cyborg cockroach are back—this time, with a wired-up scorpion. Be afraid. Backyard Brains, a small Michigan-based company dedicated to spreading the word about neuroscience, has been running surgical experiments on these deadly arachnids for the past two months, using electrical current to induce them to strike. Dylan Miller, a summer intern working the project, insists it's the first time that an electrical current has ever been used to remotely induce a scorpion to strike with its pedipalps (claws) and tail. "I was originally looking at how scorpions sense the ground vibrations of their prey," says Miller, a neuroscience major at Michigan State University, "and I just kind of stumbled on this defensive response." In retrospect, it's easy to see how Miller got there. Scorpions use vibrations and their tactile sense to navigate the world, identifying both prey and predator. A touch on the leg, for instance, tells a scorpion that it's under attack, provoking a defensive fight-or-flight reaction—either fleeing from danger or going full-out Bruce Lee. In nature, the scorpion would have to be physically touched for that to happen. But in the lab, an electrode to the leg nerves and a tiny, remote-controlled function generator feeding a signal will do the trick. The scorpion experiments build on the earlier work Backyard Brains has done with cockroaches, namely RoboRoach. A Kickstarter project back in June 2013 and now a real for-sale home kit, RoboRoach enables purchasers to surgically implant a live roach with three sets of electrodes and then control its movement with a smartphone app via a Bluetooth control unit worn on the roach's back. The controversial kit has been criticized as cruel by people like cognitive ethologist Marc Bekoff, but the company argues that RoboRoach's educational "benefits outweigh the cost." Undaunted by the criticism, Backyard Brains co-founder Gregory Gage was already tossing around the idea of robo-scorpions last October. ©2014 Hearst Communication, Inc
Link ID: 19891 - Posted: 07.29.2014
Using data from over 18,000 patients, scientists have identified more than two dozen genetic risk factors involved in Parkinson’s disease, including six that had not been previously reported. The study, published in Nature Genetics, was partially funded by the National Institutes of Health (NIH) and led by scientists working in NIH laboratories. A gene chip. Scientists used gene chips to help discover new genes that may be involved with Parkinson's disease “Unraveling the genetic underpinnings of Parkinson’s is vital to understanding the multiple mechanisms involved in this complex disease, and hopefully, may one day lead to effective therapies,” said Andrew Singleton, Ph.D., a scientist at the NIH’s National Institute on Aging (NIA) and senior author of the study. Dr. Singleton and his colleagues collected and combined data from existing genome-wide association studies (GWAS), which allow scientists to find common variants, or subtle differences, in the genetic codes of large groups of individuals. The combined data included approximately 13,708 Parkinson’s disease cases and 95,282 controls, all of European ancestry. The investigators identified potential genetic risk variants, which increase the chances that a person may develop Parkinson’s disease. Their results suggested that the more variants a person has, the greater the risk, up to three times higher, for developing the disorder in some cases.
By Smitha Mundasad Health reporter, BBC News Scientists have discovered a central hub of brain cells that may put the brakes on a desire to eat, a study in mice shows. And switching on these neurons can stop feeding immediately, according to the Nature Neurosciences report. Researchers say the findings may one day contribute to therapies for obesity and anorexia. Experts say this sheds light on the many complex nerve circuits involved in appetite control. Scientists from the California Institute of Technology suggest the nerve cells act as a central switchboard, combining and relaying many different messages in the brain to help reduce food intake. Using laser beams they were able to stimulate the neurons - leading to a complete and immediate stop to food consumption. Prof David Anderson, lead author of the study told the BBC: "It was incredibly surprising. "It was like you could just flick a switch and prevent the animals from feeding." Researchers then used chemicals to mimic a variety of scenarios - including feelings of satiety, malaise, nausea and a bitter taste. They found the neurons were active in all situations, suggesting they may be integral in the response to many diverse stimuli. BBC © 2014
Link ID: 19887 - Posted: 07.28.2014
|By James Phillips Our inner ear is a marvel. The labyrinthine vestibular system within it is a delicate, byzantine structure made up of tiny canals, crystals and pouches. When healthy, this system enables us to keep our balance and orient ourselves. Unfortunately, a study in the Archives of Internal Medicine found that 35 percent of adults over age 40 suffer from vestibular dysfunction. A number of treatments are available for vestibular problems. During an acute attack of vertigo, vestibular suppressants and antinausea medications can reduce the sensation of motion as well as nausea and vomiting. Sedatives can help patients sleep and rest. Anti-inflammatory drugs can reduce any damage from acute inflammation and antibiotics can treat an infection. If a structural change in the inner ear has loosened some of its particulate matter—for instance, if otolith (calcareous) crystals, which are normally in tilt-sensitive sacs, end up in the semicircular canals, making the canals tilt-sensitive—simple repositioning exercises in the clinic can shake the loose material, returning it where it belongs. After a successful round of therapy, patients no longer sense that they are tilting whenever they turn their heads. If vertigo is a recurrent problem, injecting certain medications can reduce or eliminate the fluctuating function in the affected ear. As a last resort, a surgeon can effectively destroy the inner ear—either by directly damaging the end organs or by cutting the eighth cranial nerve fibers, which carry vestibular information to the brain. The latter surgery involves removing a portion of the skull and shifting the brain sideways, so it is not for the faint of heart. © 2014 Scientific American
Link ID: 19886 - Posted: 07.28.2014
By Michael Brooks Occasionally, scientific research comes up with banal findings that should nonetheless stop us in our tracks. For example, researchers recently published a study showing that a father’s brain will change its hormonal outputs and neural activity depending on his parenting duties. The conclusion of the research is, in essence, that men make good parents, too. Surely this is not news. Yet it does provide evidence that is sadly still useful. Those involved with issues of adoption, fathers’ rights, gay rights, child custody, and religion-fuelled bigotry will all benefit from understanding what we now know about what makes a good parent. The biggest enemy of progress has been the natural world, or at least our view of it. Females are the primary caregivers in 95 percent of mammal species. That is mainly because of lactation. Infants are nourished by their mothers’ milk, so it makes sense for most early caring to be done by females. Human beings, however, have developed more sophisticated means of nourishing and raising our offspring. Should the circumstances require a different set-up, we have ways to cope. It turns out that this is not just in terms of formula milk, nannies or day care: We also have a flexible brain. The new study, published in Proceedings of the National Academy of Sciences, scanned the brains of parents while they watched videos of their interactions with their children. The researchers found that this stimulated activity in two systems of the brain. One is an emotional network that deals with social bonding, ensures vigilance and coordinates responses to distress, providing chemical rewards for behaviours that maintain the child’s well-being. The other network is concerned with mental processing. It monitors the child’s likely state of mind, emotional condition, and future needs, allowing for planning. 2014 © The New Republic.
Keyword: Sexual Behavior
Link ID: 19883 - Posted: 07.26.2014
By James Gallagher Health editor, BBC News website Even low levels of light in bedrooms may stop breast cancer drugs from working, US researchers have warned. Animal tests showed light, equivalent to that from street lamps, could lead to tumours becoming resistant to the widely used drug Tamoxifen. The study, published in the journal Cancer Research, showed the light affected sleep hormones, which in turn altered cancer cell function. UK experts said it was an intriguing finding, but not proven in people. Tamoxifen has transformed the treatment of breast cancer by extending lives and increasing survival times. It stops the female hormone oestrogen fuelling the growth of tumours although the cancerous cells may eventually become resistant to the drug. Light Researchers at the Tulane University School of Medicine investigated the role of the body clock in Tamoxifen resistance. They focused their research on the sleep-promoting hormone melatonin, which normally begins to rise in the evening and continues through the night, before falling away as dawn approaches. However, light in the evening - such as from a smartphone, tablet or artificial lights - can lower melatonin levels. Rats, with human breast cancer and treated with Tamoxifen, were left to sleep in a completely dark cage or one that had dim light. The scientists showed that in dim light, melatonin levels were lower, the tumours were bigger and were resistant to Tamoxifen. A second set of tests showed that giving those mice melatonin supplements kept Tamoxifen working and resulted in smaller tumours. BBC © 2014
Keyword: Biological Rhythms
Link ID: 19881 - Posted: 07.26.2014
by Claudia Caruana GOT that ringing in your ears? Tinnitus, the debilitating condition that plagued Beethoven and Darwin, affects roughly 10 per cent of the world's population, including 30 million people in the US alone. Now, a device based on vagus nerve stimulation promises to eliminate the sounds for good by retraining the brain. At the moment, many chronic sufferers turn to state of the art hearing aids configured to play specific tones meant to cancel out the tinnitus. But these do not always work because they just mask the noise. The new device, developed by MicroTransponder in Dallas, Texas, works in an entirely different way. The Serenity System uses a transmitter connected to the vagus nerve in the neck – the vagus nerve connects the brain to many of the body's organs. The thinking goes that most cases of chronic tinnitus result from changes in the signals sent from the ear to neurons in the brain's auditory cortex. This device is meant to retrain those neurons to forget the annoying noise. To use the system, a person wears headphones and listens to computer-generated sounds. First, they listen to tones that trigger the tinnitus before being played different frequencies close to the problematic one. Meanwhile, the implant stimulates the vagus nerve with small pulses. The pulses trigger the release of chemicals that increase the brain's ability to reconfigure itself. The process has already worked in rats (Nature, doi.org/b63kt9) and in a small human trial this year, where it helped around half of the participants. "Vagus nerve stimulation takes advantage of the brain's neuroplasticity – the ability to reconfigure itself," says Michael Kilgard at the University of Texas at Dallas, and a consultant to MicroTransponder. © Copyright Reed Business Information Ltd.
Posted by Katie Langin In a battle of wits, could a bird outsmart a kindergartner? Don’t be too quick to say no: One clever young bird solved a problem that has stumped 5-year-old children, according to a new study. The bird—a New Caledonian crow named Kitty—figured out that dropping rocks in one water-filled tube was the key to raising the water level in another, seemingly unconnected tube, giving her access to a floating morsel of meat. To solve this problem, Kitty needed to decipher a confusing cause-and-effect relationship, basically akin to figuring out that if you flip a switch on the wall, a ceiling light will turn on. This mental ability was once thought to be restricted to humans, but causal reasoning—the ability to understand cause and effect—has now been identified in a handful of animals, from chimpanzees to rats. Crows are the Einsteins of the bird world, renowned for their ability to make tools and solve complex puzzles. (Watch a video of a New Caledonian crow solving problems.) Their impressive mental capacity was even apparent to the ancient Greeks. In one of Aesop’s fables, a thirsty crow is presented with a dilemma when he cannot reach the water at the bottom of a pitcher. He figures out that the water level rises when he drops pebbles into the pitcher, and many pebbles later he is rewarded with a drink. As it turns out, there’s some truth to this fictional story. A study published earlier this year reported that New Caledonian crows will place rocks in water-filled tubes if they can’t reach a piece of meat that is attached to a floating cork. © 1996-2013 National Geographic Society.
By JAMES GORMAN Any dog owner would testify that dogs are just as prone to jealousy as humans. But can one really compare Othello’s agony to Roscoe’s pique? The answer, according to Christine Harris, a psychologist at the University of California, San Diego, is that if you are petting another dog, Roscoe is going to show something that Dr. Harris thinks is a form of jealousy, even if not as complex and twisted as the adult human form. Other scientists agree there is something going on, but not all are convinced it is jealousy. And Roscoe and the rest of his tribe were, without exception, unavailable for comment. Dr. Harris had been studying human jealousy for years when she took this question on, inspired partly by the antics of her parents’ Border collies. When she petted them, “one would take his head and knock the other’s head away,” she said. It certainly looked like jealousy. But having studied humans, she was aware of different schools of thought about jealousy. Some scientists argue that jealousy requires complex thinking about self and others, which seems beyond dogs’ abilities. Others think that although our descriptions of jealousy are complex, the emotion itself may not be that complex. Dog emotions, as owners perceive them, have been studied before. In one case, Alexandra Horowitz, a cognitive scientist who is an adjunct associate professor at Barnard College and the author of “Inside of a Dog,” found that the so-called guilty look that dogs exhibit seemed to be more related to fear of punishment. Dr. Harris ventured into the tricky turf of dog emotion by devising a test based on work done with infants. © 2014 The New York Times Company
By Phil Plait From the twisted mind of brusspup comes another brain-hurting illusion. This one is really, really convincing, so tell me: When you look at this video, you’re seeing a circle of eight dots rotating as it spins around inside a bigger circle, right? No, you’re not. As brusspup shows, each individual white dot is moving in a straight line! The trick here is two-fold: One is that the dots aren’t moving at constant velocity (you can see that in the video at the 0:44 mark), and that combined their motion mimics what we’d see if a smaller circle is rolling around inside a big one. Try as I may, when I look at this video I can’t make my brain see the dots moving linearly; it looks like a circle rolling. If I focus on one of the dots I can see it moving back and forth along a line, but the others still look like the rim of a circle rolling around. For most illusions there’s a moment when your brain can see what’s going on and the illusion shatters, but not with this one. It’s maddening. When I was a kid, Spirograph was a very popular “game.” It wasn’t really a game, but a set of clear plastic disks with gear teeth around them (or rings with teeth on the inside). They had holes in them; you’d pin a ring down on a piece of paper, then take another disk, place it inside the ring, put your pencil tip in a hole, and roll the inner disk around inside the outer ring. The results were really lovely and graceful interlocking and overlapping curves. If you’re a lot younger than me and missed this craze, here’s a video that’ll help you picture it: © 2014 The Slate Group LLC.
Link ID: 19874 - Posted: 07.24.2014
By Emily Underwood The Broad Institute, a collaborative biomedical research center in Cambridge, Massachusetts, has received a $650 million donation from philanthropist and businessman Ted Stanley to study the biological basis of diseases such as schizophrenia and bipolar disorder. The largest donation ever made to psychiatric research, the gift totals nearly six times the current $110 million annual budget for President Barack Obama’s Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative. Stanley has already given Broad $175 million, and the $650 million will be provided as an annual cash flow on the order of tens of millions each year, with the remainder to be given after Stanley’s death. The gift accompanies a paper published online today in Nature from researchers at Broad and worldwide, which identifies more than 100 areas of the human genome associated with schizophrenia, based on samples from almost 37,000 people with schizophrenia and about 113,000 without the disease. Researchers are likely to find hundreds of additional genetic variations associated with the disease as the number of patients sampled grows, says psychiatrist Kenneth Kendler of the Virginia Institute for Psychiatric and Behavioral Genetics in Richmond, a co-author on the study. Identifying the variants themselves is unlikely to lead directly to new drug targets, Kendler says. Instead, the hope is that researchers at Broad and elsewhere will be able to use those data to reveal clusters of genetic variation, like placing pins on a map, he says. © 2014 American Association for the Advancement of Science.
by Bethany Brookshire Even when we love our jobs, we all look forward to some time away. During the week, as stress builds up and deadlines accumulate, Friday looks better and better. Then, with a sigh of relief, the weekend arrives. But come Monday, it seems like the whole weight of responsibility just comes crashing down again. It’s not just you. Rats feel it, too. Rats given a two-day break from a stressful procedure show more signs of strain on “Monday” than rats who never got the weekend, researchers report July 11 in PLOS ONE. The results show that in some cases, an unpredictable getaway can cause more stress than just working through the pressure. Wei Zang, J. Amiel Rosenkranz and colleagues at the Rosalind Franklin University of School of Medicine and Science in Chicago wanted to understand how changes to a stressful situation alter an animal’s response to stress. Normally, when rats are exposed over and over to a stress such as a restraint (in which a rat is placed in a small tube where it can’t turn around or get out), they begin to get used to the stress. Over a few days, rats stop avoiding the tube and stay calmly in the restraint without struggling, until they are set free. Hormones like corticosterone — which spikes in response to stress — go down. This phenomenon is called habituation. Zhang and colleagues wanted to see what happens when this pattern of stress is interrupted. They restrained rats for 20 minutes each for five days. By day five, the animals were hanging out comfortably in the tubes. Then, the scientists introduced an interruption: They gave half of the rats two days off, a science-induced weekend. The scientists continued to restrain the other group of rats daily. © Society for Science & the Public 2000 - 2013
Link ID: 19872 - Posted: 07.23.2014
By Janice Lynch Schuster I have never been one to visit a doctor regularly. Even though I had accumulated my share of problems by age 50— arthritic knees, poor hearing — I considered myself to be among the mostly well. But 19 months ago I developed a perplexing problem that forced me to become not only a regular patient but also one of the millions of Americans with chronic pain who struggle to find relief, in part through treatment with opioids. The trouble began with a terrible and persistent pain in my tongue. It alternately throbbed and burned, and it often hurt to eat or speak. The flesh looked red and irritated, and no amount of Orajel or Sensodyne relieved it. My doctor suggested I see my dentist; my dentist referred me to an oral surgeon. The surgeon thought the problem was caused by my being “tongue-tied,” a typically harmless condition in which the little piece of tissue under the tongue, called the frenulum, is too short. It seems I have always had this condition but had never noticed, because it hadn’t affected my ability to eat or speak. Now things had changed. The doctor recommended a frenectomy, a procedure to remove the frenulum and relieve tension on the tongue. “Just a snip,” he promised. It sounded trivial, and I was eager to be done with it. Although I make a living writing about health care, I didn’t even bother to do a Web search on the procedure. It never occurred to me that “a snip” might entail some risks. I trusted the oral surgeon.
Keyword: Pain & Touch
Link ID: 19871 - Posted: 07.23.2014
By Sid Perkins Forget the phrase “blind as a bat.” New experiments suggest that members of one species of these furry flyers—Myotis myotis, the greater mouse-eared bat—can do something no other mammal is known to do: They detect and use polarized light to calibrate their long-distance navigation. Previous research hinted that these bats reset their magnetic compass each night based on cues visible at sunset, but the particular cue or cues hadn’t been identified. In the new study, researchers placed bats in boxes in which the polarization of light could be controlled and shifted. After letting the bats experience sundown at a site near their typical roost, the team waited until after midnight (when polarized light was no longer visible in the sky), transported the animals to two sites between 20 and 25 kilometers from the roost, strapped radio tracking devices to them, and then released them. In general, bats whose polarization wasn’t shifted took off for home in the proper direction. But those that had seen polarization shifted 90° at sunset headed off in directions that, on average, pointed 90° away from the true bearing of home, the researchers report online today in Nature Communications. It’s not clear how the bats discern the polarized light, but it may be related to the type or alignment of light-detecting pigments in their retinas, the team suggests. The bats may have evolved to reset their navigation system using polarized light because that cue persists long after sunset and is available even when skies are cloudy. Besides these bats (and it’s not known whether other species of bat can do this, too), researchers have found that certain insects, birds, reptiles, and amphibians can navigate using polarized light. © 2014 American Association for the Advancement of Science
By Katherine Harmon Courage Octopuses do the darndest things. Like kill their mate during mating—by strangling him with three arms, according to new observations from the wild. Enterprising scientists Christine Huffard and Mike Bartick watched wild octopuses in action. They found that, for males, mating can be a dangerous game. Especially when your lady has long limbs. Some of the more dicey encounters are detailed in a new paper, published online July 11 in Molluscan Research. Hold on a second, you say. Strangling octopuses? Octopuses don’t even have necks—or inhale air. So how, exactly, does that work? The strangulation seems to happen when “an octopus wraps at least one arm around the base of the mantle of the competitor” (or mate), Huffard wrote in 2010. This constriction then keeps the octopus from taking in fresh water to run past its gills—starving the animal of its oxygen source. Octopuses are not known to get cuddly with one another on a day-to-day basis. In fact, “octopuses touch each other with their arms primarily in the context of mating and aggression,” the researchers write. And in this case it seems to have been both. Huffard came across a pair of mating day octopuses (Octopus cyanea) near Fiabacet Island in Indonesia. The female, as is often the case in this species, was larger—with a body about seven-and-a-half inches long; the male was closer to six inches long. They were positioned on a reef, outside the female’s den, the male’s mating arm (hectocotylus) inserted into the female’s mantle from a (presumably) safe distance. © 2014 Scientific American
Keyword: Sexual Behavior
Link ID: 19869 - Posted: 07.23.2014