A pregnant tsetse fly
The tsetse fly’s claim to fame is spreading the parasite that causes sleeping sickness in Africa. This public health concern has overshadowed much weirder facts about the tsetse, like the fact it gives birth to live, crawling larva—one at a time. (Sound familiar to you, mammal?) They also make “milk” to feed those larvae in utero, which uses some of same enzymes as mammals, according to new study published in the journal Biology of Reproduction. In fact, the sleeping sickness parasite is not even the most interesting organism living inside tsetse flies; no, that distinction would below to a bacterium called Wigglesworthia, without which females are sterile.
It’s time to take a journey through tsetse fly reproduction.
Insects are generally negligent parents: a female lays dozens or hundreds of eggs and flies off, leaving the young to fend for themselves. Most will die but a few will survive to lay hundreds more eggs and keep playing the numbers game. Tsetse flies, not unlike mammals, have taken the opposite tack, investing a whole lot of energy in each offspring. She keeps her eggs and larvae in the safest place possible for the longest time: inside her uterus. That’s the evolutionary explanation for live birth.
Mutated shrimp from Al Jazeera’s video report
Al Jazeera‘s report on seafood in the Gulf Coast reads like a horror story: eyeless shrimp, fish with oozing sores, clawless crabs. Unfortunately these deformities are very real and disturbingly common two years after the Deepwater Horizon oil spill in 2010. Chemical dispersants used by BP to “clean up” the oil spill are the likely cause.
Deformities happen even in ordinary circumstances, but scientists and fishers are seeing them in unprecedented scales in Gulf marine life. For example, half the shrimp caught in a Louisiana bay lacked eye sockets, according to fishers interviewed by journalist Dahr Jamail.
“Some shrimpers are catching these out in the open Gulf [of Mexico],” [commercial fisher Tracy Kuhn] added, “They are also catching them in Alabama and Mississippi. We are also finding eyeless crabs, crabs with their shells soft instead of hard, full grown crabs that are one-fifth their normal size, clawless crabs, and crabs with shells that don’t have their usual spikes … they look like they’ve been burned off by chemicals.
Perhaps the most troubling line in the whole article is this: “Questions raised by Al Jazeera’s investigation remain largely unanswered.” When Jamail went knocking on doors at government and corporate offices, nobody wanted to talk. One scientist he interviews mentions the difficulty in getting funds to study the oil spill’s environmental impact. The Deepwater Horizon oil spill may be rapidly fading in our memories, but its impact on the ocean is not.
Image via Al Jazeera English
Walk through a crowded city and you’re making dozens of instinctive choices: swerve to avoid the guy staring at his Blackberry, walk around those subway grates, speed up so you don’t walk side by side with a stranger, and on and on. While pedestrians aren’t usually thinking too hard about these decisions, scientists are. Over at Slate, Tom Vanderbilt has a four-part series on the history, the science, and the future of walking in American. In part two, about the science of walking, Vanderbilt profiles a company that models how people walk with mathematics:
The Legion model seeks to understand, with each step the pedestrian takes, what their next step will be, based on a mathematically weighted combination of three factors (the tolerance for, and wish to avoid, inconvenience, frustration, and discomfort). More minor things are often observed—people pausing briefly in London before exiting a transit station to see if it’s raining—but not fully modeled yet. (Plottner [Legion's VP] notes the company already has some 9 million pedestrian measurements.)
Mount Everest is often the site of impressive physical feats, as climbers brave brutal conditions to scale the tallest peak in the world. But the extreme altitude takes quite a toll on the body, causing hypoxia, muscle loss, sleep apnea, and other ill effects. Many of the same symptoms are more commonly found in elderly patients suffering from heart conditions or other chronic ailments—meaning Everest provides a natural laboratory for researchers to gain a better understanding of these diseases.
Using carbon nanotubes and a dash of boron, scientists at Rice University have created a sponge that only absorbs oil. The superabsorbent sponge may not be of much use in the kitchen, but selective sucking of oil could be very helpful in cleaning up oil spills in the ocean. Other perks: the nanosponge is attracted to magnets, so that’s they’re easily controlled, and they’re reusable. At the end of this video, grad student Daniel Hashim shows how to extract energy from the oil-soaked nanosponge by burning it. Then you’re left with just the nanosponge, all ready to absorb oil again.
If you want to know what the cool kids will be listening to next month, here are two hints: 1) Head to Atlanta. 2) It’s probably hip hop. That’s according to a recently posted arXiv paper mapping the geographic flow of music on the social-networking music site Last.fm.
Last.fm users sync their iTunes listening histories to the site, recording some 11 billion tracks played in 2011. The site has been a gold mine for data viz lovers like LastGraph, and social-network researchers are getting in on the action, too. In this study, they looked for trendsetting cities that started (and stopped—those snobs) listening to new artists before everyone else. Among American Last.fm users, Atlanta is the trendsetting city.
But when they sorted by music genre, the researchers found subtler patterns. Atlanta dominates the overall music flow mostly because it’s a hip hop center, and hip hop has been ubiquitous to American ears. When it comes to other genres such as indie music, the trendsetting city of North America is further north—much further north—in Montreal.
Update 4/17: The paper’s author, Dutch virologist Ron Fouchier, has announced that he plans on resubmitting his paper to Science without an export permit, regardless of what Dutch authorities decide. Read more at Nature News.
Publication of the controversial mutant avian flu papers have hit yet another roadblock. In March, a US advisory panel reversed its prior decision to take out experimental details from two reports about research that seemed to turn the H5N1 bird flu virus into a more virulent and deadly form. Under the original decision, some redacted information would have been available only to accredited researchers.
But in a new, international twist, one of the papers is encountering another obstacle: NPR reported that the Netherlands-based team behind one of the studies is being stifled by Dutch law, which limits the export of technology that could be weaponized. So now there are two main questions about whether the flu research would be published for all to see: how dangerous the virus is, and whether the Dutch law would apply to this research.
What’s the News: Retrieving a memory in your brain is a bit like taking an old keepsake off the shelf. If you get startled while holding grandma’s old vase in your hands, you could drop and break it. Memory retrieval is just as vulnerable to disruption, and scientists have tried to exploit this fact to erase PTSD-associated memories with drugs.
A new study in Science tries a different tack, using a behavioral approach to rid people of addictions to drugs. Addiction is sometimes treated with “extinction,” which means showing patients drug-related images while they’re off drugs, so that, for example, they stop associating needles with a high. The researchers found that retrieving drug memories right before an extinction session—basically, giving them a short exposure to drug-related stimulus, followed by a similar but longer exposure session—made the treatment more effective in both rats and humans.
The microscopic animals called water bears already have quite a number of accomplishments under their belts. In experiments, they’ve survived the vacuum of space, large doses of radiation, extreme heat, extreme cold, and extreme pressure, giving scientists cause to believe that the little guys could potentially live on other planets and weather long journeys across space (they also make for great tattoos).