Author: Discover Main Feed

There’s an intriguing geoengineering discussion going on here: PRI has brought in the economist Scott Barrett of Columbia, who thinks the economics of geoengineering are just going to be irresistable to most countries, especially when compared with the economics of carbon emissions cuts. That’s a scary thought, although not exactly a surprising one. You can read Barrett’s academic paper on the topic here, and head over here to join in the dialogue it has occasioned. Meanwhile, we’re finishing up the next Point of Inquiry, and I promise my intro isn’t as soapbox long this time. (Hey, I’m learning.) Eli Kintisch was a great guest, so tune in tomorrow….

I’ve got a feature in the latest issue of New Scientist. It’s sort of a four-step guide to interpreting studies looking at genes and behaviour, using one particular gene as a case study. The piece is out today, but it harkens back to lines of thinking that began over a century ago.

Italy, 1876. The criminologist and physician Cesare Lombroso has just published L’uomo delinquente (The Criminal Man), a work that will define European understanding of criminal behaviour for several decades. Lombroso believed that some people were born criminals, whose penchant for crime was set from birth and who had diminished responsibility for their own misdeeds.

Skip forward 133 years, and Lombroso’s theories seem antiquated, even distasteful. Our modern understanding of biology has put paid to simplistic ideas about the origins of criminality and violence. Discoveries from the growing field of ‘behavioural genetics’ show us how nature and nurture conspire to influence our actions. But because of these same discoveries, the idea of the born criminal has resurfaced in modern Italy under a different guise, a century after Lombroso’s death.

Last year, Italian courts cut the sentence of a convicted murderer by one year, on the basis that his genetic make-up supposedly predisposed him to violence. The man, Abdelmalek Bayout, carried a version of a gene called monoamine oxidase A, or MAOA, which has been linked to aggression and violence. The gene has a history of controversy. It has been linked to gang membership and psychological disorders, and it has been used to define an entire ethnic group as warriors.

The story of MAOA is the perfect case study for how gradual revelations about the tango between genes and environment can be translated into unconvincing applications and overplayed interpretations. There is no better example of the dangerous state of modern behavioural genetics, no better poster child for how to miscommunicate, misinterpret and misuse genetic discoveries.

The feature takes the form of four lessons, each covering a different area of research or controversy around MAOA:

1. A catchy name is bound to be misleading
2. Nature and nurture are inextricably linked
3. Beware of reinforcing stereotypes
4. Genes do not dictate behaviour

Go read the article to find out more.

When the topic of flying saucers comes up, someone inevitably talks about the government’s secret installation in the Nevada desert called Area 51. The base has been public knowledge for a long time, though I suspect a lot of folks heard about it through the movie “Independence Day”. The idea is that the alien spaceships that crashed at Roswell New Mexico and other sites were carted off to Area 51, and the technology there examined and reverse engineered to create a lot of modern tech today.

You can just guess what I think of this theory.

But I’ll spell it out: it’s nonsense. Yes, Area 51 exists, but the idea that we keep alien tech there is pretty silly. First, all our technology has a clear line of antecedents; the transistor, velcro, smart metals, and so on didn’t just pop up ex nihilo as some UFO enthusiasts claim.

Second, we have a simpler and more logical line of reasoning here. We know that the military has a black budget to create advanced tech. They don’t want our enemies to know what’s going on, and the Nevada desert is pretty isolated. When the news came out that a base was out there, of course the government’s first line of defense is to deny it. When the rumors and evidence pile up, they admit it exists, but won’t say what it’s for. Of course they don’t! That’s kinda the point of it being a secret.

And we know that advanced tech comes from the military; the SR 71 Blackbird is an incredible piece of engineering, and it was designed in the 1960s. Stealth tech can be thought of in a similar way, and it’s decades old as well. They are clearly designing amazing stuff at Area 51 and perhaps other locations, and this is exactly the sort of hardware that we need to keep secret. Like it or not, there are bad guys out there who would love to see America fall, and this kind of technology helps prevent that from happening.

Jumping from that to harboring aliens and their flying saucers is a wee bit of jump of logic. Of course, I have said for years that I’m sure the government loves the UFO rumors, since it takes the pressure off the real secrets there.

And so it goes: an article in the Statesman corroborates that view. Several Area 51 vets have come out and discussed recently declassified information. My favorite bit is at the very end:

[Area 51 radar specialist] Barnes thinks the Air Force and the CIA didn’t mind the stories about alien spacecraft. They helped cover up the real secret planes that were being tested.

Ya think? Anyway, while I may not be happy with everything that supposedly goes on at Area 51, I can be reasonably — stress the word reasonably — sure that it involves stuff developed right here on good old planet Earth.

Tip o’ the tin foil beanie to James Oberg.

New York City has been attacked by all manner of monsters and alien invaders, but never before have its assailants been so, well, low-res.

A magnificent new video from Patrick Jean and One More Production shows an assault on the city that begins when a stream of pixels explode out of TV screen. Soon, the unwary streets of Manhattan are under attack from pixellated Space Invaders. Pac-Man runs amok in the subway stations, Tetris blocks slam down on skyscrapers, and Donkey Kong stands atop the Empire State Building.

For anyone whose childhood dreams were invaded by these crude villains, the video is pure nostalgic delight. Watch and enjoy.

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For years an obscure doctor hailing from Australia’s hardscrabble west coast watched in horror as ulcer patients fell so ill that many had their stomach removed or bled until they died. That physician, an internist named Barry Marshall, was tormented because he knew there was a simple treatment for ulcers, which at that time afflicted 10 percent of all adults. In 1981 Marshall began working with Robin Warren, the Royal Perth Hospital pathologist who, two years earlier, discovered the gut could be overrun by hardy, corkscrew-shaped bacteria called Helicobacter pylori. Biopsying ulcer patients and culturing the organisms in the lab, Marshall traced not just ulcers but also stomach cancer to this gut infection. The cure, he realized, was readily available: anti­biotics. But mainstream gastroenterologists were dismissive, holding on to the old idea that ulcers were caused by stress.

Unable to make his case in studies with lab mice (because H. pylori affects only primates) and prohibited from experimenting on people, Marshall grew desperate. Finally he ran an experiment on the only human patient he could ethically recruit: himself. He took some H. pylori from the gut of an ailing patient, stirred it into a broth, and drank it. As the days passed, he developed gastritis, the precursor to an ulcer: He started vomiting, his breath began to stink, and he felt sick and exhausted. Back in the lab, he biopsied his own gut, culturing H. pylori and proving unequivocally that bacteria were the underlying cause of ulcers.

Marshall recently sat down with DISCOVER senior editor Pam Weintraub in a Chicago hotel, wearing blue jeans and drinking bottled water without a trace of Helicobacter. The man The Star once called “the guinea-pig doctor” can now talk about his work with the humor and passion of an outsider who has been vindicated. For their work on H. pylori, Marshall and Warren shared a 2005 Nobel Prize. Today the standard of care for an ulcer is treatment with an antibiotic. And stomach cancer—once one of the most common forms of malignancy—is almost gone from the Western world.

Stem cells have been the subject of worldwide scrutiny for years, yet they remain a puzzle. Although they carry the same DNA as regular body cells, they have a uniquely flexible identity that lets them develop into a wide variety of different tissues.

A team led by Joseph Ecker of the Salk Institute for Biological Studies in California recently made significant progress in discerning how stem cells keep their options open. He compared embryonic stem cells with cells from the lung called fibroblasts by analyzing their epigenetics—chemical changes that affect how genes behave without altering their DNA code. One major difference was in methylation, the way in which chemical structures called methyl groups cling to the rungs of DNA…

Dr. Daniel MacArthur points to a long article by Edmund Yong, Dangerous DNA: The truth about the ‘warrior gene’. Dr. MacArthur notes on his twitter account: “Nice piece on behavioural genetics…but should emphasize MOST behav. gene assocs are actually false.” I think he’s pointing to the winner’s curse; there are lots of people studying various topics, but only a subset of studies pass which yield appropriate effect sizes and p-values actually get published. A sequence of such may give a false sense of certitude as to the strength of the association between a locus and a trait, as negative results are not usually published. I hope David Dobbs keeps this in mind in relation to his new book on the ‘orchid hypothesis’. We have decades of research which suggest that a lot of human behavior is due to variation in genes within the population. In other words, many psychological traits and predispositions are heritable. But both the earlier linkage studies and now the associations which try and establish a particular gene as the primary causal factor are much more provisional, and like much of science wrong or ultimately of marginal long term value.

The incredible amount of press which genetics and genomics research with behavioral implications receive in the press is more about our psychology than the state of science as it is now. Similarly, consider the enormous swell of neuroimaging research within the past decade. Both genetics and neuroscience offer up the possibility of establishing a sturdier biophysical grounding for the human sciences, but we shouldn’t get ahead of ourselves. Finally, the fact that we know that psychological traits are heritable is useful in and of itself, whether we know the underlying genetic architecture of the trait or the neurobiology mediating between the genetic and behavioral level. Look to the parents, and you shall know a great deal.

Microorganisms can live the far reaches of the planet, in extreme temperatures and pressures, and in some cases even without oxygen. But now scientists say they have found the first multicellular organisms inhabiting an anoxic environment. In other words: They’ve found the first animals living without oxygen.

They belong to the group called loriciferans, a phylum of creatures that live in marine sediment. About a millimeter long, they look something like a half-jellyfish, half-crab. The beasts live in conditions that would kill every other known animal. As well as lacking oxygen, the sediments are choked with salt and swamped with hydrogen sulphide gas [New Scientist].

Roberto Danovaro and his colleagues, who documented this find in BMC Biology, had been searching the salty, oxygen-free depths of the Mediterranean Sea down below 10,000 feet for life. When previous searches turned up animal bodies, he says, researchers wrote them off, thinking they had fallen to those depths from oxygenated waters closer to the surface. But Danovaro says his team recovered living loriciferans from the area, including ones with eggs.

Unlike plants, all previously discovered animals, and fungi, the newly discovered animal species don’t use mitochondria, the cellular organelle that converts sugar and oxygen into water, CO2 and, energy, to power their cells [Popular Science]. Instead, the animals pack the hydrogenosome organelle, a feature common among the miccoorganisms that live in oxygen-free zones.

Danovaro’s find should lead other life-hunters to start seeking animal life in locations that had been labeled inhospitable to animals, like subduction zones, hydrothermal vents, and other places only simpler organisms had been discovered. And every time we push back the preconceived limits of life on our own planet, it excites those seeking life on others. Says oceanographer Lisa Levin: “Are there metazoans on other planets with atmospheres different from our own?” Levin added. “Our ability to answer this question would be strengthened considerably by more intensive studies of animal-microbe interactions in extreme settings of our own inner space — the deep ocean” [LiveScience].

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Image: Roberto Danovaro

It’s tough work raising teenagers. As if worrying about their studies, drinking, partying, driving, and raging hormones wasn’t all-consuming enough, parents have recently had to fret about their Facebook usage. But one mom in Arkansas may have taken her parental concern too far.

A 16-year-old boy in the town of Arkadelphia is suing his mom, claiming that she hacked into his Facebook account and posted slanderous stuff about him on his page. The teen, Lane New, also alleges that his mom changed his email and Facebook passwords to lock him out of his accounts.

The mom, Denise New, is flabbergasted by the harrassment lawsuit. She says that like any other parent, she was just looking out for her son, and adds that her actions weren’t driven by any malicious intent. She told local TV station KATV:

“I read things on his Facebook about how he had gone to Hot Springs one night and was driving 95 m.p.h. home because he was upset with a girl and it was his friend that called me and told me about all this that prompted me to even actually start really going through his Facebook to see what was going on.”

Denise says she was so upset at what she read on Lane’s profile that she had to post some response on his page–though the specifics of the posts she left haven’t been revealed. Denise New told Associated Press:

“The things he was posting in Facebook would make any decent parent’s eyes pop out and his jaw drop…. He had been warned before about things he had been posting.”

Like any teenager, when Lane found out his mom was snooping around his profile, he wasn’t pleased. But instead of storming off to his bedroom to sulk, Lane slapped mom with a lawsuit. The suit alleges that Denise’s posts contained untrue material, and that they damaged his reputation.

PC World reports that Denise admits to changing the passwords on Lane’s accounts, but denies hacking into his Facebook page; she says the page was left open on her computer.

She also admits to making “maybe three, maybe four actual postings,” but says the rest of it was a “conversation” between her, her son, and his friends.

The teenager has been living with his grandmother over the last five years and Denise says, despite the current suit, she and Lane share a “great relationship.” Denise also issued a warning to parents worldwide via the Associated Press: “If I’m found guilty on this it is going to be open season on parents.”

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Image:Facebook

Duke’s celebrating more than just the return of this season’s NCAA champions… While we’re on the subject of bonobos, it’s worth mentioning that readers in Durham, NC are in for a treat from April 14-17 as the Blue Devils host ‘Primate Palooza’–an initiative to raise awareness for primates. Internationally renowned conservationist Claudine André will be speaking at the university. From the press release: André founded and runs the world’s only sanctuary and release program for orphaned bonobos in the Democratic Republic of Congo. Bonobos, like chimpanzees, are our closest living relative and are highly endangered. However, unlike chimpanzees and humans, bonobos are the only ape that has found a way to maintain peace in their groups. — “Having Claudine here at Duke is a wonderful opportunity to share with students and the general public the difference a single individual can make,” says Duke researcher Brian Hare. “Claudine has done more for bonobo conservation than anyone else in the world. If you want to meet a conservation heroine this is your chance.”
These events are open to the public:
Primate Symposium: Why you need to know you are a primate
5-8 p.m., Wednesday, April 14 Duke faculty studying primates will discuss how knowing you’re …

When you see a flock of birds flying in formation, it might seem like their group dynamics are fairly simple: The one out front leads the way. But does the same birds always take the lead in a group? And do the birds in the back follow the overall leader, or rather the middle managers in front of them?

To find out, Tamás Vicsek and colleagues strapped backpacks equipped with GPS sensors to pigeons for a study out this week in Nature. The lightweight trackers recorded the birds on both solo flights and group flight and measured their positions five times per second. Indeed, Vicsek found, birds fly according to the group pecking order, with the leader out front. When it changed direction, its direct followers would do the same in less than a second, and then the more junior members of the group would respond to the direction of those middle managers.

But there were surprises, too. Sometimes the lead bird wouldn’t fly out front; it may have been tired from leading the pack and needed some time off. So perhaps birds are like cycling teams, occasionally trading off who carries the taxing burden of leading the group.

For more details about the study—including why it’s not as obvious as you might think that the leading bird flies in the front of the group, and why left and right matter so much to pigeons—check out DISCOVER blogger Ed Yong’s post at Not Exactly Rocket Science.

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Image: Zsuzsa Ákos

A freewheeling flock of birds is one of nature’s most endearing spectacles. The flock’s members move with uncanny coordination, changing direction in unison, splitting and reforming, and even landing as one. The intricacies of these synchronised flights are very difficult to entangle. Who is following whom? Is there even a leader and, if so, does the same bird always take up pole position? Our feeble eyes could never hope to discern the answers just by watching a flying flock. But fortunately, we have technology that can do the job for us.

Máté Nagy from the University of Eötvös, Budapest, has found that flying pigeons obey strict chains of command, even when in flight. He used state-of-the-art GPS devices to track the movements of groups of ten pigeons with exquisite sensitivity. The lightweight monitors, just 16g in weight, captured the subtleties of the pigeons’ twists and turns in mere fractions of a second. Back on the ground, Nagy analysed their recordings to show that pigeons fly according to the pecking orders they establish on the ground. The dominant bird takes the lead and the others follow his directions.

Studying the collective movements of animal groups has been a difficult challenge. Many cameras can be used to film animals moving within the same block of space, but the jostling bodies often block one another from view. Mathematical models can tell us about the basic rules that groups of moving animals adhere to, but they are difficult to test in real life.

But our technology has now become advanced enough to start skirting around these problems. For scientists studying birds, the key breakthrough was the creation of sensors that are light enough to be strapped to a flying bird without compromising its aerial abilities. Now, these sensors include GPS devices that can record a bird’s speed and direction every fifth of a second. Nagy attached such devices to 13 homing pigeons and watched as they flew in flocks of 7 to 11 birds.

Nagy catalogued every instance when one pigeon changed direction only to be followed by another. By pooling together this data, he created a network of leaders and followers, showing the relationship of each bird to its peers. This colourful diagram shows one such network. Each circle represents an individual pigeon, the arrows point from a leading bird to one that follows it, and the numbers represent the time delay between the leader’s movements and those of its follower’s.

The networks showed that flocking pigeons maintain a dependable hierarchy on the wing. On average, when a leading bird changed direction, its followers would follow suit after around a third of a second. Birds will consistently copy the movements of specific individuals further up the pecking order and, in turn, they are consistently copied by more junior underlings.

What makes a leading pigeon? It seems that skill counts for something. Nagy released each of his birds on a solo flight, some distance from home. When they returned, he found that those who arrived home quickest were also most likely to wield leadership authority, although this link between navigation ability and seniority wasn’t quite statistically significant.

Indeed, the chains of seniority within pigeon flocks are fairly flexible, changing dynamically from flight to flight. Influential birds tend to remain influential but Tamas Vicsek, who led the study, says, “There are days when the pigeon which takes the role most of the time is less active. Perhaps it did not have a good sleep! During these days some of the birds on lower levels of the hierarchy have their chance to lead.”

Nagy’s data also revealed that leaders do indeed take up pole position at the front of the flock. That may seem intuitively obvious to us, but remember that pigeons have a field of vision that extends for almost a full 360 degrees. When you can easily see individuals flying behind you, the leading bird doesn’t necessarily need to be at the front, and yet it does.

More surprisingly, leaders also tend to stay on the left of the flock. Nagy found that the more time that a bird spent behind a leading partner, the more likely it was to be flying on that partner’s right. There’s an obvious reason for this – like us, pigeons have highly asymmetric brains with each half wielding greater influence over certain thought processes. Their right brain, which receives signals from the left eye, controls the ability to recognise other pigeons. So if a pigeon sees one of its peers through its left eye, rather than its right, it responds more quickly or more strongly.

Reference: Nagy, M., Ákos, Z., Biro, D., & Vicsek, T. (2010). Hierarchical group dynamics in pigeon flocks Nature, 464 (7290), 890-893 DOI: 10.1038/nature08891

Images: by Zsuzsa Ákos

More on bird flight:

• Chasing daylight – tiny trackers reveal the incredible flight plans of the Arctic tern
• Anna’s hummingbird outflies falcons and fighter pilots
• Light-detecting backpacks record the complete migration routes of songbirds

I’ve blogged in the past about Duke primate scientist Vanessa Woods and now I encourage readers to go visit her newest blog at Psychology Today Your Inner Bonobo where she writes about bonobos, sex, and whatever happens to be on her mind on any given day. Besides being one of my best friends, Woods is a fantastic and funny writer, and her forthcoming book Bonobo Handshake debuts in June. Here’s a sample from Tuesday:
‘Can animals be gay?’ – are you serious NYT? Having a story about same sex sex in animals then leaving out bonobos is like writing an article about big ears without mentioning elephants.The science of homosexuality in animals (or socio-sexual behavior) and then you talk about albatrosses?? that don’t even have a clitoris?? Or do they? the point is, even if they do have them, it’s not like you would ever notice. I know the albatrosses are the latest thing, and I love albatross and think it’s really cool the female raise babies together, but does that really compete with two females rubbing their clitorises together with ever increasing frenzy until they orgasm – which by the way helps them reduce social tension and …

Howard Hughes Medical Institute is showing Sean B. Carroll the love today. HHMI named him the next Vice President of Science Education. Since he already has published several popular books I think this turns out to be after the fact recognition of his service in this area. But I noticed in my RSS that HHMI also put out a lavish press release on a paper which just came out by Carroll’s lab, Preexisting Patterns Guide Evolution’s Paintbrush:

One of the enduring mysteries of the animal world is how colored patterns come to adorn different species’ skin, scales, or feathers. Now, a team led by Howard Hughes Medical Institute investigator Sean B. Carroll has discovered how wing spots evolved in a species of polka-dotted fruit fly.

The new studies show that pigment production in the wing is patterned according to the spatial distribution of a molecule that helps sculpt the shape of the body during development. The finding underscores the concept that evolution likes to tinker with existing genetic machinery to evolve new patterns and forms.

Here’s the paper in Nature, Generation of a novel wing colour pattern by the Wingless morphogen:

The complex, geometric colour patterns of many animal bodies have important roles in behaviour and ecology. The generation of certain patterns has been the subject of considerable theoretical exploration, however, very little is known about the actual mechanisms underlying colour pattern formation or evolution. Here we have investigated the generation and evolution of the complex, spotted wing pattern of Drosophila guttifera. We show that wing spots are induced by the Wingless morphogen, which is expressed at many discrete sites that are specified by pre-existing positional information that governs the development of wing structures. Furthermore, we demonstrate that the elaborate spot pattern evolved from simpler schemes by co-option of Wingless expression at new sites. This example of a complex design developing and evolving by the layering of new patterns on pre-patterns is likely to be a general theme in other animals.

In case you don’t know the “back story,” Carroll has gotten into it with other evolutionary biologists such as Jerry Coyne over his interest in particular types of constraints in evolution and development. I’ve heard him be termed the “King of Evo-Devo” in private conversation. What Richard Dawkins did for the “selfish gene” in the 1970s I think Carroll is trying to pull off for gene regulation in this century.

Oh, and by coincidence, I notice that the Sean Carroll has a paper in the current issue of Nature, Infrared images of the transiting disk in the ϵ Aurigae system. You read his take over at his blog.

For a long time now, my day job has been “theoretical physicist,” as a quick glance at my papers will confirm. But it was not always thus! Very few people are actually born as theoretical physicists. When I was an undergraduate astronomy major at Villanova, I wasn’t thinking about quantum field theory or differential geometry; I was working on photometric studies of variable stars. My personal favorite star was Epsilon Aurigae, a mysterious eclipsing binary. One of the very few stars out there that has both a Facebook page and a Twitter feed. And now Epsilon is in the news again!

Among this star’s claims to fame is that it has the longest period of any known eclipsing binary: over 27 years. But it’s not just about facile record-holding; this system is truly puzzling, especially the nature of the secondary (the thing that eclipses the primary star). The basic problem is that the eclipse has a fairly flat bottom, as seen in this light curve from the previous eclipse in 1982-84.

A flat-bottomed light curve is usually associated with a total eclipse; the secondary completely blocks the light from the primary for a while. But in this case, the spectrum of the system seemed to remain unchanged, indicating that most of the light was still coming from the primary star, even in the middle of the eclipse. This led Huang in 1965 to propose a clever model, in which the secondary is actually a disk seen edge-on; the eclipse is therefore not total, but the disk blocks out part of the light without emitting much of its own. And indeed, with modern infrared telescopes we can discern the light from the secondary — it does look like a relatively cold disk, about four astronomical units in radius, with a hot central star.

The 1982-84 eclipse raised a problem with Huang’s model, however. If you look closely at that light curve above, you’ll notice that it gets brighter right near the middle. (The gap in data is from when the star was behind the Sun and unobservable.) Your first guess is that this is probably just a fluctuation in the in brightness of the primary star; but it turns out that this can’t be right. The primary is indeed variable, but its color changes in lockstep with its brightness, an effect that can be measured by observing with different filters. And the mid-eclipse brightening shows no variation in color. It’s not due to variability in the primary; somehow the disk is letting more light past, right during mid-eclipse.

This is where I come in, as an undergrad doing research under Ed Guinan. For my undergraduate thesis, we tried to put together the most sensible picture we could manage of Epsilon Aurigae; our picture has now become the consensus model. (One difference is that we thought the primary was a supergiant, but now it appears that it’s likely to be a smaller star.) As far as the disk is concerned, we built on a variation of Huang’s disk model, due to Wilson in 1971. Wilson suggested that the disk should be thin and tilted, rather than thick and edge-on, with a semi-transparent inner region. In that case, we could imagine that the central star (presumably holding the disk together) could clear out a region near the center, and light passing through that hole could account for the brightening. I wrote a simple computer program (QuickBASIC on an IBM PC!) to calculate the light curve in this model, and we were able to get an extremely good fit to the data. Here’s the killer plot from our paper, with three different models: edge-on thick disk, opaque tilted disk with a central hole, and tilted disk with a central hole surrounded by a larger semi-transparent region.

And now, it’s eclipse time again! (I’m getting old.) Epsilon started going into eclipse in August 2009, right on schedule, and the eclipse is predicted to last until May 2011, so we’re just a bit before mid-eclipse right now. Here’s the current light curve. But technology has advanced quite a bit since my student years. Nowadays, we don’t need to puzzle out the meaning of a light curve and come up with an elaborate story involving tilted disks; we can just take pictures of the thing.

And that’s just what we did. Under the leadership of Brian Kloppenborg and Robert Stencel at the University of Denver, we put together a proposal to observe the eclipse using CHARA, the Center for High Angular Resolution Astronomy. CHARA is an array of optical telescopes on Mt. Wilson that act as an interferometer, enabling extremely high-resolution imaging of astronomical objects. And by “we,” I do mean that I was included in the proposing team — a little return to my roots. My contributions to the final results were not zero, but they were small; the lion’s share of the credit certainly goes to Brian and Bob and the rest of the team.

And our results just appeared in the form of a paper in Nature. Unfortunately behind a paywall, but there is an extensive NSF press release. But who cares about the words? The stunning things are these pictures — you can actually see the disk begin to move across the surface of the star. There’s even a video where you can compare a model to the actual data. Click to embiggen.

I have to admit that, while these images are unambiguously amazing, the result is somewhat bittersweet for me. John Monnier, another one of the team leaders, admits that he was skeptical about all this tilted-disk business; it just seemed like a house of cards. But I wasn’t skeptical for a moment, having gone through the work of trying to fit the data with various different possibilities. The extraordinary thing to me about observational astronomy was always how you could put together an apparently baroque model of some complicated system, just on the basis of a precious few data points, and yet have some degree of confidence that you were on the right track. Reality is very constraining. So in some perverse sense, it almost seems like cheating to actually take pictures of the thing. Where’s the fun in that? (Of course it’s a great deal of fun.)

And now we need to see what happens at mid-eclipse! I predict we’ll be able to image that small central hole we posited many years ago. Not at all certain about that — I suspect the star at the center of the disk is pretty active itself, and there are probably significant variations in the opacity of the central disk region. That’s what data are for. I will always love being a crazy-eyed theoretical physicist, but there’s something uniquely rewarding about digging into the data and coming to an understanding of far-flung pieces of our universe.

Is Drosophila melanogaster, one of science’s favorite creatures, about to lose its name? Rex Dalton at Nature has the story of this taxonomic imbroglio.

[Image by André Karwath aka Aka via Flickr]

Did pregnancy tests help drive frogs extinct around the world? In my latest podcast, I talk to wildlife disease expert Peter Daszak about his research on how germs can drive animal species to extinctions, and jump from animals to us. Check it out.

Transcultural sexology: formicophilia*, a newly named paraphilia in a young Buddhist male.

*The sexual interest in being crawled upon or nibbled by small insects, such as ants

“Children whose species-specific, juvenile sexual rehearsal play is thwarted or traumatized are at risk for developing a compensatory paraphilia. The case of a Buddhist male exemplifies the cross-cultural application of this principle. His syndrome, formicophilia, was endogenously generated without reference to or influence by commercial pornography. The complete causal explanation of paraphilia will require both a phylogenetic (phylismic) and an ontogenetic (life-history) component. The treatment of paraphilia may combine an antiandrogenic hormone with sexological counseling.”

Image: flickr/jurvetson

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Discoblog: NCBI ROFL: Word of the day: cacodemonomania.
Discoblog: NCBI ROFL: You put the deer tongue where?!?

This solar eclipse happens only once every 27 years, and John Monnier was there to see it.

Epsilon Aurigae is a star system about 2,000 light years from Earth. Astronomers have been able to see it for nearly two centuries, and noticed that it dims every 27 years or so. It made sense to assume that they were dealing with a binary star system, with a larger primary star and a smaller secondary star circling around the first. But that didn’t answer all their questions. Why, for instance, did the primary star normally appear dimmer than it should? And if there is a smaller star orbiting the main star, why can’t we see it? To explain that, astronomers developed the unlikely theory that a thick disk of dust was orbiting the smaller star in the same plane as the smaller star’s orbit of the larger star [UPI].

Monnier says he first felt there was a slim probability that this explanation—a secondary star shrouded in dust—was true. To find out for sure, Monnier and his colleagues needed to catch the eclipse when the smaller star passed in front of the larger, and capture really telling images. That’s just what they did. The astronomers used the Michigan Infra-Red Combiner instrument to combine the light entering four telescopes at the CHARA array at Georgia State University. The effect is a virtual telescope that is much larger than its four constituents [Space.com].

The results, published in Nature, were staggering to Monnier. Despite the improbability of the explanation, there was indeed a “thin, dark, dense, but partially translucent cloud” passing in front of the star in the infrared pictures. Monnier says: “It kind of blows my mind that we could capture this. There’s no other system like this known. On top of that, it seems to be in a rare phase of stellar life. And it happens to be so close to us. It’s extremely fortuitous” [Space.com].

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Image: John Monnier

Here’s a new way to prove the maxim that we are what we eat: Take a peek into the teeming universe of bacteria that thrive in a Japanese person’s gut. Trillions of microbes in the gut help digest the foods we eat, and researchers have found that the “gut microbiomes” of Japanese people have adapted over the centuries to help digest seaweed–an integral part of sushi. Remarkably, they adapted by taking in genetic material found in that very sushi.

The new study, published in Nature, reveals that these gut bacteria engaged in a gene swap, grabbing algae-digesting genes from marine bacteria that live on red algae like nori, the seaweed used to wrap sushi. The marine bacteria traveled on the seaweed into human digestive systems, where the crucial genes were transferred to bacteria in the gut.

Scientists stumbled on this swap when they identified a new group of enzymes from the algae-chomping marine bacteria that help the microbes break down the unique carbohydrates in seaweed. When they searched for other organisms that had the same enzymes, they found one match that, oddly, came from a species of bacteria that lived in the gut of a Japanese volunteer. Further study revealed that this species of gut bacteria is seen only in Japanese individuals.

For an in-depth look at what the horizontal gene transfer means and how this could affect your sushi-chomping habits, turn to the new DISCOVER blog Not Exactly Rocket Science and Ed Yong’s illuminating post, “Gut bacteria in Japanese people borrowed sushi-digesting genes from ocean bacteria.”

Related Content:
Not Exactly Rocket Science: Gut bacteria in Japanese people borrowed sushi-digesting genes from ocean bacteria
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80beats: Scientists Sequence DNA From the Teeming Bacterial Universe in Your Guts
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Image: Flickr/johndmelo