Wrap up: Donors Choose | Bad Astronomy

Posted on by

I want to thank everyone who contributed to the Donors Choose science blogger challenge. Because of you all — 90 people who donated in total coming from this blog and my other outlets like Twitter and Google+ — we raised $5,887, and 2,480 students will see new science materials in their clasrooms!

Wow.

Think about that. Nearly 2500 students, positively affected by strangers who simply want more science taught in school. Some of the donations were for a little bit, and some for a lot, but they all added up to a huge effect on those kids’ lives.

So thank you to every who participated, and know that you have been a great help. And for those of you who donated in the last couple of days, I’ve been told the matching donation email has been sent. Check your inbox, and in just a minute of your time you can double your impact.

Y’all are great. Thanks again.


NCBI ROFL: Gross gods and icky atheism: Disgust responses to rejected religious beliefs. | Discoblog

Posted on by

“Disgust is an emotional response that helps to maintain and protect physical and spiritual purity by signaling contamination and motivating the restoration of personal cleanliness. In the present research we predicted that disgust may be elicited by contact with outgroup religious beliefs, as these beliefs pose a threat to spiritual purity. Two experiments tested this prediction using a repeated taste-test paradigm in which participants tasted and rated a drink before and after copying a passage from an outgroup religion. In Experiment 1, Christian participants showed increased disgust after writing a passage from the Qur’an or Richard Dawkins’ The God Delusion, but not a control text. Experiment 2 replicated this effect, and also showed that contact with an ingroup religious belief (Christians copying from the Bible) did not elicit disgust. Moreover, Experiment 2 showed that disgust to rejected beliefs was eliminated when participants were allowed to wash their hands after copying the passage, symbolically restoring spiritual cleanliness. Together, these results provide evidence that contact with rejected religious beliefs elicits disgust by symbolically violating spiritual purity. Implications for intergroup relations between religious groups is discussed, and the role of disgust in the protection of beliefs that hold moral value.”

Photo: flickr/tonystl
Thanks to bboybutzemann for today’s ROFL!

Related content:
Discoblog: NCBI ROFL: What did God do with Adam’s penis bone?
Discoblog: NCBI ROFL: Disgusting smells cause decreased liking of gay men.
Discoblog: NCBI ROFL: Why does this study make me feel unclean?

WTF is NCBI ROFL? Read our FAQ!


Prediction is very hard | Gene Expression

Posted on by

Nate Silver has an important post, Herman Cain and the Hubris of Experts. It’s not really about Herman Cain. Rather, it’s about the reality that pundits tend to underestimate uncertainty and complexity. Saying you don’t know isn’t as satisfying as making a definitive categorical assertion. This manifests particularly in the domains of sports and politics because there are clear and distinct criteria to assess predictive power. Politicians win or lose elections, while teams win or lose games. And yet despite the long history of minimal value-add on the part of pundits they persist in both domains. Why? I think it’s pretty obviously a cognitive bias toward storytelling. Similarly, in the 1930s the Alfred Cowles concluded that financial newsletters didn’t help their readers “beat the market,” but he also assumed these newsletters would persist. There was a psychological need for them.

The key here is to change the attitude of the pundit class. The populace will always have a preference for stories with plausible and clean conclusions over radical uncertainty. Not surprisingly many professional pundits reacted with hostility to Silver’s observation that they’re quite often wrong. I don’t venture into political punditry often, but when the Democrats passed health care reform I predicted that Mitt Romney would have no shot to win the the Republican nomination. The facts in this case seemed so clear. Romney was going to be walloped over and over again over his record on health care reform when he was governor. I was wrong. Romney may not win, but obviously he’s a contender. My logic was simple and crisp, but the logic was wrong. That’s why you let reality play out. If what was “on paper” determined national elections, then we’d be talking about President Hillary Clinton.

Of course political journalists that engage in analysis still have a role to play. Don’t newspapers have horoscopes and style sections?

My love letter to the makers of Frozen Planet | Not Exactly Rocket Science

Posted on by

The first episode of Frozen Planet – the BBC’s new mega-series on life at the poles, fronted by the peerless David Attenborough – aired on Wednesday. It exceeded my already lofty expectations, and I’ve written a comment piece for the Guardian that’s a bit of a love letter to the makers of the show, the BBC’s Natural History Unit, and the BBC’s attitude to science programmes more generally. Extract below; go read the whole thing.

Giant unicorn-whales with tusks? That’s why I pay my licence fee

Here is what I do when I’m feeling down about the country: I load up the Wikipedia page for the BBC Natural History Unit and click on the “In Production” link. Happy sighs ensue.

The unit’s latest product, aired on Wednesdays, is Frozen Planet, a majestic tour of Arctic and Antarctic wildlife ably narrated by Sir David Attenborough, an 85-year-old man who insists on travelling to the south pole while people many decades his junior make a small noise whenever we sit down.

On the screen, polar bears mate and fight, wolves run down herds of bison and lunging whales create concentric ripples of fleeing fish. It would take several thousands of pounds to see these sights in person, but for £145.50 a year, I can recline on my sofa and watch the world’s jammiest penguin escape from the world’s most incompetent sea lion. From the screen, that velvety voice: “Never have the roles of hunter and hunted been played with so little skill.” Fortunately, the same can’t be said for the people behind the cameras.

Photo via BBC NHU

Study: Killer Whales Migrate Thousands of Miles to…Exfoliate? | Discoblog

Posted on by

orca
Before: scuzzy yellow (top); and after: pearly white! (bottom)

Killer whales are best known for their picturesque profiles and predilection for seal flesh, but they also like to travel, a recent study confirms. And these aren’t your basic joyrides through ice flows. These are 6,200-mile excursions to the tropics, where scientists speculate they engage in a pursuit familiar to anyone who’s headed to a Bermuda spa in February: getting rid of that wintry dead skin.

To get detailed information about whales’ movements, a group of scientists equipped whales with tags that would record swim velocity and current location. At first they just noodled around the Antarctic hunting, a behavior the scientists could identify from the bursts of speed they put on as they went after prey. But then, each in their own time, they started to rocket northwards, moving nonstop until they reached the balmy waters hear Uruguay and southern Brazil, nearly 6,000 miles away. Then, just as suddenly, they whipped around and came back. One whale made the trip in just 42 days.

These trips didn’t happen at any particular time of year, nor did they seem to involve mating or following traveling prey, and those high speeds imply that they weren’t stopping much to eat. The researchers suggest that one explanation for the journeys is that the whales have to get to warmer waters before they can shed their worn-out, outer layers of skin and grow fresh ones—the Antarctic is so frigid that removing a protective layer there could be dangerous. And before and after photos make a strong visual point: this whale is definitely whiter after its trip to tropics than before.

Maybe they get together with these sponge-wielding dolphins and loofah each other up. Cuter things (though not many) have happened.

Images courtesy of John Durban / NOAA via San Diego Union Tribune


A recipe for growing bigger hearts, found in the blood of pythons | Not Exactly Rocket Science

Posted on by

In comic books, many superheroes have gained extraordinary powers after being transfused with the (often modified or irradiated) blood of animals. But, as so often happens, life proves stranger than fiction. At the University of Colorado, Boulder, a group of mice have grown bigger hearts after scientists injected them a chemical cocktail, inspired by the blood of pythons.

When the situation demands it, the muscles of mammal hearts grow larger and pump more vigorously. That’s useful for pregnant women who need to pump for two, toddlers who need to fuel their rapid growth, or athletes who need to power their regularly exercise. But growing hearts can also be bad news if they’re triggered by genetic disorders, high blood pressure or heart attacks. These situations can cause “hypertrophic cardiomyopathy”, where the heart’s thickening walls force it to work harder to pump blood.

To understand how hearts get bigger, Cecilia Riquelme turned to an animal whose heart swells in size every time it eats – the Burmese python. Pythons can swallow extremely large prey like pigs or deer, and they remodel their organs to cope with their meals.  Their intestines and liver nearly double in size and their hearts become 40 percent bigger in just two to three days. For comparison, most mammal hearts only become 10 to 20 percent bigger after months of exercise.

The python’s swollen heart is proportionately mighty. Its vigorous pumping sends oxygen coursing through the snake’s bloodstream, allowing it to up its metabolism by 44 times. Its cells produce more proteins that strip electrons from food molecules and shunt them onto oxygen, producing water and liberating energy. Its blood vessels fill with 52 times the usual level of triglycerides, substances found in fats and oils. Such levels would clog mammal hearts with fat, but the pythons seem immune. These changes turn the snake into a long, supercharged energy-extracting machine

Riquelme discovered that there is something in the python’s blood that triggers the transformation. She extracted plasma from the blood of pythons that had just been fed, and placed it on rat heart cells. They grew in size. Could a protein be responsible? Riquelme used either heat or digestive enzymes to destroy the proteins in the python plasma, but it still managed to engorge the rat cells. Not a protein; something else.

The mystery ingredients turned out to be fats. The blood of fasted and fed pythons contained very different blends of fatty acids, and the team identified three that are particularly important – myristic acid, palmitic acid and palmitoleic acid. Well-fed pythons have lots of all three fats, balanced at a very specific ratio. When Riquelme mixed up this cocktail and injected it into a fasting python, the snake’s heart grew as if it had just eaten a big meal.

This trick isn’t restricted to pythons. The same fatty acid cocktail also increased the size of mouse hearts within a week. The effects were very specific – the cocktail didn’t affect the size of the rodents’ other muscles or livers. The enlarged hearts showed no signs of clumps of fat, or fibrosis – a condition that stiffens the heart and accompanies disease.

The implications are intriguing. Might it one day be possible to give someone the heart of an athlete by administering the right combination of python-inspired fatty acids? “That is the hope, but we are not advocating that people take pills instead of exercising,” says Leslie Leinwand, who led the study. “We are hoping first to show that these fatty acids might be beneficial in the setting of heart disease and it is a long way off to humans from here.”

Reference: Riquelme, Magda, Harrison, Wall, Marr, Secor & Leinwand. 2011.Fatty Acids Identified in the Burmese Python Promote Beneficial Cardiac Growth. Science http://dx.doi.org/10.1126/science.1210558

New Genomics X Prize: Sequence 100 Genomes of 100-Year-Olds | 80beats

Posted on by

oldInsight into long life is one of the new prize’s goals.

In 2006, the Genomics X Prize competition was announced: $10 million for sequencing 100 human genomes in 10 days for $10,000 apiece, to be kicked off in 2013. The idea was to spur innovation in technology by asking the (currently) impossible, the hallmark of the X Prize Foundation.

But while sequencing has gotten cheap, it hasn’t gotten all that much faster in the last five years, and none of the eight teams who signed up have ever gotten to the point where such a short time span could be feasible. So, Archon and Medco, the two companies funding the competition, have revamped the requirements. This week they’ve announced the new, improved Genomics X prize: $10 million for sequencing 100 human genomes in 30 days—but for $1,000 apiece. (Currently, getting your genome sequenced commercially runs about $5000 at the cheapest.) The new version of the competition, which will kick off on January 3, 2013, also has clearer standards for judging: the genomes have to be 98 percent complete and have no more than one error per million nucleotides.

And this time around, they have to be the genomes of old folks—seriously old folks. The foundation is currently recruiting 100 centenarians who will provide samples to the competitors, and the hope is that the competition’s byproducts will include not only revolutionary sequencing technology but insights into the genetics of longevity. No one’s promising a miracle on that front; longevity is hugely complicated, and understanding it will require more than a string of DNA bases.

But the set up alone is great. Picture a hundred people who were born 40 years before the double helix was discovered listening to an eager scientist explain why they really (really!) need to spit into this vial.

[via ScienceInsider]

Image courtesy of Monrovia Public Library / flickr


Scientists: Scamming America | Cosmic Variance

Posted on by

From The Daily Show, via Why Evolution is True, here’s a hard-hitting expose on the slick con called “science” that is scamming America.

The Daily Show With Jon StewartMon – Thurs 11p / 10c
Weathering Fights – Science – What’s It Up To?
http://www.thedailyshow.com
Daily Show Full EpisodesPolitical Humor & Satire BlogThe Daily Show on Facebook

I am generally a fan of the two-party system. Sadly, at the moment in this country, one of the parties is completely crazy.

Update: Sorry that the video isn’t available outside the U.S. Note that Lisa Randall was a guest earlier on the show.


From unknown cancer gene to potential cancer drug | Not Exactly Rocket Science

Posted on by

It’s a seemingly simple idea: if you can find the genetic changes that turn normal cells into cancerous ones, you could find new ways of treating cancer. But that’s easier said than done. The genome of a cancer cell is a chaotic mess. Typos build up throughout its DNA, corrupting the encoded information. Entire sections can be flipped, relocated, doubled and deleted. Some of these changes drive the cells to grow and multiply uncontrollably; others are irrelevant passengers that are just along for the ride. Separating the former form the latter is like finding a needle in a haystack made of needles.

And that’s exactly what Elisa Oricchio from the Sloan-Kettering Memorial Cancer Center has done. Using powerful genetic techniques, she has identified a gene – EPHA7 – whose loss can lead to a sluggish but hard-to-treat type of lymphoma called follicular lymphoma. The gene encodes a protein of the same name, and Oricchio even used the EPHA7 protein to shrink the size of tumours in mice with lymphoma.

Oricchio is still a long way from a drug that could treat human patients, but she has already taken several important steps. Mere months ago, no one knew about EPHA7’s role in lymphoma. Now, the team is already working on developing it into a potential treatment. It’s a stark reminder of the power of modern genetics, and the promise that it heralds for cancer research.

Follicular lymphomas tend to grow slowly, and while they’re incurable, they can also be kept under control for years or decades. With the use of new antibodies like rituximab, people could soon expect to survive up to 20 years after a diagnosis. That all sounds rosy, but these cancers are very common and many people suffer multiple relapses. The laid-back tumours also have a habit of transforming into a much more aggressive type that’s hard to treat and spreads rapidly.

Oricchio analysed the genomes of 64 follicular lymphomas and found 92 genetic changes that occurred in at least ten percent of them. One such change stood out – a quarter of the tumours were missing a big chunk of their sixth chromosome called 6q. Other studies have found something similar, and some scientists have shown that people who are missing this segment have poorer odds of survival. There must be something in the missing segment that normally keeps cancer at bay, but it’s so large and varied that the identity of the key gene (or genes) isn’t obvious.

To narrow things down, Oricchio systematically silenced every single gene within the missing piece of chromosome. She used small RNA molecules designed to take them out of play individually. Again, one candidate stood out – EPHA7. Without it, mice were more likely to develop follicular lymphomas, and they did so more quickly. “We have known for a long time that 6q is deleted in many cases of lymphoma, but until this study, we had little information as to which genes might be implicated,” says Peter Johnson from the University of Southampton, who wasn’t involved in the study.

When Oricchio looked at a broader collection of follicular lymphomas, she found that EPHA7 is completely inactivated in around three quarters of them. Whether deleted outright or tagged in way that makes it unreadable, it no longer does its job.

EPHA7 is a jack of many trades: it helps to carry chemical signals between cells, it’s active when embryos are developing, and it’s important for the development the nervous system. The gene produces two different proteins – a full-length version that stays on the surface of cells, and a shortened one that can be shed. Oricchio found that white blood cells (the ones that give rise to lymphomas) only produce the shortened version. This abridged protein blocks a network of genes that can fuel the development of lymphoma. EPHA7, it turns out, is a “tumour suppressor”, one of a number of genes that keep cancers in check.

So, losing the EPHA7 gene, and the short protein that it produces, increases the risk of lymphoma. But how do you fix the problem? One option would be to go into the cells and add back the missing gene. But there was an alternative. The EPHA7 protein is shed from cells and dissolves in liquid, so it should be possible to compensate for its loss by simply purifying it and injecting it back into tumours.

Oricchio did just that, and found that the restored protein can protect against tumours. In mice with human lymphomas, the extra dose of EPHA7 stopped the cancer cells from growing, prompted them to kill themselves, and forced the tumours to shrink. Oricchio even managed to target the protein directly to the tumours, by fusing it to an antibody called rituximab, which homes in on lymphoma cells. The antibody acts as a guidance system that sends an EPHA7 missile to the right target.

EPHA7 is also lost in other types of lymphoma and possibly other types of cancer, including prostate, lung, stomach and bowel. Perhaps restoring the missing protein could also help to treat these cancers. There’s still a lot of research to do, though. Next, Oricchio wants to work out which part of the EPHA7 protein keeps lymphoma at bay, for a smaller fragment would be easier to make and deliver. She also wants to compare the protein to current treatments, such as rituximab on its own.

As Erika Check Hayden brilliantly argues here, simply sequencing the genes of a cancer isn’t always enough to pinpoint clues that will lead to treatments. However, sequencing might hold more promise when people combine it with other powerful genetic techniques, as Oricchio has done. “This is a great example of how new genetic studies can not only dissect out the genes involved in lymphoma development, but can also point out whole new lines of treatment, using changes in the malignant  cells as their Achilles’ heel,” says Johnson.

Reference: Oricchio, Nanjangud, Wolfe, Schatz, Konstantinos, Mavrakis, Jiang, Liu, Bruno, Heguy, Olshen, Socci, Teruya-Feldstein, Weis-Garcia, Tam, Shaknovich, Melnick, Himanen, Chaganti & Wendel. 2011. The Eph-Receptor A7 Is a Soluble Tumor Suppressor for Follicular Lymphoma. Cell http://dx.doi.org/10.1016/j.cell.2011.09.035

Image by Euthman

1000 Genomes Tutorial | Gene Expression

Posted on by

I don’t have time for this, but I’m sure some readers do. 1000 Genomes has put a tutorial up. Breakdown:

1. Description of the 1000 Genomes Data, Gabor Marth pdf|pptx

2. How to access the Data, Paul Flicek pdf|pptx

3. Lessons in variant calling and genotyping, Hyun Min Kang pdf|pptx

4. Structural Variants, Ryan Mills pdf|pptx

5. Imputation in GWAS studies, Bryan Howie pdf|pptx

 

All Slides in PDF

America has had ‘non-Christian’ presidents! | Gene Expression

Posted on by

A few weeks ago over at Slate Dave Weigel stated that “Electing Mitt Romney in 2012 would mean electing, for the first time, a president whose religion is not part of orthodox Christianity.” I tweeted to Weigel that this was just plain wrong. There have been plenty of presidents who rejected orthodox Christianity, the last one being William Howard Taft, a Unitarian who rejected the Trinity. And now Jeffrey Goldberg is saying the same thing in Bloomberg View:

But theological honesty demands that we recognize that. Romney would be the first president to be so far outside the Christian denominational mainstream.

There is much in Mormonism that stands in opposition to Christian doctrine, including the belief that the Book of Mormon completes the Christian Bible. Christianity had an established creed about 1,500 years before Joseph Smith appeared in upstate New York with a new truth, codified in the Book of Mormon, which he said was revealed to him by an angel named Moroni.

“The Nicene Creed and the Apostles’ Creed settled the basic ideas of Christianity,” said Michael Cromartie, an evangelical who is vice president of the Ethics and Public Policy Center in Washington. “The canon was closed, and then Joseph Smith comes along and says that there’s a new book, an extra-biblical addition to the agreed-upon canon.”


I know this is a science blog, but sometimes I frankly can’t stand how little specific information generalist pundits seem to have (though Jeff Goldberg is famous for being the guy who got promoted after convincing many liberals of the feasibility and justice of the Iraq War, so perhaps I shouldn’t be surprised). Here’s a “fact check.” Four American presidents have been Unitarian.

In the United States Unitarianism evolved out of the liberal wing of the Congregational movement (in New England most Unitarian churches used to be Congregational churches, with King’s Chapel in Boston being the primary exception). Today Unitarianism is predominantly a non-Christian denomination, with about a half and half split between ‘humanist’ and ‘theist’ Unitarians. But in the 18th, 19th, and early 20th centuries Unitarians were generally Christian in self-conception, though they rejected the Trinity as outlined in the Nicene Creed. Thomas Jefferson was never an avowed Unitarian, but his personal correspondence indicates that his views toward religion were in line with more radical Unitarians during his presidency, though he did become more of a liberal Episcopal Christian in his later years. It has to be remembered that Jefferson invited Thomas Paine back to the United States in 1802. Keep in mind that Paine was the Christopher Hitchens of his day when it came to religious opinions (Christian churches would not take his body for burial upon his death because of his reputation).

Jefferson’s religious heterodoxy can be understood best by observing the substance of the Bible he produced by redacting much of the material. In content:

The Life and Morals of Jesus of Nazareth begins with an account of Jesus’s birth without references to angels, genealogy, or prophecy. Miracles, references to the Trinity and the divinity of Jesus, and Jesus’ resurrection are also absent from The Life and Morals of Jesus of Nazareth…It does, however, include references to Noah’s Ark, the Great Flood, the Tribulation, and the Second Coming, as well as Heaven, Hell, and the Devil.

There is a movement in the United States to erase the reality of the heterodoxy of these early Founding Fathers from historical memory, and that movement originates out of the evangelical Protestant Right which puts a premium on theological orthodoxy, and cannot brook the fact that the more prominent Founders were not Christians as they would understand it. Strangely these views are now spreading through repetition. I recall running into a doctor a few years ago who was raised evangelical in Texas who told me that “of course the Founders were orthodox Christians….” This person is no longer an evangelical, and was totally taken aback when I corrected the fake history he’d been fed in Sunday School.

Now, it must be remembered that the Founders themselves conceived of themselves as Christians. Unitarian Christians of the period believed themselves to be the real Christians. Even many of the heterodox Founders with Deist sympathies like Jefferson perceived the Christianity of their day to be in a degraded condition. Kind of like Mormons.

Hagfish filmed choking sharks with slime, and actively hunting fish | Not Exactly Rocket Science

Posted on by

The hagfish looks like an easy meal. Its sinuous, eel-like body has no obvious defences, but any predator that moves in for a bite is in for a nasty surprise. The hagfish releases a quick-setting slime that clogs up the predator’s gills, causing it to gag, choke and flee. Scientists have known about this repulsive defence for decades, but Vincent Zintzen has finally filmed it in the wild. His videos also prove that hagfish, generally thought to be scavengers of the abyss, are also active hunters that can drag tiny fish from their burrows.

Hagfish are sometimes classed as fish although that’s in dispute, for they lack both backbones and jaws. Instead, their mouths contain a wide plate of cartilage, armed with two rows of horny teeth. It uses these to rasp away at carcasses that sink from above. Watch a dying whale settle on the ocean floor, and it will soon be covered in writhing hagfishes.

They are disgusting feeders. They burrow deep into corpses and eat their way out, and can even absorb nutrients through their skin. And if they’re threatened or provoked, they produce slime – lots of slime, oozing from the hundreds of pores that line their bodies. The slime consists of large mucus proteins called mucins, linked together by longer protein threads. When it mixes with seawater, it massively expands, becoming almost a thousand times more dilute than other animal mucus.

A single hagfish can clog a bucket of water within minutes, and in 2006, Jeanette Lim showed that the slime can equally clog the gills of predators. But until now, no one had ever seen the animals use this defence against an actual predator. They have mostly been filmed at whale carcasses with remote vehicles; their predators had a glut of whale meat at hand, and may have been put off by the noisy, bright vehicles. Instead, Zintzen filmed hagfish in more natural conditions, using a network of baited cameras. “Our units are not moving, producing minimum noise and using lights emitting only in the blue to avoid deterring the fauna,” he says.

You can see the results below. The hagfish in the videos are attacked by sharks, conger eels, wreckfishes and more. In less than half a second, the predator’s mouth and gills are filled with slime. It leaves, gagging and convulsing, slime hanging in long wisps from its head. Even voracious seal sharks turn tail. The cameras didn’t follow the fleeing predators, so Zintzen doesn’t know if they eventually died or if the slime dissolved away. Either way, the hagfish, uninjured and oblivious, just carried on feeding. Its defence is so effective that it can totally ignore the fact that a shark just tried to bite it.

The slime could also give the hagfish a competitive edge among other scavengers. If many hagfish were feeding off Zintzen’s bait, it soon became draped in slime. The mucus puts off fish competitors, allowing the hagfish to monopolise their morsels.

Zintzen also filmed some hagfish hunting, a behaviour that had been suspected but never witnessed. While they’re typically regarded as scavengers, some scientists have suggested that their numbers are so great that they couldn’t possibly be sustained by corpses alone. On top of that, some people have found the flesh of prawns, worms and fish among the stomach contents of hagfish.

Zintzen filmed slender hagfish chasing after red bandfish, ensconced in sandy burrows. The hagfish completely ignored the bait that Zintzen was offering. Instead, they seemed to search the ocean floor for hidden burrows, using the whisker-like barbels on their faces. Once they found an entrance, they rapidly burrowed inside, emerging several minutes later.

“When I first reviewed this video, I thought: those hagfish are not very clever. They have the bait right above their head and they keep on searching the sediment for it.” Then, Zintzen noticed one particular hagfish that had stuck the front third of its body inside a hole. It twisted its body into a knot, using it for leverage to push against the sediment. Twenty seconds later, it withdrew from the burrow with a red bandfish, dead and motionless, in its mouth. “I then only understood what was actually happening: they were hunting!”

Hagfish are well known for their ability to tie themselves in knots, which can travel down the length of their bodies. This could help to clear their own bodies of slime (they can choke on their own mucus) or free themselves from the grip of a predator. Here, the knot seemed to give the hagfish leverage for pulling the bandfish from its burrow. Zintzen thinks that the hagfish may even have used its mucus as an offensive weapon, to choke the bandfish inside its burrow.

Hagfish have been swimming in the oceans for 300 million years, and there are 77 species spread all over the world. While the jawed fishes have undoubtedly taken over the seas, the hagfishes have clung on. They have a defence that makes them all but untouchable. Their only predators are either very large fish whose gills are too big to clog, or mammals, which don’t have gills and whose stomachs can easily digest or expel the slime. They also have a versatile style of feeding that includes scavenging, opportunistic feeding and active hunting.

“They are fantastic animals, but most probably, you need to be a scientist (and a somewhat strange one) to state this and love them,” writes Zintzen.

PS It’s sad that this paper didn’t come out on October 16th, which was designated as Hagfish Day.

Reference: Zintzen, Roberts, Anderson, Stewart, Struthers & Harvey. 2011. Hagfish predatory behaviour and slime defence mechanism. Scientific Reports. http://dx.doi.org/10.1038/srep00131

Images and videos by Zintzen et al.

More on hagfish: When diving into food, why not absorb it through your skin?

Wolves May Not Need to be Smart to Hunt in Packs | 80beats

Posted on by

Wolves have been observed working together to ambush a prey animal, leading researchers to consider whether they are displaying foresight, planning, and other signs of impressive smarts. But new work suggests that as long as each wolf obeys a couple simple rules, the seemingly complex behavior emerges naturally, without any need for higher intelligence.

Using a computer model, researchers had each virtual “wolf” follow two rules: (1) move towards the prey until a certain distance is reached, and (2) when other wolves are close to the prey, move away from them. These rules cause the pack members to behave in a way that resembles real wolves, circling up around the animal, and when the prey tries to make a break for it, one wolf sometimes circles around and sets up an ambush, no communication required.

Just because certain aspects of pack hunting could be emergent—arising from the interplay of certain basic rules—rather than the fruits of intelligence doesn’t mean that they necessarily are, nor does it mean that wolves are dumb. But it does suggest that pack hunting isn’t necessarily the reason that wolves form packs, which opens up space for evolutionary biologists to jump and discuss why, if not for hunting, wolves live the way they do.

[via New Scientist]

Image courtesy of Doug Smith / US Park Service

 


NCBI ROFL: How to make pooping babies more appealing. | Discoblog

Posted on by

 When Pooping Babies Become More Appealing: The Effects of Nonconscious Goal Pursuit on Experienced Emotions.

“In this report, we argue that the intensity of the emotions people experience is partly determined by the goals they nonconsciously pursue, and that this effect is functional in nature: Emotions are modulated in ways that may increase the probability of goal achievement. To test this hypothesis, we primed female participants with a motherhood goal and then measured their level of disgust in response to mildly disgusting pictures. Priming led to a reduction of disgust in response to goal-relevant stimuli (e.g., pictures of babies with runny noses) but not goal-irrelevant stimuli. This effect was moderated by the women’s probability of conception, a proxy of their ability to pursue the motherhood goal.”
|
|
|

Photo: Flickr/nateOne

Related content:
Discoblog: NCBI ROFL: Get this baby out of me!
Discoblog: NCBI ROFL: When life gives babies lemons, they make cute faces.
Discoblog: NCBI ROFL: Finally, science brings you…the baby poop predictor (with alarm)!

WTF is NCBI ROFL? Read our FAQ!


Guest Post: Don Page on Quantum Cosmology | Cosmic Variance

Posted on by

Following the guest post from Tom Banks on challenges to eternal inflation, we’re happy to post a follow-up to this discussion by Don Page. Don was a graduate student of Stephen Hawking’s, and is now a professor at the University of Alberta. We have even collaborated in the past, but don’t hold that against him.

Don’s reply focuses less on details of eternal inflation and more on the general issue of how we should think about quantum gravity in a cosmological context, especially when it comes to counting the number of states. Don is (as he mentions below) an Evangelical Christian, but by no means a Young Earth Creationist!

Same rules apply as before: this is a technical discussion, which you are welcome to skip if it’s not your cup of tea.

———————-

I tend to agree with Tom’s point that “it is extremely plausible, given the Bekenstein Hawking entropy formula for black holes, that the quantum theory of a space-time , which is dS in both the remote past and remote future, has a finite dimensional Hilbert space,” at least for four-dimensional spacetimes (excluding issues raised by Raphael Bousso, Oliver DeWolfe, and Robert Myers for higher dimensions in Unbounded entropy in space-times with positive cosmological constant) if the cosmological constant has a fixed finite value, or if there are a finite number of possible values that are all positive. The “conceptual error … that de Sitter (dS) space is a system with an ever increasing number of quantum degrees of freedom” seems to me to arise from considering perturbations of de Sitter when it is large (on a large compact Cauchy surface) that would evolve to a big bang or big crunch when the Cauchy surface gets small and hence would prevent the spacetime from having both a remote past and a remote future. As Tom nicely puts it, “In the remote past or future we can look at small amplitude wave packets. However, as we approach the neck of dS space, the wave packets are pushed together. If we put too much information into the space in the remote past, then the packets will collide and form a black hole whose horizon is larger than the neck. The actual solution is singular and does not resemble dS space in the future.”

So it seems to me that, for fixed positive cosmological constant, we can have an arbitrarily large number of quantum states if we allow big bangs or big crunches, but if we restrict to nonsingular spacetimes that expand forever in both the past and future, then the number of states may be limited by the value of the cosmological constant.

This reminds me of the 1995 paper by Gary Horowitz and Robert Myers, The value of singularities, which argued that the timelike naked singularity of the negative-mass Schwarzschild solution is important to be excluded in order to eliminate such states which would lead to energy unbounded below and instabilities from the presumably possible production (conserving energy) of arbitrarily many possible combinations of positive and negative energy. Perhaps in a similar way, big bang and big crunch singularities are important to be excluded, as they also would seem to allow infinitely many states with positive cosmological constant.

Now presumably we would want quantum gravity states to include the formation and evaporation of black holes (or of what phenomenologically appear similar to black holes, whether or not they actually have the causal structure of classical black holes), which in a classical approximation have singularities inside them, so presumably such `singularities’ should be allowed, even if timelike naked singularities and, I would suggest, big bang and big crunch singularities should be excluded. Perhaps one can postulate that one should restrict to states of immortal de Sitter spacetime, which has no timelike naked singularities anywhere, and which is asymptotically a single region in the very distant past that is locally de Sitter (though globally it can be highly distorted) and which is also asymptotically a single region in the very distant future that is likewise locally de Sitter, without any big crunch or big bang singularities in between, or between more than one asymptotic region (as one would expect to get from perturbations of the Nariai metric that lead to asymptotic de Sitter regions separated by big bang and big crunch singularities). Such singularities might be considered mortal wounds for de Sitter, allowing an infinite number of states to fester up from such wounds, killing the hope for a finite number of states and for unitarity. On the other hand, a localized black hole that forms within de Sitter could be considered a wound that is not mortal and which can be healed by Hawking evaporation without going outside the assumed finite number of quantum states for immortal de Sitter with a strictly positive cosmological constant. I have considered such a possibility in my paper No-Bang Quantum State of the Cosmos.

On the other hand, even if we find such a restriction for positive cosmological constant to a finite set of states, the number of such states for the observed tiny value of the cosmological constant seems so huge that it would seem surprising to me if most of them can explain our observations, so I now am skeptical of the maximally mixed state I proposed in No-Bang Quantum State of the Cosmos and now tend to prefer a pure state like what I proposed in Symmetric-Bounce Quantum State of the Universe. When coupled with a solution to the measure problem, such as what I proposed in Agnesi Weighting for the Measure Problem of Cosmology, this pure state seems to be consistent with all our observations, though of course these are highly preliminary proposals and are not yet fully precisely specified, nor are they nearly so simple and esthetically pleasing as I would hope for in a final complete theory of the universe. We would like a simple quantum state for the universe and simple rules for extracting the probabilities of observations from it. (In The Born Rule Dies and in related papers, I showed that the Born rule, interpreted mathematically in the form that probabilities of observations are expectation values of projection operators, does not work in a universe large enough for multiple copies of an observation, but the probabilities still could be expectation values of other quantum operators, though it is so far unknown what they should be; this knowledge would be a solution of the measure problem if the quantum state were also known.)

Some people seem to prefer the simple state that is the maximally mixed state out of a finite-dimensional Hilbert space, but if this does not explain our observations, I see no objection to postulating that the state is some other simple state, perhaps (but not necessarily) a pure state. By Occam’s razor, we scientists tend to ascribe higher prior probabilities to simpler theories, so we would tend to prefer a simpler quantum state, but I don’t think we should take so narrow a view that such a simple state has to be a thermal state, or a maximally mixed state.

Now even if the quantum state of the universe is chosen (perhaps as a simple mixed state, perhaps as a simple pure state) from a finite set of states, or even if it is a particular pure state, I’m agnostic as to whether or not this could be a state with eternal inflation. Eternal inflation may lead to a huge universe in which there are an arbitrarily large number of nearby states, but those may be states with mortal perturbations (evolving forward and/or backward in time to mortal singularities in a classical description) that would be excluded from the allowed states. So I don’t see that there is any problem with having disallowed states that at some time look nearby to the allowed states. Our universe looks very much as if it could have had a big bang in its past (which would allow an infinite number of states), and presumably a generic quasiclassical perturbation of the present state would evolve back to such a mortal singularity, but the actual state of our universe might have been one of the very large but finite number of states that did not have such a mortal singularity but instead had a bounce. If it did have a bounce, the size at the bounce seems that it might have been much smaller than the throat of de Sitter with the observed value of the cosmological constant, which suggests to me that the quantum state is much more restricted than just the restriction to the large but finite number of states that have bounces rather than mortal singularities.

The question seems to be open, even if the state is immortal de Sitter (by which I mean having a positive cosmological constant but no mortal singularities, not that it is metrically de Sitter or even close to de Sitter), whether this state consists of a superposition of quasiclassical spacetimes with most of them with significant amplitudes having a huge or infinite number of bubbles that keep forming and branching off (and presumably attaching on as well). Even from the considerations of Tom Banks and of my discussion above, I don’t see any obvious reason why it might not. One could presumably have a single simple pure state such that, if it were decomposed into quasiclassical components, would have components that are individually very complex, rather as the binary representation of the Bible, or of the Library of Congress, or of the eprint arXiv, or the entire Internet, or of all the words that have ever been written on earth, is each a very large and presumably very complex integer but is just one component of the set of all integers, which is a simple whole, of which almost all of the separate parts are individually much more complex.

I would guess that presumably at least some quasiclassical components of any simple quantum state that could describe our universe would be very complex and perhaps have a huge number of bubble or pocket subuniverses that could be described as having eternal inflation. Perhaps a more relevant question is whether the probabilities of our observations are given by something like a path integral that is dominated by such eternal inflating spacetimes, or whether the path integral (or whatever procedure gives the quantum probabilities) is dominated by simpler spacetimes, such as ones with only one region and a single bounce. For thermodynamic reasons I presently have some slight personal inclination toward the latter view, that for the dominant contribution it is sufficient to consider only one bounce in the past, at roughly five trillion days ago (an easily memorized value for the age of the universe that fits to four digits the middle of the range of the current measurements of 13.69(13) Gyr), rather than an infinite sequence of bubble formations in my past. Though I am not a Young Earth Creationist as some of my fellow Evangelical Christians are, perhaps I am still a Young Universe Creationist (for thermodynamic reasons rather than for theological reasons, since I personally do not see any theological reason that God could not have created an infinite eternally inflating universe) in the sense that I suspect that most of the quantum amplitude for our observations can be ascribed to quasiclassical universes (or spacetimes in a path integral) that each had its smallest spatial size (say in a foliation of Cauchy surfaces that are closed hypersurfaces of constant extrinsic curvature, to exclude nearly null hypersurfaces of arbitrarily tiny three-volume) not much more than about five trillion days ago. But so far as I can see, this question of whether or not eternally inflating spacetimes are important for the quantum probabilities of our observations is very much an open question, even if the set of quantum states is restricted to be finite or to be a single pure state.


The long shadow of Mt. Rainier | Bad Astronomy

Posted on by

Here in Boulder we get magnificent sunsets, especially in the summer when the clouds interplay with the mountains to the west. But I have never seen anything like this: the shadow of Washington state’s Mt. Rainier cast along the clouds at sunrise:

Holy (yes, in this case appropriately) Haleakala! [Click to cascadenate.]

That’s amazing. Mt. Rainier is a volcano, climbing to a height of over 14,000 feet (4300 meters). There are no other mountains anywhere near that height nearby, so it’s really prominent in the landscape (by comparison, there are several fourteeners, as they’re called, in the Rockies, so they don’t stick out as much though they’re still breathtaking). The rising Sun catches the peak, and the shadow is cast on the underside of the cloud layer. The dramatic sunrise colors really make this an incredibly beautiful shot.

The KOMO news site has lots more pictures of this, too. Go take a look!

And remember, when you’re outside, it always pays to look around you for a moment. You never know what incredible vista nature may have in store for you.

Tip o’ the snow cap (har har) to John Baxter.

Related posts:

- Amazing video of a bizarre, twisting, dancing cloud
- The fist of an angry cloud
- Time spent doing what you love is never wasted
- Windswept clouds over Boulder


Smartphone Apps Tell Your Friends You’ve Been Arrested, Help You Stay Calm in the Clink | Discoblog

Posted on by

Hopefully this guy has the “I’m Getting Arrested” app.

Plan on going to #OccupyWallStreet and getting arrested? There’s an app for that! A Brooklyn programmer (abhorred by getting so much coverage in the “lame-stream” press, no doubt) has made a free android app that allows would-be arrestees to alert their friends. Beforehand, you can program in a message and recipients, who you can alert upon pushing a single button. The app is appropriately called “I’m Getting Arrested.”

Once you’re in jail, you may need help calming down (if you manage to smuggle in your phone). Look no farther than MyCalmBeat, a smartphone app that measures your heart rate and helps you establish an optimal breathing rate, or “resonant frequency.” It works by calculating the breathing rate at which your heart rate has the highest variability, which is correlated with how relaxed you feel. Stressed people, the app’s programmers say, have relatively constant rates of heart rate, which makes stress worse.

Now all we’re missing is an app that redistributes wealth and does our job for us.

Image: WarmSleepy / Flickr


Study Links Fetal Bisphenol A Exposure to Behavioral Problems in Girls | 80beats

Posted on by

A study published this week in the journal Pediatrics found a link between levels of bisphenol-A in pregnant moms and behavioral problems such as anxiety and hyperactivity in their daughters at age 3. No such effects were seen in boys. BPA has estrogen-like activity and can lead to developmental and behavioral problems in animals—but whether or not it does the same in humans, and at what dosages, is a subject of considerable debate. This study won’t settle the debate but highlights the need to answer some basic questions about BPA that remain surprisingly unclear.

What’s the Context:

  • Bisphenol-A is used in many types of plastics like polycarbonate, linings of metal cans, and in receipts (even some labeled “BPA-free”). It shows up in the urine of the vast majority of Americans.
  • Since BPA mimics estrogen in the body, it may effect mental and sexual development, especially if it is present very early in life. For this reason it has been explicitly banned from being used in baby bottles in several European countries, and BPA manufacturers say they don’t sell the chemical to makers of baby bottles.
  • Animal studies show fetal or early-life exposure to the chemical can interfere with mental development and behavior, like hyperactivity and impaired sociality.

How the Heck:

  • 244 pregnant women from Cincinnati, Ohio, had levels of BPA in the urine tested at weeks 16 and 26 of pregnancy, and again within 24 hours of giving birth. BPA levels were also tested in the urine of their children at ages 1, 2, and 3.
  • Behavioral problems were measured by two surveys filled out by parents when the children were 3 years old. The tests sought to identify problems in executive function, depression, anxiety, and attentional deficits.
  • Levels of BPA in the children were not linked to behavioral problems. However, the average level of BPA found in the urine at weeks 16 and 26 did appear related to behavioral issues in the girls (but not boys), namely increased levels of depression, anxiety, and hyperactivity.
  • Researchers don’t know why BPA may impact girls more than boys. They speculate that it may disrupt early neural processes that give rise to behavioral differences between males and females, like aggression and anxiety.

Not So Fast:

  • Critics of this study rightly point out that BPA is quickly metabolized in the body; a 2002 study found its half-life to be about 6 hours. However, a more recent study found that BPA may be metabolized more slowly and that there are significant non-food sources of the contaminant.
  • Another study found that people who ate food with high levels of BPA showed very low levels of it in their blood.
  • It remains unclear exactly how much BPA is absorbed into the bloodstream and how BPA may accumulate in fat stores within the body.
  • Given this uncertainty, measuring urine levels of BPA only twice during pregnancy may not be a good indicator of a fetus’ total BPA exposure. It would be better to measure blood levels of the chemical more often and earlier in the pregnancy.

The Future Holds:

  • Despite the uncertainties in this study, it may make sense for pregnant women to try to limit BPA exposure during pregnancy, especially early on—this can be done by avoiding packaged foods and eating fresh fruits and vegetables, etc.—which is healthy anyway.
  • The FDA says it’s still “looking into” the health effects of BPA, although it remains legal in almost all food containers.
  • There’s enough evidence to curtail our use of BPA, at least in products aimed at pregnant women and infants. This is, of course, easier said than done, considering how cheap, useful, and ubiquitous the chemical is.

Reference: Joe M. Braun, Amy E. Kalkbrenner, Antonia M. Calafat, Kimberly Yolton, Xiaoyun Ye, Kim N. Dietrich, Bruce P. Lanphear. Impact of Early Life Bisphenol A Exposure on Behavior and Executive Function in Children. Pediatrics, Published online Oct. 24, 2011. DOI: 10.1542/peds.2011-1335

Image: katerha / Flickr