If yeast could sing, it might sound something like this.

This single-celled fungus–for which we should give thanks for bread, beer, and wine–can reproduce in several ways. Most of the time, it produces buds that eventually split off as free-living cells of their own. Its daughters are identical to itself, carrying the same two sets of chromosomes. Sometimes, however, life get rough for yeast, and they respond by making spores, each with only one set of chromosomes. Later, when times get better, the spores can germinate. In some cases the yeast cells that emerge just grow and divide. But they can also have sex. One yeast cell merges with another one, combining their DNA to produce a new yeast cell with two sets of chromosomes.

What makes yeast sex especially interesting is that the cells communicate with each other first. A yeast cell produces a pheromone that can cause another cell to stop dividing and start crawling towards the source of the signal. These pheromones divide yeasts into two groups. Yeast cells carry one of two genes for making pheromones and will only mate with yeast cells that produce the opposite type.

But if you surround a yeast cell with a ring of pheromone producers, the yeast will not just pick a partner at random. It will exercise a choice. The cell will measure the pheromones coming from each suitor, and it will creep its way to the strongest source.

Some scientists have suggested that natural selection favors this choice because it lets yeast be efficient about sex. Rather than creep a long way to find a mate, a yeast cell can just love the one it’s with. But there are some problems with this explanation.

First off, yeast make a lot of pheromones–much more than they would need simply to be detected. For another thing, yeast cells vary in how much pheromone they make. A strong pheromone maker will be more likely to attract a mate than a weak one that’s closer. What’s more, when a pheromone-producing yeast cell detects a signal from the opposite mating type, it cranks up its own signal. If you didn’t know better, you might think yeast cells were trying to get some attention.

In fact, some scientists think that yeast are doing exactly that. They argue that yeast cells release pheromones like a love song, in order to attract mates.

Carl Smith and Duncan Grieg, two evolutionary biologists at University College London, wondered if the same pressures drove the evolution of yeast pheromones that have driven the evolution of more familiar kinds of sexual displays, like peacock tails, frog croaks, and elk horns. According to one particularly influential hypothesis, the Handicap Principle, females could benefit from being choosy about mates if that choice led them to have more success reproducing. Of course, a male frog can’t offer a female frog a DNA test documenting his good genes. So he needs some way of advertising his quality. A song or a horn or a fragrance are all possible ways to send this signal.

The problem with this sort of communication is that it can be hacked. A weak male can, in theory, channel some extra energy into building a false sexual display. If some males start to cheat, females who are choosy will end up with no advantage over other females. Female choice will disappear, and male displays will vanish as well.

Honesty is thus crucial to the evolution of sexual displays. And one way for displays to be honest is for them to be expensive. A weak male with fewer resources will have a harder time producing an expensive display than a strong one. In effect, a long-tailed widowbird is saying, “I’ve got so much to offer that I can waste a lot of energy on these magnificent tail feathers.”

To see if yeast were wooing each other with expensive signals, Smith and Grieg disabled the genes in some cells so that they could not make pheromones. Then they compared how fast healthy and engineered yeast cells reproduced asexually. The quiet yeast grew far faster, the scientists found, presumably because they no longer had to use up a lot of energy making pheromones. This result confirmed a key prediction of the handicap principle: a signal has to be costly. In fact, yeasts can suffer a 30% drop in their viability by making pheromones.

But some yeast pay a bigger price than others. Some strains of yeast Smith and Grieg studied carried mutations that caused them to grow relatively slowly, while other cells could grow faster. Smith and Grieg found that when they disabled pheromone genes in low-quality yeast, the cells enjoyed a much bigger boost than high-quality yeast. In other words, making pheromones is a bigger sacrifice for low-quality cells than for high-quality ones. That difference could help ensure that pheromones remain an honest signal.

Finally, the scientists compared how much pheromones each kind of yeast produced. They found that yeast of higher quality churned out more pheromones than yeast of lower quality. So a yeast that chooses to mate with a strong pheromone producer will be endowing its offspring with good genes.

Smith and Grieg’s experiment makes me think about the yeast in a glass of wine in a different way: I now imagine an ocean of love songs. But it also makes me appreciate just how far-reaching Darwin’s ideas about the evolution of sex have turned out to be. The same rules apply–to bird, frog, and fungus alike.

In Israel’s Loewenstein Rehabilitation Hospital, the patient known as LI1 is a prisoner of her own body. She is a 51-year-old woman who was paralysed by a stroke several months ago. Suffering from “locked-in syndrome”, she is completely aware but unable to move or speak. She cannot even control the blinks of her eyes. And yet LI1 has recently been able answer questions from her doctors and communicate with her family through written messages. All she has to do is sniff.

LI1 uses a ‘sniff controller’, an incredible new technology that allows paralysed patients to control machines with their noses. It’s the brainchild of Anton Plotkin and Lee Sela at the Weizmann Institute of Science. Whenever a patient sniffs, the device measures the change in pressure inside their noses. It converts these into electrical signals that are passed to a computer via a simple USB connection. With just a sniff, people can move a cursor on a screen, allowing locked-in patients to write messages. Quadriplegics can even use the device to surf the web, or drive a wheelchair.

This technology was developed almost by accident in the lab of Noam Sobel, who studies the way of brains process our sense of smell. The group use a device called an olfactometer, which produces waves of smell to see how sensitive a person’s senses are. For one of their experiments, the team rigged the olfactometer so that volunteers triggered the odour pulse themselves when they sniffed. “We noticed that sniffs are a very good and fast trigger,” says Sobel. “It then simply dawned on us that instead of triggering odor, we could trigger anything: letters in a text writer or turns of a wheelchair. The rest just flowed (or rather, rushed) from there.” It’s a fantastic example of the useful and unpredictable roads that basic scientific research can lead to.

Steven Laureys, head of the Coma Science Group at the University of Liege, says he had “serious doubts” when he first heard about the device. “But the israeli team clearly proved us wrong,” he says. “It’s a good illustration of creative translational research and how lab-thinking outside the box, combined with a rigorous scientific approach validated in clinical settings, now offers exciting, unexplored tools for locked-in syndrome patients.”

Sniffing may be a simple act but it’s not one to be sniffed at – people have very tight control over the length, intensity, pattern and, obviously, direction of their sniffs. The sniff controller can measure all of these traits, independently of the user’s regular breathing. If the user can breathe on their own, they only need to wear a couple of nasal tubes. If they need the help of a machine to breathe, they have to wear a larger nasal mask.

Plotkin and Sela found that healthy volunteers could use the controller to press a button in a computer game as quickly and accurately as they could with a mouse or joystick. They also developed writing software using the sniff controller. It takes three sniffs to write a character. The first selects one of three blocks containing letters, signs of completed words (much like a predictive text menu). The second selects a line in the chosen block and the third picks a character. A cursor flits between the various options and a sniff chooses the one it highlights. The video below explains how it works.

These trials in healthy volunteers were promising, but LI1 was their first big success. She was so badly paralysed that it took her 19 days to produce a sniff on demand, with 20 minutes of practice a day. But once she gained this ability, she started using the writing software immediately. A few days later, completely of her own accord, she had written her first message to her family – a “very moving” and “unexpected” missive that Sobel is keeping a secret. To this date, the sniff controller is still her only means of expressing herself.

The successes came thick and fast. LI2, a man who had been locked-in for 18 years after a car accident, took to the controller immediately. Within 20 minutes, he had written his own name and he still uses the device. QU1, a quadriplegic woman who can speak with severe difficulty, used the controller to write for the first time in 10 years. After 3 weeks, Plotkin and Sela upgraded her to more advanced software (see video below) that lets her move a cursor by sniffing. She can type on a virtual keyboard, surf the net and even write email. Ten other quadriplegics can do the same.

Writing text is still a long and tedious process. LI1 is one of the quickest users and she only manages around three letters per minute, with one mistake with every six letters. That’s may seem frustrating but the freedom of expression more than makes up for it. As Plotkin and Sela write, “The speed of this self-expression is less important to individuals who, put bluntly, have no other options.” When LI1 and LI2 were asked to suggest improvement to the controller, neither mentioned speed.

Neils Birbaumer, who has worked on communication technologies for paralysed people, thinks that the sniff controller will only work for a small proportion of completely locked-in patients. “Sniffing needs muscular control and a partly intact motor system, but that’s exactly what most patients with ALS or complete locked-in syndrome don’t have,” he explains. Indeed, one patient, LI3, never learned to control his sniffs, even after 2 months of practice. Whether he simply couldn’t muster the right amount of control, or whether he was too severely depressed to learn, the device failed him.

Nonetheless, Sobel is hopeful that the sniff controller will be widely useful. His “pessimistic expectation” is that two-thirds of locked-in patients could use the device. “My optimistic yet not unrealistic expectation would be that nearly all would be able to, at least all those who are locked-in due to stroke or trauma,” he says. “Those with ALS may be worse-off at the end stage.” However, he’ll need to test the device on many more patients first.

There are other possible ways locked-in patients to communicate. “Brain-computer interfaces”, which allow users to control cursors through thought alone, are the most promising avenue yet, but they’re still in their infancy. Other alternatives include machines that track the movements of the tongue, the head or the eyes. The French journalist Jean-Dominique Bauby used blinks to dictate his famous memoirs, The Diving Bell and the Butterfly. A nurse read out a stream of letters while Bauby blinked to select the right one; eye-tracking machines could do the same thing automatically.

But the sniff controller has many advantages over eye-trackers and similar technologies. Sniffing itself can code a lot of information in the length and strength of sniff. It depends on neural networks that are widely spread and harder to knock out entirely. And these networks overlap with those for language production, so writing messages through sniffs may come particularly easily.

The sniff controller is simple and doesn’t involve cumbersome equipment (LI2 rejected eye-trackers because they were too uncomfortable). It works for locked-in patients like LI1, who can’t control their head or eye movements. For those with more movement, sniffing allows them to shift their head or eyes while communicating, without sending the wrong signal. And finally, the sniff controller is potentially very cheap. Plotkin and Sela built the version that controlled the wheelchair for $358. If it was mass-produced, that cost could fall substantially. By contrast, and eye-tracking system can cost up to $20,000.

Sobel thinks that his machine is certainly very competitive without rendering others obsolete. The truth is that disability isn’t a one-size-fits-all problem and a technology that works well with one patient may be terrible for another. As Laureys says, “The more tools, the better.”

For severely disabled patients who aren’t confined to beds, the sniff controller has another use – it can drive an electric wheelchair with a simple two-sniff code. “Two-sniffs-in” send the chair forward; “two-sniffs-out” reverses; “sniff-out-then-in” turns left; and “sniff-in-then-out” turns right. After just 15 minutes of practice, QU2, a man paralysed from the neck down, took only two goes to use this simple code to drive round a complex obstacle course, strewn with right angles.

Unlike the writing software, a driving programme raises obvious safety issues. By measuring the carbon dioxide levels in the users’ breaths, Plotkin and Sela think that the risk of hyperventilating is minimal. They also used double commands to avoid the possibility of crashing the chair by breathing. More complex codes could provide even more safety but the duo doesn’t think this is necessary. With practice, people should be able to drive the chairs without mistakes; certainly, Plotkin and Sobel have learned to use the software themselves and they can talk and drive at the same time without any problems.

Reference: http://dx.doi.org/10.1073/pnas.1006746107

Find out more:

• Stem cells created from ALS patient and used to make neurons
• Monkey see, monkey control prosthetic arm with thoughts
• How Kenny Rogers and Frank Sinatra could help stroke patients

If the citation link isn’t working, read why here

Yes, I know I just linked to a David Mitchell video the other day, but this one is so good I figured why not.

Ha! That’s from the UK show "That Mitchell and Webb Look", which is a great satirical show. There are about a gazillionty billion reasons the Moon Hoax folks are wrong, but M&W have boiled it down to its very essence. Well done!

Tip o’ the spacesuit visor to TheShickle.

The nature and character of your financial decisions is shaped by your genes. That shouldn’t be too horrible. Many decisions are the outcome of a combination of heritable and non-heritable predispositions. But I have to honestly express a bit of alarm at this segment I just heard on Marketplace, There’s only so much you can teach your kids. Here’s the subhead:

For better or for worse, kids take after their parents — but studies show parental influence only goes so far when it comes to how your children will handle money.

I’m not one to be worried about “genetic determinism” (usually just an insult which describes very few scholars), but this is a bit ridiculous. First, the primary research, of which you can find a pre-print online, seems to indicate that around ~30% of the outcome of financial decisions are heritable. That is, that ~30% of the variation in financial decisions within the population can be accounted for by variation in genes within the population. Additionally, there’s some context missing. The researcher expresses surprise that monozygotic twins converge in behavior as they age, and that parental influence tends to wear off as people leave the home. I don’t know if the researcher was taken out of context, but this is a totally unsurprising result. Over time shared home environment, what your parents model and teach you, tends to wear off, and gene-environment correlation increases the correspondences between particular genetic makeups and behaviors (i.e., identical twins resemble each other more at maturity than in their youth). For most behavioral traits heritability increases with age.

But the problem that microeconomic analyses like this create is that they confuse the public as to the relevance of charts such as this:

That’s the median savings rate in the USA.

There’s not enough time to explain this sort of volatility as the result of changes in gene frequencies. Some of the trends, as the recent increase in savings, have easy contextual explanations. The point is that individual dispositions express themselves within an environmental context, and culture is such an environment. This is why we have to be careful about the high heritabilities of obesity. Your genes may indicate how high your masts are going to be in the flotilla, but the rising and falling of the tide are going to have a huge absolute impact on the position of the whole constellation of ships.

Image Credit: Wikimedia

Produced by Lawrence Livermore National Laboratory and featured at the National Academies terrific website What You Need to Know About Energy. Click on the photo to get interactive.

The data are from the Energy Information Administration of the U.S. Department of Energy (DOE/EIA-0384(2008), June 2009). Hydro, wind, and solar electricity inputs are expressed using fossil-fuel plants’ heat rate to more easily account for differences between the conversion efficiency of renewables and the fuel utilization for combustion- and nuclear-driven systems. This enables hydro, wind, and solar to be counted on a similar basis as coal, natural gas, and oil. For this reason, the sum of the inputs for electricity differs slightly from the displayed total electricity output. Distributed electricity represents only retail electricity sales and does not include self-generation. The efficiency of electricity production is calculated as the total retail electricity delivered divided by the primary energy input into electricity generation. End use efficiency is estimated as 80% for residential, commercial, and industrial sectors, and as 25% for the transportation sector. Totals may not equal the sum of components due to independent rounding.

Apparently it’s hard to teach an old frog a new trick: landing on its legs. As painfully demonstrated in the video below, the primitive frog family Leiopelmatidae prefers to belly-flop.

In a study soon to appear in the journal Naturwissenschaften, Southern Illinois University’s Richard Essner Jr. and his team compared, via high-speed video, five frog species’ jumping techniques: three “primitive” frogs and two “modern” frogs (so named because they evolved more recently than the “primitive” species). Though all the frogs started their jumps similarly, the primitive frogs kept their legs extended when they land–keeping their Superman pose to the skidding end.

The researchers believe the frog jump may have evolved in two steps: first the shared leg starting position and then the mid-flight leg repositioning, which the primitive frogs lack. They think the apparently more modern landings may offer an evolutionary advantage, as it allows frogs to quickly execute another jump–a nice advantage when looking for food or escaping an enemy.

But evolutionary biologist T. Ryan Gregory proposes a potential alternative interpretation: Given that the primitive frogs also have a different swimming style, is the belly-flop really more “primitive,” or did it emerge along with other traits adapted for the frogs’ fast-running stream habitat?

Old or new, the belly-flopping frogs come equipped with their own gut protection: “shield-shaped” pelvic cartilage and abdominal ribs which researchers believe may soften the blow.

For more, check out Ed Yong’s post on Not Exactly Rocket Science.

Related content:
Discoblog: Video: How Male Frogs Kick up a Frog Froth to Protect Their Young
Discoblog: Endangered Frogs Encouraged to Get Amorous in an Amphibian “Love Shack”
Discoblog: Frogs Pee Away Scientists’ Attempt to Study Them
Discoblog: It’s Raining Tadpoles? Fish, Frogs Shower Japanese Residents

Video: Video by Essner; soundtrack by Ed Yong.

NASA’s next Mars rover took its first tiny test drive at the Jet Propulsion Laboratory on Friday. If all goes well, it will be en route to the Red Planet by late next year on a mission to look for environments that could have once harbored life.

The Mars Science Laboratory rover, now christened “Curiosity,” received its key parts this month:

Spacecraft technicians and engineers attached the Curiosity rover’s neck and head (called the Remote Sensing Mast) to its body, and mounted two navigation cameras (Navcams), two mast cameras (Mastcam) and the laser-toting chemistry camera (ChemCam). Curiosity was also sporting a new set of six aluminum wheels, each about 20 inches (about half a meter) in diameter, as it took its first drive on Earth. The large rover now stands at about 7 feet (2 meters) tall [MSNBC].

With its major pieces attached, Curiosity is about the size of an SUV. It dwarfs the overachieving Spirit and Opportunity rovers that have been on the martian surface since 2004. JPL scientists broadcast a live feed of the rover’s first roll back and forth.

“It’s the first full integrated test of the rover, where we have all the wheels assembled, the mobility system as well as the electronics that drive the rover,” said Rene Fradet, the mission’s flight system manager [Spaceflight Now].

But there are baby steps for Curiosity, with its handlers giving it basic instructions via an electronic hookup rather than running the software that will guide the rover on Mars. The trip there takes about nine months, so if the Mars Science Laboratory project takes off on schedule, Curiosity should arrive there in August 2012.

Curiosity will study martian geology in greater detail than previously possible. It may get the chance to expand on the work of the Phoenix Lander, which uncovered water ice on Mars, or even investigate the mysterious methane plumes that some scientists say could point to life—but others believe could be simply geologic.

Related Content:
DISCOVER: Those Mars Rovers Keep on Going and Going…
80beats: Photo Gallery: The Best Views from Spirit’s 6 Years of Mars Roving
80beats: Mars Rover Sets Endurance Record: Photos from Opportunity’s 6 Years On-Planet
80beats: “Life on Mars” Theories Get a Boost from Methane Plumes

Video: NASA/JPL

Birds do it, bees do it, even educated viruses do it. And for some reason my stack of interesting scientific papers is particularly heavy at the moment with research on the evolution of sex. So let’s not be shy. All this week, I will blog about sex.

[Image: mating sand wasps, Alex Wild]

Nature has two papers out about something called “Behçet’s disease.” It has apparently also been termed the “Silk Road Disease”, because of its associations with populations connected to the Central Eurasian trade networks.Though described by Hippocrates 2,500 years ago, apparently it was “discovered” only in the 20th century by a Turkish physician. The reason that that might be is obvious; the prevalence of Behçet’s disease is far higher in Turkey than any other nation. Two orders of magnitude difference between Northwest Europeans and Turks. East Asian populations are somewhere between Europeans and Turks, while the coverage of Inner Asia itself is thin (the first case diagnosed in Mongolia was in 2003). Additionally, the relatively similar frequency in Morocco and Iran, despite the latter nation being strong influenced by Turkic migration (25-30% of Iranian citizens are ethnically Turk), and the former not at all, leads to me wonder if there may be convergence or parallelism, rather than common ancestry, at work (or, more likely, a combination of both). The relationship between Morocco and Japan to the Silk Road in a direct fashion is tenuous at best. These were two polities which managed to be just outside the maximum expanse of Turanian empires. The Japanese famously repulsed the Mongol invasion ordered by Kublai Khan, while the Arab rulers of Morocco never fell under Ottoman control.And the early documentation by Hippocrates makes me wonder at the frequency of the disease in Greece itself. Greeks presumably contributed to the ancestry of modern Anatolian Turks, but it is far less likely because of the nature of the Ottoman system that Turks would have contributed to the ancestry of Greeks. I can’t find prevalence data for Greece, but it may be an open question in what direction the disease spread along the Silk Road.

But studies like these are nice because they are steps to overcoming one of the main issues with genome-wide associations: they use a narrow population sample, and so are not of necessary world wide relevance. Remember that even if a risk allele is not the direct cause of the disease, if it is closely associated with that alleles which are, it is of diagnostic utility. At least within that particular population. This study used groups from western and eastern Eurasia to check the power of particular single nucleotide polymorphisms (SNPs) to predict disease risk. First, Genome-wide association studies identify IL23R-IL12RB2 and IL10 as Behçet’s disease susceptibility loci:

Behçet’s disease is a chronic systemic inflammatory disorder characterized by four major manifestations: recurrent ocular symptoms, oral and genital ulcers and skin lesions¹. We conducted a genome-wide association study in a Japanese cohort including 612 individuals with Behçet’s disease and 740 unaffected individuals (controls). We identified two suggestive associations on chromosomes 1p31.3 (IL23R-IL12RB2, rs12119179, P = 2.7 × 10^?8) and 1q32.1 (IL10, rs1554286, P = 8.0 × 10^?8). A meta-analysis of these two loci with results from additional Turkish and Korean cohorts showed genome-wide significant associations (rs1495965 in IL23R-IL12RB2, P = 1.9 × 10^?11, odds ratio = 1.35; rs1800871 in IL10, P = 1.0 × 10^?14, odds ratio = 1.45).

And, Genome-wide association study identifies variants in the MHC class I, IL10, and IL23R-IL12RB2 regions associated with Behçet’s disease:

Behçet’s disease is a genetically complex disease of unknown etiology characterized by recurrent inflammatory attacks affecting the orogenital mucosa, eyes and skin. We performed a genome-wide association study with 311,459 SNPs in 1,215 individuals with Behçet’s disease (cases) and 1,278 healthy controls from Turkey. We confirmed the known association of Behçet’s disease with HLA-B*51 and identified a second, independent association within the MHC Class I region. We also identified an association at IL10 (rs1518111, P = 1.88 × 10^?8). Using a meta-analysis with an additional five cohorts from Turkey, the Middle East, Europe and Asia, comprising a total of 2,430 cases and 2,660 controls, we identified associations at IL10 (rs1518111, P = 3.54 × 10^?18, odds ratio = 1.45, 95% CI 1.34–1.58) and the IL23R-IL12RB2 locus (rs924080, P = 6.69 × 10^?9, OR = 1.28, 95% CI 1.18–1.39). The disease-associated IL10 variant (the rs1518111 A allele) was associated with diminished mRNA expression and low protein production.

Observe that the SNPs differ between the two studies. Here are the tables which show the SNPs, their odds ratios and statistical significance for the first and second paper respectively.

In the second paper they actually did an analysis of the effect of the disease associated allele at one of the SNPs, rs1518111. The A allele is disease associated.

Finally, the last paragraphs to the two papers:

We report here a GWAS identifying two new susceptibility loci for Behçet’s disease; these loci include interleukin and interleukin receptor genes, which are central in immune response. The quantitative alteration of these cytokines (and others in the same cascade) could help explain in part the complex pathophysiology of Behçet’s disease and suggest new therapeutic avenues.

And:

In summary, we report a GWAS and meta-analysis identifying common variants in IL10 and at the IL23R-IL12RB2 locus that predispose to Behçet’s disease. Our study also supports the association of HLA-B*51 as the primary association to Behçet’s disease within the MHC region and reveals another independent MHC Class I association telomeric to HLA-B. Expression studies indicate that the disease-associated IL10 variants are associated with decreased expression of this anti-inflammatory cytokine. This may suggest a mechanism, possibly in concert with commensal microorganisms…that results in an inflammation-prone state that increases susceptibility to Behçet’s disease.

The relationship to commensal microorganisms may be pointing to a major reason why the frequency of the illness seems to decrease as one moves north. This could be a case where genetically susceptibilities toward expression of the illness interact with environmental factors. One could imagine, for example, that the harsh cold and light population of Inner Asia may have incubated particular susceptibilities which never manifested themselves because of the environment. But with the shift toward the denser and moister climes of western and eastern Eurasia the combination of genes and environment resulted in the emergence of the disease.

With that said, again, I’m curious as to the nature of the SNPs, and the phylogenetics of the disease causing mutations. Do they derive from common mutants? Implying then that common ancestry via the Silk Road was critical. If the genetic variation around the mutants implies common descent then the Silk Road may have been critical in the spread of the risk alleles, but it would still be an open question whether they flowed from east to west or west to east, contingent on patterns of genetic variation. Or, are they independent mutations? Perhaps they’re side effects of adaptations?

Citation: Remmers EF, Cosan F, Kirino Y, Ombrello MJ, Abaci N, Satorius C, Le JM, Yang B, Korman BD, Cakiris A, Aglar O, Emrence Z, Azakli H, Ustek D, Tugal-Tutkun I, Akman-Demir G, Chen W, Amos CI, Dizon MB, Kose AA, Azizlerli G, Erer B, Brand OJ, Kaklamani VG, Kaklamanis P, Ben-Chetrit E, Stanford M, Fortune F, Ghabra M, Ollier WE, Cho YH, Bang D, O’Shea J, Wallace GR, Gadina M, Kastner DL, & Gül A (2010). Genome-wide association study identifies variants in the MHC class I, IL10, and IL23R-IL12RB2 regions associated with Behçet’s disease. Nature genetics PMID: 20622878

Citation: Mizuki N, Meguro A, Ota M, Ohno S, Shiota T, Kawagoe T, Ito N, Kera J, Okada E, Yatsu K, Song YW, Lee EB, Kitaichi N, Namba K, Horie Y, Takeno M, Sugita S, Mochizuki M, Bahram S, Ishigatsubo Y, & Inoko H (2010). Genome-wide association studies identify IL23R-IL12RB2 and IL10 as Behçet’s disease susceptibility loci. Nature genetics PMID: 20622879

After floating on plastic for more than 9,000 miles, the crew of the Plastiki arrived in Sydney, Australia today, more than four months after the ship set sail from San Francisco.

The boat of 12,500 bottles was the brainchild of David de Rothschild, who sought a way to bring more of the world’s attention to the problem of discarded plastic bottles and their tendency to wind up in the ocean.

He figured a good way to prove that trash can be effectively reused was to use some of it to build a boat. The Plastiki … is fully recyclable and gets its power from solar panels and windmills. The boat is almost entirely made up of bottles, which are held together with an organic glue made of sugar cane and cashews, but includes other materials too. The mast, for instance, is recycled aluminum irrigation pipe [AP].

The crew of six spent their four-month voyage cramped together in the catamaran’s cabin, taking showers in salt water, and eating dehydrated food. But they didn’t leave all the comforts at home behind. The team’s filmmaker managed to get a Skype connection at sea, which he used to witness the birth of his first child.

Storms and inconveniences aside, the crew sailed through environmentally important sites like the Great Pacific Garbage Patch and into Sydney on schedule, showing that sailing is a much better use for old plastic bottles than just throwing them away.

“The story that has been told to us about plastic is that it’s cheap, it’s valueless, it’s non-toxic, it’s easy to use, and don’t worry about throwing it out because we can just make some more,” said de Rothschild. “The reality is it’s not cheap, it’s not non-toxic, it’s not valueless. It’s valuable, it uses a lot of resources…. We need to start taking a serious look at the way we produce and design every product we use in our lives” [National Geographic].

Now, the bottle boat is going on temporary display at Sydney’s Australian National Maritime Museum as a nod to low-tech boating, which inspired the Plastiki’s name.

De Rothchild named the craft “Plastiki” in honour of the original Kon-Tiki voyage in 1947 by Norwegian explorer Thor Heyerdahl who sailed 4,300 miles on a raft made from balsa wood and other materials from South America to the Tuamotu Islands in French Polynesia in the Pacific Ocean [Reuters].

Related Content:
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Image: Plastiki

The Eyjafjallajökull eruption as seen by NASA’s Terra satellite

In theory, geoengineering seems like the ideal remedy for our climate ills. Some white reflective roofs here, a little ocean fertilization there, a few simulated volcanic eruptions, and voilà! you have a potential fix for one of the world’s most intractable problems.

But there’s good reason to believe that many of these proposed schemes would prove much costlier to the planet over both the short- and long-term than more mainstream approaches to addressing climate change—and leave a number of critical problems, like ocean acidification, in the lurch.

Take the injection of sulfate aerosol particles into the stratosphere, which I alluded to earlier. The idea would be to recreate the cooling effects of a volcanic eruption by blanketing the sky with a thin layer of particles that would reflect a fraction of incoming sunlight back into space. For this method to put a crimp on greenhouse warming, studies estimate that it would have to cut solar radiation by roughly 1.8 percent—not an easy feat by any means, but not entirely out of the question either.

In addition to being (relatively) cheap, costing around several billion dollars a year according to some projections, stratospheric geoengineering would actually be doable. In a recent paper, Alan Robock of Rutgers University and his colleagues suggested that it could be done by sending fleets of military planes to dump large quantities of sulfur gas into the lower stratosphere several times a year. While it all sounds good on paper, it’s worth emphasizing, as if it wasn’t obvious already, that much of this is still highly speculative. The rapidly changing nature of climate models, from which most of these findings are drawn, also makes it inherently difficult to predict with any uncertainty what this scheme’s exact outcome will be. What is certain, however, is that it would have a fair number of unintended consequences—almost all of which would be bad.

According to a new paper in Nature Geoscience, stratospheric geoengineering, or “solar-radiation management,” as the authors refer to it, would affect different parts of the world differentially (go figure), helping to cool down some countries while cooking others. It would deal a particularly harsh blow to many parts of Africa and Asia, disrupting rainfall and storm patterns and fomenting drought-like conditions. The particles would also spur the destruction of the already vulnerable ozone layer, hindering the recovery of the Antarctic ozone hole and blasting a few new ones.

To compound matters, the cooling effects would be short-lived—a few years at best—and many of the problems would only become worse with time. In other words, it’s mostly a lose-lose situation: stop short and you lose the benefits; keep going and you continue to dig yourself into a hole. It shouldn’t come as too much of a surprise then that the authors’ main takeaways are that: 1) regional geoengineering isn’t such a great idea and that 2) reaching any sort of agreement on the “right” amount of geoengineering needed will be, shall we say, tricky.

But what is the alternative? Sure, there are a number of other proposed methods on the docket, ranging from solar shields in space (I kid you not) to carbon dioxide-sucking artificial trees, but most researchers would point to stratospheric geoengineering as being the one with the most promise. Which isn’t exactly encouraging. Of course, very few scientists are genuinely enthusiastic about the prospects of unleashing geoengineering unto the world. Most would argue that much more research is needed before we can engage in a serious conversation about relying on it and, even then, it should only be deployed in conjunction with other time-tested mitigation strategies.

Given the global community’s sluggish, half-hearted response to climate change, it is unfortunately probably only a matter of time before a few governments decide to take matters into their own hands. And, if anything, I can easily imagine some variant of these techniques being eventually used to “terraform” (i.e. make more Earth-like) Mars and other currently inhospitable planets—think Star Trek II’s Genesis device but much slower and less cool and advanced. That is, unless an alien race gets to us first and reverse-terraforms our planet like in The War of the Worlds.

Image: NASA

As I write this, last night I was at W00tstock, an incredible evening of geekery that was one of the most fun and wonderful things with which I have ever participated.

Run by Adam Savage™, Wil Wheaton, and singer/songwriters Paul and Storm, it features lots of geeks singing and talking about the stuff they love. A friend of mine called it a talent show for nerds. That’s about right.

I was invited by the gents above to give a ten minute presentation while I’m at Comic Con, and I didn’t hesitate to accept! I mean, c’mon. Adam? Wil? Chris Hardwick? Veronica Belmont, the Rifftrax guys, Marian Call? How could I turn that down?

When they asked me I didn’t hesitate to say yes, but then one minute later realized this meant I had to come up with a talk, and not just any talk: it had to be funny, geeky, and only 10 minutes long. Yikes!

I knew it had to be astronomy-related, and after a few more minutes of pondering and back-and-forthing with Mrs. BA, the topic seemed obvious: astronomical pareidolia, objects in the sky that look like other things. The obvious choices are things like the Eskimo Nebula, and all the heart-shaped craters and nebulae I post every Valentine’s Day.

But it had to be funny. And not just funny, but nerd funny. That became obvious too, once I realized what I could do. Without going into too much detail, let me just say that I borrowed a couple of pictures from my friend Amanda Bauer’s Astropixie website. I’d seen most of her imagery before, so I felt safe enough using them, and gave her full credit, of course. I ran with the premise, and perhaps went a little "bluer" than most people would expect from an upstanding citizen like me. But it was a lot of fun to do. I haven’t seen any video of my talk on YouTube yet, but if anyone finds any, please let me know!

I also showed the new trailer to my TV show, "Phil Plait’s Bad Universe", which got a very healthy and warm reception. In fact, I was overwhelmed with the response; a whole lot of folks came up to me and told me how happy they were and how they couldn’t wait to see the show! That makes me very happy and adds thermal energy to the cockles of my cardiac muscle. I realized later that I was nervous after my presentation; a common event for performers. But I was surprised to realize that I was more nervous about showing the trailer than I was about the talk itself! Interesting. I’m sure a psych student could write a thesis about me. If you do, be prepared for the inevitable B- you’ll get.

Anyway, the acts were incredible. I haven’t laughed so hard for so long in ages. But for me, the real magic was behind the stage. Paul said it was like a parallel world running along at the same time; I got to hang with so many cool kids!

That picture is fairly typical of the behind the w00tstock scene: Adam Savage telling (a probably dirty) story to Nerdist podcaster Chris Hardwick, fellow Mythbuster Grant Imahara, and magician Jamy Ian Swiss.

Here’s online goddess Veronica Belmont and my friend, the siren Marian Call:

You can see more of my pictures from the event and Comic Con at large on my Flickr page.

Aaron Douglas (Chief from BSG) was there, Jamie Hyneman made a cameo, and so many others. I can’t tell you in words how awesome and amazing the evening was. Smart people! A thousand of them! Laughing, sharing their joy, being unabashed geeks reveling in their nerdery! It was warm, it was welcoming, and wonderful.

In other words, it was w00tstock.

Thank you thank you thank you to Wil, Adam, Paul, Storm, and everyone else who was there and made this dorky astronomer feel like know that he belongs. And if you ever, ever have a chance to attend one, do not hesitate. If you’re a geek — and you are, it’s time to admit it — then this will be one of the best evenings you’ll have.

So that reader survey that I mentioned last week is done. I’m mostly interested in seeing the changes since I’ve moved to Discover from ScienceBlogs. I assume that the standard 85% male readership has shifted somewhat toward more balance, but I don’t know. Many of the basic demographic questions (sex, race, age, etc.) are the same, but I swapped out ones I usually ask with others. At this point I’m rather sure that a huge proportion of the readers of this weblog are introverted nerds, so I’m not going to ask about personality type and what not. I took some reader suggestions, so there are questions about what you read, as well what your somatotype is. I converted the political question to a 0 to 10 scale that I wouldn’t have to recode if I did a scatter plot, and also so that it’s a little more fine-grained.

As usual all questions are optional. I timed it and should take you 5 minutes max, though I guess I can’t account for lack of clarity in prose. If you don’t see your exact response, but want to respond, I think it is totally fine to give the closest equivalent.

To take the survey, click here. After you’re done it’ll bring you back to this website. You can review results here.

Below are percentage breakdowns of last winter’s survey by sex.

Ray Bradbury is the last living of the great early titans of science fiction, now that Isaac Asimov and Arthur C. Clarke have passed. He said he’s attended every Comic-Con since the first one, when he went to the El Cortez Hotel and spoke to a few of the 300 attendees that year. These days, 125,000 people turn out for Comic-Con every year, and I had to wait 30 minutes to get in to see Bradbury speak. He’ll be 90 in August, and he’s hard of hearing, but he’s still sharp, and he’s forgotten nothing.

The Bradbury panel featured Bradbury talking to his biographer, Sam Weller. I’m just going to share select quotes from his remarks. These are in order, but incomplete.

“The Internet to me is a great big goddamn stupid bore.”

“I got a call from a man who wanted to publish my books on the Internet. I told him, prick up your ears and go to hell.”

[Bradbury has met most, if not all, of the Apollo and Gemini astronauts.]

“All those astronauts had read the Martian Chronicles. When they were young men, they read my books and decided they wanted to become astronauts.”

“[Twilight Zone creator] Rod Serling came to my house many years ago, he didn’t know anything about writing science fiction and fantasy. So I took him down to my basement and gave him copies of books by Richard Matheson, copies of books by Henry Kuttner, copies of books written by Roald Dahl and by John Collier, and a couple of books by myself. And Rod Serling forgot he read all those books, and when he wrote the program, he copied some of the ideas without telling me. So we got into a big argument, so finally I walked away from the Rod Serling show. He had a great show, but he forgot the basis of the show were all the books I gave him by all my friends.”

[* Thanks to commenter John Joseph Adams for figuring this one out.]

“I read comic strips all my life I have all of Prince Valiant put away. I have all of Buck Rogers put away, too. I put away those starting when I was 19 years old. So my background in becoming a writer was falling in love with comic strips.”

“I read the comic strips, I learned how to write.”

“My favorite that’s in the paper every day is called Mutts.”

[Bradbury is a tireless advocate for free public libraries.]

“When I left high school, I had all my grades to go to college, but I had no money. I decided I will not worry about getting money to go to college, I will educate myself. I walked down the street, I walked into the library, for three days a week, for 10 years, and educate myself. It’s all free, that’s the great thing about libraries. When I was 28 years old, I graduated from library.”

“We have to reinvest in space travel. We should never have left the moon. We have to go back to the moon and build a firm base there, so we can take off from there to the planet Mars. We have to become the Martians. I tell you to become the Martians. We have to civilize Mars, build a whole civilization on Mars, and then move out 300 years from now, into the universe, and when we do that, we have the chance of living forever. Our future is investing right now in space travel. Money should be given to NASA to build the rockets to go back to the moon.”

“It’s been 90 god-damned incredible years.”

“Every day I’ve loved it. Because I’ve remained a boy. The man you see here is a 12-year-old boy, and the boy is still having fun.”

“You remain invested in your inner child by exploding every day. You don’t worry about the future, you don’t worry about the past, you just explode. If you are dynamic, you don’t have to worry about what it is you are. I’ve remained a boy, because boys run everywhere, they never look back, they run everywhere, they keep running running running. That’s me, the running boy.”

[Weller asked: Do you have any regrets?]

“I regret that I didn’t have more time with Bo Derek.”

“She came up to me in a train station in Paris 30 years ago and said ‘Mr. Bradbury?’, I said, ‘Yes.’ She said, ‘I love you,’ I said ‘Who are you?’ She said. ‘My name is Bo Derrick Derek.” She said, “Mr. Bradbury will you travel on the train with me?’ I said, ‘Yeah, I will.’”

“Mel Gibson owns the [movie] rights to Fahrenheit 451. Did you see him on TV last week? Right now he’s not doing a thing with Fahrenheit 451.”

“I’ve got a new book of short stories, I’m working on, that will be published next Christmas. The title of it is Juggernaut, a book of 20 new short stories, which will be published next Christmas.”