Dienekes already mentioned it, but readers might be curious about the Ancient Roman DNA Project. Here are the details:

I’m asking for $6,000 for this project, which will cover the cost of testing DNA from the 20 immigrants to Rome I found in my previous project. Of course, I would love to test additional individuals but recognize that testing the 100+ skeletons I have sampled is out of the realm of possibility. Still, any additional funding over the $6,000 goal will be put to good use: analyzing DNA from more Romans! Be a part of the #SciFund Challenge and help me bring science to ancient Rome!

Human serum albumin is used in everything from vaccines to cell culture.

Human blood is in demand these days. Donor blood is required for transfusions, of course, but it also contains human serum albumin, a blood protein used to treat shock, severe burns, and liver injuries that also shows up in vaccines and in cell culture materials. Worldwide, we use about 500 tons of human serum albumin (abbreviated HSA) a year.

Shortages of the protein and the potential for contamination by blood-borne viruses have encouraged scientists to look beyond donor blood for sources. One promising approach, inserting the gene for HSA into plants and then harvesting the resulting protein, has always yielded too little for the method to make sense financially, but a new paper details a way to get around that: get the plant to make HSA in its seeds, which are lean, mean protein-concentrating machines. HSA made up 10% of the soluble protein in the rice seeds produced by the research team, one of the highest yields on record from a transgenic plant. And when the team put it through its chemical paces, it worked exactly like normal, human-grown HSA, indicating that its sojourn in the plant world hadn’t impaired its usefulness. If all goes as planned, the team will be testing rice-grown HSA in people in clinical trials in the next two years, with an eye towards supplanting donor blood as a source.

[via Nature News]

Image courtesy of Borislav Mitel / Wikimedia Commons

A few stray thoughts, which might be worth having a discussion about. Unless one wants to go Soylent Green or Logan’s Run both the proponents of stable/declining world population and continued growth have to look to technology. More people means more economic productivity to keep everyone afloat ahead of the Malthusian trap. But even if the population stabilizes, there is still the major problem of the rising dependency fraction due to aging. The only way that we can keep up is by increasing the productivity of the work force. This is especially going to be an issue in a nation like China because of the one child policy (which practically turned out to be a 1.5 child policy). Either “working age” people have to work more productively, or health care has to reduce late in life morbidity so that people can work longer and get the ratio of retirees to workers reasonable.

Secondarily, I’m kind of getting sick of the fact that everyone’s battery is dying. My battery is dying, your battery is dying. “Hey, can I call you later? My battery is dying.” With the rising penetration of smartphones batteries are dying all over the place. I remember a time, back in 2006, when I must have been charging my phone once a week or something! The days. I know that smartphone technology is a step forward, but it goes to show how difficult it is to make a good battery, insofar as we’ve taken a massive step backward in terms of the battery life that we had come to expect. There’s a creeping element of zero sum in all of this; more features means less juice per feature.

I believe without reservation that this may be the greatest instance of pareidolia of all time: an ultrasound of a man experiencing epididymo-orchitis, or pain and swelling of a testicle:

Having suffered through a similar (if less traumatic) version of this, may I add that the expression on the man’s, um, "face" is exquisitely accurate.

Tip o’ the codpiece to my Hive Overmind co-blogger Ed Yong on Google+. Original image: Elsevier, Inc.

Today Science Ink is published! Amazon has already run out of copies to sell, but not to worry–the books are spitting out of printers as I blog this. Order your copy, and it will get to you soon. If you’re on the fence, check out this review from Nature (yes, that Nature, the venerable scientific [...]

Dragonflies can literally be scared to death of fish. Who knew? In a study published in November in the journal Ecology, researchers found that dragonfly larvae reared in the presence of fish were four times more likely to die before reaching adulthood, compared to larvae raised in an environment without predators. Similarly, 2.5 times more dragonflies croaked when raised in the same tank as an invertebrate predator. The larvae were kept in cages in full view of the predators, although the cages kept the predators from entering, and each one contained a small cup where the larvae could hide.

The study also found dragonfly nymphs raised in tanks with a fish were 10 percent more likely to die while metamorphosing into their winged adult form that we know so well. Apparently growing up is not only stressful for humans, and being constantly reminded of one’s mortality doesn’t help. (But of course, I’m anthropomorphizing their metamorphosizing.)

The researchers also measured body size in surviving larvae and adult dragonflies (a species called the dot-tailed whiteface, or Leucorrhinia intacta). They found no difference between the different groups, which came as a bit of a surprise since previous studies on other animals have shown that various types of stress can affect development and growth rate, affecting adult body size.

So why did higher numbers of dragonflies die when raised alongside predators? The researchers don’t know but have several guesses. For one, the stressed-out larvae may have an impaired response to disease or pathogens. It’s well-established that stress can hamper immune response in a wide variety of animals (including humans), and the fact that a small percentage of the predator-free larvae died hints at a low level of disease in the population, gathered from lakes in Michigan. The researchers also suggest stress may lead baby dragonflies to use and store energy less effectively. But their best guess is that stress causes a variety of negative responses that can combine synergistically. This has been shown in other animals; for example, tadpoles exposed to predatory newts are more susceptible to herbicide poisoning.

All this seems somewhat intuitive, but few studies have examined concrete effects of stress in invertebrates. The findings could help pave the way for understanding stress in other animals, including the one that complains about stress the most: us humans.

Reference: Shannon J. McCauley, Locke Rowe, Marie-Josée Fortin. The deadly effects of “nonlethal” predators. Ecology, 2011; 92 (11): 2043 DOI: 10.1890/11-0455.1

Image: Gary Yankech / Flickr

Here at BA Central, I have my hands full trying to battle the Forces of Darkness: those who would spin, fold, and mutilate reality for their own gain. They may be motivated by greed, or power, or ignorance, or ideology, but the thing they all have in common is, they’re wrong. They come in many flavors: homeopaths, psychics, creationists, antivaxxers… and yes, sadly, far too many politicians.

And I can rail against them time and again, my arsenal filled with the facts from an entire Universe at my disposal, yet make hardly a dent in their armor.

Sometimes, though, a small dose of satire penetrates right through that shielding and pierces the very heart of antiscience. Thank you, The Daily Show, for fighting this good fight:

Ancient DNA suggests the leading role played by men in the Neolithic dissemination:

The impact of the Neolithic dispersal on the western European populations is subject to continuing debate. To trace and date genetic lineages potentially brought during this transition and so understand the origin of the gene pool of current populations, we studied DNA extracted from human remains excavated in a Spanish funeral cave dating from the beginning of the fifth millennium B.C. Thanks to a “multimarkers” approach based on the analysis of mitochondrial and nuclear DNA (autosomes and Y-chromosome), we obtained information on the early Neolithic funeral practices and on the biogeographical origin of the inhumed individuals. No close kinship was detected. Maternal haplogroups found are consistent with pre-Neolithic settlement, whereas the Y-chromosomal analyses permitted confirmation of the existence in Spain approximately 7,000 y ago of two haplogroups previously associated with the Neolithic transition: G2a and E1b1b1a1b. These results are highly consistent with those previously found in Neolithic individuals from French Late Neolithic individuals, indicating a surprising temporal genetic homogeneity in these groups. The high frequency of G2a in Neolithic samples in western Europe could suggest, furthermore, that the role of men during Neolithic dispersal could be greater than currently estimated.

Some notes:

- Otzi the Iceman is G2a.

- A continuity of local maternal lineages would not be so surprising. Recall that ~50% of Argentine mtDNA seems to be indigenous, even though they’re ~80% European in total ancestry, and ~95% European in the paternal line.

- This is not limited to Latin America. In South Asia the majority of the maternal lineages are non-West Eurasian, while the majority of paternal lineages are West Eurasian. Autosomal ancestry seems to be about half West Eurasian.

- There are now several instances of Neolithic settlements yielding relatively rare paternal lineages, which are almost certainly intrusive, but left little impact. The authors step forward with the most plausible, and frankly suprising, rationale:

The high frequency of G2a haplogroup in Neolithic specimens, whereas this haplogroup is very rare in current populations, also suggests that men could have played a particularly important role in the Neolithic dissemination that is no longer visible today. This would imply that intra-European migrations related to the metal ages may have strongly affected the modern
gene pool.

In other words, the European paternal lineage landscape may not be determined primarily by the hunter-gatherers or first farmers, but subsequent groups. The relative lack of the two dominant European haplogroups, R1a and R1b, is particularly notable. What’s going on? Perhaps male lineages were “winner-take-all,” and have a tendency to rise to near fixation and then shift toward extinction, more than female lineages? The Genghis Khan haplotype story may be less exceptional than we think. If this is right then we need to be very careful about the historical lessons we draw from mtDNA and Y chromosomes, because they may give us a skewed and unrepresentative picture of the demographics of the past.

It’s time for October’s Science Writer Tip-Jar picks. For those new to this, here’s the low-down:

Throughout the blogosphere, people produce fantastic writing for free. That’s great, but I believe that good writers should get paid for good work. To set an example, I choose ten pieces every month that were written for free and I donate £3 to the author. There are no formal criteria other than I found them unusually interesting, enjoyable and/or important.

I also encourage readers to support these writers through two buttons on the sidebar. There are two ways to help. Any donations via “Support Science Writers” are evenly distributed to chosen ten at the end of the month. Donations via the “Support NERS” button go to me; I match a third of the total figure and send that to the chosen writers too.

So without further ado, and in no particular order, here are the picks:

• Meera Lee Sethi for this fantastic story about internet spider porn, and the dogged passion of scientists
• Tom Holtz for “Love the tyrant, not the hype” – a great piece on T.rex that makes this most familiar of dinosaurs seem fascinatingly new.
• Cassie Willyard for a thoughtful piece on why science writers need to ask dumb questions.
• Erika Check Hayden for an important piece on why sequencing Steve Jobs’ genome couldn’t save his life, and the limits of modern genetics.
• Razib Khan for a thought-provoking post on whether Neanderthals simply lacked leadership.
• Paul Norris for his take on dolphin Curiosity, and whether they seek knowledge for knowledge’s sake.
• Michael Eisen on the “myth of the scientific martyr” and why Daniel Shechtman is not Felisa Wolfe-Simon.
• Jennifer Frazer for a wonderful account of a fountain of life at the bottom of the Dead Sea.
• Mo Costandi for a magical post on whether magicians can teach neuroscientists a few tricks
• Christie Wilcox for a personal account of the science of heartbreak

The New York Times has a article out about environmentalists who are now looking at population control again, after shying away from it. This is probably prompted by the hullabaloo over “7 billion.” This comes in the wake of a long piece, The Last Taboo, in the Lefty periodical Mother Jones.

The rationale for why environmentalists have moved away from population control is alluded to only elliptically in The New York Times piece. They make a big deal about abortion, but I don’t think this is the most terrifying issue in principle. Environmentalists tend to be on the pro-choice side of the Culture Wars anyway. To cut to the chase it is the fear of being called racist (and to be fair, racial nationalists from Madison Grant to John Tanton have synthesized ethnic concerns with genuine conservationist impulses). Only environmentalists with rock-solid credentials or a lean toward anti-humanistic Deep Ecology philosophies remained vocal about their opposition to mass immigration over the past few decades. David Brower, founder of the Sierra Club, was one such individual. And it’s no surprise that the founder of the radical Earth First movement is also an immigration restrictionist.

The logic behind environmentalist skepticism of immigration is pretty clear. Citizens of the developed world have a huge impact in comparisons to citizens of the developing world. Without immigration since 1965 the population of the United States would have already stabilized a generation ago, while today it will likely approach 400 million in the mid-21st century.

I’m much more optimistic about the medium term future than most environmentalists. Though I’m not a Panglossian, I think that science and technology will probably be able to manage to keep civilization creaking along. And when it comes to population control sometimes I wonder if the ultimate reason why we care about population control isn’t being muddled. Those who espouse a full-throated Deep Ecology ethos which is basically anti-humanistic in orientation are at least honest. People who are militant about not having children, and attempt to convert others to the cause, sometimes strike me as curious. Who exactly are they saving the world for? The people who they claim should not reproduce?

But I’m a biologist enough to understand that Malthusian conditions aren’t made up out of whole cloth. I understand the fixation upon controlling the numbers of middle class Westerners in the medium term, but observe in the plot above that the crappiest countries in the world have the highest fertilities! One thing that seems true is that a demographic transition results in a positive shift in the dependency ratio, so that economic growth and higher quality of life ensues. Nations which aren’t proceeding through the demographic transition don’t benefit from this dividend. To not put a too fine a point on it they remain shitholes for their residents, and require the resources and energy of societies which actually function to prop up. The “carbon footprint” of a Somali really isn’t a big deal. 5 million Somalis vs. 10 million Somalis makes no real difference to the planet. But it makes a huge difference to the probability of a given Somali starving or not! If you want to go Julian Simon on me I have a bet I could make with you about the relationship between Somalia’s population and its stability and per capita prosperity (at least normalized for world levels of prosperity).

The game of understanding, and shaping, human population seems to be forced into two artificial extremes. On the one hand there are absolutists for reproductive freedom who believe that to have children is a right, who also believe that food, healthcare, and housing are rights. What are rights without responsibilities? There is no honor is starving to death because your nation is too dangerous for CNN camera crews to come film large numbers of children and infants with bloated bellies, which might prompt those societies with surplus to divert it so you can live to breathe and breed another day. As for environmentalists who scold others for daring to produce more humans, often in the zeal of their proselytization they can confuse others into wondering if a world extirpated of humanity wouldn’t be their ideal. This is not the truth of the matter, after all ZPG activists aim for stabilization in large part so that the affluence and security which we take for granted might become sustainable, extending human well being and flourishing out indefinitely. Instead of one-size-fits-all maxims, what we need are case-by-case solutions for a complex world.

As the Sun rotates roughly once per month, we see different features come into view… and the latest is an enormous sunspot system which just came around the limb of the Sun:

[Click to magneticfieldentanglenate.]

That shot was taken by the Mexican "amateur" astronomer César Cantú, and shows the spots — called Active Region 1339 — from November 4. The size of this system is staggering; the whole thing is well over 100,000 km (60,000 miles) across, and the dark cores are each about the size of our entire Earth!

They’re active, too: On November 3rd they popped off a pretty big X 1.9 class flare:

That image was taken by NASA’s Solar Dynamics Observatory in the ultraviolet, where violent activity is easier to see. NASA made a video of the flare, and you should take a look. It’s pretty amazing.

So we have a recipe for some action here: big spots, known to be active, and they’re riding the Sun’s surface as it rotates them more fully toward us. Over the next week and a half we might get some more flares from them, and maybe some coronal mass ejections… and that means we might get more aurorae. Stay tuned here; if any occur I’ll report them as soon as I hear. Also keep your browser pointed at SpaceWeather.com, which always has the latest info as well.

Image credits: César Cantú; NASA/SDO

Last August I had a post up, The point mutation which made humanity, which suggested that it may be wrong to conceive of the difference between Neanderthals and the African humans which absorbed and replaced them ~35,000 years ago as a matter of extreme differences at specific genes. I was prompted to this line of thinking by Svante Pääbo‘s admission that he and his colleagues were searching for locations in the modern human genome which differed a great deal from Neanderthals as a way through which we might understand what makes us distinctively human. This sort of method has a long pedigree. Much of the past generation of chimpanzee genetics and now genomics has focused on finding the magic essence which differentiates us from our closest living relatives. Because of our perception of massive phenotypic differences between H. sapiens and Pan troglodytes the 95-99% sequence level identity is thought by some to be perplexing. Therefore models have emerged which appeal to gene regulation and expression, or perhaps other forms of variation such as copy number, to clear up how it can be that chimpanzees and humans differ so much. Setting aside that the perception of difference probably has some anthropocentric bias (i.e., would an alien think that chimpanzees and humans are actually surprisingly different in light of their phylogenetic similarities? I’m not so sure), it doesn’t seem to be unreasonable on the face of it to plumb the depths of the genomes of hominids so as to ascertain the source of their phenotypic differentiation.

But can this model work for differentiating different hominin lineages? Obviously there’s going to be a quantitative difference. The separation between chimpanzees and modern humans is on the order of 5 million years. The separation between Neanderthals and modern humans (or at least the African ancestors of modern humans ~50,000 years B.P.) is on the order of 500,000 years. An order of magnitude difference should make us reconsider, I think, the plausibility of fixed differences between two populations explaining phenotypic differences.

Backing up for a moment, why do we think there might be fixed differences between Neanderthals and modern humans? The argument, as outlined in books like The Dawn of Human Culture, is that H. sapiens sapiens is a very special lineage, whose protean cultural flexibility allowed it to sweep of the field of all other hominin sister lineages. The likelihood of some admixture from these “dead end” lineages aside, this rough model seems to stand the test of time. Consider that the Mousterian technology persisted for nearly 300,000 years, while the Oldowan persisted for 1 million! In contrast, our own species seems to switch and improve cultural styles much, much, faster. Behavioral modernity does point to a real phenomenon. The hypothesis of many scholars was that there was a genetic difference which allowed for modern humans to manifest language as we understand it in all its diversity and flexibility. The likelihood of this seems lower now that modern humans and Neanderthals have the same variants of FOXP2, the locus which seems to be correlated to elevated vocal and auditory capabilities across many vertebrate lineages. And, if it is correct that ~2.5% or so of modern human ancestry in Eurasia, and nearly ~10% in Papua, comes from “archaic” lineages, then I think that should reduce our estimates of how different these humans were from the Africans.

Therefore you can posit two stylized scenarios of contrasts between Neanderthals/modern humans and chimpanzees/modern humans. In one model the difference between the two comparisons is fundamentally of degree. Neanderthals and chimpanzees are still disjoint from modern humans. That is, there’s no overlap in the traits. But, Neanderthals are far closer to modern humans, as would be likely expected from the phylogenetic relationship. Another model though is that Neanderthals and modern humans did differ, but there was a great deal of overlap. This is a model with qualitative differences from that of chimpanzees vs. humans. If the second model is correct, and I think with all that we know from the Neanderthal genome project would should take it more seriously, then looking for disjoint pairwise differences in allele frequencies is not the way to go in understanding how the two human lineages diverged in phenotype.

In the second model, where there is a great deal of overlap, there is still a difference in the tails of the distribution. The idea I had in mind with my earlier post was that it is at these tails that the differences between Neanderthals and modern humans will be found when it comes to cultural differences. I think one might wonder where the Michelangelo or a Bachs of the Neanderthals were, but then one has to observe that the vast majority of modern humans are not Michelangelo or a Bachs! One of the primary indications of the transition to behavioral modernity is the proliferation of symbolism. But are we to presume that every member of an ancient Paleolithic tribe was equally capable of creative virtuosity? I think likely not. It could be that in fact the vast majority of “modern humans” are no different from all Neanderthals in the sort of things we might expect to be different across the two lineages. Rather, it may be that a small minority of modern humans crossed a particular threshold at the edge of the distribution of the phenotype, and when that transition was made the world was never the same.

Julius Caesar

I’m not proposing here that the victory of African humans ~50,000 years ago was due to artists. What I’m proposing is that at some point a critical mass of exceptional individuals arose. These individuals were possessed of peculiar characteristics, but instead of these characteristics making them outcasts, the qualities which they possessed were seen by their fellow humans as marks of greatness. In short, they were the children of gods among men.

Or perhaps demons. Men such as Alexander, Napoleon, and Hitler, were possessed of peculiar charisma, but whether they were good or evil is a matter of dispute and perspective. The point is not that they achieved greatness, but that they were the catalysts for a great number of events. As charismatic leaders they took collections of human beings, and turned them to there purpose. Individual humans became more than the sum of their parts, and for moments exhibited almost organismic levels of cohesion. Though the number one predictive variable in who won wars in the pre-modern world is the simple one of numbers, organization and structure also mattered. The Roman legion operating in a Testudo formation could beat off the attacks of more numerous barbarians who were physically more robust on a per person basis because the unit exhibited synergy, and translated cohesion into efficient collection action. This does not occur bottom up, but requires a personality type, a genius, to serve as the nexus or locus.

The model I have in mind then is one where the African humans faced up against their near relations, but not as one against one. Rather, under the guidance of charismatic leaders, Paleolithic megalomaniacs driven by fervid nightmares and irrational dreams, they ground through the many enemies who fought as sums of singulars as a cohesive social machine. It was not because they were superior on a per unit basis, but because they were superior on a per tribe basis, driven by individuals who turned the many to their own ambitions. With the lever of superior social organization the few moved the world, and swept over it. How many insane voyages were their east over the horizon from Sundaland before one tribe finally made landfall in Sahul? How many tribes perished in the ice of the far north, before some finally made it to Beringia? Why did humans look over the horizon, and venture out across the black waters? Perhaps just because they could. This answer is likely confusing and disquieting to many alive today, and perhaps it was disquieting to the more reasonable and level-headed “archaics” who were confronted with the zealous organizational insanity of the African humans who were rolling all opposition. But these insane individuals still move among us today, and they are still the objects of curiosity, fear, and adulation.

Is this a crazy model? Yes, somewhat. But is it really anymore crazy than the model that there is a mutation which can encapsulate all that differentiates man from beast-man? I think not.

UPDATE:  Solved by Gary at 12:33 CDT

Happy Saturday, Riddlers.  North central Texas weather is trying desperately to make up for the other fifty-one weeks by giving us a couple of perfect days and clear, cold nights.  What more could a girl want?  I think the rest of the weekend is going to find me happily busy ignoring the matter at hand.

Speaking of which, how about a riddle to chew on?  As Tom and I creep ever closer to the close of this riddle cycle, make sure your name is on the list and ready to go.  Remember, if you’ve already solved several riddles this cycle (but still want to play), email your guesses to me.  If you solve it, I’ll credit you in the comments and the riddle will remain “open” for play.  Good luck!

You'll think of it here. Not much, but you will think of it.

You’ll find today’s answer in the real world.  That it shows up, also, in fiction is beside the point.

This is something of an event.

Although never alive, you know when this has died.

Big honking tube worms

We associate this with the Earth, although it is hardly indigenous to the Earth alone.

We also associate this with heat, although it is hardly heat specific.

There’s a certain association with “fire” that doesn’t hold up, either.

Yes, you do TOO know what this is.

This has the power of construction or destruction; of life or death.

We find the echoes of this wholly natural event in the murky waters of the human subconscious.
…(ha!  “murky waters”!  you liked that one, didn’t you?)

Although common in nature, if it moves much “over the line” it’s an extinction level event.

(oops)

There you go!  That should keep you busy for… oh, say about 30 seconds.  Let me know what you think is the answer to this tasty little riddle.  I’m hanging out in the comments, as usual, unless I’m stuck hanging out in the ICU!

A couple of antivax stories hit the web in the past day or so, and both have me pretty angry, shaking my head about how people can manage to get things so wrong.

First, the antivax organization that is (Orwellianly) called the National Vaccine Information Center has paid for ads to run on in-flight Delta airline TVs. These ads give what can charitably be called misleading information about vaccines. Skepchick has the details, as does Harpocrates Speaks.

NVIC is an organization that is resolutely antivaccination, despite the overwhelming evidence that vaccines are one of the greatest medical science triumphs of all time, having saved hundreds of millions of lives. NVIC, on the other hand, is a group that likes to try to sue critics into silence while at the same time spouting statements so ridiculous they make my irony gland fear for its life.

I decided to make a short and simple tweet about the ads being run on Delta airlines:

I mean it, too. The link in the tweet goes to the Skepchick article linked above, which also links to a change.org petition, which I signed — and I rarely do such things. But Delta really needs to take those ads down. Groups like NVIC are a public health threat.

I also write about this on Google+. It got some of the usual anti-vax nonsense in the replies, but also overwhelmingly positive responses in general. With this many people involved, I’m hoping Delta takes notice.

The second bit of news is so appalling it’s difficult to overstate. On Facebook, parents belonging to an antivax group were encouraging others to send postal mail to each containing items like lollipops infected with saliva containing chicken pox.

I will give you a moment to pick your jaw up from off the floor. When you’re done, watch this:

I can hear jaws all over the world right now smashing right through the ground.

Yes, this is for real. The idea is to have what’s called a "Chicken pox party", where parents purposefully infect their kids with a disease that can put them at great health risk, because they so strongly dislike the idea of vaccinating their children. This idea all by itself is incredibly bad — once you’re infected, the virus stays with you for life, putting you at risk for shingles as an adult, and can cause severe complications to people with compromised immune systems.

I understand that a lot of parents don’t think chicken pox is that big a risk. Many of us had it as a kid, and it wasn’t much more than an inconvenience. I had it, and I remember being miserable and itching like crazy, but that was about it.

But even so, sending a known biohazard through the mail? Does this not cause alarm bells to go off in anyone’s head? And rubella? Measles? Are you kidding me? Measles can kill.

Incredible.

Again, Harpocrates Speaks has more on this, as does Tara Smith, who is a Professor of Epidemiology, and knows of what she speaks.

I just hope none of these people have mail carriers with rheumatoid arthritis or lupus, and are taking immunosuppressants.

All I can add is to say what I did on Google+ on this issue:

Once you let go of evidence-based reasoning, anything at all makes sense. Sometimes even putting your own children at grave risk.

What’s the News: Epidemiologists have long noticed that people with drug addictions often start out smoking cigarettes before moving on to harder stuff. Whether that’s because there’s something about cigarettes that makes people vulnerable to other drugs or because certain kinds of people are predisposed to addiction (or for some other reason entirely) is an open question, and the idea of so-called “gateway drugs” has been a controversial topic in addiction for years. Now, an elegant new study in mice has discovered a mechanism that could explain the gateway drug effect: nicotine actually changes the expression of genes linked to addiction.

How the Heck:

• First, the researchers (including biologist Denise Kandel and her Nobel laureate husband, Eric Kandel) gave mice nicotine to mimic the effects of cigarette addiction before giving them several injections of cocaine.
• Watching their behavior, the team saw that mice that had been given nicotine for many days returned again and again to locations where they had been given cocaine, far more—nearly double the frequency—than mice who had only received nicotine for 24 hours. In studies with drugs, this is a well-established sign of addiction.
• Opening up the brains of the mice, they found that the neuronal pathway that delivers cocaine’s rewards was much more strongly activated in mice that had had days of nicotine. This suggests that nicotine actually enhances the pleasure derived from cocaine.
• Looking deeper at the brain cells implicated in addiction and reward, they found that FosB, a gene whose expression helps cement addiction, was expressed at levels 74% higher than in mice who hadn’t had nicotine.
• Investigating how nicotine could have this effect, they discovered that it was acting at an epigenetic level—in other words, changing the chemical packing of DNA. Here’s how:
• When certain chemical tags are present on DNA, the double helix unfurls a bit, making it easier for the cellular machinery to get a hold of a gene, read off its code, and translate it into a protein. When mice were exposed to nicotine for many days, an enzyme that removes those tags and thus keeps certain genes out of circulation was knocked down. That was how nicotine caused FosB production, and thus, addiction, to go into overdrive.
• Importantly, the team found that this relationship was a one-way street: giving cocaine before nicotine did nothing. For this effect to take place, nicotine has to come first.

What’s the Context:

• The idea of gateway drugs has been discussed heatedly and at length, with many people pointing out that what most epidemiology studies show is correlation, not causation—just because people start out smoking cigarettes or marijauna and often move to harder drugs doesn’t indicate that cigarettes or marijauna caused the shift.
• While that’s certainly true, this particular study isn’t about observing trends in drug use—it’s a stringent investigation into what biological changes cigarettes might cause that could accelerate cocaine addiction later. It provides the first biological evidence for the gateway drug theory.

The Future Holds:

• This study will be a hard act to follow—it’s admirably thorough, progressing from animal behavior all the way down to the tags on DNA—but it should spur other addiction researchers to see whether nicotine has a similar effect when paired with other drugs. Also, alcohol and marijuana are frequently described as gateway drugs, and it will be interesting to see if they do anything similar to the brain.
• Outside the lab, the more we understand the biological mechanisms behind addiction, the closer we’ll come to figuring out a way to prevent or treat it. The researchers suggest that manipulating the enzyme that nicotine knocks down might be able to do something to reverse the effect.

Reference: Levine, et al. Molecular Mechanism for a Gateway Drug: Epigenetic Changes Initiated by Nicotine Prime Gene Expression by Cocaine. Science Translational Medicine, 2 November 2011: 107ra109

Image courtesy of SuperFantastic / flickr

One of the latest views of the geysers on Enceladus. Credit: NASA/JPL-Caltech/Space Science Institute

Yes Cassini is still out in the Saturn system doing great science, recently The Cassini spacecraft did a flyby of Enceladus getting within 765 miles of the surface and returned some really nice images even if they aren’t calibrated.

Check out the rest at the Cassini website.

A radar image of 2005 YU55 back in 2010 taken by the Arecibo Radar Telescope in Puerto Rico. Image credit: NASA/Cornell/Arecibo

2005 YU55 a 1,300-foot-wide (400 meters) asteroid is set to make a close pass by Earth. The November 8th pass will be no closer than 201,700 miles (324,600 km) will be as close as any of this size since 1976 and we didn’t even know about that one. The next time one will get as close will be in 2028.

Many agencies will no doubt be tracking 2005 YU55 including NASA scientists who will be using the Deep Space Network at Goldstone California and radar observations will done by the Arecibo Planetary Radar Facility in Puerto Rico.

If you have a telescope with an aperture of six inches or more it is possible you could get a glimpse of the asteroid too. Maybe. The asteroid has a surface darker than charcoal. I will be looking if clouds don’t get in the way.

 Read the press release here for much more detail.

An avalanche is captured in progress by the the HiRISE camera aboard the Mars Reconnaissance Orbiter.

Yes, this really is an avalanche in progress and not an artist concept. The HiRISE has captured avalanches before at least since 2008. Thanks to the great resolution possible with HiRISE, the imaging team can zoom in on these areas quite nicely.

The information given with the images pegs the reddish cloud at 600 feet (200 meters) across. You can get all of the details AND a huge assortment of images sizes to suit your desktop at the HiIRISE page for this image. Natually you can get the full res versions too.

The mystery of the 185 A.D. "guest star" has been solved at last. Click for a slightly larger version with a large version linked below. Image credit: NASA/ESA/JPL-Caltech/UCLA/CXC/SAO

Between new observations by the Spitzer Space Telescope and WISE and previous observations by the Chandra X-ray Telescope and ESA’s XMM-Newton Observatory the mystery of the “Guest star” as it was called by the Chinese in 185 A.D. appears to have been solved.

This “guest star” isn’t to be confused with the 1054 supernova that became the Crab Nebula, this one refers to what is regarded as the oldest recorded supernova known, also called Supernova RCW86. Interestingly enough, a paper published in Nature by Y.-N. Chin and Y.-L. Huang in 1994 suggested the interpretation of the the records is not consistent with a supernova and instead suggesting the guest star was a comet. You can’t get the full text online but you can read the abstract of “Identification of the guest star of AD 185 as a comet rater than a supernova’ by looking here.

Here’s the press release with a link to larger versions of the beautiful picture above:

PASADENA, Calif. — A mystery that began nearly 2,000 years ago, when Chinese astronomers witnessed what would turn out to be an exploding star in the sky, has been solved. New infrared observations from NASA’s Spitzer Space Telescope and Wide-field Infrared Survey Explorer, or WISE, reveal how the first supernova ever recorded occurred and how its shattered remains ultimately spread out to great distances.

The findings show that the stellar explosion took place in a hollowed-out cavity, allowing material expelled by the star to travel much faster and farther than it would have otherwise.

“This supernova remnant got really big, really fast,” said Brian J. Williams, an astronomer at North Carolina State University in Raleigh. Williams is lead author of a new study detailing the findings online in the Astrophysical Journal. “It’s two to three times bigger than we would expect for a supernova that was witnessed exploding nearly 2,000 years ago. Now, we’ve been able to finally pinpoint the cause.”

A new image of the supernova, known as RCW 86, is online at http://go.nasa.gov/pnv6Oy. (edit: many different sizes including suitable sizes for a desktop background, be sure to check it out!!)

In 185 A.D., Chinese astronomers noted a “guest star” that mysteriously appeared in the sky and stayed for about 8 months. By the 1960s, scientists had determined that the mysterious object was the first documented supernova. Later, they pinpointed RCW 86 as a supernova remnant located about 8,000 light-years away. But a puzzle persisted. The star’s spherical remains are larger than expected. If they could be seen in the sky today in infrared light, they’d take up more space than our full moon.

The solution arrived through new infrared observations made with Spitzer and WISE, and previous data from NASA’s Chandra X-ray Observatory and the European Space Agency’s XMM-Newton Observatory.

The findings reveal that the event is a “Type Ia” supernova, created by the relatively peaceful death of a star like our sun, which then shrank into a dense star called a white dwarf. The white dwarf is thought to have later blown up in a supernova after siphoning matter, or fuel, from a nearby star.

“A white dwarf is like a smoking cinder from a burnt-out fire,” Williams said. “If you pour gasoline on it, it will explode.”

The observations also show for the first time that a white dwarf can create a cavity around it before blowing up in a Type Ia event. A cavity would explain why the remains of RCW 86 are so big. When the explosion occurred, the ejected material would have traveled unimpeded by gas and dust and spread out quickly.

Spitzer and WISE allowed the team to measure the temperature of the dust making up the RCW 86 remnant at about minus 325 degrees Fahrenheit, or minus 200 degrees Celsius. They then calculated how much gas must be present within the remnant to heat the dust to those temperatures. The results point to a low-density environment for much of the life of the remnant, essentially a cavity.

Scientists initially suspected that RCW 86 was the result of a core-collapse supernova, the most powerful type of stellar blast. They had seen hints of a cavity around the remnant, and, at that time, such cavities were only associated with core-collapse supernovae. In those events, massive stars blow material away from them before they blow up, carving out holes around them.

But other evidence argued against a core-collapse supernova. X-ray data from Chandra and XMM-Newton indicated that the object consisted of high amounts of iron, a telltale sign of a Type Ia blast. Together with the infrared observations, a picture of a Type Ia explosion into a cavity emerged.

“Modern astronomers unveiled one secret of a two-millennia-old cosmic mystery only to reveal another,” said Bill Danchi, Spitzer and WISE program scientist at NASA Headquarters in Washington. “Now, with multiple observatories extending our senses in space, we can fully appreciate the remarkable physics behind this star’s death throes, yet still be as in awe of the cosmos as the ancient astronomers.”