It makes me sad that my fine colleagues and rivals at Science magazine already beat me to this story, but it is too much fun not to note here. There's a poster here at AGU in which seismologists report detecting 'footquakes' - the sound of jubilant soccer fans (football to you British types) celebrating goals during a major competition.

Garrett Euler, of Washington University in St. Louis and colleagues, were initially puzzled by instaneous tremors that appeared to happen all over Cameroon one day soon after the researchers installed new seismic equipment. But finally one of them figured out it was the stomping of joyous fans across the country, each time the Cameroon team scored a goal in the African Cup of Nations. And the stomping got worse the longer the match went on. "Goals that came later in the match - when the tensions were near boiling point - caused substantially larger tremors," they write.

For the full story, go to page 13 of the IRIS seismology newsletter found here.

Posted by Alex Witze on December 13, 2007
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Turns out that Jim Hansen, the outspoken NASA climatologist, didn’t attend John Marburger’s talk on Monday night, in which Marburger (who is President Bush’s science advisor), called accusations of censoring US climate scientists ‘ignorant’.

Hansen, who has long gone public with his thoughts about the problems of human-caused global warming, has said in the past that NASA public-affairs people censored his public speeches and media interviews to play down the risks of climate change. On Monday, Marburger charged that such accusations were baseless, saying that he personally had tracked down each claim and found it to be wanting. Marburger didn’t mention Hansen by name, but the subtext was clear to everyone in the audience.

Asked for his response today, Hansen simply pointed to a new book called Censoring Science: Inside the Political Attack on Dr. James Hansen and the Truth of Global Warming. (I haven’t read it and thus can’t recommend it, but here is a link so you can see at least what it looks like.) According to Hansen, it details a systematic effort to suppress climate scientists such as himself.

Asked if he had ever spoken to Marburger about the issue of censorship, Hansen said simply: “Not about this.”

Hansen isn't just confining his criticisms to US leadership, though. He's got a draft letter in the works to UK prime minister Gordon Brown and the German chancellor Angela Merkel, criticising the planned construction of coal-fired power plants in their countries.

Asked today why he was focusing on these leaders when China is constructing a coal-fired power plant at the rate of nearly one per week, Hansen said he feels that the developed world needs to take responsibility, as it has been the source of the majority of carbon dioxide emissions up until this point.

Posted by Alex Witze on December 13, 2007
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Susan Solomon, an atmospheric scientist and lead author on the 2007 IPCC report, had a handy hint for any future authors attending her lecture today on stratospheric ozone depletion and climate change:

Proofread your papers.

The famous 1974 Nature paper by Mario Molina and Sherwood Roland, describing how chlorofluorocarbon chemicals are the trigger for ozone destruction in the stratosphere, contains an embarrassing typo in its title - one that has endured for more than 20 years of citations.

Check it out here.

Posted by Alex Witze on December 13, 2007
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News from the Arctic just continues to get worse. A fair number of presentations here have been dealing with the dire 2007 conditions for sea ice and the Greenland ice sheet.

First up, Greenland. Last summer, more ice melted atop Greenland than ever before measured, adding to a consistent downward trend of some 135 gigatons of ice disappearing per year. Marco Tedesco, of the Goddard Space Flight Center in Maryland, told the meeting that surface temperatures in Greenland were four to six degrees Celsius warmer than usual this summer, which helped accelerate melting, particularly at high latitudes.

The situation is even more precarious for sea ice. A couple of researchers here have been tossing around dates like 2012 or 2014 for estimates of when the Arctic might be completely ice-free in summer. While these sorts of numbers are pretty arm-waving at the moment (numbers like 2040 were previously considered to be aggressive), there’s little reason to think the situation will get better in the next couple of years. Mark Serreze, of the University of Colorado, spent a keynote lecture on Tuesday showing images of Arctic ice shrinking like a snowman left out too long in the sun. In September of this year, sea ice covered just 4.2 million square kilometers - by far the lowest record ever.

And the ice isn’t only shrinking in extent – it’s also thinning. Don Perovich, of a US army cold regions and research laboratory in New Hampshire, reported on a single but extraordinary ice buoy in the Beaufort Sea. In June the buoy measured sea ice at that location as 3.3 metres thick – “really a healthy piece of ice,” as he put it. But by the end of the summer, 70 centimetres had melted off the top – and 2.2 metres (yes, metres) off the bottom.

When you see those dramatic maps of the Arctic ice extent shrinking over time, don’t forget that it’s also thinning – a complicating factor that may just make things worse in summers to come.

Posted by Alex Witze on December 13, 2007
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NASA Night is always a stressful evening at AGU. Researchers who depend on NASA funding pack into a lecture hall to hear the head of NASA science talk from on high about how dire the funding situation. Everyone usually ends up leaving the room complaining.

Things are a little different this year, though. The new chief of science at NASA is Alan Stern, who for many years was "one of you", as he put it -- a scientist struggling to fly new missions in an era of ever-uncertain NASA budgets. Fortified with a glass of chardonnay, he held forth from the other side of the podium at NASA Night with an approach that some call a refreshing change. (You can read a Q&A piece Nature did recently with Stern here - subscription required.)

The main thing to remember, Stern cautioned the crowd at AGU, is that blaming the budget is not cool. The science mission directorate at NASA gets $5.4 billion a year. That's on the scale of the entire National Science Foundation. It has 53 missions currently flying, and a host more are slated for launch in 2008, such as the GLAST gamma-ray telescope and the Lunar Reconnaissance Orbiter. In other words, NASA's space and earth science programs are the envy of the international research community.

But the big problem is cost overruns. This has been known for some time - projects such as the James Webb Space Telescope, the successor to the Hubble Space Telescope, balloon in cost annually. But Stern made it abundantly clear just how much cost overruns are hurting the science community. Over the past five years, overruns on NASA science missions have cost the agency $5.8 billion. Yes, that's more than a billion dollars a year. The biggest offenders are the James Webb scope, which ran over by $1.3 billion over the past five years, and the SOFIA airborne telescope, at $1.1 billion (and it isn't even flying yet, despite having been finished years ago).

As a result, NASA is going to focus ever more strongly on cost control. "Once you're selected to run a mission, we're going to hold your feet to the fire," says Stern. How he will do that isn't exactly clear, but in many cases it might mean descoping a mission -- taking off an instrument or two -- or placing it in a different, less risky, orbit.

Of course, even with the most stringent belt-tightening measures at NASA, the agency is still subject to the whims of Congress. If Congress goes into the same financial meltdown it did last year, and passes a 'continuing resolution' to keep the government operating at fiscal year 2006 levels, NASA will suffer. A long-term continuing resolution, says Stern, "would almost certainly mean mission cancellations".

Posted by Alex Witze on December 11, 2007
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What a difference a year makes. Last AGU meeting, the evening keynote lecture was by Al Gore. This AGU, Gore was in Oslo, having picked up his Nobel Peace Prize for his climate activism, on the same day President Bush's science advisor John Marburger was giving a lecture here on climate change.

Gore got a standing ovation from the AGU scientists. Marburger got a slew of hostile questions. He probably should have expected this, given the Bush administration's policies on climate change. And lines like "scientists have lost credibility in this debate" didn't help either.

Marburger spoke for about 45 minutes on US climate policy, reinforcing many of the same messages he's put out there before. Bush recognizes the significance of climate change, Marburger argues, and has been saying as much since June 2001. The US is doing plenty to move towards taking action, including hosting a summit of major emitters in September and adopting 'aspirational' goals to improve energy consumption and develop new technologies to deal with it. Too much emphasis is being placed on mitigiation strategies for reducing carbon emissions, instead of adaptation strategies to get people to live differently in a greenhouse world.

Such messages did not go down well with the audience. Questioners pressed Marburger on mandatory emissions caps for US industries (ask Congress, says Marburger); alleged censorship of climate scientists (not a word of truth in it, he argues); and Bush's refusal to move the Kyoto protocol forward (Congress would have stymied it anyway).

Marburger also included a plea for people to read the details of the IPCC technical reports issued this year, not just the policymakers' summaries. Only in the technical reports, he argues, are the details and the complexity that everyone needs to understand in order to make informed decisions about what to do about climate change.

No one's arguing with that. But surely he hadn't forgotten that his very audience was made up of many of those who wrote the IPCC technical reports in the first place -- and they still don't agree with him.

Posted by Alex Witze on December 11, 2007
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Those Mars rovers just keep on trucking. It's been nearly four years since Spirit and Opportunity touched down separately on opposite sides of the red planet, but they're both still going strong. Steve Squyres of Cornell and John Callas of NASA provided an update here on how they're doing - and how they're still making surprising discoveries.

First to Spirit, which has been something of the underdog of the rovers. But finally, scientifically, "it's caught up to Opportunity," said Squyres. And it's all because of a problem mission managers have been cursing for some time: the fact that Spirit's right front wheel is stuck, and whenever they have to move the six-wheeled vehicle they have to drag the stuck wheel behind it like a recalcitrant shopping cart.

But this awkward movement means that there's a deep trench behind the rover wherever it moves. And that recently revealed a glistening white trail in the wheel trench. Chemical analyses show that the stuff is nearly entirely made of silica -- the stuff that makes up glass -- with a touch of titanium. And that, says Squyres, suggests two possible environments: either hot springs or volcanic fumaroles, both of which mean heat plus water -- and potentially life. It's the first time Spirit has found potentially habitable environments, the kind of warm watery places where microorganisms like to thrive.

But Spirit is also running out of time. The Martian winter is approaching, and mission managers have about two weeks to get it into a position where it can catch as much sunlight as possible during the long winter. "It's a scramble" to get it into place in time, Callas told reporters. The rover is running low on battery power -- dust has covered its solar arrays -- and it can move only every other day, taking a rest period in between to recharge its batteries. Rover operators expect the solar arrays to go down to just 30 percent power over the winter - and that may or may not be enough for it to survive. Its first winter, the batteries stayed around 70 percent; the second winter, about 55 percent. The team has many backup plans, such as turning off the survival heater for a miniature chemical analyzer on board, to keep the juice flowing as long as possible.

Meanwhile, on the other side of the planet, Opportunity continues to shine. It is exploring the Victoria crater, grinding holes into the layers of rock formations that encircle the crater like a ring in a bathtub. Opportunity doesn't have such a problem with survival, because the wind patterns there mean that gusts regularly clear off its solar panels.

It's anyone's guess as to how long these rovers might eventually last. But no one can say they've been slackers.

Posted by Alex Witze on December 11, 2007
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...it's 4:15 pm, and the exhibit hall, where the posters are displayed, are already smelling of beer.

Posted by Alex Witze on December 11, 2007
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Join Nature at the American Geophysical Union meeting in San Francisco. Our reporters will be posting diary reports here from Monday 10 December, with all the latest news on the Earth, the ocean, and beyond to the stars.

Posted by Nicola Jones on December 07, 2007
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I had a primo vantage point for this year’s Cell Slam, ably covered by our intrepid reporter Ewen Callaway here. Cell Slam is a free form poetry and performance art competition for life science geeks. There are few rules to follow -- basically three minutes, a mic and no Powerpoint -- and the event drew quite a crowd. I was involved (as an absurdly non-illustrious member of an otherwise illustrious panel of judges, including NYTimes’ Natalie Angier, WaPo’s Rick Weiss, NPR’s Joe Palca, Science’s Jennifer Couzin, and NIH director Elias Zerhouni), so I can’t really cover the event in an official unbiased way. Nevertheless, I thought I’d share just a bit of what went on behind the scenes.

For a competition in which the participants were greatly outnumbered by the judges and in which the prizes would be meagre and unevenly distributed, Randy Hampton the evening’s MC, made the obvious comparison to peer review at the NIH. Hampton, a UCSD researcher and former standup comic took lighthearted potshots at “Dr. Z” with little fear of having his funding pulled. “I lost my funding after this last year,” he said, and so had nothing to lose.

Zerhouni did indeed run things like an NIH study section in the hush, hush, closed, door judging section that immediately followed the acts. “I don’t know if you’ve ever heard of something called ‘triage’” he said, pausing for laughter, “But I think we can effectively triage one of the performances right away.” The unlucky performer, Catholic University’s Roland Nardone, used his three minutes, and then another two and half to make an impassioned plea for more diligence in identifying contamination in cell lines. An important topic, to be sure. Nardone was DQ’d because a lot of judges thought he missed the point that Cell Slam is supposed to be fun. Maybe he would have done better with a rap: “Check your cells before you wreck your cells” comes to mind. For what it’s worth, I applaud him for taking the chance to reach out to a packed room, mostly of young researchers, with a message they might have missed had they not been paying attention in, say 1968. Nevertheless, he still got the lowest score I gave last night (nine thumbs up). Sorry, in my book, time limits are sacrosanct. Better luck next year!

Posted by Brendan Maher on December 05, 2007
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I stopped in for a press briefing today on the origins of life. It’s one of the few talks I’ve seen at the American Society for Cell Biology meeting that had no cells in it whatsoever. One of the great questions of our time has been how complex molecules began to aggregate in meaningful ways and pitch forward into something that could be recognized as life. The Stanley Miller experiments helped establish the idea that some primordial soup gave rise to complex interacting organisms. But folks have recongized that in a vast sea – or even a small puddle, interactions wouldn’t be energetically favourable or concentrated enough to get anywhere. So, folks have proposed that early macromolecules were affixed to clay particles or bubbled through porous rocks that would compartmentalize interactions and provide substrate for advancing enzymatic reactions. Helen Hansma, who is a rotating program director for the National Science Foundation, has another idea and she was at ASCB presenting a poster on it.

While looking at a chunk of mica under a microscope one day, she noticed bits of organic gunk growing in between it’s flaky layers and thought, “Hey that would be a neat place for an organism to thrive.” Having spent years tuning atomic force microscopes to observe biomolecules on mica sheets, she knew how amenable the structure of mica is to interaction. Another clue had her hooked on the hypothesis. No one, she says, has ever adequately explained how cells first obtained potassium. All cells tend to keep potassium in and sodium out despite the vast majority of ions that would have existed in primordial seas would have been sodium. But when the nanometer thick sheets of mica separate they do so by breaking covalent bonds and sometimes releasing free potassium. In her vision of this prebiotic model, mechanical forces of water infiltrating mica sheets could produce energy to power little bioreactors for molecules that stick to the surfaces between. RNA, she says, seems somewhat amenable to binding the surfaces within. So Hansma has added to the soup paradigm, a sandwich!

Posted by Brendan Maher on December 05, 2007
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Since at least June, NIH peer review, the process by which the bulk of U.S. federal funding for biomedical research is meted out, has been under an intense review process by two groups working in parallel. The reason, funding increases haven’t kept pace with inflation and the biomedical research community is feeling the pinch. With slim funding prospects the approval rate for funding proposals has dropped from a historic 25% to somewhere around 10%. At ASCB Keith Yamamoto of UCSF, Mary Beckerle of the University of Utah, and Katherine Wilson of Johns Hopkins University talked about some of the radical ideas that have been floating around to totally revamp the process by which investigators compete for funding. While Yamamoto emphasized that these were not anything like final recommendations that they would be making, he wanted to offer a glimpse of the ideas they’ve been batting around and invite more feedback from the research community, a process that has officially close, but that these three at least say they are still open to. Incidentally Elias Zerhouni, the head at the NIH intends to implement changes to the review process in the first quarter of 2008. Read on for some specifics.

The challenges as Yamamoto and his colleagues presented them are fourfold and presented in no particular order:
1 To reaffirm and emphasize core values of review
2 To support new (read young) investigators
3 To reduce administrative burden
4 To strengthen review leadership and participation through training

While the reasons for these needs are probably apparent to anyone who’s participated in NIH review – either as participant or receiver, just how to address them is a tricky matter. Here are six ideas that Yamamoto outlined. They drew a lot of interest from the participants, and if you weren’t there to offer your feedback last night, please feel free to do so here.

1. An editorial board structure. This was really an overarching theme of the changes they were talking about that models the traditional study section more after an editorial board that is smaller but can request input from outside experts. It slims down study sections to fewer participants and dictates how they respond to proposals. It may even include incentivizing participation in study sections.

2. Shorter applications and processing. The magic number here seemed to be 7 pages. Rather than having researchers give rich detail and background on their work, they’d call for brief distillations of the big ideas, including strong statements as to how a proposed project, if completed, would have an impact on the field. R01s, the primary grant that NIH distributes would be broken into two categories. Most would be innovation on current trends or themes, but researchers could risk applying for transformative, revolutionary kinds of research. For the latter type of grant (estimated at 1% award) Triage would be limited to this single criterion, impact, and if it failed, the submitter would not be encouraged to reapply.

3. Prebuttals. For the majority of grants after initial comments come in via email from different reviewers and technical advisers, major concerns would be sent to the submitter for a prebuttal, prior to the study section meeting to discuss the grant. This is a chance for the submitter to clear any misconceptions or miscommunications in the original application and possibly salvage their chances of getting funded.

4. Straight rankings. Yamamoto suggested doing away with the current differential scoring systems completely and dealing with plain old rankings based on merit.

5. Short reviews on merit only. Rather than providing feedback to submitters on why their grant didn’t make it, reviewers would simply give a clear statement that it didn’t make the cut. Such mentoring would be better provided by the submitter’s colleagues.

6. Discussions led by a primary reviewer. Better training for reviewers and section chairs should lead to succinct presentation of papers to committees. A lot of time was spent on how the study sections should be composed – basically with more generalists and less vested interests. With shorter, less detailed proposals and the rebuttal system in place to allay miscommunication, Yamamoto and his colleagues presented these possibilities as a way of delivering a much more streamlined process that would reward meritous study and close the gap between the scientific have and the have nots.

It’s a deeply truncated list of the wide ranging topics and possibilities they discussed, but they’re obviously leaders in the thought pool. What do you think?

Posted by Brendan Maher on December 04, 2007
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There was an interesting session on epigenetics at ASCB this evening. Epigenetics is a term with a slippery definition, but it is basically the study of changes to the way the genome is managed that are heritable but generally don’t affect the genome sequence itself. A lot of research in this area looks at the histone proteins around which DNA wraps, and the specific chemical modifications that can be made to them that in turn appear to affect gene expression in a persistent way.

One talk by David Katz, a postdoc at Emory focused on specific modifcations made to histones in the germline of an organism – that is the cells that become eggs or sperm and lead to future offspring. Katz works with Caenorhabditis elegans, a roundworm. He looked at methylation on Histone H3. Apparently in developing C. elegans practically every cell shows a good deal of methylation of H3 at the fourth lysine residue (K4). H3K4 is not methylated in the germ cells. Without methylation at this specific spot, the genes that wrap around the histones are more likely to be silenced, which is normal for germ cells. They won’t be needed for a while, so why express them. So, Katz looked to see what happened if he disrupted a so-called demethylase gene that removes these methyl marks. It appeared to have absolutely no effect in the first generation, but after following more than 20 generations of the mutant worms, he noticed that their fertility was dropping off to the point that by the 26th generation (if I saw the graph correctly) the worms are practically sterile. Their oogenesis was highly abnormal. If these results are easily confirmed it is another powerful statement for the effects epigenetic changes might have on the germline over a number of generations, a startling testament to the sometimes slow and subtle effects of epigenetics on reproductive health.

A talk later in the evening focused on histone variants associated with DNA damage and how they co-localize with other DNA damage associated proteins. Unfortunately, however, her powerpoint presentation failed to show any red coloured figures. I’ve never seen anyone’s presentation get so derailed by a technical difficulty. Green spots that revealed the location of one DNA repair protein showed up fine, but the red spots that were supposed to show us where the histones appeared in the cell simply weren’t there. It was impossible to understand what she was trying to show. Eventually she got the presentation working. An Apple computer apparently got her back on track, apparently. But during the minor meltdown, someone behind me commented to a colleague, “Now you know what it’s like to be red/green colour blind.” It is amazing to me that so many people present microarray heat maps and cell biological information in red and green with out considering the 7% to 10% of folks (almost all of them male) that can’t distinguish the two.

Posted by Brendan Maher on December 04, 2007
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I talked to Kai Simons today. He’s the fellow who, I think, had some interesting ideas on new approaches to Alzheimer’s disease research last night. He praised the format of the minsymposium on AD that was designed not to present data but to direct approaches and identify future goals in a field that really has stymied researchers for a time. The style allowed for a lot of discussion and argument, and that’s not something that happens a lot in regular talks. Simons had an interesting take on all this calling out the stodgier aspects of the traditional symposium for not engaging in debate. Simons told me he doesn’t even read abstracts anymore. So often the things folks write up are not what they can present, but what they hope they can present by the time the talk comes up.

But here's some really interesting news. Well, news to me, anyway. Simons is the president of the European Life Science Organization ELSO, a somewhat unique grassroots organization of biologists that contains as many as 40% graduate students. He told me that the efforts of maintaining the organization are no longer feasible and that it would fuse with the much larger European Molecular Biology Organization (EMBO) and eventually disappear. The next ELSO meeting in September in Nice, France is co-sponsored by EMBO in late August and early September. The decision was made in October and announced in EMBO’s most recent newsletter.

Posted by Brendan Maher on December 04, 2007
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OK, I’ve got to admit. I’m a little excited about being a judge at the ASCB 2007 cell slam tomorrow night. For the uninitiated, a cell slam is kind of like a poetry slam -- which are geeky enough on their own -- but adds the extra geeky element of being all about biology. The basic remit is “three minutes, one microphone, no AV.” For the record and in interest of full disclosure, I’ve participated something akin to this before. My colleague Erika Check Hayden caught the action last year, and it sounds like it was quite a trip.

John Fleischman, an information officer for the meeting who’s been promoting the event, tells me that last year he walked up to find the room they’d reserved for the event filled spilling out into the hallway. It was 180 person occupancy room. He cleverly thought, I’ll just open the room divider and instantly double the space. When he went to draw the wall back, he found that the other room was already filled. “The fire marshal was not happy,” he said.

Apparently selling beer was a major draw. This year the event may even get a spotlight. The organizers didn’t have a budget for it. But apparently ASCB found some money for it. Events that popular can’t go unlit. I’m excited to see the acts, but even more excited to query co-judge Elias Zerhouni on the revamp NIH peer review is getting. More on that later.

Posted by Brendan Maher on December 04, 2007
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Olive Heffernan, editor of Nature Reports Climate Change, is at the UN Framework Convention for Climate Change meeting in Bali for the next two weeks. You can read her diary reports from the event on the Climate Feedback blog.

Check out all of Nature's coverage in our special.

Posted by Nicola Jones on December 03, 2007
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I had a chance to ask ASCB president Bruce Alberts what had him excited about this year’s meeting. He directed me to a session (actually two sessions) that take a bit of a departure from the usual format. I went to the working group symposium on the cell biology of Alzheimer’s disease (AD). Rather than present data, we got outlines of future prospects and directions from two established experts in AD research and two cell biologists who have come to study AD from different directions. Audience participation was encouraged, and it made for some good arguments that I daresay seemed the slightest bit productive. I’ll warn you that there’s a bit of alphabet soup coming, but bear with me, there are some neat new ideas here.

The proposition that Amyloid Beta (AB) plaques are a causative entity in Alzhiemer’s disease generated some lively debate. AB plaques are one of several types of proteinaceous clumps that are closely associated with brains affected by AD. They’re made when a protein of unknown purpose called Amyloid Precursor Protein (APP) is cut in two very specific places releasing an AB protein fragment that aggregates in the spaces between neurons and appears associated with said neurons atrophying and wasting away, but there are doubts that the plaques themselves are causing the problems.

There are good reasons to believe that AB-aggregate formation is causative. Several mutations associated with increased risk for the disease appear in APP itself or the proteins that process it. Nevertheless, it’s clear this isn’t the whole story. It may be intermediate building blocks of of the plaques, so called soluble AB aggregates. Or AB formation might be a response to some other pathological factor. A presentation by AD expert Gopal Thinakaran, from the University of Chicago, drew some sharp critiques that AB has really become a ‘lamp post.’ This is a reference to an old joke about a drunk searching for his keys under a streetlight. A policeman comes along and asks, “Did you lose them here?” The drunk replies, “No, but the light’s better here.” AB may not be the best target, but it's one of the most studied aspects of AD.

Nevertheless, I believe a lot of light came out in this meeting. AD specialist Lennart Mucke of the Gladstone Institute challenged the group with a number of imperatives, but in a more offhand statement he opined how AB clustering around blood vessels is “vastly understudied.” Kai Simons, a self proclaimed AD amateur from Max-Planck-Institute of Molecular Cell Biology and Genetics in Dresden, talked about how his specialty, investigating the dynamics of lipid rafts in cell membranes, could point to new therapeutic targets in minimizing the production of AB fragments. The implication of lipids jives with a well known variant of the ApoE gene known to increase risk for AD. William Balch, of Scripps Research Institute in La Jolla Calif., talked about the program of aging. (We've got a neat story on an institute devoted to this kind of research in our current issue.) Apparently interfering with an insulin growth factor receptor protein in C. elegans not only extends life in worms, it reduces the toxicity of aggregating proteins. Surprisingly (or not surprising to some, I suppose), the reduction in toxicity didn’t necessarily mean that the worms faced fewer heavy protein aggregates. He made a plea for more cell biologists to start looking into the problems of AD.

People seemed genuinely excited by the debate and discussion. Hats off to Alberts for the great suggestion. I wonder if the other working group session he suggested (on the nature of cytoplasm) was as lively. If anyone made it, I’d love to hear how it went.

Posted by Brendan Maher on December 03, 2007
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This week, somewhere in the neighbourhood of 7500 biologists descend upon Washington DC for the American Society for Cell Biology. I made it here today just in time to hear a lecture given by Alejandro Sanchez Alvarado, a Howard Hughes Medical Institute Investigator at University of Utah, who’s been using the planarian Schmidtea mediterranea as a model for regeneration. His website has beautiful pictures. Planarians are regenerative heroes -- long know for their ability to completely redevelop from pieces as small as 1/279th of the original. And even though they’re strange – they have a mouth that doubles as an anus that Sanchez Alvarado calls a “manus” – they are actually surprisingly complex. Thomas Hunt Morgan studied them and did a great job of characterizing their regenerative abilities, but when genetics came on the scene at the turn of the 20th century, the planarian was left behind in favour of more genetics friendly organisms like Drosophila.

But developments in the past decade have changed that. The 800 Mb genome of planaria has been sequenced, and manipulating genes is possible thanks to RNA interference. His group can shut down any gene they want just by feeding it bacteria engineered to produce short RNA strand specific to that gene. I’ve spoken with Sanchez Alvarado before, and I find his work fascinating. He talked about a number of projects he’s been exploring with the tiny worms, including investigating the properties of so-called neoblasts, a population of stem cells that exists almost everywhere in the organism and appears responsible for its regenerative prowess. A particularly interesting project, however, was a follow up from an 1898 paper written by Morgan. Morgan cut a very thin slice from the middle of a planarian and watched it regenerate. For a piece cut from the middle of the worm, normally the head end (anterior) would regenerate a head and the tail end (posterior) would regenerate a tail. Instead these slices grew into worms with two heads and no tail. Morgan called them ‘janus,’ not to be confused with the worm’s ‘manus.’ And he apparently wrote in the paper: “There is something here that is important to find an explanation for.”

Using RNA interference to tinker with genes known for their roles in setting up anterior/posterior polarity (these are genes from the Wnt pathway, which was discovered in Drosophila), Sanchez Alvarado’s group has recreated the janus worms. When they fed the worms RNA designed to block the production of beta catenin and cut the worms up, pieces from the middle grew two heads. By blocking a gene that is known to work antagonistically with beta catenin, known as APC, the group was able to produce these freakish worms with no heads – just two tails. The videos Sanchez Alvarado showed were great … the two tails battled against one another in a pushmepullyou fashion.

For folks who know their fly genetics this probably isn’t too surprising, but I’m fairly amazed at how well the pathways are conserved and that they work not only in the early development of the organism, but in the maintenance of developed organ structures and their ‘re-development’ in the regenerative program. Also, when silencing a gene very high up in the pathway, the group found they got no phenotype, which suggests that there may be another sequence of genetic events running the pathway in this instance. The E.E. Just lecture is a minority in science award to honour Sanchez Alvarado, a native of Venezuela, for his pioneering work in rejuvenating this classic model for regeneration. What a great first lecture to fall into!

Posted by Brendan Maher on December 03, 2007
Categories: American Society for Cell Biology | Permalink | Comments (0) | TrackBacks (0)