NGC 1309

Hubble Snaps Images of a Pinwheel-Shaped Galaxy

Recent observations of the galaxy taken in visible and infrared light come together in a colorful depiction of many of the galaxy's features. Bright blue areas of star formation pepper the spiral arms, while ruddy dust lanes follow the spiral structure into a yellowish central nucleus of older-population stars. The image is complemented by myriad far-off background galaxies.

NGC 1309 - click for 800×746 image

A very similar galaxy is actually known as the Pinwheel Galaxy (Messier 101, NGC 5457). More information: here.

Alzheimer's disease

Progress in understanding -- let alone treating -- Alzheimer's disease has been painfully slow. But a few interesting clues have turned up recently.

Alzheimer's Found To Be Mostly Genetic

Alzheimer disease has a genetic cause in up to 80 percent of cases, according to a USC-led study of nearly 12,000 twin pairs.

A twin study like this one involves analyzing data on identical twins. (Twin pairs that are not identical, and therefore do not have identical DNA, provide much less information about genetic effects). The study can give a statistical figure for the percentage of risk for some condition (Alzheimer's disease in this case) that is attributable to genetics. In this case, the risk is 79% (with 95% confidence). The implication is that in only about one fifth of identical twin pairs the disease will develop in one of the twins but not the other, presumably on account of some sort of environmental influence. In fact, in only about 45% of pairs where one twin has developed the disease has it appeared in the other also -- though it may well appear if the other twin lives long enough.

The general belief up to now has been that there are two types of Alzheimer's disease: "familial", or "early onset", (having a genetic basis) and "sporadic", or "late onset", (due more to random environmental factors). This study raises doubts about that assumption, although environmental factors may still play a role, such as by acting on genetic predispositions.

At least one genetic factor is already well known to indicate an increased risk for the disease: the so-called epsilon4 allele of the apolipoprotein E (ApoE) gene. (An allele is one variant of a gene that exists in several forms.) The ApoE protein is an interesting one, which normally regulates cholesterol metabolism. The epsilon4 allele has been associated with cardiovascular disease, such as atherosclerosis -- as well as Alzheimer's disease.

There is recent research indicating that the presence of ε4 ApoE is associated with differences in brain function that can be detected with an fMRI scan even before any other Alzheimer's disease symptoms are observable:

Epsilon4 allele carriers show altered brain activity before onset of Alzheimer’s symptoms

Healthy individuals who are at risk of Alzheimer’s disease show reduced activity in the hippocampal region of the brain when performing tasks related to forming new memories. In a study published today in the open access journal BMC Medicine, individuals carrying the apolipoprotein E (APOE) epsilon4 allele, which has previously been associated with high risk of developing Alzheimer’s disease (AD), showed altered brain activity compared to APOE epsilon3 homozygotes. According to the authors of the study, this supports the idea that certain regions of the brain exhibit functional decline associated with the AOPE epsilon4 allele, and this decline begins before the onset of AD symptoms.

What's new here is that changes in memory-related brain function associated with ApoE/ε4 show up before actual disease symptoms.

Given that the ApoE/ε4 allele is associated with abnormalities in the metabolism of lipoproteins, which assist in carrying fats in the bloodsteram, it's interesting that other recent research has shown a correlation between obesity and development of Alzheimer's:

Jefferson Scientists Discover Mechanism Tying Obesity to Alzheimer’s Disease

A team led by researchers at the Farber Institute for Neurosciences at Thomas Jefferson University in Philadelphia and Edith Cowan University in Joondalup, Western Australia has shown that being extremely overweight or obese increases the likelihood of developing Alzheimer’s. They found a strong correlation between body mass index and high levels of beta-amyloid, the sticky protein substance that builds up in the Alzheimer’s brain and is thought to play a major role in destroying nerve cells and in cognitive and behavioral problems associated with the disease.

Of course, this does not necessarily mean that obesity "causes" Alzheimer's. It could be that ApoE/ε4 plays a role in promoting both conditions. It would be interesting to know whether this research took ApoE or other genetic factors into account. The only allusion to this in the press release is:

According to, Dr. Gandy, evidence has emerged over the last five years that many of the conditions that raise the risk for heart disease such as obesity, uncontrolled diabetes, hypertension and hypercholesterolemia also increase the risk for Alzheimer’s. Yet exactly how such factors made an individual more likely to develop Alzheimer’s remained a mystery.

What's the possible connection? Perhaps it's myelin, a substance that is an electrically insulating phospholipid (a type of fat) layer that surrounds the axons of many neurons. This covering of the axons is known as the myelin sheath. It is not present around young neurons, but builds up slowly in the process known as myelination. Myelination, and hence brain maturity, is not complete in humans until adulthood. Myelinated neurons conduct electrical signals much faster than unmyelinated ones. And so, anything that disrupts existing myelination can cause pathology. Yet another piece of recent research connects this to Alzheimer's:

Imaging Study Links Key Genetic Risk Factor for Alzheimer Disease to Breakdown of Myelin Insulation Coating Brain Cell Connections

A new UCLA imaging study shows that age-related breakdown of myelin, the fatty insulation coating the brain's internal wiring, correlates strongly with the presence of a key genetic risk factor for Alzheimer disease.

The findings are detailed in the January edition of the peer-reviewed journal Archives of General Psychiatry and add to a growing body of evidence that myelin breakdown is a key contributor to the onset of Alzheimer disease later in life.

The press release continues:

Myelin is a sheet of lipid, or fat, with very high cholesterol content — the highest of any brain tissue. The high cholesterol content allows myelin to wrap tightly around axons, speeding messages through the brain by insulating these neural "wire" connections.

As the brain continues to develop in adulthood and as myelin is produced in greater and greater quantities, cholesterol levels in the brain increase and eventually promote the production of a toxic protein that attacks the brain. The protein attacks myelin, disrupts message transfer through the axons and eventually can lead to the brain/mind-destroying plaques and tangles visible years later in the cortex of Alzheimer patients.

The Apolipoprotein E (ApoE) genotype is the second most influential Alzheimer risk factor, after only advanced age. The study used MRI to assess myelin breakdown in 104 healthy individuals between ages 55 and 75 and determine whether the shift in the age at onset of Alzheimer disease caused by the ApoE genotype is associated with age-related myelin breakdown.

The results show that in later-myelinating regions of the brain, the severity and rate of myelin breakdown in healthy older individuals is associated with ApoE status. Thus both age, the most important risk factor for Alzheimer disease, and ApoE status, the second-most important risk factor, seem to act through the process of myelin breakdown.

Looks like the case that ApoE/ε4 is implicated with Alzheimer's is getting pretty convincing, no? But wait. We're not done yet. There's also this:

Region of DNA strongly associated with Alzheimer's disease

An international team of researchers, led by investigators at Washington University School of Medicine in St. Louis, are zeroing in on a gene that increases risk for Alzheimer's disease. They have identified a region of chromosome 10 that appears to be involved in risk for the disease that currently affects an estimated 4.5 million Americans.

"There are a few genes that have been implicated in the development of early-onset Alzheimer's disease, but other than APOE, no genes have been found that increase risk for the more common, late-onset form of the disease," says principal investigator Alison M. Goate, D. Phil., the Samuel and Mae S. Ludwig Professor of Genetics in Psychiatry at Washington University. "The region of DNA identified in our study showed evidence of replication in four independent series of experiments. I haven't seen a putative risk factor show such consistent results since the e4 variant of the APOE gene was identified as a risk factor for late-onset Alzheimer's disease more than 10 years ago."

What these researchers have found is different from ApoE, because their results come from a search for single-nucleotide polymorphisms (SNPs) -- i. e., gene variations -- on chromosome 10. They found only a single SNP on chromosome 10 that was consistently associated with Alzheimer's. It isn't related to ApoE, which is on chromosome 19.

"The region of DNA implicated in our study contains six genes," Goate says. "We don't know which of those genes is most likely to harbor this particular risk factor for Alzheimer's disease, but we're getting closer. We're now trying to nail down which one of these six genes is the most likely to be involved."

Goate expects between five and 10 genes eventually will be implicated as possible risk factors for late-onset Alzheimer's disease, and she says it's possible that more than one of those genes is located on chromosome 10.

"One thing we're trying to do at a functional level is to see whether any of the six genes that we've identified might be involved in pathways that we already know are related to Alzheimer's disease," she says. "For example, we know amyloid-beta peptide plays a role, so we want to see whether any of these genes might have a role in amyloid-beta metabolism.

"We don't really know the nature of this risk factor yet. What we can say is that we believe we know where it's located, and we know there are six genes in that region. But there also could be other regulatory elements within that strand of DNA that don't directly produce a protein but may somehow affect proteins produced elsewhere in the genome. At this point, we can say that there is a variant in this region of DNA that is increasing risk for Alzheimer's disease, but we can't yet say how," Goate says.

There's one more piece of recent research which has nothing (apparently) to do with ApoE, but might implicate whatever gene the preceding research seems to have found on chromosome 10:

Fruit Fly Reveals A Potential Connection Between Dementia And Cancer

Neurons in the brain generally do not divide. It is therefore perplexing that in Alzheimer's disease, and other dementias associated with a protein called tau, dying neurons actually re-express proteins normally seen during cell division or in cancer. It has previously been unclear whether such cell-division proteins cause neuronal death, protect neurons from death, or are irrelevant.

In the present work, the researchers used a fruit-fly model of Alzheimer's disease to examine the relationship of cell-division proteins to neurodegeneration. The power of this model, which recapitulates key features of the human disease, lies in the ability to use genetic tools to establish a causal connection between a molecular pathway and neuronal death. Khurana and colleagues found that, as in human disease, abnormal expression of cell-cycle proteins accompanied neuronal death in their fly model. Most importantly, loss of neurons could be prevented when the cell cycle was genetically blocked or when flies were fed anticancer drugs. Cell-cycle activation depended upon a hyperactive cell growth molecule, TOR (target of rapamycin), also known to be abnormally activated in Alzheimer's disease.

Is there a connection here? At this point it's anyone's guess. But there certainly seem to be signs of progress here.

What would be really, really interesting to know is how any of these results are related to the pathological conditions that have long been known to be associated with Alzheimer's. Namely the presence of plaques outside the neurons consisting of beta amyloid protein fragments, and neurofibrillary tangles inside of neurons consisting of tau protein.

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Tags: Alzheimer's disease, health, Apolipoprotein E, neuroscience

Artificial gene design and synthesis

An individual molecule of DNA can be quite large, but it's made up entirely of four different units ("bases") plus a simple chemical backbone to which the bases are attached. DNA normally consists of two such strings of bases twisted together, and genes are just segments of this double-stranded DNA. Typically, a gene contains from less than a hundred to upwards of ten thousand complementary pairs of bases.

Proteins are constructed from different units: 20 particular amino acids (out of a much larger number). The sequence of these amino acids in a protein is determined by the sequence of bases in a corresponding gene. There are some subtleties to this process, but in general it is possible in principle to construct a protein with any desired sequence of amino acids by first constructing an appropriate gene, and then allowing the existing gene transcription process of a cell to build the protein.

Proteins are the main chemical entities that make up cells and control most processes within cells. Now there is Web-based software to construct appropriate genes for making just about any protein one might want.

Web program simplifies artificial gene design

A web-based program that simplifies many tricky steps involved in designing artificial DNA has been released by US microbiologists.

The software suite, called GeneDesign, should make it easier for researchers to modify and study DNA. The cost of gene synthesis is rapidly falling with dozens of companies around the world now offering to create genes to order from the chemical components of DNA.

Tags: gene, artificial gene, synthetic biology, biology

Headaches at NASA

It has not been a good couple of weeks for NASA. Things are not going well there. Not well at all. You've probably read about some of the recent problems in the news, but there have been so many, it's hard to keep them all straight.

A few months ago, it was possible to look forward to great things from NASA's scientific research program. Now the outlook is much bleaker.

Let's take the most recent bad news -- such as interference with and censorship of contacts between NASA scientists and the outside world -- first and work backwards.

On Thursday the New York Times ran a story detailing additional incidents of poltical pressure to restrict or alter disclosure of scientific information by NASA scientists: Call for Openness at NASA Adds to Reports of Pressure.

Top political appointees in the NASA press office exerted strong pressure during the 2004 presidential campaign to cut the flow of news releases on glaciers, climate, pollution and other earth sciences, public affairs officers at the agency say.

The disclosure comes nearly two weeks after the NASA administrator, Michael D. Griffin, called for "scientific openness" at the agency. In response to that, researchers and public affairs workers at the agency have described in fresh detail how political appointees altered or limited news releases on scientific findings that could have conflicted with administration policies.

We'll revisit a little later some of the earlier reporting about this topic. But there are a couple of interesting points to take special note of. First, the political watchdogs monitoring NASA's public relations are especially keen to enforce approved terminology. Recall how it quickly became verboten last year to refer to the Administration's proposed "personal" Social Security accounts as "private" accounts. Likewise, the Administration has a strict policy about how global warming can be described:

In a more recent example of possible political pressure at the agency, press officers and scientists cited an e-mail message sent last July from NASA's headquarters to its Jet Propulsion Laboratory in Pasadena, Calif. It said a Web presentation describing the uncontroversial finding that Earth was a "warming planet" could not use the phrase "global warming." It is "standard practice," the message went on, to use the phrase "climate change."

The second observation is that the Administration -- and its Congressional supporters -- has a standard talking point that addresses allegations of political interference with science:

"The issue is where does science end and policy begin," said David Goldston, chief of staff to Representative Sherwood Boehlert, chairman of the House Science Committee.

This talking point goes back at least to the time of the statement in early 2004 of the Union of Concerned Scientists regarding Restoring Scientific Integrity in Policymaking. Immediately after that statement came out, the president's science adviser, John Marburger, started making the rounds to inform everyone who would listen that the Administration, of course, had no problem with scientists talking about science. They simply should not talk about science as it relates to public policy, or vice versa, because so many other factors in addition to scientific facts affect public policy. (For instance, the need of oil companies to make huge profits.)

OK, fine. But clearly the Administation wants to go far beyond a legitimate distinction between scientific facts and public policy. Otherwise, why insist on using the hazy term "climate change" instead of the very factual and accurate "global warming"?

To his credit, Griffin seems to be doing the right things, according to the Washington Post on Friday: NASA to Draft New Rules for Media Office:

NASA Administrator Michael D. Griffin said yesterday he has convened a team of scientists and public information officials to draft new guidelines to ensure that news of agency research or events will not be tailored or curtailed to reflect political or ideological bias.

NASA's 2007 budget

And right in the middle of this guerrilla warfare between NASA scientists and the political PR flacks, the Administration's 2007 budget proposal for NASA was announced on February 6.

The Planetary Society, which is certainly not a disinterested observer, but does strongly support both manned and unmanned space exploration and science missions, described the 2007 budget as follows: NASA 2007 Budget: Science Not Just Cut -- It Was Eviscerated. The Society's Executive Director Louis Friedman bluntly explained the problem: "As one Washington official put it, 'Science and exploration have to pay the bill for the shuttle.'"

A further public statement elaborates on criticism of placing funding for the Shuttle ahead of everything else:

Full funding of the shuttle was the result of political pressure from Congressional representatives from areas with vested interests in shuttle work, as well as international pressure from partners focused on completing the space station.

Friedman questioned the realism of the shuttle's even being able to do 17 more flights in any reasonable time period (before 2010) and said, "Investing in the shuttle is an investment in the past. NASA should be investing in the future."

I'll come back to the Shuttle issue at the end of this article.

While The Planetary Society can fairly be regarded as a "special interest group", members of Congress -- even Republicans -- are also quite upset with the NASA budget, as came out in a hearing before the House Science Committee on Thursday: Congress Criticizes NASA Budget Request

The House Science Committee’s Republican chairman and senior Democrat told NASA Administrator Mike Griffin they had little interest in accelerating the U.S. space agency’s exploration plans at the expense of science and research.

Republican committee chairman Boehlert further stated

“I am extremely uneasy about this budget, and I am in a quandary at this point about what to do about it,” [Sherwood] Boehlert told [NASA Administrator Mike] Griffin. “This budget is bad for space science, worse for Earth science, perhaps worse still for aeronautics. It basically cuts or de-emphasizes every forward looking, truly futuristic program of the agency to fund operational and development programs to enable us to do what we are already doing or have done before.”

How convenient that Earth science -- a lot of which involves studies of global warming... oops, climate change -- will be cut way back! Didn't Bush once or twice say that we couldn't be sure about global warming without more studies?

A very good New Scientist article from February 7 echoes the same themes: NASA to divert cash from science into shuttle. It lists some of the key scientific programs that would be delayed indefinitely or simply canceled. Two of these are designed to search for extrasolar planets and would tell us much about the existence of other planets like ours around other stars. These are the Space Inteferometry Mission (delayed at least three years) and the Terrestrial Planet Finder (delayed indefinitely). Two other missions, proposed to be delayed indefinitely, had been designed to study profound questions of cosmology -- the Laser Interferometer Space Antenna, to search gravitational waves predicted by Einstein's general theory of relativity, and Constellation-X, to study black holes.

And that's not the end of the list of programs to be cut or delayed. Also on the chopping block are several robotic missions to Mars (the Mars Sample Return Mission and the Mars Telecommunications Orbiter), and a mission to Jupiter's moon Europa, considered by many planetary scientists to be the most likely place in the solar system besides the Earth to harbor some form of life.

FBI investigation of NASA's Inspector General

Continuing back in time a few more days to February 3, the Washington Post ran this rather alarming story: NASA's Inspector General Probed

An FBI-led watchdog agency has opened an investigation into multiple complaints accusing NASA Inspector General Robert W. Cobb of failing to investigate safety violations and retaliating against whistle-blowers. Most of the complaints were filed by current and former employees of his own office.

Written complaints and supporting documents from at least 16 people have been given to investigators. They allege that Cobb, appointed by President Bush in 2002, suppressed investigations of wrongdoing within NASA, and abused and penalized his own investigators when they persisted in raising concerns.

The complaints are being reviewed by the Integrity Committee of the President's Council on Integrity and Efficiency. The complaints describe efforts by Cobb to shut down or ignore investigations on issues such as a malfunctioning self-destruct procedure during a space shuttle launch at the Kennedy Space Center, and the theft of an estimated $1.9 billion worth of data on rocket engines from NASA computers.

In documents obtained by The Washington Post and in interviews, NASA employees and former employees said Cobb's actions had contributed to a lack of attention to safety problems at NASA.

The petitioners also said Cobb had disregarded the inspector general's mandate to root out "waste, fraud and abuse" and caused dozens of longtime NASA employees to leave the IG's 200-person office and seek investigative work elsewhere.

What's this? NASA's own inspector general being investigated for malfeasance? Rather incredibly, I haven't seen any further reference or follow-up on this story. I'd surely like to hear more about this!

Among other revelations in this article we find:

Cobb, a 1986 graduate of George Washington University's law school, became NASA's inspector general on April 22, 2002, after working for a year as an ethics lawyer in the office of the White House General Counsel.

Under the Inspector General Act of 1978, the president appoints independent officials to monitor Cabinet departments and larger federal agencies through audits and investigations. Cobb is among four of 11 inspectors general appointed by Bush who previously worked in the White House, and one of nine with no audit experience.

Uh huh. Cobb is a former White House employee appointed as an agency inspector general -- one of nine out of eleven people Bush appointed to such a position without any audit experience. Another Michael Brown. Is anyone surprised?

Political censorship of scientific information

On January 29, the New York Times reported that NASA's top climate scientist, James Hansen, claimed he was being censored by political public relations appointees within NASA: Climate Expert Says NASA Tried to Silence Him. It was this claim that led to the reports of additional scientific censorship discussed at the beginning of this article.

The Hansen story has been extensively reported on, so I'll try to be brief here. As usual, Administration flacks claim that all they want is to avoid the appearance that scientists are speaking for the government when they discuss issues of public policy. But scientific facts inevitably have implications for public policy, so the two cannot be separated as neatly as the flacks would like. However, Hansen responds that this restrictive policy

prevented the public from fully grasping recent findings about climate change that point to risks ahead.

"Communicating with the public seems to be essential," he said, "because public concern is probably the only thing capable of overcoming the special interests that have obfuscated the topic."

Clearly, Hansen isn't neutral about public policy implications of the scientific facts. Although his opinions certainly should not be taken as the official government position, the public interest equally certainly requires that top scientists be allowed to inform the public about scientific facts -- even if these scientists happen to be employed by the government. Here's a New Scientist article on the same story: Top climatologist accuses US of trying to gag him.

Less than a week later, on February 4, NASA administrator Michael Griffin came out strongly in support of his scientists: NASA Chief Backs Agency Openness

A week after NASA's top climate scientist complained that the space agency's public-affairs office was trying to silence his statements on global warming, the agency's administrator, Michael D. Griffin, issued a sharply worded statement yesterday calling for "scientific openness" throughout the agency.

"It is not the job of public-affairs officers," Dr. Griffin wrote in an e-mail message to the agency's 19,000 employees, "to alter, filter or adjust engineering or scientific material produced by NASA's technical staff."

All well and good. But a bit further on in the article was this little tidbit:

In October, for example, George Deutsch, a presidential appointee in NASA headquarters, told a Web designer working for the agency to add the word "theory" after every mention of the Big Bang, according to an e-mail message from Mr. Deutsch that another NASA employee forwarded to The Times.

Hmmmm. A presidential appointee is trying to tamper with scientific documentation in order to advance a religious agenda. How on Earth does that have anything to do with keeping scientists away from meddling with public policy? Might government biologists next be censored when discussing evolution? Yup, could be!

It turns out that this Deutsch guy was also involved with asserting more control over Hansen's public statements:

The Big Bang memo came from Mr. Deutsch, a 24-year-old presidential appointee in the press office at NASA headquarters whose résumé says he was an intern in the "war room" of the 2004 Bush-Cheney re-election campaign. A 2003 journalism graduate of Texas A&M, he was also the public-affairs officer who sought more control over Dr. Hansen's public statements.

In October 2005, Mr. Deutsch sent an e-mail message to Flint Wild, a NASA contractor working on a set of Web presentations about Einstein for middle-school students. The message said the word "theory" needed to be added after every mention of the Big Bang.

The Big Bang is "not proven fact; it is opinion," Mr. Deutsch wrote, adding, "It is not NASA's place, nor should it be to make a declaration such as this about the existence of the universe that discounts intelligent design by a creator."

It continued: "This is more than a science issue, it is a religious issue. And I would hate to think that young people would only be getting one-half of this debate from NASA. That would mean we had failed to properly educate the very people who rely on us for factual information the most."

This produced quite a strong and immediate reaction from the blogosphere, such as this from AMERICAblog: 24 year old Bush political appointee tells NASA to push "intelligent design by a creator". (Very worth reading, as it expands on the global warming issue.)

But the best was yet to come. Blogger Nick Anthis at The Scientific Activist, himself a graduate of Texas A&M (as Deutsch claimed to be), on February 6 revealed that George Deutsch Did Not Graduate From Texas A & M University! So, not only was this Deutsch unqualified for his job, like so many of the Administration's political appointees, he was also mendacious -- like so many of the Administration's political appointees.

Two days later, Deutsch resigned. See here, here, here. Read 'em and weep.

But the scientific censorship story is far from finished (unfortunately). And James Hansen is not letting go of it: Censorship Is Alleged at NOAA (2/11/06)

James E. Hansen, the NASA climate scientist who sparked an uproar last month by accusing the Bush administration of keeping scientific information from reaching the public, said Friday that officials at the National Oceanic and Atmospheric Administration are also muzzling researchers who study global warming.

Russia may beat NASA to the Moon

Let's get on to other problems at NASA. Recall George Bush's grand vision for space exploration -- you know, the one which calls for Americans to return to the Moon by 2020, which Bush grandiosely proposed in his 2005 State of the Union address, which has been such a disaster for NASA's budget, and which wasn't even mentioned in the 2006 State of the Union. Yeah, that grand vision.

Now, it's 2006, so we're not talking about any breakneck crash program. 2020 is fourteen years away. Recall that JFK proposed the first American program to plant our flag on the Moon in 1961. Merely eight years later, in 1969, we were there. But now it's going to take us fourteen years to do the same thing? Even though we designed, built, tested, and flew the whole damn project once already! What happened? Did someone lose the engineering plans, and NASA has to do the whole thing over again from scratch using modern computers? Oh, right. The computers probably run Microsoft Windows. Or maybe Bush plans to put Michael Brown in charge of the project. Nevermind. Forget I even asked.

But here's the really bad news. Russia may already be on the Moon in 2020, waiting for us when we get there: Russia plans mine on the moon by 2020.

Take that with a big grain of salt. But it sure would be funny if it turned out that way, wouldn't it?

The Space Shuttle and the International Space Station

Let's finish up with a few words about the Space Shuttle program, which crashed and burned in the Columbia disaster just over three years ago. The more than $6 billion a year that goes into that program, even though the whole thing will be mothballed in 2010, seems to be sucking all the air out of NASA's budget, so it has to be regarded as a major part of NASA's malaise.

Since that disaster in early 2003, NASA has been able to fly a Shuttle only once, in July 2005. It was discovered that the problem with dangerous shedding of foam insulation that doomed Columbia was still not fixed. The next attempt to get things right is scheduled, at this time, for May. NASA is hoping to pull off at least 17 more Shuttle flights before the program is ended in 2010.

In 2010, the Shuttle program will have been in existence for almost 40 years, not counting preliminary studies. Almost 30 years will have passed since the first orbital flight. Although it's no surprise that the Shuttle will then be considered obsolete and unsuitable for further use, hardly any planning or preparations for a replacement have been done until recently. No one will be surprised if a replacement isn't ready in 2012 or so, as currently planned.

But then, the only mission for the Shuttle or a similar vehicle in this time frame (except, prehaps, one final servicing mission for the Hubble Space Telescope) is completion of the International Space Station (ISS). NASA found that most other missions originally foreseen for the Shuttle, such as launches of satellites and space probes, could be done more cost-effectively and reliably with conventional unmanned vehicles.

As for the Space Station itself, if and when it is completed in 2010, its scientific value remains at least as questionable as it has always been. At present, almost no scientific work is being done on the ISS, because the two-person crew has little time to do anything beyond necessary maintenance. Whether much of anything useful is done once the ISS is completed remains to be seen.

Of course, this whole boondoggle isn't mostly NASA's fault. From the beginning, the main purpose of the ISS has been other than science. The purpose, in part, has been to justify continued funding of the Shuttle, which by 2010 will have consumed about $175 billion. And in turn, the main (though never officially acknowledged) reason for continued funding of the Shuttle has been a combination of (1) furthering the military's desire to ensure its control of near-Earth space, (2) furthering the goal of NASA, the military, and their contractors to keep their spacecraft engineering teams employed, and (3) keeping that stream of funds flowing to the contractors and to politically strategic geographic regions of the country (especially Florida and Texas).

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Tags: NASA, Space Shuttle, International Space Station

Just for Valentine's day...

Can't allow this to pass without mention.

Penetrative sex the answer to speaking nerves

Stuart Brody, a psychologist at Britain's University of Paisley, compared the impact of different sexual activities on blood pressure when a person later undergoes a stressful experience.

Brody asked 24 women and 22 men to keep a diary of their sexual activities for two weeks.

The volunteers then underwent a stressful ordeal that involved making a speech in public and doing mental arithmetic out loud.

Volunteers who had had penetrative sex during the previous week or so had the least stress, and their blood pressure returned to normal fastest after their test.

Penetrative sex was far more effective in this regard than masturbation or oral sex. But those who had abstained completely from any sexual activity had the highest stress levels and blood pressure of all.

Something to keep in mind for the next time your boyfriend/girlfriend/spouse complains that you're seeming cranky or irritable.

And there may be some serious science behind this finding. Brody speculates that the hormone oxytocin may account for this calming effect of sex. The Wikipedia article suggests that (among other things) oxytocin is

Thought to induce pair bonding in people. Plasma concentrations of oxytocin have been reported to be higher amongst people who claim to be falling in love. It is also thought that oxytocin might mediate other forms of pair bonding such as friendship and family relationships as given above. Reduction of sociophobic behavior was shown after treatment with oxytocin.

Perhaps oxytocin tablets might be a more appropriate gift for Valentine's day than chocolate...

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See also: Sex before stressful events keeps you calm

Tags: stress, sex, health, oxytocin, Valentine's day

207th AAAS meeting

The American Astronomical Society holds two main meetings a year, at which major research findings are announced and presented. The most recent meeting, the 207^th, was held in Washington, DC January 8 through 12.

This meeting had an unusually large number of especially interesting research presentations, or so it seems to me. They cover a wide range of topics in astronomy, planetary science, astrophysics, cosmology -- as you would expect.

I'm just going to list very briefly some of what seem to be the most significant results. As time permits (ha!) I'll try to write more in depth about some of these.

Black holes

Although black holes have been discussed as a hypothetical possibility for decades, it's only been within about the past five years that pretty good evidence has been obtained for the actual existence of black holes. The evidence continues to grow more substantial and more detailed. One study investigated the internal motions of gas surrounding the nucleus of the active galaxy NGC 1097. It was able to track the gas to within about 10 light-years of the central black hole of NGC 1097. Reference: Scientists Probe Black Hole’s Inner Sanctum.

Another study compared neutron stars and (apparent) black holes using NASA's Rossi X-ray Timing Explorer. X-ray emissions from the vicininty of the two kinds of objects behave quite differently. Those from near a black hole are what would be expected from a black hole event horizon into which matter falls without a trace. Reference: Scientists find black hole's 'point of no return'.

Like just about all other known spiral galaxies, the Milky Way contains a supermassive black hole at its center. This location has been identified with the region known as Sagittarius A*. A study using both ground- and space-based telescopes has found rapid flares close to the innermost region of the black hole in many different wavelengths and that these emissions go up and down together. Reference: Astronomers shed surprising light on our galaxy's black hole.

A team of astronomers has observed a region less than 100 miles from the event horizon of a spinning black hole system called GRO J1655-40. They documented the existence of periodic fluctuations, at predictable frequencies, of X-ray emissions from that region. Reference: Spinning black hole leaves dent in space-time.

Galaxies and their central black holes

Several years ago it became clear that there is a rough correlation between the size of a galaxy (especially the central bulge of a spiral galaxy) and the size of the central black hole that seems to be almost always there. In 2004 the Hubble Space Telescope completed (after about 115 days) a single image of some of the farthest -- and consequently youngest -- visible galaxies in the universe. Careful examination of this image -- called the Hubble Ultra Deep Field -- now reveals details of how those young galaxies developed at an early age. Galaxies grow simply by merging with their nearest neighbors. And at the same time, the central black hole in the merged galaxy grows by consuming stars, dust, and gas that has been swept up during the merger. Reference: Monster Black Holes Grow After Galactic Mergers

One of the most intriguing questions about supermassive black holes is how they get started in the first place, before they begin to grow by accretion. Are they remnants of enormous stars that formed in the early universe and then exploded as supernovae? Or did they coalesce directly out of especially dense regions of matter in the early universe? The initial stage of a supermassive black hole is simply a black hole of intermediate mass. But examples of such intermediate mass objects are difficult to find, since they have grown substantially over time unless they are rather young. Now a careful study of data from the Sloan Digital Sky Survey has turned up 19 black holes with masses less than one million solar masses -- which qualifies as merely "intermediate" size. Young intermediate mass black holes are in effect mini-quasars that produced enormous quantities of energy as they consumed infalling matter. Consequently, they may have played an important role during the period of re-ionization of the universe several hundred years after the big bang. Reference: Growing Supermassive Black Holes from Seeds.

Dark matter galaxy

Dark matter galaxies, consisting entirely of dark matter and hydrogen gas but with no visible stars, have been reported before. (Here, for example.) Now another cloud of hydrogen gas, called VIRGOHI 21, at a distance of 50 million light-years in the Virgo Cluster, has been identified by radio telescope studies as a dark matter galaxy, since its total mass appears to be 100 times as large as accounted for by the hydrogen. The total mass is 10 billion solar mass units, even though there are no visible stars. Reference: New evidence for a Dark Matter Galaxy.

Warping and vibration of the Milky Way produced by dark matter

The Milky Way, apparently like all galaxies, is enveloped in a cloud of dark matter that is much more massive than the visible galaxy itself. It has also been known that the galaxy warps and vibrates like a limp pizza. A computer model has shown that this distortion of the Milky Way can be explained by movement of the two main satellite galaxies (the Large and Small Magellanic Clouds) through the dark matter. This represents yet more evidence that dark matter is real, even though we still don't know what it is. Reference: Milky Way galaxy is warped and vibrating like a drum.

High-energy source of X-rays and gamma-rays

It's been known for years that there is an source of very high-energy X-rays and gamma-rays inside our galaxy. Now that source has been identified as a very massive star cluster, about 20 times as massive as the average cluster. It contains 14 relatively rare red supergiant stars. Reference: Mystery Solved: High-Energy Fireworks Linked to Massive Star Cluster.

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To be continued... there's much more

Mirror neurons

Here's an extremely interesting and well-written article by Sandra Blakeslee in the New York Times. It's a lot better than most newspaper science articles. Although it does not go into technical details, its virtue is how it describes so many interrelated aspects of the subject, while still remaining comprehensible.

Cells That Read Minds (January 10, 2006)

The cells in question are "mirror neurons". They were discovered around 1990 in the laboratory of Giacomo Rizzolatti, a neuroscientist at the University of Parma, Italy. Researchers in the laboratory had been studying brain activity in macaque monkeys.

The monkey brain contains a special class of cells, called mirror neurons, that fire when the animal sees or hears an action and when the animal carries out the same action on its own.

But if the findings, published in 1996, surprised most scientists, recent research has left them flabbergasted. Humans, it turns out, have mirror neurons that are far smarter, more flexible and more highly evolved than any of those found in monkeys, a fact that scientists say reflects the evolution of humans' sophisticated social abilities.

The human brain has multiple mirror neuron systems that specialize in carrying out and understanding not just the actions of others but their intentions, the social meaning of their behavior and their emotions.

"We are exquisitely social creatures," Dr. Rizzolatti said. "Our survival depends on understanding the actions, intentions and emotions of others."

He continued, "Mirror neurons allow us to grasp the minds of others not through conceptual reasoning but through direct simulation. By feeling, not by thinking."

The discovery is shaking up numerous scientific disciplines, shifting the understanding of culture, empathy, philosophy, language, imitation, autism and psychotherapy.

Everyday experiences are also being viewed in a new light. Mirror neurons reveal how children learn, why people respond to certain types of sports, dance, music and art, why watching media violence may be harmful and why many men like pornography.

I highly recommend you go read the whole article yourself at the link given above. It's well worth your time.

I'd like to write a whole book on this set of interrelated issues connected with mirror neurons -- but that would be an investment of a lot more time than I have available at the moment, so I'll just set down a few notes about some of the topics touched upon in Blakeslee's article.

If you'd like a little more background on mirror neurons to begin with, you might try this Wikipedia article. Unfortunately it's rather sketchy and lacks references for most assertions.

However, it does refer to a longer article at Edge by V. S. Ramachandran that was written in early 2000. You might also want to look at the introductory material and especially a discussion of the article by several experts in related fields. You may find the critiques in this discussion to be a bit confusing, as they assume some acquaintance with fields like neuroscience, linguistics, anthropology, and so forth. But if that doesn't scare you off, the discussion is worth reading. You may even wish you could jump in yourself to reply to some of the arguments, especially with an individual like Rafael Nuñez (a rather ideological anti-reductionist).

Also, keep in mind that many of the remarks in the Ramachandran paper are conjectural or speculative. There are many hypotheses about the role that mirror neurons may play in the workings of the human brain. A great deal of work remains for scientific research to confirm or disprove many of these speculations -- probably enough to keep researchers busy for decades. Ramachandran himself has recently been working on some of these questions, as we will see.

Anyhow, let's get back to Blakeslee's article. She summarizes the key property of mirror neurons as follows:

Studies show that some mirror neurons fire when a person reaches for a glass or watches someone else reach for a glass; others fire when the person puts the glass down and still others fire when the person reaches for a toothbrush and so on. They respond when someone kicks a ball, sees a ball being kicked, hears a ball being kicked and says or hears the word "kick."

So mirror neurons are associated with a wide variety of fairly complex actions, where many muscles have to be activated in order to accomplish some intended goal. This idea of "intention" is very important. Blakeslee quotes neuroscientist Marco Iacoboni:

"When you see me pull my arm back, as if to throw the ball, you also have in your brain a copy of what I am doing and it helps you understand my goal. Because of mirror neurons, you can read my intentions. You know what I am going to do next."

This is the sense in which mirror neurons can "read minds" -- some of your mirror neurons respond to seeing another person do something in the same way as the neurons would if you were doing the action yourself. And you are able to detect this neural activity and correlate it with the particular action.

For example, in February 2005 Iacoboni and colleagues published a paper that described research demonstrating that the firing patterns of mirror neurons discriminated between moving a teacup to drink from it or to remove it from the table. See UCLA Neuroscientists Pinpoint New Function For Mirror Neurons. (Here's an earlier study from the same laboratory: UCLA Imaging Study Reveals How Active Empathy Charges Emotions; Physical Mimicry Of Others Jump-starts Key Brain Activity (4/8/03).)

Being able to infer the intentions of other people is an extremely important ability for humans in their social interactions with others. It's a large part of what makes humans such a social species. Think of the importance of being able to tell from the way someone else handles a rock whether he is just studying it or getting ready to throw it at you.

Psychologists describe this ability as being part of a "theory of mind". This is the idea that humans (and possibly a few other animals) recognize that others have minds like their own and that people can make accurate hypotheses about beliefs, desires, intentions, and mental states of others. As a scientific notion, the idea seems to have originated in the 1970s. It seems to have been suggested by various people. The discussion of Ramachandran's article exposes some of the controversy about who gets the credit. Some of the names offered are Nicholas Humphrey, Simon Baron-Cohen, David Premack, and Daniel Dennett. Ramachandran was onto the idea himself at an early stage.

Dennett is also known for extending the idea to his notion of the "intentional stance". As the Wikipedia article says, "To use the intentional stance in explanation one looks at a particular bit of behaviour and ask what beliefs and desires could give rise to that behaviour. One then assumes that those beliefs and desires are actually held by the creature." Clearly, mirror neurons could well be a basis for inferring beliefs and desires from observed behavior of others. Dennett's theorizing goes on to incorporate this intentional stance into his ideas about consciousness, as described in his book Consciousness Explained.

This is hardly the time to launch into an extended discussion of consciousness. But we can't help noting a slightly different way in which mirror neurons may play a part. Blakeslee has a further quote from Iacoboni:

"[I]f you see me choke up, in emotional distress from striking out at home plate, mirror neurons in your brain simulate my distress. You automatically have empathy for me. You know how I feel because you literally feel what I am feeling."

In other words, mirror neurons help us understand not only the intentions of other people, but their feelings and emotions as well. They enable us to empathize with others.

For instance, most people can easily read the emotions of others from facial expression, tone of voice, and other body language. It seems rather likely this is because our mirror neurons simulate the muscular activity that underlies these kinds of emotion-expressing behaviors. Further, if one tries to imitate facial expressions associated with emotional states (like fear, sadness, joy, etc.), one actually feels at least a little bit of the emotion itself.

Some neuroscientists have suggested that emotions originate, at least in part, from our perceptions of how our own bodies react when in situations that naturally evoke fear, pleasure, and so forth. This idea is propounded, for instance, in Antonio Damasio's book Descartes' Error. Damasio then goes on, in The Feeling of What Happens to construct from these ideas a more general theory of consciousness. So it's not too much of a stretch to think of mirror neurons as important parts of the neural basis for the phenomenon of consciousness.

But we're still not done. As if enabling consciousness were not enough, mirror neurons may also play a big role in the development of human culture, by enabling humans, from a very early age, to acquire complex behaviors (such as using tools, learning language, participating in group social activities, etc.) by a process of imitation. Blakeslee quotes psychologist Patricia Greenfield:

Until now, scholars have treated culture as fundamentally separate from biology, she said. "But now we see that mirror neurons absorb culture directly, with each generation teaching the next by social sharing, imitation and observation."

And adds

Other animals - monkeys, probably apes and possibly elephants, dolphins and dogs - have rudimentary mirror neurons, several mirror neuron experts said. But humans, with their huge working memory, carry out far more sophisticated imitations.

This isn't just speculation. There's already research that has implicated the mirror neuron system in imitation. For example, this from January 2005: Human See, Human Do: Ballet Dancers' Brains Reveal The Art Of Imitation

While previous studies have found that the system contains mirror neurons or brain cells which fire up both when we perform an action and when we observe it, the new study shows that this system is fine tuned to each person's 'motor repertoire' or range of physical skills. The mirror system was first discovered in animals and has now been identified in humans. It is thought to play a key role in helping us to understand other people's actions, and may also help in learning how to imitate them.

It's hard to overestimate the importance of learning by imitation in the transmission of human culture. Most things humans really need to learn how to do can only be learned by carefully observing someone who already has the skill. For early humans it was things like making stone tools, building a fire, or throwing a spear. For more modern humans it's painting a landscape scene, playing a violin, or making wooden furniture.

What else might mirror neurons be involved in? Well, how about learning language? Blakeslee mentions neuroscientist Michael Arbib's work. Some of this goes back to 1998. For instance, this: Monkey Do, Monkey See ... Pre-Human Say?

"This mechanism provides the neural prerequisite for development of inter-individual communication, and finally of speech," Dr. Arbib says.

"For communication to succeed, both the individual sending a message and the individual receiving it must recognize the significance of the sender's signal. Mirror neurons are thus the missing link in the evolution of language. They provide a mechanism for the sharing of meaning."

And the language involved need not be just literal statements of facts. It could extend to figurative language such as simile and metaphor. When we talk about "reaching for an understanding" we are using the physical act of reaching in a metaphor. Or Shakespeare's "Tomorrow, and tomorrow, and tomorrow, Creeps in this petty pace from day to day..." Ramachandran's Center for Brain and Cognition at the University of California, San Diego is investigating metaphors and slyly using them in their press releases (May 2005): Grasping Metaphors: UC San Diego Research Ties Brain Area To Figures Of Speech

Ramachandran's lab is continuing work on linking other brain areas, the supramarginal gyrus and human homologues of mirror neurons, for example, to other types of metaphoric abilities.

Recall that it's not only the act of observing another person doing something that activates mirror neurons. Just thinking about an action or hearing about one or (especially) reading about one can also cause activation. This may well account for a large amount of the pleasure we obtain from viewing photographs or reading literature depicting people engaged in all kinds of activities -- running a marathon race, climbing Mt. Everest, or having sex. (Reading or viewing pornography was bound to come up, no?) It's called vicarious experience. (I wrote here about a related, though different, way that literature seems to arise out of characteristic ways that human brains work.)

So there's plenty of evidence now about the great things that mirror neurons do. But what happens if there's a problem in the mirror neuron system? The answer appears to be simple: autism. Mirror neurons enable humans to understand the intentions of other people and have a "theory of mind", to have empathy with the emotions of others, and to learn cultural skills by imitation from watching others. A person who is lacking in those abilities, especially a child, is autistic. Actually, some autistic children can mimic facial expressions other actions of others, but they don't understand the corresponding emotions or intentions of others.

Research is accumulating that impairment of the mirror neuron system is implicated in autism. Here are reports of some of the studies: UCLA Imaging Study Of Children With Autism Finds Broken Mirror Neuron System (12/6/05), Abnormal Brain Activity During The Observation Of Others' Actions (2/18/05), Autism's Fogged-up Mirror (1/3/05).

Undoubtedly, there's still much more to learn about mirror neurons and other brain systems that may also be involved in such things as imitation and perceiving the emotions and intentions of others. But what we've figured out so far is pretty interesting.

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Here are reports of some other studies in the same general area --

Brain Patterns The Same Whether Doing Or Just Watching, Queen's Researcher Discovers (8/14/03)

Brain Senses The Pain Of Someone Else's 'Ouch!' (2/24/04)

Discovering That Denial of Paralysis Is Not Just a Problem of the Mind (8/2/05)

The First Laugh: New Study Posits Evolutionary Origins Of Two Distinct Types Of Laughter (11/22/05)

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Tags: mirror neurons, neuroscience, autism, empathy, imitation, theory of mind