Over on the Brain Waves blog Richard Glen Boire is arguing for the unlimited right to erase one's memories.
The right to cognitive liberty posits that the power to enhance, erase, or otherwise modify one’s own memory ought to be an individual decision; something that is neither compelled nor prohibited by laws. While some people will undoubtedly make poor decisions with regard to modifying their own memories, it should not be a crime to modify your own thinking processes. Government may rightfully police our actions, but it does not, and should not, have the power to police our minds.
I would argue that in order for people to be granted full rights they must be held responsible to maintain cognitive competence and sufficient memory recall abilities to provide sufficient support to the proper functioning of the legal system and of society as a whole. For instance, suppose someone witnesses a brutal murder and can identify the person who commited a crime. Does that person have a right to go home afterward and erase that memory? Or suppose someone commits a crime. Does that person have a right to erase that memory? Imagine someone taking a lie detector test and being able to truthfully state that they have no memory of having raped someone because they conveniently had that memory erased.
Widespread memory erasure would allow a person to claim no memory of making a verbal contract. It would also make it difficult for, say, white collar crime prosecutors to trace a complex trail of fraud if perfectly innocent unknowing tools of the fraud had the memory of their last bank back office job erased because they didn't want to remember the drudgery that the job entailed.
There are aspects of how our minds work that are essential for the proper functioning of a rights-based society. The exercise of some kind of modification of the brain that undermines the ability to make a rights-based society work can not itself be an unlimited right. The biggest challenge facing us with mind engineering is that it will eventually become possible to modify minds in a number of ways to create sentient beings that are highly rational but which behave in ways that make the continued existence of a rights-based society highly problematic.
Jay A. Gottfried, John O'Doherty and Raymond J. Dolan of the Institute of Neurology in London, U.K. have found that human brains, not too surprisingly, form connections between environmental stimuli and desired foods rather like Pavlov's dog.
For their Science study, the scientists used brain imaging on a group of 13 hungry human volunteers. The experiments involved an initial training period, in which the volunteers were shown abstract images in association with the smell of vanilla or peanut butter. Meanwhile, a functional magnetic resonance imaging (fMRI) machine monitored their brain activity.
The volunteers began to automatically associate certain images with either smell, according to the researchers.
Then, the volunteers ate their fill of either vanilla ice cream or peanut butter sandwiches, being asked to eat until they didn't want any more, but weren't uncomfortably full.
Back in the fMRI machine, the volunteers again experienced the various combinations of images and the two food smells. The researchers observed a change in brain activity for the responses related to the food that they had just eaten, but not for the other food.
The change was primarily in the brain's amygdala and orbitofrontal cortex, where the activity decreased significantly. Previous studies have also implicated these regions in conditioning. The researchers also observed some activity differences in other areas, including the ventral striatum, which is associated with the reward pathways in drug addiction.
About the role the amygdala and orbitofrontal cortex might play in the conditioning process, Gottfried stressed the importance of the fact that this activity decreased only when the volunteers were shown images corresponding to the particular food they had eaten.
Thus, this sort of brain activity is likely involved with anticipating the enjoyment of a given food – which also decreased after the volunteers had eaten until they didn't want any more. The volunteers' amygdala and orbitofrontal cortex responses remained the same for the smell (or corresponding picture) of the second food, which they did not eat.
Ultimately, this brain system may be far more versatile and wide-reaching than just a possible explanation for why food cravings can strike out of nowhere. It may be offer an adaptable system for learning, Gottfried said, that allows us to recognize cues that predict important events, and to discard cues that are no longer useful.
Jay Gottfried speculates that people who suffer from obesity may not respond as well to eating some kind of food by having a decrease in the stimulus effect of images that are correlated with availability of that type of food. How quickly we get disgusted wtih a food may in part determine how well we can regulate our eating.
Importantly, the team also showed that the human brain can put a "brake" on the powerful desire for certain foods once the appetite has been sated. This system to turn the "delectable into the distasteful" may be crucial in regulating behaviour, they say. Detecting faults in this system might in future help shed light on compulsive eating disorders and substance addictions, speculates Gottfried, a neurologist.
Since satiation tends to be at least partially specific for particular foods people are more likely to overeat if presented with a succession of different kinds of foods.
Gottfried was trying to explain what he calls the "restaurant phenomenon."
"You sit down to your eight-course meal for your birthday and you have gone though all the appetizers and entrees and just as you feel you can't fit one more thing in your tummy, then they bring the dessert menu or the dessert cart rolls by and suddenly you discover you have room for the chocolate fondant," Gottfried said in a telephone interview.
"This is specific satiation -- you are full of one thing but not another."
"These processes operate in a very food-specific fashion, and this is important," Gottfried explains. "If, ultimately, what you need is a good balance of nutrients, vitamins, minerals, and so forth, it's important for you to be sampling different foods." A braking effect is in place as long as it comes to the same food item.
This result suggests a couple of potential strategies for limiting calorie consumption. One is to avoid any environmental stimulation separate from food itself that reminds you of some kind of food. Another is to avoid food pictures, food smells, or real food. Another is to eat meals with fewer courses.
People with short versions of the serotonin transporter gene are more prone to binge drinking and anxiety. (bold emphasis added)
NIAAA clinical investigators Paolo B. DePetrillo, M.D., and Research Fellow Aryeh I. Herman B.A., along with researchers from George Washington University in Washington, D.C., conducted the study of 262 male and female college students and analyzed data from the largest homogenous group: 204 male and female Caucasian college students aged 17 to 23 years. To assess the frequency and patterns of alcohol consumption, the scientists asked all the students a set of questions, for example, how many times in the past two weeks they had engaged in binge drinking (five or more drinks for men and four or more drinks for women on one occasion).
The research team also analyzed each student's genotype with a focus on the 5-HTT gene, which is involved in recycling the chemical serotonin after it is secreted into the synapse of a cell. The researchers determined which students had long or short versions of this so-called serotonin transporter gene.
Everyone inherits two copies of each gene, one from each parent. There are two normal variations, or polymorphisms, of the serotonin transporter gene, labeled the long and the short variants. Most people are heterozygous, that is, they have one copy of each variant, but about 30 percent of the Caucasian population are homozygous (carry duplicate copies) of either the long or the short version. This percentage varies depending on the ethnic background of the individual.
The researchers found that the students who carried two copies of the short version of 5-HTT were more likely to report troublesome drinking patterns. Dr. DePetrillo says, "Our findings reveal a significant association of the serotonin transporter promoter polymorphism with increased alcohol consumption behavior in the students that we studied. Taken together with other research, this finding suggests that genetically mediated differences in serotonergic response play an important role in mediating patterns of alcohol intake." The students with two copies of the short form of the gene engaged more frequently in binge drinking, drank more often to get drunk, and consumed more alcoholic drinks per occasion than did students with the other genotypes.
Another difference the researchers observed was that students with at least one copy of the long variant of the 5-HTT gene tended to consume a smaller number of drinks at a sitting, even though they went out to drink as often as the other students.
Why should the presence of the shorter gene variant make such a difference? The authors speculate that, because individuals who are homozygous for the short version are known to be at risk for higher levels of anxiety, they may use alcohol to reduce tension. Further studies are needed to understand the influence of the serotonin transporter gene on drinking behavior, with special attention given to replication in other ethnic groups.
Does anyone happen to know what the distribution of 5-HTT variations is in various ethnicities and races? There are probably regional differences in distribution well below the level of the major races.
The short version of the serotonin transporter gene also predisposes a person to depression in response to stressful life events.
Among people who suffered multiple stressful life events over 5 years, 43 percent with one version of a gene developed depression, compared to only 17 percent with another version of the gene, say researchers funded, in part, by the National Institute of Mental Health (NIMH). Those with the "short," or stress-sensitive version of the serotonin transporter gene were also at higher risk for depression if they had been abused as children. Yet no matter how many stressful life events they endured, people with the "long" or protective version experienced no more depression than people who were totally spared from stressful life events. The short variant appears to confer vulnerability to stresses, such as loss of a job, breaking up with a partner, death of a loved one, or a prolonged illness, report Drs. Avshalom Caspi and Terrie Moffitt, University of Wisconsin and King's College London, and colleagues, in the July 18, 2003 Science.
The serotonin transporter gene codes for the protein in neurons, brain cells, that recycles the chemical messenger after it's been secreted into the synapse, the gulf between cells. Since the most widely prescribed class of antidepressants act by blocking this transporter protein, the gene has been a prime suspect in mood and anxiety disorders. Yet, its link to depression eluded detection in eight previous studies.
"We found the connection only because we looked at the study members' stress history," noted Moffitt. She suggested that measuring such pivotal environmental events — which can include infections and toxins as well as psychosocial traumas — might be the key to unlocking the secrets of psychiatric genetics.
Although the short gene variant appears to predict who will become depressed following life stress about as well as a test for bone mineral density predicts who will get a fractured hip after a fall, it's not yet ready for use as a diagnostic test, Moffitt cautioned. If confirmed, it may eventually be used in conjunction with other, yet-to-be-discovered genes that predispose for depression in a "gene array" test that could help to identify candidates for preventive interventions. Discovering how the "long" variant exerts its apparent protective effect may also lead to new treatments, added Moffitt.
Everyone inherits two copies of the serotonin transporter gene, one from each parent. The two versions are created by a slight variation in the sequence of DNA in a region of the gene that acts like a dimmer switch, controlling the level of the gene's turning on and off. This normal genetic variation, or polymorphism, leads to transporters that function somewhat differently. The short variant makes less protein, resulting in increased levels of serotonin in the synapse and prolonged binding of the neurotransmitter to receptors on connecting neurons. Its transporter protein may thus be less efficient at stopping unwanted messages, Moffitt suggests.
There is one odd thing about their dataset: half of them had one of each variant. But far more had two long versions than had two short versions.
Moffitt and colleagues followed 847 Caucasian New Zealanders, born in the early l970s, from birth into adulthood. Reflecting the approximate mix of the two gene variants in Caucasian populations, 17 percent carried two copies of the stress-sensitive short version, 31 percent two copies of the protective long version, and 51 percent one copy of each version.
Is this dataset representative of the larger population of New Zealanders? If so, then something interesting is going on. If the carriers of the short and long gene versions were equally likely to reproduce and equally likely to mate with others regardless of whether the others are the same or different for this gene and if half the population was heterozygous for this gene then we'd expect to see equal numbers homozygous for the short and long versions. But in this study group the homozygous short versions were less common than homozygous long versions even though half the study participants were heterozygous short-long.
Is there some kind of preferential mating going on where those who pair up with opposite homozygous types have more children than matings between pairs who are homozygous for the short version? Or are heterozygous people more fecund than the homozygous for this gene? Or are homozygous shorts less likely to mate with their own kind but more likely to have more children when they pair up with a member of the other groups? There are a lot of possibilities and those are just a few of them.
The reseachers ought to survey these people for how many children they've had and at what age. Also, they should test the serotonin transporter genes of their children and the other parents of their children to see if there are any obvious patterns at work.
"We now understand the biological basis of some people's ability to bounce back successfully from adverse life events," said Science's deputy editor, life sciences, Katrina Kelner. "This is tremendously exciting. The research adds to the findings published in Science by the same team last year which showed why certain maltreated children grow up to be healthy adults and certain ones develop antisocial behaviors."
So this is the same research team that published a report showing that a particular variation in the gene for monoamine oxidase-A caused mistreated children to become violent and anti-social.
By age 11, 36 percent of the subjects had been maltreated (8 percent severely), as defined by frequent changes in primary caregiver, rejection by the mother and physical or sexual abuse. Although only 12 percent of the maltreated children had low activity levels of the MAO A, they accounted for 44 percent of their generation's total convictions for assault and other violent crimes.
"As adults, 85 percent of the severely maltreated children who also had the gene for low MAO A activity developed antisocial outcomes, such as violent criminal behavior," says Moffitt. "The combination of maltreatment and the genetic variation magnified the odds by nine times."
On the other hand, the group found that children who had been maltreated but who had higher levels of MAO A were unlikely to develop behavior problems, suggesting that the gene regulating the enzyme does serve a protective function. "The genotype of high MAO A activity," explains Moffitt, "may promote 'trauma resistance.'"
Based on these initial findings, Moffitt says, "The combination of the low-activity MAO A genotype and maltreatment predicts antisocial behaviors about as well as high cholesterol predicts heart disease."
Low levels of the MAO A enzyme may help explain why some abused children are more likely to develop aggressive or criminal behavior, but Moffitt stresses that it does not explain why people are violent: "Low levels of the enzyme did not predict antisocial outcomes in the whole population. It's relation to aggression only emerged when we considered whether the children had been maltreated."
However, the UW-Madison researchers suspect that the MAO A genetic variation may play a similar role in protecting people who have experienced other stressful events, such as car accidents or wars.
Differences in the brain derived neurotrophic factor (BDNF) gene cause differences in memory formation and recall capabilities.
In the new research, reported in the Journal of Neuroscience, Daniel R. Weinberger and his colleagues at the National Institute of Mental Health in Bethesda, Maryland, studied 28 people who carried genes that encoded either the “Val” form or the “Met” form of the BDNF protein.
People with the "Val" form of BDNF are better at recalling visual memories.
The researchers noticed significant differences in brain activity between the two groups during both the encoding and retrieval phases of the task. Those with the “Val” form of the gene were better at remembering pictures than were those with the “Met” form, and they also had greater brain activity during the encoding and retrieval phases of memory.
There are still other factors at work besides BDNF gene variations.
Remarkably, the interaction between the BDNF val66met genotype and the hippocampal response during encoding accounted for 25% of the total variation in recognition memory performance. These data implicate a specific genetic mechanism for substantial normal variation in human declarative memory and suggest that the basic effects of BDNF signaling on hippocampal function in experimental animals are important in humans.
So you might be thinking that it is better to have two copies of the "Met" form of BDNF. Well, not so fast. It depends on what kind of memory you want to be better at forming and recalling. Earlier work by the same group of scientists showed that the "Val" variant is better for recalling episodic memory.
Drawing on participants in the NIMH intramural sibling study of schizophrenia, Egan and colleagues first assessed their hippocampal function and related it to their BDNF gene types.
Among 641 normal controls, schizophrenia patients, and their unaffected siblings, those who had inherited two copies of the "met" variant scored significantly lower than their matched peers on tests of verbal episodic (event) memory. Most notably, normal controls with two copies of "met" scored 40 percent on delayed recall, compared to 70 percent for those with two copies of "val." BDNF gene type had no significant effect on tests of other types of memory, such as semantic or working memory.
The researchers then measured brain activity in two separate groups of healthy subjects while they were performing a working memory task that normally turns off hippocampus activity. Functional magnetic resonance imaging (fMRI) scans revealed that those with one copy of "met" showed a pattern of activation along the sides of the hippocampus, in contrast to lack of activation among those with two copies of "val."
Next, an MRI scanner was used to measure levels of a marker inside neurons indicating the cell's health and abundance of synapses -- tiny junctions through which neurons communicate with each other. Again, subjects with one copy of "met" had lower levels of the marker, N-acetyl-aspartate (NAA), than matched individuals with two copies of "val." Analysis showed that NAA levels dropped as the number of inherited "met" variants increased, suggesting a possible "dose effect."
Unlike other growth factors, hippocampal BDNF is secreted, in part, in response to neuronal activity, making it a likely candidate for a key role in synaptic plasticity, learning and memory. To explore possible mechanisms underlying the observed "met"- related memory effect, the researchers examined the distribution, processing and secretion of the BDNF proteins expressed by the two different gene variants within hippocampal cells. When they tagged the gene variants with green fluorescent protein and introduced them into cultured neurons, they discovered that "val" BDNF spreads throughout the cell and into the branch-like dendrites that form synapses, while "met" BDNF mostly clumps inside the cell body without being transported to the synapses. To regulate memory function, BDNF must be secreted near the synapses.
"We were surprised to see that 'met' BDNF secretion can't be properly regulated by neural activity," said Lu.
These scientists are tracing the differences in memory recall all the way down to the molecular level.
Neurons transfected with met-BDNF-GFP showed lower depolarization-induced secretion, while constitutive secretion was unchanged. Furthermore, met-BDNF-GFP failed to localize to secretory granules or synapses. These results demonstrate a role for BDNF and its val/met polymorphism in human memory and hippocampal function and suggest val/met exerts these effects by impacting intracellular trafficking and activity-dependent secretion of BDNF.
It is quite possible that there exist variations of other genes which complement either the "Val" or "Met" variations so as to allow superior memory formation and recall for both episodic and visual memories.
Hydrogen would inevitably leak if we shifted to a hydrogen economy and the question arises: would large quantities of leaked hydrogen cause environmental problems?
In the August 21 issue of the journal Nature, a group of researchers from the California Institute of Technology and other institutions reports results of a study of the atmospheric chemical reactions that produce and destroy hydrogen in the stratosphere. Funded in part by the National Science Foundation (NSF), the study concludes that most of the hydrogen eliminated from the atmosphere goes into the ground, and therefore that scientists will need to turn their focus toward developing an understanding of soil destruction of hydrogen to accurately predict whether hydrogen emissions will eventually accumulate in the air.
The researchers reached this conclusion after carefully measuring the abundance of a rare isotope of hydrogen known as deuterium. It has long been known that atmospheric hydrogen is rich in deuterium, but it was unclear why. The only reasonable explanation, scientists believed, is that atmospheric hydrogen is mostly destroyed by chemical reactions in the air, and that those reactions are relatively slow for deuterium-rich hydrogen, so it accumulates like salt in an evaporating pan of water.
If correct, this would mean that oxidizing atmospheric trace gases control the natural hydrogen cycle and that soils are relatively unimportant. But new research results suggest that one of the main natural sources of atmospheric hydrogen--the breakdown of methane--is actually responsible for the atmosphere's enrichment in deuterium. This result implies that reactions with atmospheric oxidants may be less important to the hydrogen cycle, and that uptake by soils, where microbial processes involve methane, is the driving force.
Air samples from the stratosphere indicate that most atmospheric hydrogen is taken up by the soil.
Hydrogen is a highly reactive element, but answers to the questions of when and where it reacts, and under what circumstances, are difficult to unravel. These questions are simplified in the stratosphere, where it's easier to single out and understand specific reactions. According to John Eiler, a geochemist at the California Institute of Technology and an author of the Nature paper, the new data were gathered from air samples taken from the stratosphere with one of the high-flying ER-2 planes operated by the NASA Dryden Flight Research Center in the Mojave Desert.
The big question is whether the inevitable hydrogen leakage in an economy converted to hydrogen would accumulate in the atmosphere and cause harmful effects.
With precise information on the deuterium content of hydrogen formed from methane, the researchers were able to calculate that the soil uptake of hydrogen is as high as 80 percent. It is suspected that this hydrogen is used by soil-living microbes to carry on their biological functions, although the details of this process are poorly understood and have been the subject of only a few previous studies.
It seems likely, according to the scientists, that the hydrogen taken up by soils is relatively free of environmental consequences, but the question still remains of how much more hydrogen the soil can "consume." If future use of hydrogen in transportation results in a significant amount of leakage, then soil uptake must increase dramatically or it will be inadequate to cleanse the released hydrogen from the atmosphere, Eiler says.
It is assumed by most advocates of hydrogen as an energy storage form that it will not have any harmful pollutant effects. Well, this assumption might turn out to be correct. But for atmospheric scientists this is still an open question.
Michael May lost his sight at age 3 in an accident and over 40 years later stem cell therapy helped restore sight to one eye. A few years later it is clear that parts of his brain that do image processing never developed and show no signs of going thru the necessary development now.
He can discern motion, two-dimensional forms and color. "That was the most amazing thing. Initially I hadn't thought about color. To all of a sudden have the faucet turned on for this whole world of colors, it was amazing. Somewhere in the recesses of my mind was the ability to discern colors," May said in a telephone interview.
What he can't do is recognize objects in three dimensions, make sense of complex landscapes, recognize faces or interpret facial expressions.
Fine and Donald MacLeod of the University of California at San Diego have conducted a battery of tests. Brain scans showed that the part of the brain that becomes activated in sighted people when they see faces and objects remained dormant in May. But when he looks at an object that is moving, the motion detection part of his brain lights up with activity.
The findings suggest that certain visual skills, such as detecting color and motion, are more hard-wired and develop earlier in infancy than others.
May can recognise some objects better when they move than when they are still.
When asked to identify a cube illustrated on a two-dimensional computer screen, for example, Mr. May failed. But once Miss Fine commanded the cube to rotate, simulating motion in three dimensions, he immediately recognized it.
One scientist likens it to how it is easier to learn languages when younger than when older. This result is also consistent with experiments done on cats decades ago where their heads were kept in harnesses when they were young and they were only shown vertical or horizontal lines for a key number of weeks (its been too long since I learned this to recall it with precise detail). After that the cats which had been exposed to vertical bars could recognise them but not recognise horizontal bars. The cats exposed to horizontal bars during the critical developmental period could see only horizontal bars.
It may eventually become possible to feed neural stem cells and hormones to the part of the mind that processes sight in order to get it to revert to a more plastic state so that in cases where sight is restored the mind can once again go thru the process of learning how to see.
Scientists at the University of California at San Diego have adapted an inkjet printer and a CD player to make a scientific instrument that detects types of proteins molecules present in a solution by measuring where they bind on the surface of a specially prepared CD.
To do molecular screening, the researchers took a CD encoded with digital data, and enhanced the chemical reactivity of the plastic on the readable surface. They then added molecules they wanted to attach to this surface to the empty ink wells of an inkjet printer cartridge and used the printer to “print” the molecules onto the CD. This resulted in a CD with molecules bound to its readable surface in specific locations relative to the pits in the metal layer of the CD encoding the digital information. When the CD with these molecules attached is placed in a CD player, the laser detects a small error in the digital code relative to what is read from the CD without the molecules attached.
To detect proteins or other large molecules in a solution like a blood sample, the modified CD is allowed to react with the sample solution. Like a key that only fits in a certain lock, some proteins bind to specific target molecules. Thus, specific molecules on the surface of a CD can be used to “go fishing” for certain proteins in a sample. The attachment of these proteins will introduce further errors into the reading of the CD. Furthermore, since the molecules on the surface of the CD are at known locations relative to the bits of encoded information, the errors tell the researchers what molecules have attached to their target protein and, thus, whether or not that protein is present in the sample.
“James has even done this using CDs with music, like Beethoven’s Fifth Symphony,” says Burkart. “And you can actually hear the errors.”
“How many people on this planet can actually hear a molecule attached to another molecule?” asks La Clair.
While a few bugs need to be ironed out before the technique can be used to accurately quantify the amount of a given protein in solution, Burkart plans to apply it immediately to help him screen for new compounds in his natural products chemistry research laboratory. Compared to the $100,000 price tag for a fluorescent protein chip reader, he points out, a CD player costs as little as $25.
The researchers envision many other potential applications for this technology outside the laboratory, particularly in the development of inexpensive medical diagnostic tests, now beyond the means of many people around the world, particularly in developing countries.
“In theory, anyone who has a computer with a CD drive could do medical tests in their own home,” says La Clair.
Basically, they use an inkjet printer cartridge to put different kinds of molecules at differnet locations on the CD. Each kind of molecule has affinity for a different type of target protein molecule. Then they expose the CD to a solution that has unknown assortment of proteins. Those proteins with affinity for specific places on the CD bind in those places and then when the CD is read the signal in those areas is changed by the addition of the larger proteins that have bound to the molecules which have been anchored to the CD.
This work demonstrates how advances in electronic technology are helping to lower the cost and increasing the speed of doing biomedical research and clinical testing. This is not the first use of inkjet printer technology as tools for doing biomedical research. See Modified Printers Used For Tissue Engineering and STMicro Releases Silicon DNA Analysis Chip for other examples.
Higher temperatures unexpectedly make soil more moist.
Grassland ecosystems could become wetter as a result of global warming, according to a new study by researchers from Stanford University and the Carnegie Institution of Washington. This surprising result, published in the Proceedings of the National Academy of Sciences (PNAS), contradicts numerous climate models predicting that higher temperatures could dry out natural landscapes, including grasslands.
The study, to be posted the week of Aug. 4 on PNAS Online, is based on a two-year field experiment conducted in the grassy foothills above Stanford's main campus. Instead of causing the soil to dry up, the experiment revealed that higher temperatures actually increased soil moisture by as much as 10 percent.
"Warming accelerates evaporation, so we expected warmer to mean drier," said lead author Erika S. Zavaleta, a former Stanford doctoral student now on the faculty of the University of California-Santa Cruz. "We were surprised to find that warming actually increased moisture in our grassland plots during those critical weeks in late spring at the end of the growing season, when moisture shapes which plant species prevail. We traced this unexpected moisture increase to the plants themselves."
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The discovery that higher temperatures can significantly dampen soil is at odds with several climate models that predict that global warming will make grassland ecosystems drier, not wetter. Those models are based on the assumption that higher temperatures will increase the amount of water that evaporates from the soil and the surface of living plants -- a process called "evapotranspiration."
At the Jasper Ridge site, most soil moisture evaporates through plants. But during the course of the experiment, researchers discovered that warming caused the early demise of numerous grasses and wildflowers. In fact, some experimental plots that were exposed to higher temperatures suffered the premature loss of 17 percent of their green vegetation. Since evapotranspiration only occurs through living plants, the fact that so many died early could explain the unexpected rise in soil moisture, the authors noted.
"In California grasslands, plants control most of the water exiting the system by transpiring water through their leaves until they die," Zavaleta said. "Simulated global warming accelerated the death of the dominant grasses in our plots, leaving slightly more water in the soil for other species like oaks and summer wildflowers to use. This doesn't mean climate change is good for California grasslands, but it reinforces the importance of paying attention to how plants and animals could modify its effects."
If higher temperatures kill off some of the plants but leave more moisture for the other plants then what are the effects on the remaining plants? Do they stay healthy longer during dry periods? It is not clear what the net effect is of the higher temperatures. One effect might be to cause a change in the ratios of species of plants in any given area to select for more heat-resistant plants.
Note that independent of the heat effect the plots that were exposed only to higher CO2 also had more moisture in their soil. That result, while not unexpected due to previous research, is also interesting in light of another report previous posted here: Rising Carbon Dioxide Causing Forests To Expand Into Deserts. A hotter planet with more CO2 in the atmosphere may turn out to be a much greener planet overall.
Some see youthful rejuvenation as something that can be accomplished within 50 years.
A few of our more radical experts believe that, in the next 50 years, 90-year-olds could look like 30-year-olds and feel as fit as a 45-year-old thanks to an explosion in regenerative medicine, genetic research and biotechnology.
And today's children could live to 120 - or longer. The Centre for Strategic and International Studies in Washington predicts that a female born today will have a 40 per cent chance of surviving until she is 150 years old.
I don't see how someone can do a calculation to come up with a percent odds. What is more likely the case is that at some point we will reach the ability to keep people perpetually young and then life expectancy predictions will be based chiefly on non-aging related causes of death. The mystery is just when will we reach the point where we can reverse aging?
Nicholas D. Kristof of the New York Times quotes a much more radical prediction by biogerontologist Aubrey de Grey.
"Our life expectancy will be in the region of 5,000 years' in rich countries in the year 2100, predicts Aubrey de Grey, a scholar at Cambridge University. (This is, of course, a great prediction to make, because none of us will be around in 2100 to mock him if he's wrong.)
Kristof is wrong on his last point. The year 2100 is only 97 years away as of this writing. Barring the end of human civilization (which is a distinct possibility) even without advances in medicine there are already many people alive now who will be alive then. Even under the most conservative estimates of the rate of biomedical research advance it seems likely that average life expectancy will increase by decades in this century. So tens or hundreds of millions of people alive right now should live to the year 2100.
Aubrey expects that within 100 years we will have total mastery of technology for growing replacement organs, making youthful replacements of adult stem cell reservoirs in the body, the ability to eliminate accumulated of intracellular aggregate junk, and still other parts of the rejuvenation puzzle.
In an interview with The Speculist after listing what he considers to be the 7 most promising approaches for rejuvenation Aubrey says that those 7 rejuvenation approaches could all be tried in mice within a decade's time.
What do you consider a realistic timeframe for putting treatments in place that address all seven?
That's hard to say, because some of them need really good gene therapy, which is still rather black magic. I won't stop there, though, because I feel that biogerontologists have a duty to give their best guess at timescales. What I can say is that we should be able to implement all seven in mice within a decade. This is because gene therapy in mice is a lot easier, for the simple reason that we don't have to worry about safety. And the thing is that as soon as we do implement them in mice, and presuming that they give the sort of life-extension benefits I predict, the general public will realize that aging is not inevitable after all, and will push incredibly hard for more work on human gene therapy etc. to get the therapies working in humans as fast as possible.
This is key. Aubrey's attitude is that we don't have to wait for every single molecular mechanism of aging to be elucidated in excruciating detail before we start trying to role back the clock. If we take more of an angineering approach and just start trying to replace or repair what most likely needs to be replaced or repaired we can get useful anti-aging therapies much sooner.
Aubrey thinks that on the outside we will achieve engineered negligible senescence within 60 years.
Assuming you live to be 100, what will be the biggest difference be between the world you were born into and the world you leave?
Um, do you mean if I die aged 100? I fully intend not to leave the world at such a paltry age. But even if I died aged 100, that's still 60 years away — far too long to be able to make such predictions. Hmm, well, in 60 years we'll definitely have aging under complete control — I guess it would be difficult to imagine a bigger difference than that.
Aubrey has a lot more on his website about strategies of engineered negligible senescence.
Smart kids use more of their brains to solve puizzles.
James Wood, 14, uses more of his brain to solve puzzles than other children. To the surprise of Melbourne experts conducting research, James - and seven other mathematically gifted children - used both hemispheres, and parts he wasn't expected to.
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"It may be there's big education consequences of this work," says Fred Mendelsohn, head of the Howard Florey Institute. "If it's something that can be learned, you can obviously make a big difference to the way you teach people, the way they learn, they way they develop skills."
It could be that the brains of smarter kids have connections coded for genetically to allow them to recruit more parts of the brain to work on a given problem. If so, it may not be possible to train a brain using teaching techniques to connect various parts of the brain in ways that would allow more of it to be used when solving problems.
The Washington Post has a great article on the growing problem of identity theft.
Identity theft is perhaps the most glaring symptom of the ills that have accompanied the data revolution of the 1990s. Bounced checks. Loan denials. Harassment from debt collectors. Victims of identity theft -- and there are millions of them -- are often haunted by the consequences for years.
Some government officials estimate that as many as 750,000 people a year are victimized. Others think that number is way too low. Last month Gartner Inc., a business research group, estimated that 7 million Americans have fallen prey to identity thieves in the past year alone, an extraordinary figure mirrored by a new survey from Privacy & American Business, an industry-funded think tank. Another study, by Star Systems, a company that facilitates the majority of U.S. ATM transactions, suggests that almost 12 million Americans in all, or about one in 19 adults, have been hit by such fraud.
One of the tales of identity theft has a Washington DC think tank manager worrying that he'd be arrested for murder because of murders committed by someone using his identity.
Bergin explained the warrant meant that he, the real Michael Berry, could be picked up for murder. The law enforcement computers would tell officers they were looking for a black man. But cops are so used to getting reports marred by mistakes, she said, they might ignore that detail if they had the right name.
The article is worth reading in full. As electronic information acquisition and transmission becomes steadily easier to do we are going to be faced with the problem that it is going to become just too easy to gather the key pieces of information needed to pull off identity theft. We need the widespread adoption of reliable biometric means of identification. We also need legal changes to put more responsibility on financial institutions to prevent identity theft. A person suffering under the consequences of identity theft has limited means by which to put a stop to it while financial institutions hand out key information far too readily while simultaneously making too little effort to verify identity.
If we count the faking of sender email addresses the commission of identity theft even more common than this article reports. I'm currently getting a large number of 100k+ email messages on one of my email accounts and many of the messages appear to be bounces of email by spam filters on other pop servers. Someone is sending out 100k sized junk mail using my email address as the return address.
MIT chemistry professor and former CIA chief John Deutch has co-authored a New York Times Op-Ed with MIT physics professor Ernest Moniz entitled Nuclear Power Can Work.
We built a model to compare the costs of producing electricity from new nuclear, coal and natural gas plants. The model focuses on economic cost, not regulated or subsidized cost. According to our study, the baseline cost of new nuclear power is 6.7 cents per kilowatt-hour, compared to 4.2 cents for coal and natural gas (when the price of gas is $4.50 per thousand cubic feet). Plausible, but unproved, technology could reduce nuclear costs to those of coal and gas.
However, if a cost is assigned to carbon emissions — either through a tax or some other way, as in a current Congressional proposal that would limit emissions but allow companies to buy and sell the right to discharge more pollutants — nuclear power could become an attractive economic option. For example, a $50 per ton carbon value, about the cost of capturing and separating the carbon dioxide product of coal and natural gas combustion, raises the cost of coal to 5.4 cents and natural gas to 4.8 cents.
Well, even with the cost of CO2 removal included that still leaves fossil fuels cheaper than nuclear power. Clearly nuclear power can not currently compete on the basis of production costs.
The Op-Ed alludes to a recent study done at MIT on the future of nuclear power of which both Deutch and Moniz were among the co-authors. That study, The Future Of Nuclear Power, outlines a number of problems with nuclear power.
"Fossil fuel-based electricity is projected to account for more than 40% of global greenhouse gas emissions by 2020," said Deutch. "In the U.S. 90% of the carbon emissions from electricity generation come from coal-fired generation, even though this accounts for only 52% of the electricity produced. Taking nuclear power off the table as a viable alternative will prevent the global community from achieving long-term gains in the control of carbon dioxide emissions."
But the prospects for nuclear energy as an option are limited, the report finds, by four unresolved problems: high relative costs; perceived adverse safety, environmental, and health effects; potential security risks stemming from proliferation; and unresolved challenges in long-term management of nuclear wastes.
The study examines a growth scenario where the present deployment of 360 GWe of nuclear capacity worldwide is expanded to 1000 GWe in mid-century, keeping nuclear's share of the electricity market about constant. Deployment in the U.S. would expand from about 100 GWe today to 300 GWe in mid-century. This scenario is not a prediction, but rather a study case in which nuclear power would make a significant contribution to reducing CO2 emissions.
"There is no question that the up-front costs associated with making nuclear power competitive, are higher than those associated with fossil fuels," said Dr. Moniz. "But as our study shows, there are many ways to mitigate these costs and, over time, the societal and environmental price of carbon emissions could dramatically improve the competitiveness of nuclear power"
Nuclear power used worldwide would greatly accelerate nuclear proliferation. In my view this isn't just a hypothetical risk to manage and minimize. Place nuclear reactors all over the world and it is inevitable that more countries will use the presence of reactors as an opportunity to get the materials needed to make nuclear weapons. Just a single nuclear bomb exploded in an American city could kill millions of people and cause hundreds of billions or even trillions of dollars in economic losses. Nuclear power has to be weighed against that risk.
The biggest argument Deutch and Moniz make for nuclear power is that increasing its use will slow the growth in CO2 emissions. For the sake of discussion leave aside the question of whether CO2 emissions are a threat to the environment. Reduction in CO2 emissions can be accomplished at less cost by using methods to capture CO2 emitted by fossil fuel plants.
The use of fossil fuels from the Middle East also sends money to the Middle East that helps fund the spread of Wahhabism, support for terrorism, and efforts to make weapons of mass destruction. But an increased use of nuclear power only in the United States will do little to decrease those cash flows. What is needed are power sources that can displace Middle Eastern fossil fuels at a cost much lower than current Middle Eastern fossil fuels market prices.
As far as increasing the use of nuclear power is concerned, the US government should pursue two main policy objectives:
If a form of nuclear power that does not pose proliferation risks could be developed and if it could be made to be much cheaper than current fossil fuel-powered electricity then it would become a viable option.
Richard A. Muller says that while lie detector tests are not admissible in court due to their error rates...
It is also true that this accuracy figure implies that only 85 percent of truth-tellers will be exonerated; 15 percent will be falsely accused of lying. That is why the National Academy of Sciences’ report came down so hard on the process.
...we rely instead on the ability of jurors to measure the honesty of testimony and the jurors have even higher error rates.
To do this, they were told to take into account “the demeanor” of the witness, his directness in answering questions, and anything else that they thought indicated truthfulness. Ironically, scientific tests show that the average person’s probability of catching a lie in this way is only “slightly better than chance,” according to Ekman. Moreover, the jurors who use this approach have the conviction that their accuracy is near 100 percent, despite their knowledge that most witnesses are extensively coached in methods of appearing sympathetic and truthful—in other words, in methods to defeat the system.
The jury trial system is in great need of technologies that would make it more accurate. Juror tests could be developed that use Statistical Prediction Rules (SPRs) to choose jurors who are more capable of discerning the truth. Additional SPRs could be developed for analysing types of evidence and even of testimony. Our criminal justice system is based on the false conceit that we are excellent judges of character and of other forms of evidence.
The US Postal Service is proposing to implement a system similar to what Federal Express and UPS have where they label and use computers to track the movement of every single item they deliver. This has predictably raised objections from privacy advocates.
The Postal Service estimates that it delivers about 670 million pieces of mail to more than 138 million addresses daily, leading to concerns among law enforcement and government officials that it is too easy to use the system for criminal or terrorist activity.
The commission said the Intelligent Mail could bolster security, as well as let consumers track the progress of anything they send. The latter has been identified as a top consumer demand in the commission's independent surveys.
One objection that privacy advocates raise is cost. But as computer storage, CPU, and communications costs continually fall the costs of implementing such a system fall as well. Their real objection is the threat to privacy. They want anonymous means of communication. But unless the postal service eliminates drop-box mailing and anonymous purchasing of stamps this proposal will not stop someone from sending mail without revealing their identity. Granted, a letter may be traced back to its originating mail box but letters are already marked with the town they originated from. One can easily drive to another town and drop a letter in the mail there under the current system and likely under the new system as well.
If privacy advocates do not like what computers can accomplish in terms of monitoring and tracking human activity now they face a bleak future. Computer speed, storage, and communications bandwidth will all increase by orders of magnitude in coming decades. Sensor networks are going to be cheap and pervasive. New readers to this site should check out my Surveillance Society archive and look for posts that discuss the argument that the death of privacy is inevitable.
Blaine Harden has an interesting article in the Washington Post about the dangers posed by a volcanic eruption of Mount Rainier in Washington State.
"A monumental threat," said William E. Scott, scientist in charge of the Cascades Volcano Observatory, a USGS center that monitors volcanoes from California to Alaska.
...
About 150,000 people now live atop lahars that have rioted down the slopes of Mount Rainier over the past 5,000 years. The lahars ran all the way to what are now the ports of Tacoma and Seattle, distances, respectively, of 50 and 75 miles.
No volcano in the lower 48 states packs so much risk so close to so many people, Scott said. Mount St. Helens, which erupted in 1980 and killed 57 people, is more active than Rainier, but it is not near large population centers.
Based on the historical pattern Rainier is expected to erupt some time in the next 500 years. The population is growing around the volcano. A really large eruption could send flows running all the way to Seattle.
Thanks to Joe Katzman for the heads-up.
With the federal government having been effectively legislated and browbeaten out of the data mining business for capturing terrorists the activity has shifted to the states with Florida leading the way with a system called Matrix (Multistate Anti-Terrorism Information Exchange).
Organizers said the system, dubbed Matrix, enables investigators to find patterns and links among people and events faster than ever before, combining police records with commercially available collections of personal information about most American adults. It would let authorities, for instance, instantly find the name and address of every brown-haired owner of a red Ford pickup truck in a 20-mile radius of a suspicious event.
Some might see this as the triumph of federalism and the power of distributed networks where no one single large entity is in charge. Some might even see this as signs of the inevitability of as surveillance and data collection technologies spread far and wide in society and people sitting at home are even recruited to watch critical facilities remotely.
The database is being developed by a company called Seisint which already markets a commercial database service called Accurint which is a database service for locating people and past and present addresses.
Accurint uses a name, past address, phone number or Social Security Number to obtain the current name, address and phone number of targeted subjects. Using proprietary compilation of data sources and association algorithms, Accurint’s ability to deliver high-quality matches and find rates is unparalleled. Accurint can also provide previous addresses and location information for relatives, associates, and neighbors. As a result, Accurint is the most accurate and detailed source for forward-looking and historical views of consumer contact information.
By leveraging unmatched capability for processing billions of records per second, Accurint has compiled the world’s largest set of accessible location data. Accurint searches more than 20 billion records that cover recent relocation to historical addresses dating back 30 years and more. Individual queries are supported via web and client applications. For high-volume requests, Accurint provides on-demand batch capabilities, drastically reducing the cost of searches. For direct legacy application access Accurint supports XML API's.
With its unique combination of data, association algorithms and search technology, Accurint offers the best-performing solution in the marketplace.
Many companies have large databases of records of their transactions and contacts with millions of people and organizations. It is not a big stretch to use these databases to do data mining to look for activity that correlates with patterns found in investigations of known terrorists.
Clearly grasping at straws the Cato Institute is peddling the idea that automated systems of collection and analysis of information will drain resources from more productive approaches to finding terrorists.
Florida's database is similar in many ways to the Pentagon's controversial Terrorist Information Awareness program. In "Total Information Awareness for the Ages," Clyde Wayne Crews Jr., director of technology policy, writes: "Ironically, the project could also increase security risks. Even the Pentagon's resources are limited: Most people are not terrorists, and it can be a costly diversion to attempt to monitor the torrent of chatter that will be generated by this misguided program. Terrorists already immerse themselves in mainstream society, even using their real names and official government documents. They can learn and anticipate the trigger patterns that will supposedly generate red flags, and then avoid them."
The Florida project will simultaneously automate information searches for commonplace police investigations and also bring together data that can be mined to patterns of potential terrorist activity. As computers become cheaper and more powerful and as communications costs fall as well the trend is clearly running in the direction where computer automation becomes increasingly more cost effective than traditional methods of police and intelligence work.
The Berkeley Intellectual Property Weblog is also worried. (my emphases added)
But if each state collects and maintains citizen's data, each with different standards for correcting, aggregating and using the data, and if states string together their databases, as several states would like to collaborate with Florida to do (Alabama, Connecticut, Florida, Georgia, Kentucky, Louisiana, Michigan, New York, Ohio, Oregon, Pennsylvania, South Carolina, and Utah so far in the MATRIX -- click here for their contacts list; and the District of Columbia and Virginia, Maryland, Pennsylvania and New York in the DC program as reported by Spencer S. Hsu/WDC Post), I think we will have a far more dispersed and frightening problem than what the TIA proposed. Does this mean Safire, and Harrow do another round of columns, Congress and (hopefully) State Legislatures get involved to control this effort toward Too much surveillance (by Safire) of citizens? How effective can we as citizens be in asking for legislative oversight when there are so many different states and entities involved?
Things are spinning out of control? Woe is us? At the risk of sounding like I'm playing a broken record, these worrywarts show little sign of being familiar with science fiction writer David Brin's argument that the death of privacy is inevitable and our only choice is whether only governments or everyone will use the surveillance and data collection technologies which are continually advancing in sophistication and ease of use. In Brin's view we effectively face a choice between privacy and freedom. But those who scream loudest against government surveillance and data collection seem wholly unaware of Brin's analysis.
Melissa Jungers, Caroline Palmer, and Shari Speer, of Ohio State University have discovered that musicians and speakers adjust the speed and, in the case of the speakers, even the pattern of phrase breaks to match what they just heard.
In one study, the researchers used 16 experienced adult pianists. The pianists sight-read two melodies to establish their preferred performing rate. They then alternated listening to computer-generated melodies and playing different melodies on the piano. They heard 10 melodies and played 10 melodies. The participants were led to believe they were participating in a memory test – they were given no direction about how slow or fast to play.
The melodies they heard were performed at relatively slow or relatively fast rates. When they played, the pianists were provided notations that did not include bar lines or time signatures so there would be no indication of meter or any indirect indication of a rate at which the tune should be played.
After listening to a slow melody, the pianists played their melody slower (an average of 6.8 seconds) when compared to when they had first heard the faster melody (an average of 5.3 seconds). The pianists preferred rate – the rate they played before they heard other melodies – was in between those two times, at 6.1 seconds.
The second study was designed to be as close as possible to the first study – except that the researchers examined speech rather than music. In this study, 64 native English speakers spoke 10 short sentences (6 to 7 words each). First, speakers read two sentences aloud from a computer screen to measure their preferred speaking rate. Next, speakers alternated listening to and reading sentences. In some cases, they listened to sentences spoken at a fast rate, in other cases at a slow rate. The participants were not told how fast or slow to speak – they were simply told to try to remember the sentences for a later memory test.
For 43 of the 64 speakers, they spoke faster after they heard a sentence spoken at a fast tempo and spoke slower when they heard a slower speaking delivery.
When they heard the slow speakers, their sentences averaged 1.81 seconds long, while when they heard the fast speakers their sentences averaged 1.72 seconds long. Their preferred rate of speech averaged 1.80 seconds per sentence.
In addition, this study showed that speakers were also influenced by the pattern of phrase breaks in the recordings they heard. If the recordings had the largest pause in the sentence after the verb, for example, that is where the speakers tended to put their biggest pause.
It would be interesting to play music at different rates and then see if people will speak at different speeds as a result.
Ottawa University Heart Institute researcher Maria Viaznikova has developed a fast easy way to extract DNA from fingerprints for sequencing.
Viaznikova said her team's method consistently yields 10 billionths of a gram of DNA, on average, from a single fingerprint. The findings were revealed at the American Society for Microbiology's nanotechnology conference in New York earlier this month. Although 10 "nanograms" might not sound like much, for DNA analysis, even 0.1 nanogram is enough, Viaznikova said. "Scientists try not to use less than 5 to 10 nanograms, so this is fine." She said forensic scientists have known for about five years that fingerprints contain DNA. However, commonly used extraction techniques need several hours or even days of lab work. "We can do it in 15 minutes," she added.
The article quotes experts who want restrictions on when government agencies can sequence a person's DNA with required notifications to tell a person their DNA is being sequenced. But these kinds of demands miss a very important point: once DNA sequencing becomes cheap and easy enough to be done by devices that can be operated by a single individual who has no special skills it will be impossible to discover the bulk of sequencing that will be done.
See my previous posts Will The Death Of Genetic Privacy Hasten The End Of Freedom? and Genetic privacy: can it be protected? for more on the implications of advances of this kind. What already seems naive about my previous posts is that I speculated on how women would try to get saliva samples or other cell samples from close contact with guys in order to get DNA samples. Well, getting a DNA sample will be easier than that. It will be easy to get a DNA sample from any person seen holding a drink in a bar. When they get up to leave someone could walk by and grab one of their drinking glasses to take a quick sample off of it. The person trying to get the sample never even has to meet their quarry. Combine the ease of sample acquisition and cheap DNA sequencing and personal genetic privacy will become impossible to maintain.
This ability to sequence another's DNA is going to have interesting ramifications for paternity suits. A woman will be able to stalk a guy by going to the same bar or restaurant, grab a glass he held, get a sample, and then sequence the guy's DNA. The woman can then judge the suitability of the guy's DNA. If he passes muster in terms of what she wants in a child she will also be able to use the DNA sample to have it be manipulated in a microfluidic device to make a viable set of chromosomes to use in artificial fertilization. Then she'll be able to sue for paternity. Will courts hold men responsible for offspring when the men start claiming they never even met the women who sue them for paternity?
A pair of scientists argue that variations in the amount of cosmic ray flux hitting the Earth's atmosphere is the biggest cause of changes in Earth's climate.
Global warming will not be helped much by efforts to reduce carbon dioxide emission into the atmosphere, say two scientists who have studied the matter.
Dr. Nir Shaviv, an astrophysicist from the Racah Institute of Physics of the Hebrew University of Jerusalem, and Prof. Jan Veiser a geochemist at the University of Ottawa in Canada and Ruhr University in Germany, say that temperature variations are due more to cosmic forces than to the actions of man.
In a recent article published in GSA Today (the journal of the Geographic Society of America) and described in Nature, Shaviv and Veiser tell of their studies illustrating a correlation between past cosmic ray flux – the high-energy particles reaching us from stellar explosions -- and long-term climate variability, as recorded by oxygen isotopes trapped in rocks formed by ancient marine fossils. The level of cosmic ray activity reaching the earth and its atmosphere is reconstructed using another isotopic record in meteorites.
The study showed that peak periods of cosmic rays reaching the earth over the past 550 million years coincided with lower global temperatures, apparently due to the way that the cosmic rays promote low-level cloud formation (hence blocking out sun warming). No correlation was obtained, however, with the changing amount of atmospheric carbon dioxide.
The conclusion of the two scientists is, therefore, that celestial processes seem to be the dominant influence on climate change, and that increased carbon dioxide release, while certainly not beneficial, is only secondary to those forces which are beyond our control.
In practical terms, says Dr. Shaviv, "The operative significance of our research is that a significant reduction of the release of greenhouse gases will not significantly lower the global temperature, since only about a third of the warming over the past century should be attributed to man." Thus, say the scientists, the Kyoto accord of 1997 -- which was aimed at tackling the global warming phenomenon through limitations on carbon dioxide -- is not the panacea some thought it would be.
Taking the long-range view, Dr. Shaviv and Prof. Veiser believe that fluctuations in cosmic ray emissions account for about 75 percent of climate variation throughout the millennia. They acknowledge that this position pits them against prevailing scientific opinion, which still places a heavy emphasis on the negative role of greenhouse gases.
They see a smaller effect of CO2 on climate trends.
More specifically the authors assert that the long-term "warming effect of CO2" is "potentially lower" than generally thought. They say the carbon dioxide factor would appear to have a minimum impact of 1.9C on sea temperatures rather than the 5.5C projected in certain worst-case scenarios.
A consortium of researchers is going to identify and discover interactions of all lipid metabolites in macrophages.
The five-year, $35 million grant from the National Institute of General Medical Sciences (NIGMS) will support more than 30 researchers at 18 universities, medical research institutes, and companies across the United States, who will work together in a detailed analysis of the structure and function of lipids. The principal investigator of this collaboration is Edward Dennis, Ph.D, professor of chemistry and biochemistry in UCSD’s Division of Physical Sciences and UCSD’s School of Medicine.
Dennis notes that while sequencing the human genome was a scientific landmark, it is just the first step in understanding the diverse array of systems and processes within and among cells. Establishment of this consortium is a significant step in an emerging field called “metabolomics,” or the study of metabolites, chemical compounds that “turn on or off cellular responses to food, friend, or foe,” he explained.
Lipids are a water-insoluble subset of metabolites central to the regulation and control of normal cellular function, and to disease. Stored as an energy reserve for the cell, lipids are vital components of the cell membrane, and are involved in communication within and between cells. For example, one class of lipids, the sterols, includes estrogen and testosterone.
The initial phases of the project, known as Lipid Metabolites And Pathways Strategy (LIPID MAPS), will be aimed at characterizing all of the lipid metabolites in one type of cell. The term “Lipidomics” is used to describe the study of lipids and their complex changes and interactions within cells. Because this task is too extensive for a single laboratory to complete, researchers at participating centers will each focus on isolating and characterizing all of the lipids in a single class. This information will then be combined into a database (at http://www.lipidmaps.org) to identify networks of interactions amongst lipid metabolites and to make this information available to other researchers. Shankar Subramaniam, Ph.D., professor of chemistry and bioengineering at UCSD’s Jacobs School of Engineering and San Diego Supercomputer Center, will coordinate this aspect of the project.
The cell type selected for study is the macrophage, best known for its role in immune reactions, for example scavenging bacteria and other invaders in the body. Macrophage cells from mice will be used, rather than human cells, because there exists a “library” of mouse cells with specific genetic mutations. By studying cells missing certain genes, the research team will attempt to identify what genes code for those enzymes key in synthesis and processing of lipid metabolites. Christopher Glass, M.D., Ph.D., professor of cellular and molecular medicine at UCSD’s School of Medicine, will coordinate the macrophage biology and genomics aspects of the consortium.
What is interesting about this project is that it typifies a trend in biological sciences toward the more systematic and thorough collection of information on all the parts of each subsystem or category of cellular metabolism. Systematic efforts to collect data on cellular metabolites and components will provide the raw data needed to construct of far more detailed models of cellular metabolism. Coded up as computer programs these models will eventually be able to predict how each imaginable intervention in cellular metabolism will affect all the subsystems in a cell and in the larger organism that the cell is part of. Computer models built with sufficient detail will allow simulation runs to a serve in place of laboratory experiments that currently require real cells and real organisms. The systematic collection of data on the subsystems and components of cells will therefore lead to a great acceleration in the rate of biological science and in biological engineering.
Update: In another sign of the times the LIPID MAPS project has been made possible by instrumentation advances.
The LIPID MAPS project has become possible thanks to the refinement of mass spectrometers, which determine the type and quantity of lipids in a mixture. Today, machines can identify hundreds of lipids in a sample simultaneously using electron spray ionization mass spectrometry. Particles are fired at lipid molecules to chisel off shards, the chemical structures of which are determined one by one.
The development of better instrumentation does more to accelerate the rate of advance in biology than any other factor.
J.D. Trout & Michael Bishop, writing in an essay entitled "50 Years of Successful Predictive Modeling Should be Enough: Lessons for Philosophy of Science" argue that we continue to rely too much on the individual judgements of experts to make important decisions on subject matters where automated computer implementation of Statistical Prediction Rules would yield more accurate results. (PDF format)
In 1954, Paul Meehl wrote a classic book entitled, Clinical Versus Statistical Prediction: A Theoretical Analysis and Review of the Literature. Meehl asked a simple question: Are the predictions of human experts more reliable than the predictions of actuarial models? To be a fair comparison, both the experts and the models had to make their predictions on the basis of the same evidence (i.e., the same cues). Meehl reported on 20 such experiments. Since 1954, every non−ambiguous study that has compared the reliability of clinical and actuarial predictions (i.e., Statistical Prediction Rules, or SPRs) has supported Meehl’s conclusion. So robust is this finding that we might call it The Golden Rule of Predictive Modeling: When based on the same evidence, the predictions of SPRs are more reliable than the predictions of human experts.
It is our contention that The Golden Rule of Predictive Modeling has been woefully neglected. Perhaps a good way to begin to undo this state of affairs is to briefly describe ten of its instances. This will give the reader some idea of the range and robustness of the Golden Rule.
1. A SPR that takes into account a patient’s marital status, length of psychotic distress, and a rating of the patient’s insight into his or her condition predicted the success of electroshock therapy more reliably than a hospital’s medical and psychological staff members (Wittman 1941).
2. A model that used past criminal and prison records was more reliable than expert criminologists in predicting criminal recidivism (Carroll 1982).
3. On the basis of a Minnesota Multiphasic Personality Inventory (MMPI) profile, clinical psychologists were less reliable than a SPR in diagnosing patients as either neurotic or psychotic. When psychologists were given the SPR’s results before they made their predictions, they were still less accurate than the SPR (Goldberg 1968).
4. A number of SPRs predict academic performance (measured by graduation rates and GPA at graduation) better than admissions officers. This is true even when the admissions officers are allowed to use considerably more evidence than the models (DeVaul et al. 1957), and it has been shown to be true at selective colleges, medical schools (DeVaul et al. 1957), law schools (Dawes, Swets and Monohan 2000, 18) and graduate school in psychology (Dawes 1971).
5. SPRs predict loan and credit risk better than bank officers. SPRs are now standardly used by banks when they make loans and by credit card companies when they approve and set credit limits for new customers (Stillwell et. al. 1983).
6. SPRs predict newborns at risk for Sudden Infant Death Syndrome (SIDS) much better than human experts (Lowry 1975; Carpenter et. al. 1977; Golding et. al. 1985).
7. Predicting the quality of the vintage for a red Bordeaux wine decades in advance is done more reliably by a SPR than by expert wine tasters, who swirl, smell and taste the young wine (Ashenfelter, Ashmore and Lalonde 1995).
The writers cite additional examples not excerpted here. Paul Meehl thinks we should place more trust in models for decision-making.
Upon reviewing this evidence in 1986, Paul Meehl said: “There is no controversy in social science which shows such a large body of qualitatively diverse studies coming out so uniformly in the same direction as this one. When you are pushing [scores of] investigations [140 in 1991], predicting everything from the outcomes of football games to the diagnosis of liver disease and when you can hardly come up with a half dozen studies showing even a weak tendency in favor of the clinician, it is time to draw a practical conclusion” (Meehl 1986, 372−3).
The writers discuss why humans are reluctant to admit that their subjective judgement has a high error rate.
Resistance to the SPR findings runs very deep, and typically comes in the form of an instance of Pierce’s Problem. Pierce (1878, 281−2) raised what is now the classic worry about frequentist interpretations of probability: How can a probability claim (say, the claim that 99 out of 100 cards are red) be relevant to a judgment about a particular case (whether the next card will be red)? After all, the next card will be red or not, and the other 99 cards can’t change that fact. Those who resist the SPR findings are typically quite willing to admit that in the long run, SPRs will be right more often than human experts. But their (over)confidence in subjective powers of reflection leads them to deny that we should believe the SPR’s prediction in some particular case.
The writers go on to discuss why experts have excessive confidence about their abilities and how they underestimate their rate of errors when making judgements.
On a practical personal level what can we do to get better diagnoses and better advice? Try to get direct access to automated decision-making systems and when that is not possible seek out experts who use such systems routinely. Given that most experts in most fields are unwilling to use such systems for the foreseeable future we will have to continue to rely on flawed human judgement the vast bulk of the time.
Vermont Dr. Lawrence L. Weed has developed an expert system for medical diagnosis called the Problem Knowledge Coupler. See this Boston Globe report on Dr. Weed and the reception that the Problem Knowledge Coupler has received in the medical community.
Humans, Weed argues, cannot consistently process all of the information needed to diagnose and treat a complicated problem. The more information the physician gets about a patient, the more complex the task becomes. A doctor working without software to augment the mind, he argues, is like a scientist working without a microscope to augment the eye.
Some accomplished physicians and scientists who have explored ways to use artificial intelligence to diagnose patients say that it is impossible with today's technology. Many other doctors strongly oppose the mere concept, calling software incapable of matching their expertise; computers merely get in the way, they argue. But a small band of physicians and Weed's company's biggest customer, the US Department of Defense, have begun to use the Knowledge Couplers, and an early study suggests that their patients are healthier for it. If the software catches on, Weed's ideas may forever change the way doctors make decisions, removing much of the mystery and leaving us, the patients, with more control over our care. Weed's supporters say the medical industry will one day recognize the genius behind the software, much as it recognized the promise of Weed's first major innovation, which changed medicine four decades ago.
Training of large numbers of experts by universities has probably had the perverse effect of increasing the number of people running around making highly confident but wrong judgements. But the tendency to not notice our errors and to place excessive confidence in our subjective judgements is something that all humans suffer from to varying degrees. Unfortunately, few people receive much training in statistics and in methods of making more rational judgements and a great deal of potential for expert systems is unrealized because people are unwilling to acknowledge how much expert systems could help them.
Use neurofeedback to become a better musician.
Researchers from Imperial College London and Charing Cross Hospital have discovered a way to help musicians improve their musical performances by an average of up to 17 per cent, equivalent to an improvement of one grade or class of honours.
The research published in this months edition of Neuroreport, shows that using a process known as neurofeedback, students at London's Royal College of Music were able to improve their performance across a number of areas including their musical understanding and imagination, and their communication with the audience.
Dr Tobias Egner, from Imperial College London at Charing Cross Hospital, one of the authors of the study, comments: "This is a unique use of neurofeedback. It has been used for helping with a number of conditions such as attention deficit disorder and epilepsy, but this is the first time it has been used to improve a complex set of skills such as musical performance in healthy students."
Two experiments were conducted involving a total of 97 students. In both experiments, the students were assessed on two pieces of music, both before and after the neurofeedback training, according to a 10-point scale adapted from a standard set of music performance evaluation criteria of the Associated Board of the Royal Schools of Music, by a panel of expert judges. The judges evaluated video-recorded performances, and were unaware of whether the performance had been given before or after the intervention.
Neurofeedback monitors brain activity through sensors attached to the scalp which filter out the brainwaves. These filtered brainwaves are then fed back to the individual in the form of a video game displayed on screen, and the participant learns to control the game by altering particular aspects of their brain activity. This alteration in brain activity can influence cognitive performance.
In the first experiment, 22 students out of 36 were trained on two neurofeedback protocols (SMR and beta1), commonly used as tools for the enhancement of attention, and, following this, on a deep relaxation alpha/theta (a/t) protocol. In addition a second group of 12 was engaged in a regime of weekly physical exercise and a mental skills training programme derived from applications in sports psychology. A third group consisted of a scholastic grade and age matched no-training group, which served as a control grade.
In the second experiment, a different cohort of students were randomly allocated to one of six training groups: alpha/theta neurofeedback, beta1 neurofeedback, SMR neurofeedback, physical exercise, mental skills training, or a group that engaged in Alexander Technique training.
All of the students who received neurofeedback training were found to have improved their performances marginally compared with those who received other forms of training, but those who had received the alpha/theta (a/t) protocol improved their performance the most. The range of improvement in performance for the alpha/theta group was between 13.5 per cent and 17 per cent.
Professor John Gruzelier, from Imperial College London at Charing Cross Hospital, and senior author of the study, adds: "These results show that neurofeedback can have a marked effect on musical performance. The alpha/theta training protocol has found promising applications as a complementary therapeutic tool in post-traumatic stress disorder and alcoholism. While it has a role in stress reduction by reducing the level of stage fright, the magnitude and range of beneficial effects on artistic aspects of performance have wider implications than alleviating stress."
In light of other recent results about musical training improving verbal abilities it would be interesting to know whether neurofeedback training can improve verbal abilities as well.
Update: Links to published papers of their research available here.
Dr. Arthur Ho of the University of New South Wales and a member of Australia's Vision Co-operative Research Centre (Vision CRC) believe his team has developed a gel which can be placed inside aged eye lenses to correct eyesight.
A CURE FOR AGING EYESIGHT is on the way, with the development by an Australian team of a permanent lens and gel that can replace the normal lens of the eye.
Scientists at the Vision CRC are well advanced in their quest to develop an implant that overcomes both loss of focus in aging eyes - or presbyopia - and other vision problems such as short sightedness.
Its developers believe that if successful in human trials - due to begin in 2004/05 - the technique will also overcome cataracts as a cause of loss of sight.
Tests found that the implantable gel lens has around four times the focal power of a pair of reading glasses - significantly better than the researchers' had aimed for, says team leader Dr Arthur Ho. "However we have yet to test it in human patients, so we won't know for sure till then," he adds.
Work on the implantable gel lens began in the CRC for Eye Research and Technology and is being carried on in the new Vision CRC. "Our initial aim was to overcome the inability of the aging eye to focus close-up, caused by the gradual hardening of the lens," Dr Ho explains. "This affects almost everyone aged 45 or more. In Australia, that's about 6.7 million people now - and around 9.9 million by the end of this decade, or 44 per cent of the population."
However the team also wanted to combine the ability to focus close-up with other forms of vision correction, such as distance refractive error - to provide total correct vision, short and long, for the ageing eye.
Besides inserting the soft gel lens, they also propose to insert a novel 'mini-lens' to correct other aspects of vision. This 'mini-lens' will be embedded in the gel within the human lens itself, giving both distance and close-up vision and, potentially, good vision at all distances that will last many years - maybe even a lifetime.
The theoretical potential of this approach has been known for some time due to research at other universities. But a suitable material has not been found up till now. The scientists will not reveal many details about the material until it is patented.
After evaluating more than 30 different polymer formulations created at collaborating Australian research institute, CSIRO Molecular Science in Melbourne, Ho thinks the group has cracked it. Vision CRC is staying tight-lipped about the new formulation while it is being patented. All the team will say is that it is a siloxane-based material, which is cured with UV or visible light after injection to turn it from a liquid to a gel.
The procedure would be quick and easy to do.
The gel, which has the consistency of thick oil, is pumped in and a burst of UV or visible light transforms it into jelly. "This could be a quick 15-minute procedure," said Mr Ho.
Anyone in their mid 40s or older could benefit from this technique once it becomes available. Five years from now the market for reading glasses may be shrinking rapidly.
UCLA researchers have developed a method to add a compressed air energy storage system to cars for a low cost and low weight increase.
Air hybrid cars could bring big fuel savings for city drivers, according to a recent study released by UCLA engineers. Experiments based on modeling and simulations showed that the air hybrid engine improved fuel efficiency by 64 percent in city driving and 12 percent in highway driving. The study also suggested that by adopting the air hybrid approach, carmakers could avoid some of the manufacturing costs associated with the more common electric hybrid design.
Tsu-Chin Tsao, professor of mechanical and aerospace engineering at the UCLA Henry Samueli School of Engineering and Applied Science, and graduate student Chun Tai have been collaborating with engineers at Ford Motor Co. and consultant Michael M. Schechter for more than a year on an air hybrid vehicle design that uses a camless valvetrain. Tai presented the team's findings at the Society of Automotive Engineers World Congress in March.
Like its cousin the electric hybrid, air hybrid vehicles are being explored as a more fuel-efficient means of traveling the nation's roads, especially in urban areas, where stop-and-go traffic leads to a wasteful use of gas. During a typical day of city driving, fuel energy used to accelerate the vehicle is partially wasted during deceleration, when kinetic energy is converted into heat in the friction brakes.
Fuel economy could be greatly improved, say researchers, if that braking energy could be captured, stored and later used to help the vehicle speed up, for instance.
To make the air hybrid design work, Tsao introduced a few clever modifications to a traditional 2.5 liter V6 engine, including a valve design that allows the engine to not only burn fuel more efficiently, but to compress and expand air captured during braking as well. When it is compressed, air can store energy that is neither toxic nor explosive. Once the air is expanded, the burst of energy that is released can be used to help accelerate the car.
The concept is closely tied to that of electric hybrid vehicles, which are becoming an increasingly well-known alternative to traditional automobiles and have already proven capable of reusing braking energy. While still fueled by gasoline, the electric hybrid vehicle's engine and transmission combination is augmented by an energy conversion and storage system housed in a black box under the car's hood. This collection of sophisticated electronic components captures brake energy, stores it as electricity and then releases it when it is needed.
The additional hardware required to make it work includes a battery and a supplemental electric motor, which adds weight to the car and drives up costs. Manufacturers are forced to reduce weight in other ways.
"Automobile manufacturers are turning to more expensive lightweight materials like aluminum to compensate for the added weight involved with the electric hybrid approach," Tsao said. "With an air hybrid you don't have to worry about that."
Thanks to Tsao's innovative valve design, the air hybrid can achieve similar fuel efficiencies but needs only an air storage unit weighing no more than 30 kilograms.
"The air hybrid does not require a second propulsion system," Tsao said. "This approach allows for significant improvements in fuel economy without the added complexity of the electric hybrid model."
The UCLA researchers avoid the need for an additional motor by introducing greater functionality into the engine's valve system. During conventional combustion engine operation, the camshaft causes the intake and exhaust valves to open and close in a synchronized fashion to let in air and fuel and to let out exhaust. The camshaft is designed to perform in a predictable and fixed way. The same operation occurs over and over — nothing more.
Tsao's industrial collaborators designed an electrohydraulic camless valvetrain system that allows for more variable valve operation, with greater control over when a valve opens and for how long. Tsao developed methods to precisely control the valve operation over a wide temperature range. This, in turn, makes it possible for the traditional engine to do more than just burn fuel.
Tsao's proposed valve system allows the engine to operate in four different modes. When a vehicle decelerates, the engine is used as an air compressor to absorb the braking energy and store it into the air tank. Whenever the vehicle stops, at a red light for example, the engine is shut down. Once the light turns green and the driver touches the accelerator pedal, the engine is started by compressed air. As the car speeds up, the engine is used as an air motor to drive the vehicle until the compressed air is depleted, at which point the engine is switched to conventional combustion mode and begins burning fuel.
Road tests are needed to prove Tsao's concept, and other challenges need to be addressed before air hybrid vehicles become widely accepted. "We want to optimize the size of the air storage tank, and begin testing the air hybrid operation using a diesel engine," Tsao said.
Compressed air for vehicle propulsion is already being explored by others. Ford is even exploring compressed air hybrids. There is even a group explor