"Speak the speech, I pray you, as I pronounced it to you, trippingly on the tongue; but if you mouth it, as many of your players do, I had as lief the town-crier spoke my lines." How about tongue braille as a novel way to read Hamlet?
The tongue, asserts Paul Bach-y-Rita, is a terrific portal to the brain. The UW-Madison physician and inventor says the tongue might serve as the ideal tactile environment to help blind people navigate, give Navy Seals directions in dim underwater environments and guide urban search-and-rescue teams as they comb the confusion of smoke-filled buildings for people to rescue.
"You don't see with your eyes, you see with your brain," says Bach-y-Rita, who, with colleague Kurt Kaczmarek, has applied for a patent on a device that uses electrical impulses to route spatial information through the tongue to the brain.
"The brain is very malleable," says Bach-y-Rita. "You can compensate for sensory loss by rehabilitating the brain" and turning to surviving sensory systems such as the skin and the tongue to substitute for lost vision.
Loaded with nerves and bathed in its own conductive saline solution, the tongue is an ideal surface for a tiny array of 144 electrodes that can, through the coordinated firing of mild electrical impulses, route images from a camera, computer or other device straight to the brain.
New miniaturized electronics, say Bach-y-Rita and Kaczmarek, will permit the device to be as small or smaller than a dental retainer and enable it to be built directly into the respirators used by divers and firefighters.
A related, tongue-based application is being developed by UW-Madison researcher Mitch Tyler to help people who have lost their sense of balance.
The technology has even caught the attention of some in the video gaming industry who see it as a bold new frontier for controlling the action of electronic gaming.
Yet more ideas for tongue sensors:
In addition to systems for the blind, Bach-y-Rita says the technology could have other applications, because designers can create impulses from any measurable source.
He is in discussions with the military regarding devices to allow divers to "see" more effectively through murky water using their mouthpieces, or to allow soldiers to receive night vision readouts through their tongues. He adds that the tongue sensors could one day be used in conjunction with video games, and his team has received a federal grant for a system that will aid people who've lost their sense of balance.
Researchers at the Naval Aerospace Medical Research Laboratory and the Institute for Human and Machine Cognition used Bach-y-Rita’s ideas to cram a pilot’s brain with expanded spatial awareness akin to sight. Instead of electrodes on the tongue, the Tactile Situation Awareness System uses a flight suit embedded with as many as 96 transducers – mini-vibrators like the ones found in cell phones. The TSAS makes pilots less dependent on their eyes. "The visual workload has gone up so high that we’re seeing an increase in the number of human factor-related mishaps," says Anil Raj, who heads the program at the University of West Florida. Now pilots can gauge their orientation from a buzz on the torso. If the plane banks left, they feel a zap on the left. If the plane makes a 180-degree turn, the zap will travel from one side of the body to the other. It usually takes months of training before pilots can look at their altimeters, attitude indicators, and compasses and understand a plane’s location in space. With TSAS, it takes 10 minutes.
On the Gene Expression blog Razib has a discussion on (among other things) IQ, scientists, and religious belief. One question is particularly interesting:
I wanted to start my series on religion discussing scientists because many of us who believe in genetic engineering and the promise of the post-human future do not think in great detail about the cultural implications on the individual level. What would changes in the germ-line imply for faith in the soul for instance? Many of us secularists might imagine that high intellectual ability will mean that religions will whither away, and the scientists with their low levels of belief serve as models. But I think close examination of the data and some analysis indicates that scientists might not be the best models, that their atheism is the product of a complex interplay of variables, and not just the result of their super-human levels of intellect (cough, cough).
I believe it will be possible to genetically engineer minds to be more prone to feel something that they will interpret as a divine presence. At the same time, I think it will be possible to genetically engineer minds that do not easily feel anything that seems transcendentally supernatural and that are extremely skeptical, analytical, intensely curious, and altogether faithless. So how will germ line genetic engineering affect people's views of the supernatural? It depends on how their minds will be genetically engineered.
While it is not yet possible to genetically engineer transcendental experiences Michael Persinger has had success in invoking the feeling of being in the presence of an other-worldly being by use of electromagnetic field wavelength patterns.
If the mind can be trained to experience sensed presences then isn't it likely that genetic engineering could make the mind more easily trainable to have such experiences?Technically speaking, what's about to happen is simple. Using his fixed wavelength patterns of electromagnetic fields, Persinger aims to inspire a feeling of a sensed presence - he claims he can also zap you with euphoria, anxiety, fear, even sexual stirring. Each of these electromagnetic patterns is represented by columns of numbers - thousands of them, ranging from 0 to 255 - that denote the increments of output for the computer generating the EM bursts.
Some of the bursts - which Persinger more precisely calls "a series of complex repetitive patterns whose frequency is modified variably over time" - have generated their intended effects with great regularity, the way aspirin causes pain relief. Persinger has started naming them and is creating a sort of EM pharmacological dictionary. The pattern that stimulates a sensed presence is called the Thomas Pulse, named for Persinger's colleague Alex Thomas, who developed it. There's another one called Burst X, which reproduces what Persinger describes as a sensation of "relaxation and pleasantness."
Again, if all these experiences described below can be induced in minds in a lab then won't they also turn out to be genetically engineerable to happen more easily in people while they carry out their every day activities?_Perceptual and Motor Skills_, 1993, 76, 80-82.
TRANSCENDENTAL MEDITATION(TM) AND GENERAL MEDITATION ARE ASSOCIATED WITH ENHANCED COMPLEX PARTIAL EPILEPTIC-LIKE SIGNS: EVIDENCE FOR "COGNITIVE" KINDLING?
M. A. Persinger
Laurentian University
Summary. - The Personal Philosophy Inventories of 221 university students who had learned to meditate (about 65% to 70% Transcendental Meditation(TM)) were compared to 860 nonmeditators. Meditators displayed a significantly wider range of complex partial epileptic-like signs. Experiences of vibrations, hearing one's name called, paranormal phenomena, profound meaning from reading poetry/prose, and religious phenomenology were particularly frequent among meditators. Numbers of years of TM practice were significantly correlated with the incidence of complex partial signs and sensed presences but not with control, olfactory, or perseverative experiences. The results support the hypothesis that procedures which promote cognitive kindling enhance complex partial epileptic-like signs.
"...The brain can discriminate and respond to different kinds of very subtle, external magnetic fields, without the individual necessarily being aware of it, except through their imagery."
"We attempted to determine if the light flashing frequency in conjunction with, that is, synergistically, a magnetic field being applied to the brain would enhance suggestibility and imagery. What we found was there was indeed a change in imagery, and that the imagery was specific to those kinds of properties that are unique to temporal lobe activity; feelings of floating, movement, certain complex visual sensations." - Michael Persinger"There is little doubt that the class of experiences that comprise mystical experiences in general, and NDE's in particular, is strongly correlated with temporal lobe activity....Kate Makarec and I have found that all of the major components of the NDE [near death experience], including out-of-body experiences, floating, being pulled towards a light, hearing strange music, and profound meaningful experiences can occur in experimental settings during minimal electrical current induction to the temporal region due to exogenous spike-and-wave magnetic field sources."
"The hypothesis that temporal lobe excitability is tied to these kinds of experiences goes back to the clinical literature, in which we know that there are ceratin personality and subjective experience features that are associated with electrical foci in the temporal lobe, specifically epileptic foci....We found that the normal population shows these symptoms, too, and that they appear to lie along a continuum.""The personalities of normal people who display enhanced temporal lobe activity... usually display enhanced creativity, suggestibility, memory capactity and intuitive processing. Most of them experience a rich fantasy or subjective world that fosters their adaptability. These people have more frequent experiences of a sense of presence during which time 'an entity is felt and sometimes seen;' exotic beliefs rather than traditional religious concepts are endorsed."
- Michael Persinger in Report on Communion by Ed Conroy
Imagine a future in which a religious war is fought over whether people should be genetically engineered to believe in the supernatural. Or imagine a war fought over which types of religiously significant mental states people should have genetic tendencies to experience.
In a large number of species it has been found that a calorie restriction (CR) diet increases lifespan. Scientists have been looking for a clue as to what molecular mechanisms are at work in CR that cause a slowing in the rate of aging. A possible clue has been found in experiments on fruit flies:
In a report in Friday's edition of the journal Science, researchers said studies with fruit flies, which have many genes similar to mammals, showed that an enzyme called Rpd3 histone deacetylase likely is a key to longevity.
"If you decrease the level of enzyme without eating less, you still get life span extension," said Stewart Frankel, a Yale research scientist and the study's senior author.
This result needs to be repeated in a warm blooded mammalian species. Another avenue of investigation would be to try to find pharmacological agents that will block the activity of Rpd3 histone deacetylase in mammals.
The Energy Information Administration of the US Department Of Energy has just released its Renewable Energy Annual report for 2001. The summary is available on a web page.
There were dramatic changes in the patterns of photovoltaic (PV) cell and module shipments. Domestic shipments shot up nearly 80 percent in 2001 to 36.3 peak megawatts, while exports declined 10 percent. This reverses a 10-year history of largely modest growth in domestic shipments and strong gains in exports. Overall, total PV cell and module shipments rose 11 percent in 2001 to 98 peak megawatts.
There were also substantial changes in the type of module produced. For example, thin-film silicon, which had never had more than 4 peak megawatts shipped in a single year, had almost 13 peak megawatts of cells and modules shipped in 2001. This was partially at the expense of cast-and-ribbon cells and modules, whose shipments decreased from 33 peak megawatts in 2000 to 30 peak megawatts in 2001.
Module manufacturers purchased substantially less product in 2001, receiving shipments of 14 peak megawatts of cells and modules, compared with 19 peak megawatts in 2000. Despite this trend, total module.shipments rose from 55,007 peak kilowatts to 67,033 peak kilowatts.
The total value of PV cell and module shipments rose to $305 million in 2001, a 13-percent gain over 2000. The average price per peak megawatt held fairly steady for both cells and modules during 2001 at $2.46 and $3.42, respectively.
A 34-percent surge in shipments to the residential market enabled it to regain its ranking as the top market for PV cells and modules in 2001. Manufacturers shipped 33 peak megawatts of cells and modules to the residential market in 2001, compared with 25 in 2000. Shipments to the second-largest market sector, industrial, declined slightly from 29 to 28 peak megawatts.
What's interesting here is that thin film solar photovoltaics are expanding their marketshare at the expense of other types of photovoltaics. Also, wind is growing faster than solar and has almost equalled solar as seen in the table H1. My guess is that hydroelectric's decline is due to changes in weather patterns.
As can be seen in this chart renewables are only 6% of total US energy production and solar is only 1% of total renewables (so solar is about 0.06% of total energy production). What's surprising (at least to me) is that biomass is a bigger source of energy than hydroelectric. Three quarters of the biomass is wood and wood wastes.
There is no dramatic trend of declining prices in the photovoltaics market. From the full text PDF version of the report:
Looked at over a longer period of time a more dramatic price drop can be seen:The total value of photovoltaic cell and module shipments grew 13 per cent to $305 million in 2001 from $270 million in 2000 (Table 29). The average price for modules (dollars per peak watt) d ecr eased 1 per cent, from $3.46 in 2000 to $3.42 in 2001. For cells, the average price increased 3 per cent, from $2.40 in 2000 to $2.46 in 2001.
Twenty-one companies were involved in the production of 88,221 kWp of solar PV in 2000, says the Energy Information Administration in its 'Renewable Energy Annual' report. The total of 85,155 kW of crystalline silicon and 2,736 kW of thin-film silicon is an increase from the 12,492 and 1,321 (respectively) produced in 1990. The cost was US$3.46 per peak watt for modules and $2.40 for cells, compared with $5.69 and $3.84 a decade earlier.
Still, we aren't going to get cost effective photovoltaics any time soon unless annual price drops become consistent and dramatic. Gradual refinement of existing photovoltaics manufacturing techniques is probably not going to be what makes photovoltaic devices into a low cost energy source. The research on thin films and nanotechnology will probably be what produces the technological breakthrus that will finally make solar power cost competitive with fossil fuels.
An article by Selena Roberts in The New York Times examines the International Olympic Committee's half-hearted attempts to police athletic doping by the World Anti-Doping Agency which now has a lab which is supposed to develop new tests to detect hormonal and genetic enhancement of athletic performance. Their efforts are seen by various experts as a cynical attempt to be seen as doing something to control doping. The IOC has such a large interest in the high viewing ratings that come with seeing world records broken that it is argued that they just want to appear to be sincere about controlling doping:
To experts, $18 million is hardly enough in the lab-room chase to develop drug tests that will stand up in a court of law. Athletes remain ahead of the science to nab them, with a head start from the I.O.C.
"I think a lot of the I.O.C. is driven by money," Yesalis said. "A lot of them are greedy. What has evolved is they've done a controlled retreat. At first, they didn't do drug tests at all. Then people started talking about doping, and it was bad for publicity. So it's like, `Well, we'll put in place a drug-testing system that we all know won't catch anyone, but the public won't know.'
There is just no way that the WADA and the USADA (United States Anti-Doping Agency) are going to manage to prevent wider doping by athletes. First of all, they are just not going to apply the resources needed to tackle the problem. But even if they did try harder the problem of detection will become steadily more difficult as gene therapy techniques for optimizing tissues buried deep in the body become possible. See my previous posts on the subject.
It would be great if human learning could be enhanced so easily.
A new study by researchers in Italy and the United States has found 140 genes, located in an area of the brain called the hippocampus, that had significantly altered activity when rats navigate a water maze. By enhancing the protein product of one of those genes, the scientists significantly boosted the rodents' spatial learning ability.
By "enhancing" it sounds like all they did was to inject a protein called fibroblast growth factor 18:
In another experiment, Alkon's group showed that they could improve spatial learning in rats by injecting them with FGF-18.
Update: It sounds like they first used DNA microarray technology to identify the list of genes that were upregulated during learning as a clue as to which compounds made by the neurons might enhance learning. The Reuters Health write-up gives the clearest indication of what they did:
There were six major groups of memory-related genes, with the largest being genes involved in cell signaling. One of these signaling genes contains the blueprints for a substance called fibroblast growth factor (FGF)-18. Cavallaro's team found that injecting extra FGF-18 into the rats' brains improved their ability to learn.
They identified the genes activated during learning, categorized the genes by type of function, and then focused on genes that are involved in cell signalling. In other words they focused on genes that control other genes and that control other parts of the cell. This allowed them to narrow down their candidates for intervention to compounds that would have the best chance to have an impact on cell development under the conditions of learning.
Their ability to carry out this experiment was made possible by advances in DNA microarray technology (Affymetrix is best known for its DNA microarray assay technology) that allow the watching of the regulatory state of thousands of genes at once. In this case the researchers watched the state of 2500 genes in order to discover the 140 that were involved in learning. The development of better tools to monitor biological systems accelerates the rate at which the function of cells can be puzzled out.
Stanford has set up a privately funded energy and climate research effort to the tune of $225 million dollars. From the project FAQ:
The money:
Q: What corporations are providing funding for this Project and how much are they contributing?
A: To date, sponsors and their contributions to help fund the research are:
- ExxonMobil (NYSE: XOM), the world's largest publicly traded petroleum and petrochemical company (up to $100 million);
- General Electric (NYSE: GE), the world leader in power generation technology and services ($50 million); and
- Schlumberger (NYSE: SLB), a global technology services company ($25 million).
The university expects to involve additional global companies in the automotive and technology industries as the research progresses. E.ON, Europe's largest privately owned energy service provider, has signaled its intention to contribute $50 million and join G-CEP along with other academic and corporate sponsors from Europe. The value of this combined sponsorship is equal to the total of all the corporate-sponsored research at Stanford over the past 10 years.
The areas of research:
Q: What are some immediate projects/innovations that you will be exploring?
A: This Project will give researchers the freedom to explore a variety of new energy technology fields, some of which are in their infancy now but need further exploration. Stanford will develop and maintain a portfolio of specific research options that would further the objectives of the Project and will consider at a minimum the following topics:
- Low greenhouse gas electric power production, storage, and distribution
- Advanced transportation techniques
- Production, distribution, and use of hydrogen
- Production, distribution, and use of biomass fuels
- Advanced nuclear technologies
- Renewable energy supplies (for example, wind and solar energy)
- Carbon sinks, CO2 separation and storage
- Coal utilization
- Material, combustion, and systems science
- Enabling infrastructure
- Geoengineering
Specific research initially will focus on:
- Development of a methodology for an integrated assessment of technology options
- Hydrogen production and utilization, including biological hydrogen production and efficient hydrogen fuel cells
- Advanced combustion systems aimed at increasing efficiency of combustion devices and reducing environmental impact
- Geologic sequestration of CO2
The ownership of the resulting intellectual property:
Q: Who will hold title to new technologies brought to market through this initiative?
A: Stanford will hold formal legal title to all technology and information derived from this program. It also will hold formal legal title to all patents sought.
The complete project white paper is available as a downloadable PDF.
The use of fuel cells to generate electricity in the US is set to rise dramatically.
The market for fuel cells that generate electric power is expected to be $3 billion by 2005, says Principia Partners, a market research firm. Meanwhile, the current $40-million stationary fuel cell market used for onsite generation is predicted to grow more than $10 billion by 2011, adds Alliance Business Intelligence. That's a jump from a generating capacity of 75 megawatts today to 15,000 megawatts by 2011.
To put that in perspective the total US electric generation capacity in 2000 was 639,429 megawatts.Coal fired plants represent nearly 38 percent of that capacity. In terms of actual generated electricity coal represents a larger percentage.
The US Department Of Energy is forecasting a fairly slow rate of rise in renewable electric power generation.
Total renewable generation, including CHP, is projected to increase from 298 billion kilowatthours in 2001 to 476 billion kilowatthours by 2020 in AEO2003, an increase of 2.5 percent per year. Growth in renewable generation was projected to grow at a slower 2.1 percent per year between 2001 and 2020 in AEO2002. Total renewable generation reaches 495 billion kilowatthours by 2025 in AEO2003.
I don't think that a forecast like this is going to turn out to be accurate because it seems reasonable to expect dramatic breakthroughs in an assortment of energy technologies. A lot of money is flowing into energy research.
PALO ALTO, Calif. - Stanford University said this week that a roster of corporate giants in energy and engineering had donated $225 million to fund research in developing less-polluting power sources, one of the largest such tie-ups between a university and major corporations.
BASF is going after the future market for fuel cells as a way to power portable electronic devices. The hope is that a fuel cell combined with a storage device would yield a higher power to weight ratio than existing rechargeable batteries and hence longer battery life.
The hydrogen in the cartridge would be subject to 10 times atmospheric pressure-- about the same level as in a butane cigarette lighter, BASF says. The nanocubes provide controlled release of the hydrogen to the fuel cell, the company says. The hydrogen-- fed fuel cells could power portable devices for more than 10 hours, it adds.
However, as a portable power source the hydrogen fuel cells face a competitor in the form of liquid powered fuel cells. There are companies bringing out prototype liquid fuel cells for portable electric power sources. A company called Smart Fuel Cell argues that methanol fuel cells will be more convenient since recharging will be easier.
In April 2002 SFC had presented the first prototype power supply for mobile office applications at the Hanover Fair. Manfred Stefener, founder and CEO of Smart Fuel Cell: "So far we have miniaturised our products every six months by more than 50 %. The recent progress demonstrated now is based upon an entirely new DMFC stack design. Furthermore, we have made every system component smaller in close collaboration with our supplier network."
SFC has furthermore built up the first infrastructure for fuel cartridges. Stefener said, "It is essential that cartridges are widely available for the consumers, for example at filling stations and supermarkets. This is a lot easier to establish for methanol cartridges than for hydrogen-based systems, and we have already realized the complete logistics chain of the cartridges for our first series product."
Update: Another interesting article on recent fuel cell advances can be found here.
Sounds like this project is still at a fairly early stage of development. Still, what is interesting is that this sort of technology is under active development in the first place. Electronics technology has advanced far enough that embeddable sensor systems can be moved into active development.
Using a tiny wireless sensor developed at Oak Ridge National Laboratory, doctors will know in minutes instead of hours if an organ is getting adequate blood flow after transplant or reconstructive surgery.
Conventional methods for assessing circulation involve invasive procedures or extensive laboratory testing. In some cases, by the time doctors realize there isn't adequate blood flow to an organ or tissue, irreversible damage already has occurred.
"Our goal is to offer a technique that provides the physician with a very early indication of whether the surgery is successful," said Nance Ericson, who leads the effort from ORNL's Engineering Science and Technology Division. Ericson is working with Mark Wilson, a surgeon at the University of Pittsburgh, and Gerard Coté of Texas A&M University.
The tiny implantable sensor – about the diameter of a quarter -- and micro-instrumentation being developed by Ericson would provide real-time information by transmitting data to a nearby receiver. Specifically, the unit employs optical sensors to assess tissue circulation. Preliminary tests using laboratory rats have provided encouraging results.
Embedded optical sensors could do other kinds of measurement as well:
Although not a part of this project, Ericson sees this leading to several other photonics-based microsensors for making measurements in a number of areas. For example, this approach could be useful for measuring arterial blood gases, which are primary indicators of respiratory function, or serum lactate, which is a marker for the severity of tissue injury. Current methods require obtaining blood samples and then sending those samples to a lab for analysis.
It starts off from $4.81 billion this year and doubles by 2007.
The bill provides a 15 percent increase for the foundation in each of the next five years, taking its budget from $4.81 billion in fiscal year 2002, which ended Sept. 30, to $9.8 billion in fiscal year 2007.
Note the nanotech targetting for the increase in funding:
The legislation, which has been passed by both the House of Representatives and the Senate, is now headed to Bush for final review and a signature. The bill authorizes $5.5 billion in funds for 2003, rising to $9.83 billion by 2007, for the NSF, a primary source of research grants for universities and, in turn, many start-up companies.
The increased funding is specifically targeting research on campus and startups involved in nanotechnology and plant genome research.
Funding for the NIH increased 15.5 percent last year. The current measure would increase NSF funds by 15 percent each year over a five-year period that could begin as early as the 2004 fiscal year.
The targetted increase for nanotechnology will yield especially dramatic results. The rate of scientific and technological advance looks set to accelerate.
Writing in Prospect Magazine Michael Gross surveys the field of nanotechnology and points out a surprising (at least to me) widely available use of nanotechnology:
The first nanotechnology breakthrough outside the information technology market is the microfabricated impact sensor to trigger airbags in cars. The new kind of sensor is based on a Mems (micro-electromechanical system) device, which means that it is fabricated by the same kind of technology as a computer chip, only that its function is mainly mechanical rather than electronic. When it was introduced in 1995, it turned out to be not only smaller and more efficient than the sensors previously available, but also 100 times cheaper. Understandably, it took over the world market in a matter of months.
But how about products designed from molecules upwards? There is at least one that you can buy already. It is the self-cleaning window. It uses a combination of two clever molecular tricks. First, it contains a catalyst that uses the energy of light to oxidise common kinds of dirt, to convert them into smaller, more soluble molecules that wash away with rain water. At this point, the second trick comes in. Ordinary glass is fairly water-repellent (hydrophobic), which means that water does not cover it smoothly, but tends to form droplets. The surface of self-cleaning glass, however, is coated in molecules that attract water and encourage it to spread out. So, instead of sitting around as drops which leave drying spots when they evaporate, the rain will cover the surface evenly, dissolve what the photocatalyst made of the dirt, and run off. Simple. Yet it would not be possible without molecular design on the nanometre scale.
If an elevator could take you up into space would you feel like you were ridiing a spacecraft as you journeyed upward? HighLift Systems thinks nanotube nanotechnology research is advancing far enough to make a space elevator viable:
For the last few months, officials at HighLift Systems have been talking it up with an alphabet soup of government agencies, like NASA, the Defense Advanced Research Projects Agency (DARPA), the Federal Aviation Administration (FAA), as well as the National Reconnaissance Office (NRO).
Meanwhile, testing of prototype space elevator equipment is near at hand. And by far the strongest link that keeps the concept on the straight and narrow is worldwide work now underway by the carbon nanotube research community.
Overall, progress is being made in attaining the lofty goal of operating a 21st century elevator to space.
From the HighLift Systems web site:
Simply put, a space elevator is a revolutionary way of getting from Earth into space. A space elevator is a ribbon with one end attached to Earth on a floating platform located at the equator and the other end in space beyond geosynchronous orbit (35,800 km altitude). The space elevator will ferry satellites, spaceships, and pieces of space stations into space using electric lifts clamped to the ribbon. Ultimately, the space elevator will serve as a means for commerce, scientific advancement, and exploration.
Once relegated to the realm of science fiction, the space elevator is now the subject of serious research by Seattle-based company HighLift Systems. The NASA Institute for Advanced Concepts granted funds to Eureka Scientific and Dr. Bradley Edwards to investigate the feasibility of designing and building a space elevator. As commercial applications are being explored, HighLift Systems was co-founded by Dr. Edwards and Michael Laine to move the development of the space elevator forward. With the discovery of carbon nanotubes and the ongoing development to implement them into a composite, HighLift Systems believes that building a space elevator will be viable in the coming years. In its initial report, HighLift Systems has found that a space elevator capable of lifting 5-ton payloads every day to all Earth orbits, the Moon, Mars, Venus or the asteroids could be operational in 15 years. This first space elevator could be built for between $7-$10 billion and would reduce lift costs immediately to $100 per kilogram, as compared to current launch costs, which are $10,000-$40,000 per kilogram, depending on destination and choice of rocket launch system. Additional and larger elevators, built utilizing the first one, would allow large-scale manned and commercial activities in space and reduce lift costs even further.
See their summary of how it would be built and what it would cost.
A new discovery raises the prospect of a more efficient photovoltaic cell for lower cost solar energy. Two layers of indium gallium nitride in a solar cell design could convert sunlight to electricity at 50% efficiency.
BERKELEY, CA — Researchers in the Materials Sciences Division (MSD) of Lawrence Berkeley National Laboratory, working with crystal-growing teams at Cornell University and Japan's Ritsumeikan University, have learned that the band gap of the semiconductor indium nitride is not 2 electron volts (2 eV) as previously thought, but instead is a much lower 0.7 eV.
The serendipitous discovery means that a single system of alloys incorporating indium, gallium, and nitrogen can convert virtually the full spectrum of sunlight -- from the near infrared to the far ultraviolet -- to electrical current.
"It's as if nature designed this material on purpose to match the solar spectrum," says MSD's Wladek Walukiewicz, who led the collaborators in making the discovery.
What began as a basic research question points to a potential practical application of great value. For if solar cells can be made with this alloy, they promise to be rugged, relatively inexpensive -- and the most efficient ever created.
The original URL for the article has a graph.
Update: For more details also see this article from the Lawrence Berkeley National Laboratory site:
Working with crystal growers from Cornell and Ritsumeikan University, Japan, the LBNL team performed optical tests (absorption and “photoluminescence”) on a wide range of extremely high quality InN and InxGa1-xN films grown under carefully controlled conditions. It was found that the direct band gap of pure InN is 0.7 eV rather than the previously reported 2.0 eV, which had been measured in lower quality material. Furthermore, it was shown that alloying the InN with GaN to form InxGa1-xN can produce materials whose bandgaps can be continuously varied from 0.7 eV to 3.4 eV. This single semiconductor alloy system, therefore, has an almost perfect match to the entire solar spectrum. Not only does this range include the optimal bandgap values (1.1 and 1.7 eV) for a two-layer cell, it will also enable the fabrication of optimized tandem cells with more layers, for which materials whose band gaps extend close to the lower and nearly all the way to the upper bounds of the usable region of the solar spectrum are required. More recent work has shown that the InxAl1-xN system has direct band gaps spanning an even wider energy range: from 0.7 – 6.2 eV; thus, this related materials system may be useful for both solar energy conversion and for other optoelectronic applications in the near-IR to deep ultraviolet regions of the spectrum.
Although grown on lattice mismatched substrates, all the InxGa1-xN films show an exceptionally strong and robust photoluminescence, demonstrating insensitivity of the optoelectronic properties to structural imperfections. This observation bodes very well for applications of these materials in environmentally harsh conditions. To fully implement the InxGa1-xN alloys for photovoltaic applications some additional hurdles such as control of p-type doping must be overcome, however the work demonstrates that III-V nitride alloys are promising candidates for the development of new solar cells with efficiencies as high as 50%. Furthermore, the discovery extends the range of potential optoelectronic applications of III-V nitride alloys from the near infrared to the deep ultraviolet spectral regions.
Update II: The reason that InGaN turned out to have a different absorption spectrum than expected may have been due to impurities in previously used samples. The InGaN used in this recent set of experiments was much purer but also much expensive. Now the researchers need to find out whether less pure material can exhibit a similar wide light absorption spectrum:
The samples Walukiewicz tested were made using a painstaking, and prohibitively expensive, method to grow very pure crystals of InGaN one atomic layer at a time. The team now hopes to collaborate with the National Renewable Energy Laboratory in Colorado to try to build cheap InGaN solar cells.
Update III: These scientists have a number of problems to solve before this breakthru turns into something useful. They need to find out how to make other forms of this material:
There's a lot of work to be done before practical solar cells can be made from indium nitride, however. The researchers have not yet made the p-type form of the material. "One of the biggest challenges is to make p-type doped indium nitride," said Walukiewicz. The indications are good, however. It is theoretically easier to make p-type doped indium nitride than to do the same with gallium nitride, which has already been done, he said. Gallium nitride is also a direct band-gap material.
The researchers' next step is to make p-type indium nitride. They are also working to make p-type gallium indium nitride, he said. And they are more thoroughly testing the properties of the two materials under high-energy particle irradiation, he said.
The researchers have only tested a few samples, said Cheng Hsiao Wu, a professor of electrical and computer engineering at the University of Missouri at Rolla. The reasons for the measurements are not yet clear; there could be a mechanism involved other than a different band gap, he said.
Recall the recent post about how youthful stem cells from embryo livers outcomputed older adult stem cells in cows. It is not known what exactly about the youthful stem cells made them more competitive. One possibility is that their telomeres are longer and hence they can divide more times. A recent report of a group at Stanford provides a way to more easily lengthen telomeres:
Writing in the Nov. 18 Proceedings of the National Academy of Sciences (PNAS), Stanford researchers described how newly created circles of synthetic DNA - called "nanocircles" - could help researchers learn more about the aging process in cells.
"In the long run, we have this dream of making laboratory cells live longer," said Eric Kool, a professor of chemistry at Stanford and co-author of the PNAS study. "We thought of this pie-in-the-sky idea several years ago, and we've been working toward it ever since."
All cells carry chromosomes - large molecules of double-stranded DNA that are capped off by single-strand sequences called telomeres. In their study, the research team successfully used synthetic nanocircles to lengthen telomeres in the test tube.
"The telomere is the time clock that tells a cell how long it can divide before it dies," Kool noted. "The consensus is that the length of the telomere helps determine how long a cell population will live, so if you can make telomeres longer, you could have some real biological effect on the lifespan of the cell. These results suggest the possibility that, one day, we may be able to make cells live longer by this approach."
Cellular death Human telomeres consist of chemical clusters called "base pairs" that are strung together in a specific sequence known by the initials TTAGGG. This sequence is repeated several thousand times along the length of the telomere. But each time a cell divides during its normal lifecycle, its telomeres are shortened by about 100 base pairs until all cell division finally comes to a halt.
"Suddenly there's a switch in the cell that says, 'It's time to stop dividing,'" Kool explained. "It's still not completely clear how that works, but it is clear that once telomeres reach the critically short length of 3,000 to 5,000 base pairs, they enter senescence and die."
In nature, a chromosome can be lengthened by the enzyme telomerase, which adds new TTAGGG sequences to the end of the telomere. But because telomerase is difficult to produce in the lab, Kool and his co-workers decided to create synthetic nanocircles that mimic the natural enzyme.
Each nanocircle consists of DNA base pairs arranged in a sequence that is complementary to the telomere. When placed in a test tube, the nanocircles automatically lengthen the telomeres by repeatedly adding new TTAGGG sequences.
"Nanocircles are so simple they're amazing," Kool observed. "Each nanocircle acts like a template that says, 'Copy more of that sequence.' In the test tube, we start with very short telomeres and end up with long ones that are easy to see under the microscope with fluorescent labeling. This suggests the possibility that one day we may be able to make cells live indefinitely and divide indefinitely, so they essentially become refreshed, as if they were younger."
Aging and cancer Kool pointed out that most cells have a limited lifespan, which is part of the normal aging process.
"The link between organism aging and cell aging is less clear, but there very likely is a link," he noted. "On the other hand, it is pretty clear that telomere length governs how long an individual cell lives."
In some diseases, such as premature aging (progeria) and cirrhosis, patients have cells with unusually short telomeres, Kool said. Cancer is another disease closely associated with telomere size.
"In order for a cell to become cancerous, one of the things it has to do is switch on the telomerase gene which makes the telomeres longer," he said. "The body has decided that the best way to keep an organism alive is to keep telomerase turned off, because otherwise you can get mutations and cancer too easily."
Because researchers need to study cells that live a long time, many labs rely on tumor-derived cells, which continuously divide and therefore are immortal. Kool predicted that nanocircle technology could one day provide an alternative method that would allow researchers to use healthy cells in their experiments instead of cancerous ones.
This is a very useful technique for aging research. For example, to test why younger stem cells can outcompete adult stem cells one could take adult bone marrow blood-forming stem cells, lengthen their telomeres, and then test to see if they can do just as well as clone embryo liver stem cells to outcompete adult stem cells that have not had their telomeres lengthened.
Even if telomere lengthening makes adult stem cells more able to replicate and even if this results in better body repair that doesn't mean that telomere lengthening would become a generally good thing to do to all adult stem cells in a human body. It is possible that telomere lengthening will allow cells that have otherwise damaged DNA to survive and to become cancerous. It is theorized that telomere shortening is a safeguard mechanism to help prevent cells from turning into cancer cells.
Another part of the puzzle needed to make a safe and effective rejuvenation therapy is the ability to sort thru adult stem cells and separate out the ones that have the least amount of DNA damage. Then one could take the better less damaged cells and extend the telomeres and reimplant them into the body. These more carefully selected cells would present less risk of becoming cancerous. To further reduce the risk of cancer from stem cells that have had their telomeres lengthened it will some day be possible to apply gene therapies that would repair a small number of locations in the genome where mutations contribute to the conversion of cells into cancers.
To summarize the significance of this latest report: This new technique for telomere lengthening will initially be useful to investigate the relative contribution that telomere shortening makes to cellular senescence. In the longer run it may also be useful in adult stem cell rejuvenation therapies and as part of organ replacement growth methods.
We are still many years away from having the software that will emulate all human thought processes. Also, this thing will weigh 197 tons:
"ASCI Purple," slated to be completed in 2003, is expected to be the world's first 100-teraflops supercomputer, capable of processing data almost three times faster than current supercomputers.
A human brain's probable processing power is around 100 teraflops, roughly 100 trillion calculations per second, according to Hans Morvec, principal research scientist at the Robotics Institute of Carnegie Mellon University.
A Bell Labs team used organic molecules to achievea new speed record for modulating a laser fiber optic signal.
"We achieved a practical, useful bandwidth of between 150 gigahertz and 200 gigahertz," Lee told United Press International. "Even in the worst-case scenario, we were at about 110 gigahertz, which is about three times better than (cutting-edge semiconductor modulators)."
Currently available modulators run at 10 Ghz. While this latest breakthru is not ready to be incorporated into commercial products it demonstrates that communications speeds will continue to increase by orders of magnitude.
After 30 years working as a researcher at UC San Francisco, American born Roger Pedersen moved to the UK to do embryonic stem cell research:
So Pedersen called his British colleague back, said yes to the job offer, and took 30 years of knowledge and a still-burning desire to heal across the Atlantic Ocean. He assumed a powerful perch in the Renaissance-towered University of Cambridge's surgery department, from which he now guides an all-out national push, tinged with Union Jack patriotism, to bring stem cell medicine to England first.
This demonstrates why therapies using embryonic stem cells will be developed regardless of what any particular national government decides. A huge unexpected change in attitudes in Britain wouldn't affect the ultimate outcome. If the Brits weren't working solve the problems of turning embryonic stem cells into useful therapies then the Chinese or Japanese would anyway.
U Cambridge biogerontologist Aubrey de Grey has just delivered a presentation to the Fifth Alcor Conference on Extreme Life Extension. The conference proceedings are not online but an abstract of Aubrey's presentation is very intriguing:
Cancer: why it is now the main barrier to extreme life extension, and a revolutionary new approach to defeating it indefinitely
The genomic instability that underlies cancer makes it enormously harder to combat indefinitely than any other aspect of aging. Its only clear-cut "Achilles heel" is the absolute need to stabilise telomeres (usually with telomerase); if this can be prevented with total certainty by deleting (not just suppressing) a vital gene, cancer will be prevented. However, many of our normal cells need telomerase for their normal function. I will explain why existing anti-cancer approaches are unlikely ever to postpone cancer by more than a decade or two, and then present a radical, feasible solution, involving the periodic re-seeding of our various stem cell pools with cells whose telomeres have been re-lengthened ex vivo.
Adult stem cells are considered by some researchers to be a major source of cancer. Adult stem cells divide much more than most other cell types. Therefore they accumulate more damage from errors in replication. At the same time, since they do divide (they are mitotic in biological terms) the settings of their genetic switches are closer than the settings of post-mitotic (ie cells that never divide) cell types to the settings that allow cancers to divide without control.
The replenishment of aged adult stem cells with younger adult stem cells would serve multiple purposes. First, the youthful adult stem cell replacements would be more vigorous and hence would serve as better sources of replacement cells when fully differentiated cells die. Also, I'm guessing that Aubrey is arguing that the replacement stem cells would have fewer genetic defects and longer telomeres and hence be less prone to become cancer cells.
For a general scientific discussion of aging also see Aubrey de Grey's book The Mitochondrial Free Radical Theory of Aging.
Update: On a related subject see this report of the work of Stanford biological chemist Eric Kool on a newer faster method to elongate telomeres.
Two new results reported on transplanting cells into damaged hearts. The first with humans increased the pumping capacity of hearts:
Researchers conducted the multi-center trial, overseen by the U.S. Food and Drug Administration, in patients who had suffered heart attacks or heart failure and whose hearts had reduced pumping ability evidenced by left-ventricular ejection fraction (EF) less than 30 percent. EF measures the quantity of blood pumped from the heart with each beat. A healthy heart pumps out a little more than half the heart's volume of blood with each beat for an EF of 55 percent or higher.
Eleven patients were undergoing coronary artery bypass surgery (CABG) and five were having a left ventricular assist device (LVAD) implanted. An LVAD helps a failing heart until a donor heart becomes available for transplant.
The patients' myoblasts cells (immature cells that become muscle cells) were extracted from thigh muscle. Large quantities of the cells were grown in the laboratory for three to four weeks using a controlled cell expansion manufacturing process. During the surgery, one to 30 direct injections – containing 10 million cells each – were made into the damaged area of the hearts. The dosages ranged from 10 million to 300 million cells.
"We found that the transplanted myoblasts survived and thrived in patients. Areas damaged by heart attack and cardiovascular disease showed evidence of repair and viability," Dib says.
No significant adverse reactions were found related to the cell transplant procedure in either group of patients in follow-up testing nine months later.
There was one death due to infection of the device in the LVAD group three months after cell transplantation, and one patient in the CABG group had non-sustained ventricular tachycardia – a fast heart rate that starts in the lower chambers (ventricles).
While the trial was not designed to evaluate the effect of cell transplant on cardiac function, Dib calls the results extremely encouraging. Examining the heart by echocardiogram, magnetic resonance imaging (MRI), and positron emission tomography (PET scan) showed evidence of scar tissue regeneration in the area of the graft, which indicates repair.
EF rates improved, on average, from 22.7 percent to 35.8 percent – a 58 percent increase – after 12 weeks.
The second result with rats showed transplanted cells can repair the heart beat transmission signals that currently require artificial pacemakers to treat:
CHICAGO, Nov. 17 – Preliminary findings of a study in rats suggests that a person's own cells might one day replace artificial pacemakers, researchers reported today at the American Heart Association's Scientific Sessions 2002.
Studies conducted at Children's Hospital Boston tested the ability of immature skeletal muscle cells to interconnect with heart cells and spread the electrical impulses that keep the heart beating properly.
"The cells have survived in rats for more than a year and they appear to have made connections with cardiac cells," says Douglas B. Cowan, Ph.D., a cell biologist who led the study. "The electrical pathway developed within 10 weeks of implantation.
"Ultimately – maybe a decade down the road – we may be able to use such cell-based technologies in humans to free them from cardiac pacemaker devices," says Cowan, also an assistant professor of anesthesia at Harvard University Medical School in Boston.
Heart contraction starts with an electrical signal that begins in the atrium, a tiny area of the heart's upper-right chamber. The signal then moves to the other chambers. Damage to the electrical pathway between the atrium and ventricles (the lower chambers) can result in complete heart block, a potentially fatal condition that can only be treated by implanting a cardiac pacemaker.
"We have gathered preliminary evidence that immature skeletal muscle cells can establish a pathway to transmit electrical signals from the heart's upper right chamber to its lower right chamber," he says.
In one sense these treatments were fairly low tech (though heart surgey isn't exactly low tech). It wasn't necessary to apply complex chemical treatments to embryonic stem cells in order to get them to differentiate into heart cells. They used myoblasts which are essentially muscle stem cells. Also, their method of growing them up may be fairly sophisticated. It seems logical to expect that in the longer run younger sources of myoblast cells will eventually be used because they will be more efficient and last longer.
Update: A third result has blood vessels being grown from human skin cells:
CHICAGO, Nov. 17 – Researchers have built mechanically sound blood vessels out of tissue from human skin cells, according to a study reported today at the American Heart Association's Scientific Sessions 2002. The technique involves tissue engineering, an emerging science that takes cells from the body, manipulates them in the laboratory to create functional tissue, and puts the new tissue back into the patient.
The goal is to produce healthy, functioning blood vessels built exclusively from a person's own cells, so the body's immune system won't reject the new tissue. Such vessels would be important in heart and leg bypass operations and for vessels called arteriovenous shunts used for dialysis patients.
The scientists reported that tissue-engineered blood vessels didn't burst or develop blood clots in laboratory tests and short-term animal experiments.
"The study's most important findings were: First, the technology works from a commercial perspective, meaning we can build mechanically sound vessels for a wide array of patients using the exact same protocol," says Todd McAllister, Ph.D., president and chief executive officer of Cytograft Tissue Engineering in Novato, Calif., which developed the vessel-building technique.
"Second, we demonstrated that thrombogenesis (the formation of blood clots) does not appear to be a problem in the short term – up to 14 days. Short-term blood clots are the biggest challenge facing most synthetic materials, whether they are used for blood vessels, new heart valves, or other vascular prostheses. We expect to begin this research in humans within 18 months."
Update II: A fourth result show bone marrow transplantation improving arteries in the legs and feet:
“This is the first multicenter and double-blind clinical study to prove the clinical efficacy of growing new blood vessels (angiogenesis) using bone marrow cell transplantation,” says the study’s lead author Hiroya Masaki M.D., Ph.D. He hopes that transplanting bone marrow cells will establish a new therapy for peripheral artery disease (PAD).
PAD is a condition similar to coronary artery disease in which fatty deposits build up along artery walls and reduce blood circulation, mainly in arteries leading to the legs and feet. In its early stages, a common symptom is cramping or fatigue in the legs and buttocks during activity. PAD causes severe pain, ulcers and sores. In its later stages, it can lead to gangrene or a dangerous lack of blood flow, called critical limb ischemia, which can be treated by revascularization (such as angioplasty) or amputation.
Bone marrow cells are promising for this type of therapy because they have the natural ability to supply endothelial progenitor cells, says Masaki, an associate professor in the department of laboratory medicine and clinical sciences at Kansai Medical University in Osaka, Japan. Endothelial progenitor cells can develop into endothelial cells, which, in turn, can form new blood vessels.
The researchers randomly implanted either a person’s own bone marrow mononuclear cells or saline (a placebo) into the calf muscles of 45 PAD patients. Twenty patients had bilateral ischemia (both legs) and 25 had unilateral ischemia (one leg). There was a “striking” increase in new capillary formation in the legs of patients who received bone marrow mononuclear cell transplants. Patients injected with saline showed much smaller increases in collateral perfusion.
Researchers found that CD34-cells, which can develop into endothelial progenitor cells, expressed basic fibroblast growth factor, vascular endothelial growth factor and angiopoietin-1. These vascular growth factors play key roles in angiogenesis.
“Endothelial progenitor cells have vascular growth factors inside the cells,” Masaki says. “This is very advantageous for angiogenesis. By implanting the bone marrow mononuclear cells, we deliver endothelial progenitor cells and vascular growth factors at the same time.”
In limbs that received the bone marrow cells, researchers noted an increase in ankle-brachial pressure index (ABI) in 31 of 45 patients. Baseline ABI was 0.35. Four weeks after implantation it was 0.42, and at 24 weeks it was 0.46. The ankle-brachial index test measures blood pressure at the ankle and in the arm and divides the two to help predict the severity of PAD. A normal resting ABI is 0.30 – 0.91. Patients with leg pain typically have ABI indexes ranging from 0.41 – 0.90, and those with critical leg ischemia have indexes of 0.4 or less.
Researchers also noted newly visible collateral vessels in 27 limbs. Pain occurring at rest in the ischemic limbs diminished significantly in 39 of 45 patients, and the amount of time they could walk on a treadmill without pain was significantly improved (from 1.3 minutes at baseline to 3.6 at week four and 3.7 at week 24). Participants’ ischemic ulcers or gangrenes were healed in 21 of 28 limbs.
Update III: A fifth result shows bone marrow transplantation improves the function of damaged hearts:
The study by British researchers adds to mounting evidence that muscle-generating cells in bone marrow can rejuvenate hearts deadened by infarctions, or loss of blood to the tissue. Previously, scientists had considered that damage irreversible.
"It has been the belief in general that you are born with a fixed number of [heart muscle cells], and that when they die they die forever," says Dr. Manuel Galinañes, a heart surgeon at the University of Leicester and leader of the research effort. "This has been challenged."
There is an important report out in New Scientist about therapeutic cloning and the relative vigor of different stem cell types. But it is difficult to puzzle out exactly what this report is saying. If anyone with relevant knowledge can go read the full article in New Scientist I'd appreciate your feedback in the comments for this post: (or email me)
Now New Scientist has uncovered a patent application that claims cloned stem cells have a big advantage over other stem cells. A team at Advanced Cell Technology (ACT) in Massachusetts, working with Malcolm Moore of the Memorial Sloan-Kettering Cancer Center in New York, cloned skin cells from two cows. They then injected blood-forming stem cells (which also give rise to immune cells) from the cloned fetuses back into the cows. One cow had its immune systems suppressed with drugs.
The cloned cells seemed to have an amazing ability to take over from adult ones, replacing up to 50 per cent of the cows' blood stem cells after just one infusion, even in the cow whose immune system was untouched.
UPDATE: Upon reflection, my interpretation: First, they took skin cells from the cows. Then they cloned them by putting their nucleuses into unfertilized eggs (from the same or different cows?). Then they grew cow fetuses to the 100 day point. Then they harvested blood stem cells from the fetuses. Then they injected those blood stem cells back into the adult cows that had been cloned. These cloned stem cells outcompeted the existing blood stem cells. Okay, then how did they know that the cloned cells outcompeted the existing stem cells that were already in the adults? Did they inject each cow's clone-derived stem cells into the other cow in the pair? They would need some genetic marker that would let them tell the cloned cells apart from the native cells of the cow. Possibly they used mitochondrial DNA for that purpose by using a different cow as the egg donor for the cloning.
While this article doesn't convey the details of these experiments with sufficient clarity the article does seem to be claiming that the cloned stem cells were in some sense younger than the more adult stem cells. If this is what the ACT researchers found then this is very important. Many scientists are trying to coax adult stem cells into becoming various differentiated cell types and some successes are even being reported. However, the cells in the adult stem cell reservoirs in the body age along the rest of the body. This latest result underscores this point. As scientists find ways to coax adult stem cells into becoming various assorted differentiated cell types will they find that the adult stem cells will be too old and tired to become enough of each needed cell type to be useful? Or will they find that the differentiated cells so produced are too old to function properly?
Old People Most Need Replacement Cells. The Old people are the group who have the most amount of illness and who are most in need of having their stem cells coaxed into making various kinds of differentiated replacement cells. Yet the adult stem cells of old people are also going to be old and therefore less vigorous than those of younger adults.
Youthful adult stem cells are not just useful for treating illnesses. If the adult stem cell reservoirs could be replenished with youthful cells then we could become at least partially youthful again. Just as embryonic stem cells (whether created by classical fertilization or by cloning) can be converted into fully differentiated cells it ought to be possible to find ways to coax them into becoming each of the specialized adult stem cell types. This is desireable because adult stem cells are creating differentiated cells throughout our bodies every day. They are making new skin cells, blood cells, neurons, and assorted other cell types.
However, coaxing embryonic stem cells to become adult stem cell types may not turn out to be any easier than coaxing a given adult stem cell type into becoming other different adult stem cell types. We need to understand in far more detail what makes each adult stem cell type be that type and not some other adult stem cell type or the embryonic stem cell type. It is a lot easier to find indications that one has created a differentiated cell type because differentiated cell types have unique proteins that are well known and used for doing what they do and they make various chemicals that can be tested for. But to stop differentiation at an intermediate step (ie at the adult stem cell step) is harder.
While this latest report may demonstrate an advantage of stem cells created by cloning it doesn't answer the question of why those cells are more vigorous. If the report really did find that adult skin fibroblast cells, when cloned, became stem cells that were more vigorous than existing adult stem cells in the same animal then why? One potential explanation is that the cloning process presented the differentiated adult fibroblast's genome with chemical signals that induced it to grow its telomeres. However, there are other possibilities. One big one is that the cloning procedure may just have selected for less damaged DNA. If the scientists had to clone many nucleuses in order to get one that worked then the scientists may have just been selecting for a cell that had the least amount of accumuation of aging-related damage to its genome.
Fixing Telomere Length: If telomere length is the problem a technique may be found to take adult stem cells out of the body, bath them with in genes or drugs that induce telomerase to make long telomeres, and then to transfer the reinvigorated stem cells back into the body. There is a caution here. Even if such a procedure worked and the stem cells became more vigorous the cells might still have a dangerous amount of accumulated DNA damage in them as well. The risk of cancer and metabolic disorders might be increased.
Fixing Accumulated DNA Damage: However, if adult stem cells become old due to accumulation of DNA damage then that becomes a much harder problem to fix. The genome is 3 billion base pairs lone. It will some day be possible to locate and identify all the mutations in an extracted line of adult stem cells. But then all the mutations (or at least all the important ones) would need to be fixed. Gene therapy to fix that amount of damage is far in advance of where gene therapy is today.
Select Cells With Less Damaged DNA: Another possible approach would be to take out large numbers of adult stem, let each cell divide, and take one of each pair and sequence its DNA. Look for cells that have the least amount of DNA damage. Then fix their telomeres and/or do gene therapy to fix the damage that the chosen cells do have. This approach depends on DNA sequencing technology that is under development but not yet available. It also depends on gene therapy technology that is not yet available.
Some people have ethical objections to using embryonic stem cells in to develop medical therapies. Embryonic stem cells can be created by fertilizing an egg with a sperm to make an embryo and then letting the embryo divide. However, cloning has now been demonstrated (at least in other species besides humans) as a way to create a viable embryo. This is done by taking an unfertilized egg, taking out its nucleus and putting an adult nucleus into it. Do that enough times and some small percentage of the resulting cells will be capable of developing into a fetus and then baby and then adult. But since cloning can create viable embryos (at least some small percentage of the time) many of the same people who object to using fertilized eggs to create stem cells also object to the use of cloning to make stem cells as well. In their view the fact that a cell has the potential to become a full human adult should imbue that cell with special rights and legal protections.
Note that it is not the objective of this essay to argue for or against the various positions taken in the ethics debate about various forms cloning and stem cell research. My goal here is to show why this latest report about ACT's research is pertinent to those who are making supporting arguments.
Many who argue against embryonic stem cell research claim that ways will be found to induce adult stem cells to do anything that embryonic stem cells can do. One objection to that line of argument is that it may take longer to find ways to tell adult stem cells to become less differentiated and then to differentiate down a different path. For instance, find a way to make blood stem cells to become not just locked into being blood stem cells so that they can then be told to become muscle stem cells. But this latest report strengthens another argument against adult stem cells as competitors to embryonic stem cells: adult stem cells are older and therefore generally less able to do any job they can be coaxed into doing. Therefore adult stem cells may be less able to replace embryonic stem cells for many therapeutic purposes.
Will ACT be able to do anything with the results that were the occasion for this discussion? There is reason to doubt on that score. ACT is not doing too well:
Advanced Cell, based in Worcester, Mass., temporarily suspended Cibelli's human cloning efforts for lack of money, and also sold its cattle-cloning subsidiary, Cyagra LLC, to raise cash.
Geron, the Menlo Park, Calif.-based industry leader, laid off a third of its work force and cut research spending to bolster its lagging stock price.
At least in some cases there may be a way to get relatively younger stem cells without either using embryos or cloning. One way to do it is to take stem cells from the umbilical cord of a newborn bady. The umbilical cord is going to be thrown out anyway. Using it for this purposee does not cost any real or potential life. Most kinds of ethical objections that are raised about cloned and embryo stem cells don't really apply to umbilical stem cells because umbilical stem cells are more differentiated than embryo stem cells (ie they are not at the point in development where a cell is at when it is ready to become a full fetus). The problem with umbilical stem cells up to now has been that they are few in number and haven't been easy to grow. However, here's a recent report of a better way to get stem cells from umbilical cords:
One obstacle to using cord blood more routinely as a source of stem cells in transplantation patients is the amount of blood required. Clinical trials have established that higher numbers of blood cells per kilogram of body weight of the recipient are associated with improved transplantation outcome. However, the amount of blood cells collected from cords is often not sufficient for an adult recipient. Scientists have therefore attempted to culture and expand cord blood-derived cells before transplanting them into patients. As they report in the October 21 issue of the Journal of Clinical Investigation, Irwin Bernstein and colleagues (Fred Hutchinson Cancer Center, Seattle, and University of Washington, Seattle), have been successful in doing so. Exposing human cord blood to a particular molecule called Delta-1 under defined culture conditions resulted in an over 100-fold increase in the number of the most immature stem cells. Other progenitors that maintained the potential to differentiate into multiple different blood cell types were also expanded.
On one hand the stem cells in a new born's umbilical cord should be very young and vigorous. On the other hand, these umbilical cord cells are already partially differentiated stem cells that are good at making blood cell types. Therefore it may be much more difficult to coax them to become all the other cell types that embryonic stem cells can become.
Here's another short report that again is not sufficiently detailed. Some sort of stem cell is induced to become a more differentiated neuron.
In November 11 advanced online Nature Neuroscience, Ping Wu and colleagues at the University of Texas Medical Branch, Galveston, Texas, USA, show that a novel priming procedure for fetal human neural stem cells (hNSCs) can transform them into cholinergic neurons in adult rat CNS (Nature Neuroscience, DOI:10.1038/nn974, November 11, 2002).
Did they take a fairly advanced rat fetus and extract already partially differentiated stem cells from the hippocampus to use to perform this procedure? Or did they take stem cells out of a fetus that was at a much earlier stage in development? Were the extracted stem cells more like embryonic stem cells or where they as differentiated as the sorts of stem cells that are found in adult brains?
Regardless of the type of stem cell these researchers started out with there is one note of caution to bear in mind when reports are made that stem cells have been converted into differentiated cells: It is not a certainty that the conversion was done perfectly accurately. Since we do not know exactly what pattern of genetic regulatory state characterises each cell type we don't know whether some attempt to make, say, a cholinergic neuron really made exactly that and nothing more or nothing less. Each cell type needs large sets of genes turned on and off in a pattern unique to that cell type. Its possible that some of these experiments are yielding cells that have a few extra genes turned on or a few genes turned off that shouldn't be turned on or off.
Scientists are gradually identifying and elucidating the function of the genes that control embryonic development and cellular differentiation:
Philadelphia, PA – In the search to understand the nature of stem cells, researchers at the University of Pennsylvania School of Medicine have identified a regulatory gene that is crucial in maintaining a stem cell's ability to self-renew. According to their findings, the Foxd3 gene is a required factor for pluripotency – the ability of stem cells to turn into different types of tissue – in the mammalian embryo. Their research is presented in the October 15th issue of the journal Genes and Development.
"Stem cells represent a unique tissue type with great potential for disease therapy, but if we are to use stem cells then we ought to know the basis of their abilities," said Patricia Labosky, PhD, an Assistant Professor in the Department of Cell and Developmental Biology. "Among the stem cell regulatory genes, it appears that Foxd3 gene expression keeps stem cells from quickly differentiating – that is, developing into different types of tissue – holding back the process so that an embryo will have enough stem cells to continue developing normally."
This latest report about Foxd3 adds to an existing list of genes that control embryonic development:
"Our findings implicate Foxd3 as one of the few genes serving as a 'master switch' of the developing embryo," said Labosky. "These genes determine the fate of cells by turning on or off other genes in response to signals in the embryo."
Foxd3 joins previously identified genes, such as Oct4, Fgf4, and Sox2, which control the pluripotency of embryonic stem cells in the early stages of embryogenesis. In their experiments, Labosky and her colleagues found that these genes are still expressed despite the lack of Foxd3. This suggests Foxd3 functions either downstream of Oct4, Fgf4 and Sox2, or along a parallel pathway.
At a molecular level what makes an embryonic cell different than an adult stem cell is probably just a different set of proteins and methyl groups bound at different places on the genome on different genes and regulatory sites. It should eventually become possible to change an adult stem cell (or, for that matter, a fully differentiated cell of any number of cell types) into an embryonic cell by sending in the right kinds and sequences of signals (hormones, drugs that will be discovered, gene therapy) to change the pattern of bound proteins and methyl groups on the DNA. At that point it should be equally possible to change an adult stem cell of one type into an adult stem cell of another type.
The development of a full understanding and the ability to fine tune control of all the genes that govern development could take a long time (10 years? 15 perhaps? my guess is 20 years max). Many scientists who are working with embroynic and adult stem cells are basically hoping that without first taking the time to understand all the details of how genes control cellular growth and differentiation they will be able to find ways to make these cells grow into needed replacement cell types and organs. So the debate about the use of human embryonic stem cells is about what approaches are ethically acceptable as ways to develop new therapies in the short and medium term.
My guess is that most of the people who hold that it is immoral to use embryonic stem cells in experiments are motivated by a spiritual definition of a human life. In their minds the moment of fertilization is a moment when a spirit enters the fertilized egg. As has already been demonstrated in other species, it is possible to put an adult cell nucleus into an unfertilized egg and the chemicals in the unfertilized egg cytoplasm somehow (as yet not understood) causes changes in the DNA in the nucleus of the adult cell genome that converts it into a state is similar enough to that of a freshly fertilized egg that the cloned cell can develop into an adult of that species. Therefore there is already a method other than fertilization that allows the creation of a new life. These will not remain as the only two methods for creating cells that are capable of developing into mature adults.
Some day we will have the knowledge and techniques to allow us to manipulate adult stem cells into all other types of cells. This would allows us to bypass the use of embryonic stem cells. But it would be a mistake to think this ability would allow us to entirely avoid the need to confront the ethical issues that cause some to oppose the use of embryonic stem cells. The ability to make adult stem cells into increasing numbers of other cell types will eventually extend to include the ability to make adult stem cells into embryonic stem cells. When the details come out about what makes embryonic stem cells different from adult stem cells the bright line that separates them in the minds of many opponents of embryonic stem cell use will become intellectually untenable. If the difference between embryonic and adult stem cells is just a set of molecular switches turned to different states then how can the opponents of embryonic stem cell use define the type of cell that deserves special legal protections? One could start with an adult stem cell and flip just one switch at a time to make it more and more like the switch settings that are characteristic of embryonic stem cells. How many of the switches will have to be flipped into the state that embryonic stem cells have them in before we would have to start treating the cells as embryonic and therefore entitled to special legal protection? Would they all have to be exactly as they are in an embryonic cell in order to warrant legal protection?
Advances in biotechnology promise to obsolesce the historical definitions of how we determine that something has enough of the characteristics of a human to be eligible for some degree of legal protection. The embryonic stem cell and cloning debates are just bush league warm-ups for much larger debates to come. The distance that has historically separated all manner of existing life forms from what we recognize as a human is going to narrow as it becomes possible to create humans in new ways, to give other species some of the qualities of what makes us unique (eg raise the intelligence of other species), and by methods of creating parts and keeping parts alive. We already have the problem of brain-dead humans and humans who are born with brains so defective they lack the thinking abilities that we associated with what it means to be a human. But as it becomes possible to create creatures that possess various subsets of the qualities that define humanity the question of what is a human will grow steadily more difficult to answer. Theoretical philosphical questions will become practical questions needing immediate answers. The debate over such basic questions promises to be highly divisive both within and between different human societies.
Many reseach and development groups in academia and in industry are working on the design of chips that can function as micro-labs. These will will make it possible to do biomedical tests and manipulations of biological materials less expensive and more widely available. This will lower the cost of medical testing, lower the cost and speed the rate of progress of basic research, and allow new types of therapies to be developed. The cost of labor and materials for doing biochemical manipulations can be lowered by orders of magnitude once these kinds of chips become functional. A University of Rochester group is working on the problem of how to get liquids to move around on micro-lab chips:
University of Rochester researchers are working on a new way to move and distribute microscopic amounts of fluid around a chip, essentially mimicking the work of scientists testing dozens of samples in a laboratory. The research is in response to a growing demand for "laboratories on a chip," programmable devices that automatically perform the multiple tests on much smaller amounts of material-on site and more efficiently than ever before. Researchers around the world are already working to develop chips that will allow instant glucose monitoring, DNA testing, drug manufacturing, and environmental monitoring.
In order to work, all of these chips need some sort of plumbing system to move liquid. Thomas B. Jones, professor of electrical engineering, and his team have developed a way to use the electrostatic attraction of water to electric fields, called dielectrophoresis, to divide a single drop of water into dozens of incredibly tiny droplets and move them to designated sites on a chip. The droplets can be mixed with specialized testing chemicals or biological fluids, or positioned for diagnostic tests with lasers or electrical pulses. Essentially, any laboratory test that can be shrunk to fit on a chip will be able to be serviced by the new plumbing system.
"Microchemical analysis is a rapidly advancing field, but while there are ways to test minuscule liquid volumes, no one has yet come up with a practical way to dispense and move these liquid samples around a chip," says Jones. "We're hoping to change all that. We've been able to take a single drop of water and split it up into as many as 30 droplets of specific sizes, route them around corners, send different droplets to different points on a chip and even mix different drops together."
Other microfluidic schemes use tiny channels and passages machined into substrates, but these are not only hard to make, but the pressure needed to move the fluid inside means that the slightest defect in fabrication could produce leaks. Jones' system uses narrow electrodes etched onto glass-so thin that they're almost invisible to the naked eye. AC voltage at about 60 kilohertz is applied to the electrodes and the resulting electrical force causes a "finger" to project from the drop. The finger stretches out along the electrode until it reaches the end, sort of a widened cul-de-sac. When the voltage is then switched off, the surface tension of the water itself pulls about half of the finger of water back toward the initial drop while half is left to form the droplets. This cul-de-sac can be quite a distance away across the chip-close to a centimeter in Jones' laboratory-and the path to it can even take sharp turns with ease.
Mixing different droplets together is as simple as setting the cul-de-sacs of two paths next to each other and then changing the electrical connections so that the droplets are attracted toward each other. To produce multiple droplets from a single finger, Jones widens the wires at certain areas along the path, making the finger bulge in that area and accumulating a droplet when the finger retracts.
In the same way that miniaturization changed computers from room-sized machines to pocket calculators, a similar change is coming to chemistry and the biological sciences. Familiar laboratory procedures are being automated and scaled down to the size of microchips. Some companies are even looking to such chips to manipulate and investigate individual cells, while others could benefit from a chip's ability to carry out possibly hundreds of tests on a new drug in just minutes. As the field expands, scientists are finding more uses for such micro-labs.
A new nanotechnology method for delivering a toxic compound only to cancer cells is reported here:
Researchers believe the remarkably versatile "nanoclinic" has the potential to be adapted for treating numerous cancers and other diseases, as well as drug-delivery and diagnostic applications, and for nonmedical applications, such as use in cosmetic and skin-care products.
The magnetic nanoclinic is a thin silica bubble, the surface of which can be customized using a peptide carrier group to selectively target cancer cells. Inside the bubble are ferromagnetic nanoparticles that exhibit a strong inclination to align in the direction of a magnetic field.
The researchers foresee patients receiving the nanoclinics—which would be taken up by cancer cells but not normal cells and tissue—intravenously or by injection at the tumor site. They then would undergo an MRI procedure that would "switch on" the destructive capability of the particles, causing the membranes of cancer cells to rupture.
In a scientific paper in press with Biomedical Microdevices, the UB and Nanobiotix scientists describe how magnetic nanoclinics, less than 70 nanometers in diameter, can selectively destroy human breast and ovarian cancer cells in vitro when a magnetic field is applied. Studies are under way in animals aimed at demonstrating the selective uptake of nanoclinics by tumor cells.
What isn't clear from this is just how exactly are they getting the magnetic nanoclinic to be taken up only by the cancer cells. Have they solved that problem in a way that will work across a large assortment of different types of cancers? Do they need to get a sample from each tumor of each cancer sufferer and then look for a unique surface protein to build a binding peptide to match it? That strikes me as the hardest part of the problem.
The abstract for the scientific paper can be found here. Also, the home page of Paras Prasad, one of the authors of the paper, can be found here.
Higher maternal testosterone levels in pregnant women correlate with tomboy behavior in young femal children:
"Because hormones influence basic processes of brain development, they also exert permanent influences on behavior," says lead author Melissa Hines, Ph.D., of City University in London "In both rats and rhesus monkeys, genetic female animals treated with testosterone during critical periods of prenatal or early postnatal life show increased levels of … male-typical play behavior as juveniles."
Hines and her co-authors note that girls with congenital adrenal hyperplasia (CAH), a genetic disorder involving prenatal exposure to high levels of male hormones, tend to prefer masculine-typical toys and activities.
The study results appear in the November-December issue of Child Development.
Participants were part of the Avon Longitudinal Study of Parents and Children, a long-term study of biological, environmental and social factors associated with pregnancy outcomes and child health. A total of 13,998 pregnant women -- who represented 90 percent of all pregnancies occurring in the Avon, England, area during an 18-month period in the early 1990s -- enrolled in the study. Data from 679 offspring of the 14,138 children born during the study were analyzed.
The researchers obtained blood samples from the pregnant women during routine prenatal medical care; 55 percent of the women had blood taken between weeks 8 and 24 of the pregnancy; a quarter of the women had the samples taken between weeks 5 and 7, and the remainder after week 25. The samples were analyzed for levels of testosterone and a hormone that limits the ability of testosterone to act, called sex hormone binding globulin.
Once each child reached age 3 1/2, a primary caregiver completed the Pre-School Activities Inventory (PSAI), which assesses the child's engagement in various sex-typed behaviors, such as play with certain toys, games and activities. Higher scores indicate more masculine-typical behavior. The questionnaire was completed again when the child was 3 1/2.
The authors found a link between testosterone level in mothers and girls' scores on the PSAI, with high testosterone levels related to high "masculine" scores. No relationship was found between testosterone levels and boys' gender-role behavior, however.
In case it seems odd that I post alot on research about neurobiology and behavior on a blog dedicated to the future I'd like to explain why I do this. These studies demonstrate jut how much of human nature is determined by genes and by hormones and other biochemical factors that regulate genetic expression. In the future we are going to be able to make choices about the genetic sequences of genes for our offspring and we therefore will be able to change the mental aspects of human nature. It is important to appreciate just how many ways biological variations can cause variations human minds and human behavior because all of those variations and many more will be manipulated intentionally. When we acquire the ability to control gene that determine personality characteristics in offspring this it will simultaneously provide a great benefit and pose a great threat. It is important that we start thinking about this topic now.
A computerized image processing system is being used in public places in the UK to identify criiminal activity and other problems in crowds:
EU policy to encourage more people off the roads and onto public transport, as well as addressing the needs of public service operators, has led to a series of collaborative research projects between universities and industry for several years. Leading UK universities in this area include Kingston University, Reading University, University College London (UCL), and Kings College London (KCL), among others. The research groups in the Digital Imaging Research Centre (DIRC) at Kingston University, led by Dr. Sergio A Velastin, formerly of KCL, and the Centre for Transport Studies (CTS) at UCL, where the key researcher is Dr Maria-Alicia Vicencio-Silva, are working collaboratively in a number of related areas directly aimed at alleviating some of the public transport issues highlighted.
Under EPSRC and EU-funded projects, the teams have developed a distributed pedestrian monitoring system, based on image processing techniques, that brings suspicious images to the prompt attention of staff. The system consists of a set of networked modular components using open standards for communications and annotation along with a number of dedicated supervisory PCs, called MIPSA (Modular Integrated Pedestrian Surveillance Architecture). It can be connected to an existing conventional CCTV system (16 cameras/MIPSA), collecting and storing the video streams, routing them to image processing devices, and feeding processed data back to the CCTV control centre using a unified interface.
In order to ensure the system is reliable and robust, thus reducing the possibility of false alarms, simple image processing techniques have been used. Video data is first processed to separate motion from the fixed background. One of the key enabling elements of this project is the DSP video processing based hardware, designed and manufactured by UK firm, Sollatek Ltd (www.sollatek.com), which is used to provide the fast calculation of motion data from the video streams. While UCL researchers have identified the features that need to be extracted, the Kingston University team has concentrated on the image acquisition and processing requirements.
In operation, the system takes conventional video inputs, combined with site-specific information from the CCTV operators, to detect unusual motion patterns which can arise due to situations such as congestion, trespassing and threatening behaviour. Excessive permanence of an object that is known not to be part of the background, for example, could indicate loitering, an injured person or even a suspect package. Similarly, large areas of motionless objects could indicate congestion, while an object moving against the flow could indicate an incident requiring further attention, such as gate jumping. In this application, extracting the basic image properties is sufficient; the system does not need to refine the nature of the incident further, but simply alert the relevant CCTV monitor operator.
It can detect patterns of movement characteristic of pickpockets:
He fends off concerns by explaining that it's very difficult to recognize people in these images, and also that no one is going to be targeted for features like unusual clothes or an identifiable walk. Instead, he says, more universal situations will be programmed into the system, such as people walking against a crowd, which can be a sign of pickpocketing. "They're only going to be stopped and investigated if there is sufficient reason to do so," he says.
This technology of course will become increasingly sophisticated. Science fiction author David has argued that pervasive monitoring by computer cameras and other sensor systems is coming in our future. See his book The Transparent Society: Will Technology Force Us to Choose Between Privacy and Freedom?. You can also find out more about his book at this page on his web site.
First off, kids enterting puberty experience a big drop in their ability to read the emotions of others. So suddenly the likelihood for misunderstandings shoots way up:
Robert McGivern and his team of neuroscientists at San Diego State University found that as children enter puberty, their ability to quickly recognise other people's emotions nosedives. What's more, this ability does not return to normal until they are around 18 years old. McGivern reckons this goes some way towards explaining why teenagers tend to find life so unfair, because they cannot read social situations as efficiently as others.
Previous studies have shown that puberty is marked by sudden increases in the connectivity of nerves in parts of the brain. In particular, there is a lot of nerve activity in the prefrontal cortex. "This plays an important role in the assessment of social relationships, as well as planning and control of our social behaviour," says McGivern.
He and his team devised a study specifically to see whether the prefrontal cortex's ability to function altered with age. Nearly 300 people aged between 10 and 22 were shown images containing faces or words, or a combination of the two. The researchers asked them to describe the emotion expressed, such as angry, happy, sad or neutral.
The team found the speed at which people could identify emotions dropped by up to 20 per cent at the age of 11. Reaction time gradually improved for each subsequent year, but only returned to normal at 18 (Brain and Cognition, vol 50, p 173).
During adolescence, social interactions become the dominant influence on our behaviour, says McGivern. But at just the time teenagers are being exposed to a greater variety of social situations, their brains are going through a temporary "remodelling", he says. As a result, they can find emotional situations more confusing, leading to the petulant, huffy behaviour adolescents are notorious for.
This study may not have used subjects with an early enough starting age to detect the initial decline in ability detected in the previous study:
Another series of MRI studies is shedding light on how teens may process emotions differently than adults. Using functional MRI (fMRI), a team led by Dr. Deborah Yurgelun-Todd at Harvard's McLean Hospital scanned subjects' brain activity while they identified emotions on pictures of faces displayed on a computer screen.5 Young teens, who characteristically perform poorly on the task, activated the amygdala, a brain center that mediates fear and other "gut" reactions, more than the frontal lobe. As teens grow older, their brain activity during this task tends to shift to the frontal lobe, leading to more reasoned perceptions and improved performance. Similarly, the researchers saw a shift in activation from the temporal lobe to the frontal lobe during a language skills task, as teens got older. These functional changes paralleled structural changes in temporal lobe white matter.
During a time period when teens are already having a hard enough time sorting thru their own emotions they become far more sensitive to emotion-altering recreational drugs:
Researchers at Jefferson Medical College have evidence in animals that the young, adolescent brain may be more sensitive to addictive drugs such as cocaine and amphetamines than either the adult or newborn. The work may help someday lead to a better understanding of how the adolescent human brain adapts to such drugs, and provide clues into changes in the brain that occur during drug addiction.
Scientists led by Michelle Ehrlich, M.D., professor of neurology at Jefferson Medical College of Thomas Jefferson University in Philadelphia and a member of the Farber Institute for Neurosciences at Jefferson, and Ellen Unterwald, Ph.D., associate professor of pharmacology at the Temple University School of Medicine in Philadelphia, found a greater increase in a certain protein in the part of the adolescent mouse brain called the striatum following chronic exposure to drugs such as amphetamine or cocaine than they did in either very young mice or adults.
Such psychostimulant drugs affect the brain's striatum in different ways, potentially affecting both movement and locomotion, or the "reward" system. This "molecular adaptation," says Dr. Ehrlich, could be significant. "An increase in this protein may be important because it could also affect other molecules that could lead to long-lasting changes in the brain in response to psychostimulant drugs." The protein, called Delta FosB, is a transcription factor and plays a role in regulating gene expression. Earlier research by other scientists had shown increased amounts of Delta FosB in adult brains following chronic exposure to psychostimulants.
The team, which includes scientists at the Nathan Kline Institute in Orangeburg, New York, reports its findings November 1 in the Journal of Neuroscience.
Teens are at risk of developing life long harmful habits and their brains change in a way to puts them at greater risk of developing addiction to the demon weed:
When they did, researchers at Duke University found that adolescent brains respond more intensely to nicotine. The scientists injected rats with nicotine every day for more than two weeks, a dose comparable to what a typical smoker receives. In all of the rats the number of chemical receptors dedicated to nicotine increased -- a sign of addiction. But in adolescents, the number of nicotine receptors increased twice as much compared to adults.
"What we found is that the adolescent brain gets a lot more bang for the buck," says Theodore Slotkin, one of the scientists who performed the research.
A follow-up study published in the October issue of Brain Research showed that adolescent nicotine exposure caused permanent behavioral problems as well, especially for females. Even after two weeks with no nicotine, female rats were less interested in moving around and raising their young than counterparts who had never been exposed.
That may be because nicotine retards cell division in the hippocampus, a brain region that continues growing into adulthood in females, but not males.
The larger society is forcing teenagers to wake up earlier than their teen biological clocks are telling them to:
When teenagers insist that they are not tired at 9 or 10 p.m., they are very likely telling the truth. For reasons that are not fully understood, Dr. Carskadon said, their body clocks shift, so that their natural tendency is to stay up later at night and wake up later in the morning than when they were younger. But that inner clock often clashes with the outer world: early starting times in high school and demanding schedules of sports, clubs, music lessons, homework and part-time jobs.
There are consequences. For one thing, lack of sleep can interfere with learning: tired students have a hard time paying attention, and even if they do somehow manage to focus, they may forget what they were taught because memory formation takes place partly during sleep.
In "Adolescent Sleep Patterns," a book published in August and edited by Dr. Carskadon, she wrote, "The students may be in school, but their brains are at home on their pillows."
What's worse, the types of brain activities engaged in during adolescence probably have a significant impact on what cognitive abilities people will have the rest of their lives:
Even though it may seem that having a lot of synapses is a particularly good thing, the brain actually consolidates learning by pruning away synapses and wrapping white matter (myelin) around other connections to stabilize and strengthen them. The period of pruning, in which the brain actually loses gray matter, is as important for brain development as is the period of growth. For instance, even though the brain of a teenager between 13 and 18 is maturing, they are losing 1 percent of their gray matter every year.
Giedd hypothesizes that the growth in gray matter followed by the pruning of connections is a particularly important stage of brain development in which what teens do or do not do can affect them for the rest of their lives. He calls this the "use it or lose it principle," and tells FRONTLINE, "If a teen is doing music or sports or academics, those are the cells and connections that will be hardwired. If they're lying on the couch or playing video games or MTV, those are the cells and connections that are going to survive."
On the bright side, the spurts in cell growth in various parts of the brain during adolescence open up the possibility of therapies to boost intelligence by developing hormonal and/or gene therapies that would make the burst of nerve growth more intense. Also, with better understanding it may become possible to structure the institutions that deal with adolescents to better accommodate the developmental stages of their brains. Obviously, just moving starting times forward for schools is a fairly easy accommodation.
Update: These results provide a sense of just how much the mind changes during adolescence:
Researchers at studied the post-mortem cerebral cortexes of six 12- to 17-year-olds and five 17- to 24-year-olds. All of the individuals had been of normal health and intelligence. They studied 43 different areas in each brain hemisphere, measuring for cortical thickness, neuronal density and pyramidal neuronal size. Corrections were made for gender differences in the size of the brain.
The average pyramidal soma size was 15.5 percent smaller in the older age group than in the younger one. This suggests that these nerve cells undergo “pruning” or “streamlining” of their processing during adolescence, said de Courten-Myers.
Other measures of the brain were slightly larger in the older age group, including cortical thickness (1.9 percent), neural density (1.8 percent), the number of neurons/standard cortical columns (3.8 percent), neuropil volume/standard cortical column (3.1 percent), and neuropil volume/neuron (1.3 percent).
Update II The part of the brain that inhibits risky behavior does not fully develop until age 25.
A National Institutes of Health study suggests that the region of the brain that inhibits risky behavior is not fully formed until age 25, a finding with implications for a host of policies, including the nation's driving laws.
"We'd thought the highest levels of physical and brain maturity were reached by age 18, maybe earlier -- so this threw us," said Jay Giedd, a pediatric psychiatrist leading the study, which released its first results in April. That makes adolescence "a dangerous time, when it should be the best."
So that is why teenagers are so reckless. Hardly comforting news. You can know this and they will still be reckless after all.
Consanguineous mating is even more widely practiced in Arab countries. Genetic testing will change the mating practices in many socities.
"In south India many people marry their relatives," Dr Sridevi Hegde said, clinical geneticist at Bangalore's Manipal Hospital.
"It is the elders who decide and mostly women get married to their uncles.
"When this happens, most of them are at risk of bearing an abnormal child," Dr Sridevi said.
"I see an increasing trend in the number of people approaching us to check their family tree and find faulty genes."
Two years ago about 100 couples used to walk into the two genetic departments of hospitals based in Bangalore.
Now the figure is about 1,500 every year.
As the genetic tests become cheaper and more detailed expect to see millions of people per year testing themselves and seeking counseling for mate choice.
US Genomics is developing technology to do linear single strand DNA analysis. They are not the only ones attempting this and it is not clear how successful they will be. But they have made progress jumping over some of the hurdles that they face with their approach. Notice the high speed per minute. At that rate they could in theory read the entire 3 billion DNA sequence of a human genome in less than 11 days..
Chan has developed a way to spool out the tangle of DNA in a chromosome using a 'nanofluidic' chip smaller than a computer key. Fluid flowing through the chip draws the DNA through an array of pegs like bowling pins. One end works loose and is drawn into a funnel at the end.
Rather than sequencing every letter, Chan and his team spot the differences between individuals — and use the reference genome to fill in the rest. Fluorescent tags stick to variable spots; a detector reads their order as they flow past. The speed-reading technique gets through around 200,000 letters a minute, he claims.
They are trying to develop the ability to unravel and read thru a genome as fast as a regular cell can when it replicates its genome during cell division.
The company's technologies are premised upon the direct and linear reading of large sections of genomes. Linear analysis is powerful because there is no upper limit on the size of DNA that is read. Furthermore, this is the method which nature has perfected over millions of years. DNA, during cell division, is replicated with DNA polymerase, an enzyme that tracks along DNA in a linear fashion. Identification of the bases is mediated by base-pairing and enzyme-DNA specific interactions. By reproducing nature's method of DNA reading, the highest readout speeds are possible. A human cell can replicate and read its DNA in less than thirty minutes. The company's technology is a biophysical rendering of the polymerase-DNA interaction and allows for speeds on the same time scale as nature's DNA polymerases.
U.S. Genomics's technology platform, the GeneEngine™, has two components, (1) nanotechnology systems for positioning DNA so that it can be read linearly (broadly termed DNA Delivery Mechanism(s)™) and (2) detection technologies that allow the reading of information from the DNA Delivery Mechanism(s)™. The combination of different DNA Delivery Mechanism(s)™ with particular technologies makes possible different applications in genomic analysis, such as complete genome analysis, sequencing, polymorphism analysis, and gene expression determination.
Here's the announcement for their patent for moving single DNA strands past a reader sensor.
US Genomics is getting US military money to develop their technology to detect bioweapons attacks:Woburn, MA (JUNE 13 2001) – U.S. Genomics announced today that its first patent has been granted by the United States Patent and Trademark Office (6,210,896 Molecular Motors). The issued patent covers the first of a suite of proprietary techniques that U.S. Genomics has developed to allow the direct, linear reading of extremely long sequences of DNA.
Specifically, the patent covers the Company's technology for using molecules that interact with cellular polymers (such as nucleic acid -- DNA or RNA) in such a way that the molecules cause the polymers to move. The segments of the polymer that are moved by the "molecular motor" flow past a fixed point, emitting specific signals that reveal genetic information embedded on the strand of nucleic acid.
Eugene Chan, Chairman and CEO of U.S. Genomics, commented, "The granting of this first patent for U.S. Genomics is a validation of our approach to direct linear analysis of DNA. Modeled after the nearly instantaneous readings of DNA that natural cellular machinery executes, our approach to deciphering and understanding genetic information is directed towards complete-genome analysis - reading the entire sequence of genetic coding contained in a full, unbroken strand of DNA." U.S. Genomics has developed the GeneEngine™, a set of laboratory devices that enable researchers to uncurl and separate individual strands of DNA or RNA which are then run through a microarray sequencer in extremely long, unbroken, linear segments. The genetic information captured through such direct linear readings is relatively much more comprehensive and integrated than data available through other current techniques. The molecular motors covered in this first patent provide the physical mechanism for moving the strands of DNA through the sequencer.
Woburn, MA (September 04, 2002) – U.S. Genomics announced today it was awarded a $499,500 contract by the Defense Advanced Research Projects Agency (DARPA) to examine the use of the Company’s direct linear DNA analysis technology to detect Class A pathogens, such as anthrax and smallpox. The contract will enable the company to study the use of its GeneEngine™ technology as a tool to create genomic maps or signatures of organisms; such maps have the potential to enable very rapid detection and identification of deadly bacteria.
While they do not sound like they are going to be ready to ship fully working products any time soon they have entered into an agreement The Wellcome Trust Sanger Institute to try out their GeneEngine technology in the study of genetic variations.
It is hard to interpret the announcement with The Wellcome Trust Sanger Institute. When will US Genomics deliver usable technology and what will that initial technology be capable of?
Woburn, MA (January 28, 2002) – U.S. Genomics and The Wellcome Trust Sanger Institute have entered into a collaboration to examine the use of U.S. Genomics’ direct, linear DNA analysis technology in research on the human genome. The partnership will study the use of this new technology to investigate human genetic data at a level of complexity, comprehensiveness, and accuracy not previously studied. The collaboration marks the first application of U.S. Genomics’ technology in an outside research setting.
Under the agreement, The Wellcome Trust Sanger Institute and U.S. Genomics will jointly employ their scientific expertise to conduct genetic research using the GeneEngine™ technology and other aspects of U.S.Genomics’ technology platform. The research collaboration will explore the application of U.S. Genomics’ technology to human genetic analysis at the highest level of detail and complexity. Financial terms of the agreement were not disclosed.
If we step back and look at it from a higher level what is interesting about this company and others like it is that venture capitalists are funding attempts to drive down the cost and accelerate the speed of DNA sequencing by orders of magnitude. Some of these companies will succeed. A lot of progress has already been made.
The US Genomics press releases are here.
The MIT Technology Review has an article entitled "Why Not a 40-MPG SUV?". It reviews a number of promising technologies that could make the standard internal combustion engine vehicle much more efficient. For example, electromechanical actuators could replace standard camshafts for controlling valve opening:
But the ultimate move toward optimization throws the camshaft away. Instead, electromechanical actuators would provide software-driven control for each valve (see “The Camless Engine,” below). By providing full control over the timing, lift, and duration of each valve motion, such a camless engine optimizes power delivery with the least possible fuel at every engine-rotation speed. The payoff is huge: a camless engine could improve fuel economy by 10 to 18 percent while also increasing engine torque by 15 to 20 percent at low speeds for faster acceleration.
The problem is that to prevent excessive wear and minimize engine noise and vibration, valves must decelerate before landing. A camshaft, though relatively inefficient, does this quite well, thanks to its ovoid shape, which produces a corresponding acceleration and deceleration in the valve motion. Actuators are different; they slam up and down, on and off.
The way to make actuators as gentle as camshafts involves a combination of hardware and software, and many companies are working on the problem.
It is surprising just how much more refinement can be done to the design of the internal combustion engine.
Do you all remember the Star Trek episode "Is There No Truth In Beauty" in the original series with Diana Muldaur as the blind Miranda Jones who wore a cape over her that served as a sensor net that allowed her to see? Real life is starting to catch up with science fiction:
The aim of STRETCH (not an acronym) is to develop large e-textile fabrics that will look like typical military equipment, such as tents or camouflage nets. The electronic wires and sensors woven into the fabric will perform the complex procedure of listening for the faint sounds of distant vehicles being deployed by the enemy.
Within the fabric, the sensors and their connecting wires will communicate with one another to create patterns of information. This information can then be translated by computer software into images that will enable soldiers to determine the location of detected sounds.
"We're designing and constructing a 30-foot-long prototype for the STRETCH fabric," Jones said. "The goal of the project is to develop a low-cost, flexibly deployable e-textile system that has low power requirements and doesn't rely on radio waves." The Virginia Tech and ISI researchers plan to test the prototype in November.
The military already has sound detection systems that rely on radio waves, but communication via radio waves can alert an adversary to a military unit's location. The e-textiles system being developed as part of STRETCH produces no detectable energy and also requires less power than radio-wave-operated systems.
"Cloth has properties that can be useful for certain electronic applications," said Robert Parker, director of ISI and co-principal investigator on the STRETCH project. "We can easily and cheaply make large pieces of cloth, light and strong, that can be stretched over frames into any desired shape."
Sound detection is not the only potential use for the STRETCH e-textile system. Fabrics can be woven with sensors that can detect chemicals, pick up satellite signals, and perform other feats. Jones and his colleagues also foresee numerous industrial uses.
Jones and Martin also have received a $400,000 National Science Foundation Information Technology Research (ITR) grant to design wearable computers made of e-textiles.
The generic concept of wearable computers is a small CPU in a fanny-pack connected to a cumbersome head gear that holds a display screen at eye-level. The Virginia Tech ITR project is something completely different.
Because the wires and sensors in e-textiles are woven into the fabric, wearable computers could be constructed much like normal-looking shirts or hats or other types of cloth apparel. These computers wouldn't connect users to the internet or send and receive e-mail, but would perform specific functions necessary to the wearers.
"Wearable computers constructed of e-textiles offer context awareness," Martin said. "They can be designed to be aware of the user's motions and of his surroundings."
For example, sensors called accelerometers -- which are used to cue airbags to deploy -- can detect changes in speed and direction. There are visual sensors that can project images to tiny displays clipped to eye glasses. An e-textile shirt for a blind user might include tiny vibrating motors that would provide cues about approaching objects.
Of course this opens up some interesting possibilities. These textiles will eventually become very advanced. You could leave your jacket in your chair in a business meeting, step out temporarily, and be able to come back and ask your jacket later what people said while you were gone. Or of you were trying to leave the house and couldn't figure out where you left your jacket you could yell out and ask it where it was. If it was smart enough it could recognize your voice (you'd have to give it a name too in order to call to it) and respond. Plus, you could have an artificially intelligent talking couch. It could warn someone if they were falling asleep with a lit cigarette in their hand: "Wake up you idiot, you're about to burn me!".
There would also be the erotic talking towel that would go ooh and aah as a person toweled off after a shower. Then there'd be the hat that could tell you that someone was coming up on you from behind. Or how about the computer chair that a man's wife might get him that would tell him he's spending too much time in front of the computer and to get out and work on the yard?
This result suggests that college students should sit and watch parts of slasher movies interleaved with reading textbooks and class notes:
Nielson asked 32 people to memorize a list of words, such as fire, queen and butterfly. Half of them then watched a film of a full dental extraction, complete with blood and screeching drill. "It was nasty - it made you crawl," she says.
24 hours later, the traumatized subjects' word memory was around 10% better than that of those who'd sat through a dull video on tooth brushing. Emotion helps us remember, concludes Nielson, "but it doesn't have to be [personally] meaningful".
The next obvious round of experiments would be to use hormones such as adrenaline to try to see if the same mental state caused by watching the dental extraction can be invoked pharmacologically. The explanation for this might be that excitement increases the release of some hormones or neurotransmitters than, in turn, stimulate the division of neural stem cells in the hippocampus.
The semiconductor industry is going to do to biotech what it has already done to computers: make things dramatically smaller, faster, cheaper, and more powerful:
Philadelphia, October 31, 2002 - At the Chips-to-Hits conference in Philadelphia today, STMicroelectronics (NYSE:STM), the world's third largest semiconductor maker, presented a prototype silicon chip for DNA analysis that integrates both DNA amplification and detection on the same chip. This device is based on Micro-Electro-Mechanical-System (MEMS) technology that applies silicon-chip manufacturing technologies to produce miniature devices with a combination of mechanical, electrical, fluidic and optical elements.
The primary end use targeted by the DNA analysis chip is in medical diagnostics, to detect genetically related disease directly at the point of care without the delays of laboratory testing. Other applications of the DNA analysis chip include drug discovery - the search for more effective new drugs, the testing of livestock for genetic disease, and the monitoring of water supplies for biological contamination.
"The advantage of using silicon rather than plastic or glass for this function is that it has excellent thermal properties, which is extremely useful in analysis techniques like the Polymerase Chain Reaction (PCR) which are based on temperature cycling," said Benedetto Vigna, Manager of ST's MEMS Development Unit. "In addition it can be 'micromachined' readily using well-known and cost effective silicon-chip manufacturing techniques."
Compared to traditional tests, the ST silicon MEMS device offers a very compact solution that reduces the overall testing cost and delivers results in minutes. Using this technology, extremely small quantities of fluid can be analyzed; the limitation is in the external hardware used to transfer samples.
One of the world's leading manufacturers of conventional electronic silicon chips, ST also develops and manufactures silicon MEMS devices using in-house-developed technologies covering a broad range of applications. The microfluidic technology used in the DNA analysis device builds on the company's long experience in the manufacture of inkjet printer chips combining electronic and fluidic elements.
"Our goal in presenting this device to the life sciences community here at Chips-to-Hits," said Barbara Grieco, Business Development Manager in ST's Printhead and Microfluidics Business Unit, "is to identify potential partners in the biomedical field for the joint development of new devices that combine ST's knowhow in silicon MEMS technology with the partners expertise in biomedical technologies and markets." ST currently partners with leading companies in other fields for the joint development of MEMS-based devices for inkjet printers and optical switches.
The prototype DNA analysis device presented at Chips-To-Hits performs DNA amplification in microscopic channels buried in the silicon and then identifies DNA fragments in the sample. DNA amplification is performed using the Polymerase Chain Reaction technique. A prepared DNA sample mixed with suitable reagents flows into the buried channels in the chip where it is repeatedly cycled through three temperatures which doubles the quantity of DNA with each cycle. When the sample has been amplified sufficiently, it flows into a detection area on the same chip where gold electrodes are pre-loaded with DNA fragments. Fragments in the sample attach to matching fragments on the electrodes and are detected optically.
The US military is funding the development of nanotech smart coatings might contain switches, gears, and motors that would be used to report problems, do repairs, and even rapidly change appearances:
U.S. Army experts are trying to embed microscopic electromechanical machines in paint that could detect and heal cracks and corrosion in the bodies of combat vehicles, as well as give vehicles the chameleon-like quality of rapidly altering camouflage to blend in with changing operating environments.
Officials of the Army Tank-automotive and Armaments Command's Armament Research, Development and Engineering Center (TACOM-ARDEC) at Picatinny Arsenal, N.J., are working with scientists at the New Jersey Institute of Technology in Newark, N.J., to develop nanotechnology-based "smart" coatings for Army vehicles and other materiel.
If the coatings are going to be that sophisticated it also seems reasonable to expect the coatings will eventually embed sensors as well.
The military might want to consider incorporating some of the ideas that Jonathan Dordick is working on for self cleaning surfaces. The ability of surfaces to kill pathogens on contact would be great for defense against bioweapons:
Nov. 8, 2002 – Detergent manufacturers have long used enzymes in their formulations for fighting really tough dirt. Jonathan Dordick, a chemical engineer at Rensselaer Polytechnic Institute in Troy, N.Y., is taking the battle against dirt a step further, using nanotechnology to design a self-cleaning plastic in which the enzyme molecules are an integral part of the material. When the plastic comes into contact with bacteria or other pathogens, the enzymes attack the microbes and destroy their ability to bind to its surface.
This is even more useful for bioweapons defense than it appears at first glance. If a vehicle has travelled thru an area that has airborne bioweapons in it and if the vehicle is sealed its occupants might be safe. But eventually they have to get out wearing their bioweapons gear and then get back in. Now the inside of the vehicle is contaminated by the outer coatings of their protective suits and they can't take off their suits. The ability of surfaces to self-sanitize would be a great time and life saver.
These developments demonstrate just how different the future will be. Will we need to take our cars to the car washer? Or will we just have to flip a switch and suddenly energy will flow across the surfaces of cars powering nanotech cleaners that will clear off cars in a minute? Or how about self cleaning bathtubs, toilets, sinks and floors? Picture a floor that collects up and moves the dust and dirt in a wave into a corner where a nanotech processor ejects the dirt into an outside receptacle.
Also, will houses of the future still have to be repainted periodically? Or will an underlying nanotech layer create a huge surface network that will transport repair material to wherever a wind blown branch has created a scratch? Will nanotech surfaces in the house also clean the smears off of walls and repair scratches there as well? Will one be able to change the color of the house inside and out just by dialing a switch?
The oldest rodents living in captivity are the naked mole-rats (Heterocephalus glaber), the oldest of which are now at least 26 years old. Because of their living conditions they are less at risk of being killed by predators or accidents in the wild than are other rodent species. Therefore their longer natural lifespans are predicted by the evolutionary theory of aging. There was no big selective pressure for them to be more vigorous when younger and instead the selective pressure on all the genes that affect aging was toward longer lasting compoents.
In nature, naked mole-rats are known to live at least 10 years. "We think they live longer in the laboratory than they do in the wild because they're safer here, but they're pretty safe in nature, too," Sherman says. One of the factors contributing to the evolution of longer life spans is reduced extrinsic mortality, which Sherman defines as causes of death that are outside an animal's control, such as drowning in a flash flood or being devoured by a snake. In nature, naked mole-rats are largely protected from sources of extrinsic mortality by inhabiting subterranean burrows in extremely hard soils. Protection is enhanced by cooperative defense against predators. As a result, naked mole-rats have evolved genetic traits that make them more resistant to senescence than similar-sized, solitary, surface-dwelling rodents. Indeed, the only rodent known to live as long as the naked mole-rat is the African porcupine Hystrix brachyura , which is protected by its large body size and quills.
The diminutive naked mole-rat has something else going for it: greater fecundity with advancing age. "A large, old breeding female mole-rat gives birth to an incredible number of young and continues to do so year after year," Sherman says. "Our record for a laboratory female is 28 pups in one litter and more than 900 pups in a lifetime." Fecundity seems related to body size, Sherman adds, noting that mole-rat queens, like queens in honeybees and termites, are considerably larger than workers in their colonies. Fecundity is important because if old individuals can make disproportionate reproductive contributions, there will be strong selection to postpone senescence.
While naked mole-rats are models that support senescence theory, they are not perfect role models for humans. Senescence occurs, simultaneously, on all aspects of any organism, which means there is no single gene for aging or for youth. "Senescence theory," says Sherman, "tells us why the fountain of youth still eludes us -- and probably always will."
It isn't clear exactly what argument Paul Sherman is making when he claims that the fountain of youth will always elude us. It will be very hard to redesign out bodies in a way that totally precludes aging from happening. But that is not what is necessary. We will be able to repair and improve our bodies to make them young again. What we really need are techniques for repairing the accumulating damage and to slow the rate of accumulation. When biotechnology advances far enough we can repair the damage with periodic medical treatments (eg organ replacements, gene therapy, cell therapy) then we will get effective rejuvenaton and be able to feel and be young again. Rejuvenation by repair and replacement will be achieveable within the next 20 to 40 years.
Using the enzyme chondroitinase ABC Italian and British researchers found they could free up nerve cells from a layer of sugar and protein so that they could once again spread and this may be useful for brain trauma treatments:
Pizzorusso and his team sealed one eye shut in each of about a dozen adult lab rats with otherwise perfect vision. Normally, the critical period for vision passes about five weeks after birth.
When the rats were anaesthetized and their visual cortexes given the bacterial enzyme, the biochemical digested the sugary proteins and unlocked the nerve cells, allowing them once again to grow new connections. Nerves from the sealed eye, in a case of "use it or lose it," began reaching towards the open eye and its stream of sensory input.
Its possible to suppress a trained fear response in rats:
The researchers then electrically stimulated the infralimbic area in rats that had been fear conditioned but not extinguished — in effect simulating the safety signal, while pairing it with the tone. Remarkably, the rats showed little freezing. Later, the rats continued to be unafraid of the tone even without the stimulation, suggesting that memory for extinction was strengthened by experimentally mimicking the safety signal.
Since the prefrontal cortex is known to project to the amygdala, a hub of fear memory deep in the brain, the researchers propose that increased activity of infralimbic neurons in the prefrontal cortex strengthens memory of safety by inhibiting the amygdala's memory of fear. They speculate that stimulating parts of the prefrontal cortex in anxiety disorder patients, using an experimental technique called transcranial magnetic stimulation, might help them control fear.
Imagine some future battlefield where one of the combatant countries has implanted mini-electrodes in the brains of its soldiers. It could suppress all fear and make its soldiers fearless. They wouldn't panic when under fire.
The neural stem cells in this study are adult stem cells that are present in the adult human brain. While this article doesn't state it they are probably from the hippocampus. These cells normally differentiate to create neurons to form new memories and to replace lost cells. In Parkinson's Disease there is a particular type of neuron that makes the neurotransmitter dopamine that dies at a much faster rate than normal. One potential way to treat Parkinson's is to induce the adult stem cells to reproduce at a faster rate and to differentiate into dopamine-producing neurons to replace the lost neurons. A research group at Jefferson Medical College has demonstrated that it is possible to induce human adult neural stem cells to produce dopamine:
Developmental biologist Lorraine Iacovitti, Ph.D., professor of neurology at Jefferson Medical College of Thomas Jefferson University in Philadelphia, is searching for ways to convert stem cells into dopamine-making neurons to replace those lost in Parkinson's. In previous work, she and her co-workers showed that mouse neural stem cells placed in rats with Parkinson's disease could develop into brain cells that produced tyrosine hydroxylase (TH), the enzyme needed to make dopamine.
Dr. Iacovitti, who also is associate director of the Farber Institute for Neurosciences at Jefferson, wanted to see if human neural stem cells could become dopamine-producing brain cells as well. She and her colleagues grew neural stem cells in a laboratory dish. Using a cocktail of protein growth factors and nutrients, the researchers found they could coax approximately 25 percent of the stem cells to make TH in the dish, proving the stem cells had the capacity to manufacture dopamine. What's more, when they removed the growth factor-cocktail, the cells continued to produce the enzyme. She reports her team's findings November 5 at the annual meeting of the Society for Neuroscience in Orlando.
"We have two examples of human stem cells that do this," she says. "The obvious extension [of these results] is to take those predifferentiated human dopamine neurons and transplant then into Parkinson's disease model systems."
This is still a long way away from a useful therapy. But the value of this result is that it shows that the neural stem cells have the potential to produce dopamine. They haven't gone down a differentiation path that precludes their ability to make dopamine. This is great news.
Using adult stem cells to do this has a few advantages aside from the obvious one of avoiding the ethical objections some people have to the use of embryonic stem cells. First of all, it is theorized by some scientists that adult stem cells may be at lesser risk of converting into cancer cells than embryonic stem cells. Also, neural stem cells, being more differentiated than embryonic stem cells, are some unknown number of steps closer to being neurons. So to convert them to neurons of a particular type may turn out to be easier to do. Adult stem cells are also already immunologically compatible with their hosts. Another big potential advantage is that adult stem cells are already in the host body. It may be possible to come up with a mix of drugs and/or gene therapy that would flow up into the brain and tell those adult neural stem cells to reproduce at a much faster rate and convert into dopamine-producing neurons.
The ability to better control adult neural stem cells has other applications in treatment of disease. See this recent post on hippocampal stem cells and depression for another example. In the long run the ability to do gene therapy on adult neural stem cells and to control their cell division and differentiation will be useful not only for treating classical neurological disorders such as Parkinson's but also to rejuvenate aging brains, to help lift depression, to repair traumas to the brain, and even to raise intelligence.
From the Columbia University web site of Associate Professor Jingyue Ju comes a description of a massively parallel DNA sequencing method.
Fluorescence Imaging Chip System for Massive Parallel DNA Sequencing. The use of electrophoresis for DNA sequencing has been a major bottleneck for high-throughput DNA sequencing projects. The need for electrophoresis is eliminated when sequencing DNA by synthesis, that is, when detecting the identity of each nucleotide as it is incorporated into the growing strand of DNA in a polymerase reaction. Such a scheme, if coupled to the chip format, has the potential to markedly increase the throughput of sequencing projects. Our laboratory is developing a chip-based 'sequencing by synthesis' platform. This DNA sequencing system includes the construction of a chip with immobilized single stranded DNA templates that can self prime for the generation of the complementary DNA strand in polymerase reaction, and 4 unique fluorescently labeled nucleotide analogues with 3'-OH capped by a small chemical moiety to allow efficient incorporation into the growing strand of DNA as terminators in the polymerase reaction. A 4-color fluorescence imager is then used to identify the sequence of the incorporated nucleotide on each spot of the chip. Upon removing the dye photochemically and the 3'-OH capping group, the polymerase reaction will proceed to incorporate the next nucleotide analogue and detect the next base. It is a routine procedure now to immobilize high density (>10,000 spots per chip) single stranded DNA on a 4cm x 1cm glass chip. Thus, in the chip based DNA sequencing system, more than 10,000 bases will be identified after each cycle and after 100 cycles million of base pairs will be generated from one sequencing chip. Massively parallel DNA sequencing promises to bring genetic analysis to the next level where we can envision, for example, the comparison on individual genome profiles.
New research on the Drosophila melanogaster fruit fly species yields results that support the mutation accumulation (MA) theory of ageing:
The other, more widely accepted theory of antagonistic pleiotrophy (AP) says that aging occurs when genes that offer help during the reproductive years -- those that produce estrogen, for example -- take on harmful roles later in life. Selection under AP theory favors the early life effects because these lead to the production of offspring but does not oppose the deleterious effects in late life, Hughes said. Building on her theoretical study of age-related inbreeding depression and genetic variability (PNAS, June 1996) while a doctoral student at the University of Chicago, Hughes and colleagues raised fruit flies to test the effect of delayed mutations.
The new study found that the deleterious effects of mutations on reproduction rose dramatically with age during the reproductive years in both genotypes -- homozygous (those with many identical genes, or inbreeding) and heterozygous (those having a variety of genes present). Reproductive success declined more rapidly, however, in the homozygous lines, as predicted by the MA theory.
"This study allowed us to detect certain kinds of genetic effects called dominance variance that are predicted to increase with age only under the MA theory," Hughes said. "The power to detect these effects is critical to tests of evolutionary aging theories, because an age-related increase appears to be a unique prediction of the MA theory, while other kinds of genetic effects can increase under either model."
There are other explanations for aging aside from the mutation accumulation (MA) theory. It is likely that aging is caused by an assortment of changes. For instance, cells accumulate trash molecules (eg lipofuscin) that the cells are unable to break down or expel. One way to solve assorted aging problems for cells that can be replaced is to replace them with younger cells. If an organ or reservoir of cells is replaced then all the aging effects for that group of cells are eliminated until the damage accumulates again. However, there are cell types for which it is far more preferable to repair than to replace (eg brain cells). So treatments utilizing both approaches will be developed.
An interesting report in The New Scientist about sea lion memory:
California sea lions may have the best memory of all non-human creatures. A female called Rio that learned a trick involving letters and numbers could still perform it 10 years later - even though she hadn't performed the trick in the intervening period.
Here is an advance in techniques for watching what goes on in cells during viral infection:
This new technology, an imaging method known as in vivo bioluminescence, enables investigators to track changes in the viral population in the same animal day after day. The device is located in the Molecular Imaging Center at the University's Mallinckrodt Institute of Radiology.
"This technology can be used to explore questions about this virus that are possible only by studying entire living animals over time," says Gary D. Luker, M.D., an assistant professor of radiology with the Molecular Imaging Center and first author of the paper.
"This is an excellent example of the unique information and new collaborations that are generated when we examine fundamental biological processes with molecular imaging tools," says David Piwnica-Worms, M.D., Ph.D., professor of radiology and of molecular biology and pharmacology and director of the Molecular Imaging Center.
The investigators first added a gene for luciferase, an enzyme produced by fireflies, to a strain of herpes simplex type 1 virus. After determining that the modified virus behaves in cells like the normal virus, they injected the modified virus into several locations in mice, including the brain and abdominal cavity.
Daily for nine days, the mice were injected with luciferin, a compound also produced by fireflies that emits light when exposed to luciferase. They then were anesthetized, placed in a light-free box and photographed using a charged-coupled device, or CCD camera. The camera captures light emitted through the tissues of the mouse by the actively replicating virus. The image produced by the camera shows the location and amount of virus in a mouse as areas of color, ranging from blue (low levels) to red (high levels), superimposed on a photograph of the anesthetized animal. Light produced by the luciferase-luciferin reaction is known as bioluminescence because it is generated by biological chemicals.
This imaging method enabled the investigators to monitor the infection as it spread and receded over nine days. In a second experiment, mice infected with the modified virus were treated with the antiviral drug valacyclovir. The investigators found that decreases in bioluminescence correlated with the decline in the amount of virus present.
The method works in part because bioluminescence produced by fireflies contains a significant amount of red light, which penetrates tissues more effectively than other wavelengths of light. This effect can be seen by shining a flashlight through a finger; it is red light that penetrates the finger.
Different nanoparticles with affinities to different proteins can be placed into the same cell. Then using different frequency lasers the locations and movements of different proteins can be tracked in the cell. Among the many potential applications for this technology would be more rapid and accurate tissue biopsy and drug delivery:
Because quantum dots are so small, their electrons are compacted, causing them to emit light or to act as a fluorescent tag. Quantum dots can bond chemically to biological molecules, enabling them to trace specific proteins within cells. Nie calls them "bioconjugated nanoparticles" – small particles that are chemically linked to biological materials.
Nanoparticle probes can be used as contrast markers in magnetic resonance imaging (MRI), in positron emission tomography (PET) for in-vivo molecular imaging, or they can be used as fluorescent tracers in optical microscopy. These tags can trace specific proteins in cells for cancer diagnosis or monitor the effectiveness of drug therapy. Because the dots glow with bright, fluorescent colors, scientists hope they will improve the sensitivity of diagnostic tests for molecules that are difficult to detect, such as those in cancer cells, or even the AIDS virus, Nie said.
Update: See this previous article on quantum dots as well.
"The technology could considerably accelerate and reduce the costs of developing and evaluating drug candidates," he said. "On the clinical side, molecular diagnostics are growing in popularity. It's an industry driven by costs and speed. This technology creates new forms of assaying biomedical indications for a lot less money in a lot less time."
Nie, meanwhile, said the technology ultimately may be so effective that it will be used in individualized medicine, or studying, for example, how drugs work in individuals.
Modafinil improves the mental functioning of healthly volunteers:
Danielle Turner, from the Department of Psychiatry at the University of Cambridge, says modafinil could revolutionise current understanding of the way we form and retain memories. It seems to have a unique mechanism of action in the brain.
"In the study, the volunteers given modafinil performed significantly better at neuropsychological tests involving short-term memory and showed less impulsive responding and an increased tendency to reflect on the tasks they were given," she said.
Modafinil provided this benefit without the side effects seen with amphetamines and other drugs:
Sixty healthy young men were tested using touch-sensitive computer screens and easy-to-understand computer games after they were given either a dummy tablet or modafinil.
The ones on modafinil showed improved ability in planning complex problems, recalling longer strings of numbers and remembering abstract patterns.
Modafinil is available as Provigil and is used to treat narcolepsy (uncontrollable sleepiness). Read more about modafinil here and here and also here as Provigil. You can also read an ABC News article on modafinil as well this article which includes mention of military uses for modafinil.
An article in The Globe And Mail written by Shafiq Qaadri surveys the progress in developing a large number of kinds of artificial implants for the human body:
But the next level of integration is bionics (bio-mechanics), in which the body talks to the machine, actually giving the artificial part its cue to function. Dextra is a prosthetic hand, which was developed at Rutgers University, and is one of the first artificial limbs to use a person's own nerves to feed electricity to the machine's fingers.
"Communication is key," says Dr. William Craelius, the biomedical engineer who developed Dextra. "Human-machine communication could soon lose its distinction as the No. 1 obstacle to bionics." With a seamless human-to-device connection, Dextra patients have such natural control that they can type and play the piano.
With the development of synthetic muscle, entire joints need not be replaced, but select muscles can be restored.
So far, scientists at the Artificial Muscle Research Institute at the University of New Mexico hope to help people who have lost muscle function. But as the technology progresses, researchers could also reinforce existing muscles, perhaps inserting muscles into new locations, leading to entirely new movements and power.
This is an intermediate stage technique that will be used until it becomes possible to grow new replacement ovaries:
Collecting ovary tissue from rare animals and growing eggs in other species "could help preserve genetic diversity within endangered species," says one of the researchers, Shae-Lee Cox of Monash University in Clayton,Victoria. It could also speed up livestock breeding, help the study of egg development in exotic species, and even preserve fertility in cancer patients.
Cox and her colleagues grafted sections of mouse ovaries onto rat kidneys. The rats had their immune systems suppressed and so did not reject the tissue. The scientists collected eggs from the ovaries, fertilized them and then implanted the resulting embryos into a surrogate mouse.
Five healthy pups were born from 31 different transplants. All five mice were fertile and went on to produce their own healthy pups.
Why, when thinking about technology, does Martin Hoffert think that 50 years is not a long time?
There is no current alternative to fossil fuels that would maintain world economic growth while generating fewer environmental toxins, the team found.
"We don't have those energy sources off the shelf right now, but we have some time to develop them," the report's lead author, Martin Hoffert, a professor of physics at New York University in New York City, told United Press International.
"We have about 50 years. However, 50 years is not a long time."
Given the rate at which biotech and electronics tech are advancing the next 50 years is an extremely long time for technological advances. 50 years from now we will have computers that are many orders of magnitude faster than the computers of today. Those computers will be able to simulate all manner of physical processes and simulation experiments will turn out all sorts of ways to make photovoltaic cells, fuel cells, materials for wind catching propellers for wind power, and for countless other energy-related technologies. We will have complete control of DNA and will be able to make new species of plants and single cell organisms that would make for better biomass energy generators. As an example of where future biotech advances can make a big difference consider how gene tweaking will allow improvements on the already promising prospects for using algae to generate hydrogen fuel:
The breakthrough, Melis said, was discovering what he calls a "molecular switch." This is a process by which the cell's usual photosynthetic apparatus can be turned off at will, and the cell can be directed to use stored energy with hydrogen as the byproduct. "The switch is actually very simple to activate," Melis said. "It depends on the absence of an essential element, sulfur, from the micro alga growth medium." The absence of sulfur stops photosynthesis and thus halts the cell's internal production of oxygen. Without oxygen from any source, the anaerobic cells are not able to burn stored fuel in the usual way, through metabolic respiration. In order to survive, they are forced to activate the alternative metabolic pathway, which generates the hydrogen and may be universal in many types of algae. "They're utilizing stored compounds and bleeding hydrogen just to survive," Melis said. "It's probably an ancient strategy that the organism developed to live in sulfur-poor anaerobic conditions." He said the alga culture couldn’t live forever when it is switched over to hydrogen production, but that it can manage for a considerable period of time without negative effects.
The folks at Melis Energy are working to improve the yields of naturally occurring algae. But imagine what bioengineering of the DNA of algae will make possible to accomplish in 10 or 20 years. Algae will be optimizeable for energy generation tasks. Also, nanotechnological advances will allow fabrication of materials we can only dream about today. The onus to justify their pessimistic viewpoints belongs on the people who do not believe that photovoltaics, fuel cells, and biomass will be cost effective in 30 or 40 years.
Why is it that some people think that only a large scale international coordination of efforts by governments can solve large scale problems?
"What our research clearly shows is that scientific innovation can only reverse this trend if we adopt an aggressive, global strategy for developing alternative fuel sources that can produce up to three times the amount of power we use today," New York University physicist Martin Hoffert said.
Scientific innovations will reverse the trend even if governments do not get involved in funding alternative energy research. Could government money accelerate the process? Only if the government restricts its involvement to basic research and if it stays clear of picking particular technologies to be winners. If it picks the wrong ones and that intimidates private funders from pursuing competitors it is even possible that government involvement could slow the rate of progress. But the development of new energy sources is a process that is going to happen anyhow.
They drag out the proposal to build solar arrays in space to then beam energy down here.
Is it feasible to replace fossil fuels with cleaner sources of energy? A new study concludes that it could be done with enough “political will” and what the lead researcher described as a global effort pursued with the same urgency as the Apollo space program. Europe is showing that will, recently embarking on a massive investment program in hydrogen and fuel cells. But the researchers didn’t see a similar push in the United States.
For space enthusiasts that is a fun proposal. But wouldn't it make more sense to spend a small fraction of that amount ot money to just develop processes that will lower the cost of making solar panels?
Policy discussions ought to be restricted to how much to give university basic researchers to work on basic related science problems.
Joel Darmstadter, an energy researcher at Resources for the Future, an energy think tank, said the study by Hoffert and others is a useful review of the technical status of the world's alternate energy systems. The study, he said, could prompt policy discussions because it gives an evaluation of what is possible to replace fossil fuels.
But Darmstadter said the study failed to draw a clear picture of which of the alternative systems should have the highest priority and bases some of the discussion on ``far out and highly speculative'' technologies, such as the power satellite.
If governments wanted to increase funding to basic physics and chemistry reseachers who are trying to understand the qualities of photovoltaic materials then I think the rate of advance could be accelerated. Ditto for scientists who are investigatng how to do nanotech manipulations with materials or biological scientists who are studying how chloroplasts do photosynthesis. But if governments fund production line construction or other types of decisions that are best left to business then I have serious doubts about the ability of governments to increase the rate of progress.
You can find my previous energy technology posts here.
It seems likely that the same holds true for humans as well:
Researchers at Jefferson Medical College have evidence in animals that the young, adolescent brain may be more sensitive to addictive drugs such as cocaine and amphetamines than either the adult or newborn. The work may help someday lead to a better understanding of how the adolescent human brain adapts to such drugs, and provide clues into changes in the brain that occur during drug addiction.
Scientists led by Michelle Ehrlich, M.D., professor of neurology at Jefferson Medical College of Thomas Jefferson University in Philadelphia and a member of the Farber Institute for Neurosciences at Jefferson, and Ellen Unterwald, Ph.D., associate professor of pharmacology at the Temple University School of Medicine in Philadelphia, found a greater increase in a certain protein in the part of the adolescent mouse brain called the striatum following chronic exposure to drugs such as amphetamine or cocaine than they did in either very young mice or adults.
Such psychostimulant drugs affect the brain’s striatum in different ways, potentially affecting both movement and locomotion, or the “reward” system. This “molecular adaptation,” says Dr. Ehrlich, could be significant. “An increase in this protein may be important because it could also affect other molecules that could lead to long-lasting changes in the brain in response to psychostimulant drugs.” The protein, called Delta FosB, is a transcription factor and plays a role in regulating gene expression. Earlier research by other scientists had shown increased amounts of Delta FosB in adult brains following chronic exposure to psychostimulants.
The team, which includes scientists at the Nathan Kline Institute in Orangeburg, New York, reports its findings November 1 in the Journal of Neuroscience.
The compound delta opioid peptide is used in squirrels to induce stroke but it also is made in human nerves in response to stroke and larger doses administered therapeutically may reduce stroke damange and provide protection against other neural disorders:
In an animal model for stroke, delta opioid peptide reduced by as much as 75 percent the damage to the brain’s striatum, the deeper region of the brain and a major target for strokes, according to Dr. Cesario V. Borlongan, neuroscientist.
In fact, evidence suggests that the compound, which puts cells in a temporary state of suspended animation, may help protect brain cells from the ravages of Parkinson’s disease as well.
“When the animals were introduced to an experimental stroke, then injected with delta opioid peptide, we could see a reduction in the damage done by stroke; brain damage is reduced and the neurological deficits associated with stroke are definitely reduced,” Dr. Borlongan said.
This compound may even be useful in slowing the aging process and protecting ogans while waiting to transplant them:
The researcher believes this cell hibernation may have other roles as well, including slowing the aging process. Its potential for helping donated livers, hearts and kidneys remain viable longer until they are transplanted already is being explored by others in clinical trials.
Researchers Dr. Michael Soules, Dr. Nancy Klein, Dr. Angela Thyer are leading a project at the University Of Washington Fertility and Endocrine Center to develop a technique that within 3 years may allow prediction of how many years of fertility a woman has left:
After puberty, some of these eggs begin to grow and move toward the center of the ovary. The layers of cells that surround these eggs also grow, secreting a liquid as they do. And in that liquid lie the hopes of the project.
The growing egg and surrounding cells are known as antral follicles, and the UW researchers believe there is a correlation between the number of them at any given time and the total number of eggs in the ovary. The more antral follicles, the more eggs remaining. What makes this so important is that the liquid in antral follicles shows up on sonograms.
Soon, doctors may be able to tell a woman how many eggs she has with a simple ultrasound.
The team wants to count another 100 or so ovaries before it draws any conclusions, but the researchers believe that a normal, fertile woman has between 20 and 25 antral follicles at any time. Women with 10 or fewer will have a hard time conceiving.
By sandwiching tiny but super-tough carbon nanotubes between layers of polymer, researchers have created a revolutionary material that is six times stronger than conventional carbon-fibre composites and as hard as some ultrahard ceramic materials used in engineering.
An international team led by Nicholas Kotov of Oklahoma State University in Stillwater say their new material could be used in space engineering or for long-lasting medical implants.
Highly customized application-specific nanotube creation:
WEST LAFAYETTE, Ind. — Using a more complex system of atoms than carbon nanotubes, scientists at Purdue University have devised a tunable approach to nanotube creation that allows them to build application-specific varieties. Called "rosette nanotubes" and built from a combination of carbon, nitrogen, hydrogen and oxygen, the new structures offer unique physical, chemical and electrical properties, the researchers said.
Duke University researchers may have found a way to fabricate nanotubes with enough consistency for use as electronic circuitry: (same artlcle also here as well)
DURHAM, N.C. -- Duke University chemists report they have made a significant advance toward producing tiny hollow tubes of carbon atoms, called "nanotubes," with electronic properties reliable enough to use in molecular-sized circuits.
In a report posted Oct. 28, 2002, in the online version of the Journal of the American Chemical Society, the Duke group described a method to synthesize starting catalytic "nanocluster" particles of identical size that, in turn, can foster the growth of carbon nanotubes that vary in size far less than those produced previously.
"This is really a first step toward a big future," said Jie Liu, a Duke associate professor of chemistry and the group's leader, of the unprecedented nanotube uniformity they achieved using this process.
Sometimes called "buckytubes," carbon nanotubes' properties were first studied by Japanese researchers in the early 1990s. The nanotubes, measuring just billionths of a meter in diameter (nano means "billionths"), were found to be lightweight but exceptionally strong, with unusual electronic properties.
Depending upon their atomic arrangements, nanotubes can act like conducting metals or like semiconductors, Liu said.
Since microelectronic devices such as computer chips use both semiconductors and metals, researchers foresee nanotubes as the building blocks for even smaller electronic circuitry than the millionths-of-a-meter scale resolutions of today's microchips.
However, "controlling the electronic properties of the nanotubes is becoming the biggest bottleneck that limits the development of nanotube research," Liu said in an interview.
The control problem arises because those electronic properties vary with the way nanotubes' atoms are arranged. And how their atoms are arranged is directly tied to the nanotubes' diameters -- which, until the fabrication advance by Liu and his colleagues, could vary considerably.
Penn and Lindley believe it is possible to design a paraffin-powered rocket engine that would require very little maintenance and that the rocket would be reusable for tens of thousands of flights. The articles that are reporting their claim provide no indication of why they believe this. The first stage would fly itself back to Earth for refueling:
But Jay Penn and Charles Lindley, from the Aerospace Corporation in California believe a ticket into orbit could come substantially down in price.
They say that by using a two-part craft, space travel would become much cheaper.
They think this could be done in fairly short order:
In a forthcoming paper in the journal Acta Astronautica, Penn and Lindley say the reusable system will allow the number of flights to be stepped up dramatically to around 9500 a year, compared with the current 10 or so shuttle launches.
The fleet and infrastructure would take about seven years to develop, and could start to turn in a profit after only six years of flights (see chart).
This scheme would rely on an orbital space tourist hotel:
In the first stage, a small fat rocket with wings would carry the smaller second stage winged rocket to the edge of space.
The second rocket would then fire up its own engines to carry it to a station orbiting the earth. Here it would unload passengers and fill up with returning tourists, while the first rocket glided back to earth ready for another launch.