- Space-Based Solar Power Coming to California in 2016
- Scorpion venom with nanoparticles slows spread of brain cancer
- Researchers use brain interface to post to Twitter (w/Video)
- Stem cells free diabetics from insulin treatment
- One Sponge-Like Material, Three Different Applications
- The story of X -- evolution of a sex chromosome
- Transformers: Protecting pedestrians from killer cars
Space-Based Solar Power Coming to California in 2016April 15th, 2009 by Lisa Zyga
Solaren Corp., a solar power start-up, has convinced Pacific Gas & Electric (PG&E), California's largest utility company, to purchase 200 megawatts of electricity when its system is in place, which is expected to be 2016. According to Solaren, the system could generate 1.2 to 4.8 gigawatts of power at a price comparable to that of other renewable energy sources.
In Solaren's proposal, solar power satellites would be positioned in stationary orbit about 22,000 miles above the equator. The satellites - whose arrays of mirrors could be several miles across - would collect the sun's rays on photoelectric cells and convert them into radio waves. The radio waves would then be beamed to a receiving station on the ground, where they would be converted into electricity and delivered to PG&E's power grid. Because the radio beam is spread out over a wide area, it would not be dangerous to people, airplanes, or wildlife.
The plan requires a large area of land to host the ground receiving station's antenna array, and several square miles of scrubland in western Fresno County could provide an ideal location. In addition to being sparsely populated, the region is also near transmission lines and a load center. While many of today's land-based solar stations are located far out in the desert, a station closer to customers could offer greater convenience and economic advantages.
Gary Spirnak, CEO of Solaren Corp. and a former aerospace engineer, noted that the project will cost more than $2 billion, mostly going toward engineering development and building of the ground station, as well as launching four or five satellites. So far, Solaren has raised an undisclosed sum from private investors.
Solaren's project is not the only space-based solar system in the works; Japan's space agency, JAXA, has recently begun testing a space-based solar array that beams energy to Earth in the form of microwaves. If the tests are successful, the agency plans to launch an array of satellites that would transmit power to a 1.8-mile-wide receiving station, which would generate enough electricity to power about half a million homes. source
My comment: Hm, I don't think microwaves are good for beaming down to Earth. Their effect on humans is way too...questionable. But radio waves are ok, I guess. In any case, those projects are stunningly cool, because they definitely leave a sense of science fiction in me. And it's totally harmless (or could be done to be so) to the Earth-unlike the big solar plants in the deserts that have to sacrifice life there for electricity. Not to mention that if the radio emission passes the efficiency test, it could be used for wireless electricity! Cool, huh?
Scorpion venom with nanoparticles slows spread of brain cancerApril 16th, 2009
By combining nanoparticles with a scorpion venom compound already being investigated for treating brain cancer, University of Washington researchers found they could cut the spread of cancerous cells by 98 percent, compared to 45 percent for the scorpion venom alone.
For more than a decade scientists have looked at using chlorotoxin, a small peptide isolated from scorpion venom, to target and treat cancer cells.
Chlorotoxin binds to a surface protein overexpressed by many types of tumors, including brain cancer. Previous research by Zhang's group combined chlorotoxin with nanometer-scale particles of iron oxide, which fluoresce at that size, for both magnetic resonance and optical imaging.
Chlorotoxin also disrupts the spread of invasive tumors - specifically, it slows cell invasion, the ability of the cancerous cell to penetrate the protective matrix surrounding the cell and travel to a different area of the body to start a new cancer. The MMP-2 on the cell's surface, which is the binding site for chlorotoxin, is hyperactive in highly invasive tumors such as brain cancer. Researchers believe MMP-2 helps the cancerous cell break through the protective matrix to invade new regions of the body. But when chlorotoxin binds to MMP-2, both get drawn into the cancerous cell.
Other researchers are currently conducting human trials using chlorotoxin to slow cancer's spread.Zhang's group investigated chlorotoxin action when it is attached to nanoparticles and found the resultant complex doubles the therapy's effect compared to chlorotoxin alone. Adding nanoparticles often improves a therapy, partly because the combination lasts longer in the body and so has a better chance of reaching the tumor. Combining also boosts the effect because therapeutic molecules clump around each nanoparticle. In the newly published study an average of 10 chlorotoxin molecules were attached to each nanoparticle. Each clump thus offers many therapeutic molecules that can simultaneously latch on to many MMP-2 proteins.
Experiments were performed using mouse brain-cancer cells that were grown in the lab. The imaging results confirm that adding nanoparticles means more of the MMP-2 ends up safely tucked away inside the cell, thus preventing MMP-2 from helping the cancer spread.
Further images showed that the cells containing nanoparticles plus chlorotoxin were unable to elongate, whereas cells containing only nanoparticles or only chlorotoxin could stretch out. This suggests that the nanoparticle-plus-chlorotoxin disabled the machinery on the cell's surface that allows cells to change shape, yet another step required for a tumor cell to slip through the body. source
My comment: Nice, but we have the same problem-after the treatment is done, what happens with those nanoparticles. Because they cannot obviously be left hanging in the body just like that. Not without a clear knowledge how they would affect that body later.
Researchers use brain interface to post to Twitter (w/Video)April 20th, 2009
(PhysOrg.com) -- In early April, Adam Wilson posted a status update on the social networking Web site Twitter -- just by thinking about it.
Just 23 characters long, his message, "using EEG to send tweet," demonstrates a natural, manageable way in which "locked-in" patients can couple brain-computer interface technologies with modern communication tools.
A University of Wisconsin-Madison biomedical engineering doctoral student, Wilson is among a growing group of researchers worldwide who aim to perfect a communication system for users whose bodies do not work, but whose brains function normally. Among those are people who have amyotrophic lateral sclerosis (ALS), brain-stem stroke or high spinal cord injury.Some brain-computer interface systems employ an electrode-studded cap wired to a computer. The electrodes detect electrical signals in the brain — essentially, thoughts — and translate them into physical actions, such as a cursor motion on a computer screen.
In collaboration with research scientist Gerwin Schalk and colleagues at the Wadsworth Center in Albany, N.Y., Williams and Wilson began developing a simple, elegant communication interface based on brain activity related to changes in an object on screen.
The interface consists, essentially, of a keyboard displayed on a computer screen. "The way this works is that all the letters come up, and each one of them flashes individually," says Williams. "And what your brain does is, if you're looking at the 'R' on the screen and all the other letters are flashing, nothing happens. But when the 'R' flashes, your brain says, 'Hey, wait a minute. Something's different about what I was just paying attention to.' And you see a momentary change in brain activity."Wilson, who used the interface to post the Twitter update, likens it to texting on a cell phone. "You have to press a button four times to get the character you want," he says of texting. "So this is kind of a slow process at first."
However, as with texting, users improve as they practice using the interface. "I've seen people do up to eight characters per minute," says Wilson.
While widespread implementation of brain-computer interface technologies is still years down the road, Wadsworth Center researchers, as well as those at the University of Tübingen in Germany, are starting in-home trials of the equipment. Wilson, who will finish his Ph.D. soon and begin postdoctoral research at Wadsworth, plans to include Twitter in the trials. source
My comment: That's very fun. I don't like Twitter at all, even texting is better than it, but what the hell. The most important thing is that they are moving in very correct direction. If they can develop T9 for brain-twitter, that would be a great improvement. I still have no idea how to use T9, maybe because it's not working in Bulgarian anyway, but if all the phones have it, it probably serves some purpose.
Stem cells free diabetics from insulin treatment
- 15:21 14 April 2009 by Andy Coghlan
A controversial stem cell treatment tested in Brazil has freed patients with type-1 diabetes from dependence on insulin. Since the treatment some patients have been able to stop from injecting the drug for years.
The treatment is designed to stop the immune systems of patients with type-1 diabetes from mistakenly destroying the pancreatic islet cells which manufacture insulin, the hormone that keeps blood sugar levels in check.
The latest results, which include updates on the original 15 patients and data from a further eight, suggest the treatment may indeed work as proposed. Demonstrating that most patients had elevated blood concentrations of C-peptide, a breakdown product of insulin production, Burt says is a clear sign that the patients were making insulin themselves.
In some patients, the levels of C-peptide trebled, reaching a peak about two to three years after treatment compared with beforehand.
Developed mainly by Burt's colleague Júlio Voltarelli of the Regional Blood Center in Ribeirão Preto, Brazil, the treatment relies on extracting and storing CD34 stem cells from the blood of patients. These stem cells can grow into all white blood cells of the immune system.
In the next step, patients receive drugs that destroy what remains of their immune systems, obliterating at the same time the components of the immune system that attack the islets.
Finally, the saved stems are returned to the patient so that they can regenerate afresh an immune system that will no longer attack islet cells.
The latest results appear to show that in the 20 patients benefiting from the treatment, their blood contained elevated levels of C-peptide, proving that the patients were making insulin themselves.
Even the eight patients who relapsed have been on lower doses of insulin than beforehand, and still have higher levels of C-peptide, suggesting that their islet cells have benefitted from the treatment. Two became insulin-independent again after receiving the sugar-lowering drug, sitagliptin.
The treatment didn't work in three patients, and nine men later suffered from low sperm counts. Another two suffered from pneumonia. None of the patients died.
Burt says that a larger trial is now planned to take place both in Brazil and in the US. This time, it will randomised so that some of the patients receive placebo.
A similar procedure developed by Burt has already shown some success in another autoimmune disease, multiple sclerosis. Results published in January showed that many patients benefitted, again, through reprogramming of their immune systems, this time to stop it from attacking nerve and brain cells. source
My comment: I'm absolutely impressed. Even if destroying the whole immune system is somewhat bold action, I still find it simply amazing how far scientists are gone. And if I understand correctly, if we have such stem sells isolated, even patients with killed immune systems could restore it. Well, that's so cool! I wish them so much luck, because my grandma had diabetes and it's horrible!
One Sponge-Like Material, Three Different ApplicationsMay 26th, 2009
(PhysOrg.com) -- A new sponge-like material that is black, brittle and freeze-dried (just like the ice cream astronauts eat) can pull off some pretty impressive feats. Designed by Northwestern University chemists, it can remove mercury from polluted water, easily separate hydrogen from other gases and, perhaps most impressive of all, is a more effective catalyst than the one currently used to pull sulfur out of crude oil.
Hydrodesulfurization might be a mouthful, but it is also a widely used catalytic chemical process that removes sulfur from natural gas and refined petroleum products, such as gasoline and diesel and jet fuels. Without the process, which is highly optimized, we’d be burning sulfur, which contributes to acid rain.
Scientists have tried to improve hydrodesulfurization, or HDS, but have made no progress. The Northwestern researchers, in collaboration with colleagues at Western Washington University, report that their material is twice as active as the conventional catalyst used in HDS while at the same time being made of the same parts.
The material, cobalt-molybdenum-sulfur, is a new class of chalcogels, a family of material discovered only a few years ago at Northwestern. (Chalcogels are random networks of metal-sulfur atoms with very high surface areas.) The new chalcogel is made from common elements, is stable when exposed to air or water and can be used as a powder.
Mercouri G. Kanatzidis, the paper’s senior author says “In principle, our catalyst could process and desulphurize twice as much crude oil as the same amount of conventional catalyst. We currently are conducting studies to see how the catalyst operates under more commercial conditions.”The Northwestern material is a gel made of cobalt, nickel, molybdenum and sulfur that then is freeze-dried, producing a sponge-like material with a very high surface area. (One cubic centimeter has approximately 10,000 square feet of surface area, or about half a football field.) It is this high surface area and the material’s stability under catalytic conditions that make the cobalt-molybdenum-sulfur chalcogel so active.
The researchers also demonstrated that the new chalcogel soaks up toxic heavy metals from polluted water like no other material. The chalcogel removed nearly 99 percent of the mercury from contaminated water containing several parts per million. Mercury likes to bind to sulfur, and the chalcogel is full of sulfur atoms.
Two years ago, Kanatzidis and Bag reported a chalcogel that could remove mercury from liquid, but the chalcogel contained expensive platinum; the new chalcogel contains only inexpensive elements, with cobalt and nickel replacing the platinum. The cobalt and nickel link through the sulfur atoms of the thiomolybdate anions to create a three-dimensional porous network.
In addition to being a better HDS catalyst and a mercury sponge, the chalcogel also is very effective at gas separation. The researchers showed that the material easily removes carbon dioxide from hydrogen, an application that could be useful in the hydrogen economy.
The gas separation process takes advantage of the ‘soft’ sulfur atoms of the chalcogel’s surface. These atoms like to interact with other soft molecules passing by, slowing them down as they pass through. Hydrogen, the smallest element, is a ‘hard’ molecule. It zips right through while softer molecules like carbon dioxide take more time. source
My comment: Awesome! I so love sponge materials. But I must admit that it sounds to be true. Not that I care so much about oil/gas production, but cleaning up waters and making hydrogen is well worthy.
The story of X -- evolution of a sex chromosomeApril 16th, 2009 By Robert Sanders
(PhysOrg.com) -- Move over, Y chromosome - it's time X got some attention. In the first evolutionary study of the chromosome associated with being female, University of California, Berkeley, biologist Doris Bachtrog and her colleagues show that the history of the X chromosome is every bit as interesting as the much-studied, male-determining Y chromosome, and offers important clues to the origins and benefits of sexual reproduction.
"Contrary to the traditional view of being a passive player, the X chromosome has a very active role in the evolutionary process of sex chromosome differentiation," said Bachtrog, an assistant professor of integrative biology and a member of UC Berkeley's Center for Theoretical Evolutionary Genomics.
But in life forms that do set aside a pair of chromosomes to specify sex - from fruit flies to mammals and some plants - the two X chromosomes inherited by females look nearly identical to the other non-sex chromosomes, so-called autosomes, Bachtrog said. The Y chromosome, however, which is inherited by males in concert with one X chromosome, is a withered version of the X, having lost many genes since it stopped recombining with the X chromosome.In mammals, that probably took place about 150 million years ago, while in the fruit fly Drosophila melanogaster, a laboratory favorite, the sex chromosomes arose independently about 100 million years ago. In both humans and fruit flies, the Y chromosome has dwindled from a few thousand genes to a few dozen.
Hence the intense interest in why and how the Y chromosome lost genes once it stopped interacting with the X. Scientists have found that, as the only chromosome pair that doesn't break and recombine every time a cell divides, the XY pair in males is unable to take advantage of the main way deleterious genetic mutations are eliminated. The XX pair in females does recombine, but for the Y, the only way to get rid of a bad mutation in a gene is to inactivate or delete the entire gene. Over millions of years, inactive genes are lost, and the Y shrinks.
"If you have no recombination, natural selection is less effective at removing detrimental genes," said Bachtrog. "Y is an asexual chromosome, and it pays a price for that: It keeps losing genes."
Bachtrog, whose career has revolved mostly around the study of the degeneration of the Y chromosome, decided to focus on the X chromosome several years ago and went about searching for sex chromosome pairs that have arisen more recently - and thus might be in the process of adapting to their new role. Her paper centers around study of the three sex chromosomes in a rare western fruit fly, Drosophila miranda, a darker-colored cousin of D. melanogaster. (Many creatures have more than one pair of sex chromosomes; the platypus, for example, has five pairs, all inherited together.)
While one of D. miranda's sex chromosomes is descended from the original sex chromosome that appeared in Drosophila nearly 100 million years ago, a second originated perhaps 10 million years ago, and the third about a million years ago. The older two look much alike, Bachtrog said: The Y chromosome in each pair has lost genes to become a shadow of its former self, while the two X chromosomes are indistinguishable from each other.
The third and youngest sex chromosome is different. The Y is not yet shriveled, though it contains many non-functional genes - about half the total - that will eventually be lost. The X, which is dubbed neo-X, is undergoing rapid change, however, with about 10 times the normal amount of adaptation seen in the autosomes, according to the researchers.
By adaptation, Bachtrog means that the gene sequences in the X chromosome are becoming fixed as random mutations have finally settled on a few beneficial changes that accommodate the increasingly irrelevant Y chromosome. Between 10 and 15 percent of neo-X genes show adaptation, compared to only 1-3 percent of autosome genes.
"In hindsight, that is not surprising," Bachtrog said. "Neo-X is facing a much more challenging situation than the autosomes because its pair, the Y chromosome, is degenerating. Its genes are no longer producing proteins, so neo-X has to compensate by up-regulating its genes. We find a lot of genes on the X chromosome are involved in dosage compensation."
In humans, for example, all genes on the X chromosome are twice as active to account for the lack of genes on the Y. Women accommodate this by inactivating one entire X chromosome so as not to produce too much protein, Bachtrog said.
Another change in neo-X that Bachtrog suspects is taking place is the elimination of genes that are harmful to females. Biologists have realized recently that some genes have opposite effects in males and females, and evolution is a tug of war between males jettisoning genes that they find detrimental only to have females put them back, and vice versa. source
Transformers: Protecting pedestrians from killer cars
- 15 April 2009 by Nic Fleming
While vehicle drivers and their passengers are cocooned in a crash, people hit by a car have no such protection. Now that could change, thanks to a variety of systems that when built into a vehicle will improve a pedestrian's chances.
A Europe-wide collaboration led by Roger Hardy of the Cranfield Impact Centre at Cranfield University near Bedford in the UK has developed an experimental system for cars that aims to cut this death toll and reduce the severity of injuries. When the system detects that the car is about to hit a pedestrian, it automatically raises the rear of the bonnet (hood), releasing a giant airbag in front of the windscreen.
The raised bonnet absorbs some of the energy of the impact, reducing the risk of serious injury to the pedestrian, says Hardy, whose project forms part of the European Union-funded APROSYS.
The airbag system used by Hardy was developed by the German company Takata Petri. To test its efficacy when combined with the raised bonnet, they were incorporated into a prototype Fiat Stilo by engineers at the Fiat Research Centre in Turin, Italy.
A standard Stilo hitting a pedestrian at 40 kilometres per hour, so that their heads struck the back of the bonnet, would have a score of around 1000 on the Head Impact Criterion (HIC) scale - corresponding to an 18 per cent chance of a life-threatening injury. For pedestrians hitting Hardy's bonnet, the scores were reduced to between 234 and 682, while the windscreen airbag scores ranged from 692 to 945.
Hardy's team has also helped to design a windscreen-mounting system to cushion impacts with the edge of the windscreen. This consists of a flexible Z-shaped section of metal, up to 15 millimetres wide, separating the windscreen from its frame so that it can flex inwards to absorb energy in a collision. The team say it could reduce HIC scores by more than 50 per cent.
Another APROSYS collaboration, led by Jürgen Gugler at Graz University of Technology in Austria, studied how changing the shape of the front of a truck could reduce harm to pedestrians. Computer simulations of 20 accident scenarios showed that a smooth sloping surface with a central bulge reduces the likelihood of a pedestrian involved in a front-end accident being run over by 80 to 90 per cent.
Fiat researchers led by Roberto Puppini have also had some success in early tests of an adaptive bumper system. Four gas springs kick in at speeds between 4 and 80 kilometres per hour to move the bumper forward so that it will absorb energy in an impact. source