Archive for the ‘science’ Category

OK, here’s an opportunity for organlegging

December 13, 2008

BBC NEWS | Health | Windpipe transplant breakthrough

To make the new airway, the doctors took a donor windpipe, or trachea, from a patient who had recently died.
Then they used strong chemicals and enzymes to wash away all of the cells from the donor trachea, leaving only a tissue scaffold made of the fibrous protein collagen.

This gave them a structure to repopulate with cells from Ms Castillo herself, which could then be used in an operation to repair her damaged left bronchus – a branch of the windpipe.

How windpipe transplant works

By using Ms Castillo’s own cells the doctors were able to trick her body into thinking the donated trachea was part of it, thus avoiding rejection.

Two types of cell were taken from Ms Castillo: cells lining her windpipe, and adult stem cells – very immature cells from the bone marrow – which could be encouraged to grow into the cells that normally surround the windpipe.

After four days of growth in the lab in a special rotating bioreactor, the newly-coated donor windpipe was ready to be transplanted into Ms Castillo.

I think this is really cool, because there’s a huge list of semi-structural stuff in the body that could use a similar technique if it works. Might take a little longer to do the regrowth part, but templates is templates…


Memristors at work

December 6, 2008

Technology Review: Memristors Make Chips Cheaper

“Because memristors are made of the same materials used in normal integrated circuits,” says Williams, “it turns out to be very easy to integrate them with transistors.” His team, which includes HP researcher Qiangfei Xia, built a field-programmable gate array (FPGA) using a new design that includes memristors made of the semiconductor titanium dioxide and far fewer transistors than normal.
“When you decide what logic operation you want to do, you actually flip a bunch of switches and configuration bits in the circuit,” says Williams. In the new chip, these tasks are performed by memristors. “What we’re looking at is essentially pulling out all of the configuration bits and all of the transistor switches,” he says.

According to Williams, using memristors in FPGAs could help significantly lower costs. “If our ideas work out, this type of FPGA will completely change the balance,” he says.

FPGAs aren’t the only thing, but an FPGA comparable in price to a normal chip would change a lot of things.

Also: memristor symposium

Green Mars

December 4, 2008

NASA – NASA Spacecraft Detects Buried Glaciers on Mars

“Altogether, these glaciers almost certainly represent the largest reservoir of water ice on Mars that is not in the polar caps,” said John W. Holt of the University of Texas at Austin, who is lead author of the report. “Just one of the features we examined is three times larger than the city of Los Angeles and up to one-half-mile thick. And there are many more. In addition to their scientific value, they could be a source of water to support future exploration of Mars.”

In geological terms, a few thousand cubic kilometers of water is nothing — it’s the contents of a couple middling lakes. But if one wanted to use the stuff, that’s a few quadrillion liters. Without recycling, enough to supply the current consumption of New York City for a million years or so. Gosh.

Of course if it’s exposed to martian atmosphere it all goes away in relatively short order, but still.

If this works for the cochlea, what about other nerves?

December 1, 2008

BBC NEWS | Health | Light-wave implant hope for deaf

Surgeons who used lasers to perform a surgical procedure in the ear discovered that they were able to stimulate the nerve cells there to send an electrical message back to the brain.

Exactly why this happens is unclear, although Dr Richter believes that the heat that accompanies the light may be responsible.

However, the narrow beam possible using light rather than an electrode offers the possibility of a far more precise targeting of these neurons.

He shone infrared light into the neurons of deaf guinea pigs, while measuring electrical activity in a nerve “relay” between the inner ear and the brain.

This seems like a nice result, and kinda to have been expected. But also possibly rather difficult to exploit. We have lots of nice nonmechanical ways of varying the frequency, and amplitude of laser beams, but not so much the direction. Although you could probably just fabricate an array of little IR lasers and be done with it…


November 12, 2008

UAVs: Unmanned Helicopter Flies Low, Dodges Obstacles With 3D Laser Camera

Once loaded with preexisting topographical data, the sighted UAV is able to hug the ground at altitudes of 5m, fly around obstacles with just 3m of clearance and sense oncoming obstructions as small as 6mm.

Though the ability to hover at extremely low altitudes has some obvious military applications, the fact that drones may now be able to dodge unanticipated barriers could help UAVs fly in civilian airspace, something which regulatory authorities in this country don’t traditionally allow unless they have a reasonable guarantee against the surprise pulping of unsuspecting bystanders.

Make one of these a little quieter, or assist it with a small blimp, and every news organization and paprazzo in the world will want a dozen.

800-mile electric cars

November 11, 2008

Laptops: New Laptop Batteries to Last 8 Times Longer Than Current Crop

Researchers at Hanyang University in South Korea have developed new Lithium batteries that can last a whopping eight times longer than today’s models. They’ve achieved this by using cathode materials in the batteries, replacing less-efficient graphite with more-efficient silicon.

A quick search on Jaephil Cho, the guy who’s been leading the research, suggests he may well know what’s he’s talking about.

From the horse’s mouth: Wiley InterScience :: JOURNALS :: Angewandte Chemie International Edition

Complete etching of the SiO2 from the SiO2/carbon-coated Si (c-Si) composite results in the retention of the remaining c-Si as a highly porous but interconnected structure, which preserves the starting morphology.

Which is a fancy way of saying you can use fairly simple techniques to get porous silicon particles that you then fill up with lithium/electrolyte. Much easier than the nanowire growth some of his earlier papers were based on (although with less ultimate capacity).

Whee! Of course this is as far from realization as any number of other superduper battery technologies, but it kinda gives us something to shoot for. An electric car with current-sized battery packs and a range as far as anyone might drive in a day would be cool. Or laptops that run for a full workday. Or think of cellphones and pocket gizmos with the same running times as they have now, but where the battery is 1/8 the size — essentially negligible.

You could change the face of the planet for 1 percent of the wall street bailout…

Annals of bad study conclusions

November 10, 2008

BBC NEWS | Health | Surgery beneficial in heartburn

A year after keyhole surgery, only 14% of patients were still taking medication, compared with 90% of those treated with drugs alone.

The £1m trial of 800 patients suggests surgery should be done more routinely in patients with chronic acid reflux.

The results so far suggest the procedure, although expensive at £2000 per patient, is cost-effective because reflux sufferers no longer have to take medication and their quality of life improves.

But they are following the patients for five years to check the benefits are long-term.

Professor Roger Jones, head of general practice at King’s College London and chair of the Primary Care Gastroenterology Society said surgery was often regarded as “too extreme” for something which is not a serious problem.

“But for some people, it is a serious problem which could potentially mean a lifetime of tablet taking.”

Let’s review: the operation costs $4000, plus recovery time, plus risk of complications. For this, we get only 14% of patients still taking acid blockers at the end of a year. Those same pills cost 50 cents to a a dollar a day, and 90% of patients will be taking those at the end of a year.

So for the first year our expected costs for a thousand patients treated with surgery are about $4,040,000. For a thousand patients treated with drugs, about $330,000. Obviously a lot depends on longterm results — how many of the patients taking pills at the end of a year will continue to need them indefinitely? how many of the patients who don’t need pills after surgery will come to need them in the future? But a first cut suggests that breakeven for the surgical treatment will come only 12-13 years down the road; if you’re paying 6% for the money that funds the treatment, breakeven may never come at all.

I don’t know whether taking a pill for years on end is a cost that makes the surgery worthwhile, but I am betting that in another four years when the followup is finished we won’t be hearing much.

Also great if true

October 24, 2008

BBC NEWS | Health | Drug may reverse MS brain damage

The latest three-year study, of 334 patients with relapsing-remitting MS which had yet to be treated, found that the drug cut the number of attacks of disease by 74% more than the reduction achieved by conventional interferon-beta therapy.

Alemtuzumab also reduced the risk of sustained accumulation of disability by 71% compared to beta-interferon.

People on the trial who received the drug also recovered some function that had been thought to be permanently lost, and as a result were less disabled after three years than at the beginning of the study

The NHS don’t want to use it because of the side effects (including death), but I can sure think of a lot of patients who would want to take that risk.

Why so much “groundbreaking” research is wrong?

October 24, 2008

The fallibility of scientific journals | Publish and be wrong | The Economist

Dr Ioannidis made a splash three years ago by arguing, quite convincingly, that most published scientific research is wrong. Now, along with Neal Young of the National Institutes of Health in Maryland and Omar Al-Ubaydli, an economist at George Mason University in Fairfax, Virginia, he suggests why.

PLoS Medicine – Why Current Publication Practices May Distort Science

The current system of publication in biomedical research provides a distorted view of the reality of scientific data that are generated in the laboratory and clinic. This system can be studied by applying principles from the field of economics. The “winner’s curse,” a more general statement of publication bias, suggests that the small proportion of results chosen for publication are unrepresentative of scientists’ repeated samplings of the real world. The self-correcting mechanism in science is retarded by the extreme imbalance between the abundance of supply (the output of basic science laboratories and clinical investigations) and the increasingly limited venues for publication (journals with sufficiently high impact). This system would be expected intrinsically to lead to the misallocation of resources. The scarcity of available outlets is artificial, based on the costs of printing in an electronic age and a belief that selectivity is equivalent to quality. Science is subject to great uncertainty: we cannot be confident now which efforts will ultimately yield worthwhile achievements. However, the current system abdicates to a small number of intermediates an authoritative prescience to anticipate a highly unpredictable future. In considering society’s expectations and our own goals as scientists, we believe that there is a moral imperative to reconsider how scientific data are judged and disseminated.

Of course, the authors are part of the same system they criticize, so if this gets cited a lot, prepare for it to be debunked…

(I’m also a little leery of the original claim, which doesn’t really seem to address what you need to know — fer example, how wrong are the famous wrong papers, since plenty of revisions don’t affect your central thesis, how does this wrongness compare to the wrongness of nonfamous papers, and how much of the difference, if any, is the result of many more people bothering to examine the famous papers, while the nonfamous ones don’t even get examined for accuracy.)

The line about selectivity is also a bit misguided — it’s not about the cost of print, it’s about the cost of attention. Selectivity is there because people can’t keep up with even a couple journals in their own field, much less everything that would like to be published. (or maybe those are my editorial biases talking)

Wind on Mars

October 23, 2008

The Space Fellowship

(NASA) – This series of images show Phoenix’s telltale instrument waving in the Martian wind. Documenting the telltale’s movement helps mission scientists and engineers determine what the wind is like on Mars.

On the day these images were taken, one of the images seemed to be “out-of-phase” with other images, possibly indicating a dust devil occurrence. Preliminary analysis of the images taken right before and after the passing of this possible dust devil indicates winds from the west at 7 meters per second. The image taken during the possible dust devil shows 11 meters per second wind from the south.

This is just so thoroughly cool. It’s actually another whole planet up there.