Quotulatiousness

September 30, 2009

Artificial skin

Filed under: Science — Tags: — Nicholas @ 12:53

Victor is doing some research on artificial skin for a school project, and he found this link, which he sent along to me, writing “Ghost in the Shell: Closer than we think?”.

What we’re trying to do is to interface electronic components with the human body. One of the challenges is that conventional electronics is typically made on very hard and flat surfaces. If you look at our own body we are a 3D object that is moving all around. The challenge is not only electrical but also mechanical because we need to find ways to make electronic things that can conform the body and therefore use materials that are no longer hard and brittle but materials that can be elastic, similar to our own skin, for example.

[. . .]

This is the second aspect of the project. In my group we’re looking at ways to make these prosthetic skins but there’s also this application where we’re looking at a way to use these very soft electronic devices to interface everything with the nervous system. Because the human body and particularly the nervous system is made of extremely compliant material we cannot use a silicon chip to interface directly with your nerve for a long time. What we’re doing is to use this polymer and elastomer substrate with embedded electrodes in it to connect directly with a peripheral nerve — so a nerve which is in the limb, not in the spinal cord or the brain — really in the limb, from the electrical signal from the neurons. Once we can do that then the idea would be to connect these peripheral implant directly to the prosthetic skin so that we could take the signals that are coming out of the prosthetic skin and convert them into a neuron format and feed that directly into the implant which would then communicate to the nerve and back to the brain.

Testing whether incentive pay for teachers improves student outcomes

Filed under: Economics, Education, India — Tags: , — Nicholas @ 12:13

A post up at Marginal Revolution summarizes a new paper by Karthik Muralidharan and Venkatesh Sundararaman, examining whether incentive pay for teachers (PDF) improves student performance:

1) Evidence comes from a very large sample, 500 schools covering approximately 55,000 students, and treatment regimes and controls are randomly assigned to schools in a careful, stratified design.

2) An individual-incentive plan and a group-incentive plan are compared to a control group and to two types of unconditional extra-spending treatments (a block grant and hiring an extra teacher). Thus the authors can test not only whether an incentive plan works relative to no plan but also whether an incentive plan works relative to spending a similar amount of money on “improving schools.”

3) The authors understand incentive design and they test for whether their incentive plan reduces learning on non-performance pay margins.

In the west, with most students being taught in publicly funded schools with strong teaching unions, these results will not be welcomed by the majority of school systems or unions. From the abstract:

Performance pay for teachers is frequently suggested as a way of improving education outcomes in schools, but the theoretical predictions regarding its effectiveness are ambiguous and the empirical evidence to date is limited and mixed. We present results from a randomized evaluation of a teacher incentive program implemented across a large representative sample of government-run rural primary schools in the Indian state of Andhra Pradesh. The program provided bonus payments to teachers based on the average improvement of their students’ test scores in independently administered learning assessments (with a mean bonus of 3% of annual pay). At the end of two years of the program, students in incentive schools performed significantly better than those in control schools by 0.28 and 0.16 standard deviations in math and language tests respectively. They scored significantly higher on “conceptual” as well as “mechanical” components of the tests, suggesting that the gains in test scores represented an actual increase in learning outcomes. Incentive schools also performed better on subjects for which there were no incentives, suggesting positive spillovers. Group and individual incentive schools performed equally well in the first year of the program, but the individual incentive schools outperformed in the second year. Incentive schools performed significantly better than other randomly chosen schools that received additional schooling inputs of a similar value.

I’m surprised that the results were so positive for relatively minor incentive bonus amounts.

More background on that broken hockey stick

Filed under: Bureaucracy, Environment, Media, Politics — Tags: , , — Nicholas @ 09:53

I don’t want to sound like a climate crank — there are more than enough of them out there, on both sides of the issue — and I’m still very much of the opinion that the question of anthropogenic global warming/climate change still needs a lot of work to answer. If human activities are causing the planet’s atmosphere to warm up in excess of what the natural feedback systems of the planet can handle, then we do need to look at ways to reduce our contribution to that warming.

Politicians and power-seeking bureaucrats jumping up and down in front of the cameras, insisting that the crisis is upon us and we need to do something now are in no way to be trusted with additional powers: without sufficient scientific evidence, we’d just be installing petty dictators over all sorts of different areas of our lives.

The specific piece of “evidence” most useful to the “do something now” faction has been the famous Hockey Stick Graph, which has been debunked. The data was carefully selected to support pre-decided conclusions. Everyone who took high school science knows the temptation . . . you know how the experiment is supposed to turn out, and who’ll know if you just write it up as if you got textbook results? The answer is . . . that’s why you do the experiment: to determine if the result matches the expectation. Skipping the whole “do the experiment” step saves time, but it’s not science.

Bishop Hill explains how the hockey stick became the best-known case of junk science in decades:

The story of Michael Mann’s Hockey Stick reconstruction, its statistical bias and the influence of the bristlecone pines is well known. McIntyre’s research into the other reconstructions has received less publicity, however. The story of the Yamal chronology may change that.

The bristlecone pines that created the shape of the Hockey Stick graph are used in nearly every millennial temperature reconstruction around today, but there are also a handful of other tree ring series that are nearly as common and just as influential on the results. Back at the start of McIntyre’s research into the area of paleoclimate, one of the most significant of these was called Polar Urals, a chronology first published by Keith Briffa of the Climate Research Unit (CRU) at the University of East Anglia. At the time, it was used in pretty much every temperature reconstruction around. In his paper, Briffa made the startling claim that the coldest year of the millennium was AD 1032, a statement that, if true, would have completely overturned the idea of the Medieval Warm Period. It is not hard to see why paleoclimatologists found the series so alluring.

Some of McIntyre’s research into Polar Urals deserves a story in its own right, but it is one that will have to wait for another day. We can pick up the narrative again in 2005, when McIntyre discovered that an update to the Polar Urals series had been collected in 1999. Through a contact he was able to obtain a copy of the revised series. Remarkably, in the update the eleventh century appeared to be much warmer than in the original – in fact it was higher even than the twentieth century. This must have been a severe blow to paleoclimatologists, a supposition that is borne out by what happened next, or rather what didn’t: the update to the Polar Urals was not published, it was not archived and it was almost never seen again.

With Polar Urals now unusable, paleclimatologists had a pressing need for a hockey stick shaped replacement and a solution appeared in the nick of time in the shape of a series from the nearby location of Yamal.

Yes, it’s long, and somewhat convoluted . . . but that is the point. Researchers were being deliberately obstructive to other researchers, concealing data necessary to reproduce the experimental results, yet publishing in numerous journals (who all should have enforced their own standards, but failed to do so) as if the data was impossible to refute.

And it was . . . because the raw data was kept out of the hands of other scientists. This is not science. It’s a deliberate fraud.

Update: JoNova adds to the story, including an image showing the relative locations of the sampled sites:

Busted_Hockey_Stick_locations

Update, the second: Tom Kelley corrects my use of the word “anthropogenic”, which I had idiotically written as “anthropomorphic”. Thanks, Tom.

Felicia Day interview in Wired

Filed under: Gaming, Media — Tags: , — Nicholas @ 09:21

Felicia Day, creator of The Guild, interviewed by Gus Mastrapa:

Felicia Day’s stardom wasn’t handed down to her from on high by Hollywood. She’s guest-starred on Buffy the Vampire Slayer and House, but most of her legions of fans still know her because of a show she wrote and produced herself that doesn’t air on any network.

Now in its third season, The Guild — Day’s microbudget comedic web series about a group of online gamers — enjoys financing from Microsoft as well as cushy placement on the Xbox 360 dashboard. But fans are still discovering Day and her nerdy ways online.

After landing a plum role in Joss Whedon’s Emmy-winning web series Dr. Horrible’s Sing-Along Blog last year, Day’s got a bona fide viral hit on her hands this year, thanks to a funny promo video for Season 3 of The Guild.

If you’ve ever done online gaming, especially MMORPG gaming, you’ll probably enjoy watching The Guild. If you haven’t done any online gaming, you may not find the humour to be to your taste.

Or you have no taste.

Your call.

A different approach to healthcare reform

Filed under: Government, Health, Politics — Tags: , — Nicholas @ 09:03

“John Galt” has a different suggestion for fixing what ails the American healthcare field:

We have some real problems: Bizarre incentives that have led to runaway costs. Rescission. An employer stranglehold over workers’ healthcare. Overuse in the form of care prescribed to protect doctors from lawyers, rather than protecting patients from illness. Arbitrary requirements to carry coverage for other people’s expensive risks.

The truth is that every one of those issues could be addressed — right now, and in a bipartisan fashion — without a single-payer system, a mandate, or any other form of “universal healthcare.” It wouldn’t even take a single massive “reform” bill — just a few simple bills, mostly repealing existing regulation.

But the left has settled on universal healthcare. The “public option.” No other reform is acceptable. No other reform will be permitted. Nothing can actually be fixed if it will lower the number of people who might benefit from a universal system, or if it will reduce national dissatisfaction with market-based care.

It’s quite true that there’s already massive government involvement in the health market, and that a lot of that consists of regulations that have dubious health benefits, but measurable detriments to patients, doctors, and hospitals.

The intersection of the War on Drugs with the government’s role in healthcare, for example, has led to a number of doctors being imprisoned for “inappropriate” prescriptions of painkillers to patients with chronic pain issues. It has also led to a huge number of doctors being afraid to prescribe what their patients actually need, for fear of being charged and convicted of “drug trafficking”. Many patients now suffer prolonged pain because they can’t get an adequate dose of painkillers and can’t find doctors to prescribe them.

All this, in pursuit of getting tough on illicit use of prescription medicine. Government at its finest.

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