Category Archives: Education

Robot Water Striders

Scientists crack how insect bounces on water:

Walking on water may seem like a miracle to humans. But it is a humdrum achievement for the little water strider, which is able to bounce up and down on water too. Scientists have already solved the mystery of how their six slender, stilt-like legs evenly distribute their scant body weight over a relatively large area so that the “skin” formed by the surface tension of the water supports them, so four millimetre across dimples form under each foot as they skim about.

But scientists remained puzzled by how they could jump up and down upon the surface of water. Now a team in South Korea is about to report that it has at last explained the water strider’s baffling ability to leap onto water without sinking, in a forthcoming issue of the journal Langmuir, an achievement that could help further develop robots that can move about on lakes and reservoirs to monitor water quality, spy or explore.

Time’s Top 10 Scientific Discoveries of 2007

Time’s Top 10 Scientific Discoveries of 2007 – I don’t really agree with these but a couple are interesting:

#1. Stem Cell Breakthroughs
In November, Shinya Yamanaka of Kyoto University and molecular biologist James Thomson of the University of Wisconsin reported that they had reprogrammed regular skin cells to behave just like embryonic stem cells. The breakthrough may someday allow scientists to create stem cells without destroying embryos
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#4. Hundreds of New Species
…700 new species of organisms — including carnivorous sponges and giant sea spiders — some 2,300 ft. to 19,700 ft. (700 m to 6,000 m) down in the Weddell Sea off Antarctica. Scientists also reported the identification of 24 new species in an isolated area of Suriname, where the exploration for bauxite, which is used to make aluminum, led to the discovery of 12 dung beetles, an ant species, six species of fish and five new frogs, including one with fluorescent purple markings. Other fauna finds include a legless amphibian near Goa, India; 11 new species of plants and animals in central Vietnam’s tropical “green” corridor; a new monkey in Uganda; a sucker-footed bat in Madagascar; a clouded leopard in Sumatra and Borneo, and a sea cucumber off the coast of Taiwan, nicknamed “Little Strawberry.”

Roachbot: Cockroach Controlled Robot

“Roaches are gross. Robots are good. But — cockroach-controlled robots?” Nice quote 🙂 The video shows roboticist Garnet Hertz’s large robot moved by a cockroach on a pingpong ball (a cockroach trackball).

Scientists Cure Mice Of Sickle Cell Using Stem Cell Technique

Using a recently developed technique for turning skin cells into stem cells, scientists have cured mice of sickle cell anemia — the first direct proof that the easily obtained cells can reverse an inherited, potentially fatal disease.
…
researchers also cautioned that aspects of the new approach will have to be changed before it can be tried in human patients. Most important, the technique depends on the use of gene-altered viruses that have the potential to trigger tumor growth. “The big issue is how to replace these viruses,” said Rudolf Jaenisch of the Whitehead Institute for Biomedical Research in Cambridge, Mass., who led the new work with co-worker Jacob Hanna and Tim M. Townes of the University of Alabama Schools of Medicine and Dentistry in Birmingham.
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The researchers converted those skin cells into iPS cells by infecting them with viruses engineered to change the cells’ gene activity so they would resemble embryonic cells. Using DNA splicing techniques in those cells, the researchers then snipped out the small mutated stretches of DNA that cause sickle cell disease and filled those gaps with bits of DNA bearing the proper genetic code.

Next, the researchers treated the corrected iPS cells with another kind of virus — this time one designed to induce a genetic change that encouraged the cells to mature into bone marrow cells.

Finally, each mouse that gave up a few skin cells at the beginning of the experiment was given an infusion with the corrected marrow cells created from its own skin cells. Those cells set up permanent residence in the animals’ bones and began producing blood cells — the major function of marrow cells — and releasing them by the millions into the circulatory system.

But now the blood cells being produced were free of the sickle cell mutation.

Ebola Outbreak in Uganda

Ebola is a truly scary virus. Read more on Ebola Hemorrhagic Fever at the CDC and WHO:

Ebola haemorrhagic fever (EHF) is one of the most virulent viral diseases known to humankind, causing death in 50-90% of all clinically ill cases. Several different species of Ebola virus have been identified. The Ebola virus is transmitted by direct contact with the blood, body fluids and tissues of infected persons. Transmission of the Ebola virus has also occurred by handling ill or dead infected chimpanzees.

Panic spreads as Uganda reports 101 Ebola cases:

Uganda has 101 suspected cases of Ebola fever and hundreds more people being closely monitored, officials said on Friday, as fear grew in Uganda and neighboring countries that the deadly virus might spread. Twenty two people have so far died of the fever
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The outbreak, which started in August, has sparked panic amongst officials, health workers and the public, with the medical union calling on staff to refuse looking after patients unless they are issued proper protective gear. The affected region borders Democratic Republic of the Congo, whose Ebola river gave the virus its name after some of the first cases were recorded in its valley in 1976. The independent Daily Monitor said Congo had sealed its border with the district. Congolese officials denied this.
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The last Ebola outbreak in Uganda was in 2000, when 425 people caught it and more than half died. Meanwhile, north of the Ebola-hit district, a separate epidemic of bubonic plague has infected 160 people and killed 19 since July, Health Ministry spokesman Paul Kabwa said.

I happen to be reading The Hot Zone right now. It is a non-fiction book which explores several Ebola virus outbreaks from 1967 to 1993 including one at surburban Washington, DC laboratory in 1989.

Nanotube-producing Bacteria Show Manufacturing Promise

Genus Shewanella

Nanotube-producing Bacteria Show Manufacturing Promise:

The photoactive arsenic-sulfide nanotubes produced by the bacteria behave as metals with electrical and photoconductive properties. The researchers report that these properties may also provide novel functionality for the next generation of semiconductors in nano- and opto-electronic devices.

In a process that is not yet fully understood, the Shewanella bacterium secretes polysacarides that seem to produce the template for the arsenic sulfide nanotubes, Myung explained. The practical significance of this technique would be much greater if a bacterial species were identified that could produce nanotubes of cadmium sulfide or other superior semiconductor materials, he added.

“This is just a first step that points the way to future investigation,” he said. “Each species of Shewanella might have individual implications for manufacturing properties.”

USA Teens 29th in Science

The 2006 Programme for International Student Assessment (PISA) report has been released. The report examines the science of 15 year olds from 57 countries in math, science and reading. Once you get passed the poor design of the PISA web site you can find a great deal of data (which gives a great deal more depth to the results than just a simple listing of the top countries by mean score). But that list is interesting too.

*Rant* I find it amazing that sites can be so poorly run that they fail to even display without Javascript enabled. That is how badly run the PISA web site is, though. Here is the home page they direct you too: www.pisa.oecd.org/pages/0,2987,en_32252351_32235731_1_1_1_1_1,00.html – they need to have some people read about web usability (they should hire someone that knows how to apply the ideas of Jakob Neilsen, Jared Spool or 37 Signals).

Results for the Science portion (rank – country – mean score)(I am not listing all countries):

1 – Finland – 563
2 – Hong Kong – 542
3 – Canada – 534
4 – Taiwan – 532
6 – Japan – 531
7 – New Zealand – 530
8 – Australia – 527
9 – Netherlands – 525
11 – Korea – 522
13 – Germany – 516
14 – United Kingdom – 515
25 – France – 495
29 – USA – 489
49 – Mexico – 410

Study Shows Why the Flu Likes Winter

Study Shows Why the Flu Likes Winter:

The answer, they say, has to do with the virus itself. It is more stable and stays in the air longer when air is cold and dry, the exact conditions for much of the flu season.

“Influenza virus is more likely to be transmitted during winter on the way to the subway than in a warm room,” said Peter Palese, a flu researcher who is professor and chairman of the microbiology department at Mount Sinai School of Medicine in New York and the lead author of the flu study. Dr. Palese published details of his findings in the Oct. 19 issue of PLoS Pathogens.

Reading a paper published in 1919 in the Journal of the American Medical Association on the flu epidemic at Camp Cody in New Mexico, he came upon a key passage: “It is interesting to note that very soon after the epidemic of influenza reached this camp, our laboratory guinea pigs began to die.”
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Dr. Palese bought some guinea pigs and exposed them to the flu virus. Just as the paper suggested, they got the flu and spread it among themselves. So Dr. Palese and his colleagues began their experiments. By varying air temperature and humidity in the guinea pigs’ quarters, they discovered that transmission was excellent at 41 degrees. It declined as the temperature rose until, by 86 degrees, the virus was not transmitted at all.

The virus was transmitted best at a low humidity, 20 percent, and not transmitted at all when the humidity reached 80 percent. The animals also released viruses nearly two days longer at 41 degrees than at a typical room temperature of 68 degrees.

Very interesting and you can read the actual paper since it is open access: Influenza Virus Transmission Is Dependent on Relative Humidity and Temperature.

Robo-One Grand Championship in Tokyo

Two-legged robots battle for supremacy at the the Robo-One Convention in Tokyo. Very fun video. The robots has to be built from scratch by amateurs. Also see ROBO-ONE: Grand Championship Competition @ IREX (with full video of final match).

Playing Dice and Children’s Numeracy

My father, Willaim Hunter, a professor of statistics and of Chemical Engineering at the University of Wisconsin, was a guest speaker for my second grade class (I think it was 2nd) to teach us about numbers – using dice. He gave every kid a die. I remember he asked all the kids what number do you think will show up when you roll the die. 6 was the answer from about 80% of them (which I knew was wrong – so I was feeling very smart).

Then he had the kids roll the die and he stood up at the front to create a frequency distribution of what was actually rolled. He was all ready for them to see how wrong they were and learn it was just as likely for any of the numbers on the die to be rolled. But as he asked each kid about what they rolled something like 5 out of the first 6 said they rolled a 6. He then modified the exercise a bit and had the kid come up to the front and roll the die on the teachers desk. Then my Dad read the number off the die and wrote on the chart 🙂

This nice blog post, reminded me of that story: Kids’ misconceptions about numbers — and how they fix them

in the real study, conducted by John Opfer and Rober Siegler, the kids used lines with just 0 and 1000 labeled. They were then given numbers within that range and asked to draw a vertical line through the number line where each number fell (they used a new, blank number line each time). The figure above represents (in red) the average results for a few of the numbers used in the study. As you can see, the second graders are way off, especially for lower numbers. They typically placed the number 150 almost halfway across the number line! Fourth graders perform nearly as well as adults on the task, putting all the numbers in just about the right spot.

But there’s a pattern to the second-graders’ responses. Nearly all the kids (93 were tested) understood that 750 was a larger number than 366; they just squeezed too many large numbers on the far-right side of the number line. In fact, their results show more of a logarithmic pattern than the proper linear pattern.