Category Archives: Education

Extensively Drug-resistant Tuberculosis (XDR TB)

The journey to Dr. Moll’s terrifying discovery began in early 2005, when he noticed something peculiar. The staff at his hospital had become accustomed to the marvellous “Lazarus effect” of anti-retroviral treatment for AIDS: seeing desperately sick people quickly start gaining weight and return home or go back to work. But now, in his ward, he had two men in their 30s on ARVs whose HIV infections were suppressed to undetectable levels. Yet their TB, which would normally have cleared up in a matter of weeks, kept getting worse.

He suspected multidrug-resistant TB, or MDR, believed at the time to be as bad as the disease could get. So he collected sputum from 45 patients and sent it off to a lab in Durban for cell culturing. (The only way to tell if a TB strain is drug-resistant is to grow cultures from a patient sample, zap it with the different drugs and see which, if any, fail to kill it.) The process takes six to eight weeks. “In that time, we more or less forgot about it,” Dr. Moll said. One of his two young men died.

But the phone call from the lab, when it eventually came, slammed the issue to the top of their agenda: Of the 45 samples, 10 were indeed drug-resistant. But they weren’t resistant to just one or two of the drugs used against TB. They were resistant to all six medications available for use in Tugela Ferry. In other words, there was nothing to cure that TB at all.

As we have discussed previously, antibiotic resistance is a huge problem today and especially looming in the future. Perhaps we will find new fantanstic cures but the failure to take sensible action puts us at great risk.

High-efficiency Power Supplies

High-efficiency power supplies for home computers and servers (pdf) by Urs Hoelzle and Bill Weihl – Google:

Most likely, the computer you’re using wastes 30-40% of the electrical power it consumes because it is using an inefficient power supply. It’s difficult to believe that something as basic as a power supply could be responsible for that amount of waste, but it’s true.
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The opportunity for savings is immense — we estimate that if deployed in 100 million PCs running for an average of eight hours per day, this new standard would save 40 billion kilowatt-hours over three years, or more than $5 billion at California’s energy rates.
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The net result of these changes is a dramatic improvement in efficiency (including the power supply and the regulators) to about 85%, at virtually no cost. In other words, you won’t have to pay more for a higher-efficiency PC, because the power supply is actually getting simpler, not more complicated. By spending another $20 or so extra, it is possible to use higher-quality components and achieve efficiencies well over 90%.

Female Sharks Can Reproduce Alone

Female Sharks Can Reproduce Alone, Researchers Find

A team of American and Irish researchers have discovered that some female sharks can reproduce without having sex, the first time that scientists have found the unusual capacity in such an ancient vertebrate species. The[y] report that sharks can reproduce asexually through the process known as parthenogenesis
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Though the three females had been caught before they reached sexual maturity and held in captivity for more than three years, researchers initially thought one had stored sperm from a male shark before fertilizing an egg. But the team — which included scientists at Nova Southeastern University in Florida, Queen’s University Belfast and the zoo — determined that the baby shark’s genetic makeup perfectly matched one of the females in the tank, with no sign of a male parent.

Mahmood Shivji — Nova Southeastern’s Guy Harvey Research Institute director and one of the paper’s authors — said that he and his colleagues determined that a byproduct formed when sharks produce eggs, known as a sister polar body, had fused with an unfertilized egg to produce the baby shark, whose DNA had only half as much genetic variability as the mother.

Programming with Pictures

Carnegie Mellon University’s Randy Pausch…argues, many computer science departments are a quarter century behind on adapting their instructional methods for the purpose of attracting and retaining students, continuing to teach the gateway course to the field — introductory programming — just as they did 25 years ago.
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About 10 percent of the nation’s colleges now use Alice, an open-source, graphical software program available free online that allows users to learn the very basics of programming — concepts like iteration, if statements and methods — while making 3-D animations. Alice’s growth within college computer science departments has been impressive: Most colleges only began incorporating Alice in their introductory CS0 or CS1 courses within the past 18 months, since the release of an accompanying textbook.

But the software, currently readable to users in plain old English (a major drawback for many faculty who of course teach programming in standard computer languages like Java and C++), is potentially poised to penetrate far more colleges in 2008, when Alice 3.0 comes out in Java — featuring, this time around, sophisticated graphics, made available free by Electronic Arts Inc., from “The Sims,” the best-selling PC video game of all time. (And significantly, Pausch adds, one of the few games more popular with girls than boys. Computer science, he notes drily, has the unfortunate distinction of being the only discipline in the sciences to actually face declining female enrollments percentage-wise in the last 25 years).

Update: The Last Lecture Book by Randy Pausch

Remote-Controlled Submarines

Remote-Controlled Omnidirectional Submarines:

These remote-controlled submarines fit into the palm of your hand and have dual propeller propulsion systems that allow omnidirectional movement underwater in a bathtub, swimming pool, or in shallow ponds. The submarines dive and surface like an actual naval submarine, and the three high-powered motors ensure rapid movement forward, backward, left, right, and while performing 360 progressive rolls. The submarines have dual LED headlights and each unit operates on a unique radio frequency, allowing underwater races with multiple submarines. Includes rechargeable batteries that run for three minutes after a three minute charge.

Fun looking toy. Via: Remote-Controlled Submarines. Related: Science and Engineering Gadgets and Gifts – Lego Autopilot Project Update – Underwater Robots Collaborate

Water Buffaloes, Lions and Crocodiles Oh My

Pretty amazing video. A look at real wild life with lots of excitement, a bit violence and some surprising turns. On my trip to Kenya I saw an interaction between lions and one water buffalo but it was without much of this action. Basically there was a standoff for like half an hour with half charges and the like. Even that was very interesting.

Building Engineering Outside the Box

Helix — a 1D skyscraper with a single corridor:

The principle is a cylindrical building with a helical shape for the floor. The slope of the floor is 1.5% (it rises by 1.5 cm every meter), thus hardly noticeable. The height of each ’storey’ is 3 meters, so that when you walk 200 meters along the corridor, you have walked a full circle, but you end up one ’storey’ above or below your starting point. This results in a diameter of approximately 60 meters, therefore quite common for large skyscrapers. The corridor is on the outside, so that everybody has access to the fabulous views over the city. Offices are all on the inside. As the tower is hollow in the middle, and the inner diameter of the patio is still approximately 40 meters, this makes for a very nice light shaft with peaceful lighting conditions.

The floor of each office is made horizontal, so that your chair does not roll down and hit the separation. But if you take your chair in the corridor, be careful not to let go of it. All things rolling naturally find their way to the lost+found in the lobby.

Ok, this doesn’t seem really practical for a skyscaper but it still is a cool thought experiment. And as they mention it works fine for the Guggenheim Museum in NYC.

International Student Collaboration

Contest links high school students worldwide:

During the school year, 58 teams of American students coupled with students from China, India and Japan tackled technological solutions to global warming. They chatted online, divided jobs based on skill, consulted with advisers, and in the final grueling weeks, wrote a professional business plan.

“The most important goal is to engage U.S. students in international collaboration using science and technology,” said David Gibson, executive director of the Global Challenge and a research assistant professor in computer sciences at the University of Vermont. The idea for the contest came to management consultant Craig DeLuca two years ago as one of his clients planned to outsource design and manufacturing, and his community in Stowe considered putting off buying science textbooks.

“I’ve got to do something so that our kids have a shot in the global economy,” he said then. He launched the contest in Vermont, and last fall it was awarded a $900,000 National Science Foundation Grant and expanded worldwide. Winners will be announced in June.

Not only does the contest encourage interaction between students across the globe to solve problems, it also exposes them to opportunities in science, technology, engineering and math, Gibson said. “We need projects like this across the nation, so we can scoop these kids up because schools don’t do it for them,” he said.

Chemistry of Common Items

The American Chemistry Society offers interesting articles on the chemistry of everyday products including: amber, henna, catnip and honey:

To make this delicious treat, foraging bees start out by guzzling nectar, a dilute solution of sugars in flowers. Then, they mix the nectar with enzymes in their stomachlike honey sacs. Back at the hive, the foragers pass the digested material to house bees who reduce the moisture content of the mixture by ingesting and regurgitating it. They then deposit concentrated drops into honeycomb cells. Over the next few days, bees fan the fluid with their wings to further concentrate it, and finally, they cap the cells with wax. At the same time, enzyme-mediated changes produce a range of sugars and acids in the honey.

Bee enzymes also show up in the finished product. Invertase is the most critical. It splits the sucrose in the nectar into fructose and glucose and also produces some erlose. Another enzyme, glucose oxidase, converts glucose to gluconolactone, which is then hydrolyzed to give gluconic acid, the principal acid in honey. Formic, acetic, butyric, and lactic acids are also found in honey, which explains why its pH typically measures 3.8-4.0 and bacteria have a hard time growing in it.

Engineering, Math and Physics Applets

Java applets illustrating concepts in math, physics and engineering including: Coupled Oscillations, Digital Filters, 3-D Magnetostatic Fields and Ordinary Differential Equations.