Category Archives: Students

Items for students and others, interested in learning about science and engineering and the application of science in our lives. We post many of the general interest items here.

Warning on Two Cholesterol Drugs

Journal Issues Warning on Two Cholesterol Drugs

Two widely prescribed cholesterol-lowering drugs, Vytorin and Zetia, may not work and should be used only as a last resort, The New England Journal of Medicine said in an editorial published on Sunday.

The journal’s conclusion came as doctors at a major cardiology conference in Chicago saw for the first time the full results of a two-year clinical trial that showed that the drugs failed to slow, and might have even sped up, the growth of fatty plaques in the arteries. Growth of those plaques is closely correlated with heart attacks and strokes.

Merck and Schering-Plough, the companies that make Vytorin and Zetia, said on Sunday that despite the results of the trial, they would continue to promote their medicines as first-line treatments for high cholesterol.

Ethanol Scam

The Clean Energy Scam

The Amazon was the chic eco-cause of the 1990s, revered as an incomparable storehouse of biodiversity. It’s been overshadowed lately by global warming, but the Amazon rain forest happens also to be an incomparable storehouse of carbon, the very carbon that heats up the planet when it’s released into the atmosphere. Brazil now ranks fourth in the world in carbon emissions, and most of its emissions come from deforestation.
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Meanwhile, by diverting grain and oilseed crops from dinner plates to fuel tanks, biofuels are jacking up world food prices and endangering the hungry. The grain it takes to fill an SUV tank with ethanol could feed a person for a year. Harvests are being plucked to fuel our cars instead of ourselves. The U.N.’s World Food Program says it needs $500 million in additional funding and supplies, calling the rising costs for food nothing less than a global emergency. Soaring corn prices have sparked tortilla riots in Mexico City, and skyrocketing flour prices have destabilized Pakistan, which wasn’t exactly tranquil when flour was affordable.
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One groundbreaking new study in Science concluded that when this deforestation effect is taken into account, corn ethanol and soy biodiesel produce about twice the emissions of gasoline. Sugarcane ethanol is much cleaner, and biofuels created from waste products that don’t gobble up land have real potential, but even cellulosic ethanol increases overall emissions when its plant source is grown on good cropland. “People don’t want to believe renewable fuels could be bad,” says the lead author, Tim Searchinger, a Princeton scholar and former Environmental Defense attorney. “But when you realize we’re tearing down rain forests that store loads of carbon to grow crops that store much less carbon, it becomes obvious.”

Appetite for Destruction

photo of Mountain Pine Beetle

Appetite for Destruction (link broken, so I removed it) by Eric R. Olson:

“Once the beetles are at the level they’re at in British Columbia, there’s nothing you can do – it’s like a rapidly spreading fire,” says Barbara Bentz, research entomologist with the U.S. Department of Agriculture Forest Service. If the beetle continues to devour trees at the current rate, 80 percent of British Columbia’s mature pines will be killed off by 2013, according to Natural Resources Canada, an arm of the Canadian government.

Global climate change, which is pushing temperatures higher, has altered the beetle’s natural life cycle. Now the insect threatens one of the world’s largest forest systems: Canada’s boreal forest, a 600-mile-wide band of pine woodlands that stretches from the Yukon in Alaska all the way to Newfoundland on the East Coast.
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The source of all this destruction is an insect not much bigger than a grain of rice. A native of North America, the pine beetle does its damage by burrowing beneath the bark and feeding on the living tissue of the tree called the phloem. This tissue is composed of long tubes that transport nutrients from root to limb, and once it is destroyed, the tree can no longer survive.

In the past, cold snaps — quick drops in temperature in the spring and fall — have kept beetle populations in check. Although the insects can survive temperatures as low as minus 35 degrees Fahrenheit in the winter, it takes time for their bodies to accumulate enough glycol, the same ingredient found in antifreeze, to survive such frigid temperatures.

Photo: Mountain Pine Beetle (Dendroctonus Ponderosae) under a scanning electron microscope. [Credit: Leslie Manning/Canadian Forest Service]

Squid Materials Engineering

Scientists find that squid beak is both hard and soft

The sharp beak of the Humboldt squid is one of the hardest and stiffest organic materials known. Engineers, biologists, and marine scientists at the University of California, Santa Barbara, have joined forces to discover how the soft, gelatinous squid can operate its knife-like beak without tearing itself to pieces.
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The key to the squid beak lies in the gradations of stiffness. The tip is extremely stiff, yet the base is 100 times more compliant, allowing it to blend with surrounding tissue. However, this only works when the base of the beak is wet. After it dries out, the base becomes similarly stiff as the already desiccated beak tip.
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“You can imagine the problems you’d encounter if you attached a knife blade to a block of Jell-o and tried to use that blade for cutting. The blade would cut through the Jell-o at least as much as the targeted object. In the case of the squid beak, nature takes care of the problem by changing the beak composition progressively, rather than abruptly, so that its tip can pierce prey without harming the squid in the process. It’s a truly fascinating design!”
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“If we could reproduce the property gradients that we find in squid beak, it would open new possibilities for joining materials,” explained Zok. “For example, if you graded an adhesive to make its properties match one material on one side and the other material on the other side, you could potentially form a much more robust bond,” he said. “This could really revolutionize the way engineers think about attaching materials together.”

Propeller Innovation by Engineering Students

Innovation propels students’ careers

Four fifth-year students from the electrical and mechanical departments won a national innovation competition and are now in preliminary talks with oil and gas behemoth Shell for a propeller design that is more efficient, watertight, pressurized and powerful than other models. “The motor housing creates drag (on other models),” said electrical engineering student Dave Shea. “So we integrated it into the propeller itself. There’s no drag, there’s no dead zone. It’s also much bigger and more powerful.”

Most propellers have a body encasing the motor. There’s air inside, which can cause the body to collapse when submerged in oceanic depths. The casing also creates drag, slowing the machine down and making it difficult to move backward.

But Shea, along with Brian Claus, Peter Crocker and Toren Gustafson, devised a way to build the motor in the casing that surrounds the propeller blades. The parts are assembled in a ring shape then encased in epoxy, making the motor waterproof. The propeller is fastened inside the ring, allowing it to easily move forward or backward.

Solar Energy: Economics, Government and Technology

An American Solar Opportunity Gets Shipped Abroad

The project will pour $1 billion into utility-scale photovoltaic solar farms that will directly feed power into a country’s electrical grid. The installations will range from fewer than 2 MW to up to 50 MW, while a single farm could cover hundreds and hundreds of acres.

They’ll be installed in Europe. In Asia. And maybe even in America too, one day. Why not now? Because AES wants to sow its solar seeds in only those countries that offer the most “attractive tariffs.” That eliminates the US from the list of potentials, immediately. And it gives countries like Germany, Spain, Italy and South Korea the clear advantage. They all have can’t-beat national incentives for solar developers.

It’s one of the sad facts of Washington’s incoherent clean energy policy these days. How can a country lure in clean energy projects when there are far more appealing offers elsewhere?

Government actions impact economic decisions. It will likely take more than 10 years to have good data on what government investments pay off in the energy sector. But I would say it is a pretty good bet to invest in technology such as: solar, geothermal, wind… Countries that create global centers of excellence in these areas are likely to benefit greatly. The only question I think is that many countries are smart enough to see the benefits and so likely many countries will try.

Any time many actors pursue the same economic strategy there is the risk that the payoff is diluted with so many others having done the same thing. Still the reason so many countries have adopted the strategy of developing centers of excellence in science, engineering and technology is that it is such a good idea. The USA has a problem in that we are spending more than we produce on luxuries today so there is much less available to invest compared to other countries (and compared to 40 years ago).

Secrets of Spider Silk’s Strength

The strength of a biological material like spider silk lies in the specific geometric configuration of structural proteins, which have small clusters of weak hydrogen bonds that work cooperatively to resist force and dissipate energy, researchers in Civil and Environmental Engineering have revealed.

This structure makes the lightweight natural material as strong as steel, even though the “glue” of hydrogen bonds that hold spider silk together at the molecular level is 100 to 1,000 times weaker than the powerful glue of steel’s metallic bonds or even Kevlar’s covalent bonds.
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“Using only one or two hydrogen bonds in building a protein provides no or very little mechanical resistance, because the bonds are very weak and break almost without provocation,” said Buehler, the Esther and Harold E. Edgerton Assistant Professor in the Department of Civil and Environmental Engineering. “But using three or four bonds leads to a resistance that actually exceeds that of many metals. Using more than four bonds leads to a much-reduced resistance. The strength is maximized at three or four bonds.”

Mutation Rate and Evolution

Stop the Mutants! by Olivia Judson

I’m going to wave a magic wand and reduce the mutation rate to zero, instantly, in all species, and forever. Then I’m going to watch to see how long it takes for evolution to stop.
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Actually stopping mutations is a physical impossibility – hence the need for a magic wand. But if they were to stop, so would raw invention. But evolution would not. Not for a long time.
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And sometimes natural selection actively promotes the persistence of genetic variation. This can happen when there’s an advantage to having genes that are rare. Among guppies, for example, males with rare color patterns are much more likely to survive than those with common color patterns, presumably because predators get good at spotting the patterns they encounter often. In such situations, the rare type does well, begins to become common – and then becomes the victim of its own success and starts to do badly. In situations like this, the frequencies of different genes can rise and fall, cycling indefinitely.
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Among lifestyles that promote genetic diversity, far and away the most important is sex. Sex shuffles up genes, continually producing new gene combinations. (An important difference between sex and mutation is that sex can only create genetic novelty if it already exists in the population. If everyone is genetically identical, sex will have no effect.) Sex also – and this is important – decouples the fates of genes from one another.

2008 Intel Science Talent Search

When Shivani Sud was six years old, one of her immediate family members was diagnosed with a brain tumor. Inspired by the doctors who helped her loved one recover, Shivani set her sights on a career in medicine.

Fast forward to Intel STS 2008, where the 17-year-old senior from Durham, North Carolina, presented research focused on identifying stage II colon cancer patients at high risk for recurrence and the best therapeutic agents for treating their tumors. Whereas the standard method of characterizing tumors relies on visual information (such as size, degree
of metastasis, and microscopic structure), Shivani developed a “50-gene model” which uses gene expression to link multiple genetic events that characterize various tumor types to more accurately predict the recurrence of colon cancer. Additionally, Shivani’s model can be used to identify drugs that may be most effective in treating each patient.

In 2006 she attended the Davidson Institute, summer program at Davidson College and received the Davidson Fellows Scholarship.

And now I can segue to the Davidson Wildcats victories in the NCAA basketball tournament last weekend (I graduated from Davidson, by the way, and grew up in Madison). Davidson will play the Wisconsin Badgers on Friday. My picks are doing pretty well.

Ballast-free Ships

ballast-free ship’ could cut costs while blocking aquatic invaders

University of Michigan researchers are investigating a radical new design for cargo ships that would eliminate ballast tanks, the water-filled compartments that enable non-native creatures to sneak into the Great Lakes from overseas. At least 185 non-native aquatic species have been identified in the Great Lakes, and ballast water is blamed for the introduction of most—including the notorious zebra and quagga mussels and two species of gobies.

This week, the U.S. Saint Lawrence Seaway Development Corp. will implement new rules designed to reduce Great Lakes invaders. Ships will be required to flush ballast tanks with salt water before entering the Seaway, a practice corporation officials describe as an interim measure, not a final solution.
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Instead of hauling potentially contaminated water across the ocean, then dumping it in a Great Lakes port, a ballast-free ship would create a constant flow of local seawater through a network of large pipes, called trunks, that runs from the bow to the stern, below the waterline.

“In some ways, it’s more like a submarine than a surface ship,” Parsons said. “We’re opening part of the hull to the sea, creating a very slow flow through the trunks from bow to stern.