Author Archives: curiouscat

Androgenesis

All Dad by Carl Zimmer

This week’s revelation is androgenesis. Androgenesis is what happens when kids get all their genes from their father.
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Androgenesis, it turns out, transforms fatherhood into a parasitic invasion. It begins like normal fertilization, with a sperm fusing to an egg. But then the egg’s DNA gets hurled out of its nucleus, so that the sperm’s genes are the only ones left in the egg. The egg begins to develop into an embryo, but only after it has lost the mother’s DNA.

Cancer Deaths Increasing, Death Rate Decreasing

Last year I questioned this quote “confirming” a declining trend of cancer deaths: “Cancer deaths in the United States dropped for the second year in a row, health officials reported yesterday, confirming that the trend is real and becoming more pronounced, too.” Well the data is in for the next year (2005) and cancer deaths increased – so much for the 2 year “trend.”

Despite a continuing decline in the cancer death rate from 2004 to 2005, there was an increase of 5,424 deaths (559,312 cancer deaths in 2005 compared to 553,888 cancer deaths in 2004). This increase follows a decrease in the number of cancer deaths in the two previous years.

The American Cancer Society provides much better wording this year, I believe:

“The increase in the number of cancer deaths in 2005 after two years of historic declines should not obscure the fact that cancer death rates continue to drop, reflecting the enormous progress that has been made against cancer during the past 15 years.” said John R. Seffrin, Ph.D., American Cancer Society chief executive officer. “While in 2005 the rate of decline was not enough to overtake other population factors, the fact remains that cancer mortality rates continue to drop, and they’re doing so at a rate fast enough that over a half million deaths from cancer were averted between 1990/1991 and 2004.”

Good news, and well stated. Related: Leading Causes of Death – Cancer Cure – Not so Fast

Babbage Difference Engine In Lego

Building A Calculating Machine Using Lego Pieces by Andrew Carol

Before the day of computers and pocket calculators all mathematics was done by hand. Great effort was expended to compose trigonometric and logarithmic tables for navigation, scientific investigation, and engineering purposes. The larger efforts involved rooms of semi skilled people, called ‘computers’, capable of doing reliable arithmetic who would be under the direction of a skilled mathematician.

In the mid-19th century, people began to design machines to automate this error prone process. Many machines of various designs were eventually built but, the most advanced and famous of these was not. The Babbage Difference Engine.

Because of engineering issues as well as political and personal conflict the Babbage Difference engines construction had to wait until 1991 when the Science Museum in London decided to build the Babbage Difference Engine No.2 for an exhibit on the history of computers.

Babbage’s design could evaluate 7th order polynomials to 31 digits of accuracy. I set out to build a working Difference Engine using standard LEGO parts which could compute 2nd or 3rd order polynomials to 3 or 4 digits. I have built two generations of Difference Engines and am designing the third version now.

Don’t Eat What Doesn’t Rot

Here is a nice interview of Michael Pollan by Amy Goodman – Don’t Eat Anything That Doesn’t Rot:

Another assumption of nutritionism is that you can measure these nutrients and you know what they’re doing, that we know what cholesterol is and what it does in our body or what an antioxidant is. And that’s a dubious proposition.
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if you look at the layout of the average supermarket, the fresh whole foods are always on the edge. So you get produce and meat and fish and dairy products. And those are the foods that, you know, your grandmother would recognize as foods. They haven’t changed that much. All the processed foods, the really bad stuff that is going to get you in trouble with all the refined grain and the additives and the high-fructose corn syrup, those are all in the middle. And so, if you stay out of the middle and get most of your food on the edges, you’re going to do a lot better.

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]

Thompson and Tits share 2008 Abel Prize (Math)

Thompson and Tits share the Abel Prize for 2008

John Griggs Thompson, Graduate Research Professor, University of Florida, and Jacques Tits, Professor Emeritus, CollÃ¨ge de France, have been awarded the 2008 Abel Prize “for their profound achievements in algebra and in particular for shaping modern group theory.” In the prize citation, the Abel Committee writes that “Thompson revolutionized the theory of finite groups by proving extraordinarily deep theorems that laid the foundation for the complete classification of finite simple groups, one of the greatest achievements of twentieth century mathematics.”

In 1963, Thompson and Walter Feit proved that all nonabelian finite simple groups were of even order, work for which they both won the Frank Nelson Cole Prize in Algebra from the AMS in 1965. Thompson also won a Fields Medal in 1970. In the Abel citation for Tits, the committee writes that “Tits created a new and highly influential vision of groups as geometric objects. He introduced what is now known as a Tits building, which encodes in geometric terms the algebraic structure of linear groups.” The committee noted the link between the two winners’ work: “Tits’s geometric approach was essential in the study and realization of the sporadic groups, including the Monster.” Tits received the Grand Prix of the French Academy of Sciences in 1976, and the Wolf Prize in Mathematics in 1993.

The Abel Prize is awarded by the Norwegian Academy of Science and Letters for outstanding scientific work in the field of mathematics. The prize amount is 6,000,000 Norwegian kroner (over US$1,000,000).

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.