Consumers warned about tainted meat

CNN) -- Federal and state health officials issued a consumer alert Thursday after nine people were sickened by contaminated beef.

A day before the start of what historically is a popular weekend for grilling, officials urged consumers to check the beef in their freezers and make sure it doesn't include possibly tainted meat.

The 41,205 pounds (approximately 20 tons) of beef identified as possibly tainted is no longer on store shelves, because the sell-by dates have already expired.

But the alert was issued anyway in case the product remains in consumers' freezers, the U.S. Dept. of Agriculture said.

Nine people have been sickened -- six in Washington, two in Oregon, and one in Idaho -- by the beef, which is contaminated with E. coli bacteria, state health officials reported.

The meat, processed between July 19 and July 30, according to the company, was also sold in Alaska, but no illnesses have been reported there.

Authorities identified the suspect products as 16-ounce packages of "Northwest Finest 7% Fat, Natural Ground Beef" with UPC code label "752907 600127" and 16-ounce packages of "Northwest Finest 10% Fat, Organic Ground Beef" with expiration dates between August 1 to August 8.

The beef was sold in Safeway, QFC, and Fred Meyer and other stores.

DNA tests confirmed that the nine people sickened by E. coli were infected with the same strain of the bacteria.

Federal and state health officials say that E. coli bacteria are killed if beef is cooked at 160

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Frozen Bacteria Repair Own DNA

Mason Inman
for National Geographic News

Bacteria can survive in deep freeze for hundreds of thousands of years by staying just alive enough to keep their DNA in good repair, a new study says. In earlier work, researchers had found ancient bacteria in permafrost and in deep ice cores from Antarctica.

These bacteria, despite being trapped for millennia, were able to be revived and grown in the lab.

Some researchers had thought that bacteria would have to turn into dormant spores to survive for so long.

But if bacteria merely went dormant, metabolism would stop and various environmental factors would begin damaging their DNA.

Like an ancient scroll that's crumbling apart, the DNA becomes so damaged that it's indecipherable after about a hundred thousand years. Then the cells can't ever reproduce and the bacteria are effectively dead.

"Our results show that the best way to survive for a long time is to keep up metabolic activity," said Eske Willerslev, lead study author and a researcher at the University of Copenhagen in Denmark.

Doing this "allows for continuous DNA repair," Willerslev added.

The work suggests that if bacterial life existed on Mars or on Jupiter's moon Europa, it might still survive locked in icy soils.

The new study appears this week in the online advance edition of the Proceedings of the National Academy of Sciences.

Living, Just Barely

The new study examined DNA from bacteria found in permafrost from Siberia in Russia and Canada. The permafrost dated back to about a half-million years ago.

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Source:

• http://news.nationalgeographic.com/news/2007/08/070827-frozen-dna_2.html
  

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http://www.allaboutscience.org/dna-double-helix-video.htm

• DNA Double Helix
  DNA Double Helix: A Recent Discovery of Enormous ComplexityThe DNA Double Helix is one of the greatest scientific discoveries of all time. First described by James Watson and Francis Crick in 1953, DNA is the famous molecule of genetics that establishes each organism's physical characteristics. It wasn't until mid-2001, that the Human Genome Project and Celera Genomics jointly presented the true nature and complexity of the digital code inherent in DNA. We now understand that each human DNA molecule is comprised of chemical bases arranged in approximately 3 billion precise sequences. Even the DNA molecule for the single-celled bacterium, E. coli, contains enough information to fill all the books in any of the world's largest libraries.
  DNA Double Helix: The "Basics"DNA (deoxyribonucleic acid) is a double-stranded molecule that is twisted into a helix like a spiral staircase. Each strand is comprised of a sugar-phosphate backbone and numerous base chemicals attached in pairs. The four bases that make up the stairs in the spiraling staircase are adenine (A), thymine (T), cytosine (C) and guanine (G). These stairs act as the "letters" in the genetic alphabet, combining into complex sequences to form the words, sentences and paragraphs that act as instructions to guide the formation and functioning of the host cell. Maybe even more appropriately, the A, T, C and G in the genetic code of the DNA molecule can be compared to the "0" and "1" in the binary code of computer software. Like software to a computer, the DNA code is a genetic language that communicates information to the organic cell. The DNA code, like a floppy disk of binary code, is quite simple in its basic paired structure. However, it's the sequencing and functioning of that code that's enormously complex. Through recent technologies like x-ray crystallography, we now know that the cell is not a "blob of protoplasm", but rather a microscopic marvel that is more complex than the space shuttle. The cell is very complicated, using vast numbers of phenomenally precise DNA instructions to control its every function. Although DNA code is remarkably complex, it's the information translation system connected to that code that really baffles science. Like any language, letters and words mean nothing outside the language convention used to give those letters and words meaning. This is modern information theory at its core. A simple binary example of information theory is the "Midnight Ride of Paul Revere." In that famous story, Mr. Revere asks a friend to put one light in the window of the North Church if the British came by land, and two lights if they came by sea. Without a shared language convention between Paul Revere and his friend, that simple communication effort would mean nothing. Well, take that simple example and multiply by a factor containing many zeros. We now know that the DNA molecule is an intricate message system. To claim that DNA arose by random material forces is to say that information can arise by random material forces. Many scientists argue that the chemical building blocks of the DNA molecule can be explained by natural evolutionary processes. However, they must realize that the material base of a message is completely independent of the information transmitted. Thus, the chemical building blocks have nothing to do with the origin of the complex message. As a simple illustration, the information content of the clause "nature was designed" has nothing to do with the writing material used, whether ink, paint, chalk or crayon. In fact, the clause can be written in binary code, Morse code or smoke signals, but the message remains the same, independent of the medium. There is obviously no relationship between the information and the material base used to transmit it. Some current theories argue that self-organizing properties within the base chemicals themselves created the information in the first DNA molecule. Others argue that external self-organizing forces created the first DNA molecule. However, all of these theories must hold to the illogical conclusion that the material used to transmit the information also produced the information itself. Contrary to the current theories of evolutionary scientists, the information contained within the genetic code must be entirely independent of the chemical makeup of the DNA molecule.
  DNA Double Helix: Its Existence Alone Defeats any Theory of EvolutionThe scientific reality of the DNA double helix can single-handedly defeat any theory that assumes life arose from non-life through materialistic forces. Evolution theory has convinced many people that the design in our world is merely "apparent" -- just the result of random, natural processes. However, with the discovery, mapping and sequencing of the DNA molecule, we now understand that organic life is based on vastly complex information code, and such information cannot be created or interpreted without a Master Designer at the cosmic keyboard.
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Source:

• http://www.allaboutscience.org/dna-double-helix.htm

DNA Double Helix Video

Source:

• http://www.allaboutscience.org/dna-double-helix-video.htm

PNA/DNA

Thermodynamic comparison of PNA/DNA and DNA/DNA hybridization reactions at ambient temperature

Source:

• http://nar.oxfordjournals.org/cgi/content/full/27/24/4792

Where Broken DNA Is Repaired

A cell nucleus is shown after irradiation by high-energy particles like those in cosmic rays. At top, the white arrow tracks one particle through regions of high-density DNA (blue) and low-density DNA.

Green signals are RIF, "radiation-induced foci," accumulations of proteins associated with radiation damage. Middle and bottom panels model DNA density topographically the higher the peak, the denser the DNA showing that RIF prefer low-density regions and tend to locate themselves at the interface between high and low density.

*"NASA has long been interested in the radiation hazards in space," says LSD's Sylvain Costes, who led the study. "On a trip to Mars, astronauts will be exposed to cosmic rays for as long as three years, so NASA has been trying to come up with a mechanistic model of DNA repair to estimate the increased risk of cancer. We are helping to develop such a model."

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Link Science Daily

Kool Jokes!

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• http://www.go-quiz.com/cocktail/cocktail.php

Unknotting DNA Clue To Cancer Syndrome

Science Daily — A new UC Davis study that explains the actions of a gene mutation that causes early onset cancer provides a fundamental insight into the mechanism of DNA-break repair.

UC Davis microbiologist Neil Hunter used spaghetti as a model to explain the gene mutation that causes early onset cancer. (Credit: UC Davis)

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