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Crime

Submission + - Using mains hum to authenticate audio recordings (bbc.co.uk)

another random user writes: A hum that comes from mains electricity has allowed forensic scientists to establish whether recordings are genuine.

For the last seven years, at the Metropolitan Police forensic lab in south London, audio specialists have been continuously recording the sound of mains electricity.

It is an all pervasive hum that we normally cannot hear. But boost it a little, and a metallic and not very pleasant buzz fills the air.

"The power is sent out over the national grid to factories, shops and of course our homes. Normally this frequency, known as the mains frequency, is about 50Hz," explains Dr Alan Cooper, a senior digital forensic practitioner at the Met Police.

Any digital recording made anywhere near an electrical power source, be it plug socket, light or pylon, will pick up this noise and it will be embedded throughout the audio.

This buzz is an annoyance for sound engineers trying to make the highest quality recordings. But for forensic experts, it has turned out to be an invaluable tool in the fight against crime.

Science

Submission + - Complex Logic Circuit Made from Bacterial Genes (wustl.edu)

another random user writes: Just as electronic circuits are made from resistors, capacitors and transistors, biological circuits can be made from genes and regulatory proteins. Engineer Tae Seok Moon’s dream is to design modular “genetic parts” that can be used to build logic controllers inside microbes that will program them to make fuel, clean up pollutants, or kill infectious bacteria or cancerous cells.

The circuit Moon eventually built consisted of four sensors for four different molecules that fed into three two-input AND gates. If all four molecules were present, all three AND gates turned on and the last one produced a reporter protein that fluoresced red, so that the operation of the circuit could be easily monitored.

Biotech

Submission + - The half-life of DNA - seems that Jurassic Park was impossible (nature.com)

another random user writes: Few researchers have given credence to claims that samples of dinosaur DNA have survived to the present day, but no one knew just how long it would take for genetic material to fall apart. Now, a study of fossils found in New Zealand is laying the matter to rest — and putting paid to hopes of cloning a Tyrannosaurus rex.

After cell death, enzymes start to break down the bonds between the nucleotides that form the backbone of DNA, and micro-organisms speed the decay. In the long run, however, reactions with water are thought to be responsible for most bond degradation. Groundwater is almost ubiquitous, so DNA in buried bone samples should, in theory, degrade at a set rate.

Determining that rate has been difficult because it is rare to find large sets of DNA-containing fossils with which to make meaningful comparisons. To make matters worse, variable environmental conditions such as temperature, degree of microbial attack and oxygenation alter the speed of the decay process.

By comparing the specimens' ages and degrees of DNA degradation, the researchers calculated that DNA has a half-life of 521 years. That means that after 521 years, half of the bonds between nucleotides in the backbone of a sample would have broken; after another 521 years half of the remaining bonds would have gone; and so on.

Republicans

Submission + - Rep. Paul Broun says scientists are tools of the devil (talkingpointsmemo.com) 2

another random user writes: Rep. Paul Broun (R-GA) tore into scientists as tools of the devil in a speech at the Liberty Baptist Church Sportsman’s Banquet last month.

All that stuff I was taught about evolution and embryology and the Big Bang Theory, all that is lies straight from the pit of Hell.

And it’s lies to try to keep me and all the folks who were taught that from understanding that they need a savior

According to Broun, the scientific plot was primarily concerned with hiding the true age of the Earth. Broun serves on the House Science Committee, which came under scrutiny recently after another one of its Republican members, Rep. Todd Akin (R-MO), suggested that victims of “legitimate rape” have unnamed biological defenses against pregnancy.

You see, there are a lot of scientific data that I’ve found out as a scientist that actually show that this is really a young Earth,

he said.

I don’t believe that the Earth’s but about 9,000 years old. I believe it was created in six days as we know them. That’s what the Bible says.


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