Stories tagged monitoring

Sep
27
2009

H1N1 vaccination
H1N1 vaccinationCourtesy AJC1

How do I know it is safe?

"The recurring question is, 'How do we know it's safe?'" said Dr. Gregory Poland of the Mayo Clinic. What if, after getting a flu shot, a person goes home. then suddenly has a heart attack. Was the heart attack a side effect of the flu shot?

More than 3,000 people a day have a heart attack. This happens when no flu shots are given. When no flu shots are given, from 14,000 to 19,000 miscarriages happen every week.
When we start giving flu shots to 100s of millions of people, how do we differentiate side effects caused by the vaccination, from what would have happened even without the vaccination?

Intensive monitoring of side effects planned

This year there will be intense new monitoring.

Harvard Medical School scientists are linking large insurance databases that cover up to 50 million people with vaccination registries around the country for real-time checks of whether people see a doctor in the weeks after a flu shot and why. The huge numbers make it possible to quickly compare rates of complaints among the vaccinated and unvaccinated, said the project leader, Dr. Richard Platt, Harvard's population medicine chief.

Johns Hopkins University will direct e-mails to at least 100,000 vaccine recipients to track how they're feeling, including the smaller complaints that wouldn't prompt a doctor visit. If anything seems connected, researchers can call to follow up with detailed questions.

The Centers for Disease Control and Prevention is preparing take-home cards that tell vaccine recipients how to report any suspected side effects to the nation's Vaccine Adverse Event Reporting system.

However the flu season turns out, the extra vaccine tracking promises a lasting impact.

"Part of what we hope is that it will teach us something about how to monitor the safety of all medical products quickly," said Harvard's Platt.

Source: Associated Press

Feb
25
2009

Last night, Louisiana Governor Bobby Jindal criticized government spending authorized by the stimulus bill, calling particular attention to "something called volcano monitoring." Hey, $140 million is a lot of money, and what does it get us? Turns out volcano monitoring is actually kind of a big deal.

Fluffy cloud of water vapor, or engine-clogging agent of doom?: Taken from Alaska Airlines jet on July 20, 2008. This photo of Alaska's Okmok volcano was taken from 37,000 feet up, looking south from about 15 miles to the north. Scientists estimate the top of the ash cloud was at 20,000 ft.
Fluffy cloud of water vapor, or engine-clogging agent of doom?: Taken from Alaska Airlines jet on July 20, 2008. This photo of Alaska's Okmok volcano was taken from 37,000 feet up, looking south from about 15 miles to the north. Scientists estimate the top of the ash cloud was at 20,000 ft.Courtesy Phil Walgren, Alaska Volcano Observatory (USGS) and Alaska Airlines

It teaches us a lot about earth processes, of course, but some folks aren't swayed by talk of scientific advancement.

An argument for everyone is that monitoring enables authorities to plan and implement evacuations when necessary.

"The USGS has issued several warnings over the past 10 years, though predicting the timing and size of eruptions remains a difficult task.

Volcano monitoring likely saved many lives — and significant money — in the case of the 1991 eruption of Mount Pinatubo in the Philippines (where the United States had military bases at the time), according to the USGS.

The cataclysmic eruption lasted more than 10 hours and sent a cloud of ash as high as 22 miles into the air that grew to more than 300 miles across.

The USGS spent less than $1.5 million monitoring the volcano and was able to warn of the impending eruption, which allowed authorities to evacuate residents, as well as aircraft and other equipment from U.S. bases there.

The USGS estimates that the efforts saved thousands of lives and prevented property losses of at least $250 million (considered a conservative figure)."

Still not convinced? Here's another benefit: volcano monitoring keeps our air routes safer, too. See, a pilot can't easily tell the difference between an ash cloud and a regular cloud. But ash clouds can damage flight control systems and kill jet engines. Don't think that's really a big problem? Some 10,000 passengers and millions of dollars' worth of cargo are ferried by US aircraft over the North Pacific every day, and there are 100 potentially dangerous volcanoes under those air routes.

Suddenly "volcano monitoring" doesn't seem like a goofy piece of esoteric research...

Oct
10
2006

Nuclear test detection: photo from wikimedia
Nuclear test detection: photo from wikimedia

Was N. Korean nuclear test a dud?

James Acton of Vertic, an independent non-governmental organisation (NGO) in London that specialises in verification research, noted enormous discrepancies in the estimated size of the blast.

“I’ve heard from three different sources that it (the North Korean blast) was less than one kilotonne,” “If it turns out to be less than a kilotonne, it could look very much like a fizzle,” a bomb that failed to detonate properly and achieve a full chain reaction," said Acton, a nuclear physicist by training. Kahleej Times.

Russian Defence Minister Sergei Ivanov, however, has been quoted as saying that the nuclear device tested by North Korea ranged between five and 15 kilotons. That is the normal size of a successful test.

What data, besides seismic, can be used?

  • In addition to seismic sensors run by national governments, the UN’s Comprehensive Nuclear-Test-Ban Treaty Organisation (CBTO) in Vienna also has a network of 189 seismic and hydroacoustic monitoring stations designed to detect nuclear tests.
  • Radioactive particles and gases that can vent from an underground nuclear blast are also a telltale, providing clues as to the type of material (uranium or plutonium) that was used and to the size of the weapon.
  • A third monitoring technique is to use satellites with ground-scanning radars, which record the topography of a test site before and after an event. Movement or subsidence of the soil is the sign of a big blast.

How do we tell if it was a nuclear explosion?

Like earthquakes, large explosions send out shockwaves that can be detected on seismographs. Big nuclear bombs make big waves, with clear signatures that make them fairly easy to detect, analyze and confirm that they were caused by splitting atoms. But smaller blasts - as North Korea's appears to have been - are trickier to break down. York Daily Record

A nuclear explosion has a more instant shockwave than a chemical one. The differences between regular bombs and a nuclear explosion are very fine and subtle, and you need time to analyse the signatures.

"People have different way of cross cutting the data and interpreting them,"
The CTBTO's stations are more extensive than those used by most countries. They monitor seismic events but also underwater data, radioactive particles in the air and radiowaves.
"Within 72 hours we will have full data. Then all this will be available to member states," said Lassina Zerbo, director of the International Data Center at the CTBTO, which is based in Vienna, Austria.

While the North Korean explosion was small, potentially complicating monitoring efforts, sensors in South Korea were likely close enough to categorize it as nuclear, if that is what is was, said Friedrich Steinhaeusler, professor of physics at Salzburg University.

A nuclear blast also gives off a clear signature - a clear graph of peaks and curves - that differentiates it from other kinds of shocks, he added.

"We'll have the confirmation soon," he said.

Additional reading can be found on Rueters.
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