North Americans may remember 2005 as the year of Hurricane Katrina, but below the equator another fearsome tempest wrought its own devastation that year. From January 16th to 18th a line of thunderstorms tore through the Amazon basin, and researchers who conducted a botanical “body count” after the storm estimate that it laid low between 441 and 663 million trees.

Over the course of two days, a squall line measuring 620 miles (1,000 km) long and 124 miles (200 km) wide raged across the region from southwest to northeast, with buzzsaw-like winds of 90 mph (146 km/hr) causing widespread damage to property and a handful of deaths [Time].

Jeffrey Chambers, a forest ecologist at Tulane University, wanted to assess the damage caused throughout the massive Amazon basin, so he turned to satellites.

Using satellite images of about 34,000 square kilometers of the region from 2004 and comparing them with post-storm images, the researchers discovered that the wind had cut an enormous swath through the rainforest, running in a northeasterly direction across the Amazon basin. In all, the storm affected possibly 70% of the basin. [ScienceNOW]

Previously, other researchers had suggested that drought was responsible for a massive tree die-off in 2005, but Chambers says the satellite data and investigations of five field sites disproved the drought theory. In the hardest hit areas, the researchers found up to 80 percent of the trees snapped in half or blown over from their roots. Says Chambers:

“If a tree dies from drought, it generally dies standing…. It looks very different from trees that die snapped by a storm.” [Discovery News]

The paper and its full details will appear in the journal Geophysical Research Letters. Environmentalists note that the huge blow-down didn’t do the planet any favors, since the Amazon acts as a carbon sink–its living trees suck up and store planet-warming carbon dioxide. But as fallen trees rot, they release their stored carbon dioxide back into the atmosphere. What’s more, some climate change forecasts predict that there will be more severe storms in a warmer world, so it’s possible that the Amazon will be battered by more mega-storms in the future.

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Image: Jeffrey Chambers/Tulane University

The talented professors/writers Claudia Dreifus and Andrew Hacker have a new book coming out in August called Higher Education? How Colleges Are Wasting Our Money and Failing Our Kids—and What We Can Do About It. It's a topic CM and I frequently explore here so I'm very much looking forward to this one. Yesterday's Chronicle of Higher Eduction included an interesting article adapted from their book entitled, Are Colleges Worth the Price of Admission? Good question. Hacker and Dreifus begin: Tuition charges at both public and private colleges have more than doubled—in real dollars—compared with a generation ago. For most Americans, educating their offspring will be the largest financial outlay, after their home mortgage, they'll ever make. And if parents can't or won't pay, young people often find themselves burdened with staggering loans. Graduating with six figures' worth of debt is becoming increasingly common. So are colleges giving good value for those investments? What are families buying? What are individuals—and our society as a whole—gaining from higher education?
So after years of interviews with policymakers, students, and university leaders... Their conclusion?
Colleges are taking on too many roles and doing none of them well. They are staffed by casts ...

Sure, your GPS-enabled cellphone might tell you which way is north, but why settle for a mere compass when you can monitor the Earth’s entire magnetic field?

According to its developer, Tomasso, a Droid app called Solaris weaves together data from several satellites that monitor the Sun’s activity and its effects on our planet’s magnetic field.

NASA satellite team STEREO (Solar TErrestrial RElations Observatory) provides information on “Earth-directed solar ejections.” NASA’s SDO (Solar Dynamics Observatory) also gives stats on what the Sun is sending our way in the forms of solar wind and energetic particles. Finally, the NOAA’s polar orbiter satellites provide information on the Earth’s weather.

Combining this information, the app allegedly can show (almost) real-time changes in the Earth’s magnetic field from solar activity and even indicate when trapped, Sun-spewed subatomic particles are making a spectacular show, in the form of the northern or southern lights.

The app can also tell you when to look up since, as reported by Gizmodo, the “Phone vibrates when geomagnetic storm level rises or aurora may be overhead at your location.”

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Image: Solaris / Tomasso via AndriodPIT

Finally, a big head comes in handy.

For a study out this week in Neurology, scientists looked at 270 Alzheimer’s patients from the Multi-Institutional Research in Alzheimer’s Genetic Epidemiology study (MIRAGE) and found that a larger head size was correlated with better-preserved cognitive and memory skills. The team, led by Robert Perneczky, argues that a bigger cranial circumference could mean a person has more “brain reserve,” offering some protection against the deterioration brought on by Alzheimer’s.

Finding this out took a lot more than just scanning the patients for cerebral atrophy and then wrapping a tape measure around their heads to gauge circumference:

They took blood to see which variant of the APOE gene was in their DNA (having one or two copies of the e4 version of APOE is thought to increase one’s risk of Alzheimer’s). They looked up the results of each patient’s most recent mini-mental state examination (MMSE) to measure cognitive function. They also took into account each patient’s age and ethnicity, how long they’d had Alzheimer’s and whether they had diabetes, hypertension or major depression [Los Angeles Times].

When the scientists controlled for the other factors and simply compared head size to cognitive function, they found that patients with the larger heads scored higher on the MMSE cognitive test.

Unfortunately for most of us, the brain reaches nearly its full size—93 percent of it—by the time we’re 6. So if the researchers are right about brain size and its effect against the ravages of Alzheimer’s, then the best time to start protecting a person’s mental health late in life is early in life.

Dr Simon Ridley, head of research for the Alzheimer’s Research Trust, said: “Alzheimer’s is a very complex disease, so we should be careful not to focus too much on a single risk factor, particularly as there is little we can do about the size of our heads. The researchers have also posed the idea that nutrition, injury or infection in early life can have an impact on brain reserve, suggesting that we should look after our brain from day one” [BBC News].

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Image: flickr / Délirante bestiole