In honor of the Oscars, I spent last night watching a movie. It was set on another world, populated by exotic flora and fauna (e.g., a blue creature with a long tail). The good inhabitants of this world live as one with all nature, and refuse to kill or do harm. A caucasian human shows up, and saves the world from disaster by being brave enough to kill. The movie was in 3-D, creatively combining real-action and animation, and was lushly filmed with dramatic scenes of waterfalls and forests and mountains. The movie’s title starts with the letter “A”.

Of course, I’m talking about Alice in Wonderland. What, is there some other movie you were thinking of? Spoilers follow (although it’s not the type of movie that gets spoiled), so if you’re hyper-sensitive about such things (as I am), cease reading now.

Alice and Avatar make an excellent study in contrasts. They both use the same canvas, and there are remarkable superficial similarities between the two. However, I found Alice to be much more interesting and satisfying as a film. Avatar, as the entire world seems to have noted, has a completely mundane and predictable story, with a sound-byte message. Within about ten minutes of the film, you know more-or-less the full arc. It’s a reasonable story, with lots of visual candy, and I can’t say I was bored (which is saying a lot for a three hour film). But, at least for me, it left little mark. To go to such great lengths to build up an entire world, you’d think you’d have something profoundly new and interesting to say. Sean does a nice job of summarizing some of Avatar’s failings.

I found Alice, on the other hand, to be much more entertaining. For any self-respecting science geek, having a movie which revolves around a vorpal sword has to warm the cockles of your heart. But there’s substance behind all of the talking flowers and Jabberwocks. For example, consider the good and bad queens. They had interesting, quirky personalities, and didn’t play directly to stereotype. In Avatar, these roles would have been completely one dimensional. In Alice, the Red Queen has moments of doubt, and seems genuinely surprised that she is not loved. Images of hearts proliferate, to no avail. The White Queen, meanwhile, swats at “dragonflies” while professing her love for all creatures. She seems somewhat annoyed that she’s not allowed to wreak mayhem on her rival, as if she’s struggling within the bounds of the “good queen” convention. There are subtle physical manifestations as well: her snow white hair is dark underneath, and she has slightly dark circles about her eyes. The distance between the two queens (and sisters) is not as great as it initially appears. These satisfying levels of grey give the characters more depth and nuance (something that is completely absent in Avatar). Alice demands that the viewer do some work; the movie does not present everything neatly wrapped with a bow. The moral of the film is left a bit hazy. It has something to do with letting your imagination run wild. Resisting convention. Living in the world you want, rather than the one you find. At the end of Avatar, the main character remains on Pandora. Alice, on the other hand, chooses to leave Wonderland and return to London. Which film is more courageous?

Will we ever get a solid answer on what killed the dinosaurs? According to a new “K-T Boundary Dream Team” comprising of 41 international experts, including geophysicists and paleontologists, yes, the question has been settled: An asteroid is indeed to blame.

For years, scientists have argued over different theories of what killed the dinos–including one hypothesis that has gained ground recently, which suggests that massive volcanic activity in India’s Deccan Traps wiped them out 65 million years ago. However, the latest expert panel stuck to the asteroid theory, saying a massive impact wiped out the dinos and more than half of the Earth’s other species. The panel’s review was published in the journal Science.

After studying all the available data on the Cretaceous-Tertiary (K-T) mass extinction, the panel concluded that the catastrophic event was caused by a 6-mile-wide asteroid that struck Earth at an angle of 90 degrees and a speed of about 12.4 miles per second – about 20 times faster than a speeding bullet [Guardian]. The asteroid hit Chicxulub, Mexico, with a force one billion times more powerful than the atomic bomb at Hiroshima [Science Daily News].

The impact of the crash would have triggered large scale fires, landslides, earthquakes that measured 10 on the Richter scale, and subsequent tsunamis, scientists said. Debris loosened by the impact would have shrouded the planet, clouding the skies, causing a global darkness, and “killing off many species that couldn’t adapt to this hellish environment” [Science Daily News], according to study coauthor Joanna Morgan.

The scientists noted that the asteroid put an end to dinosaurs, the bird-like pterosaurs, and large marine reptiles, but it also marked a new beginning. Said study coauthor Gareth Collins: “Ironically, while this hellish day signalled the end of the 160 million year reign of the dinosaurs, it turned out to be a great day for mammals, who had lived in the shadow of the dinosaurs prior to this event. The KT extinction was a pivotal moment in Earth’s history, which ultimately paved the way for humans to become the dominant species on Earth” [Science Daily News].

The asteroid theory is far from new. The idea was first proposed by the father-son duo of Luis and Walter Alvarez three decades ago, when they found high levels of iridium in geological samples around the world. The element iridium is rare in the Earth’s crust but is common in asteroids, and can be found at asteroid impact sites. The current panel analyzed soil samples to find that immediately after the iridium layer, there is a dramatic decline in fossil abundance and species, indicating that the KT extinction followed very soon after the asteroid hit [Science Daily News].

The team also based their conclusions on “shocked” quartz. Quartz is shocked when it is hit very quickly by a huge force; shocked quartz is found only at asteroid impact locations and nuclear explosion sites. The abundance of shocked quartz in the rock layers associated with the KT boundary add further weight to the asteroid impact theory, the team declared.

Study coauthor Kirk Johnson says the team discarded the theory that large-scale volcanism made the dinosaurs extinct because the eruptions at the Deccan traps site started at least 400,000 years before the Chicxulub impact with no effect on life. The team traces the extinctions to within plus-or-minus 10,000 years of the impact 65.5 million years ago. “So we are back to where we started with the Alvarez hypothesis, a single, large, (6-mile-wide) impact,” Johnson says [USA Today].

Related Content:
80beats: Forget “The Asteroid”: Could Supervolcanoes Have Killed the Dinosaurs?
80beats: In the Permian Period, Erupting Super-Volcanoes May Have Killed Half the Planet
80beats: Dinosaurs Ruled the World Because They “Got Lucky,” Say Scientists
DISCOVER: Did an Asteroid Really Dust the Dinosaurs?
DISCOVER: When North America Burned explains how the asteroid could have set our continent on fire

Image: Nasa

We’ve been studied. Bora points to a new paper by Inna Kouper in the Journal of Science Communication. The title is “Science blogs and public engagement with science: Practices, challenges, and opportunities,” which pretty much explains what it’s about. The author picks out a collection of eleven blogs — Pure Pedantry, Synthesis, MicrobiologyBytes, Bioethics, Wired Science, DrugMonkey, Scientific Activist, Pharyngula, Panda’s Thumb, and our own humble offering — and analyzes posts and comments to judge how effective these sites are at promoting science communication.

The list of blogs chosen is — okay, I guess. I have no idea how it was constructed, and the paper doesn’t seem to provide much guidance. Bora has a critique of the methodology that wonders about that, and about exactly how objective the study is. It’s very hard to assign numbers to things like “ratio of informative posts vs. rants,” or “degree to which the cause of collegial communication was harmed by use of intemperate language.” The paper reads like someone read a bunch of blogs and typed up their personal impressions.

For the most part I don’t disagree too strongly with the impressions, with the obvious caveat that it’s almost completely useless to study “science blogs” as a group. People don’t read randomly chosen collections of blogs; they read very intentionally chosen subsets that appeal to their own interests, and different reading lists will lead to wildly divergent impressions about what blogs are really like.

More significantly, though, I can’t really agree with the moral that the author draws from these experiences. Here is the telling quote from the paper:

The blogs employ a variety of writing and authoring models, and no signs of emerging or stabilizing genre conventions could be observed. Even though all blogs mentioned science or a particular scientific discipline in their descriptions, they differed in their voice representations, points of view, and content orientation.

It’s hard to disagree with that, but I think it’s a good thing, and the author clearly does not. Blogs differ in many ways, and happily avoid the encroachment of stabilizing genre conventions. That’s one of the biggest benefits of opening up communication channels to a tremendous variety of content providers, rather than restricting things to just a few mainstream outlets; writers can have their voices, and readers can choose who to read, and everyone is happy.

It’s clear that a lot of people want blogs to be just like some pre-existing communication medium, just with comments and occasional expertise. And there are blogs like that, if that’s what you’re into. And there are blogs that aren’t, likewise. I hope it stays that way.

For a study this week in the journal Nature Medicine, Kathleen Collins and her team have uncovered another of HIV’s dirty tricks: the virus can hide out in bone marrow cells and lie in wait for the right time to strike.

In recent years, drugs have reduced AIDS deaths sharply, but patients need to keep taking the medicines for life or the infection comes back, she said. That’s an indication that while the drugs battle the active virus, some of the disease remains hidden away to flare up once the therapy is stopped [AP]. One place the researchers already knew HIV could hide was inside resting T cells. However, Collins says, she thought T cells alone didn’t offer a complete picture of the virus’ ability to play hide-and-seek.

So she and her team took hematopoietic progenitor cells (HPCs) from bone marrow cells—so called because they eventually turn into blood cells—and exposed them to HIV. The infection killed some cells right away. But when the team forced the others to differentiate, becoming blood cells, they say, they saw a dramatic increase in viral activity triggered by the differentiation. In short, HPCs represented another HIV reservoir. “To my knowledge, we are the first to find another real reservoir beyond the resting T cell,” Collins said [The Scientist]. When the scientists then studied HIV patients who’d had undetectable viral loads for six months or more, they found HIV infecting the bone marrow of about 40 percent.

The study is an important step for scientists trying to track how HIV behaves over an infected person’s lifetime, and why it’s able to come back with a vengeance even after a long latent period. But it also presents new challenges because killing off bone marrow cells is a dicey proposition [BusinessWeek]. Killing all the infected bone marrow cells would also kill the patient, Collins says. However, “maybe we could find ways of targeting only the latently infected bone marrow cells,” she added [BusinessWeek].

Related Content:
80beats: S. African HIV Plan: Universal Testing & Treatment Could End the Epidemic
80beats: If Everyone Got An Annual AIDS Test, Could We Beat Back the Epidemic?
80beats: HIV/AIDS Patients in Papua May Be Tracked with Microchips
80beats: Beware of Hype: AIDS “Cure” is Good Science, But Won’t Halt the Epidemic
DISCOVER: Hope For HIV Vaccine

Image: iStockphoto

Struggling for a gift idea? How about gifting a rat through “Adopt-a-HeroRat.” These are no regular New York City-type rats, creepily scampering across train tracks or spreading disease; these so-called HeroRats help save lives by sniffing out unexploded landmines in Mozambique. For just six dollars a month, you can choose to support the good work of “Allan,” “Kim,” “Tyson,” or “The Chosen One.”

The rats being used in Mozambique’s mine-sweeping operations are African pouched rats; they’re small, lightweight (weighing about 3 pounds), and, according to the BBC, surprisingly cute. Traditionally, mine-detection has been carried out by metal detectors and sniffer-dogs, but the rats are the latest workers to join the team. However, the mine-removal process is still dangerous and labor-intensive: Once a rat discovers a mine it has to be dismantled by a human.

A bunch of these rats have been trained by APOPO, a joint Belgian/Tanzanian organization that taught the rodents to associate the smell of TNT in unexploded explosives with food. So, much like the dogs that Igor Pavlov taught to associate a certain stimuli with a particular response, the rats associate mines with delicious snacks, and are highly motivated to find them.

APOPO’s rats aren’t deployed in the field without proper training, of course. First, they must attend a grueling boot camp in Tanzania, where, much like sniffer dogs, they work with individual human trainers. Each rat works in a training box and is fastened to a search line, which is strung between its two trainers. The rat sniffs up and down the box, moving through different lanes, systematically. When it smells an explosive, it starts scratching the top soil. The trainer clicks a clicker, the rat steps aside and gets his reward–a piece of banana. APOPO trainers say they’re proud that the HeroRats are helping to find and eliminate the three million unexploded mines that still clutter Mozambique in the aftermath of a deadly civil war.

But the HeroRats’ life is not all sniffing and bananas, they have had their share of criticism too. British Army vet Andy Smith, who works with de-mining groups worldwide, told the online magazine Miller-McCune that while mine-detecting rats are “media-sexy” and attract a lot of money, they’re highly inefficient:

Their legs are too small to walk regular patterns in overgrown fields, so vegetation must be trimmed, and the rats attached to a string to literally keep them in line. “You need to spend so much time clearing space, you’re better off doing it manually,” Smith says.

But maybe mine detecting personnel who are working through the painstaking process of defusing deadly landmines across 70 countries need all the help they can get. And maybe “The Chosen One” can, in some small way, contribute to this effort.

Related Content:
Discoblog: Could Rats Be the Next Sniffing Dogs?
Discoblog: Fanged Frogs, Giant Woolly Rats Found In Papua New Guinea
DISCOVER: The Ancient Rat As Big As A Bull

Image: HeroRat.org