Is this the banana your grandchildren will eat?

By at 1:33 pm Monday, Apr 23 • Comments • Share

maggiekb

I do the Twitter, the Google+, and (to a much lesser extent) the Facebook.

Books
• Before the Lights Go Out: Conquering the Energy Crisis Before It Conquers Us, my book about the future of energy in the United States, will be published April 10th.

Upcoming Appearances
• April 2 at Skeptics in the Pub, Boston, Mass.— 7:00 pm at Tommy Doyle's in Harvard Square. Please RSVP.
•April 4 at MIT: "Shedding Light, Online", a discussion about how blogging and a dynamic audience helped shape my book, Before the Lights Go Out—4:00 pm in Maseeh Hall. Please RSVP.
• April 6 at Carnegie Mellon University: More details to come
• April 9-13 at University of Colorado, Boulder: 64th Annual Conference on World Affairs
• April 10 at Colorado State University, Fort Collins: "Putting the Fun Back in Infrastructure"—3:30 pm in the Rocky Mountain Innosphere.
• April 19 at The Bakken Museum in Minneapolis: Book Launch Party! Come enjoy snacks, a presentation by me, and some fun with the Bakken's Leyden jar.
• April 21 at Science Museum of Minnesota, St. Paul: Earth Day Tweetup event with Will Steger and Sean Otto—events run 10:00 am to 2:00 pm.
• May 2 at University of California, Berkeley: "Putting the Fun Back in Infrastructure"—6:00 pm, location TBA.
• May 3 at the American Institute of Architects, San Francisco Chapter—Lunchtime lecture, time and location TBA.
• May 3 at Barnes and Noble, El Cerrito, Cali.—7:00 pm.
• May 30 in New York City—Panel on local and DIY energy with the New America Foundation
• June 22-25 in Aspen, Colorado: Aspen Environment Forum
• July 5-8 at CONvergence in Minneapolis, Minn.—exact times and dates TBA

Over the weekend, I stumbled over a great Damn Interesting post about the history and future of the banana. Some of you already know the basic story here: Bananas, as we know them, cannot reproduce. The ones we eat are sterile hybrids. Like mules. The only way that there are more bananas is that humans take offshoots from the stems of existing banana trees, transplant them, and allow them to grow into a tree of their own. It's basically a cheap, low-tech version of cloning, and it has a long history in agriculture. (Note: This would be why Christian evangelist Ray Comfort's video on bananas has become a classic Internet LOL. In the video, Comfort presents the banana—particularly its seedless flesh, handy shape, and easy-access peel&mash;as a testament to the perfection of supernatural design ... completely ignoring the fact that all those things are the result of human-directed agricultural selection.)

The downside to this is that clones are, shall we say, not terribly genetically diverse. Turns out, a lack of genetic diversity is a great way to make yourself vulnerable to disease. Back in the 1950s, a fungus all but wiped out a variety of banana called the Gros Michael. Up until then, the Gros Michel had been the top-selling banana in the world. It was the banana your grandparents ate. You eat the Cavendish, a different variety that replaced Gros Michael largely on the strength of its resistance to the killer fungus.

Read the rest

Why we still don't totally understand how diseases spread

By at 4:34 pm Monday, Apr 16 • Comments • Share

maggiekb

I do the Twitter, the Google+, and (to a much lesser extent) the Facebook.

Books
• Before the Lights Go Out: Conquering the Energy Crisis Before It Conquers Us, my book about the future of energy in the United States, will be published April 10th.

Upcoming Appearances
• April 2 at Skeptics in the Pub, Boston, Mass.— 7:00 pm at Tommy Doyle's in Harvard Square. Please RSVP.
•April 4 at MIT: "Shedding Light, Online", a discussion about how blogging and a dynamic audience helped shape my book, Before the Lights Go Out—4:00 pm in Maseeh Hall. Please RSVP.
• April 6 at Carnegie Mellon University: More details to come
• April 9-13 at University of Colorado, Boulder: 64th Annual Conference on World Affairs
• April 10 at Colorado State University, Fort Collins: "Putting the Fun Back in Infrastructure"—3:30 pm in the Rocky Mountain Innosphere.
• April 19 at The Bakken Museum in Minneapolis: Book Launch Party! Come enjoy snacks, a presentation by me, and some fun with the Bakken's Leyden jar.
• April 21 at Science Museum of Minnesota, St. Paul: Earth Day Tweetup event with Will Steger and Sean Otto—events run 10:00 am to 2:00 pm.
• May 2 at University of California, Berkeley: "Putting the Fun Back in Infrastructure"—6:00 pm, location TBA.
• May 3 at the American Institute of Architects, San Francisco Chapter—Lunchtime lecture, time and location TBA.
• May 3 at Barnes and Noble, El Cerrito, Cali.—7:00 pm.
• May 30 in New York City—Panel on local and DIY energy with the New America Foundation
• June 22-25 in Aspen, Colorado: Aspen Environment Forum
• July 5-8 at CONvergence in Minneapolis, Minn.—exact times and dates TBA

 

When I was little, I read a Reader's Digest book of great disasters, which included a segment on the Black Death. One of the things the book tried to do was explain, on a child's level, why it wasn't easy to figure out that rats and fleas were the source of the plague. You couldn't just look for patterns, because there seemed to be no pattern. Half a household might drop dead while the other half only got a little sick, or remained entirely healthy. Plague doctors who handled the sick every day lived another 20 years. The real spread of disease wasn't like the movies, where one person coughing means everyone in close proximity is doomed.

One reason for the emergence of strange non-patterns like this is something called "super spreaders"—basically, some people spread disease more effectively than others. The infamous Typhoid Mary is the poster child for super spreaders, but the effect has been well-documented in a range of infectious diseases and it goes beyond the simple story of one woman who infected thousands. In fact, what makes the super spreader phenomenon so fascinating is that it isn't an anomaly at all. Super spreaders are the primary way some diseases spread. The Contagions blog—which is all about the history of infectious disease—has a great post up about this.

Eventually new models arose like the “20/80″ rule that says that 20% of cases are responsible for 80% of the transmission and formed a core ‘high risk’ group. This model works well for some diseases but not all.

For pathogens that do rely on super-spreaders, the majority of cases will not transmit the infection to anyone. This can lead to a sense of false security because it seems poorly communicated. As Galvani and May assert, “heterogeneously infectious emerging disease will be less likely to generate an epidemic, but if sustained, the resulting epidemic is more likely to be explosive”. Super-spreaders tend to beget more super-spreaders, although most of the cases they generate will still not transmit the infection to anyone. For example, a super-spreader begets 30 cases, 3 (10%) of which become new super spreaders. The rest may transmit to 0-1 people.

Super-spreading has been documented for HIV, SARS (Sudden Acute Respiratory Syndrome), measles, malaria, smallpox and monkeypox, pneumonic plague, tuberculosis, Staphylococcus aureus, typhoid fever, and a variety bacterial sexually transmitted diseases.

And that brings us back to medical mysteries because, the Contagion blog explains, we don't know exactly why some people are super spreaders and others aren't—or why some people are more vulnerable to infection than others. So far, what we have to go on is a list of well-established correlations.

Read about what makes a super-spreader at the Contagions blog.

Image: Thomas Bartholini's illustration of beak doctor from 1661. Via Wikipedia.

Weird laws (or lack thereof)

By at 10:36 am Tuesday, Aug 9 • Comments • Share

maggiekb

I do the Twitter, the Google+, and (to a much lesser extent) the Facebook.

Books
• Before the Lights Go Out: Conquering the Energy Crisis Before It Conquers Us, my book about the future of energy in the United States, will be published April 10th.

Upcoming Appearances
• April 2 at Skeptics in the Pub, Boston, Mass.— 7:00 pm at Tommy Doyle's in Harvard Square. Please RSVP.
•April 4 at MIT: "Shedding Light, Online", a discussion about how blogging and a dynamic audience helped shape my book, Before the Lights Go Out—4:00 pm in Maseeh Hall. Please RSVP.
• April 6 at Carnegie Mellon University: More details to come
• April 9-13 at University of Colorado, Boulder: 64th Annual Conference on World Affairs
• April 10 at Colorado State University, Fort Collins: "Putting the Fun Back in Infrastructure"—3:30 pm in the Rocky Mountain Innosphere.
• April 19 at The Bakken Museum in Minneapolis: Book Launch Party! Come enjoy snacks, a presentation by me, and some fun with the Bakken's Leyden jar.
• April 21 at Science Museum of Minnesota, St. Paul: Earth Day Tweetup event with Will Steger and Sean Otto—events run 10:00 am to 2:00 pm.
• May 2 at University of California, Berkeley: "Putting the Fun Back in Infrastructure"—6:00 pm, location TBA.
• May 3 at the American Institute of Architects, San Francisco Chapter—Lunchtime lecture, time and location TBA.
• May 3 at Barnes and Noble, El Cerrito, Cali.—7:00 pm.
• May 30 in New York City—Panel on local and DIY energy with the New America Foundation
• June 22-25 in Aspen, Colorado: Aspen Environment Forum
• July 5-8 at CONvergence in Minneapolis, Minn.—exact times and dates TBA
Technically, it's not illegal to distribute Salmonella-tainted food.