Lauren Gravitz – Science, Medical, & Environmental Journalist

A Reporter's Miscellany

Social Networks for Public Health

A few weeks ago, I wrote about how popular people could be used as an early-detection mechanism for flu or other epidemics. The research, published in PLoS One by UCSD’s James Fowler and Harvard’s Nicholas Christakis, shows that during the H1N1 or “swine flu” epidemic of 2009, popular kids at Harvard got sick about two weeks earlier than others on campus. You can read my story here:

Friends Provide an Epidemic’s Early Warning

Connected: Fowler and Christakis's book, about the impact of social networks, was published in 2009.

Basically, Fowler and Christakis called up random students on the Harvard campus and asked them to participate in the study. Then, they asked the students to name some friends to participate, too. Just having been suggested meant that these friends were a more popular sample than those the researchers chose at random.

Initially, it seemed like odd logic, but Fowler explained it this way. “It’s called the friendship paradox,” he said. “If the person from the population is someone you name as a friend, the likelihood that this person has more friends than you is pretty high. The person who has ten friends is going to be ten times more likely to be named as a friend than someone who has one.”

Fowler and Christakis specialize in social networks, both the computerized and the face-to-face types. And the Harvard campus provides a perfect setting. (Mark Zuckerberg proved the case for this when he launched Facebook from his Harvard dorm room back in 2004.) University campuses have small, comparatively insular networks that don’t have the same complexity as large cities. But what the researchers are learning there could potentially be applied to larger populations, too.

I didn’t have space to talk about this in the Technology Review post above, but Fowler told me that their strategy had potential for broader public health use. If, he said, they could identify popular people at the hub of different networks around the country, those people (or their internet search activity) could be monitored identify populations that are most at risk.

In the event of a vaccine shortage, like the one that occurred last year, such a monitoring technique could tell you which areas of the country were succumbing first. “You could redirect shipments of vaccines to the place that will give you the most bang for your buck,” Fowler said. And the uses aren’t just limited to geography. “During the shortage, everyone talked about how pregnant women should get the vaccine first. If you had a large enough sample, you could look at the friends inside each of those subcategories,” he said. “In case of a shortage, it could help you determine which women should get the vaccines.”

Creating a sample large enough to do this, however, will prove quite a feat. Fowler and Christakis hope to get the data they need by collaborating with public health departments.

Written by Lauren Gravitz

October 5th, 2010 at 7:34 pm

A Kidney Benefits from NASA Engineering

Filter this: An artificial kidney uses a silicon membrane coated with kidney cells to simulate the real thing. Credit: William Fissell, The Cleveland Clinic

Because patients with chronic kidney failure can no longer  clear toxins from their blood, they rely on dialysis to do the job for them. They must travel to hospitals or specialized clinics three to five times a week, where they’re hooked up to refrigerator-sized machines for multiple hours at a stretch. It’s the time commitment of a part-time job, it interferes with lives and careers, and yet it’s still only a partial solution: After five years, only 35 percent of people on dialysis are still alive. Transplants are the best solution, but there just aren’t enough donated kidneys to go around.

Researchers at UCSF are developing an implantable, bioengineered kidney that has the potential to be far more effective that dialysis and could potentially help patients survive until a donor kidney becomes available. You can find my Technology Review story on the device here:

Building an Implantable Artificial Kidney

Not only could the device filter blood 24/7, but because it uses real kidney cells it could provide other important functions, too, such as producing vitamin D and helping prevent precipitous drops in blood pressure.

The researchers were able to shrink the dialysis machine down into an implantable size by creating a silicon membrane with very dense, precisely shaped nano-pores. The membrane was developed by Cleveland Clinic researcher William Fissell, while he was an engineering undergrad at MIT. The coolest bit about this, I thought, was the fact that it was developed for a wholly different purpose:

“It was part of an optical instrument that’s now flying on Chandra,” NASA’s X-ray observatory, Fissell told me. “But it’s the same underlying principle.”

The resemblance occurred to him while he was studying for his medical board exams, he says. ” The filtration structures in the kidney that are ruined in kidney disease are very similar to the ones I was making when I was an engineer at MIT–nanoscale, featured membranes.”

Just another example of how collaboration between seemingly disparate fields is leading to innovative solutions.

Written by Lauren Gravitz

October 2nd, 2010 at 7:36 pm

The Reporter’s Miscellany

In a journalist’s daily life, she comes across any number of fascinating facts, blurbs, and gems that never make it into the articles she writes. There’s either no space for them or they have only passing relevance to the story at hand. So here, a blog dedicated to the assorted miscellany that never makes into the final draft… Enjoy!

Written by Lauren Gravitz

March 24th, 2010 at 7:58 pm

Posted in Housekeeping

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