The richness and depth of the book is universally respected yet often undiscovered as the monopoly of the form and relevance of the information fades over time. The book’s intended function has decreased and the form remains linear in a non-linear world. By altering physical forms of information and shifting preconceived functions, new and unexpected roles emerge. This is the area I currently operate in. Through meticulous excavation or concise alteration I edit or dissect communicative objects or systems such as books, maps, tapes and other media. The medium’s role transforms. Its content is recontextualized and new meanings or interpretations emerge.
Some things are so awesomely enormous that it’s difficult to grasp just how big they are until they’re put into a more relatable perspective. Today, thanks to Belgian amateur astronomer Michel (@quark1972), we get to appreciate the size of comet 67P/Churyumov-Gerasimenko (aka the rubber ducky comet).
This is the comet that the ESA’sRosetta spacecraft reached on August 6, 2014 after a ten year, five month and four day-long journey nearly 4 million miles into space. The Rosetta will now spend the next two years studying the comet, including the deployment of a lander, the Philae, down to the comet’s surface.
Head over to the ESA website to learn lots more about this amazing mission.
There are tens of trillions of microbes in our guts, which are important for our digestion and our health. The antibiotics that we take to kill off disease-causing bacteria also indiscriminately nuke these beneficial bugs. Now, a new set of experiments in mice have shown that low, regular doses of antibiotics at an early age can disrupt these microbe communities, leading to weight gain later in life. The increase in body weight was small, but compounded by a high-fat diet. If the results apply to humans, they would add to the large body of evidence suggesting that antibiotics should be used more carefully in infants and children.
“I’m not saying people should never take antibiotics,” says Martin Blaserfrom the NYU Langone Medical Centre, who led the study. “But we need to be more judicious. Antibiotics can have long-term consequences. I hope that knowledge will enter the examining room, so that parents don’t demand antibiotics and doctors are more cautious about using them.”
This sounds familiar…
Two years ago, Blaser’s team showed that antibiotics can change the gut microbes of young mice, which then grow up fatter. This new study confirms and builds upon those earlier results. More generally, farmers have been fattening livestock for decades by giving them low doses of antibiotics in their food—it’s the microbe connection that’s new. And Blaser himself has been discussing these ideas a lot, in the wake of his recent book, Missing Microbes.
What did the new experiments show?
The new studies represent a huge amount of work, largely done by graduate student Laurie Cox. First, she exposed mice to low doses of penicillin at two points in time: either when they were being weaned at four weeks old, or right from the start of their lives (by dosing their mothers). By 20 weeks of age, the mice that experienced penicillin from birth were heavier and fatter, especially the males. They also had very different gut microbes.
A high-fat diet exacerbated this effect, especially in females. If female mice were raised on fatty chow and penicillin, they put on twice as much fat as those that ate the fatty chow alone. (It’s not clear why there’s a gender difference.)
In these experiments, the mice were on antibiotics for their entire lives. Next, Cox showed that much shorter bursts are enough. Four weeks of early exposure can change the rodents’ gut microbes. These communities returned to normal after eight weeks, but the mice still got fatter, and their immune systems were still weaker. This suggests that there’s a critical window where microbial upheavals have long-lasting consequences. This makes sense: our gut microbes are an active part of our development. As we grow up, they help to set our metabolism and train our immune systems. Just as schooling and education can have lasting effects on our lives, microbial education might permanently affect a mammal’s health.
Finally, Cox transplanted the microbes from the antibiotic-treated mice into germ-free ones that had no microbes of their own. These recipients alsobecame heavier and fatter. “The fact that you can transfer the [effects] by transferring the microbes is pretty solid evidence of causality,” says Jack Gilbert from the University of Chicago. “It is excellent confirmation of what [Blaser] has been expounding for a while.”
Which microbes were affected?
The penicillin depleted four particular groups, and they’re a slightly weird quartet. One of them, Lactobacillus, is very well known—common in our guts and in probiotics. But the others—two species called Allobaculum andArthromitus, and a wider group called the Rikenellaceae—are more obscure.Allobaculum was only discovered ten years ago. Arthromitus seems to only live in mice and not humans. These microbes might help to prevent their hosts from putting on too much weight, but it’s too early to say.
How does antibiotic treatment lead to weight gain?
It’s clear that the penicillin did at least four things: it changed the gut microbes; it changed the rodents’ metabolism; it increased inflammation in the gut; and it increased the risk of obesity. But, as Les Dethlefsen from Stanford University told me, it’s hard to know how these effects are connected. The microbes could be responsible for everything else. Alternatively, the drugs themselves could cause some of the effects, and the microbes others. We’re probably looking at a tangled web of causality rather than a linear chain.
Physics educator James Lincoln helps people understand the natural world. The gifs above are from a Youtube video he made on how to “see” an electric field, the region around a charged object where electric force is experienced. When the object is positively charged, electric field lines extend radially outward from the object. When the object is negatively charged, the lines extend radially inward.
Click the gifs for more info or see the full video below.
A team led by researchers at the University of Exeter Medical School and King’s College London has uncovered some of the strongest evidence yet that epigenetic changes in the brain play a role in Alzheimer’s disease.
Epigenetic changes affect the expression or activity of genes without…