Off Switches for Killer Bacteria

Genetically engineered (GE) bacteria are not just the stuff of science fiction novels. They can be used to carry biomarkers and treatments to cancer tumors as well as to control and eliminate oil spills.

But how do we get rid of these helpers once their task is complete? 

Off switches.

Clement T Y Chan, Jeong Wook Lee, D Ewen Cameron, Caleb J Bashor & James J Collins, (researchers at MIT's Institute for Medical Engineering & Science, Cambridge, Massachusetts) have created synthetic gene circuits that act as "OFF Switches" that kill GE microbes once their job is done. Two circuits, described in the Dec. 7th issue of Nature Chemical Biology, increase the safety of diagnostics, therapies, or environmental remediation strategies based upon GE bacteria. They are called appropriately called "Deadman" and "Passcode." Its good to know folks are thinking ahead. Go science!

Arkansas Science Festival

Since I love science and technology, some of you have probably heard me say, "All science, all the time" when asked about my interests and this blog. Well, here is another chance to share science research and discoveries. On October 6th, 2014, I will be hosting a Science Cafe at Godfrey's in Jonesboro, AR, starting at 6:30 p.m. as part of the Arkansas Science Festival.

The topic is: Rocket Science - Motors, Models, and Microorganisms in Space Exploration. My panelists will be David Thomas, Ph.D., Prof. of Biology, Lyon College, Ed Wilson, Ph.D., Professor of Chemistry, Harding University, and Tillman Kennon, Ph.D., Associate Professor of Science Education, Arkansas State University. Each of these folks do research in various aspects of space exploration. It will be a fun and relaxed evening with each panelist speaking for a few minutes about his work and then the event opened up for Q&A.

I may also be persuaded to provide a few stories from my 13 years at NASA- Johnson Space Center, Houston, TX and will have a some of my science books available for purchase afterwards. I look forward to seeing you there! Go science!

Scientists studying the songs of songbirds have found it to be mostly a learned behavior subject to environmental influences like rearing and food availability. In fact, researchers from the Max Planck Institute for Ornithology in Seewiesen compared song and brain structure of parents and offspring in zebra finches that were raised with genetic or foster parents. They also varied the amount of food during breeding. They found that song and underlying brain structure didn't appear to be as affected by genetics as by strong environmental factors.

These results related to a human behavioral biology question (i.e., which aspects of behavior are learned compared to those expressed by genetic predisposition). It's known that human personality and behavior are much less set by genetic background. Environmental factors shape brain and behavior by so-called epigenetic effects. In fact, hormones play an big role and can have long lasting effects. 

Research with zebra finch breeding pairs (where half of the hatchlings were raised by their genetic parents, and the other half were raised by their foster parents) showed this too. At 100 days when the male offspring were grown, the researchers recorded their songs. The results showed that genetic heritability was low for most song characteristics, except the number of song syllables and maximum frequency. The rearing environment and song of the foster father mainly predicted the unique syllables of the sons' songs and was dependent on food availability. 

So keep feeding the birds in your backyard and providing a healthy environment. Songbirds will be happy and singing. Go Science!

The Tiny World of Sand

The world at the nanoscale is so interesting. It never ceases to amaze me. I recently came across several TED videos on nano and other small members of our planet. Check out the variety of life in our unseen world. The biological and geological record of life on this planet is all there. It will change the way you think of materials, physics, and even environmentalism. This video shows many components within sand (even sand on the moon). Amazing.