By Patricia Daukantas

Imagine seeing the real-time beating heart of an embryo, complete with red cells flowing through the blood vessels. That’s the kind of detail that Texas (U.S.A.) researchers are getting with optical coherence tomography (OCT).

Granted, the team used mouse embryos, but the scientists hope that their work will someday lead to a better understanding of humans’ congenital cardiovascular abnormalities, which occur in 1 percent of live births.

Kirill Larin of the University of Houston (UH), working with colleagues from UH and Baylor College of Medicine, showed his audience stunning 48-frames-per-second images of mouse embryos from 7.5 to 10.5 days old. At 7.5 days, the heart is not yet formed, although a small spot on the embryo is “beating” rhythmically. At 8.5 days, a tube-shaped structure is beating within the thoracic cavity. At 9.5 days, the embryo clearly has a four-chambered heart whose beat has increased to a normal embryonic speed.

The Texas group has been studying this type of imaging at the red-blood-cell level for about a year and has published in several journals including Optics Letters (Larina et al., Vol. 34, p. 986 [2009]).

Larin’s presentation was one of a number of interesting talks last Thursday, the final day of the Frontiers in Optics/Laser Science (FiO/LS) conference in San Jose, Calif., U.S.A. I would like to wrap up this blog’s coverage of FiO with notes on several other noteworthy sessions that I simply did not have time to write about while the meeting was still going on.

Acetylene: Not just for welding

Robert W. Field of the Massachusetts Institute of Technology (U.S.A.), who gave the American Physical Society’s Arthur L. Schawlow Prize lecture, called acetylene his favorite molecule. He’s been studying it for 30 years – longer, he said, than he’s known his wife.

Acetylene is a simple hydrocarbon with the chemical formula HC₂H, and I’d always thought of it as a fuel for welding and metal cutting (thanks to my late father, who was a welder by trade). But Wood, a physical chemist, has used the tiny molecule as the subject of multiple-resonance laser spectroscopy probing the fundamental mechanisms of bond-breaking and isomerization.

Wood laced his talk with humor, calling his spectroscopy experiments “laser and microwave tricks to thwart the evil that lurks in the hearts of small molecules.”

MWOSA: Testing implicit assumptions

At a teatime gathering of Minorities and Women in OSA (MWOSA), featured speaker Linda M. Garverick, a leadership consultant based in Cleveland, Ohio (U.S.A.), challenged her audience to assess the hidden biases that everyone carries.

“We make connections much more quickly between pairs of ideas that are already related in our minds than we do between pairs of ideas that are unfamiliar to us,” she cautioned. When role models don’t exist, unconscious bias is perpetuated to the next generation. Self-reflection is the key to becoming conscious of our biases and motivations.

Garverick led a lively discussion about diversity in gender, race and ethnicity in the academic community. Some of the ideas in her talk came from Malcolm Gladwell’s recent book Blink: The Power of Thinking Without Thinking as well as The Fifth Discipline Fieldbook: Strategies and Tools for Building a Learning Organization by Peter Senge et al.

She suggested some techniques for “powerful advocacy” that are also outlined in Senge’s book. Examples: Make your thinking and reasoning explicit; listen, stay open and encourage other people to express different perspectives; and try not to get defensive when your ideas are questioned.

Biophysics and virtual photonics

Eric Mazur and his colleagues at Harvard University (U.S.A.) have been performing nano-neurosurgery on C. elegans, a nematode whose genome has been fully sequenced. “They’re very easy to handle, even for a physicist,” Mazur quipped. These tiny worms have 302 neurons, and all of them are wired exactly the same way, which isn’t true of most other animals. By snipping one or two neurons at a time with a femtosecond laser and then watching to see whether the worm can still detect the presence of substances it dislikes, scientists can infer the role of each neuron in the worm’s behavior.

Transport-based models of radiative, photo thermal and photochemical interactions between light and living tissues are necessary in nearly all biomedical optics applications. However, said Vasan Venugopalan of the University of California at Irvine (U.S.A.), the biomedical community lacks ready access to advanced computational tools for modeling these light interactions with cells and tissues.

Venugopalan and colleagues are developing an open-source framework called the Virtual Tissue Simulator, or VTS, which will solve, analyze and visualize biophysical models. Scientists with more experience in optics than computer science would be able to plug in problem-specific VTS “application toolkits” to simulate fiber-optic probes, small-animal imaging, phototherapy and other experiments. The team is looking for both toolkit developers and bio-optical experimentalists; check out its Web site at http://www.virtualphotonics.org/.

The third dimension

One of the special symposia at this year’s FiO/LS was “The Future of 3-D Display: The Marketplace and the Technology.” But in many ways, the future is already here, said symposium keynoter Rod Archer, engineering vice president of RealD Inc. (Beverly Hills, Calif., U.S.A.).

If you’ve purchased a high-def TV in the last year or so, chances are it’s already 3D-capable, even if you’re not yet receiving any 3D programming. By 2012, millions of TV sets will have 3D, according to Archer, and the first 3D Xbox game debuted just a few weeks ago. FiO blogger Adam Zysk also attended Archer’s talk and covered some of the technology.

For 3D to really take off, companies need to develop eyegear-free stereo viewing, and RealD is among the companies working on that. Headgear-free 3D will probably first appear on small screens for personal use, such as cell phones and handheld gaming devices – applications that Archer called the “brass ring” for the technology.

Other coverage

I’ve mentioned Adam Zysk’s blog, but Bob Schoonover and Shalin Mehta also covered the conference and provided novel insights. Links to all three blogs remain up on FiO’s online media page.

Next year, FiO/LS moves back to Rochester, N.Y. (U.S.A.) during the last week of October 2010. See you there!

2009-10 October fio