The Laboratory in the News

Advanced Biodetection with Microbiome Array

Veterinarians and agricultural inspectors who seek to detect and contain the spread of animal diseases can now turn to a newer, faster, and less expensive biological detection system. The device is the commercialized successor to Lawrence Livermore’s earlier detection platform—the Lawrence Livermore Microbial Detection Array (LLMDA), which was licensed in 2016 to Thermo Fisher Scientific and went on sale later that year as Applied Biosystems™ AMA.

In a yearlong evaluation, published in the February 8, 2019, issue of PLOS ONE, a team of researchers from Livermore, Kansas State University, and Thermo Fisher Scientific used AMA to test 14 veterinary samples and 30 environmental samples for pathogens and found that AMA performed at a resolution similar to the highly effective LLMDA, but with a much higher throughput. Livermore biologist Crystal Jaing, who leads the detection system effort, says, “AMA increases the throughput by 10- to 20-fold and decreases the cost by 5-fold.”

The AMA device is the most comprehensive and efficient microorganism detection platform built to date. It can analyze 96 samples in just 3 days (compared to 4 samples in a single day with LLMDA) and detect more than 12,000 microorganisms, including 6,901 bacteria; 4,770 viruses; and a combined total of 842 archaea, fungi, and protozoa. The new arrays can also analyze a variety of sample types and have applications in nutrigenomics, agrigenomics, and animal research and modeling.
Contact: Crystal Jaing (925) 424-6574 (jaing2@llnl.gov).

Printing the “Building Blocks” of Computers

Lawrence Livermore scientists and engineers with colleagues from the University of California at Los Angeles are using three-dimensional (3D) printing to create mechanical logic gates (see image at right)—the basic building blocks of computers that can perform any kind of mathematical calculation. The work is part of an effort to create materials that respond to changes in their surroundings, including in extreme environments such as high radiation, heat, or pressure, which would destroy electronic components. The research was reported in the February 20, 2019, edition of Nature Communications.

The mechanical logic gates incorporate flexure components that allow the system to bend and move, behaving similar to switches. The flexures are chained together and, when stimulated, trigger a cascade of configurations that can be used to perform mechanical logic calculations without external power. Results are translated into movement, creating a domino effect throughout all the gates that physically changes the device’s shape. Lead researcher Andy Pascall says, “If these logic gates were embedded into a material, it could respond to its environment in a controlled, precise way.”

Mechanical logic gates, while not as powerful as the physical ones used in typical computers, could prove useful in rovers sent to hostile environments, such as Venus, or in low-power computers intended to survive nuclear or electromagnetic pulse blasts. The gates also have potential uses in vaccine and food safety processes as well as industrial applications. “Using 3D printing, our design is not limited in scale,” says Pascall. “We can fabricate components down to several micrometers or up to as big as we need them to be, and they can be rapidly prototyped.”
Contact: Andy Pascall (925) 423-1926 (pascall1@llnl.gov).

Extreme Volcanism Played Role in Dinosaur Extinction

The catastrophic Chicxulub meteorite impact in Mexico has long been viewed as the sole cause of the mass extinction at the Cretaceous–Paleogene boundary—the geological moment when many creatures from the age of dinosaurs vanish from the fossil record. In research that appeared in the February 22, 2019, edition of Science, Lawrence Livermore scientist Kyle Samperton and colleagues present the most compelling evidence yet that massive volcanic eruptions in the Deccan Traps region of India also contributed to the fall of the dinosaurs approximately 66 million years ago.

Previously, the team analyzed ratios of uranium and lead isotopes in the mineral zircon to determine that Deccan flood basalt volcanoes began their main eruptions roughly 250,000 years before the extinction and were ongoing for the next 750,000 years, unleashing about 80 to 90 percent of the area’s lava flows. The team’s new findings suggest Deccan eruptions were highly nonlinear, having four major volcanic pulses. According to this eruptive age model, the largest volcanic pulse immediately precedes the mass extinction event with an approximate 90 percent probability.

Volcanoes spew both sulfur dioxide, which cools the atmosphere on short timescales, and carbon dioxide, which warms the atmosphere on long timescales. The pulsed eruptions likely resulted in extreme short-term cooling, followed by long-term warming. “Such dramatic shifts in atmospheric temperature can be catastrophic for delicately balanced ecosystems,” says Samperton. “Our finding confirms what researchers have long suspected regarding the pulsed tempo of flood basalt eruptions over Earth’s history.”
Contact: Kyle Samperton (925) 422-9258 (samperton1@llnl.gov).