Lightning Strikes Can Change Rocks' Atomic Structure

New research suggests that rock crystals melt under the intense force and heat of lightning

Lightning strikes near the U.S. Capitol building (Tech. Sgt. Cherie A. Thurlby/U.S. Air Force)

When lightning strikes sand in the desert, it instantly melts the grains, creating complex structures that geologists call fulgurites. These structures of partially melted minerals can also be found in lightning-struck rocks. But that's just the beginning: While investigating this phenomenon on an outcropping in southern France, researchers discovered that the changes can go even further — down to the atomic level. 

Lightning can warp quartz crystals in rock to form distinct structures typically found in meteorites, reports Elizabeth Goldbaum for LiveScience. So-called shock lamellae are minute parallel lines that run through the quartz and indicate the rock was hit with an intense force. 

"It's like if someone pushes you, you rearrange your body to be comfortable," researcher Reto Gieré of the University of Pennsylvania says in a press statement by Katherine Unger Baillie. "The mineral does the same thing." Lightning's push, however, is equivalent to a force that's 20 million times greater than a boxer's punch, as Baillie writes.

Goldbaum reports for LiveScience:

After looking at very thin, almost transparent, slices of the fulgurites under a powerful microscope, the researchers noticed that the black fulgurite looked glossy, "almost like a ceramic glaze," Gieré said. The fulgurite was also porous, similar to foam; the researchers suspect it got that way when the sizzling lightning vaporized the rock's surface.

Chemical traces of sulfur dioxide and phosphorous pentoxide were all that remained of what the researcher believe was once lichen growing on the rock’s surface. Under the foamy, glassy fulgurite layer, shock lamellae were hidden, only visible with a transmission electron microscope. There, a thin layer of what were once quartz crystals had melted and deformed so much that the crystal structure was destroyed. The team published their findings in American Mineralogist.

Once he knew what to look for, Gieré started seeing a wet, darkened look to rocks that indicated the presence of fulgurites in many places. He suggests that hikers should stay on the lookout for such rocks — especially when trekking across exposed rocky faces or scrambling to the crowns of mountaintops. Fulgurites could warn of an area prone to lightning strikes and are a good reason to keep an eye on the clouds.

The fulgurite on this rock resembles a dark stain. Via PennNews (PennNews)

ORIGINAL: Smithsonian

By Marissa Fessenden SMITHSONIAN.COM 

AUGUST 17, 2015

DARPA Project Starts Building Human Memory Prosthetics

The first memory-enhancing devices could be implanted within four years

Photo: Lawrence Livermore National LaboratoryRemember This? Lawrence Livermore engineer Vanessa Tolosa holds up a silicon wafer containing micromachined implantable neural devices for use in experimental memory prostheses.

“They’re trying to do 20 years of research in 4 years,” says Michael Kahana in a tone that’s a mixture of excitement and disbelief. Kahana, director of the Computational Memory Lab at the University of Pennsylvania, is mulling over the tall order from the U.S. Defense Advanced Research Projects Agency (DARPA). In the next four years, he and other researchers are charged with understanding the neuroscience of memory and then building a prosthetic memory device that’s ready for implantation in a human brain.

DARPA’s first contracts under its Restoring Active Memory (RAM) program challenge two research groups to construct implants for veterans with traumatic brain injuries that have impaired their memories. Over 270,000 U.S. military service members have suffered such injuries since 2000, according to DARPA, and there are no truly effective drug treatments. This program builds on an earlier DARPA initiative focused on building a memory prosthesis, under which a different group of researchers had dramatic success in improving recall in mice and monkeys.

Kahana’s team will start by searching for biological markers of memory formation and retrieval. For this early research, the test subjects will be hospitalized epilepsy patients who have already had electrodes implanted to allow doctors to study their seizures. Kahana will record the electrical activity in these patients’ brains while they take memory tests.

“The memory is like a search engine,” Kahana says. “In the initial memory encoding, each event has to be tagged. Then in retrieval, you need to be able to search effectively using those tags.” He hopes to find the electric signals associated with these two operations.

Once they’ve found the signals, researchers will try amplifying them using sophisticated neural stimulation devices. Here Kahana is working with the medical device maker Medtronic, in Minneapolis, which has already developed one experimental implant that can both record neural activity and stimulate the brain. Researchers have long wanted such a “closed-loop” device, as it can use real-time signals from the brain to define the stimulation parameters.

Kahana notes that designing such closed-loop systems poses a major engineering challenge. Recording natural neural activity is difficult when stimulation introduces new electrical signals, so the device must have special circuitry that allows it to quickly switch between the two functions. What’s more, the recorded information must be interpreted with blistering speed so it can be translated into a stimulation command. “We need to take analyses that used to occupy a personal computer for several hours and boil them down to a 10-millisecond algorithm,” he says.

In four years’ time, Kahana hopes his team can show that such systems reliably improve memory in patients who are already undergoing brain surgery for epilepsy or Parkinson’s. That, he says, will lay the groundwork for future experiments in which medical researchers can try out the hardware in people with traumatic brain injuries—people who would not normally receive invasive neurosurgery.

The second research team is led by Itzhak Fried, director of the Cognitive Neurophysiology Laboratory at the University of California, Los Angeles. Fried’s team will focus on a part of the brain called the entorhinal cortex, which is the gateway to the hippocampus, the primary brain region associated with memory formation and storage. “Our approach to the RAM program is homing in on this circuit, which is really the golden circuit of memory,” Fried says. In a 2012 experiment, he showed that stimulating the entorhinal regions of patients while they were learning memory tasks improved their performance.

Fried’s group is working with Lawrence Livermore National Laboratory, in California, to develop more closed-loop hardware. At Livermore’s Center for Bioengineering, researchers are leveraging semiconductor manufacturing techniques to make tiny implantable systems. They first print microelectrodes on a polymer that sits atop a silicon wafer, then peel the polymer off and mold it into flexible cylinders about 1 millimeter in diameter. The memory prosthesis will have two of these cylindrical arrays, each studded with up to 64 hair-thin electrodes, which will be capable of both recording the activity of individual neurons and stimulating them. Fried believes his team’s device will be ready for tryout in patients with traumatic brain injuries within the four-year span of the RAM program.

Outside observers say the program’s goals are remarkably ambitious. Yet Steven Hyman, director of psychiatric research at the Broad Institute of MIT and Harvard, applauds its reach. “The kind of hardware that DARPA is interested in developing would be an extraordinary advance for the whole field,” he says. Hyman says DARPA’s funding for device development fills a gap in existing research. Pharmaceutical companies have found few new approaches to treating psychiatric and neurodegenerative disorders in recent years, he notes, and have therefore scaled back drug discovery efforts. “I think that approaches that involve devices and neuromodulation have greater near-term promise,” he says.

This article originally appeared in print as “Making a Human Memory Chip.”

ORIGINAL: IEES Spectrum

By Eliza Strickland

Posted 27 Aug 2014

DARPA Wants a Memory Prosthetic for Injured Vets—and Wants It Now

Photo: Getty Images

No one will ever fault DARPA, the Defense Department's mad science wing, for not being ambitious enough. Over the next four years, the first grantees in its Restoring Active Memory (RAM) program are expected to develop and test prosthetic memory devices that can be implanted in the human brain. 

It's hoped that such synthetic devices can help veterans with traumatic brain injuries, and other people whose natural memory function is impaired. The two teams, led by researchers Itzhak Fried at UCLA and Mike Kahana at the University of Pennsylvania, will start with the fundamentals. 

They'll look for neural signals associated with the formation and recall of memories, and they'll work on computational models to describe how neurons carry out these processes, and to determine how an artificial device can replicate them. They'll also work with partners to develop real hardware suitable for the human brain. Such devices should ultimately be capable of recording the electrical activity of neurons, processing the information, and then stimulating other neurons as needed.The RAM research derives from an engineering approach to memory that's gaining traction. (Spectrum covered the work of one of its leading proponents, Ted Berger, in the recent article The End of Disability.) If the brain is essentially a collection of circuits, the thinking goes, a memory is formed by the sequential actions of many neurons. If a person has a brain injury that knocks out some of those neurons, the whole circuit may malfunction, and the person will experience memory problems. But if electrodes can pick up the signal in the neurons upstream from the problem spot, and then convey that signal around the damage to intact neurons downstream, then the memory should function as normal.

In a press briefing yesterday, program manager Justin Sanchez said that the first human experiments will be conducted with hospitalized epilepsy patients who have electrodes implanted in their brains as they await surgery (this is done so their doctors can pinpoint the origin of their seizures). Since epilepsy patients often experience memory loss as well, Sanchez said they're a natural fit for the research. Eventually trials would include military servicemembers who suffer the aftereffects of traumatic brain injuries, and finally civilians with similar injuries. 

DARPA recently decided to beef up its research in biological technologies, spurred in part by the needs of veterans returning from Iraq and Afghanistan. But it seems likely that the agency's increased attention to programs like RAM was also prompted by the recognition that neural engineering is one of the most exciting frontiers in science, with the neural technologies advancing faster than the science that guides it.

The RAM program is part of the overarching federal BRAIN Initiative, announced with much fanfare by President Obama in 2013. With a first-year budget of $110 million parceled out to three agencies and considerable cooperation from deep-pocketed private institutions, you can expect this decade to be a brainy one.

ORIGINAL: Spectrum
By Eliza Strickland
9 Jul 2014

Can Gene Therapy Cure HIV?

Why It Matters

There is no cure for HIV, which can cause AIDS. In 2012, 1.6 million people died of AIDS-related illnesses.

The immune cells of HIV patients can be genetically engineered to resist infection, say researchers. In a small study in humans, scientists report that by creating a beneficial mutation in T cells, they may be able to nearly cure patients of HIV.

In a study published in the New England Journal of Medicine on Wednesday, researchers report that they can use genome editing to re-create the rare mutations responsible for protecting about 1 percent of the population from the virus in infected patients. They report that some of the patients receiving the genome-modifying treatment showed decreased viral loads during a temporary halt of their antiretroviral drugs. In one patient, the virus could no longer be detected in his blood.


Zinc-finger nucleases are one of a few genome-editing tools that researchers use to create specific changes to the genomes of living organisms and cells (see “Genome Surgery”). Scientists have previously used genome-editing techniques to modify DNA in human cells and nonhuman animals, including monkeys (see “Monkeys Modified with Genome Editing”). Now, the NEJM study suggests the method can also be safely used in humans.

From each participating patient, the team harvested bone marrow stem cells, which give rise to T cells in the body. They then used a zinc finger nuclease to “break” copies of the CCR5 gene that encodes for proteins on the surface of immune cells that are a critical entry point of HIV. The stem cells were then infused back into each patient’s bloodstream. The modification process isn’t perfect, so only some of the cells end up carrying the modification. “About 25 percent of the cells have at least one of the CCR5 genes interrupted,” says Edward Lanphier, CEO of Sangamo Biosciences, the Richmond, California, biotech company that manufactures zinc finger nucleases.

Because the cells are a patient’s own, there is no risk of tissue rejection. The modified stem cells then give rise to modified T cells that are more resistant to infection by HIV, say the researchers.

One week after the infusion, researchers were able to find modified T cells in the patients’ blood. Four weeks after the infusion, six of the 12 patients in the study temporarily stopped taking their antiretroviral drugs so the researchers could assess the effect of the genome-editing treatment on the amount of the virus in the patients’ bodies. In four of these patients, the amount of HIV in the blood dropped. In one patient, the virus could no longer be detected at all. The team later discovered that this best responder had naturally already had one mutated copy of the CCR5 gene.

Patients who carry one broken copy of the CCR5 progress to AIDS more slowly than those who don’t, says Bruce Levine, a cell and gene therapy researcher at the University of Pennsylvania School of Medicine and coauthor on the study. Because all of the cells in that best-responder patient already carried one disrupted copy of CCR5, the modification by the zinc finger nuclease led to T cells with no functional copies of the gene. That means the cells are fully resistant to HIV infection. The team is now working to increase the number of immune cells that end up carrying two broken copies of CCR5.

ORIGINAL: Technology Review