Month: January 2017

fMRI images of a brain during a memory task (not from the present study). (credit: Walter Reed National Military Medical Center)

A group of researchers has constructed an experiment to examine how emotional experiences affect the formation of memories. It’s already well-documented that emotional experiences are not only more likely to be recorded in memory. But emotional events also affect unrelated memories, strengthening the recall of unassociated events that happened just before the emotional surge. The new study looks at the flipside of that—how long an emotional event affects memory after the stimulation ends. This is a relatively unexplored area of research.

To find out, the researchers constructed a test using an fMRI. One group of participants was exposed to emotional stimuli for about 23 minutes, followed by a nine-minute rest, followed by a 23-minute period with emotionally neutral stimuli. The second group had these experiences reversed a neutral period followed by a rest and then some emotionally charged experiences. The final group simply had two emotionally neutral periods with the same gap between them.

The researchers hypothesized that the emotional period's influence on memory would last into the neutral period. If this is correct, the first setup—emotional then neutral—should trigger improved memory during the neutral period. The other two arrangements, however, shouldn’t have this effect if the researchers’ hypothesis is accurate.

Enlarge / The summer minimum sea ice extent in 2016 (which tied for 2nd lowest on record) compared to the 1981-2010 median. (credit: NASA Earth Observatory)

There are a couple different ways to come at the problem of climate change—you can focus on eliminating the cause, or on mitigating the symptoms. The latter approach includes obvious things like preventing flooding from rising sea levels. But it also ranges into “geoengineering” schemes as radical as injecting sunlight-reflecting aerosol droplets into the stratosphere. Such schemes are band-aids rather than cures, but band-aids have their uses.

One worrying change driven by the climate is the loss of Arctic sea ice. The late-summer Arctic Ocean is on track to become ice-free around the 2030s. The rapid warming of the Arctic has serious implications for local ecosystems, but it also influences climate elsewhere in ways we’re still working to fully understand. One frequently mentioned effect is the increased absorption of sunlight in the Arctic as reflective snow and ice disappears—a positive feedback that amplifies warming.

What if we could slap a sea ice band-aid on the Arctic? In a recent paper, a group of Arizona State researchers led by astrophysicist Steven Desch sketch out one hypothetical band-aid—a geoengineering scheme to freeze more ice during the Arctic winter.

The launch of SpaceX's Eutelsat/ABS mission, on June 15, 2016. (credit: SpaceX)

Four months after a fueling accident led to the loss of a Falcon 9 rocket and its satellite payload, SpaceX said Monday morning that it has concluded an investigation into the incident and submitted its findings to the Federal Aviation Administration. The company also announced a target date of January 8th for a return to flight.

The SpaceX investigation, in concert with the FAA, US Air Force, NASA, and the National Transportation Safety Board, concluded that one of three composite overwrapped pressure vessels, or COPVs, inside the rocket's second stage liquid oxygen tank failed. "Specifically, the investigation team concluded the failure was likely due to the accumulation of oxygen between the COPV liner and overwrap in a void or a buckle in the liner, leading to ignition and the subsequent failure of the COPV," the company stated in an update.

COPVs are used in rocketry to contain high pressure fluids and offer a substantial weight savings over all-metal tank designs. In a general sense, a composite simply means a matrix of carbon fibers contained within a resin, which is then wrapped over a pressure barrier. The Falcon 9 rocket uses COPVs that consist of a carbon wrap over an aluminum liner to store cold helium, which in turn is used to maintain tank pressure.

Video shot/edited by Jennifer Hahn. (video link)

LAS VEGAS—Dell kicked off CES 2017 by adding a some flexibility to one of its most popular notebooks. The company announced the new Dell XPS 13 two-in-one, which takes everything good about the latest Dell XPS 13 notebook and puts it into a convertible design. According to Dell, the priority with this new convertible (as well as the rest of its two-in-one notebooks) was to make a device that could perform well in tablet, tent, and other modes, but that didn't lose the practicality and functionality of a regular laptop.

The cosmetic differences between the new XPS 13 convertible and Dell's original notebook aren't glaring, but they are important. Most noticeable is the new hinge connecting the display to the keyboard deck. Using two geometric attachments, the display is able to flip backwards and lie nearly flat against the back of the keyboard deck. There is space in between the two panels, making it look less seamless than a device like Lenovo's Yoga Book. Also, the display panel and the keyboard deck are not the same length, which makes the keyboard deck jut out slightly more than the lid when in tablet mode.

Nature

Forty years after she was discovered, Lucy, the world’s most famous fossil australopithecine, just might have a cause of death. In August of this year, a team of paleoanthropologists led by John Kappelman argued in Nature that Lucy died 3.2 million years ago by falling out of a tree. Their conclusion has been met with skepticism among fellow researchers, and Lucy's death-by-tree-fall hypothesis has generated no shortage of debate within the scientific community of paleoanthropology.

But there's a takeaway here that's more significant than the study’s conclusion—this study's approach to sharing data with the scientific community and the public at large. In a move that is in keeping with the growing trend across paleoanthropology and other sciences to open up access to data, the study’s scientists have published CT scans of Lucy’s tibia, femur, humerus, and scapula—all bones they analyzed in their study. Now, they invite colleagues, detractors, educators, and ardent fossil enthusiasts to download and print Lucy’s scans, encouraging audiences to “evaluate the hypothesis for themselves.”