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Scientists report the first scientific results from NASA’s Juno mission, now in orbit around Jupiter.

This week, a suite of 46 separate scientific papers describe different aspects of the giant planet Jupiter, from its massive polar cyclones, to its complex magnetic field, to its unique radiation environment. The papers mark the first full scientific results from NASA’s Juno mission, which arrived in orbit around Jupiter last summer. Later this July, the craft is slated to overfly the planet’s Great Red Spot, bringing back still more data. Juno program scientist Jared Espley and Juno radiation monitoring investigation lead Heidi Becker join Ira to sum up some of the Jovian surprises, as well as give a preview of what still lies ahead for the Juno mission. Listen here to learn more.

[Photos by NASA/JPL/MSSS/Gerald Eichstädt/Justin Cowart/Alexis Tranchandon/Solaris]

Hold a buoyant sphere like a ping pong ball underwater and let it go, and you’ll find that the ball pops up out of the water. Intuitively, you would think that letting the ball go from a lower depth would make it pop up higher – after all, it has a greater distance to accelerate over, right? But it turns out that the highest jumps comes from balls that rise the shortest distance. When released at greater depths, the buoyant sphere follows a path that swerves from side to side. This oscillating path is the result of vortices being shed off the ball, first on one side and then the other. (Image and research credit: T. Truscott et al.)

Researchers identify method of creating long-lasting memories

Imagine if playing a new video game or riding a rollercoaster could help you prepare for an exam or remember other critical information.

A new study in mice shows this link may be possible.

Attention-grabbing experiences trigger the release of memory-enhancing chemicals. Those chemicals can etch memories into the brain that occur just before or soon after the experience, regardless of whether they were related to the event, according to researchers at UT Southwestern Medical Center’s Peter O’Donnell Jr. Brain Institute.

The findings, published in Nature, hold intriguing implications for methods of learning in classrooms as well as an array of potential uses in the workplace and personal life, researchers said.

The trick to creating long-lasting memories is to find something interesting enough to activate the release of dopamine from the brain’s locus coeruleus (LC) region.

“Activation of the locus coeruleus increases our memory of events that happen at the time of activation and may also increase the recall of those memories at a later time,” said Dr. Robert Greene, the study’s co-senior author and a Professor of Psychiatry and Neurosciences with the O’Donnell Brain Institute.

The study explains at the molecular level why people tend to remember certain events in their lives with particular clarity as well as unrelated details surrounding those events: for instance, what they were doing in the hours before the Sept. 11, 2001, terrorist attacks; or where they were when John F. Kennedy was assassinated.

“The degree to which these memories are enhanced probably has to do with the degree of activation of the LC,” said Dr. Greene, holder of the Sherry Gold Knopf Crasilneck Distinguished Chair in Psychiatry, in Honor of Mollie and Murray Gold, and the Sherry Knopf Crasilneck Distinguished Chair in Psychiatry, in Honor of Albert Knopf. “When the New York World Trade Center came down on 9/11, that was high activation.”

But life-changing events aren’t the only way to trigger the release of dopamine in this part of the brain. It could be as simple as a student playing a new video game during a quick break while studying for a crucial exam, or a company executive playing tennis right after trying to memorize a big speech.

“In general, anything that will grab your attention in a persistent kind of way can lead to activation,” Dr. Greene said.

Scientists have known dopamine plays a large role in memory enhancement, though where the chemical originates and how it’s triggered have been points of study over the years.

Dr. Greene led a study published in 2012 that identified the locus coeruleus as a third key source for dopamine in the brain, besides the ventral tegmental area and the substantia nigra. That research demonstrated the drug amphetamine could pharmacologically trigger the brain’s release of dopamine from the LC.

The latest study builds upon those findings, establishing that dopamine in this area of the brain can be naturally activated through behavioral actions and that these actions enhance memory retention.

The new study suggests that drugs targeting neurons in the locus coeruleus may affect learning and memory as well. The LC is located in the brain stem and has a range of functions that affect a person’s emotions, anxiety levels, sleep patterns, memory and other aspects of behavior.

The study tested 120 mice to establish a link between locus coeruleus neurons and neuronal circuits of the hippocampus – the region of the brain responsible for recording memories – that receive dopamine from the LC.

One part of the research involved putting the mice in an arena to search for food hidden in sand that changed location each day. The study found that mice that were given a “novel experience” – exploring an unfamiliar floor surface 30 minutes after being trained to remember the food location – did better in remembering where to find the food the next day.

Researchers correlated this memory enhancement to a molecular process in the brain by injecting the mice with a genetically encoded light-sensitive activator called channelrhodopsin. This sensor allowed them to selectively activate dopamine-carrying neurons of the locus coeruleus that go to the hippocampus and to see first-hand which neurons were responsible for the memory enhancement.

They found that selectively activating the channelrhodopsin-labeled neurons with blue light (a technique called optogenetics) could substitute for the novelty experience as a memory enhancer in mice. They also found that this activation could cause a direct, long-lasting synaptic strengthening – an enhancement of memory-relevant communication occurring at the junctions between neurons in the hippocampus. This process can mediate improvement of learning and memory.

Some next steps include investigating how big an impact this finding can have on human learning, whether it can eventually lead to an understanding of how patients can develop failing memories, and how to better target effective therapies for these patients, said Dr. Greene.

In California’s Salinas Valley, known as the “Salad Bowl of the World,” a push is underway to expand agriculture’s adoption of technology. Special correspondent Cat Wise reports on how such innovation is providing new opportunities for the Valley’s largely Hispanic population. Watch her full piece here: http://to.pbs.org/2gLmEga

Spinal Stimulators Repurposed to Restore Touch in Lost Limb

Imagine tying your shoes or taking a sip of coffee or cracking an egg but without any feeling in your hand. That’s life for users of even the most advanced prosthetic arms.

Although it’s possible to simulate touch by stimulating the remaining nerves in the stump after an amputation, such a surgery is highly complex and individualized. But according to a new study from the University of Pittsburgh’s Rehab Neural Engineering Labs, spinal cord stimulators commonly used to relieve chronic pain could provide a straightforward and universal method for adding sensory feedback to a prosthetic arm.

For this study, published in eLife, four amputees received spinal stimulators, which, when turned on, create the illusion of sensations in the missing arm.

“What’s unique about this work is that we’re using devices that are already implanted in 50,000 people a year for pain — physicians in every major medical center across the country know how to do these surgical procedures — and we get similar results to highly specialized devices and procedures,” said study senior author Lee Fisher, Ph.D., assistant professor of physical medicine and rehabilitation, University of Pittsburgh School of Medicine. 

The strings of implanted spinal electrodes, which Fisher describes as about the size and shape of “fat spaghetti noodles,” run along the spinal cord, where they sit slightly to one side, atop the same nerve roots that would normally transmit sensations from the arm. Since it’s a spinal cord implant, even a person with a shoulder-level amputation can use this device 

Fisher’s team sent electrical pulses through different spots in the implanted electrodes, one at a time, while participants used a tablet to report what they were feeling and where.

All the participants experienced sensations somewhere on their missing arm or hand, and they indicated the extent of the area affected by drawing on a blank human form. Three participants reported feelings localized to a single finger or part of the palm.

“I was pretty surprised at how small the area of these sensations were that people were reporting,” Fisher said. “That’s important because we want to generate sensations only where the prosthetic limb is making contact with objects.”

When asked to describe not just where but how the stimulation felt, all four participants reported feeling natural sensations, such as touch and pressure, though these feelings often were mixed with decidedly artificial sensations, such as tingling, buzzing or prickling.

Although some degree of electrode migration is inevitable in the first few days after the leads are implanted, Fisher’s team found that the electrodes, and the sensations they generated, mostly stayed put across the month-long duration of the experiment. That’s important for the ultimate goal of creating a prosthetic arm that provides sensory feedback to the user. 

“Stability of these devices is really critical,” Fisher said. “If the electrodes are moving around, that’s going to change what a person feels when we stimulate.” 

The next big challenges are to design spinal stimulators that can be fully implanted rather than connecting to a stimulator outside the body and to demonstrate that the sensory feedback can help to improve the control of a prosthetic hand during functional tasks like tying shoes or holding an egg without accidentally crushing it. Shrinking the size of the contacts — the parts of the electrode where current comes out — is another priority. That might allow users to experience even more localized sensations. 

“Our goal here wasn’t to develop the final device that someone would use permanently,” Fisher said. “Mostly we wanted to demonstrate the possibility that something like this could work.”

Black phosphorus holds promise for the future of electronics

Discovered more than 100 years ago, black phosphorus was soon forgotten when there was no apparent use for it. In what may prove to be one of the great comeback stories of electrical engineering, it now stands to play a crucial role in the future of electronic and optoelectronic devices.

With a research team’s recent discovery, the material could possibly replace silicon as the primary material for electronics. The team’s research, led by Fengnian Xia, Yale’s Barton L. Weller Associate Professor in Engineering and Science, is published in the journal Nature Communications April 19.

With silicon as a semiconductor, the quest for ever-smaller electronic devices could soon reach its limit. With a thickness of just a few atomic layers, however, black phosphorus could usher in a new generation of smaller devices, flexible electronics, and faster transistors, say the researchers.

That’s due to two key properties. One is that black phosphorus has a higher mobility than silicon—that is, the speed at which it can carry an electrical charge. The other is that it has a bandgap, which gives a material the ability to act as a switch; it can turn on and off in the presence of an electric field and act as a semiconductor. Graphene, another material that has generated great interest in recent years, has a very high mobility, but it has no bandgap.

Read more.

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by: Jannik Obenhoff

Engineers build world’s lightest mechanical watch thanks to graphene

An ultralight high-performance mechanical watch made with graphene is unveiled today in Geneva at the Salon International De La Haute Horlogerie thanks to a unique collaboration.

The University of Manchester has collaborated with watchmaking brand Richard Mille and McLaren F1 to create world’s lightest mechanical chronograph by pairing leading graphene research with precision engineering.

The RM 50-03 watch was made using a unique composite incorporating graphene to manufacture a strong but lightweight new case to house the delicate watch mechanism. The graphene composite known as Graph TPT weighs less than previous similar materials used in watchmaking.

Graphene is the world’s first two-dimensional material at just one-atom thick. It was first isolated at The University of Manchester in 2004 and has the potential to revolutionise a large number of applications including, high-performance composites for the automotive and aerospace industries, as well as flexible, bendable mobile phones and tablets and next-generation energy storage.

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How to Make a Motor Neuron

A team of scientists has uncovered details of the cellular mechanisms that control the direct programming of stem cells into motor neurons. The scientists analyzed changes that occur in the cells over the course of the reprogramming process. They discovered a dynamic, multi-step process in which multiple independent changes eventually converge to change the stem cells into motor neurons.

“There is a lot of interest in generating motor neurons to study basic developmental processes as well as human diseases like ALS and spinal muscular atrophy,” said Shaun Mahony, assistant professor of biochemistry and molecular biology at Penn State and one of the lead authors of the paper. “By detailing the mechanisms underlying the direct programing of motor neurons from stem cells, our study not only informs the study of motor neuron development and its associated diseases, but also informs our understanding of the direct programming process and may help with the development of techniques to generate other cell types.”

The direct programming technique could eventually be used to regenerate missing or damaged cells by converting other cell types into the missing one. The research findings, which appear online in the journal Cell Stem Cell on December 8, 2016, show the challenges facing current cell-replacement technology, but they also outline a potential pathway to the creation of more viable methods.

“Despite having a great therapeutic potential, direct programming is generally inefficient and doesn’t fully take into account molecular complexity,” said Esteban Mazzoni, an assistant professor in New York University’s Department of Biology and one of the lead authors of the study. “However, our findings point to possible new avenues for enhanced gene-therapy methods.”

The researchers had shown previously that they can transform mouse embryonic stem cells into motor neurons by expressing three transcription factors – genes that control the expression of other genes – in the stem cells. The transformation takes about two days. In order to better understand the cellular and genetic mechanisms responsible for the transformation, the researchers analyzed how the transcription factors bound to the genome, changes in gene expression, and modifications to chromatin at 6-hour intervals during the transformation.

“We have a very efficient system in which we can transform stem cells into motor neurons with something like a 90 to 95 percent success rate by adding the cocktail of transcription factors,” said Mahony. “Because of that efficiency, we were able to use our system to tease out the details of what actually happens in the cell during this transformation.”

“A cell in an embryo develops by passing through several intermediate stages,” noted Uwe Ohler, senior researcher at the Max Delbrück Center for Molecular Medicine (MDC) in Berlin and one of the lead authors of the work. “But in direct programming we don’t have that: we replace the gene transcription network of the cell with a completely new one at once, without the progression through intermediate stages. We asked, what are the timing and kinetics of chromatin changes and transcription events that directly lead to the final cell fate?“

The research team found surprising complexity – programming of these stem cells into neurons is the result of two independent transcriptional processes that eventually converge. Early on in the process, two of the transcription factors – Isl1 and Lhx3 – work in tandem, binding to the genome and beginning a cascade of events including changes to chromatin structure and gene expression in the cells. The third transcription factor, Ngn2, acts independently making additional changes to gene expression. Later in the transformation process, Isl1 and Lhx3 rely on changes in the cell initiated by Ngn2 to help complete the transformation. In order for direct programming to successfully achieve cellular conversion, it must coordinate the activity of the two processes.

“Many have found direct programming to be a potentially attractive method as it can be performed either in vitro – outside of a living organism – or in vivo – inside the body and, importantly, at the site of cellular damage,” said Mazzoni. “However, questions remain about its viability to repair cells – especially given the complex nature of the biological process. Looking ahead, we think it’s reasonable to use this newly gained knowledge to, for instance, manipulate cells in the spinal cord to replace the neurons required for voluntary movement that are destroyed by afflictions such as ALS.”