Precision nanobatteries by the billions

Tiny batteries formed inside nanopores demonstrate that properly scaled nanostructures can use the full theoretical capacity of the charge storage material. These nanobatteries delivered their stored energy efficiently at high power (fast charge and discharge) and for extended cycling.

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'Growth Spurt' from a Newborn Protostar

Using data from orbiting observatories, including NASA's Spitzer Space Telescope, and from ground-based facilities, an international team of astronomers has discovered an outburst from a star thought to be in the earliest phase of its development. The eruption, scientists say, reveals a sudden accumulation of gas and dust by an exceptionally young star, or protostar, known as HOPS 383.

Stars form within collapsing fragments of cold gas clouds. As the cloud contracts under its own gravity, its central region becomes denser and hotter. By the end of this process, the collapsing fragment has transformed into a hot central protostar surrounded by a dusty disk roughly equal in mass, embedded in a dense envelope of gas and dust. Astronomers call this a "Class 0" protostar.

"HOPS 383 is the first outburst we've ever seen from a Class 0 object, and it appears to be the youngest protostellar eruption ever recorded," said William Fischer, a NASA Postdoctoral Program Fellow at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

The Class 0 phase is short-lived, lasting roughly 150,000 years, and is considered the earliest developmental stage for stars like the sun.

A protostar has not yet developed the energy-generating capabilities of a sun-like star, which fuses hydrogen into helium in its core. Instead, a protostar shines from the heat energy released by its contraction and by the accumulation of material from the disk of gas and dust surrounding it. The disk may one day develop asteroids, comets and planets.

Because these infant suns are thickly swaddled in gas and dust, their visible light cannot escape. But the light warms dust around the protostar, which reradiates the energy in the form of heat detectable by infrared-sensitive instruments on ground-based telescopes and orbiting satellites.

HOPS 383 is located near NGC 1977, a nebula in the constellation Orion, and is a part of its sprawling star-formation complex. Located about 1,400 light-years from Earth, the region constitutes the most active nearby "star factory" and hosts a treasure trove of young stellar objects still embedded in their natal clouds.

A team led by Thomas Megeath at the University of Toledo in Ohio used Spitzer to identify more than 300 protostars in the Orion complex. A follow-on project using the European Space Agency's Herschel Space Observatory, called the Herschel Orion Protostar Survey (HOPS), studied many of these objects in greater detail. NASA's Jet Propulsion Laboratory in Pasadena, California, manages Spitzer and, while Herschel was still active, managed the U.S. portion of that mission as well.

The eruption of HOPS 383 was first recognized in 2014 by astronomer Emily Safron shortly after her graduation from the University of Toledo. Under the supervision of Megeath and Fischer, she had just completed her senior thesis comparing the decade-old Spitzer Orion survey with 2010 observations from NASA's Wide-field Infrared Survey Explorer (WISE) satellite, which was also managed by JPL. Using software to analyze the data, Safron had already run through it several times without finding anything new. But with her thesis completed and graduation behind her, she decided to take the extra time to compare images of the "funny objects" by eye.

That's when she noticed HOPS 383's dramatic change. "This beautiful outburst was lurking in our sample the whole time," Safron said.

Safron's catalog of observations included Spitzer data at wavelengths of 3.6, 4.5 and 24 microns and WISE data at 3.4, 4.6 and 22 microns. HOPS 383 is so deeply enshrouded in dust that it wasn't seen at all before the outburst at the shortest Spitzer wavelength, and an oversight in a version of the catalog produced before Safron's involvement masked the increase at the longest wavelengths. As a result, her software saw a rise in brightness in only one wavelength out of three, which failed to meet her criteria for the changes she was hoping to find.

Once they realized what had happened, Safron, Fischer and their colleagues gathered additional Spitzer data, Herschel observations, and images from ground-based infrared telescopes at the Kitt Peak National Observatory in Arizona and the Atacama Pathfinder Experiment in northern Chile. Their findings were published in the Feb. 10 edition of The Astrophysical Journal.

The first hint of brightening appears in Spitzer data beginning in 2006. By 2008, they write, HOPS 383's brightness at a wavelength of 24 microns had increased by 35 times. According to the most recent data available, from 2012, the eruption shows no sign of abating.

"An outburst lasting this long rules out many possibilities, and we think HOPS 383 is best explained by a sudden increase in the amount of gas the protostar is accreting from the disk around it," explained Fischer.

Scientists suspect that instabilities in the disk lead to episodes where large quantities of material flow onto the central protostar. The star develops an extreme hot spot at the impact point, which in turn heats up the disk, and both brighten dramatically.

The team continues to monitor HOPS 383 and has proposed new observations using NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA), the world's largest flying telescope.

NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

For more information about Spitzer, visit: http://www.nasa.gov/spitzer

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NASA’s research shows threat to iceberg

Researchers at the University of Texas at Austin, NASA and other research organizations have discovered two seafloor troughs that could allow warm ocean water to reach the base of Totten Glacier, East Antarctica's largest and most rapidly thinning glacier. The discovery likely explains the glacier's extreme thinning and raises concern about its impact on sea level rise.

The result, published in the journal Nature Geoscience today, March 16, has global implications because the ice flowing through Totten Glacier alone is equivalent to the entire volume of the more widely studied West Antarctic Ice Sheet. If Totten Glacier were to collapse completely, global sea levels would rise by at least 11 feet (3.3 meters). As in the West Antarctic Ice Sheet, complete collapse of Totten Glacier may take centuries, although the timing of retreat in both places is the subject of intensive research.

East Antarctica has appeared to be stable compared with the rapidly melting western side of the continent. The new finding shows that "Totten Glacier and the East Antarctic Ice Sheet are a much more interesting and dynamic part of the sea level rise story than we'd previously thought," said co-author Dustin Schroeder, a scientist at NASA's Jet Propulsion Laboratory, Pasadena, California. Schroeder helped analyze data from an ice-penetrating radar to demonstrate that ocean water could access the glacier through the newfound troughs.

In some areas of the ocean surrounding Antarctica, warm water can be found below cooler water because it is saltier, and therefore heavier, than the shallower water. Seafloor valleys that connect this deep warm water to the coast can especially compromise glaciers, but this process had previously been seen only under the West Antarctic Ice Sheet. Deep warm water had been observed seaward of Totten Glacier, but there was no evidence that it could compromise coastal ice.

The newly discovered troughs are deep enough to give the deep warm water access to the huge cavity under the glacier. The deeper of the two troughs extends from the ocean to the underside of Totten Glacier in an area not previously known to be floating.

The data for this study were gathered as part of the International Collaboration for Exploration of the Cryosphere through Airborne Profiling (ICECAP) project, which, together with the East Antarctic component of NASA's Operation IceBridge mission, made the first comprehensive survey of the Totten Glacier Ice Shelf and nearby regions between 2008 and 2012. Other coauthors of the study come from research organizations and universities in Australia, France and England.

The paper is available at
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2388.html

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Space Technology will help in kidney dialysis

The color represented speed of blood

A team of researchers in the United Kingdom has found a way to redesign an artificial connection between an artery and vein, known as an Arterio-Venous Fistulae, which surgeons form in the arms of people with end-stage renal disease so that those patients can receive routine dialysis, filtering their blood and keeping them alive after their kidneys fail.
Related Articles Dialysis Kidney transplantationTensile strength
Constructal theory Sports medicine Heart failure The new design, described in the journal Physics of Fluids, from AIP Publishing, may decrease the likelihood of blockages in Arterio-Venous Fistulae, which is a major complication of dialysis.
While the AVF would have to prove effective in clinical trials before they could be deemed a success, the researchers are enthusiastic about their approach, which used software from the aerospace industry to design the novel configurations.
"At the moment, the process of creating an Arterio-Venous Fistulae for dialysis is rather 'one-size-fits-all'," said Peter Vincent, a senior lecturer and EPSRC early career fellow in the Department of Aeronautics at Imperial College London. "Our ultimate aim is to use computational simulation tools to design tailored, patient-specific Arterio-Venous Fistulae configurations that won't block and fail."
Dialysis and Chronic Kidney Disease
Dialysis is a life-saving treatment for end-stage renal disease -- the last stage of chronic kidney disease -- a serious and often fatal health condition in which a person's kidneys become damaged and can no longer filter blood as effectively as healthy kidneys. As a result, wastes from the blood remain within the body and often lead to other health problems such as cardiovascular disease, anemia and bone disease.
Chronic kidney disease is a global health challenge. For perspective, in the United States alone, the Centers for Disease Control and Prevention estimates that more than 20 million adults -- more than 10 percent of the U.S. adult population -- may have the disease, although many are undiagnosed. Kidney disease is now the 9th leading cause of death in the U.S.
Once a person's kidney's fail, they require either a kidney transplant or regular treatment via a dialysis machine to keep filtering the blood like a kidney. Transplant surgeries often have very good outcomes, but the procedures are limited by the availability of donated kidneys, and only a few thousand become available every year in the United States, while tens of thousands of people are on the waiting list for a kidney transplant. People often wait for a new kidney transplant for years, having to undergo periodic dialysis the entire time.
One problem that arises with dialysis is that the connections made between the body and a dialysis machine via an Arterio-Venous Fistulae frequently become blocked and fail shortly after they are created -- leading to unfavorable clinical outcomes and a significant additional cost burden for healthcare systems worldwide.
So an interdisciplinary team of U.K. researchers -- including members from aeronautics, bioengineering, computational engineering, medical imaging and clinical medicine -- from Imperial College London, Imperial College Renal and Transplant Centre at Hammersmith Hospital, and St. Mary's Hospital set out to design an Arterio-Venous Fistulae with reduced failure rates.
Design Based on Aerospace Software
To do this, the researchers first needed to gain a better understanding of how arterial curvature affects blood flow and oxygen transport patterns within Arterio-Venous Fistula.
Blood flow patterns within AVF are "inherently 'un-natural,' and it's thought that these unnatural flow patterns lead to their ultimate failure," explained Vincent.
By using computational simulation software originally developed for the aerospace sector, the team is able to simulate and predict flow patterns in various Arterio-Venous Fistula configurations. "This allows us to design Arterio-Venous Fistula with much mor

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How brain transforms with aging: a report

Typical cognitive aging may be defined as age-associated changes in cognitive performance in individuals free of dementia. To assess brain imaging findings associated with typical aging, the full adult age spectrum should be included, according to the study background.
Clifford R. Jack, Jr., M.D., of the Mayo Clinic and Foundation, Rochester, Minn., and coauthors compared
 age, sex and APOE ɛ4 effects on memory, brain structure (as measured by adjusted hippocampal volume, HVa) and amyloid [brain plaques associated with Alzheimer disease] positron emission tomography (PET) in 1,246 cognitively normal individuals between the ages of 30 and 95.
The authors found:
Overall memory worsened from age 30 through the 90s.
HVa worsened gradually from age 30 to the mid-60s and more steeply after that with advancing age.
Median amyloid accumulation seen on PET scans was low until age 70 but increased after that.
Memory was worse in men than women overall, especially after 40.
The HVa was lower in men than women overall, especially after 60.
For both males and females, memory performance and HVa were not different by APOE ɛ4 carrier status at any age.
From age 70 onward, APOE ɛ4 carriers had greater median amyloid accumulation seen on PET scans than noncarriers.
The ages at which 10 percent of the population was "amyloid PET positive" were 57 years for APOE ɛ4 carriers and 64 years for noncarriers. Amyloid PET positive indicates individuals are accumulating amyloid in their brain as seen on PET scans and, while they may be asymptomatic, they are at risk for Alzheimer disease.
"We believe that this study of typical aging reveals interesting sex and APOE ɛ4 effects on age-related trends in brain structure, function and β-amyloidosis [buildup of plaque deposits in the brain]. To date, these effects have not been widely appreciated. Our findings are consistent with a model of late-onset AD [Alzheimer disease] in which β-amyloidosis arises later in life on a background of preexisting structural and cognitive decline that is associated with aging and not with β-amyloid deposits," the study concludes.
Editorial: A Call for New Thoughts on What Might Influence Human Brain Aging
In a related editorial, Charles DeCarli, M.D., of the University of California at Davis, Sacramento, writes: "In their article, Jack et al present new information that challenges the notion that amyloid accumulation explains memory performance across the entire age range. Importantly, this work does not only address the likely highly significant impact of cerebral amyloid accumulation on dementia risk, but also extends current knowledge relating to the impact of the aging process across the spectrum of ages 30 to 95 years to brain structure, amyloid accumulation and memory performance among cognitively normal individuals."
"Understanding the basic biology of these early processes are likely to substantially inform us about ways in which we can maintain cognitive health and optimize resistance to late-life dementia. However, such work requires the necessary motivation found by seminal work, such as that of Jack et al, which tell us where and when to investigate these processes. Establishing what is normal creates avenues for new research, increasing the likelihood of discovering novel therapeutics for late-life disease states, which is a laudable goal indeed," the editorial concludes.

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