. Scientific Frontline

Wednesday, September 7, 2022

Researchers use combined imaging techniques to monitor stem cell therapies

Samuel Grant, professor and postdoctoral fellow director in Chemical and Biomedical Engineering at the FAMU-FSU College of Engineering, works with graduate student Dayna Richter on a 900-megahertz magnet at the National High Magnetic Field Laboratory in Tallahassee, Florida.
Credit: Mark Wallheiser/FAMU-FSU College of Engineering

When patients are treated for strokes and other neurological disorders, understanding what is happening inside the nervous system is a crucial part of treatment. Doctors rely on imaging tools such as magnetic resonance imaging (MRI) to peer inside the body and see if interventions are helping.

A Florida State University research team has found that a combination of two MRI techniques can provide early answers on the effectiveness of stem cell therapies for treating strokes, which could help physicians quickly know if a treatment is working or if they should change their strategy. Their work was published in the journal Translational Stroke Research.

“With strokes, the sooner that you can salvage tissue that might be at risk, because it’s been starved from oxygen and glucose, the sooner you can avoid some of that inflammatory response and help the tissue recover,” said Sam Grant, a professor at the FAMU-FSU College of Engineering and faculty researcher at the National High Magnetic Field Laboratory.

The researchers examined rat brains that had suffered a stroke and been injected with stem cells, specifically adult mesenchymal stem cells, which come from a variety of sources in the human body and are the focus of treatments for neurological diseases.

New measurements point to silicon as a major contributor to performance limitations in superconducting quantum processors

A superconducting-based quantum processor, composed of several thin film materials deposited on top of a silicon substrate.
Photo credit: Rigetti Computing

Silicon is a material widely used in computing: It is used in computer chips, circuits, displays and other modern computing devices. Silicon is also used as the substrate, or the foundation of quantum computing chips.

Researchers at the Superconducting Quantum Materials and Systems Center, hosted by the U.S. Department of Energy’s Fermi National Accelerator Laboratory, demonstrated that silicon substrates could be detrimental to the performance of quantum processors. SQMS Center scientists have measured silicon’s effect on the lifespan of qubits with parts-per-billion precision. These findings have been published in Physical Review Applied.

New approaches to computing

Calculations once performed on pen and paper have since been handed to computers. Classical computers rely on bits, 1 or 0, which have limitations. Quantum computers offer a new approach to computing that relies on quantum mechanics. These novel devices could perform calculations that would take years or be practically impossible for a classical computer to perform.

Using the power of quantum mechanics, qubits—the basic unit of quantum information held within a quantum computing chip—can be both a 1 and a 0 at the same time. Processing and storing information in qubits is challenging and requires a well-controlled environment. Small environmental disturbances or flaws in the qubit’s materials can destroy the information.

Qubits require near-perfect conditions to maintain the integrity of their quantum state, and certain material properties can decrease the qubit lifespan. This phenomenon, called quantum decoherence, is a critical obstacle to overcome to operate quantum processors.

As threats to the U.S. power grid surge

WVU Lane Department of Computer Science and Electrical Engineering students Partha Sarker, Paroma Chatterjee and Jannatul Adan, discuss a power grid simulation project led by Anurag Srivastava, professor and department chair, in the GOLab.
Photo credit: Brian Persinger | WVU

The electrical grid faces a mounting barrage of threats that could trigger a butterfly effect – floods, superstorms, heat waves, cyberattacks, not to mention its own ballooning complexity and size – that the nation is unprepared to handle, according to one West Virginia University scientist.

But Anurag Srivastava, professor and chair of the Lane Department of Computer Science and Electrical Engineering, has plans to prevent and respond to potential power grid failures, thanks to a pair of National Science Foundation-funded research projects.

“In the grid, we have the butterfly effect,” Srivastava said. “This means that if a butterfly flutters its wings in Florida, that will cause a windstorm in Connecticut because things are synchronously connected, like dominos. In the power grid, states like Florida, Connecticut, Illinois and West Virginia are all part of the eastern interconnection and linked together.

“If a big event happens in the Deep South, it is going to cause a problem up north. To stop that, we need to detect the problem area as soon as possible and gracefully separate that part out so the disturbance does not propagate through the whole.”

How Fat Signals Us to Eat More of It

Charles S. Zuker
Columbia University Neuroscience Physiology
Source: HHMI
Scientists discover how fat triggers a gut-to-brain mechanism that drives us to keep consuming more of it. Their findings could one day lead to interventions to help treat obesity and associated disorders.

Short ribs glazed in a sweet sticky sauce and slow-cooked to perfection, potato chips hand-fried and tossed with a generous coating of sour cream, chicken wings battered and double-fried so that they stay crispy for hours. What is it about these, and other, mouth-watering — but incredibly fatty — foods that makes us reach out, and keep coming back for more?

How they taste on the tongue is one part of the story, but to really understand what drives “our insatiable appetite for fat,” we have to examine what happens after fat is consumed, says Columbia University’s Charles Zuker, a neuroscientist and molecular geneticist who has been a Howard Hughes Medical Institute (HHMI) Investigator since 1989.

Two years ago, Zuker and his team reported how sugar, upon reaching the gut, triggers signals that are sent to the brain, thus fueling cravings for sweet treats. Now, in an article published in Nature on September 7, 2022, they describe a similar gut-to-brain circuit that underlies a preference for fat.

“The gut is the source of our great desire for fat and sugar,” says Zuker.

The topic in question is an incredibly timely one, given the current global obesity epidemic. An estimated 13 percent of adults worldwide are obese — thrice that in 1975. In the US, that figure is even higher — at a staggering 42 percent. “It’s a very significant and important health problem,” says Zuker.

Having a high body-mass index is a risk factor for stroke, diabetes, and several other diseases. “It’s clear that if we want to help make a difference here, we need to understand the biological basis for our strong appetite for fat and sugar,” he says. Doing so will help us design interventions in the future to “suppress this strong drive to consume” and combat obesity.

Using science to solve ancient Chinese art mystery

UC assistant professor Pietro Strobbia consulted with the Cincinnati Art Museum to solve a mystery about one of its ancient Chinese masterpieces.
Photo credit: Andrew Higley/University of Cincinnati

The Cincinnati Art Museum turned to a scientist at the University of Cincinnati for help solving a mystery 1,300 years in the making.

The museum’s Chinese dancing horse sculpture is so realistic that the fiery steed seems ready to gallop off its pedestal. But East Asian art curator Hou-mei Sung questioned the authenticity of a decorative tassel on the terracotta horse’s forehead that resembles the horn of a mythological unicorn.

The museum reached out to UC College of Arts and Sciences assistant professor of chemistry Pietro Strobbia for help to determine if the tassel was original to the work.

“Many museums have a conservator but not necessarily scientific facilities needed to do this kind of examination,” Strobbia said. “The forehead tassel looks original, but the museum asked us to determine what materials it was made from.”

Strobbia and his collaborators wrote about the project for a paper published in the journal Heritage Science.

Highly reflective mirrors from the inkjet printer

Colored, printed mirror layer on a film. Inkjet printing allows structuring so that large-scale logos can also be printed
Credit: Qihao Jin, KIT

Dielectric mirrors, also called Bragg mirrors, can almost completely reflect light. They are therefore suitable for countless applications, such as in camera systems, in microscopy, in medical technology or in sensor systems. So far, these mirrors had to be manufactured in expensive vacuum devices. Researchers at the Karlsruhe Institute of Technology (KIT) have now printed high quality Bragg mirrors with inkjet printers for the first time. The process could open the way to digital production of tailor-made mirrors. The results appeared in Advanced Materials.

For Bragg mirrors, several layers of material are applied thinly to a carrier. These mirrors, which consist of a large number of thin layers, form an optical mirror that ensures that light of a certain wavelength is specifically reflected. How strongly Bragg mirrors reflect depends on the materials, but also on how many layers you apply and how thick they are. So far, Bragg mirrors have had to be manufactured with expensive vacuum production systems. The Karlsruhe team succeeded for the first time in printing them on different carriers. This can considerably simplify production.

The bean bug brain’s biological clock

 Brain glutamate dynamics photoperiodically change based on the circadian clock gene and mediate the cellular response of oviposition-promoting neurons.
Credit: Masaharu Hasebe and Sakiko Shiga

Did you know that not only does an organism’s body have a biological clock that can tell the time of the day, it can also tell the time of the year? Now, researchers from Japan have found that one capable little molecule may be behind the mechanism by which the biological clock keeps track of the seasons.

In a study that was recently published in PLOS Biology, researchers from Osaka University reveal that glutamate signaling is responsible for the seasonal regulation of reproduction in bean bugs by genes involved in maintaining circadian rhythm.

The circadian rhythm is driven by a biological clock that controls body processes based on time of day. A related process is photoperiod sensitivity, or seasonal regulation, in which body processes are regulated on a seasonal basis based on the length of the daytime and nighttime periods.

“Previous studies have shown that circadian clock genes are involved not only in regulating daily processes, but also in regulating seasonal events, such as reproduction in insects,” states Masaharu Hasebe, first author on the study. “However, the mechanism governing this interaction was unclear.”

Turning carbon dioxide into valuable products

Professor Ariel Furst (center), undergraduate Rachel Ahlmark (left), postdoc Gang Fan (right), and their colleagues are employing biological materials, including DNA, to achieve the conversion of carbon dioxide to valuable products.
Credits: Gretchen Ertl

Carbon dioxide (CO2) is a major contributor to climate change and a significant product of many human activities, notably industrial manufacturing. A major goal in the energy field has been to chemically convert emitted CO2 into valuable chemicals or fuels. But while CO2 is available in abundance, it has not yet been widely used to generate value-added products. Why not?

The reason is that CO2 molecules are highly stable and therefore not prone to being chemically converted to a different form. Researchers have sought materials and device designs that could help spur that conversion, but nothing has worked well enough to yield an efficient, cost-effective system.

Two years ago, Ariel Furst, the Raymond (1921) and Helen St. Laurent Career Development Professor of Chemical Engineering at MIT, decided to try using something different — a material that gets more attention in discussions of biology than of chemical engineering. Already, results from work in her lab suggest that her unusual approach is paying off.

Two new rocky worlds around an ultra-cool star

The telescopes of the SPECULOOS Southern Observatory gaze out into the stunning night sky over the Atacama Desert, Chile.
Credit: ESO/ P. Horålek

An international research team, with the participation of the University of Bern and the National Centre of Competence in Research (NCCR) PlanetS, discovered two "super-Earth" exoplanets. One is located at just the right distance from its star to potentially hold liquid water on its surface.

Most of the planets that have been discovered around other stars – also known as exoplanets – are bad candidates for life as we know it. They are either scorching hot or freezing cold, and the majority consist of nothing but gas. Relatively small terrestrial planets, like our Earth, are difficult to detect. Only a handful are known that receive just the right amount of radiation from their star to allow liquid water on their surface. The reported discovery of a promising candidate for such a world, made by a team of researchers with the participation of the University of Bern and the National Centre of Competence in Research (NCCR) PlanetS, is therefore a significant one. The team published their results in the journal Astronomy & Astrophysics. (As of this posting not yet released)

Tuesday, September 6, 2022

Endangered Amargosa Voles Begin to Repopulate Desert Habitat

This landscape shows the Amargosa Valley at sunset. Amargosa voles are endemic to unique Mojave Desert marshes fed by natural springs and the Amargosa River.
Credit: University of California, Davis

Seven years of carefully planned habitat restoration on private land in the Mojave Desert have yielded hope for the persistence of the endangered Amargosa vole. In early August, a photograph from a wildlife camera placed by researchers from the University of California, Davis, and dated July 3 revealed the presence of one, possibly two, vole pups born from parents that were reintroduced to restored marsh habitat on private land in Shoshone Village, Inyo County.

The Amargosa vole was first discovered in the marshes of Shoshone in the late 1800s but had disappeared by the early 1900s because of habitat conversion to agriculture and other uses that destroyed the marshes. The only other place in the world where the voles persist in the wild is near the town of Tecopa, about 8 miles south of Shoshone.

Restoration of the Shoshone Spring marsh started in 2015 as a joint effort of Shoshone Village, the Amargosa Conservancy, UC Davis and the California Department of Fish and Wildlife (CDFW). The restoration was funded by U.S. Fish and Wildlife Service (USFWS) Section 6 and Partners in Fish and Wildlife grants.

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