Saturday, October 1, 2022

Exploring Europa Possible with Silicon-Germanium Transistor Technology

Europa Image
Credit: NASA/JPL-Caltech/SETI Institute

Europa is more than just one of Jupiter’s many moons – it’s also one of most promising places in the solar system to look for extraterrestrial life. Under 10 kilometers of ice is a liquid water ocean that could sustain life. But with surface temperatures at -180 Celsius and with extreme levels of radiation, it’s also one of the most inhospitable places in the solar system. Exploring Europa could be possible in the coming years thanks to new applications for silicon-germanium transistor technology research at Georgia Tech.

Regents’ Professor John D. Cressler in the School of Electrical and Computer Engineering (ECE) and his students have been working with silicon-germanium heterojunction bipolar transistors (SiGe HBTs) for decades and have found them to have unique advantages in extreme environments like Europa.

“Due to the way that they're made, these devices actually survive those extreme conditions without any changes made to the underlying technology itself,” said Cressler, who is the project investigator. “You can build it for what you want it to do on Earth, and you then can use it in space.”

The researchers are in year one of a three-year grant in the NASA Concepts for Ocean Worlds Life Detection Technology (COLDTech) program to design the electronics infrastructure for upcoming Europa surface missions. NASA plans to launch the Europa Clipper in 2024, an orbiting spacecraft that will map the oceans of Europa, and then eventually send a landing vehicle, Europa Lander, to drill through the ice and explore its ocean. But it all starts with electronics that can function in Europa’s extreme environment.

Cressler and his students, together with researchers from NASA Jet Propulsion Lab (JPL) and the University of Tennessee (UT), demonstrated the capabilities of SiGe HBTs for this hostile environment in a paper presented at the IEEE Nuclear and Space Radiation Effects Conference in July.

What caused the holes in SUE the T. rex ’s jaw? Probably not an infection

Field Museum paleontologist Jingmai O’Connor with SUE the T. rex’s skull.
Resized Image using AI by SFLORG
Credit: Katharine Uhrich, Field Museum

SUE the T. rex is one of the most complete, best-preserved Tyrannosaurus rex specimens ever found. That level of preservation helps reveal details about SUE’s life. For instance, SUE lived to a ripe old age of about thirty-three, and in those years, suffered their fair share of injuries. SUE’s most mysterious ailment might be the holes in their jawbone. These holes, some the diameter of a golf ball, dot the back half of the left lower jaw. It’s not clear what caused them, but similar injuries have been found in other T. rex fossils. In a new study published in Cretaceous Research, scientists showed that one of the popular theories-- that SUE had suffered an infection from a protozoan parasite-- couldn’t be true.

“These holes in SUE’s jaw have been a mystery for decades,” says Jingmai O’Connor, the associate curator of fossil reptiles at Chicago’s Field Museum and a co-author of the study. “Nobody knows how they formed, and there have been lots of guesses.”

One early hypothesis was that SUE suffered from a fungus-like bacterial infection, but that was later shown to be unlikely. It was re-hypothesized that SUE had a protozoan infection. Protozoans are microbes with more complex cell structures than bacteria. There are lots of protozoan-caused maladies out there; one common such disease is called trichomoniasis, caused by a microbe called Trichomonas vaginalis. Humans can get infected with trichomoniasis as an STD, but other animals can catch it too.

What a reptile’s bones can teach us about Earth’s perilous past

An illustration of how Palacrodon may have looked.
Credit: K.M. Jenkins

An extinct reptile’s oddly shaped chompers, fingers, and ear bones may tell us quite a bit about the resilience of life on Earth, according to a new study.

In fact, paleontologists at Yale, Sam Houston State University, and the University of the Witwatersrand say the 250-million-year-old reptile, known as Palacrodon, fills in an important gap in our understanding of reptile evolution. It’s also a signal that reptiles, plants, and ecosystems may have fared better or recovered more quickly than previously thought after a mass extinction event wiped out most of the plant and animal species on the planet.

“We now know that Palacrodon comes from one of the last lineages to branch off the reptile tree of life before the evolution of modern reptiles,” said Kelsey Jenkins, a doctoral student in Yale’s Department of Earth and Planetary Sciences in the Faculty of Arts and Sciences and first author of the study, which appears in the Journal of Anatomy. “We also know that Palacrodon lived in the wake of the most devastating mass extinction in Earth’s history.”

That would be the Permian-Triassic extinction event, which occurred 252 million years ago. Known as “the Great Dying,” it killed off 70% of terrestrial species and 95% of marine species.

Although a large number of reptile species eventually bounced back from this extinction event, the details of how that happened are murky. Researchers have spent decades trying to fill in the gaps in our understanding of key adaptations that enabled reptiles to flourish after the Permian-Triassic extinction — and what those adaptations may reveal about the ecosystems where they lived.

Machine learning may enable bioengineering of the most abundant enzyme

Photo Credit: Melissa Askew

A Newcastle University study has for the first time shown that machine learning can predict the biological properties of the most abundant enzyme on Earth - Rubisco.

Rubisco (Ribulose-1,5-bisphosphate carboxylase/oxygenase) is responsible for providing carbon for almost all life on Earth. Rubisco functions by converting atmospheric CO2 from the Earth’s atmosphere to organic carbon matter, which is essential to sustain most life on Earth.

For some time now, natural variation has been observed among Rubisco proteins of land plants and modelling studies have shown that transplanting Rubisco proteins with certain functional properties can increase the amount of atmospheric CO2 crop plants can uptake and store.

Study lead author, Wasim Iqbal, a PhD researcher at Newcastle University’s School of Natural and Environmental Sciences, part of Dr Maxim Kapralov’s group, developed a machine learning tool which can predict the performance properties of numerous land plant Rubisco proteins with surprisingly good accuracy. The hope is that this tool will enable the hunt for a ‘supercharged’ Rubisco protein that can be bioengineered into major crops such as wheat.

Friday, September 30, 2022

The majority of reindeer grazing land is under cumulative pressures

 Male reindeer walking on a national road in Jämtland, Sweden.
Credit: Marianne Stoessel/Stockholm University.

Reindeer herding has a long history in northern Norway, Sweden and Finland. It has shaped the Fennoscandian mountain landscape, and is also seen as a means to mitigate climate change effects on vegetation. Yet a new study published in Scientific Reports shows that the majority of this grazing land is exposed to cumulative pressures, threatened by the expansion of human activities towards the north.

The grazing land in northern Fennoscandia is increasingly disturbed by cumulative land-use pressures. Intensive forestry, outdoor tourism, road and railway traffic, but also mining and wind farms are developing in the north. The newly published study has mapped and estimated the overall extent of these cumulative pressures, together with other stressors, namely predator presence and climate change.

Previous studies have mostly focused at regional scales, here the authors have used an integrated large-scale GIS analysis over three countries: Norway, Sweden and Finland. Their results suggest that about 60 per cent of the region is subjected to multiple pressures, and that 85 per cent is exposed to at least one pressure. This dramatically reduces the size and the quality of the summer grazing area. The study found that only 4 per cent of the area still remains undisturbed.

How Stiff Is the Proton?

Compton scattering setup at the High Intensity Gamma Ray Source. The central cylinder is the liquid hydrogen target. High energy gamma rays are scattered from the liquid hydrogen into eight large detectors that measure the gamma rays’ energy.
Image courtesy of Mohammad Ahmed, North Carolina Central University and Triangle Universities Nuclear Laboratory

The proton is a composite particle made up of fundamental building blocks of quarks and gluons. These components and their interactions determine the proton’s structure, including its electrical charges and currents. This structure deforms when exposed to external electric and magnetic (EM) fields, a phenomenon known as polarizability. The EM polarizabilities are a measure of the stiffness against the deformation induced by EM fields. By measuring the EM polarizabilities, scientists learn about the internal structure of the proton. This knowledge helps to validate scientific understanding of how nucleons (protons and neutrons) form by comparing the results to theoretical descriptions of gamma-ray scattering from nucleons. Scientists call this scattering process nucleon Compton scattering.

When scientists examine the proton at a distance and scale where EM responses dominate, they can determine values of EM polarizabilities with high precision. To do so, they use the theoretical frame of Effective Field Theories (EFTs). The EFTs hold the promise of matching the description of the nucleon structure at low energies to the current theory of the strong nuclear force, called quantum chromodynamics (QCD). In this research, scientists validated EFTs using proton Compton scattering. This approach also validated the framework and methodology that underlie EFTs.

Proton Compton scattering is the process by which scientists scatter circularly or linearly polarized gamma rays from a hydrogen target (in this case, a liquid target), then measure the angular distribution of the scattered gamma rays. High-energy gamma rays carry strong enough EM fields that the response of the charges and currents in the nucleon becomes significant. In this study, scientists performed new measurements of Compton scattering from the proton at the High Intensity Gamma Ray Source (HIGS) at the Triangle Universities Nuclear Laboratory. This work provided a novel experimental approach for Compton scattering from the proton at low energies using polarized gamma rays. The study advances the need for new high-precision measurements at HIGS to improve the accuracy of proton and neutron polarizabilities determinations. These measurements validate the theories which link the low-energy description of nucleons to QCD.

This work was funded by the Department of Energy Office of Science, the National Science Foundation, the U.K. Science and Technology Facilities Council Grants, and funds from the Dean of the Columbian College of Arts and Sciences at George Washington University and its Vice-President for Research. The researchers also acknowledge the financial support of the Natural Sciences and Engineering Research Council of Canada and the support of Eugen-Merzbacher Fellowship.

X. Li et al., “Proton Compton Scattering from Linearly Polarized Gamma Rays”, Physical Review Letters. 

Source/Credit: U.S. Department of Energy


Queen Mary chemical engineers have developed technologies to slash energy consumption in industry

Photo Credit: Quinten de Graaf

In two papers published in the journals Nature and Science, Queen Mary's Professor Livingston and Dr Zhiwei Jiang present their work on nanomembranes – exquisitely thin membranes that can provide an energy efficient alternative to current industry practices.

They demonstrate their technology can be used to refine crude oil and cannabidiol (CBD) oil – two industry giants. Around 80 million barrels of crude oil are processed every day to create fuel and plastic, in a process which consumes massive amounts of energy. The cannabidiol oil industry is fast growing - the Global Cannabidiol (CBD) Market is estimated to reach USD 47.22 Billion by 2028, up from USD 4.9 Billion in 2021.

Andrew Livingston, Professor of Chemical Engineering at Queen Mary, said: 'A vast amount of energy is consumed in industry separating molecules. The aim of our research is to provide low energy alternatives to these processes. Due to the innovations in the chemistry we used to make these membranes, we can achieve molecular architectures that achieve exquisite separations, and provide less resource intensive techniques for the separation of molecules.'

Dr Zhiwei Jiang, Research Associate at Queen Mary, said: 'Thinner is better - the liquid passes through the membranes much more quickly, rapidly speeding up the process, and therefore reducing the plant footprint while processing the same quantity of liquids.’

Chipping away at the many unknowns of obscure animal viruses

Patas monkeys are among the wild African monkeys believed to be natural reservoirs for the simian hemorrhagic fever virus. 
Photo Credit: Andrew S

Researchers have identified enough biological details about a virus endemic in African primates to suggest that this virus, which causes a hemorrhagic fever disease in monkeys, has decent potential to spill over to humans.

The findings suggest a surveillance program is warranted for citizens in Africa who may be at risk for exposure to the virus. But the study teaches a much larger lesson as well, researchers say: It’s never too early to start preparing for the next animal virus to come along and unexpectedly cause disease in people.

“There are a lot of unknown animal viruses out there that may pose risk to humans,” said Cody Warren, first author of the study and assistant professor of veterinary biosciences at The Ohio State University.

“We need to be prospectively looking at animal viruses that have been ignored to see if they have the capacity to replicate in human cells. If they do, will we continue to ignore them? I don’t think we should,” he said.

Warren completed this work at the University of Colorado Boulder as a postdoctoral researcher in the lab of senior author Sara Sawyer, professor of molecular, cellular & developmental biology.

Research finds link between poor health and low breast milk production

Photo Credit: seeseehundhund

Research from the University of Cincinnati shows that poor metabolic health parameters are linked to low breast milk production. The study was published in the journal Breastfeeding Medicine.

“We wanted to see if we could understand what stands out as different in these moms. So, we conducted a case control study to see why, despite their best efforts at doing everything right with breastfeeding, they were not making enough milk,” says Laurie Nommsen-Rivers, PhD, associate professor of nutrition, and the Ruth Rosevear Endowed Chair of Maternal and Child Nutrition in the UC College of Allied Health Sciences. “The prevailing dogma is if you try hard enough at breastfeeding, your body will be able to do this.”

Nommsen-Rivers and her team analyzed data from a randomized controlled trial from February 2015 to June 2016 involving women screened for a low-milk supply. Mothers who were aged 20 years or older and one to eight weeks postpartum with a healthy infant born at 37 weeks of gestation or later were included. Participants completed at-home infant test-weighing to measure milk output.

New Superconducting Qubit Testbed Benefits Quantum Information Science Development

A superconducting qubit sits in a dilution refrigerator in a Pacific Northwest National Laboratory (PNNL) physics lab. This experimental device is the first step in establishing a qubit testbed at PNNL.
  Photo Credit: Andrea Starr | Pacific Northwest National Laboratory

If you’ve ever tried to carry on a conversation in a noisy room, you’ll be able to relate to the scientists and engineers trying to “hear” the signals from experimental quantum computing devices called qubits. These basic units of quantum computers are early in their development and remain temperamental, subject to all manner of interference. Stray “noise” can masquerade as a functioning qubit or even render it inoperable.

That’s why physicist Christian Boutan and his Pacific Northwest National Laboratory (PNNL) colleagues were in celebration mode recently as they showed off PNNL’s first functional superconducting qubit. It’s not much to look at. Its case—the size of a pack of chewing gum--is connected to wires that transmit signals to a nearby panel of custom radiofrequency receivers. But most important, it’s nestled within a shiny gold cocoon called a dilution refrigerator and shielded from stray electrical signals. When the refrigerator is running, it is among the coldest places on Earth, so very close to absolute zero, less than 6 millikelvin (about −460 degrees F).

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