Monday, February 28, 2022

Patagonian Mountains Rise as Ice Caps Shrink

Mount Fitz Roy and surrounding peaks on the border between Argentina and Chile.
(Photo: Ben Tiger)

The icefields that stretch for hundreds of miles atop the Andes in Chile and Argentina are melting at some of the fastest rates on the planet. The ground that was beneath this ice is rising as these glaciers disappear.

Geologists have discovered a link between recent ice mass loss, rapid rock uplift and a gap between tectonic plates that underlie Patagonia.

Scientists at Washington University in St. Louis, led by seismologist Douglas Wiens, the Robert S. Brookings Distinguished Professor in Arts & Sciences, recently completed one of the first seismic studies of the Patagonian Andes. In a new publication in the journal Geophysical Research Letters, they describe and map out local subsurface dynamics.

Shrinking icefields have reduced weight that previously caused the continent to flex downward. The scientists found very low seismic velocity within and around the gap, as well as a thinning of the rigid lithosphere overlying the gap. The ongoing movement of land is known as glacial isostatic adjustment.

These particular mantle conditions are driving many of the recent changes that have been observed in Patagonia, including the rapid uplift in certain areas once covered by ice. 

Researcher Wiens reports, "Low viscosities mean that the mantle responds to deglaciation on the time scale of tens of years, rather than thousands of years, as we observe in Canada for example." Wiens explains, "This explains why GPS has measured large uplift due to the loss of ice mass.

"Another significant thing is that the viscosity is higher beneath the southern part of the Southern Patagonia Icefield compared to the Northern Patagonia Icefield, which helps to explain why uplift rates vary from north to south," Wiens said.

Wiens specializes in seismology and geophysics and has done extensive research on large deep earthquakes in the Pacific Ocean, the effect of ice melt, and the seismology of Antarctica. 

Read more herehere, and here.

Saturday, February 19, 2022

A Turbulent Sun

NOAA Solar Cycle Chart, October 29, 2020

News sources are picking up on the fact that the solar maximum is approaching in July 2025, with an increase in the number of sunspots. Sunspots often appear in pairs with different magnetic polarities. They become more prevalent every 11 years (solar cycle) and they migrate through latitudes, moving closer to the equator as the solar cycle progresses. 

SpaceWeatherLive tracks solar activity and reports that the Sun has erupted from February 1st through the 17th with some days featuring multiple flares. That includes three flares of the second-most powerful category: an M1.4 on February 12; an M1 on February 14; and an M1.3 on February 15. 

There were also five M-class flares in January. The mild geomagnetic storm that knocked 40 newly launched Starlink satellites from low-Earth orbit followed an M-class flare that took place on January 29.

Solar flares happen because of the constantly moving magnetic fields in the Sun's atmosphere. The frequency of solar flares coincides with the Sun's 11-year cycle. When the solar cycle is at a minimum, fewer solar flares are detected. Flares increase in number as the Sun approaches the maximum part of its cycle.

A solar cycle: a montage of ten years' worth of Yohkoh SXT images, showing the variation in solar activity during a sunspot cycle, after 30 August 1991 to 6 September 2001. Credit: Yohkoh mission of ISAS (Japan) and NASA.

The Sun's magnetic field has a north pole and a south pole. About every 11 years, the Sun's magnetic field does a flip. The north pole becomes the south pole, and vice versa.

This flip is one feature of the solar cycle. As the cycle progresses, the Sun's stormy behavior builds to a maximum, and that is when the magnetic field reverses. Then the Sun settles back down to a minimum, only to start another cycle.

Solar storms are not unusual. An ancient solar storm happened around7200 BC when most humans lived at Earth's middle latitudes, not near the poles. Another big storm came between 775-774 BC. By then humans were more widely dispersed and yet they survived that event. 

However, in those times people did not rely on the technologies that we have today. On March 13,1989 the entire province of Quebec, Canada suffered an electrical power blackout caused by a solar storm. Some are concerned that a future large solar storm could return Earth to the dark ages.

Tuesday, February 15, 2022

Potential AI Breakthrough on Neurodegenerative Disease


Jeremy Linsley: Scientific Program Leader at Gladstone Institutes, University of California, San Francisco. 

new artificial intelligence technology his research team developed can identify dead cells with both superhuman accuracy and speed. This advance could potentially turbocharge all kinds of biomedical research, especially on neurodegenerative disease.

Jeremy explains:

Understanding when and why a cell dies is fundamental to the study of human development, disease and aging. For neurodegenerative diseases such as Lou Gehrig’s disease, Alzheimer’s and Parkinson’s, identifying dead and dying neurons is critical to developing and testing new treatments. But identifying dead cells can be tricky and has been a constant problem throughout my career as a neuroscientist.

Until now, scientists have had to manually mark which cells look alive and which look dead under the microscope. Dead cells have a characteristic balled-up appearance that is relatively easy to recognize once you know what to look for. My research team and I have employed a veritable army of undergraduate interns paid by the hour to scan through thousands of images and keep a tally of when each neuron in a sample appears to have died. Unfortunately, doing this by hand is a slow, expensive and sometimes error-prone process.

Making matters even more difficult, scientists recently began using automated microscopes to continually capture images of cells as they change over time. While automated microscopes make it easier to take photos, they also create a massive amount of images to manually sort through. It became clear to us that manual curation was neither accurate nor efficient. Furthermore, most imaging techniques can detect only the late stages of cell death, sometimes days after a cell has already begun to decompose. This makes it difficult to distinguish between what actually contributed to the cell’s death from factors just involved in its decay.

My colleagues and I have been trying for some time to automate the curation process. Our initial attempts could not handle the wide range of cell and microscope types we use in our research, nor rival the accuracy of our interns. But a new artificial intelligence technology my research team developed can identify dead cells with both superhuman accuracy and speed. This advance could potentially turbocharge all kinds of biomedical research, especially on neurodegenerative disease.

Source: The Conversation: New AI technique identifies dead cells under the microscope 100 times faster than people can

Jeremy Linsley is a neuroscientist with a demonstrated and diverse skillset within academic biomedical research. Skilled in calcium imaging, cell culture, high-throughput microscopy, 4D microscopy, behavioral analysis, molecular biology, disease genetics, zebrafish, drosophila, hIPSC, primary tissue, organotypic slice culture, deep learning and artificial intelligence. Doctor of Philosophy (PhD) in Cellular and Molecular Biology with John Kuwada at the University of Michigan, and postdoctoral fellowship at Gladstone Institutes with Steve Finkbeiner.

Wednesday, February 9, 2022

University of Delaware Engineers Attack CO2 Pollution


Three fuel cell experts discuss their project. From left to right, Yushan Yan, Brian P. Setzler, and Shimshon Gottesfeld. (Photo: Evan Krape)

The University of Delaware engineers captured 99% of carbon dioxide in the air when using their novel hydrogen-powered electrochemical system. The UD engineers have developed a fuel cell technology that uses cheaper catalysts and structural components, but these hydroxide exchange membrane fuel cells (HEMFCs) have a limitation. They cannot use direct supply of ambient air, because the carbon dioxide in the air reduces their performance.

The alkaline environment of hydroxide exchange membrane fuel cells potentially allows use of cost-effective catalysts and bipolar plates in devices. However, HEMFC performance is adversely affected by CO2 present in the ambient air feed. Here, we demonstrate an electrochemically driven CO2 separator (EDCS) to remove CO2 from the air feed using a shorted membrane that conducts both anions and electrons. This EDCS is powered by hydrogen like a fuel cell but needs no electrical wires, bipolar plates or current collectors, and thus can be modularized like a typical separation membrane.

The University of Delaware team has been attempting to improve fuel cell technology for over fifteen years. They realized that the sensitivity of the fuel cell to carbon dioxide, while detrimental to its efficiency in converting the chemical energy in fuel to electricity, meant it could be used as an effective tool for capturing carbon dioxide from the atmosphere.

An early prototype they developed using this approach, about the size of a 12-ounce (355 mL) soda can, could filter 10 liters of air per minute while scrubbing out >98% of the carbon dioxide present.

Brian Setzler, assistant research professor in chemical and biomolecular engineering and paper co-author explains, "Once we dug into the mechanism, we realized the fuel cells were capturing just about every bit of carbon dioxide that came into them, and they were really good at separating it to the other side," said

"It turns out our approach is very effective. We can capture 99% of the carbon dioxide out of the air in one pass if we have the right design and right configuration," said Professor Yushan Yan, Henry Belin du Pont Chair of Chemical and Biomolecular Engineering at the University of Delaware.

“This carbon dioxide problem has been with us for long enough, and we decided to turn the problem on its head and make it into a solution,” said Yan.

Read more here and here.  

Saturday, February 5, 2022

MIT Engineers Rock the "Impossible"


Using a novel polymerization process, MIT chemical engineers have created a new lightweight material stronger than steel. The new substance is the result of polymerizing a material in two dimensions.

The new material is a two-dimensional polymer that self-assembles into sheets, unlike all other polymers, which form one-dimensional, spaghetti-like chains. Until now, scientists had believed it was impossible to induce polymers to form 2D sheets.

The researchers found that the new material’s elastic modulus — a measure of how much force it takes to deform a material — is between four and six times greater than that of bulletproof glass. They also found that its yield strength, or how much force it takes to break the material, is twice that of steel, even though the material has only about one-sixth the density of steel.

Such a material could be used as a lightweight, durable coating for car parts or cell phones, or as a building material for bridges or other structures, says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the new study.

“We don’t usually think of plastics as being something that you could use to support a building, but with this material, you can enable new things,” he says. “It has very unusual properties and we’re very excited about that.”

The researchers have filed for two patents on the process they used to generate the material, which they describe in a paper appearing today in Nature. MIT postdoc Yuwen Zeng is the lead author of the study.

Read more here and here.