Retinal immune cells may hold key to preventing diabetes-related vision loss

New research could form the basis for developing life-changing therapies that limit the impact of diabetic eye disease – a condition that could potentially affect some 1.7 million Australians, suffering from type 1 and type 2 diabetes.

Published in PNAS, the University of Melbourne research uncovers how retinal immune cells change during diabetes, which may lead to new treatments that can be used from an early stage of disease, well before any loss of vision.

“Until recently, immune cells of the nervous system were thought to sit quietly, only responding when injury or disease occurred. Our finding expands our knowledge of what these cells do and shows a highly unusual mechanism by which blood vessels are regulated. This is the first time, immune cells have been implicated in controlling blood vessel and blood flow,” co-author Professor Erica Fletcher said.

Almost everyone with type 1 diabetes, and more than 60 per cent of those with type 2 diabetes, will develop some form of diabetic eye disease within 20 years of diagnosis, according to Diabetes Australia. With an additional 280 people developing the disease every day, the breakthrough has important implications.

The research team found a specific type of immune cell, called microglia, contact both blood vessels and neurons in the retina and are able to change blood flow to meet the needs of neurons.

Deforestation-fueled heat already affecting millions of outdoor workers in the tropics

Population in deforested areas with heat exposure corresponding to greater than two hours of safe work time lost at present (top) and with additional global warming. Some of the most-affected areas are in Southeast Asia, Central America and South America.Parsons et al./One Earth

Pledges made in Glasgow at the recent United Nations Climate Change Conference, or COP26, are urgently needed by communities on the front lines of forest loss, according to a new study by a multidisciplinary team from the University of Washington, Duke University and The Nature Conservancy. New research shows how much local temperature rises in the tropics — compounded by accelerating deforestation — may already be jeopardizing the well-being and productivity of outdoor workers.

The study, published Dec. 17 in One Earth, compares established recommendations on safe working conditions with satellite observations of temperature and forest cover and population data. Results show how warming associated with recent deforestation, from 2003 to 2018, has increased heat exposure for 4.9 million people globally, including 2.8 million outdoor workers.

“Our findings highlight the vital role tropical forests play in effectively providing natural air-conditioning services for populations vulnerable to climate change — given these are typically regions where outdoor work tends to be the only option for many, and where workers don’t have the luxury of retiring to air-conditioned offices whenever the temperature rises to intolerable levels,” said lead author Luke Parsons, who began the study as a postdoctoral researcher at the University of Washington and is now a postdoctoral researcher at Duke University.

Coronal rain on a cold star

Coronal rain on the sun with Earth superimposed for scale. New high-resolution spectrographic observations of a flare on a faint distant star using the Penn State Habitable-zone Planet Finder could contain the first evidence of a similar phenomenon on an ultracool, small M-dwarf star.
Credit: NASA/SDO

High-resolution spectroscopic observations of a stellar flare on a small, cool star indicate the possibility of coronal rain, a phenomenon that has been observed on our sun but not yet confirmed on a star of this size. This faint star, known as vB 10, which is about a tenth the size of the sun and produces less than 1% of the sun’s energy, was studied using the Penn State Habitable-zone Planet Finder (HPF) at the large Hobby Eberly Telescope (with its 10 m mirror). These observations with the HPF spectrograph allowed researchers to measure a shift in the wavelength of certain atomic lines from the flare that are consistent with hot plasma raining back down on the star’s surface and are similar to observations of coronal rain from the sun.

A paper describing the observations, by a team led by Penn State scientists, includes a time-series analysis of the flare and could help astronomers put constraints on the energy and frequency of such events. The paper has been accepted for publication in The Astrophysical Journal and is available online.

Fire and Ice

How could ice loss in the Arctic contribute to wildfire weather in the western United States? Shifts in atmospheric circulation patterns, it turns out, come about through surface warming in an increasingly iceless Arctic. Watch this animation to learn more about the mechanism at play.

Animation by Sara Levine | Pacific Northwest National Laboratory

“Some say the world will end in fire,” wrote Robert Frost a century ago. The poet described one popular take on the world’s end before shifting to its apocalyptic opposite, writing, “some say in ice.”

But the relationship between fire and ice, in terms of Earth’s climate, is not quite as “either or” as Frost depicted. In the case of a study presented today at the 2021 AGU Fall Meeting in New Orleans, that relationship is more “give and take.”

The team of researchers behind the recent study published in Nature describe a link between dwindling sea ice and worsening wildfires in the western United States. As sea ice melts from July to October, sunlight warms the increasingly iceless, surrounding area. This ultimately brings heat and fire-favorable conditions to distant states like California, Washington, and Oregon later in autumn and early winter.

The researchers describe this relationship—its existence previously known, but its underlying mechanism now described for the first time—as similarly influential as climate patterns like the El Niño-Southern Oscillation.

Understanding cobalt’s human cost

Miners at a cobalt cleaning site in Lualaba Province, the Democratic Republic of the Congo. Credit Northwestern University

While driving an electric car has fewer environmental impacts than gasoline-powered cars, the production of the parts necessary for these green technologies can have dire effects on human well-being.

After studying the impacts of mining cobalt — a common ingredient in lithium-ion batteries — on communities in Africa’s Democratic Republic of the Congo (DRC), an interdisciplinary team of researchers led by Northwestern University is calling for more data into how emerging technologies affect human health and livelihoods.

Such data can inform policymakers, industry leaders and consumers to make more socially and ethically responsible decisions when developing, funding and using green technologies.

The case study and perspective paper were published today (Dec. 17) in the journal One Earth.

Using sparse data to predict lab quakes

Stick-slip events in the earth cause damage like this,
but limited data from these relatively rare earthquakes makes them
difficult to model with machine learning. Transfer learning may provide
a path to understanding when such deep faults slip.
Credit: Dreamstime

A machine-learning approach developed for sparse data reliably predicts fault slip in laboratory earthquakes and could be key to predicting fault slip and potentially earthquakes in the field. The research by a Los Alamos National Laboratory team builds on their previous success using data-driven approaches that worked for slow-slip events in earth but came up short on large-scale stick-slip faults that generate relatively little data—but big quakes.

“The very long timescale between major earthquakes limits the data sets, since major faults may slip only once in 50 to 100 years or longer, meaning seismologists have had little opportunity to collect the vast amounts of observational data needed for machine learning,” said Paul Johnson, a geophysicist at Los Alamos and a co-author on a new paper, “Predicting Fault Slip via Transfer Learning,” in Nature Communications.

To compensate for limited data, Johnson said, the team trained a convolutional neural network on the output of numerical simulations of laboratory quakes as well as on a small set of data from lab experiments. Then they were able to predict fault slips in the remaining unseen lab data.

This research was the first application of transfer learning to numerical simulations for predicting fault slip in lab experiments, Johnson said, and no one has applied it to earth observations.

New Device Advances Commercial Viability of Solar Fuels

A model solar fuels device called a photoelectrochemical cell. A research team led by Francesca Toma, a staff scientist at the Liquid Sunlight Alliance in Berkeley Lab’s Chemical Sciences Division, designed the model.
Credit: Thor Swift/Berkeley Lab

A research team has developed a new artificial photosynthesis device with remarkable stability and longevity as it converts sunlight and carbon dioxide into two promising sources of renewable fuels – ethylene and hydrogen.

The researchers’ findings, which they recently reported in the journal Nature Energy, reveal how the device degrades with use, then demonstrate how to mitigate it. The authors also provide new insight into how electrons and charge carriers called “holes” contribute to degradation in artificial photosynthesis.

“By understanding how materials and devices transform under operation, we can design approaches that are more durable and thus reduce waste,” said senior author Francesca Toma, a staff scientist in the Liquid Sunlight Alliance (LiSA) and Berkeley Lab’s Chemical Sciences Division.

Drug could more effectively treat patients hospitalized with COVID-19 pneumonia

A proof-of-concept trial led by the University of Birmingham and University Hospitals Birmingham NHS Foundation Trust has identified a drug that may benefit some patients hospitalized with COVID-19 pneumonia.

The CATALYST trial tested UK-based bio-pharmaceutical company Izana Bioscience’s namilumab (IZN-101) as a potential therapeutic to treat patients who are hospitalized with COVID-19 pneumonia, and receiving ‘usual’ care, as well as having high levels in their blood of a marker of inflammation known as C reactive protein (CRP). CRP levels rise when there is inflammation in the body, and elevated levels of CRP have been found to be a potential early marker to predict risk for severity of COVID-19.

An antibody already in late-stage trials to treat rheumatoid arthritis, namilumab targets a ‘cytokine’ which is naturally secreted by immune cells in the body but, in uncontrolled levels, is believed to be a key driver of the excessive and dangerous lung inflammation seen in COVID-19 patients.

The trial, carried out in collaboration with the University of Oxford and funded by the Medical Research Council and carried out between June 2020 and February 2021, involved patients aged over 16 with COVID-19 pneumonia either being treated on a ward or Intensive Care Unit (ICU) at nine NHS hospitals across the UK.

The study, published today in The Lancet Respiratory Medicine, involved 54 patients receiving ‘usual care’ (steroids and oxygen or ventilation, depending on the severity of disease) and 57 patients given usual care as well as a single intravenous dose of 150mg of namilumab.

Gene mutation leads to epileptic encephalopathy symptoms, neuron death in mice

A study led by Illinois postdoctoral researcher Eung Chang Kim and professor Hee Jung Chung found that mice with a genetic mutation associated with epileptic encephalopathy exhibit not only the seizure and behavioral symptoms of the disorder, but also neural degeneration and inflammation in the brain.  Photo by L. Brian Stauffer

Mice with a genetic mutation that’s been observed in patients with epileptic encephalopathy, a severe form of congenital epilepsy, exhibit not only the seizure, developmental and behavioral symptoms of the disorder, but also neural degeneration and inflammation in the brain, University of Illinois Urbana-Champaign researchers found in a new study. The findings highlight the mutation as an important part of the disease’s pathology and a potential target for treatment.

Patients with epileptic encephalopathy begin having seizures when they are born, and display progressive developmental delay, intellectual disability and autismlike behavior, said study leader Hee Jung Chung, a professor of molecular and integrative physiology.

“The dogma regarding epileptic encephalopathy has been that the epileptic seizures are driving the pathogenesis of intellectual disability and developmental delay. But we wanted to answer the question, is it really just the seizures driving the intellectual disability and developmental delay?” Chung said. “This study is the first to show that expressing this human epileptic encephalopathy mutation in mice can cause not only spontaneous seizure and intellectual disability, but also neural degeneration.”

Previous work from Chung’s group found that epileptic encephalopathy is correlated with a mutation in a gene that codes for a potassium channel essential to regulating neuron activity. The mutation prevented the potassium channel from properly embedding in the cell membranes of neurons, causing it to build up inside the neuronal cells instead. Yet, whether and how the mutation played a role in the pathology of epileptic encephalopathy remained unknown.

Room-temperature crystallography aids new study of photosynthetic bacteria

Researchers at SLAC, Stanford University and Washington University
studied a protein that helps transport electrons during bacterial photosynthesis.
Jared Weaver/Stanford University

Chemists have come to a deeper understanding of how photosynthetic bacteria convert light into chemical energy and discovered why one step in the process may be more robust than previously realized, according to a new study published this week in Proceedings of the National Academy of Sciences.

The study focused on proteins called reaction centers in a bacterium called Rhodobacter sphaeroides that help transport electrons in its cell membrane during the first steps of photosynthesis. Although these proteins, which reside in the cell membrane, have been studied for decades, many details of how they work remain unclear. To try to fill in some of those details, Stanford University's Jared Weaver, a graduate student in chemist Steven Boxer's laboratory, worked with fellow Stanford chemist Chi-Yun Lin and Washington University researchers Kaitlyn Fairies, Dewey Holten, and Chris Kirmaier, who have been studying R. sphaeroides reaction centers for over a decade. Their apporach was to replace part of the protein with amino acids – protein building blocks – that do not naturally appear in that part of the protein structure. The results could help researchers better understand how the electron-transporting protein works under normal operation.

As part of those investigations, Weaver teamed up with Irimpan Mathews, a staff scientist at the Stanford Synchrotron Radiation Lightsource (SSRL) at the Department of Energy's SLAC National Accelerator Laboratory. There, the pair worked to crystallize the modified photosynthetic proteins and study them with X-ray macromolecular crystallography at one of SSRL's beamlines.