. Scientific Frontline

Wednesday, November 10, 2021

Methane’s Short Lifespan Presents Golden Opportunity to Quickly Address Climate Change

Berkeley Lab researcher Sebastien Biraud
(Courtesy Sebastien Biraud)
Sébastien Biraud is a Berkeley Lab scientist leading an effort to identify and mitigate some of the largest emitters of methane in California’s Southern San Joaquin Valley. Methane is a short-lived air pollutant and greenhouse gas capable of warming the atmosphere about 80 times as fast as the far longer-lived carbon dioxide over 20 years. This month the U.S. and European Union launched the Global Methane Pledge at the United Nations Climate Change conference, in recognition of the chance countries have to slow climate change by tackling methane emissions–possibly even before the end of this decade. Countries joining the pledge commit to a collective goal of reducing global methane emissions by at least 30% from 2020 levels before 2030 with a particular focus on sources of high emissions.

Since 2019 Biraud and team have been setting up a framework for pinpointing and monitoring these “super emitters” in California’s Southern San Joaquin Valley where more than 50% of methane emissions can be traced back to less than 10% of super emitters from the dairy and oil and gas industries. Their goal is to identify the super emitters at the scale of individual oil wells, fields, or entire regions, quantify the amount of methane emitted, then use that information to help inform mitigation approaches across California and elsewhere.

Q. Why monitor methane? Why is it important to identify methane super-emitters?

Methane is emitted during energy production, raising livestock, and the decay of organic waste in landfills. Methane is what we call a “short-lived” climate forcer because it stays in the atmosphere for far less time than other greenhouse gasses such as carbon dioxide – 10 years versus more than 100 years for CO2. The molecular structure of methane is such that it is capable of warming the atmosphere about 80 times as fast as carbon dioxide. That’s bad news for warming as there’s evidence that methane could cause more warming over the next 10 years than CO2.

Although this is clearly a challenge, this also presents a great opportunity to act: by reducing methane emissions, we can reduce methane induced-warming and slow down the rate of warming. If we do this right, there’s potential to see results from cuts to methane emissions in as little as 10 years.

And that’s where super-emitters come in. Multiple atmospheric studies have identified that methane emissions have been significantly underestimated by greenhouse gas inventories for the U.S., California, and select cities. Other studies have provided compelling evidence indicating that in California a relatively small number of super-emitters – in some cases 1 to 10% of potential sources – contribute more than half of the methane emissions. We can’t make the reductions needed without addressing these super emitters.

Study pinpoints molecular targets of transplant rejection

Researchers from the University of Sydney and Monash University have made a significant discovery that uncovers what is happening at the molecular level when an organ transplant is recognized as foreign by the immune system.

Working in mice, the team identified the precise molecular targets of transplant rejection and showed how this knowledge could potentially be used in the future to improve immune monitoring of clinical transplant recipients.

The study is published in the Journal of Clinical Investigation.

Each year around 1500 Australian lives are saved through organ transplants, but the risk of that transplant being rejected remains significant. Rejection occurs when a person’s immune system recognizes the organ as foreign and starts to attack it, just like it would a virus.

“While the early outcomes of organ transplants are excellent, the long-term results aren’t nearly as good with many people losing their transplant within 10 to 15 years,” said senior author Associate Professor Alexandra Sharland from the University of Sydney’s Charles Perkins Centre and Faculty of Medicine and Health.

Clinicians currently detect transplant rejection through a range of techniques, including monitoring organ function via blood tests or more invasive procedures such as regular biopsies of the transplanted organ.

Tiny crystal at a distance safely measures powerful electric fields

Sandia National Laboratories researcher Israel Owens holds the optical sensor used to house the crystal that proved central to his team’s successful attempts to measure very high voltages. The two red spots on each side of the crystal are due to laser light reflecting off the side mirrors used to direct light through the middle of the crystal. The actual experiments used green laser light.
Photo by David Bret Latter

Ever since the first human placed a bare hand on an uninsulated electric line, people have refrained from personally testing energetic materials. Even meters made of metal can melt at high voltages.

Now, using a crystal smaller than a dime and a laser smaller than a shoebox, a Sandia National Laboratories team has safely measured 20 million volts without physically contacting the electrical flow. (Residential voltage is generally 120 volts.)

“No one had directly measured voltages this large anywhere in the world before our experiment,” said Sandia scientist Israel Owens of his team’s unique electrical and optical work, recently published in Nature’s Scientific Reports. “For measuring high voltages, the technique is safe, efficient and inexpensive.”

“When you have a high voltage over short distances, sensors break down,” said Sandia manager Bryan Oliver. “Israel’s diagnostic can survive these high electric fields and thus enable us to determine the voltage in an environment where that was previously not possible.”

Rapidly evolving species more likely to go extinct, study suggests

Pleurosaurus from the Late Jurassic, some 150 million years ago, of southern Germany, a remarkable, long-bodied swimming rhynchocephalian.

Researchers at the University of Bristol have found that fast evolution can lead to nowhere.

In a new study of lizards and their relatives, Dr Jorge Herrera-Flores of Bristol’s School of Earth Sciences and colleagues have discovered that ‘slow and steady wins the race’.

Evolutionary tree of the tuatara, lizards and snakes.
During the time of the dinosaurs the extinct relatives of the
tuatara evolved rapidly, whereas lizards and snakes evolved slowly.
Credit: Dr Tom Stubbs
The team studied lizards, snakes and their relatives, a group called the Lepidosauria. Today there are more than 10,000 species of lepidosaurs, and much of their recent success is a result of fast evolution in favorable circumstances. But this was not always the case.

Mr Herrera-Flores explained: “Lepidosaurs originated 250 million years ago in the early Mesozoic Era, and they split into two major groups, the squamates on the one hand, leading to modern lizards and snakes, and the rhynchocephalians on the other, represented today by a single species, the tuatara of New Zealand. We expected to find slow evolution in rhynchocephalians, and fast evolution in squamates. But we found the opposite.”

Tuesday, November 9, 2021

Can't find your keys? You need a chickadee brain

Mountain Chickadee
For the first time, researchers have shown that there is a genetic component underlying the amazing spatial memories of mountain chickadees.

These energetic half-ounce birds hide thousands of food items every fall and rely on these hidden stores to get through harsh winters in the mountains of the West. To find these caches, chickadees use highly specialized spatial memory abilities. Although the genetic basis for spatial memory has been shown for humans and other mammals, direct evidence of that connection has never before been identified in birds.

Their research, “The Genetic Basis of Spatial Cognitive Variation in a Food-Caching Bird,” published Nov. 3 in the journal Current Biology. The research is a collaboration among scientists from the Cornell Lab of Ornithology; the University of Colorado, Boulder; the University of Nevada, Reno; and the University of Oklahoma.

“We all use spatial memory to navigate our environment,” said lead author Carrie Branch, a postdoctoral researcher at the Cornell Lab of Ornithology. “Without memory there’s no learning and an organism would have to start from scratch for every task. So, it really is life and death for these birds to be able to remember where they stashed their food. We’ve been able to show that natural selection is shaping their ability to remember locations.”

If natural selection (survival of the fittest) is shaping chickadee memory, certain criteria have to be met. There has to be variation in the trait: Some chickadees are indeed better than others at re-finding their stores. There has to be a fitness advantage: Birds that perform better on a spatial memory task are more likely to survive and produce offspring. Importantly, variation in the trait must have a genetic basis.

Biodiversity 'time machine' uses artificial intelligence to learn from the past

Experts can make crucial decisions about future biodiversity management by using artificial intelligence to learn from past environmental change, according to research at the University of Birmingham.

A team, led by the University’s School of Biosciences, has proposed a ‘time machine framework’ that will help decision-makers effectively go back in time to observe the links between biodiversity, pollution events and environmental changes such as climate change as they occurred and examine the impacts they had on ecosystems.

In a new paper, published in Trends in Ecology and Evolution, the team sets out how these insights can be used to forecast the future of ecosystem services such as climate change mitigation, food provisioning and clean water.

Using this information, stakeholders can prioritize actions which will provide the greatest impact.

Principal investigator, Dr Luisa Orsini, is an Associate Professor at the University of Birmingham and Fellow of The Alan Turing Institute. She explained: “Biodiversity sustains many ecosystem services. Yet these are declining at an alarming rate. As we discuss vital issues like these at the COP26 Summit in Glasgow, we might be more aware than ever that future generations may not be able to enjoy nature’s services if we fail to protect biodiversity.”

Biodiversity loss happens over many years and is often caused by the cumulative effect of multiple environmental threats. Only by quantifying biodiversity before, during and after pollution events, can the causes of biodiversity and ecosystem service loss be identified, say the researchers.

Common Household Noises May Be Stressing Your Dog

Researchers at the University of California, Davis, have found that people may not recognize that their dog is stressed when exposed to common household noises. While it’s well established that sudden loud noises, such as fireworks or thunderstorms, commonly trigger a dog’s anxiety, a new study finds even common noises, such as a vacuum or microwave, can be a trigger. The study was published in Frontiers in Veterinary Science.

The research found that high-frequency, intermittent noises such as the battery warning of a smoke detector are more likely to cause a dog anxiety, rather than low-frequency, continuous noise.

“We know that there are a lot of dogs that have noise sensitivities, but we underestimate their fearfulness to noise we consider normal because many dog owners can’t read body language,” said lead author Emma Grigg, a research associate and lecturer at the UC Davis School of Veterinary Medicine.

Signs of anxiety

Some common signs of a dog’s anxiety include cringing, trembling or retreating, but owners may be less able to identify signs of fear or anxiety when behaviors are more subtle. For example, stressed dogs could pant, lick their lips, turn their head away or even stiffen their body. Sometimes their ears will turn back, and their head will lower below their shoulders. Grigg suggests owners better educate themselves on anxiety-related behavior.

Researchers conducted a survey of 386 dog owners about their dogs’ responses to household sounds and examined recorded dog behaviors and human reactions from 62 videos available online. The study found that owners not only underestimated their dogs’ fearfulness, but the majority of people in videos responded with amusement rather than concern over their dog’s welfare.

Fossil elephant cranium reveals key adaptations

A remarkably well-preserved fossil elephant cranium from Kenya is helping scientists understand how its species became the dominant elephant in eastern Africa several million years ago, a time when a cooler, drier climate allowed grasslands to spread and when habitually bipedal human ancestors first appeared on the landscape. Dated to 4.5 million years ago and recovered from a site on the northeast side of Lake Turkana, it is the only well-preserved elephant cranium—the portion of the skull that encloses the brain—from that time. It is about 85% intact and holds a wealth of previously unavailable anatomical detail, according to University of Michigan paleontologist William Sanders.

Known by its museum number, KNM-ER 63642, the roughly 2-ton cranium belonged to a massive adult male of the species Loxodonta adaurora, an extinct evolutionary cousin of modern African elephants but not a direct ancestor.

Preparators from the National Museums of Kenya at the Ileret research facility of the Turkana Basin Institute, starting manual preparation and supplementing the field consolidation (chemical hardening) of Loxodonta adaurora cranium KNM-ER 63642. From left to right: Cliff Onyango, Robert Moru and Christopher Kiarie.
Image credit: Steve Jabo, Smithsonian Institution

KNM-ER 63642 is both impressively immense and unexpectedly modern in aspect, displaying adaptations that likely gave L. adaurora an edge when competing with other large mammals for grasses, according to Sanders, lead author of a study published online Oct. 21 in the journal Palaeovertebrata. Co-authors include Meave and Louise Leakey, who led the recovery effort and who are best known for the discovery of early hominid specimens and artifacts from Lake Turkana and elsewhere.

Codetta Program Deciphers Genetic Code in 250,000 Genomes

Within DNA, four chemical bases (shown in green, red, blue, and orange)
strung together in long strands contain the instructions for building proteins.
Credit: Irving Geis/HHMI
Codetta, a new computational method for predicting genetic codes, could reveal insights into how some organisms have modified a code once thought to be universal.

In the 1800s, the Rosetta Stone – an ancient rock slab inscribed with three languages – helped scholars decode Egyptian hieroglyphics. Now, a computer program is doing something similar for the genetic code.

The program, named Codetta, can read the genome sequence of any organism, and then spit out its genetic code: the biological key that translates genetic information into instructions for building proteins. Across most of the tree of life, this code is universal. But scientists have found a handful of exceptions – in some organisms, genetic info codes for instructions different from those in other life-forms.

In the largest screen to date for such alternative genetic codes, the program scanned more than 250,000 genome sequences from bacteria and archaea and identified five never-before-seen codes, Harvard University’s Kate Shulgina and Howard Hughes Medical Investigator Sean Eddy report November 9, 2021, in the journal, eLife. “I told Kate that her new codes are going straight into the textbooks,” Eddy says.

The team’s method is faster, more rigorous, and more comprehensive than previous efforts, says Ken Wolfe, an evolutionary geneticist at University College Dublin who was not involved with the research. “They looked at every genome that’s available for bacteria and archaea – essentially, all the data that exists.”

The work’s practical implications are immediate: scientists using Codetta, which is freely available, will be able to correctly predict which proteins an organism is making. But the program might unlock more sweeping biological insights too.

Adding herbs and spices to meals may help lower blood pressure

Photo by Taryn Elliott from Pexels
Seasoning your food generously with herbs and spices isn’t just a great way to make your meals tastier — new research found it may have benefits for your heart’s health, as well.

In a controlled-feeding study, the researchers found that seasoning foods with 6.5 grams, or about 1.3 teaspoons, of herbs and spices a day was linked with lower blood pressure after four weeks.

Penny Kris-Etherton, Evan Pugh University Professor of Nutritional Sciences, and Kristina Petersen, assistant professor of nutritional sciences at Texas Tech University and co-principal investigator of the study while at Penn State, said the findings offer people a simple way to help improve their heart health.

“Adding herbs and spices to your food is a great way to add flavor without adding extra sodium, sugar or saturated fat,” Kris-Etherton said. “And, if you go a step further and add these seasonings to foods that are really good for you, like fruits and vegetables, you can potentially get even more health benefits by consuming that extra produce.”

According to the researchers, cardiometabolic diseases like heart disease, strokes and type two diabetes continue to be one of the leading causes of death in the United States. One of the ways health professionals aim to improve heart health is by monitoring and improving blood pressure.

One way people can improve their blood pressure is by limiting their sodium intake, usually by adding less salt to their meals. Petersen said that while people have long been encouraged to season their food with herbs and spices instead of salt to boost flavor without added sodium, less was known about whether herbs and spices have health benefits of their own.

“As nutritionists, we’re interested in new ways we can use diet to benefit health, and cardiovascular health in particular,” Petersen said. “We were curious about how herbs and spices could affect heart health, since they are versatile and can be added to many different types of food.”

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