Mastodon Scientific Frontline: September 2022

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.

Funding:
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.

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

Source/Credit: U.S. Department of Energy

phy093022_02

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).

Stone spheres could be from Ancient Greek board game

Groups of spheres from Akrotiri
Credit: Konstantinos Trimmis

Archaeologists from the University of Bristol have suggested that mysterious stone spheres found at various ancient settlements across the Aegean and Mediterranean could be playing pieces from one of the earliest ever board games.

There has been quite a lot of speculation around these spheres found at sites on Santorini, Crete, Cyprus, and other Greek Islands with theories around their use including being for some sort of sling stones, tossing balls, counting/record-keeping system or as counters/pawns.

Previous research by the same team from the University of Bristol indicated that there was variability in sphere size within specific clusters and collections of spheres. Following on from this the team wanted to explore potential patterning within these sphere concentrations, to help give an insight into their potential use.

The latest study published this week in the Journal of Archaeological Science Reports by Drs Christianne Fernée and Konstantinos Trimmis from the University of Bristol’s Department of Anthropology and Archaeology examined common features on 700 stones – which range from around 4,500 to 3,600 years old – found at the Bronze Age town of Akrotiri on the island of Santorini.

Container for Hazardous Radioactive Waste Storage Model Created

According to Oleg Tashlykov, the container protects from radiation in all directions.
Photo Credit: Anastasia Farafontova

Ural Federal University scientists designed a container to store solidified liquid radioactive waste containing "long-lived" cesium-137 and cobalt-60, the most potentially dangerous of all radioactive waste. Due to their innovative design and filling, the simulated containers are capable of reducing radiation from radioactive waste to safe levels. One such container could replace five or six of the standard type. An article about the scientific work was published in the journal Progress in Nuclear Energy.

The modeled container consists of three main layers: a stainless steel inner capsule, halloysite clay filler, and an outer cementation concrete layer. The stainless steel capsule holds more than 450,000 cm3 of radioactive waste. Radionuclides are concentrated in a special sorbent, which is used in ion-selective purification and is placed inside the capsule. Stainless steel was chosen because, unlike carbon steel, it is more resistant to corrosion and does not require shielding.

"As a rule, such containers consist of two layers: outer cementation concrete and an inner metallic hosting capsule with a radioactive sorbent (or a sorbent in a cement matrix is placed inside the container). The main disadvantage of such a container arrangement is that their shielding, i.e. protective, capacity is limited. We suggest a three-layer container - with an additional layer between the inner metal capsule and the outer shell. The material that fills this space must be inexpensive and still effectively reduce the gamma radiation emitted by the radioisotopes inside the radioactive waste container. In this case, we investigated the protective properties of the intermediate layer consisting of halloysite - a fine-dispersed nanoscale white clay with a chemical composition rich in aluminum and silicon," says Oleg Tashlykov, Associate Professor at the Department of Nuclear Power Plants and Renewable Energy Sources at UrFU, Head of Research and one of the authors of the article.

Dual-targeting CAR NK cells can prevent cell dysfunction and tumor escape

 Katy Rezvani, M.D., Ph.D
Credit: The University of Texas MD Anderson Cancer Center.

Researchers at The University of Texas MD Anderson Cancer Center have developed a new approach to engineering natural killer (NK) cells with a second chimeric antigen receptor (CAR) to act as a logic gate, requiring two signals to eliminate a target cell. In preclinical studies, these next-generation CAR NK cells improved tumor specificity and enhanced anti-tumor activity by overcoming a process that contributes to NK cell dysfunction and tumor relapse.

This study, published in Nature Medicine, demonstrated that a normal physiological process called trogocytosis contributes to tumor escape and poor responses after CAR NK cell therapy by causing tumor antigen loss, NK cell exhaustion and fratricide — the killing of sibling CAR NK cells.

“We identified a novel mechanism of relapse following CAR NK cell therapy, and we also have developed a strategy to mitigate this process,” said corresponding author Katy Rezvani, M.D., Ph.D., professor of Stem Cell Transplantation & Cellular Therapy. “We engineered CAR NK cells with dual-targeting CARs that are able to ignore tumor antigens on the surface of their sibling NK cells acquired as a result of trogocytosis and selectively eliminate tumor cells.”

Rezvani and Ye Li, M.D., a graduate student in the Rezvani Lab, led the study.

During trogocytosis, surface proteins from a target cell are transferred to the surface of an immune cell, such as an NK cell or T cell, in order to regulate their activity. Using preclinical models, Li and colleagues showed that CAR activation promotes trogocytosis, resulting in the transfer and expression of tumor antigens on CAR NK cells.

Traumatic brain injury ‘remains a major global health problem’ say experts

Photo Credit: Ian Valerio

The report – the 2022 Lancet Neurology Commission – has been produced by world-leading experts, including co-lead author Professor David Menon from the Division of Anesthesia at the University of Cambridge.

 "Over the last decade, large international collaborations have provided important information to improve understanding and care of TBI. However, significant problems remain, especially in low- and middle-income countries"
David Menon

The Commission documents traumatic brain injury (TBI) as a global public health problem, which afflicts 55 million people worldwide, costs over US$400 billion per year, and is a leading cause of injury-related death and disability.

TBI is not only an acute condition but also a chronic disease with long-term consequences, including an increased risk of late-onset neurodegeneration, such as Parkinson’s disease and dementia. Road traffic incidents and falls are the main causes, but while in low- and middle-income countries, road traffic accidents account for almost three times the number of TBIs as falls, in high-income countries falls cause twice the number of TBIs compared to road traffic accidents. These data have clear consequences for prevention.

Over 90% of TBIs are categorized as ‘mild’, but over half of such patients do not fully recover by six months after injury. Improving outcome in these patients would be a huge public health benefit. A multidimensional approach to outcome assessment is advocated, including a focus on mental health and post-traumatic stress disorder. Outcome after TBI is poorer in females compared with males, but reasons for this are not clear.

Molecular chaperones caught in flagrante

For an adequate immune response, it is essential that T lymphocytes recognize infected or degenerated cells. They do so by means of antigenic peptides, which these cells present with the help of specialized surface molecules (MHC I molecules). Using X-ray structure analysis, a research team from Frankfurt has now been able to show how the MHC I molecules are loaded with peptides and how suitable peptides are selected for this purpose.

As task forces of the adaptive immune system, T lymphocytes are responsible for attacking and killing infected or cancerous cells. Such cells, like almost all cells in the human body, present on their surface fragments of all the proteins they produce inside. If these include peptides that a T lymphocyte recognizes as foreign, the lymphocyte is activated and kills the cell in question. It is therefore important for a robust T-cell response that suitable protein fragments are presented to the T lymphocyte. The research team led by Simon Trowitzsch and Robert Tampé from the Institute of Biochemistry at Goethe University Frankfurt has now shed light on how the cell selects these protein fragments or peptides.

Peptide presentation takes place on so-called major histocompatibility complex class I molecules (MHC I). MHC I molecules are a group of very diverse surface proteins that can bind myriads of different peptides. They are anchored in the cell membrane and form a peptide-binding pocket with their outward-facing part. Like all surface proteins, MHC I molecules take the so-called secretory pathway: they are synthesized into the cell's cavity system (endoplasmic reticulum (ER) and Golgi apparatus) and folded there. Small vesicles then bud off from the cavity system, migrate to the cell membrane and fuse with it.

Study reveals how COVID-19 damages the heart

Image Credit: Sanjay k j

University of Queensland researchers have discovered how COVID-19 damages the heart, opening the door to future treatments.

This initial study – featuring a small cohort – found COVID-19 damaged the DNA in cardiac tissue, which wasn’t detected in influenza samples.

UQ Diamantina Institute researcher Dr Arutha Kulasinghe said the team found while COVID-19 and influenza are both severe respiratory viruses, they appeared to affect cardiac tissue very differently.

“In comparison to the 2009 flu pandemic, COVID has led to more severe and long-term cardiovascular disease but what was causing that at a molecular level wasn’t known,” Dr Kulasinghe said.

“During our study, we couldn’t detect viral particles in the cardiac tissues of COVID-19 patients, but what we found was tissue changes associated with DNA damage and repair.

“DNA damage and repair mechanisms foster genomic instability and are related to chronic diseases such as diabetes, cancer, atherosclerosis and neurodegenerative disorders, so understanding why this is happening in COVID-19 patients is important.”

Paleontologists Found Mammoth Baby, Ancient Bear Teeth, and Lair of Cave Hyenas

Scientists will open a new expedition season in spring.
Photo credit: TASS-Ural Press Center / Vladislav Burnashev

Paleontologists of Ural Federal University and the Institute of Plant and Animal Ecology of Ural Branch of Russian Academy of Sciences during summer expeditions found a large number of ancient bones, teeth, as well as wool and skin of a mammoth baby. The study of remains will allow us to recreate the specifics of the flora and fauna of ancient times in detail and to understand the specifics of animal nutrition. Scientists told about the results of summer expeditions at a press conference in TASS.

On the Gyda Peninsula (Far North), paleontologists found the well-preserved remains of a mammoth baby. The uniqueness of the discovery is its age - it is a six-year-old mammoth baby. If previously only single bones were found, now the researchers have found material that will help study mammoth babies, said Pavel Kosintsev, a leading expert of the Laboratory of Natural Science Methods in Humanities of UrFU, a Senior Researcher of the Institute of Plant and Animal Ecology of the Ural Branch of the Russian Academy of Sciences.

Thursday, September 29, 2022

Ancient 'Shark' from China Is Humans' Oldest Jawed Ancestor

Life reconstruction of Fanjingshania renovata.
Image Credit: ZHANG Heming)

Paleontologists discover a 439-million-year-old 'shark' that forces us to rethink the timeline of vertebrate evolution

Living sharks are often portrayed as the apex predators of the marine realm. Paleontologists have been able to identify fossils of their extinct ancestors that date back hundreds of millions of years to a time known as the Palaeozoic period. These early "sharks," known as acanthodians, bristled with spines. In contrast to modern sharks, they developed bony "armor" around their paired fins.

A recent discovery of a new species of acanthodian from China surprised scientists with its antiquity. The find predates by about 15 million years the earliest acanthodian body fossils and is the oldest undisputed jawed fish.

These findings were published in Nature.

Reconstructed from thousands of tiny skeletal fragments, Fanjingshania, named after the famous UNESCO World Heritage Site Fanjingshan, is a bizarre fish with an external bony "armor" and multiple pairs of fin spines that set it apart from living jawed fish, cartilaginous sharks and rays, and bony ray- and lobe-finned fish.

Making lab-grown brain organoids ‘brainier

 Slices of mini–brain organoids with neural stem cells (red) and cortical neurons (green).
Credit: Hajime Ozaki, Watanabe lab/UCI

By using stem cells to grow miniature brain-like organs in the lab, scientists have opened a new avenue for studies of neurological development, disease and therapies that can’t be conducted in living people. But not all mini–brain organoids are created equal and getting them to precisely mimic the human brain tissues they’re modeling has been a persistent challenge.

“Right now, it’s like the Wild West because there is no standard method for generating mini–brain organoids,” said Bennett Novitch, a member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA and the senior author of a new paper on the topic. “Every neuroscientist wants to make a brain organoid model of their favorite disease, and yet everyone’s organoids do not always look alike.”

In fact, because there is no common protocol for their production and a lack of quality-control guidelines, organoids can vary from lab to lab — and even from batch to batch — which means that a finding made in one organoid may not hold true in another.

“If my lab and another lab down the hall were to conduct drug screens using mini–brain organoid models of the same disorder, we could still get different results,” said Momoko Watanabe, the new paper’s first author and an assistant professor of anatomy and neurobiology at UC Irvine. “We won’t know whose findings are correct because the differences we’re seeing could be reflections of how our models differ rather than reflections of the disease.”

Wildfire smoke exposure hurts learning outcomes

Exposure to fine particle pollution from wildfire smoke during the school day affects average test scores. In this map of the predicted effect on average test scores by district in a relatively high-smoke year, 2016, darker shades indicate a stronger impact.
Image credit: Wen et al. 2022, Nature Sustainability

Pollution from wildfires is linked to lower test scores and possibly lower future earnings for kids growing up with more smoke days at school, a new study finds. Impacts of smoke exposure on earnings are disproportionately borne by economically disadvantaged communities of color.

When wildfire smoke pollutes the air in schoolyards and classrooms, as it does with increasing frequency and severity across the country, it hurts not only children’s health but also their ability to learn and possibly their future earning power, according to new research from Stanford University.

The new analysis, published Sept. 29 in Nature Sustainability, draws on eight years of standardized test scores from nearly 11,700 public school districts across six grades, as well as estimates of daily smoke exposure derived from satellite measurements.

The researchers found test scores in English language arts and math dropped significantly during school years even at low levels of smoke exposure, and that test-score impacts grew as students’ smoke exposure worsened.

The impact on test scores nearly doubled when students were exposed to heavy smoke during the school day compared to the weekend. Underscoring previous studies suggesting that air pollution impacts are particularly harmful for younger students, the study also revealed greater impacts for third to fifth graders compared to sixth to eighth graders.

WVU engineers bring new life to electronics recycling, address supply chain shortfalls affecting national defense

Edward Sabolsky, WVU Benjamin M. Statler College of Engineering and Mineral Resources professor uses ceramic bricks to conduct research at his lab. The U.S. Department of Defense has tasked Sabolsky and Terence Musho with developing a new process for recycling electronic waste in order to extract raw materials that are used to build technology critical to U.S. national defense, such as semiconductors. Photo Credit: WVU /Brian Persinger

West Virginia University researchers are resurrecting discarded electronics, recycling electronic waste and recovering minerals from it to make new products critical for national defense.

Terence Musho, associate professor of mechanical and aerospace engineering at the Benjamin M. Statler College of Engineering and Mineral Resources, is leading the project, which received more than $250,000 from the Defense Advanced Research Projects Agency at the U.S. Department of Defense.

The U.S. currently depends on countries like China to provide raw materials that are essential to electronics enabling its national defense. But according to Musho, that “reliance on foreign national resources has led to the White House identifying a critical shortage in the semiconductor supply chain.”

Musho said that shortage is one reason the DOD is eyeing readily available electronic waste like old “LEDs and microelectronic circuits used for amplifying radio frequencies, which contain critical supply chain materials.”

A Different Kind of Therapy for Stroke

Stroke folders and labels at the Emergency Department at UConn Health in Farmington on Sept. 29, 2020.
Photo Credit: Peter Morenus/UConn

Stroke deprives the brain of oxygen and energy, causing a cascade of spreading cell death. Blocking a specific receptor could contain the damage, researchers from UConn Health and the National Institutes of Health (NIH) report in the Journal of Medicinal Chemistry.

A stroke occurs when a blood vessel in the brain is either ruptured or clogged. The loss of blood flow deprives part of the brain of oxygen, and cells begin to die within minutes. Every 40 seconds someone in the US has a stroke, according to the Centers for Disease Control and Prevention. That’s more than 795,000 people every year. More than half of the survivors will have permanent difficulties walking, talking and caring for themselves.

The faster someone suffering from a stroke gets medical help, the more likely they are to avoid serious lasting disability. Restoring blood flow to the brain as fast as possible to avoid cell death is critical.

But other factors besides blood flow can also contribute to cell death in brain during a stroke. For example, brain cells store lots of energy in the form of the molecule ATP. When a brain cell dies, it releases all of its stored ATP. The spilled ATP triggers a receptor called P2X4 on neighboring brain cells. If the P2X4 receptor is overstimulated, it can trigger a rush of calcium ions that can activate cell death enzymes and set off a destructive cycle of brain damage.

Process converts polyethylene bags, plastics to polymer building blocks

Plastics made from polyethylene (white strands), such as the milk bottle shown in background, can now be broken down into smaller molecules — propylene — that are valuable for making another type of plastic, polypropylene. Click image for more detailed caption.
Graphic credit: Brandon Bloomer, UC Berkeley

Polyethylene plastics — in particular, the ubiquitous plastic bag that blights the landscape — are notoriously hard to recycle. They’re sturdy and difficult to break down, and if they’re recycled at all, they’re melted into a polymer stew useful mostly for decking and other low-value products.

But a new process developed at the University of California, Berkeley, and Lawrence Berkeley National Laboratory (Berkeley Lab) could change all that. The process uses catalysts to break the long polyethylene (PE) polymers into uniform chunks — the three-carbon molecule propylene — that are the feedstocks for making other types of high-value plastic, such as polypropylene.

The process, admittedly in the early stages of development, would turn a waste product — not only plastic bags and packaging, but all types of PE plastic bottles — into a major product in high demand. Previous methods to break the chains of polyethylene required high temperatures and gave mixtures of components in much lower demand. The new process could not only lower the need for fossil fuel production of propylene, often called propene, but also help fill a currently unmet need by the plastics industry for more propylene.

Flaring allows more methane into the atmosphere than we thought

Multiple flares observed in operation in the Bakken Formation in the Williston Basin in North Dakota, 2021.
Image credit: Alan Gorchov Negron, University of Michigan and Yulia Chen of Stanford University

Oil and gas producers rely on flaring to limit the venting of natural gas from their facilities, but new research led by the University of Michigan shows that in the real world, this practice is far less effective than estimated—releasing five times more methane in the U.S. than previously thought.

Methane is known to be a powerful greenhouse gas, but burning it off at oil and gas wells was believed to effectively keep it from escaping into the atmosphere.

Unfortunately, data published in the journal Science shows we overestimate flaring’s effectiveness and, as a result, underestimate its contribution to methane emissions and climate change. But if we fix flaring issues, the payoff is huge: the equivalent of removing 3 million cars from the roads.

Industry and regulators operate under the assumption flares are constantly lit and that they burn off 98% of methane when in operation. Data taken via aerial surveys in the three U.S. geographical basins, which are home to more than 80% of U.S. flaring operations, shows both assumptions are incorrect. Flares were found to be unlit approximately 3%-5% of the time and, even when lit, they were found operating at low efficiency. Combined, those factors lead to an average effective flaring efficiency rate of only 91%.

Power supply: Understand unstable networks

A stable power grid is essential for a reliable and sustainable energy system.
Photo credit: Markus Breig / KIT

A sustainable energy supply requires the expansion of the power grids. However, new lines can also make networks not more stable as expected, but more unstable. The phenomenon is called Braess paradox. This has now been simulated for the first time in detail for power grids, demonstrated on a larger scale and developed a forecasting instrument by an international team in which researchers from the Karlsruhe Institute of Technology (KIT) are also involved. It is intended to support network operators in making decisions. The researchers report in the journal Nature Communications

The sustainable transformation of the energy system requires an expansion of the networks in order to integrate renewable sources and to transport electricity over long distances. This expansion requires large investments and aims to make the networks more stable. By upgrading existing lines or adding new lines, it can also happen that the network does not become more stable, but more unstable and there are power outages. “We then speak of the Braess paradox. This means that an additional option instead of improvement leads to a deterioration in the overall situation,” says Dr. Benjamin Schäfer, head of the research group Data-driven Analysis of Complex Systems (DRACOS) at the Institute for Automation and Applied Computer Science at KIT.

The phenomenon is named after the German mathematician Dietrich Braess, who first discussed it for road networks: under certain conditions, the construction of a new road can extend the travel time for all road users. This effect was observed in traffic systems and discussed for biological systems, but has so far only been theoretically forecast for power grids and presented on a very small scale.

Genetic and environmental factors contribute to the overlap between depression and endocrine metabolic diseases

Credit: Pixabay

Depression is common in individuals with endocrine-metabolic disorders and vice versa. In a study of 2.2 million individuals in the Swedish population, researchers at Karolinska Institutet saw that those with endocrine-metabolic diseases also have an increased incidence of depression. The researchers also found higher frequencies of depression in the group's siblings. The study is published in the American Journal of Psychiatry.

Further analyzes described the relative contribution of genetic and environmental factors underlying the concomitant occurrence of depression for a variety of endocrine-metabolic diseases. It is already known that there is an increased simultaneous occurrence of endocrine-metabolic diseases and depression, but the relationships are still unclear.

Whether the overlap between these conditions is mainly genetic or environmental has consequences for whether the development of pharmacological or behavioral interventions would be more effective for treatment or prevention, says Sarah Bergen, senior researcher at the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet, who led the study.

New light for shaping electron beams

Recent experiments at the University of Vienna show that light (red) can be used to arbitrarily shape electron beams (yellow), opening new possibilities in electron microscopy and metrology.
Credit: stefaneder.at, University of Vienna

A new technique that combines electron microscopy and laser technology enables programable, arbitrary shaping of electron beams. It can potentially be used for optimizing electron optics and for adaptive electron microscopy, maximizing sensitivity while minimizing beam-induced damage. This fundamental and disruptive technology was now demonstrated by researchers at the University of Vienna, and the University of Siegen. The results are published in PRX.

When light passes through turbulent or dense material, e.g. the Earth’s atmosphere or a millimeter-thick tissue, standard imaging technologies experience significant limitations in the imaging quality. Scientists therefore place deformable mirrors in the optical path of the telescope or microscope, which cancel out the undesired effects. This so-called adaptive optics has led to many breakthroughs in astronomy and deep-tissue imaging.

However, this level of control has not yet been achieved in electron optics even though many applications in materials science and structural biology demand it. In electron optics, scientists use beams of electrons instead of light to image structures with atomic resolution. Usually, static electromagnetic fields are used to steer and focus the electron beams.

Webb and Hubble Capture Detailed Views of DART Impact

For the first time, the NASA/ESA/CSA James Webb Space Telescope and the NASA/ESA Hubble Space Telescope have taken simultaneous observations of the same target.  These images, Hubble on left and Webb on the right, show observations of Dimorphos several hours after NASA’s Double Asteroid Redirection Test (DART) intentionally impacted the moonlet asteroid. It was the world’s first test of the kinetic impact technique using a spacecraft to deflect an asteroid by modifying its orbit.  Both Webb and Hubble observed the asteroid before and after the collision took place.  Scientists will use the combined observations from Hubble and Webb to gain knowledge about the nature of the surface of Dimorphos, how much material was ejected by the collision, how fast it was ejected, and the distribution of particle sizes in the expanding dust cloud.  In the coming months, scientists will also use Webb’s Mid-Infrared Instrument (MIRI) and Near-Infrared Spectrograph (NIRSpec) to observe Dimorphos further. Spectroscopic data will provide researchers with insight into the asteroid’s composition. Hubble will monitor Dimorphos ten more times over the next three weeks to monitor how the ejecta cloud expands and fades over time.  Hubble observations were conducted in one filter, WFC3/UVIS F350LP (assigned the color blue), while Webb observed at F070W (0.7 microns, assigned the color red). 
Credit: NASA, ESA, CSA, and STScI

Two of the great observatories, the NASA/ESA/CSA James Webb Space Telescope and the NASA/ESA Hubble Space Telescope, have captured views of a unique experiment to smash a spacecraft into a small asteroid. NASA’s Double Asteroid Redirection Test (DART) impact observations mark the first time that Webb and Hubble were used to simultaneously observe the same celestial target.

On 26 September 2022 at 13:14 CEST, DART intentionally crashed into Dimorphos, the asteroid moonlet in the double-asteroid system of Didymos. It was the world’s first test of the kinetic impact technique using a spacecraft to deflect an asteroid by modifying the object’s orbit. DART is a test for defending Earth against potential asteroid or comet hazards.

The observations are more than just an operational milestone for each telescope—there are also key science questions relating to the makeup and history of our solar system that researchers can explore when combining the capabilities of these observatories.

Adverse health outcomes associated with long-term antidepressant use

Long-term antidepressant use may double the risk of heart disease, finds the most comprehensive epidemiological study to date to investigate the health consequences from using the medication over ten years. The University of Bristol-led study, published in the British Journal of Psychiatry Open, analyzed data on over 200,000 people.

Antidepressants are one of the most widely prescribed drugs in England. In 2018, over 70-million antidepressant prescriptions were dispensed. The striking rise in prescribing (nearly doubling in a decade) is due mainly to long-term treatment rather than increased diagnosis. However, little is known about the health consequences of long-term use of these medicines.

Researchers from Bristol’s Centre for Academic Mental Health aimed to find out if long-term antidepressant use (over five and ten years) was associated with the onset of six health problems: diabetes, high blood pressure, coronary heart disease, stroke and related syndromes, and two mortality outcomes (death from cardiovascular disease and from any cause).

Using data from UK Biobank, a large-scale biomedical database and research resource containing anonymized genetic, lifestyle and health information from half a million UK participants, the team linked comprehensive health data with prescription and disease data (using GP records) on 222,121 adults aged between 40 to 69-years old.

Less bird diversity in city forests

Image credit: Kev

A new study led by Lund University in Sweden shows that cities negatively affect the diversity of birds. There are significantly fewer bird species in urban forests compared with forests in the countryside - even if the forest areas are of the same quality.

The researchers examined 459 natural woodlands located in or near 32 cities in southern Sweden. They counted the occurrence of different bird species, and the result is clear: in natural forests located in a city center, there are on average a quarter fewer species of forest birds compared to forests outside the city. In terms of endangered species, about half as many species were found in urban forests compared to rural forests.

The results deepen our knowledge of the impact of cities on biodiversity, says William Sidemo Holm, one of the researchers behind the study. It is already well known that urbanization is one of the main driving forces behind the loss of biodiversity, as cities spread out across the globe. What is not as well known, however, is how cities affect protected natural areas in a city.

“Our study demonstrates that you cannot surround nature with urban development and believe that it will remain as it is, there is going to be a negative effect”, says William Sidemo Holm, who worked on the study during his time as a doctoral student at Lund University.

Wednesday, September 28, 2022

Birth of a sibling triggers long-lasting stress in young bonobos

Young bonobos as old as eight years suffer long-lasting stress after the birth of a sibling. 
Credit: MPI of Animal Behavior/ Christian Ziegler

In any family, the birth of a child is a transformative event, often greeted with positive feelings from parents—and mixed feelings from siblings. The arrival of a new brother or sister, and the loss of parental attention that comes with it, is stressful for any first-born child. Now, scientists have shown that it is not just humans who have trouble becoming siblings. Bonobos, our closest living relatives, also experience stress in the transition to siblinghood. Following the birth of a sibling, young bonobos had five times higher levels of the stress hormone cortisol and a reduced immune response, which lingered for months. The international team of researchers behind the study were able to show that the stress response was due to the birth of siblings, and not to the natural weaning process that young bonobos inevitably go through. The study on wild bonobos, which is the first to investigate physiological changes in an animal as it transitions to siblinghood, reveals similarities between humans and bonobos—and an evolutionary history behind the stressful event of becoming a sibling.

Bonobos (Pan paniscus) are a species of great ape found only in the Congolese rainforest. Like humans, bonobos and other great apes take an unusually long time to reach independence. Bonobos rely on their mothers for food and protection for eight years and only reach full adulthood at 12 years. While in most animals, offspring are weaned before the mother gives birth to another infant. In bonobos, maturation is slow and the birth of another baby happens long before the older infant has become independent—setting the scene for sibling rivalry.

How fish survive the extreme pressures of life in the oceans

Photo credit: Milos Prelevic

Scientists have discovered how a chemical in the cells of marine organisms enables them to survive the high pressures found in the deep oceans.

The deeper that sea creatures live, the more inhospitable and extreme the environment they must cope with. In one of the deepest points in the Pacific - the Mariana Trench, 11 kilometers below the sea surface - the pressure is 1.1 kbar or eight tons per square inch. That is a 1,100-fold increase of the pressure experienced at the Earth’s surface.

Under normal or atmospheric pressure, water molecules form a tetrahedron-like network. At high pressure, though, the network of water molecules begins to distort and change shape. When this happens to the water inside living cells, it prevents vital bio-chemical processes from taking place - and kills the organism.

Our study provides a bridge between water under pressure at the molecular level and the wonderful ability of organisms which thrive under high pressure in depths of the oceans.

In reporting their findings, the researchers in Leeds have for the first time been able to provide an explanation of how a molecule found in the cells of marine organisms counteracts the effect of external pressure on the water molecules.

Dead fish breathe new life into the evolutionary origin of fins and limbs

The holotype specimen of the fossil Tujiaaspis vividus from 436 million year old rocks of Hunan Province and Chongqing, China.
Credit: Zhikun Gai

A trove of fossils in China, unearthed in rock dating back some 436 million years, have revealed for the first time that the mysterious galeaspids, a jawless freshwater fish, possessed paired fins.

The discovery, by an international team, led by Min Zhu of the Institute of Vertebrate Paleontology and Palaeoanthropology, Bejiing and Professor Philip Donoghue from the University of Bristol’s School of Earth Sciences, shows the primitive condition of paired fins before they separated into pectoral and pelvic fins, the forerunner to arms and legs.

Until now, the only surviving fossils of galeaspids were heads, but these new fossils originating in the rocks of Hunan Province and Chongqing and named Tujiaaspis after the indigenous Tujia people who live in this region, contain their whole bodies.

Theories abound on the evolutionary beginnings of vertebrate fins and limbs – the evolutionary precursors of arms and legs - mostly based on comparative embryology. There is a rich fossil record, but early vertebrates either had fins or they didn’t. There was little evidence for their gradual evolution.

Scientists bring the fusion energy that lights the sun and stars closer to reality on Earth

Physicist Min-Gu Yoo with slides from his paper in background.
Photo credit: Elle Starkman/PPPL Office of Communications; collage by Kiran Sudarsanan

Physicists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have proposed the source of the sudden and puzzling collapse of heat that precedes disruptions that can damage doughnut-shaped tokamak fusion facilities. Coping with the source could overcome one of the most critical challenges that future fusion facilities will face and bring closer to reality the production on Earth of the fusion energy that drives the sun and stars.

Researchers traced the collapse to the 3D disordering of the strong magnetic fields that bottle up the hot, charged plasma gas that fuels the reactions. “We proposed a novel way to understand the [disordered] field lines, which was usually ignored or poorly modeled in the previous studies,” said Min-Gu Yoo, a post-doctoral researcher at PPPL and lead author of a Physics of Plasmas paper selected as an editor’s pick together with a figure placed on the cover of the July issue. Yoo has since become a staff scientist at General Atomics in San Diego.

The strong magnetic fields substitute in fusion facilities for the immense gravity that holds fusion reactions in place in celestial bodies. But when disordered by plasma instability in laboratory experiments the field lines allow the superhot plasma heat to rapidly escape confinement. Such million-degree heat crushes plasma particles together to release fusion energy and can strike and damage fusion facility walls when released from confinement.

Set up reserve lab capacity now for faster response to next pandemic, say researchers

Female scientist in laboratory 
Photo credit: Diane Serik

The researchers, who were on the front line of the UK’s early response to COVID-19 in 2020, say a system of reservist lab scientists should to be set up now to provide surge capacity that will help the country respond faster – and more effectively – to future outbreaks of infectious disease.

They considered a number of options for providing scientific surge capacity and concluded that the best scenario would be a mix of highly skilled paid reservists, and volunteers who could be called on when required and trained rapidly.

In their report, published today in the journal The BMJ, the researchers say the lack of early COVID-19 PCR testing capacity had a knock-on effect on other health services in 2020. This included delaying the ability to make sure hospitals were COVID-secure and patients had surgery as safely as possible, and slowing down the identification of people with COVID-19 in the community – which delayed contact tracing.

“Because COVID-19 testing wasn’t scaled up quickly enough, we couldn’t detect all cases quickly enough to try and stop the spread of the disease,” said Dr Jordan Skittrall in the University of Cambridge’s Department of Pathology and first author of the report.

“It was frustrating to hear politicians’ promises to repeatedly scale up COVID-19 testing capacity during the early stage of the pandemic. The scale-up was extremely challenging: a lot of expertise is needed to get the tests working in the early stages of dealing with a new pathogen,” he added.

Scientists chip away at a metallic mystery, one atom at a time

In this photo from 2020, Christopher Barr, right, a former Sandia National Laboratories postdoctoral researcher, and University of California, Irvine, professor Shen Dillon operate the In-situ Ion Irradiation Transmission Electron Microscope. Barr was part of a Sandia team that used the one-of-a-kind microscope to study atomic-scale radiation effects on metal.
Photo credit: Lonnie Anderson

Gray and white flecks skitter erratically on a computer screen. A towering microscope looms over a landscape of electronic and optical equipment. Inside the microscope, high-energy, accelerated ions bombard a flake of platinum thinner than a hair on a mosquito’s back. Meanwhile, a team of scientists studies the seemingly chaotic display, searching for clues to explain how and why materials degrade in extreme environments.

Based at Sandia, these scientists believe the key to preventing large-scale, catastrophic failures in bridges, airplanes and power plants is to look — very closely — at damage as it first appears at the atomic and nanoscale levels.

“As humans, we see the physical space around us, and we imagine that everything is permanent,” Sandia materials scientist Brad Boyce said. “We see the table, the chair, the lamp, the lights, and we imagine it’s always going to be there, and it’s stable. But we also have this human experience that things around us can unexpectedly break. And that’s the evidence that these things aren’t really stable at all. The reality is many of the materials around us are unstable.”

No difference between spinal versus general anesthesia in patients having hip fracture surgery

Image credit: Fernando zhiminaicela

There are no differences in the safety or effectiveness of the two most common types of anesthetics (spinal versus general anesthesia) in patients undergoing hip fracture surgery, according to the findings of a new study led by the University of Bristol in collaboration with University of Warwick researchers. The findings, published in the British Journal of Anesthesia, analyzed previously published data on nearly 4,000 hip fracture patients.

The research was funded by The Academy of Medical Sciences and supported by the NIHR Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol.

Hip fractures are devastating injuries and remain one of the largest healthcare challenges of the twenty-first century. The incidence increases with advancing age and the number of hip fractures is expected to rise to 6.26 million per year in 2050. In 2017, hip fractures cost the National Health Service (NHS) over £1 billion, which is projected to increase to £5.6 billion in 2033. Patients with hip fractures have a relatively high risk of dying within a year of their injury.

Almost all patients with a hip fracture undergo surgery, requiring anesthesia to be performed so that surgery is safe and not painful. Nearly all patients will receive either spinal or general anesthesia. Given the risk profile of hip fracture patients (older age, frailty, and comorbidities like cardiac and respiratory diseases), surgery is associated with a high risk of developing post-operative complications including delirium, myocardial infarction, pneumonia, stroke, and death.

After wildfires, do microbes exhale potent greenhouse gas?

UCR mycologist and project lead Sydney Glassman sampling burn scar soil.
Photo credit: Sydney Glassman/UCR

Laughing gas is no laughing matter — nitrous oxide is a greenhouse gas with 300 times the warming potential of carbon dioxide. Scientists are racing to learn whether microorganisms send more of it into the atmosphere after wildfires.

A research team led by UC Riverside mycologist Sydney Glassman will spend the next three years answering this question, examining how bacteria, viruses, fungi and archaea work together in post-fire soils to affect nitrous oxide emissions.

Their work is supported by a new $3.1 million grant from the U.S. Department of Energy.

“Because carbon dioxide is the largest contributor to global warming, it’s easy to focus on,” Glassman said.

“Nitrogen in the form of nitrous oxide, and the microbes that regulate it, are a less well-studied aspect of the problem, but an aspect we must solve to more fully understand how the planet is changing, and how much we can expect it to keep changing,” she said.

Novel Carrier Doping in p-type Semiconductors Enhances Photovoltaic Device Performance by Increasing Hole Concentration


The carrier concentration and conductivity in p-type monovalent copper semiconductors can be significantly enhanced by adding alkali metal impurities, as shown recently by Tokyo Tech researchers. Doping with isovalent and larger-sized alkali metal ions effectively increased the free charge carrier concentration and the mechanism was unraveled by their theoretical calculations. Their carrier doping technology enables high carrier concentration and high mobility p-type thin films to be prepared from the solution process, with photovoltaic device applications.

Perovskite solar cells have been the subject of much research as the next generation of photovoltaic devices. However, many challenges remain to be overcome for the practical application. One of them concerns the hole transport layer (p-type semiconductor) in photovoltaic cells that carries holes generated by light to the electrode. In conventional p-type organic transport semiconductors, hole dopants are chemically reactive and degrade the photovoltaic device. Inorganic p-type semiconductors, which are chemically stable, are promising alternatives, but fabrication of conventional inorganic p-type semiconductors requires high temperature treatment. In this regard, the p-type inorganic semiconductors that can be fabricated at low temperatures and have excellent hole transport ability have been desired.

Inorganic p-type copper iodide (CuI) semiconductor is a leading candidate for such hole transport materials in photovoltaic device applications. In this material, native defects give rise to charge imbalance and free charge carriers. However, the overall number of defects is generally too low for satisfactory device performance.

Ural Scientists Propose to Create Citric Acid Using Microorganisms

More than 60% of citric acid is used annually in industry: metallurgy, oil production, medicine and related fields.
Photo credit: Alina Spiridonova

New scientific development will help to create Russia's own production of citric acid, which is currently fully imported. The new method is more technologically advanced and environmentally friendly, as it involves more rational use of microscopic mushrooms for biosynthesis of acid from waste sugar production or products of deep processing of grain. It also avoids large amounts of waste, wastewater and gas emissions. Aleksey Byuler from the UrFU Research Laboratory "Mathematical Modeling in Physiology and Medicine Based on Supercomputers" talked about it on the air of the radio "Komsomolskaya Pravda".

In Russia, the traditional method of citric acid extraction from beet molasses using calcium citrate was used for citric acid production. This led to the formation of significant amounts of waste production: 1 kg of the obtained product had 2 kg of gypsum waste. Such gypsum is not applicable to construction purposes, and its processing requires a lot of energy, so all the gypsum was usually sent to waste, which created a serious impact on the environment. For this reason, the only Russian plant producing citric acid was shut down several years ago. A new linear method using membrane (ultrafiltration) and electrodialysis technologies proposed by the scientists will make it possible to synthesize and isolate citric acid without harming the environment.

Tuesday, September 27, 2022

A Different Kind of Chaos

The experimental setup used by the Weld Lab.
Photo Credit: Tony Mastres

Physicists at UC Santa Barbara and the University of Maryland, and also at the University of Washington have found an answer to the longstanding physics question: How do interparticle interactions affect dynamical localization?

“It’s a really old question inherited from condensed matter physics,” said David Weld, an experimental physicist at UCSB with specialties in ultracold atomic physics and quantum simulation. The question falls into the category of ‘many-body’ physics, which interrogates the physical properties of a quantum system with multiple interacting parts. While many-body problems have been a matter of research and debate for decades, the complexity of these systems, with quantum behaviors such as superposition and entanglement, lead to multitudes of possibilities, making it impossible to solve through calculation alone. “Many aspects of the problem are beyond the reach of modern computers,” Weld added.

Fortunately, this problem was not beyond the reach of an experiment that involves ultracold lithium atoms and lasers. So, what emerges when you introduce interaction in a disordered, chaotic quantum system?

A “weird quantum state,” according to Weld. “It’s a state which is anomalous, with properties which in some sense lie between the classical prediction and the non-interacting quantum prediction.”

The physicists’ results are published in the journal Nature Physics.

Trees get overheated in a warmer rainforest

Maria Wittemann has been conducting field studies in Rwanda with colleagues from the University of Rwanda.
Photo credit: Myriam Mujawamariya

The ability of rainforests to store carbon can decrease in pace with climate change. This is due to photosynthesis rates in the leaves of rainforest species falling at higher temperatures and the trees’ natural cooling systems failing during droughts. Increased heat threatens especially the species that store most carbon. This has been shown in a new thesis from the University of Gothenburg.

Some species of trees are able to handle rising heat in the tropics by sucking up large quantities of water to their leaves and transpiring through wide-opened pores in their leaves. These are mainly fast-growing trees that establish themselves early as a rainforest grows up. The same cannot be said for the trees that make up the canopy of rainforests in old growth forests. They grow slower, but get bigger and taller, and their leaves do not have the same ability to cool themselves via transpiration.

Water powers the ‘air conditioning’

“The tropics have not experienced Ice Ages and have thus had a relatively stable climate historically as well as seasonally. With climate change, it has started to get warmer and then we have seen that some species of trees are showing increased mortality rates, but we have not really known why before,” says Maria Wittemann, who wrote the thesis.

Neurodegenerative disease can progress in newly identified patterns


Neurodegenerative diseases — like amyotrophic lateral sclerosis (ALS, or Lou Gehrig's disease), Alzheimer’s, and Parkinson’s — are complicated, chronic ailments that can present with a variety of symptoms, worsen at different rates, and have many underlying genetic and environmental causes, some of which are unknown. ALS, in particular, affects voluntary muscle movement and is always fatal, but while most people survive for only a few years after diagnosis, others live with the disease for decades. Manifestations of ALS can also vary significantly; often slower disease development correlates with onset in the limbs and affecting fine motor skills, while the more serious, bulbar ALS impacts swallowing, speaking, breathing, and mobility. Therefore, understanding the progression of diseases like ALS is critical to enrollment in clinical trials, analysis of potential interventions, and discovery of root causes.

However, assessing disease evolution is far from straightforward. Current clinical studies typically assume that health declines on a downward linear trajectory on a symptom rating scale, and use these linear models to evaluate whether drugs are slowing disease progression. However, data indicate that ALS often follows nonlinear trajectories, with periods where symptoms are stable alternating with periods when they are rapidly changing. Since data can be sparse, and health assessments often rely on subjective rating metrics measured at uneven time intervals, comparisons across patient populations are difficult. These heterogenous data and progression, in turn, complicate analyses of invention effectiveness and potentially mask disease origin.

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