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.

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.