. Scientific Frontline

Thursday, December 9, 2021

Study finds bio-based cellulose acetate plastic used in consumer goods disintegrates in ocean much faster than assumed

WHOI postdoctoral investigator Michael Mazzotta cuts plastic samples to measure respiration signals of microbial communities respiring cellulose diacetate. A new study led by WHOI researchers finds that cellulose diacetate, a bio-based plastic, degrades in the ocean faster than previously thought.
Image credit: Collin Ward © Woods Hole Oceanographic Institution

Cellulose diacetate (CDA), a bio-based plastic widely used in consumer goods, disintegrates, and degrades in the ocean far quicker than previously assumed, according to a new study published in Environmental Science & Technology Letters.

“These findings challenge the paradigm set by governmental agencies and advocacy groups that CDA-based materials persist in the ocean for decades,” according to the paper, “Rapid Degradation of Cellulose Diacetate by Marine Microbes.” “While no one plastic type will likely meet all of the diverse and growing needs of consumers, these initial findings on the fate of CDA-based materials in the ocean, combined with previous reports in terrestrial and wastewater systems, represent a positive step towards identifying high utility, bio-based plastics with low environmental persistence.”

CDA is largely derived from wood pulp, making it a “bio-based” plastic. It is widely used in consumer goods, including cigarette filters, textiles, coatings, films, food packaging, and other products such as eye glass frames and tool handles.

Scientists Show How Wildfire Smoke Increases Ozone Pollution

Using data gathered from a specially equipped jet that spent a month flying through and studying wildfire plumes, scientists have a better understanding now of how wildfire smoke impacts air quality.

Crucially, they found a mechanism for predicting the production of the pollutant ozone—which, at the ground level, can create poor breathing conditions and also harm ecosystems. Also, the team found that mixing wildfire smoke with urban pollution ramps up the production of ozone, meaning that wildfires upwind of cities are a recipe for air quality problems.

"Of course it is well known that wildfires lower air quality. But it's important to understand the chemical and physical mechanisms by which they do so that we can more effectively forecast how individual fires will impact the communities downwind of them," says Paul O. Wennberg, R. Stanton Avery Professor of Atmospheric Chemistry and Environmental Science and Engineering.

Wennberg is a corresponding author of a paper on the research that was published by Science Advances on December 8.

The paper draws on data collected through the NASA/NOAA FIREX-AQ project, which spent

a month flying missions out of Boise, Idaho, during the summer of 2019. (The project later studied agricultural fires in the Midwest.) Riding a DC-8 that had been converted into a flying laboratory, scientists flew through smoke plumes and gathered information from instruments mounted on the plane. Included in the payload were two instruments from Caltech operated by chemistry graduate students Krystal Vasquez and Hannah Allen, staff scientist John Crounse, and lead author Lu Xu, who completed the work as a staff scientist in Wennberg's lab and is now a research scientist with the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder working in NOAA's Chemical Sciences Laboratory.

Early heat warning system to help save lives in changing climate

A Griffith University-led three-year project to develop an early warning system in homes during extreme heat events has received more than $2 million in funding.

The EtHOs project, was awarded $2.35 million by global charitable foundation Wellcome to help limit the thousands of lives lost each year to heat stress.

Led by Dr Shannon Rutherford, from the School of Medicine and Dentistry, EtHOs is a multidisciplinary research team within the Climate Action research group that includes experts in aged-care nursing, IT, human physiology, engineering, climate science, health economics and environmental epidemiology.

Dr Rutherford said the team recognized that climate change would lead to more extreme and frequent heat episodes and said action must be taken to reduce the risk to older populations who were more vulnerable to heat stress.

“We want to develop an individualized early warning system for older people living at home specific to their home environment and considering different people may be vulnerable to heat for different reasons, and we all have different needs for and levels of access to cooling options,” Dr Rutherford said.

“We would like older people living at home and in the community to have access to a system that helps them, their families and care systems feel safe and confident in their homes as the world experiences more frequent and more intense heat events.”

Burrowing snakes have far worse eyesight than their ancestors

The prong-snouted blind snake (Anilios bituberculatus)
is common across southern Australia.
Credit: Tom Charlton
The ancestor of all living snakes probably had substantially better vision than present-day burrowing snakes, according to new research.

An international team of scientists – led by the Natural History Museum and the University of Plymouth – carried out the first detailed analysis of gene sequence data for any species of the so-called 'blindsnakes' (Scolecophidia), a group of small-eyed burrowers.

They found that seven of the 12 genes associated with bright-light vision in most snakes and lizards species are not present in scolecophidians.

This, they say, demonstrates extensive vision gene loss over tens of millions of years of evolutionary history, similar to that which has also been observed in burrowing mammals with reduced vision.

It also challenges the hypothesis that all snakes living across the world today evolved from extreme burrowers, because the vision genes lost in scolecophidians are present in most other living snakes. The researchers say it would be extremely unlikely for such genetic deficiencies to have been reversed through evolution.

Scolecophidians are dedicated burrowers and form one half of the oldest divergence in the snake tree.

They comprise around 460 of the approximately 3,850 currently recognized living snake species, and likely diverged from their closest living relatives (Alethinophidia, which includes all other living snakes) more than 65 million years ago.

Wednesday, December 8, 2021

ESO telescope images planet around most massive star pair to date

This image shows the most massive planet-hosting star pair to date, b Centauri, and its giant planet b Centauri b. This is the first time astronomers have directly observed a planet orbiting a star pair this massive and hot.   The star pair, which has a total mass of at least six times that of the Sun, is the bright object in the top left corner of the image, the bright and dark rings around it being optical artefacts. The planet, visible as a bright dot in the lower right of the frame, is ten times as massive as Jupiter and orbits the pair at 100 times the distance Jupiter orbits the Sun. The other bright dot in the image (top right) is a background star. By taking different images at different times, astronomers were able to distinguish the planet from the background stars.   The image was captured by the SPHERE instrument on ESO’s Very Large Telescope and using a coronagraph, which blocked the light from the massive star system and allowed astronomers to detect the faint planet. 
Credit: ESO/Janson et al.

The European Southern Observatory’s Very Large Telescope (ESO’s VLT) has captured an image of a planet orbiting b Centauri, a two-star system that can be seen with the naked eye. This is the hottest and most massive planet-hosting star system found to date, and the planet was spotted orbiting it at 100 times the distance Jupiter orbits the Sun. Some astronomers believed planets could not exist around stars this massive and this hot — until now.

“Finding a planet around b Centauri was very exciting since it completely changes the picture about massive stars as planet hosts,” explains Markus Janson, an astronomer at Stockholm University, Sweden and first author of the new study published online today in Nature.

A new algorithm increases the efficiency of quantum computers

Photo: Mikko Raskinen
Quantum computing is taking a new leap forward due to research that has proposed a scheme to reduce the number of calculations needed to read out data stored in the state of a quantum processor. This will make quantum computers more efficient, faster, and ultimately more sustainable.

Quantum computers have the potential to solve important problems that are beyond reach even for the most powerful supercomputers, but they require an entirely new way of programming and creating algorithms. Universities and major tech companies are spearheading research on how to develop these new algorithms.

In a recent collaboration between the University of Helsinki, Aalto University, the University of Turku, and IBM Research Europe-Zurich, a team of researchers developed a new method to speed up calculations on quantum computers. The results were published in the prestigious journal PRX Quantum of the American Physical Society.

‘Unlike classical computers, which use bits to store ones and zeros, information is stored in the qubits of a quantum processor in the form of a quantum state, or a wavefunction,’ says postdoctoral researcher Guillermo García-Pérez from the University of Helsinki, first author of the paper. Therefore, special procedures are required to read out data from quantum computers.

Ancient DNA found in soil samples reveals mammoths survived thousands of years longer than believed

Anthropology PhD student Tyler Murchie is a lead author on research
about a new DNA recovery technique that pulls genomes of thousands
of ancient species from less than a gram of soil.
Photo by Emil Karpinski/McMaster University
Mere spoonsful of soil pulled from Canada’s permafrost are opening vast windows into ancient life in the Yukon, revealing rich new information and rewriting previous beliefs about the extinction dynamics, dates and survival of megafauna like mammoths, horses and other long-lost life forms.

In a new paper, published in the journal Nature Communications, researchers from McMaster University, the University of Alberta, the American Museum of Natural History and the Yukon government present a 30,000-year DNA record of past environments, drawn from cored permafrost sediments extracted from the Klondike region of central Yukon.

Researchers used DNA capture-enrichment technology developed at McMaster to isolate and rebuild, in remarkable detail, the fluctuating animal and plant communities at different time points during the Pleistocene-Holocene transition, an unstable climatic period 11,000-14,000 years ago when a number of large species such as mammoths, mastodons and sabre-toothed cats disappeared.

They reconstructed the ancient ecosystems using tiny soil samples which contain billions of microscopic genomic sequences from animal and plant species.

Optical cavities could be key to next generation interferometers

A new concept has been developed that has the potential to assist new instruments in the investigation of fundamental science topics such as gravitational waves and dark matter.

The concept is described in a paper written by UK Quantum Technology Hub Sensors and Timing researchers at the University of Birmingham and published in Communications Physics, and a related patent application filed by University of Birmingham Enterprise.

It proposes a new method of using optical cavities to enhance atom interferometers – highly sensitive devices that use light and atoms to make ultra-precise measurements.

Although itself challenging to implement, the concept presents a method of overcoming substantial technological challenges involved in the pursuit of atom interferometers operating at extreme momentum transfer – a technique which would allow atoms to be placed into a quantum superposition over large distances.

This is key to enabling the sensitivities required for these devices to investigate signals from dark matter and gravitational waves. The exploration of dark matter, and the detection of gravitational waves from the very early Universe is key to developing our collective knowledge of fundamental physics.

The new paper, written by Dr Rustin Nourshargh, Dr Samuel Lellouch and colleagues from the School of Physics and Astronomy, describes how synchronization of the input pulses, to realize a spatially resolved circulating pulse within the optical cavity, can facilitate a large momentum transfer without the need for drastic improvements in available laser power.

Azure-tailed lizard species rediscovered on Hawaiʻi Island

Azure-tailed skink
Photo credit: Gary Miller

When a former student sent William Mautz, a professor emeritus of biology at the University of Hawaiʻi at Hilo, a snapshot of a lizard once thought to be extinct in Hawaiʻi—he was instantly curious.

It was a recently snapped photograph of what appeared to be an azure-tailed skink, a lizard species once commonly found in the Hawaiian Islands and only known to dwell on a tiny 10-acre islet off Molokaʻi. UH Hilo Tropical Conservation Biology and Environmental Science alumnus Aaron Mickelson sent Mautz the photo to get his expert opinion.

“I said I know what it is, but it is not supposed to be here anymore,” Mautz explained. “The little brown skinks common in Hilo backyards are a different species called the delicate skink. They may have a slate-colored tail but it is not a true blue. The azure-tailed skink also has a stripe over the top of its head.”

To confirm its existence on Hawaiʻi Island, Mautz set off on a hike to the lizard population spotted within a small grove of pandanus trees at the edge of the ocean cliffs near Nīnole on the Hāmākua Coast. Mautz recently published an article about the species’ rediscovery in Herpetological Review.

Quetzalcoatlus, Earth’s largest flier ever

An artist’s rendition of Quetzalcoatlus northropi, a type of pterosaur and the largest flying animal that ever lived on Earth. Quetzalcoatlus stood about 12 feet tall and walked with a unique gait because of its enormous 20-foot wings, which touched the ground when folded.
Artwork courtesy of James Kuether

Look around any wetland today and you’re likely to see 3-foot-tall egrets or 4-foot-tall herons wading in the shallows in stealthy search of fish, insects or crustaceans.

But 70 million years ago, along the Rio Grande River in Texas, a more impressive and scarier creature stalked the marshes: the 12-foot-tall pterosaur known as Quetzalcoatlus. With a 37- to 40-foot wingspan, it was the largest flying animal that ever lived on Earth.

In six papers published today as a Memoir by the Society of Vertebrate Paleontology, scientists and an artist provide the most complete picture yet of this dinosaur relative, the largest example of which is represented by just a single set of fossilized bones collected in the late 1970s from Big Bend National Park. The papers describe the pterosaur’s geological and ecological setting during the Upper Cretaceous, its anatomy and taxonomic position, and how it moved on the ground and in the air.

One of the papers, co-authored by University of California, Berkeley, paleontologist Kevin Padian, emeritus professor of integrative biology and emeritus curator in the UC Museum of Paleontology, answers some of the mysteries surrounding the flying and walking behavior of this unique animal, about which little has been published since its discovery more than 45 years ago. How can an animal walk with wings so long that they touch the ground when folded? What did it eat, and how did it feed? How strong a flier was it? And how does an animal whose wings span 40 feet, yet whose legs are only 6 feet high at the hip, launch itself into the air?

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