. Scientific Frontline

Monday, January 23, 2023

Brunt Ice Shelf in Antarctica calves giant iceberg

Chasm-1 remained dormant for many years but has now created a new iceberg.
Photo Credit: British Antarctic Survey

A huge iceberg (1550 km²), almost the size of Greater London, has broken off the 150m thick Brunt Ice Shelf. It calved after cracks that have been developing naturally over the last few years extended across the entire ice shelf, causing the new iceberg to break free. This occurred on Sunday 22 January between 19.00 and 20.00 UTC during spring tide. 

The iceberg calved when the crack known as Chasm-1 fully extended through the ice shelf. The break off is the second major calving from this area in the last two years and has taken place a decade after scientists at British Antarctic Survey (BAS) first detected growth of vast cracks in the ice. 

The Brunt Ice Shelf is the location of BAS Halley Research Station. BAS glaciologists, who have been monitoring the behavior of the ice shelf, say that the area of the ice shelf where the research station is located currently remains unaffected by the recent calving events.  

 The glaciological structure of the Brunt Ice Shelf is complex, and the impact of calving events is unpredictable.  In 2016, BAS took the precaution of relocating Halley Research Station 23 km inland of Chasm-1 after it began to widen.  

New Tool Uses Ultrasound ‘Tornado’ to Break Down Blood Clots

Ultrasonic Tornado
Illustration Credit: Xiaoning Jiang / Courtesy of North Carolina State University

Researchers have developed a new tool and technique that uses “vortex ultrasound” – a sort of ultrasonic tornado – to break down blood clots in the brain. The new approach worked more quickly than existing techniques to eliminate clots formed in an in vitro model of cerebral venous sinus thrombosis (CVST).

“Our previous work looked at various techniques that use ultrasound to eliminate blood clots using what are essentially forward-facing waves,” says Xiaoning Jiang, co-corresponding author of a paper on the work. “Our new work uses vortex ultrasound, where the ultrasound waves have a helical wavefront.

“In other words, the ultrasound is swirling as it moves forward,” says Jiang, who is the Dean F. Duncan Professor of Mechanical and Aerospace Engineering at North Carolina State University. “Based on our in vitro testing, this approach eliminates blood clots more quickly than existing techniques, largely because of the shear stress induced by the vortex wave.”

“The fact that our new technique works quickly is important, because CVST clots increase pressure on blood vessels in the brain,” says Chengzhi Shi, co-corresponding author of the work and an assistant professor of mechanical engineering at Georgia Tech. “This increases the risk of a hemorrhage in the brain, which can be catastrophic for patients.

Scientists explain emotional ‘blunting’ caused by common antidepressants

Depression
Photo Credit: Ethan Sykes

According to the NHS, more than 8.3 million patients in England received an antidepressant drug in 2021/22. A widely-used class of antidepressants, particularly for persistent or severe cases, is selective serotonin reuptake inhibitors (SSRIs). These drugs target serotonin, a chemical that carries messages between nerve cells in the brain and has been dubbed the ‘pleasure chemical’.

One of the widely-reported side effects of SSRIs is ‘blunting’, where patients report feeling emotionally dull and no longer finding things as pleasurable as they used to. Between 40-60% of patients taking SSRIs are believed to experience this side effect.

To date, most studies of SSRIs have only examined their short-term use, but, for clinical use in depression these drugs are taken chronically, over a longer period of time. A team led by researchers at the University of Cambridge, in collaboration with the University of Copenhagen, sought to address this by recruiting healthy volunteers and administering escitalopram, an SSRI known to be one of the best-tolerated, over several weeks and assessing the impact the drug had on their performance on a suite of cognitive tests.

In total, 66 volunteers took part in the experiment, 32 of whom were given escitalopram while the other 34 were given a placebo. Volunteers took the drug or placebo for at least 21 days and completed a comprehensive set of self-report questionnaires and were given a series of tests to assess cognitive functions including learning, inhibition, executive function, reinforcement behavior, and decision-making.

Anti-aging gene shown to rewind heart age by 10 years

Centenarian
Photo Credit: Mehmet Turgut Kirkgoz

An anti-aging gene discovered in a population of centenarians has been shown to rewind the heart’s biological age by ten years. The breakthrough, published in Cardiovascular Research and led by scientists at the University of Bristol and the MultiMedica Group in Italy, offers a potential target for patients with heart failure.

Associated with exceptional longevity, carriers of healthy mutant genes, like those living in blue zones of the planet, often live to 100 years or more and remain in good health. These individuals are also less prone to cardiovascular complications. Scientists funded by the British Heart Foundation believe the gene helps to keep their hearts young by protecting them against diseases linked to aging, such as heart failure.

In this new study, researchers demonstrate that one of these healthy mutant genes, previously proved particularly frequent in centenarians, can protect cells collected from patients with heart failure requiring cardiac transplantation.

Avian flu could decimate Australian black swans

Australian black swan
UQ research shows black swans lack some immune genes which help other wild waterfowl combat avian flu.
Photo Credit: Holger Detje

The unique genetics of the Australian black swan leaves the species vulnerable to viral illnesses such as avian flu, University of Queensland research has revealed.

The UQ-led study has generated a first-ever genome of the black swan which revealed the species lacks some immune genes which help other wild waterfowl combat infectious diseases.

Associate Professor Kirsty Short from UQ’s School of Chemistry and Molecular Biosciences said the geographic isolation of Australia’s black swans has meant limited exposure to pathogens commonly found in other parts of the world leading to reduced immune diversity.

“Unlike Mallard ducks for example, black swans are extremely sensitive to highly pathogenic avian influenza – HPAI which is often referred to as bird flu - and can die from it within three days,” Dr Short said.

Grassland Ecosystems Become More Resilient with Age

In diverse plant communities, evolution increases the division of labor between species over time.
Photo Credit: Alexandra Weigelt

Reduced biodiversity affects the stability of the entire ecosystem. A long-term experiment now shows that grassland plant communities with multiple species need about 10 years to adjust to each other and produce an even amount of biomass again.

Recent experiments have shown that the loss of species from a plant community can reduce ecosystem functions and services such as productivity, carbon storage and soil health. This reduced functioning may also destabilize the ecosystem in its ability to maintain ecosystem functions and services in the long term. However, assessing this is only possible if experiments can be maintained for a sufficient length of time.

Stable biomass production after 10 years

In a new study, researchers from the University of Zurich and colleagues from Leipzig and Jena analyzed the stability of plant biomass production over two decades in one of the longest-running grassland biodiversity experiments in the world, the Jena Experiment in Germany. After more than a decade, plant species in more diverse experimental communities complemented each other in producing stable biomass at the community level. At low plant diversity, by contrast, this “compensatory” effect was observed and community biomass varied much more from year to year. During the first decade of the experiment, species-rich communities had not yet stabilized because of large fluctuations in species populations. This long-term research shows that biodiversity plays an increasingly important role in stabilizing ecosystem productivity over time as plant communities mature.

Sunday, January 22, 2023

Stanford Medicine researchers measure thousands of molecules from a single drop of blood

A single drop of blood can yield measurements for thousands of proteins, fats and other biomarkers, researchers at Stanford Medicine found.
Photo Credit: PublicDomainPictures

Researchers at Stanford Medicine have shown they can measure thousands of molecules — some of which are signals of health — from a single drop of blood.

The new approach combines a microsampling device — a tool used to self-administer a finger prick — with “multi-omics” technologies, which simultaneously analyze a vast array of proteins, fats, by-products of metabolism and inflammatory markers.

“Even more importantly, we’ve shown you can collect the blood drop at home and mail it into the lab,” said Michael Snyder, PhD, director of the Center for Genomics and Personalized Medicine and senior author on the research, which was published in Nature Biomedical Engineering on Jan. 19.

Unlike finger-prick testing for diabetes, which measures a single type of molecule (glucose), multi-omics microsampling gives data about thousands of different molecules at once.

The research sounds similar to a well-known approach promoted in the past for testing a single drop of blood, but there are important differences: While the earlier approach was based on replicating existing diagnostic tests, multi-omic microsampling uses a different type of data analysis based on a technology called mass spectrometry, which sorts molecules based on their mass and electronic charge. In addition, the data analysis is performed in a lab, not in a portable box.

Removing water, stains, contaminants with hydrogel beads

Snapshots of the hydrogel bead impacting the droplet causing the droplet to lift off the surface.
Photo Credit: Courtesy of University of Hawaiʻi

There may be a more efficient future for water repellent materials and methods thanks to new research from the University of Hawaiʻi at Mānoa College of Engineering. Associate Professor John S. Allen III and an international team of researchers have discovered a method to remove liquid from non-stick surfaces using hydrogel beads, a material similar to gel cap medications.

“Ever want to remove a puddle completely without touching it? How about removing staining coffee off your clothes? Do you know that all the dangerous contaminants are off the surface? All these might be facilitated with low-cost hydrogel beads in the future,” Allen explained.

For a variety of everyday and industrial waterproof/water resistant objects, it is important to reduce the contact time of an impacting water or liquid drop with the surface. Many people are familiar with water repellent coating on buildings and on clothing. Repellants are also used to mitigate icing on a plane, as bouncing droplets are less likely to have time to freeze.

Traded species have distinctive life histories with extended reproductive lifecycles

Chameleon
Invasive species can cause huge environmental problems and monetary costs
Photo Credit: Pierre Bamin

A new study by researchers from Durham University, UK, Queen’s University Belfast, UK, University of Extremadura, Spain and Swansea University, UK have revealed that vertebrate species involved in the live wildlife trade have distinctive life history traits, biological characteristics that determine the frequency and timing of reproduction.

Researchers discovered that traded species produce large numbers of offspring across long reproductive lifespans, an unusual profile that is likely financially advantageous for trades involving captive breeding such as the pet, food and fur/skin trades.

Traded species that have also been introduced into non-native areas have a more extreme version of this same life history profile, suggesting that species most likely to become problematic invaders are at a heightened risk of trade and release.

The study suggests that humans favor species with high reproductive output for trade and release, which are the very species likely to become problematic invaders in future.

Researchers point out that life history traits are therefore potentially useful for predicting future invasions.

Saturday, January 21, 2023

DARPA Selects Aurora Flight Sciences for Phase 2 of Active Flow Control X-Plane

DARPA CRANE X-Plane configuration in development for flight testing Active Flow Control (AFC) technologies
Image Credit: Defense Advanced Research Projects Agency

DARPA has selected Aurora Flight Sciences to move into the detailed design phase of the Control of Revolutionary Aircraft with Novel Effectors (CRANE) program. This follows successful completion of the project’s Phase 1 preliminary design, which resulted in an innovative testbed aircraft that used active flow control (AFC) to generate control forces in a wind tunnel test. Phase 2 will focus on detailed design and development of flight software and controls, culminating in a critical design review of an X-plane demonstrator that can fly without traditional moving flight controls on the exterior of the wings and tail.

The contract includes a Phase 3 option in which DARPA intends to fly a 7,000-pound X-plane that addresses the two primary technical hurdles of incorporation of AFC into a full-scale aircraft and reliance on it for controlled flight. Unique features of the demonstrator aircraft will include modular wing configurations that enable future integration of advanced technologies for flight testing either by DARPA or potential transition partners.

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