Tyler O'Neal, Staff Editor DEVELOPER TOOLS

University of New South Wales shows how the Southern Ocean takes on the heat of climate change

In the past 50 years, the oceans have absorbed more than 90% of the excess heat caused by our carbon dioxide emissions, with one ocean absorbing the vast majority. Paradise Bay in the Southearn Ocean, MarcAndreLeTourneux/Shutterstock CREDIT MarcAndreLeTourneux/Shutterstock

“The Southern Ocean dominates this ocean heat uptake, due in part to the geographic set-up of the region,” said UNSW Ph.D. candidate Maurice Huguenin, the lead author of the new study.

“Antarctica, which is surrounded by the Southern Ocean, is also surrounded by strong westerly winds,” Mr. Huguenin said.

“These winds influence how the waters absorb heat, and around Antarctica, they can exert this influence while remaining uninterrupted by land masses – this is key to the Southern Ocean being responsible for pretty much all of the net global ocean heat uptakes,” he said.

Mr. Huguenin said that these winds blow over what is effectively an infinite distance – cycling uninterrupted at southern latitudes – which continuously draws cold water masses to the surface. The waters are pushed northward, readily absorbing vast quantities of heat from the atmosphere, before the excess heat is pumped into the ocean’s interior around 45-55°S.

But, while ocean warming helps slow the pace of climate change, it is not without cost said co-author Professor Matthew England at UNSW Science and Deputy Director of ACEAS.

“Sea levels are rising because heat causes water to expand and ice to melt. Ecosystems are experiencing unprecedented heat stress, and the frequency and intensity of extreme weather events is changing” Prof. England said.

“We still have a lot to learn about ocean warming beyond the 50 years highlighted in our study,” Mr Huguenin added.

“All future projections, including even the most optimistic scenarios, predict warmer oceans in the future.”

“If the Southern Ocean continues to account for the vast majority of heat uptake until 2100, we might see its warmth increase by up to seven times more than what we have already seen up to today.”

Prof. England said this will have an enormous impact around the globe including disturbances to the Southern Ocean food web, rapid melting of Antarctic ice shelves and changes in the conveyor belt of ocean currents.

The scientists used a novel experimental approach to find exactly where excess heat is taken up by the oceans and where it ends up after absorption. This was previously difficult to detect due to relatively sparse and short-lived measurement records.

The team ran a model with atmospheric conditions fixed in the 1960s – prior to any significant human-caused climate change. They then compared this model to others in which the oceans experience the past 50 years of climate change one ocean basin at a time. The results revealed that the Southern Ocean is the most important absorber of greenhouse gas-trapped heat and that its circulation – driven by winds – is uniquely set up to force this excess heat into the ocean interior.

To better understand how Southern Ocean heat uptake continues to evolve, the scientists call for ongoing monitoring of this remote ocean – including the deployment of additional deep-reaching Argo floats, which are pivotal for tracking ocean heat content. They also stress the urgency of reducing greenhouse gas emissions.

“The less carbon dioxide we emit into the atmosphere, the less ocean change and sea-level rise we will lock in,” the authors said.

“This can help limit the level of adaptation required by the billions of people living near the ocean, by minimising the detrimental impacts of ocean warming on both sea-level and their primary food source.”

Helsinki researchers use ML to unlock the genomic code in clinical cancer samples

Tyler O'Neal, Staff Editor DEVELOPER TOOLS

A new paper from the University of Helsinki suggests a method for accurately analyzing genomics data in archival cancer biopsies. This tool uses machine learning methods to correct damaged DNA and unveil the true mutation processes in tumor samples. This helps to unlock tremendous medicine values in millions of archival cancer samples.

Molecular-based diagnosis helps to match the right patient with the right cancer treatment. Researchers took particular interest in DNA profiling in clinical cancer samples.

This invaluable source is currently not being used for molecular diagnosis due to the poor DNA quality. Formalin causes severe damage to DNAs, which is an inevitable challenge to analyse cancer genomes in preserved tissues, says lead author Qingli Guo from the University of Helsinki.

Analyzing mutation processes in cancer genomes can help early cancer detection, accurately diagnose cancer, and reveal why some cancers become resistant to treatment. The new method can dramatically accelerate the development of clinical applications that can directly impact future cancer patient care.

The new method predicted more than 90% of developing cancer processes

Lead author Qingli Guo works in close collaboration with scientists from The Institute of Cancer Research (ICR), London, and the Queen Mary University of London, developed machine learning methods, named FFPEsig, to unravel exactly how formalin mutates DNA.

Our results show that normally nearly half of the cancer processes will be missed without noise correction. However, using FFPEsig, more than 90% of them were accurately predicted. says Qingli.

Cancer evolves gradually. Profiling mutational processes in longitudinal samples help to identify clinical informative predictors and make a diagnosis of each tumor stage.

Our finding enables the characterization of clinically relevant signatures from the preserved tumor biopsies stored at room temperatures for decades. With a deep understanding of how formalin impacts the cancer genome, our study opens a huge opportunity to transform the developed signature detection assays using large cost-effective archival samples.

The researchers pointed out that the method currently does not completely remove artifacts that appeared in FFPE samples showing batch effects, and how well the tool performs varies by cancer type, so care must be taken to interpret any findings. We are also interested in further applying their methods to a much broader spectrum of archival samples in the future.

The research was funded by Cancer Research UK, the University of Helsinki, and in part by the Academy of Finland. This project is co-led by senior authors Prof. Ville Mustonen (University of Helsinki) and Prof. Trevor Graham (the ICR).

VLBA produces first full 3D view of binary star-planet system

Tyler O'Neal, Staff Editor DEVELOPER TOOLS

By precisely tracing a small, almost imperceptible, wobble in a nearby star’s motion through space, astronomers have discovered a Jupiter-like planet orbiting that star, which is one of a binary pair. Their work, using the National Science Foundation’s Very Long Baseline Array (VLBA), produced the first-ever determination of the complete, 3-dimensional structure of the orbits of a binary pair of stars and a planet orbiting one of them. This achievement, the astronomers said, can provide valuable new insights on the process of planet formation. Credit: Sophia Dagnello, NRAO/AUI/NSF.

Though more than 5,000 extrasolar planets have been discovered so far, only three have been discovered using the technique — called astrometry — that produced this discovery. However, the feat of determining the 3-D architecture of a binary-star system that includes a planet “cannot be achieved with other exoplanet discovery methods,” said Salvador Curiel, of the National Autonomous University of Mexico (UNAM).

“Since most stars are in binary or multiple systems, being able to understand systems such as this one will help us understand planet formation in general,” Curiel said.

The two stars, which together are called GJ 896AB, are about 20 light-years from Earth — close neighbors by astronomical standards. They are red dwarf stars, the most common type in our Milky Way galaxy. The larger one, around which the planet orbits, has about 44 percent of the mass of our Sun, while the smaller one is about 17 percent as massive as the Sun. They are separated by about the distance of Neptune from the Sun and orbit each other once every 229 years.

For their study of GJ 896AB, the astronomers combined data from optical observations of the system made between 1941 and 2017 with data from VLBA observations between 2006 and 2011. They then made new VLBA observations in 2020. The continent-wide VLBA’s supersharp resolution — the ability to see fine detail — produced extremely precise measurements of the stars’ positions over time. The astronomers performed an extensive analysis of the data that revealed the stars’ orbital motions as well as their common motion through space.

Detailed tracing of the larger star’s motion showed a slight wobble that revealed the existence of the planet. The wobble is caused by the planet’s gravitational effect on the star. The star and planet orbit a location between them that represents their common center of mass. When that location, called the barycenter, is sufficiently far from the star, the star’s motion around it can be detectable.

The astronomers calculated that the planet has about twice the mass of Jupiter and orbits the star every 284 days. Its distance from the star is slightly less than Venus’ distance from the Sun. The planet’s orbit is inclined roughly 148 degrees from the orbits of the two stars.

“This means that the planet moves around the main star in the opposite direction to that of the secondary star around the main star,” said Gisela Ortiz-León, of UNAM and the Max Planck Institute for Radioastronomy. “This is the first time that such dynamical structure has been observed in a planet associated with a compact binary system that presumably was formed in the same protoplanetary disk,” she added.

“Additional detailed studies of this and similar systems can help us gain important insights into how planets are formed in binary systems. There are alternate theories for the formation mechanism, and more data can possibly indicate which is most likely,” said Joel Sanchez-Bermudez, of UNAM. “In particular, current models indicate that such a large planet is very unlikely as a companion to such a small star, so maybe those models need to be adjusted,” he added.

The astrometric technique will be a valuable tool for characterizing more planetary systems, the astronomers said. “We can do much more work like this with the planned Next Generation VLA (ngVLA),” said Amy Mioduszewski, of the National Radio Astronomy Observatory. “With it, we may be able to find planets as small as the Earth.”