(Press-News.org) Oxygenation in the tropical North Pacific Ocean increased during a warm climatic interval that occurred roughly 56 million years ago, despite high global temperatures, according to a new study. Its findings offer insights into how modern tropical oceans may respond to ongoing anthropogenic climate warming. The availability and distribution of dissolved oxygen in Earth’s oceans play a fundamental role in supporting marine ecosystems and marine life. However, oxygen in the global oceans is declining in response to anthropogenic warming. Although these trends writ large are predicted to continue, the future of oxygen in the highly productive and biodiverse tropical ocean isn’t fully understood. Analyzing nitrogen isotope measurements in sedimentary records from the vicinity of the tropical oceans’ oxygen-diffident zones (ODZs) provides a means to understand how ocean oxygenation responded to periods of abrupt climate change in the past. The Paleocene-Eocene Thermal Maximum (PETM) is often considered a geologic analog to anthropogenic warming. Thus, the state of the oceans during the PETM could offer a prophetic glimpse of the future state of Earth’s oceans. Here, Simone Moretti and colleagues use foraminifera-bound nitrogen isotopes from ocean sediment cores as a proxy for tracking past changes in marine denitrification, a process that occurs in oxygen-poor waters, including ODZs. Moretti et al. found that the tropical North Pacific ODZ contracted at the onset of the PETM, indicating a broader increase in oxygen availability in the shallow subsurface waters throughout the topical North Pacific despite the period’s rapidly warming climate. The authors found that the findings were consistent with predictions from ocean circulation models of the PETM, which show that a reduction in primary productivity-driven oxygen demand allows tropical subsurface oxygen to rise, even as global ocean oxygen declines. Moretti et al. suggest that this compensation effect may help to explain the relatively moderate level of pelagic extinction observed in the fossil record of the PETM. “By contrast,” they write, “increased tropical subsurface oxygen change was not adequate to ward off massive losses of tropical biodiversity at the end-Permian nor is it predicted to be in future projections of human-driven global warming.”
END
Oxygen increased in the tropical ocean during the Paleocene-Eocene Thermal Maximum
2024-02-15
ELSE PRESS RELEASES FROM THIS DATE:
Introducing Cresomycin, a synthetic antimicrobial molecule highly effective against multidrug-resistant bacteria
2024-02-15
Cresomycin – a novel synthetic molecule – demonstrates remarkably robust efficacy against multiple, evolutionary divergent forms of antimicrobial resistance (AMR), researchers report. The emergence and widespread distribution of bacteria broadly resistant to approved antibiotics raises serious global public health concerns. Given the growing rate of deaths attributable to antimicrobial resistance (AMR) worldwide, it’s evident the pace of discovery and development of antibiotics effective against AMR has not kept up with the need. Many small ...
Prizewinner’s research unveils STING as a pivotal immune sensor channel
2024-02-15
For his work in furthering the understanding of how the human immune system senses dangerous invading pathogens, Bingxu Li has received the 2024 Michelson Philanthropies & Science Prize for Immunology. Li’s prize-winning essay investigates the role that Stimulator of Interferon Genes, or STING, plays in including multiple distinct defenses against viruses, bacteria, and tumors and in orchestrating myriad downstream responses upon activation – resolving a significant mystery in the field of innate immunity. The sensing and clearance of invading pathogens ...
Researchers observe highly excited ‘roaming’ energy pathway in chemical reactions
2024-02-15
Scientists have observed so-called 'roaming' chemical reactions, those that at certain points move away from the lowest minimum energy 'path of least resistance', in highly excited energy states for the first time.
Chemical reactions are supposed to occur along their minimum energy paths. In recent years, so-called roaming reactions that stray far from this path have begun to be observed, but only for chemical species in their ground state or, at most, their first excited state. However, researchers have now observed a roaming reaction even in highly excited energy states.
The researchers ...
MSU, Carnegie Science introduce a big new idea with the help of tiny plankton
2024-02-15
Researchers at Michigan State University and the Carnegie Institution for Science have developed a model that connects microscopic biology to macroscopic ecology, which could deepen our understanding of nature’s laws and create new opportunities in ecosystem management.
Reporting in the journal Science on Feb. 16, the team showed how microscopic relationships in plankton — such as between an organism’s size and nutrient consumption — scales up to predictably affect food webs.
“Using data that other researchers have measured at the microscale about these organisms, our model can predict what’s happening at the scale of whole ecosystems,” said Jonas ...
First-ever atomic freeze-frame of liquid water
2024-02-15
RICHLAND, Wash.—In an experiment akin to stop-motion photography, scientists have isolated the energetic movement of an electron while “freezing” the motion of the much larger atom it orbits in a sample of liquid water.
The findings, reported today in the journal Science, provide a new window into the electronic structure of molecules in the liquid phase on a timescale previously unattainable with X-rays. The new technique reveals the immediate electronic response when a target is hit with an X-ray, an important step in understanding the effects of radiation exposure on objects and people.
“The chemical reactions induced by radiation ...
Superbug killer: New synthetic molecule highly effective against drug-resistant bacteria
2024-02-15
A new antibiotic created by Harvard researchers overcomes antimicrobial resistance mechanisms that have rendered many modern drugs ineffective and are driving a global public health crisis.
A team led by Andrew Myers, Amory Houghton Professor of Chemistry and Chemical Biology, reports in Science that their synthetic compound, cresomycin, kills many strains of drug-resistant bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa.
“While we don’t yet know whether cresomycin and drugs like it are safe ...
With just a little electricity, MIT researchers boost common catalytic reactions
2024-02-15
CAMBRIDGE, MA — A simple technique that uses small amounts of energy could boost the efficiency of some key chemical processing reactions, by up to a factor of 100,000, MIT researchers report. These reactions are at the heart of petrochemical processing, pharmaceutical manufacturing, and many other industrial chemical processes.
The surprising findings are reported today in the journal Science, in a paper by MIT graduate student Karl Westendorff, professors Yogesh Surendranath and Yuriy Roman-Leshkov, and two others.
“The results are really striking,” says Surendranath, a professor of chemistry ...
Keeping telomerase in check
2024-02-15
The natural ends of chromosomes appear alarmingly like broken DNA, much as a snapped spaghetti strand is difficult to distinguish from its intact counterparts. Yet every cell in our bodies must have a way of differentiating between the two because the best way to protect the healthy end of a chromosome also happens to be the worst way to repair damaged DNA.
Consider the enzyme telomerase, which is responsible for maintaining protective telomeres at the natural ends of chromosomes. Were telomerase to seal off a broken strand of DNA with a telomere, it would prevent further repair of that break and delete essential genes. Now, a new study in Science describes how cells avoid ...
Competition for food drives the planet’s remaining mass migration of herbivores
2024-02-15
Upending the prevailing theory of how and why multi-species mass-migration patterns occur in Serengeti National Park, researchers from Wake Forest University have confirmed that the millions-strong wildebeest population pushes zebra herds along in competition for the most nutrient-dense grasses.
The study resulting from this research, “Interplay of competition and facilitation in grazing succession by migrant Serengeti herbivores,” appears today in the peer-reviewed journal Science.
For decades, biologists have believed the major grazing ...
UT Dallas Wind Energy Center to expand with new headquarters, resources
2024-02-15
The University of Texas at Dallas’ wind energy research programs have expanded rapidly in recent years, with labs, offices and facilities spread out on campus. In 2020 UT Dallas formed the Wind Energy Center, called UTD Wind, to bring its wind energy programs under one virtual umbrella.
Now, a new initiative will give UTD Wind a physical headquarters for the first time with additional labs, meeting areas and office space. The project also includes additional equipment for wind energy research and education.
UT Dallas has received $1.6 million through the federal Consolidated Appropriations Act to support the expansion, which will bring most of the center’s ...