Ancient ocean sediments link changes in currents to cooling of Northern Hemisphere 3.6 million years ago

Trinity College Dublin

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The research team discussing preliminary results on the ship at the core table.

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Credit: J Field.

New research from an international group looking at ancient sediment cores in the North Atlantic has for the first time shown a strong correlation between sediment changes and a marked period of global cooling that occurred in the Northern Hemisphere some 3.6 million years ago. The changes in sediments imply profound changes in the circulation of deep water currents occurred at this time.

This crucial piece of work, which showed sediments changed in multiple sites east of the mid-Atlantic ridge but not west of that important geographical feature, opens multiple doors to future research aimed at better understanding the link between deep water currents, Atlantic Ocean heat and salt distribution and ice-sheet expansion, and climatic change.

The new work, just published in leading international journal Nature Communications was led by Dr Matthias Sinnesael from Trinity College Dublin’s School of Natural Sciences and Dr Boris Karatsolis from Vrije Universiteit Brussel.

“In recent decades, humanity has increasingly felt the impacts of global warming,” said Dr Sinnesael. “From rising sea levels that endanger coastal cities to heatwaves and floods, the world is currently living within the ‘storm’ of extreme weather events. Collectively, the short-term daily-to-monthly changes in weather that persist over long periods, eventually become part of the climate, which constitutes the long-term average state of these weather conditions. At the same time, changes in climate can act in timescales larger than humanity itself, influenced by complex interactions between various processes like plate tectonics, greenhouse gases, biotic evolution, and ocean circulation patterns.”

Climate researchers around the world aim to understand these long-term processes and the effect they have on climate, as well as to decouple them from the ones humans are inducing,. To do that, they target major climatic systems (e.g., icesheets, river and ocean basins) and look for clues of their evolution in past periods of Earth’s history. 

One of the most crucial systems for Earth’s climate is the ocean “conveyor belt” – a set of currents that act together to redistribute heat on the global ocean. The Gulf Stream is the upper limb of this belt, known for bringing warm waters from the tropics to higher latitudes, resulting in the relatively mild climate that western Europe is experiencing today. 

The lower limb of the “conveyor belt” acts in the deeper ocean and consists of three main systems of southward flowing currents, the Iceland Scotland Overflow Water (ISOW), the Denmark Strait Overflow water (DSOW) and the Labrador Sea Water (LSW). Together, they form the return flow known as the North Atlantic deep water (NADW). 

Dr Karatsolis said: “Concerns have been growing that the conveyor belt is slowing down due to ocean warming and ice melting, with serious implications for all life on Earth and in the oceans.” 

“To be able to predict how – and why – these changes may occur, we first need to understand what happened when things shifted in the deep past. Our chief aim with this work was to reconstruct the past activity of the “conveyor belt” during a period of Earth’s history when temperatures and CO2 concentrations were higher than today but similar to the ones projected for the next hundreds of years.” 

Drs Sinnesael and Karatsolis led this study as part of an international, multidisciplinary project, implemented by the International Ocean Discovery Program. The project, with the code name “IODP Expedition 395/395C”, involved two seagoing research expeditions in the North Atlantic (summer of 2021 and 2023) and focused on recovering and investigating deep sea sediments. 

These sediments are nowadays transported in the bottom of the ocean by strong deep-sea currents related to the lower limb of the “conveyor belt” (ISOW and DSOW) and therefore hold information about the activity of the NADW in hundred-to-million-year timescales. 

Although this area had been previously drilled, “IODP Expeditions 395C/395” managed to go deeper and therefore investigate the sediment deposition during a warmer-than-present period of Earth’s history that occurred roughly 5 to 2.8 million years ago. 

Key Results

After analysing the composition and the physical properties of the sediments, the scientists noticed a remarkable change in the type of sediments they were retrieving: a pale looking carbonate mud very sharply transitioned into a dark grey pile of fine silt and clay particles. 

Interestingly, they kept finding the same change in multiple sites located to the east of mid-Atlantic ridge, all related to the ISOW deep current system. In contrast, the sites west of the mid-Atlantic ridge do not show much change, looking rather the same throughout the studied interval. 

Dr Sinnesael added: “After detailed further investigations in turns out that the changes seen in sediments east of the mid-Atlantic ridge all happened around the same time – about 3.6 million years ago. The timing of this change is intriguing as it coincides with a period of strong cooling and the development of large ice bodies on the Northern Hemisphere.” 

“We must be careful not to infer a cause and effect relationship before we understand the system more completely, but the most intuitive way to interpret the change in the type of sediment is to assume it reflects a fundamental shift in ocean circulation in the North Atlantic Ocean, which is likely related to strong formation of deep-water currents – much like we know them today – in the eastern part of the Atlantic Ocean.”

"Further research will refine our understanding of the link between deep ocean circulation and the development of contemporaneous ice sheets, and help us predict what is likely to come in the future."

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The scientific research vessel Joides Resolution. 

Credit

T. Fulton / IODP / TAMU.

Journal

Nature Communications

DOI

10.1038/s41467-025-59265-5 

Article Title

Onset of strong Iceland-Scotland overflow water 3.6 million years ago

 

Hazardous reactions made safer through flow technology

Researchers have developed a new platform to safely produce bio-based nitrofuran antibiotics.

University of Liège

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Hubert Hellwig, CiTOS, ULiègeAutomated continuous flow system for furfural nitration

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Credit: Hubert Hellwig, CiTOS, ULiège

Researchers at the University of Liège (BE) have designed a high-performance, open-access continuous flow process to safely produce key antibacterial drugs from bio-based furfural. This work was carried out within an international consortium supported by the U.S. Food and Drug Administration (FDA). The results of the study—published in Angewandte Chemie International Edition—are available in open access.

Nitration reactions are among the most hazardous in chemistry. In addition to their explosive nature, conventional nitrating agents are highly aggressive and poorly suited to sensitive bio-based molecules. Furfural, a key precursor for nitrofuran antibiotics, is a fragile biomass-derived compound. Traditional methods often lead to poor yields, inconsistent reproducibility, and significant safety risks.

To address these challenges, researchers from CiTOS (Center for Integrated Technology and Organic Synthesis) developed an automated continuous flow platform for the in situ generation and immediate use of acetyl nitrate—a milder, more selective nitrating agent. This enables the rapid, scalable, and much safer synthesis of nitrofuran drug precursors.

“This platform combines advanced automation with practical simplicity,” explains Prof. Jean-Christophe Monbaliu, Director of CiTOS. “It can be remotely operated by a single person and delivers high-quality results, representing a major step toward safer pharmaceutical manufacturing. In addition, we can produce multiple nitrofuran-based drugs using the same setup.”

The process uses furfural, a compound derived from biomass and identified by the U.S. Department of Energy as a high-value bio-based molecule. It is transformed via nitration using acetyl nitrate within a series of interconnected flow modules equipped with real-time IR/UV analytical tools, temperature and pressure sensors, and an automated separation unit. “Acetyl nitrate is extremely dangerous when handled or stored,” adds Loïc Bovy, PhD student and co-author of the study. “But by generating it in situ and consuming it instantly in flow, we eliminate the risk while maintaining full control.”

The system was successfully tested on four antibacterial compounds listed by the World Health Organization, all produced in under five minutes with excellent purity and high yield. “This is not just a chemical process—it offers a complete and open-access solution,” says Hubert Hellwig, senior postdoctoral researcher and lead author of the study. “We designed custom modules, electronics, and control systems to make this platform safe, scalable, and reproducible — and all data was made freely available.”

With this automated continuous flow system developed at CiTOS, it is now possible to efficiently and safely produce key antibacterial drugs from biomass-derived furfural. By reducing the risks associated with nitration, this open-access solution paves the way toward a safer, more sustainable and more efficient pharmaceutical industry.

The project involved partners from the Massachusetts Institute of Technology, Northeastern University, the University of Puerto Rico, and the National Institute for Pharmaceutical Technology.

a. Furfural is derived from agricultural waste; b. Acetyl nitrate is a mild but explosive nitrating agent; c. Examples of four drugs derived from nitrofurfural

Credit

Jena-Chrsitophe Monbaliu/CITOS/ULiège

Journal

Angewandte Chemie International Edition

DOI

10.1002/anie.202501660 

Article Title

Continuous Flow Synthesis of Nitrofuran Pharmaceuticals using Acetyl Nitrate

Article Publication Date

12-May-2025

 

Light-to-electricity nanodevice reveals how Earth’s oldest surviving cyanobacteria worked

Atomic-level snapshot of a 3-billion-year-old photosynthetic assembly shows life nailed the design early

Queen Mary University of London

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A cryo-electron microscopy (cryo-EM) structure of Photosystem I isolated from the bacterium Anthocerotibacter panamensis.

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Credit: Han-Wei Jiang et al./PNAS.

An international team of scientists have unlocked a key piece of Earth’s evolutionary puzzle by decoding the structure of a light-harvesting "nanodevice" in one of the planet’s most ancient lineages of cyanobacteria. The discovery, published in Proceedings of the National Academy of Sciences, provides an unprecedented glimpse into how early life harnessed sunlight to produce oxygen – a process that transformed our planet forever. 

The team, including Dr Tanai Cardona from Queen Mary University of London, focused on Photosystem I (PSI), a molecular complex that converts light into electrical energy, purified from Anthocerotibacter panamensis – a recently discovered species representing a lineage that diverged from all other cyanobacteria roughly 3 billion years ago. Remarkably, this living relic shares almost no close relatives, with its nearest known evolutionary "sister" species parting ways some 1.4 billion years ago. 

“We cannot travel back three billion years to observe the cyanobacteria on Earth,” said Dr Ming-Yang Ho of National Taiwan University, lead author of the study. “That is why the early-branched A. panamensis is so crucial; it lets us glimpse what occurred in the past.” 

Most cyanobacteria, plus all algae and plants, pack their photosynthetic machinery into stacked membrane sheets called thylakoids: imagine several layers of solar panels. A. panamensis lacks thylakoids, confining its entire photosynthetic toolkit to a single membrane layer. That restriction limits photosynthesis, so these thylakoid-less cyanobacteria grow slowly and tolerate only dim light in the lab. 

“With this PSI structure in hand,” added co-author Dr Christopher Gisriel from University of Wisconsin-Madison, “We can compare it to others and see which features are ancient and which are recent evolutionary innovations.” 

The team found that, although the protein sequences have drifted like those in any bacterium, PSI’s architecture is almost unchanged: three PSI units join in a three-leaf-clover arrangement, collectively carrying more than 300 light-absorbing pigments such as chlorophylls and carotenoids. 

Dr Tanai Cardona concluded, “Even three billion years ago, photosynthesis appears to have reached a remarkable degree of sophistication. To find the true origin of oxygen-producing photosynthesis, we’ll have to look even further back — before cyanobacteria themselves evolved.” 

The study was funded National Science and Technology Council (Taiwan), NIH, U.S. Department of Energy and UKRI. 

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Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2427090122 

Article Title

Structure and evolution of photosystem I in the early-branching cyanobacterium Anthocerotibacter panamensis

Article Publication Date

14-May-2025

 

HKUST researchers develop new model for accurate landslide prediction

With applications in sustainable agriculture, energy, healthcare, and beyond

Hong Kong University of Science and Technology

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Prof. ZHAO Jidong (center) and Dr. Amiya Prakash DAS (right) from HKUST, together with Dr. Thomas SWEIJEN (left) from Utrecht University, have developed a groundbreaking computational model to study the movement of granular materials such as soils, sands and powders. 

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Credit: HKUST

The Hong Kong University of Science and Technology (HKUST) announced today that a research team from its School of Engineering has developed a groundbreaking computational model to study the movement of granular materials such as soils, sands and powders. By integrating the dynamic interactions among particles, air and water phases, this state-of-the-art system can accurately predict landslides, improve irrigation and oil extraction systems, and enhance food and drug production processes.  

The Challenge of Predicting Granular Materials
The flow of granular materials – such as soil, sand and powders used in pharmaceuticals and food production - is the underlying mechanism governing many natural settings and industrial operations. Understanding how these particles interact with surrounding fluids like water and air is crucial for predicting behaviors such as soil collapse or fluid leakage.  However, existing models face challenges in accurately capturing these interactions, especially in partially saturated conditions where forces like capillary action and viscosity come into play.

PUA-DEM: A Paradigm Shift in Granular Modelling 
To address these challenges, a team led by Prof. ZHAO Jidong from the Department of Civil and Environmental Engineering at HKUST has developed the Pore Unit Assembly-Discrete Element Model (PUA-DEM).  Unlike conventional models that often rely on oversimplified one-way coupling (e.g., static particles), PUA-DEM incorporates rigorous physical principles to govern the dynamic interactions among particles, air, and water phases.  This allows for robust multi-way coupling that accurately captures fluid flow, particle movement, and evolving stress and pressure across the entire spectrum of saturation conditions— from fully saturated to completely dry states.  

Rooted in fundamental physics, the high-fidelity model is the first of its kind, achieving exceptional precision in predicting complex multiphase behaviors. It holds significant potential to advance applications in geotechnical engineering, environmental science, and many industrial processes. 

Broad Applications Across Industries
The team is now exploring collaboration opportunities with the government and industry to apply their model to real-world challenges. That includes developing an early landslide warning system, optimizing irrigation strategies through simulations of water retention and root-soil interactions, and enhancing carbon sequestration and oil extraction efficiency with the model’s accurate multiphase flow predictions. Its precise control of powder processing also offers transformative potential for pharmaceutical manufacturing, enabling safer, more effective, and efficient drug production with enhanced consistency in dosage forms, which is critical for improving therapeutic efficacy and patient outcomes. The model’s capabilities may also extend to the food industry, potentially revolutionizing the design and processing of granular products like coffee, sugar, and infant formula by optimizing texture, dissolution rates, and shelf stability while reducing waste and energy consumption.     

Prof. Zhao explained, “PUA-DEM represents a paradigm shift in modeling unsaturated granular systems. By resolving pore-scale fluid-solid interactions, we can now predict how microscopic processes - like capillary bridge formation and particle swelling, govern macroscopic behaviors such as soil collapse or fluid leakage in energy reservoirs. This opens new avenues for designing safer infrastructures, optimizing agricultural practices, improving pharmaceutical manufacturing, and addressing energy-related engineering challenges.” 

Future Directions: Expanding PUA-DEM’s Capabilities
Looking ahead, Dr. Amiya Prakash DAS, the first author of this work and a recent HKUST PhD graduate, said the team planned to expand PUA-DEM’s capabilities. “In the next stage of our research, we aim to incorporate irregular particle shapes and wettability effects, further narrowing the gap between laboratory findings and field-scale applications. Future work will also explore hybrid computational strategies to model reactive transport and drying-induced cracking,” he said.

The study was conducted in collaboration with Dr. Thomas SWEIJEN of Utrecht University, Netherlands. The paper, titled “Micromechanical Modeling of Triphasic Granular Media”, has been published in the prestigious academic journal Proceedings of the National Academy of Sciences (PNAS).

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(A) Illustration of PUA-DEM partitioning fluid-solid domains for modeling a triphasic system. Distribution of air-water interfaces and capillary forces juxtaposed on DEM particle. (B) Capillary regime. (C) Funicular regime. (D) Fluid-fluid interface instability, capillary fingering (left) and viscous fingering (right). (E) Force chain evolution in granular medium embedded with swellable material, low confinement (left) and high confinement (right).

Credit

HKUST

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2420314122 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Micromechanical modeling of triphasic granular media

Article Publication Date

20-May-2025

 

Wild orangutans show communication complexity thought to be uniquely human

University of Warwick

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Two Sumerian Orangutans

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Credit: Madeleine Hardus

In groundbreaking work from The University of Warwick, researchers have found that wild orangutans vocalise with a layered complexity previously thought to be unique to human communication, suggesting a much older evolutionary origin.

Consider the phrase – ‘This is the dog that chased the cat that killed the rat that ate the cheese’. It is a simple sentence comprised of repeated verb noun phrases - ‘chased the cat’, ‘ate the cheese’ - and is an example of layered complexity called recursion.

Recursion is the repetition of language elements in an embedded way so that they form a comprehensible thought/phrase. Like Russian nesting dolls, the power of recursion mean we can combine a finite set of elements to deliver an infinite array of messages with increasing complexity.

It is widely believed that nested communication is a unique feature of human language, allowing us greater complexity of thought, but research from The University of Warwick, published today in Annals of The New York Academy of Sciences, tells a different story.

Dr. Chiara De Gregorio, Research Fellow at The University of Warwick, who performed this work alongside Adriano Lameira (also Warwick) and Marco Gamba (University of Torino), said: “When analysing the vocal data of alarm calls from female Sumatran orangutans, we found that the rhythmic structure of orangutans’ sounds made were self-embedded across three levels - an impressive third-order recursion. Finding this feature in orangutan communication challenges the idea that recursion is uniquely human.”

The three-layered (recursive) structure of the orangutan’s calls was as follows:

• Individual sounds made by orangutans occurred in small combinations (first layer)
• These combinations could be grouped into larger bouts (second layer)
• And these bouts could be grouped into even larger series (third layer), all with a regular rhythm at each level

Just like a musical piece with repeating patterns, orangutans nested one rhythm inside another, and then another, creating a sophisticated multi-layered vocal structure, not thought possible by non-human great apes.

This pattern wasn’t accidental because orangutans also changed the rhythm of their alarm calls depending on the type of predator they encounter: When they saw a real threat, like a tiger, their calls were faster and more urgent. When they saw something that seemed like a threat but lacked the credibility of a real danger (like a cloth with colourful spots), their calls were slower and less regular.

This ability to adapt vocal rhythms to different dangers shows that orangutans aren't just making noise, they are using structured vocal recursion to carry meaningful information about the outside world.

"This discovery shows that the roots of one of the most distinctive features of human language — recursion - was already present in our evolutionary past," adds lead author Dr. De Gregorio. "Orangutans are helping us understand how the seeds of language structure might have started growing millions of years ago."

This research presents the first empirical support for the idea that these powerful recursive capacities could have been selected for and evolved incrementally in a much earlier ancestor.

ENDS

For further information contact:

Matt Higgs, Media & Communications Officer (Science), The University of Warwick | Matt.Higgs@Warwick.ac.uk / 07880 175403

The paper, ‘Third-order self-embedded vocal motifs in wild orangutans and the selective evolution of recursion’ is published in Annals of The New York Academy of SciencesLink opens in a new window

DOI: https://doi.org/10.1111/nyas.15373Link opens in a new window

Recursion Order Embedding Image Credit: University of Warwick

Sumerian Orangutan Photographs are available to use in connection with this story and must be credited to Madeleine Hardus

16 May 2025

2 Sumerian Female Orangutans

Credit

Madeleine Hardus

Diagram demonstrating three level recursion in female orangutan vocalisations

Credit

University of Warwick

Journal

Annals of the New York Academy of Sciences

DOI

10.1111/nyas.15373 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Third-order self-embedded vocal motifs in wild orangutans, and the selective evolution of recursion

Article Publication Date

16-May-2025