Earth

BEER-SHEVA, Israel...October 19, 2020 -- What if an MRI scan could determine whether a weight loss program was likely to be effective? Ben-Gurion University of the Negev (BGU) researchers have discovered a neural subnetwork of connected regions between the brain and gastric basal electric frequency that correlates with future weight loss based on connectivity patterns.

BGU's multidisciplinary team's findings, published in the journal NeuroImage, support a prevalent neural theory that people with an increased neural response to seeing and smelling food consistently overeat and gain weight.

"To our surprise, we discovered that while higher executive functions, as measured behaviorally, were dominant factors in weight loss, this was not reflected in patterns of brain connectivity," says Gidon Levakov, a graduate student, who led the study from the BGU Department of Brain and Cognitive Sciences.

"Consequently, we found that weight loss is not merely a matter of willpower, but is actually connected to much more basic visual and olfactory cues."

The researchers identified a connection between the stomach basal electric rhythm within the subnetwork and weight loss. That rhythm governs the gastric waves that are associated with hunger and satiety. They also found that the brain's pericalcarine sulcus, the anatomical location of the primary visual cortex, was the most active node in this subnetwork.

The team assessed 92 people during an 18-month lifestyle weight loss intervention led by Prof. Iris Shai, of BGU's Department of Epidemiology. The participants were selected based on large waist circumference, abnormal blood lipid levels and age.

Before the intervention, the participants underwent a battery of brain imaging scans and behavioral executive function tests. The participants' weight loss was measured after six months of dieting, in which, according to Prof. Shai, the maximum weight loss is generally achieved.

The team found that the subnetwork of brain regions corresponded more closely to basic sensory and motor regions rather than higher, multi-modal regions.

"It appears that visual information may be an important factor triggering eating," says principal investigator Prof. Galia Avidan, from the BGU Departments of Brain and Cognitive Sciences and Psychology. "This is reasonable, given that vision is the primary sense in humans."

The researchers note that these results may have significant implications toward understanding the cause of obesity and the mechanism of response to dieting.

The Columbia River is home to one of the West Coast's most important Chinook salmon runs. Through late spring and early summer, mature fish return from the sea and begin their arduous journey upriver to spawn. In recent years, these fish have faced an additional challenge: hungry California sea lions.

A new University of Washington and NOAA Fisheries study found that sea lions have the largest negative effect on early-arriving endangered Chinook salmon in the lower Columbia River. The results of this study will publish Oct. 18 in the Journal of Applied Ecology.

Opportunistic sea lions have learned that by swimming as far as 145 miles upriver, they can easily feast on migrating salmon, including those hindered by the Bonneville Dam.

"We investigated whether mortality rates varied depending on the specific threatened Chinook salmon population, determined by when they arrive in the river," said lead author Mark Sorel, a doctoral student at the UW School of Aquatic and Fishery Sciences. "We found that, based on their individual return timing and the abundance of sea lions in the river when they return, individual populations experience different levels of sea lion-associated mortality."

Researchers learned that the earliest arriving populations of Chinook salmon experienced an additional 20% mortality over previous years, and the later arriving populations experienced an additional 10%. This increase in mortality was associated with increased sea lion abundance at those times of year in the period of 2013 to 2015 compared to the period of 2010 to 2012.

The numbers of California sea lions are highest at the mouth of the Columbia in early spring, before they depart for their breeding grounds in southern California. The researchers also discovered that the earliest arriving salmon migrate through the lower Columbia River more slowly than those arriving later in the season, thereby increasing their exposure to predation.

"This information on how different populations are affected by sea-lion associated mortality is key because recovery of endangered Chinook salmon requires multiple of the individual populations to be healthy," said Sorel.

California sea lions have seen their numbers rebound along much of the U.S. West Coast since the passage of the Marine Mammal Protection Act of 1972, which protects them from being killed, captured and harassed. The increased presence of sea lions is now at odds with the endangered salmon populations on which they feed, putting managers in a difficult position.

Researchers are concerned that something must be done quickly as these hunting behaviors are learned, and the problem could continue to grow exponentially. In August, the National Marine Fisheries Service granted approval for Washington, Idaho, Oregon and several Pacific Northwest tribes to capture and euthanize both problematic California and Steller sea lions within a larger area of the lower Columbia and Willamette Rivers. Previously, only California sea lions could be killed in these rivers if managers deemed them a threat to salmon.

This complicated decision was enacted after non-lethal methods, such relocation and hazing, to limit the impact sea lions have on salmon -- plus some targeted lethal removal -- were met with limited success.

"This is often a challenging management problem as both sea lions and salmon are of strong interest to the public, and both are protected under federal statutes," said Sorel. "Management must consider multiple social values and operate within existing legal frameworks."

Continued monitoring will help to reduce the remaining uncertainty about the effects of sea lions on salmon and the expected outcomes of alternative management actions.

The Western Antarctic Peninsula is one of the fastest warming places on earth. It is also home to threatened humpback and minke whales, chinstrap, Adélie and gentoo penguin colonies, leopard seals, killer whales, seabirds like skuas and giant petrels, and krill - the bedrock of the Antarctic food chain.

With sea ice covering ever-smaller areas and melting more rapidly due to climate change, many species' habitats have decreased. The ecosystem's delicate balance is consequently tilted, leaving species in danger of extinction.

Cumulative threats from a range of human activities including commercial fishing, research activities and tourism combined with climate change is exacerbating this imbalance, and a tipping point is fast approaching.

Dr Carolyn Hogg, from the University of Sydney School of Life and Environmental Sciences, was part of the largest ever all-female expedition to the Antarctic Peninsula, with the women in STEMM initiative, Homeward Bound, in late 2019. There, she witnessed the beauty and fragility of the area, and the negative impacts of climate change and human activity on native species, first-hand. As part of the Homeward Bound program she learnt about the science, conservation and governance of Antarctica.

In a new commentary piece published in Nature, Dr Hogg and her colleagues from the expedition outline these threats, and importantly, offer ways to counter them. More than 280 women in STEMM who have participated in the Homeward Bound initiative are co-signatories to the piece.

A global initiative, Homeward Bound 'aims to elevate the voices of women in science, technology, engineering mathematics and medicine in leading for positive outcomes for our planet'.

Women are noticeably absent in Antarctica's human history, which is steeped in tales of male heroism. Female scientists are still a minority in the region's research stations.

"Now, more than ever, a broad range of perspectives is essential in global decision-making, if we are to mitigate the many threats our planet faces," said Dr Hogg.

"Solutions include the ratification of a Marine Protected Area around the Peninsula, set to be discussed on 19 October, at a meeting of a group of governments that collectively manage the Southern Ocean's resources," said Dr Hogg. "The region is impacted by a number of threats, each potentially problematic in their own right, but cumulated together they will be catastrophic."

Decreasing krill affects whole ecosystem

The Peninsula's waters are home to 70 percent of Antarctic krill. In addition to climate change, these krill populations are threatened by commercial fishing. Last year marked the third largest krill catch on record. Nearly 400,000 tonnes of this animal were harvested, to be used for omega-3 dietary supplements and fishmeal.

"Even relatively small krill catches can be harmful if they occur in a particular region, at a sensitive time for the species that live there," said Dr Cassandra Brooks, a co-author on the comment from the University of Colorado, Boulder. "For example, fishing when penguins are breeding lowers their food intake, and affects their subsequent breeding success. A Marine Protected Area will conserve and protect this unique ecosystem and its wildlife, and we need to implement it now."

Climate change is fundamentally altering the Western Antarctic Peninsula:

temperatures reached a record 20.75°C in February 2020

the average daily temperature that month was two degrees higher than the mean over the past 70 years

almost 90 percent of the region's glaciers are receding rapidly

in spring 2016, sea-ice levels reached their lowest since records began

if carbon emissions keep climbing, within 50 years the area of sea-ice will almost halve, and the volume of ice-shelves will decrease by one quarter

As sea ice recedes, populations of larval and juvenile krill, which use the ice for shelter and to feed off the algae it attracts, decline.

A warmer climate and less sea-ice cover will also give opportunities to invasive species, which can enter the territory via international ships, including those carrying tourists.

The lasting tourism and research footprint

Tourism's footprint is growing. The Peninsula is the most-visited region in Antarctica, owing to its proximity to South America, dramatic beauty and rich marine ecosystem.

Tourist numbers have more than doubled in the past decade, with 74,000 visiting last year compared to 33,000 in 2009.

"Ships can pollute the ocean with micro-plastics, oils and ship noise," said Dr Justine Shaw, another co-author from the University of Queensland.

While the International Association of Antarctica Tour Operators (IAATO), a self-regulating association that advocates for safe and environmentally responsible travel, provides guidelines for cruise ships and tourists, "an increasing number of vessels that are not IAATO members and that carry up to about 500 passengers have begun visiting the region, and this is concerning as it adds greater pressure," Dr Shaw said.

While the collection of data and knowledge is important, research activities can also potentially damage the Antarctic Peninsula's sensitive environment, the team stated.

The Peninsula hosts science facilities belonging to 18 nations - the highest concentration on the continent. New stations and expansions are ever-present.

While these scientific endeavours can increase our understanding of native species', there can be negative impacts on the region if not properly managed. Dr Shaw explained: "Buildings and infrastructure displace wildlife and vegetation."

Three ways to protect the Peninsula

1. A Marine Protected Area (MPA) designation for the waters

The authors endorse a proposed MPA for the western Antarctic Peninsula. Led by Chile and Argentina, this is due to be discussed during a two-week meeting commencing 19 October by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), a group of governments that collectively manage the Southern Ocean's resources.

The MPA would reduce commercial fishing in ecologically sensitive areas, helping preserve the food chain and ensuring greater sustainability for the future in surrounding areas.

A comparable MPA for the Ross Sea, in southern Antarctica, was agreed to in October 2016 to global celebration.

2. Protect land areas

Only 1.5 percent of Antarctica's ice-free terrain enjoys formal protected status. Much unprotected land is adjacent to research and tourist areas and is therefore vulnerable to human-generated risks like pollution and invasive species.

The authors call for a greater extent and variety of landscapes to be protected.

"Globally, parties to the Convention on Biological Diversity have agreed that 17 percent of land should be protected to ensure conservation of biodiversity. This is a good starting point for Antarctica," Dr Hogg said.

3. Integrate conservation efforts

For conservation efforts to be effective, they have to be collaborative. Dr Shaw furnished examples: "The Council of Managers of National Antarctic Programs (COMNAP) must work to limit the expansion of research infrastructure. Tour operators' body IAATO and parties to the Antarctic Treaty System should cooperate to better manage tourist activity - ensuring all tour operators abide by IAATO regulations regardless of whether they are IAATO members."

The cover for issue 30 of Oncotarget features Figure 4, "RNAseq results demonstrating differences between normal, cancer, and redirected cells," by Frank-Kamenetskii, et al. which reported that the influence of breast cancer cells on normal cells of the microenvironment, such as fibroblasts and macrophages, has been heavily studied but the influence of normal epithelial cells on breast cancer cells has not.

Here using in vivo and in vitro models the Oncotarget authors demonstrate the impact epithelial cells and the mammary microenvironment can exert on breast cancer cells.

Under specific conditions, signals that originate in epithelial cells can induce phenotypic and genotypic changes in cancer cells.

The authors have termed this phenomenon “cancer cell redirection.” Once breast cancer cells are redirected, either in vivo or in vitro, they lose their tumor forming capacity and undergo a genetic expression profile shift away from one that supports a cancer profile towards one that supports a non-tumorigenic epithelial profile.

These findings indicate that epithelial cells and the normal microenvironment influence breast cancer cells and that under certain circumstances restrict proliferation of tumorigenic cells.

Dr. Brian W. Booth from Clemson University said, "Tissue microenvironments are complex regions that consist of multiple cell types such as epithelial cells, adipocytes, fibroblasts, vascular endothelial cells, resident and transient immune cells, and somatic stem cells"

"Tissue microenvironments are complex regions that consist of multiple cell types such as epithelial cells, adipocytes, fibroblasts, vascular endothelial cells, resident and transient immune cells, and somatic stem cells"

Tissue microenvironments are complex regions that consist of multiple cell types such as epithelial cells, adipocytes, fibroblasts, vascular endothelial cells, resident and transient immune cells, and somatic stem cells.

Using rodent models, it was discovered that when mammary epithelial cells were transplanted into a mammary fat pads of pre-pubescent female mice devoid of endogenous epithelium an entire functional mammary outgrowth could be recapitulated regardless of age or parity status of the transplanted cells.

When dispersed cell suspensions of mammary epithelial cells are used in these models the cells participate in the formation of new microenvironments allowing for the normal development of mammary outgrowths.

Stem cells isolated from the central nervous system, bone marrow, testes, and embryonic stem cells have been introduced into reforming mammary microenvironments and adopted mammary epithelial phenotypes.

Lineage-traced daughter cells of the non-mammary stem cells participated in the normal development of mammary ductal trees and differentiated into luminal epithelial cells, myoepithelial cells, and milk protein-producing secretory epithelial cells during lactation.

The Booth Research Team concluded in their Oncotarget Research Paper, "our data collectively argue that epithelial cells provide signals that influence HER2+ breast cancer cells to reduce tumor formation. The reduction in tumor-forming capacity is due to a shift in gene expression profiles from a tumorigenic towards a normal epithelial profile. The phenotypic switch, known as cancer cell redirection, includes changes in the activity of multiple intracellular signaling pathways. Modulation of these affected pathways may be a new approach towards cancer treatments."

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DOI - https://doi.org/10.18632/oncotarget.27679

Full text - https://www.oncotarget.com/article/27679/text/

Correspondence to - Brian W. Booth - brbooth@clemson.edu

Keywords -
breast cancer,
cancer cell redirection,
microenvironment,
stem cells

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Journal

Oncotarget

DOI

10.18632/oncotarget.27679

A pioneering technique which captures precisely how mountains bend to the will of raindrops has helped to solve a long-standing scientific enigma.

The dramatic effect rainfall has on the evolution of mountainous landscapes is widely debated among geologists, but new research led by the University of Bristol and published today in Science Advances, clearly calculates its impact, furthering our understanding of how peaks and valleys have developed over millions of years.

Its findings, which focused on the mightiest of mountain ranges - the Himalaya - also pave the way for forecasting the possible impact of climate change on landscapes and, in turn, human life.

Lead author Dr Byron Adams, Royal Society Dorothy Hodgkin Fellow at the university's Cabot Institute for the Environment, said: "It may seem intuitive that more rain can shape mountains by making rivers cut down into rocks faster. But scientists have also believed rain can erode a landscape quickly enough to essentially 'suck' the rocks out of the Earth, effectively pulling mountains up very quickly.

"Both these theories have been debated for decades because the measurements required to prove them are so painstakingly complicated. That's what makes this discovery such an exciting breakthrough, as it strongly supports the notion that atmospheric and solid earth processes are intimately connected."

While there is no shortage of scientific models aiming to explain how the Earth works, the greater challenge can be making enough good observations to test which are most accurate.

The study was based in the central and eastern Himalaya of Bhutan and Nepal, because this region of the world has become one of the most sampled landscapes for erosion rate studies. Dr Adams, together with collaborators from Arizona State University (ASU) and Louisiana State University, used cosmic clocks within sand grains to measure the speed at which rivers erode the rocks beneath them.

"When a cosmic particle from outer space reaches Earth, it is likely to hit sand grains on hillslopes as they are transported toward rivers. When this happens, some atoms within each grain of sand can transform into a rare element. By counting how many atoms of this element are present in a bag of sand, we can calculate how long the sand has been there, and therefore how quickly the landscape has been eroding," Dr Adams said.

"Once we have erosion rates from all over the mountain range, we can compare them with variations in river steepness and rainfall. However, such a comparison is hugely problematic because each data point is very difficult to produce and the statistical interpretation of all the data together is complicated."

Dr Adams overcame this challenge by combining regression techniques with numerical models of how rivers erode.

"We tested a wide variety of numerical models to reproduce the observed erosion rate pattern across Bhutan and Nepal. Ultimately only one model was able to accurately predict the measured erosion rates," Dr Adams said.

"This model allows us for the first time to quantify how rainfall affects erosion rates in rugged terrain."

Research collaborator Professor Kelin Whipple, Professor of Geology at ASU, said: "Our findings show how critical it is to account for rainfall when assessing patterns of tectonic activity using topography, and also provide an essential step forward in addressing how much the slip rate on tectonic faults may be controlled by climate-driven erosion at the surface."

The study findings also carry important implications for land use management, infrastructure maintenance, and hazards in the Himalaya.

In the Himalaya, there is the ever-present risk that high erosion rates can drastically increase sedimentation behind dams, jeopardising critical hydropower projects. The findings also suggest greater rainfall can undermine hillslopes, increasing the risk of debris flows or landslides, some of which may be large enough to dam the river creating a new hazard - lake outburst floods.

Dr Adams added: "Our data and analysis provides an effective tool for estimating patterns of erosion in mountainous landscapes such as the Himalaya, and thus, can provide invaluable insight into the hazards that influence the hundreds of millions of people who live within and at the foot of these mountains."

The research was funded by the Royal Society, the UK Natural Environmental Research Council (NERC), and the National Science Foundation (NSF) of the US.

Building on this important research, Dr Adams is currently exploring how landscapes respond after large volcanic eruptions.

"This new frontier of landscape evolution modelling is also shedding new light on volcanic processes. With our cutting-edge techniques to measure erosion rates and rock properties, we will be able to better understand how rivers and volcanoes have influenced each other in the past," Dr Adams said.

"This will help us to more accurately anticipate what is likely to happen after future volcanic eruptions and how to manage the consequences for communities living nearby."

Sea floor sediments of the Arctic Ocean can help scientists understand how permafrost responds to climate warming. A multidisciplinary team from Stockholm University has found evidence of past permafrost thawing during climate warming events at the end of the last ice age. Their findings, published in Science Advances, caution about what could happen in the near future: That Arctic warming by only a few degrees Celsius may trigger massive permafrost thawing, coastal erosion, and the release of the greenhouse gases carbon dioxide (CO2) and methane (CH4) into the atmosphere.

Arctic permafrost stores more carbon than the atmosphere does. When permafrost thaws, this carbon may be converted to greenhouse gases (CO2 and CH4) that then enter the atmosphere and may affect the climate system. To improve predictions of future greenhouse gas emissions from permafrost, scientists have started to look into the past, exploring how previous climate warming, for example at the end of the last ice age, affected permafrost and its vast pool of carbon.

"Our new study shows for the first time the full history of how warming at the end of the last ice age triggered permafrost thawing in Siberia. This also suggests the release of large quantities of greenhouse gases," says Jannik Martens, PhD student at Stockholm University and lead author of the study. "It appears likely that past permafrost thawing at times of climate warming, about 14,700 and 11,700 years ago, was in part also related to the increase in CO2 concentrations that is seen in Antarctic ice cores for these times. It seems that Arctic warming by only a few degrees Celsius is sufficient to disturb large areas covered by permafrost and potentially affect the climate system."

In the current study, the scientists used an eight meters long sediment core that was recovered from the sea floor more than 1 000 meters below the surface of the Arctic Ocean during the SWERUS-C3 expedition onboard the Swedish icebreaker Oden back in 2014. To reconstruct permafrost thawing on land, the scientists applied radiocarbon (14C) dating and molecular analysis to trace organic remains that once were released by thawing permafrost and then washed into the Arctic Ocean.

"From this core we also learned that erosion of permafrost coastlines was an important driving force for permafrost destruction at the end of the last ice age. Coastal erosion continues to the present day, though ten times slower than during these earlier rapid warming period. With the recent warming trends, however, we see again an acceleration of coastal erosion in some parts of the Arctic, which is expected to release greenhouse gases by degradation of the released organic matter," says Örjan Gustafsson, Professor at Stockholm University and leader of the research program. "Any release from thawing permafrost mean that there is even less room for anthropogenic greenhouse gas release in the earth-climate system budget before dangerous thresholds are reached. The only way to limit permafrost-related greenhouse gas releases is to mitigate climate warming by lowering anthropogenic greenhouse gas emissions."

Gustafsson, Martens and their colleagues are now again in the Arctic Ocean as part of the International Siberian Shelf Study (ISSS-2020) onboard the Russian research vessel Akademik Keldysh. The expedition left the port of Arkhangelsk on September 26 and is currently in the East Siberian Sea, seeking more answers to how changing climate may trigger release of carbon, including greenhouse gases, from Arctic permafrost systems, including coastal erosion and permafrost below the sea bottom preserved from the past ice age.

Nearly all of Madagascan megafauna - including the famous Dodo bird, gorilla-sized lemurs, giant tortoises, and the Elephant Bird which stood 3 meters tall and weighted close to a half ton - vanished between 1500 and 500 years ago. Were these animals overhunted to extinction by humans? Or did they disappear because of climate change? There are numerous hypotheses, but the exact cause of this megafauna crash remains elusive and hotly debated. The Mascarene islands east of Madagascar are of special interest because they are among the last islands on earth to be colonized by humans. Intriguingly, the islands' megafauna crashed in just a couple of centuries following human settlement. In a recent study published by Science Advances, a team of international researchers found that it was likely a "double whammy" of heightened human activities in combination with a particularly severe spell of region-wide aridity that may have doomed the megafauna. The researchers rule out climate change as the one and only cause, and instead suggest that the impact of human colonization was a crucial contributor to the megafaunal collapse. Hanying Li, a postdoctoral scholar at the Xi'an Jiaotong University in China and the lead author of this study, pieced together a detailed history of the regional climate variations. The primary source of this new paleoclimate record came from the tiny Mascarene island of Rodrigues in the southwest Indian Ocean approximately 1600 km east of Madagascar. "An island so remote and small that one will not find it on most schoolbook atlases," says Gayatri Kathayat, one of the co-authors and an associate professor of climate science at Xi'an Jiaotong University.

Analysis of Cave Deposits

Li and colleagues built their climate records by analyzing the trace elements and carbon and oxygen isotopes from each incremental growth layer of stalagmites which they collected from one of the many caves from this island. The bulk of these analyses were conducted at the Quaternary Research Group at the Institute of Geology at the University of Innsbruck, led by Prof. Christoph Spötl: "Variations in the geochemical signatures provided the information needed to reconstruct the region's rainfall patterns over the last 8000 years. To analyze the stalagmites we used the stable isotope method in our lab in Innsbruck". Despite the distance between the two islands, the summer rainfall at Rodrigues and Madagascar is influenced by the same global-wide tropical rain belt that oscillates north and south with the seasons." And when this belt falters and stays further north of Rodrigues, droughts can strike the whole region from Madagascar to Rodrigues," Hai Cheng explains, the study's senior coauthor. "Li's work from Rodrigues demonstrates that the hydroclimate of the region experienced a series of drying trends throughout the last 8 millennia, which were frequently punctuated by 'megadroughts' that lasted for decades," notes Hubert Vonhof, scientist at Max Planck Institute of Chemistry in Mainz, Germany and coauthor.

Resilient to climate stress

The most recent of the drying trends in the region commenced around 1500 years ago at a time when the archaeological and proxy records began to show definitive signs of increased human presence on the island. "While we cannot say with 100 percent certainty whether human activity, such as overhunting or habitat destruction, was the proverbial last straw that broke the camel's back, our paleoclimate records make a strong case that the megafauna had survived through all the previous episodes of even greater aridity. This resilience to past climate swings suggests that an additional stressor contributed to the elimination of the region's megafauna," notes Ashish Sinha, professor of earth science at California State University Dominguez Hills, USA. "There are still many pieces missing to fully solve the riddle of megafauna collapse. This study now provides an important multi-millennial climatic context to megafaunal extinction," says Ny Rivao Voarintsoa from KU Leuven in Belgium, a native of Madagascar, who participated in this research. The study sheds new light on the decimation of flora and fauna of Mauritius and Rodrigues: "Both islands were rapidly stripped of endemic species of vertebrates within two centuries of the initial human colonization, including the well-known flightless 'Dodo' bird from Mauritius and the saddle-backed 'Rodrigues giant tortoise' endemic to Rodrigues," adds Aurele Anquetil André, the reserve manager and chief conservator at the Francois Leguat Giant Tortoise and Cave Reserve at Rodrigues.

"The story our data tells is one of resilience and adaptability of the islands' ecosystems and fauna in enduring past episodes of severe climate swings for eons - until they were hit by human activities and climate change", the researchers conclude.

Researchers from Trinity College Dublin have discovered a uniquely quantum effect in erasing information that may have significant implications for the design of quantum computing chips. Their surprising discovery brings back to life the paradoxical "Maxwell's demon", which has tormented physicists for over 150 years.

The thermodynamics of computation was brought to the fore in 1961 when Rolf Landauer, then at IBM, discovered a relationship between the dissipation of heat and logically irreversible operations. Landauer is known for the mantra "Information is Physical", which reminds us that information is not abstract and is encoded on physical hardware.

The "bit" is the currency of information (it can be either 0 or 1) and Landauer discovered that when a bit is erased there is a minimum amount of heat released. This is known as Landauer's bound and is the definitive link between information theory and thermodynamics.

Professor John Goold's QuSys group at Trinity is analysing this topic with quantum computing in mind, where a quantum bit (a qubit, which can be 0 and 1 at the same time) is erased.

In just-published work in the journal, Physical Review Letters, the group discovered that the quantum nature of the information to be erased can lead to large deviations in the heat dissipation, which is not present in conventional bit erasure.

Thermodynamics and Maxwell's demon

One hundred years previous to Landauer's discovery people like Viennese scientist, Ludwig Boltzmann, and Scottish physicist, James Clerk Maxwell, were formulating the kinetic theory of gases, reviving an old idea of the ancient Greeks by thinking about matter being made of atoms and deriving macroscopic thermodynamics from microscopic dynamics.

Professor Goold says:

"Statistical mechanics tells us that things like pressure and temperature, and even the laws of thermodynamics themselves, can be understood by the average behavior of the atomic constituents of matter. The second law of thermodynamics concerns something called entropy which, in a nutshell, is a measure of the disorder in a process. The second law tells us that in the absence of external intervention, all processes in the universe tend, on average, to increase their entropy and reach a state known as thermal equilibrium.

"It tells us that, when mixed, two gases at different temperatures will reach a new state of equilibrium at the average temperature of the two. It is the ultimate law in the sense that every dynamical system is subject to it. There is no escape: all things will reach equilibrium, even you!"

However, the founding fathers of statistical mechanics were trying to pick holes in the second law right from the beginning of the kinetic theory. Consider again the example of a gas in equilibrium: Maxwell imagined a hypothetical "neat-fingered" being with the ability to track and sort particles in a gas based on their speed.

Maxwell's demon, as the being became known, could quickly open and shut a trap door in a box containing a gas, and let hot particles through to one side of the box but restrict cold ones to the other. This scenario seems to contradict the second law of thermodynamics as the overall entropy appears to decrease and perhaps physics' most famous paradox was born.

But what about Landauer's discovery about the heat-dissipated cost of erasing information? Well, it took another 20 years until that was fully appreciated, the paradox solved, and Maxwell's demon finally exorcised.

Landauer's work inspired Charlie Bennett - also at IBM - to investigate the idea of reversible computing. In 1982 Bennett argued that the demon must have a memory, and that it is not the measurement but the erasure of the information in the demon's memory which is the act that restores the second law in the paradox. And, as a result, computation thermodynamics was born.

New findings

Now, 40 years on, this is where the new work led by Professor Goold's group comes to the fore, with the spotlight on quantum computation thermodynamics.

In the recent paper, published with collaborator Harry Miller at the University of Manchester and two postdoctoral fellows in the QuSys Group at Trinity, Mark Mitchison and Giacomo Guarnieri, the team studied very carefully an experimentally realistic erasure process that allows for quantum superposition (the qubit can be in state 0 and 1 at same time).

Professor Goold explains:

"In reality, computers function well away from Landauer's bound for heat dissipation because they are not perfect systems. However, it is still important to think about the bound because as the miniaturisation of computing components continues, that bound becomes ever closer, and it is becoming more relevant for quantum computing machines. What is amazing is that with technology these days you can really study erasure approaching that limit.

"We asked: 'what difference does this distinctly quantum feature make for the erasure protocol?' And the answer was something we did not expect. We found that even in an ideal erasure protocol - due to quantum superposition - you get very rare events which dissipate heat far greater than the Landauer limit.

"In the paper we prove mathematically that these events exist and are a uniquely quantum feature. This is a highly unusual finding that could be really important for heat management on future quantum chips - although there is much more work to be done, in particular in analysing faster operations and the thermodynamics of other gate implementations.

"Even in 2020, Maxwell's demon continues to pose fundamental questions about the laws of nature."

During metastasis, cancer cells actively interact with microenvironments of new tissues. How metastatic cancer cells respond to new environments in the secondary tissues is a crucial question in cancer research but still remains elusive. Recently, researchers from the Hong Kong University of Science and Technology (HKUST), along with their international collaborators, discovered a novel mechanical mechanism of metastatic cancer cells in substrates of different stiffness, which could contribute to developing diagnostic tools for metastatic cancer cells and cancer therapeutics.

This study was published in the Journal of Physical Chemistry Letters on Sept 18, 2020.

In the study, the team of researchers, led by Prof. Hyokeun Park, assistant professor at the Department of Physics and Division of Life Science, HKUST, mimicked mechanical stiffness of diverse tissues from soft brain to bone using polyacrylamide (PAA) substrates and measured the mechanical responses of single metastatic breast cancer cells (MDA-MB-231 cells) against different stiffness, using advanced imaging techniques and the state-of-the-art magnetic tweezers which Prof. Park's group built in HKUST.

Using single-molecule tension sensors, they found that metastatic breast cancer cells change their tension in focal adhesions against the stiffness to adapt new environments whereas normal breast cells (MCF-10A cells) keep the similar tension regardless of stiffness. They also measured the viscoelasticity of single metastatic breast cancer cells using magnetic tweezers and found that metastatic cancer cells become more elastic on stiffer substrates while the viscoelasticity of normal cells remain similar.

These results show that metastatic breast cancer cells have stronger capacity to adapt to the mechanical environments of diverse tissues.

"How do metastatic breast cancer cells migrate and proliferate the secondary tissues of different stiffness from soft to hard tissue interface like brain to bone is a crucial question in cancer research," said Prof. Park. "Our work addressed how metastatic breast cancer cells proliferate the substrate of varying stiffness from 1kPa (similar to brain) to 50GPa(similar to bone), and we discovered that metastatic cancer cells change their viscoelasticity depending on physical environment to adapt their new physical environment and survive their new environment. This is one of big achievements in cancer physics and mechanobiology. The findings will contribute to developing diagnostic tools for metastatic cancer cells and, eventually, treatment of cancer."

This work was done in collaboration with Prof. Ching-Hwa Kiang at Rice University, Professor Jun Chu at Shenzhen Institutes of Advanced Technology and Prof. Ophelia Tsui in Department of Physics of HKUST.

The team is planning to develop a cancer diagnostic kit making use of the mechanism to measure tension of living potential cancer cells at different stiffness, which will be much simpler and more user-friendly than the existing diagnosis tools for metastatic cancer cells. Such mechanism could also be used to develop a drug-screening test for metastatic cancer to see how metastatic cancer cells' focal adhesion and viscoelasticity respond to different drugs and find the most effective drug for them.

First-in-class antispastic drug candidate to reach clinical phase is published in the prestigious life science journal, Cell. Drug candidate MPH-220 could mean new hope for millions of patients suffering from spasticity.

Chronic muscle spasticity after nervous system defects like stroke, traumatic brain and spinal cord injury, multiple sclerosis and painful low back pain affect more than 10% of the population, with a socioeconomic cost of about 500 billion USD. Currently, there is no satisfying remedy to help these suffering people, which generates an immense medical need for a new generation antispastic drug.

András Málnási-Csizmadia, co-founder of Motorpharma Ltd. and professor at Eötvös Loránd University in Hungary leads the development of a first-in-class drug candidate co-sponsored by Printnet Ltd. MPH-220 directly targets and inhibits the effector protein of muscle contraction, potentially by taking one pill per day. By contrast, current treatments have low efficacy and cause a wide range of side effects because they act indirectly, through the nervous system.

"We receive desperate emails from stroke survivors, who suffer from the excruciating symptoms of spasticity, asking if they could participate in our research. We work hard to accelerate the development of MPH-220 to alleviate these people's chronic spasticity" - said Prof. András Málnási-Csizmadia.

The mechanism of action of MPH-220 and preclinical studies are recently published in Cell. Dr. Máté Gyimesi, CSO of Motorpharma Ltd. highlighted: "The scientific challenge was to develop a chemical compound which discriminates between skeletal and cardiac muscle myosins, the motor proteins of these contractile systems. This feature of MPH-220 makes it highly specific and safe."

Prof. James Spudich, co-founder of Cytokinetics, MyoKardia and Kainomyx, all companies developing drugs targeting cytoskeletal components, is also very excited about MPH-220 as a possible next generation muscle relaxant. "Cytokinetics and MyoKardia have shown that cardiac myosin is highly druggable, and both companies have potential drugs acting on cardiac myosin in late phase clinical trials. Skeletal myosin effectors, however, have not been reported. Motorpharma Ltd. has now developed a specific inhibitor of skeletal myosin, MPH-220, a drug candidate that may reduce the everyday painful spasticity for about 10% of the population that suffers from low back pain and neurological injury related diseases"- said Professor Spudich, former chair of Stanford medical school's Biochemistry department, a Lasker awardee.

Drug development specifically targeting myosins is becoming a distinguished area, indicated by last week's acquisition of MyoKardia by Bristol-Myers Squibb Co. for 13.1 billion dollars in an all-cash deal, in the hope of marketing their experimental heart drug targeting cardiac myosin. This business activity shows the demand for start-up biotech companies such as Myokardia or Motorpharma.

"Motorpharma focusing on muscle research is ready to offer an antispastic drug candidate, MPH-220 with a new mechanism of action. The treatment of spasticity is an unmet need causing huge burden in diseases like poststroke conditions or chronic low back pain" said Prof. Istvan Bitter, former head of CNS in a regional hub of Eli Lilly Co.

BOSTON - An experimental medication that was recently shown to slow the progression of the neurodegenerative disease amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, has now demonstrated the potential to also prolong patient survival. The findings come from a clinical trial conducted by investigators at the Sean M. Healey & AMG Center for ALS at Massachusetts General Hospital (MGH) and Amylyx Pharmaceuticals, Inc., the company that manufactures the medication. Amylyx developed AMX0035, the investigational neuroprotective therapy evaluated in the CENTAUR trial and designed to reduce the death and dysfunction of motor neurons.

ALS, a degenerative condition without a cure, attacks brain and spinal cord nerve cells to progressively affect individuals' ability to move, speak, eat and even breathe. The new results, reported in the journal Muscle and Nerve, provide additional proof of the benefits that patients with ALS may experience when taking the oral drug called AMX0035, which is a combination of sodium phenylbutyrate and taurursodiol. These components target oxidative stress within nerve cells' energy-producing mitochondria and protein-processing endoplasmic reticulum to help prevent neurodegeneration.

In the CENTAUR trial, 137 participants with ALS were randomized two-to-one to receive AMX0035 or placebo. Recently, investigators demonstrated that AMX0035 slowed ALS disease progression over six months, with impacts on various activities of daily living such as a patient's ability to walk, talk, use utensils or swallow food. Patients who completed CENTAUR were eligible to participate in an open-label extension (in which all patients received AMX0035) aimed at assessing the long-term safety and efficacy of the medication.

Investigators' nearly three-year survival analysis incorporated all participants who enrolled in CENTAUR, whether they continued long-term treatment with AMX0035 in the open-label extension or not. The team found that participants originally randomized to receive AMX0035 lived for a median of 6.5 months longer than those originally randomized to receive the placebo.

"These findings are an important step forward because, in this trial, early treatment with AMX0035 was associated with longer survival in people with ALS," said the study's leader Sabrina Paganoni, MD, PhD, investigator at the Healey & AMG Center for ALS and assistant professor of Physical Medicine and Rehabilitation at Harvard Medical School and Spaulding Rehabilitation Hospital. "These results provide substantial evidence supporting the role of AMX0035 for the treatment of ALS. Next steps will depend on ongoing discussions with regulatory agencies."

Senior author Merit Cudkowicz, MD, director of the Healey & AMG Center for ALS at MGH, chief of Neurology at MGH, and the Julieanne Dorn Professor of Neurology at Harvard Medical School, added: "This is one of the first studies to show effect on both function and survival. We are hopeful that this is just the beginning of many new treatments for ALS."

Multidrug resistance (MDR) -- a process in which tumors become resistant to multiple medicines -- is the main cause of failure of cancer chemotherapy. Tumor cells often acquire MDR by boosting their production of proteins that pump drugs out of the cell, rendering the chemotherapies ineffective. Now, researchers reporting in ACS' Nano Letters have developed nanoparticles that release bursts of calcium inside tumor cells, inhibiting drug pumps and reversing MDR.

A pump protein called P-glycoprotein (P-gp) often plays a key role in MDR. P-gp is in the cell membrane, where it uses energy in the form of adenosine triphosphate (ATP) to pump drugs out of tumor cells. Scientists have tried to block P-gp in various ways, such as with small-molecule inhibitors or by depleting ATP. However, the strategies used so far can cause side effects, or they are unstable in the body. Some of the treatments can be difficult to prepare. Kaixiang Zhang, Zhenzhong Zhang, Jinjin Shi and colleagues wanted to block P-gp using a different approach. Previous research suggested that overloading tumor cells with calcium ions could both decrease production of P-gp and reduce ATP levels. But the team needed to find a way to deliver bursts of calcium, along with a chemotherapy drug, inside cancer cells.

The researchers made a "calcium ion nanogenerator" (TCaNG) by loading calcium phosphate nanoparticles with the chemotherapy drug doxorubicin and then coating them with molecules that would allow TCaNG to target and enter cancer cells. Once inside cells, TCaNGs entered an acidic compartment, where the TCaNGs disintegrated, releasing both doxorubicin and bursts of calcium ions. When the team tested TCaNG on cancer cells in a petri dish in the lab, both ATP and P-gp production decreased, which allowed doxorubicin to kill the previously resistant tumor cells. When tested in tumor-bearing mice, TCaNG-treated mice showed significantly smaller tumors after 21 days of treatment than control mice, with no apparent side effects.

Chestnut Hill, Mass. (10/16/2020) - The Southern Ocean played a critical role in the rapid atmospheric carbon dioxide increase during the last deglaciation that took place 20,000 to 10,000 years ago, according to a new report by Boston College geochemist Xingchen (Tony) Wang and an international team in the online edition of Science Advances.

In this new study, Wang and his coauthors analyzed deep-sea coral fossils from 20,000 to 10,000 years ago, when atmospheric carbon dioxide was on the rise.

By examining the chemical signatures of nitrogen and carbon in the coral fossils, the researchers revealed that ocean carbon sequestration decreased as phytoplankton failed to devour macronutrients supplied by upwelling currents in the Southern Ocean and trap carbon dioxide in the deep ocean.

As atmospheric carbon dioxide levels rise because of human activities - dominated by fossil fuel consumption - the findings raise questions about the ocean's ability to absorb the anthropogenic carbon dioxide and the environmental consequences, including global warming, rising sea levels, and more frequent wildfires, according to Wang.

For all the carbon dioxide emitted by human activities since the industrial revolution, roughly 50 percent stayed in the atmosphere, with about a quarter absorbed by the ocean and approximately 25 percent sequestered by the ecosystem on land. To better predict the fate of anthropogenic carbon dioxide in the future, Wang and his collaborators have looked at the past variations in atmospheric carbon dioxide before any significant human activities, from 20,000 to 10,000 years ago when the Earth was moving out of the last ice age.

"A clearer understanding of carbon dioxide variations in the past provides important insights into the fate of anthropogenic carbon dioxide in the future," said Wang, an assistant professor in the Department of Earth and Environmental Sciences.

By studying air bubbles trapped in ancient ice from Antarctic, scientists learned that the atmospheric carbon dioxide concentration during the ice ages was about 30 percent lower than the preindustrial level. This lower carbon dioxide level encouraged the growth of large ice sheets in North America and cooled the ice-age Earth. However, there has been strong debates about why the carbon dioxide concentration was lower during the ice ages. In a previous study led by Wang, he found strong evidence suggesting that the Southern Ocean was largely responsible for the lower concentrations of carbon dioxide during the ice ages.

Phytoplankton growth in the ocean, supported by macronutrients nitrogen and phosphorus, assimilates carbon dioxide from the atmosphere and transforms them into organic carbon. When these organisms die, their biomass sinks into the deep ocean and decomposes back to carbon dioxide. This process, called the "biological pump", transfers carbon dioxide from the atmosphere and surface ocean into the dark, deep ocean. In most parts of the modern ocean, phytoplankton consume all the nutrients supplied to the sunlit ocean and the "biological pump" reaches its maximum efficiency. However, in the Southern Ocean, phytoplankton growth is limited by the supply of the key nutrient iron, as well as sunlight. As a result, large amounts of nitrogen and phosphorus remain in this ocean region, representing a wasted opportunity for atmospheric carbon dioxide sequestration.

By analyzing the isotopic composition of nitrogen in deep-sea coral fossils, Wang found that the biological pump in the Southern Ocean was more efficient during the last ice age, sequestering more carbon dioxide from the atmosphere and thus reducing the concentration of atmospheric carbon dioxide.

Nitrogen has two stable isotopes, Nitrogen-14 and Nitrogen-15, with Nitrogen-15 representing approximately 0.4 percent of the total nitrogen atoms in nature. The small variations in the ratios of Nitrogen-15 to Nitrogen-14 in natural samples contain useful information about the cycling of the nitrogen in the ocean. For example, when phytoplankton assimilates nitrogen to build their biomass, they prefer Nitrogen-14 to Nitrogen-15, leaving behind nitrogen that is enriched in Nitrogen-15.

Wang has previously developed a highly sensitive and precise method to measure the ratios of the nitrogen isotopes in coral's skeleton with a mass spectrometer. This capability has allowed him to measure the isotopic composition of nitrogen in deep-sea coral fossils from the Southern Ocean.

"Deep-sea corals are a wonderful archive for studying the ocean's history. You can find them in a lot of places in the deep ocean. And their ages can be known very precisely using radiometric dating methods," said Nanjing University's Tao Li, first author of the new study, titled "Rapid shifts in circulation and biogeochemistry of the Southern Ocean during deglacial carbon cycle events."

In this new study, Wang and his coauthors focused on well-dated deep-sea coral fossils from 20,000 to 10,000 years ago, when the atmospheric carbon dioxide was increasing from the ice age level to the preindustrial level. The precise ages of the deep-sea coral fossils made it possible to directly compare the changes in the Southern Ocean with the carbon dioxide record from the ice cores in Antarctic.

"If you look closely at the carbon dioxide record during the deglaciation, you will see that there are a few sudden jumps," said Wang. "Each of these jumps is a 10-15 parts-per-million carbon dioxide increase over 100 to 200 years. That's pretty fast but we didn't quite understand why these jumps happened."

The new data from deep-sea coral fossils, including nitrogen isotopes and radiocarbon, suggest that the Southern Ocean was also the primary cause of these rapid carbon dioxide jumps 20,000-10,000 years ago. When these rapid carbon dioxide changes happened, the biological pump in the Southern Ocean was less efficient and the ventilation of the Southern Ocean was faster, the study found.

"However, it should be noted that the current anthropogenic carbon dioxide increase is at least 10 times faster than these natural rapid carbon dioxide jumps during the last deglaciation. We are changing our planet at an unprecedented rate," said Wang.

Wang said he plans to continue his research on past atmospheric carbon dioxide variations using deep-sea corals.

"It's very exciting to collect deep-sea corals using remotely operated vehicles," said Wang. "We plan to go the Brazil margin for the next phase of our research."

New research published in Nature Communications Earth & Environment uses data from two sustained open-ocean hydrographic stations in the North Atlantic Ocean near Bermuda to demonstrate recent changes in ocean physics and chemistry since the 1980s. The study shows decadal variability and recent acceleration of surface warming, salinification, deoxygenation, and changes in carbon dioxide (CO2)-carbonate chemistry that drives ocean acidification.

The study utilized datasets from Hydrostation 'S' and the Bermuda Atlantic Time-series Study (BATS) projects at the Bermuda Institute of Ocean Sciences (BIOS). Both are led by Professor Nicholas Bates, BIOS senior scientist and the projects' principal investigator (PI), and Rod Johnson, BIOS assistant scientist and the projects' co-PI. Together, these time-series represent the two longest continuous records of data from the global open ocean.

"The four decades of data from BATS and Hydrostation 'S' show that the ocean is not changing uniformly over time and that the ocean carbon sink is not stable over recent time with variability from decade to decade," Bates said.

Of the two sites, Hydrostation 'S' is the oldest, located approximately 15 miles (25 km) southeast of Bermuda and consisting of repeat biweekly hydrographic observations of temperature, salinity, and dissolved oxygen conducted through the water column since 1954. The Bermuda Atlantic Time-series Study (BATS) site is located approximately 50 miles (80 km) southeast of Bermuda. It consists of monthly sampling of the physics, chemistry, and biology of the entire water column since 1988. The study's datasets represent more than 1381 cruises to Hydrostation 'S' from 1954 to 2020 and more than 450 cruises to BATS from 1988 to the end of 2019.

Results showed that, over the last 40 years, surface temperatures in the Sargasso Sea have increased by 0.85 +/- 0.12oC, with the summer surface temperatures rising at a higher rate than winter. Additionally, the winter (

The data also show a trend of dissolved oxygen (DO) decline in the Sargasso Sea since the 1980s, representing a loss of ~2% per decade. Given the ocean warming observed in the Sargasso Sea, the researchers estimate that the warming impact on DO solubility would likely have contributed to about 13% of the total decline of DO over the past nearly 40 years. The remaining deoxygenation (~87%) must have resulted from the combined effect of changes in ocean biology and physics.

The BATS and Hydrostation 'S' time-series data allow direct detection of the ocean acidification signal in the surface waters of the North Atlantic Ocean. The typical pH range of surface waters in the 1980s ranged from wintertime highs of ~8.2 to summertime lows of ~8.08-8.10, with the ocean remaining mildly alkaline at present (~7.98-8.05). The rate of pH change is ~0.0019 +/- 0.0001 year-1, which is a more negative rate than previously reported and represents a 20% increase in hydrogen ion concentration since 1983. These changes were accompanied with significant increases of dissolved inorganic carbon and CO2 and decreases in both calcite and aragonite saturation states.

"In forty years, seawater CO2-carbonate chemistry conditions are now altered beyond the seasonal chemical changes observed in the 1980s," Johnson said. "The modification of seawater CO2 -carbonate chemistry will continue with future anthropogenic CO2 emissions."

The observations off Bermuda reveal the substantial decadal variations and highlight the need for long-term data to determine trends in other ocean physical and biogeochemical properties, particularly when linking local measurements to basin-scale changes. Long-term data on ocean chemistry and physical from time-series sites such as Hydrostation 'S' and BATS provide critically needed and unparalleled observations that, when coupled with ocean-atmosphere models, allow for a more complete understanding of drivers of the global carbon cycle.

Mammals and birds today are warm-blooded, and this is often taken as the reason for their great success.

University of Bristol palaeontologist Professor Mike Benton, identifies in the journal Gondwana Research that the ancestors of both mammals and birds became warm-blooded at the same time, some 250 million years ago, in the time when life was recovering from the greatest mass extinction of all time.

The Permian-Triassic mass extinction killed as much as 95 per cent of life, and the very few survivors faced a turbulent world, repeatedly hit by global warming and ocean acidification crises. Two main groups of tetrapods survived, the synapsids and archosaurs, including ancestors of mammals and birds respectively.

Palaeontologists had identified indications of warm-bloodedness, or technically endothermy, in these Triassic survivors, including evidence for a diaphragm and possible whiskers in the synapsids.

More recently, similar evidence for early origin of feathers in dinosaur and bird ancestors has come to light. In both synapsids and archosaurs of the Triassic, the bone structure shows characteristics of warm-bloodedness.
The evidence that mammal ancestors had hair from the beginning of the Triassic has been suspected for a long time, but the suggestion that archosaurs had feathers from 250 million years ago is new.

But a strong hint for this sudden origin of warm-bloodedness in both synapsids and archosaurs at exactly the time of the Permian-Triassic mass extinction was found in 2009. Tai Kubo, then a student studying the Masters in Palaeobiology degree at Bristol and Professor Benton identified that all medium-sized and large tetrapods switched from sprawling to erect posture right at the Permian-Triassic boundary.

Their study was based on fossilised footprints. They looked at a sample of hundreds of fossil trackways, and Kubo and Benton were surprised to see the posture shift happened instantly, not strung out over tens of millions of years, as had been suggested. It also happened in all groups, not just the mammal ancestors or bird ancestors.

Professor Benton said: "Modern amphibians and reptiles are sprawlers, holding their limbs partly sideways.

"Birds and mammals have erect postures, with the limbs immediately below their bodies. This allows them to run faster, and especially further. There are great advantages in erect posture and warm-bloodedness, but the cost is that endotherms have to eat much more than cold-blooded animals just to fuel their inner temperature control."

The evidence from posture change and from early origin of hair and feathers, all happening at the same time, suggested this was the beginning of a kind of 'arms race'. In ecology, arms races occur when predators and prey have to compete with each other, and where there may be an escalation of adaptations. The lion evolves to run faster, but the wildebeest also evolves to run faster or twist and turn to escape.

Something like this happened in the Triassic, from 250 to 200 million years ago. Today, warm-blooded animals can live all over the Earth, even in cold areas, and they remain active at night. They also show intensive parental care, feeding their babies and teaching them complex and smart behaviour. These adaptations gave birds and mammals the edge over amphibians and reptiles and in the present cool world allowed them to dominate in more parts of the world.

Professor Benton added: "The Triassic was a remarkable time in the history of life on Earth. You see birds and mammals everywhere on land today, whereas amphibians and reptiles are often quite hidden.

"This revolution in ecosystems was triggered by the independent origins of endothermy in birds and mammals, but until recently we didn't realise that these two events might have been coordinated.

"That happened because only a tiny number of species survived the Permian-Triassic mass extinction - who survived depended on intense competition in a tough world. Because a few of the survivors were already endothermic in a primitive way, all the others had to become endothermic to survive in the new fast-paced world."