Sun is likely an unaccounted source of the Earth’s water

Curtin University researchers have helped unravel the enduring mystery of the origins of the Earth's water, finding the Sun to be a surprising likely source.

A University of Glasgow-led international team of researchers including those from Curtin's Space Science and Technology Centre (SSTC) found the solar wind, comprised of charged particles from the Sun largely made of hydrogen ions, created water on the surface of dust grains carried on asteroids that smashed into the Earth during the early days of the Solar System.

SSTC Director, John Curtin Distinguished Professor Phil Bland said the Earth was very water-rich compared to other rocky planets in the Solar System, with oceans covering more than 70 percent of its surface, and scientists had long puzzled over the exact source of it all.

"An existing theory is that water was carried to Earth in the final stages of its formation on C-type asteroids, however previous testing of the isotopic 'fingerprint' of these asteroids found they, on average, didn't match with the water found on Earth meaning there was at least one other unaccounted for source," Professor Bland said.

"Our research suggests the solar wind created water on the surface of tiny dust grains and this isotopically lighter water likely provided the remainder of the Earth's water.

"This new solar wind theory is based on meticulous atom-by-atom analysis of miniscule fragments of an S-type near-Earth asteroid known as Itokawa, samples of which were collected by the Japanese space probe Hayabusa and returned to Earth in 2010.

"Our world-class atom probe tomography system here at Curtin University allowed us to take an incredibly detailed look inside the first 50 nanometres or so of the surface of Itokawa dust grains, which we found contained enough water that, if scaled up, would amount to about 20 litres for every cubic metre of rock."

Curtin graduate Dr Luke Daly, now of the University of Glasgow, said the research not only gives scientists a remarkable insight into the past source of Earth's water, but could also help future space missions.

"How astronauts would get sufficient water, without carrying supplies, is one of the barriers of future space exploration," Dr Daly said.

"Our research shows that the same space weathering process which created water on Itokawa likely occurred on other airless planets, meaning astronauts may be able to process fresh supplies of water straight from the dust on a planet's surface, such as the Moon."

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Extinct swordfish-shaped marine reptile discovered

A team of international researchers from Canada, Colombia, and Germany has discovered a new marine reptile. The specimen, a stunningly preserved metre-long skull, is one of the last surviving ichthyosaurs -- ancient animals that look eerily like living swordfish.

"This animal evolved a unique dentition that allowed it to eat large prey," says Hans Larsson, Director of the Redpath Museum at McGill University. "Whereas other ichthyosaurs had small, equally sized teeth for feeding on small prey, this new species modified its tooth sizes and spacing to build an arsenal of teeth for dispatching large prey, like big fishes and other marine reptiles."

"We decided to name it Kyhytysuka which translates to 'the one that cuts with something sharp' in an indigenous language from the region in central Colombia where the fossil was found, to honour the ancient Muisca culture that existed there for millennia," says Dirley Cortes, a graduate student under the supervision of Hans Larsson and Carlos Jaramillo of the Smithsonian Tropical Research Institute.

The big picture of ichthyosaur evolution is clarified with this new species, the researchers say. "We compared this animal to other Jurassic and Cretaceous ichthyosaurs and were able to define a new type of ichthyosaurs," says Erin Maxwell of the State Natural History Museum of Stuttgart (a former graduate student of Hans Larsson's lab at McGill). "This shakes up the evolutionary tree of ichthyosaurs and lets us test new ideas of how they evolved."

According to the researchers, this species comes from an important transitional time during the Early Cretaceous period. At this time, the Earth was coming out of a relatively cool period, had rising sea levels, and the supercontinent Pangea was splitting into northern and southern landmasses. There was also a global extinction event at the end of the Jurassic that changed marine and terrestrial ecosystems. "Many classic Jurassic marine ecosystems of deep-water feeding ichthyosaurs, short-necked plesiosaurs, and marine-adapted crocodiles were succeeded by new lineages of long-necked plesiosaurs, sea turtles, large marine lizards called mosasaurs, and now this monster ichthyosaur" says Dirley Cortes.

"We are discovering many new species in the rocks this new ichthyosaur comes from. We are testing the idea that this region and time in Colombia was an ancient biodiversity hotspot and are using the fossils to better understand the evolution of marine ecosystems during this transitional time," she adds. As next steps the researchers are continuing to explore the wealth of new fossils housed in the Centro de Investigaciones Paleontológicas of Villa de Leyva in Colombia. "This is where I grew up," says Cortes "and it is so rewarding to get to do research here too."

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Extraordinary Roman mosaic and villa discovered beneath farmer's field in Rutland, UK

Archaeologists have unearthed the first Roman mosaic of its kind in the UK. Today (Thursday 25th November 2021), a rare Roman mosaic and surrounding villa complex have been protected as a Scheduled Monument by DCMS on the advice of Historic England. The decision follows archaeological work undertaken by a team from University of Leicester Archaeological Services (ULAS), working in partnership with Historic England and in liaison with Rutland County Council.

The initial discovery of the mosaic was made during the 2020 lockdown by Jim Irvine, son of landowner Brian Naylor, who contacted the archaeological team at Leicestershire County Council, heritage advisors to the local authority. Given the exceptional nature of this discovery, Historic England was able to secure funding for urgent archaeological investigations of the site by ULAS in August 2020. Further excavation involving staff and students from the University of Leicester's School of Archaeology and Ancient History examined more of the site in September 2021. The remains of the mosaic measure 11m by almost 7m and depict part of the story of the Greek hero Achilles.

The artwork forms the floor of what's thought to be a large dining or entertaining area. Mosaics were used in a variety of private and public buildings across the Roman Empire, and often featured famous figures from history and mythology. However, the Rutland mosaic is unique in the UK in that it features Achilles and his battle with Hector at the conclusion of the Trojan War and is one of only a handful of examples from across Europe.

The room is part of a large villa building occupied in the late Roman period, between the 3rd and 4th century AD. The villa is also surrounded by a range of other buildings and features revealed by a geophysical survey and archaeological evaluation, including what appear to be aisled barns, circular structures and a possible bath house, all within a series of boundary ditches. The complex is likely to have been occupied by a wealthy individual, with a knowledge of classical literature.

Fire damage and breaks in the mosaic suggest that the site was later re-used and re-purposed. Other evidence uncovered includes the discovery of human remains within the rubble covering the mosaic. These burials are thought to have been interred after the building was no longer occupied, and while their precise age is currently unknown, they are later than the mosaic but placed in a relationship to the villa building, suggesting a very late Roman or Early-Medieval date for the repurposing of this structure. Their discovery gives an insight into how the site may have been used during this relatively poorly understood early post-Roman period of history.

Evidence recovered from the site will be analysed by ULAS at their University of Leicester base, and by specialists from Historic England and across the UK, including David Neal, the foremost expert on mosaic research in the country.

The protection as a scheduled monument recognises the exceptional national importance of this site. It ensures these remains are legally protected and helps combat unauthorised works or unlawful activities such as illegal metal detecting. The site has been thoroughly examined and recorded as part of the recent investigations and has now been backfilled to protect it for future generations.

The villa complex was found within an arable field where the shallow archaeological remains had been disturbed by ploughing and other activities. Historic England is working with the landowner to support the reversion of these fields to a sustainable grassland and pasture use. These types of agri-environment schemes are an essential part of how we can protect both the historic and natural environments and have contributed around £13 million per year towards the conservation and maintenance of our rural heritage. They help to preserve sites like the Rutland mosaic so that people can continue to enjoy and learn about our fascinating history.

In collaboration with the University of Leicester and other stakeholders, Historic England is planning further excavations on the site for 2022.

Discussions are on-going with Rutland County Council to explore the opportunity for an off-site display and interpretation of the villa complex and its finds. The form and scope of this work will be informed by the proposed future excavations and will be the subject of a future National Lottery Heritage Fund bid.

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Scientists can control brain circuits, behavior, and emotion using light

Controlling signal transmission and reception within the brain circuits is necessary for neuroscientists to achieve a better understanding of the brain's functions. Communication among neuron and glial cells is mediated by various neurotransmitters being released from the vesicles through exocytosis. Thus, regulating vesicular exocytosis can be a possible strategy to control and understand brain circuits.

However, it has been difficult to freely control the activity of brain cells in a spatiotemporal manner using pre-existing techniques. One is an indirect approach that involves artificially controlling the membrane potential of cells, but it comes with problems of changing the acidity of the surrounding environment or causing unwanted misfiring of neurons. Moreover, it is not applicable for use in cells that do not respond to the membrane potential changes, such as glial cells.

To address this problem, South Korean researchers led by Director C. Justin LEE at the Center for Cognition and Sociality within the Institute for Basic Science (IBS) and professor HEO Won Do at Korea Advanced Institute of Science and Technology (KAIST) developed Opto-vTrap, a light-inducible and reversible inhibition system that can temporarily trap vesicles from being released from brain cells. Opto-vTrap directly targets transmitters containing vesicles, and it can be used in various types of brain cells, even the ones that do not respond to membrane potential changes.

In order to directly control the exocytotic vesicles, the research team applied a technology they previously developed in 2014, called light-activated reversible inhibition by assembled trap (LARIAT). This platform can inactivate various types of proteins when illuminated under blue light by instantly trapping the target proteins, like a lariat. Opto-vTrap was developed by applying this LARIAT platform to vesicle exocytosis. When the Opto-vTrap expressing cells or tissues are shined under blue light, the vesicles form clusters and become trapped within the cells, inhibiting the release of transmitters.

Most importantly, the inhibition triggered using this new technique is temporary, which is very important for neuroscience research. Other previous techniques that target vesicle fusion proteins damage them permanently and disable the target neuron for up to 24 hours, which is not appropriate for many behavioral experiments with short time constraints. By comparison, vesicles that were inactivated using Opto-vTrap decluster in about 15 minutes, and the neurons regain their full functions within an hour.

Opto-vTrap directly controls the signal transmitters' release, enabling the researchers to freely control brain activity. The research team verified the usability of Opto-vTrap in cultured cells and brain tissue slices. Furthermore, they tested the technique in live mice, which enabled them to temporarily remove fear memory from fear-conditioned animals.

In the future, Opto-vTrap will be used to uncover complex interactions between multiple parts of the brain. It will be a highly useful tool for studying how certain brain cell types affect brain function in different circumstances.

Professor Heo stated, "Since Opto-vTrap can be used in various cell types, it is expected to be helpful in various fields of brain science research," He explained, "We plan to conduct a study to figure out the spatiotemporal brain functions in various brain cell types in a specific environment using Opto-vTrap technology."

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Orbital harmony limits late arrival of water on TRAPPIST-1 planets

Seven Earth-sized planets orbit the star TRAPPIST-1 in near-perfect harmony, and U.S. and European researchers have used that harmony to determine how much physical abuse the planets could have withstood in their infancy.

"After rocky planets form, things bash into them," said astrophysicist Sean Raymond of the University of Bordeaux in France. "It's called bombardment, or late accretion, and we care about it, in part, because these impacts can be an important source of water and volatile elements that foster life."

In a study available online today in Nature Astronomy, Raymond and colleagues from Rice University's NASA-funded CLEVER Planets project and seven other institutions used a computer model of the bombardment phase of planetary formation in TRAPPIST-1 to explore the impacts its planets could have withstood without getting knocked out of harmony.

Deciphering the impact history of planets is difficult in our solar system and might seem like a hopeless task in systems light-years away, Raymond said.

"On Earth, we can measure certain types of elements and compare them with meteorites," Raymond said. "That's what we do to try to figure out how much stuff bashed into the Earth after it was mostly formed."

But those tools don't exist for studying bombardment on exoplanets.

"We'll never get rocks from them," he said. "We're never going to see craters on them. So what can we do? This is where the special orbital configuration of TRAPPIST-1 comes in. It's a kind of a lever we can pull on to put limits on this."

TRAPPIST-1, about 40 light-years away, is far smaller and cooler than our sun. Its planets are named alphabetically from b to h in order of their distance from the star. The time needed to complete one orbit around the star -- equivalent to one year on Earth -- is 1.5 days on planet b and 19 days on planet h. Remarkably, their orbital periods form near-perfect ratios, a resonant arrangement reminiscent of harmonious musical notes. For example, for every eight "years" on planet b, five pass on planet c, three on planet d, two on planet e and so on.

"We can't say exactly how much stuff bashed into any of these planets, but because of this special resonant configuration, we can put an upper limit on it," Raymond said. "We can say, 'It can't have been more than this.' And it turns out that that upper limit is actually fairly small.

"We figured out that after these planets formed, they weren't bombarded by more than a very small amount of stuff," he said. "That's kind of cool. It's interesting information when we're thinking about other aspects of the planets in the system."

Planets grow within protoplanetary disks of gas and dust around newly formed stars. These disks only last a few million years, and Raymond said previous research has shown that resonant chains of planets like TRAPPIST-1's form when young planets migrate closer to their star before the disk disappears. Computer models have shown disks can shepherd planets into resonance. Raymond said it's believed that resonant chains like TRAPPIST-1's must be set before their disks disappear.

The upshot is TRAPPIST-1's planets formed fast, in about one-tenth the time it took Earth to form, said Rice study co-author Andre Izidoro, an astrophysicist and CLEVER Planets postdoctoral fellow.

CLEVER Planets, led by study co-author Rajdeep Dasgupta, the Maurice Ewing Professor of Earth Systems Science at Rice, is exploring the ways planets might acquire the necessary elements to support life. In previous studies, Dasgupta and colleagues at CLEVER Planets have shown a significant portion of Earth's volatile elements came from the impact that formed the moon.

"If a planet forms early and it is too small, like the mass of the moon or Mars, it cannot accrete a lot of gas from the disk," Dasgupta said. "Such a planet also has much less opportunity to gain life-essential volatile elements through late bombardments."

Izidoro said that would have been the case for Earth, which gained most of its mass relatively late, including about 1% from impacts after the moon-forming collision.

"We know Earth had at least one giant impact after the gas (in the protoplanetary disk) was gone," he said. "That was the moon-forming event.

"For the TRAPPIST-1 system, we have these Earth-mass planets that formed early," he said. "So one potential difference, compared to the Earth's formation, is that they could have, from the beginning, some hydrogen atmosphere and have never experienced a late giant impact. And this might change a lot of the evolution in terms of the interior of the planet, outgassing, volatile loss and other things that have implications for habitability."

Raymond said this week's study has implications not only for the study of other resonant planetary systems, but for far more common exoplanet systems that were believed to have begun as resonant systems.

"Super-Earths and sub-Neptunes are very abundant around other stars, and the predominant idea is that they migrated inward during that gas-disk phase and then possibly had a late phase of collisions," Raymond said. "But during that early phase, where they were migrating inward, we think that they pretty much -- universally maybe -- had a phase where they were resonant chain structures like TRAPPIST-1. They just didn't survive. They ended up going unstable later on."

Izidoro said one of the study's major contributions could come years from now, after NASA's James Webb Space Telescope, the European Southern Observatory's Extremely Large Telescope and other instruments allow astronomers to directly observe exoplanet atmospheres.

"We have some constraints today on the composition of these planets, like how much water they can have," Izidoro said of planets that form in a resonant, migration phase. "But we have very big error bars."

In the future, observations will better constrain the interior composition of exoplanets, and knowing the late bombardment history of resonant planets could be extremely useful.

"For instance, if one of these planets has a lot of water, let's say 20% mass fraction, the water must have been incorporated into the planets early, during the gaseous phase," he said. "So you will have to understand what kind of process could bring this water to this planet."

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Researchers identify behavioral adaptations that may help Antarctic fishes adapt to warming Southern Ocean

At first glance, Antarctica seems inhospitable. Known for howling gales and extremely cold temperatures, the continent is blanketed with a mile-thick ice shelf. Occasional elephant seals and seabirds fleck the glacial shorelines.

Yet dipping below the waves, the Southern Ocean teems with biodiversity: vibrant swaths of sea ice algae and cyanobacteria, swarming krill and crustaceans, bristling kelp forests, gigantic polar sea spiders and sponges, whale pods, and abundant Antarctic fish fauna.

These fishes play a vital role in the Southern Ocean's food web of 9,000 known marine species, yet their subzero haven may be at risk. A 2021 climate analysis posited that by 2050 some areas of the Antarctic continental shelf will be at least 1 degree Celsius warmer.

Researchers from Virginia Tech's Fralin Biomedical Research Institute at VTC have published a new study in PLOS ONE describing how two species of Antarctic fish -- one with hemoglobin in its blood cells and one without -- respond to acute thermal stress.

The research team, directed by Virginia Tech Vice President for Health Sciences and Technology Michael Friedlander, observed that both species responded to progressive warming with an elaborate array of behavioral maneuvers, including fanning and splaying their fins, breathing at the surface, startle-like behavior, and transient bouts of alternating movement and rest.

"Remarkably, our team found that Antarctic fishes compensate for increasing metabolic demands by enhancing respiration through species-specific locomotor and respiratory responses, demonstrating resilience to environmental change and possibly to global warming," said Friedlander, who is also the Fralin Biomedical Research Institute's executive director, senior dean for research at the Virginia Tech Carilion School of Medicine, and a professor in the College of Science's Department of Biological Sciences. "Ambient warming presents a multi-faceted challenge to the fish, including increased temperature of the central nervous system and target tissues such as skeletal and cardiac muscles, but also reduced availability of dissolved oxygen in the water that passes through the gills during respiration. While these findings suggest that Antarctic fishes may be able to behaviorally adapt somewhat under extreme conditions, little is known about the effects of environmental warming on their predation habits, food availability, and fecundity,"

Iskander Ismailov, the study's first author and a research assistant professor in Friedlander's laboratory during the study, said, "Behavioral manifestations that we've described show that these fishes have powerful physiological capacities to survive environmental changes," said

Through millions of years of isolation from the rest of the world -- corralled by the Antarctic Circumpolar Current -- Southern Ocean fish species have become well adapted to their frosty ecosystem.

Blackfin icefish, Chaenocephalus aceratus, one of the two species studied by the team, have unique opalescent blood. These fish are among the few known vertebrates lacking hemoglobin, a molecule in red blood cells that efficiently carries oxygen from the lungs of land-dwelling vertebrates, or from the gills of aquatic vertebrates, throughout tissues in the body. Instead, blackfin icefish transport oxygen dissolved in blood plasma, harboring roughly 10% of the oxygen carrying capacity of hemoglobin.

Oxygen is more soluble in cold water, allowing white-blooded icefish to thrive in the Southern Ocean. As water temperature rises, however, these species experience increased metabolic demand, potentially making white-blooded fish more vulnerable to global warming. To test this hypothesis, the team examined five specimens of white-blooded blackfin icefish and five red-blooded black rockcod, Notothenia coriiceps, in a climate-controlled shoreline laboratory that circulated, and progressively warmed, saltwater straight from the Southern Ocean.

The fishes acclimated to the lab conditions, before being transferred to the experimental tank, where water temperature rose from -1.8 degrees Celsius to 13 degrees, at a rate of 3 degrees per hour. The researchers captured extensive video recordings, allowing them to examine and quantify the fishes' motility, breathing rate, maneuvers in the tank, and fin movements.

As the water temperature rose, the white-blooded icefish displayed intensive pectoral fin fanning -- a behavior previously observed in icefish during egg guarding -- that the researchers suggest may help facilitate respiration. By contrast, the red-blooded fish employed complex maneuvers, including pectoral fin fanning and splaying, followed by startle-like C-turns, which may augment gill ventilation, according to Ismailov.

"The findings provide a new perspective on the effects of rising temperature on these highly cold-adapted species," said George Somero, professor emeritus of marine biology at Stanford University and a leader in studying how marine life adapts to thermal stress, who was not involved in the research.

Preparation for the expedition began in early 2014. The research team designed, custom-built, and shipped laboratory equipment to Palmer Station in Antarctica before living there for three months in 2015. The journey included a flight to Punta Arenas, Chile, then crossing the Drake Passage by boat during the austral fall.

Ismailov was the first to arrive, setting up experimental rigs. Six weeks later, he was joined by Jordan Scharping, then a second-year Virginia Tech Carilion School of Medicine student conducting research in Friedlander's lab. The pair worked in overlapping 12-hour shifts running experiments in the laboratory at near-freezing temperatures.

"Dr. Friedlander drew me to this project. I remember him presenting the Antarctic project proposal to us medical students and everyone just lighting up about it. It was an incredible opportunity and I appreciate him giving it to me," said Scharping, who is now a physician at Northwestern Memorial Hospital.

Researchers were responsible for collecting their own fish specimens during a series of four, week-long fishing trips. At sea, with the help of the research vessel crew, the researchers worked around the clock -- sometimes during harsh conditions.

"One stormy night while we were fishing, a two-story wave overtook the stern, drenching me from head to toe in ice-cold seawater -- the captain of the boat stopped the fishing after that," Ismailov recalled. "As a graduate of medical school, I never could have imagined that my career would lead me to Antarctica to study fish, but this research project has become one of the most extraordinary and memorable in my life."

The field work was funded by a National Science Foundation Grant awarded to Elizabeth Crockett, professor emerita at Ohio University, and Kristin O'Brien, professor at the University of Alaska Fairbanks. Crockett and O'Brien -- both former graduate students of Bruce Sidell, who was trained by C. Ladd Prosser -- invited Friedlander to join the expedition along with collaborators from the University of British Columbia, the University of Leeds, and Valdosta State University.

But the underpinnings of this recent study started 45 years ago. Friedlander, then a graduate student under the mentorship of Prosser at the University of Illinois at Urbana-Champaign -- a pioneer in the field of comparative animal physiology and thermal biology -- conducted research to advance experimental approaches to evaluate how temperature change affects molecular, cellular, and behavioral processes in an entire organism. Their landmark study, published in the Journal of Comparative Physiology in 1977, examining the common goldfish, was lauded by Somero in a 2015 review in the Journal of Experimental Biology.

"I find it gratifying that the pathbreaking studies of temperature effects on goldfish behavior carried out by Dr. Friedlander several decades ago have evolved into this fascinating new work on fishes of the Southern Ocean," Somero said.

While the research team observed that stenothermal Antarctic fishes show remarkable capacity to withstand acute thermal stress, Ismailov warns that these vulnerable species still need protection.

"There's a history of severe overexploitation in the Southern Ocean in the '70s and '80s due to unregulated commercial fishing. These activities had depleted the populations of some fish species so badly that the prospects of their recovery are still unclear," Ismailov said.

Friedlander expounds on this, noting that all species play important roles in a fragile ecosystem.

"If left unregulated, anthropogenic activities could produce irreversible damage, impacting not just icefish, but many other species in the Antarctic food webs as well," Friedlander said. "By doing these types of proof of principle experiments now to begin to understand the physiological repertoire available to species at risk, we can begin to make more informed predictions about what sort of perturbations within complex ecosystems that climate change may trigger, and what type of reserve and adaptive capacity individual species may deploy,"

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How can our brain still perceive familiar objects even when they become indistinct?

Researchers have explored the brain neuronal mechanism that allows the perception of familiar images even if they are indistinct. They found that the number of neurons responding to low-contrast rather than high-contrast visual stimuli increased in rats performing a visual orientation discrimination task after repeated experiences. These neurons showed stronger activities in correct-choice than incorrect-choice trials. These neurons efficiently represented low-contrast stimulations. Thus, the low-contrast preference in V1 activity may contribute to improved low-contrast visual.

The appearance of objects can often change. For example, in dim evenings or fog, the contrast of the objects decreases, making it difficult to distinguish them. However, after repeatedly encountering specific objects, the brain can identify them even if they become indistinct. The exact mechanism contributing to the perception of low-contrast familiar objects remains unknown.

In the primary visual cortex (V1), the area of the cerebral cortex dedicated to processing basic visual information, the visual responses have been considered to reflect directly the strength of external inputs. Thus, high-contrast visual stimuli elicit strong responses and vice versa.

In this study, Rie Kimura and Yumiko Yoshimura found that in rats, the number of V1 neurons preferentially responding to low-contrast stimuli increases after repeated experiences. In these neurons, low-contrast visual stimuli elicit stronger responses, and high-contrast stimuli elicit weaker responses. These low contrast-preferring neurons show a more evident activity when rats correctly perceive a low-contrast familiar object. It was first reported in Science Advances that low-contrast preference in V1 is strengthened in an experience-dependent manner to represent low-contrast visual information well. This mechanism may contribute to the perception of familiar objects, even when they are indistinct.

"This flexible information representation may enable a consistent perception of familiar objects with any contrast," Kimura says. "The flexibility of our brain makes our sensation effective, although you may not be aware of it. An artificial neural network model may reproduce the human sensation by incorporating not only high contrast-preferring neurons, generally considered until now, but also low contrast-preferring neurons, the main focus of this research."

From Science Daily

Spicy breast milk?

Breast milk is the first food that babies consume. Various studies have suggested that the "taste experience" in early childhood influences eating behavior in adults. Unlike standardized infant formula, natural milk does not taste and smell the same every day. The differences are largely due to the maternal diet.

No one-to-one transfer

However, the taste and aroma of food consumed by the mother are not transferred one-to-one to her milk. Research has already shown that odor and taste active substances from garlic or coffee partly enter the mother's milk as an odor active metabolic product, while flavors from fish oil or nursing tea were of little to no significance in this respect.

The extent to which pungent substances from chili, ginger, or pepper are found in breast milk has been even less researched than aroma and taste substances. For this reason, a scientific team led by TUM has now investigated whether these substances are transferred from food to breast milk and if so, which ones.

Piperine detectable after just one hour

Through extensive mass spectrometric analyses, the team has shown that already one hour after consumption of a standardized curry dish, piperine is detectable in breast milk for several hours. "The observed maximum concentrations of 14 to 57 micrograms per liter were about 70- to 350-fold below the taste perception threshold of an adult," says Professor Corinna Dawid, who heads the Chair of Food Chemistry and Molecular Sensory Science at TUM commissarial for Professor Thomas Hofmann.

Roman Lang, who was initially involved in the study as a scientist at TUM and later at the Leibniz Institute for Food Systems Biology (LSB) adds, "It seems rather unlikely to us that the infants consciously perceive the sharpness. Nevertheless, it is conceivable that regular, low-threshold activation of the "pungent receptor" TRPV1 could help to increase tolerance for such substances later on."

Pungents from ginger or chili as well as the secondary plant compound curcumin, which is also abundant in curry, did not enter milk, according to the research. "We were particularly surprised by the latter, since piperine is supposed to significantly increase the bioavailability of curcumin according to the results of other studies," reports Roman Lang, who heads the Biosystems Chemistry & Human Metabolism research group at the LSB.

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A new way to generate electricity from waste heat: Using an antiferromagnet for solid devices

Forcing electrons to flow perpendicularly to a heat flow requires an external magnetic field – this is known as the Nernst effect. In a permanently magnetized material (a ferromagnet), an anomalous Nernst effect (ANE) exists that can generate electricity from heat even without a magnetic field. The anomalous Nernst effect scales with the magnetic moment of the ferromagnet. An antiferromagnet, with two compensating magnetic sublattices shows no external magnetic moment and no measurable external magnetic field and therefore should not exhibit any ANE. However, we have recently understood that by the new concept of topology can be applied to achieve large Nernst effects in magnets. In particular, we have learned that the quantity known as the Berry phase is related to the ANE and can greatly increase it. However, the ANE in antiferromagnets is still largely unexplored, in part because the ANE was not thought to exist. Remarkably, a joint research team from the Max Planck Institute for Chemical Physics of Solids in Dresden, Germany, together with collaborators at the Ohio State University and the University of Cincinnati, has found a large anomalous Nernst effect, larger than is known in almost all ferromagnets in YbMnBi2, an antiferromagnet.

The ANE that has been observed is likely a result of topology, the high spin-orbit coupling, and the complex and not fully compensated magnetic structure of YbMnBi2. The canted spin structure in YbMnBi2 breaks time reversal symmetry and provides a non-zero Berry curvature. At the same time, the large spin-orbit coupling of the heavy bismuth element helps to produce a large extrinsic contribution. Based on this recipe, a certain class of antiferromagnets with a non-collinear spin structure and with large spin-orbit coupling can exhibit a large anomalous Nernst effect. The researchers were surprised when they observed such a large ANE in YbMnBi2, reaching 6 mV/K, which is a record value for antiferromagnets and as high as those values previously observed for the best ferromagnets.

For practical applications, one could use this new phenomenon to make simple energy converters: a transverse thermoelectric device where the voltage is generated perpendicular to the heat flow. The device consists of only one block of material. The commercially available thermoelectric generators based on the Seebeck effect are complex assemblies built from small blocks of n- and p-type semiconductor materials. Unlike ferromagnets, which often suffer from low carrier mobility, antiferromagnets can also exhibit higher mobilities and therefore show better electrical conductivity. Together with low thermal conductivity, an anomalous thermoelectric figure of merit (zT) is achieved in YbMnBi2, which is an order of magnitude higher than that of all known ferromagnets.

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Aspirin is linked with increased risk of heart failure in some

Aspirin use is associated with a 26% raised risk of heart failure in people with at least one predisposing factor for the condition. That's the finding of a study published today in ESC Heart Failure, a journal of the European Society of Cardiology (ESC).1 Predisposing factors included smoking, obesity, high blood pressure, high cholesterol, diabetes, and cardiovascular disease.

"This is the first study to report that among individuals with a least one risk factor for heart failure, those taking aspirin were more likely to subsequently develop the condition than those not using the medication," said study author Dr. Blerim Mujaj of the University of Freiburg, Germany. "While the findings require confirmation, they do indicate that the potential link between aspirin and heart failure needs to be clarified."

The influence of aspirin on heart failure is controversial. This study aimed to evaluate its relationship with heart failure incidence in people with and without heart disease and assess whether using the drug is related to a new heart failure diagnosis in those at risk.

The analysis included 30,827 individuals at risk for developing heart failure who were enrolled from Western Europe and the US into the HOMAGE study. "At risk" was defined as one or more of the following: smoking, obesity, high blood pressure, high cholesterol, diabetes and cardiovascular disease. Participants were aged 40 years and above and free of heart failure at baseline. Aspirin use was recorded at enrolment and participants were classified as users or non-users. Participants were followed-up for the first incidence of fatal or non-fatal heart failure requiring hospitalisation.

The average age of participants was 67 years and 34% were women. At baseline, a total of 7,698 participants (25%) were taking aspirin. During the 5.3-year follow-up, 1,330 participants developed heart failure.

The investigators assessed the association between aspirin use and incident heart failure after adjusting for sex, age, body mass index, smoking, alcohol use, blood pressure, heart rate, blood cholesterol, creatinine, hypertension, diabetes, cardiovascular disease, and treatment with renin-angiotensin-aldosterone-system inhibitors, calcium channel blockers, diuretics, beta-blockers and lipid-lowering drugs. Taking aspirin was independently associated with a 26% raised risk of a new heart failure diagnosis.

To check the consistency of the results, the researchers repeated the analysis after matching aspirin users and non-users for heart failure risk factors. In this matched analysis, aspirin was associated with a 26% raised risk of a new heart failure diagnosis. To check the results further, the analysis was repeated after excluding patients with a history of cardiovascular disease. In 22,690 participants (74%) free of cardiovascular disease, aspirin use was associated with a 27% increased risk of incident heart failure.

Dr. Mujaj said: "This was the first large study to investigate the relationship between aspirin use and incident heart failure in individuals with and without heart disease and at least one risk factor. Aspirin is commonly used -- in our study one in four participants were taking the medication. In this population, aspirin use was associated with incident heart failure, independent of other risk factors."

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