Astronomers make rare exoplanet discovery, and a giant leap in detecting Earth-like bodies

Astronomers have made the rare discovery of a small, cold exoplanet and its massive outer companion -- shedding light on the formation of planets like Earth.

The findings include a planet with radius and mass between that of the Earth and Neptune, with a potential orbit around its host star of 146 days. The star system also contains an outer, large companion, 100 times the mass of Jupiter.

This is a rare discovery, with exoplanets smaller and lighter than Neptune and Uranus being notoriously hard to detect, with only a few being identified to this day. Such rare systems are particularly interesting to better understand planetary formation and evolution; they are thought to be a key step for the detection of Earth-like planets around stars.

The new planetary system is discovered around the star HD88986. This star has a similar temperature to the Sun with a slightly larger radius and is bright enough to be seen by keen observers at dark sky sites across the UK, such as Bannau Brycheiniog National Park (Brecon Beacons).

This study, published in the journal Astronomy & Astrophysics, is led by Neda Heidari, an Iranian postdoctoral fellow at the Institut d'astrophysique de Paris (IAP). In the UK, Thomas Wilson, a senior research fellow at the University of Warwick, co-led the analysis of satellite data including searching for new planets. The team also includes researchers at 29 other institutes from nine countries including Switzerland, Chile, and the USA.

A cold, Neptune-like exoplanet

The planetary system includes a cold planet smaller than Neptune, a so-called sub-Neptune, HD88986b. This planet has the longest orbital period (146 days) among known exoplanets smaller than Neptune or Uranus with precise mass measurements.

Neda Heidari, IAP, explained: "Most of the planets we've discovered and measured for their mass and radius have short orbits, typically less than 40 days. To provide a comparison with our solar system, even Mercury, the closest planet to the Sun, takes 88 days to complete its orbit. This lack of detection for planets with longer orbits raises challenges in understanding how planets form and evolve in other systems and even in our solar system. HD88986b, with its orbital period of 146 days, potentially has the longest known orbit among the population of small planets with precise measurements."

HD88986b was detected using the SOPHIE -- a high-precision spectrograph (a machine that analyses wavelengths of light from exoplanets) at the Haute-Provence Observatory, France. SOPHIE detects and characterises exoplanets using the 'radial-velocity method'; measuring tiny motion variations of the star induced by planets orbiting it.

These observations revealed the planet and allowed the team to estimate its mass to approximately 17 times that of the Earth.

Complementary observations obtained with NASA's space telescope Transiting Exoplanet Survey Satellite (TESS) and the European Space Agency's (ESA) space telescope CHaracterising ExOPlanet Satellite (CHEOPS) indicate that the planet probably "transits" in front of it host star. This occurs when its orbit passes on the line of sight between the Earth and the star, partially occulting the star -- causing a decrease in its brightness that can be observed and quantified.

These observations by both satellites allowed the team to directly estimate the diameter of the planet as about twice that of the Earth. The findings of the study rely on more than 25 years of observations, also including data from ESA's Gaia satellite and the Keck Telescope in Hawaii.

Moreover, with an atmosphere temperature of only 190 Celsius degrees, HD88986b provides a rare opportunity for studying the composition of the so-called "cold" atmospheres, as most of the detected atmospheres for exoplanets are above 1,000 Celsius degrees.

Due to the wide orbit of the sub-Neptune HD88986b (as large as 60% of the Earth-Sun distance), HD88986b probably underwent rare interactions with other planets that may exist in the planetary system, and weak loss of mass from the strong ultraviolet radiation of the central star. It may therefore have retained its original chemical composition, allowing scientists to explore the possible scenarios for the formation and evolution of this planetary system.

Thomas Wilson, Department of Physics, University of Warwick, said: "HD88986b is essentially a scaled-down Neptune, between the orbits of Mercury and Venus. It becomes one of the best studied small, cold exoplanets paving the way for studying its atmosphere to understand the similarity to our own planet Earth. It also orbits a star with a similar temperature to the Sun making it a precursor to the Earth-like planets to be found by the PLATO space telescope, in which Warwick plays a leading role."

A second, outer companion

The astronomers also revealed a second, outer companion around the central star. This exoplanet is particularly massive (more than 100 times the mass of Jupiter), and its orbit has a period of several tens of years. Further observations are needed to understand its nature and better determine its properties.

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Record heat in 2023 worsened global droughts, floods and wildfires

Record heat across the world profoundly impacted the global water cycle in 2023, contributing to severe storms, floods, megadroughts and bushfires, new research from The Australian National University (ANU) shows.

The findings are outlined in a new report released today by the Global Water Monitor Consortium and led by ANU researchers.

Lead author Professor Albert van Dijk, from ANU, said the report underscores the consequences of persistent fossil fuel burning on natural disasters, water resources, biodiversity and food security.

"Record-breaking heat waves swept across the globe in 2023, shattering previous records, from Canada to Brazil and from Spain to Thailand," Professor van Dijk said.

"The lack of rainfall and high temperatures exacerbated multi-year droughts in South America, the Horn of Africa and around the Mediterranean.

"Extremely hot and dry conditions inflicted extensive ecological damage on the world's largest forests. Massive wildfires ravaged Canada during the northern summer, while the Amazon rainforest and rivers rapidly descended into severe drought in late 2023."

Some of the worst disasters of 2023 were linked to unusually strong cyclones bringing extreme rainfall to New Zealand, Mozambique and Malawi, Myanmar, Greece, Libya and Australia.

According to Professor van Dijk, who is also Chair of the Global Water Monitor Consortium, rising sea surface and air temperatures caused by fossil fuel burning have been intensifying the strength and rainfall intensity of monsoons, cyclones and other storm systems.

This was also evident closer to home, where Cyclone Jasper battered northern Queensland and severe storms hit southeast Queensland.

"Some areas around Cairns recorded more than 800 millimetres of rain. The torrential rains caused widespread flooding. That was because the cyclone moved much slower than expected," he said.

"The recent cyclones and intensive storms in Queensland and elsewhere in Australia should not be seen as isolated freak events but part of a global pattern that was quite clear in 2023.

"In 2023, we saw cyclones behave in unexpected and deadly ways. The longest-lived cyclone ever recorded battered southeastern Africa for weeks.

"Warmer sea temperatures fuelled those freak behaviours, and we can expect to see more of these extreme events going forward."

Professor van Dijk said the last two decades have seen increased air temperatures and declining air humidity, causing increased heat stress and water requirements for people, crops and ecosystems, while intensifying droughts.

Relative air humidity over the global land surface in 2023 was the second driest on record after 2021, continuing a trend towards drier and more extreme conditions.

2023 was Earth's hottest year on record, showing what a typical future year with 1.5 degrees warming may look like.

"A total of 77 countries experienced the highest average annual temperature in at least 45 years," Professor van Dijk said.

Professor van Dijk said 2023 was a year of extremes, with increasing extreme dry and wet conditions and more unprecedented weather events.

This is in line with ongoing changes in the water cycle over the last two decades.

"The events of 2023 show how ongoing climate change is threatening our planet and lives more with every passing year," he said.

"Globally, we're seeing an increase in the frequency and intensity of rainfall events and river flooding. But at the same time, there are also more frequent and faster developing droughts, or 'flash droughts'.

"That can cause crop failure and destructive wildfires in a matter of weeks or months. With the global food challenge, biodiversity crisis and an extremely urgent need to reduce carbon emissions, these droughts and wildfires are among our greatest global threats."

The research team used data from thousands of ground stations and satellites orbiting the Earth to provide real-time information on rainfall, air temperature, air humidity, soil and groundwater conditions, vegetation, river flows, flooding, and lake volumes.

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Oldest known fossilized skin is 21 million years older than previous examples

Researchers have identified a 3D fragment of fossilized skin that is at least 21 million years than previously described skin fossils. The skin, which belonged to an early species of Paleozoic reptile, has a pebbled surface and most closely resembles crocodile skin. It's the oldest example of preserved epidermis, the outermost layer of skin in terrestrial reptiles, birds, and mammals, which was an important evolutionary adaptation in the transition to life on land. The fossil is described on January 11 in the journal Current Biology along with several other specimens that were collected from the Richards Spur limestone cave system in Oklahoma.

"Every now and then we get an exceptional opportunity to glimpse back into deep time," says first author Ethan Mooney, a paleontology graduate student at the University of Toronto who worked on the project as an undergraduate with paleontologist Robert Reisz at the University of Toronto.

"These types of discoveries can really enrich our understanding and perception of these pioneering animals."

Skin and other soft tissues are rarely fossilized, but the researchers think that skin preservation was possible in this case because of the cave system's unique features, which included fine clay sediments that slowed decomposition, oil seepage, and a cave environment that was likely an oxygenless environment.

"Animals would have fallen into this cave system during the early Permian and been buried in very fine clay sediments that delayed the decay process," says Mooney.

"But the kicker is that this cave system was also an active oil seepage site during the Permian, and interactions between hydrocarbons in petroleum and tar are likely what allowed this skin to be preserved."

The skin fossil is tiny -- smaller than a fingernail. Microscopic examination undertaken by coauthor Tea Maho of the University of Toronto Mississauga revealed epidermal tissues, a hallmark of the skin of amniotes, the terrestrial vertebrate group that includes reptiles, birds, and mammals and which evolved from amphibian ancestors during the Carboniferous Period.

"We were totally shocked by what we saw because it's completely unlike anything we would have expected," says Mooney.

"Finding such an old skin fossil is an exceptional opportunity to peer into the past and see what the skin of some of these earliest animals may have looked like."

The skin shares features with ancient and extant reptiles, including a pebbled surface similar to crocodile skin, and hinged regions between epidermal scales that resemble skin structures in snakes and worm lizards.

However, because the skin fossil is not associated with a skeleton or any other remains, it is not possible to identify what species of animal or body region the skin belonged to.

The fact that this ancient skin resembles the skin of reptiles alive today shows how important these structures are for survival in terrestrial environments.

"The epidermis was a critical feature for vertebrate survival on land," says Mooney.

"It's a crucial barrier between the internal body processes and the harsh outer environment."

The researchers say that this skin may represent the ancestral skin structure for terrestrial vertebrates in early amniotes that allowed for the eventual evolution of bird feathers and mammalian hair follicles.

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Researchers discover potential microbiome links to skin aging

The effects of aging and external factors like UV exposure on skin are well documented. As people age or spend more time in the sun, their skin tends to become drier and more wrinkled,

Recent findings have identified an exciting potential new link to signs of skin aging -- the skin microbiome, the collection of microorganisms that inhabits our skin. The results come from a collaborative study carried out by researchers at the Center for Microbiome Innovation (CMI) at the University of California San Diego (UC San Diego) and L'Oréal Research and Innovation.

Their work was published in Frontiers in Aging on January 11, 2024, in an article entitled "A multi-study analysis enables identification of potential microbial features associated with skin aging signs." To the best of the team's knowledge, the study is the first to isolate microbes associated specifically with signs of skin aging and skin health, rather than chronological age.

Combining CMI's sophisticated data analysis abilities with L'Oréal's knowledge and expertise in skin health assessment, the study comprehensively examined data collected during 13 studies that L'Oréal had carried out in the past, consisting of 16S rRNA amplicon sequence data and corresponding skin clinical data for over 650 female participants, aged 18 -- 70. While each of the studies included in the analysis had focused on one particular area of interest -- for example, crow's feet wrinkles or moisture loss -- this multi-study analysis collated the data to search for trends related to specific microbes while accounting for other variables, such as age.

"Previous studies have shown that the types of microbes on our skin change fairly predictably with age," said corresponding author Se Jin Song, the CMI Director of Research. "Our skin also changes physiologically with age; for example, we gain wrinkles and our skin gets drier. But there is variation in what this looks like in people -- you've probably noticed that there are some people who have younger or older looking skin than many others their age. Using advanced statistical methods, we were able to tease apart the microbes that are associated with these types of aging signs for skin, like crow's feet wrinkles, from those that are associated with simply age as a chronological number."

Two notable trends emerged from the analysis. First, the team found a positive association between skin microbiome diversity and lateral cantonal lines (crow's feet wrinkles), which are generally viewed as one of the key signs of skin aging. Second, they observed a negative correlation between microbiome diversity and transepidermal water loss, which is the amount of moisture that evaporates through the skin. In further exploring the trends, the researchers identified several potential biomarkers that warrant investigation as microorganisms of interest. It would be premature to infer causation or actionable insights, but the study's results have provided researchers with directions on the next steps to hone in on better understanding microbial associations with skin aging.

"At L'Oréal, our commitment is to create beauty products that meet the unique needs of each individual. Our recent collaboration with the Center for Microbiome Innovation has shed light on the role of the skin microbiome in aging, particularly in how it affects wrinkles and overall skin quality," said co-author Qian Zheng, Head of Advanced Research, North America at L'Oréal. "This research is groundbreaking in identifying new microbial biomarkers linked to visible signs of aging like crow's feet wrinkles. It marks a significant step towards developing technologies for healthier, more youthful skin. We look forward to sharing new results as they become available, furthering the scientific community's understanding and contributing to advancing new skincare solutions."

Future paths of investigation the team has suggested include metabolomics work to discover chemical biomarkers related to skin aging, as well as meta-transcriptomics research into potential targets for genetic engineering. Research into other layers of the skin has also been considered, as many studies focus on the outer skin due to the ease of sample collection.

"While the study's findings represent an advance of our knowledge of the skin microbiome, we view them as just the beginning of a new phase of research," said co-author Rob Knight, the CMI Faculty Director and Professor of Pediatrics, Bioengineering, Computer Science & Engineering and Data Science at UC San Diego. "By confirming a link between the microbiome and skin health, we've laid the groundwork for further studies that discover specific microbiome biomarkers related to skin aging, and, one day, show how to modify them to generate novel and highly targeted recommendations for skin health."

Read more at Science Daily

Unlocking the secrets of a 'Hot Saturn' and its spotted star

Led by researchers from Université de Montréal's Trottier Institute for Research on Exoplanets (iREx), a team of astronomers has harnessed the power of the revolutionary James Webb Space Webb Telescope (JWST) to study the "hot Saturn" exoplanet HAT-P-18 b.

Their findings, published last month in the journal Monthly Notices of the Royal Astronomical Society, paint a complete picture of the HAT-P-18 b's atmosphere while exploring the great challenge of distinguishing its atmospheric signals from the activity of its star.

HAT-P-18 b is located over 500 light-years away with a mass similar to Saturn's but a size closer to that the larger planet Jupiter. As a result, the exoplanet has a "puffed-up" atmosphere that is especially ideal for analysis.

Passing over a spotted star

Observations from the JWST were taken while the HAT-P-18 b was passing in front of its Sun-like star. This moment is called a transit and is crucial to detect and further characterise an exoplanet from hundreds of light-years away with surprising precision.

Astronomers don't observe light that is being emitted directly by the distant planet. Rather, they study how the central star's light is being blocked and affected by the planet orbiting it, and so must try to disentangle signals caused by the presence of the planet from those caused by the star's own properties.

Just like our Sun, stars do not have uniform surfaces. They can have dark star spots and bright regions, which can create signals that mimic a planet's atmospheric attributes. A recent study of the exoplanet TRAPPIST-1 b and its star TRAPPIST-1 led by UdeM doctoral student Olivia Lim witnessed an eruption, or flare, on the surface of the star, which affected observations.

In the case of planet HAT-P-18 b, Webb caught the exoplanet right as it was passing over a dark spot on its star, HAT-P-18. This is called a spot-crossing event, and its effect was evident in the data collected for the new study. The iREx team also reported the presence of numerous other star spots on HAT-P-18's surface which were not blocked out by the exoplanet.

To accurately determine the exoplanet's atmospheric composition, the researchers had to simultaneously model the planet's atmosphere as well as its star's peculiarities. In their study, they point out that such consideration will be crucial in treating future exoplanet observations via the Webb to fully harness their potential.

"We found that accounting for stellar contamination implies the existence of spots and clouds instead of haze and recovers a water vapour abundance of almost an order of magnitude lower," said lead author Marylou Fournier-Tondreau.

"So considering the system's host star makes a big difference," added Fournier-Tondreau, who did the work as a master's student at iREx and is now pursuing a Ph.D. at the University of Oxford.

"It's actually the first time that we clearly disentangle the signature of hazes versus starspots, thanks to Canada's NIRISS (Near-Infrared Imager and Slitless Spectrograph) instrument, which provides wider wavelength coverage extending into the visible light domain."

H2O, CO2, and clouds in a scorching atmosphere

After modelling the exoplanet and the star in the HAT-P-18 system, the iREx astronomers performed a meticulous dissection of HAT-P-18 b's atmospheric composition. By inspecting the light that filters through the exoplanet's atmosphere as it transits its host star, the researchers discerned the presence of water vapour (H2O) and carbon dioxide (CO2).

The researchers also detected the possible presence of sodium and observed strong signs of a cloud deck in HAT-P-18 b's atmosphere, which appears to be muting the signals of many of the molecules found within it. They also concluded that the star's surface was covered by many dark spots that can significantly influence the interpretation of the data.

An earlier analysis of the same JWST data led by a team at Johns Hopkins University had also revealed a clear detection of water and CO2, but also reported the detection of small particles at high-altitudes called hazes and found hints of methane (CH4). The iREx astronomers paint a different picture.

The CH4 detection was not confirmed, and the water abundance they determined was 10 times lower than previously found. They also found that the previous study's detection of hazes could instead be caused by star spots on the star's surface, highlighting the importance of considering the star in the analysis.

Could the exoplanet support life? Not likely. While molecules like water, carbon dioxide, and methane can be interpreted as biosignatures, or signs of life, in certain ratios or in combination with other molecules, HAT-P-18 b's scorching temperatures of close to 600 degrees Celsius do not bode well for the planet's habitability.

Read more at Science Daily

Protecting coral 'nurseries' as important as safeguarding established coral reefs

When imagining corals, the picture that comes to mind is usually a stationary one: a garden of rock-like structures covering sections of the ocean floor.

Reef conservation efforts typically focus on preserving established coral and protecting them from known stressors such as pollution, overfishing and runoff from coastline populations.

However, new research near Miloliʻi in the southwestern part of the island of Hawaii, shows that identifying and protecting marine ecosystems both down-current and up-current of coral reefs, specifically areas where coral larvae are more likely to survive and thrive, is crucial to future coral conservation and restoration efforts -- especially as reefs face increasing pressure from the devastating effects of climate change.

The research, completed by Arizona State University scientists and their collaborators, appears in the current issue of Proceedings of the National Academy of Sciences.

Rachel Carlson, an ASU affiliate scientist and the study's first author, along with Greg Asner, director of ASU's Center for Global Discovery and Conservation Science, Larry Crowder, professor of oceans at Stanford University, and Robin Martin, associate professor with the ASU School of Ocean Futures in the Julie Ann Wrigley Global Futures Laboratory, collaborated on the project.

Additionally, the ʻĀkoʻakoʻa Reef Restoration Program, a regional effort that fuses cultural leadership, multi-modal education, advanced science and government engagement, backed the research.

Carlson says this type of collaborative work -- partnerships combining local, Indigenous knowledge and Western science -- is crucial to mapping out a future that ensures the survival of coral populations.

"There's a lot of Indigenous knowledge about coral spawning and fish populations in West Hawaii. In this study, we addressed an open question: How connected are coral populations between embayments along this coastline?" Carlson said. "What we essentially found is that the major factors in helping the coral keiki, known as larvae, settle down and survive are the nearshore current and the structure of the reef."

The study shows that the larvae more often settle in and inhabit areas with large boulders and uneven surfaces, or "chunky features," said Carlson, who is also a Chancellor's Postdoctoral Fellow at the UC Davis Bodega Marine Lab. Adult coral will spawn millions of larvae into the water column and those larvae prefer to settle in places with large knolls and boulders.

This discovery is good news: These kinds of seafloor features have been mapped via ASU's Global Airborne Observatory, a highly specialized aircraft that uses several types of remote sensing technologies to track both underwater and land-based habitats. This means that the researchers have the capability to help find and map priority reefs for conservation and restoration.

"This is foundational research in several important ways," said Asner, the study's senior author. "First, it gives us an understanding of the connectivity of different parts of reefs along our coastline and tells us the level of connectivity in the context of the birth, settlement and growth of corals miles apart. Second, our unique remote sensing capabilities can identify reef sites where coral restoration could be most viable in the future. Finally, these findings provide a critical building block for future restoration efforts by our ʻĀkoʻakoʻa team and collaborators."

The group's goal is to preserve and restore vitality to Hawaii's coral reefs and coastline health.

"We as lineal descendants of the Miloliʻi area have always relied on the reef for our ʻOhana (families). Our reef is our sustenance and is of enormous cultural value to us," said Kaʻimi Kaupiko, president of the nonprofit organization Kalanihale, which manages the Miloliʻi Community-Based Subsistence Fishing Area where the study took place.

Asner said the intertwined nature of reefs along Hawaii's coastlines is crucial to consider in reef protection strategies. Narrowing in on one area without consideration for the reproductive corridors of corals, he said, would be akin to worrying about planting trees in a certain place and not thinking about the forest as a whole. This sentiment is echoed by Martin, who said reef connectivity is an underutilized tool in reef restoration efforts globally.

"In Hawaii and worldwide, we're trying to figure out where we should place protections and restore areas to help reefs," Martin said. "This study is highly technical, but it needs to be part of that conversation and part of that work, because if you aren't protecting the upcurrent reefs, you are cutting off important reproductive areas."

Martin said reef restoration could, for example, expand a protected area of reefs beyond just the spots that have more dense coral coverage on the ocean floor; protection efforts would also be needed in the upcurrent path that the coral larvae traveled through before they settled in a new location.

Asner adds that this research could very well help conservation efforts expand to much greater distances than have been achieved previously.

"These kinds of studies of connectivity, flow and movement are needed because the west Hawaii island coastline is longer than the whole circumference of any other island," Asner said. "We have a lot of degraded reefs along our coastline, so knowing where and how to help baby corals thrive is fundamental to the ʻĀkoʻakoʻa restoration effort."

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How did the bushpig cross the strait? A great puzzle in African mammal biogeography solved by genomics

Africa has a huge diversity of large mammals, but their evolutionary relationships and movement across the continent over time often remain a mystery. A new scientific study sheds light on longstanding questions about the interplay between evolution and geography in one of these mammals, namely the iconic African bushpig, and helps settle a major question regarding prehistoric human activities shaping biodiversity patterns in Africa.

In the ongoing biodiversity crisis, large terrestrial animals are more threatened by extinction than any other group of organisms. The African continent holds an impressively intact large-mammal community, but there is still a lot we do not know about how these species evolved, became diverse and adapted to the changing climate and habitats. Many of these questions can be addressed by investigating the genomes and genetic variation across species.

New research, published in Nature Communications, uses genomics to answer these evolutionary questions that have been debated amongst scientists for decades: 1) how and when did bushpigs cross the Mozambique Channel and arrive at the island of Madagascar, 2) is there one or two species of bushpigs?

"This study is a result of a large international collaboration with researchers from Africa and Europe. We sequenced 67 complete bushpig genomes and by using a range of different genetic analyses, we were able to address these long-standing puzzles in African evolution and biogeography," explains one of the senior authors of the study, Associate Professor at the Department of Biology, Rasmus Heller.

Were pigs ferried across the channel during the Medieval era?

The island of Madagascar separated from the African mainland around 160 million years ago, resulting in a largely unique flora and fauna. Remarkably, the bushpig is the only large, wild terrestrial mammal species that has somehow historically crossed the 400-kilometer-wide Mozambique Channel and made it from mainland Africa to the island of Madagascar.

"Our study establishes that the bushpig was introduced to Madagascar ≈1,000-5,000 years ago from South/South-East Africa," Rasmus states. Their arrival therefore coincides with the arrival of humans to Madagascar from a region around southern Africa. Rasmus continues: "The likely explanation for this is that people transported these bushpigs across the channel. These results contradict previously published studies which dated the arrival of bushpigs ≈480,000 years ago, well before humans were present on the island." It has been suggested that some endemic Madagascar species might have arrived by rafting as passengers on floats of vegetation.

"Intriguingly, our results raise a host of new questions: was the bushpig actually brought to Madagascar as a somewhat domesticated species? There is no archaeological or other evidence of bushpig domestication ever occurring, despite them being an important source of protein for many rural communities. And who was it that transported these animals to Madagascar? Was it Bantu-speakers, Austronesian-speakers or both? These questions and others still remain to be explored," explains Renzo F. Balboa, postdoc at the Department of Biology and one of the leading authors of the study.

Does two actually equal one?

African bushpigs, which primarily are found in East/Southern Africa, and red river hogs, which are found in West/Central Africa, were considered the same species in the past, but were subsequently redefined as two species around the 1990s, largely due to their quite distinctive looks.

The red river hogs are, as the name implies red, and have long, tufted ears reminiscent of a comical Star Wars character, while eastern and southern African bushpigs are greyish and look more like our own wild boar, although with a beautiful white mane thrown in for good measure.

Biologists have been arguing for decades about whether these two forms are actually one or two different species -- a debate that is characteristic of similar scientific uncertainty surrounding many other African mammals.

"In this study, we were able to conclude that red river hogs and bushpigs have had lots of gene flow, which means they are not only able to potentially interbreed, but they have in fact done so extensively when they have met in central Africa. Furthermore, the branching of the two types in the Tree of Life is not all that old, only a few hundred thousand years, which is not long in the evolutionary scheme of things. Hence, we now know that although there are two quite different-looking lineages of bushpigs, their biological separation is incomplete, depending on how you define species," explains Laura D. Bertola, postdoc at the Department of Biology and the other leading author of the study.

Laura continues: "Genomic data can give us insights into patterns of biodiversity on a much higher resolution than previously possible. For example, we can infer detailed population structure, but also underlying processes like gene flow and selection. Gaining improved insights into patterns of biodiversity and the underlying processes that drive them, will be crucial for effective conservation measures."

Africa is a unique continent regarding the diversity of the megafauna which is still around. Studying the evolutionary history of these species can give us important insights into African biodiversity, which is highly relevant at a time where biodiversity is being lost at an alarming pace. The new findings contribute to our understanding of prehistoric relations between Africa's humans and wildlife, but also the very fundamentals about how much biodiversity there is on this amazing continent.

"This study is a great example of how involving local researchers and wildlife management authorities can lead to more robust and inclusive scientific research," co-author Vincent Muwanika, Associate Professor of Conservation Biology, at Makerere University, Uganda, concludes.

Read more at Science Daily

Stranger than friction: A force initiating life

As the potter works the spinning wheel, the friction between their hands and the soft clay helps them shape it into all kinds of forms and creations. In a fascinating parallel, sea squirt oocytes (immature egg cells) harness friction within various compartments in their interior to undergo developmental changes after conception. A study from the Heisenberg group at the Institute of Science and Technology Austria (ISTA), published in Nature Physics, now describes how this works.

The sea is full of fascinating life forms. From algae and colorful fish to marine snails and sea squirts, a completely different world reveals itself underwater.

Sea squirts or ascidians in particular are very unusual: after a free-moving larvae stage, the larva settles down, attaches to solid surfaces like rocks or corals, and develops tubes (siphons), their defining feature.

Although they look like rubbery blobs as adults, they are the most closely related invertebrate relatives to humans.

Especially at the larval stages, sea squirts are surprisingly similar to us.

Therefore, ascidians are often used as model organisms to study the early embryonic development of vertebrates to which humans belong.

"While ascidians exhibit the basic developmental and morphological features of vertebrates, they also have the cellular and genomic simplicity typical of invertebrates," explains Carl-Philipp Heisenberg, Professor at the Institute of Science and Technology Austria (ISTA). "Especially the ascidian larva is an ideal model for understanding early vertebrate development."

His research group's latest work, published in Nature Physics, now gives new insights into their development.

The findings suggest that upon fertilization of ascidian oocytes, friction forces play a crucial role in reshaping and reorganizing their insides, heralding the next steps in their developmental cascade.

Decoding oocyte transformation

Oocytes are female germ cells involved in reproduction. After successful fertilization with male sperm, animal oocytes typically undergo cytoplasmic reorganization, altering their cellular contents and components.

This process establishes the blueprint for the embryo's subsequent development.

In ascidians, for instance, this reshuffling leads to the formation of a bell-like protrusion -- a little bump or nose shape -- known as the contraction pole (CP), where essential materials gather that facilitate the embryo's maturation.

The underlying mechanism driving this process, however, has been unknown.

A group of scientists from ISTA, Université de Paris Cité, CNRS, King's College London, and Sorbonne Université set out to decipher that mystery.

For this endeavor, the Heisenberg group imported adult ascidians from the Roscoff Marine Station in France.

Almost all sea squirts are hermaphrodites, as they produce both male and female germ cells.

"In the lab, we keep them in saltwater tanks in a species-appropriate manner to obtain eggs and sperm for studying their early embryonic development," says Silvia Caballero-Mancebo, the first author of this study and previous PhD student in the Heisenberg lab.

The scientists microscopically analyzed fertilized ascidian oocytes and realized that they were following very reproducible changes in cell shape leading up to the formation of the contraction pole.

The researchers' first investigation focused on the actomyosin (cell) cortex -- a dynamic structure found beneath the cell membrane in animal cells.

Composed of actin filaments and motor proteins, it generally acts as a driver for shape changes in cells.

"We uncovered that when cells are fertilized, increased tension in the actomyosin cortex causes it to contract, leading to its movement (flow), resulting in the initial changes of the cell's shape," Caballero-Mancebo continues.

The actomyosin flows, however, stopped during the expansion of the contraction pole, suggesting that there are additional players responsible for the bump.

Friction forces impact cell reshaping

The scientists took a closer look at other cellular components that might play a role in the expansion of the contraction pole.

In doing so, they came across the myoplasm, a layer composed of intracellular organelles and molecules (related forms of which are found in many vertebrate and invertebrate eggs), positioned in the lower region of the ascidian egg cell.

"This specific layer behaves like a stretchy solid -- it changes its shape along with the oocyte during fertilization," Caballero-Mancebo explains.

During the actomyosin cortex flow, the myoplasm folds and forms many buckles due to the friction forces established between the two components.

As actomyosin movement stops, the friction forces also disappear.

"This cessation eventually leads to the expansion of the contraction pole as the multiple myoplasm buckles resolve into the well-defined bell-like-shaped bump," Caballero-Mancebo adds.

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Final supernova results from Dark Energy Survey offer unique insights into the expansion of the universe

In 1998, astrophysicists discovered that the universe is expanding at an accelerating rate, attributed to a mysterious entity called dark energy that makes up about 70% of our universe. While foreshadowed by earlier measurements, the discovery was somewhat of a surprise; at the time, astrophysicists agreed that the universe's expansion should be slowing down because of gravity.

This revolutionary discovery, which astrophysicists achieved with observations of specific kinds of exploding stars, called type Ia (read "type one-A") supernovae, was recognized with the Nobel Prize in Physics in 2011.

Now, 25 years after the initial discovery, the scientists working on the Dark Energy Survey have released the results of an unprecedented analysis using the same technique to further probe the mysteries of dark energy and the expansion of the universe. They placed the strongest constraints on the expansion of the universe ever obtained with the DES supernova survey.

In a presentation at the 243rd meeting of the American Astronomical Society on Jan. 8 and in a paper submitted to the Astrophysical Journal in January titled, "The Dark Energy Survey: Cosmology results with ~1500 new high-redshift type Ia supernovae using the full 5-year dataset," DES astrophysicists report results that are consistent with the now-standard cosmological model of a universe with an accelerated expansion. Yet, the findings are not definitive enough to rule out a possibly more complex model.

Taking a unique approach to analysis

The Dark Energy Survey is an international collaboration comprising more than 400 astrophysicists, astronomers and cosmologists from over 25 institutions led by members from the U.S. Department of Energy's Fermi National Accelerator Laboratory. DES mapped an area almost one-eighth the entire sky using the Dark Energy Camera, a 570-megapixel digital camera built by Fermilab and funded by the DOE Office of Science. It was mounted on the Víctor M. Blanco Telescope at the National Science Foundation's Cerro Tololo Inter-American Observatory, a Program of NSF's NOIRLab in 2012. DES scientists took data for 758 nights across six years.

To understand the nature of dark energy and measure the expansion rate of the universe, DES scientists perform analyses with four different techniques, including the supernova technique used in 1998.

This technique requires data from type Ia supernovae, which occur when an extremely dense dead star, known as a white dwarf, reaches a critical mass and explodes. Since the critical mass is nearly the same for all white dwarfs, all type Ia supernovae have approximately the same actual brightness and any remaining variations can be calibrated out. So, when astrophysicists compare the apparent brightnesses of two type Ia supernovae as seen from Earth, they can determine their relative distances from us.

Astrophysicists trace out the history of cosmic expansion with large samples of supernovae spanning a wide range of distances. For each supernova, they combine its distance with a measurement of its redshift -- how quickly it is moving away from Earth due to the expansion of the universe. They can use that history to determine whether the dark energy density has remained constant or changed over time.

"As the universe expands, the matter density goes down," said DES director and spokesperson Rich Kron, who is a Fermilab and University of Chicago scientist. "But if the dark energy density is a constant, that means the total proportion of dark energy must be increasing as the volume increases."

The culmination of a decade of effort

The standard cosmological model is ΛCDM, or Lambda Cold Dark Matter, or Lambda Cold Dark Matter, a model based on the dark energy density being constant over cosmic time. It tells us how the universe evolves, using just a few features, such as the density of matter, type of matter and behavior of dark energy. The supernova method constrains two of these features very well: matter density and a quantity called w, which indicates whether the dark energy density is constant or not.

According to the standard cosmological model, the density of dark energy in the universe is constant, which means it doesn't dilute as the universe expands. If this is true, the parameter represented by the letter w should equal -1.

When the DES collaboration internally unveiled their supernova results, it was a culmination of a decade's worth of effort and an emotional time for many of the astrophysicists involved. "I was shaking," said Tamara Davis, a professor at the University of Queensland in Australia and co-convener of DES's supernova working group. "It was definitely an exciting moment."

The results found w = -0.80 +/- 0.18 using supernovae alone. Combined with complementary data from the European Space Agency's Planck telescope, w reaches -1 within the error bars. "w is tantalizingly not exactly on -1, but close enough that it's consistent with -1," said Davis. "A more complex model might be needed. Dark energy may indeed vary with time."

To come to a definitive conclusion, scientists will need more data. But DES won't be able to provide that; the survey stopped taking data in January 2019. The supernova team, led by many Ph.D. students and postdoctoral fellows, will soon have extracted all they can from the DES observations.

"More than 30 people have been involved in this analysis, and it is the culmination of almost 10 years of work," said Maria Vincenzi, a research fellow at Duke University who co-led the cosmological analysis of the DES supernova sample. "Some of us started working on this project when we were barely at the beginning of our Ph.D., and we are now starting faculty positions. So, the DES Collaboration contributed to the growth and professional development of an entire generation of cosmologists."

Pioneering a new approach

This final DES supernova analysis made many improvements upon DES's first supernova result released in 2018 that used just 207 supernovae and three years of data.

For the 2018 analysis, DES scientists combined data about the spectrum of each supernova to determine their redshifts and to classify them as type Ia or not. They then used images taken with different filters to identify the flux at the peak of the light curve -- a method called photometry. But spectra are hard to acquire, requiring lots of observing time on the largest telescopes, which will be impractical for future dark energy surveys like the Legacy Survey of Space and Time, LSST, to be conducted at the Vera C. Rubin Observatory, operated jointly by NSF's NOIRLab and DOE's SLAC National Accelerator Laboratory.

The new study pioneers a new approach to use photometry -- with an unprecedented four filters -- to find the supernovae, classify them and measure their light curves. Follow-up spectroscopy of the host galaxy with the Anglo-Australian Telescope provided precise redshifts for every supernova. The use of the additional filters also enabled data that is more precise than previous surveys and is a major advancement compared to the Nobel-winning supernovae samples, which only used one or two filters.

DES researchers used advanced machine-learning techniques to aid in supernova classification. Among the data from about two million distant observed galaxies, DES found several thousand supernovae. Scientists ultimately used 1,499 type Ia supernovae with high-quality data, making it the largest, deepest supernova sample from a single telescope ever compiled. In 1998, the Nobel-winning astronomers used just 52 supernovae to determine that the universe is expanding at an accelerating rate. "It's a really massive scale-up from 25 years ago," said Davis.

There are minor drawbacks of the new photometric approach compared to spectroscopy: Since the supernovae do not have spectra, there is greater uncertainty in classification. However, the much larger sample size enabled by the photometric approach more than makes up for this.

The innovative techniques DES pioneered will shape and further drive future astrophysical analyses. Projects like Rubin's LSST and NASA's Nancy Grace Roman Space Telescope will pick up where DES left off. "We're pioneering these techniques that will be directly beneficial for the next generation of supernova surveys," said Kron.

"This new supernova result is exciting because this means we can really tie a bow on it and hand it out to the community and say, 'This is our best attempt at explaining how the universe is working,'" said Dillon Brout, an assistant professor at Boston University who co-led the cosmological analysis of the DES Supernova sample with Vincenzi. "These constraints will now be the gold standard in supernova cosmology for quite some time."

Even with more advanced dark energy experiments forthcoming, DES scientists emphasized the importance of having theoretical models to explain dark energy in addition to their experimental observations. "All of this is really unknown territory," said Kron. "We do not have a theory that puts dark energy into a framework that relates to other physics that we do understand. For the time being, we in DES are working to constrain how dark energy works in practice with the expectation that, later on, some theories can be falsified."

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Global study of extreme drought impacts on grasslands and shrublands

A global study organized and led by Colorado State University scientists shows that the effects of extreme drought -- which is expected to increase in frequency with climate change -- has been greatly underestimated for grasslands and shrublands.

The findings -- published in Proceedings of the National Academy of Sciences -- quantify the impact of extreme short-term drought on grassland and shrubland ecosystems across six continents with a level of detail that was not previously possible.

It is the first time an experiment this extensive has been undertaken to generate a baseline understanding of the potential losses of plant productivity in these vital ecosystems.

Melinda Smith, a professor in the Department of Biology at CSU, led the study and is the first author on the paper.

She said the observed reduction in a key carbon cycle process after a single 1-in-100-year drought event greatly exceeds previously reported losses for grasslands and shrublands.

"We were able to determine that the loss of aboveground plant growth -- a key measure of ecosystem function -- was 60% greater when short-term drought was extreme compared to the less severe droughts that have been more commonly experienced historically," she said.

"Past studies suffered from methodological differences when estimating the impacts of extreme drought in natural ecosystems, but our standardized, distributed approach here addressed that problem."

Smith added that the project also showcases the variability in drought response across grassland and shrubland ecosystems -- offering both a review of the global impacts of climate change as well as a glimpse into which areas will be most stressed or most resilient in the coming years.

Gathering global extreme drought data on grassland and shrubland ecosystems Known as the International Drought Experiment, the newly published research originally dates back to 2013 as part of the National Science Foundation's Drought-Net Research Coordination Network.

Altogether, there are more than 170 authors representing institutions from around the world cited in the new PNAS study, which was completed over the last four years.

To gather their data, researchers built rainfall manipulation structures to experimentally reduce the amount of naturally occurring precipitation available to ecosystems for at least a full growing season.

About half of the participating sites imposed extreme drought conditions with these structures, while the rest imposed less severe drought for comparison.

As Earth's climate continues to change, short-term droughts that are statistically extreme in intensity will become more common, with what were once considered 1-in-100-year droughts now potentially happening every two to five years, said Smith.

But because of the historic rarity of extreme droughts researchers had been unable to estimate the actual magnitude of their ecological consequences.

Smith said grasslands and shrublands were perfect test areas to fill that research gap because they are easier to manipulate for study than other systems, such as forests.

They also store more than 30% of the global stock of carbon and support key industries such as livestock production.

"They are key ecosystems that are scalable to the globe, which makes them highly relevant for this kind of work," said Smith, who also serves as chair of the Faculty Council on campus.

"Grasslands and shrublands cover between 30% and 40% of the globe and frequently see deficits in precipitation. That means they are more vulnerable to climate change."

Findings from the sites also provide insight into how specific climates, soil and vegetation types broadly influence drought response.

While the work shows that drier and less diverse sites like those in Colorado are likely to be the most vulnerable to extremes, Smith said the severity of the drought was the most consistent and important factor in determining an ecosystem's response.

"Our data suggests greater losses in drier sites, but if you are getting to the extremes -- which is what is being forecasted -- we can generally expect substantial losses no matter where you are in the world," she said.

"We also found that even moderate losses from less severe droughts would still likely result in large impacts to the populations that rely on these systems. And then there is a combined loss of function across the globe to consider as well."

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Bottled water can contain hundreds of thousands of previously uncounted tiny plastic bits

In recent years, there has been rising concern that tiny particles known as microplastics are showing up basically everywhere on Earth, from polar ice to soil, drinking water and food. Formed when plastics break down into progressively smaller bits, these particles are being consumed by humans and other creatures, with unknown potential health and ecosystem effects. One big focus of research: bottled water, which has been shown to contain tens of thousands of identifiable fragments in each container.

Now, using newly refined technology, researchers have entered a whole new plastic world: the poorly known realm of nanoplastics, the spawn of microplastics that have broken down even further. For the first time, they counted and identified these minute particles in bottled water. They found that on average, a liter contained some 240,000 detectable plastic fragments -- 10 to 100 times greater than previous estimates, which were based mainly on larger sizes.

The study was just published in the journal Proceedings of the National Academy of Sciences.

Nanoplastics are so tiny that, unlike microplastics, they can pass through intestines and lungs directly into the bloodstream and travel from there to organs including the heart and brain. They can invade individual cells, and cross through the placenta to the bodies of unborn babies. Medical scientists are racing to study the possible effects on a wide variety of biological systems.

"Previously this was just a dark area, uncharted. Toxicity studies were just guessing what's in there," said study coauthor Beizhan Yan, an environmental chemist at Columbia University's Lamont-Doherty Earth Observatory. "This opens a window where we can look into a world that was not exposed to us before."

Worldwide plastic production is approaching 400 million metric tons a year. More than 30 million tons are dumped yearly in water or on land, and many products made with plastics including synthetic textiles shed particles while still in use. Unlike natural organic matter, most plastics do not break down into relatively benign substances; they simply divide and redivide into smaller and smaller particles of the same chemical composition. Beyond single molecules, there is no theoretical limit to how small they can get.

Microplastics are defined as fragments ranging from 5 millimeters (less than a quarter inch) down to 1 micrometer, which is 1 millionth of a meter, or 1/25,000th of an inch. (A human hair is about 70 micrometers across.) Nanoplastics, which are particles below 1 micrometer, are measured in billionths of a meter.

Plastics in bottled water became a public issue largely after a 2018 study detected an average of 325 particles per liter; later studies multiplied that number many times over. Scientists suspected there were even more than they had yet counted, but good estimates stopped at sizes below 1 micrometer -- the boundary of the nano world.

"People developed methods to see nano particles, but they didn't know what they were looking at," said the new study's lead author, Naixin Qian, a Columbia graduate student in chemistry. She noted that previous studies could provide bulk estimates of nano mass, but for the most part could not count individual particles, nor identify which were plastics or something else.

The new study uses a technique called stimulated Raman scattering microscopy, which was co-invented by study coauthor Wei Min, a Columbia biophysicist. This involves probing samples with two simultaneous lasers that are tuned to make specific molecules resonate. Targeting seven common plastics, the researchers created a data-driven algorithm to interpret the results. "It is one thing to detect, but another to know what you are detecting," said Min.

The researchers tested three popular brands of bottled water sold in the United States (they declined to name which ones), analyzing plastic particles down to just 100 nanometers in size. They spotted 110,000 to 370,000 particles in each liter, 90% of which were nanoplastics; the rest were microplastics. They also determined which of the seven specific plastics they were, and charted their shapes -- qualities that could be valuable in biomedical research.

One common one was polyethylene terephthalate or PET. This was not surprising, since that is what many water bottles are made of. (It is also used for bottled sodas, sports drinks and products such as ketchup and mayonnaise.) It probably gets into the water as bits slough off when the bottle is squeezed or gets exposed to heat. One recent study suggests that many particles enter the water when you repeatedly open or close the cap, and tiny bits abrade.

However, PET was outnumbered by polyamide, a type of nylon. Ironically, said Beizhan Yan, that probably comes from plastic filters used to supposedly purify the water before it is bottled. Other common plastics the researchers found: polystyrene, polyvinyl chloride and polymethyl methacrylate, all used in various industrial processes.

A somewhat disturbing thought: the seven plastic types the researchers searched for accounted for only about 10% of all the nanoparticles they found in samples; they have no idea what the rest are. If they are all nanoplastics, that means they could number in the tens of millions per liter. But they could be almost anything, "indicating the complicated particle composition inside the seemingly simple water sample," the authors write. "The common existence of natural organic matter certainly requires prudent distinguishment."

The researchers are now reaching beyond bottled water. "There is a huge world of nanoplastics to be studied," said Min. He noted that by mass, nanoplastics comprise far less than microplastics, but "it's not size that matters. It's the numbers, because the smaller things are, the more easily they can get inside us."

Among other things, the team plans to look at tap water, which also has been shown to contain microplastics, though far less than bottled water. Beizhan Yan is running a project to study microplastics and nanoplastics that end up in wastewater when people do laundry -- by his count so far, millions per 10-pound load, coming off synthetic materials that comprise many items. (He and colleagues are designing filters to reduce the pollution from commercial and residential washing machines.) The team will soon identify particles in snow that British collaborators trekking by foot across western Antarctica are currently collecting. They also are collaborating with environmental health experts to measure nanoplastics in various human tissues and examine their developmental and neurologic effects.

"It is not totally unexpected to find so much of this stuff," said Qian. "The idea is that the smaller things get, the more of them there are."

Read more at Science Daily

Meteorite analysis shows Earth's building blocks contained water

When our Sun was a young star, 4.56 billion years ago, what is now our solar system was just a disk of rocky dust and gas. Over tens of millions of years, tiny pebbles of dust coalesced, like a snowball rolling larger and larger, to become kilometer-sized "planetesimals" -- the building blocks of Earth and the other inner planets.

Researchers have long tried to understand the ancient environments in which these planetesimals formed.

For example, water is now abundant on Earth, but has it always been?

In other words, did the planetesimals that accreted into our planet contain water?

Now, a new study combines meteorite data with thermodynamic modeling and determines that the earliest inner solar system planetesimals must have formed in the presence of water, challenging current astrophysical models of the early solar system.

The research was conducted in the laboratory of Paul Asimow (MS '93, PhD '97), Eleanor and John R. McMillan Professor of Geology and Geochemistry and appears in the journal Nature Astronomy on January 9.

Researchers have samples of the earliest years of the solar system in the form of iron meteorites.

These meteorites are the remnants of the metallic cores of the earliest planetesimals in our solar system that avoided accretion into a forming planet and instead orbited around the solar system before ultimately falling onto our planet.

The chemical compositions of meteorites such as these can reveal information about the environments in which they formed and answer questions such as whether the building blocks of Earth formed far from our Sun, where cooler temperatures allowed the existence of water ice, or if they instead formed closer to the Sun, where the heat would have evaporated any water and resulted in dry planetesimals.

If the latter is correct, then Earth would have formed dry and gained its water through some other method later in its evolution.

Though the meteorites themselves do not contain any water, scientists can infer its long-lost presence by examining its impact on other chemical elements.

Water is composed of two hydrogen atoms and one oxygen atom.

In the presence of other elements, water will often transfer its oxygen atom away in a process called oxidation.

For example, iron metal (Fe) reacts with water (H2O) to form iron oxide (FeO). A sufficient excess of water can drive the process further, producing Fe2O3 and FeO(OH), the ingredients of rust.

Mars, for example, is covered in rusty iron oxide, providing strong evidence that the Red Planet once had water.

Damanveer Grewal, a former Caltech postdoctoral scholar and first author of the new study, specializes in using chemical signatures from iron meteorites to gather information about the early solar system.

Though any iron oxide from the earliest planetesimals is now long gone, the team could determine how much iron would have been oxidized by examining the metallic nickel, cobalt, and iron contents of these meteorites.

These three elements should be present in roughly equal ratios relative to other primitive materials, so if any iron was "missing," this would imply that the iron had been oxidized.

"Iron meteorites have been somewhat neglected by the planet-formation community, but they constitute rich stores of information about the earliest period of solar system history, once you work out how to read the signals," says Asimow.

"The difference between what we measured in the inner solar system meteorites and what we expected implies an oxygen activity about 10,000 times higher."

The researchers found that those iron meteorites thought to be derived from the inner solar system had about the same amount of missing iron metal as meteorites derived from the outer solar system.

For this to be the case, the planetesimals from both groups of meteorites must have formed in a part of the solar system where water was present, implying that the building blocks of planets accreted water right from the beginning.

The signatures of water in these planetesimals challenge many of the current astrophysical models of the solar system.

If planetesimals formed at Earth's current orbital position, water would have existed only if the inner solar system was much cooler than models currently predict.

Alternatively, they may have formed further out, where it was cooler, and migrated in.

"If water was present in the early building blocks of our planet, other important elements like carbon and nitrogen were likely present as well," says Grewal.

"The ingredients for life may have been present in the seeds of rocky planets right from the start."

"However, the method only detects water that was used up in oxidizing iron," adds Asimow.

"It is not sensitive to excess water that might go on to form the ocean. So, the conclusions of this study are consistent with Earth accretion models that call for late addition of even more water-rich material."

Read more at Science Daily

Three iron rings in a planet-forming disk

The origin of Earth and the Solar System inspires scientists and the public alike. By studying the present state of our home planet and other objects in the Solar System, researchers have developed a detailed picture of the conditions when they evolved from a disk made of dust and gas surrounding the infant sun some 4.5 billion years ago.

Three rings hinting at two planets

With the breathtaking progress made in star and planet formation research aiming at far-away celestial objects, we can now investigate the conditions in environments around young stars and compare them to the ones derived for the early Solar System. Using the European Southern Observatory's (ESO) Very Large Telescope Interferometer (VLTI), an international team of researchers led by József Varga from the Konkoly Observatory in Budapest, Hungary, did just that. They observed the planet-forming disk of the young star HD 144432, approximately 500 light-years away.

"When studying the dust distribution in the disk's innermost region, we detected for the first time a complex structure in which dust piles up in three concentric rings in such an environment," says Roy van Boekel. He is a scientist at the Max Planck Institute for Astronomy (MPIA) in Heidelberg, Germany and a co-author of the underlying research article to appear in the journal Astronomy & Astrophysics. "That region corresponds to the zone where the rocky planets formed in the Solar System," van Boekel adds. Compared to the Solar System, the first ring around HD 144432 lies within Mercury's orbit, and the second is close to Mars's trajectory. Moreover, the third ring roughly corresponds to Jupiter's orbit.

Up to now, astronomers have found such configurations predominantly on larger scales corresponding to the realms beyond where Saturn circles the Sun. Ring systems in the disks around young stars generally point to planets forming within the gaps as they accumulate dust and gas on their way. However, HD 144432 is the first example of such a complex ring system so close to its host star. It occurs in a zone rich in dust, the building block of rocky planets like Earth. Assuming the rings indicate the presence of two planets forming within the gaps, the astronomers estimated their masses to resemble roughly that of Jupiter.

Conditions may be similar to the early Solar System

The astronomers determined the dust composition across the disk up to a separation from the central star that corresponds to the distance of Jupiter from the Sun. What they found is very familiar to scientists studying Earth and the rocky planets in the Solar System: various silicates (metal-silicon-oxygen compounds) and other minerals present in Earth's crust and mantle, and possibly metallic iron as is present in Mercury's and Earth's cores. If confirmed, this study would be the first to have discovered iron in a planet-forming disk.

"Astronomers have thus far explained the observations of dusty disks with a mixture of carbon and silicate dust, materials that we see almost everywhere in the Universe," van Boekel explains. However, from a chemical perspective an iron and silicate mixture is more plausible for the hot, inner disk regions. And indeed, the chemical model that Varga, the main author of the underlying research article, applied to the data yields better-fitting results when introducing iron instead of carbon.

Furthermore, the dust observed in the HD 144432 disk can be as hot as 1800 Kelvin (approx. 1500 degrees Celsius) at the inner edge and as moderate as 300 Kelvin (approx. 25 degrees Celsius) farther out. Minerals and iron melt and recondense, often as crystals, in the hot regions near the star. In turn, carbon grains would not survive the heat and instead be present as carbon monoxide or carbon dioxide gas. However, carbon may still be a significant constituent of the solid particles in the cold outer disk, which the observations carried out for this study cannot trace.

Iron-rich and carbon-poor dust would also fit nicely with the conditions in the Solar System. Mercury and Earth are iron-rich planets, while the Earth contains relatively little carbon. "We think that the HD 144432 disk may be very similar to the early Solar System that provided lots of iron to the rocky planets we know today," says van Boekel. "Our study may pose as another example showing that the composition of our Solar System may be quite typical."

Interferometry resolves tiny details

Retrieving the results was only possible with exceptionally high-resolution observations, as provided by the VLTI. By combining the four VLT 8.2-metre telescopes at ESO's Paranal Observatory, they can resolve details as if astronomers would employ a telescope with a primary mirror of 200 metres in diameter. Varga, van Boekel and their collaborators obtained data using three instruments to achieve a broad wavelength coverage ranging from 1.6 to 13 micrometres, representing infrared light.

MPIA provided vital technological elements to two devices, GRAVITY and the Multi AperTure mid-Infrared SpectroScopic Experiment (MATISSE). One of MATISSE's primary purposes is to investigate the rocky planet-forming zones of disks around young stars. "By looking at the inner regions of protoplanetary disks around stars, we aim to explore the origin of the various minerals contained in the disk -- minerals that later will form the solid components of planets like the Earth," says Thomas Henning, MPIA director and co-PI of the MATISSE instrument.

However, producing images with an interferometer like the ones we are used to obtaining from single telescopes is not straightforward and very time-consuming. A more efficient use of precious observing time to decipher the object structure is to compare the sparse data to models of potential target configurations. In the case of the HD 144432 disk, a three-ringed structure represents the data best.

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Evolution is not as random as previously thought

A groundbreaking study has found that evolution is not as unpredictable as previously thought, which could allow scientists to explore which genes could be useful to tackle real-world issues such as antibiotic resistance, disease and climate change.

The study, which is published in the Proceedings of the National Academy of Sciences (PNAS), challenges the long-standing belief about the unpredictability of evolution, and has found that the evolutionary trajectory of a genome may be influenced by its evolutionary history, rather than determined by numerous factors and historical accidents.

The study was led by Professor James McInerney and Dr. Alan Beavan from the School of Life Sciences at the University of Nottingham, and Dr. Maria Rosa Domingo-Sananes from Nottingham Trent University.

"The implications of this research are nothing short of revolutionary," said Professor McInerney, the lead author of the study.

"By demonstrating that evolution is not as random as we once thought, we've opened the door to an array of possibilities in synthetic biology, medicine, and environmental science."

The team carried out an analysis of the pangenome -- the complete set of genes within a given species, to answer a critical question of whether evolution is predictable or whether the evolutionary paths of genomes are dependent on their history and so not predictable today.

Using a machine learning approach known as Random Forest, along with a dataset of 2,500 complete genomes from a single bacterial species, the team carried out several hundred thousand hours of computer processing to address the question.

After feeding the data into their high-performance computer, the team first made "gene families" from each of the gene of each genome.

"In this way, we could compare like-with-like across the genomes," said Dr. Domingo-Sananes.

Once the families had been identified, the team analysed the pattern of how these families were present in some genomes and absent in others.

"We found that some gene families never turned up in a genome when a particular other gene family was already there, and on other occasions, some genes were very much dependent on a different gene family being present."

In effect, the researchers discovered an invisible ecosystem where genes can cooperate or can be in conflict with one another.

"These interactions between genes make aspects of evolution somewhat predictable and furthermore, we now have a tool that allows us to make those predictions," adds Dr. Domingo-Sananes.

Dr Beavan said: "From this work, we can begin to explore which genes "support" an antibiotic resistance gene, for example. Therefore, if we are trying to eliminate antibiotic resistance, we can target not just the focal gene, but we can also target its supporting genes.

"We can use this approach to synthesise new kinds of genetic constructs that could be used to develop new drugs or vaccines. Knowing what we now know has opened the door to a whole host of other discoveries."

Read more at Science Daily

Building on CO2

The construction industry as a CO2 sink? Researchers at Empa's Concrete & Asphalt lab are working on this. By incorporating biochar into concrete, they are exploring the potential of CO2-neutral or even CO2-negative concrete. For optimal applicability, they process the biochar into pellets and use them to replace conventional aggregates.

To achieve the goal of a climate-neutral Switzerland by 2050, strategies and processes with a negative CO2 balance are necessary.

These so-called negative emission technologies (NET) are intended to counterbalane the remaining "hard-to-avoid" emissions in 2050 and should help ensure that we eventually achieve net zero.

As one of the main emitters, the construction sector has a particular obligation.

Around eight percent of global greenhouse gas emissions are caused by cement production.

At the same time, initial efforts are emerging to use the construction sector, with its massive consumption of resources, as a possible carbon sink.

What sounds paradoxical will succeed if we start "building with CO2" -- or rather, using carbon to produce building materials and thus removing it from the atmosphere in the long term.

For such visions to become reality, a great deal of research is needed -- such as is currently being done at Empa's Concrete & Asphalt lab.

A team led by Pietro Lura is developing a process for integrating biochar into concrete.

Difficulties due to porosity

Biochar is produced by a pyrolytic carbonization process of biomass in the absence of oxygen and consists to a high extent of pure carbon -- the carbon that the plants have extracted from the atmosphere in the form of CO2 as they grow.

While CO2 is emitted when plants are burned, it remains bound in the biochar over the long term.

The first concrete products with integrated biochar are already on the market.

However, biochar is often introduced into the concrete untreated, which can lead to difficulties.

"Biochar is very porous and therefore not only absorbs a lot of water, but also expensive admixtures used in concrete production," explains Empa researcher Mateusz Wyrzykowski.

"Moreover, it is difficult to handle and not completely harmless either." The fine coal dust is problematic for the respiratory tract and carries a certain risk of explosion.

For these reasons, the researchers propose in a paper that has just published in the Journal of Cleaner Production processing the biochar into pellets.

"Such lightweight aggregates already exist from other materials such as expanded clay or fly ash. The knowhow in handling these materials is available in industry, and this increases the chances that the concept will be put into practice," says Wyrzykowski.

Net zero at 20 percent share

To produce the pellets, the team used a concrete mixer with a rotating pan in which they mixed the biochar with water and cement and, as a result of the rotation, obtained small pellets with a diameter of between 4 and 32 millimeters.

In turn, they used these pellets to produce normal concrete of strength classes C20/25 to C30/37 -- the classes that are most widely used in civil engineering today.

"With a proportion of 20 percent by volume of carbon pellets in the concrete, we achieve net zero emissions," says Mateusz Wyrzykowski.

That is, the amount of carbon stored offsets all the emissions produced in the production of both the pellets and the concrete.

While the limit has probably not yet been reached for normal concrete (density between 2,000 and 2,600 kg/m3) with 20 percent by volume, the negative emission potential is particularly striking for lightweight concrete (density approx.

1,800 kg/m3): An admixture of 45 percent by volume of carbon pellets in the concrete leads to total negative emissions of minus 290 kg CO2/m3. By comparison, conventional concrete emits around 200 kg CO2/m3.

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Could a drug prevent hearing loss from loud music and aging?

Researchers have found a gene that links deafness to cell death in the inner ear in humans -- creating new opportunities for averting hearing loss.

A person's hearing can be damaged by loud noise, aging and even certain medications, with little recourse beyond a hearing aid or cochlear implant.

But now, UCSF scientists have achieved a breakthrough in understanding what is happening in the inner ear during hearing loss, laying the groundwork for preventing deafness.

The research, published on Dec. 22, 2023, in the Journal of Clinical Investigation Insight, links animal studies on hearing loss with a rare type of inherited deafness in humans. In both cases, mutations to the TMTC4 gene trigger a molecular domino effect known as the unfolded protein response (UPR), leading to the death of hair cells in the inner ear.

Intriguingly, hearing loss from loud noise exposure or drugs such as cisplatin, a common form of chemotherapy, also stems from activation of the UPR in hair cells, suggesting that the UPR may underly several different forms of deafness.

There are several drugs that block the UPR -- and stop hearing loss -- in laboratory animals. The new findings make a stronger case for testing these drugs in people who are at risk of losing their hearing, according to the researchers.

"Millions of American adults lose their hearing due to noise exposure or aging each year, but it's been a mystery what was going wrong," said Dylan Chan, MD, PhD, co-senior author on the paper and director of the Children's Communication Center (CCC) in the UCSF Department of Otolaryngology. "We now have solid evidence that TMTC4 is a human deafness gene and that the UPR is a genuine target for preventing deafness."

How hair cells in the ear self-destruct

In 2014, Elliott Sherr, MD, PhD, director of the UCSF Brain Development Research Program and co-senior author of the paper, noticed that several of his young patients with brain malformations all had mutations to TMTC4. But laboratory studies of this gene soon presented a conundrum.

"We expected mice with TMTC4 mutations to have severe brain defects early on, like those pediatric patients, yet to our surprise, they seemed normal at first," Sherr said. "But as those animals grew, we saw that they didn't startle in response to loud noise. They had gone deaf after they had matured."

Sherr partnered with Chan, an expert on the inner ear, to look into what was happening to the mice, which looked like an accelerated version of age-related hearing loss in humans. They showed that mutations to TMTC4 primed hair cells in the ear to self-destruct, and loud noise did the same thing. In both cases, hair cells were flooded with excess calcium, throwing off the balance of other cellular signals, including the UPR.

But they found there was a way to stop this. ISRIB, a drug developed at UCSF to block the UPR's self-destruct mechanism in traumatic brain injury, prevented animals who were exposed to noise from going deaf.

The first adult human deafness gene

In 2020, scientists from South Korea, led by Bong Jik Kim, MD, PhD, connected Chan and Sherr's 2018 findings with genetic mutations they found in two siblings who were losing their hearing in their mid-20s. The mutations were in TMTC4 and matched what Chan and Sherr had seen in animals, although they were distinct from those in Sherr's pediatric neurology patients.

"It's rare to so quickly connect mouse studies with humans," Sherr said. "Thanks to our Korean collaborators, we could more easily prove the relevance of our work for the many people who go deaf over time."

Kim, an otolaryngologist at the Chungnam National University College of Medicine (Korea), facilitated the shipping of cells from those patients to UCSF. Sherr and Chan tested those cells for UPR activity and found that, indeed, this flavor of TMTC4 mutation turned on the destructive UPR pathway in a human context.

When Chan and Sherr mutated TMTC4 only in hair cells in mice, the mice went deaf. When they mutated TMTC4 in cells from individuals in the Korean family who hadn't gone deaf, and in laboratory human cell lines, the UPR drove the cells to self-destruct. TMTC4 was more than a deafness gene in mice -- it was a deafness gene in humans, too.

Translating a discovery to prevent deafness

Understanding TMTC4 mutations gives researchers a new way of studying progressive deafness, since it is critical for maintaining the health of the adult inner ear. The mutations mimic damage from noise, aging or drugs like cisplatin.

The researchers envision a future where people who must take cisplatin, or who have to be exposed to loud noises for their jobs, take a drug that dampens the UPR and keeps hair cells from withering away, preserving their hearing.

The science also suggests that the UPR could be targeted in other contexts where nerve cells become overwhelmed and die, including diseases long thought to be incurable, like Alzheimer's or Lou Gehrig's disease.

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Mysterious missing component in the clouds of Venus revealed

What are the clouds of Venus made of? Scientists know it's mainly made of sulfuric acid droplets, with some water, chlorine, and iron. Their concentrations vary with height in the thick and hostile Venusian atmosphere. But until now they have been unable to identify the missing component that would explain the clouds' patches and streaks, only visible in the UV range.

In a new study published in Science Advances, researchers from the University of Cambridge synthesised iron-bearing sulfate minerals that are stable under the harsh chemical conditions in the Venusian clouds.

Spectroscopic analysis revealed that a combination of two minerals, rhomboclase and acid ferric sulfate, can explain the mysterious UV absorption feature on our neighbouring planet.

"The only available data for the composition of the clouds were collected by probes and revealed strange properties of the clouds that so far we have been unable to fully explain," said Paul Rimmer from the Cavendish Laboratory and co-author of the study.

"In particular, when examined under UV light, the Venusian clouds featured a specific UV absorption pattern. What elements, compounds, or minerals are responsible for such observation?"

Formulated on the basis of Venusian atmospheric chemistry, the team synthesized several iron-bearing sulfate minerals in an aqueous geochemistry laboratory in the Department of Earth Sciences.

By suspending the synthesized materials in varying concentrations of sulfuric acid and monitor the chemical and mineralogical changes, the team narrowed down the candidate minerals to rhomboclase and acid ferric sulfate, of which the spectroscopic features were examined under light sources specifically designed to mimic the spectrum of solar flares (Paul Rimmer and Samantha Thompson's FlareLab at the Cavendish Laboratory).

A photochemistry lab at Harvard collaborated in the research by providing measurements of the UV absorbance patterns of ferric iron under extreme acidic conditions, in an attempt to mimic the even more extreme Venusian clouds.

The scientists are part of the newly established Origins Federation, which promotes such collaborative projects.

"The patterns and level of absorption shown by the combination of these two mineral phases are consistent with the dark UV-patches observed in Venusian clouds," said co-author Clancy Zhijian Jiang, from the Department of Earth Sciences, Cambridge.

"These targeted experiments revealed the intricate chemical network within the atmosphere, and shed light on the elemental cycling on the Venusian surface."

"Venus is our nearest neighbour, but it remains a mystery," said Rimmer.

"We will have a chance to learn much more about this planet in the coming years with future NASA and ESA missions set to explore its atmosphere, clouds and surface. This study prepares the grounds for these future explorations."

Read more at Science Daily

Arctic cold snap transforms into a blessing

A recent cold spell plunged the nation of Korea into a deep freeze, resulting in the closure of 247 national parks, the cancellation of 14 domestic flights, and the scrapping of 107 cruise ship voyages. While the cold snap brought relief by significantly reducing the prevalence of particulate matter obscuring our surroundings, a recent study indicates that, besides diminishing particulate matter, it is significantly contributing to the heightened uptake of carbon dioxide by the East Sea.

According to research conducted by a team of researchers including Professor Kitack Lee from the Division of Environmental Science & Engineering at Pohang University of Science and Technology (POSTECH), and Professor Tongsup Lee and So-Yun Kim from the Department of Oceanography at Pusan National University, the cold atmosphere in the Arctic is influencing the absorption of carbon dioxide by the East Sea.

The research findings were published in Geophysical Research Letters, an international journal by the American Geophysical Union (AGU).

The research team investigated the correlation between the East Sea's surface-deep circulation and its carbon dioxide absorption capacity, drawing insights from observations in 1992, 1999, 2007, and 2019.

During the initial period (1992-1999), the ocean absorbed 20 million tons of carbon dioxide annually.

In the subsequent period (1999-2007), this amount decreased to under 10 million tons per year.

However, in the final period (2007-2019), the carbon dioxide uptake surged to 30 million tons per year.

The team observed that the internal circulation along the East Coast within the East Sea was influenced by the Arctic cold wave.

Cold air from the Arctic infiltrates the East Sea, causing the surface water, laden with carbon dioxide, to become denser.

This process induces vertical ventilation as the water descends into the middle and deep ocean layers.

Consequently, the intensified descent of cold air from the Arctic strengthens the internal circulation, leading to a heightened uptake of carbon dioxide in the East Sea.

Professor Kitack Lee who led the research remarked, " The oceans represent an immense reservoir of carbon dioxide and offer a secure and sustainable avenue for mitigating atmospheric carbon dioxide levels." He further stated, "It is crucial to anticipate the global ocean's capacity for carbon removal as we navigate future climate changes and identify suitable methods to leverage this potential."

In a related development, the team's earlier research uncovered the mechanism through which the ocean absorbs carbon dioxide.

Approximately half of the carbon dioxide generated by human activities remains in the atmosphere with the other half entering marine and terrestrial ecosystems.

With a carbon content 400,000 times greater than that of the atmosphere, the oceans present vast and promising potential for storing carbon dioxide.

Read more at Science Daily

Protected areas for elephants work best if they are connected

Conservation measures have successfully stopped declines in the African savanna elephant population across southern Africa, but the pattern varies locally, according to a new study.

The evidence suggests that the long-term solution to elephant survival requires not only that areas are protected but that they are also connected to allow populations to stabilize naturally, an international research team says.

Their study, published on January 5th in the peer-reviewed journal Science Advances, collected survey estimates and calculated growth rates for more than 100 elephant populations in southern Africa between 1995 and 2020, accounting for an estimated 70% of the global savanna elephant population.

"This is the most comprehensive analysis of growth rates for any large mammal population in the world," said co-author Rob Guldemond, director of the Conservation Ecological Research Unit (CERU) at the University of Pretoria, in South Africa.

Overall, the survey's results are positive: There are the same number of elephants now as there were 25 years ago, a rare conservation win at a time when the planet is rapidly losing biodiversity.

However, the pattern is not consistent across regions. Some areas, such as south Tanzania, eastern Zambia, and northern Zimbabwe, experienced severe declines due to illegal ivory poaching.

In contrast, populations in other regions like north Botswana are booming.

"Unchecked growth isn't necessarily a good thing, however," says study co-author Stuart Pimm, the Doris Duke Professor of Conservation at Duke University in North Carolina.

"Rapidly increasing populations can outgrow and damage their local environment and prove hard to manage -- introducing a threat to their long-term stability," Pimm says.

In addition to documenting local growth rates, the team also looked at the features of the local populations to identify what makes them stable, that is neither growing nor declining.

Elephant populations in well-protected but isolated parks, sometimes called "fortress conservation," grow rapidly in the absence of threats but are unsustainable in the long term.

These elephants will likely need future conservation interventions, such as translocation or birth control, which are both costly and intensive endeavors.

The team found that the most stable populations occur in large, core areas that are surrounded by buffer zones.

The core areas are defined by their strong levels of environmental protection and minimal human impact, whereas the buffers allow some activities such as sustainable farming, forestry, or trophy hunting.

Unlike the insular fortresses, core areas are connected to other parks, allowing herds to move naturally.

"What's crucial is that you need a mix of areas with more stable core populations linked to more variable buffer areas," said lead author Ryan Huang, a Duke Ph.D. now doing postdoctoral research at CERU.

"These buffers absorb immigrants when core populations get too high, but also provide escape routes when elephants face poor environmental conditions or other threats such as poaching," Huang said.

Connecting protected areas means elephants can freely move in and out.

This allows a natural equilibrium to occur without human intervention, sparing conservationists from using their limited resources to maintain balance.

"Calling for connecting parks isn't something new. Many have done so," Huang said.

"But surprisingly, there has not been a lot of published evidence of its effectiveness so far. This study helps quantify why this works."

Read more at Science Daily