Webb Telescope captures rarely seen prelude to supernova

The rare sight of a Wolf-Rayet star -- among the most luminous, most massive, and most briefly detectable stars known -- was one of the first observations made by NASA's James Webb Space Telescope in June 2022. Webb shows the star, WR 124, in unprecedented detail with its powerful infrared instruments. The star is 15,000 light-years away in the constellation Sagittarius.

Massive stars race through their lifecycles, and only some of them go through a brief Wolf-Rayet phase before going supernova, making Webb's detailed observations of this rare phase valuable to astronomers. Wolf-Rayet stars are in the process of casting off their outer layers, resulting in their characteristic halos of gas and dust. The star WR 124 is 30 times the mass of the Sun and has shed 10 Suns' worth of material -- so far. As the ejected gas moves away from the star and cools, cosmic dust forms and glows in the infrared light detectable by Webb.

The origin of cosmic dust that can survive a supernova blast and contribute to the universe's overall "dust budget" is of great interest to astronomers for multiple reasons. Dust is integral to the workings of the universe: It shelters forming stars, gathers together to help form planets, and serves as a platform for molecules to form and clump together -- including the building blocks of life on Earth. Despite the many essential roles that dust plays, there is still more dust in the universe than astronomers' current dust-formation theories can explain. The universe is operating with a dust budget surplus.

Webb opens up new possibilities for studying details in cosmic dust, which is best observed in infrared wavelengths of light. Webb's Near-Infrared Camera (NIRCam) balances the brightness of WR 124's stellar core and the knotty details in the fainter surrounding gas. The telescope's Mid-Infrared Instrument (MIRI) reveals the clumpy structure of the gas and dust nebula of the ejected material now surrounding the star. Before Webb, dust-loving astronomers simply did not have enough detailed information to explore questions of dust production in environments like WR 124, and whether the dust grains were large and bountiful enough to survive the supernova and become a significant contribution to the overall dust budget. Now those questions can be investigated with real data.

Stars like WR 124 also serve as an analog to help astronomers understand a crucial period in the early history of the universe. Similar dying stars first seeded the young universe with heavy elements forged in their cores -- elements that are now common in the current era, including on Earth.

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Neolithic ceramics reveal dairy processing from milk of multiple species

A new study has found evidence of cheesemaking, using milk from multiple animals in Late Neolithic Poland.

The research suggests that early farmers reduced the lactose content in milk by making it into cheese or other dairy products like yoghurt, and used dairy products from a number of different animals, such as cows, sheep or goats.

Lactose intolerance was a common condition in almost everyone in Europe during the Neolithic and until the Late Bronze Age when the genetic mutation became widespread, enabling adults to produce lactase, the enzyme which breaks down lactose in the body.

Researchers looked at the practice of dairy processing in the Late Neolithic, identifying high curd-content residues in pottery indicating cheesemaking, and revealing that multiple dairy species were utilised.

Dr Harry Robson, from the Department of Archaeology at the University of York, said: "These results contribute significantly to our understanding of the use of dairy products by some of the earliest farmers of Central Europe.

"Whilst previous research has shown that dairy products were widely available in some European regions during this period, here, for the first time, we have clear evidence for a diversified dairy herd, including cattle, sheep and goats, from the analysis of ceramics."

The scientists and archaeologists from the Universities of York, Cambridge, Toru? and Kraków used a multi-stranded proteomic and lipid-analysis approach to investigate ceramics and deposits on their surface, from the site of S?aw?cinek in central Poland.

The new development provides evidence that cheesemaking (and other curd-enriching dairy processing) can be directly detected by scrutinising the proportion of curd proteins, by comparing proteomic data. The results are also the first of their kind in Europe.

Despite widespread lactose intolerance in the period, there is evidence of dairy being consumed during the Neolithic, such as animal bones with kill patterns expected for dairy herds, dairy lipids in ceramic vessels, and dairy proteins in ancient dental calculus or plaque.

Lead author, Miranda Evans, PhD student at Cambridge's Department of Archaeology, said: "The proteomic results showed that the ancient residues closely resembled both the modern cheesemaking residues and cheese itself and not whole milk. This reveals that the people of S?aw?cinek practised cheesemaking or another form of curd-enriching dairy processing."

Evidence of multiple species used for cheesemaking was backed up by the presence of both cow and sheep or goat bones on the site."

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Extensive catalog of exploding stars

Celestial phenomena that change with time such as exploding stars, mysterious objects that suddenly brighten and variable stars are a new frontier in astronomical research, with telescopes that can rapidly survey the sky revealing thousands of these objects.

The largest data release of relatively nearby supernovae (colossal explosions of stars), containing three years of data from the University of Hawaiʻi Institute for Astronomy's (IfA) Pan-STARRS telescope atop Haleakalā on Maui, is publicly available via the Young Supernova Experiment (YSE). The project, which began in 2019, surveyed more than 1,500 square degrees of sky every three days, and discovered thousands of new cosmic explosions and other astrophysical transients, dozens of them just days or hours after exploding.

The newly-released data contains information on nearly 2,000 supernovae and other luminous variable objects with observations in multiple colors. It is also the first to extensively use the multi-color imaging to classify the supernovae and estimate their distances.

Astrophysicists use large imaging surveys -- systematic studies of large areas of the sky over time -- and different parts of the electromagnetic spectrum for many scientific goals. Some are used to study distant galaxies and how they evolve over cosmic time, or look at specific regions of the sky that are especially important, such as the Andromeda Galaxy.

"Pan-STARRS produces a steady stream of transient discoveries, observing large areas of the sky every clear night with two telescopes," said Mark Huber, a senior researcher at IfA. "With over a decade of observations, Pan-STARRS operates one of the best calibrated systems in astronomy, with a detailed reference image of the static sky visible from Haleakalā. This enables rapid discovery and follow-up of supernovae and other transient events, well suited for programs like YSE to build up the sample required for analysis and this significant data release."

YSE is designed to find energetic astrophysical "transient" sources such as supernovae, tidal disruption events and kilonovae (extremely energetic explosions). These transients evolve quickly, rising to their maximum brightness and then fading away after a few days or months.

Multi-institution collaboration

The images from Pan-STARRS are transferred to UH's Information Technology Center for initial processing and scientific calibration by the Pan-STARRS Image Processing Pipeline. Higher-level processing, detailed analysis and storage was then performed using computing systems at the National Center for Supercomputing Applications' (NCSA) Center for Astrophysical Surveys (CAPS), the University of California, Santa Cruz (UCSC), and the Dark Cosmology Centre (DARK) at the Niels Bohr Institute at the University of Copenhagen.

The survey and the tools used to analyze the data are critical precursors to the upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time, a new 8.4-meter telescope being built in Chile. Rubin Observatory will survey the entire sky every three nights, discovering so many variable and exploding objects that it will be impossible to obtain detailed follow-up observations. The ability to classify these objects from the survey data alone will be vital to choosing the most interesting ones for astronomers to target with other telescopes.

Gautham Narayan, deputy director of CAPS, is leading the cosmological analysis for the data sample and former CAPS graduate fellow Patrick Aleo is lead author of the paper, "The Young Supernova Experiment Data Release 1 (YSE DR1): Light Curves and Photometric Classification of 1975 Supernovae."

"Much of the time-domain universe is uncharted. We still do not know the progenitor systems of many of the most common classes of transients, such as type Ia supernovae, while still using these sources to try and understand the expansion history of our universe," Narayan said. "We've also seen one electromagnetic counterpart to a binary neutron star merger. There are many kinds of transients that are theoretically predicted, but have never been seen at all."

Ken Chambers, Pan-STARRS director, added that "this collaboration with the Young Supernova Experiment makes exceptional use of Pan-STARRS' ability to routinely survey the sky for transient phenomena and moving objects. We have provided an unprecedented sample of young supernovae discovered before their peak luminosity that will be an important resource for supernova researchers and cosmologists for many years. Looking ahead, Pan-STARRS will remain a crucial resource in the Northern Hemisphere to complement the Rubin Observatory in the Southern Hemisphere."

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Bird flu associated with hundreds of seal deaths in New England in 2022

Researchers at Cummings School of Veterinary Medicine at Tufts University found that an outbreak of highly pathogenic avian influenza (HPAI) was associated with the deaths of more than 330 New England harbor and gray seals along the North Atlantic coast in June and July 2022, and the outbreak was connected to a wave of avian influenza in birds in the region.

The study was published on March 15 in the journal Emerging Infectious Disease.

HPAI is more commonly known as bird flu, and the H5N1 strain has been responsible for about 60 million poultry deaths in the U.S. since October 2020, with similar numbers in Europe. The virus was known to have spilled over from birds into mammals, such as mink, foxes, skunk, and bears, but those were mostly small, localized events. This study is among the first to directly connect HPAI to a larger scale mortality event in wild mammals.

The co-first authors on the paper -- virologist and senior scientist Wendy Puryear and post-doctoral researcher Kaitlin Sawatzki, who both work in the Runstadler Lab at Cummings School -- have been researching viruses in seals for years. They credit their findings in the new study to a unique and robust data set made possible by a collaboration with wildlife clinics and rehabilitation and response organizations in the region, in particular with Tufts Wildlife Clinic and director Maureen Murray, V03, associate clinical professor at Cummings School, and an author on the paper.

"We have a better resolution and greater depth of detail on this virus than before because we were able to sequence it and detect changes almost in real time," said Puryear. "And we have pairings of samples, sometimes literally from a bird and a seal on the same beach."

The clinic has been conducting avian influenza surveillance on birds and some mammals since January 2022, shortly after this strain of avian influenza took a trans-Atlantic journey from Europe into the U.S. Through this testing, the team found a wide range of flu viruses, including at least three strains that crossed the Atlantic, and they witnessed consistent waves of infection in birds.

At the same time, in collaboration with NOAA's Greater Atlantic Region Marine Mammal Stranding Network, they were able to screen nearly all seals that came through the network, whether or not the animal appeared sick. The stranding network is composed of experts from state and federal wildlife and fisheries agencies, non-profit rehabilitation and response facilities, aquariums, and academic institutions who respond to strandings.

"Because of the genetic data that we gathered, we were the first to see a strain of the virus that's unique to New England. The data set will allow us to more meaningfully address questions of which animals are passing the virus to which animals and how the virus is changing," said Sawatzki.

How HPAI Is Transmitted

In addition to poultry, H5N1 also has had a huge impact on wild birds, especially sea birds. Multiple locations around the globe have experienced large die-offs, such as recently in Peru, where the virus killed 60,000 pelicans, penguins, and gulls.

At the time of the seal mortality event in New England, the virus was hitting gulls particularly hard, the researchers found. There are lots of ways gulls and other birds may transmit the virus to seals, they said. Seals and sea birds are coastal animals living in the same areas that have environmental contact, if not direct contact, since they share the same water and shoreline. A seal may contract the virus if it comes in contact with a sick bird's excrement or water contaminated by that excrement, or if it preys upon an infected bird.

The accepted knowledge is that H5N1 is nearly 100% fatal for domestic and wild birds other than waterfowl, and the same is proving true when it comes to spillover in wild mammals. All the seals that tested positive for HPAI were deceased at the time of sampling or succumbed shortly after. None of the animals that tested positive recovered. However, it's possible some asymptomatic or recovered cases never came into the stranding networks.

In addition to the seal mortality event in New England, which was the first time H5N1 was detected in marine mammals in the wild, other locations have lost marine mammals to the virus. Peru announced about 3,500 sea lions died from the virus, Canada reported a seal mortality event along the St. Lawrence Estuary, and there was a similar event with seals in the Caspian Sea, according to news reports from Russia.

A hotly debated topic among scientists is whether there has been mammal-to-mammal transmission of HPAI between seals.

"It's not surprising that you might have transmission between the seals, because it has happened with low pathogenic avian influenza," said Puryear. "However, we can't say definitively whether or not there has been mammal-to-mammal transmission of HPAI."

"To get strong evidence of mammal-to-mammal transmission, you need two things: lots of infected animals and time," explained Sawatzki. "Time for the virus to mutate, and time for the mutated virus to be transmitted to another seal. As the virus acquires mutations, we can see shared mutations in the sequences that are specific only to mammals and that haven't been seen in a bird before. We had the numbers, but this outbreak didn't last long enough to provide evidence for seal-to-seal transmission."

The research team found evidence that the virus mutated in a small number of seals. But fortunately, they have not seen a case of bird flu in seals along the Atlantic coast since the end of last summer. However, stranding season is about to start for harbor seals and gray seals, so they are bracing themselves for what might happen.

Prevention and Risk to Humans

The risk to the public remains low, according to the Centers for Disease Control and Prevention. Since December 2021, less than 10 human cases of H5N1 have been reported globally, and those cases occurred in people with direct exposure to infected poultry. There are no documented cases of human transmission for this variant.

However, there is the possibility it could become a larger issue for human health. Avian influenza emerged in 1996, and since 2003, 868 cases of human infection with H5N1 have been reported worldwide, according to the World Health Organization. Of those, 457 were fatal, roughly a 50% fatality rate.

"And that's why people get nervous about it," Puryear said.

There is a single-dose vaccine available for poultry, but it's not currently administered on a large scale -- in part because of cost and logistics, and in part because there's some concern it may make future surveillance of the virus more difficult. There's not much that can be done in terms of responding to the virus for wildlife, particularly given the scale at which infection is occurring.

Biosecurity is important in limiting the ways in which the virus can spread between and within species, the researchers said. For example, wild birds should be kept separate from domestic birds, such as backyard chickens. In addition, thorough and timely surveillance of domestic animals and wildlife is key to understanding how the virus is evolving to prepare the best possible vaccines and treatments.

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How fishermen benefit from reversing evolution of cod

Leipzig. Intense fishing and overexploitation have led to evolutionary changes in fish stocks like cod, reducing both their productivity and value on the market. These changes can be reversed by more sustainable and far-sighted fisheries management. The new study by researchers from the German Centre for Integrative Biodiversity Research (iDiv), Leipzig University and the Institute of Marine Research in Tromsø, which was published in Nature Sustainability, shows that reversal of evolutionary change would only slightly reduce the profit of fishing, but would help regain and conserve natural genetic diversity.

The impact of global fisheries on marine ecosystems is severe: fish stocks have declined and the degradation of marine habitats as well as the loss of biodiversity have been accelerated. Less visible, intense fishing has also affected the age and size structure of fish stocks and caused evolutionary change, often towards lower growth rates, smaller maturation sizes and earlier reproduction age. For example, cod in the North Sea, which has been heavily exploited in the past, matures at sizes just above 50 cm, compared to more than 70 cm expected in an unfished population.

Earlier reproduction can increase stock resilience in the short-term, but over time results in populations with smaller fish that have less offspring. "At the end of the day, this can reduce both the productivity of a stock and the value on the market," says first author Hanna Schenk from iDiv and Leipzig University. "Apart from this, we don't know much about potential consequences such as trophic cascades and other ecosystem changes that feed back onto the harvested species and may interfere with critical ecological functions."

Only long-term planning can reverse evolutionary decline

But evolution is not a one-way street. This is why the researchers from iDiv, Leipzig University and the Institute of Marine Research in Tromsø (Norway) wanted to find out what it takes to reverse evolutionary decline after decades of intensive exploitation, in particular with regard to planning horizons in fisheries management. For this, they developed a model that took various processes into account: Biological growth and reproduction as well as economic harvesting costs and consumer preferences. The researchers also analysed potential trade-offs between economic profit and conservation targets.

They found that evolutionary decline is profitable to reverse under century-long planning horizons. With more typical short-term planning, stock recovery in terms of biomass is achieved, but evolutionary decline continues, albeit at much lower rates. "Fisheries typically consider short planning horizons of a few years. This stands in contrast to long-term sustainability and biodiversity targets," says Hanna Schenk. The researchers found that more far-sighted planning horizons would help to rebuild the stock but evolutionary decline continues. According to Schenk, reversing this process takes much longer than the recovery of the stock biomass and is only achieved with century-long planning horizons.

Appropriate conservation targets only slightly reduce profit

The researchers also show that setting conservation targets for restoring not only fish stocks, but also their genetic composition would only slightly reduce profits. The cost and time of evolutionary reversal could be reduced further if fisheries can select fish depending on their genes, which may be possible to some extent by choosing the time and place of harvest. However, current conservation agendas do not include the restoration of genetic diversity, for example target 14 of the Sustainable Development Goals (SGDs), which calls for an end to overfishing.

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Preterm babies do not habituate to repeated pain

Preterm infants do not get used to repeated pain in the way that full-term infants, children and adults do habituate to pain, finds a study led by UCL (University College London) researchers.

The authors of the new Current Biology paper say that if preterm infants have not yet developed the mechanism that enables people to get used to moderate pain, medical procedures in their first few weeks of life could potentially impact their development.

Lead author Dr Lorenzo Fabrizi (UCL Neuroscience, Physiology & Pharmacology) said: "The way that we can get used to things can be seen as the simplest example of behavioural and brain plasticity, and it is a basic part of memory and learning. Pain habituation is important because it enables us to preserve physical, emotional, and cognitive resources by not overreacting to pain that is unavoidable or not life-threatening.

"Our findings suggest that the ability to get used to repeated pain might develop during the third trimester of pregnancy, so that babies born prematurely have not yet developed this ability that full-term babies have right from birth."

The study involved 20 infants at University College London Hospitals (UCLH). Half of them were preterm (and tested while still younger than 35 weeks gestational age*), while the other half were either born at full term (seven infants) or preterm but tested at term age (three infants). The two groups were comparable in terms of their actual postnatal age, as the preterm babies had a median age of 14 days, compared to 10 days among the full-term (or term age) group.

The researchers were measuring the infants' responses to a painful but clinically required heel lance (blood test), which was conducted twice (three to 18 minutes apart) for each infant (two lances are sometimes required to collect enough blood; this is not needed for most infants so only those that needed a second lance were included in the study).

Heel lances can elicit substantial pain responses in infants, but it was not previously known whether this decreases on repeated lances. To understand this, the researchers recorded the infants' brain activity with EEG (electroencephalography) electrodes placed on the scalp, and their heart rates using ECG (electrocardiography), while also monitoring their facial expressions and reflexes in withdrawing the leg.

The researchers found that the brain activity was not as strong immediately after the second heel lance, compared to the first, suggesting a habituation response, but this was only the case for full-term infants. They found a similar pattern for heart rate and facial expressions, as preterm infants reacted just as strongly to both heel lances, while the full-term infants appeared to habituate to the pain.

The team says this habituation response might be due to the full-term infants anticipating the imminent pain when they receive a second heel lance, so their reaction is less pronounced, or it may instead or additionally be due to their brains modulating their reflexive survival responses.

They add that habituation to pain might protect the full-term infants, but not those who were pre-term, from potential consequences to their development.

First author Dr Mohammed Rupawala (UCL Neuroscience, Physiology & Pharmacology) said: "While unpleasant and painful clinical procedures are necessary for many young infants, there is the potential to impact their development, such as by altered pain perception, or potentially reduced grey matter or disrupted white matter in the brain."

Co-author Dr Judith Meek, consultant neonatologist at UCLH, said: "This work raises awareness of the extra vulnerability of premature babies to pain. Clinicians need to do their best to protect them from repeated painful experiences. This should be regarded as an essential component of brain oriented newborn care."

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'Terminator zones' on distant planets could harbor life

In a new study, University of California, Irvine astronomers describe how extraterrestrial life has the potential to exist on distant exoplanets inside a special area called the "terminator zone," which is a ring on planets that have one side that always faces its star and one side that is always dark.

"These planets have a permanent day side and a permanent night side," said Ana Lobo, a postdoctoral researcher in the UCI Department of Physics & Astronomy who led the new work, which just published in The Astrophysical Journal. Lobo added that such planets are particularly common because they exist around stars that make up about 70 percent of the stars seen in the night sky -- so-called M-dwarf stars, which are relatively dimmer than our sun.

The terminator is the dividing line between the day and night sides of the planet. Terminator zones could exist in that "just right" temperature zone between too hot and too cold.

"You want a planet that's in the sweet spot of just the right temperature for having liquid water," said Lobo, because liquid water, as far as scientists know, is an essential ingredient for life.

On the dark sides of terminator planets, perpetual night would yield plummeting temperatures that could cause any water to be frozen in ice. The side of the planet always facing its star could be too hot for water to remain in the open for long.

"This is a planet where the dayside can be scorching hot, well beyond habitability, and the night side is going to be freezing, potentially covered in ice. You could have large glaciers on the night side," Lobo said.

Lobo, alongside Aomawa Shields, UCI associate professor of physics & astronomy, modeled the climate of terminator planets using software typically used to model our own planet's climate, but with a few adjustments, including slowing down planetary rotation.

It's believed to be the first time astronomers have been able to show that such planets can sustain habitable climates confined to this terminator region. Historically, researchers have mostly studied ocean-covered exoplanets in their search for candidates for habitability. But now that Lobo and her team have shown that terminator planets are also viable refuges for life, it increases the options life-hunting astronomers have to choose from.

"We are trying to draw attention to more water-limited planets, which despite not having widespread oceans, could have lakes or other smaller bodies of liquid water, and these climates could actually be very promising," Lobo said.

One key to the finding, Lobo added, was pinpointing exactly what kind of terminator zone planet can retain liquid water. If the planet is mostly covered in water, then the water facing the star, the team found, would likely evaporate and cover the entire planet in a thick layer of vapor.

But if there's land, this effect shouldn't occur.

"Ana has shown if there's a lot of land on the planet, the scenario we call 'terminator habitability' can exist a lot more easily," said Shields. "These new and exotic habitability states our team is uncovering are no longer the stuff of science fiction -- Ana has done the work to show that such states can be climatically stable."

Recognizing terminator zones as potential harbors for life also means that astronomers will need to adjust the way they study exoplanet climates for signs of life, because the biosignatures life creates may only be present in specific parts of the planet's atmosphere.

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Bigger flowers, greater rewards: Plants adapt to climate disruptions to lure pollinators

There's been a well-documented shift toward earlier springtime flowering in many plants as the world warms. The trend alarms biologists because it has the potential to disrupt carefully choreographed interactions between plants and the creatures -- butterflies, bees, birds, bats and others -- that pollinate them.

But much less attention has been paid to changes in other floral traits, such as flower size, that can also affect plant-pollinator interactions, at a time when many insect pollinators are in global decline.

In a study published online in the journal Evolution Letters, two University of Michigan biologists and a University of Georgia colleague show that wild populations of the common morning glory in the southeastern United States increased the size of their flowers between 2003 and 2012.

Increased flower size suggests a greater investment by the plants in pollinator attraction, according to the researchers. The changes were most pronounced at more northern latitudes, in line with a broad range of previous work showing that northern plant populations tend to show more dramatic evolutionary responses to climate change.

A shift to earlier flowering was also observed among those morning glory populations. In addition, there were tantalizing indications that the plants have increased their investment in floral rewards -- the nectar and pollen obtained by the bees, syrphid flies and wasps that pollinate the white, pink and blue morning glory flowers.

"There is a major gap in our understanding of how traits that are crucial for plant-pollinator interactions may be evolving over time as a response to a changing climate," said study lead author Sasha Bishop, a doctoral student in the U-M Department of Ecology and Evolutionary Biology.

"We show that -- in addition to well-documented shifts to earlier flowering -- floral architecture and rewards can also play significant roles in the evolutionary response to contemporary environmental change."

The common morning glory is an annual weedy vine found across the eastern, midwestern and southern United States. It is frequently seen along roadsides and crop fields.

The U-M-led study used a "resurrection" approach that involved germinating morning glory seeds collected from the edges of agricultural soy and corn fields in Tennessee, North Carolina and South Carolina in two years: 2003 and 2012.

During that nine-year span, the region experienced rising temperatures -- particularly rising minimum and nighttime temperatures -- and an increase in the number of extreme rainfall events interspersed with more extreme drought.

To look for changes in floral morphology, the researchers planted field-collected seeds from both years in a greenhouse at U-M's Matthaei Botanical Gardens. When the flowers bloomed, various floral traits were measured with digital calipers.

Measurements showed that morning glory corollas became significantly wider during the nine-year interval -- 4.5 centimeters (1.8 inches) in diameter in 2003 and 4.8 centimeters (1.9 inches) in 2012, and the change in corolla width was greatest in populations at more northern latitudes. The petals of a flower are collectively known as the corolla.

The study also revealed a shift to earlier flowering times between 2003 and 2012, driven primarily by populations at more northern latitudes. The start of flowering occurred an average of four days earlier for the plants grown from seeds collected in 2012.

Interestingly, the researchers also observed a latitude-influenced trend toward greater investment in floral rewards (pollen and nectar) over time. On average, morning glory flowers grown from 2012-collected seeds produced more pollen grains and more nectar sucrose than the flowers from the 2003-collected seeds.

However, the pollen and nectar analyses involved only four populations of morning glory plants. Due to the low number of populations examined, the floral rewards findings were not included in a statistical test to look for evidence that adaptation through natural selection is occurring in the plants.

"Nonetheless, it appears likely that there is a temporal increase in investment in pollinator attraction and that this result is driven by populations at northern latitudes," said study senior author Regina Baucom, an associate professor in the U-M Department of Ecology and Evolutionary Biology.

The study found no evidence that morning glories are increasing the rate at which they self-pollinate. Evidence from some previous studies pointed to increased "selfing" as a possible response to climate change and/or pollinator declines associated with land-use change.

"This is the first article to use the resurrection approach to examine the potential that traits responsible for plant-pollinator interactions may be evolving over time, concomitant to decreases in pollinator abundance and dramatic environmental changes due to changing climate and land-use regimes," Bishop said.

Fifteen morning glory populations were included in the resurrection experiment looking at changes in floral morphology. Twenty-three populations were included in the study of earlier springtime flowering. In total, 2,836 flowers were measured from 456 plants.

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Scientists develop a 'cosmic concrete' that is twice as strong as regular concrete

Manchester scientists have created a new material, dubbed 'StarCrete' which is made from extra-terrestrial dust, potato starch, and a pinch of salt and could be used to build homes on Mars.

Building infrastructure in space is currently prohibitively expensive and difficult to achieve. Future space construction will need to rely on simple materials that are easily available to astronauts, StarCrete offers one possible solution. The scientists behind the invention used simulated Martian soil mixed with potato starch and a pinch of salt to create the material that is twice as strong as ordinary concrete and is perfectly suited for construction work in extra-terrestrial environments.

In an article published in the journal Open Engineering [EB1] , the research team demonstrated that ordinary potato starch can act as a binder when mixed with simulated Mars dust to produce a concrete-like material. When tested, StarCrete had a compressive strength of 72 Megapascals (MPa), which is over twice as strong as the 32 MPa seen in ordinary concrete. Starcrete made from moon dust was even stronger at over 91 MPa.

This work improves on previous work from the same team where they used astronauts' blood and urine as a binding agent. While the resulting material had a compressive strength of around 40 MPa, which is better than normal concrete, the process had the drawback of requiring blood on a regular basis. When operating in an environment as hostile as space, this option was seen as less feasible than using potato starch.

"Since we will be producing starch as food for astronauts, it made sense to look at that as a binding agent rather than human blood. Also, current building technologies still need many years of development and require considerable energy and additional heavy processing equipment which all adds cost and complexity to a mission. StarCrete doesn't need any of this and so it simplifies the mission and makes it cheaper and more feasible.

"And anyway, astronauts probably don't want to be living in houses made from scabs and urine!" Dr Aled Roberts, Research Fellow at the Future Biomanufacturing Research Hub, and lead researcher for this project.

The team calculate that a sack (25 Kg) of dehydrated potatoes (crisps) contain enough starch to produce almost half a tonne of StarCrete, which is equivalent to over 213 brick's worth of material. For comparison, a 3-bedroom house takes roughly 7,500 bricks to build. Additionally, they discovered that a common salt, magnesium chloride, obtainable from the Martian surface or from the tears of astronauts, significantly improved the strength of StarCrete.

The next stages of this project are to translate StarCrete from the lab to application. Dr Roberts and his team have recently launched a start-up company, DeakinBio, which is exploring ways to improve StarCrete so that it could also be used in a terrestrial setting.

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Making sense of scents: Deciphering our sense of smell

Breaking a longstanding impasse in our understanding of olfaction, scientists at UC San Francisco (UCSF) have created the first molecular-level, 3D picture of how an odor molecule activates a human odorant receptor, a crucial step in deciphering the sense of smell.

The findings, appearing online March 15, 2023, in Nature, are poised to reignite interest in the science of smell with implications for fragrances, food science, and beyond. Odorant receptors -- proteins that bind odor molecules on the surface of olfactory cells -- make up half of the largest, most diverse family of receptors in our bodies; A deeper understanding of them paves the way for new insights about a range of biological processes.

"This has been a huge goal in the field for some time," said Aashish Manglik, MD, PhD, an associate professor of pharmaceutical chemistry and a senior author of the study. The dream, he said, is to map the interactions of thousands of scent molecules with hundreds of odorant receptors, so that a chemist could design a molecule and predict what it would smell like.

"But we haven't been able to make this map because, without a picture, we don't know how odor molecules react with their corresponding odor receptors," Manglik said.

A Picture Paints the Scent of Cheese

Smell involves about 400 unique receptors. Each of the hundreds of thousands of scents we can detect is made of a mixture of different odor molecules. Each type of molecule may be detected by an array of receptors, creating a puzzle for the brain to solve each time the nose catches a whiff of something new.

"It's like hitting keys on a piano to produce a chord," said Hiroaki Matsunami, PhD, professor of molecular genetics and microbiology at Duke University and a close collaborator of Manglik. Matsunami's work over the past two decades has focused on decoding the sense of smell. "Seeing how an odorant receptor binds an odorant explains how this works at a fundamental level."

To create that picture, Manglik's lab used a type of imaging called cryo-electron microscopy (cryo-EM), that allows researchers to see atomic structure and study the molecular shapes of proteins. But before Manglik's team could visualize the odorant receptor binding a scent molecule, they first needed to purify a sufficient quantity of the receptor protein.

Odorant receptors are notoriously challenging, some say impossible, to make in the lab for such purposes.

The Manglik and Matsunami teams looked for an odorant receptor that was abundant in both the body and the nose, thinking it might be easier to make artificially, and one that also could detect water-soluble odorants. They settled on a receptor called OR51E2, which is known to respond to propionate -- a molecule that contributes to the pungent smell of Swiss cheese.

But even OR51E2 proved hard to make in the lab. Typical cryo-EM experiments require a milligram of protein to produce atomic-level images, but co-first author Christian Billesbøelle, PhD, a senior scientist in the Manglik Lab, developed approaches to use only 1/100th of a milligram of OR51E2, putting the snapshot of receptor and odorant within reach.

"We made this happen by overcoming several technical impasses that have stifled the field for a long time," said Billesbøelle. "Doing that allowed us to catch the first glimpse of an odorant connecting with a human odorant receptor at the very moment a scent is detected."

This molecular snapshot showed that propionate sticks tightly to OR51E2 thanks to a very specific fit between odorant and receptor. The finding jibes with one of the duties of the olfactory system as a sentinel for danger.

While propionate contributes to the rich, nutty aroma of Swiss cheese, on its own, its scent is much less appetizing.

"This receptor is laser focused on trying to sense propionate and may have evolved to help detect when food has gone bad," said Manglik. Receptors for pleasing smells like menthol or caraway might instead interact more loosely with odorants, he speculated.

Just a Whiff

Along with employing a large number of receptors at a time, another interesting quality of the sense of smell is our ability to detect tiny amounts of odors that can come and go. To investigate how propionate activates this receptor, the collaboration enlisted quantitative biologist Nagarajan Vaidehi, PhD, at City of Hope, who used physics-based methods to simulate and make movies of how OR51E2 is turned on by propionate.

"We performed computer simulations to understand how propionate causes a shape change in the receptor at an atomic level," said Vaidehi. "These shape changes play a critical role in how the odorant receptor initiates the cell signaling process leading to our sense of smell."

The team is now developing more efficient techniques to study other odorant-receptor pairs, and to understand the non-olfactory biology associated with the receptors, which have been implicated in prostate cancer and serotonin release in the gut.

Manglik envisions a future where novel smells can be designed based on an understanding of how a chemical's shape leads to a perceptual experience, not unlike how pharmaceutical chemists today design drugs based on the atomic shapes of disease-causing proteins.

Read more at Science Daily

Evidence that Venus is volcanically active

Venus appears to have volcanic activity, according to a new research paper that offers strong evidence to answer the lingering question about whether Earth's sister planet currently has eruptions and lava flows.

Venus, although similar to Earth in size and mass, differs markedly in that it does not have plate tectonics. The boundaries of Earth's moving surface plates are the primary locations of volcanic activity.

New research by University of Alaska Fairbanks Geophysical Institute research professor Robert Herrick revealed a nearly 1-square-mile volcanic vent that changed in shape and grew over eight months in 1991. Changes on such a scale on Earth are associated with volcanic activity, whether through an eruption at the vent or movement of magma beneath the vent that causes the vent walls to collapse and the vent to expand.

The research was published today in the journal Science.

Herrick studied images taken in the early 1990s during the first two imaging cycles of NASA's Magellan space probe. Until recently, comparing digital images to find new lava flows took too much time, the paper notes. As a result, few scientists have searched Magellan data for feature formation.

"It is really only in the last decade or so that the Magellan data has been available at full resolution, mosaicked and easily manipulable by an investigator with a typical personal workstation," Herrick said.

The new research focused on an area containing two of Venus' largest volcanoes, Ozza and Maat Mons.

"Ozza and Maat Mons are comparable in volume to Earth's largest volcanoes but have lower slopes and thus are more spread out," Herrick said.

Maat Mons contains the expanded vent that indicates volcanic activity.

Herrick compared a Magellan image from mid-February 1991 with a mid-October 1991 image and noticed a change to a vent on the north side of a domed shield volcano that is part of the Maat Mons volcano.

The vent had grown from a circular formation of just under 1 square mile to an irregular shape of about 1.5 square miles.

The later image indicates that the vent's walls became shorter, perhaps only a few hundred feet high, and that the vent was nearly filled to its rim. The researchers speculate that a lava lake formed in the vent during the eight months between the images, though whether the contents were liquid or cooled and solidified isn't known.

The researchers offer one caveat: a nonvolcanic, earthquake-triggered collapse of the vent's walls might have caused the expansion. They note, however, that vent collapses of this scale on Earth's volcanoes have always been accompanied by nearby volcanic eruptions; magma withdraws from beneath the vent because it is going somewhere else.

The surface of Venus is geologically young, especially compared to all the other rocky bodies except Earth and Jupiter's moon Io, Herrick said.

"However, the estimates of how often eruptions might occur on Venus have been speculative, ranging from several large eruptions per year to one such eruption every several or even tens of years," he said.

Herrick contrasts the lack of information about Venusian volcanism with what is known about Jupiter's moon Io and about Mars.

"Io is so active that multiple ongoing eruptions have been imaged every time we've observed it," he said.

On a geological time scale, relatively young lava flows indicate Mars remains volcanically active, Herrick said.

"However, nothing has occurred in the 45 years that we have been observing Mars, and most scientists would say that you'd probably need to watch the surface for a few million years to have a reasonable chance of seeing a new lava flow," he said.

Herrick's research adds Venus to the small pool of volcanically active bodies in our solar system.

"We can now say that Venus is presently volcanically active in the sense that there are at least a few eruptions per year," he said. "We can expect that the upcoming Venus missions will observe new volcanic flows that have occurred since the Magellan mission ended three decades ago, and we should see some activity occurring while the two upcoming orbital missions are collecting images."

Read more at Science Daily

Where did Earth's water come from? Not melted meteorites, according to scientists

Water makes up 71% of Earth's surface, but no one knows how or when such massive quantities of water arrived on Earth.

A new study published in the journal Nature brings scientists one step closer to answering that question. Led by University of Maryland Assistant Professor of Geology Megan Newcombe, researchers analyzed melted meteorites that had been floating around in space since the solar system's formation 4 1/2 billion years ago. They found that these meteorites had extremely low water content -- in fact, they were among the driest extraterrestrial materials ever measured.

These results, which let researchers rule them out as the primary source of Earth's water, could have important implications for the search for water -- and life -- on other planets. It also helps researchers understand the unlikely conditions that aligned to make Earth a habitable planet.

"We wanted to understand how our planet managed to get water because it's not completely obvious," Newcombe said. "Getting water and having surface oceans on a planet that is small and relatively near the sun is a challenge."

The team of researchers analyzed seven melted, or achondrite, meteorites that crashed into Earth billions of years after splintering from at least five planetesimals -- objects that collided to form the planets in our solar system. In a process known as melting, many of these planetesimals were heated up by the decay of radioactive elements in the early solar system's history, causing them to separate into layers with a crust, mantle and core.

Because these meteorites fell to Earth only recently, this experiment was the first time anyone had ever measured their volatiles. UMD geology graduate student Liam Peterson used an electron microprobe to measure their levels of magnesium, iron, calcium and silicon, then joined Newcombe at the Carnegie Institution for Science's Earth and Planets Laboratory to measure their water contents with a secondary ion mass spectrometry instrument.

"The challenge of analyzing water in extremely dry materials is that any terrestrial water on the sample's surface or inside the measuring instrument can easily be detected, tainting the results," said study co-author Conel Alexander, a scientist at the Carnegie Institution for Science.

To reduce contamination, researchers first baked their samples in a low-temperature vacuum oven to remove any surface water. Before the samples could be analyzed in the secondary ion mass spectrometer, the samples had to be dried out once again.

"I had to leave the samples under a turbo pump -- a really high-quality vacuum -- for more than a month to draw down the terrestrial water enough," Newcombe said.

Some of their meteorite samples came from the inner solar system, where Earth is located and where conditions are generally assumed to have been warm and dry. Other rarer samples came from the colder, icier outer reaches of our planetary system. While it was generally thought that water came to Earth from the outer solar system, it has yet to be determined what types of objects could have carried that water across the solar system.

"We knew that plenty of outer solar system objects were differentiated, but it was sort of implicitly assumed that because they were from the outer solar system, they must also contain a lot of water," said Sune Nielsen, a study co-author and geologist at the Woods Hole Oceanographic Institution. "Our paper shows this is definitely not the case. As soon as meteorites melt, there is no remaining water."

After analyzing the achondrite meteorite samples, researchers discovered that water comprised less than two millionths of their mass. For comparison, the wettest meteorites -- a group called carbonaceous chondrites -- contain up to about 20% of water by weight, or 100,000 times more than the meteorite samples studied by Newcombe and her co-authors.

This means that the heating and melting of planetesimals leads to near-total water loss, regardless of where these planetesimals originated in the solar system and how much water they started out with. Newcombe and her co-authors discovered that, contrary to popular belief, not all outer solar system objects are rich in water. This led them to conclude that water was likely delivered to Earth via unmelted, or chondritic, meteorites.

Newcombe said their findings have applications beyond geology. Scientists of many disciplines -- and especially exoplanet researchers -- are interested in the origin of Earth's water because of its deep connections with life.

Read more at Science Daily

Humans are leaving behind a 'frozen signature' of microbes on Mount Everest

Almost 5 miles above sea level in the Himalayan mountains, the rocky dip between Mount Everest and its sister peak, Lhotse, lies windswept, free of snow. It is here at the South Col where hundreds of adventurers pitch their final camp each year before attempting to scale the world's tallest peak from the southeastern side.

According to new University of Colorado Boulder-led research, they're also leaving behind a frozen legacy of hardy microbes, which can withstand harsh conditions at high elevations and lie dormant in the soil for decades or even centuries.

The research not only highlights an invisible impact of tourism on the world's highest mountain, but could also lead to a better understanding of environmental limits to life on Earth, as well as where life may exist on other planets or cold moons. The findings were published last month in Arctic, Antarctic, and Alpine Research, a journal published on behalf of the Institute of Arctic and Alpine Research (INSTAAR) at CU Boulder.

"There is a human signature frozen in the microbiome of Everest, even at that elevation," said Steve Schmidt, senior author on the paper and professor of ecology and evolutionary biology.

In decades past, scientists have been unable to conclusively identify human-associated microbes in samples collected above 26,000 feet. This study marks the first time that next-generation gene sequencing technology has been used to analyze soil from such a high elevation on Mount Everest, enabling researchers to gain new insight into almost everything and anything that's in them.

The researchers weren't surprised to find microorganisms left by humans. Microbes are everywhere, even in the air, and can easily blow around and land some distance away from nearby camps or trails.

"If somebody even blew their nose or coughed, that's the kind of thing that might show up," said Schmidt.

What they were impressed by, however, was that certain microbes which have evolved to thrive in warm and wet environments like our noses and mouths were resilient enough to survive in a dormant state in such harsh conditions.

Life in the cryosphere

This team of CU Boulder researchers -- including Schmidt, lead author Nicholas Dragone and Adam Solon, both graduate students in the Department of Ecology and Evolutionary Biology and the Cooperative Institute for Research in Environmental Science (CIRES) -- study the cryobiosphere: Earth's cold regions and the limits to life in them. They have sampled soils everywhere from Antarctica and the Andes to the Himalayas and the high Arctic. Usually, human-associated microbes don't show up in these places to the extent they appeared in the recent Everest samples.

Schmidt's work over the years connected him with researchers who were headed to Everest's South Col in May of 2019 to set up the planet's highest weather station, established by the National Geographic and Rolex Perpetual Planet Everest Expedition.

He asked his colleagues: Would you mind collecting some soil samples while you're already there?

So Baker Perry, co-author, professor of geography at Appalachian State University and a National Geographic Explorer, hiked as far away from the South Col camp as possible to scoop up some soil samples to send back to Schmidt.

Extremes on Earth, and elsewhere

Dragone and Solon then analyzed the soil in several labs at CU Boulder. Using next-generation gene sequencing technology and more traditional culturing techniques, they were able to identify the DNA of almost any living or dead microbes in the soils. They then carried out extensive bioinformatics analyses of the DNA sequences to determine the diversity of organisms, rather than their abundances.

Most of the microbial DNA sequences they found were similar to hardy, or "extremophilic" organisms previously detected in other high-elevation sites in the Andes and Antarctica. The most abundant organism they found using both old and new methods was a fungus in the genus Naganishia that can withstand extreme levels of cold and UV radiation.

But they also found microbial DNA for some organisms heavily associated with humans, including Staphylococcus, one of the most common skin and nose bacteria, and Streptococcus, a dominant genus in the human mouth.

At high elevation, microbes are often killed by ultraviolet light, cold temperatures and low water availability. Only the hardiest critters survive. Most -- like the microbes carried up great heights by humans -- go dormant or die, but there is a chance that organisms like Naganishia may grow briefly when water and the perfect ray of sunlight provides enough heat to help it momentarily prosper. But even for the toughest of microbes, Mount Everest is a Hotel California: "You can check out any time you like/ But you can never leave."

The researchers don't expect this microscopic impact on Everest to significantly affect the broader environment. But this work does carry implications for the potential for life far beyond Earth, if one day humans step foot on Mars or beyond.

"We might find life on other planets and cold moons," said Schmidt. "We'll have to be careful to make sure we're not contaminating them with our own."

Read more at Science Daily

Mild fever helps clear infections faster, new study suggests

It may be better to let a mild fever run its course instead of automatically reaching for medication, new University of Alberta research suggests.

Researchers found that untreated moderate fever helped fish clear their bodies of infection rapidly, controlled inflammation and repaired damaged tissue. "We let nature do what nature does, and in this case it was very much a positive thing," says immunologist Daniel Barreda, lead author on the study and a joint professor in the Faculty of Agricultural, Life & Environmental Sciences and the Faculty of Science.

Moderate fever is self-resolving, meaning that the body can both induce it and shut it down naturally without medication, Barreda explains. The health advantages of natural fever to humans still have to be confirmed through research, but the researchers say because the mechanisms driving and sustaining fever are shared among animals, it is reasonable to expect similar benefits are going to happen in humans.

That suggests we should resist reaching for over-the-counter fever medications, also known as non-steroidal anti-inflammatory drugs, at the first signs of a mild temperature, he says. "They take away the discomfort felt with fever, but you're also likely giving away some of the benefits of this natural response."

The study helps shed light on the mechanisms that contribute to the benefits of moderate fever, which Barreda notes has been evolutionarily conserved across the animal kingdom for 550 million years. "Every animal examined has this biological response to infection."

For the study, fish were given a bacterial infection and their behaviour was then tracked and evaluated using machine learning. Outward symptoms were similar to those seen in humans with fever, including immobility, fatigue and malaise. These were then matched to important immune mechanisms inside the animals.

The research showed that natural fever offers an integrative response that not only activates defences against infection, but also helps control it.The researchers found that fever helped to clear the fish of infection in about seven days -- half the time it took for those animals not allowed to exert fever. Fever also helped to shut down inflammation and repair injured tissue.

Read more at Science Daily

Thousands of native plants are unphotographed, and citizen scientists can help fill the gaps

Scientists have documented plant species for centuries to help us understand and protect the incredible diversity of flora in our world. But according to new research, many have never actually been photographed in their natural habitats -- and that's a problem.

Researchers from UNSW Sydney and the Australian Institute of Botanical Science, part of the Royal Botanic Gardens and Domain Trust, surveyed 33 major online databases of plant photographs to examine the photographic record of Australian plant species. The findings, published in New Phytologist, reveal out of 21,077 native Australian vascular plant species, almost 20 per cent lack a verifiable photograph.

Lead author of the study and UNSW Science PhD student Thomas Mesaglio says Australia is one of the richest areas in the world for native species.

"It was surprising to see how many plant species had just line drawings, illustrations, paintings, or even no media at all," Mr Mesaglio says.

Dr Hervé Sauquet, co-author of the study and Senior Research Scientist at the Australian Institute of Botanical Science, is based at the National Herbarium of New South Wales.

"All species of plants ultimately rely on specimens in herbarium collections for their identification," Dr Sauquet says. "Yet, even in this digital age where most herbarium specimens have been scanned and are accessible on the web, photos of live plants in the wild remain in critical need."

Senior author of the study from UNSW Science Associate Professor Will Cornwell says a lack of detailed photos can have real consequences. Many plant species that are difficult to identify in the wild may go extinct if scientists cannot properly identify them with the help of photos.

"We had assumed every plant species would have simply been photographed by someone, somewhere, throughout history. But it turns out this isn't the case," says A/Prof. Cornwell.

"This is where citizen scientists can come in and help us fill this gap with their photos."

Gaps in the photographic record

Photographs can help botanists and taxonomists who work with plant specimens by preserving characteristics like flower colour that get lost over time in their samples. They can also show additional features, such as the orientation of leaves or bark appearance, and add ecological context.

"Having a comprehensive photographic set helps us to be confident in our identifications," Mr Mesaglio says. "Particularly when it is practically challenging to collect and preserve the entire plant, photos complement the physical voucher by showing the soil type, the habitat it's growing in, and other species growing alongside it."

But it turns out not all plant groups are photographed equally. Just as some animals receive less attention than others, there might also be a bias against less charismatic plants.

The study found the most well-photographed plant groups tend to be shrubs or trees with more noticeable or spectacular features, such as colourful flowers. Banksia, for example, is one of only two Australian plant genera with more than 40 species to have a complete photographic record. Meanwhile, the family with the most significant photo deficit was Poaceae -- commonly known as grasses -- with 343 unphotographed species.

"We noticed a charisma deficit, so the species that tend to be harder to see are the ones missing out," Mr Mesaglio says. "They may have innocuous or pale-looking flowers or be smaller and harder to spot grasses, sedges and herbs."

Geography also affected the photographic record. While most species across the south-eastern states of Australia have comprehensive records, Western Australia had the largest void, with 52 per cent of all unphotographed species found there.

"The primary 'hotspots' for unphotographed Australian plants are areas with high plant diversity, but the environments are rugged and often difficult to access, particularly by road," Mr Mesaglio says. "But it means there's an exciting opportunity to visit these locations because we might capture something that has never before been photographed."

Activating citizen scientist snaps

It's one thing to have comprehensive photographic records for professional scientists to use in identification guides. But when the plant world is under threat from multiple fronts, including habitat clearing and climate change, photos can help engage the public in plant science.

"People can engage with, sympathise with, and get much more excited about plants with photographs, which is vital when our natural environments are more at risk than ever," Mr Mesaglio says.

"Because digital photography is so accessible now, anyone can also help make a meaningful contribution to science using the camera in their pocket."

Using a platform like iNaturalist, keen citizen scientists can have their snaps identified by experts and share the data with aggregators like the Atlas of Living Australia and the Global Biodiversity Information Facility to be used in research and conservation.

"Since April last year, we've identified nearly 10 per cent of those previously unphotographed species thanks to members of the public uploading their photographs and experts who've kindly identified them," Mr Mesaglio says. "There could be many more in personal collections or behind paywalls just waiting to be shared."

The researchers recommend a standardised system for scientific plant photography be developed, starting with a requirement in the International Code of Nomenclature for Plants to include at least one field photograph where possible in new species descriptions. They also suggest all new species descriptions be published as Open Access in searchable databases with Creative Commons licensing to maximise their usage.

"We also suspect more photos exist, but they're hidden away on social media or behind scientific paywalls that aren't accessible, discoverable, or searchable," Mr Mesaglio says.

Read more at Science Daily

Switching to hydrogen fuel could prolong the methane problem

Hydrogen's potential as a clean fuel could be limited by a chemical reaction in the lower atmosphere, according to research from Princeton University and the National Oceanic and Atmospheric Association.

This is because hydrogen gas easily reacts in the atmosphere with the same molecule primarily responsible for breaking down methane, a potent greenhouse gas. If hydrogen emissions exceed a certain threshold, that shared reaction will likely lead to methane accumulating in the atmosphere -- with decades-long climate consequences.

"Hydrogen is theoretically the fuel of the future," said Matteo Bertagni, a postdoctoral researcher at the High Meadows Environmental Institute working on the Carbon Mitigation Initiative. "In practice, though, it poses many environmental and technological concerns that still need to be addressed."

Bertagni is the first author of a research article published in Nature Communications, in which researchers modeled the effect of hydrogen emissions on atmospheric methane. They found that above a certain threshold, even when replacing fossil fuel usage, a leaky hydrogen economy could cause near-term environmental harm by increasing the amount of methane in the atmosphere. The risk for harm is compounded for hydrogen production methods using methane as an input, highlighting the critical need to manage and minimize emissions from hydrogen production.

"We have a lot to learn about the consequences of using hydrogen, so the switch to hydrogen, a seemingly clean fuel, doesn't create new environmental challenges," said Amilcare Porporato, Thomas J. Wu '94 Professor of Civil and Environmental Engineering and the High Meadows Environmental Institute. Porporato is a principal investigator and member of the Leadership Team for the Carbon Mitigation Initiative and is also associated faculty at the Andlinger Center for Energy and the Environment.

The problem boils down to one small, difficult-to-measure molecule known as the hydroxyl radical (OH). Often dubbed "the detergent of the troposphere," OH plays a critical role in eliminating greenhouse gases such as methane and ozone from the atmosphere.

The hydroxyl radical also reacts with hydrogen gas in the atmosphere. And since a limited amount of OH is generated each day, any spike in hydrogen emissions means that more OH would be used to break down hydrogen, leaving less OH available to break down methane. As a consequence, methane would stay longer in the atmosphere, extending its warming impacts.

According to Bertagni, the effects of a hydrogen spike that might occur as government incentives for hydrogen production expand could have decades-long climate consequences for the planet.

"If you emit some hydrogen into the atmosphere now, it will lead to a progressive build-up of methane in the following years," Bertagni said. "Even though hydrogen only has a lifespan of around two years in the atmosphere, you'll still have the methane feedback from that hydrogen in 30 years from now."

In the study, the researchers identified the tipping point at which hydrogen emissions would lead to an increase in atmospheric methane and thereby undermine some of the near-term benefits of hydrogen as a clean fuel. By identifying that threshold, the researchers established targets for managing hydrogen emissions.

"It's imperative that we are proactive in establishing thresholds for hydrogen emissions, so that they can be used to inform the design and implementation of future hydrogen infrastructure," said Porporato.

For hydrogen referred to as green hydrogen, which is produced by splitting water into hydrogen and oxygen using electricity from renewable sources, Bertagni said that the critical threshold for hydrogen emissions sits at around 9%. That means that if more than 9% of the green hydrogen produced leaks into the atmosphere -- whether that be at the point of production, sometime during transport, or anywhere else along the value chain -- atmospheric methane would increase over the next few decades, canceling out some of the climate benefits of switching away from fossil fuels.

And for blue hydrogen, which refers to hydrogen produced via methane reforming with subsequent carbon capture and storage, the threshold for emissions is even lower. Because methane itself is the primary input for the process of methane reforming, blue hydrogen producers have to consider direct methane leakage in addition to hydrogen leakage. For example, the researchers found that even with a methane leakage rate as low as 0.5%, hydrogen leakages would have to be kept under around 4.5% to avoid increasing atmospheric methane concentrations.

"Managing leakage rates of hydrogen and methane will be critical," Bertagni said. "If you have just a small amount of methane leakage and a bit of hydrogen leakage, then the blue hydrogen that you produce really might not be much better than using fossil fuels, at least for the next 20 to 30 years."

The researchers emphasized the importance of the time scale over which the effect of hydrogen on atmospheric methane is considered. Bertagni said that in the long-term (over the course of a century, for instance), the switch to a hydrogen economy would still likely deliver net benefits to the climate, even if methane and hydrogen leakage levels are high enough to cause near-term warming. Eventually, he said, atmospheric gas concentrations would reach a new equilibrium, and the switch to a hydrogen economy would demonstrate its climate benefits. But before that happens, the potential near-term consequences of hydrogen emissions might lead to irreparable environmental and socioeconomic damage.

Thus, if institutions hope to meet mid-century climate goals, Bertagni cautioned that hydrogen and methane leakage to the atmosphere must be held in check as hydrogen infrastructure begins to roll out. And because hydrogen is a small molecule that is notoriously difficult to control and measure, he explained that managing emissions will likely require researchers to develop better methods for tracking hydrogen losses across the value chain.

Read more at Science Daily

Research highlights gender bias persistence over centuries

New research from Washington University in St. Louis provides evidence that modern gender norms and biases in Europe have deep historical roots dating back to the Middle Ages and beyond, suggesting that DNA is not the only thing we inherit from our ancestors.

The findings -- published on March 13, 2023 in the Proceedings of the National Academy of Sciences (PNAS) -- highlight why gender norms have remained stubbornly persistent in many parts of the world despite significant strides made by the international women's rights movement over the last 100-150 years.

Using dental records of more than 10,000 people from 139 archaeological sites throughout Europe, researchers found that individuals who live in areas that historically favored men over women display more pro-male bias today than those who live in places where gender relations were more egalitarian centuries ago -- evidence that gender attitudes are "transmitted" or handed down from generation to generation.

These biases outlasted monumental socioeconomic and political changes such as industrialization and world wars. Researchers found one exception to the rule, however: In regions that experienced abrupt, large-scale population replacement -- such as a pandemic or natural disaster -- transmission of these values was interrupted.

"The median age of the skeletons in this study is about 1,000 years dating back to the medieval era. It is therefore remarkable that the patterns of gender bias that existed during those times and earlier are still replicated in contemporary attitudes," said Margit Tavits, the Dr. William Taussig Professor in Arts & Sciences at WashU.

"Given the enormous social, economic and political changes that have taken place in Europe during this time, our findings speak to the power of cultural transmission of gender norms."

The incredible stability of these norms over hundreds, if not thousands, of years also explains why it has been difficult in some regions to move the needle toward gender equality.

"There has been a widespread belief that gender norms are a byproduct of structural and institutional factors like religion and agricultural practices. Our findings draw attention to the fact that gender-equal norms passed down from one generation to the next can persist even if institutions or structures incentivize inequality, and vice versa," Tavits said.

"For those working to foster gender equality, the message from our research is that rules and policies are not going to be enough to undermine deeply rooted sexist beliefs and sustain equal ones. We must also address the cultural forces channeling these beliefs."

Taylor Damann and Jeremy Siow -- doctoral students in the Department of Political Science at WashU -- conducted research and co-authored the paper with Tavits.

About the research

Previous archaeological research has used linear enamel hypoplasias -- permanent lesions on the teeth caused by trauma, malnutrition or disease -- to analyze prehistoric gender equality. Because the lesions form exclusively in cases of sustained bodily stress, their presence or absence can tell researchers a great deal about the person's health and living conditions. Further, differences between male and female teeth at the same location are an indication of which sex received preferential treatment in terms of health care and dietary resources at the time.

According to Tavits, studying gender norms in Europe is advantageous given the relative similarity of various institutional and environmental conditions across the region. This allowed researchers to control for factors that could affect modern gender attitudes, such as religion and political institutions.

Because differences in gender attitudes are fairly small across the continent, compared with the rest of the world, this setting also set a higher bar for detecting significant associations between historical and contemporary attitudes. Yet, time and time again, researchers found evidence of this association. For example, individuals living in an area that was historically egalitarian were 20% more likely to have pro-female attitudes than people living in areas that were historically the most pro-male.

Additional tests showed that historical gender bias failed to predict modern gender attitudes for immigrant populations. Researchers also found no evidence of historical gender bias impacting contemporary attitudes in areas hardest hit by the bubonic plague of the 14th century. Finally, they looked to the United States, where the arrival of European settlers in the 16th century led to large-scale displacement of Native Americans. Once again, they found no association between historical and current gender norms.

"Together, these findings provide further support for the idea that historical biases persist because they are passed down from one generation to the next and occur only when the transmission across generations is not interrupted. We were surprised that such a clear relationship emerged," Tavits said.

A tale of two cities

In the paper, Tavits, Damann and Siow highlight two archaeological sites to illustrate how the contrasting historical treatment of women relative to men is reflected in current gender attitudes.

At the first site in Istria, a small urban Greek settlement on the Black Sea in the modern Dobruja region of Romania, researchers found evidence of a pro-male bias in historical dental records dating back to around 550 A.D. Out of the 49 skeletons for whom sex and dental information could be extracted, 58% of females show signs of malnutrition and trauma in their teeth, while only 25% of males do.

According to the authors, the status of men and women in society today has remained relatively unequal in the southeastern region of Romania, based on modern indicators of gender equality. For example, they note, only 52.5% of women participate in the labor market compared with 78% of men, and only 18% of the representatives in the modern municipal council are women.

The population's beliefs about gender norms are similarly unequal, they write. More than half of the residents believe that men have more of a right to jobs than women and there is near consensus (89%) that a woman must have children to be fulfilled.

Contrast this with Plinkaigalis, a rural community in modern-day western Lithuania made up of a population of Balts. Unlike Istria, Plinkaigalis favored women's health. Of the 157 skeletons at this site -- also dating back to 550 A.D. -- 56% of males show dental signals of trauma and malnutrition whereas only 46% of females do. Separate studies have also found evidence that gender norms here were favorable to women.

In the modern era, this location, now called Ke ?dainiai, remains relatively gender equal. Employment levels in western Lithuanian do not vary strongly by gender: 76% men vs. 72.7% women. And women are nearly proportionally represented in local politics (48%). Likewise, less than a quarter of residents of the modern location believe men have more of a right to a job than women, and 56% believe women need children to be fulfilled.

Read more at Science Daily

Biological network in cells helps body adapt to stresses on health

Every minute of every day, our body adapts to meet the needs of each moment. When we binge on carbs, exercise, or become sick, chemical reactions inside our cells switch on, slow down, or shift strategy so that we have the energy and strength we need.

All this happens without us knowing it, perhaps explaining why so little is understood about how the body senses and responds to these constant demands. Seeking answers to this question, scientists at University of Utah Health led research that opens up a whole new world within our cells. Their study, published in Science, uncovers a vast network of interactions that suggest how cells adjust in real time to withstand stresses on our health.

"We're discovering how nature has evolved to 'drug' its own proteins and pathways," says Jared Rutter, Ph.D., distinguished professor in the Department of Biochemistry at University of Utah and the study's corresponding author. "By following nature's lead, we're learning how to make better therapeutics."

These findings -- and the technology that made them possible -- has become the basis for the biotechnology company Atavistik Bio, co-founded by Rutter. The company is leveraging this new understanding to accelerate drug discovery for metabolic diseases and cancer.

At a more fundamental level, Rutter says, the advance deepens knowledge about how cells and our bodies work.

A New Frontier

The network described in the study represents an underappreciated layer of regulation in cells that comes from an unexpected source. For nearly 20 years, Rutter's lab has researched metabolism, the chemical reactions that produce energy and build essential components to keep cells running smoothly. Their new research finds that intermediate products of those chemical reactions are more than passive building blocks and sources of fuel for cells, as had long been thought.

Instead, these intermediate products, along with other metabolites, make up an expansive web of sentries that monitor the environment and prompt cells to adapt when needed. They do this by interacting with proteins and modifying how they work. Does a big meal pump too many carbs in the body? Or too much fat? Like a railroad switch that guides a train onto a new track, these protein-metabolite interactions shift metabolic operations to break down those nutrients and steady the course.

The study's first author Kevin Hicks, Ph.D., developed a new technology, termed MIDAS, that reveals the enormity of the regulatory network that acts as an interface between environmental cues and cell metabolism, called the protein-metabolite interactome. The highly sensitive technique identified interactions that had never been seen. An analysis of 33 human proteins involved in converting carbohydrates into fuel found 830 interactions with metabolites. Given that there are thousands of proteins in the cell, the full scale of the network is predicted to be much larger.

"It's surprising how little we know about the extent of these interactions," Hicks says. "We are pushing our understanding of the biological network in new directions."

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Rutgers scientists identify substance that may have sparked life on Earth

A team of Rutgers scientists dedicated to pinpointing the primordial origins of metabolism -- a set of core chemical reactions that first powered life on Earth -- has identified part of a protein that could provide scientists clues to detecting planets on the verge of producing life.

The research, published in Science Advances, has important implications in the search for extraterrestrial life because it gives researchers a new clue to look for, said Vikas Nanda, a researcher at the Center for Advanced Biotechnology and Medicine (CABM) at Rutgers.

Based on laboratory studies, Rutgers scientists say one of the most likely chemical candidates that kickstarted life was a simple peptide with two nickel atoms they are calling "Nickelback" not because it has anything to do with the Canadian rock band, but because its backbone nitrogen atoms bond two critical nickel atoms. A peptide is a constituent of a protein made up of a few elemental building blocks known as amino acids.

"Scientists believe that sometime between 3.5 and 3.8 billion years ago there was a tipping point, something that kickstarted the change from prebiotic chemistry -- molecules before life -- to living, biological systems," Nanda said. "We believe the change was sparked by a few small precursor proteins that performed key steps in an ancient metabolic reaction. And we think we've found one of these 'pioneer peptides'."

The scientists conducting the study are part of a Rutgers-led team called Evolution of Nanomachines in Geospheres and Microbial Ancestors (ENIGMA), which is part of the Astrobiology program at NASA. The researchers are seeking to understand how proteins evolved to become the predominant catalyst of life on Earth.

When scouring the universe with telescopes and probes for signs of past, present or emerging life, NASA scientists look for specific "biosignatures" known to be harbingers of life. Peptides like nickelback could become the latest biosignature employed by NASA to detect planets on the verge of producing life, Nanda said.

An original instigating chemical, the researchers reasoned, would need to be simple enough to be able to assemble spontaneously in a prebiotic soup. But it would have to be sufficiently chemically active to possess the potential to take energy from the environment to drive a biochemical process.

To do so, the researchers adopted a "reductionist" approach: They started by examining existing contemporary proteins known to be associated with metabolic processes. Knowing the proteins were too complex to have emerged early on, they pared them down to their basic structure.

After sequences of experiments, researchers concluded the best candidate was Nickelback. The peptide is made of 13 amino acids and binds two nickel ions.

Nickel, they reasoned, was an abundant metal in early oceans. When bound to the peptide, the nickel atoms become potent catalysts, attracting additional protons and electrons and producing hydrogen gas. Hydrogen, the researchers reasoned, was also more abundant on early Earth and would have been a critical source of energy to power metabolism.

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Arctic climate modelling too conservative

Climate models used by the UN's IPCC and others to project climate change are not accurately reflecting what the Arctic's future will be. Researchers at the University of Gothenburg argue that the rate of warming will be much faster than projected.

Due to the Arctic´s sea ice cover and its harsh climate, relatively few observations are made in that part of world. This means that the climate models used for projecting the future of the Arctic have not been calibrated to the same extent there as in other parts of the world.

Two recent scientific studies involving researchers from the University of Gothenburg compared the results of the climate models with actual observations. They concluded that the warming of the Arctic Ocean will proceed at a much faster rate than projected by the climate models.

Climate models underestimate the consequences

"These climate models underestimate the consequences of climate change. In reality, the relatively warm waters in the Arctic regions are even warmer, and closer to the sea ice. Consequently, we believe that the Arctic sea ice will melt away faster than projected," explains Céline Heuzé, climatologist at the University of Gothenburg and lead author of one of the studies.

Warm water flows into the Arctic Ocean via Fram Strait between Greenland and Svalbard. However, the volume of water in these ocean currents and its temperature in the climate models are too low, which is one of the reasons why the climate models' projections will not be accurate. Even the stratification of the Arctic Ocean is incorrect. The researchers argue that since roughly half of the models project an increase and the other half a decrease in stratification, the consequences of global warming cannot be estimated accurately.

Acquiring hard data in the Arctic must be prioritised

"This is a serious situation. If governments and organisations all over the world are going to rely on these climate models, they must be improved. Which is why research and data acquisition in the Arctic ocean must be prioritised. At present, we cannot provide a useful prediction of how quickly the Arctic sea ice is melting," Céline Heuzé explains.

The Arctic is an important region for projecting what the future intensity of global warming will be. Its sea ice contributes an albedo effect -- a white surface that reflects sunlight away from the planet. If the ice were to disappear, more solar radiation would reach the Earth.

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Experiment unlocks bizarre properties of strange metals

Physicists are learning more about the bizarre behavior of "strange metals," which operate outside the normal rules of electricity.

Theoretical physicist Yashar Komijani, an assistant professor at the University of Cincinnati, contributed to an international experiment using a strange metal made from an alloy of ytterbium, a rare earth metal. Physicists in a lab in Hyogo, Japan, fired radioactive gamma rays at the strange metal to observe its unusual electrical behavior.

Led by Hisao Kobayashi with the University of Hyogo and RIKEN, the study was published in the journal Science. The experiment revealed unusual fluctuations in the strange metal's electrical charge.

"The idea is that in a metal, you have a sea of electrons moving in the background on a lattice of ions," Komijani said. "But a marvelous thing happens with quantum mechanics. You can forget about the complications of the lattice of ions. Instead, they behave as if they are in a vacuum."

Komijani for years has been exploring the mysteries of strange metals in relation to quantum mechanics.

"You can put something in a black box and I can tell you a lot about what's inside it without even looking at it just by measuring things like resistivity, heat capacity and conductivity," he said.

"But when it comes to strange metals, I have no idea why they are showing the behavior they do. The mystery is what is happening inside this strange system. That is the question."

Strange metals are of interest to a wide range of physicists studying everything from particle physics to quantum mechanics. One reason is because of their oddly high conductivity, at least under extremely cold temperatures, which gives them potential as superconductors for quantum computing.

"The thing that is really exciting about these new results is that they provide a new insight into the inner machinery of the strange metal," said study co-author Piers Coleman, a distinguished professor at Rutgers University.

"These metals provide the canvas for new forms of electronic matter -- especially exotic and high temperature superconductivity," he said.

Coleman said it's too soon to speculate about what new technologies strange metals might inspire.

"It is said that after Michael Faraday discovered electromagnetism, the British Chancellor William Gladstone asked what it would be good for," Coleman said. "Faraday answered that while he didn't know, he was sure that one day the government would tax it."

Faraday's discoveries opened a world of innovation.

"We feel a bit the same about the strange metal," Coleman said. "Metals play such a central role today -- copper, the archetypal conventional metal, is in all devices, all power lines, all around us."

Coleman said strange metals one day could be just as ubiquitous in our technology.

The Japan experiment was groundbreaking in part because of the way that researchers created the gamma particles using a particle accelerator called a synchrotron.

"In Japan, they use a synchrotron like they have at CERN [the European Organization for Nuclear Research] that accelerates a proton and smashes it into a wall and it emits a gamma ray," Komijani said. "So they have an on-demand source of gamma rays without using radioactive material."

Researchers used spectroscopy to study the effects of gamma rays on the strange metal.

Researchers also examined the speed of the metal's electrical charge fluctuations, which take just a nanosecond -- a billionth of a second. That might seem incredibly fast, Komijani said.

"However, in the quantum world, a nanosecond is an eternity," he said. "For a long time we have been wondering why these fluctuations are actually so slow. We came up with a theory with collaborators that there might be vibrations of the lattice and indeed that was the case."

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Minke whales are as small as a lunge-feeding baleen whale can be

A new study of Antarctic minke whales reveals a minimum size limit for whales employing the highly efficient "lunge-feeding" strategy that enabled the blue whale to become the largest animal on Earth.

Lunge feeding whales accelerate toward a patch of prey, engulf a huge volume of water, and then filter out the prey through the baleen plates in their mouths. This strategy is used by the largest group of baleen whales, known as rorquals, which includes blue, fin, humpback, and minke whales.

The ability to engulf large amounts of prey-laden water is essential to making this feeding strategy pay off, and the energy efficiency increases with larger body size. An 80-ton blue whale, for example, can engulf a water volume equivalent to 135% of its body mass, whereas a 5-ton minke whale can engulf a volume equal to 42% of its body mass.

In the new study, published March 13 in Nature Ecology & Evolution, researchers used noninvasive suction tags to observe 23 Antarctic minke whales in the waters off the West Antarctic Peninsula, tracking their daytime and nighttime foraging behavior as they fed on Antarctic krill. Data from previous studies of krill-feeding humpback whales and blue whales were used for comparison.

"When we calculate how much energy they use in foraging and what their overall intake should be based on their size, we find that minke whales are right at the threshold," said first author David Cade, who led the study as a postdoctoral researcher at UC Santa Cruz and is now at Stanford's Hopkins Marine Station. "Anything smaller than a minke could not achieve the foraging rates necessary to survive."

Minke whales are not as well studied as other species of baleen whales, in part because they can be harder to find and tag.

"The data in this study represent more information on a poorly studied species than has ever been published previously and is helping us to better understand not only the species, but the role of baleen whales in marine ecosystems," said coauthor Ari Friedlaender, professor of ocean sciences at UC Santa Cruz. "With so little known about this species that is being impacted by climate change, the more we understand their ecology and behavior the better we can protect them."

The researchers observed remarkably high feeding rates for minke whales, especially at night, when they were often lunging every 15 seconds or so. Krill come to the surface at night and stay in the depths during the day, so daytime feeding requires deep dives, which are less efficient for smaller animals.

"During the day they feed at depths comparable to humpbacks and blue whales, but their foraging rates aren't as high because they're smaller," Cade said. "Their nighttime feeding rates are two to five times the day rate."

At night, the smaller, more maneuverable minke whales are well suited for pursuing small, scattered patches of krill at the surface. "When they're surface feeding, they don't have to hold their breath during dives and they can do lunges over and over again," Cade said. "Only at night can they get the really high feeding rates they need."

The study also addresses questions about the evolution of baleen whales and the origins of a feeding strategy that depends on large body size. Lunge feeding is thought to have arisen first in whales about the size of today's Antarctic minke whales. This enabled the evolution of whales with gigantic body sizes, such as blue whales, during the past 5 million years when changing ocean conditions led to the formation of predictable regions with large prey patches that could be efficiently exploited by lunge-feeding whales.

"Minke whales represent one extreme, at the small end of the spectrum, for how filter feeding in ocean predators evolved," Friedlaender said. "Understanding both the maximum and minimum size constraints on baleen whale size really helps us understand how this group of animals has evolved and how they affect and are impacted by marine ecosystems."

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How does the immune system react to altered gravity?

Space travel has always tested the human body by the effects of the new conditions of altered gravity on biological systems. It has long been known that continuous exposure to microgravity conditions human physiology and causes effects that compromise muscular, sensory, endocrine and cardiovascular functions. But is it also risky to be exposed to altered gravity for short periods of time?

Now, a paper published in the journal Acta Astronautica examines the effects on the human immune system of microgravity generated by a parabolic flight. After a short exposure to altered gravity, there were no significant changes in the defensive capacity of blood cells in the volunteers who took part in the study. In addition, the study found no evidence of aggregation processes in erythrocytes -- the cells that transport O2 and CO2 to the cardiovascular system -- after the parabolic flight.

The study was coordinated by Ginés Viscor, professor at the Department of Cell Biology, Physiology and Immunology of the Faculty of Biology of the University of Barcelona, and it included the participation of experts Jordi Petriz, from the Germans Trias i Pujol Research Institute (IGTP), and Antoni Pérez-Poch, from the Technical University of Catalonia-BarcelonaTech (UPC) and the Institute of Space Studies of Catalonia (IEEC), among other authors. The first author of the study is the researcher Abril Gorgori-González (UB). It counted on the support from the Medical Service of the Safety, Health and Environment Office (OSSMA) of the UB, the Aeroclub Barcelona-Sabadell and the company Thermo Fisher Scientific.

Parabolic flights: a simulated gravity laboratory

Space travel is the ideal scenario to study the effect of microgravity on the human body. These trips make it possible to study the consequences of long-term exposure to microgravity on different astronauts simultaneously, but they require a high cost in terms of time, funding and infrastructure. Without leaving the Earth's atmosphere, it is also possible to simulate simulated gravity conditions on different platforms. For example, through parabolic flights in aircraft, which make it possible to study the effect of altered microgravity in the short term -- even for a few seconds -- at an affordable cost.

"Artificial platforms such as parabolic flights in aircraft provide valuable but more limited results, as they only allow the effects of altered gravity to be studied in the short term (seconds or minutes). Therefore, the profiles of physiological changes that can be recreated with parabolic flights are immediate and transitory changes that microgravity generates in the human body," says Ginés Viscor, head of the Adaptive Physiology Group: Exercise, Hypoxia and Health at the UB.

As part of the study, a 20-minute parabolic flight was conducted with the Mudry CAP10 aircraft -- a 2-seat aerobatic training aircraft -- during which fifteen parabolas were performed. "Each parabola allows a period of microgravity to be reached for approximately eight seconds, which is followed and preceded by hypergravity phases of about two seconds," says the researcher Antoni Pérez-Poch, from the Department of Computer Science at the UPC, and lecturer of the School of Engineering of Barcelona East (EEBE) of the UPC and the IEEC.

These parabolic flights with an aerobatic plane -- a pioneering method in the world, developed in Catalonia -- were operated by the Aeroclub Barcelona-Sabadell and are the result of an aeronautical research carried out in collaboration with the UPC. "This innovative technique has a good ratio of time achieved in microgravity compared to the cost of maintenance, which is very favourable compared to the greater use of aircraft, although it also has some limitations (logistical and space). In the case of parabolic flights with a larger aircraft, a more expensive operation that has been used since the beginning of the space race by agencies such as NASA or ESA (European Space Agency), up to 25 seconds per parabola could be achieved," says Pérez-Poch.

Immune function under pressure

The immediate effects of microgravity on the blood system derive from the redistribution of blood volume, blood flow and body fluids to the upper body. "Cardiovascular adaptations consist of an altered cardiovascular response causing abnormalities in body orientation and balance, poor response to orthostatic stress, decreased cardiac function and inadequate cardiovascular response to exercise," says Ginés Viscor.

One of the most vulnerable physiological systems to any change in environmental conditions is the immune system, and this is explained by its great plasticity and responsiveness to internal and external imbalances. In the scientific literature, there are still no conclusive results on the immune response to short exposure in flights with altered gravity, and in some cases the conclusions are even contradictory.

In this study, the team analysed the response of the immune system to short exposure to microgravity based on several parameters: erythrocyte and leukocyte counts, haemoglobin concentration, phagocytic capacity and oxidative metabolism.

"The results reveal that the human blood samples' exposure to altered gravity conditions in parabolic flight did not involve negative effects in relation to samples that were left parallelly on the ground during the experimental study. There are also no significant changes in peripheral blood cell counts," says Jordi Petriz (IGTP).

"Except for the monocytes -- a type of leukocyte -- no significant differences have been observed in the functionality of immune cells in terms of either their oxidative metabolism or their phagocytic capacity," says researcher Abril Gorgori-González (UB). "Hypothetically, if there were changes in the functionality of leukocytes when exposed to an altered gravity, the immune function and defence against external infections or tumour processes would also be compromised."

The team has applied the technique of flow cytometry with acoustic focusing with little manipulation of the volunteers' blood samples. According to the authors, the sample limitation typical of acrobatic flight studies -- with logistical constraints -- does not allow general conclusions to be drawn. Therefore, the goal now is to continue research on the human immune system with other microgravity simulation platforms to study physiological alterations, avoid complications and anticipate risk situations.

Space tourist warning

Space tourism is an activity of great economic interest for some business sectors. However, one of the main differences between space tourists and astronauts is the physical and psychological preparation prior to the trip.

"Altered gravity or the constant lack of gravity is one of several changes in the environment faced by these space travellers. The human body has evolved under the conditions of Earth's gravity and is not adapted to the absence of this attractive force. In space travel, other factors such as ionising radiation, constant noise, isolation, confinement, a total distortion of circadian rhythms and short exposure to extreme temperatures during the return to the atmosphere have to be considered," the experts warn.

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