70 new rogue planets discovered in our galaxy

Rogue planets are elusive cosmic objects that have masses comparable to those of the planets in our Solar System but do not orbit a star, instead roaming freely on their own. Not many were known until now, but a team of astronomers, using data from several European Southern Observatory (ESO) telescopes and other facilities, have just discovered at least 70 new rogue planets in our galaxy. This is the largest group of rogue planets ever discovered, an important step towards understanding the origins and features of these mysterious galactic nomads.

"We did not know how many to expect and are excited to have found so many," says Núria Miret-Roig, an astronomer at the Laboratoire d'Astrophysique de Bordeaux, France and the University of Vienna, Austria, and the first author of the new study published today in Nature Astronomy.

Rogue planets, lurking far away from any star illuminating them, would normally be impossible to image. However, Miret-Roig and her team took advantage of the fact that, in the few million years after their formation, these planets are still hot enough to glow, making them directly detectable by sensitive cameras on large telescopes. They found at least 70 new rogue planets with masses comparable to Jupiter's in a star-forming region close to our Sun, in the Upper Scorpius and Ophiuchus constellations.

To spot so many rogue planets, the team used data spanning about 20 years from a number of telescopes on the ground and in space. "We measured the tiny motions, the colours and luminosities of tens of millions of sources in a large area of the sky," explains Miret-Roig. "These measurements allowed us to securely identify the faintest objects in this region, the rogue planets."

The team used observations from ESO's Very Large Telescope (VLT), the Visible and Infrared Survey Telescope for Astronomy (VISTA), the VLT Survey Telescope (VST) and the MPG/ESO 2.2-metre telescope located in Chile, along with other facilities. "The vast majority of our data come from ESO observatories, which were absolutely critical for this study. Their wide field of view and unique sensitivity were keys to our success," explains Hervé Bouy, an astronomer at the Laboratoire d'Astrophysique de Bordeaux, France, and project leader of the new research. "We used tens of thousands of wide-field images from ESO facilities, corresponding to hundreds of hours of observations, and literally tens of terabytes of data."

The team also used data from the European Space Agency's Gaia satellite, marking a huge success for the collaboration of ground- and space-based telescopes in the exploration and understanding of our Universe.

The study suggests there could be many more of these elusive, starless planets that we have yet to discover. "There could be several billions of these free-floating giant planets roaming freely in the Milky Way without a host star," Bouy explains.

By studying the newly found rogue planets, astronomers may find clues to how these mysterious objects form. Some scientists believe rogue planets can form from the collapse of a gas cloud that is too small to lead to the formation of a star, or that they could have been kicked out from their parent system. But which mechanism is more likely remains unknown.

Further advances in technology will be key to unlocking the mystery of these nomadic planets. The team hopes to continue to study them in greater detail with ESO's forthcoming Extremely Large Telescope (ELT), currently under construction in the Chilean Atacama Desert and due to start observations later this decade. "These objects are extremely faint and little can be done to study them with current facilities," says Bouy. "The ELT will be absolutely crucial to gathering more information about most of the rogue planets we have found."

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Tracking down the forces that shaped our Solar System’s evolution

Meteorites are remnants of the building blocks that formed Earth and the other planets orbiting our Sun. Recent analysis of their isotopic makeup led by Carnegie's Nicole Nie and published in Science Advances settles a longstanding debate about the geochemical evolution of our Solar System and our home planet.

In their youth, stars are surrounded by a rotating disk of gas and dust. Over time, these materials aggregate to form larger bodies, including planets. Some of these objects are broken up due to collisions in space, the remnants of which sometimes hurtle through Earth's atmosphere as meteorites.

By studying a meteorite's chemistry and mineralogy, researchers like Nie and Carnegie's Anat Shahar can reveal details about the conditions these materials were exposed to during the Solar System's tumultuous early years. Of particular interest is why so-called moderately volatile elements are more depleted on Earth and in meteoritic samples than the average Solar System, represented by the Sun's composition. They are named because their relatively low boiling points mean they evaporate easily.

It's long been theorized that periods of heating and cooling resulted in the evaporation of volatiles from meteorites. Nie and her team showed that an entirely different phenomenon is the culprit in the case of the missing volatiles.

Solving the mystery involved studying a particularly primitive class of meteorites called carbonaceous chondrites that contain crystalline droplets, called chondrules, which were part of the original disk of materials surrounding the young Sun. Because of their ancient origins, these beads are an excellent laboratory for uncovering the Solar System's geochemical history.

"Understanding the conditions under which these volatile elements are stripped from the chondrules can help us work backward to learn the conditions they were exposed to in the Solar System's youth and all the years since," Nie explained.

She and her co-authors set out to probe the isotopic variability of potassium and rubidium, two moderately volatile elements. The research team included Shahar and colleagues from The University of Chicago, where Nie was a graduate student prior to joining Carnegie -- Timo Hopp, Justin Y. Hu, Zhe J. Zhang, and Nicolas Dauphas -- as well as Xin-Yang Chen and Fang-Zhen Teng from University of Washington Seattle.

Each element contains a unique number of protons, but its isotopes have varying numbers of neutrons. This means that each isotope has a slightly different mass than the others. As a result, chemical reactions discriminate between the isotopes, which, in turn, affects the proportion of that isotope in the reaction's end products.

"This means that the different kinds of chemical processing that the chondrules experienced will be evident in their isotopic composition, which is something we can probe using precision instruments," Nie added.

Their work enabled the researchers to settle the debate about how and when in their lifespans the chondrules lost their volatiles. The isotopic record unveiled by Nie and her team indicates that the volatiles were stripped as a result of massive shockwaves passing through the material circling the young Sun that likely drove melting of the dust to form the chondrules. These types of events can be generated by gravitational instability or by larger baby planets moving through the nebular gas.

"Our findings offer new information about our Solar System's youth and the events that shaped the geochemistry of the planets, including our own," Nie concluded.

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Ancient DNA reveals the world’s oldest family tree

Analysis of ancient DNA from one of the best-preserved Neolithic tombs in Britain has revealed that most of the people buried there were from five continuous generations of a single extended family.

By analysing DNA extracted from the bones and teeth of 35 individuals entombed at Hazleton North long cairn in the Cotswolds-Severn region, the research team was able to detect that 27 of them were close biological relatives. The group lived approximately 5700 years ago -- around 3700-3600 BC -- around 100 years after farming had been introduced to Britain.

Published in Nature, it is the first study to reveal in such detail how prehistoric families were structured, and the international team of archaeologists and geneticists say that the results provide new insights into kinship and burial practices in Neolithic times.

The research team -- which included archaeologists from Newcastle University, UK, and geneticists from the University of the Basque Country, University of Vienna and Harvard University -- show that most of those buried in the tomb were descended from four women who had all had children with the same man.

The cairn at Hazleton North included two L-shaped chambered areas which were located north and south of the main 'spine' of the linear structure. After they had died, individuals were buried inside these two chambered areas and the research findings indicate that men were generally buried with their father and brothers, suggesting that descent was patrilineal with later generations buried at the tomb connected to the first generation entirely through male relatives.

While two of the daughters of the lineage who died in childhood were buried in the tomb, the complete absence of adult daughters suggests that their remains were placed either in the tombs of male partners with whom they had children, or elsewhere.

Although the right to use the tomb ran through patrilineal ties, the choice of whether individuals were buried in the north or south chambered area initially depended on the first-generation woman from whom they were descended, suggesting that these first-generation women were socially significant in the memories of this community.

There are also indications that 'stepsons' were adopted into the lineage, the researchers say -- males whose mother was buried in the tomb but not their biological father, and whose mother had also had children with a male from the patriline. Additionally, the team found no evidence that another eight individuals were biological relatives of those in the family tree, which might further suggest that biological relatedness was not the only criterion for inclusion. However, three of these were women and it is possible that they could have had a partner in the tomb but either did not have any children or had daughters who reached adulthood and left the community so are absent from the tomb.

Dr Chris Fowler of Newcastle University, the first author and lead archaeologist of the study, said: "This study gives us an unprecedented insight into kinship in a Neolithic community. The tomb at Hazleton North has two separate chambered areas, one accessed via a northern entrance and the other from a southern entrance, and just one extraordinary finding is that initially each of the two halves of the tomb were used to place the remains of the dead from one of two branches of the same family. This is of wider importance because it suggests that the architectural layout of other Neolithic tombs might tell us about how kinship operated at those tombs."

Iñigo Olalde of the University of the Basque Country and Ikerbasque, the lead geneticist for the study and co-first author, said: "The excellent DNA preservation at the tomb and the use of the latest technologies in ancient DNA recovery and analysis allowed us to uncover the oldest family tree ever reconstructed and analyse it to understand something profound about the social structure of these ancient groups."

David Reich at Harvard University, whose laboratory led the ancient DNA generation, added: "This study reflects what I think is the future of ancient DNA: one in which archaeologists are able to apply ancient DNA analysis at sufficiently high resolution to address the questions that truly matter to archaeologists."

Ron Pinhasi, of the University of Vienna, said: "It was difficult to imagine just a few years ago that we would ever know about Neolithic kinship structures. But this is just the beginning and no doubt there is a lot more to be discovered from other sites in Britain, Atlantic France, and other regions."

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Researchers lay groundwork for potential dog-allergy vaccine

There have been many research efforts describing the nature and progression of dog allergies, but there have been very few applied studies that use this information to try to cure people of dog allergies entirely by artificially inducing immune tolerance. But researchers have now for the first time identified candidates for those parts of the molecules that make up dog allergens that could give us precisely that: a "dog allergy vaccine."

Their findings were published in the Federation of European Biochemical Societies journal on October 26.

Being allergic to dogs is a common malady and one that is growing worldwide. Over the years, scientists have been able to identify seven different dog allergens -- molecules or molecular structures that bind to an antibody and produce an unusually strong immune response that would normally be harmless.

These seven are named Canis familiaris allergens 1 to 7 (Can f 1-7). But while there are seven, just one, Can f 1, is responsible for the majority (50-75 percent) of reactions in people allergic to dogs. It is found in dogs' tongue tissue, salivary glands, and their skin.

Researchers have yet to identify Can f 1's IgE epitopes -- those specific parts of the antigens that are recognized by the immune system and stimulate or 'determine' an immune response (which is why epitopes are also called antigen determinants). More specifically, epitopes are short amino acid sequences making up part of a protein that induces the immune response.

Epitopes bind to a specific antigen receptor on the surface of immune system antibodies, B cells, or T Cells, much like how the shape of a jigsaw puzzle piece fits the specific shape of another puzzle piece. (The part of the receptor that binds to the epitope is in turn called a paratope). Antibodies, also known as immunoglobulin, come in five different classes or isotypes: IgA (for immunoglobulin A), IgD, IgE, IgG, or IgM. The IgE isotype (only found in mammals) plays a key role in allergies and allergic diseases. There is also an IgE epitope that is the puzzle piece that fits the IgE isotype's paratope.

In recent years, there has been extensive effort at developing epitope-focused vaccines -- in this case, a vaccine against dog allergies.

"We want to be able to present small doses of these epitopes to the immune system to train it to deal with them, similar to the principle behind any vaccine," said Takashi Inui, a specialist in allergy research, professor at Osaka Prefecture University and a lead author of the study. "But we can't do this without first identifying the Can f 1's IgE epitope."

So the researchers used X-ray crystallography (in which the diffraction of x-rays through a material is analyzed to identify its 'crystal' structure) to determine the structure of the Can f 1 protein as a whole -- the first time this had ever been done.

They found that the protein's folding pattern is at first glance extremely similar to three other Can f allergens. However, the locations of surface electrical charges were quite different, which in turn suggest a series of 'residues' that are good candidates for the IgE epitope.

Using this basic data, further experimental work needs to be performed to narrow the candidates down, but the findings suggest the development of a hypoallergenic vaccine against Can f 1 -- a dog-allergy vaccine -- is within our grasp.

Read more at Science Daily

COVID-19 infection detected in deer in six Ohio locations

Scientists have detected infection by at least three variants of the virus that causes COVID-19 in free-ranging white-tailed deer in six northeast Ohio locations, the research team has reported.

Previous research led by the U.S. Department of Agriculture had shown evidence of antibodies in wild deer. This study, published today (Dec. 23, 2021) in Nature, details the first report of active COVID-19 infection in white-tailed deer supported by the growth of viral isolates in the lab, indicating researchers had recovered viable samples of the SARS-CoV-2 virus and not only its genetic traces.

Based on genomic sequencing of the samples collected between January and March 2021, researchers determined that variants infecting wild deer matched strains of the SARS-CoV-2 virus that had been prevalent in Ohio COVID-19 patients at the time. Sample collection occurred before the Delta variant was widespread, and that variant was not detected in these deer. The team is testing more samples to check for new variants as well as older variants, whose continued presence would suggest the virus can set up shop and survive in this species.

The fact that wild deer can become infected "leads toward the idea that we might actually have established a new maintenance host outside humans," said Andrew Bowman, associate professor of veterinary preventive medicine at The Ohio State University and senior author of the paper.

"Based on evidence from other studies, we knew they were being exposed in the wild and that in the lab we could infect them and the virus could transmit from deer to deer. Here, we're saying that in the wild, they are infected," Bowman said. "And if they can maintain it, we have a new potential source of SARS-CoV-2 coming in to humans. That would mean that beyond tracking what's in people, we'll need to know what's in the deer, too.

"It could complicate future mitigation and control plans for COVID-19."

A lot of unknowns remain: how the deer got infected, whether they can infect humans and other species, how the virus behaves in the animals' body, and whether it's a transient or long-term infection.

The research team took nasal swabs from 360 white-tailed deer in nine northeast Ohio locations. Using PCR testing methods, the scientists detected genetic material from at least three different strains of the virus in 129 (35.8%) of the deer sampled.

The analysis showed that B.1.2 viruses dominant in Ohio in the early months of 2021 spilled over multiple times into deer populations in different locations.

"The working theory based on our sequences is that humans are giving it to deer, and apparently we gave it to them several times," Bowman said. "We have evidence of six different viral introductions into those deer populations. It's not that a single population got it once and it spread."

Each site was sampled between one and three times, adding up to a total of 18 sample collection dates. Based on the findings, researchers estimated the prevalence of infection varied from 13.5% to 70% across the nine sites, with the highest prevalence observed in four sites that were surrounded by more densely populated neighborhoods.

White-tailed deer functioning as a viral reservoir of SARS-CoV-2 would likely result in one of two outcomes, Bowman said. The virus could mutate in deer, potentially facilitating transmission of new strains to other species, including humans, or the virus could survive in deer unmutated while it simultaneously continues to evolve in humans, and at some point when humans don't have immunity to the strains infecting deer, those variants could come spilling back to humans.

How transmission happened initially in these deer, and how it could happen across species, are among the pending questions related to these findings. The research team speculated that white-tailed deer were infected through an environmental pathway -- possibly by drinking contaminated water. Research has shown that the virus is shed in human stool and detectable in wastewater.

The white-tailed deer tested for this study were part of a population control initiative, so they are not a transmission threat.

Though there are an estimated 600,000 white-tailed deer in Ohio and 30 million in the United States, Bowman said this sampling focused on locations close to dense human populations and is not representative of all free-ranging deer.

Read more at Science Daily

Engineers test an idea for a new hovering rover

Aerospace engineers at MIT are testing a new concept for a hovering rover that levitates by harnessing the moon's natural charge.

Because they lack an atmosphere, the moon and other airless bodies such as asteroids can build up an electric field through direct exposure to the sun and surrounding plasma. On the moon, this surface charge is strong enough to levitate dust more than 1 meter above the ground, much the way static electricity can cause a person's hair to stand on end.

Engineers at NASA and elsewhere have recently proposed harnessing this natural surface charge to levitate a glider with wings made of Mylar, a material that naturally holds the same charge as surfaces on airless bodies. They reasoned that the similarly charged surfaces should repel each other, with a force that lofts the glider off the ground. But such a design would likely be limited to small asteroids, as larger planetary bodies would have a stronger, counteracting gravitational pull.

The MIT team's levitating rover could potentially get around this size limitation. The concept, which resembles a retro-style, disc-shaped flying saucer, uses tiny ion beams to both charge up the vehicle and boost the surface's natural charge. The overall effect is designed to generate a relatively large repulsive force between the vehicle and the ground, in a way that requires very little power. In an initial feasibility study, the researchers show that such an ion boost should be strong enough to levitate a small, 2-pound vehicle on the moon and large asteroids like Psyche.

"We think of using this like the Hayabusa missions that were launched by the Japanese space agency," says lead author Oliver Jia-Richards, a graduate student in MIT's Department of Aeronautics and Astronautics. "That spacecraft operated around a small asteroid and deployed small rovers to its surface. Similarly, we think a future mission could send out small hovering rovers to explore the surface of the moon and other asteroids."

The team's results appear in the current issue of the Journal of Spacecraft and Rockets. Jia-Richards' co-authors are Paulo Lozano, the M. Alemán-Velasco Professor of Aeronautics and Astronautics and director of MIT's Space Propulsion Lab; and former visiting student Sebastian Hampl, now at McGill University.

Ionic force

The team's levitating design relies on the use of miniature ion thrusters, called ionic-liquid ion sources. These small, microfabricated nozzles are connected to a reservoir containing ionic liquid in the form of room-temperature molten salt. When a voltage is applied, the liquid's ions are charged and emitted as a beam through the nozzles with a certain force.

Lozano's team has pioneered the development of ionic thrusters and has used them mainly to propel and physically maneuver small satellites in space. Recently, Lozano had seen research showing the levitating effect of the moon's charged surface on lunar dust. He also considered the electrostatic glider design by NASA and wondered: Could a rover fitted with ion thrusters produce enough repulsive, electrostatic force to hover on the moon and larger asteroids?

To test the idea, the team initially modeled a small, disk-shaped rover with ion thrusters that charged up the vehicle alone. They modeled the thrusters to beam negatively charged ions out from the vehicle, which effectively gave the vehicle a positive charge, similar to the moon's positively charged surface. But they found this was not enough to get the vehicle off the ground.

"Then we thought, what if we transfer our own charge to the surface to supplement its natural charge?" Jia-Richards says.

By pointing additional thrusters at the ground and beaming out positive ions to amplify the surface's charge, the team reasoned that the boost could produce a bigger force against the rover, enough to levitate it off the ground. They drew up a simple mathematical model for the scenario and found that, in principle, it could work.

Based on this simple model, the team predicted that a small rover, weighing about two pounds, could achieve levitation of about one centimeter off the ground, on a large asteroid such as Psyche, using a 10-kilovolt ion source. To get a similar liftoff on the moon, the same rover would need a 50-kilovolt source.

"This kind of ionic design uses very little power to generate a lot of voltage," Lozano explains. "The power needed is so small, you could do this almost for free."

In suspension

To be sure the model represented what could happen in a real environment in space, they ran a simple scenario in Lozano's lab. The researchers manufactured a small hexagonal test vehicle weighing about 60 grams and measuring about the size of a person's palm. They installed one ion thruster pointing up, and four pointing down, and then suspended the vehicle over an aluminum surface from two springs calibrated to counteract Earth's gravitational force. The entire setup was placed within a vacuum chamber to simulate the airless environment of the moon and asteroids.

The researchers also suspended a tungsten rod from the experiment's springs, and used its displacement to measure how much force the thrusters produced each time they were fired. They applied various voltages to the thrusters and measured the resulting forces, which they then used to calculate the height the vehicle alone could have levitated. They found these experimental results matched with predictions of the same scenario from their model, giving them confidence that its predictions for hovering a rover on Psyche and the moon were realistic.

The current model is designed to predict the conditions required to simply achieve levitation, which happened to be about 1 centimeter off the ground for a 2-pound vehicle. The ion thrusters could generate more force with larger voltage to lift a vehicle higher off the ground. But Jia-Richards says the model would need revising, as it doesn't account for how the emitted ions would behave at higher altitudes.

"In principle, with better modeling, we could levitate to much higher heights," he says.

In that case, Lozano says future missions to the moon and asteroids could deploy rovers that use ion thrusters to safely hover and maneuver over unknown, uneven terrain.

Read more at Science Daily

Exquisitely preserved embryo found inside fossilized dinosaur egg

A 72 to 66-million-year-old embryo found inside a fossilised dinosaur egg sheds new light on the link between the behaviour of modern birds and dinosaurs, according to a new study.

The embryo, dubbed 'Baby Yingliang', was discovered in the Late Cretaceous rocks of Ganzhou, southern China and belongs to a toothless theropod dinosaur, or oviraptorosaur. Among the most complete dinosaur embryos ever found, the fossil suggests that these dinosaurs developed bird-like postures close to hatching.

Scientists found the posture of 'Baby Yingliang' unique among known dinosaur embryos -- its head lies below the body, with the feet on either side and the back curled along the blunt end of the egg. Previously unrecognised in dinosaurs, this posture is similar to that of modern bird embryos.

In modern birds, such postures are related to 'tucking' -- a behaviour controlled by the central nervous system and critical for hatching success. After studying egg and embryo, researchers believe that such pre-hatching behaviour, previously considered unique to birds, may have originated among non-avian theropods.

Led by scientists from the University of Birmingham and China University of Geosciences (Beijing), the research team from institutions in China, UK and Canada today published its findings in iScience.

The embryo is articulated in its life position without much disruption from fossilisation. Estimated to be 27 cm long from head to tail, the creature lies inside a 17-cm-long elongatoolithid egg. The specimen is housed in Yingliang Stone Nature History Museum.

Fion Waisum Ma, joint first author and PhD researcher at the University of Birmingham, said: "Dinosaur embryos are some of the rarest fossils and most of them are incomplete with the bones dislocated. We are very excited about the discovery of 'Baby Yingliang' -- it is preserved in a great condition and helps us answer a lot of questions about dinosaur growth and reproduction with it.

"It is interesting to see this dinosaur embryo and a chicken embryo pose in a similar way inside the egg, which possibly indicates similar prehatching behaviours."

'Baby Yingliang' was identified as an oviraptorosaur based on its deep, toothless skull. Oviraptorosaurs are a group of feathered theropod dinosaurs, closely related to modern-day birds, known from the Cretaceous of Asia and North America. Their variable beak shapes and body sizes are likely to have allowed them to adopt a wide range of diets, including herbivory, omnivory and carnivory.

Birds are known to develop a series of tucking postures, in which they bend their body and bring their head under their wing, soon before hatching. Embryos that fail to attain such postures have a higher chance of death due to unsuccessful hatching.

By comparing 'Baby Yingliang' with the embryos of other theropods, long-necked sauropod dinosaurs and birds, the team proposed that tucking behaviour, which was considered unique to birds, first evolved in theropod dinosaurs many tens or hundreds of millions of years ago. Additional discoveries of embryo fossils would be invaluable to further test this hypothesis.

Professor Lida Xing from China University of Geosciences (Beijing), joint first author of the study, said: "This dinosaur embryo was acquired by the director of Yingliang Group, Mr Liang Liu, as suspected egg fossils around the 2000. During the construction of Yingliang Stone Nature History Museum in 2010s, museum staff sorted through the storage and discovered the specimens.

"These specimens were identified as dinosaur egg fossils. Fossil preparation was conducted and eventually unveiled the embryo hidden inside the egg. This is how 'Baby Yingliang' was brought to light."

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The Hitchhiker’s guide to the soil

The interaction of fungi and bacteria in the transport of viruses in the soil ecosystem has been examined by a UFZ research team in a study recently published in the journal of the International Society for Microbial Ecology (ISME Journal). The scientists showed a novel mechanism of viral transport by bacterial shuttles traveling along fungal hyphae. Bacteria thereby benefit from taking along viruses on the conquest of new habitats.

There are up to one billion viruses in just one gram of soil. However, little is known about their influence on the nutrient and carbon cycle in the soil ecosystem. Soils can sometimes be inhospitable places. Dry zones and air-filled soil pores are almost impossible obstacles for bacteria and viruses. In order for them to move around -- for example, to get to a place with better conditions -- they need water. But the situation is not completely hopeless. Because there is an excellently developed infrastructure in the soil: the fungal network. Fungi are always in search of water and nutrients. To do this, they form hyphae, long, thin threads that run through the soil as a widely branched network. Fungi are thus able to bridge dry and nutrient-poor zones.

In an earlier study, UFZ researchers showed that soil bacteria use the mucus-covered fungal hyphae in order to move around on them and thus reach new food sources. In their current study, the research team led by environmental microbiologist Dr. Lukas Y. Wick has now been able to identify another beneficiary of the underground fungal network. "Phages, i.e. viruses that have bacteria as their sole target, also travel this fungal highway," says Wick. "Not independently but rather by hitching a ride with bacteria. Physical forces cause the viruses to adhere to the surface of bacteria -- much like mussels adhere to the hull of a ship." In this way, viruses hitch a ride through the soil -- until they arrive at a place that is better suited for them. But what exactly is a good place for soil-dwelling viruses?

"Wherever the host bacteria of the viruses are found," says Wick. "Not every phage can infect every bacterium," says Wick. "Because of a kind of lock-and-key principle, phages can smuggle their genetic material only into their respective host bacteria." If this succeeds, the bacterium is reprogrammed to produce new phages. The bacterial cell then bursts, thereby releasing the phages of the next generation. These can then once again infect new host bacteria. "The phages are highly efficient at this. This obviously also gives the shuttle bacteria a real advantage," says Wick. "We were able to show that soil bacteria with phages attached to them were able to spread far better in their new location than bacteria without this viral baggage."

It is well known from macro-ecology that migratory species can cause problems for the established residents of a habitat. Also that invasive species can bring pathogens that increasingly contribute to the displacement of native species. The UFZ research group therefore interpreted their data using MAFIA (MAecological Framework of Invasive Aliens), a well-known model of invasion ecology. "With our fungus-bacteria-phage system, we were able to detect the same invasion patterns on a micro-scale as we did in the macro-ecological system," says Wick. "And because our microbial laboratory model can be quickly and easily sampled and modified, it could be used as a model system to answer various questions and hypotheses in invasion ecology -- such as the transport of pests or pathogens."

For their studies, the research team recreated a micro-attack of bacteria and phages in the laboratory. For this purpose, two zones with culture medium were used. These were connected to each other only via fungal hyphae. "In Zone A, we used typical soil bacteria as shuttles as well as phages that cannot harm this bacterial species," explains Xin You, first author of the study and PhD student at the UFZ Department of Environmental Microbiology. "Zone B was colonised with a phage-specific host bacterium." In different experimental approaches, the research team had the shuttle bacteria travel along the fungal hyphae highway with and without viral baggage. "The result was clear: the bacteria-phage duo had a clear advantage in the invasion of Zone B," says You. "The shuttle bacteria benefited from the power of the phages, which effectively disabled their host bacteria and thus also eliminated food competition for the invading bacteria."

Read more at Science Daily

Where does the special scent of thyme and oregano come from?

Thyme and oregano are not only popular herbs for cooking, but also valuable medicinal plants. Their essential oils contain thymol and carvacrol which impart the typical flavors and are medically important. A team from Martin Luther University Halle-Wittenberg (MLU) and Purdue University in the USA has now fully identified how the plants produce these two substances. The results could simplify the breeding process and improve the pharmaceutical value of thyme and oregano. The study appears in the journal Proceedings of the National Academy of Sciences.

Thymol, which is mainly extracted from thyme, has secretolytic, antibacterial and antispasmodic properties. The plant is therefore often used in tea for colds, cough syrups and as an herbal remedy for bronchitis. In contrast, oregano contains particularly high levels of carvacrol, which has similar properties. Its smell is often associated with pizza sauce and other Mediterranean dishes. Both substances are chemically closely related and are produced by thyme and oregano in multi-stage processes. "It's like a production line in a factory: Every step needs to be coordinated and the desired product only emerges when the steps are carried out in the right order," explains Professor Jörg Degenhardt from the Institute of Pharmacy at MLU. Instead of machines, specific biomolecules -- enzymes -- carry out this work in special glands on the surface of the leaves.

Together with researchers from Purdue University in the USA, the team in Halle decoded the individual production steps, thereby solving a decades-old mystery. "For a long time it was assumed that p-Cymene was an intermediate product of thymol and carvacrol synthesis. However, it was chemically not feasible for thymol or carvacrol to ultimately be produced from this substance," says Degenhardt. In fact, normal production of the two substances does not produce any p-Cymene at all, but rather an extremely unstable intermediate product. "This is only present for a few moments in the plant cells, which is why observing it is so difficult. However, it represents the hitherto missing step in the synthesis of the two substances," says Degenhardt. The processes start out the same for both thymol and carvacrol; only in step four do different enzymes that produce the respective substances come into play. In a fifth step, thymol and carvacrol can be further converted to thymohydroquinone and thymoquinone, which have anti-inflammatory and anti-tumour effects.

The researchers were also able to use these new findings to genetically reprogramme a species of tobacco, the model plant N. benthamiana, to produce thymol. "Even though this only happened in small quantities, it meant that we were able to fully understand the synthesis pathways and the associated enzymes," summarises Degenhardt.

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First genetic risk factors identified for sudden unexplained death in children after age one

A new study found that changes in specific genes may contribute each year to the roughly 400 sudden unexplained deaths in children (SUDC) aged one year and older -- and separately from sudden infant death syndrome (SIDS).

Children younger than 1 year old who die suddenly are diagnosed with SIDS, and older children with SUDC. But the conditions likely have many factors in common, say the study authors. Although SIDS causes 3 times as many deaths as SUDC each year, it receives more than 20 times the research funding. Parents who lost a child older than age 1 have had few options to support their search for answers, and no research organization to join.

For this reason, study author Laura Gould, after losing her daughter, Maria, to SUDC at the age of 15 months in 1997, asked NYU Langone Health neurologist Orrin Devinsky, MD , to co-found the SUDC Registry and Research Collaborative (SUDCRRC). Since 2014, registry staff have worked with bereaved parents to enroll their families in the registry, which collects and analyzes genetic specimens from parents and their deceased child. Such molecular autopsies are not currently part of the standard cause-of-death investigations conducted by most medical examiner's and coroner's offices.

Published online December 20 in the Proceedings of the National Academy of Sciences, the new study is the first to identify genetic differences present in a large group of SUDC cases, most of which involved children who died between the ages of 1 and 4.

Led by researchers from the NYU Grossman School of Medicine, the study analyzed the DNA codes of 124 sets of parents, and of the child that each couple lost to SUDC. They found that nearly 9 percent -- or 11 of the 124 children -- had DNA code changes in genes that regulate calcium function. Calcium-based signals are important for brain cell and heart muscle function. When such signals are abnormal, they may cause arrhythmias (abnormal heart rhythms) or seizures, both of which increase the risk of sudden death.

The researchers discovered that most of these DNA changes were new. The mutations were not inherited, instead arising randomly in the children of parents who did not have that genetic change, says Gould. Thus, if SUDC occurs in one child, it is unlikely to occur again if the same couple has another child. This provides some reassurance to families who want to have another child.

"Our study is the largest of its kind to date, the first to prove that there are definite genetic causes of SUDC, and the first to fill in any portion of the risk picture," says senior study author Richard Tsien, DPhil, chair of the Department of Neuroscience and Physiology and director of the Neuroscience Institute at NYU Langone. "Along with providing comfort to parents, new findings about genetic changes involved will accumulate with time, reveal the mechanisms responsible, and serve as the basis for new treatment approaches."

First Hints

"We focused on 137 genes linked by past studies to cardiac arrhythmias, epilepsy , and related conditions, because seizures and sudden cardiac death are known to be more prevalent in SUDC," says study author Dr. Devinsky, director of NYU Langone's Comprehensive Epilepsy Center. "Among the children that died, we found a tenfold greater frequency of genetic changes in these genes than in the general population."

In a partial explanation for these trends, the study's statistical analysis found that the genetic changes present in the children with SUDC occurred in clusters with similar functions, most controlling calcium channels in brain and heart muscle cells. After receiving the right signal, a cell opens the channels, enabling calcium ions to rush across membranes to create an electric current. In neurons this current triggers signals along nerve pathways, and in heart muscle cells, contractions as the heart beats.

Mutations found in the current study are known to slow calcium channel inactivation, prolong the current running through them, and potentially lead to abnormal heart rhythms that can cause the heart to stop, say the study authors. The two genes with de novo mutations in calcium processing found in more than one child in the study were RYR2 and CACNA1C, both of which are known to be linked to a cardiac arrhythmia. Other genes mutated in the SUDC group have been linked to seizures.

In addition, more than 91 percent of the children died while asleep or resting, including 50 percent of those with de novo mutations affecting genes involved with calcium physiology in the heart and brain -- CACNA1C, RYR2, CALM1, and TNNI3. Moving forward, the team plans larger studies to look at the role of neurohumoral status (sleep vs. waking, rest vs. exercise), identify more mutations that may be harmful in SUDC, and determine if the calcium channel flaws cause more dire problems in brain cells or heart muscle.

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