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The Mars Express Delivers Truly Epic Views of The Solar System’s Biggest Canyon

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The biggest known canyon in the Solar System is getting the star treatment in new images from the European Space Agency’s Mars Express orbiter.

As it whooshed by in Martian orbit, the spacecraft captured a pair of gouges in the planet’s surface that make up part of the Valles Marineris, a system of canyons known as the Grand Canyon of Mars.

 

The Martian Grand Canyon, however, makes the Earth version seem like a canyon for ants.

At 4,000 kilometers (2,485 miles) long and 200 miles wide, Valles Marineris is almost 10 times longer and 20 times wider than the vast canyon system found in North America. Earth has nothing that comes even close to comparing to Valles Marineris, which makes the feature intensely interesting to planetary scientists.

The segment images by Mars Express include sections of two chasmata, Ius on the left and Tithonium on the right. Close study of the details of these incredible natural structures can help scientists understand Mars’ geology and geological history.

The location of the two chasmata. (NASA/MGS/MOLA Science Team)

For example, Mars seems to be tectonically extinct now, with its crust fused into one discrete layer that encases the planetary interior. This is in contrast to Earth, the crust of which is divided into plates that can shift around, with a whole range of consequences.

Valles Marineris, scientists think, formed back when Mars did have tectonic plates. Recent research has proposed that the canyon system formed as the result of a widening crack between plates, a long time ago. This makes Valles Marineris very interesting indeed.

 

The images from Mars Express make the canyon look relatively shallow, but the two chasmata are incredibly large; the full resolution version is approximately 25 kilometers per pixel. Ius Chasma extends 840 kilometers in length in its entirety, and Tithonium Chasma 805 kilometers.

The orbiter is also equipped with 3D imaging capabilities, which reveal that, in this image, the canyon reaches about as deep as it can – around 7 kilometers, five times deeper than the Grand Canyon.

The topography of the two chasmata. (ESA/DLR/FU Berlin)

There are several features of note that the images reveal in the two chasmata. Within Ius, a row of jagged mountains probably formed as the two tectonic plates pulled apart. As that was some time ago, these mountains are pretty eroded.

Tithonium is partially colored a darker hue in the top part of the image. This may have come from the nearby Tharsis volcanic region to the west of the chasma. Paler mounds arise from within this dark sand; these are actually mountains that stand more than 3 kilometers tall.

However, the mountains’ tops have been scoured off thanks to erosion. This suggests that whatever material the mountain is made of is softer and weaker than the rock around it.

That rock isn’t impervious, either, though. To the lower right of the more visible of the mountains, features suggest a recent landslide of the canyon wall to the right.

An annotated map showing various features in the chasmata. (ESA/DLR/FU Berlin)

Interestingly, Mars Express has detected sulfate-bearing minerals in some of the features within Tithonium Chasma. This has been interpreted as evidence that the Chasma was once (at least partially) filled with water.

The evidence is far from conclusive, but recent detections of hydrogen in the chasma suggest that a lot of water may be bound up with minerals beneath the surface.

 

As with most Mars science, it’s difficult to make conclusions with any certainty, since we are forced – currently, at least – to study it remotely. But identifying areas of interest could help in the planning of future Mars missions, both crewed and uncrewed; sending a rover to Valles Marineris would certainly aid scientists in answering some of the burning questions that have arisen.

Images like these are scientifically useful because they help formulate and sometimes answer those questions. But they’re also just spectacularly gorgeous.

The images have been published on the ESA website.

 

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Science

Scientists Analyzed Penguin DNA And Found Something Quite Remarkable

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Penguins are no strangers to climate change. Their life history has been shaped by rising and falling temperatures, and their bodies are highly specialized for some of Earth’s most extreme conditions.

 

And yet, scientists are concerned the evolutionary path of the penguin may be grinding to a halt, thanks to what appears to be the lowest evolutionary rates ever detected in birds.

A team of international researchers has just published one of the most comprehensive studies of penguin evolution to date, which is the first to integrate data from living and fossil penguin species.

The research unveils the tumultuous life history of penguins in general, with three-quarters of all known penguin species – now represented by fossils only – already extinct.

“Over 60 million years, these iconic birds have evolved to become highly specialized marine predators, and are now well adapted to some of the most extreme environments on Earth,” the authors write.

“Yet, as their evolutionary history reveals, they now stand as sentinels highlighting the vulnerability of cold-adapted fauna in a rapidly warming world.”

On land, penguins can appear a bit ridiculous, with their awkward waddle and seemingly useless wings. But underwater, their bodies are transformed into hydrodynamic torpedoes that would make any fleeing fish wish it could fly.

 

Penguins had already lost their ability to fly 60 million years ago, before the formation of the polar ice sheets, in favor of wing-propelled diving.

The fossils and genomic data suggest the unique features that enable penguins’ aquatic lifestyles emerged early in their existence as a group, with rates of evolutionary change generally trending downwards over time.

The scientists think penguins originated on a Gondwanan micro-continent called Zealandia, which is now mostly submerged under the ocean.

The paper suggests the ancestors of modern penguins – crown penguins – emerged approximately 14 million years ago, a whole 10 million years after genetic analyses have hinted at.

This particular period would coincide with a moment of global cooling named the middle Miocene climate transition. Living penguins, however, split into separate genetic groups within the last 3 million years.

Penguins spread out across Zealandia before dispersing to South America and Antarctica multiple times, with later groups likely hitching a ride on the Antarctic Circumpolar Current.

The scientists found that almost every penguin species experienced a period of physical isolation during the Last Glacial Period.

 

Their contact with other penguins was limited during this time, as groups were forced to live in more fragmented areas of habitat further north, where they could still find food and shelter.

As a result, the DNA pool of each group became narrower, pushing species further apart genetically.

In the period of warming that followed, they moved back towards the poles, and some groups, now much more genetically distinct, crossed paths once more.

The way certain groups of penguins experienced these significant climate events offers insight into how they might cope with human-caused climate change.

The groups that increased in number when warming occurred shared some features: They were migratory, and foraged offshore. The researchers think these features allowed them to respond to changing climates better, especially the ability to look further afar for prey and to move to lower latitudes.

Those that decreased in number, on the other hand, lived in one particular place, and foraged closer to shore for food: a lifestyle that doesn’t cope too well when the conditions ‘at home’ drastically change.

 

But penguins’ ability to change might be limited by more than just lifestyle – it seems to be embedded in their genes.

It turns out that penguins have the lowest evolutionary rates yet detected in bird species, along with their sister order, Procellariiformes, which includes birds like petrels and albatrosses.

The researchers compared 17 different orders of birds overall, using several genetic signatures closely related to rates of evolutionary change.

They noticed that aquatic birds generally had slower rates of evolution than their terrestrial kin, so they think the adoption of an aquatic lifestyle might go hand-in-hand with low evolutionary rates. They also think that evolutionary rates in birds are lower in cooler climates.

The order Pelecaniformes, which includes seafaring birds like pelicans and cormorants, were a near third for lowest evolutionary rate, and waterfowl (order Anseriformes) had much lower rates than earthbound fowls like turkeys, chickens, and quails (order Galliformes).

The researchers note that the ancestral crown penguins evolved at a faster rate than living penguins, but even then, this was slow compared to other birds.

Half of all living penguin species are endangered or vulnerable, and the scientists say their slow evolutionary rates and niche lifestyles could send penguins towards a dead end.

“The current pace of warming combined with limited refugia in the Southern Ocean will likely far exceed the adaptive capability of penguins,” they write.

“The risks of future collapses are ever-present as penguin populations across the Southern Hemisphere are faced with rapid anthropogenic climate change.”

This research was published in Nature Communications.

 

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Science

Plants Appear to Be Self-Medicating by Producing Their Own Aspirin When Stressed

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You might find yourself reaching for a painkiller when a headache strikes, and it seems plants do something similar: when under stress from hazards around them, plants are capable of producing their own aspirin.

 

A new study takes a closer look at this particular self-defense mechanism in plants, and how the production of the active metabolite of aspirin – salicylic acid – is regulated. 

Where salicylic acid has been used by humans for centuries as a treatment for pain and inflammation, in plants, it plays a fundamental role in signaling, regulation, and pathogen defense.

Produced in chloroplasts (the tiny green organelles where the process of photosynthesis is carried out), it is typically generated in response to stress.

“It’s like plants use a painkiller for aches and pains, just like we do,” says plant biologist Wilhelmina van de Ven from the University of California, Riverside (UCR).

To better understand the complex chain of reactions that plants perform when under stress, van de Ven and her team performed biochemical analyses on plants mutated to block the effects of key stress signaling pathways.

Environmental stresses produce reactive oxygen species (ROS) in all living organisms. One example you might be familiar with is sunburn on your skin if you spend too long exposed to direct sunlight without any sunscreen.

 

In the case of plants, these stresses include unfriendly insects, drought, and excessive heat. While high levels of ROS in plants can be lethal, smaller amounts have an important safety function – and so regulation is key.

Researchers used Rockcress or Arabidopsis as the model plant for the experiments. They focused on an early warning molecule called MEcPP, which has also been seen in bacteria and malaria parasites.

It seems that as MEcPP is accumulated in a plant, it triggers a chemical reaction and response, which includes salicylic acid.

That knowledge could help us modify plants to be more resistant to environmental hazards in the future.

“At non-lethal levels, ROS are like an emergency call to action, enabling the production of protective hormones such as salicylic acid,” says plant geneticist Jin-Zheng Wang from UCR. “ROS are a double-edged sword.”

“We’d like to be able to use the gained knowledge to improve crop resistance. That will be crucial for the food supply in our increasingly hot, bright world.”

There’s still a lot that we don’t know about the MEcPP molecule and its function, but understanding how this mechanism works could help scientists harness it for their own use: producing plants that are better able to cope with stresses and strains.

 

We know that plants, as well as animals, are under an increasing amount of pressure from a warming world, and it’s not clear how many species are going to be able to survive as average temperatures keep on climbing.

As the researchers point out, the stresses examined in this study – reactions to high heat, constant sunlight, and a lack of water – are all being experienced by plants out in the world right now… and of course, if plants are in trouble, so are we.

“Those impacts go beyond our food,” says molecular biochemist Katayoon Dehesh from UCR.

“Plants clean our air by sequestering carbon dioxide, offer us shade, and provide habitat for numerous animals. The benefits of boosting their survival are exponential.”

The research has been published in Science Advances.

 

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Science

A Wasp, Flower, And Fly Trapped in Amber Reveal 30-Million-Year Old Microcosm

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A newly-discovered plant, a recently-discovered wasp, and a developing fly larva have been found trapped in amber, in an exquisitely-preserved moment of prehistoric ecology. 

If the image of an insect trapped in amber seems familiar, you have George Poinar, Jr. – the entomologist who made this discovery – to thank. His early work extracting insect DNA from Dominican amber directly inspired the premise of Jurassic Park.

 

His latest study documents the first fossil record of the plant genus Plukenetia, and the first record of the plant genus on the Caribbean island of Hispaniola.

“Fossil flowers of members of this family are quite rare,” said Poinar. “I could only find one previously known fossil, from sedimentary deposits in Tennessee.”

The famed Dominican amber is a fossilized form of resin from the extinct Hymenaea protera tree, which scientists think once grew in a moist tropical forest ecosystem, based on the variety of life forms its resin entombed. 

(George Poinar, Jr., 2022, Historical Biology)

This particular specimen was mined from la Cordillera Septentrional mountain range. 

There is debate over the age of Dominican amber fossils, with conflicting theories based on the microorganisms used for dating specimens. 

Some say that the presence of foraminifera – single-celled protists sometimes referred to as ‘armored amoebae’ – indicate the amber was formed roughly 20-15 million years ago.

Others suggest a date of 45-30 million years ago, based on the presence of coccoliths – plates of calcium carbonate formed by single-celled phytoplankton called coccolithophores.

 

Poinar notes this is further complicated because the amber was swished about and redeposited in turbulent sediment that later solidified into rock. What’s more, similar amber specimens discovered in Puerto Rico and Jamaica are dated to the Oligocene (33.9-23 million years ago) and the Maastrichtian-Palaeocene (72.1-66 million years ago), respectively.

He estimates this specimen to be 30 million years old.

The fossil reveals not only a new plant species but also a whole ecological microcosm, which Poinar thinks may include pollination, predation, and even parasitism.

Modern members of the Euphorbia genus (the fossilized plant’s living relatives) are indeed pollinated by small wasps, so it’s possible this wasp played a similar ecological role. 

The fossilized wasp – Hambletonia dominicana, discovered and named by Poinar in 2020 – is an encyrtid wasp, a group of parasites known for laying their offspring with the eggs or larvae of smaller insects, which become a meal for the developing young wasps.

Using high-resolution imaging, Poinar noticed a tiny gall gnat (Cecidomyiidae) larva within one of the flower’s developing seeds and the damage to the ovary capsule the gnat inhabits.

 

He thinks the wasp could have been attracted to the infected flower to lay an egg that, after hatching, would have soon parasitized the gall gnat larva. 

Of course, the wasp’s devious plot was interrupted when a blob of sticky resin abruptly froze all three organisms in the tableau they’ve been stuck in for millions of years. 

Poinar was so taken with the beauty of this fossilized moment that he compared its appearance to 20th-century art movements, with the flower’s “elegant curves” and “long lines” reminding him of Art Nouveau styles, and the wasp’s “dancing”, “decorative” shapes and “sharp angles” evoking Art Deco design.

“Based on interests, background, and current environment, everybody has their own way of interpreting visual images in the natural world,” Poinar said.

“An organism can be described, given a scientific name, and then stored away in a taxonomic hierarchy.”

Fossil studies do often focus on individual organisms and their place in the timeline of the tree of life, perhaps because it is rare to come across complete specimens, let alone such a clear indication of multispecies interaction. 

“In many cases, unrelated organisms become entombed together in amber just by chance,” Poinar said.

“But I feel that in this case, the wasp was attracted to the flower, either for obtaining nectar or in attempts to deposit an egg on the capsule that contains the fly larva.”

The paper was published in Historical Biology. 

 

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Science

A 4-Billion-Year-Old Piece of Earth’s Crust Has Been Identified Beneath Australia

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Scientists can use various clues to figure out what’s under Earth’s surface without actually having to do any digging – including firing super-fine lasers thinner than a human hair at minerals found in beach sand.

 

This technique has been used in a new study that points to a 4-billion-year-old piece of Earth’s crust about the size of Ireland, which has been sitting under Western Australia and influencing the geological evolution of the area across millions of millennia.

It might be able to provide clues to how our planet went from being uninhabitable to supporting life.

The researchers think that the huge expanse of crust would have heavily influenced the formation of rocks as old materials were mixed with new, having first appeared as one of the planet’s earliest protocrust formations and surviving multiple mountain-building events.

“When comparing our findings to existing data, it appears many regions around the world experienced a similar timing of early crust formation and preservation,” says geology PhD student and lead author Maximilian Dröellner, from Curtin University in Australia.

“This suggests a significant change in the evolution of Earth some 4 billion years ago, as meteorite bombardment waned, crust stabilized, and life on Earth began to establish.”

The lasers were used to vaporize grains of the mineral zircon, taken from sand sampled from rivers and beaches in Western Australia.

 

Technically known as laser ablation split stream-inductively coupled plasma-mass spectrometry, the method enables scientists to date the grains and compare them with others to see where they might have come from.

This gave the team an insight into the crystalline basement under Earth’s surface in this particular region – showing where the grains had originally eroded from, the forces used to create them, and how the geology of the region had built up over time.

As well as the significance of the protocrust remnant still being there – about 100,000 square kilometers (38,610 square miles) of it – the boundaries of the block will also help scientists to chart out what else is hidden away under Earth’s surface, and how it might have evolved to be in its current state.

“The edge of the ancient piece of crust appears to define an important crustal boundary controlling where economically important minerals are found,” says research supervisor geologist Milo Barham, from Curtin University.

“Recognizing these ancient crustal remnants is important for the future of optimized sustainable resource exploration.”

As you might expect after 4 billion years, there’s not much left of Earth’s original crust to study, which makes findings like this one all the more interesting and useful to experts – giving us an important window into the distant past.

 

The shifting of Earth’s crust and the swirling of the hot mantle underneath are difficult to predict and to retrospectively map out. When evidence of interior movement and geology can be found on the surface, scientists are therefore very keen to make use of it.

Further down the line, the results of the study described here could also help scientists who are looking at other planets – the way these planets are formed, how their earliest crust is shaped, and even how alien life might get established on them.

“Studying the early Earth is challenging given the enormity of time that has elapsed, but it has profound importance for understanding life’s significance on Earth and our quest to find it on other planets,” says Barham.

The research has been published in the journal Terra Nova.

 

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Science

We Have a New Record For The Fastest Star Zooming Around a Supermassive Black Hole

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A newly discovered star is so close to our galaxy’s central supermassive black hole that it completes an orbit in just four years.

That’s the shortest orbit yet for one of the stars looping around the Sagittarius A*. It’s an oval-shaped journey around the black hole that brings the star to orbital velocities over 2.5 percent of the speed of light.

 

The discovery adds fascinating new information about the strange dynamics of the center of the Milky Way.

Although our galactic center is pretty quiet compared to other galaxies, the environment around Sgr A* is an extreme sort of place. The black hole is a monster, clocking in at around 4 million times the mass of the Sun. Before astronomers confirmed its existence with a direct image, scientists inferred its presence and calculated its mass based on a star locked in orbit around Sgr A*.

That star, called S2, is just one of a group of stars known as S-stars, which follow long, sharply elliptical orbits around Sgr A*, with the black hole at one end of the ellipse. That end, at which the star is closest to the black hole, is periapse, and the way stars change their velocities as they move into and out of periapse is one of the tools that helped ‘weigh’ the black hole.

But S2 is far from the only star at the party.

A team of astrophysicists led by Florian Peissker at the University of Cologne in Germany has been looking to see what else they might turn up in this weird, high-speed treasure trove.

“S2 behaves like a large person sitting in front of you in a movie theater: It blocks your view of what’s important,” Peissker explained. “The view into the center of our galaxy is therefore often obscured by S2. However, in brief moments we can observe the surroundings of the central black hole.”

The orbits of several S stars in the galactic center. (Peissker et al., ApJ, 2022)

Researchers discovered this star, named S4716, thanks to the evolution of observation and analysis techniques. It was clearly seen in data from five different instruments on its breakneck orbit around Sgr A*.

The team calculated that its periapse was about 15 billion kilometers (9.3 billion miles) from the supermassive black hole, about 100 times the distance between Earth and the Sun. As it approaches and enters periapse, the star reaches a velocity of about 8,000 kilometers (4,970 miles) per second.

 

That’s not the closest, nor the fastest, S star in the galactic center. That honor belongs to a star named S4714, also discovered by Peissker and his colleagues, which comes as close to Sgr A* as 1.9 billion kilometers, reaching velocities up to 24,000 kilometers per second.

However, S4714 has an orbital period of 12 years. S4716, with its four-year orbit, has the shortest mean distance to the black hole throughout its entire orbit of any of the S stars discovered to date.

“For a star to be in a stable orbit so close and fast in the vicinity of a supermassive black hole was completely unexpected and marks the limit that can be observed with traditional telescopes,” Peissker said.

The discovery tidies up several oddities in previous observations attributed to other S stars. However, S4716 presents something of a new mystery: It’s not entirely clear how it got there. This, the researchers said, may take some more work to solve.

“The short-period, compact orbit of S4716 is quite puzzling,” said astrophysicist Michael Zajaček of Masaryk University in Czechia.

“Stars cannot form so easily near the black hole. S4716 had to move inwards, for example by approaching other stars and objects in the S cluster, which caused its orbit to shrink significantly.”

The research has been published in The Astrophysical Journal.

 

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Large Hadron Collider Finds Evidence of 3 Never-Before-Seen Particles

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Physicists say they’ve found evidence in data from Europe’s Large Hadron Collider for three never-before-seen combinations of quarks, just as the world’s largest particle-smasher is beginning a new round of high-energy experiments.

 

The three exotic types of particles – which include two four-quark combinations, known as tetraquarks, plus a five-quark unit called a pentaquark – are totally consistent with the Standard Model, the decades-old theory that describes the structure of atoms.

In contrast, scientists hope that the LHC’s current run will turn up evidence of physics that goes beyond the Standard Model to explain the nature of mysterious phenomena such as dark matter. Such evidence could point to new arrays of subatomic particles, or even extra dimensions in our Universe.

The LHC had been shut down for three years to upgrade its systems to handle unprecedented energy levels. That shutdown ended in April, and since then, scientists and engineers at the CERN research center on the French-Swiss border have been getting ready for today’s resumption of scientific operations.

CERN’s control center was abuzz as the LHC began its third run of data collection and analysis.

“It’s a magic moment now,” CERN Director-General Fabiola Gianotti said during today’s webcast. “We just had collisions at an unprecedented energy, 13.6 tera-electronvolts, and this opens a new era of exploration at CERN.”

 

Gianotti said the LHC’s scientists expect to collect as much data during this third run as they collected over the course of 13 years during the collider’s previous two runs. “This, of course, will increase our opportunities for discovery or for understanding the fundamental laws of the Universe,” she said.

The 27-kilometer-round (17-mile-round) ring of superconducting magnets and its particle detectors are due to be in operation around the clock for nearly four years during Run 3.

Today’s start of the run comes 10 years and a day after LHC physicists announced their biggest discovery to date: evidence for the existence of the Higgs boson, a subatomic particle that helps explain the phenomenon of mass.

The three new types of subatomic particles, described today during a CERN seminar, aren’t quite Higgs-level revelations. But they do suggest that the LHC is hot on the trail to discover still more previously unseen building blocks of the Universe.

The Large Hadron Collider smashes protons together at velocities close to the speed of light to study combinations of quarks that are known as hadrons.

 

“The more analyses we perform, the more kinds of exotic hadrons we find,” Niels Tuning, physics coordinator for the collider’s LHCb detector, said in a news release.

“We’re witnessing a period of discovery similar to the 1950s, when a ‘Particle Zoo’ of hadrons started being discovered and ultimately led to the quark model of conventional hadrons in the 1960s. We’re creating ‘Particle Zoo 2.0’.”

LHCb spokesperson Chris Parkes said studying new combinations of quarks “will help theorists develop a unified model of exotic hadrons, the exact nature of which is largely unknown”.

Most hadrons aren’t so exotic. Protons and neutrons, for instance, are made up of three quarks bound together. (In fact, the origin of the word “quark” goes back to a line from Finnegan’s Wake by James Joyce: “Three quarks for Muster Mark!”) Pions are two-quark combinations.

Four-quark and five-quark combinations are much rarer, and are thought to exist for only an instant before decaying into different types of particles.

Quarks come in six different “flavors”: up and down, top and bottom, charm and strange.

 

The LHCb team analyzed the decays of negatively charged B mesons and saw evidence for the existence of a pentaquark consisting of a charm quark and a charm antiquark, plus an up, down and strange quark. It’s the first pentaquark known to include a strange quark.

The two newly identified tetraquarks include a “doubly electrically charged” combination of four quarks: a charm quark, a strange antiquark, an up quark, and a down antiquark.

That tetraquark was spotted in combination with its neutral counterpart, which has a charm quark, a strange antiquark, an up antiquark, and a down quark. CERN says this is the first time a pair of tetraquarks has been observed together.

Some theoretical models visualize exotic hadrons as single units of tightly bound quarks. Others see them as pairs of standard hadrons that are loosely bound together, similar to the way that atoms are bound together to form molecules.

“Only time and more studies of exotic hadrons will tell if these particles are one, the other or both,” CERN says.

This article was originally published by Universe Today. Read the original article.

 

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Health

A Deadly Fungus Has Been Having Sneaky Sex, And It Could Bode Ill For Humans

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In 2009, a never-before-seen yeast emerged from the ear canal of a 70-year-old Japanese lady. Unfortunately, this yeast – known as Candida auris – is a health menace, having now spread around the world and become resistant to multiple drugs. A new study now shows it also reproduces in an unexpected way.

 

C. auris isn’t your helpful bakers or brewer’s yeast. It has a bad track record of ending up in hospitals and infecting those with weakened immune systems. Unfortunately, it doesn’t just stay in the ear, it can enter the bloodstream as well; without an effective antifungal, patients can die.  

Normally, yeast undergoes asexual reproduction through budding and splitting into daughter cells. But researchers from McMaster University in Canada have now detected evidence of sexual reproduction in C. auris. This could result in more drug-resistant and virulent strains of the fungus.

“So far, no evidence for mating and sexual reproduction have been reported in C. auris,” the team writes in their new paper.

“This study identified limited but unambiguous evidence of recombination in both the total sample and within individual clades.”

Recombination – the reshuffling of genetic information – can’t happen in asexual reproduction, meaning that at some point during the past there had to be some hanky panky on the cards (or some other way of shuffling around genetic information).

Although we haven’t seen the yeast in action, the idea that C. auris occasionally sexually reproduces is actually not as crazy as it sounds. We already know that a much more famous type of yeast, Saccharomyces cerevisiae (this is the yeast used in baking, winemaking, and brewing) will very occasionally mate with each other – particularly when undergoing stressful conditions.

 

The team didn’t catch C. auris in the act, but they were able to analyze the fungal and mitochondrial genes in 1,285 strains of fungus. This allowed them to look at the genetic differences between the five clades of C. auris, as well as within the clades themselves.

The team found some recombination, but most of it occurred before the yeast split into the five clades. Some clades have seemingly lost the ability to mate, while others have had limited recombination since the split. So, although sex might occasionally be happening, it’s absolutely not frequent.

But even infrequent sex can potentially cause new resistances or other ways of making this pathogen worse for us humans.

“The research tells us that this fungus has recombined in the past and can recombine in nature, which enables it to generate new genetic variants rather quickly,” explains McMaster’s University microbial geneticist Jianping Xu.

“That may sound frightening, but it’s a double-edged sword. Because we learned they could recombine in nature, we could possibly replicate the process in the lab, which could allow us to understand the genetic controls of virulence and drug resistance and potentially other traits that make it such a dangerous pathogen, much faster.”

Although there are lots more we need to know about C. auris, looking deep at its genes to discover a sex life is a good place to start.

The research has been published in Computational and Structural Biotechnology Journal.

 

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There’s a Change Happening to Earth’s Outer Core, as Revealed by Seismic Wave Data

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Most of our knowledge about what sits at the center of our planet comes from the study of seismic waves rolling out from earthquakes. Careful analysis of these waves can reveal the composition of rocks and metal below Earth’s surface.

 

A new study of seismic waves propagating from two different earthquakes – in similar locations but separated by a gap of 20 years – has revealed changes that are happening in Earth’s outer core, the swirling layer of liquid iron and nickel between the mantle (the rock underneath the surface) and the inner core (the deepest layer).

The outer core and the iron contained within it directly influence our planet’s magnetic field, which in turn provides protection from space and solar radiation that would otherwise make life on Earth impossible.

That makes understanding the outer core and its evolution over time vitally important. The data recorded from four seismic wave monitors across both earthquakes showed that waves from the later event traveled around one second faster when passing through the same region of the outer core.

“Something has changed along the path of that wave, so it can go faster now,” says geoscientist Ying Zhou from Virginia Tech. “The material that was there 20 years ago is no longer there.”

“This is new material, and it’s lighter. These light elements will move upward and change the density in the region where they’re located.”

 

The types of waves analyzed here are SKS waves: they pass through the mantle as shear waves (the S), then into the outer core as compressional waves (the K), then out the other side and back through the mantle again as more shear waves (the second S). The timing of that travel can be revealing.

As for the two earthquakes, both were near the Kermadec Islands in the South Pacific Ocean – the first in May 1997 and the second in September 2018, giving researchers a unique opportunity to see how Earth’s core may have changed over time.

How seismic waves travel through the outer core. (Ying Zhou)

The convection occurring in the liquid iron of Earth’s outer core as it crystalizes onto the inner core creates flowing electrical currents, which is what controls the magnetic field around us. However, the relationship between the outer core and Earth’s magnetic field isn’t fully understood – a lot of it is based on hypothetical modeling.

“If you look at the north geomagnetic pole, it’s currently moving at a speed of about 50 kilometers [31 miles] per year,” says Zhou. “It’s moving away from Canada and toward Siberia. The magnetic field is not the same every day. It’s changing.”

 

“Since it’s changing, we also speculate that convection in the outer core is changing with time, but there’s no direct evidence. We’ve never seen it.”

This new study – and potentially future studies like it – could provide useful insights into exactly how the outer core and its convection are changing. While the changes noted here aren’t huge, the more we know, the better.

In this case, Zhou suggests that lighter elements such as hydrogen, carbon, and oxygen have been released in the outer core since 1997. It corresponds to a density reduction of around 2–3 percent and a convection flow speed of about 40 kilometers (25 miles) per hour, according to the published paper.

There are currently 152 Global Seismographic Network stations around the world, monitoring seismic waves in real-time. While we can’t control the location or timing of earthquakes, we can make sure that as much data as possible is logged about them.

“We’re able to see it now,” says Zhou. “If we’re able to see it from seismic waves, in the future, we could set up seismic stations and monitor that flow.”

The research has been published in Nature Communications Earth & Environment.

 

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Science

New Study Reveals Devastating Effect on Astronaut Bones From Living in Space

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Astronauts lose decades’ worth of bone mass in space that many do not recover even after a year back on Earth, researchers said Thursday, warning that it could be a “big concern” for future missions to Mars.

 

Previous research has shown astronauts lose between 1 to 2 percent of bone density for every month spent in space, as the lack of gravity takes the pressure off their legs when it comes to standing and walking.

To find out how astronauts recover once their feet are back on the ground, a new study scanned the wrists and ankles of 17 astronauts before, during and after a stay on the International Space Station.

The bone density lost by astronauts was equivalent to how much they would shed in several decades if they were back on Earth, said study co-author Steven Boyd of Canada’s University of Calgary and director of the McCaig Institute for Bone and Joint Health.

The researchers found that the shinbone density of nine of the astronauts had not fully recovered after a year on Earth – and were still lacking around a decade’s worth of bone mass.

The astronauts who went on the longest missions, which ranged from four to seven months on the ISS, were the slowest to recover.

“The longer you spend in space, the more bone you lose,” Boyd told AFP.

 

Boyd said it is a “big concern” for planned for future missions to Mars, which could see astronauts spend years in space.

“Will it continue to get worse over time or not? We don’t know,” he said.

“It’s possible we hit a steady state after a while, or it’s possible that we continue to lose bone. But I can’t imagine that we’d continue to lose it until there’s nothing left.”

A 2020 modelling study predicted that over a three-year spaceflight to Mars, 33 percent of astronauts would be at risk of osteoporosis.

Boyd said some answers could come from research currently being carried out on astronauts who spent at least a year onboard the ISS.

Guillemette Gauquelin-Koch, the head of medicine research at France’s CNES space agency, said that the weightlessness experienced in space is “most drastic physical inactivity there is”.

“Even with two hours of sport a day, it is like you are bedridden for the other 22 hours,” said the doctor, who was not part of the study.

“It will not be easy for the crew to set foot on Martian soil when they arrive – it’s very disabling.”

 

‘The silent disease’

The new study, which was published in Scientific Reports, also showed how spaceflight alters the structure of bones themselves.

Boyd said that if you thought of a body’s bones like the Eiffel Tower, it would as if some of the connecting metal rods that hold the structure up were lost.

“And when we return to Earth, we thicken up what’s remaining, but we don’t actually create new rods,” he said.

Some exercises are better for retaining bone mass than others, the study found.

Deadlifting proved significantly more effective than running or cycling, it said, suggesting more heavy lower-body exercises in the future.

But the astronauts – who are mostly fit and in their 40s – did not tend to notice the drastic bone loss, Boyd said, pointing out that the Earth-bound equivalent osteoporosis is known as “the silent disease”.

Canadian astronaut Robert Thirsk, who has spent the most time in space, said that for him bones and muscles took the longest to recover after spaceflight.

“But within a day of landing, I felt comfortable again as an Earthling,” he said in a statement accompanying the research.

© Agence France-Presse

 

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