Monday, September 28, 2020

Time Travel Without Paradoxes Possible Say Physicists Who "Squared the Numbers"



Paradox-free time travel is theoretically possible, according to the mathematical modelling of a prodigious University of Queensland undergraduate student.

Fourth-year Bachelor of Advanced Science (Honours) student Germain Tobar has been investigating the possibility of time travel, under the supervision of UQ physicist Dr Fabio Costa.

“Classical dynamics says if you know the state of a system at a particular time, this can tell us the entire history of the system,” Mr Tobar said.

Delorean Time Machine Replica
Credit:  DeLorean Rental / Wikimedia Commons

“This has a wide range of applications, from allowing us to send rockets to other planets and modelling how fluids flow.

“For example, if I know the current position and velocity of an object falling under the force of gravity, I can calculate where it will be at any time.

“However, Einstein's theory of general relativity predicts the existence of time loops or time travel – where an event can be both in the past and future of itself – theoretically turning the study of dynamics on its head.”

Mr Tobar said a unified theory that could reconcile both traditional dynamics and Einstein’s Theory of Relativity was the holy grail of physics.

“But the current science says both theories cannot both be true,” he said.

“As physicists, we want to understand the Universe’s most basic, underlying laws and for years I’ve puzzled on how the science of dynamics can square with Einstein’s predictions.

“I wondered: “is time travel mathematically possible?”


Image: Dr Fabio Costa (left) with Bachelor of Advanced Science (Honours) student Germain Tobar.

Credit: University of Queensland

Mr Tobar and Dr Costa say they have found a way to “square the numbers” and Dr Costa said the calculations could have fascinating consequences for science.

“The maths checks out – and the results are the stuff of science fiction,” Dr Costa said.

“Say you travelled in time, in an attempt to stop COVID-19’s patient zero from being exposed to the virus.

“However if you stopped that individual from becoming infected – that would eliminate the motivation for you to go back and stop the pandemic in the first place.

“This is a paradox – an inconsistency that often leads people to think that time travel cannot occur in our universe.

“Some physicists say it is possible, but logically it’s hard to accept because that would affect our freedom to make any arbitrary action.

“It would mean you can time travel, but you cannot do anything that would cause a paradox to occur.”

However the researchers say their work shows that neither of these conditions have to be the case, and it is possible for events to adjust themselves to be logically consistent with any action that the time traveller makes.

“In the coronavirus patient zero example, you might try and stop patient zero from becoming infected, but in doing so you would catch the virus and become patient zero, or someone else would,” Mr Tobar said.

“No matter what you did, the salient events would just recalibrate around you.

“This would mean that – no matter your actions - the pandemic would occur, giving your younger self the motivation to go back and stop it.

“Try as you might to create a paradox, the events will always adjust themselves, to avoid any inconsistency.

“The range of mathematical processes we discovered show that time travel with free will is logically possible in our universe without any paradox.”

The research is published in Classical and Quantum Gravity (DOI: 10.1088/1361-6382/aba4bc).




Contacts and sources:
Dominic Jarvis
University of Queensland

 





Saturday, September 26, 2020

Scientists Discover Why Tarantulas Come in Vivid Blues and Greens



Researchers from Yale-NUS College and Carnegie Mellon University have discovered that tarantulas have the ability to see in colour, contrary to previous thought, and suggest functions for their green and blue coloration

A Cobalt Blue Tarantula (Hapolpelma lividum), with brilliant cobalt blue hair-like setae on its legs. 
Image provided by Bastian Rast.

Why are some tarantulas so vividly coloured? Scientists have puzzled over why these large, hairy spiders, active primarily during the evening and at night-time, would sport such vibrant blue and green colouration – especially as they were long thought to be unable to differentiate between colours, let alone possess true colour vision.

In a recent study, researchers from Yale-NUS College and Carnegie Mellon University (CMU) find support for new hypotheses: that these vibrant blue colours may be used to communicate between potential mates, while green colouration confers the ability to conceal among foliage. Their research also suggests that tarantulas are not as colour-blind as previously believed, and that these arachnids may be able to perceive the bright blue tones on their bodies. The study was published in Proceedings of the Royal Society B on 23 September, and is featured on the front cover of the current (30 September 2020) issue.

The research was jointly led by Dr Saoirse Foley from CMU, and Dr Vinod Kumar Saranathan, in collaboration with Dr William Piel, both from the Division of Science at Yale-NUS College. To understand the evolutionary basis of tarantula colouration, they surveyed the bodily expression of various opsins (light-sensitive proteins usually found in animal eyes) in tarantulas. They found, contrary to current assumptions, that most tarantulas have nearly an entire complement of opsins that are normally expressed in day-active spiders with good colour vision, such as the Peacock Spider.

These findings suggest that tarantulas, long thought to be colour-blind, can perceive the bright blue colours of other tarantulas. Using comparative phylogenetic analyses, the team reconstructed the colours of 110 million-year-old tarantula ancestors and found that they were most likely blue. They further found that blue colouration does not correlate with the ability to urticate or stridulate – both common defence mechanisms — suggesting that it did not evolve as a means of deterring predators, but might instead be a means of attracting potential mates.

The team also found that the evolution of green colouration appears to depend on whether the species in question is arboreal (tree-dwelling), suggesting that this colour likely functions in camouflage.

“While the precise function of blueness remains unclear, our results suggest that tarantulas may be able to see these blue displays, so mate choice is a likely potential explanation. We have set an impetus for future projects to include a behavioural element to fully explore these hypotheses, and it is very exciting to consider how further studies will build upon our results,” said Dr Foley.

The team’s survey of the presence of blue and green colouration across tarantulas turned up more interesting results. They found that the blue colouration has been lost more frequently than it is gained across tarantulas. The losses are mainly in species living in the Americas and Oceania, while many of the gains are in the Old World (European, Asian, and African) species. They also found that green colouration has evolved only a few times, but never lost.

“Our finding that blueness was lost multiple times in the New World, while regained in the Old, is very intriguing. This leaves several fascinating avenues for future research, when considering how the ecological pressures in the New and the Old Worlds vary,” said Dr Saranathan. “For instance, one hypothesis would be differences in the light environments of the habitats between the New and the Old World, which can affect how these colours might be perceived, if indeed they can be, as our results suggest.”



Contacts and sources:

Yale-NUS College

Publication: The evolution of coloration and opsins in tarantulas
Saoirse Foley, Vinodkumar Saranathan, William H. Piel. . Proceedings of the Royal Society B: Biological Sciences, 2020; 287 (1935): 20201688 DOI: 10.1098/rspb.2020.1688






Friday, September 25, 2020

Solving the Strange, Unusually Geometric Pattern of Storms on Jupiter




At the south pole of Jupiter lurks a striking sight—even for a gas giant planet covered in colorful bands that sports a red spot larger than the earth. Down near the south pole of the planet, mostly hidden from the prying eyes of humans, is a collection of swirling storms arranged in an unusually geometric pattern.

Storms gathered at the south pole of Jupiter, as imaged by the Juno probe.


Credit: NASA-JPL/Caltech

Since they were first spotted by NASA's Juno space probe in 2019, the storms have presented something of a mystery to scientists. The storms are analogous to hurricanes on Earth. However, on our planet, hurricanes do not gather themselves at the poles and twirl around each other in the shape of a pentagon or hexagon, as do Jupiter's curious storms.

Under some simulated conditions, and on Saturn, cyclonic storms merge with one another instead of repelling each other.


Credit: Caltech


Now, a research team working in the lab of Andy Ingersoll, Caltech professor of planetary science, has discovered why Jupiter's storms behave so strangely. They did so using math derived from a proof written by Lord Kelvin, a British mathematical physicist and engineer, nearly 150 years ago.

Ingersoll, who was a member of the Juno team, says Jupiter's storms are remarkably similar to the ones that lash the East Coast of the United States every summer and fall, just on a much larger scale.

"If you went below the cloud tops, you would probably find liquid water rain drops, hail, and snow," he says. "The winds would be hurricane-force winds. Hurricanes on Earth are a good analog of the individual vortices within these arrangements we see on Jupiter, but there is nothing so stunningly beautiful here."

Under some experimental conditions, and on Jupiter, cyclonic storms repel each other, rather than merging.


Credit:  Caltech


As on Earth, Jupiter's storms tend to form closer to the equator and then drift toward the poles. However, Earth's hurricanes and typhoons dissipate before they venture too far from the equator. Jupiter's just keep going until they reach the poles.

"The difference is that on the earth hurricanes run out of warm water and they run into continents," Ingersoll says. Jupiter has no land, "so there's much less friction because there's nothing to rub against. There's just more gas under the clouds. Jupiter also has heat left over from its formation that is comparable to the heat it gets from the sun, so the temperature difference between its equator and its poles is not as great as it is on Earth."

However, Ingersoll says, this explanation still does not account for the behavior of the storms once they reach Jupiter's south pole, which is unusual even compared to other gas giants. Saturn, which is also a gas giant, has one enormous storm at each of its poles, rather than a geometrically arranged collection of storms.

The answer to the mystery of why Jupiter has these geometric formations and other planets do not, Ingersoll and his colleagues discovered, could be found in the past, specifically in work conducted in 1878 by Alfred Mayer, an American physicist, and Lord Kelvin. Mayer had placed floating circular magnets in a pool of water and observed that they would spontaneously arrange themselves into geometric configurations, similar to those seen on Jupiter, with shapes that depended on the number of magnets. Kelvin used Mayer's observations to develop a mathematical model to explain the magnets' behavior.

"Back in the 19th century, people were thinking about how spinning pieces of fluid would arrange themselves into polygons," Ingersoll says. "Although there were lots of laboratory studies of these fluid polygons, no one had thought of applying that to a planetary surface."

Under some simulated conditions, and on Saturn, cyclonic storms merge with one another instead of repelling each other


Credit: Caltech

  
To do so, the research team used a set of equations known as the shallow-water equations to build a computer model of what might be happening on Jupiter, and began to run simulations.

"We wanted to explore the combination of parameters that makes these cyclones stable," says Cheng Li (Phd '17), lead author and 51 Pegasi b postdoctoral fellow at UC Berkeley. "There are established theories that predict that cyclones tend to merge at the pole due to the rotation of the planet and that's what we found in the initial trial runs."

Eventually, however, the team found that a Jupiter-like stable geometric arrangement of storms would form if the storms were each surrounded by a ring of winds that turned in the opposite direction from the spinning storms, or a so-called anticyclonic ring. The presence of anticyclonic rings causes the storms to repel each other, rather than merge.

Ingersoll says the research could help scientists better understand how weather on Earth behaves.

"Other planets provide a much wider range of behaviors than what you see on Earth," he says, "so you study the weather on other planets in order to stress-test your theories."

The paper, titled, "Modeling the Stability of Polygonal Patterns of Vortices at the Poles of Jupiter as Revealed by the Juno Spacecraft," appears in the September 8 Issue of the Proceedings of the National Academy of Sciences. Co-authors are Cheng Li of UC Berkeley, and Harriet Brettle (MS '19) and undergraduate student Alexandra Klipfel, both of Caltech.



Contacts and sources:
Emily Velasco
Caltech
 






Silk Masks Offers More Protection than Cotton or Synthetics for COVID-19 Prevention

With personal protective equipment still in short supply, researchers at the University of Cincinnati examined what common household fabrics might work best as a face covering.

UC postdoctoral researcher Adam Parlin holds up a silk face mask. A UC study found that silk masks might work better at repelling COVID-19 than cotton or synthetic masks. 
Photo/Joseph Fuqua II/UC Creative + Brand

Next to a single-use N95 respirator or surgical mask, UC found the best alternative could be made by a hungry little caterpillar. Silk face masks are comfortable, breathable and repel moisture, which is a desirable trait in fighting an airborne virus.

Perhaps best of all, silk contains natural antimicrobial, antibacterial and antiviral properties that could help ward off the virus, said Patrick Guerra, assistant professor of biology in UC’s College of Arts and Sciences.

Studies have shown that copper, in particular, can kill bacteria and viruses on contact. And that’s where the little caterpillars have their own superpower, Guerra said.

“Copper is the big craze now. Silk has copper in it. Domesticated silk moths eat mulberry leaves. They incorporate copper from their diet into the silk,” Guerra said.

The project demonstrates UC's commitment to making an impact in the community as described in UC's strategic direction called Next Lives Here.


UC biologist Patrick Guerra has helped to unravel the mysteries of monarch butterfly migration. His knowledge of entomology inspired his research into silk masks.

 Photo/Lisa Ventre/UC Creative + Brand



Many health care providers are wearing a surgical mask in combination with an N95 respirator. The outer covering helps prolong the life of the N95 respirator by keeping it clean. Guerra, whose wife, Evelyn, is a medical doctor, said silk might be an especially good choice for this outer cover as they perform similarly to surgical masks that are in short supply.

“Cotton traps moisture like a sponge. But silk is breathable. It’s thinner than cotton and dries really fast,” Guerra said.

With COVID-19 surging in parts of the United States, face masks have become a focal point of prevention.

In the UC biology lab, researchers tested cotton and polyester fabric along with multiple types of silk to see how effective a barrier each is for repelling water, representing respiratory droplets containing the virus. They found that silk worked far better as a moisture barrier than either polyester or cotton, both of which absorb water droplets quickly.

UC’s study concluded that silk performs similarly to surgical masks when used in conjunction with respirators but has the added advantages of being washable and repelling water, which would translate to helping to keep a person safer from the airborne virus.

“The ongoing hypothesis is that coronavirus is transmitted through respiratory droplets,” Guerra said. “If you wore layers of silk, it would prevent the droplets from penetrating and from being absorbed. Recent work by other researchers also found that increasing layers of silk improves filtration efficiency. This means that silk material can repel and filter droplets. And this function improves with the number of layers.”

The study was published this month in the journal Plos One.


Postdoctoral researcher Adam Parlin holds up a styrofoam head draped with a silk mask. UC biologists examined how well face masks made from different materials repelled water or aerosolized droplets. Silk impeded the penetration and absorption of liquid and aerosolized droplets better than cotton or synthetic fabrics. 
Photo/Joseph Fuqua II/UC Creative + Brand


Because of the timeliness of their work during the global pandemic, UC researchers posted their results early to medRxiv, a preprint server for health sciences.

“We’re trying to address this critical problem. Health care workers still don’t have enough personal protective equipment, namely N95 respirators or basic surgical masks,” Guerra said.

Previously, Guerra studied the neurobiology behind the incredible multigenerational migration of monarch butterflies across North America. As an entomologist, he’s studied everything from giant lobster katydids in South America to Madagascar hissing cockroaches.

Now UC students raise silk moths (Bombyx mori) in Guerra’s biology lab.

UC postdoctoral researcher Adam Parlin wrote an undergraduate instruction manual for care and feeding of the moths he titled, “How to Train Your Bombyx,” a riff on the DreamWorks’ animated dragon movies. The cover features a picture of the adult moth. With its big head, enormous eyes and fanned wings, the silk moth indeed resembles a night fury from the films.

“These little guys are entertaining,” he said.

A time-lapse video shows a silkworm building a cocoon in 72 hours.
<iframe width="700" height="403" src="https://www.youtube.com/embed/2YSjS2kEmVM" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 Video/Adam Parlin

As part of his research, Parlin studied how the caterpillars make their protective silk cocoons. When they reach a point in their life cycle, the caterpillars become manic workaholics. For 72 straight hours they spin and spin their silk to create a luxurious, breathable fortress where they can pupate safely into a fuzzy white moth.

UC found that silk repelled moisture better than other common fabrics used in face masks. 

Photo/Joseph Fuqua II/UC Creative + Brand

Researchers created cardboard arenas with a wooden dowel in the center upon which the caterpillars can spin their silk cocoons. The caterpillars work methodically and nonstop, initially spinning silk from the top of the dowel at an angle to the cardboard like a tent. Once the tent is finished, they work in earnest on building their grape-sized cocoon in a corner of it.

“If the cocoon gets damaged, they just build a second layer around it,” Parlin said.

The moisture-trapping cocoon provides an ideal microclimate to keep the caterpillars happy despite any sudden changes in the weather.

“The silk cocoons prevent moisture from getting in and keeps the animal from desiccation or drying out,” Guerra said.

UC postdoctoral researcher Adam Parlin is studying butterfly migration in UC assistant professor Patrick Guerra's biology lab.

 Photo/Joseph Fuqua II/UC Creative + Brand

Now Guerra is investigating how long the virus survives on silk and other materials. 

As shortages of personal protective equipment continue to plague health care providers, Guerra said homemade masks will continue to play an important role in keeping people safe from COVID-19.

“Silk has been with us for a while — since the days of the Silk Road,” Guerra said. “It’s not a new fabric, yet now we’re finding all these new uses for it.”






Contacts and sources:
David Olejarz / Michael Miller
University of Cincinnati


Publication: A laboratory-based study examining the properties of silk fabric to evaluate its potential as a protective barrier for personal protective equipment and as a functional material for face coverings during the COVID-19 pandemic Adam F. Parlin,Samuel M. Stratton,Theresa M. Culley,Patrick A. Guerra https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0239531 http://dx.doi.org/10.1371/journal.pone.0239531






Navy Invention Detects Feverish People in Crowds Up to 200 Yards Away, Available for Licensing

A federal research facility in Crane, Indiana, has developed a temperature scanning sensor system and software to help contain the coronavirus.

The U.S. Naval Surface Warfare Center's "sensor agnostic thermal imaging system" was licensed to Greene County General Hospital, according to a news release Tuesday, allowing the staff to detect feverish persons up to 200 yards away.

The Naval Surface Warfare Center, Crane Division has licensed its sensor agnostic thermal imaging system to Greene County General Hospital to screen incoming staff and patients for fever, a symptom of COVID-19.


Credit: Courtesy NSWC-Crane

"Since the tech can detect temperatures in a crowd and from a long distance, it's more flexible than other solutions we had been looking at," said Stacy Burris, the hospital's director of community outreach. "This will cause less interruption in normal operations and allow for more social distancing between staff and anyone coming into the hospital. That could mean less screening staff having to quarantine from exposure."

The U.S. has suffered more than 200,000 deaths from the coronavirus, adding to the one million globally. And public health experts are concerned that a COVID-19 resurgence is mounting as the weather cools and schools and universities reopen.

High body temperature is a key indicator of COVID-19 infection. Burris said the hospital had not found a system for fever detection until they learned of Crane's thermal imaging technology.

"Without Crane, we might still be weighing the pros and cons of other solutions," she said. "Instead, we're already working to schedule a time for the Crane scientists to set the equipment up."

The software runs on any laptop with USB capability, which is paired with a capture card, a commercial infrared sensor, and a calibrated black body, a temperature reference tool that the software compares with the temperature of a person.

The Navy's software-enabled system, invented by Aaron Cole and Marcin Malec, is also capable of detecting fevers in near real-time - every 0.016 seconds and works on individuals and moving crowds.

Tech Transfer Opportunity

The Navy's temp-scanning invention, a novel combination of technical knowledge, sensors, and software, was made available to the hospital via a royalty-free license agreement and a cooperative research and development agreement, with support from Radius Indiana, an economic development agency, and TechLink, the Department of Defense's national partnership intermediary for tech transfer.

In April, the Navy lab's Tech Transfer Office, led by Ms. Jenna Dix, made its 300+ patent portfolio available through a new "Rapid Response Licensing Program," giving licensees up to 18 months to develop COVID-19 related applications before paying the royalties normally part of a patent license agreement.

Dix said that tech transfer allows federal R&D to spur growth in the private sector, creating jobs and new tech solutions for the public. Dix said other private companies and entrepreneurs can also license then use, or license to manufacture and sell, the temp-checking tech.

"This technology was made for sailors and Department of Defense civilians, but has applicability just about anywhere," said Dix. "We want Crane's resources to be made available to others-out of the lab and right into the hands of the public."

Licensing inquiries can be sent to Sean Patten, senior tech manager at TechLink, at spatten@montana.edu or to Ms. Jenna Dix at jenna.dix@navy.mil


Contacts and sources:
Troy Carter
Techlink 

 






Greater Risks of Parkinson's Disease One of COVID-19's Neurological Consequences

Is the world prepared a wave of neurological consequences that may be on its way as a result of COVID-19? This question is at the forefront of research underway at the Florey Institute of Neuroscience and Mental Health. A team of neuroscientists and clinicians are examining the potential link between COVID-19 and increased risk of Parkinson's disease, and measures to get ahead of the curve.

"Although scientists are still learning how the SARS-CoV-2 virus is able to invade the brain and central nervous system, the fact that it's getting in there is clear. Our best understanding is that the virus can cause insult to brain cells, with potential for neurodegeneration to follow on from there," said Professor Kevin Barnham from the Florey Institute of Neuroscience & Mental Health.


The hidden face of Parkinson's

 
Credit: Verbeeldingskr8 a.k.a. Sparks / Wikimedia Commons

In a review paper published today, researchers put spotlight on the potential long-term neurological consequences of COVID-19, dubbing it the 'silent wave'. They are calling for urgent action to be taken to have available more accurate diagnostic tools to identify neurodegeneration early on and a long-term monitoring approach for people who have been infected with the SARS-CoV-2 virus.

The write, "Since the initial reports of COVID-19 in December 2019, the world has been gripped by the disastrous acute respiratory disease caused by the SARS-CoV-2 virus. There are an ever-increasing number of reports of neurological symptoms in patients, from severe (encephalitis), to mild (hyposmia), suggesting the potential for neurotropism of SARS-CoV." in the Journal of Parkinson's Disease 

The researchers report that neurological symptoms in people infected with the virus have ranged from severe, such as brain hypoxia (lack of oxygen), to more common symptoms such as loss of smell.

"We found that loss of smell or reduced smell was on average reported in three out of four people infected with the SARS-CoV-2 virus. While on the surface this symptom can appear as little cause for concern, it actually tells us a lot about what's happening on the inside and that is that there's acute inflammation in the olfactory system responsible for smell," explained Florey researcher Leah Beauchamp.

Inflammation is understood to play a major role in the pathogenesis of neurogenerative disease and has been particularly well studied in Parkinson's. Further research into these illnesses may prove critical for future impacts of SARS-CoV-2.

"We believe that loss of smell presents a new way forward in detecting someone's risk of developing Parkinson's disease early. Armed with the knowledge that loss of smell presents in around 90% of people in the early stages of Parkinson's disease and a decade ahead of motor symptoms, we feel we are on the right track," added Ms Beauchamp.

Clinical diagnosis of Parkinson's disease currently relies on presentation of motor dysfunction, but research shows that by this time 50-70% of dopamine cell loss in the brain has already occurred.

"By waiting until this stage of Parkinson's disease to diagnose and treat, you've already missed the window for neuroprotective therapies to have their intended effect. We are talking about an insidious disease affecting 80,000 people in Australia, which is set to double by 2040 before even considering the potential consequences of COVID, and we currently have no available disease-modifying therapies," said Professor Barnham.

The researchers hope to establish a simple, cost-effective screening protocol aiming to identify people in the community at risk of developing Parkinson's, or who are in early stages of the disease, at a time when therapies have the greatest potential to prevent onset of motor dysfunction. They plan to put the proposal forward for funding from the Australian Government's Medical Research Future Funding scheme.

Additionally, the team have developed two neuroprotective therapies currently under investigation and have identified a cohort of subjects who are ideally suited to study the treatments. Through their research they gained new evidence that people with REM sleep behaviour disorder have a higher predisposition to go on to develop Parkinson's disease.

Parkinson's disease is a significant economic burden costing the Australian economy in excess of $10 billion a year.

"We have to shift community thinking that Parkinson's not a disease of old age. As we've been hearing time and time again, the coronavirus does not discriminate - and neither does Parkinson's," said Professor Barnham.

"We can take insight from the neurological consequences that followed the Spanish Flu pandemic in 1918 where the risk of developing Parkinson's disease increased two to three-fold. Given that the world's population has been hit again by a viral pandemic, it is very worrying indeed to consider the potential global increase of neurological diseases that could unfold down track."

He added, "The world was caught off guard the first-time, but it doesn't need to be again. We now know what needs to be done. Alongside a strategized public health approach, tools for early diagnosis and better treatments are going to be key."
 
The study has been published in the Journal of Parkinson's Disease [DOI:10.3233/JPD-202211]


Contacts and sources:
Diana Murray
IOS Press


Publication:
Parkinsonism as a Third Wave of the COVID-19 Pandemic?
http://dx.doi.org/10.3233/JPD-202211





Wednesday, September 23, 2020

Chromium Steel Was First Made in Ancient Persia



Chromium steel - similar to what we know today as tool steel - was first made in Persia, nearly a millennium earlier than experts previously thought, according to a new study led by UCL researchers.

The discovery, published in the Journal of Archaeological Science, was made with the aid of a number of medieval Persian manuscripts, which led the researchers to an archaeological site in Chahak, southern Iran.

Crucible slag adhering to the interior of a crucible sherd

 
Credit: Rahil Alipour, UCL

The findings are significant given that material scientists, historians and archaeologists have long considered that chromium steel was a 20th century innovation.

Dr Rahil Alipour (UCL Archaeology), lead author on the study, said: "Our research provides the first evidence of the deliberate addition of a chromium mineral within steel production. We believe this was a Persian phenomenon.

"This research not only delivers the earliest known evidence for the production of chromium steel dating back as early as the 11th century CE, but also provides a chemical tracer that could aid the identification of crucible steel artefacts in museums or archaeological collections back to their origin in Chahak, or the Chahak tradition."

Chahak is described in a number of historical manuscripts dating from the 12th to 19th century as a once famous steel production centre, and is the only known archaeological site within Iran's borders with evidence of crucible steel making.

While Chahak is registered as a site of archaeological importance, the exact location of crucible steel production in Iran remained a mystery and difficult to locate today, given numerous villages in Iran are named Chahak.

The manuscript 'al-Jamahir fi Marifah al-Jawahir' ('A Compendium to Know the Gems', 10th-11th c. CE) written by the Persian polymath Abu-Rayhan Biruni, was of particular importance to the researchers given it provided the only known crucible steel making recipe.

This recipe recorded a mysterious ingredient that they identified as chromite mineral for the production of chromium crucible steel.

The team used radiocarbon dating of a number of charcoal pieces retrieved from within a crucible slag and a smithing slag (by-products left over after the metal has been separated) to date the industry to the 11th to 12th century CE.

Crucially, analyses using Scanning Electron Microscopy enabled them to identify remains of the ore mineral chromite, which was described in Biruni's manuscript as an essential additive to the process.

They also detected 1-2 weight percent of chromium in steel particles preserved in the crucible slags, demonstrating that the chromite ore did form chromium steel alloy - a process that we do not see used again until the late 19th and early 20th century.

Professor Thilo Rehren (UCL Archaeology and The Cyprus Institute), co-author on the study, said: "In a 13th century Persian manuscript translated by Dr Alipour, Chahak steel was noted for its fine and exquisite patterns, but its swords were also brittle, hence they lost their market value. Today the site is a small modest village, which prior to being identified as a site of archaeological interest, was only known for its agriculture."

Chahak people and the layer
Credit: Rahil Alipour, UCL

The researchers believe it marks a distinct Persian crucible steel-making tradition - separate from the more widely known Central Asian methods in Uzbekistan and Turkmenistan - for the production of low-chromium steel (produced at around 1 (one) weight percent of chromium).

Professor Marcos Martinon-Torres (University of Cambridge), last author on the study, said: "The process of identification can be quite long and complicated and this is for several reasons. Firstly, the language and the terms used to record technological processes or materials may not be used anymore, or their meaning and attribution may be different from those used in the modern science.

"Additionally, writing was restricted to social elites, rather than the individual that actually carried out the craft, which may have led to errors or omissions in the text."

Commenting on their next steps, Dr Alipour said: "We are hoping to work with museum experts to share our findings, supporting efforts to date and provenance more early crucible steel objects with the unique chromium steel signature."
 
The study was conducted by the lead author as part of her PhD research at UCL, with supervision by the other authors who now work at The Cyprus Institute in Nicosia, and the University of Cambridge respectively. It was funded by UCL Qatar with additional support from the Institute for Archaeo-Metallurgical Studies.


Contacts and sources:
Natasha Downes
University College London (UCL)

Publication:
Chromium crucible steel was first made in Persia
Author lRahil AlipouraThilo Rehrenbc Marcos Martinón-Torresda Gerda Henkel Research Fellow, UCL Institute of Archaeology, London, WC1H 0PY, UKbA.G. 
Leventis Professor for Archaeological Sciences, The Cyprus Institute, 2121, Aglantzia Nicosia, Cyprusc
UCL Institute of Archaeology, London, WC1H 0PY, UK
dPitt-Rivers Professor of Archaeological Science, Department of Archaeology, University of Cambridge, CB2 3DZ, UK
Received 29 October 2019, Revised 1 July 2020, Accepted 10 August 2020, Available online 23 September 2020. http://dx.doi.org/10.1016/j.jas.2020.105224








Most Infants Are Well Even When Moms are Infected by COVID-19

Infants born to women with COVID-19 showed few adverse outcomes, according to the first report in the country of infant outcomes through eight weeks of age.

The study, led by researchers at UC San Francisco, suggests that babies born to mothers infected with the virus generally do well six to eight weeks after birth, however there was a higher rate of neonatal intensive care unit (NICU) admissions reported if the mothers had COVID-19 up to two weeks prior to delivery.



Credit:  UC San Francisco

Among 263 infants in the study, adverse outcomes – including preterm birth, NICU admission, and respiratory disease – did not differ between those born to mothers testing positive for SARS-CoV-2, the virus that causes COVID-19, and those born to mothers testing negative. No pneumonia or lower respiratory tract infection were reported through eight weeks of age.

The study is published as a prepublication accepted manuscript in Clinical Infectious Diseases.

“The babies are doing well, and that’s wonderful,” said lead author Valerie J. Flaherman, MD, MPH, associate professor of pediatrics and of epidemiology and biostatistics at UCSF. “When coronavirus first hit, there were so many strange and unfortunate issues tied to it, but there was almost no information on how COVID-19 impacts pregnant women and their newborns. We didn’t know what to expect for the babies, so this is good news.”

The prospective study is part of a national project led by UCSF called PRIORITY (Pregnancy Coronavirus Outcomes Registry), which began in March 2020, shortly after the pandemic erupted in the United States. The project is designed for pregnant women with suspected or confirmed COVID-19, with the goal of better understanding how pregnant and postpartum women and their infants are affected by the virus.

It’s known that pregnant women have alterations in their immune system that may increase the risk of severe illness from influenza viruses. In past outbreaks, women who contracted flu during pregnancy have been at higher risk for hospitalization, miscarriage or stillbirth, and their babies have had an increased likelihood of having birth defects.

While studies have reported that maternal SARS-CoV-2 infection increases the risk of preterm birth and can be transmitted from the mother to the infant, overall risks for the infants were not known and almost no information is available about how COVID-19 affects infants as they grow.

The new paper reports on live births among 179 mothers with a positive test for SARS-CoV-2 and 84 mothers who had a negative test. The births occurred at more than 100 U.S. hospitals. On average, the mothers were about 31 years old. Among women testing positive, 146 (81 percent) were symptomatic; among those testing negative, 53 (63 percent) were symptomatic.

Of the 263 infants in total, 44 were admitted to a NICU but no pneumonia or lower respiratory tract infections were reported during the study. Among the 56 infants assessed for upper respiratory infection, it was reported in two infants with COVID-positive mothers, and in one with a COVID-negative mother.

Among infants born to mothers who tested positive, the estimated incidence of a positive infant SARS-CoV-2 test was low at 1.1 percent, and COVID did not appear to impact those infants, the authors said.

“Overall, the initial findings regarding infant health are reassuring, but it’s important to note that the majority of these births were from third trimester infections,” said senior author Stephanie L. Gaw, MD, PhD, assistant professor of obstetrics, gynecology and reproductive sciences at UCSF. “The outcomes from our complete cohort will give the full picture of risks throughout pregnancy.”

Two infants born to mothers who tested positive in the third trimester were reported to have birth defects, each with multiple congenital anomalies reported (one had cardiac, vertebral, renal and pulmonary anomalies, while the other had facial, genital, renal, brain and cardiac anomalies). One mother who tested negative reported an infant with gastrointestinal, renal and cardiac anomalies.

The researchers said the findings could help inform national and international guidelines and policies, but also noted some study limitations. Among those, tests for infection might be biased by false-positive or false-negative results. They also said that Latinas and Blacks were underrepresented in the study – in May, PRIORITY launched a new project to increase enrollment of underrepresented groups – and noted that further research is needed on infant incidence following maternal infection.

Funding: The research was supported by the UCSF National Center of Excellence in Women’s Health; California Health Care Foundation; the Centers for Disease Control and Prevention Foundation; the Bill and Melinda Gates Foundation; and individuals who provided financial support through crowdfunding.

Co-authors: UCSF co-authors are John Boscardin, PhD; Roberta L. Keller, MD; Anne Mardy, MD; Mary K. Prahl, MD; Carolyn Phillips, MD, Ifeyinwa V. Asiodu, RN, PhD; Brittany D. Chambers, PhD, and Vanessa Jacoby, MD, MAS. Other co-authors are Yalda Afshar, MD, PhD, UCLA; W. Vincenzo Berghella, MD, Thomas Jefferson University; Joia Crear-Perry, MD, National Birth Equity Collaborative; and Denise J. Jamieson, MD, MPH, Emory University.



Contacts and sources:
Elizabeth Fernandez
University of California - San Francisco



Publication: Infant Outcomes Following Maternal Infection with SARS-CoV-2: First Report from the PRIORITY Study.
Valerie J Flaherman, Yalda Afshar, John Boscardin, Roberta L Keller, Anne Mardy, Mary K Prahl, Carolyn Phillips, Ifeyinwa V Asiodu, W Vincenzo Berghella, Brittany D Chambers, Joia Crear-Perry, Denise J Jamieson, Vanessa L Jacoby, Stephanie L Gaw.Clinical Infectious Diseases, 2020; DOI: 10.1093/cid/ciaa1411

Marine Sponges Inspire the Next Generation of Skyscrapers and Bridges

The skeleton of Euplectella aspergillum, a deep-water marine sponge. 

Image courtesy of Matheus Fernandes/Harvard SEAS

When we think about sponges, we tend to think of something soft and squishy. But researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) are using the glassy skeletons of marine sponges as inspiration for the next generation of stronger and taller buildings, longer bridges, and lighter spacecraft.

In a new paper published in Nature Materials, the researchers showed that the diagonally-reinforced square lattice-like skeletal structure of Euplectella aspergillum, a deep-water marine sponge, has a higher strength-to-weight ratio than the traditional lattice designs that have used for centuries in the construction of buildings and bridges.

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“We found that the sponge's diagonal reinforcement strategy achieves the highest buckling resistance for a given amount of material, which means that we can build stronger and more resilient structures by intelligently rearranging existing material within the structure,” said Matheus Fernandes, a graduate student at SEAS and first author of the paper.

“In many fields, such as aerospace engineering, the strength-to-weight ratio of a structure is critically important,” said James Weaver, a Senior Scientist at SEAS and one of the corresponding authors of the paper. “This biologically-inspired geometry could provide a roadmap for designing lighter, stronger structures for a wide range of applications.”

If you’ve ever walked through a covered bridge or put together a metal storage shelf, you’ve seen diagonal lattice architectures. This type of design uses many small, closely spaced diagonal beams to evenly distribute applied loads. This geometry was patented in the early 1800s by the architect and civil engineer, Ithiel Town, who wanted a method to make sturdy bridges out of lightweight and cheap materials.


Composite rendering that transitions from a glassy sponge skeleton on the left to a welded rebar-based lattice on the right, highlighting the biologically inspired nature of the research. 


Image Courtesy of Peter Allen, Ryan Allen, and James C. Weaver/Harvard SEAS
 
“Town developed a simple, cost-effective way to stabilize square lattice structures, which is used to this very day,” said Fernandes. “It gets the job done, but it’s not optimal, leading to wasted or redundant material and a cap on how tall we can build. One of the main questions driving this research was, can we make these structures more efficient from a material allocation perspective, ultimately using less material to achieve the same strength?”

Luckily, the glass sponges, the group to which Euplectella aspergillum — otherwise known as Venus' Flower Basket belongs — had a nearly half billion-year head start on the research and development side of things. To support its tubular body, Euplectella aspergillum employs two sets of parallel diagonal skeletal struts, which intersect over and are fused to an underlying square grid, to form a robust checkerboard-like pattern.

“We’ve been studying structure-function relationships in sponge skeletal systems for more than 20 years, and these species continue to surprise us,” said Weaver.

In simulations and experiments, the researchers replicated this design and compared the sponge’s skeletal architecture to existing lattice geometries. The sponge design outperformed them all, withstanding heavier loads without buckling. The researchers showed that the paired parallel crossed-diagonal structure improved overall structural strength by more than 20 percent, without the need to add additional material to achieve this effect.

“Our research demonstrates that lessons learned from the study of sponge skeletal systems can be exploited to build structures that are geometrically optimized to delay buckling, with huge implications for improved material use in modern infrastructural applications,” said Katia Bertoldi, the William and Ami Kuan Danoff Professor of Applied Mechanics at SEAS and a corresponding author of the study.

The Harvard Office of Technology Development has protected the intellectual property relating to this project and is exploring commercialization opportunities.

This paper was also co-authored by Joanna Aizenberg, the Amy Smith Berylson Professor of Materials Science and Professor of Chemistry & Chemical Biology at SEAS, and the research was supported in part by the National Science Foundation through the Harvard University Materials Research Science and Engineering Center DMR-2011754 and NSF DMREF Grant DMR-1922321


Contacts and sources:
Leah Burrows
Harvard John A. Paulson School of Engineering and Applied Sciences


Publication: Mechanically robust lattices inspired by deep-sea glass sponges
Matheus C. Fernandes, Joanna Aizenberg, James C. Weaver, Katia Bertoldi. . Nature Materials, 2020; DOI: 10.1038/s41563-020-0798-1

It Is Time to Embrace Cannabis for Medicinal Use, Say Experts





20 months after cannabis-based products for medicinal use were legalised in the UK, attitudes towards using them are still highly sceptical, say researchers

Attitudes towards cannabis products for medicinal use need to change with much greater appropriate use of such products to help alleviate patients’ pain, suggests research published in the journal BMJ Open.

Medical Marijuana cannabis shop


 


Credit: © O'Dea at Wikimedia Commons, CC BY-SA 4.0

Researchers found that hundreds of thousands of UK patients were self-medicating with illegal cannabis-based products for medicinal use due to the fact that much of the medical and pharmacy professions have so far not embraced and prescribed legal cannabis-based products for their patients.

In November 2018 when the UK made cannabis-based products for medicinal use (CBPMs) legal, most people assumed these would immediately be made available to patients, but this has not happened.

In the year since then, almost no NHS prescriptions have been issued and less than a hundred have been made available from private providers at a cost of at least £1,000 a month.

Consequently, some parents of children with severe epilepsy continue to go overseas to get their children access to the only treatment which has proven to be effective for their condition – cannabinoid medication.

In addition, it is estimated that the vast majority of the estimated 1.4 million medical cannabis users source from the black market with its problems of illegality, unknown quality, content and provenance.

This is despite that fact that there is existing substantial evidence of effectiveness with cannabis products for medicinal use in many disorders as identified in the US National Academy of Sciences review in 2017.

Researchers from Imperial College London, London School of Economics and Drug Science (formerly known as the Independent Scientific Committee on Drugs), therefore, set out to understand why the UK was lagging behind so many other countries which also have legalised medical cannabis.

They consulted with parents and patients, prescribers, pharmacists and decision makers.

They found that there appeared to be a series of distinct barriers to prescribing that needed to be overcome in order to improve patient access to medical cannabis in the UK.

These include concerns about a perceived lack of scientific evidence but the researchers said these concerns were misplaced because many patient-centred approaches including patient reported outcomes, pharmacoepidemiology (study of the uses and effects of drugs) and trials involving a single patient could be applied.

International database evidence suggested this new class of drug offered a significant advance in treatment for many in whom current medicines were either ineffective or poorly tolerated.

Various reasons to explain why there was resistance to use of these drugs were given, such as the fact the use of medicinal cannabis products were something being driven by patients and not doctors, which the latter group might resent.

In addition, the current government insistence that medical cannabis be considered as a “special’ product, meant challenges for prescribers.

For example, they faced additional organisational bureaucracy and the prescriber had to hold responsibility for any untold harm caused unlike any other product for which responsibility lay with the manufacturer.

Another reason for the resistance to prescribing of these products was that for almost 50 years, the medical profession focused on the risks of cannabis with claims of harms, including male sterility, lung cancer and schizophrenia. Though these have now been largely debunked and were generally the result of recreational rather than prescribed medical use, many practitioners may not know this.

The researchers say that the many thousands of UK patients self-medicating with non-regulated cannabis products for medicinal use and the international evidence suggested these new medical products offered an advance in treatment for many people.

They also offered the potential of cost savings to the NHS in terms of reduced hospital stays and less prescribing of other medicines particularly opioids for chronic pain, they argued.

They conclude: “The failure of the medical and pharmacy professions to embrace CBPMs despite their being made ‘legal’ over 18 months ago is a great worry to patients” and may, they say, have led to preventable deaths from conditions such as epilepsy.

“We hope that this paper will help policymakers and prescribers understand the challenges to prescribing and so help them develop approaches to overcome the current highly unsatisfactory situation.”



Contacts and sources:
Chalisa Iamsrithong
BMJ


Publication: So near yet so far: why won’t the UK prescribe medical cannabis?
David Nutt, Steve Bazire, Lawrence D Phillips, Anne Katrin Schlag. BMJ Open, 2020; 10 (9): e038687 DOI: 10.1136/bmjopen-2020-038687





COVID-19 Mortality Rates Higher Among Men than Women

A new review article from Beth Israel Deaconess Medical Center (BIDMC) shows people who are biologically male are dying from COVID-19 at a higher rate than people who are biologically female. In a review published in Frontiers in Immunology, researcher-clinicians at BIDMC explore the sex-based physiological differences that may affect risk and susceptibility to COVID-19, the course and clinical outcomes of the disease and response to vaccines.

“The COVID-19 pandemic has revealed a striking gender bias with increased mortality rates in men compared with women across the lifespan,” said corresponding author Vaishali R. Moulton, MD, PhD, an assistant professor of medicine in the Division of Rheumatology and Clinical Immunology at BIDMC. “Apart from behavioral and lifestyle factors that differ between men and women, sex chromosome-linked genes, sex hormones and the microbiome control aspects of the immune responses to infection and are potentially important biological contributors to the sex-based differences we’re seeing in men and women in the context of COVID-19.”


This transmission electron microscope image shows SARS-CoV-2—also known as 2019-nCoV, the virus that causes COVID-19. isolated from a patient in the U.S., emerging from the surface of cells cultured in the lab.

Credit: National Institute of Allergy and Infectious Diseases-Rocky Mountain Laboratories, NIH


Moulton and co-authors Nirupa Gadi, Samantha C. Wu and Allison P. Spihlman, all medical students in Moulton’s laboratory at BIDMC, acknowledge that demographic differences between men and women predispose each group to risk in different ways. Men, for example, are more likely to smoke cigarettes, a known risk factor for severe COVID-19, and are more likely to have cardiovascular disease and hypertension, important underlying comorbidities in COVID-19; while women are more likely to hold jobs in health care, increasing their potential exposure to the virus.

Nonetheless, many animal and human studies demonstrate that females tend to mount stronger immune responses to infections than males, a trait that may be linked to increased susceptibility to inflammatory and autoimmune diseases. Reviewing the scientific literature regarding sex-based differences in cells of the immune system, X chromosome-linked genetics, sex hormones, the ACE-2 receptor and the microbiome, the scientists conclude that sex is a crucial yet understudied and often overlooked variable in research related to immunity and infectious disease.

“Vaccine-related research and clinical trials, including those currently underway for COVID-19, must include sex as a key variable when measuring and reporting outcomes,” said Moulton, who is also an assistant professor of medicine at Harvard Medical School. “Understanding these factors will both help us better understand COVID-19 and guide the design of effective therapies and vaccine strategies towards sex-based personalized medicine moving forward.”

The authors declare no conflicts of interest associated with this manuscript.


Contacts and sources:
Lindsey Diaz-MacInnis
Beth Israel Deaconess Medical Center



Publication: What’s Sex Got to Do With COVID-19? Gender-Based Differences in the Host Immune Response to Coronaviruses.
Nirupa Gadi, Samantha C. Wu, Allison P. Spihlman, Vaishali R. Moulton. Frontiers in Immunology, 2020; 11 DOI: 10.3389/fimmu.2020.02147






Ecologists Confirm Alan Turing’s Theory for Australian Fairy Circles



International research team led by Göttingen University shows patterned vegetation regenerates by “ecosystem engineering” of the grasses

Fairy circles are one of nature’s greatest enigmas and most visually stunning phenomena. An international research team led by the University of Göttingen has now, for the first time, collected detailed data to show that Alan Turing’s model explains the striking vegetation patterns of the Australian fairy circles. In addition, the researchers showed that the grasses that make up these patterns act as “eco-engineers” to modify their own hostile and arid environment, thus keeping the ecosystem functioning. The results were published in the Journal of Ecology.

Researchers from Germany, Australia and Israel undertook an in-depth fieldwork study in the remote Outback of Western Australia. They used drone technology, spatial statistics, quadrat-based field mapping, and continuous data-recording from a field-weather station. With the drone and a multispectral camera, the researchers mapped the “vitality status” of the Triodia grasses (how strong and how well they grew) in five one-hectare plots and classified them into high- and low-vitality.

The systematic and detailed fieldwork enabled, for the first time in such an ecosystem, a comprehensive test of the “Turing pattern” theory. Turing’s concept was that in certain systems, due to random disturbances and a “reaction-diffusion” mechanism, interaction between just two diffusible substances was enough to allow strongly patterned structures to spontaneously emerge. Physicists have used this model to explain the striking skin patterns in zebrafish or leopards for instance. Earlier modelling had suggested this theory might apply to these intriguing vegetation patterns and now there is robust data from multiple scales which confirms that Alan Turing’s model applies to Australian fairy circles.

Drone image of the Australian fairy circles, taken at a flying altitude of 40 m above ground. The gaps have average diameters of 4 m and the spatially periodic pattern results from approximately equal distances between the centers of nearest-neighbouring gaps. This study plot burnt in 2014 and the recovering spinifex grasses were two years and eight months old.
Photo: S Getzin, University of Göttingen


The data show that the unique gap pattern of the Australian fairy circles, which occur only in a small area east of the town of Newman, emerges from ecohydrological biomass-water feedbacks from the grasses. In fact, the fairy circles – with their large diameters of 4m, clay crusts from weathering and resultant water run-off – are a critical extra source of water for the dryland vegetation. Clumps of grasses increased shading and water infiltration around the nearby roots.

With increasing years after fire, they merged more and more at the periphery of the vegetation gaps to form a barrier so that they could maximize their water uptake from the fairy circle’s runoff. The protective plant cover of grasses could reduce soil-s­urface temperatures by about 25°C at the hottest time of the day, which facilitates the germination and growth of new grasses. In summary, the scientists found evidence both at the scale of the landscape and at much smaller scales that the grasses, with their cooperative growth dynamics, redistribute the water resources, modulate the physical environment, and thus function as “ecosystem engineers” to modify their own environment and better cope with the arid conditions.

The active formation of nearly circular grassland gaps (fairy circles), as seen from a helicopter. At this transition from Eucalypt and Acacia trees to a Triodia grassland, the hummock grasses arrange themselves to form round bare-soil gaps. This “ecoystem-engineering” results in the most green and vital grasses growing next to the fairy circle while grey and less vital grasses further away cannot benefit from this extra source of water in the same way.

Photo: S Getzin, University of Göttingen


Dr Stephan Getzin, Department of Ecosystem Modelling at the University of Göttingen, explains, “The intriguing thing is that the grasses are actively engineering their own environment by forming symmetrically spaced gap patterns. The vegetation benefits from the additional runoff water provided by the large fairy circles, and so keeps the arid ecosystem functional even in very harsh, dry conditions.” This contrasts with the uniform vegetation cover seen in less water-stressed environments. “Without the self-organization of the grasses, this area would likely become desert, dominated by bare soil,” he adds. The emergence of Turing-like patterned vegetation seems to be nature’s way of managing an ancient deficit of permanent water shortage.

In 1952 when the British mathematician, Alan Turing, published his ground-breaking theoretical paper on pattern formation, he had most likely never heard of the fairy circles before. But with his theory he laid the foundation for generations of physicists to explain highly symmetrical patterns like sand ripples in dunes, cloud stripes in the sky or spots on an animal’s coat with the reaction-diffusion mechanism. Now, ecologists have provided an empirical study to extend this principle from physics to dryland ecosystems with fairy circles.

This research, which was funded by the German Research Foundation (DFG), has implications for modelling and understanding similar ecosystems as well as for identifying systems that can “self-engineer” their surroundings to protect fragile environments.

 
 


Contacts and sources:
Dr Stephan Getzin 
University of Göttingen



Publication: Bridging ecology and physics: Australian fairy circles regenerate following model assumptions on ecohydrological feedbacks.
Stephan Getzin, Todd E. Erickson, Hezi Yizhaq, Miriam Muñoz‐Rojas, Andreas Huth, Kerstin Wiegand. Journal of Ecology, 2020;  DOI: 10.1111/1365-2745.13493 and https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2745.13493






Spinosaurus Was a Real Life ‘River Monster’



A discovery of more than a thousand dinosaur teeth, by a team of researchers from the University of Portsmouth, proves beyond reasonable doubt that Spinosaurus, the giant predator made famous by the movie Jurassic Park III as well as the BBC documentary Planet Dinosaur was an enormous river-monster.

Research published today in the journal Cretaceous Research proves that Spinosaurus aegyptiacus, a 15 metre long, six-tonne beast was in fact the most commonly found creature in the Kem Kem river system, which flowed through the Sahara Desert 100 million years ago.

Credit: University of Portsmouth


Until recently it was believed that dinosaurs lived exclusively on land. However, research published earlier this year showed that Spinosaurus was well adapted to an aquatic lifestyle, due to its newly discovered tail. This latest research of 1,200 teeth found in the same region further supports this theory.

Scientists from the University of Portsmouth collected the fossilised remains from the site of an ancient river bed in Morocco. After analysing all of them it was discovered there was an abundance of Spinosaurus teeth, which are distinct and easily identifiable.

David Martill, Professor of Palaeobiology at the University of Portsmouth, said:"The huge number of teeth we collected in the prehistoric river bed reveals that Spinosaurus was there in huge numbers, accounting for 45 per cent of the total dental remains. We know of no other location where such a mass of dinosaur teeth have been found in bone-bearing rock.

"The enhanced abundance of Spinosaurus teeth, relative to other dinosaurs, is a reflection of their aquatic lifestyle. An animal living much of its life in water is much more likely to contribute teeth to the river deposit than those dinosaurs that perhaps only visited the river for drinking and feeding along its banks.

"From this research we are able to confirm this location as the place where this gigantic dinosaur not only lived but also died. The results are fully consistent with the idea of a truly water-dwelling, "river monster"."

Professor Martill worked alongside two students studying for their Masters Degree in Paleontology at the University of Portsmouth.

Thomas Beevor said: “The Kem Kem river beds are an amazing source of Spinosaurus remains. They also preserve the remains of many other Cretaceous creatures including sawfish, coelacanths, crocodiles, flying reptiles and other land-living dinosaurs. With such an abundance of Spinosaurus teeth, it is highly likely that this animal was living mostly within the river rather than along its banks.”

Aaron Quigley, explained the process of sorting through the teeth: “After preparing all the fossils, we then assessed each one in turn. The teeth of Spinosaurus have a distinct surface. They have a smooth round cross section which glints when held up to the light. We sorted all 1200 teeth into species and then literally counted them all up. Forty-eight per cent of our total find were Spinosaurus teeth.”


Contacts and sources:
University of Portsmouth



Publication: Taphonomic evidence supports an aquatic lifestyle for Spinosaurus.
Thomas Beevor, Aaron Quigley, Roy E. Smith, Robert S.H. Smyth, Nizar Ibrahim, Samir Zouhri, David M. Martill. Cretaceous Research, 2021; 117: 104627 DOI: 10.1016/j.cretres.2020.104627






Modelling of Ancient Fossil Movement Reveals Step in the Evolution of Posture in Dinosaur and Crocodile Ancestors




Scientists from the University of Bristol and the Royal Veterinary College (RVC) used three-dimensional computer modelling to investigate the hindlimb of Euparkeria capensis–a small reptile that lived in the Triassic Period 245 million years ago–and inferred that it had a “mosaic” of functions in locomotion.

Life reconstruction of Euparkeria highlighting the body parts investigated in this study.

 Illustration: Oliver Demuth.


The study, which was published today in Scientific Reports, was led by researcher Oliver Demuth, joined by Professors Emily Rayfield (Bristol) and John Hutchinson (RVC). Their new micro-computed tomography scans of multiple specimens revealed unprecedented information about the previously hidden shape of the hip bones and structure of the foot and ankle joint.

Euparkeria has been known from numerous fossil specimens since the early 1900s and was found to be a close relative of the last common ancestor of both crocodiles and birds. While birds and crocodiles show different locomotion strategies, two-legged birds with an upright (erect) posture, shared with two and four-legged dinosaurs, and crocodiles having a four-legged (quadrupedal) sprawling posture, their ancestor once shared a common mode of locomotion and Euparkeria can provide vital insight into how these differences came to be.

The oblique ankle joint did not allow Euparkeria to assume a fully upright posture as the foot also turns medially when the ankle joint is extended. An ankle joint allowing a more upright posture evolved later independent from the hip structure.


Credit: University of Bristol 

The authors’ new reconstruction of the hip structure showed that Euparkeria had a distinctive bony rim on the pelvis, called a supra-acetabular rim, covering the top of the hip joint. This feature was previously known only from later archosaurs on the line to crocodiles and often was used to infer a more erect posture for these animals; reversed in crocodiles as they became more amphibious. The hooded rim allowed the pelvis to cover the top of the thigh bone and support the body with the limbs in a columnar arrangement; hence this type of joint is called ‘pillar-erect’. Euparkeria is so far the earliest reptile with this structure preserved. Could it therefore have assumed a more erect, rather than more sprawling, posture as well?

To test how the hindlimb could or could not have moved in life, the team estimated how far the thigh bone could have rotated until it collided with the hip bones, and their models addressed how the ankle joint could have been posed, too. The computer simulations suggested that while the thigh bone could have been held in an erect posture, the foot could not have been placed steadily on the ground due to the way the foot rotates around the ankle joint, implying a more sprawling posture. However, the bony rim covering the hip joint restricted the movement of the thigh bone in a way that is unknown in any living animal capable of a more sprawling gait, hinting at a more upright posture.

This projection of the hip bone above the hip joint is called "supra-acetabular rim" and allowed to tuck the limbs under the body to support the body in a columnar arrangement.


Credit: University of Bristol 

The team’s simulations thus revealed seemingly contradictory patterns in the hip and ankle joint. While Euparkeria is so far the earliest reptile with this peculiar hip structure, an ankle joint allowing a more erect posture appeared later on in Triassic archosaurs. Dr John Hutchinson, Professor of Evolutionary Biomechanics at the RVC, commented:

“The mosaic of structures present in Euparkeria, then, can be seen as a central stepping-stone in the evolution of locomotion in archosaurs.”

First author Oliver Demuth, research technician at the RVC and former Masters student at the University of Bristol, commented:

“The hip structure of Euparkeria was extremely surprising, especially as it functionally contradicts the ankle joint. Previously it was thought that both were linked and evolved synchronously. However, we were able to demonstrate that these traits were in fact decoupled and evolved in a step-wise fashion.”

Dr Emily Rayfield, Professor of Palaeobiology at the University of Bristol commented:

“This approach is exciting because Using CT scan datasets and computer models of how the bones and joints fitted together has allowed us to test long-standing ideas of how these ancient animals moved and how the limbs of the earliest ancestors of birds, crocodiles and dinosaurs may have evolved”

 

Contacts and sources:

University of Bristol


Publication: 3D hindlimb joint mobility of the stem-archosaur Euparkeria capensis with implications for postural evolution within Archosauria in Scientific Reports by Demuth, O. E. et al. 






Sunday, September 20, 2020

World’s largest Ever DNA Sequencing of Viking Skeletons Reveals They Weren’t All Scandinavian

Invaders, pirates, warriors – the history books taught us that Vikings were brutal predators who travelled by sea from Scandinavia to pillage and raid their way across Europe and beyond.

Now cutting-edge DNA sequencing of more than 400 Viking skeletons from archaeological sites scattered across Europe and Greenland will rewrite the history books as it has shown:
  • Skeletons from famous Viking burial sites in Scotland were actually local people who could have taken on Viking identities and were buried as Vikings.
  • Many Vikings actually had brown hair not blonde hair.
  • Viking identity was not limited to people with Scandinavian genetic ancestry. The study shows the genetic history of Scandinavia was influenced by foreign genes from Asia and Southern Europe before the Viking Age.
  • Early Viking Age raiding parties were an activity for locals and included close family members.
  • The genetic legacy in the UK has left the population with up to six per cent Viking DNA.

The six-year research project, published in Nature today (16 September 2020), debunks the modern image of Vikings and was led by Professor Eske Willerslev, a Fellow of St John’s College, University of Cambridge, and director of The Lundbeck Foundation GeoGenetics Centre, University of Copenhagen.


A mass grave of around 50 headless Vikings from a site in Dorset, UK. Some of these remains were used for DNA analysis. 
Credit: Dorset County Council/Oxford Archaeology

He said: “We have this image of well-connected Vikings mixing with each other, trading and going on raiding parties to fight Kings across Europe because this is what we see on television and read in books – but genetically we have shown for the first time that it wasn’t that kind of world. This study changes the perception of who a Viking actually was – no one could have predicted these significant gene flows into Scandinavia from Southern Europe and Asia happened before and during the Viking Age.”

The word Viking comes from the Scandinavian term ‘vikingr’ meaning ‘pirate’. The Viking Age generally refers to the period from A.D. 800, a few years after the earliest recorded raid, until the 1050s, a few years before the Norman Conquest of England in 1066. The Vikings changed the political and genetic course of Europe and beyond: Cnut the Great became the King of England, Leif Eriksson is believed to have been the first European to reach North America – 500 years before Christopher Columbus - and Olaf Tryggvason is credited with taking Christianity to Norway. Many expeditions involved raiding monasteries and cities along the coastal settlements of Europe but the goal of trading goods like fur, tusks and seal fat were often the more pragmatic aim.

Professor Willerslev added: “We didn’t know genetically what they actually looked like until now. We found genetic differences between different Viking populations within Scandinavia which shows Viking groups in the region were far more isolated than previously believed. Our research even debunks the modern image of Vikings with blonde hair as many had brown hair and were influenced by genetic influx from the outside of Scandinavia.”
 
The team of international academics sequenced the whole genomes of 442 mostly Viking Age men, women, children and babies from their teeth and petrous bones found in Viking cemeteries. They analysed the DNA from the remains from a boat burial in Estonia and discovered four Viking brothers died the same day. The scientists have also revealed male skeletons from a Viking burial site in Orkney, Scotland, were not actually genetically Vikings despite being buried with swords and other Viking memorabilia.

There wasn’t a word for Scandinavia during the Viking Age - that came later. But the research study shows that the Vikings from what is now Norway travelled to Ireland, Scotland, Iceland and Greenland. The Vikings from what is now Denmark travelled to England. And Vikings from what is now Sweden went to the Baltic countries on their all male ‘raiding parties’.


An artistic reconstruction of ‘Southern European’ Vikings emphasising the foreign gene flow into Viking Age Scandinavia detected in the study. 
Credit: Jim Lyngvild

Dr Ashot Margaryan, Assistant Professor at the Section for Evolutionary Genomics, Globe Institute, University of Copenhagen and first author of the paper, said: “We carried out the largest ever DNA analysis of Viking remains to explore how they fit into the genetic picture of Ancient Europeans before the Viking Age. The results were startling and some answer long-standing historical questions and confirm previous assumptions that lacked evidence.

“We determined that a Viking raiding party expedition included close family members as we discovered four brothers in one boat burial in Estonia who died the same day. The rest of the occupants of the boat were genetically similar suggesting that they all likely came from a small town or village somewhere in Sweden.”

DNA from the Viking remains were shotgun sequenced from sites in Greenland, Ukraine, The United Kingdom, Scandinavia, Poland and Russia.

Professor Martin Sikora, a lead author of the paper and an Associate Professor at the Centre for GeoGenetics, University of Copenhagen, said: “We found that Vikings weren’t just Scandinavians in their genetic ancestry, as we analysed genetic influences in their DNA from Southern Europe and Asia which has never been contemplated before. Many Vikings have high levels of non-Scandinavian ancestry, both within and outside Scandinavia, which suggest ongoing gene flow across Europe.”

The team’s analysis also found that genetically Pictish people ‘became’ Vikings without genetically mixing with Scandinavians. The Picts were Celtic-speaking people who lived in what is today eastern and northern Scotland during the Late British Iron Age and Early Medieval periods.

Dr Daniel Lawson, lead author from The University of Bristol, explained: “Individuals with two genetically British parents who had Viking burials were found in Orkney and Norway. This is a different side of the cultural relationship from Viking raiding and pillaging.”

The Viking Age altered the political, cultural and demographic map of Europe in ways that are still evident today in place names, surnames and modern genetics.

Professor Søren Sindbæk, an archaeologist from Moesgaard Museum in Denmark who collaborated on the ground-breaking paper, explained: “Scandinavian diasporas established trade and settlement stretching from the American continent to the Asian steppe. They exported ideas, technologies, language, beliefs and practices and developed new socio-political structures. Importantly our results show that ‘Viking’ identity was not limited to people with Scandinavian genetic ancestry. Two Orkney skeletons who were buried with Viking swords in Viking style graves are genetically similar to present-day Irish and Scottish people and could be the earliest Pictish genomes ever studied.”


DNA from a female skeleton named Kata found at a Viking burial site in Varnhem, Sweden, was sequenced as part of the study.
 Credit: Västergötlands museum

Assistant Professor Fernando Racimo, also a lead author based at the GeoGenetics Centre in the University of Copenhagen, stressed how valuable the dataset is for the study of the complex traits and natural selection in the past. He explained: This is the first time we can take a detailed look at the evolution of variants under natural selection in the last 2,000 years of European history. The Viking genomes allow us to disentangle how selection unfolded before, during and after the Viking movements across Europe, affecting genes associated with important traits like immunity, pigmentation and metabolism. We can also begin to infer the physical appearance of ancient Vikings and compare them to Scandinavians today.”

The genetic legacy of the Viking Age lives on today with six per cent of people of the UK population predicted to have Viking DNA in their genes compared to 10 per cent in Sweden.

Professor Willeslev concluded: “The results change the perception of who a Viking actually was. The history books will need to be updated.”


Contacts and sources:
St John's College, University of Cambridge



Publication: Population genomics of the Viking world.
Margaryan, A., Lawson, D.J., Sikora, M. et al. Nature, 2020 DOI: 10.1038/s41586-020-2688-8