. Scientific Frontline

Monday, February 27, 2023

London falcons ate fewer pigeons during lockdowns

Peregrine falcon
Photo Credit: Jasmin777

The study by King’s researchers suggests that predatory birds in urban spaces are vulnerable to changes in human activities that support prey populations.

Changes in peregrine falcon diets during COVID-19 lockdowns highlight the impact of human behavior on urban predators. The findings are from a new study co-authored by King’s researchers published in the British Ecological Society journal, People and Nature.

Researchers from King’s College London and University of Bristol found that during lockdowns, peregrine falcons in London were forced to change their diet away from pigeons since fewer of these birds were being drawn in by human food supplies such as discarded food waste or direct feeding.

Brandon Mak, a PhD student in the Department of Geography who co-led the study with Ed Drewitt from the University of Bristol, said: “Our results indicate that peregrines in larger, highly urbanized cities like London may be more dependent on, and hence more vulnerable to changes in, human activities which support their prey populations, particularly feral pigeons.”

Producing extreme ultraviolet laser pulses efficiently through wakesurfing behind electron beams

A 3D simulation of the wake behind the electron beam (purple) and how a light pulse (blue and red stripe) might surf behind it. The plasma wake is shown in alternating yellow for the absence of electrons and green for peaks in the electron density. When a light pulse sits on that boundary, it can continuously gain energy—the trick is keeping it there.
Image Credit: Ryan Sandberg, High Field Science Group

Simulations suggest this mechanism could provide a tenfold increase in frequency—likely hitting a peak power of 100 trillion watts in XUV

A laser pulse surfing in the wake of an electron beam pulse could get upshifted from visible to extreme ultraviolet light, simulations done at the University of Michigan have shown.

The approach could enable more efficient generation of high-energy laser light, perhaps even to X-rays. The 3D simulation showed up to a tenfold increase in the frequency of the light, while the 1D simulation went up to a 50-fold increase. In principle, the researchers say it is possible to continue amping up the energy of the laser pulse by extending the period of time that it can ride in the wake of the electron beam.

“Future lasers, potentially including those used to pattern semiconductor chips for computers, could take advantage of this effect to produce higher energy pulses more efficiently,” said Alec Thomas, U-M professor of nuclear engineering and radiological sciences and corresponding author of the study in Physical Review Letters.

Dinosaur claws used for digging and display

Therizinosaurs claw hooking and pulling trees
Image Credit: Shuyang Zhou for the 3D modelling and functional scenario restoration

Dinosaur claws had many functions, but now a team from the University of Bristol and the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing has shown some predatory dinosaurs used their claws for digging or even for display.

The study focused on two groups of theropod dinosaurs, the alvarezsaurs and therizinosaurs, that had weird claws whose function had been a mystery up to now. It turns out that alvarezsaurs used their rock-pick-like claws for digging, but their close relatives, the giant therizinosaurs, used their overdeveloped, meter-long, sickle-like claws for display.

The new work is led by Zichuan Qin, a PhD student at the University of Bristol and the IVPP. He developed a new, computational approach in biomechanics to identify functions based on detailed comparison with living animals. First, the claws were modelled in three dimensions from CT scans, then modelled for stress and strain using engineering methods, and finally matched to functions of pulling, piercing and digging by comparison with modern animals whose claw functions are known.

“Alvarezsaurs and therizinosaurs are definitely the strangest cousins among dinosaurs,” said Professor Michael Benton, one of Zichuan’s supervisors. “Alvarezsaurs were the tiniest dinosaurs ever, the size of chickens, with stubby forelimbs and robust single claws, but their closest relative, the therizinosaurs, evolved in the exact opposite path.”

Hackers could try to take over a military aircraft; can a cyber shuffle stop them?

Sandia National Laboratories cybersecurity expert Chris Jenkins sits in front of a whiteboard with the original sketch of the moving target defense idea for which he is the team lead. When the COVID-19 pandemic hit, Jenkins began working from home, and his office whiteboard remained virtually undisturbed for more than two years.
Photo Credit: Craig Fritz

A cybersecurity technique that shuffles network addresses like a blackjack dealer shuffles playing cards could effectively befuddle hackers gambling for control of a military jet, commercial airliner or spacecraft, according to new research. However, the research also shows these defenses must be designed to counter increasingly sophisticated algorithms used to break them.

Many aircraft, spacecraft and weapons systems have an onboard computer network known as military standard 1553, commonly referred to as MIL-STD-1553, or even just 1553. The network is a tried-and-true protocol for letting systems like radar, flight controls and the heads-up display talk to each other.

Securing these networks against a cyberattack is a national security imperative, said Chris Jenkins, a Sandia National Laboratories cybersecurity scientist. If a hacker were to take over 1553 midflight, he said, the pilot could lose control of critical aircraft systems, and the impact could be devastating.

Jenkins is not alone in his concerns. Many researchers across the country are designing defenses for systems that utilize the MIL-STD-1553 protocol for command and control. Recently, Jenkins and his team at Sandia partnered with researchers at Purdue University in West Lafayette, Indiana, to test an idea that could secure these critical networks.

Voluntary UK initiatives to phase out toxic lead shot for pheasant hunting have had little impact

Pheasant
Photo Credit: Julie Mayo

The pledge, made in 2020 by nine major UK game shooting and rural organizations, aims to protect the natural environment and ensure a safer supply of game meat for consumers. Lead is toxic even in very small concentrations, and discarded shot from hunting poisons and kills tens of thousands of the UK’s wild birds each year.

A Cambridge-led team of 17 volunteers bought whole pheasants from butchers, game dealers and supermarkets across the UK in 2022-23. They dissected the birds at home and recovered embedded shotgun pellets from 235 of the 356 pheasant carcasses.

The main metal present in each shotgun pellet was revealed through laboratory analysis - conducted at the Environmental Research Institute, University of the Highlands and Islands, UK. Lead was the main element in 94% of the recovered shot pellets; the remaining 6% were predominantly composed of steel or a metal called bismuth.

Australia’s rarest bird of prey disappearing at alarming rate

Researchers analyzed 40 years of sightings by citizen scientists to uncover concerning population trends.
Photo Credit: Chris McColl

Australia’s rarest bird of prey - the red goshawk - is facing extinction, with Cape York Peninsula now the only place in Queensland known to support breeding populations.

PhD candidate Chris MacColl from The University of Queensland’s School of Earth and Environmental Sciences led the research project that made the discovery and was shocked by the hawk’s dwindling numbers.

“Over four decades the red goshawk has lost a third of its historical range, which is the area that’s it’s previously been known to occupy,” Mr. MacColl said.

“It’s barely hanging on in another 30 per cent of regions it has previously been known to inhabit.”

Mr. MacColl said the species is now considered extinct in New South Wales and the southern half of Queensland.

Let's get wasted and apply some deep thinking to rubbish

Photo Credit: John Cameron

Artificial intelligence has made a giant leap into our rubbish bins thanks to new technology being deployed at the University of South Australia.

Using algorithms to analyze data from smart bin sensors, UniSA PhD student Sabbir Ahmed is designing a deep learning model to predict where waste is accumulating in cities and how often public bins should be cleared.

“Sensors in the public smart bins can give us a lot of information about how busy specific locations are, what type of rubbish is being disposed of and even how much methane gas is being produced from food waste in bins,” Ahmed says.

“All that data can be fed into a neural network model to predict where bins in parks, shopping centers and other public places are likely to fill up quickly and, conversely, which locations are rarely visited.

“This can help councils to optimize their waste management services, schedule bin clearances and even relocate rarely used bins to where they are needed most.”

Researchers Uncover How Photosynthetic Organisms Regulate and Synthesize ATP


The redox regulation mechanism responsible for efficient production of ATP under varying light conditions in photosynthetic organisms has now been unveiled by Tokyo Tech researchers. They investigated the enzyme responsible for this mechanism and uncovered how the amino acid sequences present in the enzyme regulate ATP production. Their findings provide valuable insights into the process of photosynthesis and the ability to adapt to changing metabolic conditions.

ATP, the compound essential for the functioning of photosynthetic organisms such as plants and algae, is produced by an enzyme called "chloroplast ATP synthase" (CFoCF1). To control ATP production under varying light conditions, the enzyme uses a redox regulatory mechanism that modifies the ATP synthesis activity in response to changes in the redox state of cysteine (Cys) residues, which exist as dithiols under reducing (light) conditions, but forms a disulfide bond under oxidizing (dark) conditions. However, this mechanism has not been fully understood so far.

Now, in a study published in the Proceedings of the National Academy of Sciences, a team of researchers from Japan, led by Prof. Toru Hisabori from Tokyo Institute of Technology (Tokyo Tech), has uncovered the role of the amino acid sequences present in CFoCF1, revealing how the enzyme regulates ATP production in photosynthetic organisms.

Wednesday, February 22, 2023

New Study Shows Archery Appeared in Europe Thousands of Years Earlier than Previously Thought

Laure Metz making experimental bow and arrow shots with arrows armed with Neronian light points.
 Photo Credit: Ludovic Slimak

The use of bow-and-arrow technology gave humans an edge over Neanderthal neighbors in hunting game

A new study published in Science Advances contextualizes the traditions and technological knowledge of early, pioneering Homo sapiens. The study demonstrates the mastery of archery by modern populations and extends the evidence of archery in Europe back by about 40,000 years.

The researchers analyzed lithic artifacts from a cave in Mediterranean France called Grotte Mandrin, which reveals the oldest occupation of modern humans on the European continent. The study focuses on a very rich level, attributed to the Neronian culture, and testifies to Homo sapiens occupations dating back 54,000 years, interposed between numerous Neanderthal occupations in the cave before and after the modern humans. That’s roughly 10,000 years earlier than what had been previously believed to be the earliest occupation of modern humans in Europe.

The research was directed by Laure Metz, an associated researcher at UMR 7269 (UMR LAMPEA, CNRS, Aix-Marseille University), and Ludovic Slimak, CNRS researcher (UMR 5608 TRACES, Toulouse Jean Jaurès University). Metz is a UConn-affiliated researcher and former post-doctoral researcher in the UConn Department of Anthropology Deep History Lab led by Professor Christian Tryon.

Custom, 3D-printed heart replicas look and pump just like the real thing


No two hearts beat alike. The size and shape of the heart can vary from one person to the next. These differences can be particularly pronounced for people living with heart disease, as their hearts and major vessels work harder to overcome any compromised function.

MIT engineers are hoping to help doctors tailor treatments to patients’ specific heart form and function, with a custom robotic heart. The team has developed a procedure to 3D print a soft and flexible replica of a patient’s heart. They can then control the replica’s action to mimic that patient’s blood-pumping ability.

The procedure involves first converting medical images of a patient’s heart into a three-dimensional computer model, which the researchers can then 3D print using a polymer-based ink. The result is a soft, flexible shell in the exact shape of the patient’s own heart. The team can also use this approach to print a patient’s aorta — the major artery that carries blood out of the heart to the rest of the body.

To mimic the heart’s pumping action, the team has fabricated sleeves similar to blood pressure cuffs that wrap around a printed heart and aorta. The underside of each sleeve resembles precisely patterned bubble wrap. When the sleeve is connected to a pneumatic system, researchers can tune the outflowing air to rhythmically inflate the sleeve’s bubbles and contract the heart, mimicking its pumping action. 

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