First Modern Humans Arrived in Europe Earlier Than Previously Known

Close-up of the Grotte Mandrin in southern France where scientists have uncovered layers of history that include both modern human and Neanderthal activity.
Credit: Ludovic Slimak

Some 30 years of archeological and other types of scientific research around the ancient artifacts and human remains in the Grotte Mandrin, located in the Rhone River Valley in southern France, has revealed that humans may have arrived in Europe about 10,000 years earlier than originally thought. This conclusion, drawn by an international team of researchers including Jason Lewis, PhD, of Stony Brook University, will help scientists rethink the arrival of humans into Europe and their replacement of and interactions with Neanderthals who also lived in the cave. The research is detailed in a paper published in Science Advances.

Previous studies have suggested that the first modern humans reached the European continent – originally from Africa and via the Levant, the eastern Mediterranean crossroads – between 43,000 and 48,000 years ago. But this discovery of modern human presence in the heart of the Rhone River Valley at Grotte Mandrin points to about 54,000 years ago.

The area of the cave excavated and analyzed that proved the evidence of modern human presence is Mandrin’s Layer E. It is sandwiched between 10 other layers of artifacts and fossils that contain evidence of Neanderthal life.

Vaccinated Patients Less Likely to Need Critical Care During Omicron Surge

A new study of COVID-19 patients who had the omicron variant of the disease shows that vaccinated adults had less severe illness than unvaccinated adults and were less likely to land in intensive care. Source: Cedars-Sinai

The highly contagious omicron variant of SARS-CoV-2 became the dominant strain in the United States in mid-December 2021, coinciding with a rise in hospitalizations of patients with COVID-19. Among those admitted during the omicron surge, vaccinated adults had less severe illness compared with unvaccinated adults and were less likely to land in intensive care, according to a new study by Cedars-Sinai and the Centers for Disease Control and Prevention (CDC).

"Overall, the omicron-period group had a lower likelihood of being admitted to the intensive care unit (ICU) and were also less likely to require invasive mechanical ventilation compared with the delta-period group,” said Matthew Modes, MD, a pulmonologist at Cedars-Sinai and co-first author of the paper.

Investigators also found that during the omicron period fewer patients died while hospitalized (4.0%), compared with those admitted when the delta variant was dominant (8.3%).

This Bizarre Looking Helmet Can Create Better Brain Scans

Ke Wu, a PhD student in BU’s department of mechanical engineering, demonstrates a new magnetic metamaterial device intended to be used in conjunction with MRI machines to boost the quality of brain scans.
Credit: Cydney Scott

It may look like a bizarre bike helmet, or a piece of equipment found in Doc Brown’s lab in Back to the Future, yet this gadget made of plastic and copper wire is a technological breakthrough with the potential to revolutionize medical imaging. Despite its playful look, the device is actually a metamaterial, packing in a ton of physics, engineering, and mathematical know-how.

It was developed by Xin Zhang, a College of Engineering professor of mechanical engineering, and her team of scientists at BU’s Photonics Center. They’re experts in metamaterials, a type of engineered structure created from small unit cells that might be unspectacular alone, but when grouped together in a precise way, get new superpowers not found in nature. Metamaterials, for instance, can bend, absorb, or manipulate waves—such as electromagnetic waves, sound waves, or radio waves. Each unit cell, also called a resonator, is typically arranged in a repeating pattern in rows and columns; they can be designed in different sizes and shapes, and placed at different orientations, depending on which waves they’re designed to influence.

Animals deceive opponents by producing giant weapons on a small budget

En Garde! Belligerent fiddler crabs intimidate before striking, relying on relatively cheap prop weapons to scare.
Lillie via Wikimedia Commons

Two knights stand face to face. One has a plain average-sized sword. The other has a massive fear-inducing sword stained with blood. After one quick look at it, the first knight quickly puts his average sword away, backs off to a safe distance, and runs for his life.

He’ll never know that the massive fear-inducing sword was actually a plastic toy.

In a new study appearing in the journal Biology Letters, Jason Dinh, Ph.D. candidate in Biology at Duke University, shows that animal weapons can be a lot like plastic swords: impressive, but ultimately cheap.

From deer antlers to lobster claws, many animals have weapons. These are often large, clunky and heavy appendages that are metabolically costly for the animal to maintain. In clawed crustaceans, such as shrimps, lobsters, and crabs, their weapons can weigh more than a third of the animal’s body mass. That’s a lot of extra tissue to feed and maintain, even when the animal is perfectly still.

“Some animals can spend 40% of their energy budget for the day just maintaining themselves sitting there doing nothing,” Dinh said. “It's a very slow and steady cost that's happening throughout the animal’s adult life.”

Unlocking the mechanical secrets of giant Amazonian waterlilies

Giant Amazonian waterlilies at Oxford Botanic Garden
Credit: Chris Thorogood

Researchers studying giant Amazonian waterlilies grown at the University's Botanic Garden have unraveled the engineering enigma behind the largest floating leaves in nature.

In a study published recently in Science Advances, researchers found that the distinctive pattern on the underside of the gargantuan leaves is the secret to the success of the giant Amazonian waterlily (genus Victoria).

The crisscross framework makes up the vascular structure of the lily pad (or leaf), supporting its large surface area and keeping it afloat. The giant leaves can grow 40cm a day, reaching nearly 3m in diameter – ten times larger than any other species of waterlily – and carry the weight of a small child.

Dr Chris Thorogood, Deputy Director at the University of Oxford Botanic Garden said:

'I used to marvel at this extraordinary plant on childhood trips to botanic gardens. I remember wondering how on earth does it grow this big.'

The researchers compared the high-sided giant Amazonian waterlily leaf which has thick veins to Nymphaea – a smaller relation with disc-like leaves and a less prominent vascular system. Using in-situ experiments and mathematical modelling, the team found that the giant Amazonian waterlily leaves had a greater rigidity for a given volume of plant matter.

New study unlocks mystery origin of iconic Aussie snakes

Tiger Snake (Notechis scutatus)
Credit: Max Tibby- Snake Catchers Adelaide

New research led by the University of Adelaide has found the first tangible evidence that the ancestors of some of Australia’s most venomous snakes arrived by sea rather than by land – the dispersal route of most other Australian reptiles.

In a paper published in Genes, the researchers analyzed the genomes of two Australian elapids (front fanged snakes), a tiger and a brown snake, and compared them to marine and semi-marine elapid sea snakes and Asian elapids.

“Some believe their ancestors travelled by land, whereas others hold the more contentious view that a marine or semi-marine ancestor swam here."

Professor David Adelson

They inferred that the ancestor of all Australian elapids had accumulated self-replicating and self-mobilizing genes (jumping genes) that were not present in their land relatives but came from another source altogether.

Einstein’s photoelectric effect: The time it takes for an electron to be released

COLTRIMS reaction microscope at electron storage ring BESSY II, Helmholtz-Zentrum Berlin für Materialien und Energie (HZB).
Photo: Miriam Weller, Goethe University Frankfurt

When light hits a material, electrons can be released from this material – the photoelectric effect. Although this effect played a major role in the development of quantum theory, it still holds a number of secrets: To date it has not been clear how quickly the electron is released after the photon is absorbed. Jonas Rist, a Ph.D. student working within an international team of researchers at the Institute for Nuclear Physics at Goethe University Frankfurt, has now been able to find an answer to this mystery with the aid of a COLTRIMS reaction microscope which had been developed in Frankfurt: The emission takes place lightning fast, namely within just a few attoseconds – within a billionth of billionths of a second.

It is now exactly one hundred years ago that Albert Einstein was awarded the Nobel Prize in Physics for his work on the photoelectric effect. The jury had not yet really understood his revolutionary theory of relativity – but Einstein had also conducted ground-breaking work on the photoelectric effect. With his analysis he was able to demonstrate that light comprises individual packets of energy – so-called photons. This was the decisive confirmation of Max Planck's hypothesis that light is made up of quanta, and paved the way for the modern quantum theory.

Researchers identify brain region associated with feeling full after eating

Feeling full, or satiated, after a meal is healthy and normal, but what causes that feeling is complicated and not well understood. New University of Arizona-led research published in the journal Molecular Metabolism has identified a brain region and neural circuitry that mediate satiation, which could help scientists better target drugs to treat eating disorders or manage weight.

There are currently six Food and Drug Administration-approved medications for weight management, but they often come with side effects.

"When we can more precisely target the part of the brain responsible for feelings of satiation, then we can create treatments with fewer side effects," said lead study author Haijiang Cai, an associate professor in the Department of Neuroscience.

Previous research has mapped the circuits for satiation to the brain's central amygdala, which also controls fear, pain and other strong emotions. But the complexity of the neurons in this part of the brain has made it difficult for scientists to map where the signal goes next.

Cai and his team found that after the amygdala, the signal heads to neurons located in a brain region called the parasubthalamic nucleus, or PSTh, responsible for the feeling of satiation.

Here's how they did it: First, they knew that the hormone cholecystokinin, or CCK, is secreted by the gut to tell the brain "I'm full" after a meal. They also knew that specific neurons in the amygdala, called PKC-delta neurons, mediate the satiation effect of CCK by turning off other central amygdala inhibitory neurons. The researchers reasoned that the neurons downstream of the central amygdala should be turned on by PCK-delta neurons while also being turned on by CCK, Cai said.

Notches on lions’ teeth reveal poaching in Zambia’s conservation areas

UCLA biologist Paula White displays two leopard skulls.
Credit: Paula White

In a hunting camp in Zambia more than a decade ago, UCLA biologist Paula White puzzled over the heavy skull of a trophy-hunted lion. Zambia permits limited hunting in certain areas to help fund its national conservation program, and White had gained permission to examine the trophy skulls and hides to evaluate how hunting was affecting conservation efforts.

This particular skull had a pronounced horizontal V-shaped notch on one of the canine teeth — a marking White had never seen before from natural wear. Over the next few months, she began noticing similar notches on other lions’ teeth.

It wasn’t until three years later, when she visited lions bred in captivity and saw them gnawing on a wire fence, that it clicked: The tooth notches in wild lions resulted from the animals chewing their way out of wire snares — noose-like traps set by poachers. The sheer number of notched teeth she’d seen suggested that such traps, illegal in conservation areas, were injuring far more lions than experts had estimated.

“It was an odd mix of thrilling to figure out the cause of the notches and horrifying to realize that so many animals had been entangled in a snare at some point in their lives,” said White, director of the Zambia Lion Project and a senior research fellow with the Center for Tropical Research at UCLA’s Institute of the Environment and Sustainability.

Earth's Inner Core: A Mixture of Solid Fe and Liquid-like Light Elements

Earth's interior structure and superionic inner core
Image by IGCAS

Earth's core, the deepest part of our planet, is characterized by extremely high pressure and temperature. It is composed of a liquid outer core and solid inner core.

The inner core is formed and grows due to the solidification of liquid iron at the inner core boundary. The inner core is less dense than pure iron, and some light elements are believed to be present in the inner core.

A joint research team of Prof. LI Heping and Prof. HE Yu from the Institute of Geochemistry of the Chinese Academy of Sciences (IGCAS) and Prof. MAO Ho-kwang and Prof. KIM Duck Young from Center for High Pressure Science & Technology Advanced Research (HPSTAR) has found that the inner core of the Earth is not a normal solid but is composed of a solid iron sublattice and liquid-like light elements, which is also known as a superionic state. The liquid-like light elements are highly diffusive in iron sublattices under inner core conditions.

This study was published in Nature on Feb. 9.

A superionic state, which is an intermediate state between solid and liquid, widely exists in the interior of planets. Using high-pressure and high-temperature computational simulations based on quantum mechanics theory, researchers from IGCAS and the Center for High Pressure Science & Technology Advanced Research (HPSTAR) found that some Fe-H, Fe-C and Fe-O alloys transformed into a superionic state under inner core conditions.

In superionic iron alloys, light elements become disordered and diffuse like a liquid in the lattice, while iron atoms remain ordered and vibrate about their lattice grid, forming the solid iron framework. The diffusion coefficients of C, H and O in superionic iron alloys are the same as those in liquid Fe.

"It is quite abnormal. The solidification of iron at the inner core boundary does not change the mobility of these light elements, and the convection of light elements is continuous in the inner core," said Prof. HE Yu, the first and corresponding author of the study.