Last summer, archaeologists from Gothenburg University and Kiel University excavated a dolmen, a stone burial chamber, in Tiarp near Falköping in Sweden. The archaeologists judge that the grave has remained untouched since the Stone Age. However, the odd thing is that parts of the skeletons of the people buried are missing.

Skulls and large bones are missing and may have been removed from the grave. We don’t know whether that has to do with burial rituals or what’s behind it,” says Karl-Göran Sjögren.

Now that the researchers have examined the material from the grave, they have found that it contains bones from hands and feet, fragments of rib bones and teeth. But skulls and larger bones such as thigh and arm bones are very few.

“This differs from what we usually see in megalith graves, i.e. stone burial chambers from the Neolithic period,” Karl-Göran Sjögren explains. “Usually, the bones that are missing are smaller bones from feet and hands.”

Torbjörn Ahlström, Professor of Osteology at Lund University, studied the bone finds. His conclusion is that the bones come from at least twelve people, including infants and the elderly. But the archaeologists don’t yet know why they died.

“We haven’t seen any injuries on the people buried so we don’t think violence is involved. But we are continuing to study their DNA and that will show whether they had any diseases,” says Karl-Göran Sjögren.

Falköping has long been known for its many passage graves dating from a somewhat later period, approximately 3300 BCE. Agriculture reached Falbygden in about 4000 BCE, i.e. about 500 years before the grave in Tiarp was built. In all likelihood, the people buried in the dolmen were farmers.

“They lived by growing grain and keeping animals and they consumed dairy products,” says Karl-Göran Sjögren.

Are the people buried in the grave related?

A number of samples were taken at the excavation last summer, including DNA from the skeletal remains.

“The preliminary DNA results show that the DNA in the bones is well preserved. This means we will be able to reconstruct the family relationships between the people in the grave and we are working on that now,” says Karl-Göran Sjögren.

Falbygden is known for its many traces of people from the Stone Age. There are more than 250 passage graves here, large graves built of blocks of stone.

“But this dolmen is older. It’s about 200 to 150 years older than the passage graves, making it one of the oldest stone burial chambers in Sweden and across the whole of Scandinavia,” says Karl-Göran Sjögren.

There is another thing that makes the grave unique.

“It’s the way it is constructed. There’s a little niche at each end. This is unique for graves in Falbygden,” says Karl-Göran Sjögren.

The study is freely available as open access in Journal of Neolithic Archaeology. Tiarp Backgården. An Early Neolithic Dolmen in Falbygden, Sweden and Early Megalithic Tombs in South Scandinavia and Northern Central Europe.

Facts

• The grave in Tiarp Backgården in Falköping, was first found in 1929. It was studied by archaeologists at the time, and then again in 2014, which was when it was discovered that the grave was more or less intact and had bodies buried inside it.

• The archaeological excavation in Tiarp in summer 2023 was carried out jointly by Gothenburg and Kiel Universities.

• Study participants Karl-Göran Sjögren, Malou Blank and Tony Axelsson, Department of Historical Studies, Gothenburg University. Torbjörn Ahlström, Lund University Stefan Dreibrodt, Institute for Ecosystem Research, Kiel University Johannes Müller, Institute of Prehistoric and Protohistoric Archaeology, Kiel University.

Wildlife filmmaker Carlos Gauna and UC Riverside biology doctoral student Phillip Sternes were scanning the waters for sharks on July 9, 2023, near Santa Barbara on California’s central coast. That day, something exciting appeared on the viewfinder of Gauna’s drone camera. It was a shark pup unlike any they’d ever seen.

Great whites, referred to only as white sharks by scientists, are gray on top and white on the bottom. But this roughly 5-foot-long shark was pure white.

“We enlarged the images, put them in slow motion, and realized the white layer was being shed from the body as it was swimming,” Sternes said. “I believe it was a newborn white shark shedding its embryonic layer.”

These observations are documented in a new paper in the Environmental Biology of Fishes journal. The paper also details the significance of having seen a live newborn white shark.

Gauna is known online as The Malibu Artist. He has spent thousands of hours filming sharks around the world, and his videos of them swimming close to beachgoers have millions of views. What he and Sternes observed could help solve the longstanding mystery of great white birthing habits.

“Where white sharks give birth is one of the holy grails of shark science. No one has ever been able to pinpoint where they are born, nor has anyone seen a newborn baby shark alive,” Gauna said. “There have been dead white sharks found inside deceased pregnant mothers. But nothing like this.”

Though the paper authors acknowledge it is possible the white film the shark shed could have been a skin condition, the duo do not believe this to be the case. “If that is what we saw, then that too is monumental because no such condition has ever been reported for these sharks,” Gauna said.

For many reasons, the duo believes what they saw was in fact a newborn great white.

First, great white females give birth to live pups. While in utero, the embryonic sharks might feed on unfertilized eggs for protein. The mothers offer additional nourishment to the growing shark pups with a ‘milk’ secreted in the uterus.

“I believe what we saw was the baby shedding the intrauterine milk,” Sternes said.

A second reason is the presence of large, likely pregnant great whites in this location. Gauna had observed them here in previous years, and in the weeks leading up to the observation. “I filmed three very large sharks that appeared pregnant at this specific location in the days prior. On this day, one of them dove down, and not long afterwards, this fully white shark appears,” Gauna said. “It’s not a stretch to deduce where the baby came from.”

Thirdly, the shark’s size and shape are also indicative of a newborn. What the two observed was thin, short, and rounded. “In my opinion, this one was likely hours, maybe one day old at most,” Sternes said.

Finally, this location off the coast of central California has long been proposed as a birthing location for great whites. “There are a lot of hypothetical areas, but despite intense interest in these sharks, no one’s seen a birth or a newborn pup in the wild,” Sternes said. “This may well be the first evidence we have of a pup in the wild, making this a definitive birthing location.”

Many scholars believe great whites are born farther out at sea. That this pup was filmed so close to shore — roughly 1,000 feet from the beach — is significant because its age means it was likely born in shallow waters.

Great whites are listed as an international endangered species. “Further research is needed to confirm these waters are indeed a great white breeding ground. But if it does, we would want lawmakers to step in and protect these waters to help white sharks keep thriving,” Sternes said.

In addition to its physical effects, Alzheimer’s causes psychological, social and economic ramifications not only for the people living with the disease, but also for those who love and care for them. Because its symptoms worsen over time, it is important for both patients and their caregivers to prepare for the eventual need to increase the amount of support as the disease progresses.

To that end, researchers at The University of Texas at Arlington have created a novel learning-based framework that will help Alzheimer’s patients accurately pinpoint where they are within the disease-development spectrum. This will allow them to best predict the timing of the later stages, making it easier to plan for future care as the disease advances.

“For decades, a variety of predictive approaches have been proposed and evaluated in terms of the predictive capability for Alzheimer’s disease and its precursor, mild cognitive impairment,” said Dajiang Zhu, an associate professor in computer science and engineering at UTA. He is lead author on a new peer-reviewed paper published open access in Pharmacological Research. “Many of these earlier prediction tools overlooked the continuous nature of how Alzheimer’s disease develops and the transition stages of the disease.”

In work supported by more than $2 million in grants from the National Institutes of Health and the National Institute on Aging, Zhu’s Medical Imaging and Neuroscientific Discovery research lab and Li Wang, UTA associate professor in mathematics, developed a new learning-based embedding framework that codes the various stages of Alzheimer’s disease development in a process they call a “disease-embedding tree,” or DETree. Using this framework, the DETree can not only predict any of the five fine-grained clinical groups of Alzheimer’s disease development efficiently and accurately but can also provide more in-depth status information by projecting where within it the patient will be as the disease progresses.

To test their DETree framework, the researchers used data from 266 individuals with Alzheimer’s disease from the multicenter Alzheimer’s Disease Neuroimaging Initiative. The DETree strategy results were compared with other widely used methods for predicting Alzheimer’s disease progression, and the experiment was repeated several times using machine learning-methods to validate the technique.

“We know individuals living with Alzheimer’s disease often develop worsening symptoms at very different rates,” Zhu said. “We’re heartened that our new framework is more accurate than the other prediction models available, which we hope will help patients and their families better plan for the uncertainties of this complicated and devastating disease.”

He and his team believe that the DETree framework has the potential to help predict the progression of other diseases that have multiple clinical stages of development, such as Parkinson’s disease, Huntington’s disease, and Creutzfeldt-Jakob disease.

In new research published in the journal Science Advances, a team led by UCLA and The University of Oslo shows that at some point, the crater filled with water, depositing layers of sediments on the crater floor. The lake subsequently shrank and sediments carried by the river that fed it formed an enormous delta. As the lake dissipated over time, the sediments in the crater were eroded, forming the geologic features visible on the surface today.

The periods of deposition and erosion took place over eons of environmental changes, the radar indicates, confirming that inferences about the Jezero crater’s geologic history based on Mars images obtained from space are accurate.

“From orbit we can see a bunch of different deposits, but we can’t tell for sure if what we’re seeing is their original state, or if we’re seeing the conclusion of a long geological story,” said David Paige, a UCLA professor of Earth, planetary and space sciences and first author of the paper. “To tell how these things formed, we need to see below the surface.”

The rover, which is about the size of a car and carries seven scientific instruments, has been exploring the 30-mile-wide crater, studying its geology and atmosphere and collecting samples since 2021. Perseverance’s soil and rock samples will be brought back to Earth by a future expedition and studied for evidence of past life.

Between May and December 2022, Perseverance drove from the crater floor onto the delta, a vast expanse of 3 billion-year-old sediments that, from orbit, resembles the river deltas on Earth.

As the rover drove onto the delta, Perseverance’s Radar Imager for Mars’ Subsurface Experiment, or RIMFAX, instrument fired radar waves downward at 10-centimeter intervals and measured pulses reflected from depths of about 20 meters below the surface. With the radar, scientists can see down to the base of the sediments to reveal the top surface of the buried crater floor.

Years of research with ground-penetrating radar and testing of RIMFAX on Earth have taught scientists how to read the structure and composition of subsurface layers from their radar reflections. The resulting subsurface image shows rock layers that can be interpreted like a highway road cut.

“Some geologists say that the ability of radar to see under the surface is kind of like cheating,” said Paige, who is RIMFAX’s deputy principal investigator.

RIMFAX imaging revealed two distinct periods of sediment deposition sandwiched between two periods of erosion. UCLA and the University of Oslo report that the crater floor below the delta is not uniformly flat, suggesting that a period of erosion occurred prior to the deposition of lake sediments. The radar images show that the sediments are regular and horizontal — just like sediments deposited in lakes on Earth. The existence of lake sediments had been suspected in previous studies, but has been confirmed by this research.

A second period of deposition occurred when fluctuations in the lake level allowed the river to deposit a broad delta that once extended far out into the lake, but has now eroded back closer to the river’s mouth.

“The changes we see preserved in the rock record are driven by large-scale changes in the Martian environment,” Paige said. “It’s cool that we can see so much evidence of change in such a small geographic area, which allows us extend our findings to the scale of the entire crater.”