Tsunami threats are greatly underestimated in current models

USC researchers found that large earthquake-generated tsunamis emerge after horizontal oceanic water movement is transferred to uplift in the tsunami excitation zone, the outer wedge of sediment between the continental shelf and the deep ocean trench. 
USC Graphic/Mesa Schumacher and Edward Soleto

The 2004 Sumatra earthquake generated one of the most destructive tsunamis ever recorded, with 100-foot waves that killed nearly 230,000 and resulted in an estimated $10 billion in damage. It also ushered in a new understanding that potent tsunamis are triggered by shallow earthquake ruptures of underwater fault lines. Future tsunamis are likely to be just as severe, if not worse, potentially killing even more people and wiping out whole communities. Although current research points to rupture depth as a key factor in predicting tsunami severity, those models fail to explain why large tsunamis still occur following relatively small earthquakes.

Now, USC researchers have found a correlation between tsunami severity and the width of the outer wedge — the area between the continental shelf and deep trenches where large tsunamis emerge — that helps explain how underwater seismic events generate large tsunamis. Drawing insights from a survey of previous tsunamis, the authors analyzed the geophysical, seismic and bathymetric data of global subduction zones to identify and discuss potential tsunami hazards.

Newly discovered ancient Amazonian cities reveal how urban landscapes were built without harming nature

Lidar image of the large settlement site Cotoca with cross sections A–B and C–D. m.a.s.l., meters above sea level.
Credit: University of Exeter

A newly discovered network of “lost” ancient cities in the Amazon could provide a pivotal new insight into how ancient civilizations combined the construction of vast urban landscapes while living alongside nature.

A team of international researchers, including Professor Jose Iriarte from the University of Exeter, has uncovered an array of intricate settlements in the Llanos de Mojos savannah-forest, Bolivia – that have laid hidden under the thick tree canopies for centuries.

The cities, built by the Casarabe communities between 500-1400 AD, feature an unprecedented array of elaborate and intricate structures unlike any previously discovered in the region – including 5m high terraces covering 22 hectares – the equivalent of 30 football pitches – and 21m tall conical pyramids.

Researchers also found a vast network of reservoirs, causeways and checkpoints, spanning several kilometers.

Bat Brains Organized for Echolocation and Flight

Researchers at the UC Davis Center for Neuroscience mapped the brain regions controlling movements in Egyptian fruit bats. Large regions of motor cortex are dedicated to the tongue, which makes sonar sounds, and coordinated movements of fore- and hindlimbs for flying

A new study shows how the brains of Egyptian fruit bats are highly specialized for echolocation and flight, with motor areas of the cerebral cortex that are dedicated to sonar production and wing control. The work by researchers at the University of California, Davis, and UC Berkeley was published May 25 in Current Biology.

Professor Leah Krubitzer’s lab at the UC Davis Center for Neuroscience studies how evolution produces variation in brain organization across a wide variety of mammals, including opossums, tree shrews, rodents and primates. This comparative neurobiology approach shows how both evolution and development influence brain organization.

Although bats represent a quarter of all living mammalian species, this is the first time the full motor cortex of any bat has been mapped, said first author Andrew Halley, a postdoctoral researcher in Krubitzer’s lab.

Secrets of tree hyraxes uncovered with new research techniques

Tree hyraxes of Taita mountain forests are vociferous nocturnal mammals.
Credit: Hanna Rosti

Tree hyraxes are medium-sized mammals living in the canopies of tropical forests. They are shy and only move at night, which is why next to nothing has been known about their living habits or behavior so far.

However, researchers from the University of Helsinki have now, by combining various techniques, been able to observe the life of a local tree hyrax species living in the fragmented mountain forests of Taita Hills in Kenya.

The movements of nocturnal tree hyraxes were monitored with the help of a thermal imaging camera. The camera revealed which tree and vine species were particularly favored by the tree hyraxes, which species’ leaves they ate and which species provided them with suitable hiding places for the day. Among other things, the new data revealed that tree hyraxes are social. They do not sulk in a fork of a tree, as has been previously commonly assumed.

Tiny robotic crab is smallest-ever remote-controlled walking robot

Northwestern University engineers have developed the smallest-ever remote-controlled walking robot — and it comes in the form of a tiny, adorable peekytoe crab.

Just a half-millimeter wide, the tiny crabs can bend, twist, crawl, walk, turn and even jump. The researchers also developed millimeter-sized robots resembling inchworms, crickets and beetles. Although the research is exploratory at this point, the researchers believe their technology might bring the field closer to realizing micro-sized robots that can perform practical tasks inside tightly confined spaces.

The research was published today (May 25) in the journal Science Robotics. Last September, the same team introduced a winged microchip that was the smallest-ever human-made flying structure (published on the cover of Nature).

“Robotics is an exciting field of research, and the development of microscale robots is a fun topic for academic exploration,” said John A. Rogers, who led the experimental work. “You might imagine micro-robots as agents to repair or assemble small structures or machines in industry or as surgical assistants to clear clogged arteries, to stop internal bleeding or to eliminate cancerous tumors — all in minimally invasive procedures.”

Common drug offers fertility hope for women with obesity

Researchers may have found a solution to improving fertility in women with obesity, following a successful trial in mice using diabetes medication to reduce blood glucose levels.

The University of Queensland study found the common type 2 diabetes medication, Dapagliflozin, altered reproductive hormones in obese mice, and could be the key to improving fertility in humans.

Professor Chen Chen, from UQ’s School of Biomedical Sciences, said the results were a promising sign, as human and mouse reproductive cycles are similar.

“After eight weeks of treatment, blood glucose levels in the mice normalized, body weight reduced, reproductive cycles recovered, and reproductive hormones and ovulation were largely restored, compared with mice that were not treated,” Professor Chen said.

“The drug we used – Dapagliflozin – is known for reducing blood glucose levels and improving other biomarkers of metabolic health, but its effects on reproductive health and fertility have yet to be fully investigated.

“Our findings suggest that normalizing blood glucose metabolism with Dapagliflozin in obesity may be a promising route for restoring reproductive function, at the very least.”

Stars are heavier than we thought

The Andromeda galaxy, our Milky Way's closest neighbor, is the most distant object in the sky that you can see with your unaided eye.
Credit: NASA and J. Olmsted (STScI)

A team of University of Copenhagen astrophysicists has arrived at a major result regarding star populations beyond the Milky Way. The result could change our understanding of a wide range of astronomical phenomena, including the formation of black holes, supernovae and why galaxies die.

For as long as humans have studied the heavens, how stars look in distant galaxies has been a mystery. In a study published today in The Astrophysical Journal, a team of researchers at the University of Copenhagen’s Niels Bohr Institute is doing away with previous understandings of stars beyond our own galaxy.

Since 1955, it has been assumed that the composition of stars in the universe's other galaxies is similar to that of the hundreds of billions of stars within our own – a mixture of massive, medium mass and low mass stars. But with the help of observations from 140,000 galaxies across the universe and a wide range of advanced models, the team has tested whether the same distribution of stars apparent in the Milky Way applies elsewhere. The answer is no. Stars in distant galaxies are typically more massive than those in our "local neighborhood". The finding has a major impact on what we think we know about the universe.

Taking dinosaurs’ temperature with a new biomarker

Allosaurus bone extracellular matrix: microscopic view of bone soft tissues of one of the dinosaur specimens (Allosaurus) that were investigated for metabolic signals (metabolic crosslinks) in the fossilization products of the proteinaceous bone matrix. Fossilization introduces additional crosslinks that, in combination with metabolic crosslinks, generate the characteristic brown color of the fossil extracellular matrix which holds bone cells and blood vessels in place. The extracellular matrix also holds the crystalline, white bone mineral, apatite, in place.
Credit: J. Wiemann

A Yale-led research team has turned up the heat on dinosaur metabolism — establishing that the earliest dinosaurs and pterosaurs had exceptionally high metabolic rates and were warm-blooded animals.

The findings, published May 25 in the journal Nature, also show that dinosaurs’ metabolism did not decide their fate after an asteroid strike wiped out most animal species on the planet 65 million years ago.

“While modern ecologists tend to emphasize the importance of metabolic rate to ensure that animals survive environmental perturbations, we showed that metabolism is not the reason why birds were the only group of dinosaurs to survive the mass extinction event at the end of the Cretaceous period,” said lead author Jasmina Wiemann, a former Yale paleontologist who is now at CalTech. “Many dinosaurs with metabolisms as efficient as those in modern birds went extinct.”

Lunar cycle triggers Hawaiian box jellyfish to spawn on Oʻahu shores

Lead author Angel Yanagihara with Hawaiian Box Jellyfish.
Photo credit: Keoki Stender

A key number of hours of darkness during the lunar cycle triggers mature Hawaiian box jellyfish (Alatina alata) to swim to leeward shores on Oʻahu to spawn. That’s according to a published study in the journal ScienceDirect comprising more than a decade of work by a cross-disciplinary team of University of Hawaiʻi at Mānoa researchers.

Led by Angel Yanagihara, associate research professor at the UH Mānoa School of Ocean and Earth Science and Technology (SOEST) and the John A. Burns School of Medicine, UH Mānoa researchers have been carefully tracking local box jellyfish for more than 20 years. While the monthly shoreline aggregations are understood to occur like clockwork 8–10 days after each full moon, with jelly forecasts included on the local news, mysteries have remained: Why are they appearing at this particular part of the lunar cycle? Where do these box jellyfish come from and where are they found in the rest of the lunar cycle? Why has this become a monthly problem in only the last 30 years?

Combining biology, oceanography

With the new study, the team provided in-depth answers based upon cutting-edge oceanographic approaches including nightlong offshore vessel tracking, computer modeling of local currents and side scan sonar, as well as fundamental field ecology methods and anatomical microscopy.

Silk layer improves function of surgical masks

UC researchers studied the effectiveness of surgical masks in combination with a silk face mask. Biology student Adam Parlin, now with SUNY-ESF, examined the properties of silk in a UC biology lab.
Photo/Joseph Fuqua II/UC Creative + Brand

University of Cincinnati researchers found that a double layer of silk in combination with a surgical mask can enhance its ability to prevent the spread of viruses like COVID-19.

UC biologist Patrick Guerra, UC biologist Theresa Culley, UC postdoctoral researcher Adam Parlin, now at SUNY-ESF, and UC graduate student Samuel Stratton, now at the University of Michigan, began investigating silk as an alternative face mask material at the start of the COVID-19 pandemic in 2020 when personal protective equipment such as the N95 face mask was in short supply.

UC researchers found that double masking with a silk face mask also helps prolong the life of surgical masks without impeding a person's ability to breathe comfortably.

The study was published in the journal Aerosol and Air Quality Research.