Sea turtle conservation gets boost from new DNA detection method

DNA “fingerprints” left behind by sea turtles offer scientists a simple, powerful way of tracking the health and whereabouts of these endangered animals, a key step forward in their conservation.

A study led by University of Florida researchers is the first to sequence environmental DNA, or eDNA, from sea turtles — genetic material shed as they travel over beaches and in water. The research project is also the first to successfully collect animal eDNA from beach sand. The techniques could be used to trace and study other kinds of wildlife, advancing research and informing conservation strategies.

“We wanted to test the boundaries of this technology, which hadn't really been applied to sea turtles before and certainly not on sand,” said David Duffy, UF assistant professor of wildlife disease genomics and Rising Star Condron Family Endowed Assistant Professor. “This is a way to survey areas for elusive animals or species that can be hard to study otherwise. It’s essentially wildlife forensics.”

Nearly all of the planet’s sea turtle species are endangered and face a multitude of threats, including warming temperatures, habitat destruction and degradation, disease, hunting and pollutants such as plastics. Conserving sea turtles is further complicated by the fact that current survey methods rely on spotting them in one of their multiple habitats — in the open sea, coastal ecosystems or on beaches where they nest. This makes it difficult to monitor their numbers, genetic diversity and overall health and tailor conservation efforts accordingly, Duffy said.

Drugs used to treat blood cancer could activate “sleeping” cancer-causing gene

Hypomethylating agents (HMA) are currently used as a first-line treatment for patients with myelodysplastic syndrome (MDS) - a group of disorders where there is insufficient production of healthy mature blood cells in the bone marrow - and increasingly in other diseases, but their mechanism of action remains unclear. One potential risk is that they could potentially activate a sleeping oncogene, although this has not been clearly demonstrated to date.

In a recent study, scientists from the Cancer Science Institute of Singapore (CSI Singapore) at the National University of Singapore (NUS), working in close collaboration with the Brigham and Women’s Hospital (BWH), and the Harvard Medical School (HMS) in Boston have established that HMA can and does activate the oncofetal protein, SALL4.

The study, which was also conducted in collaboration with University of Tor Vergata in Rome, Italy, and the Institute of Hematology and Blood Diseases Hospital, Tianjin, China, was published in scientific journal New England Journal of Medicine on 26 May 2022.

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.”