Tuesday, May 10, 2022

Fossils reveal tropically hot North America 95 million years ago

Cretaceous oysters of the genus Pycnodonte investigated in the new study. These specimens were collected in San Miguel County, Colorado (top left), Kane County, Utah (top right), Big Horn County, Wyoming (bottom left), and Natrona County, Wyoming (bottom right), with a penny for scale.
Image credit: Matt Jones

A new University of Michigan study that used fossil oyster shells as paleothermometers found the shallow sea that covered much of western North America 95 million years ago was as warm as today’s tropics.

The study provides the first direct temperature data from that vast mid-latitude sea during the height of the Cretaceous Thermal Maximum, one of the planet’s hottest climate intervals of the past several hundred million years.

The findings, published online May 9 in the journal Geology, also hint at what may be in store for future generations unless emissions of heat-trapping greenhouse gases are reined in.

“These data indicate that the North American interior during the peak of the Cretaceous greenhouse was as warm as the hottest conditions in the modern-day tropics—imagine the climate of Bali, Indonesia, in places like Utah or Wyoming,” said study lead author Matt Jones, a former University of Michigan postdoctoral researcher now at the Smithsonian Institution’s National Museum of Natural History.

Hidden Distortions Trigger Promising Thermoelectric Property

Brookhaven Lab members of the research team: Simon Billinge, Milinda Abeykoon, and Emil Bozin adjust instruments for data collection at the Pair Distribution Function beamline of the National Synchrotron Light Source II. In this setup, a stream of hot air heats samples with degree-by-degree precision as x-rays collect data on how the material changes.
Credit: Brookhaven National Laboratory

In a world of materials that normally expand upon heating, one that shrinks along one 3D axis while expanding along another stands out. That’s especially true when the unusual shrinkage is linked to a property important for thermoelectric devices, which convert heat to electricity or electricity to heat.

In a paper just published in the journal Advanced Materials, a team of scientists from Northwestern University and the U.S. Department of Energy’s Brookhaven National Laboratory describe the previously hidden sub-nanoscale origins of both the unusual shrinkage and the exceptional thermoelectric properties in this material, silver gallium telluride (AgGaTe2). The discovery reveals a quantum mechanical twist on what drives the emergence of these properties—and opens up a completely new direction for searching for new high-performance thermoelectrics.

Newly Discovered Lake May Hold Secret to Antarctic Ice Sheet’s Rise and Fall

The coast of Antarctica is near where the East Antarctic Ice Sheet meets the sea.
Credit: Shuai Yan/UT Jackson School of Geosciences

Scientists investigating the underside of the world’s largest ice sheet in East Antarctica have discovered a city-size lake whose sediments might contain a history of the ice sheet since its earliest beginnings. That would answer questions about what Antarctica was like before it froze, how climate change has affected it over its history, and how the ice sheet might behave as the world warms.

Revealed by heavily instrumented polar research aircraft, Lake Snow Eagle is covered by 2 miles of ice and lies in a mile-deep canyon in the highlands of Antarctica’s Princess Elizabeth Land, a few hundred miles from the coast.

“This lake is likely to have a record of the entire history of the East Antarctic Ice Sheet, its initiation over 34 million years ago, as well as its growth and evolution across glacial cycles since then,” said polar expert Don Blankenship, one of the paper’s authors and a senior research scientist at The University of Texas at Austin’s Institute for Geophysics (UTIG). “Our observations also suggest that the ice sheet changed significantly about 10,000 years ago, although we have no idea why.”

Bat urine reveals extended range for new Hendra virus variant

Source/Credit: Griffith University

Griffith University researchers have discovered a new Hendra virus variant that may pass to horses and humans much more widely across Australia than previously known.

Published in Emerging Infectious Disease, the variant was detected in the urine of black and grey-headed flying foxes across an extended geographical distribution from mid-north coast NSW to southeast Queensland.

The new Hendra virus variant (HeV-g2) was recently discovered in samples from a horse that died in 2015 with acute illness and was previously detected in flying fox organs.

“Detection of the novel Hendra variant in urine is important, as contact with infected flying fox urine is how horses can become infected,” said lead researcher Dr Alison Peel, from the Centre for Planetary Health and Food Security.

“Our study, by revealing associations with particular flying fox species, helps to identify the variant’s distribution in these animals and the risk of spill-over into horses and subsequently humans.

Monday, May 9, 2022

Sale of donkey skins linked to trade in illegal wildlife products

A working donkey pulling a farmer's cart
Credit: Katja/Pixabay

Newly published research raises important concerns about whether the trade in donkey skins is being used as a cover for smuggling elephant tusks, pangolin scales and other illegal wildlife products.

Research published in Conservation Science and Practice has revealed novel links between the global trade in donkey skins and the wildlife trade. The study by an interdisciplinary team from the University of Oxford’s Saïd Business School and Wildlife Conservation Research Unit (WildCRU) and supported by The Donkey Sanctuary suggests that these trades operate in parallel, creating new avenues and transportation pathways for wildlife trade.

The trade of donkey skins is largely driven by demand for E-Jiao, a traditional Chinese medicine, which uses gelatin from donkey skins. As increasing demand has outstripped the Chinese domestic supply of donkeys, E-Jiao producers have looked to international markets for skins.

Using network analysis of online markets, the research team examined seven large international b2b eCommerce platforms, which all hosted vendors selling donkey skins. Nearly one-fifth of the vendors selling donkey skins also offered some other form of wildlife product – in some cases even species protected by CITES, the international treaty on the trade of endangered species.

Future super cyclones would expose vastly greater numbers of people in most vulnerable parts of the world to extreme flooding

Image shows impact of cyclone Yaas in Bangladesh in May, 2021.
Source: University of Bristol

A new study has revealed super cyclones, the most intense form of tropical storm, are likely to have a much more devastating impact on people in South Asia in future years.

The international research, led by the University of Bristol, looked at the 2020 Super Cyclone Amphan – the costliest cyclone to make landfall in South Asia – and projected its consequences in different scenarios of sea level rise due to global warming.

Its findings, published today in the Royal Meteorological Society journal Climate Resilience and Sustainability, showed if the release of greenhouse gases into the atmosphere continues at the same scale, more than two and a half times (250%) the population in India would experience flooding of greater than 1 meter, compared to the event in 2020.

Lead author Dann Mitchell, Professor of Climate Science at the university's Cabot Institute for the Environment, said: “South Asia is one of the most climate-sensitive regions in the world, with super cyclones causing tens to hundreds of thousands of deaths in historical cases. Comparatively, very little climate impact research has been done in South Asia, despite the Intergovernmental Panel on Climate Change highlighting it as such a critical region.

Male spiders use catapult mechanism to avoid sexual cannibalism

Close-up of communal orb-weaving spiders mating.
Photo credit: Shichang Zhang

In the animal word, numerous mechanisms have been described that allow for extremely fast actions or reactions via the slow storage of energy, typically in elastic structures which is then nearly instantly released, similar to the operation of a catapult. Many of these mechanisms are employed for prey capture or predator avoidance, however such superfast actions have not yet been reported as a means to dodge sexual mechanism.

Associate Professor Li Daiqin from the National University of Singapore (NUS) and a team of scientists have discovered a mechanism in the legs of male spiders enabling them to undertake a split-second catapult action immediately after mating to avoid being cannibalized by their partner. This is the first time a catapult mechanism to escape sexual cannibalism has been observed in any animal.

The scientists demonstrated that male communal orb-weaving spiders (Philoponella prominens (Family: Uloboridae)) activate the catapult mechanism by extending a joint that lacks extensor muscles, called the tibia-metatarsus, on their forelegs via hydraulic pressure. The rapid expansion of the legs greatly reduces the likelihood of the male being sexually cannibalized.

Sunday, May 8, 2022

Some Volcanoes Might Warm Climate, Destroy Ozone Layer


A new NASA climate simulation suggests that extremely large volcanic eruptions called “flood basalt eruptions” might significantly warm Earth’s climate and devastate the ozone layer that shields life from the Sun’s ultraviolet radiation.

The result contradicts previous studies indicating these volcanoes cool the climate. It also suggests that while extensive flood-basalt eruptions on Mars and Venus may have helped warm their climates, they could have doomed the long-term habitability of these worlds by contributing to water loss.

Source/Credit:
Video: NASA/Goddard Space Flight Center
Final Editing and Conversion: Scientific Frontline
Additional credits are embedded 

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Saturday, May 7, 2022

Squid and Octopus Genome Studies Reveal How Cephalopods’ Unique Traits Evolved

The Hawaiian bobtail squid (Euprymna scolopes) is a model system for studying animal-bacterial symbiosis.
Credit: Tom Kleindinst

Squid, octopus, and cuttlefish – even to scientists who study them – are wonderfully weird creatures. Known as the soft-bodied or coleoid cephalopods, they have the largest nervous system of any invertebrate, complex behaviors such as instantaneous camouflage, arms studded with dexterous suckers, and other evolutionarily unique traits.

Now, scientists have dug into the cephalopod genome to understand how these unusual animals came to be. Along the way, they discovered cephalopod genomes are as weird as the animals are. Scientists from the Marine Biological Laboratory (MBL) in Woods Hole, the University of Vienna, the University of Chicago, the Okinawa Institute of Science and Technology and the University of California, Berkeley, reported their findings in two new studies in Nature Communications.

“Large and elaborate brains have evolved a couple of times,” said co-lead author Caroline Albertin, Hibbitt Fellow at the MBL. “One famous example is the vertebrates. The other is the soft-bodied cephalopods, which serve as a separate example for how a large and complicated nervous system can be put together. By understanding the cephalopod genome, we can gain insight into the genes that are important in setting up the nervous system, as well as into neuronal function.”

In Albertin et al., published this week, the team analyzed and compared the genomes of three cephalopod species – two squids (Doryteuthis pealeii and Euprymna scolopes) and an octopus (Octopus bimaculoides).

Only 10 vaquita porpoises survive, but species may not be doomed

Credit: Paula Olson/NOAA

The vaquita porpoise, the world’s smallest marine mammal, is on the brink of extinction, with 10 or fewer still living in Mexico’s Gulf of California, their sole habitat. But a genetic analysis by a team of UCLA biologists and colleagues has found that the critically endangered species remains relatively healthy and can potentially survive — if illegal “gillnet” fishing ceases promptly.

“Interestingly, we found the vaquita is not doomed by genetic factors, like harmful mutations, that tend to affect many other species whose gene pool has diminished to a similar point,” said Christopher Kyriazis, a UCLA doctoral student in ecology and evolutionary biology and a co–lead author of the research. “Outlawed fishing remains their biggest threat.”

The small porpoises, which range from 4 to 5 feet in length, often become entangled and die in the large mesh gillnets used by poachers hunting the totoaba, an endangered fish highly valued in some countries for its perceived medicinal properties. While Mexico has outlawed totoaba fishing and made the use of these nets in the vaquitas’ habitat illegal, many say the bans are not always enforced.

The researchers analyzed the genomes of 20 vaquitas that lived between 1985 and 2017 and conducted computational simulations to predict the species’ extinction risk over the next 50 years. They concluded that if gillnet fishing ends immediately, the vaquita has a very high chance of recovery, even with inbreeding. If, however, the practice continues, even moderately, the prospects of recovery are less optimistic.

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