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Wed, 05 May 2021
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Shape of light changes our vision

Scientists at the UNIGE have shown that the response of the retina to light depends not only on the intensity of the light perceived by the eye, but also on its temporal shape and the order in which the colours are organized.
Laser Pulse
© Scientify - UNIGE
Artist's view of femtosecond laser pulses arriving in an eye.
Vision is a complex process that has been successfully deciphered by many disciplines -physics, biochemistry, physiology, neurology, etc.-: The retina captures light, the optic nerve transmits electrical impulses to the brain, which ultimately generates the perception of an image. Although this process takes some time, recent studies have shown that the first stage of vision, the perception of light itself, is extremely fast. But the analysis of this decisive step was carried out on molecules in solution in the laboratory.

Scientists from the University of Geneva (UNIGE), in collaboration with EPFL and the University Hospitals of Geneva (HUG), Switzerland, reproduced the experiment on mice, in order to observe the processing of light by a living organism in all its complexity. This non-invasive study shows that light energy alone does not define the response of the retina. Its shape -short or long- also has an impact on the signal sent to the brain to form an image. This discovery, published in the journal Science Advances, opens up a new field of research into vision, diagnostics and possibly new curative possibilities.

The cellular mechanism of vision has been successfully studied thanks to the collaboration of several disciplines. "In the eye, the first stage of vision is based on a small molecule - the retinal - which, on contact with light, changes shape," explains Geoffrey Gaulier, researcher at the Applied Physics Department of the UNIGE Faculty of Science and first author of the study. "When the retinal alters its geometric form, it triggers a complex mechanism that will result in a nerve impulse generated in the optic nerve."


Scientist: Extent of DDT dumping in Pacific is 'staggering'

ddt dumping toxic ocean california
© David Valentine/UC Santa Barbara / RV Jason via AP
In this 2011 image provided by the University of California Santa Barbara, a barrel sits on the seafloor near the coast of Catalina Island, Calif. Marine scientists say they have found what they believe to be as many as 25,000 barrels that possibly contain DDT dumped off the Southern California coast near Catalina Island.
Marine scientists say they have found what they believe to be more than 25,000 barrels that possibly contain DDT dumped off the Southern California coast near Catalina Island, where a massive underwater toxic waste site dating back to World War II has long been suspected.

The 27,345 "barrel-like" objects were captured in high-resolution images as part of a study by researchers at the University of California San Diego's Scripps Institution of Oceanography. They mapped more than 56 square miles (145 square kilometers) of seafloor between Santa Catalina Island and the Los Angeles coast in a region previously found to contain high levels of the toxic chemical in sediments and in the ecosystem.


First comprehensive single-cell atlas of human teeth

Researchers at the University Zurich have mapped the first complete atlas of single cells that make up the human teeth. Their research shows that the composition of human dental pulp and periodontium vary greatly. Their findings open up new avenues for cell-based dental therapeutic approaches.
Dentist Visit
© University of Zurich
During the last 30 years, medical and dental research has attracted a large number of scientists and practitioners working on aspects of high medical relevance that involve a combination of genetic and tissue regeneration approaches. These developments in stem cell and tissue engineering have provided medical and dental researchers with new insights and given rise to new ideas as to how everyday clinical practice can be improved. Many research groups are dealing with questions like: How can we help injured tissues and organs heal? Can lost tissue be regenerated? How can we create solid protocols that apply across all stem cell therapies?


'Deep Time' experimenters emerge from cave after 40-days

French Team
© Renata Brito (AP)
Members of the French team celebrating the end of their 40-day stay in an underground cave.
What happens if you put 15 people together in a dark cave and take away their ability to track the passage of time? An extraordinary experiment in France has attempted to answer this question, and the results are fascinating.

At 10:30 a.m. local time on Saturday April 24, 15 people emerged from Lombrives cave in Ussat les Bains, France, following 40 days of complete isolation from the outside world. Many of them had smiles on their faces, which... well, full credit to them. Had it been me, I can guarantee you that I would not be smiling, as the conditions down there were far from ideal.

The environment was most certainly rough, with the temperature fixed at 50 degrees F (10 degrees C) and the relative humidity pinned at an oppressive 100%. Not a single ray of sunlight leaks into this cave, requiring the team to depend exclusively on artificial lighting. And with no way to communicate with the outside world, team members lost touch with their friends, families, and the daily news cycle.

Importantly, they also lost track of time, as no clocks of any sort were allowed in the cave. For this was the point of the "Deep Time" project, organized by the Human Adaptation Institute, which is seeking to understand how humans adapt and work together to recreate "synchronization outside the usual indicators," as the group explains at its website.

When asked how long they had stayed in the cave, the team collectively figured it was around 30 days (though, as The Guardian reports, one person estimated the total duration at 23 days!). That the team had somehow lost track of 10 whole days (or more) is somewhat astounding and testament to our dependence on clocks or the day-night cycle to keep track of time. Our internal clocks, it would appear, really, really suck, and are subject to considerable drift — even across the relatively short time span of 40 days.


The bro bonds of sperm whales

Pair of Whales
© Photo by Francois Gohier/VWPics/Alamy Stock Photo
The finding that male sperm whales have male friends bucks the long-standing assumption about sperm whale behavior.
Scientists have long believed that male sperm whales are among nature's loneliest creatures. Unlike female sperm whales, which spend their entire lives living in matrilineal societies among their female kin, males get kicked out of their mothers' pods once they reach sexual maturity and then spend the majority of their lives alone. Or so we thought.

A new study has found evidence that male sperm whales can develop strong, long-lasting bonds, forming friendships with other males that can last for at least five years.

The findings of this landmark study are based on 12 years of observations conducted by researchers working in the Nemuro Strait, a narrow stretch of water sandwiched between Hokkaido, in northern Japan, and the southernmost Kuril Island. The strait is visited by hundreds of migrating sperm whales each year. Although male sperm whales have previously been observed feeding together, and even stranding themselves in all-male groups of unrelated individuals, no one knew what was driving them to do so.

To find out, researchers led by Hayao Kobayashi, a sociobiologist at Nagasaki University in Japan, spent thousands of hours aboard whale watching boats photographing 226 male sperm whales and listening in on their conversations using hydrophones.

"It takes a steady effort, extensive data sets, and patience to reveal the ecology of long-life animals," says Kobayashi. Although the data collection was arduous, it let the researchers determine which whales hung out together, and for how long.


Scientists probe mysterious melting of Earth's crust in Western North America

Shane, Adam and Jessie
© Jay Chapman Photo
From left, UW students Shane Scoggin, Adam Trzinski and Jessie Shields are part of new research investigating crustal melting in western North America. Here, they examine igneous rocks in the Snake Range of Nevada.
A group of University of Wyoming professors and students has identified an unusual belt of igneous rocks that stretches for over 2,000 miles from British Columbia, Canada, to Sonora, Mexico.

The rock belt runs through Idaho, Montana, Nevada, southeast California and Arizona.

"Geoscientists usually associate long belts of igneous rocks with chains of volcanoes at subduction zones, like Mount Shasta, Mount Hood, Mount St. Helens and Mount Rainer," says Jay Chapman, an assistant professor in UW's Department of Geology and Geophysics. "What makes this finding so interesting and mysterious is that this belt of igneous rocks is located much farther inland, away from the edge of the continent, and doesn't contain any evidence for producing volcanoes. In fact, all of the melting to generate the igneous rocks originally took place deep underground, five to 10 miles beneath the surface."

Chapman is lead author of a paper, titled "The North American Cordilleran Anatectic Belt," which was published online in February in the journal Earth-Science Reviews. The print version will be published this month.

The paper is a result of a special course taught by Simone Runyon, an assistant professor in UW's Department of Geology and Geophysics, and Chapman. Runyon, six UW graduate students and one undergraduate student, who took part in the course, are co-authors of the paper.

"It was really fascinating to start with a scientific question in a classroom, then collect and analyze data, and eventually publish our results," says Cody Pridmore, a UW graduate student from Orange, Calif., and co-author of the paper. "It's a process most college students don't get to experience."


Researchers find body's natural pain killers can be enhanced, while reducing side effects of opioids

back pain
© National Pain Report
A study in cells and mice finds an opioid-receptor modifying compound that works to relieve pain using the body's own pain-killers, with fewer side effects than opioids.

Fentanyl, oxycodone, morphine -- these substances are familiar to many as a source of both pain relief and the cause of a painful epidemic of addiction and death.

Scientists have attempted for years to balance the potent pain-relieving properties of opioids with their numerous negative side effects -- with mostly mixed results.


Hubble captures giant star AG Carinae on the edge of destruction

giant star hubble AG Carinae
© Hubble/NASA/ESA
AG Carinae, a Luminous Blue Variable (LBV) star located 20,000 light-years from Earth.
In celebration of the 31st anniversary of the launching of NASA's Hubble Space Telescope, astronomers aimed the renowned observatory at a brilliant "celebrity star," one of the brightest stars seen in our galaxy, surrounded by a glowing halo of gas and dust.

In celebration of the 31st anniversary of the launching of NASA's Hubble Space Telescope, astronomers aimed the renowned observatory at a brilliant "celebrity star," one of the brightest stars seen in our galaxy, surrounded by a glowing halo of gas and dust.

The price for the monster star's opulence is "living on the edge." The star, called AG Carinae, is waging a tug-of-war between gravity and radiation to avoid self-destruction.

Comment: Star's mysterious disappearance hints at new type of stellar death


New radar can 'scan' Earth's surface through any obstacle, created by Russia's MIET

drone radar

Scientists at the National Research University of Electronic Technology “MIET” (Moscow, Russia) have created a new radar remote sensing device for aircraft and spacecraft.
The researchers note that it can capture images of the Earth's surface, comparable in quality to optical images, regardless of lighting, weather, the presence of clouds, or tree crowns, the university's press service told Sputnik.

"It is known that the lower the frequency range, the greater the penetrating power of the wave, so our radar can survey not only through clouds and fog but also under foliage. Accordingly, if the optical method can capture the forest under ideal conditions, our radar can see through foliage and detect, for example, an unauthorised landfill in the forest", Ilya Kuzmin, an engineer at the Institute of Microdevices and Control Systems at MIET, said.

Comment: See also:


Dolphins learn the 'names' of their friends to form teams - first time recorded in animal kingdom

© Simon Allen
Dolphin allies form teams to help their pals fight rivals who might try to take away a fertile female. Here, two males assist their pals in guarding a lone female.
Like members of a street gang, male dolphins summon their buddies when it comes time to raid and pillage — or, in their case, to capture and defend females in heat. A new study reveals they do this by learning the "names," or signature whistles, of their closest allies — sometimes more than a dozen animals — and remembering who consistently cooperated with them in the past. The findings indicate dolphins have a concept of team membership — previously seen only in humans — and may help reveal how they maintain such intricate and tight-knit societies.

"It is a ground-breaking study," says Luke Rendell, a behavioral ecologist at the University of St. Andrews who was not involved with the research. The work adds evidence to the idea that dolphins evolved large brains to navigate their complex social environments.

Comment: See also: Enigmatic circling behavior observed in numerous marine animals