Category: science

Elsewhere on the continent things are even worse. One study of male high-school leavers in Seoul found 97% were short-sighted. Hong Kong and Singapore are not far behind. And although the problem is worst in East Asia, it is not unique to it. Reliable numbers for America and Europe are harder to come by. But one review article, published in 2015, claimed a European rate of between 20% and 40% — an order of magnitude higher than that which people working in the field think is the “natural,” background rate. For most of those affected, myopia is a lifelong, expensive nuisance. But severe myopia can lead to untreatable vision loss, says Annegret Dahlmann-Noor, a consultant ophthalmologist at Moorfields Eye Hospital, in London. A paper published in 2019 concluded that each one-dioptre worsening in myopia was associated with a 67% increase in prevalence of myopic maculopathy, an untreatable condition that causes blindness. (A dioptre is a measure of a lens’s focusing power.) In some parts of East Asia, 20% of young people have severe myopia, defined as -6 dioptres or worse (see chart 2 in linked story). “This is storing up a big problem for the coming decades,” says Kathryn Rose, head of orthoptics at the University of Technology, Sydney.

In the early spring semester, Lau, also working with Cornell’s Milk Quality Improvement Program, connected with the Cornell Dairy Bar, which sells fluid milk in addition to ice cream on campus. She wanted to assess consumer acceptance for QR code technology that may one day replace the static best-by or sell-by dates commonly found on food products. Customers had a choice: purchasing milk with printed best-by dates, or buying containers with QR codes, which when scanned by a smart phone, would display the best-by date.

In the same Cornell Dairy Bar study, Lau placed a dynamic pricing element where consumers were encouraged to purchase milk with a shorter remaining shelf life — by offering a price discount as the best-by date approached. “During two-month study, over 60% of customers purchased the milk with the QR code, showing a considerable interest in using this new technology,” Lau said. “This revealed that the use of QR codes on food products can be an innovative way to address the larger issue of food waste.” Wiedmann says the technology also exists where smart milk cartons could communicate with smart refrigerators to inform a household of the need for fresh milk.

The study has been published in the Journal of Dairy Science.

Solid water, or ice, is like many other materials in that it can form different solid materials based on variable temperature and pressure conditions, like carbon forming diamond or graphite. However, water is exceptional in this aspect as there are at least 20 solid forms of ice known to us.

A team of scientists working in UNLV’s Nevada Extreme Conditions Lab pioneered a new method for measuring the properties of water under high pressure. The water sample was first squeezed between the tips of two opposite-facing diamonds — freezing into several jumbled ice crystals. The ice was then subjected to a laser-heating technique that temporarily melted it before it quickly re-formed into a powder-like collection of tiny crystals. By incrementally raising the pressure, and periodically blasting it with the laser beam, the team observed the water ice make the transition from a known cubic phase, Ice-VII, to the newly discovered intermediate, and tetragonal, phase, Ice-VIIt, before settling into another known phase, Ice-X….

While it’s unlikely we’ll find this new phase of ice anywhere on the surface of Earth, it is likely a common ingredient within the mantle of Earth as well as in large moons and water-rich planets outside of our solar system. The team’s findings were reported in the March 17 issue of the journal Physical Review B…. The work also recalibrates our understanding of the composition of exoplanets, UNLV physicist Ashkan Salamat added. Researchers hypothesize that the Ice-VIIt phase of ice could exist in abundance in the crust and upper mantle of expected water-rich planets outside of our solar system, meaning they could have conditions habitable for life.

Thanks to long-time Slashdot reader fahrbot-bot for sharing the story…

The Washington Post reports:
Researchers at Northwestern University had two groups of 10 young adults sleep in differently lit rooms. One group slept in rooms with dim light for two nights; the other slept one night in a room with dim night and the next in a room with moderate overhead light — about the equivalent of an overcast day. Participants wore heart monitors at night. In the morning, they did a variety of glucose tests.

Both groups got the same amount of sleep but their bodies experienced very different nights. Both groups responded well to insulin the first night, when they both slept in dim lighting. On the second night, however, the group sleeping in brighter lighting didn’t respond as well to insulin. The dim light sleepers’ insulin resistance scores fell about 4 percent on the second night, while the bright sleepers’ rose about 15 percent. Their heart rates were faster on the bright night, too.

“[J]ust a single night of exposure to moderate room lighting during sleep can impair glucose and cardiovascular regulation, which are risk factors for heart disease, diabetes and metabolic syndrome,” concludes senior study author Dr. Phyllis Zee. “It’s important for people to avoid or minimize the amount of light exposure during sleep.”
From Northwestern’s announcement:
There is already evidence that light exposure during daytime increases heart rate via activation of the sympathetic nervous system, which kicks your heart into high gear and heightens alertness to meet the challenges of the day. “Our results indicate that a similar effect is also present when exposure to light occurs during nighttime sleep,” Zee said….

An earlier study published in JAMA Internal Medicine looked at a large population of healthy people who had exposure to light during sleep. They were more overweight and obese, Zee said. “Now we are showing a mechanism that might be fundamental to explain why this happens. We show it’s affecting your ability to regulate glucose,” Zee said.

Studies that use magnetic-resonance imaging technology commonly temper their conclusions with a cautionary statement noting the small sample size. But enlisting participants can be time-consuming and expensive, ranging from $600 to $2,000 an hour, said Dr. Nico Dosenbach, a neurologist at Washington University School of Medicine and another author on the paper. The median number of subjects in mental-health-related studies that use brain imaging is around 23, he added. But the Nature paper demonstrates that the data drawn from just two dozen subjects is generally insufficient to be reliable and can in fact yield ‘massively inflated’ findings,” Dr. Dosenbach said. The findings from the Nature paper can “absolutely” be applied to other fields beyond mental health, said Marek. “My hunch this is much more about population science than it is about any one of those fields,” he said.

To their surprise, they discovered a strange finger-like structure that had never been observed before. This finger reached out and stabilized the DNA sequence so the protein could still make its edit. Having uncovered this mechanism, the team tweaked this finger so that it no longer stabilized the DNA, instead pushing away from it. That prevents Cas9 from editing that sequence, making the tool 4,000 times less likely to produce off-target mutations. The team calls the new protein SuperFi-Cas9. The research was published in the journal Nature.

Co-author Katherine Zodrow, an environmental engineer at MTU, led an earlier 2020 study demonstrating the feasibility of making sustainable living filtration membranes (LFMs) out of a bacterial cellulose network and the native microorganisms of a kombucha SCOBY (symbiotic culture of bacteria and yeast) culture. Zodrow and her new collaborators made their membranes for this latest round of experiments the same way: by placing a SCOBY in a growth solution of sugar, black tea, and distilled white vinegar dissolved in deionized water. The researchers then placed the mixture in a temperature-controlled room for 10-12 days until a thick membrane formed on the mixture’s surface. The grown membranes were stored in deionized water and used in experiments within eight days. The 20 liters of raw water samples for the experiments were taken from the three drinking water treatment plants in Butte, Montana: Basin Creek Reservoir, Moulton Reservoir, and Big Hole River. The water samples were then pretreated in accordance with standard practices at each plant.

Both the LFMs and polymer-based filters, the researchers discovered, became clogged over time, causing them to flow and filter more slowly. The LFMs used in the experiments, however, showed between 19 and 40 percent better performance than their commercial counterparts on that score. The SCOBY-based LFMs were also more resistant to befouling. While biofilms eventually formed, fewer microorganisms were found in those films. Zodrow et al. sequenced the DNA of any bacteria and fungi in the SCOBY-based membrane and found that 97 percent of the bacteria present belonged to the genus Acetobacter. This is not surprising, since it’s also the dominant bacteria in kombucha, but it may explain why the LFMs performed so well with regard to biofilms. As the name implies, a defining characteristic of this genus is the ability to oxidize organic carbon sources like sucrose, glucose, and ethanol into acetic acid, which is known for its antimicrobial properties. Acetobacter has also been shown to reduce or even remove biofilms, in keeping with the results of Zodrow et al.’s experiments.