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Comment by Dr. Krishna Kumari Challa on December 21, 2024 at 12:07pm

Removing toxins from potatoes

Scientists have discovered a way to remove toxic compounds from potatoes, making them safer to eat and easier to store. The breakthrough could cut food waste and enhance crop farming in space and other extreme environments.

Potato plants naturally produce chemicals that protect them from insects. The chemicals, called steroidal glycoalkaloids, or SGAs, are found in high quantities in the green parts of potato peels, and in the sprouting areas. They render the potatoes unsafe for insects as well as humans.

These compounds are critical for plants to ward off insects, but they make certain parts of these crops inedible. 

Now that scientists have uncovered the biosynthetic pathway, they can potentially create plants that produce these compounds only in the leaves while keeping the edible parts safe.

Sunlight can induce the production of SGAs in potato "tubers"—the part of the potato plant that is eaten—even after they've been harvested. By identifying a key genetic mechanism in SGA production, researchers may be able to reduce potatoes' toxicity while preserving the plants' natural defenses. Taking SGA out of potatoes will also make them easier to store and transport in open air.

The research, published in Science, focuses on a protein dubbed "GAME15," which plays a key role in directing the plant's production of SGAs. This protein acts both as an enzyme and a scaffold, organizing other enzymes into a "conversion factory" that efficiently produces SGAs while preventing toxic compounds from leaking into other parts of plant cells, where they would wreak havoc.

Tomatoes also produce SGAs, primarily in the green, unripe fruit, as well as in the leaves, stems, and roots of the plants. When the researchers silenced the GAME15 gene in tomatoes, they eliminated SGA production but also made the plants highly susceptible to pests.

By engineering plants to control when and where SGAs are produced, for example, in the leaves but not the potatoes themselves, the researchers envision crops that can be stored without the risk of toxicity from sunlight exposure.

The team achieved these insights by initially recreating the SGA production process in tobacco plants. Surprisingly, they found that during evolution, the process redirected protein from the plasma membrane or Golgi apparatus, where it is responsible for the production of cell wall components crucial for cell growth, to the endoplasmic reticulum, a part of the cell where toxin production begins.

Green, unripe fruit may be toxic, but during ripening these molecules convert to something edible. By limiting SGAs to non-edible parts of plants, farmers and consumers alike could benefit from safer, more versatile crops.

This work demonstrates that plants have evolved ingenious ways to balance growth, reproduction, and defense. Understanding these systems allows us to redesign crops to meet modern needs without compromising their ability to thrive.

 Adam Jozwiak et al, A cellulose synthase–like protein governs the biosynthesis of Solanum alkaloids, Science (2024). DOI: 10.1126/science.adq5721

Comment by Dr. Krishna Kumari Challa on December 21, 2024 at 11:55am

Sea snakes regain advanced color vision, recovering a complex trait once lost to evolutionary time

Nine species of sea snakes have now been identified as having regained the genetic requirements for advanced color vision, demonstrating that once a complex trait has been lost to evolutionary time, it may be regained in some way.

A new study found the genetic trait may have existed in a common ancestor of the nine species, which all belong to the Hydrophis genus, dating back three million years.

Researchers previously identified one species of sea snake that had re-elaborated the visual function—the fully marine Hydrophis cyanocinctus, which did so in response to its spectrally complex environment.

With the re-elaboration now identified in so many species, the researchers say there is sufficient evidence to suggest evolutionary losses can be somewhat reversed.

We often think of evolution as a force that moves in just one direction—forward. But really, an organism's ecological circumstances are continuously dynamic, and sometimes becoming the 'fittest' means revisiting traits that were once less beneficial.

The re-elaboration of Hydrophis cyanocinctus' visual function was in response to its bright underwater environment—which differed from the low-light habitats of some of its ancestors.

Snakes descended from lizard-like ancestors which had a full visual opsin complement, which makes sense as they inhabited bright, colorful environments.

The earliest snakes underwent a period of dim-light living, and consequently lost two visual opsin genes, which caused them to lose much of their ability to distinguish colours.

Descendants of these earlier snakes inhabit a diverse variety of light environments today, including bright and colorful marine ecosystems. This opsin expansion showcases how new sensory innovations can more or less re-elaborate visual functions previously thought to be lost.

Though the species of sea snakes identified in this new research have regained the genetic requirements for advanced colour vision, the functions these expanded visual opsins have conferred upon the snakes is unclear and have to be investigated thoroughly now.

 Isaac H Rossetto et al, Dynamic Expansions and Retinal Expression of Spectrally Distinct Short-Wavelength Opsin Genes in Sea Snakes, Genome Biology and Evolution (2024). DOI: 10.1093/gbe/evae150

Comment by Dr. Krishna Kumari Challa on December 21, 2024 at 11:38am

How human eyelashes promote water drainage

Throughout human evolution, body and facial hair have notably diminished, yet eyelashes have remained a distinguishing feature. The physiological or functional purpose of eyelashes—traditionally thought to be for catching dust or filtering air—has long been debated.

However, a team of  researchers has recently elucidated the characteristics of human eyelashes. Their study reveals that eyelashes consist of a hydrophobic, curved, flexible fiber array, featuring surface micro-ratchets and a macro-curvature approximating the Brachistochrone curve. This structure enables eyelashes to rapidly and directionally expel incoming liquid, thereby preserving clear vision.

The hydrodynamic advantages of eyelashes, particularly their ability to expel unwanted liquids from the eye to maintain visual clarity, have received little attention. For instance, during facial washing or intense physical activity, the eyes are exposed to significant amounts of water or sweat without compromising clear vision.

The study is published in Science Advances on Dec. 20

The research team aimed to investigate the interaction between water and the flexible fiber array of eyelashes. They began by characterizing the structure, wettability, and water drainage process of human eyelashes. Next, they explored how the flexibility, wettability, and curvature of the fiber array influence water drainage.
Based on their findings, the researchers revealed the control mechanism governing transfer direction and contact time, which arise from the multi-scale asymmetric structures and heterogeneous elastic deformations of the fiber array. They also developed a quantitative computational model to calculate the elastic forces acting on the fiber array.
This research has also led to the design of eyelash-mimetic rapid liquid transfer edges, including aesthetically pleasing and protective false eyelashes, waterproof imaging devices, and ventilated structures.

Shan Zhou et al, Rapid water drainage on human eyelashes of a hydrophobic Brachistochrone fiber array, Science Advances (2024). DOI: 10.1126/sciadv.adr2135. www.science.org/doi/10.1126/sciadv.adr2135

Comment by Dr. Krishna Kumari Challa on December 21, 2024 at 10:45am

Intense ribbons of rain also bring the heat, scientists say

The environmental threat posed by atmospheric rivers—long, narrow ribbons of water vapor in the sky—doesn't come only in the form of concentrated, torrential downpours and severe flooding characteristic of these natural phenomena. According to a new  study, they also cause extreme warm temperatures and moist heat waves.

The atmospheric rivers—horizontal plumes that transport water vapour from the warm subtropics to cooler areas across midlatitude and polar regions of the world—are also transporting heat. As a result, atmospheric rivers may have a greater effect on global energy movement than previously recognized. 

We're seeing temperature anomalies associated with atmospheric rivers that are 5 to 10 degrees Celsius [9 to 18 degrees Fahrenheit] higher than the climatological mean. The numbers are astounding, say the researchers.

The findings are published in the journal Nature.

Scientists began using the term "atmospheric river" in the 1990s. Today, there are three to five of them winding their way through each hemisphere at any given time.

They can be thousands of miles long, but only a few hundred miles wide; the amount of water vapor they carry is about 7–15 times greater than the equivalent amount of water discharged each day by the Mississippi River. The heavy rains that often result can cause major damage and disruption.

The researchers analyzed 40 years of global weather data from NASA's MERRA-2 reanalysis, as well as seven publicly available algorithms that track atmospheric rivers worldwide. Specifically, they looked at temperature increases related to atmospheric rivers on two timescales: hourly temperature spikes and heat waves of three or more days of moist heat.

"There was no doubt—atmospheric rivers are really impactful for both timescales", they conclude.

The researchers noted that the phenomenon has a more dramatic effect in the winter than it does in summer.

The new study shows that when atmospheric rivers occur, they change the balance of energy on the surface in several ways, the researchers say. For example, while cloudy conditions block incoming sunlight, those clouds also trap more thermal radiation near the surface, creating a transient enhanced greenhouse effect. This heating balances out the loss of sunlight—but is not the cause of temperature spikes.

Instead, the main cause of warm temperatures in atmospheric rivers is simply the transport of warm air, located near the water's surface, from one region to another.

Serena R. Scholz et al, Atmospheric rivers cause warm winters and extreme heat events, Nature (2024). DOI: 10.1038/s41586-024-08238-7

Comment by Dr. Krishna Kumari Challa on December 21, 2024 at 10:34am

First demonstration of quantum teleportation over busy internet cables

Researchers and engineers successfully demonstrated quantum teleportation over a fiber-optic cable already carrying internet traffic.

The discovery introduces the new possibility of combining quantum communication with existing internet cables—greatly simplifying the infrastructure required for distributed quantum sensing or computing applications.

The study is published on the arXiv preprint server and is due to appear in the journal Optica.

Only limited by the speed of light, quantum teleportation could make communications nearly instantaneous. The process works by harnessing quantum entanglement, a technique in which two particles are linked, regardless of the distance between them. Instead of particles physically traveling to deliver information, entangled particles exchange information over great distances—without physically carrying it.

In optical communications, all signals are converted to light. While conventional signals for classical communications typically comprise millions of particles of light, quantum information uses single photons.

The researchers found a way to help the delicate photons steer clear of the busy traffic. After conducting in-depth studies of how light scatters within fiberoptic cables, the researchers found a less crowded wavelength of light to place their photons. Then, they added special filters to reduce noise from regular internet traffic.

They carefully studied how light is scattered and placed their photons at a judicial point where that scattering mechanism is minimized.  They found they could perform quantum communication without interference from the classical channels that are simultaneously present.

To test the new method, the research team set up a 30 kilometer-long fiberoptic cable with a photon at either end. Then, they simultaneously sent quantum information and regular internet traffic through it. Finally, they measured the quality of the quantum information at the receiving end while executing the teleportation protocol by making quantum measurements at the mid-point. The researchers found the quantum information was successfully transmitted—even with busy internet traffic whizzing by.

 Quantum teleportation coexisting with classical communications in optical fiber, Optica (2024).

Preprint: Jordan M. Thomas et al, Quantum teleportation coexisting with classical communications in optical fiber, arXiv (2024). DOI: 10.48550/arxiv.2404.10738

Comment by Dr. Krishna Kumari Challa on December 21, 2024 at 10:26am

Typically, aquatic toxicology studies either use a high concentration of an individual chemical to determine detailed biological responses or only determine apical effects like mortality and altered reproduction after exposure to an environmental sample.

"However, this study breaks new ground by allowing us to identify key classes of chemicals that affect living organisms within a genuine environmental mixture at relatively low concentration while simultaneously characterizing the biomolecular changes elicited.

The findings could help improve environmental protection by identifying previously unknown chemical combinations that pose risks to aquatic life, enabling more comprehensive environmental monitoring, and supporting better-informed regulations for chemical discharge into waterways.

Bioactivity Profiling of Chemical Mixtures for Hazard Characterization, Environmental Science & Technology (2024). DOI: 10.1021/acs.est.4c11095

Part 2

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Comment by Dr. Krishna Kumari Challa on December 21, 2024 at 10:25am

Hidden hazards of chemical mixtures in rivers

Artificial intelligence can provide critical insights into how complex mixtures of chemicals in rivers affect aquatic life—paving the way for better environmental protection.

A new approach, developed by researchers  demonstrates how advanced artificial intelligence (AI) methods can help identify potentially harmful chemical substances in rivers by monitoring their effects on tiny water fleas (Daphnia).

International researchers from various countries  analyzed water samples from the Chaobai River system near Beijing. This river system is receiving chemical pollutants from a number of different sources, including agricultural, domestic and industrial.

There is a vast array of chemicals in the environment. Water safety cannot be assessed one substance at a time. Now we have the means to monitor the totality of chemicals in sampled water from the environment to uncover what unknown substances act together to produce toxicity to animals, including humans, say the researchers.

The results, published in Environmental Science and Technology, reveal that certain mixtures of chemicals can work together to affect important biological processes in aquatic organisms, which are measured by their genes. The combinations of these chemicals create environmental hazards that are potentially greater than when chemicals are present individually.

The research team used water fleas (Daphnia) as test organisms in the study because these tiny crustaceans are highly sensitive to water quality changes and share many genes with other species, making them excellent indicators of potential environmental hazards.

Part 1

Comment by Dr. Krishna Kumari Challa on December 21, 2024 at 10:15am

We now have so much data that in the 21st century we can finally answer the question—how and why does a simple average expansion law emerge from complexity?

"A simple expansion law consistent with Einstein's general relativity does not have to obey Friedmann's equation."

The researchers say that the European Space Agency's Euclid satellite, which was launched in July 2023, has the power to test and distinguish the Friedmann equation from the timescape alternative. However, this will require at least 1,000 independent high quality supernovae observations.

When the proposed timescape model was last tested in 2017, the analysis suggested it was only a slightly better fit than the ΛCDM as an explanation for cosmic expansion, so the present  team worked closely with the Pantheon+ collaboration team who had painstakingly produced a catalog of 1,535 distinct supernovae.

They say the new data now provides "very strong evidence" for timescape. It may also point to a compelling resolution of the Hubble tension and other anomalies related to the expansion of the universe.

Further observations from Euclid and the Nancy Grace Roman Space Telescope are needed to bolster support for the timescape model, the researchers say.

 Antonia Seifert et al, Supernovae evidence for foundational change to cosmological models, Monthly Notices of the Royal Astronomical Society: Letters (2024). DOI: 10.1093/mnrasl/slae112

Part 3

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Comment by Dr. Krishna Kumari Challa on December 21, 2024 at 10:13am

Dark energy is commonly thought to be a weak anti-gravity force which acts independently of matter and makes up around two thirds of the mass-energy density of the universe.

The standard Lambda Cold Dark Matter (ΛCDM) model of the universe requires dark energy to explain the observed acceleration in the rate at which the cosmos is expanding.

Scientists base this conclusion on measurements of the distances to supernova explosions in distant galaxies, which appear to be farther away than they should be if the universe's expansion were not accelerating.

However, the present expansion rate of the universe is increasingly being challenged by new observations.

Firstly, evidence from the afterglow of the Big Bang—known as the Cosmic Microwave Background (CMB)—shows the expansion of the early universe is at odds with current expansion, an anomaly known as the "Hubble tension."

In addition, recent analysis of new high precision data by the Dark Energy Spectroscopic Instrument (DESI) has found that the ΛCDM model does not fit as well as models in which dark energy is "evolving" over time, rather than remaining constant.

Both the Hubble tension and the surprises revealed by DESI are difficult to resolve in models which use a simplified 100-year-old cosmic expansion law—Friedmann's equation.

This assumes that, on average, the universe expands uniformly—as if all cosmic structures could be put through a blender to make a featureless soup, with no complicating structure. However, the present universe actually contains a complex cosmic web of galaxy clusters in sheets and filaments that surround and thread vast empty voids.

Part 2

Comment by Dr. Krishna Kumari Challa on December 21, 2024 at 10:07am

Dark energy 'doesn't exist' so can't be pushing 'lumpy' universe apart, physicists say

One of the biggest mysteries in science—dark energy—doesn't actually exist, according to researchers looking to solve the riddle of how the universe is expanding.

Their analysis has been published in the journal Monthly Notices of the Royal Astronomical Society Letters.

For the past 100 years, physicists have generally assumed that the cosmos is growing equally in all directions. They employed the concept of dark energy as a placeholder to explain unknown physics they couldn't understand, but the contentious theory has always had its problems.

Now a team of physicists and astronomers are challenging the status quo, using improved analysis of supernovae light curves to show that the universe is expanding in a more varied, "lumpier" way.

The new evidence supports the "timescape" model of cosmic expansion, which doesn't have a need for dark energy because the differences in stretching light aren't the result of an accelerating universe but instead a consequence of how we calibrate time and distance.

It takes into account that gravity slows time, so an ideal clock in empty space ticks faster than inside a galaxy.

The model suggests that a clock in the Milky Way would be about 35 percent slower than the same one at an average position in large cosmic voids, meaning billions more years would have passed in voids. This would in turn allow more expansion of space, making it seem like the expansion is getting faster when such vast empty voids grow to dominate the universe.

These findings show that we do not need dark energy to explain why the universe appears to expand at an accelerating rate. Dark energy is a misidentification of variations in the kinetic energy of expansion, which is not uniform in a universe as lumpy as the one we actually live in.

The research provides compelling evidence that may resolve some of the key questions around the quirks of our expanding cosmos.

With new data, the universe's biggest mystery could be settled by the end of the decade, the physicists say.

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