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Comment by Dr. Krishna Kumari Challa on March 3, 2023 at 11:51am

Breathtakingly Beautiful Photo Gives an Astronaut's View of an Aurora

Comment by Dr. Krishna Kumari Challa on March 3, 2023 at 11:45am

Researchers have discovered a new type of coexistence between algae and fungi

Researchers  have described the symbiotic relationship between fungi and algae.  The coexistence of algae and corticioid basidiomycetes, which are common in temperate forests, has been given a new name: "alcobiosis." Their work has been published in Scientific Reports.

Years ago, during field trips, researchers were repeatedly puzzled to find a layer of green algae where some of the fungal coatings on wood or bark (so-called corticioid fungi) are disturbed. They discovered that this is a close symbiosis of fungi and algae, not a lichen, though, because the fungus does not depend on its alga for nourishment.

The new term introduced by the researchers for this type of coexistence, "alcobiosis," is formed by letters from the three key words: algae, corticioid fungi and symbiosis.

In the course of several years, the team of researchers gathered a large number of samples and performed DNA sequencing of the algal and fungal partners. They discovered that the symbiosis is very common and occurs in a great many corticioid fungi across the class of agaricomycetes. Individual fungal species are usually faithful to a specific algal species from a range of algae described in various alcobioses.

Ensuing physiological measurements of algal activity in alcobioses confirmed that the algae are alive, active and engage heavily in photosynthesis, which proves that they prosper inside fungal tissue. Alcobioses bear a striking resemblance to lichens, but differ from them in that the fungal partner does not depend on its alga for nourishment.

And so the main unknown still is in what way this symbiosis is beneficial for each of the partners.

But this study shows alcobioses as a widespread phenomenon which includes a large number of algae and fungi.

During their research, the authors also discovered that the spread of alcobioses is aided by small gastropods who often feed on corticioid fungi. Their excrements contain viable cells of algae and fungi who give rise to new alcobiotic coating shortly after. This type of reproduction is similar to lichen "isidia" (i.e., specific lichen thallus structures used in vegetative reproduction). Alcobioses are clearly visible to the naked eye and it is easy to distinguish them from similar fungi that do not form this kind of relationship.

Alcobioses are common in urban areas, too. Lyomyces sambuci, pictured here, is abundant on elder bark. Credit: Institute of Botany, Czech Academy of SciencesJan Vondrák et al, Alcobiosis, an algal-fungal association on the threshold of lichenisation, Scientific Reports (2023). DOI: 10.1038/s41598-023-29384-4. www.nature.com/articles/s41598-023-29384-4

Comment by Dr. Krishna Kumari Challa on March 3, 2023 at 11:29am

How to stop bird flu becoming a pandemic

After avian influenza killed a girl in Cambodia last week, fears are rising about the virus’s potential to spark a human pandemic. It’s hard to say whether this will actually happen, says veterinary pathologist Thijs Kuiken. Versions of the H5N1 influenza virus have been circulating in birds for about 25 years, but the discovery of a variant that transmits between mink increases the risk that the virus could start spreading in humans. Scientists say it’s important to keep tracking the disease’s spread.... Because drugs and vaccines against H5N1 are already available, a bird flu pandemic would probably be more manageable than COVID-19.

https://www.nature.com/articles/d41586-023-00591-3?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on March 3, 2023 at 11:27am

Asteroid lost 1 million kilograms after collision with DART spacecraft

Studies reveal final moments before NASA probe crashed into an asteroid.

The asteroid that was deliberately hit with NASA’s Double Asteroid Redirection Test (DART) spacecraft last September lost one million kilograms of rock, gained a 1,000-kilometre-long d.... A detailed analysis of what happened when DART smashed into the Great-Pyramid-sized asteroid Dimorphos has revealed how successful this first test of planetary defence really was. The spacecraft hit a spot close to the asteroid’s centre and caused a large spray of rubble to fly outwards, which maximized the impact’s force and added momentum.

Last September, NASA’s Double Asteroid Redirection Test (DART) spacecraft smashed into an asteroid, deliberately altering the rock’s trajectory through space in a first test of planetary defence. Now scientists have deconstructed the collision and its aftermath — and learnt just how successful humanity’s punch at the cosmos really was.

DART, which was the size of a golf cart, collided with a Great Pyramid-sized asteroid called Dimorphos. The impact caused the asteroid’s orbit around another space rock to shrink — Dimorphos now completes an orbit 33 minutes faster than before the impact, researchers report in Nature. This means that if a dangerous asteroid were ever detected heading for Earth, a mission to smash into it would probably be able to divert it away from the planet.

https://www.nature.com/articles/d41586-023-00601-4?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on March 3, 2023 at 11:12am

Scientists push the boundaries of manipulating light at the submicroscopic level

A team of researchers  has shown light can be moved within a distance which is smaller than its own wavelength—a level of unprecedented precision.

Scientists have demonstrated that a beam of light can not only be confined to a spot which is 50 times smaller than its own wavelength, but that also—in a first of its kind—the spot can be moved by miniscule amounts at the point where the light is confined. The detailed findings of their theoretical study are published in the journal Optica.

Confining and controlling light on ever smaller volumes is one of the defining challenges in modern photonics; the science behind the generation, detection and manipulation of light. How tightly the light is confined determines the limits for the observability of nanoparticles, as well as the intensity and the precision of light-based devices. One example is optical tweezers. These are widely used in laboratories around the world in fields such as that of DNA research. They consist of highly focused laser beams that trap, manipulate and move particles with astounding precision. One of the limitations with standard optical tweezers is that lenses cannot focus beams on lengths much smaller than the laser beam's own wavelength, limiting the achievable precision.

By its nature, light is indeed very difficult to localize on a smaller length scale than its wavelength, a critical threshold known as the Abbe limit. However, using a sophisticated model and numerical simulation, scientists have successfully demonstrated a novel approach to localize and dynamically manipulate light at a sub-wavelength scale.

Erika Cortese et al, Real-space nanophotonic field manipulation using non-perturbative light–matter coupling, Optica (2022). DOI: 10.1364/OPTICA.473085

Comment by Dr. Krishna Kumari Challa on March 3, 2023 at 10:10am

Social animals should limit individuality to conform with the behaviour of the group, says study

Scientists  have observed that group safety was improved when animals paid attention to the behaviours of each other.

Their findings, accepted for publication in PLoS Computational Biology, reveal that simple social behavioral rules can drive conformity behaviour in groups, eroding consistent behavioural differences shown by individual animals.

Personality suppression may be a common strategy in group-living animals, and in particular, we should tend to see the behaviors of the most adventurous or shy individuals shifting towards what the majority of the group are doing.

The team modeled the behavior of a small group of animals with differing tendencies while performing risky behaviours when traveling away from a safe home site towards a foraging site. They then compared this to their behaviour while completing the same activity in a group.

The group-aware individuals spent longer in the safe space and moved more quickly to the foraging spot, making the mission less dangerous. Groups are usually made up of individuals who are different to each other in the way that they normally behave—these consistent individual differences are what determines the personality of the individual.

This study was based on fish behaviour. 

When faced with a social task,  researchers found that the fish tend to suppress their own behavior, and instead conform with what other fish in the group are doing.

 If individuals pay attention to other group members, this has an overall impact on the efficiency of the group, and demonstrates that simple social behaviors can result in the suppression of individual personalities.

.This suggests that compromise may lie at the heart of many social behaviors across the animal kingdom.

Sean A. Rands et al, Personality variation is eroded by simple social behaviours in collective foragers, PLoS Computational Biology (2023). DOI: 10.1371/journal.pcbi.1010908. journals.plos.org/ploscompbiol … journal.pcbi.1010908 On bioRxiv: DOI: 10.1101/2022.03.21.485155

Comment by Dr. Krishna Kumari Challa on March 3, 2023 at 9:44am

'Rivers in the sky' shape African climate

East Africa is much drier than other tropical land regions, including the Amazon and Congo rainforests. The geography of East Africa was always thought to make the region dry and susceptible to drought, but the precise mechanism has been elusive until now. This research demonstrates the east to west river valleys are a crucial factor in the low annual rainfall.

Normally, when we think of valleys and water, we think of the rivers that flow along the ground. In East Africa, deep valleys, such as the Turkana Valley, channel strong winds and create invisible rivers in the sky. These invisible rivers carry millions of tons of water vapor, the key ingredient for rainfall.

New experiments show the valleys affect climate on a continental scale. It can't rain equally everywhere, and the valleys help to sustain high rainfall in the Congo basin, while leaving East Africa prone to drought.

Callum Munday et al, Valley formation aridifies East Africa and elevates Congo Basin rainfall, Nature (2023). DOI: 10.1038/s41586-022-05662-5

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Comment by Dr. Krishna Kumari Challa on March 3, 2023 at 9:31am

Satellite images show coastal algae blooms have grown larger over past two decades

A team of Earth scientists affiliated with multiple institutions has found that coastal algae blooms (also known as phytoplankton blooms) have been getting bigger over the past couple of decades. In their study, published in the journal Nature, the group analyzed satellite data supplied to them by NASA to compare the size and frequency of algae blooms along the coasts of the world's continents.

Algae blooms are accumulations of algae in a shared area atop a water source. Algae are aquatic plants that contain chlorophyll, but have no leaves, roots, stems, vascular tissue or flowers. They vary in size, from single-celled species to large strands of seaweed. They can have different colors and can inhabit either fresh or saltwater systems. Algae blooms grow larger as their food source grows, particularly nitrogen and phosphorus, both of which are supplied indirectly through human sources such as fertilizer runoff. Prior research has shown that algae blooms can serve as a food source for some sea creatures, but they can also cause problems, such as carrying and dispersing toxic material. Such toxins have been found to accumulate in ocean networks, sometimes leading to oxygen depletion, which can lead to ocean dead zones. In this new effort, the research team found evidence that algae blooms are getting larger, which suggests fertilizer runoff has been increasing.

The work involved studying satellite images obtained from NASA's Aqua satellite over the years 2003 to 2020. By comparing such blooms over time, they found them to be growing at an increasing rate of 59.2%, globally. They also found that as of 2020, the combined size of all ocean-based algae blooms was 31.47 million km², which, they note, is approximately 8.6% of total ocean surface area.

The researchers also found patterns of increase—the areas where the water temperatures were rising the fastest were the same areas where the algae blooms were growing the fastest. Additionally, they found associations between sea surface temperatures, ocean circulation and the frequency of algae blooms.

More information: Yanhui Dai et al, Coastal phytoplankton blooms expand and intensify in the 21st century, Nature (2023). DOI: 10.1038/s41586-023-05760-y

Comment by Dr. Krishna Kumari Challa on March 1, 2023 at 11:43am

Child didn’t die of global bird-flu variant

An 11-year-old girl in Cambodia who died after being infected with avian influenza A (H5N1) had a different variant from that causing mass deaths in birds globally. The strain she was carrying is endemic to the region, and last infected people in Cambodia about a decade ago. Investigations are under way into why the virus has spilled over from birds to people again. “Hopefully this is an isolated incident, but it could be indicative of a larger issue,” says virologist Erik Karlsson at the Pasteur Institute of Cambodia in Phnom Penh.

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Hints that flu arose underwater

Corals, sturgeon and other aquatic creatures harbour signs of infection by influenza and its distant relatives. A genetic analysis reveals that the virus family probably originated hundreds of millions of years ago in primordial aquatic ... that evolved well before the first fishes. It’s not clear whether influenza moved onto land with early terrestrial vertebrates, or jumped from sea to land more recently.

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The molecule that kickstarted life

For more than 15 years, scientists have been on a quest: create a functional ‘protoribosome’, a reconstructed version of the protein-building machine that many t.... The modern ribosome is a key ingredient of life as we know it because it translates genetic information into proteins. At its heart sits a small RNA pocket that some think might be closest to what the very first ribosome looked like. Now, there’s proof that some reconstructed protoribosome-like RNAs can link amino acids — the first step to making proteins. Some scientists say there are other ways for proteins to emerge, without a ribosome. But others are already thinking about repurposing these simple machines to manufacture new kinds of biomolecule.

Comment by Dr. Krishna Kumari Challa on March 1, 2023 at 11:38am

As the climate warms, increased Saharan dust is likely to get blown around the globe, with higher levels of dust in Africa, the eastern U.S., and the Caribbean. Dust over Northern Africa, including the Sahel and the Sahara, is likely to increase due to more intense West African monsoons.

Both organic aerosols and dust, as well as sea salt, black carbon, and sulfate, fall into a category of airborne pollutants known as PM_2.5, because they have a diameter of 2.5 micrometers or less. The increase in naturally sourced PM_2.5 pollution increased, in this study, in direct proportion to CO₂ levels.

The more we increase CO₂, the more PM_2.5 we see being put into the atmosphere, and the inverse is also true. The more we reduce, the better the air quality gets.

For example, if the climate warms only 2°C, the study found only a 7% increase in PM_2.5. All of these results only apply to changes found in air quality over land, as the study is focused on human health impacts.

The researchers hope the potential to improve air quality will inspire swift and decisive action to decrease CO₂ emissions. Without it, temperatures may increase 4°C by the end of this century, though it's possible for the increase to happen sooner.

If things go on like this, in the future, make sure you get an air purifier. 

James Gomez et al, The projected future degradation in air quality is caused by more abundant natural aerosols in a warmer world, Communications Earth & Environment (2023). DOI: 10.1038/s43247-023-00688-7

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