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Comment by Dr. Krishna Kumari Challa on June 12, 2024 at 10:09am

New study helps disentangle role of soil microbes in the global carbon cycle

When soil microbes eat plant matter, the digested food follows one of two pathways. Either the microbe uses the food to build its own body, or it respires its meal as carbon dioxide (CO₂) into the atmosphere.

Now a research team has, for the first time, tracked the pathways of a mixture of plant waste as it moves through bacteria's metabolism to contribute to atmospheric CO₂. The researchers discovered that microbes respire three times as much CO₂ from lignin carbons (non-sugar aromatic units) compared to cellulose carbons (glucose sugar units), which both add structure and support to plants' cellular walls.

These findings help disentangle the role of microbes in soil carbon cycling—information that could help improve predictions of how carbon in soil will affect climate change.

The study, "Disproportionate carbon dioxide efflux in bacterial metabolic pathways for different organic substrates leads to variable contribution to carbon use efficiency," was published on June 11 in the journal Environmental Science & Technology.

The carbon pool that's stored in soil is about 10 times the amount that's in the atmosphere.

What happens to this reservoir will have an enormous impact on the planet. Because microbes can unlock this carbon and turn it into atmospheric CO₂, there is a huge interest in understanding how they metabolize plant waste. As temperatures rise, more organic matter of different types will become available in soil. That will affect the amount of CO₂ that is emitted from microbial activities.

Caroll Mendonca et al, Disproportionate carbon dioxide efflux in bacterial metabolic pathways for different organic substrates leads to variable contribution to carbon use efficiency, Environmental Science & Technology (2024). DOI: 10.1021/acs.est.4c01328. pubs.acs.org/doi/10.1021/acs.est.4c01328

Comment by Dr. Krishna Kumari Challa on June 11, 2024 at 11:53am

Study: An estimated 135 million premature deaths linked to fine particulate matter pollution between 1980 and 2020

A study led by researchers from Nanyang Technological University, Singapore (NTU Singapore) revealed that fine particulate matter from 1980 to 2020 was associated with approximately 135 million premature deaths globally. The findings were published in April in the peer-reviewed journal Environment International.

In the study, premature deaths refer to fatalities that occur earlier than expected based on average life expectancy, resulting from preventable or treatable causes such as diseases or environmental factors.

The study found that the impact of pollution from fine particulate matter was worsened by climate variability phenomena such as the El Niño-Southern Oscillation, the Indian Ocean Dipole, and the North Atlantic Oscillation, and led to a 14 percent rise in premature deaths.

The researchers explain that during such weather events, the increased temperature, changes in wind patterns, and reduced precipitation can lead to stagnant air conditions and the accumulation of pollutants in the atmosphere. These result in higher concentrations of PM2.5 particles that are particularly harmful to human health when inhaled.
Fine particulate matter, or PM2.5, refers to particulate matter 2.5 micrometers in diameter or smaller. These tiny particles come from vehicle emissions, industrial processes, and natural sources such as wildfires and dust storms.

As they are so small, PM2.5 particles can easily get into the air we breathe and penetrate deep into our lungs, leading to a range of health problems, especially for vulnerable groups like children, the elderly, and people with respiratory conditions.

The study estimated that a third of the premature deaths from 1980 to 2020 were associated with stroke (33.3%); another third with ischemic heart disease (32.7%), while chronic obstructive pulmonary disease, lower respiratory infections, and lung cancer made up the rest of premature deaths.

S.H.L. Yim et al, Global health impacts of ambient fine particulate pollution associated with climate variability, Environment International (2024). DOI: 10.1016/j.envint.2024.108587

Comment by Dr. Krishna Kumari Challa on June 11, 2024 at 11:47am

Compressed titanium and sulfur nanoribbons can transmit electricity without energy loss, scientists find

When compressed, nanoribbons of titanium and sulfur can change properties dramatically, turning into materials with the ability to conduct electricity without losing energy, according to a study published in the journal Nano Letters.

The authors have made the discovery during their painstaking search for new materials that can transmit electricity without loss of energy, a hot topic that has for long haunted the scientific community.

This new research focused on one such promising material: TiS₃ nanoribbons, which are tiny, ribbon-like structures made of titanium and sulfur. In their natural state, TiS₃ nanoribbons act as insulators, meaning they do not conduct electricity well.  The researchers, however, discovered that by applying pressure to these nanoribbons, we could change their electrical properties dramatically.

The scientists exposed TiS₃ to gradual pressure. As they increased the pressure, they found that the TiS₃ system underwent a series of transitions, from being insulators to becoming metals and superconductors, for the first time.

TiS₃ materials are known to work as good insulators, but it is the first time scientists have discovered that under pressure they can function as superconductors, paving the way for the development of superconducting materials.

Mahmoud Abdel-Hafiez et al, From Insulator to Superconductor: A Series of Pressure-Driven Transitions in Quasi-One-Dimensional TiS3 Nanoribbons, Nano Letters (2024). DOI: 10.1021/acs.nanolett.4c00824

Comment by Dr. Krishna Kumari Challa on June 11, 2024 at 11:15am

Improved prime editing system makes gene-sized edits in human cells at therapeutic levels

Scientists have improved a gene-editing technology that is now capable of inserting or substituting entire genes in the genome in human cells efficiently enough to be potentially useful for therapeutic applications.

The advance could one day help researchers develop a single gene therapy for diseases such as cystic fibrosis that are caused by one of hundreds or thousands of different mutations in a gene. Using this new approach, they would insert a healthy copy of the gene at its native location in the genome, rather than having to create a different gene therapy to correct each mutation using other gene-editing approaches that make smaller edits.

The new method uses a combination of prime editing, which can directly make a wide range of edits up to about 100 or 200 base pairs, and newly developed recombinase enzymes that efficiently insert large pieces of DNA thousands of base pairs in length at specific sites in the genome. This system, called eePASSIGE, can make gene-sized edits several times more efficiently than other similar methods, and is reported in Nature Biomedical Engineering.

Pandey S, Gao XD, et al. Efficient site-specific integration of large genes in mammalian cells via continuously evolved recombinases and prime editing, Nature Biomedical Engineering (2024). DOI: 10.1038/s41551-024-01227-1

Comment by Dr. Krishna Kumari Challa on June 11, 2024 at 10:24am

This work shows that about 10% of all the crystals the researchers analyzed were older than 4 billion years. That might seem small, but it's an enormous amount of super-old grains compared to other places around the world.

To figure out whether these grains held a record of fresh water, they used tiny beams of ions on these dated zircon grains to measure the ratio of heavier to lighter oxygen. This ratio, known as an oxygen isotopic ratio, is thought to be nearly constant through time for seawater, but much lighter for fresh water.

Conspicuously, a small portion of zircon crystals from 4 billion years ago had a very light signature that could only have formed from the interaction of fresh water and rocks.
Zircon is extremely resistant to alteration. For the Jack Hills' zircon to obtain this light oxygen signature, the rock altered by fresh water had to melt and then re-solidify to impart the light oxygen isotopic signature into the zircon.

Thus, fresh water had to be present on Earth before 4 billion years ago.
Researchers now at least found evidence for the cradle of life on Earth some time before 4 billion years ago—extremely early in our planet's 4.5-billion-year history..

Hamed Gamaleldien et al, Onset of the Earth's hydrological cycle four billion years ago or earlier, Nature Geoscience (2024). DOI: 10.1038/s41561-024-01450-0

Part 2

Comment by Dr. Krishna Kumari Challa on June 11, 2024 at 10:22am

Study finds fresh water and key conditions for life appeared on Earth a half-billion years earlier than thought

We need two ingredients for life to start on a planet: dry land and (fresh) water. Strictly, the water doesn't have to be fresh, but fresh water can only occur on dry land.

Only with those two conditions met can you convert the building blocks of life, amino acids and nucleic acids into tangible bacterial life that heralds the start of the evolutionary cycle.

The oldest life on Earth left in our fragmented rock record is 3.5 billion years old, with some chemical data showing it may even be as old as 3.8 billion years. Scientists have hypothesized life might be even older, but we have no records of that being the case.

A new study published in Nature Geoscience provides the first evidence of fresh water and dry land on Earth by 4 billion years ago. Knowing when the cradle of life—water and land—first appeared on Earth ultimately provides clues as to how we came to be.

Fresh water is very different from sea water. Obviously, you might say, but how do you know if one or both were present on Earth if you can't actually go back in a time machine?

The answer is in the rock record and chemical signals preserved in that time capsule. Earth is a bit over 4.5 billion years old, and the oldest rocks scientists have found are just a little older than 4 billion years.

To really understand our planet in its first 500 million years, we have to turn to crystals that once came from older rocks and ended up deposited in younger rocks.

Unlike rocks, the oldest preserved crystals go back as far as 4.4 billion years. And the bulk of these super-old crystals comes from one place on Earth: the Jack Hills in Western Australia's midwest.

This is precisely where the researchers of this study went. They dated over a thousand crystals of a mineral called zircon, famed for its extreme resistance to weathering and alteration.

Part 1

Comment by Dr. Krishna Kumari Challa on June 10, 2024 at 7:47am

Does magic really exist?

Comment by Dr. Krishna Kumari Challa on June 10, 2024 at 7:17am

When Water Flows Uphill

Comment by Dr. Krishna Kumari Challa on June 8, 2024 at 11:07am

Researchers discover Earth and space share the same turbulence

In a paper published in Geophysical Research Letters, researchers have discovered that the turbulence in the thermosphere exhibits the same physical laws as the wind in the lower atmosphere. Furthermore, wind in the thermosphere predominantly rotates in a cyclonic direction, in that it rotates counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

The findings reveal a new unified principle for the Earth's varied environmental systems and can potentially improve future forecasting of both earth and space weather.

Facundo L. Poblet et al, Third‐Order Structure Functions of Zonal Winds in the Thermosphere Using CHAMP and GOCE Observations, Geophysical Research Letters (2024). DOI: 10.1029/2024GL108367

Comment by Dr. Krishna Kumari Challa on June 8, 2024 at 11:02am

The shells in this paper consist of a thin inner layer of positive mass and a thin outer layer of negative mass; the total mass of both layers—which is all one could measure, mass-wise—is exactly zero, but when a star lies on this shell it experiences a large gravitational force pulling it towards the center of the shell.
As gravitational force fundamentally involves the warping of space-time itself, it enables all objects to interact with each other, whether they have mass or not. Massless photons, for example, have been confirmed to experience gravitational effects from astronomical objects.
Gravitational bending of light by a set of concentric singular shells comprising a galaxy or cluster is due to a ray of light being deflected slightly inwards—that is, towards the center of the large-scale structure, or the set of shells—as it passes through one shell.
The sum total effect of passage through many shells is a finite and measurable total deflection which mimics the presence of a large amount of dark matter in much the same way as the velocity of stellar orbits.

Both the deflection of light and stellar orbital velocities is the only means by which one gauges the strength of the gravitational field in a large-scale structure, be it a galaxy or a cluster of galaxies. The contention of this paper is that at least the shells it posits are massless. There is then no need to perpetuate this seemingly endless search for dark matter.

Richard Lieu, The binding of cosmological structures by massless topological defects, Monthly Notices of the Royal Astronomical Society (2024). DOI: 10.1093/mnras/stae1258

Part 2

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