Comment

Comment by Dr. Krishna Kumari Challa on June 13, 2024 at 9:23am

A  robot that can autonomously remove weeds

Robotic systems are already being deployed in various settings worldwide, assisting humans with a highly diverse range of tasks. One sector in which robots could prove particularly advantageous is agriculture, where they could complete demanding manual tasks faster and more efficiently.

Among the many agricultural tasks that robots could tackle is the removal of weeds, which can cause significant damage to both livestock and crop farming. In fact, fast-growing and invasive weeds can both reduce the yield of crops and potentially poison animals, including horses, sheep, and cows.

Researchers recently developed a new robot that can autonomously remove an invasive weed known as Rumex longifolius, or longleaf dock, which are highly rich in oxalates, compounds that can be poisonous to some livestock. Their robot, introduced in a paper pre-published on arXiv.

Jarkko Kotaniemi et al, A Weeding Robot for Seedling Removal, arXiv (2024). DOI: 10.48550/arxiv.2405.12596

Comment by Dr. Krishna Kumari Challa on June 13, 2024 at 9:21am

African savannah elephants call one another by ‘name’

Elephants call out to each other using individual names that they invent for their fellow pachyderms, according to a recent study.

While dolphins and parrots have been observed addressing each other by mimicking the sound of others from their species, elephants are the first non-human animals known to use names that do not involve imitation, the researchers suggested.

For the new study, a team of international researchers used an AI algorithm to analyse the calls of two wild herds of African savannah elephants in Kenya.

The research not only shows that elephants use specific vocalisations for each individual, but that they recognise and react to a call addressed to them while ignoring those addressed to others.

This indicates that elephants can determine whether a call was intended for them just by hearing the call, even when out of its original context.

The researchers sifted through elephant "rumbles" recorded at Kenya's Samburu National Reserve and Amboseli National Park between 1986 and 2022.

Using a machine learning algorithm, they identified 469 distinct calls, which included 101 elephants issuing a call and 117 receiving one.

Elephants make a wide range of sounds, from loud trumpeting to rumbles so low they cannot be heard by the human ear.

Names were not always used in the elephant calls. But when names were called out, it was often over a long distance, and when adults were addressing young elephants.

Adults were also more likely to use names than calves, suggesting it could take years to learn this particular talent.

The most common call was "a harmonically rich, low-frequency sound”.

This suggests that elephants and humans are the only two animals known to invent "arbitrary" names for each other, rather than merely copying the sound of the recipient.

The evidence provided here that elephants use non-imitative sounds to label others indicates they have the ability for abstract thought.

African savannah elephants call one another by ‘name’ - Nature Ecology & Evolution
Using a combination of machine learning and playback experiments in the field, we find that African savannah elephants address members of their family with individually specific, name-like calls. These ‘names’ are probably not imitative of the receiver’s calls, which is similar to human naming but unlike known phenomena in other animals.
https://www.nature.com/articles/s41559-024-02430-8

Comment by Dr. Krishna Kumari Challa on June 13, 2024 at 9:16am

Tattoos Linked to Increased Cancer Risk, Scientists Warn

Regret was for many years considered the most severe side-effect of tattoos. But a new study suggests there could be much worse things to worry about than that.

Tattoos are now a mainstream means to express identity or celebrate milestones in life. Yet we know very little about the long-term health effects. Hazardous chemicals in tattoo ink have received attention during the last ten years. In parallel, research has shown that the ink that is injected into the skin does not stay there.

The body perceives tattoo ink as something foreign that needs to be removed, and tattooing causes an immune response that results in a large fraction of ink particles ending up in the lymph nodes. But the last piece of the puzzle has been lacking: how does tattoo ink deposited in the lymphatic system affect people's health?

To connect the dots, researchers conducted a large study to answer whether having tattoos might increase the risk of malignant lymphoma, a rare form of cancer that affects the white blood cells (lymphocytes). The study was recently published in the journal eClinicalMedicine.

Scientists found that tattooed people had a 21% higher risk of lymphoma than people without tattoos after factoring in smoking status and education level (both being factors that may be associated with getting a tattoo and developing lymphoma).

The size of the tattoos did not seem to matter. What did matter was time – how long participants had had their tattoos. The risk seemed to be higher for new tattoos (received within two years) and for older tattoos (received more than ten years ago).

https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(24)00228-1/fulltext

Comment by Dr. Krishna Kumari Challa on June 12, 2024 at 10:24am

Climate misinformation overshadows record floods worldwide

Climate skeptics are scapegoating a weather modification technique known as cloud seeding to deny the role of global warming in historic floods that have recently devastated countries from Brazil to Kenya.

Record rainfall brought to some regions by the natural weather cycle El Niño matches an expected increase in extreme events, experts say.

But online, false claims have repeatedly been made that geoengineering—not carbon emissions—is to blame.

Claims that weather had been manipulated appeared after every major flood this year, including in Zimbabwe, the United Arab Emirates and other nations. 

Cloud seeding, which introduces tiny particles into the sky to induce rain over small geographical areas, has gained popularity worldwide as a way to combat drought and increase local water supplies.

But scientists say the technique cannot create weather—nor can it trigger rainfall at the scale observed in countries such as Germany and the United States.

"Due to the strong natural variability of clouds, there exists very little scientific proof that cloud seeding has indeed a measurable effect on precipitation, say the experts.

Experts emphasize that  climate change doubled the likelihood of floods in southern Brazil and worsened the intense rains caused by El Niño.

There's definitely a consensus that climate change is responsible for many of these extreme weather events.

And there is no definitive large-scale or long-term impacts from cloud seeding. We are already manipulating the weather at a global scale (larger) than would ever be possible through cloud seeding, scientists warn.

Sours: AFP and other news agencies.

**

Comment by Dr. Krishna Kumari Challa on June 12, 2024 at 10:15am

Chemists discover spontaneous nanoparticle formation in charged microdroplets

A team of chemists has found that particles of minerals sometimes break down spontaneously when immersed in charged microdroplets, leading to the formation of nanoparticles.

In their study, published in the journal Science, the group conducted experiments with minerals and an electrospray device

Prior research has shown that natural processes often result in the creation of nanoparticles and that many types of such nanoparticles exist in nature. But not much is known about how they are formed. In this new effort, the research team suspected that some of them may be the result of minerals becoming immersed in charged liquid particles. To find out if that might be the case, they designed an experiment to replicate such natural processes.
The researchers note that charged microdroplets are plentiful in the natural world, found in clouds and sea spray. To create their own charged microdroplets, they used an electrospray device.

When filled with water and electrically charged, it can produce a mist of charged droplets. In their experiments, the research team added mineral particles to the water before putting it in the spray device. They then captured samples of the charged microdroplets and other materials that were in the mist. They found many instances of nanoparticles being spontaneously expelled from the microdroplets into the air around them.

The researchers found that shortly after droplet formation, a double electric field was generated across its surface, producing a reactive sphere. That was followed by droplet fission when coulombic energy in the droplet exceeded its surface tension—and that was followed by expulsion of a mineral nanoparticle in the form of a microdroplet.

B. K. Spoorthi et al, Spontaneous weathering of natural minerals in charged water microdroplets forms nanomaterials, Science (2024). DOI: 10.1126/science.adl3364

R. Graham Cooks et al, Breaking down microdroplet chemistry, Science (2024). DOI: 10.1126/science.adp7627

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

• ‹ Previous
• 1
• …
• 28
• 29
• 30
• 31
• 32
• …
• 897
• Next ›
• Page