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Comment by Dr. Krishna Kumari Challa on June 13, 2024 at 9:46am

Study confirms the rotation of Earth's inner core has slowed

 Scientists have proven that the Earth's inner core is backtracking—slowing down—in relation to the planet's surface, as shown in new research published in Nature.

Movement of the inner core has been debated by the scientific community for two decades, with some research indicating that the inner core rotates faster than the planet's surface. The new study provides unambiguous evidence that the inner core began to decrease its speed around 2010, moving slower than the Earth's surface.

The inner core is considered to be reversing and backtracking relative to the planet's surface due to moving slightly slower instead of faster than the Earth's mantle for the first time in approximately 40 years. Relative to its speed in previous decades, the inner core is slowing down.

The inner core is a solid iron-nickel sphere surrounded by the liquid iron-nickel outer core. Roughly the size of the moon, the inner core sits more than 3,000 miles under our feet and presents a challenge to researchers: It can't be visited or viewed. Scientists must use the seismic waves of earthquakes to create renderings of the inner core's movement.

In this study, the researchers compiled and analyzed seismic data recorded around the South Sandwich Islands from 121 repeating earthquakes that occurred between 1991 and 2023. They have also utilized data from twin Soviet nuclear tests between 1971 and 1974, as well as repeated French and American nuclear tests from other studies of the inner core.

The inner core's slowing speed was caused by the churning of the liquid iron outer core that surrounds it, which generates Earth's magnetic field, as well as gravitational tugs from the dense regions of the overlying rocky mantle.

The implications of this change in the inner core's movement for Earth's surface can only be speculated. The backtracking of the inner core may alter the length of a day by fractions of a second and we can't notice this clearly.

Wei Wang et al, Inner core backtracking by seismic waveform change reversals, Nature (2024). DOI: 10.1038/s41586-024-07536-4

Comment by Dr. Krishna Kumari Challa on June 13, 2024 at 9:36am

On the other side of the world, the team unexpectedly identified the earliest known case of P. falciparum malaria at the high Himalayan site of Chokhopani (ca. 800 BCE), located along the Kali Gandaki River Valley in the Mustang District of Nepal. At 2800 meters above sea level, the site lies far outside the habitat range for both the malaria parasite and the Anopheles mosquito.
Human genetic analysis revealed that the infected individual was a local male with genetic adaptations for life at high altitude. However, archaeological evidence at Chokhopani and other nearby sites suggests that these Himalayan populations were actively engaged in long-distance trade.Resarchersthink of these regions today as remote and inaccessible, but in fact the Kali Gandaki River Valley served as a kind of trans-Himalayan highway connecting people on the Tibetan Plateau with the Indian subcontinent.Copper artifacts recovered from Chokhopani's burial chambers prove that the ancient inhabitants of Mustang were part of larger exchange networks that included northern India, and you don't have to travel very far to reach the low-lying, poorly drained regions of the Nepalese and Indian Terai where malaria is endemic today.
Today, the human experience of malaria is at a crossroads. Thanks to advances in mosquito control and concerted public health campaigns, malaria deaths reached an all-time low in the 2010s. However, the emergence of antimalarial drug-resistant parasites and insecticide-resistant vectors threatens to reverse decades of progress, while climate change and environmental destruction are making new regions vulnerable to malaria vector species. The team hopes that ancient DNA may provide an additional tool for understanding and even combating this public health threat."For the first time, scientists are able to explore the ancient diversity of parasites from regions like Europe, where malaria is now eradicated.They see how mobility and population displacement spread malaria in the past, just as modern globalization makes malaria-free countries and regions vulnerable to reintroduction today. We hope that studying ancient diseases like malaria will provide a new window into understanding these organisms that continue to shape the world we live in today.
Megan Michel, Ancient Plasmodium genomes shed light on the history of human malaria, Nature (2024). DOI: 10.1038/s41586-024-07546-2. www.nature.com/articles/s41586-024-07546-2
Part 4

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Comment by Dr. Krishna Kumari Challa on June 13, 2024 at 9:36am

Remarkably, the team also uncovered genetic links between the Laguna de los Cóndores strain and modern Peruvian P. vivax populations 400 to 500 years later.In addition to showing that malaria spread rapidly into what is a relatively remote region today, the  data suggest that the pathogen thrived there, establishing an endemic focus and giving rise to parasites that are still infecting people in Peru today.While the role of colonialism in the spread of malaria is evident in the Americas, the team uncovered military activities that shaped the regional spread of malaria on the other side of the Atlantic.
The researchers  also identified several individuals infected with P. falciparum, a species that thrived in Mediterranean climates before eradication but was not thought to be endemic north of the Alps during this period.These virulent cases were found in non-local male individuals of diverse Mediterranean origins, who were likely soldiers recruited from northern Italy, Spain, and other Mediterranean regions to fight in the Hapsburg Army of Flanders during the 80 Years' War.They find that the large-scale troop movements played an important role in the spread of malaria during this period, similar to cases of so-called airport malaria in temperate Europe today.In our globalized world, infected travelers carry Plasmodium parasites back to regions where malaria is now eradicated, and mosquitoes capable of transmitting these parasites can even lead to cases of ongoing local transmission. Although the landscape of malaria infection in Europe is radically different today than it was 500 years ago, scientists see parallels in the ways in which human mobility shapes malaria risk.
Part 3

Comment by Dr. Krishna Kumari Challa on June 13, 2024 at 9:35am

To explore malaria's enigmatic history, an international team of researchers representing 80 institutions and 21 countries reconstructed ancient Plasmodium genome-wide data from 36 malaria-infected individuals spanning 5,500 years of human history on five continents.

These ancient malaria cases provide an unprecedented opportunity to reconstruct the worldwide spread of malaria and its historical impact at global, regional, and even individual scales.

To track the parasites' journey into the Americas, the team analyzed ancient DNA from a malaria-infected individual from Laguna de los Cóndores, a high-altitude site situated in the remote cloud forests of the eastern Peruvian Andes.

Genomic analysis revealed remarkable similarity between the Laguna de los Cóndores P. vivax strain and ancient European P. vivax, strongly suggesting that European colonizers spread this species to the Americas within the first century or so after contact.

Amplified by the effects of warfare, enslavement, and population displacement, infectious diseases, including malaria, devastated Indigenous peoples of the Americas during the colonial period, with mortality rates as high as 90% in some places.
Part 2

Comment by Dr. Krishna Kumari Challa on June 13, 2024 at 9:28am

Scientists reconstruct ancient genomes of the two most deadly malaria parasites to identify origin and spread

In a study appearing in Nature, an international team of researchers reconstructed the evolutionary history and global spread of malaria over the past 5,500 years, identifying trade, warfare, and colonialism as major catalysts for its dispersal.

Malaria, one of the world's deadliest infectious diseases, is caused by several species of single-celled parasites that are transmitted via the bite of infected Anopheles mosquitoes. Despite major control and eradication efforts, nearly half of the world's population still lives in regions where they are at risk of contracting malaria, and the World Health Organization estimates that malaria causes nearly 250 million infections and more than 600,000 deaths each year.

Beyond this massive modern impact, malaria has strongly shaped our human evolutionary history.

Although largely a tropical disease today, only a century ago the pathogen's range covered half the world's land surface, including parts of the northern U.S., southern Canada, Scandinavia, and Siberia.

Malaria's legacy is written in our very genomes: genetic variants responsible for devastating blood disorders such as sickle cell disease are thought to persist in human populations because they confer partial resistance to malaria infection.

Despite this evolutionary impact, the origins and spread of the two deadliest species of malaria parasites, Plasmodium falciparum and Plasmodium vivax, remain shrouded in mystery.

Malaria infections leave no clear visible traces in human skeletal remains, and scant references in historical texts can be difficult to decipher. However, recent advances in the ancient DNA field have revealed that human teeth can preserve traces of pathogens present in a person's blood at the time of death, providing an opportunity to study illnesses that are normally invisible in the archaeological record.

Part 1

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.

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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

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