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Its duration is 36 million years.. The geological cycle that drives biodiversity on Earth | Science



Its duration is 36 million years.. The geological cycle that drives biodiversity on Earth |  Science

As water levels rise and fall, different habitats on the continental shelf and in shallow oceans expand and contract, providing opportunities for organisms to thrive or die.

Prevailing geoscientific theory states that the Earth’s lithosphere consists of several tectonic plates, where there are 7 or 8 large plates in addition to several smaller plates that moved slowly 3.4 billion years ago.

Earthquakes and volcanoes occur, and mountains and ocean trenches form at the boundaries of tectonic plates, which are separated into oceanic lithosphere and thick continental lithosphere, both of which are topped by a special crust.

Geological cycle

At convergent boundaries of tectonic plates, the plates sink into the Earth’s crust and replace the lost material by forming new oceanic crust at divergent boundaries as a result of sea floor extension, and in this way the total surface area of ​​the globe remains constant.

By studying tectonic plate movements, scientists found that plate movement indirectly leads to biodiversity fluctuations in 36-million-year cycles, forcing sea levels to rise and fall.

And inside search In a new paper published in the Proceedings of the National Academy of Sciences (PNAS), researchers led by Associate Professor Sala Bolilla of the Sorbonne University in Paris say that as water levels rise and fall, different habitats exist on continental shelves and in shallow oceans. Expansion and contraction provide opportunities for organisms to flourish or die, and by examining the fossil record, scientists have shown that these changes lead to bursts of new life.

Biodiversity driven by plate motion

Study co-author Professor Dietmar Müller, from the University of Sydney’s School of Geosciences, says: Report In terms of tectonic movement, the 36-million-year cycle represents transitions between fast and slow seafloor subsidence, leading to cyclical changes in the depth of ocean basins and tectonic transport to Earth’s depths, leading to fluctuations. Periods of flooding and drying on continents and vast shallow seas promote biodiversity.

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It refers to the site report Scientific alert Scientifically, a closer look at the fossil record shows that biological diversity is not small and stable, but rather fluctuates greatly on scales of tens of thousands of years, punctuated by extinction events and the appearance of new species, but the purpose of these changes is not clear, and whether each event is unique in se or an underlying mechanism connecting these changes. Is there

To unravel this mystery, Professor Poulila and his team painstakingly analyzed multiple geological data sets of the past 250 million years combined with computer simulations and modelling.

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“This work was made possible by the GPlates – plate tectonics software developed by the Earthbite team at the University of Sydney, with support from the Australian National Collaborative Research Infrastructure Strategy (NCRIS) via AuScope,” Professor Muller notes.

The research team analyzed a range of geological data spanning the past 250 million years (Shutterstock)

The team based their findings on finding similar cycles in sea-level changes, Earth’s internal mechanisms and the marine fossil record, and scientists now have conclusive evidence that tectonic cycles driven by Earth dynamics and global sea-level change played a role. Biodiversity of marine life over millions of years.

Professor Müller comments, “This research challenges previous ideas about why organisms change over long periods of time.”

Tectonic plate rotation and other drivers

“Like a warm, thick soup in a slow-moving bowl, the cycles are 36 million years long because of the regular patterns of how tectonic plates, the moving part of the Earth’s core, recycle through the crust,” Professor Müller explains.

Muller says the Cretaceous Winton Formation in Queensland is an example of how changes in sea level affect ecosystems and affect biodiversity in Australia.

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Renowned for its collection of fossils, the formation provides a priceless window into a period when much of the Australian continent was submerged. As sea levels rose and fell, the continent’s flooding expanded and contracted ecological niches in the shallow seas. Unique habitats for a variety of species.

A group of gastropod fossils preserved in limestone from the Late Cretaceous period (geodiversites).

“The Cretaceous Winton Formation is evidence of the profound impact of these changes in sea level, providing a snapshot of a time when Australia’s landscape changed and amazing creatures roamed the land,” Professor Muller said.

Scientists say there are other triggers that could have driven biodiversity throughout Earth’s history. For example, the team found evidence of a 62-million-year biodiversity cycle, which the researchers say could be driven by changes in carbon dioxide levels, but this hypothesis needs to be verified. Further investigation.

Evidence : Scientific alert + Websites + Yorick warning

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Home Covid-19 tests are valid for detecting new strains



Home Covid-19 tests are valid for detecting new strains

Director of the Clinical Virology Laboratory at the American Mayo Clinic, Dr. Matthew Pinker answers frequently asked questions about the expiration dates of home testing kits for “Covid-19” and their ability to detect new strains of the virus.

Home tests

* Validity of test instruments. At-home Covid-19 tests allow you to collect your own sample and detect active Covid-19 infection. But what if you have expired or outdated Covid-19 test kits at home in your cupboard?

Dr. Matthew Pinker says: Companies arbitrarily plan original test kits; Because the development of these at-home diagnostic tests was rapid. Therefore; Check your tools before throwing them away.

“Now three and a half years into the epidemic, these manufacturers have had the opportunity to evaluate the effectiveness of the test over a longer period of time,” Dr. Pinker adds. “In many cases the expiration dates have been updated.”

Home Covid Test (Shutterstock)

Recommendations on accuracy of tests

-If you have test kits at home, search the US Food and Drug Administration (FDA) website for updated expiration dates.

– “If you take a test after the expiration date and the test is positive, this is a reliable result, especially if you have a respiratory disease.

If you get a negative result from a test that’s past the expiration date, “I recommend making sure the test doesn’t have an extended expiration date.” Beyond that, you should get another test or ask your healthcare provider to collect a swab for lab testing before ruling you (Covid-19) free,” says Dr. Beneker.

Tracking current “corona” strains

* Can home tests detect current strains of “Covid-19”?

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– Yes, it should detect currently circulating covid-19 strains. The good news is that most of the changes to the virus within these new variants are in the spike protein, the part of the virus that attaches to cells.

“The protein that the antigen tests are looking for is a different protein where there aren’t many mutations,” says Dr. Pinker. “This allows us to say with confidence that these tests should pick up cyclic strains.”

Test results

*If the test comes back positive (confirmed), are you contagious? What if you test positive for coronavirus (Covid-19)?

Often, Dr. Benniker says, “when the home antigen test is positive, it means that this person is still secreting large amounts of viral protein.” “In most cases, that means the person is excreting that amount of virus, and it can be a large amount of virus that can spread from one person to another.” If you get a positive result, he adds. Antigen testing at home Consider risk of viral transmission. If the result is positive, you may be infected with Covid-19.

*But what if you develop symptoms and test negative?

“If you test negative at home and are still experiencing common symptoms of Covid-19, such as a sore throat, cough, fever and body aches, I recommend that you visit your healthcare provider and get tested.” Dr. Pinker says. This is because “the collected swab can be sent to the laboratory and tested based on the polymerase chain reaction. This will give us more reliable information about whether you are actually infected with (Covid-19) or not.

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When is the test done?

* When should you get tested for “COVID-19”?

Testing is recommended in some situations, Dr. Pinker says. Such as:

. Symptoms appear. If you develop symptoms such as fever, cough, sore throat, runny nose or body aches.

. If you spend time with someone who has been confirmed to have the coronavirus (COVID-19).

. If you plan to visit someone who is at risk of serious illness. This includes someone with cancer, the elderly, or anyone taking medications that suppress their immune system. If you’re infected with the virus, don’t get yourself tested right away, Dr. Pinker says. “My advice is to wait a few days and not go straight home and get tested; This is because the virus does not have enough time to reach levels that would cause antigen tests to be positive. “Usually, I wait three days after that.”

. Exposure, then testing. If the result is negative, consider another test the next day or 48 hours later; Generally, by the fifth day after exposure, if you test negative within that time frame, you can clear the virus.

Atmospheric temperature and accuracy of tests

* Home temperature and “Covid-19” testsSince temperatures fluctuate greatly in geographic regions, would these tests be affected by hot or cold temperatures?

Information packages accompanying at-home antigen tests should provide information on storage conditions set by the Food and Drug Administration, Dr. Pinker says. Here is a good read. “If you live in an area that experiences subzero weather, such as during the summer months, or temperatures above 100 degrees F (37.8 C), it’s always a good idea to check the package that comes with the test for acceptable storage conditions.

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* “Mayo Clinic News Network” – “Tribune Media” Services

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Why not keep your toothbrush in the bathroom?



Why not keep your toothbrush in the bathroom?


We all know that maintaining oral hygiene is very important and the most important step to do this is to brush your teeth twice a day with mouthwash and floss.

But according to experts, you could be putting your oral hygiene at risk by storing your toothbrush in the bathroom.

“Storing your toothbrush in the bathroom can expose you to a variety of health problems, but the level of risk varies depending on the bathroom environment and your specific habits,” explains Dr. Payal Bhalla, principal dentist and medical director of Quest Dental.

Dr. Balla says that aerosolized bacteria can pose a problem because “when you flush the toilet, especially when the lid is open, small droplets containing bacteria and other microorganisms can splash out and settle on nearby surfaces, including your toothbrush.”

When your toothbrush is near the toilet, it’s “more likely to come into contact with airborne particles and water splashes” that “lead to contamination.”

Bathrooms can also be a humid environment, which can encourage the growth of bacteria and mold on your toothbrush.

In shared bathrooms, “there is a greater potential for cross-contamination as multiple people use the space and touch different surfaces.”

As for faecal particles, which can be on your toothbrush, Dr. Bhalla explains: “It’s possible to have faecal particles in the bathroom environment, including surfaces like your toothbrush. This can happen when toilets are cleaned. Not closing the lid, and brushing can release small droplets of faecal bacteria and other microbes into the air. .To reduce the risk of faecal particles coming into contact with your toothbrush, you can follow hygiene tips such as rinsing your toothbrush before using it, storing it upright, covering it with the toothbrush, and closing the toilet lid when washing.

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She also recommends “rinsing your toothbrush thoroughly under tap water before using it” because it “will help remove any potential contaminants. Also place your toothbrush upright in a toothbrush cup and allow it to air dry. Make sure it doesn’t touch other toothbrushes. ” To prevent cross contamination.

Dr. Bhalla emphasized the importance of changing toothbrushes “every three to four months or so” to keep them healthy and effective.

He added: “To reduce the spread of airborne particles, close the toilet lid before cleaning, use a breathable toothbrush cover to protect your toothbrush from bathroom contaminants, and regularly clean the toothbrush holder or cup to prevent bacteria and mold build-up. “

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The Day of the Big Clash… NASA on Historic Mission to Save Earth (Photos)



The Day of the Big Clash… NASA on Historic Mission to Save Earth (Photos)

02:35 PM

Wednesday, September 20, 2023

Scientists believe that September 24, 2182 marks the date that the asteroid “Bennu” will hit the Earth, so the American space agency NASA is preparing to undertake a dangerous mission to prevent a collision and save our planet from destruction.

According to NASA, this space rock passes close to our planet every 6 years, but it will have a very close encounter with Earth after another 159 years, and if it collides with us, its force will be equal to 22 nuclear bombs.

Although the odds of a cataclysmic impact are estimated at 1 in 2,700, NASA sent a spacecraft to Bennu 7 years ago to collect samples from it. They hope the data will help them prepare for an asteroid deflection mission similar to NASA’s DART mission, which successfully changed the orbit of the small asteroid moon Temorphos last year.

The asteroid samples will reach Earth this week, landing in the Utah desert on September 24.

“We’re now in the final stages of this seven-year mission,” Rich Burns, OSIRIS-REx program manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, told the Sunday Telegraph.

Bennu is about 492 meters wide (about half the size of the asteroid that killed the dinosaurs), so it wasn’t big enough to cause global extinction.

NASA estimated that it could have an impact 9 kilometers wide and cause devastation in a radius of about 1,000 kilometers from the crash site.

Between now and 2300 the chance of Bennu colliding with Earth is 1750.

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“The raw materials from asteroid Bennu will help shed light on how our solar system formed 4.5 billion years ago and how life began on Earth,” said Nicola Fox, associate administrator of NASA’s Science Operations Directorate in Washington.

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