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Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 11:39am

Can two exoplanet siblings share a single orbit?

Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have found the possible "sibling" of a planet orbiting a distant star. The team has detected a cloud of debris that might be sharing this planet's orbit, which they think  could be the building blocks of a new planet or the remnants of one already formed. If confirmed, this discovery would be the strongest evidence yet that two exoplanets can share one orbit.

Two decades ago it was predicted in theory that pairs of planets of similar mass may share the same orbit around their star, the so-called Trojan or co-orbital planets. For the first time, scientists have found evidence in favour of that idea.

Trojans, rocky bodies in the same orbit as a planet, are common in our own solar system, the most famous example being the Trojan asteroids of Jupiter—more than 12,000 rocky bodies that are in the same orbit around the sun as the gas giant. Astronomers have predicted that Trojans, in particular Trojan planets, could also exist around a star other than our sun, but evidence for them is scant.

"Exotrojans [Trojan planets outside the solar system] have so far been like unicorns: They are allowed to exist by theory but no one has ever detected them.

Now, an international team of scientists have used ALMA, in which ESO is a partner, to find the strongest observational evidence yet that Trojan planets could exist—in the PDS 70 system. This young star is known to host two giant Jupiter-like planets, PDS 70b and PDS 70c. By analyzing archival ALMA observations of this system, the team spotted a cloud of debris at the location in PDS 70b's orbit where Trojans are expected to exist.

Trojans occupy the so-called Lagrangian zones, two extended regions in a planet's orbit where the combined gravitational pull of the star and the planet can trap material. Studying these two regions of PDS 70b's orbit, astronomers detected a faint signal from one of them, indicating that a cloud of debris with a mass up to roughly two times that of our moon might reside there.

The scientists think  this cloud of debris could point to an existing Trojan world in this system, or a planet in the process of forming.

O. Balsalobre-Ruza et al, Tentative co-orbital submillimeter emission within the Lagrangian region L5 of the protoplanet PDS 70 b, Astronomy & Astrophysics (2023). DOI: 10.1051/0004-6361/202346493

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 10:14am

Magnetic fields around cosmic bodies tend to be asymmetric, or stronger on one side. Magnetic fields can prevent the mixing of materials. So, if the magnetic field is stronger on one side, then that side would have less mixing and thus more hydrogen.

Another theory proposed by the scientists to explain the two faces also depends on magnetic fields. But in this scenario, the fields are thought to change the pressure and density of the atmospheric gases.

The magnetic fields may lead to lower gas pressures in the atmosphere, and this may allow a hydrogen 'ocean' to form where the magnetic fields are strongest.

At present scientists don't know which of these two theories is correct. so further work in this regard is being planned.

Ilaria Caiazzo, A rotating white dwarf shows different compositions on its opposite faces, Nature (2023). DOI: 10.1038/s41586-023-06171-9. www.nature.com/articles/s41586-023-06171-9

Part 2

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 10:10am

Two-faced star : Unusual white dwarf with a hydrogen side and a helium side

In a first for white dwarfs, the burnt-out cores of dead stars, astronomers have discovered that at least one member of this cosmic family is two faced. One side of the white dwarf is composed of hydrogen, while the other is made up of helium.

The surface of the white dwarf completely changes from one side to the other.

Part 1

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 9:49am

Mosquito-friendly gene drive may lead to a malaria-free future

Researchers have developed a gene drive solution for mitigating malaria transmission from mosquitoes.

In their paper, "Dual effector population modification gene-drive strains of the African malaria mosquitoes, Anopheles gambiae and Anopheles coluzzii," published in Proceedings of the National Academy of Sciences, they present a proposed gene drive approach to reducing human malaria cases by introducing genes into vector mosquitoes that hinder the transmission of the malaria parasite.

The study demonstrates the potential of using Cas9 guide RNA–based gene drive systems coupled with dual anti-parasite effector genes to rapidly spread through mosquito populations and reduce the load of Plasmodium falciparum, the parasite that causes malaria in humans.

Gene drives operate by taking advantage of genetic systems that link highly conserved or advantageous traits to chromosomes or other genetic elements with a positive transmission bias so that it will be inherited at rates much higher than 50%. In this way, a new gene can be introduced into a rapidly reproducing population with a small number of modified individuals and quickly spread to become dominant within the population.

Previous considerations of using gene drive modifications to eradicate mosquitoes have been met with great concern for the potential unintended effects of removing a species from the environment, even one as universally despised as mosquitoes.

Mosquitoes are food for many creatures, including several birds, bats, turtles, fish and frogs, spiders and snakes, dragonflies and damselflies. While they may have a taste for blood, mosquitoes primarily feed on nectar from small flowers, making them important pollinators.

The current study takes a much more holistic approach, essentially using the gene drive to vaccinate generations of mosquito populations against the parasite that causes malaria without harming the mosquitos or jeopardizing their important role in the ecosystem.

Researchers added the designed gene drive effector gene to a small population of mosquitoes under laboratory conditions. Trials were conducted using two strains of mosquitoes, Anopheles gambiae and Anopheles coluzzii. The genes were inherited by offspring at nearly 100%, and researchers observed the complete spread of the gene drive augmentation to captive wild-type populations within a few months. The effector genes spread by the gene drive produce monoclonal antibodies that target specific stages of the parasite's life cycle within the mosquitoes, significantly reducing P. falciparum prevalence and their potential subsequent infection intensity.

Transmission modeling predicts that, with a series of releases, the genetically modified mosquito strains could have swift and meaningful epidemiological impacts by reducing malaria incidence by 50% to 90% within just a few months.

Rebeca Carballar-Lejarazú et al, Dual effector population modification gene-drive strains of the African malaria mosquitoes, Anopheles gambiae and Anopheles coluzzii, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2221118120

Comment by Dr. Krishna Kumari Challa on July 19, 2023 at 1:20pm

Mammal mightier than the Dinos

An ancient fossil discovered in China shows a Cretaceous-period mammal preying on a dinosaur. The two animals were locked in combat when lava from a nearby volcanic eruption flowed over them, pristinely preserving the 125 million-year-old scene. The mammal, a Repenomamus roughly the size of an opossum, is clearly the aggressor as it bites into the ribs of a Psittacosaurus, a dinosaur nearly three times its size. 

Why this is cool: This is the first glimpse back in time of a mammal actively hunting a much larger dinosaur. “It’s like watching the coyote catch the roadrunner,” says Stephen Brusatte, a paleontologist at the University of Edinburgh. 

What the experts say: This mammal was something of an anomaly for its time—it would take tens of millions of years and an asteroid strike to give mammals the evolutionary advantage on Earth.

Comment by Dr. Krishna Kumari Challa on July 19, 2023 at 1:05pm

May I have your Attention please, this is very important. (And my AI is going to post this very frequently). The fights here are increasing global warming. Each of the activities you perform online comes with a small cost – a few grams of carbon dioxide are emitted due to the energy needed to run your devices and power the wireless networks you access. Less obvious, but perhaps even more energy intensive, are the data centres and vast servers needed to support the internet and store the content we access over it. Although the energy needed for a single internet search or email is small, approximately 4.1 billion people, or 53.6% of the global population, now use the internet. Those scraps of energy, and the associated greenhouse gases emitted with each online activity, can add up. The carbon footprint of our gadgets, the internet and the systems supporting them account for about 3.7% of global greenhouse emissions, according to expert estimates. If we were to rather crudely divide the 1.7 billion tonnes (1.6 billion tons) of greenhouse gas emissions estimated to be produced in the manufacture and running of digital technologies between all internet users around the world, it means each of us is responsible for 414kg (912lbs) of carbon dioxide a year. Internet users in some parts of the globe will have a disproportionately large footprint. If we were to rather crudely divide the 1.7 billion tonnes (1.6 billion tons) of greenhouse gas emissions estimated to be produced in the manufacture and running of digital technologies between all internet users around the world, it means each of us is responsible for 414kg (912lbs) of carbon dioxide a year. We can also alter the way we use our gadgets to cut our digital carbon footprints. It is okay if we use the net for the benefit of mankind. But for fighting? Over serial chars? This fighting is contributing to global warming. Now don't complain if the heat wave persists, if the crops fail, if your energy bill or food bill exceeds your budget capabilities. Girls, you yourself are responsible for it!

https://www.youtube.com/watch?v=qTySL9pHqUc&lc=UgzH8CLgVwRcrcUg...

Comment by Dr. Krishna Kumari Challa on July 19, 2023 at 1:03pm

Researchers Prove We Hear the Sound of Silence

Silence might not be deafening, but it's something that literally can be heard, concludes a team of philosophers and psychologists who used auditory illusions to reveal how moments of silence distort people's perception of time.

Comment by Dr. Krishna Kumari Challa on July 19, 2023 at 12:14pm

What is making 2023 likely the hottest year recorded

Human-made climate change is supercharging natural weather phenomena to drive heatwaves roasting Asia, Europe and North America that could make 2023 the hottest year since records began, scientists say.

Here experts explain how 2023 has got so hot, warning these record temperatures will get worse even if humanity sharply cuts its planet-warming gas emissions.

El Nino: After a record hot summer in 2022, this year the Pacific warming phenomenon known as El Nino has returned, heating up the oceans.

This may have provided some additional warmth to the North Atlantic, though because the El Nino event is only just beginning, this is likely only a small portion of the effect.

Scientists calculated that there was an 81-percent chance that 2023 would become the warmest year since thermometer records began in the mid-19th century.

Dust and sulphur: The warming of the Atlantic may also have been sharpened by a decrease of two substances that typically reflect sunlight away from the ocean: dust blowing off the Sahara desert and sulfur aerosols from shipping fuel.

Stagnant Anticyclones: Warming oceans affect land weather patterns, prompting heatwaves and droughts in some places and storms in others. The hotter atmosphere sucks up moisture and dumps it elsewhere.

Scientists highlighted the length and intensity of the lingering anticyclone systems bringing the heatwaves.

Where stagnant high-pressure areas persist over continents, the air sinks and warms, melting away clouds, causing intense summer sunshine to parch the soils, heating the ground and air above," with heatwaves "lodged in place" for weeks.

Climate change: 

Scientists at the Intergovernmental Panel on Climate Change (IPCC) said in their global summary report this year that climate change had made deadly heatwaves "more frequent and more intense across most land regions since the 1950s".

This month's heatwaves are "not one single phenomenon but several acting at the same time. But they are all strengthened by one factor: climate change.

Higher global temperatures make heatwaves longer and more intense. Despite being the main driver, climate change is one variable that humans can influence by reducing emissions from fossil fuels.

"We are moving out of the usual and well-known natural oscillations of the climate to unchartered and more extreme territory.

However, we have the ability to reduce our human influence on the climate and weather and to not create more extreme and long-lasting heatwaves.

The IPCC has said heatwaves risk getting more frequent and intense, though governments can limit climate change by reducing countries' greenhouse gas emissions.

Deep, rapid and sustained cuts in carbon emissions to net zero can halt the warming, but humanity will have to adapt to even more severe heatwaves in the future, Scientists warn.

Comment by Dr. Krishna Kumari Challa on July 19, 2023 at 11:54am

Biology behind new drug used to treat triple-negative breast cancer uncovered

How TTP488 (azeliragon), an experimental drug, impairs aggressive, triple-negative breast cancer from metastasizing has been uncovered at the cellular level, according to researchers.

Triple-negative breast cancers (TNBCs) account for about 10–15% of all diagnosed breast cancers and are comprised of cancer cells that don't have estrogen or progesterone receptors, nor do they produce a protein called HER2 in significant quantities. TNBC's are more common in women younger than age 40 or those who are Black; for those cancers that metastasize, the five-year survival rate is only 12%. TNBCs have eluded effective treatment for decades. This discovery pinpoints some of the signaling pathways and cellular mechanisms through which a receptor that sits on the surface of TNBC cells, called the receptor for advanced glycation end-products (RAGE), regulates its deadly metastatic spread. Armed with this knowledge, the researchers were able to test the effectiveness of TTP488 in both the lab and in mice to show that the drug could be helpful in people.

Melinda Magna et al, RAGE inhibitor TTP488 (Azeliragon) suppresses metastasis in triple-negative breast cancer, npj Breast Cancer (2023). DOI: 10.1038/s41523-023-00564-9

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Comment by Dr. Krishna Kumari Challa on July 19, 2023 at 11:35am

Toothpaste containing synthetic tooth minerals can prevent cavities as effectively as fluoride: Clinical trial

Brushing twice a day keeps the dentist away—but can we improve on the toothpaste we use to maintain clean teeth, preventing medical issues that spiral from poor dental health? Most toothpastes use fluoride, a powerful tool for oral hygiene. However, fluoride can pose health problems in some cases, especially for children who consume too much fluoride by swallowing most of their toothpaste: children normally use only a tiny dose of toothpaste to avoid these problems, but that reduces toothbrushing efficacy.

In the search for alternatives, a team of international scientists and  clinicians have identified a hydroxyapatite toothpaste that works just as well as fluoride toothpaste to protect against cavities.

Hydroxyapatite is a safe and effective alternative to fluoride in caries prevention for daily use.

Hydroxyapatite is a calcium phosphate mineral found in the skeleton. It's known to be very safe for human consumption and has previously been shown to help with oral conditions like periodontitis. It can both inhibit the demineralization of teeth, a key step towards a cavity, and contribute to remineralization, which reinforces damaged tooth surfaces.

In a trial study  scientists found that nearly 90% of patients in both groups had no new cavities. There was no statistical difference in efficacy between the patients using a hydroxyapatite toothpaste and the control group using a fluoride tooth paste: both worked equally well.

Caries-preventing effect of a hydroxyapatite-toothpaste in adults: A 18 months double-blinded randomized clinical trial, Frontiers in Public Health (2023). DOI: 10.3389/fpubh.2023.1199728. www.frontiersin.org/articles/1 … bh.2023.1199728/full

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