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Comment by Dr. Krishna Kumari Challa on May 30, 2024 at 9:51am

More rogue planets discovered
The Euclid space telescope has discovered seven more rogue planets, shining a light on the dark and lonely worlds floating freely through the universe untethered to any star.

The Euclid study also offered clues to how rogue planets are created: Some could be formed in the outer part of a solar system before getting detached from their star and floating away.

But the study indicates that many rogue planets may be created as a "natural byproduct" of the star-formation process. This suggests a "really close connection between stars and planets and how they form".

Without being bound to a star, as the Earth is to the sun, there are no days or years on these planets, which languish in perpetual night. Yet scientists think there is a chance they could be able to host life—and estimate there may be trillions dotted throughout the Milky Way.

Last week the European Space Agency released the Euclid telescope's first scientific results since the mission launched in July.

Among the discoveries were seven new free-floating planets, gas giants at least four times the mass of Jupiter.

They were spotted in the Orion Nebula, the nearest star-forming region to Earth, roughly 1,500 light years away.

Euclid also confirmed the existence of dozens of other previously detected rogue planets. This is likely to be just the tip of the iceberg.

Because they do not reflect the light of a star, spotting rogue planets is like "finding a needle in a haystack".

Younger planets, such as those discovered by Euclid, are hotter, making them a little easier to see.

Some research has suggested there are around 20 rogue planets for every star, which could put their number in the trillions in our home galaxy alone.

Given there are thought to be hundreds of billions of galaxies across the universe, the potential number of free-floating worlds becomes difficult to fathom.

When NASA's Roman space telescope launches in 2027 it is expected to find many more rogue planets, possibly offering clarity about how many could be out there.

But not all rogue planets wander alone. Four of the more than 20 confirmed by Euclid are believed to be binaries—two planets orbiting each other in a single system.

If rogue planets are habitable, they could be a key target in humanity's search for extraterrestrial life.

Lacking heat from a nearby star, free-floating planets are believed to be cold, with frozen surfaces.

That means any life-supporting energy would have to come from inside the planet.

And geothermal vents allow animals to survive on Earth that have never seen the sun's rays.

But even under the best conditions, this extreme isolation would likely be able to support only bacterial and microbial life.

Advantages of being a rogue planet: Rogue planets could be thought of as traversing a lonely path through the cosmos.

But "being around a star has its downsides".

Once the sun becomes a red giant—in an estimated 7.6 billion years—it will greatly expand, swallowing the Earth.

Rogue planets do not have to worry about eventually being destroyed by a star. "These things will last forever". ( Maybe if they don't go near any other star or planet or anybody that can influence its path and structure).

"If you don't mind the cold temperatures you could survive on these planets for eternity."

The study published ‘s on arXiv.org e-Print archive Friday.

https://arxiv.org/abs/2405.13497

Comment by Dr. Krishna Kumari Challa on May 30, 2024 at 9:49am

Chocolate's tasty flavors might pose a health risk in other desserts

What makes chocolate taste and smell so delicious? Chemistry, of course. A variety of molecules work together to create that unmistakable aroma, but those same molecules might carry some unwanted health effects if there are too many around. According to research published in Journal of Agricultural and Food Chemistry, while many of the compounds appeared in chocolate in low enough concentrations to be safe, higher amounts were found in some baked sweet treats.

When making chocolate, cocoa beans are roasted to help their chocolatey flavors shine. During this process, new molecules like α,β-unsaturated carbonyls are formed when they react with other ingredients under high temperatures. This class of carbonyls is highly reactive and potentially genotoxic, or able to cause damage to DNA when consumed.

Though naturally found in many foods, these carbonyls are also used as flavoring additives, and some have been banned in some countries, including the buttery-tasting furan-2(5H)-one. To better understand how these molecules form naturally in foods, and whether or not they are present in levels that could pose a health concern, researchers tested chocolates and other sweet treats for 10 different α,β-unsaturated carbonyls—some of which have been confirmed as safe by the European Food Safety Authority, while others are still under evaluation.

The team created its own chocolates and found that α,β-unsaturated carbonyls formed during roasting and after the addition of cocoa butter; however, their concentrations remained too low to pose any health concerns from consuming the chocolates.

Next, researchers screened 22 commercially available desserts, including crepes, waffles, cakes and biscuits, either with or without chocolate. In these packaged treats, they found even lower concentrations of nine of the 10 carbonyls compared to the chocolates.

The remaining carbonyl—genotoxic furan-2(5H)-one—appeared in much higher concentrations in the crepe and cake samples, reaching up to 4.3 milligrams per kilogram. Considering that the recommended threshold for genotoxic substances is only 0.15 micrograms per person per day, consuming these desserts could exceed that limit, though additional studies are needed to accurately assess the potential health risk.

Researchers concluded that the furan-2(5H)-one molecule likely formed during the baking process and did not seem to correlate with the amount of chocolate present in the packaged desserts. The team says that this work helps to better understand where these carbonyls come from in chocolate and highlights the importance of monitoring flavorings in food to keep consumers informed and safe.

Occurrence and Synthesis Pathways of (Suspected) Genotoxic α,β-Unsaturated Carbonyls in Chocolate and Other Commercial Sweet Snacks, Journal of Agricultural and Food Chemistry (2024). DOI: 10.1021/acs.jafc.4c01043 , pubs.acs.org/doi/abs/10.1021/acs.jafc.4c01043

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 11:29am

This (Edible) Mushroom Could Kill You

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 11:17am

Debunking "Healthy" TikTok DESSERTS

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 10:55am

In a key result, the team then tested the susceptibility of bacteria treated with ciprofloxacin over a series of days to determine how quickly resistance to the antibiotic was developing, either with or without OXF-077. They found that the emergence of resistance to ciprofloxacin was significantly suppressed in bacteria treated with OXF-077, compared to those not treated with OXF-077.

This is the first study to demonstrate that an inhibitor of the SOS response can suppress the evolution of antibiotic resistance in bacteria. Moreover, when resistant bacteria previously exposed to ciprofloxacin were treated with OXF-077, it restored their sensitivity to the antibiotic to the same level as bacteria that had not developed resistance.

 Jacob D. Bradbury et al, Development of an inhibitor of the mutagenic SOS response that suppresses the evolution of quinolone antibiotic resistance, Chemical Science (2024). DOI: 10.1039/D4SC00995A

Part 2

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Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 10:55am

New molecule found to suppress bacterial antibiotic resistance evolution

Researchers have developed a new small molecule that can suppress the evolution of antibiotic resistance in bacteria and make resistant bacteria more susceptible to antibiotics. The paper, "Development of an inhibitor of the mutagenic SOS response that suppresses the evolution of quinolone antibiotic resistance," has been published in the journal Chemical Science.

The global rise in antibiotic-resistant bacteria is one of the top global public health and development threats, with many common infections becoming increasingly difficult to treat. It is estimated that drug-resistant bacteria are already directly responsible for around 1.27 million global deaths each year and contribute to a further 4.95 million deaths. Without the rapid development of new antibiotics and antimicrobials, this figure is set to rise significantly.

A new study led by researchers at the Ineos Oxford Institute for antimicrobial research (IOI) and the Department of Pharmacology at Oxford University offers hope in the discovery of a small molecule that works alongside antibiotics to suppress the evolution of drug-resistance in bacteria.

One of the ways that bacteria become resistant to antibiotics is due to new mutations in their genetic code. Some antibiotics (such as fluoroquinolones) work by damaging bacterial DNA, causing the cells to die. However, this DNA damage can trigger a process known as the "SOS response" in the affected bacteria.

The SOS response repairs the damaged DNA in bacteria and increases the rate of genetic mutations, which can accelerate the development of resistance to the antibiotics. In the new study, the Oxford scientists identified a molecule capable of suppressing the SOS response, ultimately increasing the effectiveness of antibiotics against these bacteria.

The researchers studied a series of molecules previously reported to increase the sensitivity of methicillin-resistant Staphylococcus aureus (MRSA) to antibiotics, and to prevent the MRSA SOS response. MRSA is a type of bacteria that usually lives harmlessly on the skin. But if it gets inside the body, it can cause a serious infection that needs immediate treatment with antibiotics. MRSA is resistant to all beta-lactam antibiotics such as penicillins and cephalosporins.

Researchers modified the structure of different parts of the molecule and tested their action against MRSA when given with ciprofloxacin, a fluoroquinolone antibiotic. This identified the most potent SOS inhibitor molecule reported to-date, called OXF-077. When combined with a range of antibiotics from different classes, OXF-077 made these more effective in preventing the visible growth of MRSA bacteria.

Part 1

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 10:25am

The digital touchscreens of the future could let you 'feel' items through your phone

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 10:05am

Even the scientists who made the original, possible detection of planet HD 26965 b—almost immediately compared to the fictional Vulcan—cautioned that it could turn out to be messy stellar jitters masquerading as a planet. They reported evidence of a "super-Earth"—larger than Earth, smaller than Neptune—in a 42-day orbit around a sun-like star about 16 light-years away. The new analysis, using high-precision radial velocity measurements not yet available in 2018, confirms that caution about the possible discovery was justified.

The bad news for "Star Trek" fans comes from an instrument known as NEID, a recent addition to the complex of telescopes at Kitt Peak National Observatory. NEID, like other radial velocity instruments, relies on the Doppler effect: shifts in the light spectrum of a star that reveal its wobbling motions. In this case, parsing out the supposed planet signal at various wavelengths of light, emitted from different levels of the star's outer shell (photosphere), revealed significant differences between individual wavelength measurements—their Doppler shifts—and the total signal when they were all combined.

That means, in all likelihood, that the planet signal is really the flickering of something on the star's surface that coincides with a 42-day rotation—perhaps the roiling of hotter and cooler layers beneath the star's surface, called convection, combined with stellar surface features such as spots and "plages," which are bright, active regions. Both can alter a star's radial velocity signals.

The demonstration of such finely tuned radial velocity measurements holds out the promise of making sharper observational distinctions between actual planets and the shakes and rattles on surfaces of distant stars.

Abigail Burrows et al, The Death of Vulcan: NEID Reveals That the Planet Candidate Orbiting HD 26965 Is Stellar Activity*, The Astronomical Journal (2024). DOI: 10.3847/1538-3881/ad34d5

Part 2

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 10:03am

The death of Vulcan: Study reveals planet is actually an astronomical illusion caused by stellar activity

A planet thought to orbit the star 40 Eridani A—host to Mr. Spock's fictional home planet, Vulcan, in the "Star Trek" universe—is really a kind of astronomical illusion caused by the pulses and jitters of the star itself, a new study shows.

A science team led by astronomer Abigail Burrows of Dartmouth College, and previously of NASA's Jet Propulsion Laboratory, has published a paper describing the new result, titled "The death of Vulcan: NEID reveals the planet candidate orbiting HD 26965 is stellar activity," in The Astronomical Journal. (Note: HD 26965 is an alternate designation for the star 40 Eridani A.)

The possible detection of a planet orbiting a star that Star Trek made famous drew excitement and plenty of attention when it was announced in 2018. Only five years later, the planet appeared to be on shaky ground when other researchers questioned whether it was there at all.

Now, precision measurements using a NASA-NSF instrument, installed a few years ago atop Kitt Peak in Arizona, seem to have returned the planet Vulcan even more definitively to the realm of science fiction.

Two methods for detecting exoplanets—planets orbiting other stars—dominate all others in the continuing search for strange new worlds. The transit method, watching for the tiny dip in starlight as a planet crosses the face of its star, is responsible for the vast majority of detections. But the "radial velocity" method also has racked up a healthy share of exoplanet discoveries.

This method is especially important for systems with planets that don't, from Earth's point of view, cross the faces of their stars. By tracking subtle shifts in starlight, scientists can measure "wobbles" in the star itself, as the gravity of an orbiting planet tugs it one way, then another. For very large planets, the radial velocity signal mostly leads to unambiguous planet detections. But not-so-large planets can be problematic.

Part 1

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 9:32am

What are the causes for landslides ?

Landslides occur due to due to failure of stability of slopes. The following factors cause failure of slopes.

Clay and shale beds are weak materials and tend to get slided particularly in the presence of water.

Groundwater and precipitation – groundwater conditions of the area depends on the geological and hydrological parameters, storage, recharge, , duration of precipitation , intensity of rainfall, lithological characteristics of the area and gradient of slope etc. In general slope stability is adversely affected by rise in groundwater table, resulting in pore water pressure . The shearing resistance of the mineral grains reduces and then this leads to landslides.

Insitu stresses – the stress within the slope rock is generated when load is placed at top of the slope. This may be due to accumulation of rain or snow water or human activities such as stock piling of ore deposits, waste deposits, mine tailings, buildings and removal of natural rocks for construction or foundation works.

Textures – anisotrophy in fabric is the weakest internal structure of a rock and it facilitates movement of the rock mass. Uniform or medium grained mineral content of rock bears a greater strength than that borne by rocks of unequal grains.

Weak planes- Schistocity, slaty structure and lamination are weak points . It has been observed that massive slides tales place in sedimentary rocks inter bedded with limestones and shales.

Weathering weakens the physical and chemical bonding in rocks and this leads to failure of mass even in hard rocks.

Structural features

Bedding planes, fractures, joints, faults , fissures and schistocity will have influence on downward slope of rock mass. In nature no rock mass is truly continuous. It will be broken by fracture, joints, bedding planes, dykes, and veins. These discontinuities will lead to instability of strata.

Seismic activity – travel of elastic waves released during an earthquake in the ground increase the shear stress in the slope and consequently decrease volume open spaces within the rock material there by increasing the pressure of water in void space and leads to failure of rock mass.

Part 3

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