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Comment by Dr. Krishna Kumari Challa on April 2, 2023 at 1:42pm

Crystallised intelligence (the ability to accumulate knowledge, facts and skills) 

Fluid intelligence (the ability to reason and think flexibly)

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 12:35pm

Neck cracking

It is thought that one of the most common causes of neck ‘cracking’ is gas bubbles in the synovial fluid escaping a tight space. This synovial fluid

is a lubricant between the joints, formed by a combination of carbon dioxide, nitrogen and oxygen.

If you deliberately roll your neck, it is thought that you can sometimes release these bubbles, resulting in a series of popping sounds that may sound like cracking. The release of the gas build-up explains why muscles or joints often feel looser and more comfortable after they’ve been ‘popped’ or ‘cracked’.

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Our joints contain synovial fluid, a sac of liquid which acts as a lubricant, protecting bones from grinding against each other. When someone cracks their knuckles, they increase the space in the joint, causing bubbles of gas (think oxygen, nitrogen and carbon dioxide) to form in the fluid. It’s the popping of these bubbles that make the cracking noise.

While it may sound worrying, there isn’t actually much evidence to suggest this is dangerous – or increases the risk of getting arthritis. The most important risk factors for developing arthritis are family history, age, gender, joint injury, and lifestyle elements such as smoking and obesity.

It is true that people with arthritis sometimes find their joints crack, but this is because their cartilage has already been damaged. Cracking isn’t usually the most common symptom of arthritis, either.

Although there are isolated reports of self-injury caused from cracking knuckles, such as sprained ligaments, these are very rare. You’re much more likely to harm yourself by cracking joints in your spine and neck, which are surrounded by important blood vessels.

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 11:54am

Gigapixel 3D Microscope Captures Life in Unprecedented Detail

A new kind of microscope that stitches together videos from dozens of smaller cameras can provide researchers with 3D views of their experiments. Whether recording 3D movies of the behavior of dozens of freely swimming zebrafish or the grooming activity of fruit flies at near cellular-level detail across a very wide field of view, the device is opening new possibilities to researchers the world over. Learn more at https://www.pratt.duke.edu/about/news...

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 11:48am

Scientists have found microplastic pollution in krill and salps from the Southern Ocean. A new study led by researchers at British Antarctic Survey shares important evidence that these animals, as well as other zooplankton, ingest plastic in their natural environment. Krill and salps are vital food sources to much of the Southern Ocean’s wildlife as well as helping to trap carbon from the atmosphere in the deep ocean. The impact of the microplastics in this environment is not fully understood and could interfere with their ability to trap carbon as well as getting transferred up the food chain to animals such as whales and penguins. The team found plastics in most krill and salp samples with the most common type being nylon, a fibre with wider ranging applications from clothing to car tires. ➡ Read this news story on the British Antarctic Survey website: https://www.bas.ac.uk/media-post/micr...

Part 2

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 11:48am

Microplastic found in Antarctic krill and salps

A new study by researchers discovered microplastics in krill (Euphausia superba), a small shrimp-like crustacean, and salps (Salpa thompsoni), a gelatinous marine invertebrate. The results were published in the journal Royal Society Open Science.

While Antarctic krill have been observed ingesting microplastics in laboratory settings, the team's findings provide important evidence that these animals, as well as other zooplankton, ingest plastic in their natural environment.

Microplastics are present in the Southern Ocean from the sea surface to seabed. Due to the small size of these particles (<5 mm), Antarctic zooplankton are likely to mistake the plastics for their natural food source. The team focused on two of the most abundant species of Southern Ocean zooplankton: Antarctic krill, and salps. These two species are critical to the diet of much of the Southern Ocean's marine wildlife. Krill is the main food source for whales, penguins, and seals while salps are eaten by some fish and larger marine birds.

Krill and salp samples were collected onboard the research ship RRS James Clark Ross on two research missions off the Northern tip of the Antarctic Peninsula in 2016 and near the island of South Georgia in 2018. Microplastics were extracted from both species with plastic microfibers most common. One of the largest sources of these fibers is shedding from clothing during washing and drying. Around 60% of the krill and salps contained nylon, a microplastic with significant commercial applications in clothing, fishing gear, ropes, and reinforcing car tires.

The findings underline how sensitive the Antarctic marine ecosystem is to plastic pollution. Due to the short food chains in the Antarctic, transfer of these microplastics from the krill to larger predators such as whales, penguins, and seals is highly likely. Plastic in krill and salps could also negatively impact the Southern Ocean as one of the planets largest carbon sinks.

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 11:15am

Ban On Tattoo Ink: Breaking Down the Chemistry

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 10:12am

Scientists observe flattest explosion ever seen in space

An explosion the size of our solar system has baffled scientists, as part of its shape—similar to that of an extremely flat disk—challenges everything we know about explosions in space.

The explosion observed was a bright Fast Blue Optical Transient (FBOT)—an extremely rare class of explosion which is much less common than other explosions, such as supernovas. The first bright FBOT was discovered in 2018 and given the nickname "the cow."

Explosions of stars in the universe are almost always spherical in shape, as the stars themselves are spherical. However, this explosion, which occurred 180 million light years away, is the most aspherical ever seen in space, with a shape like a disk emerging a few days after it was discovered. This section of the explosion may have come from material shed by the star just before it exploded.

It's still unclear how bright FBOT explosions occur, but it's hoped that this observation, published in Monthly Notices of the Royal Astronomical Society, will bring us closer to understanding them.

Justyn R Maund et al, A flash of polarized optical light points to an aspherical 'cow', Monthly Notices of the Royal Astronomical Society (2023). DOI: 10.1093/mnras/stad539

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 9:42am

There is a distinction in biology between the two ways that animals deploy poisons. There are poisonous animals that produce toxins in their bodies and others that absorb toxins from their surroundings. Like the frogs, the birds belong to the latter category. Both are believed to acquire toxins from what they eat. Beetles containing the toxin have been found in the stomachs of some of the birds. But the source of the toxin itself has yet to be determined.

What makes it possible for these birds to have a toxin in their bodies without themselves being harmed? The researchers studied this with inspiration from poison dart frogs, whose genetic mutations prevent the toxin from keeping their sodium channels open, and thereby preventing cramps.

So, it was natural to investigate whether the birds had mutations in the same genes. Interestingly enough, the answer is yes and no. The birds have mutations in the area that regulates sodium channels, and which we expect gives them this ability to tolerate the toxin, but not in the exact same places as the frogs.

Finding these mutations that can reduce the binding affinity of Batrathotoxin in poisonous birds in similar places as in poison dart frogs, is quite cool. And it showed that in order to adapt to this Batrachotoxin lifestyle, you need some sort of adaptation in these sodium channels".

Therefore, these studies of the birds establish that while their neurotoxin is similar to that of the South American poison dart frogs, the birds developed their resistance and ability to carry it in the bodies independently of the frogs. This is an example of what biologists refer to as convergent evolution.

 Kasun H. Bodawatta et al, Multiple mutations in the Nav1.4 sodium channel of New Guinean toxic birds provide autoresistance to deadly batrachotoxin, Molecular Ecology (2023). DOI: 10.1111/mec.16878

Part 3

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 9:42am

The two birds that the researchers discovered to be poisonous are the regent whistler (Pachycephala schlegelii), a species that belongs to a family of birds with a wide distribution and easily recognizable song well-known from across the Indo-Pacific region, and the rufous-naped bellbird (Aleadryas rufinucha).

Most people are familiar with South and Central America's iconic poison dart frogs—especially the golden poison frog. These small, brightly colored amphibians can kill a human at the slightest touch. The discovery of the two new poisonous bird species in New Guinea, which carry the same type of toxin in their skin and feathers, demonstrates that the frog toxin is more widespread than once believed.

The poison in these birds' bodies and plumage is called Batrachotoxin. It is an incredibly potent neurotoxin that, in higher concentrations, such as those found in the skin of golden poison frogs, leads to muscle cramps and cardiac arrest nearly immediately after contact.

The bird's toxin is the same type as that found in frogs, which is a neurotoxin that, by forcing sodium channels in skeletal muscle tissue to remain open, can cause violent convulsions and ultimately death.

Though the level of toxicity of the New Guinean birds is less lethal, it may still serve a defensive purpose, but the adaptive significance for the birds is yet uncertain.

The locals aren't fond of spicy food and steer clear of these birds, because, according to them, their meat burns in the mouth like chili. In fact that's how researchers first became aware of them. And the toxin can be felt when holding onto one of them. It feels kind of unpleasant, and hanging on to one for long isn't an appealing option. This could indicate that the poison serves them as a deterrence of those who would want to eat them to some degree.

According to the researchers, the poisonous birds are an expression of an everlasting evolutionary arms race in nature. It starts at the bottom of the food chain with beetles, insects and other invertebrates. Over time, some of these develop toxicity to avoid being eaten. Perhaps they also acquire a particular coloration that may serve as a warning. This in turn allow them to venture from their hideouts beneath logs and rocks.

Part 2

Comment by Dr. Krishna Kumari Challa on April 1, 2023 at 9:35am

 Poisonous Birds: Researchers discover birds with neurotoxin-laden feathers in New Guinea

An expedition into the jungle of New Guinea has resulted in the discovery of two new species of poisonous birds by researchers. The poisonous birds inhabit one of Earth's most pristine rainforests, a place as exotic as no other in the world. Hearing the words poisonous and bird coupled will be an eye-opener for most. But poisonous birds actually exist. And now, more species have been discovered in New Guinea's jungles. These birds contain a neurotoxin that they can both tolerate and store in their feathers.

These birds contain a neurotoxin that they can both tolerate and store in their feathers

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