Tag Archives: Adaptation

Enhancing Astronaut Durability: The Challenges of Tardigrade Adaptation

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Tardigrade Resilience

Tardigrades Exhibit Extreme Resilience

How can space explorers be shielded from cosmic radiation without using massive lead enclosures? Some researchers propose leveraging the unique properties of a protein found in tardigrades that can protect DNA, but the solution is more complex.

Corey Nislow and his team at the University of British Columbia have identified a protein named Dsup (short for Damage Suppressor) that not only protects against radiation but also against various mutagenic substances. However, this protection comes with trade-offs, such as diminished cell viability.

“All the benefits we observe come at a cost,” Nislow states.

Tardigrades, often called water bears, are known for their incredible survival abilities, thriving under extreme conditions such as high radiation, harsh temperatures, desiccation, and even the vacuum of space. In 2016, Dsup was discovered as a critical component of this resilience. When human cells were genetically modified to express Dsup, they displayed enhanced radiation resistance without any adverse effects.

This led to the hypothesis that Dsup could serve as a protective agent against harmful radiation and mutagens. One potential method involves administering the mRNA that encodes Dsup, encapsulated in lipid nanoparticles (LNPs), similar to the technology utilized in mRNA coronavirus vaccines.

“A couple of years ago, I was fully convinced that delivering Dsup mRNA through LNPs to space crews would be highly effective; it wouldn’t alter their genomes but would serve as an efficient countermeasure against DNA damage,” Nislow mentions.

However, ongoing research involving genetically engineered yeast cells producing Dsup has revealed that high concentrations can be toxic, while lower levels can inhibit growth.

Dsup seems to safeguard DNA by physically enveloping it, which, in turn, complicates access for proteins necessary for RNA synthesis and DNA replication before cellular division. It also poses challenges for DNA repair proteins attempting to mend the DNA, particularly in cells with limited repair capabilities, where significant repairs may not occur.

Nislow speculates that Dsup could be beneficial for protecting astronauts, animals, and plants, but emphasizes the importance of controlling its expression levels to optimize its protective effects.

“I completely concur,” says James Byrne, from the University of Iowa, who is studying whether Dsup can shield healthy cells during cancer radiation therapy.

Byrne notes the potential risks associated with continuous Dsup production in all human cells but suggests that temporary expression during periods of need could be advantageous.

“It is undeniable that exceeding a certain threshold can render Dsup toxic,” he acknowledges. Simon Glass from the University of Montpellier also observes that low levels of Dsup can extend the lifespan of nematodes by providing oxidative stress protection, indicating that our understanding of Dsup’s mechanisms remains incomplete.

Jessica Tyler from Weill Cornell Medicine has also engineered yeast to produce Dsup, noting that lower levels than those examined by Nislow appeared beneficial without compromising growth.

“Thus, I disagree with the assertion that Dsup’s protective benefits come at a significant cost,” Tyler affirms, while agreeing on the necessity for regulated Dsup expression.

Although current technologies do not allow for the introduction of the ideal cells to produce Dsup at desired levels, Nislow expresses optimism about future advancements. “There is significant investment and interest in developing effective delivery systems,” he remarks. “This is a challenge that many in the pharmaceutical industry are eager to tackle.”

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Source: www.newscientist.com

Baby’s Brain Development May Affect Their Slow Adaptation to Mites Compared to Adults

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The infant’s brain functions at a distinct rhythm compared to that of adults

Goodles/Aramie

When infants attempt to comprehend their surroundings, their brain activity reveals slower rhythms compared to adults, aiding them in grasping new concepts.

Our brains utilize a network of neurons to interpret sensory input. When a neuron receives a sufficiently strong signal from its neighbor, it transmits that signal to other neurons, generating synchronized waves of electrical activity that alternate between activated and silent states.

These brain waves manifest at various frequencies. A specific brain area may show a greater proportion of neurons synchronized to one frequency over others if it exhibits a range of frequencies simultaneously. For instance, prior research indicates that the adult visual cortex displays a diverse range of frequencies when individuals are observing stimuli, but in higher proportions, more neurons synchronize with the waves at a frequency of 10 hertz.

To determine if the same holds true for infants, Moritz Kester from the University of Regensburg in Germany along with his colleagues enlisted 42 eight-month-olds via their parents. The researchers recorded the infants’ brain activity with electrodes affixed to the scalp, exposing them to dozens of friendly cartoon monsters for about 15 minutes, each monster flashing for two seconds.

The team relied on the fact that brain waves tend to oscillate in sync with rapidly flickering images, enabling them to assess the number of neurons synchronized to various frequencies within the infants’ visual cortex. Each monster was toggled on and off at eight different frequencies ranging from 2 to 30 hertz.

Analysis of the brain activity data revealed that the visual cortex produces waves of synchronized activity in response to the flickering cartoons. However, the most prominent signals emerged at four hertz, indicating greater synchronization with this flicker frequency than with others.

Moreover, this 4-hertz signal was consistently present even when the brain was exposed to flickering at higher frequencies, such as 15 hertz. “What’s particularly intriguing is that regardless of the different frequencies presented, a response at 4 hertz was always observed,” comments Kester.

This rhythm falls within a frequency band known as theta, which is associated with the formation of new concepts, potentially facilitating learning for young children as they observe their environment. “It suggests that infants are in a specific learning mode,” Kester explains.

Researchers supporting this theory further discovered that there were no 4-hertz EEG signals in the visual cortex, nor EEG signals at other frequencies, suggesting a broader neural circuit involvement in other brain areas related to concept formation.

Repeating the experiment with seven adults confirmed prior findings that visual brain circuits are predominantly activated by the 10 hertz frequency, which was also found to persist in the background despite varying speeds of the cartoon flickering.

Given adults’ extensive experiences, it appears that the visual sections of their brains are fine-tuned to respond to more frequent stimuli. They block irrelevant information and concentrate on acquiring conceptual knowledge, states Kester.

Further research is necessary to establish whether exposure to 4 hertz flickering images can enhance infants’ capacity to learn new concepts, according to Emily Jones at Birkbeck, University of London. The team is hopeful to gain further insights in an ongoing study, Kester added.

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Source: www.newscientist.com

Expedition to study human adaptation to extreme heat in the face of climate change

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Walking on hot red sand is hard work, especially when the temperature exceeds 40°C (104°F). After about 40 minutes you are soaked, dehydrated and exhausted. It is hard to imagine doing this for 40 days with all your gear, including 40 liters of water for five days, on a two-wheeled trolley. But that is exactly what my traveling companions did.

I'm in the Nahud Desert, a vast expanse of sand and rocky wilderness in northern Saudi Arabia, to experience the almost unbearable heat and meet up with 20 other people who are part of an expedition. Deep ClimateHe is dedicated to understanding how humans respond to extreme situations. “The aim is to study how humans adapt to new kinds of environments,” he says. Christian Clotteleader of the expedition and director of the French Institute of Human Adaptation.

This problem becomes even more pressing as the climate gets warmer: even in the most optimistic scenarios, heatwaves exceeding 40°C, as observed in southern Europe and across the United States over the past few months, will become the norm in many parts of the world.

So the question of what happens to our brains and bodies, and how well the human physiology can handle extreme heat, is a question that matters to millions of people. “We're going to see large swaths of densely populated areas rise to unprecedented temperatures that nobody has seen in historical climates,” he said. Tim Renton He is a researcher at the University of Exeter in the UK and recently co-authored a research paper titled “…

Source: www.newscientist.com

The specialized adaptation of fox skulls for diving into snow

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Red fox diving into the snow to catch prey

Maxime Riendau/Getty Images

Some foxes can dive headfirst into snow without causing harm, and we now know how the shape of their skulls is adapted to this technique.

In colder climates, where small rodents live deep beneath the snow, red foxes (Vulpes Vulpes Vulpes) and arctic fox (Vulpes lagopus) has a special hunting technique known as mouse. They use their strong sense of hearing to pinpoint the location of their prey, then jump into the air and dive face-first into large piles of snow at speeds of up to 4 meters per second, catching their prey by surprise.

“This is a very interesting and unique behavior,” he says. Jung Sung-hwan At Cornell University in New York. “Not all foxes do that.”

To learn more about why red and arctic foxes are so adept at snow diving, Jung et al. scanned.

Their analysis found that felines tend to have broader and shorter snouts compared to foxes. This creates a stronger bite, which is more beneficial for felines, which typically hunt alone, Jung said.

Foxes, on the other hand, which hunt in packs, had much longer and more pointed skulls. This leads to a weak bite. The red fox and the arctic fox have similarly narrow muzzles that are slightly longer than other foxes.

The researchers dropped a 3D-printed model of a regular arctic fox skull and a flattened version of the skull into snow from a height of 50 centimeters.

“What we found is that a sharper nose compresses the snow less, reducing the impact,” Jung says. This reduces the risk of injury. Its longer, pointier snout gently pushes the snow aside, as if it were liquid, he said. “Such an elongated shape helps foxes dive safely into the snow so they can focus on hunting.”

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Source: www.newscientist.com