Tag Archives: distances

Deadly Fungus Causes Ill Frogs to Leap Great Distances, Possibly in Search of Mates

Posted on by
Reply

Bellow’s alpine tree frogs enhance their jumping ability when infected with a common fungus

Robert Valentich/naturepl.com

The chytrid fungus is a lethal pathogen affecting amphibians amid an ongoing global crisis, capable of wiping out entire populations. Yet, for one endangered frog species in Australia, the infection has led to an unusual positive effect: significantly larger hops.

Verreaux’s alpine tree frog (Litoria Verouki Alpina) is impacted by the chytrid fungus, Batrachochytrium dendrobatidis. Those infected can leap nearly a quarter further than their uninfected counterparts.

“These findings remind us of the incredible resilience of these amphibians and their responses to threats from this daunting pathogen. Remarkably, their bodies can display unexpected adaptations,” says Teagan McMahon from the University of Connecticut in New London, who was not involved in the research.

Alexander Wendt and colleagues at the University of Melbourne, Australia, investigated the impact of Bd infection on the health of alpine tree frogs, using their locomotion as an indicator of physiological health.

In their laboratory study, the researchers separated 60 frogs into groups based on infection status. Wendt and his team assessed how the frogs responded to extreme temperature conditions and measured their jumping distances when gently stimulated.

Remarkably, six weeks after infection, the frogs that had contracted Bd exhibited an increase in jumping distance of nearly 24% compared to uninfected ones. Typically, in other amphibian species, energy reserves are drained as the immune system combats the fungus. The physiological responses to Bd can vary significantly among amphibian species, offering temporary advantages in cases of sublethal infections.

“However, as soon as clinical symptoms emerge, it becomes exceedingly challenging for most species,” Wendt notes.

The immune response of alpine tree frogs does not appear robust enough to hinder their reaction to Bd, suggesting that such enhancements may aid them in locating mates quickly before their condition worsens. Other frog species are also known to amplify their mating calls when infected with Bd.

This short-term bolstering of jumping ability can be advantageous when faced with Bd. “From an evolutionary standpoint, it makes sense,” McMahon adds. “Enhanced mobility may contribute to increased transmission rates and prolong the host’s lifespan.”

The influence of Bd on amphibians is increasingly recognized as being shaped by complex interactions between host biology, the fungus, and the surrounding environment. “All we can do is gather as much information as possible to assist these species in surviving and mitigating the spread of Bd before it reaches a critical point,” Wendt emphasizes.

Topic:

  • Animal Behavior/
  • Amphibian

Source: www.newscientist.com

Lightning can generate energy waves that travel vast distances into space.

Posted on by
Reply

Lightning can create special energy waves

Room the Agency/Alamy

This overlooked mechanism could allow lightning energy to reach the top of the atmosphere, threatening the safety of satellites and astronauts.

When lightning strikes, the energy it carries can create special electromagnetic waves called whistlers, so named because they can be converted into sound signals. For decades, researchers thought that the whistlers produced by lightning remained confined to altitudes relatively close to the Earth's surface, below about 1,000 kilometers.

now Vikas Sonwalkar and Amani Lady Researchers at the University of Alaska Fairbanks discovered that some whistlers bounce off a layer of the atmosphere filled with charged particles called the ionosphere, which allows whistler waves and the energy they carry to travel up to 20,000 kilometers above Earth's surface—all the way into the magnetosphere, the region of space governed by Earth's magnetic field.

Researchers found evidence of these reflective whistlers in data from the Van Allen Probes, twin robotic spacecraft that measured the magnetosphere between 2012 and 2019. They also found hints of the phenomenon in studies published in the 1960s. Both the old and new data indicate that the phenomenon is very frequent and happens all the time, Reddy said.

In fact, the lightning may be depositing twice as much energy into this region as previously estimated, the researchers say, and this energy charges and accelerates nearby particles, creating electromagnetic radiation that can damage satellites and endanger the health of astronauts.

“Lightning has always been considered a bit of a smaller player. Until 10 years ago, this data wasn't available and we'd never looked at it at this level of detail.” Jacob Bortnick researcher at the University of California, Los Angeles. He says the new study is a call for others to develop a more accurate picture of the magnetosphere.

Establishing the connection between lightning and the magnetosphere is also important because changes in Earth's climate could make lightning storms more frequent, Sonwalker said.

The research team now hopes to analyze data from more satellites to learn more about how lightning-based whistlers are distributed in the magnetosphere and how they are affected by space weather.

topic:

Source: www.newscientist.com

Study finds that astronauts possess extraordinary skills in orienting themselves and calculating distances while in space

Posted on by
Reply

New research has implications for crew safety in space and could give clues about how aging affects the balance systems of people on Earth.

horges other. We addressed the question of whether body posture influences humans' perception of self-motion and distance. They found that the same amount of optical flow can elicit the sensation of traveling farther when lying on one's back and when sitting upright; that is, optical flow We found evidence that it is more effective in eliciting the sensation of movement. This constitutes evidence that visual and nonvisual cues are at least partially integrated, even when self-movement is presented only visually. However, we found no significant differences in performance in microgravity on Earth and on the ISS, suggesting that vestibular stimulation is not important, if any, in estimating visually presented self-motion.

The study's lead author, Professor Lawrence Harris from the University of York, said: “The perception of gravity has been repeatedly shown to influence perceptual abilities.”

“The most profound way to study the effects of gravity is to remove it. That's why we brought our research into space.”

“We have had a steady presence in space for nearly a quarter of a century, but our efforts in space are ever-increasing as we plan to return to the moon and beyond, ensuring health and safety. It is becoming increasingly important to answer questions about

“Based on our findings, it appears that humans are surprisingly able to use vision to adequately compensate for the lack of Earth's normal environment.

For the study, Professor Harris and his colleagues surveyed more than a dozen astronauts aboard the International Space Station (ISS), which orbits about 400 kilometers above the Earth's surface.

“Here, Earth's gravity is almost canceled out by the centrifugal force generated by the station's orbit. In the resulting microgravity, the movement of people becomes close to flight,” Professor Harris said.

“People had previously reported anecdotally that they felt like they were traveling faster or farther than they were actually in space, so this actually motivated us to record this.”

The authors compared the performance of 12 astronauts (six men and six women) before, during, and after a year-long mission to the space station and found out how far they traveled. I discovered that my sense of what I had done was almost intact.

Space missions were hectic endeavors, and it took several days for researchers to make contact with the astronauts after arriving at the space station.

“Our study may not have captured early adaptations that may have occurred during the first few days. Because whatever adaptations occur, they occur very quickly. This remains a good news message,” Professor Harris said.

Space missions are not without risks. Because the ISS orbits around the Earth, small objects can occasionally collide with it and enter the ship, where astronauts must move to safety.

“During the experiment, the ISS had to take many evasive maneuvers,” Professor Harris said.

“Astronauts need to be able to get to safety or escape through a hatch on the ISS in an emergency. So to see that they were actually able to do this with great precision was very exciting. I felt relieved.”

“Our research shows that exposure to microgravity mimics the aging process primarily at a physiological level, including bone and muscle wasting, changes in hormonal function, and increased susceptibility to infections. However, this paper found that self-movement was largely unaffected, suggesting a balance problem.''The problem, which often comes from old age, may have nothing to do with the vestibular system. ”

“This suggests that the mechanisms of movement perception in older people should be relatively unaffected, and that the problems associated with falls are probably more to do with this than in terms of perception of distance traveled. How can they translate that into a balance reflex? ”

of study Published in npj magazine microgravity.

_____

B. Horges other. 2024. Effects of long-term exposure to microgravity and body orientation relative to gravity on perceived distance traveled. NPJ microgravity 10, 28; doi: 10.1038/s41526-024-00376-6

Source: www.sci.news