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G24 INSTA NONE SCI

Diet has fast impacts on sperm quality

Men can improve their sperm health in just one or two weeks if they change their diet, suggests a new study at Linköping University in Sweden. The researchers, who published their study in PLOS Biology, found that male study subjects’ sperm became healthier or less healthy within days based on the study subjects’ daily intake of key nutrients.

The study tested 15 healthy, non-smoking young men and had them all follow a specified diet, in which they received all of their food from the researchers, for two weeks. During the second week, the researchers added about 450 grams of sugar—equal to around 3.5 liters of soft drinks—to the daily food regimen.

The researchers tested the subjects’ sperm at the start of the study, after the first week, and after the second week. One-third of the test subjects exhibited low sperm motility at the beginning, but all test subjects’ motility reached normal levels by the end of the first week.

“We see that diet influences the motility of the, and we can link the changes to specific molecules in them. Our study has revealed rapid effects that are noticeable after one to two weeks,” said Anita Öst, senior lecturer in the Department of Clinical and Experimental Medicine at Linköping University, and head of the study.

The researchers also found that small RNA fragments that are related to sperm motility also changed during the course of the study. They now plan to investigate to find out if these RNA fragments affect male fertility itself, and whether the RNA code could be used to develop new diagnostic methods that in vitro fertilization procedures could use to assess sperm quality.

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SCI

The Amazon is starting to ‘self-destruct,’ scientists warn

Only a major reforestation will save the Amazon rain forest from a complete ecosystem death, warns the leading scientific journal Science Advances. In an editorial, researchers Thomas Lovejoy and Carlos Nobre wrote that forest fires and deforestation are rapidly depleting the ecosystem’s ability to sustain itself, to the point where massive human intervention will be needed to save it.

“Although 2019 was not the worst year for fire or deforestation in the Amazon, it was the year when the extent of fires and deforestation in the region garnered full global attention,” the authors wrote. “The precious Amazon is teetering on the edge of functional destruction and, with it, so are we.”

The authors noted that the Amazon is a vital link to the global water cycle and provides crucial storage of enormous amounts of carbon dioxide. As the rain forest disappears, much of its stored water and carbon dioxide are released to the atmosphere. The carbon release further exacerbates climate change worldwide, and every country in South America except Chile would lose substantial amounts of freshwater, the authors said.

Deforestation now affects around 17% of the Amazon basin. The basin has historically been able to produce its own rainfall, due to the dense tree and foliage cover. But widespread forest depletion within the eastern and southern Amazon, in particular, hamper rainfall production for the entire basin, according to the authors. The added that human-caused global warming is already reducing rainfall throughout the region.

The basin is responding by changing in fundamental ways, they wrote: lengthier and hotter dry seasons, and the trees increasingly being replaced by tree species that favor drier climates.

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G24 INSTA NWT_Animals NWT_Biology Research SCI TECH

Study suggests narwhals and beluga whales experience menopause

A team of scientists discovered that narwhals and beluga whales experience menopause, which brings the total number of species known to experience the process to five. Humans aside, the species known to experience menopause all belong to the toothed whale parvorder.

“For menopause to make sense in evolutionary terms, a species needs both a reason to stop reproducing and a reason to live on afterwards,” said Sam Ellis of the University of Exeter, first author of the study. “In killer whales, the reason to stop comes because both male and female offspring stay with their mothers for life—so as a female ages, her group contains more and more of her children and grandchildren.”

“This increasing relatedness means that, if she keeps having young, they compete with her own direct descendants for resources such as food,” he added.

“The reason to continue living is that older females are of great benefit to their offspring and grand-offspring. For example, their knowledge of where to find food helps groups survive.”

More than four decades of intense study has documented the existence of menopause in killer whales.

“It’s hard to study human behaviour in the modern world because it’s so far removed from the conditions our ancestors lived in,” said Darren Croft, senior author of the study. “Looking at other species like these toothed whales can help us establish how this unusual reproductive strategy has evolved.”

Despite the fact that many individuals in various species fail to reproduce later in life, the team looked for evidence that suggested an “evolved strategy” where females had a post-reproductive lifespan.

The findings were published in Scientific Reports.

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G24 HEALTH HND_Disease INSTA Research SCI

Sleeping five hours or less connected to doubled risk of heart disease, study says

A new study suggests that men in middle age who sleep five hours or less each night have twice the risk of developing a major cardiovascular event in the two decades following compared to men who sleep seven to eight hours a night.

“For people with busy lives, sleeping may feel like a waste of time but our study suggests that short sleep could be linked with future cardiovascular disease,” said study author Moa Bengtsson, of the University of Gothenburg, Sweden.

Previous data provide conflicting evidence as to whether short sleep is connected to a great chance of a future cardiovascular event. The new study appears to solidify the connection.

Not only that, the new data suggests that men who sleep five or fewer hours per night are more likely to have diabetes, obesity, low physical activity, high blood pressure, and poor sleep quality compared to those who get seven to eight hours per night.

“Men with the shortest sleep duration at the age of 50 were twice as likely to have had a cardiovascular event by age 71 than those who slept a normal amount, even when other risk factors were taken into account,” Bengtsson said.

“In our study, the magnitude of increased cardiovascular risk associated with insufficient sleep is similar to that of smoking or having diabetes at age 50,” she added. “This was an observational study so based on our findings we cannot conclude that short sleep causes cardiovascular disease, or say definitively that sleeping more will reduce risk. However, the findings do suggest that sleep is important—and that should be a wake-up call to all of us.”

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Archaeology G24 INSTA NWT_Animals SCI

Researchers just discovered a fossilized turtle with no shell

Researchers just discovered a turtle fossil from 228 million years ago that doesn’t have a shell. Interestingly, the unique new species did possess a toothless break, which is a key turtle characteristic.

The new species is named Eorhynchochelys sinensis, which means “dawn beak turtle from China,” since it’s believed to be the first turtle with a beak. It also possesses a body in the shape of a Frisbee with wide ribs. However, these ribs did not contribute to the formation of the shell common in modern turtles.

“This creature was over six feet long, it had a strange disc-like body and a long tail, and the anterior part of its jaws developed into this strange beak,” said Olivier Rieppel, co-author of the study. “It probably lived in shallow water and dug in the mud for food.”

And since it was able to develop a beak prior to other turtles, the species is an example of mosaic evolution, which is when traits evolve independently and at different times.

“This impressively large fossil is a very exciting discovery, giving us another piece in the puzzle of turtle evolution,” said Nick Fraser, co-author of the study. “It shows that early turtle evolution was not a straightforward, step-by-step accumulation of unique traits but was a much more complex series of events that we are only just beginning to unravel.”

“With Eorhynchochelys’s diapsid skull, we know that turtles are not related to the early anapsid reptiles, but are instead related to evolutionarily more advanced diapsid reptiles. This is cemented, the debate is over,” Rieppel said. “Eorhynchochelys makes the turtle family tree make sense. Until I saw this fossil, I didn’t buy some of its relatives as turtles. Now, I do.”

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G24 INSTA NWT_Climate NWT_Environment Research SCI

Global warming ‘hiatus’ is about to end, study says

A new study suggests that the global warming “hiatus” is about to come to an end and make way for even higher temperatures. While the past four years have been the warmest on record, the new data suggests that natural factors are going to push our already heating planet even further into extreme temperature ranges.

“It will be even warmer than the long-term global warming is inducing,” said Florian Sevellec, lead author of the study.

The recent “hiatus” is the result of natural variability of the planet, which has been running for almost a decade.

“I’m not at all surprised by the results,” said John Fyfe, senior research scientist at the Canadian Centre for Climate Modelling and Analysis at Environment and Climate Change Canada. “And the reason for that is that we have gone down this long slowdown period primarily due to internal variability, and the expectation was that we’d come out of it.”

However, it is important to note that these predictions are based on probabilities, not certainties. In particular, the study’s model suggests that temperatures will be higher than predicted due to increased carbon dioxide levels.

“Because we tested it over the last century, we know that we are accurate for the likelihood,” Sevellac said. “But the likelihood doesn’t mean it will occur … there exists a small chance of being cold.”

While the study shows that Earth’s natural variability can have short-term influence, it also points to future trends.

“I think it’s also a demonstration that global warming will still be there after all this natural variability,” Sevellac said.

The findings were published in Nature Communications.

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G24 INSTA Physics Research SCI

MIT students solve spaghetti breaking mystery

A pair of Massachusetts Institute of Technology (MIT) researchers just solved an old physics mystery stemming from the fact that spaghetti noodles almost always break into three or more pieces when broken in half. In particular, they proved that it is possible to break a piece of spaghetti into two pieces.

“For maybe a month, a month and a half, we would just break spaghetti after class, just cover the floor in broken pieces of spaghetti,” said Heisser, who is now a PhD student at Cornell University.

“I thought it would be cool to try and complete something that a famous physicist began,” he continued.

The team used mathematical modeling, a spaghetti-breaking contraption, and a high-tech camera to reveal that by bending and twisting spaghetti pieces, you can break them into two. And apparently, the twist is the most important part.

The reasoning lies in the old discovery that long, thin objects can be broken by applying even pressure at both ends, creating a “snap-back effect.”

“In our study, we go a bit further and show that actually you can control this fracture cascade and get two pieces if you twist it,” Patil said. “You can control the fracture process and then you get two pieces instead of many, many pieces.”

“Just understanding these complex fracture systems would be interesting going forward as well,” he added. “There’s still a lot to be discovered about fracture control and this is an example of fracture control.”

The findings were published in the Proceedings of the National Academy of Sciences.

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Archaeology G24 INSTA NWT_Animals SCI

Amateur fossil hunter discovers teeth of ancient shark

An amateur fossil hunter just discovered the fossils of an ancient mega-shark believed to be the close cousin of the megalodon. The remains were found on a beach in Australia and will be revealed at the Museums Victoria.

The teeth are approximately three inches long and stem from the Great Jagged Narrow-Tooth Shark, an extinct species of mega-shark that roamed the seas of Australia approximately 25 million years ago. The shark can grow as long as 30 feet, which is twice the size of a great white shark.

The discovery was made by amateur fossil finder Philip Mullaly, who is also a teacher in Australia. He found the fossils during a walk through a fossil site on the Victoria coast.

“I was walking along the beach looking for fossils, turned and saw this shining glint in a boulder and saw a quarter of the tooth exposed,” he said. “I was immediately excited, it was just perfect and I knew it was an important find that needed to be shared with people.”

Mullaly contacted Erich Fitzgerald, the senior curator of vertebrae paleontology at Museums Victoria, and offered to donate them.

“These teeth are of international significance, as they represent one of just three associated groupings of Carcharocles angustidens teeth in the world,” Fitzgerald explained.

“By donating his discovery to Museums Victoria, Phil has ensured that these unique fossils are available for scientific research and education both now and for generations to come,” he continued. This is absolutely essential for documenting and preserving Australia’s prehistoric history.”

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G24 INSTA NWT_Earth NWT_Environment SCI

Blocking sunlight to cool Earth decrease global warming crop damage

An new study suggests that blocking sunlight by injecting particles into the atmosphere will not offset the crop damage caused by global warming. The team behind the study analyzed past effects of Earth-cooling volcanic eruptions and how crops respond to changes in sunlight to come to their conclusion.

“Shading the planet keeps things cooler, which helps crops grow better. But plants also need sunlight to grow, so blocking sunlight can affect growth. For agriculture, the unintended impacts of solar geoengineering are equal in magnitude to the benefits,” said lead author Jonathan Proctor of the University of California, Berkeley. “It’s a bit like performing an experimental surgery; the side-effects of treatment appear to be as bad as the illness.”

“Unknown unknowns make everybody nervous when it comes to global policies, as they should,” said Solomon Hsiang, co-lead author of the study and also from UC Berkeley. “The problem in figuring out the consequences of solar geoengineering is that we can’t do a planetary-scale experiment without actually deploying the technology. The breakthrough here was realizing that we could learn something by studying the effects of giant volcanic eruptions that geoengineering tries to copy.”

The team stresses the more research is needed into the ecological and human consequences of geoengineering.

“The most certain way to reduce damages to crops and, in turn, people’s livelihood and well-being, is reducing carbon emissions,” Proctor said.

“Perhaps what is most important is that we have respect for the potential scale, power and risks of geoengineering technologies,” Hsiang added. “Sunlight powers everything on the planet, so we must understand the possible outcomes if we are going to try to manage it.”

The findings were published in Nature.

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SCI

Scientists try to revive coral reefs with fish-enticing audio

Loudspeakers that play sounds intended to attract fish are helping to bring dead coral reefs back to life, according to a paper published recently in Nature Communications. The paper’s authors said that they hope that their findings could lead to efforts undo much of the mass destruction of coral that has been taking place throughout the world’s oceans in recent decades.

In the paper, the researchers described placing underwater loudspeakers at locations in a zone of ocean water north of Australia. Each site was within a formerly vibrant coral reef that had largely died out.

The speakers played sounds associated with healthy, vibrant reefs; the researchers intended for fish to hear these recordings and flock to the sites to breed. Their plan worked: The sites that had the speakers saw 50% increases in both the numbers of fish and numbers of fish species.

New fish populations won’t directly create more coral, but they can encourage new coral growth as the fish clean reef surfaces and create more spaces for corals to grow, the researchers said. Andy Radford, a paper coauthor from the University of Bristol, said that efforts such as this one to boost fish populations can be important parts of larger initiatives to bring lost coral ecoysystems back to life.

“If combined with habitat restoration and other conservation measures, rebuilding fish communities in this manner might accelerate ecosystem recovery,” said Radford.

Ocean researchers have been concerned about coral health throughout the world’s oceans in the last few decades, due to widespread deaths of coral in many locales. The main driving force behind coral death is climate change: Ocean water becoming incresaingly acidic as it absorbs larger amounts of carbon dioxide from the atmosphere, according to researchers.