Category: 7. Science

Bluesky is increasingly emerging as a rival to X, and nowhere is that more evident than in the platform’s burgeoning scientific research community. According to a new study, Bluesky boasts higher interactive engagement and content originality for scholarly posts than X.

The research, conducted by the University of Sheffield in England and the Renmin University of China, claims to be the first large-scale analysis of scientific communication on Bluesky. The study—still awaiting peer review—found that scholarly activity on the platform has surged since November 2024, coinciding with a broader migration away from X toward alternative social media sites.

Bluesky was created in 2019, initially incubated under Twitter and became independent in 2021. Officially launching in 2023 under CEO Jay Graber, the platform has since grown to more than 38 million users. While its interface looks strikingly similar to X, Bluesky differentiates itself with a decentralized, open-source network that gives users more control and personalization.

The study analyzed more than 2.6 million Bluesky posts referencing scholarly content between January 2023 and July 2025. It found that posts, users and referenced articles have all been on an upward trajectory. In October 2024, for example, there were around 10,000 posts, 3,200 users and 6,500 referenced articles. By November, those figures had surged to 239,000, 35,000 and 54,000. They peaked in January of this year at 324,000 posts by 45,000 users referencing 71,000 unique articles.

Activity has since stabilized, with a slight decline. “The stabilization of posts, users and referenced articles suggests that Bluesky has already established itself as a credible and lasting platform for science communication, rather than a short-lived trend,” Er-Te Zheng, one of the study’s authors and a Ph.D. student at the University of Sheffield, told Observer via email.

Bluesky’s growth comes amid an exodus of X users dissatisfied with Musk’s leadership and changes such as loosened content moderation. A January poll by Nature found that more than half of 5,300 respondents—most of them scientists—said they had left X.

Those who have turned to Bluesky are showing higher levels of engagement. More than 48 percent of scholarly posts received at least 10 likes, while 34 percent were reposted at least 10 times. By contrast, previous research on X found that only 3.9 percent to 7.5 percent of scientific research posts received more than 10 likes, and just 1.4 percent to 4.4 percent received 10 reposts or more.

Bluesky also fosters more original content, as shown in the low number of posts that simply replicate a research paper’s title, the study found. Only 6.3 percent of the analyzed Bluesky posts contained nothing more than an article title. On X, title replication rates have been shown to range anywhere from 11. 8 percent to 92.4 percent, depending on various scientific disciplines.

Bluesky still pales in size compared to X, which Elon Musk claimed had around 600 million monthly active users as of May 2024. But the platform’s high levels of engagement and originality suggest it’s carving out a distinct niche. “This suggests that Bluesky users participate more actively and with greater originality in interactions around scholarly articles,” Zheng said.

Carbon dioxide levels in the atmosphere vary naturally between ice ages and interglacial periods. A new study by researchers at the University of Gothenburg shows that an unexpectedly large proportion of carbon dioxide emissions after the ice age may have come from thawing permafrost.

For a long time, it was the shifts between ice ages and interglacial periods that determined how much carbon dioxide was in the atmosphere. During ice ages, CO₂ levels fell, only to rise by around 100 ppm (parts per million) during interglacial periods. Previously, the main reason for this was thought to be that warmer and more mixed oceans cannot store as much carbon and therefore release it into the atmosphere between ice ages.

However, new research from the University of Gothenburg shows that thawing permafrost may have accounted for a significant proportion of carbon dioxide emissions.

“We have concluded that land north of the Tropic of Cancer, 23.5 degrees north, emitted a lot of carbon when the average temperature rose in the northern hemisphere after our last ice age. We estimate that this carbon exchange may have accounted for almost half of the rising carbon dioxide levels in the atmosphere,” says Amelie Lindgren, researcher in ecosystem science at the University of Gothenburg.

Carbon froze into the ground

Researchers believe that large amounts of carbon were stored during the Ice Age when grass and other plants simply froze into the ground, with wind-borne rock dust settling on top. Such deposits, known as ‘loess’, are created during ice ages and can reach tens of metres in thickness. They are found across large areas of Europe and Asia, but also in North America.

Permafrost is required for the trapping of organic material in these deposits, and even normal soil with permafrost contains more organic carbon than unfrozen soil because the cold slows decomposition rates.

Pollen analyses

By combining analyses of pollen from the last 21,000 years with climate data from models, the researchers have been able to estimate the types of vegetation that existed in different places throughout history.

“We have chosen to take a snapshot every thousand years. Once we know what type of vegetation prevailed, we can estimate how much carbon were stored in the soil. In this way, we can model how carbon exchange between the soil and the atmosphere has looked since the last ice age,” says Amelie Lindgren.

Around 21,000 years ago, the continental ice sheets reached their maximum extent in the northern hemisphere. The whole of Scandinavia and what is now Canada were covered by ice at that time, and permafrost prevailed in large parts of Siberia, China and parts of central Europe. During the period 17,000–11,000 years ago, it became warmer. This led to the thawing of the permafrost, which resulted in increased emissions of CO₂ from the ground to the atmosphere.

Natural variation

Previous analyses of ice cores show that the carbon dioxide content in the atmosphere rose as follows:

* 180 ppm (parts per million) CO₂ 21,000 years ago, when the ice age reached its peak.

* 270 ppm CO₂ 11,000 years ago, during a normal interglacial period.

According to researchers, this is a natural variation between ice ages and interglacial periods. However, despite the shrinking ice sheet and continued thawing of new areas of permafrost, the carbon dioxide content did not rise much more after that.

‘We see that peatlands stored large amounts of carbon during the Holocene. Over time, the uptake in peatlands has actually compensated for the emissions that occurred from the permafrost,’ says Amelie Lindgren.

Humans disrupt the carbon cycle

However, over the past 250 years, humans have disrupted the natural carbon cycle by burning large amounts of fossil carbon, mainly coal and oil. Since the Industrial Revolution in the 19th century, the carbon dioxide content in the atmosphere has increased from 280 ppm to 420 ppm today.

“There are extremely high levels of carbon dioxide in the atmosphere right now, and the permafrost is thawing as temperatures rise. What helped us the last time the permafrost decreased was increased carbon storage in peatlands and new land areas becoming available when the continental ice sheets retreated. In the future, we will have less land due to sea level rise, and it is difficult to see where we will store the carbon that will be released, says Amelie Lindgren.

Footnote: The Holocene is the current geological epoch, which began approximately 11,700 years ago after the last ice age.

The half-lit moon will appear to skip past the red star Antares in the constellation Scorpius on the nights surrounding its first quarter phase on Aug. 30-31 this week.

On Aug. 30, skywatchers can spot the nearly half-lit moon hanging a little less than 20 degrees above the southwestern horizon at sunset. Antares will shine as a bright red point of light roughly 5 degrees to the upper left of the waxing moon. Remember, the width of your middle three fingers held at arm’s length is the equivalent of 5 degrees in the night sky, while your clenched fist accounts for approximately 10 degrees!

A new research paper was published in Volume 16 of Oncotarget on August 29, 2025, titled “In vivo manipulation of the protein homeostasis network in rhabdomyosarcoma.”

In this study led by first author Kristen Kwong and corresponding author Amit J. Sabnis from the Department of Pediatrics, Division of Oncology, University of California San Francisco, researchers discovered that disrupting the protein quality control system in cancer cells slows tumor growth in rhabdomyosarcoma (RMS), the most common pediatric soft tissue cancer. This finding points to a new strategy for treating high-risk childhood cancers that often resist current therapies.

Rhabdomyosarcoma is a rare and aggressive cancer that primarily affects children and adolescents. Standard treatments like chemotherapy and radiation often have limited long-term success in high-risk cases. This study explored a different approach: targeting the cellular machinery that maintains protein quality, known as the proteostasis network. Cancer cells rely heavily on this system to survive stress caused by rapid growth and genetic instability.

“To examine whether MAL3-101 or more drug-like proteostasis inhibitors represent a new therapeutic strategy for RMS, we screened proteostasis components that might recapitulate the effects of MAL3-101 in vivo.”

The researchers first used a compound called MAL3-101 to disrupt protein control in RMS cells. They then identified which parts of the protein quality system were affected. Based on those findings, they searched for more drug-like compounds that could target the same pathways. 

They focused on a protein called p97, which plays a critical role in removing damaged or misfolded proteins. When they blocked p97 using a drug called CB-5083, the cancer cells could no longer manage internal stress and began to self-destruct. In both laboratory models and mice implanted with human RMS tumors, the treatment significantly slowed or stopped tumor growth. The drug triggered a stress response in the cells known as the unfolded protein response, which can lead to either recovery or programmed cell death.

However, not all tumors responded the same way. Some resisted the treatment by activating a backup system called autophagy, which allows cells to recycle parts of themselves under stress. By comparing tumors that responded well to those that did not, the researchers found that higher autophagy activity could serve as a warning sign for resistance. This insight may help identify which patients are more likely to benefit from therapies that target protein quality control.

While the results are promising, the drug’s effectiveness depended on the tumor’s genetic profile and how it handled stress. Combining p97 inhibition with other treatments or blocking alternative survival pathways like autophagy may improve outcomes. The researchers also noted the importance of developing safer and more targeted drugs to reduce side effects.

This study opens new possibilities for personalized cancer treatment, particularly for children with aggressive or relapsed RMS. By weakening the systems that cancer cells depend on to survive, rather than only using toxic treatments to kill them, scientists aim to develop more effective and less harmful therapies for young patients.

These succulents got a glow up from researchers in China who injected the plants with inorganic phosphor particles (Matter 2025, DOI: 10.1016/j.matt.2025.102370). The science behind the glow is the same as in many paints and stickers found in children’s rooms the world over: Light puts the material into an excited state, and then energy is slowly released as a glow that can last for hours.

Researchers have made glow-in-the-dark plants before, for example, by adding bioluminescent pathways from mushrooms into plants. You can even buy green-glowing petunias based on that technology in the US. But these new glowing house plants come in a much wider variety of colors because chemists have developed a wide range of phosphor materials over the years.

The succulents were made by a team of researchers, led by Xuejie Zhang at South China Agricultural University, who realized that the plants’ compact microstructure and abundant intercellular spaces are ideal for injection with glow-in-the-dark microparticles. The researchers patented their technology and hope that it could lead to living light features in the future.

Credit: Matter 2025, DOI: 10.1016/j.matt.2025.102370

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Teeth are just one factor that put some shark species at the top of the ocean food chain. They can be razor sharp, and number in the hundreds in one shark’s mouth alone. They fall out and grow back at rates that are absolutely fascinating. Unlike us, sharks have an endless supply of teeth. They lose them as frequently as every few days or weeks, and how fast they grow back is critical for species like bull sharks, for example, that can have as many as 300 teeth filling up a dozen rows.

But those chompers might be in trouble, says research published this week by a group of German scientists, suggesting ocean acidification threatens those all-important teeth. In short, it could impact tooth regrowth negatively and prevent them from growing back at a rate that keeps up with how fast they fall out.

“As shark tooth roots are not protected by soft tissue, unlike in mammals, they are naturally exposed to surrounding water. This exposure makes them especially susceptible to pH-induced degradation, notably in the osteodentine-rich regions,” the researchers explained in the new study.

To test the impact, the researchers kept 60 teeth from black tip reef sharks that had recently fallen out and placed them in artificial seawater tanks. One tank matched the ocean’s current average pH of 8.1, another had water with 7.3 pH, which is an acidification level projected for the year 2300. After eight weeks in those tanks, the teeth in the tank with increased acidification levels showed “increased root corrosion … and altered serration.”

“The damage we observed to enameloid and dentin layers underlines that even the typically more crystalline components of shark teeth are not immune to acidification,” the scientists wrote in conclusion. “Degradation of the crown structure could compromise the mechanical properties of teeth, especially in regions involved in prey capture and processing. Increased serration, while potentially beneficial for cutting efficiency, might lead to structural weakness and higher susceptibility to breakage.”

“It will be interesting to see in future studies if the damage to teeth seen in studies like this one results in a functional effect on a tooth’s ability to do its job … [and if] damaged teeth can still cut or puncture prey,” Lisa Whitenack, a professor at Pennsylvania’s Allegheny College told The Guardian.

Stars are initially powered by the fusion of hydrogen to helium. These ashes serve as fuel in a series of stages, transforming massive stars into a structure of shells. These are composed of natal hydrogen on the outside and consecutively heavier compositions inside, predicted to be dominated by He, C/O, O/Ne/Mg and O/Si/S. Silicon and sulfur are fused into iron, leading to the collapse of the core and either a supernova explosion or the formation of a black hole Stripped stars, in which the outer hydrogen layer has been removed and the internal He-rich or even the C/O layer below it is exposed, provide evidence for this shell structure and the cosmic element production mechanism it reflects. The supernova types that arise from stripped stars embedded in shells of circumstellar material (CSM) confirm this scenario. However, direct evidence for the most interior shells, which are responsible for producing elements heavier than oxygen, is lacking. Here we report the discovery of the supernova (SN) 2021yfj resulting from a star stripped to its O/Si/S-rich layer. We directly observe a thick, massive Si/S-rich shell, expelled by the progenitor shortly before the supernova explosion. Exposing such an inner stellar layer is theoretically challenging and probably requires a rarely observed mass-loss mechanism. This rare supernova event reveals advanced stages of stellar evolution, forming heavier elements, including silicon, sulfur and argon, than those detected on the surface of any known class of massive stars…

Nature: Extremely stripped supernova reveals a silicon and sulfur formation site

Diamonds are the hardest mineral on Earth, useful in industry and sought after for their beauty. But for scientists, they also offer a window into the deep underground, giving us a glimpse into the mysterious processes that create and shape rock.

Binghamton University senior Kate Halpin had the opportunity to study diamond geochemistry this summer during an internship at Carnegie Science in Washington, D.C.

A love for the outdoors initially sparked the Long Island native’s curiosity about the world around her and the unseen processes that shape landscapes and rock formations. During her first year at Binghamton, she took a class with Associate Professor Alex Nikulin on earthquakes and volcanoes that proved transformative.

“I realized that it was something I wanted to pursue. The more I learn about geology, the more I’m curious about it,” explained Halpin, a geology major.