That Haunted Feeling May Be Caused by a Sound You Can’t Hear

By Frontiers, May 10, 2026

https://scitechdaily.com/that-haunted-feeling-may-be-caused-by-a-sound-you-cant-hear/

A mysterious force hiding in old buildings, basements, and even ventilation systems may be affecting people far more than they realize. Scientists studying infrasound, a deep vibration humans cannot consciously hear, found that exposure can still change mood and increase levels of the stress hormone cortisol.

 Credit: SciTechDaily.com

People exposed to infrasound may not consciously hear it, but they can show higher cortisol levels and increased irritability, which may help explain reports of “haunted” locations.

Infrasound refers to sound at very low frequencies, below 20 Hertz (Hz), a range that people usually cannot hear. It can be produced by natural events such as storms, as well as human made sources such as traffic. Some animals use infrasound for communication, while others move away from it. In a new study of whether people can sense infrasound, scientists found that although humans do not consciously detect it, their bodies still react, with exposure linked to greater irritability and higher cortisol levels.

“Infrasound is pervasive in everyday environments, appearing near ventilation systems, traffic, and industrial machinery,” said Prof. Rodney Schmaltz of MacEwan University, senior author of the article in Frontiers in Behavioral Neuroscience. “Many people are exposed to it without knowing it. Our findings suggest that even a brief exposure may shift mood and raise cortisol, which highlights the importance of understanding how infrasound affects people in real-world settings.

“Consider visiting a supposedly haunted building. Your mood shifts, you feel agitated, but you can’t see or hear anything unusual. In an old building, there is a good chance that infrasound is present, particularly in basements where aging pipes and ventilation systems produce low-frequency vibrations. If you were told the building was haunted, you might attribute that agitation to something supernatural. In reality, you may simply have been exposed to infrasound.”

Sound of the underground

The researchers recruited 36 people and asked each of them to sit alone in a room while either calming or unsettling music played. Half of the participants were also exposed to hidden subwoofers producing infrasound at 18 Hz. Afterward, they described how they felt, rated the emotional tone of the music, and said whether they believed infrasound had been present. They also provided saliva samples before and after the listening session.

Participants who had been exposed to infrasound showed higher salivary cortisol levels. They also reported feeling more irritable, less interested, and more likely to perceive the music as sad. Even so, they could not reliably tell whether infrasound had been playing.

“This study suggests that the body can respond to infrasound even when we can’t consciously hear it,” said Schmaltz. “Participants could not reliably identify whether infrasound was present, and their beliefs about whether it was on had no detectable effect on their cortisol or mood.”

“Increased irritability and higher cortisol are naturally related, because when people feel more irritated or stressed, cortisol tends to rise as part of the body’s normal stress response,” said Kale Scatterty, first author and PhD student at the University of Alberta. “But infrasound exposure had effects on both outcomes that went beyond that natural relationship.”

Felt but not heard

The results suggest that people can respond to infrasound without consciously recognizing it, though scientists still do not know exactly how this happens. The findings also raise questions about whether longer exposure could affect health by keeping cortisol elevated or by contributing to mood related problems such as irritability and reduced well being.

“Increased cortisol levels help the body respond to immediate stressors by inducing a state of vigilance,” said Prof Trevor Hamilton of MacEwan University, corresponding author. “This is an evolutionarily-adapted response that helps us in many situations. However, prolonged cortisol release is not a good thing. It can lead to a variety of physiological conditions and alter mental health.”

Because the study included a relatively small group of participants, the scientists performed sensitivity analyses before interpreting the findings. They confirmed that the study was capable of detecting moderate to large infrasound effects, including the main results. Still, larger and more diverse studies will be needed to understand how infrasound affects human emotion and behavior.

“This study was in many ways a first step towards understanding the effects of infrasound on humans,” cautioned Scatterty. “So far, we’ve only tested a specific frequency. There could be many more frequencies and combinations that have their own differential effects. We also only collected subjective reports of how the participants felt after exposure, without directly observing their responses during the trial.”

“The first priority would be testing a wider range of frequencies and exposure durations,” added Schmaltz. “Infrasound in real environments is rarely a single clean tone, and we don’t yet know how different frequencies or combinations affect mood and physiology. If those patterns become clearer, the findings could eventually inform noise regulations or building design standards. As someone who studies pseudoscience and misinformation, what stands out to me is that infrasound produces real, measurable reactions without any visible or audible source. So, the next time something feels inexplicably off in a basement or old building, consider that the cause might be vibrating pipes rather than restless spirits.”

The Life of Earth

https://chuckincardinal.blogspot.com/

Beavers Turn Rivers Into Powerful Carbon Sinks, Study Finds

By U. of Birmingham, May 10, 2026

https://scitechdaily.com/beavers-turn-rivers-into-powerful-carbon-sinks-study-finds/

Beavers are emerging as unlikely climate champions after scientists discovered their dams and wetlands can trap huge amounts of carbon dioxide. 

Credit: Shutterstock

Beavers are quietly turning rivers into powerful natural carbon traps.

Beavers may be far more important to the climate than previously thought. A new international study led by researchers at the University of Birmingham suggests these animals can transform river systems into powerful carbon dioxide sinks by reshaping wetlands and waterways.

Published in Communications Earth & Environment, the research is the first to calculate both the carbon dioxide (CO2) released and captured as a result of beaver activity in suitable wetland environments. The project involved scientists from the University of Birmingham, Wageningen University, the University of Bern, and several international partners. The study focused on a stream corridor in northern Switzerland that has experienced more than 10 years of beaver activity.

The researchers discovered that wetlands created by beavers stored carbon at rates up to ten times greater than nearby systems without beavers. During the 13-year study period, the wetland accumulated an estimated 1,194 tonnes of carbon, equal to 10.1 tonnes of CO2 per hectare annually.

Dr. Joshua Larsen, from the University of Birmingham and lead senior author of the study, said: “Our findings show that beavers don’t just change landscapes: they fundamentally shift how CO2 moves through them. By slowing water, trapping sediments, and expanding wetlands, they turn streams into powerful carbon sinks. This first-of-its-kind study represents an important opportunity and breakthrough for future nature-based climate solutions across Europe.”

How beaver dams trap carbon

Beavers have gradually returned to rivers and natural habitats across Europe after decades of conservation work. According to the researchers, these animals significantly change the way CO2 is stored, transported, and retained in headwater streams, which are the smaller upstream sections where rivers begin.

As beavers construct dams, they flood stream edges, create wetlands, redirect groundwater flow, and trap large amounts of both organic and inorganic material, including CO2. These changes reshape entire ecosystems and increase the amount of carbon stored in the landscape.

The findings suggest that restoring beaver populations in appropriate wetland areas could help capture and store large amounts of carbon while reducing the amount that returns to the atmosphere.

Beaver wetlands become long-term carbon sinks

To measure the full environmental impact, the researchers combined high-resolution hydrological data, chemical analysis, sediment sampling, greenhouse gas (GHG) monitoring, and long-term modeling. The result was the most detailed carbon budget ever created for a European landscape influenced by beavers.

The wetland acted as a net carbon sink, storing an average of 98.3 ± 33.4 tonnes of carbon each year. Scientists found this was largely driven by the removal and storage of dissolved inorganic carbon beneath the surface.

The study also revealed seasonal differences. In summer, falling water levels exposed more sediment, temporarily increasing carbon dioxide (CO2) emissions and turning the area into a short-term carbon source.

Across the full year, however, the buildup of sediments, vegetation, and deadwood led to substantial overall carbon storage. Researchers also found that methane (CH4) emissions, often a concern in wetlands, were extremely low and accounted for less than 0.1% of the total carbon budget.

Dr. Lukas Hallberg from the University of Birmingham and corresponding author of the study, said: “Within just over a decade, the system we studied had already transformed into a long-term carbon sink, far exceeding what we would expect from an unmanaged stream corridor. This highlights the enormous potential of beaver-led restorations and offers valuable insights into potential land-use planning, rewilding strategies, and climate policy.”

Beaver wetlands and climate change

As sediments and deadwood continue to build up in beaver-created wetlands, more carbon becomes locked away over time. The researchers found that these sediments contained up to 14 times more inorganic carbon and eight times more organic carbon than nearby forest soils. Deadwood from forests along riverbanks, streams, and wetlands (known as riparian forests) represented nearly half of all long-term stored carbon.

These carbon stores could remain stable for decades, suggesting that beaver-modified wetlands may function as dependable long-term carbon sinks as long as the dams remain intact.

Dr. Annegret Larsen, Assistant Professor in the Soil Geography and Landscape Group at Wageningen University, said: “Our research shows that beavers are powerful agents of carbon capture and adsorption. By reshaping waterways and creating rich wetland habitats, beavers physically change how carbon is stored across landscapes.”

Researchers estimate that if beavers recolonized all suitable floodplain areas in Switzerland, their wetlands could offset 1.2–1.8% of the country’s yearly carbon emissions. These climate benefits could occur naturally without direct human management or additional financial cost.

The study, led by the University of Birmingham, Wageningen University, the University of Bern, and international collaborators, examined a Swiss stream corridor that has supported beaver activity for more than a decade.

As beaver populations continue to grow, scientists say more research will be needed to better understand how these animals could influence future ecosystems and long-term carbon storage.

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Think the Real Fountain of Youth May Be Hiding in Your Gut

By B. Sullivan, Indiana U. May 10, 2026

https://scitechdaily.com/scientists-think-the-real-fountain-of-youth-may-be-hiding-in-your-gut/

New research investigates whether protecting or reshaping the gut microbiome could help people age more healthfully.

 Credit: Shutterstock

Scientists are uncovering surprising links between aging and the trillions of microbes living in the human gut.

Scientists are investigating whether the key to aging well may lie in the gut microbiome. Early findings suggest microbes could affect everything from inflammation to lifespan, opening new possibilities for future treatments.

People once searched for the Fountain of Youth, the mythical spring said to reverse aging. That quest has faded from legend, but some scientists are pursuing a modern version by studying whether the microbes in the gut can help explain healthy aging.

The gut microbiome is the vast community of microscopic organisms, including bacteria, fungi, and viruses, that live mostly in the colon. These microbes help digest food and produce molecules that can influence both the body and the brain. A person’s microbiome is shaped by many factors, including genetics, diet, environment, medications, and age.

The microbiome is the vast community of bacteria, fungi, viruses, and other microbes that live in and on the human body, especially in the gut, where they help regulate digestion, immunity, and overall health. 

Credit: Stock



I’m a microbiology professor and author of “Pleased to Meet Me: Genes, Germs and the Curious Forces That Make Us Who We Are,” which describes how the gut microbiome contributes to physical and mental health. As scientists have learned that the gut microbiome shifts with age, they have begun exploring whether one key to healthier aging may be hiding not in a mythical spring, but inside the gut.

You’re only as old as your gut microbes

People are most familiar with outward signs of aging, such as wrinkles and graying hair, but there are also microscopic changes taking place deep inside. The gut microbes of older people tend to be less diverse, with more bacteria that promote inflammation and other hallmarks of aging. Changes to the microbiome across age are so consistent that algorithms can reliably predict a person’s age based on their microbiome composition.

There are exceptions to this rule. Older adults and supercentenarians who age well have a gut microbiome that looks more like those of younger people. These findings support the idea that maintaining a youthful microbiome fosters healthy aging and longevity.

Regular physical activity may help reshape the gut microbiome in ways associated with better aging outcomes. 

Credit: Stock



To confirm that the microbes of youth influence aging, scientists use a technique called fecal microbiota transplantation. This procedure involves obliterating a person’s current gut microbiome and replacing it with microbes harvested from a donor’s feces. Transplanting microbiota from a young mouse into an elderly mouse reverses age-associated inflammation in the gut, brain, and eyes. Conversely, transplanting microbiota from an old mouse into a young one accelerates these aging parameters. Other studies suggest that microbiota from young mice alter metabolism in ways that reduce inflammation that accelerates aging.

The evidence that aging is linked with the microbiome is compelling. However, fecal transplantation is not without risk and is approved only as a last resort to treat severe C. difficile infections. These shortcomings have prompted researchers to search for safer and more refined ways to cultivate an age-friendly microbiome.

Diet and exercise may slow aging

Proper diet and exercise have long been tied to better aging and longevity. One way these lifestyle habits may be beneficial is through their influence on gut microbes.

What people eat – or fail to eat – has a demonstrable effect on their gut microbiomes. The standard American diet, enriched with ultraprocessed foods that are high in sugar, fat, and salt and low in nutrients and fiber, depletes microbiome diversity within days. Moving from a non-Western country to the U.S. is also associated with loss of gut microbiome diversity, partly due to dietary changes.

Lack of fiber is a major reason the microbiome adopts a configuration associated with poor aging. Studies in roundworms, mice, and rats found that fiber supplements improved overall health and extended lifespan by 20% to 35%. A 2025 study showed that increasing the amount of fiber in your diet is linked to as much as a 37% greater likelihood of healthy aging in women.

Fiber functions as a prebiotic, a nondigestible food component that nourishes the microbiome. Gut bacteria process fiber into compounds such as short-chain fatty acids that promote better aging by improving metabolic, brain, and immune function while reducing chronic inflammation. Good sources of prebiotics include most fruits and vegetables, whole grains, legumes, nuts, and seeds.

Certain foods, such as yogurt and kefir, or dietary supplements contain probiotics – living microbes that may benefit the gut microbiome. Research on probiotic foods and supplements is mixed, complicated by the variation in bacterial species and dosage in these products. The health benefits that different types of probiotics may confer is still under study.

Probiotic foods may support beneficial gut microbes, though researchers are still studying their long-term effects on aging. Credit: Shutterstock



Physical activity is also linked to a youthful microbiome. Regular exercise can reshape the microbiome of older adults to resemble those seen in younger adults. One study showed that when people ages 50 to 75 underwent 24 weeks of cardiovascular and resistance exercise, their microbiomes became populated by healthier bacteria and their blood had elevated levels of aging-friendly, short-chain fatty acids.

Treatments to manipulate the microbiome

Making healthy lifestyle changes is a noninvasive way to cultivate a youthful microbiome that may slow aging. Scientists are also exploring treatments to tailor the gut microbiome for better health outcomes.

One option may be postbiotics, nonliving but active compounds that probiotic microbes produce. For example, mouse studies have found that short-chain fatty acid supplements can improve age-related heart and lung problems. Similarly, elderly mice given heat-killed bacteria from a human infant saw reduced metabolic dysfunction and inflammation, as well as improved cognitive function.

The microbiome can also be modified with drugs, particularly antibiotics. A low-dose oral antibiotic can trigger gut bacteria to release factors that may promote good health and aging by, for example, strengthening the intestinal barrier or reducing inflammation. One such antibiotic, cephaloridine, extends the lifespan of roundworms and mice by triggering gut bacteria to make colanic acid, an anti-aging compound.

Bacteriophages, or phages, offer yet another potential way to manipulate the microbiome for health. Phages are highly selective viruses that infect and kill specific species of bacteria. Phages have been used to treat severe infections from bacteria resistant to antibiotics. Given that phages can alter the gut microbiome of mice, researchers are studying whether they could be used to eliminate gut bacteria associated with unhealthy aging.

Aging is a natural process that can bring many rewards. Cultivating a healthy microbiome could help people enjoy their golden years more fully.

The Life of Earth

https://chuckincardinal.blogspot.com/

Chuck's picture corner to May 10, 2026

It's been a cool week, a story of disaster and success. 

Still below avg. temps forecast for the next two weeks.

 I managed to unblock the drain in the basement with consistent efforts. It ran with a small whirlpool till all the water was gone, no more pumping required. 

 Secondly I managed to convince the rat family that had moved into the house to move along. Being near the corn processing factory close to the St. Lawrence and generally all along the river, rats are populous in the landscape.  I used glue traps, they seem to work fairly well, even when a rat escapes it leaves a bunch of fur behind after a lot of struggling. Moma rat didn't make it out her trap, nor one of the young ones. Two rats did escape with a lot of effort, not a sign for the past 2 days. Traps go into the now drying basement. The critters ate a pile of my pepper plant seedlings, a last straw for me.

sunrise this morning

Cherry blossoms

Yippee the second year the grafted cherry tree outside the office window is flowering. No cherries last year but I'm hopeful for this year.

Lots of viola in the lawn this spring, three colours from white to dark blue.

The Sun is still riding high at supper time.

the forget me nots are starting to bloom, they will be around for weeks before fading back into the lawn.

one of my favorite spirea beginning to leaf out.

the tulips almost ready to open

an interesting spring fungi, growing near one of the front flower circles.

the forsythia still going strong with no hot weather to stop it.

The rhubarb is coming along.

This current bush is going like crazy.

spring bulbs, just keep coming back year after year.

one of the fancier daffodils is finally opening.

A chick-a-dee's home.

road trip to pick up steel sheeting, the new siding for the back of the house.

driving the St. Lawrence is enjoyable every time.

late spring geese on the fly

the rats and mice sure process the compost bin fast, I put fresh compost in at least every second day all year round

The pear tree begins.

Elderberry

a wet part of lawn grows more moss than grass.

This monk's hood seems to enjoy it's spot in the yard.

Enjoy the Day

https://chuckincardinal.blogspot.com/

Ravens Don’t Follow Wolves, They Predict Them

By Max Planck Inst. of Animal Behavior, May 9, 2026
https://scitechdaily.com/ravens-dont-follow-wolves-they-predict-them/

Two ravens soar above a wolf pack in Yellowstone. This type of short-distance following is common, but prolonged following is extremely rare. 

Credit: Daniel Stahler / YNP

When wolves bring down prey in Yellowstone National Park, ravens often appear almost immediately. Long before the predators finish feeding, the birds gather nearby to grab scraps of meat. Their ability to locate fresh kills so quickly has puzzled observers for years, leading many people to assume that ravens simply follow wolves across the landscape.

Ravens Use Memory To Find Wolf Kills

A new study suggests the real explanation is far more impressive. After tracking ravens and wolves in Yellowstone for more than two years, researchers discovered that ravens rely heavily on memory. Instead of shadowing wolf packs over long distances, the birds remember places where wolves frequently make kills and return to those areas later.

“They can fly six hours non-stop, straight to a kill site,” says Dr. Matthias Loretto, the study’s lead author.

The findings, published in Science, indicate that ravens use spatial memory and navigation skills to search for food spread across large areas. According to Loretto, ravens do not need to stay close to wolves all the time because they can recall where food is most likely to appear. “Ravens can cover large distances by flying, and they seem to have a good memory, so they don’t need to constantly follow wolves in order to profit from the predators,” he says.

The project was led by the Research Institute of Wildlife Ecology at the University of Veterinary Medicine Vienna and the Max Planck Institute of Animal Behavior (Germany), along with several international partners, including the Senckenberg Biodiversity and Climate Research Centre (Germany); School of Environmental and Forest Sciences at the University of Washington (USA); and Yellowstone National Park (USA).

The team fitted ravens with GPS backpacks, seen here with antenna protruding. 

Credit: Matthias Loretto

Tracking Ravens and Wolves in Yellowstone

Researchers carried out the study in Yellowstone National Park, where wolves were reintroduced in the mid-90s after being absent for 70 years. About one quarter of the park’s wolves wear tracking collars each year, allowing scientists to monitor their movements.

Dr. Dan Stahler, a Yellowstone biologist who has studied the wolves since their return, says ravens often seem closely connected to the predators. “You see them flying directly above traveling packs or hopping close behind wolves as they take down prey.”

Because wolves regularly leave behind edible remains, scientists long believed ravens followed a simple strategy: stay near wolves to find food. “We all assumed that the birds had a very simple rule; just stick close to the wolves,” says Stahler.

However, nobody had thoroughly tested that idea before. “We didn’t know what ravens were capable of because nobody had ever put them at the center; nobody had taken the scavenger’s point of view,” he says.

https://www.youtube.com/watch?v=Qx2l4STmpKk&t=2s

GPS Tracking Reveals Raven Intelligence

To better understand raven behavior, the team fitted 69 ravens with tiny GPS tracking devices. Loretto describes that number as unusually high for this kind of research. Capturing the birds was difficult because ravens are highly observant and cautious around unfamiliar objects.

“Ravens are so observant of the landscape that they don’t step into traps easily,” says Loretto.

Researchers carefully disguised traps to blend into the environment. Near campsites, they even used trash and fast food as camouflage and bait. Otherwise, “the ravens would suspect that something was off and wouldn’t come near it,” Loretto explains.

The scientists also analyzed movement data from 20 collared wolves. During winter, when ravens most often interact with wolves, GPS locations were recorded every 30 minutes for ravens and every hour for wolves. Researchers also tracked the locations and timing of wolf kills involving prey such as elk, bison, and deer.

Ravens Remember Productive Hunting Areas

Over two-and-a-half years of monitoring, scientists found only one clear case in which a raven followed a wolf for more than one kilometer or longer than one hour.

“At first, we were puzzled,” says Loretto. “Once we realized that ravens are not following wolves over long distances, we couldn’t explain why the birds still arrive so quickly at wolf kills.”

A deeper analysis eventually revealed the answer. Ravens repeatedly traveled back to areas where wolf kills commonly occurred rather than directly trailing predators. Some birds flew as far as 155 kilometers in a single day, often along remarkably direct routes toward places where carcasses were likely to appear, even though the exact timing of a kill could not be predicted.

Researchers found that wolf kills often clustered in certain parts of the landscape, especially flat valley bottoms where wolves hunt more successfully. Ravens visited these areas much more often than places where kills rarely happened. This suggests the birds learn and remember long-term feeding patterns across the environment.

“We already knew that ravens can remember stable food sources, like landfills,” says Loretto. “What surprised us is that they also seem to learn in which areas wolf kills are more common. A single kill is unpredictable, but over time some parts of the landscape are more productive than others — and ravens appear to use that pattern to their advantage.”

What the Study Reveals About Animal Intelligence

The researchers believe ravens may still follow wolves over short distances in some situations. Nearby cues, including wolf behavior or howling, could help birds locate kills once they are already in the area.

“To find wolf kills locally, ravens likely use short-range cues, like monitoring wolf behavior or listening to wolf howling,” says Loretto.

Still, the broader pattern points strongly toward memory-based navigation. Ravens appear to decide where to search using knowledge gained from previous experiences, sometimes traveling across tens or even hundreds of kilometers.

Senior author Prof John M. Marzluff of the University of Washington says the findings reveal remarkable flexibility in raven behavior. “What our study clearly shows is that ravens are flexible in where they decide to feed. They don’t stay tied to a particular wolf pack. With their sharp senses and memory of past feeding locations, they can choose among many foraging opportunities far and wide. This changes how we think about how scavengers find food—and suggests we may have underestimated some species for a long time.”

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Discover Hidden Methane Source Beneath Every Major City

By V. Doon, City U. of Hong Kong, May 9, 2026

https://scitechdaily.com/scientists-discover-hidden-methane-source-beneath-every-major-city/

Methane is one of the most powerful drivers of global warming, yet scientists may have overlooked a major source hiding beneath cities worldwide. 

Credit: Stock

Scientists have discovered that urban sewers may be a surprisingly significant source of methane emissions.

Methane ranks behind carbon dioxide as the world’s second most important greenhouse gas. The Climate and Clean Air Coalition estimates that human-caused methane emissions are responsible for nearly 45% of current net warming, making methane a major driver of climate change.

Now, an international team led by a City University of Hong Kong (CityUHK) scholar has identified sewers as a previously underestimated methane source and created the first estimation tool designed for global use.

The researchers estimate that sewer systems release 1.18 to 1.95 million tons of methane worldwide each year. The finding suggests that wastewater management contributes more to greenhouse gas emissions and warming than previously recognized, and that sewer emissions should be included more accurately in climate accounting and reduction plans.

The 20-year research effort was led by Professor Yuan Zhiguo, Chair Professor of the School of Energy and Environment at CityUHK. The team included scholars from The University of Queensland, The Hong Kong Polytechnic University, Tianjin University, and Tongji University. Their study was recently published in Nature Water.

Led by Professor Yuan Zhiguo, Chair Professor of the School of Energy and Environment at CityUHK, the research lasted for 20 years. 

Credit: City University of Hong Kong



Sewers were wrongly overlooked

Urban sewers have often been treated as a negligible methane source because wastewater was thought to move through them too quickly for substantial methane formation, and because emissions from sewer networks are hard to measure and quantify. As a result, greenhouse gas inventories from the IPCC and many countries currently assume that methane emissions from urban sewers are zero.

Yet sewage contains large amounts of biodegradable organic matter, while oxygen-poor conditions are common inside sewer systems. Together, those factors can create an environment where methane can form.

A model built from pipes

Professor Yuan’s research team has long focused on new approaches for wastewater systems and environmental biotechnology. In 2008, the team developed the SeweX model, which simulates physical, chemical, and biological processes inside sewers, including the production of hydrogen sulfide and methane.

Because field data were limited for calibrating the methane prediction parts of SeweX, the team gathered measurements from sewer networks in Australia using a customized online sensor. Those data were used to calibrate and validate the model.

Using this innovative tool, the team estimates that global sewer systems emit approximately 1.18 to 1.95 million tons of methane annually. 

Credit: City University of Hong Kong

After calibrating SeweX, the researchers modeled nearly 3,000 pipeline scenarios with different structures and operating conditions. Their results showed that methane production in sewers is closely linked to the wetted surface of pipes. From that finding, they developed a simplified model that can estimate sewer methane emissions using information such as pipe size, slope, designed and actual average dry weather flows, and wastewater temperature.

The model was then tested against real-world data from 21 cities in Australia, the United States, China, and Belgium, leading to a comprehensive tool for estimating methane emissions from sewer systems.
Wastewater’s hidden climate cost

Using the new tool, the team estimated that sewer systems worldwide release about 1.18 to 1.95 million tons of methane each year. That would add 1.7% to 3.3% to current estimates of global methane emissions from the waste sector, and about 16% to 38% to the estimated overall carbon footprint of wastewater management.

Professor Yuan’s research team has been dedicated to developing innovative solutions for wastewater systems and environmental biotechnology.

 Credit: City University of Hong Kong



Professor Yuan remarked, “Our research confirms that sewers are not a zero-emission source; rather they represent a quantifiable source of methane emissions with significant global climate implications. As urban sewers continue to expand, their potential methane emissions will also increase. Therefore, including them in the greenhouse gas accounting system will help improve national greenhouse gas inventories and provide a new entry point for emissions reduction, further advancing the global goal of sustainable development.”

The Life of Earth

https://chuckincardinal.blogspot.com/

One Critical Factor Predicts Longevity Better Than Diet or Exercise, Study Finds

09 May 2026, By D. Nield

https://www.sciencealert.com/one-critical-factor-predicts-longevity-better-than-diet-or-exercise-study-finds

(rattanakun/Canva)

Diet and exercise are both factors that can influence how long you live, but they're not the single greatest predictor of your longevity, research suggests.

According to a recent study, there's something else that might have more of an effect in terms of curtailing your lifespan.

While poor sleep has been previously linked to a host of health issues, this latest investigation found that getting enough shut-eye had a stronger connection to living longer than diet and exercise – factors that are known to add years to your life.

Researchers from Oregon Health & Science University (OHSU) crunched the numbers on survey data from across the US, covering the years 2019 to 2025.

Measures of life expectancy were compared against self-reported evaluations of sleep duration, with less than seven hours per night considered a threshold for insufficient sleep.

They then factored in other variables that can affect life expectancy, including physical inactivity, employment status, and educational level. The association between insufficient sleep and lower life expectancy still held. Only smoking had a stronger link.

"I didn't expect [insufficient sleep] to be so strongly correlated to life expectancy," said OHSU sleep physiologist Andrew McHill.

"We've always thought sleep is important, but this research really drives that point home: People really should strive to get seven to nine hours of sleep if at all possible."

Life expectancy's association with sleep is stronger than with many other factors, including diet and exercise. Although, as this graph shows, physical activity and social connections also influence life expectancy. 

(McAuliffe et al., Sleep Adv., 2025)

As a purely observational study, the research, published in 2025, can't prove that less sleep knocks months or years off your life.

A study like this also can't untangle the complex interactions between sleep, diet, and exercise. The results do suggest the amount of sleep you get each night is a significant indicator of long-term health.

Adequate sleep is vital for almost every aspect of our well-being: missing a single night of slumber can impact brain circuitry and the body's immune system, for example.

It's not unreasonable to suggest that such health issues may contribute to mortality in the long run. In particular, the researchers highlight obesity and diabetes as two conditions linked with poor sleep that could reduce life expectancy.

"It's intuitive and makes a lot of sense, but it was still striking to see it materialize so strongly in all of these models," said McHill.

"Getting a good night's sleep will improve how you feel but also how long you live."

The good news is that our sleep routines are, at least to some extent, modifiable within the limits of our caregiving and work commitments.

It might be worth quitting that habit of doomscrolling in bed, or squeezing in a session of yoga or tai chi now and then.

Both the American Academy of Sleep Medicine and the Sleep Research Society recommend banking at least seven hours of sleep a night, although there is some evidence that you might be able to catch up on the weekends if you need to.

"This research shows that we need to prioritize sleep at least as much as we do what we eat or how we exercise," said McHill.

"Getting a good night's sleep will improve how you feel but also how long you live."

The Life of Earth

https://chuckincardinal.blogspot.com/

What Are You Actually Swallowing When You Take Probiotics?

09 May 2026, ByB. Langdon, The Conversation

https://www.sciencealert.com/what-are-you-actually-swallowing-when-you-take-probiotics

(Douglas Sacha/Moment/Getty Images)



Standing by the counter at the pharmacist waiting to pick up my prescription, I couldn't help noticing the prominent display of probiotics on the counter.

It was two years ago, and I was reading everything I could find on microbiomes and probiotics – whether in books, journals or in shops – in preparation for writing my book The Microbiome: What Everyone Needs to Know.

For days I had focused just on probiotics and here they were, temptingly in front of me, ready for me to buy.

The packaging was so glossy and it's claims so intriguing, I found myself picking up the box to see what they were saying.

"Supporting gut health." "Friendly bacteria."

I was about to get antibiotics for my tonsillitis. Should I get some probiotics? I'd heard they might help replace the "good" gut bacteria that antibiotics can wipe out.

The microbes in everybody's gut make up their individual microbiome.

 (Science Photo Library/Canva)



The pharmacist knew me by sight, partly because he had just looked down my throat and prescribed them for me and partly because I'm a local GP. He nodded encouragingly and pointed at the display.

"These are very popular," he said.

I turned the box over. The packaging did best when describing what it contained. Thirty capsules to be taken every day, each containing 5 billion live cultures.

I compared it with the others on the shelf. Some contained 2 billion, some 10 billion. One contained 25 billion bacteria per capsule. It was a huge number and a huge dosage range. Were these dosages safe?

It wasn't so clear on what live cultures were exactly, describing them variously as "trusted" or "friendly". Higher-dose brands described themselves as "diverse" or "powerful", sounding more like the boardroom of a Fortune 500 company than a dietary supplement.

When it came to what they did, things became vague. Apparently, probiotics are there to "complement your natural gut bacteria" or alternatively to "complement your everyday life".

It took a bit of time for the pharmacist to package up my medication and label it, so I carried on and read the small print.

Each brand was very confident in its ability to survive the stomach acid: they were also confident on the research. "Most researched live culture." "Highly researched strains." I had no difficulty in believing this, it was the lack of claims to efficacy that baffled me.

Finally, I found the actual ingredients. Each listed their various combinations of bacteria, some containing up to 15 different sorts, but always including several versions of lactobacilli and bifidobactera.

Lactobacillus acidophilus I knew as a bacteria needed to make yogurt. Bifidobacteria are also often used in the food industry. Both are typical residents of our guts, known to account for about 12% of our usual gut bacteria.

So why do probiotic products all seem to contain the same bacterial species? And why are their claims always so deliberately vague?

Almost one in 20 adults are taking probiotics: typically those of us with higher educational levels, higher incomes and better diets. If we just knew a bit more about microbes, would we still want to take them?

It is normal to consume a lot of bacteria on our food. Even with freshly washed or cooked food, on a typical day we consume 1.3 billion bacteria a day either on or in our food.

As soon as our food hits the stomach, our high levels of stomach acid kill or injure almost all the bacteria we consume. Only a few ever reach the colon and those few probiotic bacteria that survive usually only ever stay a few days.

But to swallow a probiotic capsule containing 25 billion, is 20 times the number of bacteria our body is used to handling: a huge microbial load. Even "friendly" probiotic bacteria can cause a serious infection if they get in the wrong place, such as the blood stream.

It's true that most people can manage this huge microbial load fine because of our innate gut defence systems. But probiotics should be avoided by those with weak immune systems, who may be less able to keep these bacteria contained and are at higher risk of them spreading and causing infection.

The reason that out of all the millions of bacteria available in the world, probiotic brands always home in on exactly the same microbes is because these are all bacteria that are known to be safe or used in the food industry since before 1958.

If a microbe is officially designated "Generally Recognized As Safe", then the producer need undertake no further research. And if the producer then sticks to general claims of efficacy – what's known as a "qualified health claim", they don't even have to prove it works.

https://www.youtube.com/watch?v=qg2A5B70OVE&t=1s

Generally Recognized as Safe explained.

But even with no efficacy claims at all, the probiotic industry still seems to get its message across – and, as I handled the box of probiotics, I still had a strong feeling that this product was good for me, would make me healthier, and that I should buy it.

I held the box uncertainly. "Do you want these as well?" the pharmacist asked.
I checked the price: £17.99 for 30 probiotic capsules (low dose) for something I already had inside me from eating ordinary food. I decided to stick to the antibiotic prescription only, for £9.90.

So, do probiotics work?

I have learned to equivocate when asked this, because people who ask me – usually enthusiastically and with a smile – are invested in the concept of probiotics and have often already been taking them.

To avoid upsetting people I now usually say: "Well, they probably haven't done you any harm."

Apart from the cost.

Berenice Langdon, Senior Lecturer and Honorary Consultant, St George's, University of London

The Life of Earth

https://chuckincardinal.blogspot.com/

This Popular Supplement May Boost Your Brain, Not Just Your Muscles

By Taylor & Francis Group, May 8, 2026

https://scitechdaily.com/this-popular-supplement-may-boost-your-brain-not-just-your-muscles/

Creatine is best known for boosting athletic performance, but it also plays a key role in how the body produces energy. Research shows it can enhance strength and training capacity, and may even support brain function in certain groups. Scientists are now investigating its potential in areas like mental health and aging. 

Credit: Shutterstock

Creatine is often linked to gym performance, but its real impact goes much deeper.

Creatine is widely recognized as a supplement used by athletes and fitness enthusiasts to improve performance. But its effects extend beyond the gym. Scientists have been studying how this naturally occurring compound influences both physical and mental function, revealing a more complex picture than many people expect.

From supporting energy production to its possible role in future medical treatments, creatine continues to attract attention from researchers.

Dr. Mehdi Boroujerdi, a pharmaceutical researcher and former professor, conducted a detailed review of creatine in the Handbook of Creatine and Creatinine In Vivo Kinetics. His analysis helps clarify how creatine works and what current evidence suggests about its benefits.

How Creatine Works in the Body

Creatine is produced naturally in the liver, kidneys, and pancreas using amino acids such as glycine, arginine, and methionine.

After it is made, creatine enters the bloodstream and is delivered to tissues that require energy, especially muscle. About 95% of the body’s creatine is stored in skeletal muscle, while smaller amounts are found in the brain, heart, and other organs.

Within cells, creatine is converted into phosphocreatine (PCR), which plays a key role in restoring adenosine triphosphate (ATP), the body’s primary energy source.

This rapid recycling of ATP is essential for tissues that use large amounts of energy, including skeletal muscle, the heart, and the brain. It allows cells to continue functioning during periods of intense activity or stress, which explains why creatine has become so popular among athletes.

Once creatine has been used, it breaks down into creatinine. This waste product is filtered by the kidneys and eliminated through urine.

The body can only store a limited amount of creatine, and individual levels vary. As a result, responses to supplementation can differ from person to person.

Despite frequent claims online, creatine is not a steroid. “Creatine’s role in muscle development is solely to provide energy for contraction and respiration; it is certainly not a substitute for steroids,” Dr. Boroujerdi explains.

Creatine Supplement Benefits and Performance Effects

Creatine monohydrate is the most researched and commonly used supplement form.

Studies summarized in the book show that supplementation increases creatine and phosphocreatine levels in muscle. This supports faster ATP regeneration during short, intense bursts of activity, which can improve strength, sprint performance, and overall training capacity.

Creatine may also have effects beyond physical performance. Research suggests it could support cognitive function, including memory, mood, and processing speed, particularly in individuals with lower baseline creatine levels, such as older adults.

Scientists are also exploring whether creatine could play a role in managing conditions such as Parkinson’s disease, depression, and menopause related muscle and bone loss. While early findings are encouraging, more studies are needed before firm conclusions can be drawn.

“Creatine’s anti-inflammatory and antioxidant properties further underscore its promise in clinical settings, though more robust trials are needed to confirm these benefits,” he explains.

“With sufficient justification, appropriate dosage form, and dosing regimen, creatine may eventually be recognized as an over-the-counter therapeutic agent rather than merely a dietary supplement.”

Creatine Dosage and Absorption

A common supplementation strategy starts with a loading phase of 20 grams per day (split into four doses) for 5-7 days. This is typically followed by a maintenance dose of 3-5 grams per day.

“This approach rapidly saturates muscle creatine stores, but a lower daily dose of 3-5 grams can achieve similar saturation over a longer period (approximately 28 days),” Dr. Boroujerdi says.

Not all creatine that is consumed is absorbed by the body. Absorption depends on factors such as digestive stability and the capacity of muscle tissue to store creatine. Taking creatine with carbohydrates may improve uptake by increasing insulin-mediated transport.

Factors That Influence Creatine’s Effects

Research indicates that the effects of creatine can vary based on sex, age, and diet.

Men and women may respond differently due to differences in muscle mass and starting creatine levels. Women often have lower baseline levels, which may lead to greater relative improvements with supplementation.

Older adults may benefit from creatine’s potential to help preserve muscle mass, bone density, and cognitive function.

Vegetarians and vegans, who typically consume little creatine through their diets, often have lower baseline levels and may experience stronger responses to supplementation. However, dietary patterns vary, so individual results differ.

“There is a pressing need for well-designed research projects in humans, utilizing labeled creatine to generate relevant data and illuminate the grey areas of our knowledge about these compounds,” Dr. Boroujerdi explains.

Creatine is sometimes combined with other supplements, such as the amino acid beta-alanine, to enhance its effects. However, the effectiveness of these combinations varies, and more research is needed to determine optimal approaches.

Safety, Limitations, and What to Expect

Creatine is one of the most extensively studied dietary supplements and is considered safe for healthy individuals. Its potential uses continue to expand, but it is not without limitations.

“Despite its many benefits, creatine is not a magic bullet. It does not directly build muscle or replace the need for proper training and nutrition. Additionally, the belief that larger doses yield greater benefits is unfounded, as muscle creatine stores have a saturation limit. Excess creatine is simply excreted as creatinine, offering no additional advantage,” Dr. Boroujerdi says.

Concerns about side effects such as kidney damage have largely been dismissed in healthy individuals. However, people with existing kidney conditions should consult a healthcare provider before using creatine.

The benefits of creatine are not the same for everyone. Outcomes depend on baseline levels, dosage strategies and individual physiology.

“For now, creatine is best viewed as a supplement with significant potential, but not a panacea,” Dr. Boroujerdi says. “Whether you’re an athlete, a student, or simply someone looking to support your health, understanding the science behind creatine is key to making informed decisions.”

The Life of Earth

https://chuckincardinal.blogspot.com/