Scientists turn Starlink into a giant scanner for Earth’s upper atmosphere

 The region surrounding Earth is getting more crowded as thousands of satellites and pieces of space debris move through low Earth orbit. Farther above, at altitudes of several hundred kilometers, traces of Earth's upper atmosphere can still exert enough drag to slow satellites. Accurately measuring atmospheric density at these heights is therefore important for forecasting satellite motion and reducing the risk of collisions.

More than 99 percent of the upper atmosphere consists of electrically neutral gas known as the thermosphere. The term thermospheric density refers to the density of this neutral atmosphere between about 100 and 1000 kilometers above Earth's surface. By comparison, the ionized gas of the ionosphere accounts for less than 1 percent of the atmosphere. Because ionized gas affects the way radio waves travel, the ionosphere is relatively straightforward to observe. Measuring conditions in the thermosphere is much more difficult.

A New Way to Observe the Thermosphere

Better measurements of thermospheric density could advance research into the upper atmosphere while also providing valuable information for space engineering. Motivated by both needs, researchers at Kyoto University developed a new technique for visualizing this difficult-to-observe region.

"This is a multidisciplinary study between space science and space engineering," says corresponding author Mamoru Yamamoto. "Reading papers from both research fields, we realized that deeper dialogue between researchers from both fields is necessary."

The researchers used publicly available orbital information from Starlink satellites and applied tomography, a technique commonly associated with medical imaging, to Earth's upper atmosphere. By examining atmospheric drag through the gradual decay of satellite orbits, the team estimated thermospheric density around approximately 1,200 satellites flying at an altitude of 482 kilometers.

Building a Two-Dimensional Atmospheric Map

Using those measurements, the researchers produced a two-dimensional latitude-longitude snapshot of thermospheric density at an altitude of roughly 500 kilometers. According to the team, this represents the first tomographic analysis of its kind.

The resulting density patterns also showed strong consistency with observations from the European Space Agency's SWARM satellites, which measure changes in atmospheric density along their orbital paths.

The work expands on an earlier study by the same team. In that research, scientists estimated how thermospheric density changed over time and altitude using general orbital information called Two-Line Element, or TLE, data from Starlink satellites. The new analysis adds another dimension by examining how density varies horizontally across latitude and longitude, revealing more of the thermosphere's geographic structure.

Making Crowded Orbits Safer

The findings could have practical benefits as the number of objects orbiting Earth continues to grow. More accurate information about atmospheric density can improve predictions of satellite motion, helping reduce the chance of collisions between satellites and between satellites and space debris.

The technique could also eventually support near-real-time measurements of atmospheric density around satellites. Such monitoring could improve space weather forecasting and contribute to safer, more dependable satellite operations in the future.

Source: ScienceDaily

The Atlantic Ocean can handle more warming than expected — with one big catch

 For years, climate scientists have warned that the Atlantic Meridional Overturning Circulation (AMOC) could eventually shut down if global temperatures rise too far. New findings from researchers at Utrecht University suggest that temperature alone does not determine the fate of this major ocean circulation system. The speed at which the planet warms also appears to play a critical role in whether the AMOC remains stable. The study was published in the scientific journal Nature Climate Change.

The Atlantic Meridional Overturning Circulation, or AMOC, is a vast network of ocean currents that carries warm water northward from the tropics. By moving heat around the planet, it strongly influences the global climate and helps maintain the relatively mild conditions found in Western Europe.

Scientists have long viewed this Atlantic 'heat engine' as a system that could cross a tipping point. If that happened, the AMOC could transition from its current strong circulation to a much weaker state within decades. Possible triggers include growing amounts of meltwater entering the ocean from polar regions as well as global warming itself.

Rethinking the AMOC Temperature Threshold

Researchers previously estimated that the AMOC could reach a tipping point and collapse at around +4°C of global warming. Scientists at the Institute for Marine and Atmospheric research Utrecht now say that this temperature threshold does not tell the whole story.

"Our results show there is not necessarily a fixed temperature beyond which the AMOC inevitably collapses," says lead author René van Westen. "The stability of the circulation depends on how fast the climate is changing."

The findings indicate that two worlds reaching the same eventual temperature could experience very different outcomes for the AMOC depending on how quickly the warming occurred.

Slow Warming Versus Fast Warming

To test the importance of warming speed, Van Westen and his colleagues ran two versions of a climate model. In both simulations, atmospheric CO2 increased gradually, but the rate of that increase differed substantially.

In one simulation, CO2 concentrations increased slowly (0.5 ppm per year). In the second, they climbed much more rapidly (2.5 ppm per year), which is comparable to today's rate.

The contrast produced dramatically different results. When warming occurred slowly, the AMOC remained stable well beyond +4°C and did not collapse even after warming reached +5°C. Under the faster warming scenario, however, the AMOC collapsed at around +2°C.

"We deliberately looked at a scenario that is much slower than what we're experiencing today," explains co-author Reyk Börner. "That allowed us to isolate the effect of the warming rate alone, independent of how warm it eventually gets."

Why the Ocean Needs Time to Adapt

The researchers say the difference comes down to the ocean's ability to respond to changing conditions.

"Under slow warming, the entire ocean, from the surface down to its deepest layers, has time to gradually reorganize and adapt to the changing conditions," says co-author Henk Dijkstra, professor of Dynamical Oceanography. "Under faster warming, the ocean simply can't keep up."

Slow climate change gives the ocean more time to adjust throughout its full depth. When temperatures rise more rapidly, those adjustments cannot happen quickly enough, leaving the circulation more vulnerable to instability.

A Critical Rate of Global Warming

According to the researchers, the critical warming rate is around 0.3°C per decade. The world is already approaching that pace.

Van Westen compares the situation to driving a car: "If you're driving toward a wall, it makes sense to steer around it. To do that, you need to brake, otherwise you fly off the road. When it comes to global warming, the world is still pressing extra hard on the accelerator right now."

The analogy highlights an important distinction. Avoiding dangerous climate changes may depend not only on limiting how warm the planet eventually becomes, but also on slowing how quickly it gets there.

Previous Research on AMOC Stability

The same research group has investigated AMOC stability from several different perspectives in recent years.

In 2024, the researchers found that increasing amounts of meltwater entering the North Atlantic make the AMOC less stable. Scientists had suspected this mechanism for years, but the research was the first to demonstrate it using a modern, complex climate model.

Those results showed that a critical meltwater threshold exists, beyond which the AMOC becomes unstable. However, the threshold was unrealistically high. This suggests that the present-day AMOC is unlikely to become unstable through this contribution alone. That study did not include the effects of global warming or the pace at which warming occurs.

A later study explored several global warming scenarios. It concluded that the AMOC could reach a tipping point around 2060 under both an intermediate- and high-emission scenario. In those simulations, the tipping point occurred at approximately 2.5°C of global warming.

The latest research helps explain why studies can produce different estimates for when the AMOC might reach a tipping point, as well as why temperature thresholds vary across climate models and emissions scenarios.

The AMOC does appear to have a critical threshold for meltwater, but the researchers find no universal temperature threshold for its collapse. Instead, its stability depends partly on how quickly the planet warms. Faster warming leaves the AMOC more vulnerable, while slower warming gives the ocean more time to adjust and allows the circulation to remain stable under substantially higher levels of global warming.

What the Findings Mean for Climate Policy

The findings suggest that slowing the pace of warming could reduce the near-term risk of an AMOC collapse by giving the Atlantic Ocean more time to adapt.

That could have important implications for climate policy. Much of current climate policy, including the Paris Agreement, focuses on limiting the eventual peak in global temperature.

Some strategies involve so-called overshoot pathways. Under these approaches, global temperatures would temporarily rise beyond a target limit, with the expectation that future technologies could later reduce temperatures again.

The new findings suggest that the path taken toward a given temperature may matter alongside the temperature itself. The faster global warming occurs, the less time the Atlantic Ocean has to adjust, potentially increasing the vulnerability of one of the planet's most important circulation systems.

Source: ScienceDaily

Scientists detect a surprising shift in human blood as atmospheric CO2 rises

 Rising levels of carbon dioxide in the atmosphere may already be influencing human biology. New research has identified long-term changes in blood chemistry that appear to track rising atmospheric CO2, raising concerns that an important blood marker could approach the upper end of its healthy range within the next several decades.

The findings may be particularly important for children and teenagers. Because their bodies are still developing, younger generations are expected to experience the greatest lifetime exposure to elevated atmospheric CO2.

Decades of Blood Data Reveal a Shift

In a study published in Air Quality, Atmosphere and Health, scientists from The Kids Research Institute Australia, Curtin University and The Australian National University (ANU) examined more than 20 years of U.S. population health data. They found persistent changes in several measures of blood chemistry that closely followed the upward trend in atmospheric CO2.

The researchers used information from the U.S. National Health and Nutrition Examination Survey (NHANES), analyzing blood test results from roughly 7,000 people at two-year intervals between 1999 and 2020.

Since 1999, average serum bicarbonate levels have increased by about 7 percent. Bicarbonate is a blood marker closely associated with carbon dioxide in the body. During the same period, average levels of calcium and phosphorus decreased.

Those biological trends occurred as atmospheric CO2 climbed from about 369 parts per million (ppm) in 2000 to more than 420 ppm today.

Study author Associate Professor Alexander Larcombe said the results indicate that the body may already be adjusting to changes in the composition of the atmosphere.

"What we're seeing is a gradual shift in blood chemistry that mirrors the rise in atmospheric carbon dioxide, which is driving climate change," A/Prof Larcombe said.

How the Body Responds to More CO2

Bicarbonate is essential for regulating the body's acid-base balance. As CO2 increases, the body can retain additional bicarbonate to help keep blood pH stable. Although this response helps preserve that balance, maintaining it over long periods could have physiological effects.

"If current trends continue, modeling indicates average bicarbonate levels could approach the upper limit of today's accepted healthy range within 50 years," A/Prof Larcombe said

"Calcium and phosphorus levels could also reach the lower end of their healthy ranges later this century."

Humans evolved when atmospheric CO2 concentrations were approximately 280 to 300 ppm. During the past decade, atmospheric levels have risen by an average of about 2.6 ppm each year, while 2024 alone saw an increase of 3.5 ppm.

Fellow Author Dr Phil Bierwirth, a retired environmental geoscientist affiliated with the ANU Emeritus Faculty, emphasized that the study does not establish a direct cause-and-effect relationship. However, he said the consistency of the changes across a large population warrants attention.

"I actually think that what we are seeing is because our bodies are not adapting," Dr Bierwirth said.

"It appears we are adapted to a range of CO2 in the air that may now have been surpassed.

"The normal range maintains a delicate balance between how much CO2 is in the air, our blood pH, our breathing rate and bicarbonate levels in the blood.

"As CO2 in the air is now higher than humans have ever experienced, it appears to be building up in our bodies. Maybe we can never adapt such that it is vitally important to limit atmospheric levels of CO2."

A Potential New Dimension of Climate Risk

The researchers say the results suggest that rising atmospheric CO2 could represent a form of climate-related risk that is different from more familiar threats such as heatwaves, extreme weather and sea-level rise.

According to A/Prof Larcombe, increasing CO2 may need to be considered not only as an environmental concern, but also as a long-term public health factor that should be monitored.

"We're not saying people are suddenly going to become unwell when we cross a certain threshold," he said.

"But this suggests there may be gradual physiological changes occurring at a population level, and that's something we should be monitoring as part of future climate change policy."

The researchers recommend monitoring the composition of the atmosphere together with biological markers across populations. Tracking both alongside established climate indicators could help scientists determine how slow environmental changes affect human biology over periods of decades.

Source: Science Daily

Scientists discover a hidden brain rhythm that could improve Parkinson’s treatment

 Deep brain stimulation (DBS) can reduce movement problems caused by Parkinson's disease, and new research is providing a clearer picture of why the treatment works. Scientists have found that its benefits appear to depend on stimulating a specific brain network that communicates primarily through a relatively fast beta rhythm (20 to 35 Hz).

The findings come from an interdisciplinary group of neuroscientists and clinicians at the University Hospitals of Cologne and Düsseldorf, Harvard Medical School and Charité Berlin. Published in the journal Brain, the study, 'The Deep Brain Stimulation Response Network in Parkinson's Disease Operates in the High Beta Band', is the first to bring together two approaches that have largely been studied separately: electrophysiology and brain imaging.

Pinpointing Where and How Brain Stimulation Works

"For the first time, we were able to characterize the DBS response network in Parkinson's disease in terms of space and time, simultaneously," says Professor Dr. Andreas Horn from the University of Cologne, who led the study and specializes in computational neurology. "We show that Parkinson's disease can best be treated if we stimulate a very precisely defined network. This network operates synchronized within a specific frequency band, and offers an explanation for how well patients respond to deep brain stimulation."

Deep brain stimulation of the subthalamic nucleus is already an established therapy for easing motor symptoms in people with Parkinson's disease. The treatment uses implanted electrodes to deliver small electrical pulses to areas located deep inside the brain.

Previous research has provided only part of the picture. Brain imaging studies have helped identify the locations where stimulation appears to work most effectively, while electrophysiological research has measured the frequencies of the electrical signals involved. Until now, researchers had not captured both the spatial location and timing of these signals at the same time.

Mapping a Parkinson's Brain Network

To investigate this connection, the team studied a large multicenter group consisting of fifty patients and one hundred brain hemispheres. The scientists simultaneously recorded brain activity through the implanted DBS electrodes and with magnetoencephalography (MEG).

Using these recordings, they mapped functional connections between regions deep within the brain and areas closer to its surface.

Their analysis revealed that the important network connecting the subthalamic nucleus with frontal areas of the brain communicates largely at a comparatively fast frequency (20-35 Hz). Importantly, the strength of this connection was associated with how much individual patients' motor symptoms improved following electrode implantation.

Source; ScienceDaily

Cardiologist reveals 9 simple ways to lower cholesterol without statins

 Somewhere along the way, high cholesterol stopped sounding like a problem and started sounding like a given, one more number everyone expects to go up with age. Maybe that’s why statins, the go-to drug for lowering it, have become the best-selling prescription in the US, taken by nearly 30 million people each year.

But cholesterol itself was never the villain. It’s a fat our bodies rely on, to build cells, make vitamin D, and produce hormones like oestrogen and testosterone. The danger lies in imbalance: when LDL, the so-called “bad” cholesterol, begins to outpace HDL, the “good” one that helps clear it from our arteries. Those invisible buildups quietly narrow blood vessels, setting the stage for heart disease and stroke long before symptoms appear. According to NHS guidelines, total cholesterol should stay below 5 mmol/L, with healthy HDL levels above 1.0 for men and 1.2 for women. Still, medication isn’t the only route.

Dr Ali Khavandi, a consultant interventional cardiologist at Sulis Hospital, tells The Telegraph, “In the modern world though, high cholesterol is most commonly lifestyle-related and you can smash that through dietary and lifestyle changes.”

Eat good fats, rather than ‘low fat’

Cutting saturated fat (butter, processed meats, pies, cookies) is still key, but replacing it with single-ingredient, unsaturated foods makes the difference. Think oily fish, nuts, seeds, olives and avocados rather than heavily processed “low-fat” products. Study published in The New England Journal of Medicine show that diets enriched with extra-virgin olive oil or mixed nuts lower cardiovascular risk compared with low-fat advice, supporting the idea that swapping to quality fats improves heart outcomes.

A daily glass of tomato juice

Some studies show that a tomato-heavy diet can lower LDL and help raise HDL, likely because lycopene, the tomato’s dominant antioxidant, binds to LDL and helps prevent its oxidation. In one study published in Food science and Nutrition, participants who had unlimited access to unsalted tomato juice saw significant drops in LDL and blood pressure; other short trials have found that even days or weeks of concentrated tomato juice can measurably change lipid markers. Drinking a glass of unsalted or freshly made tomato juice (or using tinned tomatoes in cooking) is an easy way to boost lycopene intake.

Have porridge for breakfast

Oats contain beta-glucan, a viscous soluble fibre that forms a gel in the gut and binds cholesterol, reducing how much is absorbed into the bloodstream. Study published in British Journal of Nutrition showed consistent LDL reductions with oat β-glucan, adding oats to your morning can lower LDL in a matter of weeks.

Get your plant sterols naturally

“Plant sterols and stanols are molecules that are similar in size and shape to cholesterol, so they almost ‘compete’ with it,” says Dr Khavandi. When we eat them and they are absorbed from the intestine into the blood, they will be preventing some of the cholesterol from being absorbed instead. Broccoli, cauliflower and avocado are all rich in sterols, while stanols are found in peanuts, almonds and sunflower seeds.

Add more beans

Don’t base meals around starchy carbohydrates like pasta, sugary cereal, baked potatoes and white bread. Refined carbs can spike blood sugar and raise LDL and triglycerides; swapping in pulses, beans, chickpeas, lentils, gives you low-saturated-fat meals that are high in fibre, especially soluble fibre that traps cholesterol and helps eliminate it.

Skip the snacks (or choose nuts)

Evidence is mixed but promising: time-restricted eating (for example, eating within a 10-hour window consistently) has been associated with reductions in LDL and triglycerides in some studies, and a large umbrella review found intermittent fasting can lower waist circumference, LDL and triglycerides across multiple trials. If you can’t give up snacking, replacing crisps and sweets with whole nuts, almonds, for example, has been shown in randomized trials to lower LDL and improve vascular function.

Reduce alcohol intake

Studies show alcohol raises fasting and postprandial triglycerides and, in heavier drinkers, increases LDL and total cholesterol; even moderate drinking raises triglycerides for many people. If you’re trying to lower lipids, cutting back on daily alcohol is one of the faster, measurable changes you can make.

Source: The Times of India

Why diabetes patients should eat onions: Study shows they slash blood sugar and cholesterol

 Type 2 diabetes affects millions of people worldwide and is characterised by persistently high blood sugar levels caused by insufficient insulin production from the pancreas. Managing this condition often requires a combination of medication, diet, and lifestyle changes. Recent research indicates that a common kitchen vegetable, the onion (Allium cepa), may offer additional benefits for diabetes management. A study presented at The Endocrine Society’s 97th annual meeting found that onion extract, when administered alongside the antidiabetic drug metformin, significantly reduced blood sugar by up to 50 percent in diabetic rats. The extract also lowered total cholesterol, suggesting that including onions in daily meals could support blood sugar and heart health naturally. Take a look...

Diabetes-friendly benefits of onions and how to include them

Onions may help regulate blood sugar levels, support cholesterol management, and improve overall metabolic health. They are low in calories but may increase metabolic rate and appetite, making them a healthy addition to meals. Diabetes patients can include onions in various ways:

• Raw in salads or sandwiches for a crunchy, flavorful addition
• Cooked in soups, stir-fries, or curries to enhance taste and nutrients
• Grilled or roasted as a side dish
• Blended into sauces or dips for everyday consumption

Cholesterol-lowering effects

In addition to reducing blood sugar, onion extract also lowered total cholesterol levels in diabetic rats. The higher doses of 400 mg/kg and 600 mg/kg produced the most significant reductions. This dual benefit on both blood sugar and cholesterol positions onions as a promising dietary supplement for managing metabolic and cardiovascular health in people with diabetes.

ncorporating onions regularly can complement existing treatments like metformin and provide a simple, cost-effective way to support diabetes management naturally. While more research is needed to confirm these effects in humans, onions could provide a simple, affordable, and effective dietary addition for diabetes patients. Incorporating onions into daily meals may help manage blood sugar levels, lower cholesterol, and support overall metabolic health while complementing medications such as metformin. Even small dietary changes, like adding onions daily, can have long-term health benefits. This makes onions not just a flavor enhancer, but also a potential natural ally in diabetes care.

Source: The Times of India

Stop eating these fruits if you have kidney failure and high potassium

When your kidneys are healthy, they quietly deal with extra minerals in the body without you needing to think about it. Potassium, for example, comes from many everyday foods, and the kidneys simply filter out what you do not need. Things change when the kidneys begin to fail. They cannot remove potassium properly, so the mineral builds up in the blood and may reach unsafe levels. This can affect how your muscles move and how your heart beats. Many people feel confused at first because fruits are usually seen as healthy, yet some of them can cause trouble if your kidneys are not working as they should.
A peer-reviewed study in PMC looking at chronic kidney disease and potassium management explains that high potassium can be dangerous in advanced kidney failure and that limiting high potassium foods becomes important when blood potassium rises. The research highlights why people with kidney failure and high potassium need clear guidance on which fruits to reduce or avoid.

Worst fruits for kidney failure and high potassium levels
Potassium is essential for health, but in kidney failure the body struggles to get rid of extra amounts. When the level becomes too high, it may lead to hyperkalaemia, a condition that can cause tiredness, muscle weakness and, in more serious cases, heart rhythm problems. Some fruits contain very high potassium in small portions, which means even regular snacking can push levels up without you noticing. Below are fruits that are commonly restricted when someone has kidney failure and high potassium.

Bananas and kidney failure with high potassium
Bananas often top the list because they pack a lot of potassium in one serving. A single medium banana can be more than someone with kidney failure should eat in one go. If bananas are a regular part of your breakfast, this habit might raise your potassium slowly over time. You may be advised to avoid them entirely or only have very small pieces occasionally, depending on your blood test results.

Oranges, orange juice and kidney failure
Oranges feel harmless because of their vitamin C content, but the potassium level is high. Orange juice is even more concentrated, so a single glass can push your daily potassium intake far beyond what your kidneys can manage. Many renal diets recommend replacing oranges with lower potassium fruits such as apples or berries if potassium levels are already high.

Avocados and kidney failure potassium spikes
Avocados are creamy, versatile and popular in modern meals, but they are extremely high in potassium. Even a small portion can be too much for someone trying to limit this mineral. If you have been eating avocado toast often and your potassium is rising, this fruit might be contributing more than you think.

Avocados are creamy, versatile and popular in modern meals, but they are extremely high in potassium. Even a small portion can be too much for someone trying to limit this mineral. If you have been eating avocado toast often and your potassium is rising, this fruit might be contributing more than you think.

Source: The Times Of India