Latest news with #StockholmUniversity
The Hindu
17-07-2025
- Science
- The Hindu
Science for all Organic molecules survive in space thanks to energy release ‘valve'
Polycyclic aromatic hydrocarbons (PAHs) are flat, ring-shaped molecules of carbon and hydrogen. Astronomers think they make up a fifth of all carbon in interstellar space. There is a hypothesis that meteors brought PAHs from space to young earth and created the first building blocks of life, attaching important value to their ability to survive in space. In Taurus Molecular Cloud 1 (TMC1), small closed-shell PAHs — molecules whose electrons are in pairs — appear in greater quantities than theory predicts even though they are constantly exposed to starlight that should have destroyed them. This persistence has been a major puzzle of astrochemistry. Now, researchers from Australia, Sweden, and the UK have cracked it by studying the indenyl cation, C 9 H 7 +, a charged fragment of a PAH called indene (C 9 H 8 ). The team found that the ions have a mechanism to cool rapidly, letting them accumulate in TMC1 over time. The findings, published recently in Physical Review Letters, mean astronomers can refine their models of how PAHs grow from tiny fragments to eventually seed planets with prebiotic carbon. TMC1 is a collection of gas, dust, and plasma about 430 lightyears away. When PAHs collide with other particles or absorb high-energy radiation, they can have more internal energy than their weakest chemical bond can handle. If the molecule doesn't lose this energy, it will disintegrate. Previous research on open-shell PAH cations has shown that recurrent fluorescence — light emitted as the molecule's electrons jump repeatedly between ground and excited states — can allow the molecule to dump energy in steps. But C 9 H 7 + is a closed-shell PAH with a different electronic structure, so scientists weren't sure whether recurrent fluorescence could protect it. Stockholm University's DESIREE facility has a pair of ion-storage rings cooled to under –260° C. When an ion is injected into the ring, it can travel for many minutes without bumping into anything. The researchers injected C 9 H 7 + ions while they carried several electron-volts of vibrational energy. If a hot ion breaks apart, the neutral fragments fly out of the ring and hit a detector. By counting those neutrals over time, the team recorded how fast the ions were breaking way, the team found that the ions' characteristic cooling rate was noticeably higher than that reported for several PAH cations, indicating C 9 H 7 + possessed an efficient cooling mechanism. Then the team put together a model that juggled three competing ways in which the ion could lose energy: dissociation, the probability that a bond snapped; infrared emission, the rate at which the molecule could lose energy by shaking or twisting its bonds; and recurrent fluorescence. When the team ran simulations, it found that including recurrent fluorescence produced data closely matching DESIREE data. 'The net effect is that many of the PAHs — in particular the small ones, think less than 50 carbon atoms — can efficiently cool rather than decompose,' study coauthor and University of East Anglia associate professor James Bull said. 'These small ones are important as there has been a surge in their discovery in space over the last few years through radioastronomy observations.' From the Science pages Question Corner How does a digital barometer work? Find out here. Flora and fauna
Yahoo
10-07-2025
- Science
- Yahoo
The Bangladesh delta is under a dangerous level of strain, analysis reveals
Bangladesh is known as the land of rivers and flooding, despite almost all of its water originating outside the territory. The fact that 80% of rivers that flow through Bangladesh have their sources in a neighbouring country, can make access to freshwater in Bangladesh fraught. And the country's fast-growing cities and farms – and the warming global climate – are turning up the pressure. In a recent analysis, my colleagues and I found that four out of the ten rivers that flow through Bangladesh have failed to meet a set of conditions known as their 'safe operating space', meaning that the flow of water in these rivers is below the minimum necessary to sustain the social-ecological systems that rely on them. These rivers included the Ganges and Old Brahmaputra, as well as Gorai and Halda. This puts a safe and reliable food and water supply not to mention the livelihoods of millions of fishers, farmers and other people in the region, at risk. Water flow on the remaining six rivers may be close to a dangerous state too, due to the construction of hydropower dams and reservoirs, as well as booming irrigated agriculture. Get your news from actual experts, straight to your inbox. Sign up to our daily newsletter to receive all The Conversation UK's latest coverage of news and research, from politics and business to the arts and sciences. The concept of a safe operating space was devised by Stockholm University researchers in 2009 and typically assesses the Earth's health as a whole by defining boundaries such as climate warming, water use and biodiversity loss which become dangerous to humanity once exceeded. A 2023 update to this research found that six of the nine defined planetary boundaries have been transgressed. Since the Bangladesh delta is one of the world's largest and most densely populated (home to around 170 million people), we thought it prudent to apply this thinking to the rivers here. We found that food, fisheries and the world's largest intertidal mangrove forest, a haven for rich biodiversity, are all under strain from water demand in growing cities such as Dhaka. During all seasons but winter, river flows in the Bangladesh delta have fallen over the past three decades. Our analysis highlights the limits of existing political solutions. The ability of the Ganges river to support life and society is severely strained, despite the Ganges water sharing treaty between India and Bangladesh, which was signed in 1996. Rivers in Bangladesh have shaped the economy, environment and culture of South Asia since the dawn of human civilisation here. And humans are not the only species suffering. Hilsha (Tenualosa ilisha), related to the herring, is a fish popular for its flavour and delicate texture. It contributes 12% to national fish production in Bangladesh but has become extinct in the upper reaches of the Ganges due to the reduction of water flow. Excessive water extraction upstream, primarily through the Farakka barrage, a dam just over the border in the Indian state of West Bengal, has also raised the salinity of the Gorai river. A healthy river flow maintains a liveable balance of salt and freshwater. As river flows have been restricted, salinity has crept up, particularly in coastal regions that are also beset by sea level rise. This damages freshwater fisheries, farm yields and threatens a population of freshwater dolphins in the Ganges. Low river flows and increasing salinisation now threaten the destruction of the world's largest mangrove forest, the loss of which would disrupt the regional climate of Bangladesh, India and Nepal. It would also release a lot of stored carbon to the atmosphere, accelerating climate change and the melting of snow and ice in the Himalayan mountain chain. Solving this problem is no simple task. It will require cooperation across national boundaries and international support to ensure fair treaties capable of managing the rivers sustainably, restoring their associated ecosystems and maintaining river flows within their safe operating spaces. This is particularly challenging in the Bangladesh delta, which contains rivers that drain many countries, including China, India, Nepal and Pakistan. The political regimes in each country might oppose transboundary negotiations, which could nevertheless resolve conflict over water which is needed to sustain nearly 700 million people. There have been success stories, however. The Mekong river commission between Cambodia, Laos, Thailand and Vietnam is a useful template for bilateral and multilateral treaties with India and Nepal for the Ganges, and China and Bhutan for the Jamuna river. Tax-based water sharing can help resolve conflicts and decide water allocation between countries in the river basin. The countries using more water would pay more tax and the revenue would be redistributed among the other countries who share rivers in the treaty. Additionally, water sharing should be based on the historical river flow disregarding existing infrastructure and projections of future changes. Reducing deforestation, alternating land use and restoring wetlands could enhance resilience to flooding and drought and ensure water security in the Bangladesh delta. Ultimately, to secure a safe operating space for the rivers here is to secure a safe future for society too. Get a weekly roundup in your inbox instead. Every Wednesday, The Conversation's environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 45,000+ readers who've subscribed so far. This article is republished from The Conversation under a Creative Commons license. Read the original article. Md Sarwar Hossain does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Observer
09-07-2025
- Health
- Observer
Sweden's secret to well-being? Tiny urban gardens
On an unseasonably warm June morning in Stockholm, Stina Larsson, 98, stood among fragrant lilacs, lilies, and lavender, inspecting the garden that she has tended for more than 40 years. Rabbits had been nibbling the nasturtiums, she noticed, and some weeds needed pulling. Larsson's garden, situated on a postage stamp of land beside the Karlbergs Canal, is one of more than 7,000 garden allotments, known as koloniträdgårdar, in Stockholm. The gardens, established as part of a social movement around the turn of the 20th century, offer city dwellers access to green space and a reprieve from crowded urban life. Though most are modest in size — Larsson's garden is about 970 square feet — koloniträdgårdar are prized for providing a rare kind of urban sanctuary, a corner of the city where residents can trade pavement for soil and the buzz of traffic for birdsong. The garden programs were specifically designed to improve the mental and physical health of city dwellers, said Fredrik Björk, a lecturer at Malmö University who specializes in environmental history. 'The idea was that a working-class family would be able to spend the summer there and work together but also have some leisure and fun,' Björk said on the phone from his own koloniträdgård in Ärtholmen, a garden association in Malmö that dates back to the 1940s. 'In those days, there was lots of heavy drinking,' Björk said. But at the garden colonies, he said, 'Instead of drinking alcohol, you would grow potatoes.' The health benefits of gardening are well established, both for the physical activity and for the time spent in nature. Cecilia Stenfors, an associate professor of psychology at Stockholm University, said her research shows that those who frequently visit green spaces, whether a forest or a koloniträdgård, 'have better health outcomes, in terms of fewer depressive symptoms, less anxiety, better sleep and fewer feelings of loneliness and social isolation.' These positive effects can be particularly pronounced in older people and can help combat symptoms of age-related mental and physical decline. Maja-Lena Säfström, 80, who owns a cotton-candy-pink cottage in a garden association outside of Uppsala, said she had seen many wellness benefits from having a koloniträdgård. 'When you're in an apartment, you don't move much, but if you have a garden, you move around differently, and that makes you feel better,' she said. Garden associations can also help foster social connection, Säfström explained, giving residents a chance to meet other people with similar interests. Rising interest in koloniträdgårdar, particularly among younger Swedes, has led to an increase in prices in recent years. Björk said cottages in his association can sell for over 1 million Swedish kronor (about $105,000). In Stockholm, however, prices are regulated to help ensure the gardens remain affordable, said Katrin Holmberg, a board member of Stockholms Koloniträdgårdar. 'It's a great leisure activity for people; it's healthy, and you're outdoors a lot,' she said. 'I think the city understands that as well as the fact that it contributes to biodiversity in urban areas.' Stockholm residents who can't afford to buy their plot can still enjoy the benefits of the koloniträdgårdar, which are all open to the general public to enjoy. But for those who wish to own a garden of their own, the biggest obstacle, apart from the price tag, is availability. There are more than 50,000 plots across Sweden, but demand far outpaces supply. Eriksdalslundens Koloniträdgårdsförening, an association of 143 plots on the southern island of Södermalm that is among the most popular garden colonies in central Stockholm, has over 1,100 people on the waiting list. And the wait times can be incredibly long. One couple I spoke to, Bengt and Susanne Kopp, were on a waiting list for 17 years before they were finally able to buy a cottage in 2023. For many Swedes like the Eklundhs, a koloniträdgård is more than just a storybook cottage and thriving garden. It's also an active hobby with wide-ranging health benefits and a restorative escape from the city without ever needing to leave it. This article originally appeared in
Time of India
04-07-2025
- Health
- Time of India
Is it safe to drink rainwater? Scientists reveal the answer
As the monsoon season arrives in India, people across the country begin to store, use, or simply enjoy the rain and the refreshing feel of rainwater. Remember your childhood, standing in the rain with arms wide open, face tilted to the sky, mouth open to catch those cool drops straight from the clouds? It felt pure and magical. Tired of too many ads? go ad free now But is rainwater really safe to drink today? Environmental scientists say the answer is more complicated than it seems. While rainwater may look clean, it can contain pollutants like dust, ash, heavy metals from rooftops, or more concerning, invisible 'forever chemicals' that never break down and now appear even in the most remote rainwater samples worldwide. What are PFAS and why are they a concern? According to Dr. Ian Cousins, an environmental scientist at Stockholm University, PFAS (per- and polyfluoroalkyl substances) are a group of synthetic chemicals that have been used for decades in firefighting foams, non-stick cookware, food packaging, and water-repellent fabrics. These chemicals are known as 'forever chemicals' because they do not degrade naturally and persist in the environment for generations. In a global study co-authored by Cousins, Dr. Bo Sha, Dr. Jana H. Johansson, Dr. Martin Scheringer, and Dr. Matthew Salter, PFAS were detected in rainwater from regions as isolated as the Tibetan Plateau and Antarctica. Their findings indicate that due to widespread atmospheric contamination, rainwater across the planet may now contain PFAS levels that exceed safety guidelines set by the US Environmental Protection Agency (EPA). Health risks linked to PFAS exposure Only four PFAS compounds—PFOS, PFOA, PFHxS, and PFNA—have been extensively studied, yet these alone are linked to serious health risks. Dr. Cousins and his team note that elevated exposure to these chemicals has been associated with increased risks of thyroid disease, liver enlargement, high cholesterol, immune suppression, pregnancy complications, and even certain cancers. One particularly concerning effect is the reduced effectiveness of vaccines in children, a risk that prompted the EPA to drastically lower its recommended PFAS limits for drinking water. Tired of too many ads? go ad free now While the overall levels of these chemicals in the environment have not increased in recent years, their extreme stability means that they have remained above health advisory thresholds since the early 2000s and are unlikely to decline significantly for decades. What can be done and is rainwater still drinkable? When asked whether rainwater is safe to drink, Dr. Cousins and colleagues expressed caution. 'We are uncertain,' they wrote. While extremely low PFAS levels (in picograms or nanograms per liter) may not cause noticeable harm immediately, the cumulative risks remain. Current health advisories are based on precautionary principles designed to protect public health even in worst-case exposure scenarios. Although technologies exist to filter PFAS from water, removing them to levels below current safety standards is difficult and expensive. There is no way to eliminate PFAS from food, and they are present even in indoor dust. As Dr. Cousins emphasizes, 'Humans will have to live with some level of PFAS exposure,' but unnecessary uses must be restricted. The team concludes that all PFAS uses should be critically evaluated for essentiality. 'PFAS have no place in the natural environment,' said Dr. Martin Scheringer, co-author of the study, adding that policy must shift toward minimizing their spread and use wherever possible. The final takeaway So, is it safe to drink rainwater during this monsoon? Not without proper treatment. While it may feel nostalgic and pure, the reality is that even rain falling in remote corners of the world can carry microscopic chemical residues that could pose risks over time. Experts like Dr. Ian Cousins and his colleagues urge caution and suggest relying on filtered or regulated water sources for drinking, while pushing for global reforms in PFAS usage. The rain still brings joy but when it comes to your drinking water, science says it's better to be safe than sorry.
Medical News Today
27-06-2025
- Health
- Medical News Today
Alternative to GLP-1 drugs may treat diabetes, weight loss without muscle loss
A new study published by Swedish researchers shared results of the clinical trial of a new drug that aids weight loss in people with type 2 diabetes and obesity. The medication is taken orally and has a different method of activation compared to the popular GLP-1 drugs. The new drug works through skeletal muscle metabolism, which the researchers say preserves muscle mass during weight of people in the United States have type 2 diabetes and/or obesity. Many of the drugs that treat these often cause people to lose muscle mass. Muscle mass loss can cause a loss of strength and slow metabolism. Osteoporosis is also a concern when losing muscle mass, especially in older people. Researchers affiliated with the Karolinska Institute and Stockholm University, both in Sweden, have developed a new drug that treats type 2 diabetes and obesity without impacting muscle recently conducted an initial phase 1 clinical trial to determine how well humans tolerate the drug. The findings appear in the journal alternative aims to preserve muscle massGLP-1 drugs, including the popular semaglutide medications Ozempic and Wegovy, work by reducing hunger signals in the brain and slowing gastric emptying. While these drugs aid in weight loss, some studies have shown that they can reduce lean muscle mass by up to 60%. Swedish researchers developed a new drug in tablet form that activates metabolism in the muscles. In animal trials, it avoided the muscle loss side effect of GLP-1 drugs. Muscle tissue is metabolically active, so it burns more calories at rest than fat. When someone loses muscle during weight loss, this causes their resting metabolic rate to slow, which can make it tough to continue losing weight or maintain weight also helps regulate blood sugar by absorbing glucose from the bloodstream. Losing muscle can make blood sugar harder to control and worsen insulin new drug is based on a beta-2 molecule. Beta-2 medications can cause an increased risk for heart problems, but the researchers say the way they developed the new drug causes 'little or no increase' in cardiac lesions or hypertrophy. After conducting animal trials with the medication, researchers moved to their first trial involving humans to see how well they tolerated the medication. The trial consisted of 48 healthy people and 25 people with type 2 groups took the 2.5 mg tablet once daily for 28 days. The scientists tracked various health metrics from the participants including heart rate and blood tolerate the new drug wellBoth healthy participants and participants with type 2 diabetes were able to tolerate the drug well overall. The researchers noted that a side effect of the drug caused 'a mild and transient reflex-driven increase in heart rate' early in the trial. This side effect did not persist by day 28 of the trial, and the authors said there was no significant difference in the heart rate or blood pressure between the groups. The authors said one participant had a severe adverse event related to the drug. However, the researchers noted that it occurred in 'a patient with preexisting cardiac abnormalities that resolved without complications, and its connection to the study drug remains uncertain.' The participants all had plasma levels consistent with being at a therapeutic level for the medication at the end of the trial. The researchers found this reassuring since it showed that participants were taking the medication as prescribed and validated the heart metrics recorded. Since this phase of the trial was successful, the next step is a longer clinical phase 2 trial. This trial will see how the drug affects people with type 2 diabetes and/or obesity in terms of muscle mass, glucose levels, and insulin weight-loss drug shows promiseMir Ali, MD, a board certified general surgeon, bariatric surgeon, and medical director of MemorialCare Surgical Weight Loss Center, spoke with Medical News Today about the trial.'This seems to be a promising drug that could be a potential weight loss and diabetes medication,' said Ali, who was not involved in this noted that a clinical trial is needed comparing the medication to the GLP-1 drugs available. 'Often, the real-world results vary significantly from initial studies,' he pointed out. The doctor also touched on why a weight loss drug that does not cause muscle loss is so important:'Preserving muscle mass is important in any kind of weight loss; the goal is to lose fat and not muscle. Losing muscle leads to weakness and a slower metabolic rate; more muscle means more calories are burned, even at rest; therefore, anything that helps preserve muscle is important.'Maria Knöbel, MBBS, medical director of Medical Cert UK, similarly who was not involved in the recent research, also spoke with MNT about the trial results. Knöbel said that, with her patients who lose weight, she has noticed that 'a great decline in musculature levels occurs, and this increases their insulin resistance and further complicates their disease.''The trial of this drug is promising since it is a solution to this issue since it provides a means of losing fat without losing muscles,' she noted. 'The saving of muscle mass with weight loss in these patients would be instrumental to the long-term control of glucose and would lead to better outcomes concerning their diabetes treatment.'
