Latest news with #eLife
The Hindu
2 days ago
- Science
- The Hindu
‘Magical' new technique brings very dilute samples into focus
Scientists use a powerful technique called cryo-electron microscopy to see the 3D shapes of biological molecules, but it normally needs the molecules to be extremely concentrated in a sample first. But for rare molecules this is hard to achieve. In a new study, researchers in the U.S. have created a workaround called Magnetic Isolation and Concentration cryo-electron microscopy (MagIC for short). It lets researchers sidestep the limitation and study samples 100x more dilute than before. The findings were published in eLife in May. The new method works by attaching molecules of interest in a sample to 50-nm beads, then using a magnet to clump the beads together. This way each micrograph ended up with several usable images even when the solution had less than 0.0005 mg/ml of the molecules. Because the beads were easy to spot even at low magnification, the scientists could quickly move the microscope to regions rich in particles, speeding up data collection. Small particles often hide in background noise. To pull them out, the authors built a computer workflow called Duplicated Selection To Exclude Rubbish (DuSTER). It picked each particle twice, kept those that landed in the same place after two rounds of 2D or 3D classification, and threw the rest away. Thus MagIC lowers the sample demand to just 5 nanograms per grid while DuSTER rescues clear classes from seemingly hopeless images.
Time of India
01-05-2025
- Science
- Time of India
IISc scientists find a new brain region for property-based visual tasks
SP Arun, Georgin Jacob and Pramod RT BENGALURU: Researchers at the Indian Institute of Science ( IISc ) have identified a specific brain region that appears to play a crucial role in how humans solve visual tasks based on properties rather than features—such as spotting an odd one out, telling if two objects are the same, or detecting symmetry. The study, led by Georgin Jacob, RT Pramod and SP Arun and published in eLife, introduces the concept of 'visual homogeneity' — a measure of how uniform or repetitive elements in an image are — as a decision variable that the brain may use to tackle a wide range of visual problems. Unlike conventional visual tasks that rely on identifying specific features (such as colour or shape), property-based tasks involve comparing the structure or layout of items. 'You might not know what the odd object looks like, but you can still spot it because the rest of the scene looks uniform,' said Georgin Jacob, the first author of the team from the Centre for Neuroscience at IISc. To test their hypothesis, the researchers ran a series of experiments combining behavioural data and brain imaging. In one set, participants were shown arrays of objects and asked whether a unique 'oddball' item was present. In another, they judged whether a shape was symmetric. Crucially, these tasks were performed while their brain activity was being recorded using fMRI. The team found that response times in both tasks could be predicted using a single computational principle: the 'distance' of a display from the centre of a perceptual space—what they call visual homogeneity . Displays with more repetition (i.e. higher homogeneity) were associated with faster or slower responses, depending on the task. For instance, in symmetry detection, more homogeneous images (symmetrical ones) produced shorter response times, and during oddball search, arrays without a target produced shorter responses. What stood out was that this measure also mapped onto brain activity. The researchers identified a localised region, just anterior to the lateral occipital cortex, that was activated by visual homogeneity in both visual search and symmetry tasks. This region, referred to as VH (for Visual Homogeneity), showed little correlation with overall task difficulty or response time, suggesting it was selectively encoding this specific visual property. 'This is possibly the first evidence that such a general-purpose visual computation—homogeneity—has a dedicated brain area,' said Prof Arun. The study also showed that visual homogeneity could explain performance in 'same-different' tasks and even object categorisation, hinting at its broader relevance in visual cognition . Importantly, the authors note that visual homogeneity does not fully determine how we perform such tasks but likely serves as an early-stage cue that guides our attention. The model offers a falsifiable framework for understanding a class of visual reasoning problems that are challenging for both humans and machine vision systems. 'We are excited for future studies exploring how visual homogeneity is computed from sensory representations and used for decision making', said Pramod RT from the team. The findings open up possibilities for studying how such computations develop and vary between individuals. They may also aid in refining machine vision algorithms by incorporating principles of perceptual homogeneity.
Indian Express
28-04-2025
- Health
- Indian Express
Five myths about reversing grey hair you need to stop believing
The internet is filled with quick fixes and bold claims, and one trending topic is reversing grey hair. Countless methods are touted as miraculous solutions to restore your natural hair colour online. But how many of these remedies are actually effective? Dr Jagadish Hiremath, public health intellectual, tells 'With countless claims circulating online about reversing grey hair naturally, it is crucial to approach such information critically.' Can grey hair truly be reversed naturally, or are these claims largely unfounded? 'The reversal of grey hair is highly unlikely in most cases,' notes Dr Hiremath. Grey hair results from the depletion of melanocytes, the cells responsible for producing melanin, which gives hair its colour. As melanin production decreases due to aging or genetic factors, hair loses its pigmentation. This process is considered irreversible under normal circumstances. However, there are exceptions, as stated by Dr Hiremath: Reversible Causes: Grey hair caused by stress, nutritional deficiencies, or illness can sometimes regain pigmentation if the underlying issue is resolved. For instance, a study published in eLife (2021) showed that removing chronic stress partially restored pigment in some individuals' hair. Permanent Greying: Age-related or genetic greying involves irreversible damage to melanocyte stem cells, making natural reversal impossible. 'The biology of hair greying underscores its permanence in most cases, as melanocyte depletion is rarely reversible,' the doctor highlights. Some myths regarding reversing grey hair online Dr Hiremath describes the myths regarding reversing grey hair that he has come across online: Myth 1: Onion juice can reverse greying Debunked: There is no credible evidence supporting the idea that onion juice can restore melanin production. A review in Dermatology Practical & Conceptual (2020) highlights that onion juice has no proven effect on pigmentation. Myth 2: Coconut oil and lemon juice can restore hair colour Debunked: While these may condition hair, there is no biochemical pathway linking coconut oil or lemon juice to melanin restoration. There is no credible evidence supporting the idea that onion juice can restore melanin production. (Source: Freepik) Myth 3: Collagen supplements prevent greying Debunked: While collagen supports hair structure, it does not influence melanin production or reverse greying. Claims suggesting otherwise lack scientific backing. Myth 4: Avoiding shampoo prevents greying Debunked: Shampoo has no impact on the melanocytes in hair follicles. This is misinformation spread by influencers promoting 'natural' lifestyles. Myth 5: Eating certain herbs restores hair pigment Debunked: No herb has been proven to regenerate melanocytes. Claims around 'miracle herbs' are anecdotal and unverified. Dietary changes or supplements that have a significant impact on grey hair While diet can support hair health, Dr Hiremath stresses that reversing greying isn't possible through food or supplements. However, certain nutrients may delay its progression, he says: Vitamin B12: Supports melanin production, found in meat, fish, eggs, and fortified cereals. Copper: Essential for melanocyte function, found in nuts, seeds, and shellfish. Antioxidants: Combat oxidative stress, found in berries, green tea, and spinach. Iron: Supports hair pigmentation, found in lentils, red meat, and leafy greens. Zinc: Supports hair follicle health, found in nuts, seeds, and seafood. Caution against misinformation: Dr Hiremath asserts, 'Many social media influencers promote false claims about reversing grey hair, leading to wasted time and money. Rely on peer-reviewed research and accredited professionals instead of unverified miracle cures. Greying is natural, driven by genetics and age, and while stress or deficiencies may accelerate it, no solution can fully reverse it. Prioritise a healthy lifestyle and credible scientific advice.'
Yahoo
17-04-2025
- Science
- Yahoo
Finland finds its first giant virus
Many viruses measure just tens of nanometers (nm) in size, but that's not always the case. In some rare instances , so-called 'giant viruses' can grow to as much as 1,000 times larger than their relatives. But despite the terrifying name, giant viruses aren't necessarily any more dangerous than a standard-sized species. And in Finland, researchers recently discovered the nation's first known example. Meet Jyvaskylavirus, a 200 nm diameter giant that's roughly two times bigger than influenza or coronavirus. Jyvaskylavirus is detailed in a study recently published in eLife, and named for Jyväskylä, the Finnish city where it was to researchers, the new species was discovered after mixing environmental samples with a culture of amoeba called Acanthamoeba castellanii. 'We elucidated the genome and structure of the Jyvaskylavirus, which was found to be related to Marseilleviruses previously isolated from France,' Lotta-Riina Sundberg, study co-author and University of Jyväskylä professor Lotta-Riina Sundberg, said in a statement on April 16. What makes Jyvaskylavirus particularly interesting to researchers is where it was found. So far, the majority of most known giant viruses so far have only been identified in Europe and South America. Finding a strain so far north leads the study's authors to theorize that giant viruses may be more widespread in soil and water than previously believed. Giant virus life cycles and spread are still not very well understood. That said, certain Arctic species have been shown to infect specific kinds of algae that are currently exacerbating the melting of Earth's polar ice caps. Because of their size, giant viruses also have exponentially larger genomes than their standard-sized counterparts—as many as 2.5 million base DNA pairs compared to the usual 7,000–20,000. While large, Jyvaskylavirus is still dwarfed by the biggest known example, Pandoravirus salinas (500 nm) Researchers hope further study of examples like Jyvaskylavirus will lead to a better understanding of the unique microscopic organisms. But while Jyvaskylavirus is Finland's first catalogued giant virus, Sundberg made clear it certainly isn't the last. 'Other new giant viruses were also detected in [our] environmental samples,' they teased.
New York Times
14-02-2025
- Science
- New York Times
Lasers, Waffle Fries and the Secrets in Pterosaurs' Tails
Above the shores of prehistoric seas and lakes, pterosaurs roamed the skies. They were feathered creatures that ranged in size from pigeons to planes, and the first vertebrates known to have been able to fly. And for millions of years, they had long tails ending in a prominent flap of skin called a vane. Paleontologists have long wondered about this strange appendage and its purpose. A team of scientists using a laser scanning technology have found new structures in four pterosaur fossils that helped keep the vane stiff, suggesting it aided maneuvering in flight. The study, published in December in the journal eLife, shows that 'even fossils that we knew and studied in detail for hundreds of years might have new things to show if you develop new technology to see them,' said Natalia Jagielska, a paleontologist at the Lyme Regis Museum in England and the paper's lead author. Dr. Jagielska, also a professional artist, became involved in the research after Michael Pittman, a paleontologist at the Chinese University of Hong Kong, approached her about illustrating a children's book. They teamed up to examine pterosaur fossils in collections in England and Scotland. After surveying over 100 pterosaur specimens, scientists picked four from the species Rhamphorhynchus, which often had diamond-shaped, kitelike tail vanes, for follow-up with laser-stimulated fluorescence. Dr. Pittman and Thomas G. Kaye, director of the Foundation for Scientific Advancement and an author of the study, have promoted the technique for exploring dinosaur-era remains and for archaeological investigations. The laser method makes use of how some minerals glow when electrons absorb and then re-emit light. As a laser passes over the fossils, long-exposure digital photography captures hidden features that stand out Pictures from the first pterosaur specimen they scanned showed a lattice structure in the tail vane. For Dr. Pittman, this was 'a ta-da moment.' 'It looks like the kind of crisscross on a waffle fry,' he said. 'But that structure in engineering is a reinforcing structure.' The 'struts' of this lattice could have been beneficial to flight, Dr. Jagielska said. They would 'tense up when you have a gust of air, similar to a sail in a ship, and that probably reduces the flutter' and might have helped the pterosaur in 'making turns,' she said. Scientists say the primary function for the vane still could have been social display, like a peacock's tail feathers are a signal to attract mates. In that vein, the vane most likely had prominent colors and patterns that are not preserved in the fossil record, Dr. Pittman said. Even so, like a modern billboard, the 'display surface' needed support structures, which this study reveals in pterosaurs for the first time, Dr. Pittman said. Had the vane fluttered unfettered, it would have been 'extremely costly and simultaneously useless as a visual signal,' said Michael Habib, a pterosaur flight expert at the University of California, Los Angeles, and an author of the study. The result is a significant advancement in the study of pterosaurs, said Andrea Cau, a paleontologist in Italy who was not involved in the study. He noted that one of the pterosaur fossils had not shown any soft-tissue details using other techniques but that the laser fluorescence had brought them out. 'Given the rarity of soft-tissue remains in paleontology, even just a single new fossil makes the difference,' he said. Future studies of pterosaur tails may illuminate 'just how good was this structure as a rudder or as a stabilizer,' said Scott Persons, a paleontologist at the College of Charleston in South Carolina who was not involved in this study. Given that different pterosaurs had differently sized vanes, more research may also show whether that variation had to do more with optimizing flight or 'fashion.' Dr. Jagielska would like to explore why the long tails with vanes disappeared in pterosaurs by the start of the Cretaceous period, about 146 million years ago. Further laser scanning may also bring out other characteristics important to pterosaur flight. A better understanding of their anatomy could even inspire airborne vehicles someday. 'If they were so efficient that they could live for hundreds of millions of years, they probably are doing something right,' Dr. Jagielska said.
