Latest news with #LudwigMaximilianUniversity
Yahoo
17-05-2025
- Science
- Yahoo
Scientists Recreated The Ancient Chemical Reactions That May Have Sparked Life
Life on Earth probably began in warm, underwater 'chemical gardens', rich in hydrogen and iron. Researchers from Germany have now simulated this environment in a vial, and found that archaic life forms that live in the deep sea today can thrive under these primordial conditions. It's difficult to imagine how life kicked off on our planet. In ecosystems today, life is so deeply entwined with itself that very few creatures live directly off Earth's raw materials. That has been the case for a very, very long time. But the first organisms on an otherwise lifeless planet would have had to make do with what the mineral environment had to offer. There was little to no oxygen, and no photosynthesis. As you can see in the video below, some deep sea organisms still live this way, surviving on hydrothermal vents at depths where the sun don't shine. Borrowing electrons from hydrogen as it spews from the Earth's core, the deep-sea microbes follow a recipe more ancient than the genes they use to conduct it, called the acetyl CoA pathway. It is the only method for carbon fixation – processing inorganic carbon into organic compounds – that can be re-created without enzymes. But when this recipe was first written, in Earth's early years, seawater contained a whole lot more dissolved iron than it does today. A team led by geochemist Vanessa Helmbrecht of Ludwig Maximilian University of Munich in Germany wanted to test how much of a difference this dissolved iron would have made, by simulating these ancient ocean conditions in the lab. "The ancient occurrence of hydrothermal iron-sulfide rich deposits in the geological record extend into the early Archaean eon (4 to 3.6 billion years ago) and exhibit fossil features interpreted as some of the oldest signatures for life on Earth," the team writes in their paper describing the experiment. "However, links between abiotic H2 [dihydrogen] production in iron-sulfide chemical gardens simulating [primordial] hydrothermal systems and early life are scarce." A single-celled microbe of the order archaea, Methanocaldococcus jannaschii, was selected as the test subject for these simulations. It was first collected from a hydrothermal vent off the western coast of Mexico, where, using the acetyl CoA pathway, it relies on carbon dioxide and hydrogen as its primary sources of energy. "Abiotic H2 was a potentially important electron donor and CO2 served as a key electron acceptor for the first cells," the team explains. "Anaerobic organisms that use the H2-dependent reductive acetyl CoA pathway for CO2 fixation are modern representatives that have preserved vestiges of the first metabolisms." The experiments placed M. jannaschii into a miniature version of the deep sea hydrothermal vents, neatly contained in a glass vial. By injecting sulfidic fluid into water devoid of dissolved oxygen, they formed a black precipitate that grew into a chimney structure within 5-10 minutes. At high temperatures, the iron and sulfur in this microcosm formed the iron sulfide minerals mackinawite (FeS) and greigite (Fe3S4). When iron sulfide is hydrated, H2 is released. Though quite different from its modern home, M. jannaschii thrived in this strange environment. "At the beginning, we expected only slight growth, as we did not add any extra nutrients, vitamins, or trace metals to the experiment," Helmbrecht says. "As well as over-expressing some genes of the acetyl CoA metabolism, the archaeans actually grew exponentially." The M. jannaschii cells tended to hang out right beside the mackinawite particles, in a scene much like some of the earliest traces of life found in fossil specimens. These chemical gardens, the scientists think, fuelled Earth's first microbes. This is evidence that the recipe for acetyl CoA metabolism emerged from the extreme and energy-limited environments where Earth life may have struck its first sparks. "Our study points to mackinawite and greigite chemical gardens as potential hatcheries of life, primordial environments that could theoretically support a continuous evolution of the first metabolizing cells," the authors conclude. The research is published in Nature Ecology & Evolution. Mystery of T. Rex's Debated North American Origins Finally Solved Wild Chimps Appear to Administer 'First Aid' to Each Other Scientists Discover Oldest Reptile Tracks, Rewriting Evolution Timeline
Observer
01-04-2025
- Politics
- Observer
Myanmar quake could have built up over 200 years
MUNICH: Decades — and possibly two centuries — of subterranean tension preceded the powerful earthquake that struck South-East Asia last Friday, German geophysics professor Martin Käser said. On Tuesday, the ruling military junta reported that the death toll has reached at least 2,719, with more than 4,500 injured and hundreds still missing. The quake's ability to bring down a Bangkok high-rise more than 1,000 km from its epicentre in Myanmar is likely attributed to the soft clay on which the Thai capital is built, according to Käeser, who heads the geophysical risk department for Munich Re reinsurers. The quake occurred along the most prominent fault line in Myanmar, the Sagaing Fault. "This fault runs through the entire country in a north-south direction. The magnitude at 7.7 was one of the highest ever recorded in Myanmar," he said. The Indian plate in the west and the Eurasian plate in the east collide here. According to Käser, they move past each other horizontally, the eastern part from north to south and the western in the opposite direction. "These plates move past each other at a constant rate of around 2 centimetres per year," Käser said. "The tension that had built up between these two plates was unleashed at one stroke by the large quake," he said. The displacement came to around 5 or 6 metres "depending on the precise point one considers," the professor at Munich's Ludwig Maximilian University said. "It could be that tension built up therefor as much as 200 years," he added. The rupture started near Mandalay in the centre of Myanmar, spreading largely southwards. This meant that the movement of the earth in the south was considerably greater than that in the north. Bangkok lies in this direction more than 1,000 km from Mandalay. A second factor behind the collapse of the building according to the geophysicist is that the Thai capital is built on extremely loose soil. The Chao Phraya River has deposited sediment reaching several hundred metres in thickness over millennia, according to Käser. "And when this mass begins to oscillate, the amplitude of the soil movement increases. And this presumably led to the fact that Bangkok has also recorded severe damage," he said. Low-frequency waves with an oscillation period of between 1 and 2 seconds spread considerably further than high-frequency oscillations, he says. "When these low-frequency waves run into loose material as in Bangkok, there will be strong oscillations even at distances of up to1,000 km." — dpa
Yahoo
01-04-2025
- Politics
- Yahoo
Geophysicist: Myanmar quake could have built up over 200 years
Decades - and possibly two centuries - of subterranean tension preceded the powerful earthquake that struck South-East Asia last Friday, German geophysics professor Martin Käser told dpa. On Tuesday, the ruling military junta reported that the death toll has reached at least 2,719, with more than 4,500 injured and hundreds still missing. The quake's ability to bring down a Bangkok high-rise more than 1,000 kilometres from its epicentre in Myanmar is likely attributed to the soft clay on which the Thai capital is built, according to Käeser, who heads the geophysical risk department for Munich Re reinsurers. The quake occurred along the most prominent fault line in Myanmar, the Sagaing Fault. "This fault runs through the entire country in a north-south direction. The magnitude at 7.7 was one of the highest ever recorded in Myanmar," he said. The Indian plate in the west and the Eurasian plate in the east collide here. According to Käser, they move past each other horizontally, the eastern part from north to south and the western in the opposite direction. "These plates move past each other at a constant rate of around 2 centimetres per year," Käser said. "The tension that had built up between these two plates was unleashed at one stroke by the large quake," he said. The displacement came to around 5 or 6 metres "depending on the precise point one considers," the professor at Munich's Ludwig Maximilian University said. "It could be that tension built up there for as much as 200 years," he added. The rupture started near Mandalay in the centre of Myanmar, spreading largely southwards. This meant that the movement of the earth in the south was considerably greater than that in the north. Bangkok lies in this direction more than 1,000 kilometres from Mandalay. A second factor behind the collapse of the building according to the geophysicist is that the Thai capital is built on extremely loose soil. The Chao Phraya River has deposited sediment reaching several hundred metres in thickness over millennia, according to Käser. "And when this mass begins to oscillate, the amplitude of the soil movement increases. And this presumably led to the fact that Bangkok has also recorded severe damage," he said. Low-frequency waves with an oscillation period of between 1 and 2 seconds spread considerably further than high-frequency oscillations, he says. "When these low-frequency waves run into loose material as in Bangkok, there will be strong oscillations even at distances of up to 1,000 kilometres."
Yahoo
14-02-2025
- Yahoo
Munich police: Suspected vehicle attack injured at least 36
The number of victims in the suspected vehicle attack in Munich on Thursday is now known to be at least 36, including a number with serious injuries, Munich police announced at a press conference on Friday. Two of the victims in the attack suffered very serious injuries, including a young child, Munich police official Christian Huber said. A 2-year-old girl being treated at the Hauner Children's Hospital in Munich was in a critical condition in intensive care, a hospital spokesman had previously said. Police believe that a 24-year-old man intentionally drove his car into a trade union rally near Stiglmaierplatz in Munich's city centre. The man, an Afghan citizen who arrived in Germany as an asylum seeker and was in the country on a valid residency permit, was quickly apprehended by police officers who had been accompanying the rally and is being held in custody. A total of 14 injured people were treated at the Ludwig Maximilian University (LMU) Hospital's two facilities. Some patients were seriously injured and four had to be operated on immediately.
