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Evolution in a test tube: These bacteria survive on deadly copper surfaces – Science Daily

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The descendants of regular wild-type bacteria can evolve to survive for a long time on metallic copper surfaces that would usually kill them within a few minutes. An international research team led by Martin Luther University Halle-Wittenberg (MLU) and the Bundeswehr Institute of Microbiology was able to produce these tiny survivalists in the lab and has been able to study them more closely. The team reports on its findings in Applied and Environmental Microbiology.

Bacterial infections are usually treated with antibiotics. However, in recent decades many pathogenic bacteria have developed an increasing tolerance to common drugs. So-called multidrug-resistant bacteria are of particular concern as they can no longer be combated with most antibiotics. Copper surfaces — for example on door handles — are a good weapon to fight these germs. “Copper surfaces are a sure-fire way to kill bacteria. Most bacteria die within minutes after landing on a copper surface,” explains Professor Dietrich H. Nies, a microbiologist at MLU. Copper is a vital trace element for bacteria — but only in very small quantities. On the copper surfaces, however, the bacteria are literally flooded to death with copper ions because that they can no longer stave them off using their normal defence strategies.

Nies’ research team wanted to find out if and how quickly two typical species of bacteria, Escherichia coli and Staphylococcus aureus, are theoretically able to adapt to survive on copper surfaces. The team therefore placed the bacteria on the surfaces for only a few minutes before returning them to a normal culture medium where they were allowed to recover. This process was repeated several times, with the survivors gradually being exposed to the deadly surface for longer and longer periods of time. Within three weeks, the researchers had produced bacteria that could survive for more than one hour on a copper surface. “Outside the laboratory, conditions are obviously not as ideal. But if copper surfaces are not cleaned regularly, insulating layers of grease can begin to form on them, which could produce a similar development over time,” says Nies.

Using comprehensive genetic analyses, the team sought to understand why the bacteria no longer died on the surfaces. “We were unable to find a gene that made them resistant to the deadly effect of metallic copper surfaces,” says Nies. Instead, the team observed a phenomenon among the surviving bacteria that was already known for quite some time, although in a slightly different manner: the bacteria’s metabolism slowed down to a bare minimum and they fell into a kind of hibernation. Because most antibiotics aim to disrupt the metabolism of growing bacteria, they are almost completely ineffective against these special bacteria, which are also known as “persisters.” “No matter how well an antibiotic works, there are always a handful of persisters in every generation,” explains Nies. However, these are not considered antibiotic-resistant bacteria, because their offspring are once again susceptible to the drugs.

Normally only a tiny proportion of bacteria become persisters. However, in the case of the isolated bacteria, it was the entire population. Although they were able to grow just as fast as their predecessors, they were also able to rescue themselves by switching rapidly into an early state of persistence under adverse conditions. The scientists were concerned one additional thing they observed: “The bacteria also inherited this capability over 250 generations, even though the offspring had not come into contact with a copper surface,” says Nies. The team therefore recommends that copper surfaces be cleaned regularly and thoroughly with special agents so that no persister bacteria can develop in the first place. At the same time, Nies points out that the use of copper surfaces is only one of many ways — including antibiotics — to effectively combat harmful bacteria.

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With the recent launch of Starlink, SpaceX set a record for rapid reuse – Sunday Vision

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Zoom in / Falcon 9, Booster 1051, broke the sound barrier on December 13, 2020. It was back again for its eighth launch a little over a month later.

SpaceX continues to make strides as it pushes the boundaries of reusing the Falcon 9 first stage rocket.

On Wednesday morning, the company plans to launch the next batch of 60 Starlink satellites, and reuse the booster number 1051. This will in fact be the eighth flight of this Falcon 9 rocket – setting a new record for the number of uses for any single rocket core. SpaceX expects to reach 10 uses of at least one stage of the Falcon 9 later this year.

The next launch attempt is also noteworthy as it would mark a rapid turnaround for this first phase. The missile last flew on December 13, launching the Sirius XM-7 mission in geostationary transport orbit. This 38-day period will significantly eclipse the previous Falcon 9 Phase 1 transformation margin, which is 51 days. This indicates that the company’s engineers and technicians are continuing to learn best practices for recovering and refurbishing the missiles.

The Starlink mission is scheduled to launch at 8:02 AM EST (13:02 UTC) on Wednesday from the Cape Canaveral Space Force Station in Florida. Its launch was originally delayed by 24 hours from Monday due to unfavorable weather conditions in the offshore recovery area, where Just read the instructions Will wait for the return of the first stage. Then the important company delayed an additional day, say More time was needed for “pre-launch inspections”. It is not clear if this refers to the missile or the payload.

This will be the sixteenth launch of “operational” Starlink satellites, in addition to an earlier launch of experimental satellites. This mission is already the largest satellite operator in the world, and will bring the total number of Starlink satellites launched by SpaceX to over 1,000. Some of these satellites are no longer operational, are in the process of exiting orbit, or have already done so.

In starting to build this constellation, SpaceX owns it Introducing a public beta To define the regions of North America and is expected to offer broader coverage later this year. First impressions It was generally positive.

At the same time, SpaceX is also working to address the concerns of scientists who are concerned that large constellations of satellites transmitting the Internet from space will distort the night sky and damage astronomical observations. Last year, the company started adding “masks” to reduce the reflection of its satellites. However, Recent analysis From these “DarkSats” they indicate that more effort may be required.

Weather conditions for launch on Wednesday appear favorable for the mission, both at the launch site and in the recovery area. SpaceX should start live 15 minutes before take off.

[embedded content]

Starlink launched.

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All-purpose dinosaur opening reconstructed – Science Daily

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For the first time ever, a team of scientists, led by the University of Bristol, have described in detail a dinosaur’s cloacal or vent — the all-purpose opening used for defecation, urination and breeding.

Although most mammals may have different openings for these functions, most vertebrate animals possess a cloaca.

Although we know now much about dinosaurs and their appearance as feathered, scaly and horned creatures and even which colours they sported, we have not known anything about how the vent appears.

Dr Jakob Vinther from the University of Bristol’s School of Earth Sciences, along with colleagues Robert Nicholls, a palaeoartist, and Dr Diane Kelly, an expert on vertebrate penises and copulatory systems from the University of Massachusetts Amherst, have now described the first cloacal vent region from a small Labrador-sized dinosaur called Psittacosaurus, comparing it to vents across modern vertebrate animals living on land.

Dr Vinther said: “I noticed the cloaca several years ago after we had reconstructed the colour patterns of this dinosaur using a remarkable fossil on display at the Senckenberg Museum in Germany which clearly preserves its skin and colour patterns.

“It took a long while before we got around to finish it off because no one has ever cared about comparing the exterior of cloacal openings of living animals, so it was largely unchartered territory.”

Dr Kelly added: “Indeed, they are pretty non-descript. We found the vent does look different in many different groups of tetrapods, but in most cases it doesn’t tell you much about an animal’s sex.

“Those distinguishing features are tucked inside the cloaca, and unfortunately, they’re not preserved in this fossil.”

The cloaca is unique in its appearance but exhibits features reminiscent to living crocodylians such as alligators and crocodiles, which are the closest living relatives to dinosaurs and other birds.

The researchers note that the outer margins of the cloaca are highly pigmented with melanin. They argue that this pigmentation provided the vent with a function in display and signalling, similar to living baboons and some breeding salamanders.

The authors also speculate that the large, pigmented lobes on either side of the opening could have harboured musky scent glands, as seen in living crocodylians.

Birds are one the few vertebrate groups that occasionally exhibit visual signalling with the cloaca, which the scientists now can extend back to the Mesozoic dinosaur ancestors.

Robert Nicholls said: “As a palaeoartist, it has been absolutely amazing to have an opportunity to reconstruct one of the last remaining features we didn’t know anything about in dinosaurs.

“Knowing that at least some dinosaurs were signalling to each other gives palaeoartists exciting freedom to speculate on a whole variety of now plausible interactions during dinosaur courtship. It is a game changer!”

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Dinosaur fossils could belong to the world's largest ever creature – CTV News

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Experts have uncovered the remains of a gigantic dinosaur in Argentina, and believe it could be one of the largest creatures to have ever walked the Earth.

Paleontologists discovered the fossilized remains of a 98 million-year-old titanosaur in Neuquén Province in Argentina’s northwest Patagonia, in thick, sedimentary deposits known as the Candeleros Formation.

The 24 vertebrae of the tail and elements of the pelvic and pectoral girdle discovered are thought to belong to a titanosaur, a diverse group of sauropod dinosaurs, characterized by their large size, a long neck and tail, and four-legged stance.

In research published in the journal Cretaceous Research, experts say they believe the creature to be “one of the largest sauropods ever found” and could exceed the size of a Patagotitan, a species which lived 100 million to 95 million years ago and measured up to a staggering 37.2 meters (122 feet) long.

“It is a huge dinosaur, but we expect to find much more of the skeleton in future field trips, so we’ll have the possibility to address with confidence how really big it was,” Alejandro Otero, a paleontologist with Argentina’s Museo de La Plata, told CNN via email.

Titanosaur fossils have been found on all continents except Antarctica. But the biggest “multi-ton” varieties of the species — including those titanosaurs exceeding 40 tons — have mostly been discovered in Patagonia.

Without analyzing the dinosaur’s humerus or femur, experts say it is not yet possible to say how much the creature weighs. However, the partially recovered dinosaur “can be considered one of the largest titanosaurs,” experts said, with a probable body mass exceeding or comparable to that of a Patagotitan or Argentinosaurus.

Patagotitans may have been the world’s largest terrestrial animal of all time, and weighed up to 77 tons, while Argentinosaurus were similarly gargantuan, and measured up to 40 meters (131 feet) and weighed up to 110 tons — weighing more than 12 times more than an African elephant (up to 9 tons).

Experts believe that the specimen strongly suggests the co-existence of larger titanosaurs together with medium-sized titanosaurs and small-sized rebbachisaurids at the beginning of the Late Cretaceous period, which began 101 million years ago.

“These size differences could indeed explain the existence of such sauropod diversity in the Neuquén Basin during the Late Cretaceous in terms of niche partitioning,” they wrote.

Researchers said that, while they don’t believe the creature to belong to a new species, they have so far been unable to assign it to a known genus of dinosaur.

The research was conducted by Argentina’s The Zapala Museum, Museo de La Plata, Museo Egidio Feruglio and the universities of Río Negro and Zaragoza.

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