Pearls in the sea, easy to come Source: pixabay.com
01
Bacteria can live on the surface of Mars for 280 million years
图源：MICHAEL J DALY/SCIENCE PHOTO LIBRARY
Microbes may survive the harsh conditions on the Martian surface for much longer than scientists previously estimated. In a new set of experiments, the researchers found that dried up bacteria can survive for up to 280 million years under Mars-like conditions, meaning that if Mars ever hosted life, we still have good hope for evidence.
Using a different tactic by drying and freezing various bacteria and yeast and placing them in a cold, dry, and high-radiation environment similar to Mars, they found that in the absence of water, all organic matter is inactive, and in turn it is difficult to destroy it. Assessments of radiation damage to the samples indicate that they still have a chance of recovery after 280 million years.
Instead of looking for these hard-to-see bacteria, find a stone with the words engraved.
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Bibliography:
https://www.newscientist.com/article/2344099-bacteria-could-survive-just-under-marss-surface-for-280-million-years/
02
How are dormant bacteria awakened?
Colored dyes are used to show the charge of Bacillus subtilis spores
图源：K. KIKUCHI AND LETICIA GALERA/SUEL LAB
Bacteria go dormant in harsh environments, no longer active and multiply, waiting for the opportunity to wake up, but how do they sense changes in the external environment and know that they can wake up again? Gürol Süel, a microbiologist at the University of California, San Diego, and colleagues believe that dormant bacteria do not appear to have measurable biological activity, speculating that there are positively charged potassium ions within the nucleus that can drift without consuming energy, and that these ions may be involved in waking up the cells.
The team exposed Bacillus subtilis spores to nutrients and used colored dyes to track the movement of potassium ions. As the exposure time becomes longer, more potassium leaves the core, at which time the electrical properties in the spore nucleus gradually become negative, and when the negative charge accumulates to a certain extent, the whole cell is awakened. If the movement of potassium ions is limited and the charge in the nucleus does not change much, the spores will not wake up no matter how long they have been exposed to nutrients.
Ultra-high sensitivity long-lasting sensor.
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Article Links:
https://www.sciencenews.org/article/bacteria-spores-cells-life-signals-environment
03
AI that automatically identifies fake papers
Photo by Raimund Koch/Getty
Adam Day, director of London's Academic Data Service, has developed a software tool called "Papermill Alarm" to identify various forged articles made by the paper factory. It uses deep learning algorithms to compare the vocabulary used in paper titles and abstracts with words known to be used in articles from paper factories, while learning uses datasets from lists of "certain types of products" provided by different academic detectives, including well-known counterfeiting fighters such as Elisabeth Bik and David Bimler. It gives different scores to different pages in a paper, marked by traffic light-like signals: red for high similarity, green for those with no similarities, and orange for suspected ones.
An evaluation of paper titles in the citation database PubMed using the tool showed that at least 1% of papers were very similar to the products of the paper factory. Although this figure is for reference only, because some may be false positives, and some "high imitation" cannot be identified, it still means that the entire system is contaminated by a considerable number of fakes, especially many fake papers have been cited, which is long-term and far-reaching damage to science.
The demon is one foot high, and the road is one foot high.
Editor
Article Links:
https://www.nature.com/articles/d41586-022-02997-x
04
Humans can speak because they have less tissue than monkeys
The howler monkey's voice is loud and harsh.
图源：JACOB C. DUNN
A new study suggests that the piece of tissue that humans lose is the key to human language. Takeshi Nishimura's team at Kyoto University in Japan used MRI and CT to scan the laryngeal structures of 43 different primates and found that all primates, except humans, have a small piece of tissue above the vocal cords called the vocal cord membrane, which acts like a reed in the clarinet, making it easier for animals to scream loudly.
Primates mostly make sounds in the same way: pushing air out of the lungs while vibrating the muscles of the larynx to produce sound waves. When the sound wave passes through the vocal cord membrane, there will be violent fluctuations in tone, which of course makes the sound more sharp and harsh, more deterrent, but also makes the sound difficult to control and cannot be converted into a more complex tone. And because humans don't have vocal cord membranes, the vocal fluctuations produced are more stable, and the control of the lips and tongue can transform stable tones into the complex sounds needed to make up language. If humans are really monkeys, then the abandonment of certain organs of our ancestors is undoubtedly a "great degradation" in the history of human evolution, and the loss of something has allowed us to gain greater abilities.
The avenue is fifty, the sky is forty or nine, people are one of them, and the changes are endless.
Editor
Article Links:
https://www.sciencenews.org/article/humans-primates-voice-control-cords-larynx-membrane