Global Science News | Scientists from many countries emphasize that the new coronavirus is not a "laboratory leak"

· Novel Coronavirus· Scientists from many countries published an article in Cell emphasizing that the novel coronavirus was not a "laboratory leak"

On August 19, 21 international scientists from China, Canada, the United Kingdom, New Zealand and other countries and regions pointed out in a commentary published in the journal Cell that there is no evidence that the new coronavirus originated from a laboratory, nor is there any evidence that early cases of new coronavirus pneumonia have any connection with the Wuhan virus. This is an important judgment made by professionals in this field on the issue of tracing the source based on existing scientific evidence.

The authors believe that the Wuhan Institute of Virology conducts routine viral genome sequencing, which does not require cell culture and the virus is inactivated during RNA extraction, so the risk is negligible. Compared with other explanations, there is a lot of scientific evidence to support the zoonotic origin. If we cannot work together to fully investigate the origin of zoonotic diseases, the world will remain vulnerable to future pandemics caused by the same human activities.

· Scientific Events ·

Renowned US medical institute expelled member of the National Academy of Sciences for alleged sexual harassment

Image credit: Massachusetts Institute of Technology

Last Friday local time, the Howard Hughes Medical Institute (HHMI), a well-known American research institution, announced that it had fired David Sabatini, a well-known biologist and member of the American Academy of Sciences. It is said that the report of a third-party investigation agency showed that Sabatini violated workplace behavioral norms, including sexual harassment and other misconduct unrelated to academic misconduct. At the same time, Sabatini resigned from his position at the Whitehead Institute of MIT. At present, MIT has not yet fired Sabatini, saying that the school is evaluating the investigation report and deciding on the next steps. The most severe measures may include revoking Sabatini's tenured position at the school. At present, Sabatini's personal homepage and laboratory homepage on the official website of the Whitehead Institute are no longer accessible.

Sabatini has worked at the Whitehead Institute since 2002. His research focuses on the regulatory mechanisms of mammalian growth and metabolism, as well as the disorders of these mechanisms in diseases such as cancer and diabetes. When he was a student, Sabatini discovered the signaling pathway of mTOR kinase, which plays an important role in regulating growth and aging. Since then, Sabatini has conducted in-depth research on this pathway and discovered many key components in it. In 2016, Sabatini was elected as a member of the US National Academy of Sciences.

Biotechnology

New CRISPR editing system can test the functions of hundreds of genes at once

Photos by: James Herron, Saba Parvez

The CRISPR-Cas9 editing system allows scientists to more easily edit the genomes of some model organisms, such as zebrafish, to study genes involved in different physiological processes. However, at present, CRISPR technology can only allow scientists to edit several genes in one operation. In a new study published in Science, scientists have developed a new CRISPR editing system MIC-Drop that can evaluate the functions of hundreds of genes in a single experiment.

When developing MIC-Drop, they first designed a library containing multiple guide RNA fragments, and encapsulated a guide RNA fragment, the Cas9 enzyme, and a specific DNA (as a marker) in a droplet. By optimizing the stability of the droplets, they mixed hundreds of similar droplets together, but they did not fuse with each other. Based on MIC-Drop, they can inject hundreds of droplets into hundreds of zebrafish embryos at a time, and each embryo contains a gene editing system. Using this method, they edited 188 genes in zebrafish and discovered several genes that play an important role in heart development and function. The researchers said that this technology may also be expanded to detect thousands of genes at the same time.

Biology

Why do humans have shorter strides than chimpanzees?

For decades, scientists have believed that humans evolved to have the longest stride possible in order to improve walking efficiency. But now scientists have discovered that even the tallest humans have a relatively short stride compared to chimpanzees. In a new study published in the Journal of Experimental Biology, researchers compared the stride lengths of humans and chimpanzees and provided an explanation for the shorter stride length of humans.

The researchers used 3D cameras to record the walking postures of humans and chimpanzees, and used 3D technology to reconstruct the stride of humans and the hip movement when walking. The study found that when walking, the human pelvis only rotates about 8 degrees, while the chimpanzee pelvis rotates between 28 and 61 degrees. Further research shows that if humans are scaled to the size of chimpanzees, the human stride is only about 3/4 of that of chimpanzees. The researchers believe that the reason why humans gave up increasing their stride by rotating the pelvis during evolution is that a large rotation of the pelvis will affect the natural swing of the arms and legs, which will reduce walking efficiency.

Biology

The widest coral ever found in the Great Barrier Reef

View image of Scientists swim over giant corals (Credit: Woody Spark)

Corals are structures made of small marine animals and calcium carbonate. Recently, in a paper published in Scientific Reports, scientists reported the discovery of a super-large coral in the Great Barrier Reef, which is the widest and sixth tallest coral in the Great Barrier Reef. The coral was found by snorkelers near the coast of Orpheus Island in the Palm Islands of Queensland, Australia. After studying it, they found that it was hemispherical, 5.3 meters high and 10.4 meters wide, 2.4 meters wider than the second widest coral in the Great Barrier Reef. Based on the coral growth rate and annual sea surface temperature, they believe that this super-large coral began to grow between 421 and 438 years ago, earlier than the time when Europeans first discovered and settled in Australia.

After reviewing environmental events over the past 450 years, scientists also found that it may have experienced up to 80 major hurricanes and has long been exposed to invasive species, coral bleaching events, low tides and human activities. However, the coral is in good health, with a live coral cover of 70%. They recommend that this rare and resilient large coral be closely monitored to minimize potential negative impacts on it in the future from climate change, deteriorating water quality, overfishing and coastal development.

· healthy·

How teaching mode affects students' sleep time

Since last year, in order to curb the spread of the COVID-19 pandemic, many schools have adopted different ways to continue teaching. Some continue to teach in person, while others switch completely to online teaching or adopt a self-directed online teaching mode. Recently, in a study published in Sleep, researchers analyzed the impact of different teaching modes on students' sleep time.

They collected data from more than 5,000 teenagers and found that in face-to-face teaching mode, only 20.4% of junior high school students and 37.2% of high school students can get enough sleep (at least 9 hours for junior high school students and at least 8 hours for high school students). However, since there is no need to prepare for school and commute, more than 38% and more than 62% of junior high school students can get enough sleep in online teaching and self-learning online courses. Among high school students, this proportion is more than 56% and more than 81% respectively. In addition, the class starts later, so junior and high school students will have more sleep time.

COVID-19

As of 10:00 Beijing time on August 23, according to the latest statistics from Johns Hopkins University, the global cumulative number of confirmed cases of COVID-19 was 211,787,856, with 4,430,632 deaths.

From 0:00 to 24:00 on August 22, there were no new local confirmed cases in Jiangsu. 39 new cases were discharged from hospital (37 local confirmed cases and 2 imported confirmed cases). One imported asymptomatic infection was released from medical observation. From July 20 to date, a total of 818 local confirmed cases have been reported in Jiangsu Province (235 in Nanjing, 12 in Huai'an, 568 in Yangzhou, and 3 in Suqian). A total of 249 local confirmed cases have been discharged. At present, there are 580 confirmed cases in designated hospitals in Jiangsu Province, including 569 local confirmed cases (98 mild cases, 469 ordinary cases, and 2 severe cases). There are 4 asymptomatic infections under medical observation, including 1 local asymptomatic infection.

According to the announcement of the Nanjing Municipal Joint Prevention and Control Command Center for the Novel Coronavirus Pneumonia Epidemic, from August 23, people leaving Nanjing by rail, road, water, etc. will no longer be required to provide nucleic acid test certificates.

According to the official website of the National Health Commission, from 0:00 to 24:00 on August 22, 21 new confirmed cases were reported in 31 provinces (autonomous regions, municipalities) and the Xinjiang Production and Construction Corps, all of which were imported cases from abroad (5 cases in Guangdong, 4 cases in Shanghai, 3 cases in Tianjin, 3 cases in Yunnan, 2 cases in Beijing, 1 case in Shanxi, 1 case in Zhejiang, 1 case in Henan, and 1 case in Sichuan); no new deaths were reported; 1 new suspected case was reported, an imported case from abroad (in Shanghai).

31 provinces (autonomous regions, municipalities) and the Xinjiang Production and Construction Corps reported 16 new asymptomatic infections (all imported from abroad); 3 cases were converted to confirmed cases on the same day (all imported from abroad); 14 cases were released from medical observation on the same day (all imported from abroad); 507 asymptomatic infections are still under medical observation (420 imported from abroad).

As of August 21, 2021, 31 provinces (autonomous regions, municipalities) and the Xinjiang Production and Construction Corps have reported a total of 193,586,900 doses of new coronavirus vaccine administered.

Text: Xie Ruyu, Li Shiyuan, Wang Yibo

Editors: Shi Yunlei, Bai Defan, Wang Yu

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