The model of stellar evolution is questioned, and Maotai Chief Engineer's shortlisted academician candidate sparks controversy | Weekly Science and Technology Guide

"Perseverance" sends back the first photo of Mars

"Perseverance" sends back the first photo of Mars

The first photo sent back after the "Perseverance" rover landed.

The source of the first photo returned after the "Perseverance" rover landed: NASA TV The source of the first photo returned after the "Perseverance" rover landed: NASA TV

At 4:55 am on February 19th, Beijing time, the Perseverance rover plunged into the Martian atmosphere without changing its orbit and successfully landed.

The landing site of Perseverance is the Jezero crater at 18 degrees north latitude.

"Perseverance" landed here, an important goal is to identify and collect sedimentary rock and soil samples in the area, explore possible signs of life on Mars, and test the technology of human survival on Mars.

In addition, "Perseverance" will also help humans understand the geology and atmospheric environment of Mars through the analysis of the physical and chemical characteristics of surface rocks and soil.

The giant panda's ultra-high-quality genome is released, and the reason for the fragile viability of the "national treasure" has been found

The giant panda's ultra-high-quality genome is released, and the reason for the fragile viability of the "national treasure" has been found

Recently, Zhejiang University, Shenzhen Huada Life Sciences Research Institute and China Giant Panda Conservation and Research Center have jointly released the latest results of the giant panda's ultra-high-quality genome research.

The study pointed out that the loss and mutation of certain elements of the giant panda's reproductive genes may be an important reason why the giant panda's fertility is lower than that of other mammals.

This research is the best assembled giant panda genome so far, and it is also the first time that it provides a high-precision genome of the Qinling subspecies giant panda.

The mass of the black hole in Cygnus X-1 challenges the stellar evolution model

The mass of the black hole in Cygnus X-1 challenges the stellar evolution model

A new study shows that the black hole in the X-ray binary system Cygnus X-1 weighs about 21 solar masses, thus challenging the current model of stellar evolution.

James Miller-Jones and colleagues introduced a new observation of Cygnus X-1 using the Very Long Baseline Array (VLBA).

According to the author, for a black hole with such a huge mass that exists in the Milky Way, the mass lost by the stellar wind during the evolution of the predecessor star will definitely be lower than the current model predicts.

The UK approves the world's first new coronavirus "human challenge test"

The UK approves the world's first new coronavirus "human challenge test"

The British government issued a statement on February 17 stating that in order to accelerate the understanding of the new crown vaccine and new crown treatment methods, the country has approved a new crown virus human challenge study (Human Challenge Study), which will allow 90 18-30 year olds to be healthy.

As a result, the United Kingdom will become the first country in the world to approve a human challenge test for the new coronavirus.

The UK said that this preliminary study will help scientists understand how the immune system responds to the coronavirus, identify factors that affect the spread of the virus, determine the minimum level of virus required to cause infection, and provide supporting information for vaccine development.

The reversal of geomagnetism 42,000 years ago triggered global environmental changes

The reversal of geomagnetism 42,000 years ago triggered global environmental changes

According to a new research report, when the earth's magnetic field reversed nearly 42,000 years ago, it triggered major changes in the environment, extinction events, and long-term changes in human behavior.

In this study, Turney, Alan Cooper, and colleagues introduced a new, accurate record of atmospheric radiocarbon that exists in the annual rings of ancient Kauri trees that have been preserved for thousands of years in New Zealand wetlands.

Cooper et al.
determined that during the period of weakening of the magnetic field strength before the earth's polarity reversal, the radiocarbon in the atmosphere increased significantly.
By modeling the consequences of this increase, they found that when the earth's magnetic field is estimated to be only about 6% of current levels, the smallest geomagnetic field triggers major changes in atmospheric ozone concentration and circulation.

These changes may have led to the simultaneous changes in the global climate and environment observed in other climate records that occurred about 42,000 years ago.

Chinese scientists take the lead in constructing a map of the global hippocampus origin and spread

Chinese scientists take the lead in constructing a map of the global hippocampus origin and spread

On February 17, Nature Communications published online the latest research results of Lin Qiang, a researcher from the South China Sea Institute of Oceanology, Chinese Academy of Sciences, and Kunming Institute of Zoology, Chinese Academy of Sciences, and the University of Konstanz, Germany.

The study takes the global seahorse population as the research object, and for the first time clarifies that the Indo-Australian Islands in the Indo-Pacific confluence area is the origin center of the global seahorse, and originally reveals the temporal and spatial characteristics of the global diffusion path of the seahorse driven by geology and ocean currents.
The ecological adaptation and evolutionary mechanism puts forward a new view that the Indo-Pacific seahorse group enters the Atlantic Ocean through two routes from the Gutertes Sea and the Cape of Good Hope in South Africa.

Less than 5 hours of sleep increases the risk of dementia by 45%

Less than 5 hours of sleep increases the risk of dementia by 45%

Source: NHATS

Source: NHATS Source: NHATS

Recently, researchers from Brigham and Women’s Hospital conducted a new study that included 2812 participants from the National Health and Aging Trends Study (NHATS) 65 and older.
Questionnaire survey of participants' sleep disorders and lack of sleep.

It turns out that over time, there is a close relationship between sleep disorders and lack of sleep and dementia.
Compared with 7-8 hours of sleep per night, participants with sleep time ≤ 5 hours and falling asleep time> 30 minutes have a 45% increased risk of dementia, difficulty in maintaining alertness, naps, poor sleep quality and very short sleep Time is related to all-cause mortality.

The mechanism of drinking green tea against cancer was discovered

The mechanism of drinking green tea against cancer was discovered

Source: Nature Communications

Source: Nature Communications Source: Nature Communications

On February 13, a new study published in Nature Communications found a direct interaction between p53 and EGCG that was previously unknown.

The chemopreventive effect of green tea on tumors is mainly attributed to polyphenolic compounds, of which epigallocatechin gallate (EGCG) is the most important.
p53 is an important tumor suppressor.
It is known that p53 mutations are found in more than 50% of human cancers.
However, the molecular mechanism of how EGCG interacts with p53 is still unclear.

In this new study, the researchers used surface plasmon resonance (SPR) and STD-NMR to determine the NTD of p53 as the main EGCG binding site, which coincides with the MDM2 binding site.
EGCG destroys the p53-MDM2 interaction by binding to NTD and inhibits the ubiquitination of p53 mediated by MDM2, which is the main degradation pathway of p53.

A new mechanism for high-affinity antibody screening has been discovered

A new mechanism for high-affinity antibody screening has been discovered

Source: Nature

Source: Nature Source: Nature

On February 18, the journal Nature published a research paper titled online.
The study found that in the antibody immune response, the chemokine CCL22 promotes a new mechanism for the production of high-affinity antibodies, which provides a new mechanism for improving the development of vaccines in the future.
Potential new targets.

CCL22 is a factor that is affinity-coupled with B cell antibodies.
As a marker, it can transmit B cell affinity information to distant T cells.
At the same time, it also establishes a positive feedback loop with T cells to help signals.

This positive feedback between cells allows T cells to patronize more high-affinity B cells, which makes it easier to obtain more help signals, and more help signals make these high-affinity cells express more CCL22 and further recruit T cells.

Maotai Chief Engineer shortlisted for academician candidates sparked controversy

Maotai Chief Engineer shortlisted for academician candidates sparked controversy

Recently, Wang Li, chief engineer of Moutai Distillery, was shortlisted for the publicity list of candidates to be recommended by Guizhou Provincial candidates for academicians of the Chinese Academy of Engineering in 2021, which aroused widespread concern and heated discussions.

On February 18, the Chinese Academy of Engineering responded that Wang Li was still at the stage of recommendation and publicity by the local Association for Science and Technology, and was not yet a valid candidate.

Regarding this, CCB stated that it is difficult to recommend the selection of academicians by researchers who are dedicated to the research of "brewing" technology, which can hardly represent the strategic direction of "rejuvenating the country by science and technology", and it will also cause people to question the direction of social scientific research and the criteria for recommendation and selection of academicians.
All parties concerned should be cautious!

According to the Beijing News, in the case that the academician title belongs to the top rank of domestic scientific workers, the chief engineer of Maotai is shortlisted for the list of co-opted academicians and needs to withstand the supervision and scrutiny of public opinion.

Guangming Daily said that experts must decide on professional issues, but the people also have the right to discuss.
Xi Zhe said: The helmsman was not selected.
Let those who can't steer sit on the rudder, the risks are geometric, and it goes without saying.
However, as for the purpose and condition of the ship, the passengers also have the right to determine and evaluate.

The cover news stated that the so-called meritocracy should have two aspects and a unified standard.
As far as the election of academicians is concerned, neither can "preferential treatment" of Wang Li because of Moutai, nor can he "discriminate" Wang Li because of Moutai.

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