Love will leave an imprint on the brain丨Tech Weekly

Compiled by Zhou Shuyi

Love leaves an imprint on the brain

Why do people go through so much trouble to invite their partners out, but have no interest in hanging out with casual acquaintances? A new study suggests that the neurotransmitter dopamine plays a key role in maintaining emotional bonds: Being with your significant other triggers more dopamine release, which leaves an imprint in the brain.

Prairie voles (Microtus ochrogaster) are one of the few (about 3% to 5%) monogamous species among mammals. They tend to form long-term partnerships, build families together, raise offspring, and experience similar emotions of grief when they lose their partners. In the first experiment, prairie voles had to press a lever or climb over a fence to reunite with their partners. The researchers used micro-fiber optic sensors to track the activity of the nucleus accumbens in the vole's brain in real time. The sensors light up when they detect an increase in dopamine concentration. The nucleus accumbens plays an important role in brain activities such as reward and addiction. The results showed that when the vole crossed the barrier and saw its partner, the sensor lit up; when they snuggled and sniffed each other, the sensor was always on; in contrast, if they saw a random stranger vole, the sensor would be much dimmer. In previous studies, voles with reduced dopamine levels would not work so hard to reunite with their partners. This shows that dopamine not only motivates animals to find a partner, but is also secreted in large quantities when they stay with their partners.

Prairie Vole | Source: NASTACIA GOODWIN

In another experiment, the researchers separated a pair of voles for four weeks, which is a long time for voles and enough for them to find a new partner in the wild. When the voles reunited, they still recognized each other, but the dopamine surge had almost disappeared. The study believes that some kind of "reset" phenomenon occurred inside the vole's brain, allowing them to move on and form new emotional bonds. The researchers stressed that more research is needed to determine whether the results of prairie voles are applicable to humans. But they believe that this research may have important implications for people who have difficulty establishing close relationships and want to get over emotional trauma. The related paper was published in Current Biology on January 12.

Paper link:
https://doi.org/10.1016/j.cub.2023.12.041

11 students jointly reported their supervisor's academic misconduct

Recently, 11 students from Huazhong Agricultural University jointly reported the school's professor Huang Moumou for suspected academic misconduct and exploitation of students, which aroused widespread concern. In the early morning of January 19, the official Weibo of Huazhong Agricultural University released a situation report: In response to the online report on academic misconduct of Huang Moumou, a teacher at Huazhong Agricultural University, on January 16, 2024, the school's Academic Ethics Committee set up an investigation team to conduct an investigation. The problems reflected in the experimental pictures, data, results, etc. in the investigated materials were found to be basically true, and it was preliminarily determined that there was academic misconduct. The school decided to suspend all Huang Moumou's positions and work on campus from now on, and set up a tutor group to be fully responsible for the postgraduate training of the research group.

Source: Huazhong Agricultural University

Public information shows that Huang is a professor and doctoral supervisor at the College of Animal Science and Technology of Huazhong Agricultural University, and the director of the Department of Animal Nutrition and Feed Science. His research focuses on animal molecular nutrition and feed processing technology. He has presided over several scientific research projects, including the "14th Five-Year Plan" National Key R&D Program, the National "973" Program, and the National Natural Science Foundation. Currently, there are 15 students in Huang's research group.

On the afternoon of January 16, 11 doctoral and master's students in Huang's research group made public 125 pages of reporting materials, jointly reporting Huang's instructions and forcing students to tamper with data, reuse pictures, and fabricate experimental results, and that many academic papers supervised by him contained academic misconduct. In addition, they also accused Huang of manipulating peer review, improperly signing papers, suppressing and exploiting students, and plagiarizing in textbook writing, among other inappropriate behaviors.

49-year-old university vice president committed suicide after being fired less than a year in office

On January 8, local time, Antoinette "Bonnie" Candia-Bailey, the African-American vice president of Lincoln University in Missouri, shot herself at home at the age of 49. It is reported that the cause of death was related to the deterioration of her relationship with the white president John Moseley. On January 12, the school issued a statement announcing the launch of an investigation into the matter, and John Moseley was placed on paid administrative leave during the review. Sherman Bonds, president of the Lincoln University Alumni Association, said that Bailey's suicide made the school "full of despair, dissatisfaction and disappointment."

Antoinette “Bonnie” Candia-Bailey (left), John Moseley (right) | Source: Lincoln University of Missouri

Bailey has served as vice president of Lincoln University in charge of student affairs since May 2023. According to her emails before her death, the school had previously evaluated her work very poorly. In November 2023, Bailey only scored 36 points (out of 100) in her professional evaluation, but no one explained to her the reason. She sent emails to the school board and Moseley, raising her psychological problems of depression and anxiety, hoping to seek help, but the other party ignored it. Moseley sent Bailey a letter of dismissal on January 3, notifying her that she needed to take administrative leave immediately and move out of the campus apartment before the dismissal took effect in February. The letter expressed "strong concerns" about Bailey's work, criticizing her for disobeying management, charging students non-compliant accommodation fees, and failing to comply with confidentiality requirements in the complaint process of two subordinates. On the day Bailey died, she sent her last email to Moseley, accusing him of "deliberately harassing and bullying" herself, causing "sufficient blows and mental damage."

On January 12, the school issued an obituary, describing Bailey as "talented" and a "beloved alumnus and leader."

School statement:
https://www.lincolnu.edu/news/2024/01/statement-from-the-lincoln-university-board-of-curators.html

Google AI geometry level comparable to that of Olympiad gold medalists

Due to the lack of reasoning ability and training data, artificial intelligence often struggles to solve complex geometry problems. On January 17, the Google DeepMind team published an article in Nature, announcing that its newly launched AI system AlphaGeometry can solve geometry problems at the International Mathematical Olympiad (IMO) level without human prompts. The test set consists of 30 IMO geometry questions from 2000 to 2022. The new system solved 25 of them within the standard competition time limit, which is close to the average level of human gold medalists (25.9 questions) and far exceeds the previous most advanced machine method (Wu method, 10 questions).

There are two main routes for machine proof of geometric theorems. One is symbolism, which uses a symbolic reasoning system to translate geometric conditions into polynomial equations of point coordinates and then perform calculations. The "Wu method" pioneered by Chinese scientist Wu Wenjun in the 1970s belongs to this category. The other is connectionism. After several ups and downs, the neural language model headed by Chat-GPT is now advancing by leaps and bounds.

Symbolic reasoning systems are based on formal logic and use clear rules to draw conclusions. The advantages are rationality and explainability, but they may be "slow" and not flexible enough. Language models are good at identifying common patterns and relationships in data and can quickly predict potentially useful structures, but they usually lack the ability to rigorously reason or explain their decisions. AlphaGeometry combines the advantages of both, using language models to guide symbolic reasoning systems to find solutions to geometric problems. When symbolic reasoning gets stuck, the language model will try to add geometric structures (auxiliary lines) to open up new deductive paths for it, and this process will continue until the answer is found. The answers output by AlphaGeometry are clear, verifiable, and human-readable. In addition, the training set of the new system contains 100 million independent examples, all of which are automatically synthesized by the algorithm without the need for human demonstration. Researchers said that AlphaGeometry demonstrates the growing logical reasoning ability of artificial intelligence and the ability to discover and verify new knowledge, which will help open up new possibilities in mathematics, science, and artificial intelligence.

AlphaGeometry open source address:
https://github.com/google-deepmind/alphageometry

Paper link:
https://www.nature.com/articles/s41586-023-06747-5

About the Wu Method:
http://www.amss.cas.cn/wwj/xslz/201705/P020170506499043854909.pdf

National Bureau of Statistics: At the end of 2023, the national population will decrease by 2.08 million compared with the end of the previous year

According to the National Bureau of Statistics, at the end of the year, the national population (including the population of 31 provinces, autonomous regions, municipalities directly under the Central Government and active military personnel, excluding residents of Hong Kong, Macao and Taiwan and foreign nationals living in 31 provinces, autonomous regions and municipalities directly under the Central Government) was 140,967 million, a decrease of 2.08 million from the end of the previous year. The number of births in the whole year was 9.02 million, with a birth rate of 6.39‰; the number of deaths was 11.10 million, with a death rate of 7.87‰; and the natural population growth rate was -1.48‰.

In terms of gender composition, the male population was 720.32 million, the female population was 689.35 million, and the sex ratio of the total population was 104.49 (with females as 100). In terms of age composition, the working-age population aged 16-59 was 864.81 million, accounting for 61.3% of the national population; the population aged 60 and above was 296.97 million, accounting for 21.1% of the national population, of which the population aged 65 and above was 216.76 million, accounting for 15.4% of the national population. In terms of urban and rural composition, the permanent urban population was 932.67 million, an increase of 11.96 million over the end of the previous year; the permanent rural population was 477 million, a decrease of 14.04 million; the proportion of urban population in the national population (urbanization rate) was 66.16%, an increase of 0.94 percentage points over the end of the previous year.

The national urban survey unemployment rate averaged 5.2% throughout the year, down 0.4 percentage points from the previous year. The average weekly working hours of employees in enterprises nationwide was 49.0 hours. (National Bureau of Statistics)

10,000-year-old "chewing gum" reveals ancient people's poor oral health

Hunter-gatherers in southwestern Scandinavia during the Mesolithic period, about 10,000 years ago, may have suffered from tooth decay and gum disease, finds a study published January 19 in Scientific Reports.

The Huseby Klev excavation site on the west coast of Sweden. | Credit: Bengt Nordquist

The researchers sequenced DNA found in three pieces of birch tar (a substance made by heating birch bark). The birch tar was excavated from Huseby Klev in Sweden in the 1990s and dates back to 9890 to 9540 years ago. The researchers created an archive of the microbial DNA contained in the samples and compared them with other samples. The results showed that the microbial composition of the birch tar was most similar to that of modern human mouths, ancient human dental plaque, and 6,000-year-old chewed birch tar samples. This suggests that the Huseby Klev samples were chewed by humans. They also found that they contained a large number of bacteria associated with gum disease. Based on the relative abundance of microbial species in birch tar, the researchers estimated that these ancient people had a 70% to 80% chance of gum disease. They believe that ancient hunter-gatherers commonly used teeth to complete various tasks, including fixing, cutting and tearing with their mouths, which may have increased their risk of exposure to microorganisms that cause gum disease.

A mold made for one of the birch tar pieces. | Source: Verner Alexandersen

Paper link:
https://www.nature.com/articles/s41598-023-48762-6

Achieve ultra-low temperature refrigeration without liquid helium, with temperatures as low as 94 milliKelvin

A new study has successfully achieved ultra-low temperature refrigeration without liquid helium, with temperatures as low as 94 milliKelvin. This is expected to provide a new solution to the problem of ultra-low temperature refrigeration in deep space exploration, quantum technology, material science and other fields.

At present, there are two main technologies for ultra-low temperature refrigeration: helium refrigeration and magnetic refrigeration. The former relies on the special low-temperature characteristics brought by the strong quantum fluctuations and weak interactions of helium, while the latter currently relies mainly on the magnetocaloric effect of hydrated paramagnetic salt working fluids. The magnetocaloric effect refers to the phenomenon that magnetic materials produce significant temperature changes under the action of a magnetic field. The researchers first confirmed the existence of supersolids (spin supersolids) in frustrated quantum magnets in the cobalt-based triangular lattice antiferromagnetic material Na2BaCo(PO4)2. Furthermore, the researchers also discovered the huge magnetocaloric effect of spin supersolids at ultra-low temperatures. Under adiabatic conditions, the magnetic field was regulated and the temperature of the material was observed to drop sharply near the quantum phase transition point of the spin supersolid, reaching a minimum of 94 millikelvin. The adiabatic temperature change rate showed a very high peak, and the peak height was four times that of the current general refrigeration working fluid Gd3Ga5O12. In addition, in the spin supersolid phase, Na2BaCo(PO4)2 can be maintained at a very low refrigeration temperature due to its strong spin fluctuations, in sharp contrast to other spin-ordered materials. These properties make cobalt-based magnetic crystals with giant magnetocaloric effect a promising ultra-low temperature refrigeration quantum material in the sub-Kelvin temperature range.

Paper link:
https://www.nature.com/articles/s41586-023-06885-w

This article is supported by the Science Popularization China Starry Sky Project

Produced by: China Association for Science and Technology Department of Science Popularization

Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.

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