Finishing | Zhou Shuyi, Wangxiang
There may have been "warm-blooded" dinosaurs 180 million years ago
Dinosaurs have long been considered to be slow-moving, "cold-blooded" creatures, like modern reptiles, relying on the sun's heat to regulate their body temperature. And a new study shows that as early as the early Jurassic period, about 180 million years ago, some dinosaurs had evolved the ability to generate heat from inside their bodies.
Although the terms "cold-blooded" and "warm-blooded" are often used to distinguish different ways of thermoregulation in animals, this description is not accurate. Corresponding to "warm-blooded animals", the academic community uses endothermy to describe the characteristics of animals that produce heat, regulate and maintain body temperature through their own metabolism. Previous studies have shown that some dinosaurs may have been endothermic, but the evolution of this trait is not clear.
雪中的驰龙艺术图，这是一类带有羽毛的兽脚亚目恐龙。| 来源:Davide Bonadonna/University of Vigo/UCL
Using fossil datasets, paleoclimate models, and dinosaur evolutionary trees, the researchers studied the reproduction and migration pathways of dinosaurs throughout the Mesozoic Era under different climatic conditions. The Mesozoic Era (251 million years ago to 66 million years ago) was the most active period for dinosaurs, which can be divided into the Triassic, Jurassic, and Cretaceous periods. It is also a time of great change in plates, climate, and biological evolution.
It was found that two of the three major dinosaur groups, theropods (such as Tyrannosaurus rex and velociraptors) and ornithischian (such as stegosaurus and triceratops), migrated to colder climates in the early Jurassic. This suggests that they may have evolved internal temperance at this time. Another large group, sauropods (such as Brontosaurus and Diplodocus), lived in warmer regions. The analysis shows that about 183 million years ago, intense volcanic activity led to global warming and the extinction of flora. The emergence of internal temperature may also be caused by this environmental crisis. As a result, theropods and ornithischian dinosaurs were able to be highly active and prolonged in colder environments, resulting in faster growth and development and more offspring.
On the other hand, "cold-blooded" sauropod dinosaurs evolved to be enormous, and studies speculate that this reduced the surface area to volume ratio of the body, helping to reduce heat loss and allowing them to remain active for longer.
Related papers: https://doi.org/10.1016/j.cub.2024.04.051
The world's first patient to receive a living donor transplant of a pig kidney has died
On May 11, local time, Massachusetts General Hospital (Massachusetts General Hospital) in the United States announced that the world's first patient to receive a living pig kidney transplant, 62-year-old Rick Slayman, died nearly two months after the operation.
Massachusetts General Hospital said in a statement that there was no indication that Sleman's death was caused by a kidney transplant and that "we are deeply grateful for his trust and willingness to advance the field of xenotransplantation." According to Science and Technology Daily, Chen Gang, deputy director of the Organ Transplantation Institute of Tongji Hospital affiliated to Tongji Medical College of Huazhong University of Science and Technology, revealed that the patient died of a sudden heart attack.
Rick Slayman | 来源：MGH
Sleman, a patient with end-stage renal disease who has suffered from type 2 diabetes and high blood pressure for many years, had been on dialysis for a long time, and underwent a human kidney transplant in 2018, but the transplanted kidney showed signs of failure a few years later and had to resume dialysis in 2023. Later, Sleman developed complications related to vascular access, and doctors recommended that he undergo a pig kidney transplant. The U.S. Food and Drug Administration (FDA) approved the transplant based on the "compassionate use" rule.
On March 16 this year, Massachusetts General Hospital successfully implanted a pig kidney into Slyman after a four-hour operation. The pig kidney used in this surgery has undergone 69 gene edits, including knocking out genes that cause rejection and adding some human genes to improve the compatibility of the organ with the human body. In addition, the research team inactivated the retrovirus gene in pigs to prevent the virus from affecting humans. Mr. Sleman was discharged from the hospital in April, when doctors expected the kidney to prolong his life by years, but acknowledged that a xenotransplant could present many unknown risks.
This is the world's first living human pig kidney transplantation and is regarded as a milestone event for xenotransplantation. Prior to this, two living human pig heart transplants had been performed in the United States, but both patients died within months of the procedure. In July last year, a team from New York University's Langone Medical Center performed a pig kidney transplant to a 57-year-old man who had been diagnosed as brain dead.
OpenAI推出多模态模型GPT-4o，交谈更像人
In the early morning of May 14th, OpenAI launched the latest multimodal model GPT-4o ("o" stands for omni, meaning "omni"), which brings more natural human-computer interaction, supports any combination of text, audio and image input and output, and the reaction speed is close to the human level, and it can also perceive human emotions through voice tone or facial expressions.
According to reports, GPT-4o is based on an end-to-end model across text, vision, and audio, and all inputs and outputs are processed by the same neural network. There is a significant improvement in performance for non-English texts, especially for visual and audio comprehension. GPT-4o is 2x faster than GPT-4 Turbo at half the cost. It can respond to audio input in an average of 320 milliseconds and a minimum of 232 milliseconds, which is close to the reaction speed of a human conversation. Previously, ChatGPT conducted conversations through voice mode, with an average delay of 2.8 seconds (GPT-3.5) and 5.4 seconds (GPT-4), and could not directly perceive tones, multiple people speaking, and background noise, nor could it laugh, sing, and express emotions.
GPT-4o's text and image features will be available to all users after the ChatGPT update, and Plus users will be able to use up to 5 times the number of messages in the free version (after reaching the upper limit, they will switch back to GPT-3.5). The new voice mode will be rolled out to Plus users in the coming weeks, while support for GPT-4o's new audio and video features will be available on a small scale via API.
Students' grades are modified by "noisy"? Xi'an University of Science and Technology reported the results
According to a report by CCTV, a full-time teacher from the School of Surveying and Mapping Science and Technology of Xi'an University of Science and Technology recently told reporters: In January this year, after the final results of his course came out, the parents of a student with unqualified grades asked the student to revise his grades on the grounds of "affecting the future of his child" and "causing stains", and verbally threatened the teacher. The relevant personnel of the college also mentioned many times that the parent "has a background" and asked the teacher to revise the grades.
In addition, the teacher also reported that in order to revise the grades of another student who took the make-up examination, the college transferred the grade entry authority of the course from the system without the teacher's knowledge, and other teachers modified the unqualified grades to passing scores.
On May 14, Xi'an University of Science and Technology issued a briefing:
After investigation, students Chen Moumou and Wang Moumou both participated in the make-up examination of the "GNSS Principles and Applications" course on April 8, 2024, and Chen's score was 89 points, which was true; Wang's score was 56 points, which was later changed to 60 points by the faculty member Zhang and the course leader Chen.
It was determined that the teaching clerk Zhang had a teaching accident at a certain level, and was given a demerit punishment and transferred from his original post; It was determined that the course leader Chen had a third-level teaching accident and was removed from the position of the course leader; It was determined that the vice dean in charge of teaching had a third-level teaching accident and was given a warning; gave the dean Li Moumou a warning; Yin Moumou, secretary of the party committee of the hospital, was given a demerit sanction.
Being online can improve well-being
Does being online make you happier? The general perception is negative, and this concern often comes from the negative side of the internet: cyberbullying, social media addiction, physical appearance anxiety...... A 16-year global study of 2.4 million people challenged this perception and found that internet use may improve people's well-being.
Previous studies of the same kind have been one-sided, with more than 90 percent of the datasets coming from a small number of English-speaking countries and surveys mainly of young people, so they are trying to get a more complete picture of the impact of the internet, the researchers said. Using data from the Gallup World Poll, the new study analyzes the relationship between internet use and eight indicators of well-being. The data, which spanned 2006 to 2021, were collected by telephone or face-to-face interviews and covered approximately 2.4 million participants aged 15 and older in 168 countries. The study controlled for possible influencing factors such as income level, employment status, education level, and health status. It was found that people who were able to access the internet scored 8% more on average in terms of life satisfaction, positive experiences and social life satisfaction than those who were unable to access the internet.
Research points out that online activities can have a beneficial impact by helping people learn new things and make new friends. This positive effect is similar to the health benefits that come with walking in nature.
However, women aged 15 to 24 who have used the internet in the past week have a lower average satisfaction with where they live than those who do not. This may be because people who are not welcome in the real community spend more time online. Further research is needed to determine whether the association between the internet and well-being is causal or merely related, the researchers said.
Related papers: https://doi.org/10.1037/tmb0000127
If you are hungry for two days a week, "fatty liver" will be saved?
"Fatty liver" usually refers to nonalcoholic fatty liver disease (NAFLD), which has replaced chronic hepatitis B as the most common chronic liver disease in China. If left uncontrolled and untreated, it may turn into metabolic dysfunction-related steatohepatitis (MASH, nonalcoholic steatohepatitis), with liver tissue damage and fibrosis, which can lead to cirrhosis and even liver cancer.
If fatty liver disease has already appeared, how can it be controlled and alleviated? Good news from a new study: Instead of reducing your total calorie intake, a simple adjustment to your eating pattern and leaving two hungry days a week may prevent steatohepatitis from developing.
This diet regimen is known as 5:2 intermittent fasting and focuses on fasting high-calorie fluids and foods (with free drinking water) for 2 days per week that are not consecutive, with each fasting cycle lasting 24 hours. This is one of the most common regimens for "intermittent fasting", and other more common intermittent fasting regimens include 6:1, which is a 24-hour cycle of fasting during the week. The researchers compared different intermittent fasting regimens in mouse model trials and found that 5:2 intermittent fasting was most effective in preventing and improving steatohepatitis.
The new study simulated a typical Western diet and fed the experimental group mice a high-sugar, high-fat diet for several months, and some of the mice began to use intermittent fasting after they developed fatty liver disease. As soon as each fasting cycle ended, the mice were immediately full, so their total weekly calorie intake did not decrease. However, they no longer gained weight, did not exhibit metabolic dysfunction, and blood samples had low levels of biomarkers indicative of liver injury. The analysis found that the transcription factor PPARα and PCK1, a key enzyme in glucose metabolism, were significantly upregulated during fasting, and they worked together to increase fatty acid breakdown and gluconeogenesis, and inhibit fat accumulation. Researchers say studies are needed in human patients to determine whether intermittent fasting can also prevent chronic hepatitis as it did in mice.
Related papers: http://dx.doi.org/10.1016/j.cmet.2024.04.015
More than 650 scholars have signed a petition to criticize AlphaFold 3 for being opaque and calling for the code to be made public
Last week, Google's DeepMind partnered with Isomorphic Labs to launch AlphaFold 3, a next-generation AI biomolecular structure model capable of predicting the structure and interactions of almost all living molecules with unprecedented precision. However, AlphaFold 3 is currently only accessible through a web server, and its May 8 paper in Nature does not disclose the underlying code. This drew widespread criticism from the scientific community. As of May 14, more than 650 researchers had signed an open letter expressing "disappointment" that the paper did not provide code and criticizing the journal for violating its own rules on code availability.
"It is true that companies have the right to profit from their innovations," the letter reads. However, if only the endorsement of academic publications is used to block the possibility of reproducing the results and further research, then it is a kind of damage to the scientific enterprise. The letter also criticized Nature's selective implementation of policies as "unfair" and "contrary to the needs of the scientific community." Roland Dunbrack, a structural biologist and reviewer of the paper, said he had repeatedly asked for code before the article was published, but there had been no response. Structural biologist James Fraser said that the paper's failure to justify the paper and its "no code" appeared to be a blatant violation of journal policy. Nature's submission guidelines state that the code that supports the main idea of a paper must be made available to reviewers upon request. Its editorial policy states that "authors must make the code available to readers in a timely manner without undue restrictions." ”
In addition to the 20 per day (10 at launch), AlphaFold 3 also limits the variety of objects to be analyzed. AlphaFold 3 is reportedly unable to predict the interaction between proteins and new drugs due to its interest in drug discovery company Isomorphic Labs.
In response, Nature editor-in-chief Magdalena Skipper responded in a statement: "Nature acknowledges that in some cases, it may not be possible to make research data or code publicly available. The editors "will consider a number of factors, including the potential impact on biosafety, and the ethical challenges that this poses." She said that the paper gives pseudocode that describes the steps in which the program runs, "providing an alternative to support reproduction." DeepMind said that the team will release the AF3 model within six months for academic research.
Previously reported: AlphaFold 3 is coming: predicting all biomolecular structures, interactions
Producer: Popular Science China
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