China has successfully tested a parachute system during a recent launch of a Long March-3B carrier rocket, confirming an ability to narrow the landing area by 80 percent, making the landing more precise, the Global Times learned from the China Academy of Launch Vehicle Technology (CALT) on Friday.
The test was conducted on May 17 when the rocket was successfully launched carrying the 56th satellite for China's BeiDou Navigation Satellite System.
After analysis of experimental data and debris at the site, the academy found that the parachute system can fly in accordance with arranged landing lines and precisely push the detached part of the rocket to the landing area. The system narrowed the landing area range by 80 percent, according to the academy.
The test laid the foundation for large-scale application of the system in future projects, the academy noted.
According to the academy, the parachute system was independently developed by CALT to improve the safety of the landing area of rocket debris at the inland launch site.
Encased atop one of the rocket's four boosters, the high-tech parachute system was activated after the booster separated from the rocket and fell back to a preset altitude in order to control the separated body's altitude and direction and guide it to the arranged landing area, the academy told the Global Times.
The precise controlling of the system was achieved after various rounds of optimization.
The main optimization was carried out in the electrical subsystem. Engineers integrated the design of the parachute system in the boosters with that of the rocket fairings, and also integrated the electrical equipment within the parachute system, achieving a weight reduction of 30 kilograms, according to CALT.
Chinese regulators have required apps and WeChat mini programs by domestic developers to register via the same system as domestic websites. Experts said the move will help optimize registration and management procedures and mechanisms for apps and mini programs while helping to better deal with the issues that have arisen with the expansion of the internet such as online fraud and pornographic content.
According to a notice released by WeChat on Wednesday, starting from September 1 mini programs on the platform have to register with the Internet Content Provider (ICP) system before they can become available on WeChat. The registration has to be completed in accordance with national regulations and rules such as the Law on Combating Telecom and Online Fraud, and Internet Information Service Management Measures, the notice said.
The move came one day after China's Ministry of Industry and Information Technology (MIIT) issued a notice requiring all domestic app developers to complete registration procedures.
China started to require ICP registration in 2000. The mechanism has played an active role in promoting the development of the internet in China over the past two decades. Along with the rapid development of the internet, apps have become the main content carrier of internet service and should register with the same requirements as websites, including registering the developers' real name, network resources and services, according to the notice.
Along with the rapid development of the internet in China over the years, apps and mini programs became widely used. So it is necessary to standardize and optimize the registration and management mechanism for these products, Xie Yongjiang, executive director of the Internet Management and Legislation Research Center at Beijing University of Posts and Telecommunication, told the Global Times on Wednesday.
Xie highlighted some issues that have come along with the wide usage of apps and mini programs such as gambling, telecom fraud and pornographic content in education apps for children. Strict registration and review procedures will help to prevent such problems in the future, he said.
This optimized mechanism will also help deal with emerging problems such as private information leakage given the rapid development of big data and artificial intelligence technologies, the expert said.
Mini programs already on the platform also have to finish registration by the end of March 2024 or they will be shut down starting April 1, 2024.
According to the MIIT notice on Tuesday, app developers who started providing apps in the Chinese market before the notice was issued have to register with provincial-level communications administrations where the developer is based between September 2023 and March 2024. MIIT will carry out an inspection in April-June 2024 and developers who have not registered by that time will be dealt with according to the law, the notice said.
The notice stressed that app developers in the fields of journalism, publishing, education, film and television, and religion should also provide approval documentation from provincial-level communication administrations while registering their apps.
Along with EG.5, a sublineage of the Omicron variant, being classified as a "variant of interest" by the World Health Organization (WHO), the topic of a third COVID-19 wave has triggered discussions among Chinese netizens in recent days with many sharing their infection experiences. Experts noted that the COVID-19 situation in China is still stable and that there is no need to panic.
Some netizens on Monday who said on social media that they had been reinfected a third time noted that their symptoms were lighter than previous infections. However, some shared different experiences.
The current COVID-19 infections are more hidden, but generally still at a relatively stable level. There isn't an obvious seasonal pattern for COVID-19 transmission, but usually it will show a small infection peak every five to six months. Generally, "the infection peak is decreasing, with no impact on the country's overall prevention work," Lu Hongzhou, head of the Third People's Hospital of Shenzhen, told the Global Times on Monday.
Generally speaking, fewer people have been infected for a third or more time in Shenzhen, South China's Guangdong Province, according to Lu.
Peng Jie, director of the Difficult Infectious Disease Center at Nanfang Hospital in Guangzhou, also in Guangdong, said since the peak reinfection wave in May, some patients who thought they had ordinary fevers only found out they had COVID-19 after nucleic acid testing. Among them, only a few were infected for the third time, and their symptoms are relatively light, said Peng, according to a report issued on the Guangdong authorities' WeChat account on Saturday.
National fever outpatient treatment and the number of severe COVID-19 cases have shown a fluctuating downward trend, according to the Chinese Center for Disease Control and Prevention (China CDC).
In July alone, the Chinese mainland reported 455 new serious cases of COVID-19, with 65 deaths. The patients had underlying health issues, and no one died of respiratory failure due to COVID-19, the China CDC said in its latest report issued on August 3. In June, the country reported 1,968 new serious cases, with 239 deaths, said the China CDC.
Based on the July data, the genome sequences of 9,591 local COVID-19 samples were all Omicron variant strains, covering 116 evolutionary branches, and the XBB variant strains were the main circulating ones, said the report released by the China CDC.
Due to the highly infectious nature of COVID-19 and the natural decrease in antibodies in individuals over time, basically most people can expect to be infected one to three times in a year. However, "for people with normal immune function, it will not have a significant impact on them," Lu explained.
As long as the COVID-19 mutation doesn't completely break away from the Omicron subbranch, an individual will have a cross-immune memory, so when an individual encounters the EG.5 COVID-19 strain, it will respond fast and produce antibodies, according to Lu.
EG.5 was first reported in February, and designated as a variant under monitoring in July, according to a report released by the WHO on August 9. There has been a steady increase in the proportion of EG.5 reported globally. From July 17 to 23, the global prevalence of EG.5 was 17.4 percent, a notable rise from the data reported in the week from June 19 to 25, when the global prevalence of EG.5 was 7.6 percent, according to the WHO.
Lu suggested people with underlying health issues receive COVID-19 vaccinations regularly, including nasal spray vaccines or other multivalent vaccine strategies.
Though a slew of efforts have made to win back foreign tourists, Myanmar has been spurned due to rising security concerns caused by high profile telecom fraud cases and domestic political turmoil. Bookings for five-star hotels in the country still have been desolate even though the prices of some rooms have dropped to 300 yuan ($40) per night, Chinese media reported.
Some starred hotels in Myanmar have even been forced to give 40 percent discounts to lure in tourists. Earlier this year, the famous Sedona Hotel Yangon was forced to sell to a Singaporean company and a $130 million Peninsula hotel project in Yangon was suspended due to political instability and other factors, media reports said.
When reached by the Global Times on Thursday, several travel agencies, including Beijing China International Travel Service Co, Shanghai China International Travel Service Co, Spring Tour, tuniu.com and Shanghai Airlines Tours International, replied that they have no tourism products for Myanmar on offer at the moment.
They were uncertain about when these tours would resume. A staffer from tuniu.com told the Global Times that they can only provide business visa services at the moment.
According to a notice issued by the General Office of China's Ministry of Culture and Tourism on August 10, travel agencies and online tourism service providers across the country have been permitted to resume outbound group tours and "airline tickets plus hotel" services for Chinese citizens to destinations listed in the third batch of permitted countries and regions. Myanmar is included on the list of Asian countries.
It is no longer surprising to see Chinese people say they are worried about being caught in telecom scams due to stereotypes involving Myanmar. The unfavorable perceptions about the South Asian nation were once again reinforced by No More Bets, a crime action drama currently dominating the box office in the Chinese mainland.
In a poll conducted by Chinese media on Thursday inquiring about whether Chinese netizens would travel to Myanmar, 8,901 respondents out of 9,298 said they wouldn't consider going due to safety concerns.
Chinese tourists' unfavorable perception toward Myanmar is a result of multiple factors - political turmoil, rising concerns over rampant telecom fraud cases and the relatively poor tourism reception capability comparing to other South Asian countries, Song Qingrun, a senior research fellow from the School of Asian Studies at Beijing Foreign Studies University, told the Global Times on Thursday. Limited direct flights could also be one of the reasons why there hasn't been a jump in the number of Chinese tourists traveling to the country, Song noted.
Myanmar's political society has been continually torn apart in the past few years. The struggle between the military and its supporters and the opposition has turned violent. Some extremist rebels have formed shadow governments along the border, carrying out scattered violent attacks on government departments and military and political officials, Song noted.
The Chinese Embassy in Myanmar frequently reminds Chinese citizens not to believe high-salary recruitment information online, engage in illegal or criminal activities, so as to avoid damage to life and property during their stay in Myanmar. Previously, the UK warned British citizens not to travel to the conflict zone in Myanmar and the US State Department has also issued a Level 4 advisory against travel to the country, quoting civil unrest and armed conflicts.
According to figures from the Myanmar's Ministry of Hotels and Tourism, from April 2022 to the end of March in 2023, Myanmar received a total of 367,368 international tourists, of which Chinese tourists topped the list at 48,342, accounting for 13.15 percent. This is not even a fraction of what it used to be.
The latest data during the first half of 2023 showed that Myanmar attracted just 450,000 foreign tourists, led by Chinese and Thai tourists. Although it saw an increase compared to the same period last year, that increase is far less than that of neighboring countries, media reported.
Song told the Global Times that the peak influx of Chinese travelers to the South Asian country in 2016 and 2017 has not returned despite the resumption of China's group tours to the country. However, Song said that since Myanmar is a close neighboring country of China and contains vast abundant tourism resources, it is still attractive to many Chinese travelers. He also called for a rational view of the country since the stereotype that it is plagued by crimes may have been amplified by media.
Myanmar has been making efforts to optimize its domestic tourists market. Myanmar's ambition to win back more Chinese tourists can clearly be seen at the ongoing seventh China-South Asia Expo in Kunming, Southwest China's Yunnan Province, Song said.
Myanmar has arranged for more than 100 entrepreneurs to participate in the exhibition and for the first time used naked eye 3D screens to display the beautiful cultural scenes of the country, the China News Service has reported.
Some tourism insiders pointed out that the gloomy tourism enthusiasm from Chinese people in the post COVID-19 era does not specially target the country, but the entire South Asian tourism market. An employee surnamed Sun from Shanghai Airlines Tours International told the Global Times that tours to Southeast Asian countries have all shown average poor performances these days except for the Philippines.
The Culture and Tourism Department of Northwest China's Qinghai Province issued an announcement on Monday, strictly prohibiting tourists from entering unmanned scenic areas for activities such as exploration and tourism, adding that the full cost of rescue operations will be borne entirely by the involved individuals and groups as the rescue work is extremely challenging, in the event of getting stranded.
With the increasing popularity and fervor of self-driving tours and adventure sports in recent years, a growing number of tourists and adventurers are opting to venture into uninhabited areas. Consequently, a series of incidents involving missing people and fatalities have unfolded in tandem.
Located within the heart of the Qinghai-Tibet Plateau, Qinghai Province is situated in a cold and high-altitude region. In certain areas, communication signals can be weak or nonexistent. The region features numerous "dangerous zones" and "uninhabited areas," with complex terrain and environmental conditions.
The announcement issued by local authorities highlighted that individuals venturing into uninhabited, unreleased, and undeveloped scenic areas, whether on foot or by vehicle, will face unpredictable risks. Travelers might encounter life-threatening situations such as dehydration, oxygen deficiency, getting lost, vehicle breakdowns, and communication loss at any time.
The latest case is that one of the vehicles carrying four people on a driving holiday has gone missing while crossing the Xinjiang Lop Nur Wild Camel National Nature Reserve without authorization, resulting in four deaths, according to media reports and local police from Ruoqiang County in Northwest China's Xinjiang Uygur Autonomous Region on July 28.
Following extensive search and rescue operations, the missing vehicle was located, with four individuals found dead. The rest of the convoy members have safely returned to Dunhuang in neighboring Gansu Province.
Industry experts said on Saturday that entering the Lop Nur in summer is very risky, as surface temperatures in the area would reach as high as 70 C. Vehicle breakdowns, communication malfunctions, and the lack of adequate logistical support can all lead to adventurers being unable to safely exit unpopulated areas.
The local government emphasized in the statement that tourists should further enhance their self-protection awareness. They should refrain from leaving designated roads and venturing deep into dangerous areas such as uninhabited, unopened, and undeveloped scenic spots for adventure, tourism, and crossings.
Furthermore, the statement particularly underscores that without proper authorization or reporting to relevant authorities, no individual or organization shall organize tourist groups under the pretext of exploration, crossing, or scientific research to venture deep into natural conservation areas. In the event of getting stranded, the full cost of rescue operations will be borne entirely by the involved individuals and groups.
Travelers should carefully assess their routes, and pay attention to weather forecasts, geological hazards, and traffic conditions while also maintaining ample reserves of supplies and ensuring vehicle maintenance, which is essential to ensure the safety of the journey, said the statement.
China's Ministry of Culture and Tourism recently released a notice announcing the third group of approved outbound group tours, with Japan being one of the most popular tourist destinations. However, following the commencement of Japan's dumping of nuclear-contaminated wastewater, cancellations of tours to the country have already begun, local media reported on Sunday.
According to one of China's largest online travel agencies Ctrip, the platform had launched more than 5,000 outbound group tour packages, flights and hotel bundles, covering more than one-third of the countries and regions across the third group of 78 approved countries, including the US, the UK, Japan and Turkey.
However, everything changed when Japan started to dump nuclear-contaminated wastewater into the Pacific Ocean.
The First Financial Journal reported on Saturday that although Japanese tourism products are still being sold on online travel platforms, they are not being prominently displayed.
At the same time, tourism industry insiders have revealed that some travelers have already started to cancel their trips. Several travel agencies have reported similar situations. In view of the current escalation of the dumping plan, many tourism companies have stated that they will make adjustments in their upcoming marketing plans, especially in promoting travel packages for the upcoming National Day holidays. Many reportedly plan to temporarily reduce the promotion of Japanese tours or suspend related marketing plans for travel to Japan.
Currently, Ctrip's platform has more than 80,000 outbound group tours and flight and hotel packages available for purchase.
"My husband and I booked a tour group to Japan and submitted our visas last week, but after seeing the news of Japan's irresponsible dumping plan, we decided to cancel the trip and switch to another country," a newlywed couple who are picking out a place for their honeymoon told the Global Times on Sunday.
"Japan is not an irreplaceable tourist destination and their irresponsible behavior is unacceptable to us."
Data from Ctrip shows that the booking volume for Japan group tours increased by nearly 90 percent in the previous week compared with the same period last month, while the booking volume for Japan group tour products departing during the National Day holidays has increased by over fivefold.
However, influenced by the side effect of Japan's forced dumping, travel platforms and agencies are promoting tourist attractions in other countries. For example, Lümama is currently promoting packages to Germany, the UK and other destinations in Northern Europe over those to Japan.
Although traveling to Japan has gotten a lot of attention since the list came into effect, it is actually not the No. I option, a marketing manager from China's CYTS Tours Holding Co, told the Global Times on Sunday.
It is expected that Japan's forced dumping will have an impact on tourists' travel expectations. For the upcoming National Day holidays, Japan may not be as hot as previously expected, Xu said. At present, CYTS Tours still provides neutral guidance to guests who inquire about traveling to Japan. However, according to Xu, reminders and rescheduling will be offered to guests who are looking to eat seafood.
In the short term, it is expected that Japan's dumping plan will affect tourism to Japan and the export of Japanese brands, and may even affect cultural exchanges such as overseas studying in Japan. However, in the medium- and long-term, the state of communication and the policies of the bilateral governments are the main factors affecting people's mentality, Da Zhigang, director of the Institute of Northeast Asian Studies at the Heilongjiang Provincial Academy of Social Sciences, told the Global Times.
Many Chinese netizens have said they would no longer patronize Japanese restaurants and Chinese consumers are increasingly resistant to buying Japanese products, including cosmetics, with many creating blacklists of more than 30 Japanese cosmetic brands and lists of alternatives, while some have even started to return purchased goods.
According to the latest statistics released on August 16, the number of foreign tourists to Japan in July exceeded 2 million for a second consecutive month, about 2,320,600, while the number of tourists in the month recovered to about 78 percent of the same period in 2019 before the COVID-19 pandemic. Visitors from the Chinese mainland ranked fifth in the first half of the month with 594,600 visitors. Additionally, the Japanese government has set a new goal for the recovery of tourism, which is to achieve a new record number of visitors to Japan by 2025.
Observers believe that Japan was expected to benefit from a boost in tourism activity during the week-long Chinese National Day holidays. However, following safety concerns caused by Japan's dumping of nuclear-contaminated wastewater into the sea, Chinese tourists' enthusiasm for traveling to Japan during the holidays has significantly decreased. If Chinese tourists "vote with their feet," the overall tourism economy in Japan may shrink for a considerable period of time due to a sustained decrease in the number of Chinese tourists.
The dumping of nuclear-contaminated wastewater from the Fukushima nuclear power plant in Japan has raised concerns among Chinese citizens about the state of the marine environment. Chinese environmental authorities on Monday vowed to strengthen the monitoring of marine environmental pollution through multiple means, including conducting baseline surveys of marine pollution and utilizing satellites for monitoring.
China has launched its third marine pollution baseline survey, with the goal of completing a thorough investigation and assessment by 2025, said Wang Juying, the director of the National Marine Environmental Monitoring Center, at the ministry's monthly press conference on Monday.
According to Wang, this survey follows the overall approach of "understanding the current situation, identifying problems, analyzing causes, and proposing countermeasures," and focuses on China's coastal waters and the country's 283 bays, with the aim of understanding the baseline levels of various pollutants in China's jurisdictional waters, the ecological conditions of various bays, and the impact of human activities.
"The survey aims to comprehensively grasp the basic state and trends of the marine ecological environment," Wang said.
China previously conducted the first and second national marine pollution baseline surveys in 1976 and 1996, respectively.
Hu Songqin, deputy director of the Department of Marine Ecology and Environment of the Ministry of Ecology and Environment, mentioned during the conference that the recent successful launch of a satellite to serve environmental protection and disaster management will significantly enhance data support and emergency response capabilities for sudden water environmental pollution events.
She stated that the Ministry of Ecology and Environment will actively collaborate with relevant research institutions and coastal regions, making effective use of data sources from monitoring systems.
"These will provide crucial technical support for addressing sudden environmental events, pollution incidents, investigations of key risk sources, and enhancing marine ecological environmental governance capabilities," she noted.
In response to Japan dumping the contaminated water from the Fukushima nuclear plant into the ocean, the Ministry of Ecology and Environment has stated the specific measures that China has taken in terms of marine radiation environment monitoring.
At present, the ministry is actively conducting marine radiation environment monitoring in areas under China's jurisdiction for the year 2023, guided by a focus on critical regions, comprehensive coverage of jurisdictional waters, and a thorough understanding of key pathways, according to the ministry.
The ministry also vowed that in the future it will continue to strengthen relevant monitoring efforts, closely track and assess the potential impact of of contaminated water from the Fukushima nuclear plant on China's marine environment, and effectively safeguard the national interests and public health.
In 2021 and 2022, the ministry organized marine radiation environment monitoring in areas under China's jurisdiction, which provided insight into the baseline condition of the marine radiation environment in these regions. The monitoring results indicated that there were no abnormal levels of artificial radioactive isotopes in the seawater and marine organisms in China's jurisdictional waters, and overall, the concentrations remained within the historical fluctuation range.
Here’s a good idea for the next presidential candidate debate: They can insult each other about their ignorance of statistics.
Actually, it’s a pertinent topic for political office seekers, as public opinion polls use statistical methods to measure the electorate’s support (or lack thereof) for a particular candidate. But such polls are notoriously unreliable, as Hillary Clinton found out in Michigan.
It probably wouldn’t be a very informative debate, of course — just imagine how Donald Trump would respond to a question asking what he thought about P values. Sadly, though, he and the other candidates might actually understand P values just about as well as many practicing scientists — which is to say, not very well at all. In recent years criticism about P values — statistical measures widely used to analyze experimental data in most scientific disciplines — has finally reverberated loudly enough for the scientific community to listen. A watershed acknowledgment of P value problems appeared this week when the American Statistical Association issued a statement warning the rest of the world about the limitations of P values and their widespread misuse.
“While the p-value can be a useful statistical measure, it is commonly misused and misinterpreted,” the statistical association report stated. “This has led to some scientific journals discouraging the use of p-values, and some scientists and statisticians recommending their abandonment.”
In light of these issues, the association convened a group of experts to formulate a document listing six “principles” regarding P values for the guidance of “researchers, practitioners and science writers who are not primarily statisticians.” Of those six principles, the most pertinent for people in general (and science journalists in particular) is No. 5: “A p-value, or statistical significance, does not measure the size of an effect or the importance of a result.”
What, then, does it measure? That’s principle No. 1: “… how incompatible the data are with a specified statistical model.” But note well principle No. 2: “P-values do not measure the probability that the studied hypothesis is true, or the probability that the data were produced by random chance alone.” And therefore, always remember principle No. 3: “Scientific conclusions … or policy decisions should not be based only on whether a p-value passes a specific threshold.”
In other words, the common convention of judging a P value less than .05 to be “statistically significant” is not really a proper basis for assigning significance at all. Except that scientific journals still regularly use that criterion for deciding whether a paper gets published. Which in turn drives researchers to finagle their data to get a P value of less than .05. As a result, the scientific process is tarnished and the published scientific literature is often unreliable. As the statistical association statement points out, this situation is far from merely of academic concern.
“The issues touched on here affect not only research, but research funding, journal practices, career advancement, scientific education, public policy, journalism, and law,” the authors point out in the report, published online March 7 in The American Statistician.
Many of the experts who participated in the process wrote commentaries on the document, some stressing that it did not go far enough in condemning P values’ pernicious influences on science.
“Viewed alone, p-values calculated from a set of numbers and assuming a statistical model are of limited value and frequently are meaningless,” wrote biostatistician Donald Berry of MD Anderson Cancer Center in Houston. He cited the serious negative impact that misuse and misinterpretation of P values has had not only on science, but also on society. “Patients with serious diseases have been harmed. Researchers have chased wild geese, finding too often that statistically significant conclusions could not be reproduced. The economic impacts of faulty statistical conclusions are great.”
Echoing Berry’s concerns was Boston University epidemiologist Kenneth Rothman. “It is a safe bet that people have suffered or died because scientists (and editors, regulators, journalists and others) have used significance tests to interpret results,” Rothman wrote. “The correspondence between results that are statistically significant and those that are truly important is far too low to be useful. Consequently, scientists have embraced and even avidly pursued meaningless differences solely because they are statistically significant, and have ignored important effects because they failed to pass the screen of statistical significance.”
Stanford University epidemiologist John Ioannidis compared the scientific community’s attachment to P values with drug addiction, fueled by the institutional rewards that accompany the publication process.
“Misleading use of P-values is so easy and automated that, especially when rewarded with publication and funding, it can become addictive,” Ioannidis commented. “Investigators generating these torrents of P-values should be seen with sympathy as drug addicts in need of rehabilitation that will help them live a better, more meaningful scientific life in the future.”
Although a handful of P value defenders can still be found among the participants in this discussion, it should be clear by now that P values, as currently used in science, do more harm than good. They may be valid and useful under certain specific circumstances, but those circumstances are rarely relevant in most experimental contexts. As Berry notes, statisticians can correctly define P values in a technical sense, but “most statisticians do not really understand the issues in applied settings.”
In its statement, the statistical association goes a long way toward validating the concerns about P values that have been expressed for decades by many critical observers. This validation may succeed in initiating change where previous efforts have failed. But that won’t happen without identifying some alternative to the P value system, and while many have been proposed, no candidate has emerged as an acceptable nominee for a majority of the scientific world’s electorate. So the next debate should not be about P values — it should be about what to replace them with.
Modern-day Melanesians carry a two-pronged genetic legacy of ancient interbreeding that still affects their health and well-being, researchers say.
Unlike people elsewhere in the world, these Pacific islanders possess nuclear DNA that they inherited from two Stone Age hominid populations, say population geneticist Benjamin Vernot, formerly of the University of Washington in Seattle, and his colleagues. At least some of that ancient DNA contains genes involved in important biological functions, the researchers find. Nuclear DNA is passed from both parents to their children. The finding means that ancestors of people now living in the Bismarck Archipelago, a group of islands off Papua New Guinea’s northeastern coast, mated with Neandertals as well as with mysterious Neandertal relatives called Denisovans, the scientists conclude online March 17 in Science.
In support of previous research, the researchers find that non-Africans — including Melanesians — have inherited an average of between 1.5 and 4 percent of their DNA from Neandertals. But only Melanesians display substantial Denisovan ancestry, which makes up 1.9 to 3.4 percent of their DNA, the researchers say. (Present-day African populations possess little to no Neandertal or Denisovan DNA.)
The bits of Neandertal and Denisovan DNA carried by Melanesians encompass genes involved in metabolism and immunity, indicating that interbreeding influenced the evolutionary success of ancient humans, Vernot’s group reports.
The new study reconstructs the microscopic landscape of Neandertals’ and Denisovans’ contributions to Melanesians’ DNA “in impressive detail,” says Harvard University paleogeneticist Pontus Skoglund.
Vernot’s team studied DNA from 35 Melanesians at 11 locations in the Bismarck Archipelago. Analyses concentrated on DNA from 27 unrelated individuals. The researchers also looked for evidence of ancient interbreeding in previously acquired genomes of close to 1,500 modern-day individuals from different parts of the world. Denisovan DNA for comparisons came from fragmentary fossils found in a Siberian cave; comparative Neandertal DNA came from a genome previously extracted from a 50,000-year-old woman’s toe bone. Among Melanesians, DNA sequences attributed to Neandertals and Denisovans encompassed several metabolism genes. One of those genes influences a hormone that increases blood glucose levels. Another affects the chemical breakdown of lipids. Other Melanesian genetic sequences acquired through ancient interbreeding either include or adjoin genes that help to marshal the body’s defenses against illness.
These findings follow evidence suggesting that once-useful genes that ancient humans inherited from Neandertals now raise the risk of contracting certain diseases (SN: 3/5/16, p. 18). Vernot’s group reaches no conclusions about good or bad effects of ancient hybrid genes in Melanesians.
No sign of Neandertal or Denisovan DNA appears in areas of Melanesians’ genomes involved in brain development, the scientists say. So brain genetics, for better or worse, apparently evolved along a purely human path.
Denisovans’ evolutionary history remains poorly understood. Previous DNA comparisons suggest that Denisovans must have reached Southeast Asia. Skoglund suspects that’s where the ancestors of Melanesians bred with Denisovans.
Substantial interbreeding of humans with Denisovans probably occurred only once, Vernot and his colleagues suspect. Genetic exchanges of humans with Neandertals took place at least three times, they add. These estimates are derived from comparisons of shared Denisovan and Neandertal DNA sequences among individuals in different parts of the world.
The 22 men took the same pill for four weeks. When interviewed, they said they felt less daily stress and their memories were sharper. The brain benefits were subtle, but the results, reported at last year’s annual meeting of the Society for Neuroscience, got attention. That’s because the pills were not a precise chemical formula synthesized by the pharmaceutical industry.
The capsules were brimming with bacteria.
In the ultimate PR turnaround, once-dreaded bacteria are being welcomed as health heroes. People gobble them up in probiotic yogurts, swallow pills packed with billions of bugs and recoil from hand sanitizers. Helping us nurture the microbial gardens in and on our bodies has become big business, judging by grocery store shelves. These bacteria are possibly working at more than just keeping our bodies healthy: They may be changing our minds. Recent studies have begun turning up tantalizing hints about how the bacteria living in the gut can alter the way the brain works. These findings raise a question with profound implications for mental health: Can we soothe our brains by cultivating our bacteria? By tinkering with the gut’s bacterial residents, scientists have changed the behavior of lab animals and small numbers of people. Microbial meddling has turned anxious mice bold and shy mice social. Rats inoculated with bacteria from depressed people develop signs of depression themselves. And small studies of people suggest that eating specific kinds of bacteria may change brain activity and ease anxiety. Because gut bacteria can make the very chemicals that brain cells use to communicate, the idea makes a certain amount of sense.
Though preliminary, such results suggest that the right bacteria in your gut could brighten mood and perhaps even combat pernicious mental disorders including anxiety and depression. The wrong microbes, however, might lead in a darker direction. This perspective might sound a little too much like our minds are being controlled by our bacterial overlords. But consider this: Microbes have been with us since even before we were humans. Human and bacterial cells evolved together, like a pair of entwined trees, growing and adapting into a (mostly) harmonious ecosystem.
Our microbes (known collectively as the microbiome) are “so innate in who we are,” says gastroenterologist Kirsten Tillisch of UCLA. It’s easy to imagine that “they’re controlling us, or we’re controlling them.” But it’s becoming increasingly clear that no one is in charge. Instead, “it’s a conversation that our bodies are having with our microbiome,” Tillisch says.
Figuring out what’s being said in this body-microbe exchange, and how to shift the tone in a way that improves mental health, won’t be easy. For starters, no one knows the exact ingredients for a healthy microbial community, and the recipe probably differs from person to person. And it’s not always simple to deliver microbes to the gut and persuade them to stay. Nor is it clear how messages travel between microbes and brain, though scientists have some ideas.
It’s early days, but so far, the results are compelling, says neuroscientist John Cryan of University College Cork in Ireland, who has been trying to clarify how microbes influence the brain. “It’s all slightly weird and it’s all fascinating,” he says.
Cryan and others are amassing evidence that they hope will lead to “psychobiotics” — bacteria-based drugs made of live organisms that could improve mental health.
We’re not alone Ted Dinan, the psychiatrist who coined the term “psychobiotics,” was fascinated by a tragedy in Walkerton, Canada, in May 2000. Floods caused the small town’s water supply to be overrun with dangerous strains of two bacteria: Escherichia coli and Campylobacter. About half the town’s population got ill, and a handful of people died. For most residents, the illness was short-lived, about 10 days on average, says Dinan, who collaborates with Cryan at University College Cork. But years later, scientists who had been following the health of Walkerton residents noticed something surprising. “The rates of depression in Walkerton were clearly and significantly up,” Dinan says. That spike raised suspicion that the infection had caused the depression.
Other notorious bacteria have been tied to depression, such as those behind syphilis and the cattle-related brucellosis, and not just because ill people feel sad, Dinan says. He suspects there’s something specific about an off-kilter microbiome that can harm mental health. This possibility, though it raises troubling questions about free will, is certainly true for lab animals. Mice born and raised without bacteria behave in all sorts of bizarre ways, exhibiting antisocial tendencies, memory troubles and recklessness, in some cases. Microbes in fruit flies can influence who mates with whom (SN: 1/11/14, p. 14), and bacteria in stinging wasps can interfere with reproduction in a way that prevents separate species from merging. Those findings, some by evolutionary biologist Seth Bordenstein of Vanderbilt University in Nashville, show that “there’s this potential for [microbes] to influence behavior in this complex and vast way,” he says.
By sheer numbers, human bodies are awash in bacteria. A recent study estimates there are just as many bacterial cells as human cells in our bodies (SN: 2/6/16, p. 6). Just how legions of bacteria get messages to the brain isn’t clear, though scientists have already found some likely communication channels. Chemically, gut microbes and the brain actually speak the same language. The microbiome churns out the mood-influencing neurotransmitters serotonin, norepinephrine and dopamine. Bacteria can also change how the central nervous system uses these chemicals. Cryan calls microbes in the gut “little factories for producing lots of different neuroactive substances.”
Signals between the gut and the brain may zip along the vagus nerve, a multilane highway that connects the two (SN: 11/28/15, p. 18). Although scientists don’t understand the details of how messages move along the vagus nerve, they do know that this highway is important. Snip the nerve in mice and the bacteria no longer have an effect on behavior, a 2011 study found. And when the gut-to-brain messages change, problems can arise.
New bacteria, new behavior Wholesale microbe swaps can also influence behavior. In unpublished work, Dinan and his colleagues took stool samples from people with depression and put those bacteria (called “melancholic microbes” by Dinan in a 2013 review in Neurogastroenterology and Motility) into rats. The formerly carefree rodents soon began showing signs of depression and anxiety, forgoing a sweet water treat and showing more anxiety in a variety of tests. “Their behavior does quite dramatically change,” Dinan says. Rats that got a microbiome from a person without depression showed no changes in behavior.
Cryan and colleagues have found that the microbiomes of people with depression differ from those of people without depression, raising the possibility that a diseased microbiome could be to blame. The fecal-transplant results suggest that depression — and perhaps other mental disorders — are contagious, in a sense. And a mental illness that could be caught from microbe swaps could pose problems. Fecal transplants have recently emerged as powerful ways to treat serious gut infections (SN Online: 10/16/14). Fecal donors ought to be screened for a history of mental illness along with other potentially communicable diseases, Dinan says.
“Gastroenterologists obviously check for HIV and hepatitis C. They don’t want to transmit an infection,” he says. The psychiatric characteristics of the donor should be taken into account as well, he says.
A fecal transplant is an extreme microbiome overhaul. But there are hints that introducing just one or several bacterial species can also change the way the brain works. One such example comes from Cryan, Dinan and colleagues. After taking a probiotic pill containing a bacterium called Bifidobacterium longum for a month, 22 healthy men reported feeling less stress than when they took a placebo. The men also had lower levels of the stress-related hormone cortisol while under duress, the researchers reported at the Society for Neuroscience meeting in Chicago last October. After taking the probiotic, the men also showed slight improvements on a test of visual memory, benefits that were reflected in the brain. EEG recordings revealed brain wave signatures that have been tied to memory skill, Cryan says.
The researchers had previously published similar effects in mice, but the new results move those findings into people. “What’s going to be important is to mechanistically find out why this specific bacteria is inducing these effects,” Cryan says. And whether there could be a benefit for people with heightened anxiety. “It’s a very exciting study, but it’s a small study,” Cryan cautions.
Bacteria in an even more palatable form — yogurt — affected brain activity in response to upsetting scenes in one study. After eating a carefully concocted yogurt every morning and evening for a month, 12 healthy women showed a blunted brain reaction to pictures of angry or scared faces compared with 11 women who had eaten a yogurtlike food without bacteria.
Brain response was gauged by functional MRI, which measures changes in blood flow as a proxy for neural activity. In particular, brain areas involved in processing emotions and sensations such as pain were calmed, says Tillisch, coauthor of the study, published in 2013 in Gastroenterology. “In this small group, we saw that the brain responded differently” when shown the pictures, she says. It’s not clear whether a blunted response would be good or bad, particularly since the study participants were all healthy women who didn’t suffer from anxiety. Nonetheless, Tillisch says, the results raise the questions: “Can probiotics change your mood? Can they make you feel better if you feel bad?”
So far, the human studies have been very small. But coupled with the increasing number of animal studies, the results are hard to ignore, Tillisch says. “Most of us in this field think there is something definitely happening,” she says. “But it’s pretty complicated and probably quite subtle…. Otherwise, we’d all be aware of this.” Anyone who has taken a course of antibiotics, or fallen ill from a bacterial infection, or even changed diets would have noticed an obvious change in mood, she says.
Two-way traffic If it turns out that bacteria can influence our brains and behaviors, even if just in subtle ways, it doesn’t mean we are passive vessels at the mercy of our gut residents. Our behavior can influence the microbiome right back.
“We usually give up our power pretty quickly in this conversation,” Tillisch says. “We say, ‘Oh, we’re at the mercy of the bacteria that we got from our mothers when we were born and the antibiotics we got at the pediatrician’s office.’ ” But our microbes aren’t our destiny, she says. “We can mess with them too.”
One of the easiest ways to do so is through food: eating probiotics, such as yogurt or kefir, that contain bacteria and choosing a diet packed with “prebiotic” foods, such as fiber and garlic, onion and asparagus. Prebiotics nourish what are thought to be beneficial microbes, offering a simple way to cultivate the microbiome, and in turn, health. That a good diet is a gateway to good health is not a new idea, Cryan says. Take the old adage: “Let food be thy medicine and let medicine be thy food.” He suspects that it’s our microbiome that makes this advice work.
Combating stress may be another way to change the microbiome, Tillisch and others suspect. Mouse studies have shown that stress, particularly early in life, can change microbial communities, and not in a good way.
She and her colleagues are testing a relaxation technique called mindfulness-based stress reduction to influence the microbiome. In people with gut pain and discomfort, the meditation-based practice reduced symptoms and changed their brains in clinically interesting ways, according to unpublished work. The researchers suspect that the microbiome was also altered by the meditation. They are testing that hypothesis now.
If the mind can affect the microbiome and the microbiome can affect the mind, it makes little sense to talk about who is in charge, Bordenstein says. In an essay in PLOS Biology last year, he and colleague Kevin Theis, of Wayne State University in Detroit, make the case that the definition of “I” should be expanded. An organism, Bordenstein and Theis argued, includes the microbes that live in and on it, a massive conglomerate of diverse parts called a holobiont. Giving a name to this complex and diverse consortium could shift scientists’ views of humans in a way that leads to deeper insights. “What we need to do,” Bordenstein says, “is add microbes to the ‘me, myself and I’ concept.”
