Part of Real Paleo Diet: It's a Tuber
Christopher Intagliata | January 3, 2020
The paleo diet is a popular high-protein diet that aims to mimic what our hunter-gatherer ancestors ate. But what we buy at the supermarket doesn't quite approximate those ancient foods. Take for example, star lily roots. Heard of those?
"They taste a bit like yams."
Lyn Wadley is an archaeologist at the University of the Witwatersrand in South Africa. Her team recently discovered the charred remains of star lily roots in South Africa's Border Cave… hunks of roasted root that date to 170,000 years ago.
"There's greater glucose availability once the root vegetables were cooked. And they knew that nearly 200,000 years ago, which I think is extraordinary. Or maybe they didn't know the chemistry of it, but they would have realized they felt far more satisfied after eating a meal that's cooked rather than one that is raw."
It's not easy to identify a charred chunk of ancient food though. So Wadley's team gathered an array of raw ancient foodstuffs, and roasted and charred them in ovens and campfires. They then did visual comparisons to the ancient sample, and observed them both in a scanning electron microscope too. Which revealed that the charred leftovers from that meal, 170,000 years ago, were probably chunks of star lily root.
Details, and photos of those roots, are in the journal Science. [Lyn Wadley et al, Cooked starchy rhizomes in Africa 170 thousand years ago]
Wadley says the find provides a better view of what the ancients ate. "I think the people who assume the paleo diet was based on protein simply haven't done their homework properly."
Source: Scientific American
https://www.scientificamerican.com/podcast/episode/part-of-real-paleo-diet-its-a-tuber/
[Rephrase 1, 01:51]
What CRISPR-baby prison sentences mean for research
David Cyranoski | January 3, 2020
[Time 2]
A Chinese court has sentenced He Jiankui, the biophysicist who announced that he had created the world’s first gene-edited babies, to three years in prison for “illegal medical practice”, and handed down shorter sentences to two colleagues who assisted him. The punishments put to rest speculation over whether the Chinese government would bring criminal charges for an act that shocked the world, and are likely to deter others from similar behaviour, say Chinese scientists.
There has been much speculation about whether other scientists would follow in He‘s footsteps, especially given the ease of using the most popular gene-editing tool, CRISPR-Cas9. But the punishments are “definitely a deterrent to similar misconduct in China”, says Wei Wensheng, a gene-editing researcher at Peking University in Beijing.
On 30 December, the People’s Court of Nanshan District of Shenzhen announced that, in the pursuit of “fame and profit”, He and two colleagues had flouted regulations and research and medical ethics by altering genes in human embryos that were then implanted into two women, according to Xinhua News Agency. One woman gave birth to twin girls in late 2018; the court said a third baby has been born but did not say when, a revelation that fits with a claim made by He in November 2018 to have implanted a gene-edited embryo in a second woman.
The court fined He 3 million yuan (US$430,000). Collaborators Zhang Renli and Qin Jinzhou received lesser prison sentences and fines.
The health ministry has also banned the researchers from ever working with human reproductive technology again, and the science ministry has banned them from applying for research funding, according to Xinhua.
Scientists in China who are currently researching CRISPR for its potential to treat various genetic diseases by modifying cells other than embryos say that they fear He's actions might have a chilling effect on their work too, even though it is not as ethically fraught.
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[Time 3]
Preliminary stage
He shocked the world’s scientists in November 2018 when he announced that his team at Southern University of Science and Technology in Shenzhen had used the CRISPR gene-editing system to edit DNA in human embryos to make them less susceptible to contracting HIV. The edits were designed to disrupt a gene that codes for a protein that allows HIV to enter immune cells.
Scientists condemned He’s actions, saying that gene-editing technology was too premature to be used for reproductive purposes. They also said the experiment was problematic because it risked introducing a mutation with potentially harmful effects while offering little benefit — the babies were not at high risk of contracting HIV. In the wake of the scandal, researchers called for a moratorium on gene editing in embryos and germline cells.
At the time, Chinese law academics told Nature that He could face a range of criminal charges, including practising medicine without adequate qualifications, which can be punished by up to ten years in prison, forging ethics documents and skirting laws banning the use of assisted reproductive technologies in people with HIV. He was fired by his university in January last year.
The court’s announcement puts to rest suspicions by some researchers that the government would not bring criminal case against He because of the increased media attention it would generate, says Tang Li, a science-policy researcher at Fudan University in Shanghai. He’s experiments seemed to embarrass the country, and discussion of them was widely censored on Chinese social media. But Tang says the immediate disclosure of the court’s result demonstrates China’s commitment on research ethics. This is a big step forward in promoting the responsible research and the ethical use of technology, she says.
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[Time 4]
Although an unpublished manuscript describing the experiments lists ten authors, according to MIT Technology Review, He, Zhang and Qin are the only ones to face penalties so far. The manuscript says Zhang “performed the human embryo microinjections”, according to MIT Technology Review. Zhang, who was affiliated with the Guangdong Academy of Medical Sciences and Guangdong General Hospital in Guangzhou at the time of the experiments, has been sentenced to two years in prison and fined one million yuan. Attempts to obtain a comment from the hospital about whether Zhang still works there were unsuccessful. Qin, an embryologist at Southern University of Science and Technology who was named as the applicant on the experiment listed on China’s clinical-trial website, was given an 18-month suspended prison sentence and fined 500,000 yuan, according to Xinhua. The university has also not responded to Nature’s queries about his current employment status.
Wei says it is unlikely that He will be able to work again as a researcher in a Chinese institution or university.
The trio’s prison sentences, combined with the research-funding ban, send a powerful message to other researchers doing any type of gene-editing work in clinical trials in China, says Lu You, an oncologist at Sichuan University in Chengdu who was the first to test CRISPR gene-editing in a person, in a trial that modified adult cells — not embryos — taken from patients in order to treat lung cancer. Lu is in the process of publishing tho results. “If I was a newcomer, a researcher wishing to start gene-editing research and clinical trials, the case would be enough to alert me to the cost of such violations,” he says.
But Wei, who uses CRISPR tools to study how humans respond to microbial diseases, is concerned that the international condemnation that followed He‘s explosive announcement in 2018 might have a wider chilling effect on CRISPR work in China. Wei worries that it might be difficult to get approval to use gene editing tools in clinical trials, including using the tool to edit adult cells, which does not raise the same ethical questions as work in embryos, although he has not heard of researchers facing such issues yet.
[361 words]
Source: Nature
https://www.nature.com/articles/d41586-020-00001-y
Why Lunar New Year prompts the world’s largest annual migration
Erin Blakemore | January 2, 2020
[Time 5]
Celebrated around the world, it prompts the planet’s largest annual migration of people. And though it is known to some in the West as Chinese New Year, it isn’t just celebrated in China. Lunar New Year is time for family reunions, plenty of food—and some very loud celebrations.
Modern China actually uses a Gregorian calendar like most of the rest of the world. Its holidays, however, are governed by its traditional lunisolar calendar, which may have been in use from as early as the 21st century B.C. When the newly founded Republic of China officially adopted the Gregorian calendar in 1912, its leaders rebranded the observation of the Lunar New Year as Spring Festival, as it is known in China today.
As its name suggests, the date of the lunar new year depends on the phase of the moon and varies from year to year. Today, Spring Festival is celebrated in China and Hong Kong; Lunar New Year is also celebrated in South Korea, Tibet, Vietnam, Singapore, Indonesia, Malaysia, and places with large Chinese populations. Though the festival varies by country, it is dominated by themes of reunion and hope.
[191 words]
[Time 6]
For Chinese people, Spring Festival lasts for 40 days and has multiple sub-festivals and rituals. The New Year itself is a seven-day-long state holiday, and on the eve of the new year, Chinese families traditionally celebrate with a massive reunion dinner. Considered the year’s most important meal, it is traditionally held in the house of the most senior family member.
The holiday may be getting more modern, but millennia-old traditions are still held dear in China and other countries. In China, people customarily light firecrackers, which are thought to chase away the fearful monster Nian. (However, the tradition has been on the decline in recent years due to air pollution restrictions that have hit the fireworks industry hard.) The color red is used in clothing and decorations to ensure prosperity, and people exchange hongbao, red envelopes filled with lucky cash. In Korea, people make rice cake soup and honor their ancestors during Seollal. And during Tet, the Vietnamese Lunar New Year, flowers play an important role in the celebrations.
Lunar New Year has even spawned its own form of travel: During chunyun, or spring migration, hundreds of million people travel to their hometowns in China for family reunions and New Year’s celebrations. This year, writes China Daily’s Kang Jia, around 3 billion travelers will be on the road during the 40-day period. Known as the world’s largest human migration, chunyun regularly clogs already busy roads, trains and airports. For many, though, it’s worth the hassle to celebrate with close family and friends.
[252 words]
Source: National Geographic
https://www.nationalgeographic.com/history/reference/holidays/lunar-new-year/
The science stories likely to make headlines in 2020
Science News Staff | January 2, 2020
[Paraphrase 7]
Incessant political turmoil in the United Kingdom, United States, and other nations will likely last well into the new year, complicating many researchers’ work. The U.K. election last month made the country’s departure from the European Union a near-certainty, and its scientists now face losing EU science grants and scientific collaborators. In the United States, a presidential election in November will determine the role of scientists in future policy deliberations; many experts on climate change and other environmental issues assert that the Trump administration has ignored scientific evidence. In this section, Science’s news staff forecasts other areas of policy and research likely to make news this year amid the chaos, from dark matter detectors to new efforts to rein in loss of species.
CONSERVATION | New goals for saving biodiversity
This year will see an attempt to revitalize the ambitious Aichi Biodiversity Targets, named for the city in Japan where they were negotiated. Since they were approved 10 years ago, there has been little to no progress in meeting most of those 20 goals, such as preventing the decline of endangered species. That alarming situation was highlighted last year in a major scientific assessment by another organization, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. But in October, nations will have a chance to try to set a more effective course when they meet in Kunming, China, to review and revise the Convention on Biological Diversity, the world's flagship conservation pact.
POLICY | Crunch time for climate policy
The politics of climate change faces crucial moments this year. The Trump administration's opposition to regulations reducing fossil fuel emissions has emerged as a primary talking point for the president's Democratic challengers. One day after the U.S. presidential election on 3 November, the country, the second largest emitter of greenhouse gases, is set to leave the Paris climate accord, although a Democratic president could quickly rejoin after taking office in 2021. Less than 1 week later, the United Nations will convene in Glasgow, U.K., for its most important climate summit since 2015, where nations are expected to increase their pledges to cut greenhouse gas emissions—even though they are behind on meeting existing ones. Without stepped-up efforts, there is little hope the world can keep future warming below 2°C, the level scientists forecast will produce catastrophic damage to human communities and ecosystems.
DEMOGRAPHICS | Counting on the census
The U.S. government has conducted a decennial census since 1790. But the 2020 census that kicks off on 1 April faces unprecedented political challenges. Although civil rights groups won a fight to block a question about citizenship that the Trump administration wanted to add, it has ordered the Census Bureau to generate the equivalent data using existing government records so that states can use the information when they redraw boundaries for federal and state elections. Researchers fear that assignment may not be doable, and that the political debate has further alienated those already hardest to count. Demographers also worry that the census' use of a new way to protect respondents' privacy could distort analyses of demographic trends. At stake are not only how more than $1.5 trillion in federal funds are distributed each year, but also the integrity of the nation's largest statistical agency.
BIOMEDICINE | CRISPR’s big clinical tests
The CRISPR gene-editing tool faces key tests this year of its promise to treat cancer and genetic diseases. A small U.S. clinical trial is using CRISPR to disable three genes in T cells that are then returned to a cancer patient's body, an approach that could help these immune system soldiers stop malignant cells from growing and extend patients' lives. More results may also come from separate CRISPR cancer trials in China. Other researchers are working to treat people with sickle cell disorder and thalassemia by using the DNA editor to turn on the gene for a fetal version of hemoglobin to compensate for a defective adult form of the oxygen-carrying protein; last fall, scientists reported success in two patients and in 2020 will present longer-term results for a larger group. Another clinical trial in the United States could show whether CRISPR improves vision in people with an inherited disorder that causes progressive blindness.
ARCHAEOLOGY | Proteins tell ancient tales
Ancient proteins will shed new light this year on the identity and behavior of humans and other animals that lived more than 1 million years ago. Proteins are more stable than DNA, and as analytical methods improve, researchers can apply them to understand more about older fossils lacking DNA, including the sex and age of remains of enigmatic ancient hominins. Most hominins are known by bones and teeth alone, and proteins could provide a new tool for sorting them in family trees and to identify fragments too small to classify. Although tooth enamel offers the best source of ancient proteins, researchers are also extracting them from bones and hair. In addition, proteins can reveal new information about artifacts made of plant and animal materials, and researchers hope this year to analyze parchment manuscripts and the beeswax once used to seal documents. Scientists are also analyzing residues on pots for more clues to whether early pastoralists in the steppelands of Mongolia, for example, drank camel or goat milk first—and what people living on the edge of the Roman Empire in England ate.
NATIONAL SECURITY | ‘Foreign influence’ worries grow
The political debate over how to respond to China's emergence as a scientific superpower is likely to intensify this year. In the United States, some federal agencies have banned their employees from participating in foreign talent recruitment programs—an approach that China has used to connect with thousands of scientists—to prevent disclosure of information that could damage national security and U.S. economic competitiveness. Two new bodies created by Congress will work to harmonize practices across federal agencies and chew over how best to balance openness and security. U.S. academic leaders are hoping to convince policymakers not to fence off certain types of research, which they say would throttle U.S. innovation. A new report to the National Science Foundation says teaching students and faculty members about acceptable and unacceptable behavior is a better approach.
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PARTICLE PHYSICS | Japan boosts neutrino efforts
Japan is expanding neutrino research to better understand properties of the phantom particles and the cosmic processes that produce them. This spring, scientists will increase the sensitivity of the 22-year-old Super-Kamiokande neutrino observatory by doping water in its observation chamber with the rare-earth metal gadolinium. The detector will then watch for signals generated when neutrinos from supernovae hit the water, providing clues about the dynamics within those exploding stars. Japan's legislature is expected to fund an even bigger step: construction of the 72 billion Japanese yen ($660 million) Hyper-Kamiokande. Ten times larger than its predecessor, it will capture that much more data about neutrinos emanating from the Sun, distant stars, and supernovae.
ASTROPHYSICS | Dueling dark matter detectors
The race to detect hypothetical particles of dark matter—the invisible stuff that binds together the galaxies with its gravity—enters a new phase this year with the startup of two powerful new underground detectors. Since the 1980s, physicists have used ever bigger and more sensitive ones to search for so-called weakly interacting massive particles (WIMPs), theorized to weigh 100 times as much as protons and to interact with other matter only through the feeble weak nuclear force. This year, the XENON-NT detector, which contains 8 tons of frigid liquid xenon, will turn on in the subterranean Gran Sasso National Laboratory in Italy. At the Sanford Underground Research Facility in South Dakota, the LUX-ZEPLIN (LZ) detector, which contains 10 tons of liquid xenon, will also power up. If XENON-NT and the LZ see nothing in the next few years, dark matter hunters could push for bigger WIMP detectors or set their sights on other hypothesized forms of dark matter. The Italian lab's future also remains uncertain, as former lab officials face prosecution for allegedly allowing contamination of local drinking water.
BIOMEDICINE | Making xenotransplants survive
The genome editor CRISPR is reinvigorating the beleaguered field of xenotransplantation, which aims to surgically replace human organs or tissues with ones harvested from animals such as pigs. Novel clinical trials of the strategy could launch this year. Xenotransplantation has long promised to alleviate a chronic shortage of human livers, hearts, and other organs. It could also provide corneas to cure blindness and insulin-producing islet cells to replace those destroyed by diabetes. But time and time again in earlier tests, human immune systems have quickly destroyed the foreign transplants. Recent CRISPR experiments have modified genes in pigs to prevent or dampen human immune responses to their tissue and have removed DNA from the porcine genome that could spawn potentially dangerous viruses in a person. Transplants from these edited pigs to monkeys, a key test of safety and efficacy before human trials, have demonstrated long-term viability in their new hosts.
COMPUTER SCIENCE | Exascale computer to debut
This year, China is expected to win the race to build the world's first exascale computer, capable of carrying out 1 billion billion (1018) calculations per second, also known as an exaflop. Just which supercomputer will be the first remains uncertain, as China has set up a competition between three institutions: the National Supercomputing Center of Tianjin, the National Supercomputing Center in Jinan, and Dawning Information Industry Co., a manufacturer also known as Sugon. The new Chinese supercomputers, and others to follow in the European Union, Japan, and the United States, will be used to analyze vast data sets from astronomical and genetic surveys, and will support the continued rise of artificial intelligence. Some computer scientists expected the exascale milestone to have come sooner; delays resulted in part from the need to develop energy efficient computer chips.
ALSO IN 2020
ALZHEIMER’S DRUG The U.S. Food and Drug Administration will decide whether to approve aducanumab, an antibody drug designed to bust the brain-clogging amyloid plaques of Alzheimer's disease. The experimental treatment has shown mixed success in clinical trials.
OCEAN CONSERVATION The United Nations intends to finish plans for a Decade of Ocean Science to begin in 2021. The goal is to coordinate work by scientists around the world to help improve ocean health. One expected emphasis is mapping more of the world's vulnerable marine ecosystems and biodiversity hot spots and more of the ocean's bottom, only about 4% of which has been charted in high resolution.
STEM CELL FUNDING California voters will decide in November whether to allocate $5.5 billion from bond sales to keep alive the California Institute for Regenerative Medicine. The funding agency was created through a $3 billion ballot initiative in 2004 to translate stem cell research into new therapies.
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Source: Science
https://www.sciencemag.org/news/2020/01/science-stories-likely-make-headlines-2020
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发表于 2020-1-9 00:08:10
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