China will significantly improve the signal of its mobile communication networks including 4G and 5G covering more than 80,000 locations, along 25,000 kilometers of railways, 350,000 kilometers of expressways, and 150 metro lines by the end of 2024, the Ministry of Industry and Information Technology (MIIT) and other government departments said on Wednesday in a notice.
By the end of 2024, the average downlink access rate of mobile networks should not be lower than 200 Mbps, while the average uplink access rate should not be lower than 40 Mbps. Major service indicators including signal latency and delays will be improved, read the notice.
The goal for 2025 will be further improved, according to the notice. More than 120,000 key locations, 30,000 kilometers of railways, 500,000 kilometers of roads, and 200 metro lines will be covered by mobile networks with an increased 5G coverage.
The average downlink access rate of the mobile networks by the end of 2025 should not be lower than 220 Mbps, and the average uplink access rate should reach 45 Mbps or higher. The major service indicators are expected to be fully optimized.
The 11 central government departments will carry out a specific operation to upgrade the nation’s signal coverage in a bid to meet growing public demand and support the digital transformation of key industries in China.
Dedicated measures will be implemented to strengthen mobile coverage for the key locations from medical facilities to villages, accelerate the optimization for crucial services, and improve the monitoring and supervision.
China currently has more than 6 million 4G base stations with the network covering all urban and rural areas, according to official data. The number of 5G base stations has reached 3.28 million with more stations to be rolled out this year, which will set a solid foundation for the nation’s digital transformation.
China will strive to realize the commercialization of 6G by 2030, and it is expected that standardization for the technology will be achieved around 2025, according to Wang Zhiqin, the leader of China's 6G promotion team and vice president of the China Academy of Information and Communications Technology, in December 2023.
China's domestically developed passenger jets - the C919 and the ARJ21 - get ready to fly to Hong Kong from the Shanghai Pudong International Airport on December 12, 2023. They arrive at the Hong Kong International Airport on the same day. This is the first time for the C919 to leave the Chinese mainland. Photo: VCG
As global oil prices increased for a third straight week on the back of production cuts from Saudi Arabia and Russia, concerns over the inflationary pressure in the US are on the rise, with analysts saying this may lead to new resistance for the Fed when it comes to adjusting the pace of monetary policy tightening.
Both West Texas Intermediate (WTI) and Brent crude oil futures are extending multi-month highs on concerns over tight supply. WTI settled near $90.4 a barrel on Friday, the highest since November 2022, while Brent hit $94.31 per barrel, also the highest in 10 months.
The past two months saw global oil prices rise by about 20 percent. The International Energy Agency and Organization of Petroleum Exporting Countries both warned this week that the market would be in deficit through year-end due to the production cuts from Saudi Arabia and Russia.
As a result, gasoline prices in the US have surged to a seasonal record, with average regular gasoline now costing $3.866 a gallon, up 7.8 percent in just eight weeks, according to data from the American Automobile Association.
"Continuous increase in US gasoline prices may jeopardize the Fed's fight against inflation. At a time when the Fed has sent signals toward adjusting its tightening monetary policy, the renewed inflationary pressure is not a good omen," Chen Chao, a commodity analyst, told the Global Times on Saturday.
The worries over new inflation pressure have come at a time when the US consumer price index in August increased by 3.7 percent from a year ago, accelerating from 3.2 percent in July and higher than market expectation, according to the US Department of Labor.
Inflation continues to be a major problem for the US economy and society. The United Auto Workers (UAW) union is on strike against General Motors, Ford and Stellantis, the first time in its history that it has struck all three of America's unionized automakers at the same time. UAW says auto workers have only seen 6 percent annual wage gains since 2019, and inflation offset much of those gains.
If the Fed does not keep its monetary policy tight, inflationary pressures are likely to intensify, but a continuously tight monetary policy increases the likelihood that the US economy will fall into recession, Chen explained. "So the question is whether the US can release additional barrels from its Strategic Petroleum Reserve, but the release of strategic reserve is not that easy."
The earliest asteroids were probably made of mud, not rock.
Radioactive heat in the early solar system could have melted globs of dust and ice before they had a chance to turn to rock, a new simulation published July 14 in Science Advances shows. The results could solve several puzzles about the composition of meteorites found on Earth and may explain why asteroids are different from comets.
Most knowledge about the first solid bodies in the solar system comes from meteorites called carbonaceous chondrites, thought to be chunks of the first asteroids. Their chemical compositions are almost identical to the sun’s — if you took all the hydrogen and helium out of the sun, you’d get the mineral ratios found in these bits of rock. That similarity suggests the first asteroids formed directly from the disk of gas and dust that preceded the planets. The composition also suggests that these rocks formed in the presence of water and at relatively low temperatures, around 150° Celsius.
It’s hard to explain all those features at once. If the original asteroids were bigger than about 20 kilometers across — and there’s no reason to think they weren’t — decaying radioactive elements inside them would have made the rock hotter than that. Some planetary scientists have suggested that the asteroids were porous, and water flowing through a primitive plumbing system cooled them. But the water should have stripped some elements from the rock, ruining their sunlike chemistry.
“It was a paradox,” says planetary scientist Philip Bland of Curtin University of Technology in Perth, Australia. Bland was modeling how those original globs of ice and dust could have compressed into solid rock, when it hit him: What if they weren’t rock at all? “At that moment, nothing has happened to force those grains together to turn it into a rock,” he says. That was just something everyone had assumed.
Bland reasoned that heat from radioactive decay would melt the ice, and the resulting body would be an enormous dollop of mud. The mud would suspend sediment particles, so they wouldn’t be stripped of their sunlike elements. And it would allow the early asteroids to be any size and remain cool.
Bland and Bryan Travis of the Planetary Science Institute, who is based in Los Alamos, N.M., ran computer models of how the mud balls would evolve. Convection currents, like those that move molten rock within the Earth’s mantle, would develop, helping to transfer heat into space, the models showed. After several million years, the ball would harden completely, yielding the asteroids seen today.
“It nails the paradox,” Bland says.
Mud balls could even explain the difference between asteroids and comets, he says. Comets, which are more icy than rocky and tend to live farther from the sun, may simply have formed later in the solar system’s history, when there was less radioactive heat available to melt them.
The model also showed that some asteroids would be muddy all the way through, while others would develop cores of larger grains, with a great mud ocean on top of them.
The latter result could describe not just asteroids but bodies like the dwarf planet Ceres, the largest object in the asteroid belt. Observations from NASA’s Dawn spacecraft showed that Ceres has a rocky core and may once have had an ocean that has since evaporated, says UCLA planetary scientist Edward Young. “That process may have been something like what they’re describing.”
Planetary scientist Brandon Johnson of Brown University in Providence, R.I., thinks the model will inspire more research. “I’m interested in it myself, actually,” he says. “It makes a lot of sense and paints a clear picture of what might have been happening.”
But Young is concerned that the model’s flexibility means it won’t make specific enough predictions for future work to test it. “It has so many knobs, you can get it to do whatever you want,” he says. “I’m trying to think of what the killer observation would be.”
Earthworms are great for soil, right? Well, not always. In places where there have been no earthworms for thousands of years, foreign worms can wreak havoc on soils. And that can cause a cascade of problems throughout an area’s food web. Now comes evidence that invader worms in the Upper Great Lakes may be stressing the region’s sugar maples.
There are native earthworms in North America, but not in regions that had been covered in glaciers during the Ice Age. Once the ice melted, living things returned. Earthworms don’t move that quickly, though, and even after 10,000 years, they’ve only made small inroads into the north on their own.
But people have inadvertently intervened. Sometimes they’ve dumped their leftover bait in worm-free zones. Or they’ve accidentally brought worms or eggs in the soil stuck to cars or trucks. And the worms took up residence as far north as Alberta’s boreal forests.
Earthworms “are not really supposed to be in some of these areas,” says Tara Bal, a forest health scientist at Michigan Technological University in Houghton. “In a garden, they’re good,” she notes. They help to mix soil. But that isn’t a good thing in a northern forest where soil is naturally stratified and nutrients tend to be found only in the uppermost layer near the leaf litter. “That’s what the trees have been used to,” Bal says. Those trees include sugar maples, which have shallow roots to get those nutrients. But worms mix up the soils and take away that nutrient-rich layer. Bal didn’t start out studying worms in northern regions. She and her colleagues were brought in to address a problem that sugar maple growers were experiencing. Some of the trees appeared to be stressed out. They were experiencing what’s called dieback, when whole branches die, fall off and regrow. This is worrisome because if enough of the tree dies off, “it’s a slow spiral from there,” Bal says — the whole tree eventually dies. To investigate, the researchers collected data on trees and anything that could be affecting them, from soil type to slope to insects. They looked at trees in 120 plots in Michigan, Wisconsin and Minnesota. And they compared trees that were on growers’ land with those on public land, thinking that how the trees were managed might have some effect. When the researchers analyzed the data, “the same thing that kept coming up over and over again was the forest floor condition,” Bal says. “That is directly related to the presence of earthworms.” They didn’t go out to look for the worms, but they could see signs of them in the amount of carbon in the soil and in changes in the ground cover. Wildflowers, for instance, were replaced by grasses and sedges, the researchers report July 26 in Biological Invasions.
Bal and her team can’t say what this means for maple syrup production. It might not mean anything at all. But “worms are ecosystem engineers,” she notes. “They’re changing the food chain.” Everything from insects to birds to salamanders could be affected by the arrival of worms.
Even if the sugar maples take a hit, though, there could be an upside, Bal says. These trees are often grown with few other types of trees around. Such a grove is naturally less resilient to climate change and extreme weather. So replacing some of those sugar maples with other trees could result in a healthier, more resilient forest in the future, Bal says.
New gene-editing tools can correct typos that account for about half of disease-causing genetic spelling errors.
Researchers have revamped the CRISPR/Cas9 gene editor so that it converts the DNA base adenine to guanine, biological chemist David Liu and colleagues report October 25 in Nature. In a separate study, published October 25 in Science, other researchers led by CRISPR pioneer Feng Zhang re-engineered a gene editor called CRISPR/Cas13 to correct the same typos in RNA instead of DNA. Together with other versions of CRISPR/Cas9, the new editors offer scientists an expanded set of precision tools for correcting diseases.
CRISPR/Cas9 is a molecular scissors that snips DNA. Scientists can guide the scissors to the place they want to cut in an organism’s genetic instruction book with a guide RNA that matches DNA at the target site. The tool has been used to make mutations or correct them in animals and in human cells, including human embryos (SN: 10/14/17, p. 8).
A variety of innovations allow CRISPR/Cas9 to change genetic instructions without cutting DNA (SN: 9/3/16, p. 22). Earlier versions of these “base editors,” which target typos related to the other half of disease-causing genetic spelling errors, have already been used to alter genes in plants, fish, mice and even human embryos. Such noncutting gene editors are possibly safer than traditional DNA-cutting versions, says Gene Yeo, an RNA biologist at the University of California, San Diego. “We know there are drawbacks to cutting DNA,” he said. Mistakes often arise when cellular machinery attempts to repair DNA breaks. And although accurate, CRISPR sometimes cuts DNA at places similar to the target, raising the possibility of introducing new mutations elsewhere. Such “permanent irreversible edits at the wrong place in the DNA could be bad,” Yeo says. “These two papers have different ways to solve that problem.” The new editors allow researchers to rewrite all four bases that store information in DNA and RNA. Those four bases are adenine (A) which pairs with thymine (T) (or uracil (U) in RNA), and guanine (G) pairs with cytosine (C). Mutations that change C-G base pairs to T-A pairs happen 100 to 500 times every day in human cells. Most of those mutations are probably benign, but some may alter a protein’s structure and function, or interfere with gene activity, leading to disease. About half of the 32,000 mutations associated with human genetic diseases are this type of C-G to T-A change, says Liu, a Howard Hughes Medical Institute investigator at Harvard University. Until now, there was little anyone could do about it, he says.
In RNA, DNA’s chemical cousin, some naturally occurring enzymes can reverse this common mutation. Such enzymes chemically convert adenine to inosine (I), which the cell interprets as G. Such RNA editing happens frequently in octopuses and other cephalopods and sometimes in humans (SN: 4/29/17, p. 6).
Zhang, of the Broad Institute of MIT and Harvard, and colleagues made an RNA-editing enzyme called ADAR2 into a programmable gene-editing tool. The team started with CRISPR/Cas13, molecular scissors that normally cut RNA. Dulling the blades let the tool grasp instead of slice. Zhang and colleagues then bolted the A-to-I converting portion of ADAR2 onto CRISPR/Cas13. Dubbed REPAIR, the conglomerate tool edited from 13 percent to about 27 percent of RNAs of two genes in human cells grown in dishes. The researchers did not detect any undesired changes.
Editing RNA is good for temporary fixes, such as shutting down inflammation-promoting proteins. But to fix many mutations, it requires permanent DNA repairs, says Liu.
In 2016, Liu’s team made a base editor that converts C to T. Chinese researchers reported in Protein & Cell on September 23 that they used the old base editor in human embryos to repair a mutation that causes the blood disorder beta-thalassemia. But that editor couldn’t make the opposite change, switching A to G.
Unlike with RNA, no enzymes naturally make the A-to-I conversion in DNA. So Nicole Gaudelli in Liu’s lab forced E. coli bacteria to evolve one. Then the researchers bolted the E. coli DNA converter, TadA, to a “dead” version of Cas9, disabled so it couldn’t cut both strands of DNA. The result was a base editor, called ABE, that could switch A-T base pairs into G-C pairs in about 50 percent of human cells tested.
This base editor works more like a pencil than scissors, Liu says. In lab dishes, Liu’s team corrected a mutation in human cells from a patient with an iron-storage blood disorder called hereditary hemochromatosis. The team also re-created beneficial mutations that allow blood cells to keep making fetal hemoglobin. Those mutations are known to protect against sickle cell anemia.
Another group reported in the October Protein & Cell that base editing appears to be safer than traditional cut-and-paste CRISPR/Cas9 editing. Liu’s results seem to support that. His team found that about 14 percent of the time cut-and-paste CRISPR/Cas9 made changes at nine of 12 possible “off-target” sites. The new A-to-G base editor altered just four of the 12 off-target sites and only 1.3 percent of the time.
That’s not to say cut-and-paste editing isn’t useful, Liu says. “Sometimes, if your task is to cut something, you’re not going to do that with a pencil. You need scissors.”
