【推荐1】The trade fight between the United States and China increased Monday as the two economic superpowers   hit   each   other   with   their   biggest   round   of   tariffs   ( 关 税 )   yet.   The   Trump administration added new 10% tariffs on $200 billion of Chinese goods just after midnight ET (noon in Beijing), coveringing thousands of products, including food seasonings, baseball gloves, network routers and industrial machinery parts. China fired back immediately with new taxes of 5% to 10% on $60 billion of US goods such as meat, chemicals, clothes and auto parts. The moves lead to the growing conflict between the world’s top two economies.

“We are squarely in the midst of the ‘it’ll get worse before it gets better’ phase,” Aninda Mitra, senior analyst at BNY Mellon Investment Management, said in a note after the latest tariffs were announced last week.President Donald Trump’s waves of new tariffs on China now apply to over $250 billion of Chinese goods, roughly half the amount the country sells to the United States. The latest   round affects   thousands of   products   bought   by   US   consumers, including   hundreds   of millions of dollars of furniture and electronics imports       (电子进口). The US tariffs added earlier in the year mostly hit industrial goods.

The measures are meant to punish China for what the Trump administration says are unfair trade practices, such as intellectual property (知识产权)     theft.

Beijing has rejected ( 拒 绝 )   the US   assertions ( 断 言 ), accusing the   United States of protectionism and bullying. It has fired back with tariffs on American goods worth more than $110 billion.

The Trump administration has made “false accusations” and sought to “add its own interests on China through great pressure,” the Chinese government said in a lengthy white paper published Monday about the two countries’ trade relationship, according to state news agency Xinhua. Unbelievably, The latest round of US tariffs is set to increase at the end of the year from 10% to 25%. China hasn’t yet spelled out how it will respond to that.

Trump has also threatened ( 威胁) tariffs on another $267 billion of Chinese products. That would mean the US measures effectively cover all China's annual goods exports ( 出 口 ) to the United States (the total for 2017 was about $506 billion).

China, which imports a far smaller amount from the United States, is running out of new products to target, but analysts say it still has other options to fire back. They include charging even higher tariffs, adding import quotas, limiting Chinese citizens’ travel to the United States for study and tourism, and reducing taxes for companies affected by the tariffs.

【推荐3】In this Pennsylvania city, Pittsburgh is shrinking but getting wealthier. Since 2000, its population has declined by 95,000 while its income per capita (人均) has shot up 24 percent. The trend is taking hold in many other cities, like Buffalo in New York, Providence in Rhode Island and New Orleans.

Some of these areas have created more high-paying jobs in energy, health care or education. Others have managed to reshape their producing industry for a new economy. Higher-paying jobs have a greater effect because they create demand for additional services. "The story in Pittsburgh is very positive, and other areas are looking at it as an example of the transformation that might be possible，”said Guhan Venkatu, who wrote an economic history of the area called “Rust and Renewal” for the Federal Reserve Bank of Cleveland.

Carnegie Mellon University and the University of Pittsburgh have helped bring tech jobs and innovation(革新) to the area by sponsoring tech centers that help graduates start companies without moving to Silicon Valley or San Francisco. This has helped keep Pittsburgh's educated young population growing even as the entire population in the city has dropped.

Pittsburgh has more STEM (science, technology, engineering and math) jobs than other shrinking cities, about 80, 000 or 7% of all jobs. STEM jobs add productivity and income growth to the area. Manufacturers of high-tech medical equipment in the Pittsburgh area also have doubled employment in the last 10 years.

However, some experts question whether growing income per capita can really make up for a declining population. According to Patrick Adler, a researcher at the University of Toronto, population loss does matter if it means lower-skilled workers have fled because of a lack of opportunity. What's more, high-paying jobs in education and health care can disappear if the population declines too greatly. So it'd be wise to find ways to increase the population.

【推荐1】Think back to when you were in a maths classroom, and the teacher set a difficult problem. Which of the two following responses is closer to the way you reacted?

A: Oh no, this is too hard for me. I’m not even going to seriously try and work it out.

B: Ah, this is quite tricky, but I like to push myself. Even if I don’t get the answer right, maybe I’ll learn something in the attempt.

Early in her career, the psychologist Carol Dweck of Stanford University gave a group of ten-year-olds problems that were slightly too hard for them. One group reacted positively and loved the challenge. She says they had a ‘growth mindset’ and are focused on what they can achieve in the future. But another group of children felt that their intelligence was being judged and they had failed. They had a ‘fixed mindset’ and were unable to imagine improving. Some of them looked for someone who had done worse than them to boost their self-esteem.

Professor Dweck believes that there is a problem in education at the moment. For years, children have been praised for their intelligence or talent, but this makes them vulnerable (脆弱的) to failure. They become performance-oriented, wanting to please by getting high grades, but they are not interested in learning for its own sake. The solution, according to Dweck, is to lead them to become mastery-oriented (i.e., interested in getting better at something). She claims that the ever-lasting effort over time is the key to outstanding achievement.

Psychologists have been testing these theories. Underperforming school children on a Native American reservation were exposed to growth mindset techniques for a year. The results were nothing less than incredible. They came top in regional tests, beating children from much more privileged backgrounds. These children had previously felt that making an effort was a sign of stupidity, but they came to see it as the key to learning.

【推荐2】Being attractive isn’t usually considered much of a disadvantage in today’s world. Actually, there is the endless potential benefit about it, but researchers have found one area that being pretty makes life a challenge securing yourself a boring, low-paying job.

This stands in contrast to a large body of research that attractiveness, in general, helps candidates in the selection process. For the most part good looks is a blessing. We treat pretty people more favorably in general, often vote for them more in elections, and pay them more in their professions. The research suggests that attractive people may be discriminated against in selection for relatively less desirable jobs.

Researchers carried out four experiments involving more than 750 participants, including university students and managers who make hiring decisions in the real world. Participants were shown photos of two potential job candidates, one attractive and the other unattractive. Participants were then asked a series of questions designed to measure their opinions of the job candidates and whether they would hire these candidates for a less-than-desirable job.

The less desirable jobs included a warehouse worker, housekeeper, customer service representative and the more desirable jobs included things like a manager, project director, IT elite(精英). In all experiments where they were asked, participants were significantly less likely to hire the attractive candidate for the less desirable job and more likely to hire the attractive candidate for the more desirable job.

Ms Lee said, “In the selection decision for an undesirable job, decision makers were more likely to choose the unattractive individual over the attractive individual. Co-author Dr Madan Pillutla said, “It is interesting that decision makers consider others’ opinions in their decisions. They thought that attractive individuals would want better outcomes, and therefore would be less satisfied, so they favored unattractive candidates when selecting for a less desirable job.”

The research also suggests the established view that attractive candidates are favored when applying for jobs might be limited to high-level jobs.

【推荐3】Oxygen, I'm sure you'd agree, is pretty important for life on Earth. We breathe it in, our cells survive on it and without it, we hardly live. Basically all multicellular life on Earth evolved over millions of years to make use of oxygen.

But take a deep breath, because we need to talk about Henneguya salminicola, a tiny parasite(寄生虫) containing fewer than100 cells that lives within the muscle tissue of salmon, a large fish with silver skin and pink flesh. The strange-looking parasite does not busy itself with such small matters as breathing oxygen. Nope, it seems that H. salminicola is the first multicellular animal we've found that survives without the stuff.

“Aerobic respiration(有氧呼吸) was thought to be commonly found in animals, but now we confirmed that this is not the case, "said Dorothee Huchon, a zoologist at Tel Aviv University in Israel, in a press release.

Huchon and a team of international researchers examined and sequenced(排序) all of. salminicola's' genes in their study, published in the journal Proceedings of the National Academy of Sciences. They found that the parasite, which is closely related to jellyfish, lacks the DNA machinery necessary to“breathe”---it doesn't' have mitochondria(线粒体), often called the "powerhouse" of the cell, because they use oxygen to make energy. It's like a little factory inside almost all cells, and DNA detectives can find mitochondrial genes during sequencing.

The discovery came as something of an accident for the team, who were examining the genome (the complete set of genes) of the species. When they went searching for the mitochondrial genes,   they came up empty-handed. "Our discovery shows that evolution can go in strange directions, ”Huchon said. "Aerobic respiration is a major source of energy, and yet we found an animal that gave up this important pathway.”

Some single-celled life forms have evolved the ability to survive without oxygen and do not have mitochondria, either. Plenty of bacteria can exist without oxygen at all. Instead of oxygen, they get their energy from fermentation(发酵) or use other molecules like iron.

But how H. salminicola produces energy is still unclear. Huchon suggests it could draw oxygen from the cells in salmon or it could have evolved similar methods to those of single-celled organisms which scientists have documented in the past.