Scientists are debating how to limit their newly-discovered power to change genetic structure (结构). Scientists already modify the genes (基因) of farm animals and agricultural plants to make them more productive or stronger. But now they can also change genes in wild animals and plants. These genes would continue into later generations. For example, it may be possible for scientists to remove from existence the kind of mosquitoes, small flying insects, that carry the Zika virus. They might also be able to permanently remove species (物种) of plants and animals that are damaging to other species.

    In a report published last week, the U. S. National Academies of Sciences, Engineering and Medicine (NAS) said it supports continued research on this kind of gene control. But it warned that it is not possible to know what will happen when these changed plants and animals are released (释放) into the wild.

    Sixteen biologists, ethicists (伦理学家) and policymakers are on an NAS committee that is examining the issue. They say that there is value to the new technology. But, they say, there is not enough evidence to support the release of modified organisms (生物体) from the laboratory into nature.

    Many people would support stopping mosquitoes and rats from carrying diseases. But scientists say we must understand the possible scientific, ethical, legal and social results of such action before we decide whether to take it. Gene modification is spread through reproduction (繁殖).

    Changed genes will continue to spread as long as an animal or plant continues to reproduce. They cannot be limited to a farm or kept within a country's borders. Scientists are wondering what may happen if a modified organism mates with another species. They are not yet sure how the modified genes would affect the other species. It is possible that those genes could harm those creatures or even lead to their disappearance from our planet.

    Their cheery song brightens many a winter's day. But robins are in danger of wearing themselves out by singing too much. Robins are singing all night一as well as during the day, British-based researchers say.

    David Dominoni, of Glasgow University, said that light from street lamps, takeaway signs and homes is affecting the birds' biological clocks, leading to them being wide awake when they should be asleep.

    Dr Dominoni, who is putting cameras inside nesting boxes to track sleeping patterns, said lack of sleep could put the birds' health at risk. His study shows that when robins are exposed to light at night in the lab, it leads to some genes being active at the wrong time of day. And the more birds are exposed to light, the more active they are at night.

    He told people at a conference, "There have been a couple of studies suggesting they are increasing their song output at night and during the day they are still singing. Singing is a costly behaviour and it takes energy. So by increasing their song output, there might be some costs of energy."

    And it is not just robins that are being kept awake by artificial light. Blackbirds and seagulls are also being more nocturnal. Dr Dominoni said, "In Glasgow where I live, gulls are a serious problem. I have people coming to me saying `You are the bird expert. Can you help us kill these gulls?'.During the breeding(繁殖)season, between April and June, they are very active at night and very noisy and people can't sleep."

    Although Dr Dominoni has only studied light pollution, other research concluded that robins living in noisy cities have started to sing at night to make themselves heard over loud noise.

    However, some birds thrive(兴旺)in noisy environments. A study from California Polytechnic University found more hummingbirds in areas with heavy industrial machinery. It is thought that they are capitalising on their predators(天敌)fleeing to quieter areas.

    Gravity signals that race through the ground at the speed of light could help seismologists(地震学家) get a better handle on the size of large, destructive quakes soon after they hit，a study suggests. The tiny changes in Earth's gravitational field, created when the ground shifts, arrive at earthquake monitoring stations well before earthquake waves.

    “The good thing we can do with these signals is have quick information on the magnitude (震级) of the quake,” says Martin Vaillée, a seismologist at the Paris Institute of Earth Physics.

    Earthquake equipment in China and South Korea picked up gravity signals immediately after the magnitude-9. 1 Tohoku earthquake that destroyed parts of Japan in 2011. The signals appear as tiny accelerations on earthquake-recording equipment, more than a minute before the seismic waves show up.

    “We can look before the earthquake waves arrive,” says Vallée. “If we see nothing, we can say that the quake that made these was maybe large, but not huge. If we see the signals, it means we really have a very big quake. ”

    Had seismologists been monitoring for gravity changes, they might have realized sooner just how big the Tohoku earthquake was. A small increase in an earthquake's magnitude means a large change in the energy released by the quake-and the destruction expected. That information is important for emergency responders as they decide what resources to arrange.

    It'll be a major contribution if gravitational waves can beat down the time needed to know that a big earthquake is big. But much work remains before gravity signals can be considered a reliable tool in the vital minutes after a big quake. A few extra minutes of warning can save lives, particularly in coastal areas where people can flee ahead of an incoming tsunami.

    A new technology is going to ripe, one that could transform our daily lives, help to form new industries, even remove world economic powers from their present positions. Unlike the wave of industrialization that began in the West and spread later to the rest of the world, the new developments are taking place in research labs all over the globe—and Asians are in the forefront. Physicists are creating a new class of materials that display an amazing property unforeseen even two years ago—superconductivity (超导体技术).

    Used today only in specialized equipment, super conductors have the potential to radically change most of the electrical and electronic appliances found in the home, making them smaller, more powerful and efficient. They could free our cities of pollution by replacing petrol and diesel (柴油) vehicles with electric cars, and cut the cost of electricity. The new materials do something that even the best of conductors such as copper and silver cannot—they do away with all electrical resistance. The significances for energy storage are great.

    The technology is in its early stage, still accessible to countries that decide to invest brains and money. For 75 years it had remained little more than a scientific curiosity with limited practical use because the phenomenon occurred only at extremely low temperatures. It was first observed in 1911 by a Dutch scientist named Heike Kamerlingh Onnes, who cooled mercury (水银) to temperatures below -269℃ with liquid helium (氦). Then in January last year, two IBM scientists, K. Alex Muller and J. George Bednorz, found a metal oxide ceramic (氧化陶瓷) that superconducted at -243℃. Their report went largely unnoticed until last December, when it was confirmed at a scientific meeting in Boston. Today Japan, India, China and other Asian countries all have their share of experts who spend their days and nights in labs, acting as midwives (助产士) to a new technology.

    "What kind of rubbish are you?" This question might normally cause anger, but in Shanghai it has brought about complaints over the past week. On July 1st, the city introduced strict trash-sorting regulations that are expected to be used as a model for our country. Residents must divide their waste into four separate kinds and put it into specific public bins. They must do so at scheduled times, when monitors are present to ensure compliance（服从）and to inquire into the nature of one's rubbish.

    Violators face the possibility of fines and worse. They could be hit with fines of up to 200 yuan ($29). For repeat violators, the city can add black marks to their credit records, making it harder for them to obtain bank loans or even buy train tickets.

    Shanghai authorities are responding to an obvious environmental problem. It generates 9 million tonnes of garbage a year, more than London's annual output and rising quickly. But like other cities in China, it lacks a recycling system. Instead, it has relied on trash pickers to sort out the waste, picking out whatever can be reused. This has limits. As people get wealthier, fewer of them want to do such dirty work. The waste, meanwhile, just keeps piling up. China produces 80 billion pairs of disposable(一次性的)chopsticks a year.

    Many residents appear to support the idea of recycling in general but are frustrated by the details. Rubbish must be divided according to whether it is food, recyclable, dry or hazardous(有害的), the differences among which can be confusing, though there are apps to help work it out. Some have complained about the rules surrounding food waste. They must put it straight in the required public bin, forcing them to tear open plastic bags and toss it by hand. Most upset are the short windows for throwing trash, typically a couple of hours, morning and evening. Along with the monitors at the bins, this means that people go at around the same time and can keep an eye on what is being thrown out; no one wants to look bad.

A latest study on people who eat red meat has found they have higher risks of heart disease and early death. The finding goes against other recent research that suggested removing meat from one's diet has few health benefits. The two opposing findings can make it difficult for people to make sense of what can seem to be conflicting messages on food.

Duane Mellor, a dietician at Aston University, and other researchers say that after examining research on the subject, moderation may be the best way forward. "In this case, eating a certain amount of meat, including red meat, is likely to be safe," Mellor said. "However, in the interest of health, reducing meat intake to the recommended less than 70 grams per day would be sensible."

A researcher with ties to the meat industry published a report on the subject in 2019, saying that people should not reduce the amount of red meat they eat. Some experts criticized the findings because they were in conflict with dietary advice from international agencies.

The latest study found that eating two servings a week of red meat or processed meat was linked to a 3% to 7% higher risk of heart disease and also a 3% higher risk of all causes of death. Norrina Allen, a co-leader of the latest study, said the health risk is small but people should try to change their diet. "It's a small difference, but it's worth trying to reduce red meat and processed meat." She added that eating red meat is also regularly "linked to other health problems like cancer."

The World Cancer Research Fund says red and processed meat may cause cancer. It recommends eating red meat with an upper limit of 500 grams cooked weight per week-and "little, if any" processed meat. They said on average, adults should reduce the amount of meat they eat by 50% and they should eat twice as much nuts, fruits, vegetables and beans.