【推荐1】Most people hate mosquitoes — but scientists are about to build a “mosquito factory” to release modified (改良的) mosquitoes.

The modified mosquitoes carry a bacterium called Wolbachia pipientis (沃尔巴克氏菌), which can be naturally found in most insect species. However, it’s rarely discovered in mosquitoes. “We actually grow these mosquitoes that contain the bacterium,” Scott O’Neill, an Australian scientist involved in the project, told CBC News. When the modified mosquitoes are released, they slowly spread the bacterium to the population.

Several studies have demonstrated the insects’ success. For example, a controlled experiment in Indonesia showed that the modified insect helped reduce the cases of the disease dengue (登革热) by 77 percent, according to a study paper published in 2021.

The World Mosquito Program has announced that it will release modified mosquitoes in many of Brazil’s urban areas over the next 10 years. The aim is to protect up to 70 million people from diseases such as dengue, an infectious disease mainly spread by mosquitoes.

Brazil has one of the highest rates of dengue infection in the world, according to the Nature website. “More than 1,000 people died of dengue in 2022 because of the spread of mosquitoes. It’s going everywhere,” Luciano Moreira, a scientist in Rio de Janeiro, Brazil, told CBC News.

Another way to prevent mosquitoes from spreading diseases is by producing genetically modified mosquitoes (GM). In 2022, the US Environmental Protection Agency approved the release of 2.4 billion GM mosquitoes in California and Florida.

According to the agency, GM mosquitoes carry two types of genes: a self-limiting gene that prevents female offspring (后代) from surviving to adulthood; and a marker gene that allows researchers to identify GM ones in the wild. After being released, GM mosquitoes lay eggs, so the genes are passed on to offspring. In this way, the number of female mosquitoes is reduced, therefore reducing the chance of spreading disease.

【推荐2】Sharks and their relatives are some of the most threatened vertebrates (脊椎动物) on Earth. Coral reefs (珊瑚礁) provide homes for countless fish species that are vital for fisheries and are therefore an especially important ecosystem for humans — and one where the decline of shark populations seems to be especially acute.

The study by Simpfendorfer will his team is the result of a worldwide collaboration called the Global FinPrint project. The data analyzed include more than 20,000 hours of standardized underwater video taken at nearly 400 reefs in 67 countries around the world. It reveals declines of 60 to 73% of once-abundant coral reef shark species at reefs around the world.

However, the findings of Simpfendorfer with his team include signs of hope and a clear path forward. Their results show that although shark populations in many reefs had declined, some healthy reef shark populations remained. The reefs with healthier shark populations had some important similarities: they tended to be in the waters of high-income countries with stronger natural resource management regulations. A country that lacks the resources to feed its people is less able to sustainably manage and protect its biodiversity.

The most unexpected result of the study is that a decline or complete loss of shark species in one reef was not always associated with similar changes in nearby reefs.They found that one reef can be over fished so badly that a once-common reef shark species is totally gone, but another reef a short distance away can have healthy populations of that same species.It is likely that healthy populations can eventually help repopulate nearby areas.

The problem is clear — animals that provide ecosystem services that are vital for human food security and livelihoods are disappearing at an alarming rate. The loss of sharks and the ecosystem services they provide represents an ecological disaster that can cause substantial harm to humans. But apparently, the findings have shown a way. If the threat that led to population decline are resolved, then these important and threatened animals may recover.

【推荐3】A team of researchers from several institutions in the UK and one in Estonia has created a type of buoy (浮标) that has proven to be effective at frightening seabirds, thus preventing them from getting caught in gill nets (刺网) — a type of fishing net that is made of a material that makes it nearly invisible underwater.

Every year, hundreds of thousands of seabirds die when they get caught in gill nets. Some estimates suggest that up to a half-million birds are caught in them each year. Over the years, researchers have created devices to prevent the birds from trying to catch fish near or in gill nets, but those didn’t work well.

To find a way that would work for all seabirds, the researchers first studied seabirds in a general sense, expecting to find things that they would avoid. They noted that seabirds avoided eye contact with other creatures. Then the researchers came up with a simple idea—they put a small pole to a regular buoy and then attached a pair of googly eyes (金鱼眼) to the top of it. They made the eyes big enough so that even birds with poor eyesight, such as geese, would see them. Adding to the effectiveness of the device, waves made the eyes move back and forth. And the wind made the buoy spin (转动) very slowly, making sure that birds from every direction would get a good look at the eyes.

To test their idea, the researchers selected several sites near the gill nets and counted how many birds approached and how many attempted to catch fish near the nets. They then set up their googly-eyed buoys and once again counted birds. Over the course of 62 days, they found the number of birds that tried to catch fish near the gill nets dropped by about 25% for a distance of up to 50 meters. They also found that the birds were less likely to fish near where the buoys had been for up to three weeks after they had been removed.

【推荐2】The world is a greener place than it was 20 years ago. Recent NASA satellites data(2000—2017) have shown that human activities in China and India dominate this greening of the planet, thanks to ambitious tree-planting programmes in China and intensive agriculture(集约农业) in both countries.

The researchers from Boston University found that global green leaf area has increased by 5 percent in the new century, an area equal to all of the Amazon rainforest. China alone accounts for 25% of the global net increase in leaf area with only 6.6% of global vegetated area. China's contribution comes in large part from its programmes to conserve and expand forests, taking up about 42 percent of the greening. The greening from farmlands in China is about 32%, but that in India is about 82%.

Rama Nemani, a research scientist at NASA's Ames Research Centre and a co-author of the study said, ''When the greening of the Earth was first observed, we thought it was due to a warmer, wetter climate and fertilisation from the added carbon dioxide in the atmosphere. But with data from NASA satellites, scientists realised that humans are also contributing, which was all against our expectations. ''

Nemani sees a positive message in the new findings. ''Once people realise there is a problem, they tend to fix it, '' he said. ''In the 1970s and 1980s in India and China, the situation around vegetation loss was not good. In the 1990s, people realised it, and today things have improved. Humans are incredibly resilient. That is what we see in the satellite data. ''

However, the researchers rang bells as well. They said that the gain in global greenness did not necessarily make up for the loss of natural vegetation in regions like Brazil and Indonesia.

【推荐3】“What kind of rubbish are you?” This question might normally provoke anger, but in Shanghai it has elicited weary groans over the past week. On July 1st the city introduced stringent trash-sorting regulations that are expected to be used as a model for the country.

Residents must divide their waste into four separate categories and toss it into specific public bins. They must do so at scheduled times, when monitors are present to ensure compliance (and to inquire into the nature of one’s rubbish.) Violators（违反者）face the prospect of fines and worse.

Shanghai authorities are responding to an obvious environmental problem. It generates 9m 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 sift through the waste, plucking 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 churns out 80bn pairs of disposable chopsticks a year.

The threat of punishment is integral to Shanghai’s drive. On the first day of enforcement, the government sent 3,600 city-management officers, a quasi-police force, to 4,216 rubbish-collection points. They began by making an example of wealthy foreigners: the first warning was issued to Swissôtel Grand, a five-star hotel, for improper sorting. Individuals who fail to recycle 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.

Some object to this. Peng Feng of the Shanghai Academy of Social Sciences warns that the use of the credit system is overkill, raising a risk that officials will abuse their power. But others say a tough campaign is necessary. “Slowly people will get used to it,” says Li Changjun of Fudan University. 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 orhazardous, the distinctions among which can be perplexing, 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 requisite public bin, forcing them to tear open plastic bags and toss it by hand. Most vexing are the short windows for dumping 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.

But it is inconvenient. “People have to get to work. We don’t have the time for this,” said Mr Wu as he threw out rubbish outside his apartment building. To your correspondent’s untrained eye, his sorting looked impeccable.

【推荐1】When it comes to medical care, many patients and doctors believe “more is better.” But what they do not realize is that overtreatment—too many scans, too many blood tests, too many procedures—may bring harm. Sometimes a test leads you down a path to more and more testing, some of which may be invasive, or to treatment for things that should be left alone.

Terrence Power, for example, complained that after his wife learned she had Wegener’s disease, an uncommon disorder of the immune system, they found it difficult to refuse testing recommended by her doctor. The doctor insisted on office visits every three weeks, even when she was feeling well. He frequently ordered blood tests and X-rays, and repeatedly referred her to specialists for even minor complaints. Even when tests came back negative, more were ordered, and she was hospitalized as prevention when she developed a cold. She had as many as 25 doctor visits during one six-month period. The couple was spending about $30,000 a year for her care.

After several years of physical suffering and near financial ruin from the medical costs, the couple began questioning the treatment after discussing with other patients in online support groups. “It’s a really hard thing to determine when doctors have crossed the line.” Mr. Power said. “You think she’s getting the best care in the world, but after a while you start to wonder: What is the purpose?” Mr. Power then spoke with his own primary care doctor, who advised him to find a new specialist to oversee Mrs. Power’s care. Under the new doctor’s care, the regular testing stopped and Mrs. Power’s condition stabilized. Now she sees the doctor only four or five times a year.