【推荐1】Shocking declines in bird populations are taking place around the world. Loss of natural habitats is cited as the key threat to bird biodiversity. Climate change is identified as a possible driver of bird population declines.

“We are now witnessing the first signs of a new wave of extinctions of continentally distributed bird species,” says lead author Alexander Lees, senior lecturer at Manchester Metropolitan University in the United Kingdom. “Bird diversity peaks globally in the tropics and it is there that we also find the highest number of threatened species.”

The study says about 48% of existing bird species worldwide are known or suspected to be undergoing population declines. Populations are stable for 39% of species. Only 6% are showing increasing population trends, and the status of 7% is still unknown. The study authors reviewed changes in bird biodiversity using data from the International Union for Conservation of Nature’s   “Red List” to reveal population changes among the world’s 11,000 bird species, The findings mirror the results of a 2019 study which determined that nearly 3 billion breeding birds have been lost during the past 50 years across the United States and Canada.

Despite their findings, study authors say there is hope for bird conservation efforts, but transformative change is needed. “The fate of bird populations is strongly dependent on stopping the loss of habitats,” says Lees. “That is often driven by demand for resources. We need to better consider how commodity (货物) flows can contribute to biodiversity loss and try to reduce the human footprint on the natural world.”

“Fortunately, the global network of bird conservation organizations taking part in this study have the tools to prevent further loss of bird species and abundance,” adds Rosenberg. “From land protection to policies supporting sustainable resource-use, it all depends on the will of governments to live side by side with nature on our shared planet.”

【推荐3】When students from Lithgow visited wetlands near their primary school, they quickly picked up on a problem: there was nowhere for turtles.

“A bunch of students said there are no logs or rocks here, so where are they going to bask (晒太阳)?” says Associate Professor Ricky Spencer from Western Sydney University. The question was raised as part of a project in which year 5 and 6 students were attempting to understand their local environment and what it needed to thrive (兴旺). The students had just learned that in spring, turtles have to bask on a rock or log to create eggs.

The students are now conducting research and developing a proposal to present to their local council for the introduction of new basking areas, such as logs or human-made platforms. “That is pretty powerful, for year 5 and year 6 students to actually know how to make change,” Spencer says. “We want kids to understand why conservation measures are important.”

Led by Western Sydney University, the Turtles in Schools program aims to encourage an informed future generation that will take care of the environment. It is currently in a trial phase, with select New South Wales schools hosting turtles in classrooms and visiting nearby wetlands. By 2023, up to 10 turtle tanks will be installed (安装) in schools. By 2024, the program will be available to all year 5 and 6 classrooms across Australia.

By guiding experiments on topics such as growth rates and behavioural observations, and introducing schools to activities in their local wetlands, Spencer says this program could encourage students to actually carry their education forward to their day-to-day life.

Presbyterian Ladies’ College has been investing in facilities including a turtle pond for six years. They will be available for nearby schools involved in the Turtles in Schools program. “We want to connect students to the real world, to develop values to look after the environment. Our students become familiar with understanding our relationship to the natural world. We are connected to it. We rely upon it. It isn’t something dispensable,” the principal, Dr Paul Bergis, says.

【推荐2】In today’s world, sleep experts say that for a better night’s rest, Americans should turn off their smartphones or iPad before sleeping. Such electronic products make the brain more active, and then influence their sleep. But according to a latest survey, more than 90% of Americans regularly use a computer or some other kinds of electronic products in the hour before bed.

Researchers are finding that man-made light from some electronic products at night may reduce the brain chemicals(化学物质) that help sleep. The researchers showed that sitting in the light from computer tablets clearly lowered levels of the chemical which manages our body clocks and plays a role in the sleep cycle.

In the study, the researchers let volunteers read, play games and watch movies on a tablet for different time while measuring(测量) how much light their eyes received. They found that two hours of sitting before a bright tablet screen at night reduced the sleep chemical levels by about 22%.

Studies of students using computers at night have got the similar results. And researchers say that may not only cause sleeplessness, but also raise the risk of obesity(肥胖症), diabetes(糖尿病) and other diseases.

To be on the safe side, the researchers advise us to use computers less before bed, or at the very least turning down your screen as much as possible.

【推荐3】Thanks to the $10bn James Webb Space Telescope, we are beginning to “see” the radiant heat of the early universe like never before. On Monday night, to the excitement of professional astronomers and amateurs the world over, the telescope’s first full-colour image of deep space was released. The striking image, taken at minimally explored wavelengths and never-before-seen resolution, reveals a large number of universal objects.

The image is yet to be fully analysed but some objects are relics (遗迹) dating to within 0.7bn years of the Big Bang, the explosion that created our universe 13.8bn years ago. A new era (时代) of astronomy, in which we can finally see the oldest objects in the universe and gain a fuller understanding of its origins, has officially begun.

Tuesday saw four more important results emerge from the Webb’s first week of observations. Chris Lintott, professor of astrophysics at Oxford University and a researcher on galaxy (星系) formation, said he was blown away by the quality and beauty of the images. “It knocked my socks off,” Lintott said on Tuesday. “I was sitting in a roomful of galaxy experts when the Stephan’s Quintet image was shown, and jaws hit the floor. The Webb is going to produce some of the most amazing pictures of the space age.”

Webb’s “first deep field”, as the image of deep space released on Monday is known, is a picture taken over 12. 5 hours. It shows the cotton-wool-like galaxy cluster (团) SMACS 0723 centrally in the foreground, plus bright white stars.

As Lintott points out, bigger light-collecting mirrors result in sharper images, of the type that Webb is now delivering. The investment in the James Webb Space Telescope’s large foldable mirror has paid off. It is hard to believe that the Earth-orbiting telescope, regarded as one of the most complex engineering projects ever attempted and nearly cancelled a decade ago, has begun operating successfully.

【推荐2】The government of Singapore has created a highly developed system that turns wastewater into drinking water. The system involves a network of tunnels and high-technology treatment centers.

Reused wastewater can now meet 40 percent of Singapore's water demand. The country's water agency says it expects to meet 55 percent of Singapore's water demand by the year 2060. Most of the water is used for microchip manufacturing centers and cooling systems in buildings. But some of it is added to the country's drinking water supplies. The system helps reduce ocean pollution, as only a small amount of the treated water is sent into the sea.

The United Nations estimates that 80 percent of the world's wastewater flows back into the oceans without being treated or reused. Singapore has few natural water sources. The island nation has long had to depend mostly on supplies from neighboring Malaysia.

Low Pei Chin is chief engineer of the water reclamation department of the Public Utilities Board. She told reporters with Agence France-Press, "Singapore lacks natural resources, and it is limited in space, which is why we are always looking for ways to explore water sources and stretch our water supply." One major plan is to "collect every drop" and "reuse endlessly," she added.

The Changi Water Reclamation Plant on Singapore's eastern coast is the main part of the country's recycling system. Parts of the water treatment center are underground. Wastewater enters the center through a 48-kilometer tunnel that is linked to sewers. The center contains a large system of steel pipes, tubes, tanks, cleaning systems and other machinery. It can treat up to 900 million liters of wastewater a day. In one building, a network of air flow systems has been put in place to keep the air smelling as fresh as possible. Waste that arrives at the plant goes through a cleaning process before powerful pumps send it flowing to areas above ground for more treatment.

There, the treated water receives additional cleaning. Bacteria and viruses are removed through highly developed cleaning processes and disinfected with ultraviolet radiation.

Singapore is also in the process of expanding its recycling system. The country will add another underground tunnel and a major water treatment center to serve the western half of the island. Officials expect work on the center to be completed by 2025. By the time the expansion is finished, Singapore will have spent about $7.4 billion on its water treatment systems.

【推荐3】Unlike thousands of tourists who hike in Yellowstone National Park to admire its natural landscape and hot springs every year, Abdelrhman Mohamed was traveling with a team of scientists to hunt for life within the hot springs.

After several hours of hiking in the Heart Lake Geyser Basin area, the team found four unpolluted pools of hot water. They carefully left a few electrodes (电极) placed into the land next to the water, hoping to attract little-known creatures out of hiding — bacteria (细菌) that can “ eat and breathe ” electricity.

After 32 days, the team returned to the hot springs to collect the electrodes. Working with other scientists, Mohamed had a look at the electrodes and found that they had succeeded in catching their small game: heat-loving bacteria that “ breathe ” electricity through the hard surface of the electrodes. These tiny creatures are not only of research interest, they may also hold a key to solving some of the biggest challenges facing humans.

As a means of fighting environmental pollution and creating more energy sources, such bacteria can “ eat ” pollution by changing deadly pollutants into less harmful matter and producing electricity in the process. “ As these bacteria pass their electrons (电子) into metals or other hard surfaces, they can produce a stream of electricity that can be used for low power applications, ” said Haluk Beyenal, a famous university professor of chemistry.

Though the researchers did not detail exactly how they would be continuing their work with the bacteria, it will hopefully lead to an exciting new tool for fighting climate change and pollution in the near future.