3 . On Christmas Eve, a team of reindeer (驯鹿) will help Santa Claus deliver gifts to children all around the world. The reindeer, led by their fearless leader Rudolph, won’t be the only ones doing something special. Back in the highest Arctic, their cousins have a remarkable ability changing their eye color.

During the summer months, when the days are long and the sun is bright, reindeer’s tapetum lucidum (荧光膜), a mirror-like layer at the back of their eye, appears golden, which helps bounce the majority of light off the eyes, effectively acting like a pair of natural sunglasses. As winter comes, and the days become shorter and darker, the tapetum lucidum turns blue to absorb more light, allowing reindeer to improve their night vision and see clear in low light conditions.

With these adaptations, reindeer can adapt and thrive in one of the harshest environments on Earth. Unlike humans, reindeer can see well into the shorter Ultra Violet (UV) range. This UV vision enables them to spot food and predators more effectively in the snowy landscape. Lichens, a key part of their winter diet, absorb UV, so they show up dark against UV-reflecting white snow. Wolf and polar bear fur also absorb UV, so instead of disappearing against snow they pop out in high contrast, allowing reindeer to spot potential threats from a distance.

Reindeer change their eyes by adjusting their tapetum lucidum, which is made of collagen fibers. In winter, the collagen fibers become packed tighter, causing the tapetum lucidum to mainly reflect blue light. This change happens when reindeer dilate their pupils (瞳孔). In summer, the reindeer’s pupils return to a smaller size, which helps reindeer reduce the amount of light entering the eye.

But their unique adaptation may hurt them. Today, the increasing use of artificial lighting, especially during the winter months, poses a potential threat to their sensitive eyes. It can make reindeer lose their way, affecting their ability to survive in their challenging environment. So it is crucial for us to be mindful of our use of electricity and make efforts to minimize light pollution to ensure the well-being and survival of these magnificent creatures.

6 . The World Health Organization warns that millions of people are dying every year from indoor air pollution. Nearly three billion people are unable to use clean fuels and technologies for cooking, heating as well as lighting.

These findings show that the use of deadly fuels in inefficient stoves, space heaters or lights is to blame for many of these deaths.

WHO officials say indoor pollution leads to early deaths from stroke, heart and lung disease, childhood pneumonia and lung cancer. Women and girls are the main victims. These diseases can often result from the burning of solid fuels. These fuels include wood, coal, animal waste, crop waste and charcoal.

The United Nations found that more than 95 percent of households in sub-Saharan Africa depend on solid fuels for cooking. It says huge populations in India, China and Latin American countries, such as Guatermala and Peru,are also at risk.

Nigel Brace is a professor of Public Health at the University of Liverpool. He says researchers are developing good cook-stoves and other equipment to burn fuels in a more efficient way.There are already multiple technologies available for use in clean fuels.There is really quite an effective and reasonably low-cost alcohol stove made by Dometic (a Sweden-based company) that is now being tested out. LPG (Liquefield Petroleum Gas) cook is obviously widely available and efforts are under way to make those efficient. Another interesting development is electric induction stoves. WHO experts note that some new, safe and low-cost technologies that could help are already available. In India, you can buy an induction stove for about $8.00. And in Africa you can buy a solar lamp for less than $1.00.

But this,the agency says, is just a start. It is urging developing countries to use cleaner fuels and increase access to cleaner and more modern cooking and heating appliances/devices.

7 . Recycling in general can be an effective way to reuse natural material resources. The U.S.’s high recycling rate of paper, 68 percent, has proved this point. But although some materials can be effectively recycled and safely made from recycled content, plastics cannot. Plastic recycling does not work and will never work.

The problem with recycling plastic lies not with the concept or process but with the material itself.   There are thousands of different plastics, each with its own characteristics. They all include different chemicals that cannot be recycled together, making it impossible to sort the trillions of pieces of plastics into separate types for processing. What’s more, plastic recycling costs more than new plastic because collecting, sorting, transporting, and reprocessing plastic waste is very expensive.

Despite this obvious failure, the plastics industry has begun a decades-long campaign to keep the lie that the material is recyclable, which reminds the public of the tobacco industry’s efforts to tell smokers that filtered (过滤的) cigarettes are healthier than unfiltered cigarettes.

Traditional mechanical recycling, in which plastic waste is ground up and melted (熔化), has been around for many decades. Now the plastics industry is promoting the benefits of so-called chemical recycling, in which plastic waste is broken down using high heat and turned into a low-quality fossil fuel. In 2018, Dow Chemical claimed that the Renewlogy chemical-recycling factory in Salt Lake City was able to reprocess mixed plastic waste through the “Hefty EnergyBag” program and turn it into diesel fuel (柴油). As Reuters showed in a 2021 survey, however, the pyrolysis (高温分解) process was not worth it.

We’re not making a case for hopelessness. Just the opposite(相反的). We need the facts so that individuals and policymakers can take action. Proven solutions to the plastic-waste and pollution problems exist and can be quickly copied across the country. These solutions include placing bans on single-use plastic bags and unrecyclable single-use plastic food-service products, and installing dishwashing equipment in schools.

Consumers can put pressure on companies to stop filling store shelves with single-use plastics by not buying them and instead choosing reusables and products in better packaging. And we should all keep recycling our paper, boxes, cans, and glass, because that actually works.

9 . A new study by researchers at the University of British Columbia (UBC) and the University of Victoria has shown that common levels of traffic pollution can damage human brain function in only a matter of hours.

“For many decades, scientists thought the brain may be protected from the harmful effects of air pollution,” said senior study author Dr. Chris Carlsten. “This study, which is the first of its kind in the world, provides fresh evidence supporting a connection between air pollution and cognition.”

For the study, the researchers briefly exposed 25 healthy adults to diesel exhaust (柴油废气) and filtered air at different times in a laboratory setting. Brain activity was measured before and after each exposure using functional magnetic resonance imaging (fMRI).

The researchers analyzed changes in the brain’s default mode network (DMN), a set of inter-connected brain regions that play an important role in memory and internal thought. The fMRI revealed that participants had decreased functional connectivity in widespread regions of the DMN after exposure to diesel exhaust, compared to filtered air.

“We know that altered functional connectivity in the DMN has been associated with reduced cognitive performance and symptoms of depression, so it’s concerning to see traffic pollution interrupting these same networks,” said Dr. Jodie Gawryluk, a psychology professor at the University of Victoria and the study’s first author. “While more research is needed to fully understand the functional impacts of these changes, it’s possible that they may impair (损害) people’s thinking or ability to work.”

Notably, the changes in the brain were temporary and participants’ connectivity returned to normal after the exposure. Dr. Carlsten assumed that the effects could be long lasting where exposure is continuous. He said that people should be mindful of the air they’re breathing and take appropriate steps to minimize their exposure to potentially harmful air pollutants like car exhaust.

10 . The African penguin is expected to go extinct in the wild in just over a decade, given its current population decline. The main reason is a lack of food caused by disturbance to ocean conditions from global heating and competition from the commercial fishing industry. According to a study, scientists have identified a possible additional cause, one that is an entirely new threat and that further prevents the penguins from finding food: noise pollution from marine (海洋的) ships in a bay.

Since 2016, a new shipping practice has started at Algoa Bay. The bay offers ship-to-ship refueling for ships anchored offshore. Since the start of this practice, marine traffic in the bay has doubled. The number of bulk carriers (散货船) pulling into the bay has increased by ten times as much. Thus the noise levels in the area had doubled and the population of penguins has dropped sharply. High noise levels affect the ability of marine animals to find food, communicate or navigate properly.

Researchers used data from ship identification tools to estimate underwater noise from passing ships. They also attached underwater microphones and accelerometers (感应器) to some of the penguins. Recording the noise will tell researchers what the penguins are hearing, if they’re talking while hunting, if they’re changing their movements in response to noise, and if the noise is drowning out their hunting conversations. This will allow researchers to determine whether the sound disturbance is a direct cause of the penguins’ ongoing difficulties in finding sufficient food.

The study is the first to explore the effects of ocean traffic noise pollution on seabirds and the consequences of offshore shipping activities on underwater noise levels. Experts are considering proposing various global best-practice approaches to reduce some of the impacts of noise pollution, such as policies that limit the number and size of ships allowed into a bay of this kind. “We also need more scientific monitoring of noise, before these measures are put in place and afterward, so that we have a proper understanding of what works.” a researcher said.