【推荐1】James Sulikowski, from the Shark and Fish Conservation Lab at the School of Mathematical and Natural Sciences at Arizona State University, was one of the scientists who captured the seven foot porbeagle (鼠鲨) shark in the Atlantic.

In a Facebook post, the lab said the shark had been growing for years with a plastic strap around its gills. “Photos ... show the female shark’s head was slowly being sliced off by the unyielding strap,” it said. “The piece of circular plastic had become lodged around her neck when she was younger. As she grew, it began to cut through her skin into her muscle, if we had not removed it, she surely would have died.”

In a message to Newsweek, Sulikowski said the strap was probably one that would normally go around a bait box. “The box went overboard, and the porbeagle shark, when younger, ate the fish in the box,” he said. “While doing so, [the] strap got wrapped around the sharks head. As the shark grew, the strap dug into the shark’s flesh. If we didn’t remove it, the shark would have surely died.”

The photos of the shark being strangled follow the discovery of a dead minke whale that had been killed by a piece of fishing line. The male minke whale was found on a beach in Dennis, Massachusetts. The fishing line had become “wrapped around its head and through its mouth, creating a bridle,” the International Fund for Animal Welfare (IFAW) said in a Facebook post.

The IFAW said the initial autopsy (验尸) suggests the whale died from injuries caused by the entanglement. It also said there were signs of possible infection. “The entanglement likely contributed to the cause of death, though additional lab results are pending.”

The problem of plastic pollution in the ocean is getting worse. It is thought there is currently over 150 million metric tons of plastic in the world’s oceans, and more and more is entering every year. A report published earlier this year estimated the amount of plastic entering the ocean every year will have doubled by 2040, amounting to 600 million metric tons.

More than one million seabirds and 100,000 marine animals are killed every year by plastic waste. “Plastic in all forms are an issue,” Sulikowski said. “We need more research to understand the extent of the long term effects of this type of pollution.”

【推荐2】George, once known as “Midnight Memory Maker,” had been given away after his original owner, Todd Mathieson, died and his wife, Diane, could no longer care for him. She found a new home for George so that he could continue to race for a number of years.

In September, 2018, George was turned over to the Animal Rescue League (ARL) of Boston. When he arrived at the league’s adoption center in Dedham, he was slightly underweight, and in need of medical care. But, over all, he was in good health, the league said.

George recuperated (休养) for a few months in Dedham before being put into foster care. “He was highly intelligent, elegant, well-trained and had clearly known love. He was very engaged with humans,” Cordula Robinson, George’s foster parent, said in the statement.

Robinson wanted to help George go home. She contacted animal rescue agencies up and down the East Coast to see if anyone recognized him. To her surprise, someone from New Jersey recognized George as once belonging to Todd Mathieson. He was well known and owned a stable in Connecticut, said Michael DeFina, a spokesman for the ARL. George is notable for his distinctive colors, such as white patches on his hooves (蹄子) that look “like socks,” DeFina said. They went through show photos to confirm George’s identity and contacted his original hostess.

Diane Mathieson was “overwhelmed and ecstatic (欣喜若狂)” about the possibility of reuniting with George.

After 13 years apart, George was transported to his family in Ocala, Florida, where he will enjoy his retirement. “He seems to be walking taller,” Diane said.

【推荐3】Fire ants dig tunnels efficiently by only a small percentage of the group doing most of the work. Free-loaders just sit around while their hard-working colleagues get things done. But might freeloaders actually be necessary for society to function efficiently? The answer could be yes.

Fire ants are highly social organisms. So, Goldman, a physicist at Georgia Tech, and his colleagues wanted to know how individual ants knew what to do without a central leader issuing orders. To find out, Goldman's team labeled individual fire ants with paint and then watched them dig their narrow tunnels —barely wide enough for two workers. Turns out, just 30 percent of the ants did 70 percent of the labor. “I was surprised that we ended up with so few workers actually doing the work at any one time. ” A quarter of the ants never even entered the tunnel. Others crawled inside, but left without digging single grain of dirt. These idling behaviors ensured the tunnels did not get clogged with insect traffic, which would make the construction process stop.

And when the scientists removed the five hardest working ants from the colony, others immediately jumped in to compensate (补偿) — with no reduction in the group's productivity. It seems that it doesn’t matter which ants are working or freeloading at a given time, as long as there is some division of labor to keep the tunnels flowing smoothly. The findings are in the journal Science.

The study could have implications for robotics. Imagine groups of robots sent to search rubble (碎石) for disaster survivors. Or nanobots (纳米机器人) coursing through our bodies to diagnose illness and deliver targeted medical treatment. Such robot groups will need to avoid getting jammed up in tight spaces. It might be necessary to program them so some just sit back and watch their comrades work.

【推荐3】Men are as likely as women to suffer from postnatal (产后的) depression, a study shows. One in ten fathers — the same ratios as mothers — are found to suffer before or after birth. By the time their child reaches 12 weeks, as many as one in four are feeling down.

The symptoms observed in the American study are not thought to be hormonal — as they are in women — and are instead probably a response to the pressures of fatherhood. These include the expense of having children, changed relationship with partners and fear of paternal (父亲的) responsibility. In the early weeks, the lack of sleep and extra domestic chores also take the toll.

The study put the overall rate of depression among new fathers at 10.4 percent — double the estimated 4.8 percent for all men in any 12-month period. Around 8 percent were affected in the 12 weeks before and after birth, according to the Eastern Virginia Medical School Research. The study found parents were more likely to be down if their partner was too.

It is estimated that around one in ten women suffers postnatal depression, even if they have never had mental health problems. Without treatment the condition can last for months. Although most women have a few days of “Baby Blues” shortly after birth, postnatal depression can kick in up to six months later. Experts say that paternal depression is serious because it can have “substantial emotional, behavioural and developmental” effects on children.