Jameson Lobb, a 24-year-old investment banker from Toronto, was just one week into his new job on Wall Street. Over the past month, he'd been settling in to the New York City apartment he was sharing with his college buddy, an artificial intelligence engineer named Raphael Jafri.

Now, on Oct. 4, 2021, the two were squeezing in a lunchtime workout on Pier（码头） 15. overlooking the East River, when Lobb froze. "Somebody's in the water," he said. Before Jafri could respond, Lobb climbed over the rail at the edge of the pier and leaped into the cold, polluted water without taking the time to remove his shoes.

Jafri didn't need to see the victim. Maybe Lobb saw someone in the water who needs our help, he thought. Or maybe it's Lobb who needs my help. Either way, I'm going in. He took off his shoes and swan-dived.

Approaching the unconscious victim, Lobb saw that it was a middle-aged man. When at last they reached Pier 15, they faced a new uncertainty. How-to get out? On the pier, a crowd had gathered. From somewhere, the onlookers produced a rope and a life preserver（救生圈）, which they threw to Jafri and Lobb. With the two men pushing from below and the crowd pulling from above, the man's dangling body slowly rose until helping hands pulled him onto the pier.

From the metal beam 梁）, Lobb climbed up onto the pier, but Jafri remained in the water a few minutes more, until he was rescued by the Coast Guard. Both men, Jafn in particular, thoroughly exhausted from 15-plus minutes in the water and bleeding from numerous barnacle cuts, watched as rescue workers loaded the nearly drowned man into an ambulance and drove away.

In place of that knowledge, they have a story they get to tell now, another experience that has further enhanced their bond. Lots of people were on the piers that day, yet only the two of them jumped in the water — because, they say, they were the fittest people there and, so, had a moral responsibility.

"If I know I'm capable," Lobb says, "why wouldn't I help?" Jafri adds, laughing, "Peoplealways say‘If your friend jumps off a cliff, are you jumping?' I think I answered that one."

The robots are alive, and now they can reproduce.

Thafs not a continuation to "The Terminator". It's the latest result of research among scientists at Harvard and the University of Vermont. These xenobots, named for the African frog Xenopus laevis, could move around and display collective behavior.

The researchers took stem cells (干细胞)from the skin of frog and put them in salt water, where they came together into balls with a covering of cilia, which are similar to small hairs and enable the organisms (生物体) to move. The scientists noticed that these organisms, xenobots, would collect any particles (粒子) placed in the dish to make piles. They started to wonder whether the tiny robots would do the same thing with individual stem cells, so they conducted a test.

Knowing that xenobots shapes affect their behavior, the researchers tried to figure out which form would help the organism to reproduce repeatedly. They discovered that a "C" shape seemed to be the best. The C-shaped xenobots gathered individual stem cells into groups, which became xenobots of their own. This type of reproduction is based on the organisms movement, rather than growing and then forming a new being as other animals and plants do.

Xenobots are on an unusual line between living organisms and robots. They are organisms because they are made of stem cells and can reproduce. But they are also robots because they can move on their own and perform physical labor. Although most robots are made of metal, robots are given the definition not by their material, but by what they can do.

Before now, Kriegman, a postdoctoral fellow at Harvard University, said, "no one has been using living materials as self-moving, self-powered robots." The researchers hope that the xenobots can help them better understand the process of reproduction 一 a fundamental quality of life — and how to control it. Faced with a world full of self-reproducing problems, such as

Covid-19, Kriegman said studying xenobots could lead scientists closer to solutions.

"Anxiety." The very word invites discomfort. Its effects—shortness of breath, pounding heart, muscle tension—are outright upsetting. But, as a clinician, I find that we tend to miss out on many valuable opportunities presented by this human emotion. In and of itself, anxiety is not deadly, nor is it a disease. Quite the contrary: it is an indicator of brain and sensory health. Once we accept that it is a normal, though uncomfortable, part of life, we can use it to help us.

We all know working out at the gym is hard. By nature, a "good workout" is uncomfortable, since it involves pushing our physical strength past what we can easily do. The sweet spot of exercise is always a somewhat challenging experience. Similarly, if you want to be emotionally stronger, you need to face some tension. For example, one effective treatment for fear is exposure therapy (疗法), which involves gradually encountering things that make one anxious, reducing fear over time.

Humans are social creatures. When my patients learn to open up to their partners about their anxieties, they almost always report a greater sense of emotional closeness. Also, as international relationship expert Sue Johnson teaches, when we express our need for connection during challenging moments (e.g., "I'm having a hard time right now and could really use your support"), it creates greater connection and turns our anxiety into love.

From time to time, we find ourselves at the end of our rope. Our responsibilities pile up, our resources break down, and we feel uncomfortably anxious—what we're experiencing is called stress. Simply put, the demands placed upon us outweigh our available resources, just like a set of scales (天平) going out of balance. Focusing on work and pretending everything is OK only leads to disastrous results. Medical treatment for stress may function for a while, but it tends to make things worse in the long run. The only solution to deal with stress is to do the mathematics to balance the scales.