“We are good mothers,” I said to my friend, as we sat on our comfortable beach chairs under our beach umbrella and watched our children playing in the waves.

    Out of nowhere, the children took off running. About fifty yards from us, a man—maybe in his fifties—was fishing. The children stood next to him and watched with their little mouths hanging open as he cast the fishing lines. He smiled at them. They ran back to us—all except my three-year-old daughter, Drew.

    My heart beat fast with horror. “Drew! Come here! Play with your friends!” I shouted, very aware that my speeches about not talking to strangers weren't working. It seemed that many parents heard of horrible stories about children being taken away by strangers. Responsible mothers should teach their children that the world is a dangerous place. So I felt relieved when Drew ran towards me and took hold of a shovel (铲子). Then she looked me in the eye: “I want to be with the person.”

    Again, she approached the middle-aged man, and started digging next to him.

    Several seconds later, she returned, waving something shiny.

    “Look, Mommy! A toy fish!”

    It was, indeed, a toy fish—yellow and rubber. This must have been what he was using to attract the fish. And he'd given it to Drew. The three other children were deeply impressed, and they didn't try to hide how jealous(妒忌的)they were—clearly, they all wanted the fish.

    “My friend gave me that fish!” Drew shouted loudly. The sand in front of the umbrella turned into a preschool cage match with a yellow rubber fish flying through the air. I felt like I might cry myself.

    Unexpectedly, there he was: the man, standing right next to us with three more rubber fish in hand. He handed them to each of the children. By their faces, you would have thought he was actually the really kind big brother.

    “Thank you,” I said, realizing that there is good and kindness in strangers.

    People have used pigeons to carry messages to one another for hundreds of years. In fact, pigeons were a common way to send messages right up through Would War II.

    In 1815, English troops were fighting Napoleon's forces in France, and the English were believed to be losing. A financial panic swept over London. Government bonds（债券）were offered at low prices. Few people noticed that Nathan Rothschild, an English banker, was snapping up these bonds when everyone else was trying to sell them. A few days later, London learned the truth: the Duke of Wellington had defeated Napoleon at the battle of Waterloo. The value of the bonds soared（暴涨）, and Rothschild became wealthy…all because his pigeons had brought him news of the victory before anyone else knew of it.

    Carrier pigeons were used by countries in both World War I and World War II. Not only were the birds often the fastest, most reliable way to send messages, they could also be used to reach soldiers far behind enemy lines, where radios and field telephone lines were useless. Since they could easily be released from airplanes or ships, every branch of the armed services used the birds.

    Carrying messages could be a dangerous job. Some pigeons performed with such bravery that they became famous and were even awarded medals. The most famous pigeon of all may have been Cher Ami. Stationed in France during World War I, he carried twelve important messages for American forces. On his last mission, though wounded, he carried a message that saved the lives of 194 American soldiers. For his amazing service, he was awarded the French “Croix de Guerre.”

    Today, modern communication methods can carry information from one place to another hundreds of times faster than a pigeon could do it. However, few people would argue with the fact that carrier pigeons — especially those that served in the military — have earned their place in history.

    In a world with limited land, water and other natural resources (资源), the harm from the traditional business model is on the rise. Actually, the past decades has seen more and more forests disappearing and globe becoming increasingly warm. People now realize that this unhealthy situation must be changed, and that we must be able to develop in sustainable (可持续的) ways. That means growth with low carbon(低碳) or development of sustainable products. In other words, we should keep the earth healthy while using its supply of natural resources.

    Today, sustainable development is a proper trend in many countries. According to a recent study, the global market for low-carbon energy will become three times bigger over the next decades. China, for example, has set its mind on leading that market, hoping to seize chances in the new round of the global energy revolution. It is now trying hard to make full use of wind and solar energy, and is spending a huge amount of money making electric cars and high-speed trains. In addition, we are also seeing great growth in the global markets for sustainable products such as palm oil (棕榈油)， which is produced without cutting down valuable rainforest. In recent years the markets for sustainable products have grown by more than 50%.

    Governments can fully develop the potential of these new markets. First, they can set high targets for reducing carbon emissions (排放) and targets for saving and reusing energy. Besides, stronger arrangement of public resources like forests can also help to speed up the development. Finally, governments can avoid the huge expenses that are taking us in the wrong direction, and redirecting some of those expenses can accelerate the change from traditional model to a sustainable one.

    The major challenge of this century is to find ways to meet the needs of growing population within the limits in this single planet. That is no small task, but it offers abundant new chances for sustainable product industries.

    A recent study led by researchers from the National University of Singapore (NUS) has found a clear link between the color of a taxi and its accident rate. An analysis of 36 months of detailed taxi, driver and accident data from two fleets of yellow and blue taxis in Singapore suggested that yellow taxis have fewer accidents than blue taxis. The higher visibility (能见度)of yellow makes it easier for drivers to avoid getting into accidents with yellow taxis, leading to a lower accident rate.

    The study was led by Prof Ho. To test whether there was a causal relationship between the color of a taxi and the number of accidents the taxi had, the research team analysed data collected by the largest taxi company in Singapore. The researchers found that yellow taxis have about 6.1 fewer accidents per 1,000 taxis per month.

    The researchers also studied the economic effect of changing the color of the entire fleet of taxis to yellow. The Singapore taxi company involved in the study owns about 16,700 taxis in a ratio(比例) of one yellow to three blue taxis. If a commercial decision is made to switch from blue to yellow taxis, 76.6 fewer accidents would occur per month or 917 fewer accidents per year. Assuming an average repair cost of $1,000 per car and a downtime of six days, switching the color of all taxis to yellow could produce an annual savings of $2 million.

    "We are eager to continue to validate(证实) the findings of our study by looking at the use of yellow in other types of public transport, such as school buses. For instance, we hope to compare the accident rates of yellow school buses against other colors to find out if yellow is indeed a safer color for school buses. Besides, we are also interested to look at private-hire vehicles and do a comparison of the accident rates of vehicles that are of different colors," explained Prof Ho.

    Cooperation at work is generally considered a good thing. The latest survey by the Financial Times of what employers need from MBA graduates found that the ability to cope with a wide variety of people was what managers have wanted most. However, managers always find ways to balance the benefits of teamwork, which helps ensure that everyone is working towards the same goal. With the dangers of "groupthink", critics are reluctant to point out a plan's drawbacks for fear of being excluded by the group. The disastrous Bay of Pigs Invasion of Cuba in 1961 was a classic case of groupthink. Skeptics were unwilling to challenge John F. Kennedy, the newly elected American president.

    Modern communication methods prove that cooperation is more frequent. Workers are constantly in touch with each other via e-mail messaging groups or mobile calls. However, does that develop, or lower performance? A new study by three American academics, tried to answer this question They set a logical problem (designing the shortest route for a travelling salesman visiting various cities) Three groups were involved: one where subjects acted independently; another where they saw the solutions posted by team members at every stage; and a third where they were kept informed of each other's views only intermittently.

    The survey found that members of the: individualist group reached the: premier solution more often than the constant cooperators but had a poorer average result The intermittent cooperators found the right result, as often as the individualists, and got a better average, solution. When it comes: to: perfect generation, giving: people a, bit of space to, a solution seems to be a great idea. Occasional cooperation can be quite beneficial: most people have benefited from a colleague's brainwave or (just as often)wise advice to avoid a, particular course of action.

    Further clues come from a book, Superminds, by Thomas, Malone of the Massachusetts Institute of Technology. He says that three factors determine the collective intelligence of cooperating groups: social intelligence (how good people were at rating the emotional states of others); the extent to which members took part equally in conversation (the more equal, the better) and the cooperation of women in the group(the higher, the better Groups ranked highly in these areas cooperated far better than others did).

    In short, cooperation may be a helpful tool but it does not work in every situation.

    Shark attacks not only disturb beach activities, but can affect associated tourist industries. Shark nets are a common solution to preventing shark attacks on beaches, but they cause dangers to sea ecosystems.

    Seeking a cost-effective way to monitor beach safety over large areas, we have developed a system called Shark Spotter. It combines artificial intelligence (AI), computing power, and drone (无人机) technology to identify and warn lifesavers to sharks near swimmers. The project is a cooperation between the University of Technology Sydney and The Ripper Group, which is pioneering the use of drones—called "Westpac Little Ripper Lifesavers"—in the search and rescue movement in Australia.

    SharkSpotter can detect sharks and other potential threats using real-time aerial imagery. The system analyses video from a camera attached to a drone to monitor beaches for sharks, send warnings, and conduct rescues. Developed with techniques known as "deep learning", the Shark Spotter system receives imagery from the drone camera and attempts to identify all objects in the scene. Once certain objects are detected, they are put into one of 16 categories: shark, whale, dolphin, rays, different types of boats, surfers, and swimmers.

    If a shark is detected, Shark Spotter provides both a visual sign on the computer screen and an audible warning to the operator. The operator confirms the warning and sends text messages from the Shark Spotter system to the Surf Life Savers for further action. In an emergency, the drone is equipped with a lifesaving flotation pod (漂浮仓) together with an electronic shark repellent (驱逐装置) that can be dropped into the water in cases where swimmers are in severe trouble, trapped in a rip, or if there are sharks close by.

    In January 2018, the Westpac Little Ripper Lifesavers was used to rescue two young swimmers caught in a rip at Lennox Head, NSW. The drone flew down the beach some 800 meters from the lifeguard station, and a lifesaving flotation pod was dropped from the drone. The complete rescue operation took 70 seconds.

    We believe Shark Spotter is a win-win for both marine life and beachgoers. This unique technology combines dynamic video image processing AI and advanced drone technology to creatively deal with the global challenge of ensuring safe beaches, protecting environments, and promoting tourism.