The Brown Bear

    My wife Laura and I were on the beach, with three of our children, taking pictures of shore birds near our home in Alaska when we spotted a bear. The bear was thin and small, moving aimlessly.

    Just a few minutes later, I heard my daughter shouting, “Dad! The bear is right behind us!” An aggressive bear will usually rush forward to frighten away its enemy but would suddenly stop at the last minute. This one was silent and its ears pinned back—the sign of an animal that is going in for the kill. And it was a cold April day. The bear behaved abnormally, probably because of hunger.

    I held my camera tripod (三脚架) in both hands to form a barrier as the bear rushed into me. Its huge head was level with my chest and shoulders, and the tripod stuck across its mouth. It bit down and I found myself supporting its weight. I knew I would not be able to hold it for long.

    Even so, this was a fight I had to win: I was all that stood between the bear and my family, who would stand little chance of running faster than a brown bear.

    The bear hit at the camera, cutting it off the tripod. I raised my left arm to protect my face; the beast held tightly on the tripod and pressed it into my side. My arm could not move, and I sensed that my bones were going to break.

    Drawing back my free hand, I struck the bear as hard as I could for five to six times. The bear opened its mouth and I grasped its fur, trying to push it away. I was actually wrestling (扭打) with the bear at this point. Then, as suddenly as it had begun, the fight ended. The bear moved back toward the forest, before returning for another attack—The first time I felt panic.

    Apparently satisfied that we caused no further threat, the bear moved off, destroying a fence as it went. My arm was injured, but the outcome for us could hardly have been better. I'm proud that my family reminded clear-headed when panic could have led to a very different outcome.

    What's more exciting than having a fresh hot pizza delivered to your door? How about having it brought to you by a robot? Thanks to Domino's Robotic Unit or DRU, that just became a reality! On March 8, the three-foot tall robot delivered its first pizza to some lucky residents in Brisbane, Australia.

    The fully autonomous DRU is the result of a cooperation between Domino's Pizza Australia and Marathon Robotics.The 450-pound machine that travels at a maximum speed of 12.4 miles an hour can traverse a distance of up to 12 miles and back, before requiring a battery recharge. LIDAR, a laser-based sensor technology similar to the one used in self-driving cars, enables DRU to detect and avoid obstacles, while traditional sensors, much like those used in vacuum robots ensure its path is safe as it heads to its destination.   

    The robot can fit up to ten pizzas and even has a separate cold area to accommodate drink orders.To access their fond, customers have to enter the unique code provided by the company.This is not only ensures that they pick up the right pizza, but also prevents the pies from getting stolen.

    Scientists expert additional DRU's to be ready for service in their various Queensland locations within the next six months. But don't expect these super cute robots to replace humans anytime soon. According to Domino's the DRU still needs extensive testing, which the company believes could take up to two years.

    And then there is also the issue of regulations.The public use of autonomous vehicles is still banned in most countries.But Don Meij, the CEO and Managing Director of Domino's Pizza Australia New Zealand Ltd, is not worried.He is “confident that one day DRU will become an   integral part of the Domino's family.”

    If a diver surfaces too quickly, he may suffer the bends. Nitrogen (氮) dissolved (溶解) in his blood is suddenly liberated by the reduction of pressure. The consequence, if the bubbles (气泡) accumulate in a joint, is sharp pain and a bent body—thus the name. If the bubbles form in his lungs or his brain, the consequence can be death.

    Other air-breathing animals also suffer this decompression (减压) sickness if they surface too fast: whales, for example. And so, long ago, did ichthyosaurs. That these ancient sea animals got the bends can be seen from their bones. If bubbles of nitrogen form inside the bone they can cut off its blood supply. This kills the cells in the bone, and consequently weakens it, sometimes to the point of collapse. Fossil (化石) bones that have caved in on themselves are thus a sign that the animal once had the bends.

    Bruce Rothschild of the University of Kansas knew all this when he began a study of ichthyosaur bones to find out how widespread the problem was in the past. What he particularly wanted to investigate was how ichthyosaurs adapted to the problem of decompression over the 150 million years. To this end, he and his colleagues traveled the world's natural-history museums, looking at hundreds of ichthyosaurs from the Triassic period and from the later Jurassic and Cretaceous periods.

    When he started, he assumed that signs of the bends would be rarer in younger fossils, reflecting their gradual evolution of measures to deal with decompression. Instead, he was astonished to discover the opposite. More than 15% of Jurassic and Cretaceous ichthyosaurs had suffered the bends before they died, but not a single Triassic specimen (标本) showed evidence of that sort of injury.

    If ichthyosaurs did evolve an anti-decompression means, they clearly did so quickly—and, most strangely, they lost it afterwards. But that is not what Dr Rothschild thinks happened. He suspects it was evolution in other animals that caused the change.

    Whales that suffer the bends often do so because they have surfaced to escape a predator (捕食动物) such as a large shark. One of the features of Jurassic oceans was an abundance of large sharks and crocodiles, both of which were fond of ichthyosaur lunches. Triassic oceans, by contrast, were mercifully shark- and crocodile-free. In the Triassic, then, ichthyosaurs were top of the food chain. In the Jurassic and Cretaceous, they were prey (猎物) as well as predator—and often had to make a speedy exit as a result.

    Can you imagine four hours of your day getting to and from work? For the last eight years, Jo Meade rode her bike each Sunday on a 16-mile round trip to her job washing dishes. It took more than an hour each way. Other days of the week she would spend two hours on three buses from her apartment to get to the other work, for a four-hour round trip.

    That was the “before” part of her life. The “after” part of her life was started by the community Police Officer Trevor Arnold, who delivered a used car to her with the help of a car dealer and other donors.

    Arnold, who spotted Meade, red and sweaty, riding her bike in the worst heat this summer, decided he would het her a car. He intended to quietly buy her a used car out of his own pocket so he turned to his friend Kody Slaght, a car salesman to ask about a car priced $1,000. That wasn't enough for a reliable ride, Slaght said, but the dealership said they would find a good car for her at a good price. Soon others were donating. Slaght and Arnold wouldn't say how much the car cost, but the value is about $4,000.

    Arnold said he was motivated by Meade's work ethic（职业道德）to help. “I see a lot of hardworking people nut that's when they are at work. Can you imagine spending four hours of your day getting to and from work?” he said.

    Meade's boss said she was awesome and really reliable when she worked and she got along with others. “She's willing to rise the three buses to get in here on her day off if we need her too.”

    Meade said she was planning to buy a car, “but I haven't been able to afford it,” she said. “Trevor, he is a very good guy. I did not expect this.”

    A newspaper reporter's job can be very interesting. He meets all types of people and lives quite a busy life. He is on the rush for news all the time, then after several years he may get a desk job, and life becomes a bit more settled. Let's look at his work a little more closely. In a day he may have to interview the prime minister of a foreign country, and the next day he may be writing about a football match. Sometimes he may be so busy that he has hardly any time to sleep. And at other times he may go on for days looking out for news materials yet return empty-handed.

    In the beginning, a reporter has to cover a very wide field. After the early years he becomes more specialized in his work. For example, he may finally be asked to write only on court cases or politics or sports. Some reporters may become so specialized that they are asked only to write on a special thing: horse racing, for example. In most newspaper houses there is at least one special racing correspondent. Some newspapers have book reviews. Their job is delightful. They read the latest book and then write reviews on the ones they like. Then there are those who write on films, so they get to see them even before they are shown in the cinema. How lucky, you would say!

    A reporter's job can also be very dangerous. A number of them have died rushing from one assignment to another, and if there is a flood or a riot(暴) they may get hurt or even be killed. Three years ago there was a reporter whose camera was smashed by a group of men, because they were angry with him for taking their picture. Dangerous or not, one thing is certain, and that is, their job is never dull!

    Cities usually have a good reason for being where they are, like a nearby port or river. People settle in these places because they are easy to get to and naturally suited to communications and trade. New York City, for example, is near a large harbour at the mouth of the Hudson River. Over 300 years its population grew gradually from 800 people to 8 million. But not all cities develop slowly over a long period of time. Boom towns grow from nothing almost overnight. In 1896, Dawson, Canada, was unmapped wilderness(荒野). But gold was discovered there in 1897, and two years later, it was one of the largest cities in the West, with a population of 30,000.

    Dawson did not have any of the natural conveniences of cities like London or Paris. People went there for gold. They travelled over snow-covered mountains and sailed hundreds of miles up icy rivers. The path to Dawson was covered with thirty feet of wet snow that could fall without warming. An avalanche(雪崩) once closed the path, killing 63 people. For many who made it to Dawson, however, the rewards were worth the difficult trip. Of the first 20,000 people who dug for gold, 4,000 got rich. About 100 of these stayed rich men for the rest of their lives.

    But no matter how rich they were, Dawson was never comfortable. Necessities like food and wood were very expensive. But soon, the gold that Dawson depended on had all been found. The city was crowded with disappointed people with no interest in settling down, and when they heard there were new gold discoveries in Alaska, they left Dawson City as quickly as they had come. Today, people still come and go — to see where the Canadian gold rush happened. Tourism is now the chief industry of Dawson City — its present population is 762.