It’s fall, and that means some trees are losing their leaves. Many people might see cleaning up all that yard waste as tiring. But Bryant Liu, 13, looked at his leaf-blanketed lawn and saw a potential source of energy.

Right now, most people fuel their cars with petrol made from fossil fuels (化石燃料), which are not renewable. So scientists are making biofuels. For example, engineers can produce bioethanol - a type of alcohol fuel - from sugars in plants. Turning to dead leaves, however, presents a challenge for biofuel developers. Dead leaves have sugar, but they also have lots of lignin - a tough substance (物质) that strengthens the walls of plant cells. To get to the sugars inside, scientists first have to break down the lignin with chemicals.

Bryant wanted to see if he could get sugar for biofuels out of dead leaves by pretreating those leaves with acids or bases (碱).The young researcher gathered up three garbage bags full of leaves from his yard. Then he went to his father’s laboratory. He broke the dead leaves into pieces, and then carefully loaded equal numbers of them into test tubes. Afterwards, he added either an acid solution or a base solution at different concentrations to the test tubes. “That was really fun,” Bryant says. “It made me feel like a real scientist.” Finally, the teen found that pretreating leaves with either an acid or base encouraged sugar to get out from his yard’s leaves. However, he explains, the process is still too expensive.

Bryant now wants to take the sugars from his finding to the next step - making ethanol. If he could create a better method for producing biofuels, he explains, people would need fewer fossil fuels and “have a renewable energy source for the future.” And, Bryant adds, if people use all those dead leaves for biofuels, he and other kids may have to do less cleaning each fall.

Jim Savage was setting out for a day’s fishing off the Florida coast when he heard the cries of a baby dolphin in trouble. The three-month-old had got her tail caught in the ropes of an abandoned crab trap. Jim knew that if he left her, the dolphin would have little chance of survival. He cut her free and got in contact with the authorities. She was taken to Clear water Marine Aquarium, but her injuries were so severe that she lost her tail.

The aquarium staff named the baby dolphin Winter and she gradually learned how to swim again. Unfortunately, because of the way she was moving in the water without her tail, she was in danger of developing a problem with her spine (脊椎). Kevin Carroll and Dan Strzempka, who ran a company making artificial limbs, heard about the problem and had a brilliant idea. Kevin and Dan told the staff at the aquarium that they would make an artificial (人造的) tail for Winter!

There were a lot of challenges that Kevin and Dan had to deal with along the way, like trying to fit an artificial tail on a playful young dolphin that doesn’t want to stay still! It took over fifty prototypes (模型) and a year and a half before Winter finally got her new 30-inch tail. After seeing her swim with it for the first time, Kevin said that the months of hard work had been truly worth it.

Making the tail was only half the story, though. For Winter to be able to swim properly, the artificial tail needed to be held in place without damaging her skin. Specialists came up with a soft material that firmly holds the skin and doesn’t hurt. Designed especially for Winter, this material was so successful that “WintersGel” is now being used to make artificial limbs more comfortable for people with false arms and legs all around the world.

In 2011 the tale (故事) was made into a film, “Dolphin Tale”, starring Winter herself. It’s about a dolphin that would have died, but survived because a few people cared.

As aging population gets bigger and dementia(老年痴呆症) more common, more families are struggling with a complex question: How do you support a love done with dementia, especially when you have a full-time job and several kids?

Reg Urbanowski may have an answer to this pressing issue—robots.

He and his team managed to develop a new type of robots named TP robots. Looking like stand-up vacuum cleaners attached to an iPad, they can be activated remotely via a smartphone and guided remotely by a controller app similar to the way a mouse is used on a desktop computer. All possess audio and visual communication capabilities, allowing the operator to be “in the room” to interact with Mom or Dad.

He believes that caregivers and family members can use a TP robot to “look in” on people with mild dementia. He says, “TP robots provide an effective solution for minimizing caregivers’ burden, especially for those who have career or other out-of-home activities.”

Urbanowski and his team have carried out a study that involves providing TP robots for 15 Toronto families. These robots are programmed to provide reminders of necessary daily routine like turning off the gas, taking medicine and having dinner. They will also help ensure patients are getting the exercise they need to maintain their health and well-being.

Erin Crawford, Program Director with the Alzheimer Society of Manitoba, says she has faith that TP robots will prove beneficial, particularly when it comes to reminding people with dementia to do certain things at certain times. “It means that family members that can’t be there, for whatever reason, know that those things are still happening,” she says.