Sequoia National Park

Located about 80 miles east of Fresno, California, in the southern Sierra Nevada mountain range, Sequoia National Park was established in 1890 as a measure to protect the giant trees from being cut down, making it America’s second national park.

Highlights of the park are, of course, the trees. Perhaps the most famous is the General Sherman Tree, which has rightfully earned the title of the world’s largest tree (it stands 275 feet tall and its base measures more than 36 feet in diameter).

·Best Months to Visit

The best time to visit Sequoia National Park is June through August, when the weather is fine. The park is open 24/7, year-round, but there are certain challenges during winter and spring seasons. Beginning in September, the park reduces its ranger(护林员)-led programming and certain facilities cut their hours.

·What You Need to Know

Don’t rely on technology

Cell service in many areas of the park is spotty, meaning your GPS or smartphone may not work. Plan to pick up paper maps at the park’s visitor centers.

Check the weather

Some areas in the park might be closed or you might need snow tires or chains to get through, even in the spring and fall. Check the park’s website for the most up-to-date information.

Gas up

No gasoline is sold within the park, so make sure you have a full tank before you start your journey.

Pay to play

A vehicle pass to the park costs $35; an individual pass, for an adult on a bike or on foot, costs $20.

When a woman bought a painting that appeared to bear the signature (签名) of N. C. Wyeth at a store in 2017, she joked that the 4-dollar item might actually be a real work by the Maine painter. Her joke was no laughing matter, and the painting is now estimated to fetch as much as $250,000 at auction (拍卖会) in September.

According to experts at Bonhams Skinner auction house, the seller unknowingly bought the work at a Savers store in Manchester, New Hampshire, while searching for frames to reuse. At that time, the Wyeth painting had been put against a wall along with mostly damaged posters and prints.

The woman took the piece home, and then made a quick Internet search but could not find any information about the work. After hanging the painting in her bedroom for several years, she eventually stored it in her study.

She rediscovered the painting this past May while doing cleaning, and this time posted images of the work on an online page titled “Things Found in Walls”, which is devoted to “stories of things you have found in walls, dug up in your backyard, or in that spare house across the street from your grandma’s”, according to the group’s description.

Comments on the post led her to contact Lauren Lewis, a former curator who worked with paintings by three generations of the Wyeths: N. C. Wyeth, his son Andrew Wyeth and his grandson Jamie Wyeth. So she did.

“After seeing the piece in person, Lewis was 99% certain it was authentic instead of a copy,” she told The Boston Globe. “While it certainly had some small scratches (划痕), it was in remarkable condition considering none of us had any idea of its journey over the last 80 years.”

Wyeth often produced cover art for publishers of periodicals and novels. The painting up for sale in September is one of four he completed for a 1939 edition of Helen Hunt Jackson’s book Ramona, originally published in 1884. In it, Wyeth painted the young title character facing her elderly mother.

Clarence DeMar would train for races by running to and from his job in Boston, up to 14 miles a day. His hard work paid off. He won the 1911 Boston Marathon and competed in the next year’s Olympics.

But at the time, many people and medical experts thought prolonged (持续很久的) exercise was dangerous. A doctor, detecting a heart murmur (杂音), warned DeMar to quit the sport.

DeMar proved them all wrong—both during his lifetime and after—in ways that helped change people’s minds about the benefits of exercise.

He became one of the most noticeable distance runners of his day, competing in two more Olympics and winning the Boston Marathon a record seven times between 1911 and 1930. He kept winning races well into his 40s. The press called him “Mr. DeMarathon”.

After he died of cancer at age 70, two Boston-area experts took a look at his heart. What they found were different from all those terrifying warnings. Not only was DeMar’s heart in good shape, but his arteries(动脉) were also two to three times the size of a typical person’s — reducing the risk of a fatal blockage. As for that heart murmur the doctor warned DeMar about? Experts say, “We now know that highly trained athletes often have a heart murmur, and it’s normal.”

The study, published in the New England Journal of Medicine in 1961, made the front page of The Boston Globe. “It was one of those first studies that taught us that the human body can really handle, very healthfully, lots and lots of exercise,” said Dr. Aaron Baggish, a professor at the University of Lausanne in Switzerland and the former medical director of the Boston Marathon.

The popularity of running exploded in the decades after DeMar’s death, as further research backed that up. It’s now well-established that regular exercise makes us healthier and prolongs our lives.

The current national guidelines recommend at least two and a half to five hours of moderate exercise like walking each week, or an hour and fifteen minutes to two and a half hours of vigorous activity like running—and research suggests more is generally better.

Artificial intelligence (AI) tools designed to operate at human levels have greatly expanded in popularity over the past year. These include OpenAI’s ChatGPT, Google’s Bard and Microsoft’s AI-powered search engine Bing. Such tools, also known as chatbots or generative AI, are computer-powered systems. They are designed to interact smoothly with humans and perform high-level writing and creative work.

In recent months, these tools have demonstrated an ability to produce high-quality work. This has led some technology experts to warn that generative AI systems could end up replacing workers in many industries.

This year, researchers at Harvard Business School and other organizations carried out an experiment. It aimed to test how well AI tools could help workers perform their usual duties or tasks. It involved more than 700 business advisors, called consultants, from Massachusetts-based Boston Consulting Group.

Harvard Business School recently published the results from the experiment in a working paper. The main findings suggest that AI tools like ChatGPT can greatly improve worker performance. For example, researchers found that, on average, workers who used OpenAI’s latest ChatGPT 4 tool completed 12 percent more tasks than non-ChatGPT users. Tasks carried out with help from the AI technology were completed 25 percent faster. And the team found the quality of work performed by consultants using ChatGPT 4 increased by about 40 percent.

However, the paper also noted areas where the performance of consultants using ChatGPT 4 dropped. The researchers said this was especially true with tasks the AI tool was not good at completing. “Of tasks the AI was good at, the experiment showed it significantly improved human performance,” the paper said. “But for tasks ChatGPT 4 was not right for, humans relied too much on the AI and were more likely to make mistakes.”

The team suggests one of the biggest barriers to companies effectively using AI is not knowing which tasks can be completed best with the technology. Finding this out will require businesses to carry out thoughtful research and training efforts in order to find the right mix of AI and human-level work.