Denali National Park, Alaska

    History

    Within Denali National Park, the Toklat River will always have a special significance, as it was the location where naturalist Charles Sheldon built a cabin and was so moved that he fought to preserve the land. He moved back east and spent nine years lobbying (游说）to create Alaska's first national park.

    When to Visit

    To avoid the crowds, visit in June, but keep in mind that there are up to 21 hours of sunlight in Alaska in summer. If it seems like a bit much for your taste, try visiting in late August or September.

    If you visit to climb Mount McKinley, May and early June are the best times to climb.

    Major Attractions

    It is difficult not to see Denali's largest attraction towering 20,320 feet high. Mount McKinley can even be seen up to 70 miles away on a clear day. If you brave the climb to the top, you will be rewarded with charming views of the Alaska Range.

    Sable Pass is a prime spot to view grizzly bears. Closed to off-road foot traffic, the area is popular for bears feeding on berries, roots, and even occasionally on other mammals.

    Beginning at just below the summit of Mount McKinley, Muldrow Glacier flows 35 miles through a gorge and across the tundra. Twice in the last hundred years, the Muldrow has surged (涌动）, most recently in the winter of 1956-1957.

Accommodation

    Five campgrounds are located within the park, and many are open from late spring to early fall.Note: reservations are strongly recommended during summer. Riley Creek campground is open all year round, and all but two (Sanctuary and Wonder Lake) offer RV (可供居住的大篷车）sites.

    Also within the park are a few lodges (旅馆）—North Face Lodge, Denali Backcountry Lodge and Kentishna Roadhouse.

    When asked how technology might improve the lives of people with vision impairments (视力障碍), Joann Becker presented a misleadingly simple challenge. “Well,” the vision impairments tech specialist recalls saying. “I'd like to be able to find my bus slop through Be My Eyes”.

    Be My Eyes, which went live in 2015, establishes a direct video connection between visually impaired users and sighted volunteers. The assumption is simple: Many people who are blind don't need any actual assistance in completing their daily tasks, but merely need a little help.

    A sighted volunteer might be asked to help identify which of two cans contains tomatoes. In this case, the visually impaired user can cook a meal just fine on his/her own-all he/she needs is a quick confirmation that he/she has the correct can. The model appears to be working; more than 540,000 volunteers and nearly 40,000 people with low vision are registered on the app.

    “An elderly woman can now help a visually impaired technician set up his computer,” says founder Hans Wiberg, who has very low vision. “She doesn't need to know a thing about computers. She only needs to read what is presented on the screen. Then he can do the rest.”

    Early assistive technology centered on dedicated devices (专用设备), because of the niche market (缝隙市场), which sold for hundreds or even thousands of dollars. But the smartphone, multipurpose and near-universal, has completely changed the economy of scale.

    “There are larger market forces driving high-powered computation, high-quality engineering and high-quality battery management in the smartphone market than those in a specialty product,” says Aaron Steinfeld, a research professor at the Robotics Institute at Carnegie Mellon University.

    “The reality is, most sighted people don't know somebody who is blind.” Becker says. “They think the solutions that a blind person needs arc far more expansive, it turns out, they need to be. I think these apps are enabling sighted people to see that blind people just need some simple clues to help them do any number of things in their lives.”

    Finding a mountain goat resting high on a cliff(悬崖) might thrill many of the millions of tourists who visit Wyoming's Grand Teton National Park every year, but park officials say it might be time for the bearded animals to go.

    The problem, according to the park, is that Grand Teton's 100 or so mountain goats threaten about 80 bighorn sheep. The bighorn sheep numbered as many as 125 just a few years ago. The strong goats spread disease and compete with bighorn sheep for food. Unlike small-sized bighorn sheep, Grand Teton's mountain goats aren't native to the park. They were introduced to the park in the 1960s.

    Grand Teton spokeswoman Denise Germann said, “We've got a management responsibility to protect the native species. After hearing from the public on the proposal (建议) in January, park officials expect to decide as soon as mid-February on what to do about the mountain goats.”

    The goats are reproducing rapidly. Now might be the best time to reduce the animals before they're too many to bring under control, according to the Park Service.

    One wildlife biologist who studies bighorn sheep praised the proposal. Mountain goats' original habitat is nowhere close to where they've been introduced in the U.S. to provide hunting opportunities, said Rob Roy Ramey II, with Nederland, Colorado-based Wildlife Science International, Inc.

    Wildlife managers should get rid of mountain goats not only in Grand Teton but elsewhere to help struggling bighorn sheep, Ramey said. “Unfortunately, state wildlife agencies sell nonnative wildlife viewing opportunities to the public,” Ramey said. “This is not a zoo in the wilderness. It should really be for native wildlife.”

Benefits and Problems of Genetic Engineering

    Plant breeding is the science of changing the characteristics of plants in order to produce desired ones. Genes in a plant are what determine what type of characteristics it will have. Plant breeders try to create a specific outcome of plants and potentially new plant varieties by changing the genes of the plants through breeding, which is making new plants from parents of different varieties or species.

    Actually, plant breeding has been practiced for thousands of years, since near the beginning of human civilization. It is practiced worldwide by individuals such as gardeners and farmers and by professional plant breeders employed by organizations such as government institutions, universities, crop-specific industry associations or research centers. They have crossbred plants to create the new types of plants that are, for example, bigger, stronger, or more attractive.

    Crossbreeding can take such a long time, however, and it is inaccurate. Now, we can change exact sections of Deoxyribonucleic acid (DNA), so the process is more accurate and faster. But people all over the world are arguing about its benefits and disadvantages. Some people use the technology to produce desired characteristics of plants and animals. Other people are concerned that the genetically engineered plants may harm the environment and worried that they may be dangerous for people to eat.

    There are many reasons for changing plants in this way. International development agencies believe that breeding new crops is important for ensuring food security by developing new varieties that are higher yielding(高产的), disease resistant, drought tolerant or regionally adapted to different environments and growing conditions. For example, some genetically engineered plants can live through frost or draught. As a result, famers can make more profit because fewer plants will die.

    Some genetically engineered plants are more nutritious. They have less fat, taste better or stay fresher than non-genetically engineered plants. This will allow people to buy better-quality fruit and vegetables.

    Some genetically engineered plants can resist natural pests such as viruses or insects. This reduces the amount of chemical needed to kill pests, which is helpful to the environment.

    However, genetically engineered plants can cause unexpected problems. Genetically engineered plants that resist pests may pass on that characteristic to a wild relative. This may cause the wild plant to spread fast, because pests are not naturally killing it.

    Genetically engineered plants can also harm animals. A type of corn has been developed which kills a species of insect that destroys it. The pollen (花粉) from this corn, however, can also kill monarch butterflies—the most beautiful of all butterflies, which do not harm the corn.

    To ensure the most adapted varieties are identified, advocates of organic breeding now promote the use of direct selection for many desired characteristics.

    Genetic engineering is a very new science and we have a lot to learn about the good it can do and the damage it can cause. The main concern is that not enough tests are being done to ensure it is safe.

Some Ohio high school students have become winners in a national contest (竞赛) after inventing a mobile phone app that helps needy families find local food pantries (公益食品仓库).

And someday the teens, who are students at Ross High School in Ross Township, may be selling the app to food pantries and food banks across America.

The app was created as part of a computer science class — coordinated (协调) by Butler Tech career school system at the high school. Three students, Jacob Kahmann, Gunner Nonnamaker and Kyle Inderhees, recently were visited by Congressman Warren Davidson, who praised their work. Davidson lauded the teens for creating "this app to set the standard for efficient food collection and distribution (分发)".

Butler Tech IT Instructor Tom O'Neill said the students' app includes characteristics that help users locate the nearest food pantry and improve food collection processes, and that the national contest provides a real-life learning chance for his students.

The students are continuing to make additions to the app and are working on turning it into a product, said O'Neill, who in recent years has helped many Ross High School teens win national honors for their computer-science-based inventions.

"The teachers and students in the Ross School District continue to amaze me with their future-thinking and creation," said Superintendent Scott Gates. "Our students are not only thinking about careers, they are thinking about problems they want to change, solve or improve. The app that was created will make serving a population in need more efficient."

One fine day, a bus driver went to the bus garage, started his bus, and drove off along his route. No problems for the first few stops—a few people got on, a few got off, and things went generally well.

At the next stop, however, a big hulk of a guy got on. Six feet eight, built like a wrestler, arms hanging down to the ground. He glared at the driver and said, "Big John doesn't pay!" and sat down at the back. The driver was five feet three, thin, and basically mild-mannered. Naturally, he didn't argue with Big John, but he wasn't happy about it.

The next day the same thing happened—Big John got on again, made a show of refusing to pay, and sat down. And the next day, and the one after that, and so forth.

This grated on the bus driver, who started losing sleep over the way Big John was taking advantage of him. Finally he could stand it no longer. He signed up for body building courses, karate, judo, and all that good stuff. By the end of the summer, he had become quite strong—what's more, felt really good about himself.

So on the next Monday, when Big John once again got on the bus and said. "Big John doesn't pay!" the driver stood up, glared back at the passenger, and screamed, "Oh, yeah? And why not?" With a surprised look on his face, Big John replied, "Big John has a bus pass."