When the explorers first set foot upon the continent of North America, the skies and lands were alive with an astonishing variety of wildlife. Native Americans had taken care of these precious natural resources wisely. Unfortunately, it took the explorers and the settlers who followed only a few decades to decimate a large part of these resources. Millions of waterfowl ( 水禽 ) were killed at the hands of market hunters and a handful of overly ambitious sportsmen. Millions of acres of wetlands were dried to feed and house the ever-increasing populations, greatly reducing waterfowl habitat.

In 1934, with the passage of the Migratory Bird Hunting Stamp Act (Act), an increasingly concerned nation took firm action to stop the destruction of migratory ( 迁徙的) waterfowl and the wetlands so vital to their survival. Under this Act, all waterfowl hunters 16 years of age and over must annually purchase and carry a Federal Duck Stamp. The very first Federal Duck Stamp was designed by J.N. “Ding” Darling, a political cartoonist from Des Moines, lowa, who at that time was appointed by President Franklin Roosevelt as Director of the Bureau of Biological Survey. Hunters willingly pay the stamp price to ensure the survival of our natural resources.

About 98 cents of every duck stamp dollar goes directly into the Migratory Bird Conservation Fund to purchase wetlands and wildlife habitat for inclusion into the National Wildlife Refuge System — a fact that ensures this land will be protected and available for all generations to come. Since 1934, better than half a billion dollars has gone into that Fund to purchase more than 5 million acres of habitat. Little wonder the Federal Duck Stamp Program has been called one of the most successful conservation programs ever initiated.

The benefits of regular exercise are well documented but there's a new bonus to add to the ever-growing list. New researchers found that middle-aged women who were physically fit could be nearly 90 percent less likely to develop dementia (失智症) in later life and is they did, it came on a decade later than less sporty women.

Lead researcher Dr. Helena Horder, of the University of Gothenburg in Sweden, said: "These findings are exciting because it's possible that improving people's cardiovascular (心血管的) fitness in middle age could delay or even prevent them from developing dementia."

For the study, 191 women with an average age of 50 took a bicycle exercise test until they were exhausted to measure their peak (最大值的) cardiovascular capacity. The average peak workload was measured at 103 watts. A total of 40 women met the criteria for a high fitness level, or 120 watts or higher.

A total of 92 women were in the medium fitness category: and 59 women were in the low fitness category, defined as a peak workload of 80 watts or less, or having their exercise tests stopped because of high blood pressure, chest pain or other cardiovascular problems.

These women were then tested for dementia six times over the following four decades. During that time, 44 of the women developed dementia. Five percent of the highly fit women developed dementia, compared to 25 percent of the women with medium fitness and 32 percent of the women with low fitness

"However, this study does not show cause and effect between cardiovascular fitness and dementia it only shows an association. More research is needed to see if improved fitness could have a positive effect on the risk of dementia and also to look at when during a lifetime a high fitness level is most important" She also admitted that a relatively small number of women were studied, all of whom were form Sweden so the results might not be applicable to other groups.

Rome can be pricey for travelers, which is why many choose to stay in a hostel ( 旅 社 ). The hostels in Rome offer a bed in a dorm room for around

$25 a night, and for that, you'll often get to stay in a central location (位置) with security and comfort.

Yellow Hostel

If I had to make just one recommendation for where to stay in Rome, it would be Yellow Hostel. It's one of the best-rated hostels in the city, and for good reason. It's affordable, and it's got a fun atmosphere without being too noisy. As an added bonus, it's close to the main train station.

Hostel Alessandro Palace

If you love social hostels, this is the best hostel for you in Rome. Hostel Alessandro Palace is fun. Staff members hold plenty of bar events for guests like free shots, bar crawls and karaoke. There's also an area on the rooftop for hanging out with other travelers during the summer.

Youth Station Hostel

If you're looking for cleanliness and a modern hostel, look no further than Youth Station. It offers beautiful furnishings and beds. There are plenty of other benefits, too; it doesn't charge city tax; it has both air conditioning and a heater for the rooms; it also has free Wi-Fi in every room.

Hotel and Hostel Des Artistes

Hotel and Hostel Des Artistes is located just a 10-minute walk from the central city station and it's close to all of the city's main attractions. The staff is friendly and helpful, providing you with a map of the city when you arrive, and offering advice if you require some. However, you need to pay 2 euros a day for Wi-Fi.