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Snow fences are an increasingly widespread cultural feature in the great east-west “snow belt” of the northern hemisphere. They are there not only to protect railroads, highways and buildings from the hazards of blowing snow, but also whole towns subject to the ravages of avalanches. Although their origin is unknown, their construction and use have been advanced and improved greatly by many experimenters of more than a dozen nationalities since the middle of the 19th century.

A modern example of snow fence use is analyzed for a locally named section of Interstate 80 between Laramie and Rawlins in southern Wyoming known as the “Sno Chi Minh Trail.” Here big systems of mostly 12 feet high snow fences line more than half of the western side of the highway for 50 miles. They have reduced accidents and plowing costs by significantly improving visibility in “ground blizzards” of fast-blowing snow.  相似文献   
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The American Kennel Club (AKC), the primary registry agency for purebred dogs in the United States, had recognized 138 breeds through September 1995. An investigation of the source areas of these breeds reveals the cultural authority of Great Britain in organized dog breeding in the United States. Although Great Britain accounts for more than one-third of the AKC breeds, however, its importance has declined. Dogs from Asia account for more than one-fifth of the breeds recognized since World War II. Breed names that contain toponymic elements (such as Sussex Spaniel) usually reinforce the importance of the area in which the breeds were developed. An analysis of the patterns of geographic names reveals a pronounced emphasis on Western Europe, particularly Great Britain. A decline in the prominence of names from Europe has occurred. Asian name sources have become more important, and Australia and Africa have begun receiving attention. North America as a source of breeds as well as a source of naming has occupied a relatively minor role throughout the AKC's history. American breeders and promoters of purebred dogs have tended to look outward, especially toward Europe, for sociocultural forms.  相似文献   
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