Advancements in technology, especially the sonogram have provided an "early" identification of the baby's gender. The Bulletin of the American Meteorology Society reported that weather may be a factor in the weight of a newborn. An article in the British Journal of Obstetrics and Gynecology indicated that an increase of a single degree in air temperature during the first trimester could create a birth weight drop of 0.2 ounces. The study included the analysis of 12,000 children born in Aberdeen, Scotland over a six-year period.  Researchers determined that lighter babies were born during the winter months after being exposed to hotter weather in the early stages of pregnancy and those babies were an ounce lighter than those born in other seasons. Heat restricts blood vessels in the mother's body, diverting nutrients from the fetus. The findings may encourage the need to keep cool during heat waves where air conditioning is unavailable. some locations in the United States, especially the ski resorts, may enjoy additional snowfall this weekend. In the construction of the transcontinental railroad, snow from the Sierras to Sacramento created avalanches that wiped out stretches of rail. In 1887 engineers used beams from local timber to construct a sturdy device that furthered construction and kept the trains rolling. They are called snow sheds and initially were placed over exposed track to funnel the sliding snow over the top of the tracks. Today, snow sheds remain a common method for combating the destructive force of avalanches on railroad and highway routes throughout the world. These days they are constructed with reinforced concrete and steel.  On steep slopes, snow fences assist in anchoring the snow packs.