Virtual water. Virtual water trade (also known as trade in embedded or embodied water) refers to the hidden flow of water if food or other commodities are traded from one place to another. For instance, it takes 1,340 cubic meters of water (based on the world average) to produce one metric tonne of wheat.
At the same time, researchers also say poor understanding of truly dangerous spider bites delays treatment when a person really has been bitten by a dangerous spider. For example, the bite of the brown recluse spider can cause death of a sizeable area of skin (skin necrosis) resulting in a deep, scarring ulcer. Yet even in areas infested with brown recluse spiders, true bites are uncommon. The analysis is published in the July 14 online issue of The Lancet.
Spider bites. 1  Brown recluse spider bites cause a painful bite that later may develop into a bruise or blister. 2  Black widow spider bites typically are not painful but within several hours patients develop a systemic reaction presenting as muscle pain, stomach pain, and breathing difficulties. small blister or pus filled bump usually occurs a few days later. In rare cases, some patients can develop anaphylaxis to fire ant bites. Lice bites usually present as small, red bumps on the shoulders, neck, and scalp. They are very itchy and are a sign that there are probably numerous nits and lice in the scalp.