RESUMO
Most of the world's crops depend on pollinators, so declines in both managed and wild bees raise concerns about food security. However, the degree to which insect pollination is actually limiting current crop production is poorly understood, as is the role of wild species (as opposed to managed honeybees) in pollinating crops, particularly in intensive production areas. We established a nationwide study to assess the extent of pollinator limitation in seven crops at 131 locations situated across major crop-producing areas of the USA. We found that five out of seven crops showed evidence of pollinator limitation. Wild bees and honeybees provided comparable amounts of pollination for most crops, even in agriculturally intensive regions. We estimated the nationwide annual production value of wild pollinators to the seven crops we studied at over $1.5 billion; the value of wild bee pollination of all pollinator-dependent crops would be much greater. Our findings show that pollinator declines could translate directly into decreased yields or production for most of the crops studied, and that wild species contribute substantially to pollination of most study crops in major crop-producing regions.
Assuntos
Agricultura , Produtos Agrícolas , Polinização , Animais , Abelhas , Abastecimento de Alimentos , Estados UnidosRESUMO
The distribution of mammography machines and related resources in West Virginia, along with the distribution of breast cancer screen-eligible women, are examined using county-specific data. This data placed on a state map shows that it is not necessary to cross more than one county line anywhere within West Virginia in order to visit a mammography facility. The overall density of these machines is 20 per 100,000 women over 45, almost double the capacity needed for screening mammography. After taking into account the projected demand for mammography, the current average cost per exam is around $65-$100. If mammography machines were placed in all the counties without machines, the cost in those countries would be around $140 per exam. It would be cheaper to provide a travel allowance to women in rural counties than to install machines in these areas. Machines that are accredited by the American College of Radiologists, the most available indicator of quality mammography, are located only in densely populated areas of the state.