The Scottish economy [September 1989]

[Abstract unavailable

Sensory Stimulation and Music Therapy Programs for Treating Disorders of Consciousness

Boyer College of Music and DanceMusic Therap

The British economy [December 1989]

The rate of growth of output continues to slow down. The form of the economic contraction still gives cause for concern as the output of tradeables shows few signs of holding up better than non-tradeable production - the necessary requirement if recession is to be avoided. On the credit side investment, and particularly manufacturing investment, appears to be holding up well in the face of monetary contraction. In addition, the rate of growth of export volumes appears to be rising slowly relative to imports. The recent downward movement of sterling perhaps signals a change in economic policy

Mujeres: Los derechos y las equivocaciones

No cuenta con resumen

Using Geostatistical Methods with Large Publicly Available Datasets to Refine a Model for the Naturally Occurring Background Concentrations of Arsenic in Groundwater

Understanding the distribution and potential risks of naturally occurring elements such as arsenic in groundwater is a critical issue for public health. Additionally, having a dataset for the evaluation of the distribution of naturally occurring elements can serve as a “background” basis for evaluation of changes to groundwater conditions that might occur due to contamination, declining groundwater elevations, or changes to areas of groundwater recharge. In many cases the costs of well installation and analysis means that there is frequently insufficient data to establish these background conditions and there are not agreed upon methods to establish whether a given well is representative of a geographic area or showing some unique local condition or evidence of anthropogenic impacts.This study seeks to establish how the publicly available dataset in California’s GeoTracker database generated from properties with groundwater contamination can be used to better understand naturally occurring arsenic in groundwater. We compare the use of traditional non-spatial statistical treatments for identification of outliers to the use of spatial statistics to isolate outliers and establish spatially representative arsenic distributions. A key objective here, related to GeoTracker, is the classification of “background” vs. “contamination” levels of groundwater metals, where “background” in the typical statistical methods, is commonly defined as not being a statistical outlier. Among the methods tested, spatial weighting and interpolation using inverse distance weighting on a log transformed dataset produced the lowest RMSE among the non-spatial and spatial approaches evaluated for arsenic in groundwater with the added benefit of the ability to provide spatial information that is useful to practitioners managing groundwater use and recharge activities.In this study we found that non-spatial methods performed following typical methods from regulatory guidance documents predict a mean concentration of 9.4 micrograms per liter (µg/L) for arsenic in shallow groundwater in the Central Valley of California (n = 756). Spatial interpolation of the same dataset using inverse distance weighting predicts a mean concentration of 4.8 µg/L with a lower RMSE. We also compared the performance of spatially weighted methods using data for four adjacent counties located within the Central Valley. Spatially weighted methods using inverse distance weighting predict mean concentrations for arsenic in shallow groundwater wells in Merced (n = 71), Sacramento (n = 139), and Stanislaus (n = 114) counties in the range of 3 to 4 µg/L with comparable values of RMSE. Shallow wells in San Joaquin county (n = 178) were found to have a predicted mean concentration of 7.8 µg/L with a much higher RMSE; however, this increased concentration is associated with known elevated levels of arsenic in groundwater in the San Joaquin delta region which dissipate with distance from these geogenic sources. Mapping of the spatially weighted data from these different geographies shows a key benefit of using spatial methods to expand the understanding of the spatial variations and local differences or sources for risk to groundwater resources and users. Spatial methods for interpreting this data provide benefits to the regulatory community and the public by providing improved prediction on the potential risks associated with shallow groundwater use and showing locations where additional characterization or groundwater management measures are needed