2001 Water Symposium: Water Pollution in Urban and Rural Settings

The Environmental and Energy Study Institute, the Federal Water Quality Association and the National Capital Chapter of the American Water Resources Association co-hosted the 2001 Water Symposium: Water Pollution In Urban And Rural Settings.The symposium examined the relative contributions of urban and rural areas to nonpoint source water pollution, and examined innovative approaches and possible synergies to improve water quality in both urban and rural portions of watersheds. Timothy L. Miller, chief of the U.S. Geological Survey's National Water Quality Assessment Program (NAWQA), outlined the major findings from 10 years of monitoring and assessing both surface and groundwater contamination in 140 rural/agricultural watersheds and more than 40 urbanized watersheds. The assessments show that water quality is affected by local land and water uses and practices, as well as population density. The urbanized study areas typically involved suburban type residential and commercial land use and low to medium population density, rather than heavily developed urban cores. Urbanized areas grew by 16 million acres between 1992 and 1995, or four to five million acres per year.For both urban and agricultural areas, nonpoint source chemical contamination is a problem. Generally such contamination was found to occur more frequently and at greater concentrations in urbanized areas, which cover less than 5 percent of the land in the continental United States, than in farming areas, which cover more than 50 percent. In both agricultural and urban settings, nutrients and pesticides were found, but the urban areas also contained volatile organics, trace metals and high insecticide concentrations. Contamination from urban areas also appeared to have a more significant detrimental influence on aquatic life. In response to a question, Miller said that arsenic exceeding the current 50 ppb (parts per billion) federal standard was found in a handful of samples, but many more exceeded the proposed 10 ppb standard

Photosynthesis dependent acidification of perialgal vacuoles in theParamedum bursaria/Chlorella symbiosis. Visualization by monensin

After treatment with the carboxylic ionophore monensin theChlorella containing perialgal vacuoles of the greenParamecium bursaria swell. TheParamecium cells remain motile at this concentration for at least one day. The swelling is only observed in illuminated cells and can be inhibited by DCMU. We assume that during photosynthesis the perialgal vacuoles are acidified and that monensin exchanges H+ ions against monovalent cations (here K+). In consequence the osmotic value of the vacuoles increases. The proton gradient is believed to drive the transport of maltose from the symbiont into the host. Another but light independent effect of the monensin treatment is the swelling of peripheral alveoles of the ciliates, likewise indicating that the alveolar membrane contains an active proton pump

U.S. Farm Income Outlook for 2015

[Excerpt] The U.S. farm sector is vast and varied. It encompasses production activities related to traditional field crops (such as corn, soybeans, wheat, and cotton) and livestock and poultry products (including meat, dairy, and eggs), as well as fruits, tree nuts, and vegetables. In addition, U.S. agricultural output includes greenhouse and nursery products, forest products, custom work, machine hire, and other farm-related activities. The intensity and economic importance of each of these activities, as well as their underlying market structure and production processes, vary regionally based on the agro-climatic setting, market conditions, and other factors. As a result, farm income and rural economic conditions may vary substantially across the United States. However, this report focuses singularly on aggregate national net farm income and the status of the farm debt-to-asset ratio as reported by the U.S. Department of Agriculture (USDA). Annual U.S. net farm income is the single most watched indicator of farm sector well-being, as it captures and reflects the entirety of economic activity across the range of production processes, input expenses, and marketing conditions that have persisted during a specific time period. When national net farm income is reported together with a measure of the national farm debt-to-asset ratio, the two summary statistics provide a quick indicator of the economic well-being of the national farm economy

Inequality of Learning amongst Immigrant Children in Industrialised Countries

Literature examining immigrants’ educational disadvantage across countries focuses generally on average differences in educational outcomes between immigrants and natives disguising thereby that immigrants are a highly heterogeneous group. The aim of this paper is to examine educational inequalities among immigrants in eight high immigration countries: Australia, Canada, Germany, New Zealand, Sweden, Switzerland, UK and USA. Results indicate that for almost all countries immigrants’ educational dispersion is considerably higher than for natives. For most countries higher educational dispersion derives from very low achieving immigrants. Quantile regression results reveal that at lower percentiles language skills impact more on educational achievement than at the top of the achievement distribution. Results are presented separately for immigrants of different age cohorts, varying time of immigrants’ residence in the host country and subject examined (maths and reading) highlighting thereby the different patterns found by immigrant group and achievement measure.education, educational inequalities, immigration, PISA, TIMSS, PIRLS

LONG-RUN PRICE RISK IN U.S. AGRICULTURAL MARKETS

The last three years have realized significant structural changes in the U.S. agricultural policy environment. These changes include nearly complete planting flexibility and the elimination of target-price-based income support for agricultural producers. Many have questioned the extent to which such policy changes may influence the variability of agricultural prices. This analysis uses price series dating from 1944 to develop a multivariate framework to evaluate the long-run (inter-season) determinants of endogenous variability for the prices of corn, wheat, and soybeans. An annual measure of price variability is calculated from monthly spot market cash prices for each of the three commodities. The generalized method of moments estimation technique is used to model the price variability measure as a function of several supply and demand variables hypothesized to be relevant. Several explicit policy variables are tested for their effect on output price variability as well as on the variable parameter estimates. Output price variability is found to be sensitive to stocks, demand shocks, yield shocks, input price variability, and policy factors. Results vary somewhat for corn, wheat, and soybeans. Implications for recent farm policy changes are offered.Agricultural and Food Policy, Demand and Price Analysis,

SOYBEAN PRODUCTION COSTS: AN ANALYSIS OF THE UNITED STATES, BRAZIL, AND ARGENTINA

U.S. farmers' share of world soybean exports has declined, while Brazil and Argentina are gaining. There is much debate concerning the competitive advantage of U.S. versus Latin American soybean producers. A detailed analysis of soybean production costs under different systems and technologies in the United States, Argentina, and Brazil was conducted.Crop Production/Industries,

Non-response biases in surveys of schoolchildren: the case of the English Programme for International Student Assessment (PISA) samples

We analyse response patterns to an important survey of schoolchildren, exploiting rich auxiliary information on respondents' and non-respondents' cognitive ability that is correlated both with response and the learning achievement that the survey aims to measure. The survey is the Programme for International Student Assessment (PISA), which sets response thresholds in an attempt to control the quality of data. We analyse the case of England for 2000, when response rates were deemed sufficiently high by the organizers of the survey to publish the results, and 2003, when response rates were a little lower and deemed of sufficient concern for the results not to be published. We construct weights that account for the pattern of non-response by using two methods: propensity scores and the generalized regression estimator. There is clear evidence of biases, but there is no indication that the slightly higher response rates in 2000 were associated with higher quality data. This underlines the danger of using response rate thresholds as a guide to quality of data

Inequalities in Secondary School Attendance in Germany

In Germany, children are sorted into differently prestigious school types according to their ability at the end of primary schooling, normally at age 10. This early decision about children’s future schooling cannot be easily corrected. However, secondary school attendance has a huge impact on future career options, so that equality in pupils’ distribution to differential school types is important. This paper examines the impact of social and economic background on children’s school type if ability is held constant. The analysis is based on national data taken from two surveys of learning achievement, the Third International Mathematics and Science Study (TIMSS) and the Programme of International Student Assessment (PISA). These data reveal that a large share of pupils in less prestigious school types would fit perfectly well in better school types given their measured ability. Children from rural areas, pupils from lower socio-economic backgrounds and boys in general have a significantly lower probability of being selected to the most academic school track even when their ability is similar to that of their urban and better socially placed counterparts. <br/