Abandoned Coal Mine Drainage and Its Remediation: Impacts on Stream Ecosystem Structure and Function

The effects of abandoned mine drainage (AMD) on streams and responses to remediation efforts were studied using three streams (AMD-impacted, remediated, reference) in both the anthracite and the bituminous coal mining regions of Pennsylvania (USA). Response variables included ecosystem function as well as water chemistry and macroinvertebrate community composition. The bituminous AMD stream was extremely acidic with high dissolved metals concentrations, a prolific mid-summer growth of the filamentous alga, Mougeotia, and .10-fold more chlorophyll than the reference stream. The anthracite AMD stream had a higher pH, substrata coated with iron hydroxide(s), and negligible chlorophyll. Macroinvertebrate communities in the AMD streams were different from the reference streams, the remediated streams, and each other. Relative to the reference stream, the AMD stream(s) had (1) greater gross primary productivity (GPP) in the bituminous region and undetectable GPP in the anthracite region, (2) greater ecosystem respiration in both regions, (3) greatly reduced ammonium uptake and nitrification in both regions, (4) lower nitrate uptake in the bituminous (but not the anthracite) region, (5) more rapid phosphorus removal from the water column in both regions, (6) activities of phosphorus-acquiring, nitrogenacquiring, and hydrolytic-carbon-acquiring enzymes that indicated extreme phosphorus limitation in both regions, and (7) slower oak and maple leaf decomposition in the bituminous region and slower oak decomposition in the anthracite region. Remediation brought chlorophyll concentrations and GPP nearer to values for respective reference streams, depressed ecosystem respiration, restored ammonium uptake, and partially restored nitrification in the bituminous (but not the anthracite) region, reduced nitrate uptake to an undetectable level, restored phosphorus uptake to near normal rates, and brought enzyme activities more in line with the reference stream in the bituminous (but not the anthracite) region. Denitrification was not detected in any stream. Water chemistry and macroinvertebrate community structure analyses capture the impact of AMD at the local reach scale, but functional measures revealed that AMD has ramifications that can cascade to downstream reaches and perhaps to receiving estuaries.

Income, Trade and Pollution in Central Asia, Russia and China: An Econometric Analysis

The study performs a panel estimation of the relationship between per capita income, trade, and airborne pollution in the five Central Asian nations, Russia and China between 1992 and 2008. First, this study uses an environmental Kuznets curve hypothesis (EKC)- an inverted-U relationship between the increase in income and the level of environmental degradation - to examine how income and pollution are related. Second, the study uses a gravity model to estimate the effect of a regional trade agreement (Shanghai Cooperation Organization: SCO) on incomes and carbon dioxide emissions in the region. Empirical analysis confirms the existence of the rising portion of the EKC curve in the region - a positive correlation between per capita income growth and carbon dioxide emissions- and that the volume of bilateral trade, and not the existence of a regional trade agreement, contributes to the increasing level of environmental pollution.

Income, Trade and Pollution in Central Asia, Russia and China: An Econometric Analysis

The study performs a panel estimation of the relationship between per capita income, trade, and airborne pollution in the five Central Asian nations, Russia and China between 1992 and 2008. First, this study uses an environmental Kuznets curve hypothesis (EKC)- an inverted-U relationship between the increase in income and the level of environmental degradation - to examine how income and pollution are related. Second, the study uses a gravity model to estimate the effect of a regional trade agreement (Shanghai Cooperation Organization: SCO) on incomes and carbon dioxide emissions in the region. Empirical analysis confirms the existence of the rising portion of the EKC curve in the region - a positive correlation between per capita income growth and carbon dioxide emissions- and that the volume of bilateral trade, and not the existence of a regional trade agreement, contributes to the increasing level of environmental pollution.

The Relationship Between the Valence of Self-Talk Statements and Social Anxiety: An Analysis of Gender and Athletic Status

The purpose of this study was to investigate the relationship between self-talk statements and social anxiety and specifically to examine the difference in this relationship between males and females and athletic status.