3 resultados para Mountain Chief Mine

em Bucknell University Digital Commons - Pensilvania - USA


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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.

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This study examines the effects of the source of whistle-blowing allegations and potential for allegations to trigger concerns about reputation threats on Chief Audit Executives’ handling of whistle-blowing allegations. The participants for this study, 79 Chief Audit Executives (CAEs) and deputy CAEs, evaluated whistle-blowing reports related to financial reporting malfeasance that were received from either an anonymous or a non-anonymous source. The whistle-blowing reports alleged that the wrongdoing resulted from either the exploitation of substantial weaknesses in internal controls (suggesting higher responsibility of the CAE and internal audit) or the circumvention of internal controls (suggesting lower responsibility of the CAE or internal audit). Findings indicate that CAEs believe anonymous whistle-blowing reports to be significantly less credible than non-anonymous reports. Although CAEs assessed lower credibility ratings for the reports alleging wrongdoing by the exploitation of substantial weaknesses in internal controls, they allocated more resources to investigating these allegations.

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The fluorescent mineral hardystonite is confirmed in a specimen from the Desert View Mine, California. Hardystonite had been known only from Franklin, New Jersey for over 100 years.