4 research outputs found

    Surface and Subsurface Application of Chemical Dispersants and Associated Ecosystem Impacts

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    Chemical dispersants are applied to spilled oil in marine environments when other, less controversial, methods are not adequate for the incident. They are considered to be a response method as opposed to a direct cleanup method, with the intended goals of reducing risk of exposure to sensitive shorelines, reducing environmental injury to surface-dwelling sea birds and marine mammals, and facilitating the biodegradation of spilled oil into the water column. For this research, both surface and subsurface application of dispersants were evaluated in terms of oil characteristics and volume, and oceanic and atmospheric conditions. More data exists to support the effectiveness of chemical dispersant application at surface water oil slicks as opposed to subsurface plumes. However, since Deepwater Horizon in 2010, there have been several hundred scientific research papers published to study subsurface application of oil spill dispersants. While the efficacy, ecosystem impacts, and ultimate fate of chemical dispersants and dispersed oil generates conflicting opinions in the scientific community, there are measures that could be taken in order to minimize potential impacts. Research that accounts for variable conditions and ecosystems could be initiated, simulating field conditions in laboratory settings, processing data from Deepwater Horizon, and utilizing current response and monitoring protocols

    Detector Fabrication Yield for SuperCDMS Soudan

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    The SuperCDMS collaboration is presently operating a 9 kg Ge payload at the Soudan Underground Laboratory in their direct search for dark matter. The Ge detectors utilize double-sided athermal phonon sensors with an interdigitated electrode structure (iZIPs) to reject near-surface electron-recoil events. These detectors each have a mass of 0.6 kg and were fabricated with photolithographic techniques. The detector fabrication advances required and the production yield encountered are described.United States. Dept. of EnergyNational Science Foundation (U.S.

    DNA methylation of heparanase promoter influences its expression and associated with the progression of human breast cancer.

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    Heparanase promotes tumor invasion and metastasis in several malignancies including breast cancer. However, the roles and regulation mechanisms of heparanase during breast cancer progression are still not fully understood. The aim of this study is to determine the differential regulation of heparanase gene expression in specific stages of breast cancer by DNA methylation. We detected levels of heparanase expression and DNA methylation patterns of its promoter in breast cancer cell lines (MCF-7 and MDA-MB-435) and clinical tissues, respectively. It has been observed that heparanase is highly expressed in the invasive MDA-MB-435 cells with low methylation modification in the heparanase promoter. In contrast, lower expression of heparanase in MCF-7 cells is accompanied by higher methylation in the promoter. Treatment of MCF-7 cells with 5-aza-2'-deoxycytidine (5-aza-dC), a potent demethylating agent, results in induction of heparanase expression and higher invasion potential in vitro and leads to an advantage of tumor formation in vivo. In 54 tissue samples, cancer samples at late stages (stage IV) showed the highest heparanase expression accomplished by little DNA methylation. On the contrary, methylation prevalence is highest in normal tissue and inversely correlated with heparanase expression. A significant correlation between DNA methylation and clinical stage was demonstrated (p = 0.012). Collectively, these results demonstrate that DNA methylation play the regulation role in heparanase gene in different stages of breast cancer and present a direct effect on tumor progression
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