8 research outputs found

    Pest Control on Poultry Farms.

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    UAS Chromatograph for Atmospheric Trace Species (UCATS) – a versatile instrument for trace gas measurements on airborne platforms

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    UCATS (the UAS Chromatograph for Atmospheric Trace Species) was designed and built for observations of important atmospheric trace gases from unmanned aircraft systems (UAS) in the upper troposphere and lower stratosphere (UTLS). Initially it measured major chlorofluorocarbons (CFCs) and the stratospheric transport tracers nitrous oxide (N2O) and sulfur hexafluoride (SF6), using gas chromatography with electron capture detection. Compact commercial absorption spectrometers for ozone (O3) and water vapor (H2O) were added to enhance its capabilities on platforms with relatively small payloads. UCATS has since been reconfigured to measure methane (CH4), carbon monoxide (CO), and molecular hydrogen (H2) instead of CFCs and has undergone numerous upgrades to its subsystems. It has served as part of large payloads on stratospheric UAS missions to probe the tropical tropopause region and transport of air into the stratosphere; in piloted aircraft studies of greenhouse gases, transport, and chemistry in the troposphere; and in 2021 is scheduled to return to the study of stratospheric ozone and halogen compounds, one of its original goals. Each deployment brought different challenges, which were largely met or resolved. The design, capabilities, modifications, and some results from UCATS are shown and described here, including changes for future missions.Support was provided for HIPPO by NSF award no. AGS-0628452, for ATTREX by NASA Earth Venture program award no. NNA11AA55I, and for ATom by NASA award no. NNH17AE26I; additional support was provided by NASA Upper Atmosphere Research Program award no. NNH13AV69I. This work was also supported in part by the NOAA Cooperative Agreement with CIRES, NA17OAR4320101

    Clioquinol and pyrrolidine dithiocarbamate complex with copper to form proteasome inhibitors and apoptosis inducers in human breast cancer cells

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    INTRODUCTION: A physiological feature of many tumor tissues and cells is the tendency to accumulate high concentrations of copper. While the precise role of copper in tumors is cryptic, copper, but not other trace metals, is required for angiogenesis. We have recently reported that organic copper-containing compounds, including 8-hydroxyquinoline-copper(II) and 5,7-dichloro-8-hydroxyquinoline-copper(II), comprise a novel class of proteasome inhibitors and tumor cell apoptosis inducers. In the current study, we investigate whether clioquinol (CQ), an analog of 8-hydroxyquinoline and an Alzheimer's disease drug, and pyrrolidine dithiocarbamate (PDTC), a known copper-binding compound and antioxidant, can interact with copper to form cancer-specific proteasome inhibitors and apoptosis inducers in human breast cancer cells. Tetrathiomolybdate (TM), a strong copper chelator currently being tested in clinical trials, is used as a comparison. METHODS: Breast cell lines, normal, immortalized MCF-10A, premalignant MCF10AT1K.cl2, and malignant MCF10DCIS.com and MDA-MB-231, were treated with CQ or PDTC with or without prior interaction with copper, followed by measurement of proteasome inhibition and cell death. Inhibition of the proteasome was determined by levels of the proteasomal chymotrypsin-like activity and ubiquitinated proteins in protein extracts of the treated cells. Apoptotic cell death was measured by morphological changes, Hoechst staining, and poly(ADP-ribose) polymerase cleavage. RESULTS: When in complex with copper, both CQ and PDTC, but not TM, can inhibit the proteasome chymotrypsin-like activity, block proliferation, and induce apoptotic cell death preferentially in breast cancer cells, less in premalignant breast cells, but are non-toxic to normal/non-transformed breast cells at the concentrations tested. In contrast, CQ, PDTC, TM or copper alone had no effects on any of the cells. Breast premalignant or cancer cells that contain copper at concentrations similar to those found in patients, when treated with just CQ or PDTC alone, but not TM, undergo proteasome inhibition and apoptosis. CONCLUSION: The feature of breast cancer cells and tissues to accumulate copper can be used as a targeting method for anticancer therapy through treatment with novel compounds such as CQ and PDTC that become active proteasome inhibitors and breast cancer cell killers in the presence of copper

    SO 2

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    Sulfur dioxide (SO2) is one of the primary source gases for aerosols in the atmosphere. Even at low concentrations, its presence in the upper troposphere and lower stratosphere (UT/LS) provides an important source for aerosol nucleation and growth, and SO2 has been postulated to be important for the stratospheric sulfur budget. To understand aerosol nucleation and global radiative effects, it is therefore important to quantify how much SO2 emitted from biogenic and anthropogenic processes at the surface is transported into the UT/LS. Much of the potential transport is expected to occur in regions of significant deep convection such as the western Pacific warm pool. Here we use measurements from the National Aeronautics and Space Administration (NASA) WB‐57F Pacific Oxidants Sulfur Ice and DehydratiON (POSIDON) mission that was based in Guam in 2016 to examine the distribution and sources of SO2 in the western Pacific UT/LS region. During POSIDON, a few events related to volcanic emissions as well as transport by tropical cyclones were observed that brought up to 86 pptv of SO2 above 14‐km altitude. Overall however, the measurements corroborate our earlier findings that SO2 near the tropical tropopause is typically quite low (~5 pptv) and globally the transport of SO2 into the stratosphere is likely a minor source of stratospheric aerosols. Key Points We report new in situ observations of UT/LS SO2 above the western Pacific Volcanic and anthropogenic SO2 in the UT/LS are identified Low ozone above the western Pacific does not appear to be an important factor allowing SO2 transport into the UT/L
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