680 research outputs found

    The Impacts of Animal Disease Crises on the Korean Meat Market

    Get PDF
    Employing the error correction method and historical decomposition with direct acyclic graphs, we quantify the impacts of domestic and oversea animal disease crises on the Korean meat markets. We find that (a) the market partially recovered 16 months after the foot-and-mouth outbreak in 2000, and 13 months after the avian influenza and the U.S. BSE incidents in 2003; (b) animal disease outbreaks have differentiate impacts by disease type and supply chain level. Retailers likely to have windfall profits as the retail price margin increased relative to the farm and wholesale levels; and (c) disease outbreaks affect dynamic price interdependence.Animal disease outbreak, Error correction model, Direct acyclic graphs, Korean meat market, Historical Decomposition, Price margins, Livestock Production/Industries, C32, Q11, L11,

    Nonstationary Collisional Dynamics in Determining Nitric Oxide Laser-Induced Flourescence Spectra

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77237/1/AIAA-8783-947.pd

    Measuring individual overpotentials in an operating solid-oxide electrochemical cell

    Full text link
    We use photo-electrons as a non-contact probe to measure local electrical potentials in a solid-oxide electrochemical cell. We characterize the cell in operando at near-ambient pressure using spatially-resolved X-ray photoemission spectroscopy. The overpotentials at the interfaces between the Ni and Pt electrodes and the yttria-stabilized zirconia (YSZ) electrolyte are directly measured. The method is validated using electrochemical impedance spectroscopy. Using the overpotentials, which characterize the cell's inefficiencies, we compare without ambiguity the electro-catalytic efficiencies of Ni and Pt, finding that on Ni H_2O splitting proceeds more rapidly than H2 oxidation, while on Pt, H2 oxidation proceeds more rapidly than H2O splitting.Comment: corrected; Phys. Chem. Chem. Phys., 201

    Paroxysmal nocturnal hemoglobinuria (PNH): higher sensitivity and validity in diagnosis and serial monitoring by flow cytometric analysis of reticulocytes

    Get PDF
    Flow cytometric analysis of GPI-anchored proteins (GPI-AP) is the gold standard for diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). Due to therapy options and the relevance of GPI-deficient clones for prognosis in aplastic anaemia detection of PNH is gaining importance. However, no generally accepted standard has been established. This study analysed the usefulness of a flow cytometric panel with CD58, CD59 on reticulocytes and erythrocytes, CD24/CD66b and CD16, FLAER on granulocytes and CD14, and CD48 on monocytes. Actual cut-off (mean + 2 SD) for GPI-deficient cells was established in healthy blood donors. We studied 1,296 flow cytometric results of 803 patients. Serial monitoring was analysed during a median follow-up of 1,039 days in 155 patients. Of all, 22% and 48% of 155 follow-up patients. showed significant GPI-AP-deficiency at time of initial analyses. During follow-up in 9%, a new PNH diagnosis, and in 28%, a significant change of size or lineage involvement was demonstrated. Highly significant correlations for GPI-AP deficiency were found within one cell lineage (r2 = 0.61–0.95, p < 0.0001) and between the different cell lineages (r2 = 0.49–0.88, p < 0.0001). Especially for detection of small GPI-deficient populations, reticulocytes and monocytes proved to be sensitive diagnostic tools. Our data showed superiority of reticulocyte analyses compared with erythrocyte analyses due to transfusion and hemolysis independency especially in cases with small GPI-deficient populations. In conclusion, a screening panel of at least two different GPI-AP markers on granulocytes, erythrocytes, and reticulocytes provides a simple and rapid method to detect even small GPI-deficient populations. Among the markers in our panel, CD58 and CD59 on reticulocytes, CD24/66b, and eventually FLAER on granulocytes as well as CD14 on monocytes were most effective for flow cytometric diagnosis of GPI deficiency

    Interplay of Mre11 Nuclease with Dna2 plus Sgs1 in Rad51-Dependent Recombinational Repair

    Get PDF
    The Mre11/Rad50/Xrs2 complex initiates IR repair by binding to the end of a double-strand break, resulting in 5′ to 3′ exonuclease degradation creating a single-stranded 3′ overhang competent for strand invasion into the unbroken chromosome. The nuclease(s) involved are not well understood. Mre11 encodes a nuclease, but it has 3′ to 5′, rather than 5′ to 3′ activity. Furthermore, mutations that inactivate only the nuclease activity of Mre11 but not its other repair functions, mre11-D56N and mre11-H125N, are resistant to IR. This suggests that another nuclease can catalyze 5′ to 3′ degradation. One candidate nuclease that has not been tested to date because it is encoded by an essential gene is the Dna2 helicase/nuclease. We recently reported the ability to suppress the lethality of a dna2Δ with a pif1Δ. The dna2Δ pif1Δ mutant is IR-resistant. We have determined that dna2Δ pif1Δ mre11-D56N and dna2Δ pif1Δ mre11-H125N strains are equally as sensitive to IR as mre11Δ strains, suggesting that in the absence of Dna2, Mre11 nuclease carries out repair. The dna2Δ pif1Δ mre11-D56N triple mutant is complemented by plasmids expressing Mre11, Dna2 or dna2K1080E, a mutant with defective helicase and functional nuclease, demonstrating that the nuclease of Dna2 compensates for the absence of Mre11 nuclease in IR repair, presumably in 5′ to 3′ degradation at DSB ends. We further show that sgs1Δ mre11-H125N, but not sgs1Δ, is very sensitive to IR, implicating the Sgs1 helicase in the Dna2-mediated pathway

    DNA damage signalling prevents deleterious telomere addition at DNA breaks

    Get PDF
    The response to DNA damage involves regulation of multiple essential processes to maximize the accuracy of DNA damage repair and cell survival 1. Telomerase has the potential to interfere with repair by inappropriately adding telomeres to DNA breaks. It was unknown whether cells modulate telomerase in response to DNA damage, to increase the accuracy of repair. Here we report that telomerase action is regulated as a part of the cellular response to a DNA double-strand break (DSB). Using yeast, we show that the major ATR/Mec1 DNA damage signalling pathway regulates telomerase action at DSBs. Upon DNA damage, MEC1-RAD53-DUN1-dependent phosphorylation of the telomerase inhibitor Pif1 occurs. Utilizing a separation of function PIF1 mutation, we show that this phosphorylation is required for the Pif1-mediated telomerase inhibition that takes place specifically at DNA breaks, but not telomeres. Hence DNA damage signalling down-modulates telomerase action at a DNA break via Pif1 phosphorylation, thus preventing aberrant healing of broken DNA ends by telomerase. These findings uncover a novel regulatory mechanism that coordinates competing DNA end-processing activities and thereby promotes DNA repair accuracy and genome integrity
    corecore