110 research outputs found

    Good degeneration of Quot-schemes and coherent systems

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    We construct good degenerations of Quot-schemes and coherent systems using the stack of expanded degenerations. We show that these good degenerations are separated and proper DM stacks of finite type. Applying to the projective threefolds, we derive degeneration formulas for DT-invariants of ideal sheaves and PT stable pair invariants

    Bichromatic field generation from double-four-wave mixing in a double-electromagnetically induced transparency system

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    We demonstrate the double electromagnetically induced transparency (double-EIT) and double four-wave mixing (double-FWM) based on a new scheme of non-degenerate four-wave mixing (FWM) involving five levels of a cold 85Rb atomic ensemble, in which the double-EIT windows are used to transmit the probe field and enhance the third-order nonlinear susceptibility. The phase-matching conditions for both four-wave mixings could be satisfied simultaneously. The frequency of one component of the generated bichromatic field is less than the other by the ground-state hyperfine splitting (3GHz). This specially designed experimental scheme for simultaneously generating different nonlinear wave-mixing processes is expected to find applications in quantum information processing and cross phase modulation. Our results agree well with the theoretical simulation.Comment: Accepted by NJ

    Associations of Pulmonary Fibrosis with Peripheral Blood Th1/Th2 Cell Imbalance and EBF3 Gene Methylation in Uygur Pigeon Breeder’s Lung Patients

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    Background/Aims Pigeon breeder’s lung (PBL) results from Th1/Th2 cell imbalance. B cells inhibit the immune activity of Th1, and EBF3 is a key B cell factor. This study explored the relationship between EBF3 and Th1/Th2 imbalance in chronic PBL cases complicated with pulmonary fibrosis (PF). Methods Twenty Uygur PBL+PF patients, 20 pigeon breeders without PBL or PF, and 20 healthy individuals without pigeon breeding history constituted the patient I, negative control, and normal control groups, respectively. Peripheral blood specimens and case backgrounds were collected between June 2016 and March 2017. EBF3 gene methylation was analyzed by matrix assisted laser desorption ionization-time of flight mass spectrometry. To compare different mechanisms of PF progression in PBL, samples from 20 Uygur PBL patients without PF (at acute and sub-acute stages) were collected between October 2017 and February 2018, constituting the patient II group. EBF3 mRNA expression was evaluated by real-time polymerase chain reaction. IFN-γ, IL-4 and IL-10 expression and Th1/Th2 imbalance in PBL were evaluated by enzyme-linked immunosorbent assay and flow cytometry. Results CpG-2 and general methylation rates in the patient I group were lower than those in the control groups (P˂0.017). The level of EBF3 mRNA expression in the patient I group was significantly higher than that in any other group. Compared with the control groups, the patient I group showed a significantly higher level of IL-4, whereas the patient II group showed a significantly lower level. IL-10 was also expressed more highly in the patient I group than in any other group (P< 0.01). Flow cytometry showed INF-γ dominance (Th1 cytokine) in PBL at the acute/sub-acute stage and IL-4 dominance (Th2 cytokine) at the chronic stage after PF occurred. The general methylation rate was negatively correlated with the mRNA level, with the latter being positively correlated with the IL-10 level and number of pigeons bred in the past 3 months. IL-4 expression was negatively correlated with INF-γ but positively correlated with PF area and duration of pigeon breeding history. Conclusions After PF occurs in chronic PBL, the inflammation type changes from Th1 dominance to Th2 dominance. During PBL development, IL-10 increases before IL-4 does, which may be associated with EBF3 hypomethylation and the involvement of B lymphocytes

    Clusters of spatial, temporal, and space-time distribution of hemorrhagic fever with renal syndrome in Liaoning Province, Northeastern China

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    <p>Abstract</p> <p>Background</p> <p>Hemorrhagic fever with renal syndrome (HFRS) is a rodent-borne disease caused by Hantavirus, with characteristics of fever, hemorrhage, kidney damage, and hypotension. HFRS is recognized as a notifiable public health problem in China, and Liaoning Province is one of the most seriously affected areas with the most cases in China. It is necessary to investigate the spatial, temporal, and space-time distribution of confirmed cases of HFRS in Liaoning Province, China for future research into risk factors.</p> <p>Methods</p> <p>A cartogram map was constructed; spatial autocorrelation analysis and spatial, temporal, and space-time cluster analysis were conducted in Liaoning Province, China over the period 1988-2001.</p> <p>Results</p> <p>When the number of permutation test was set to 999, Moran's I was 0.3854, and was significant at significance level of 0.001. Spatial cluster analysis identified one most likely cluster and four secondary likely clusters. Temporal cluster analysis identified 1998-2001 as the most likely cluster. Space-time cluster analysis identified one most likely cluster and two secondary likely clusters.</p> <p>Conclusions</p> <p>Spatial, temporal, and space-time scan statistics may be useful in supervising the occurrence of HFRS in Liaoning Province, China. The result of this study can not only assist health departments to develop a better prevention strategy but also potentially increase the public health intervention's effectiveness.</p
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