BGO quenching effect on spectral measurements of cosmic-ray nuclei in DAMPE experiment

The Dark Matter Particle Explorer (DAMPE) is a satellite-borne detector designed to measure high energy cosmic-rays and $\gamma$-rays. As a key sub-detector of DAMPE, the Bismuth Germanium Oxide (BGO) imaging calorimeter is utilized to measure the particle energy with a high resolution. The nonlinear fluorescence response of BGO for large ionization energy deposition, known as the quenching effect, results in an under-estimate of the energy measurement for cosmic-ray nuclei. In this paper, various models are employed to characterize the BGO quenching factors obtained from the experimental data of DAMPE. Applying the proper quenching model in the detector simulation process, we investigate the tuned energy responses for various nuclei and compare the results based on two different simulation softwares, i.e. GEANT4 and FLUKA. The BGO quenching effect results in a decrease of the measured energy by approximately $2.5\%$ ($5.7 \%$) for carbon (iron) at $\sim$10 GeV/n and $<1\%$ above 1 TeV/n, respectively. Accordingly, the correction of the BGO quenching effect leads to an increase of the low-energy flux measurement of cosmic-ray nuclei.Comment: 13 pages, 4 figures, to be published in Nuclear Inst. and Methods in Physics Research,

Radioprotective Effect of Grape Seed Proanthocyanidins In Vitro and In Vivo

We have demonstrated that grape seed proanthocyanidins (GSPs) could effectively scavenge hydroxyl radical (•OH) in a dose-dependent manner. Since most of the ionizing radiation- (IR-) induced injuries were caused by •OH, this study was to investigate whether GSPs would mitigate IR-induced injuries in vitro and in vivo. We demonstrated that GSPs could significantly reduce IR-induced DNA strand breaks (DSBs) and apoptosis of human lymphocyte AHH-1 cells. This study also showed that GSPs could protect white blood cells (WBC) from IR-induced injuries, speed up the weight of mice back, and decrease plasma malondialdehyde (MDA), thus improving the survival rates of mice after ionizing radiation. It is suggested that GSPs have a potential as an effective and safe radioprotective agent

Mutagenesis of PhaR, a Regulator Gene of Polyhydroxyalkanoate Biosynthesis of Xanthomonas oryzae pv. oryzae Caused Pleiotropic Phenotype Changes

Polyhydroxyalkanoates (PHAs) are intracellular carbon and energy storage materials produced in various microorganisms under nutrient-limited conditions. PhaR is a regulatory protein involved in PHA synthesis. Xanthomonas oryzae pv. oryzae (Xoo) is one of the most important bacterial pathogens in rice and has PHA biosynthesis genes in its genome, but the biological function of phaR in Xoo is unknown. In this study, we investigated the effects of the mutagenesis of phaR gene in Xoo strain PXO99A. Compared to the wildtype, the PhaR gene knock-out mutant PXO99ΔphaR was hypermotile and showed decreased growth rates in both rich and limited nutrient media. PXO99ΔphaR also showed almost 75% decrease in extracellular polysaccharide (EPS) production. When inoculated in rice leaves by leaf-clipping method, PXO99ΔphaR displayed reduced virulence in terms of lesion length and bacterial multiplication compared with the wildtype strain. PXO99ΔphaR also showed enhanced hypersensitive response (HR) induction in the leaves of non-host Nicotiana benthamiana with elevated hpa1 gene expression. Introduction of a cosmid containing the phaR coding sequence restored the phenotypes of the mutant to those of the wildtype strain. These results suggest that PhaR gene is an important gene that affects multiple bacterial characteristics, including EPS production, growth rate, defense response induced harpin production and motility, related to its virulence in plant

Prognostic role of SCAMP family in acute myeloid leukemia

Acute myeloid leukemia (AML) is a malignant disease of myeloid hematopoietic stem or progenitor cells characterized by abnormal proliferation of primary and immature myeloid cells in bone marrow and peripheral blood. Gene mutation and expression profiles can be used as prognosis predictors for different prognostic subgroups. Secretory carrier-associated membrane proteins (SCAMPs) are a multigenic family with five members and act as cell surface vectors in the post-Golgi recycling pathways in mammals. Nevertheless, the prognostic and clinical influence of SCAMP family has hardly ever been illustrated in AML. In our study, expression patterns of SCAMP family (SCAMP1-5) were analyzed in 155 AML patients which were extracted from the Cancer Genome Atlas database. In chemotherapy, only subgroup, higher SCAMP1 level was significantly associated with longer EFS and OS (all P = 0.002), and SCAMP1 was confirmed to be an independent favorable factor in un-transplanted patients by Multivariate analysis (all P <0.05). Nevertheless, in the allogeneic hematopoietic stem cell transplantation (allo-HSCT) treatment subgroup, none of the SCAMP genes had any effect on the clinical survival. Our study found that high expression level of SCAMP1 is a favorable prognostic factor in AML, but allo-HSCT may neutralize its prognostic effect

Model Seleksi Premi Asuransi Jiwa Dwiguna untuk Kasus Multiple Decrement

This article discusses a select survival model for the case of multiple decrements in evaluating endowment life insurance premium for person currently aged ( + ) years, who is selected at age with ℎ years selection period. The case of multiple decrements in this case is limited to two cases. The calculation of the annual premium is done by prior evaluating of the single premium, and the present value of annuity depends on theconstant force assumption

The Threonine Protease Activity of Testes-Specific Protease 50 (TSP50) Is Essential for Its Function in Cell Proliferation

Background: Testes-specific protease 50 (TSP50), a newly discovered threonine enzyme, has similar amino acid sequences and enzymatic structures to those of many serine proteases. It may be an oncogene. TSP50 is up-regulated in breast cancer epithelial cells, and ectopic expression of TSP50 in TSP50-deficient Chinese hamster ovary (CHO) cells has been found to promote cell proliferation. However, the mechanisms by which TSP50 exerts its growth-promoting effects are not yet fully understood. Methodology/Principal Findings: To delineate whether the threonine protease activity of TSP50 is essential to its function in cell proliferation, we constructed and characterized a mutant TSP50, called TSP50 T310A, which was identified as a protease-dead mutant of TSP50. By a series of proliferation analyses, colony formation assays and apoptosis analyses, we showed that T310A mutation significantly depresses TSP50-induced cell proliferation in vitro. Next, the CHO stable cell line expressing either wild-type or T310A mutant TSP50 was injected subcutaneously into nude mice. We found that the T310A mutation could abolish the tumorigenicity of TSP50 in vivo. A mechanism investigation revealed that the T310A mutation prevented interaction between TSP50 and the NF-kBIkBa complex, which is necessary for TSP50 to perform its function in cell proliferation. Conclusion: Our data highlight the importance of threonine 310, the most critical protease catalytic site in TSP50, to TSP50induce