260 research outputs found

    Calibration Studies and the Investigation of Track Segments within Showers with an Imaging Hadronic Calorimeter

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    The CALICE collaboration has constructed a highly granular hadronic sampling calorimeter prototype with small scintillator tiles individually read out by silicon photomultipliers (SiPM) to evaluate technologies for the ILC. The imaging capability of the detector allows detailed studies of the substructure of hadronic events, such as the identification of minimum ionizing track segments within the hadronic shower. These track segments are of high quality, so that they can be used for calibration, as an additional tool to Muons and to the built-in LED system used to monitor the SiPMs. These track segments also help to constrain hadronic shower models used in Geant4. Detailed MC studies with a realistic model of an ILC detector were performed to study the calibration requirements of a complete calorimeter system. The calibration strategy was tested on real data by transporting calibration constants from a Fermilab beam test to data recorded at CERN under different conditions.Comment: 5 pages, 3 figures, 11th ICATPP Conference Proceedin

    Comparison of hadron shower data with simulations

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    An analog hadron calorimeter (AHCAL) prototype of 5.3 nuclear interaction lengths thickness has been designed and constructed by members of the CALICE Collaboration. The AHCAL prototype consists of a 38-layer sandwich structure of steel plates and 7608 scintillator tiles that are read out by wavelength-shifting fibres coupled to SiPMs. The signal is amplified and shaped with a custom-designed ASIC. A calibration/monitoring system based on LED light was developed to monitor the SiPM gain and to measure the full SiPM response curve in order to correct for non-linearity. Ultimately, the physics goals are the study of hadronic shower shapes and testing the concept of particle flow. The technical goal consists of measuring the performance and reliability of 7608 SiPMs. The AHCAL prototype was commissioned in test beams at DESY, CERN and FNAL, and recorded hadronic showers, electron showers and muons at different energies and incident angles.Comment: 6 pages, 19 figures, LCWS2010 Proceedin

    Controllable Plasmonic Nanostructures induced by Dual-wavelength Femtosecond Laser Irradiation

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    We demonstrated an abnormal double-peak (annular shaped) energy deposition through dualwavelength synthesis of the fundamental frequency (ω) and the second-harmonic frequency (2ω) of a femtosecond (fs) Ti:sapphire laser. The annular shaped distribution of the dual-wavelength fs laser was confirmed through real beam shape detection. This uniquely simple and flexible technique enables the formation of functional plasmonic nanostructures. We applied this double-peak fs-laser-induced dewetting effect to the controlled fabrication and precise deposition of Au nanostructures, by using a simple, lithography-free, and single-step process. In this process, the double-peak energy-shaped fs laser pulse induces surface patterning of a thin film followed by nanoscale hydrodynamic instability, which is highly controllable under specific irradiation conditions. Nanostructure morphology (shape, size, and distribution) modulation can be achieved by adjusting the laser irradiation parameters, and the subsequent ion-beam polishing enables further dimensional reduction and removal of the surrounding film. The unique optical properties of the resulting nanostructure are highly sensitive to the shape and size of the nanostructure. In contrast to a nanoparticle, the resonance-scattering spectrum of an Au nanobump exhibites two resonance peaks. These suggest that the dual-wavelength fs laserbased dewetting of thin films can be an effective means for the scalable manufacturing of patterned functional nanostructures

    How does the grassroots drive just transition? Evidence from an alteration of resettlement sites in China

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    Dam-induced resettlement is a typical pattern of development-induced displacement and resettlement (DIDR), which concludes involuntariness and leads to injustice practices. Although the justice of resettlement is studied in existing works, few of them notice that the selection of resettlement sites might be holistically an opportunity for just transition, and the performance of this process is not totally a government arrangement. To address this gap, this paper takes the Multi-level Perspective (MLP) as the theoretical framework, and adopts mixed methods to examine a second selection case of resettlement sites for the Wuxikou dam in Jiangxi Province, China. Based on grounded theory, five categories of resettlees' demands for resettlement sites, namely agricultural production (AP), non-agricultural production (NAP), material life (ML), social life (SL), and reception of natural ecology (RNE) are identified. The multiple conjunctural causation between these demands and resettlees' actions for changing initial resettlement sites is analyzed by Qualitative Comparative Analysis (QCA). Four intermediate solutions as well as the core and peripheral conditions are found. Apart from the bottom-up petitions, how the political environment and governmental administration enabled the resettlees' request for altering resettlement sites is illustrated. It is found that, although the government and resettlees with different interests and action logics, the same result is promoted under the national policies, viz, the implementation of changing resettlement sites, process justice and outcome justice are therein realized. Relative policy implications and outlooks on just resettlement practice are remarked

    Characterisation of GNSS Space Service Volume

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    M2 Polarization of Macrophages Facilitates Arsenic-Induced Cell Transformation of Lung Epithelial Cells

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    The alterations in microenvironment upon chronic arsenic exposure may contribute to arsenic-induced lung carcinogenesis. Immune cells, such as macrophages, play an important role in mediating the microenvironment in the lungs. Macrophages carry out their functions after activation. There are two activation status for macrophages: classical (M1) or alternative (M2); the latter is associated with tumorigenesis. Our previous work showed that long-term arsenic exposure induces transformation of lung epithelial cells. However, the crosstalk between epithelial cells and macrophages upon arsenic exposure has not been investigated. In this study, using a co-culture system in which human lung epithelial cells are cultured with macrophages, we determined that long-term arsenic exposure polarizes macrophages towards M2 status through ROS generation. Co-culture with epithelial cells further enhanced the polarization of macrophages as well as transformation of epithelial cells, while blocking macrophage M2 polarization decreased the transformation. In addition, macrophage M2 polarization decreased autophagy activity, which may account for increased cell transformation of epithelial cells with co-culture of macrophages

    Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Pseudomyxoma Peritonei of Appendiceal Origin - 801 Cases from a Single Institution in China

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    Aim: As more and more centers has published their treatment results ofpseudomyxoma peritonei (PMP) with cytoreductive surgery (CRS) andhyperthermic intraperitoneal chemotherapy (HIPEC), the data from Chinais missing. Myxoma Department of Aerospace Hospital is the biggestcenter treating PMP in China. The purpose of this study is to report theearly and long-term outcomes for PMP from this single center. Methods:801 appendix-derived PMP out of 1008 consecutive patients treated inMyxoma Department of Aerospace Hospital between 2008 and 2019 wereretrospectively analyzed. Results: Complete cytoreductive surgery (CCRS)was achieved in 240 (30%) patients with median PCI of 14(1~39), andthe rest had maximal tumor debulking (MTD), HIPEC was implementedin 96.3% of CCRS and 78.6% of MTD. The major morbidity (gradeIII/IV) was 11.4% and the 30-day operative mortality is 0.7%. The 5-and 10-year OS of CCRS was 76.9% and 64.1%, which is significantlyhigher than MTD (5-, 10-year OS as 36.1%, 27.1%; p20, MTD, high pathologic grade and without HIPECwere independent factors predicting poorer prognosis. Conclusions: CCRS+HIPEC can benefit PMP well with controllable risks. MTD+HIPEC maybenefit PMP as well when CCRS cannot be achieved after fully asscessmentby an experienced peritoneal maglignacy center, but the surgery should beperformed as limited as possible

    Type One Protein Phosphatase 1 and Its Regulatory Protein Inhibitor 2 Negatively Regulate ABA Signaling

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    The phytohormone abscisic acid (ABA) regulates plant growth, development and responses to biotic and abiotic stresses. The core ABA signaling pathway consists of three major components: ABA receptor (PYR1/PYLs), type 2C Protein Phosphatase (PP2C) and SNF1-related protein kinase 2 (SnRK2). Nevertheless, the complexity of ABA signaling remains to be explored. To uncover new components of ABA signal transduction pathways, we performed a yeast two-hybrid screen for SnRK2-interacting proteins. We found that Type One Protein Phosphatase 1 (TOPP1) and its regulatory protein, At Inhibitor-2 (AtI-2), physically interact with SnRK2s and also with PYLs. TOPP1 inhibited the kinase activity of SnRK2.6, and this inhibition could be enhanced by AtI-2. Transactivation assays showed that TOPP1 and AtI-2 negatively regulated the SnRK2.2/3/6-mediated activation of the ABA responsive reporter gene RD29B, supporting a negative role of TOPP1 and AtI-2 in ABA signaling. Consistent with these findings, topp1 and ati-2 mutant plants displayed hypersensitivities to ABA and salt treatments, and transcriptome analysis of TOPP1 and AtI-2 knockout plants revealed an increased expression of multiple ABA-responsive genes in the mutants. Taken together, our results uncover TOPP1 and AtI-2 as negative regulators of ABA signaling. © 2016 Hou et al
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