40 research outputs found

    Subthreshold antiproton production in proton-carbon reactions

    Full text link
    Data from KEK on subthreshold antiproton as well as on pi(+-) and K(+-) production in proton-nucleus reactions are described at projectile energies between 3.5 and 12.0 GeV. We use a model which considers a hadron-nucleus reaction as an incoherent sum over collisions of the projectile with a varying number of target nucleons. It samples complete events and allows thus for the simultaneous consideration of all particle species measured. The overall reproduction of the data is quite satisfactory. It is shown that the contributions from the interaction of the projectile with groups of several target nucleons are decisive for the description of subthreshold production. Since the collective features of subthreshold production become especially significant far below the threshold, the results are extrapolated down to COSY energies. It is concluded that an antiproton measurement at ANKE-COSY should be feasible, if the high background of other particles can be efficiently suppressed.Comment: 15 pages, 5 figures, gzipped tar file, submitted to J. Phys. G v2: Modification of text due to demands of referee

    Apical Transport of Influenza A Virus Ribonucleoprotein Requires Rab11-positive Recycling Endosome

    Get PDF
    Influenza A virus RNA genome exists as eight-segmented ribonucleoprotein complexes containing viral RNA polymerase and nucleoprotein (vRNPs). Packaging of vRNPs and virus budding take place at the apical plasma membrane (APM). However, little is known about the molecular mechanisms of apical transport of newly synthesized vRNP. Transfection of fluorescent-labeled antibody and subsequent live cell imaging revealed that punctate vRNP signals moved along microtubules rapidly but intermittently in both directions, suggestive of vesicle trafficking. Using a series of Rab family protein, we demonstrated that progeny vRNP localized to recycling endosome (RE) in an active/GTP-bound Rab11-dependent manner. The vRNP interacted with Rab11 through viral RNA polymerase. The localization of vRNP to RE and subsequent accumulation to the APM were impaired by overexpression of Rab binding domains (RBD) of Rab11 family interacting proteins (Rab11-FIPs). Similarly, no APM accumulation was observed by overexpression of class II Rab11-FIP mutants lacking RBD. These results suggest that the progeny vRNP makes use of Rab11-dependent RE machinery for APM trafficking

    Proceedings of The HKIE Geotechnical Division 42nd Annual Seminar: A New Era of Metropolis and Infrastructure Developments in Hong Kong, Challenges and Opportunities to Geotechnical Engineering

    No full text
    This seminar proceedings contain articles on the various research ideas of the academic community and practitioners presented at The HKIE Geotechnical Division 42nd Annual Seminar (GDAS2022). GDAS2022 was organized by the Geotechnical Division, The Hong Kong Institution of Engineers on 13th May 2022. Seminar Title: The HKIE Geotechnical Division 42nd Annual SeminarSeminar Acronym: GDAS2022Seminar Date: 13 May 2022Seminar Location:  Hong KongSeminar Organizers: Geotechnical Division, The Hong Kong Institution of Engineers Link to the GDAS2021 Proceedings: Proceedings of The HKIE Geotechnical Division 41st Annual Semina

    Zinc-finger proteins in health and disease

    Get PDF
    Zinc-finger proteins (ZNFs) are one of the most abundant groups of proteins and have a wide range of molecular functions. Given the wide variety of zinc-finger domains, ZNFs are able to interact with DNA, RNA, PAR (poly-ADP-ribose) and other proteins. Thus, ZNFs are involved in the regulation of several cellular processes. In fact, ZNFs are implicated in transcriptional regulation, ubiquitin-mediated protein degradation, signal transduction, actin targeting, DNA repair, cell migration, and numerous other processes. The aim of this review is to provide a comprehensive summary of the current state of knowledge of this class of proteins. Firstly, we describe the actual classification of ZNFs, their structure and functions. Secondly, we focus on the biological role of ZNFs in the development of organisms under normal physiological and pathological conditions

    Soils Suppressing and Promoting Non-native Plant Invasions

    No full text

    Assessing written work by determining competence to achieve the module-specific learning outcomes.

    No full text
    This chapter describes lasers and other sources of coherent light that operate in a wide wavelength range. First, the general principles for the generation of coherent continuous-wave and pulsed radiation are treated including the interaction of radiation with matter, the properties of optical resonators and their modes as well as such processes as Q-switching and mode-locking. The general introduction is followed by sections on numerous types of lasers, the emphasis being on todayʼs most important sources of coherent light, in particular on solid-state lasers and several types of gas lasers. An important part of the chapter is devoted to the generation of coherent radiation by nonlinear processes with optical parametric oscillators, difference- and sum-frequency generation, and high-order harmonics. Radiation in the extended ultraviolet (EUV) and x-ray ranges can be generated by free electron lasers (FEL) and advanced x-ray sources. Ultrahigh light intensities up to 1021 W/cm2 open the door to studies of relativistic laser–matter interaction and laser particle acceleration. The chapter closes with a section on laser stabilization

    Lasers and Coherent Light Sources

    No full text
    corecore