33 research outputs found

    Dynamic externalities and regional manufacturing development: An exploration of the Polish experience before and after 1989

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    The impact of localization and urbanization economies on regional manufacturing development in Poland 1976-96 is assessed in terms of employment and the regional convergence or divergence of the economy. We examine current research on the role of dynamic production externalities in regional manufacturing development, starting with a review of recent literature on the nature of such externalities in manufacturing location, and how positive externalities may influence the spatial clustering of manufacturing industries. While much of the current literature is focussed on US experience, we analyse manufacturing employment data for Poland, in order to explore to what extent conclusions drawn from US experience may illuminate a regional economy in transition. The analysis also pays attention to the integration of a number of different methods from differing traditions, from economic geography, regional science, and new economic geography, including location quotients, Gini indices, shift-share, analysis of variance, Poisson regression, and Poisson regression for panel data. We find that radical changes have occurred in patterns of Polish regional manufacturing employment, both with regard to sectors and regions. Transition is refocussing the regional economy on strong regional centres, and on sectors regarded with little favour in the planned economy, such as food processing and wood products, including furniture.

    Multi-messenger characterization of Mrk 501 during historically low X-ray and γ\gamma-ray activity

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    We study the broadband emission of Mrk 501 using multi-wavelength observations from 2017 to 2020 performed with a multitude of instruments, involving, among others, MAGIC, Fermi-LAT, NuSTAR, Swift, GASP-WEBT, and OVRO. Mrk 501 showed an extremely low broadband activity, which may help to unravel its baseline emission. Nonetheless, significant flux variations are detected at all wavebands, with the highest occurring at X-rays and very-high-energy (VHE) γ\gamma-rays. A significant correlation (>>3σ\sigma) between X-rays and VHE γ\gamma-rays is measured, supporting leptonic scenarios to explain the variable parts of the emission, also during low activity. This is further supported when we extend our data from 2008 to 2020, and identify, for the first time, significant correlations between Swift-XRT and Fermi-LAT. We additionally find correlations between high-energy γ\gamma-rays and radio, with the radio lagging by more than 100 days, placing the γ\gamma-ray emission zone upstream of the radio-bright regions in the jet. Furthermore, Mrk 501 showed a historically low activity in X-rays and VHE γ\gamma-rays from mid-2017 to mid-2019 with a stable VHE flux (>>0.2 TeV) of 5% the emission of the Crab Nebula. The broadband spectral energy distribution (SED) of this 2-year-long low-state, the potential baseline emission of Mrk 501, can be characterized with one-zone leptonic models, and with (lepto)-hadronic models fulfilling neutrino flux constraints from IceCube. We explore the time evolution of the SED towards the low-state, revealing that the stable baseline emission may be ascribed to a standing shock, and the variable emission to an additional expanding or traveling shock.Comment: 56 pages, 30 figures, 14 tables, submitted. Corresponding authors are L. Heckmann, D. Paneque, S. Gasparyan, M. Cerruti, and N. Sahakya

    IT-kompetanse i Norge - behov og tilgang

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    I denne rapporten sammenstilles data fra en rekke ulike kilder for å drøfte sentrale sider ved behovet for, og tilgangen på IT-kompetent arbeidskraft i norske bedrifter, og i den offentlige forvaltning. Resultatene av undersøkelsen er knyttet til spørsmål som: på hvilke områder/innen hvilke spesialiteter vil behovet for IT-kompetanse vokse mest, utdanningsinstitusjonenes kapasitet og omstillingsevne, grad av konjunkturbestemt og/eller strukturbestemt etterspørsel, samt konsekvenser/implikasjoner av eventuell kompetansemangel på kort og lengre sikt.Kontor og Datateknisk Landsforening, Handels- og Servicenaeringens Hovedorganisasjo

    Real-time navigation guidance with intraoperative CT imaging for pedicle screw placement using an augmented reality head-mounted display: a proof-of-concept study.

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    OBJECTIVE: Augmented reality (AR) has the potential to improve the accuracy and efficiency of instrumentation placement in spinal fusion surgery, increasing patient safety and outcomes, optimizing ergonomics in the surgical suite, and ultimately lowering procedural costs. The authors sought to describe the use of a commercial prototype Spine AR platform (SpineAR) that provides a commercial AR head-mounted display (ARHMD) user interface for navigation-guided spine surgery incorporating real-time navigation images from intraoperative imaging with a 3D-reconstructed model in the surgeon\u27s field of view, and to assess screw placement accuracy via this method. METHODS: Pedicle screw placement accuracy was assessed and compared with literature-reported data of the freehand (FH) technique. Accuracy with SpineAR was also compared between participants of varying spine surgical experience. Eleven operators without prior experience with AR-assisted pedicle screw placement took part in the study: 5 attending neurosurgeons and 6 trainees (1 neurosurgical fellow, 1 senior orthopedic resident, 3 neurosurgical residents, and 1 medical student). Commercially available 3D-printed lumbar spine models were utilized as surrogates of human anatomy. Among the operators, a total of 192 screws were instrumented bilaterally from L2-5 using SpineAR in 24 lumbar spine models. All but one trainee also inserted 8 screws using the FH method. In addition to accuracy scoring using the Gertzbein-Robbins grading scale, axial trajectory was assessed, and user feedback on experience with SpineAR was collected. RESULTS: Based on the Gertzbein-Robbins grading scale, the overall screw placement accuracy using SpineAR among all users was 98.4% (192 screws). Accuracy for attendings and trainees was 99.1% (112 screws) and 97.5% (80 screws), respectively. Accuracy rates were higher compared with literature-reported lumbar screw placement accuracy using FH for attendings (99.1% vs 94.32%; p = 0.0212) and all users (98.4% vs 94.32%; p = 0.0099). The percentage of total inserted screws with a minimum of 5° medial angulation was 100%. No differences were observed between attendings and trainees or between the two methods. User feedback on SpineAR was generally positive. CONCLUSIONS: Screw placement was feasible and accurate using SpineAR, an ARHMD platform with real-time navigation guidance that provided a favorable surgeon-user experience
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