1,159 research outputs found

    Using worker flows in the analysis of establishment turnover : evidence from German administrative data

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    "Economists have long been interested in the determinants and components of job creation and destruction. In many countries administrative datasets provide an excellent source for detailed analysis on a fine and disaggregate level. However, administrative datasets are not without problems: restructuring and relabeling of firms is often poorly measured and can potentially create large biases. We provide evidence of the extent of this bias and provide a new solution to deal with it using the German Establishment History Panel (BHP). While previous research has relied on the first and last appearance of the establishment identifier (EID) to identify openings and closings, we improve on this approach using a new dataset containing all worker flows between establishments in Germany. This allows us to credibly identify establishment births and deaths from 1975 to 2004. We show that the misclassification bias of using only the EID is very severe: Only about 35 to 40 percent of new and disappearing EIDs with more than 3 employees correspond unambiguously to real establishment entries and exits. Among larger establishments misclassification is even more common. We show that many new establishment IDs appear to be 'Spin-Offs' and these have become increasingly more common over time. We then demonstrate that using only EID entries and exits may dramatically overstate, by as much as 100 percent, the role of establishment turnover for job creation and destruction. Furthermore correcting job creation and destruction measures for spurious EID entries and exits reduces these measures and aligns them closer with the business cycle." (Author's abstract, IAB-Doku) ((en))labour turnover, Arbeitsplatzwechsel, zwischenbetriebliche Mobilität, Arbeitskräftemobilität, Unternehmensgründung, zusätzliche Arbeitsplätze, Arbeitsplatzabbau, job turnover, Betriebsstilllegung, IAB-Betriebs-Historik-Panel

    Plant cell packs: a scalable platform for recombinant protein production and metabolic engineering

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    Industrial plant biotechnology applications include the production of sustainable fuels, complex metabolites and recombinant proteins, but process development can be impaired by a lack of reliable and scalable screening methods. Here, we describe a rapid and versatile expression system which involves the infusion of Agrobacterium tumefaciens into three‐dimensional, porous plant cell aggregates deprived of cultivation medium, which we have termed plant cell packs (PCPs). This approach is compatible with different plant species such as Nicotiana tabacum BY2, Nicotiana benthamiana or Daucus carota and 10‐times more effective than transient expression in liquid plant cell culture. We found that the expression of several proteins was similar in PCPs and intact plants, for example, 47 and 55 mg/kg for antibody 2G12 expressed in BY2 PCPs and N. tabacum plants respectively. Additionally, the expression of specific enzymes can either increase the content of natural plant metabolites or be used to synthesize novel small molecules in the PCPs. The PCP method is currently scalable from a microtiter plate format suitable for high‐throughput screening to 150‐mL columns suitable for initial product preparation. It therefore combined the speed of transient expression in plants with the throughput of microbial screening systems. Plant cell packs therefore provide a convenient new platform for synthetic biology approaches, metabolic engineering and conventional recombinant protein expression techniques that require the multiplex analysis of several dozen up to hundreds of constructs for efficient product and process development

    Indium-Gallium Segregation in CuInx_{x}Ga1x_{1-x}Se2_2: An ab initio based Monte Carlo Study

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    Thin-film solar cells with CuInx_xGa1x_{1-x}Se2_2 (CIGS) absorber are still far below their efficiency limit, although lab cells reach already 19.9%. One important aspect is the homogeneity of the alloy. Large-scale simulations combining Monte Carlo and density functional calculations show that two phases coexist in thermal equilibrium below room temperature. Only at higher temperatures, CIGS becomes more and more a homogeneous alloy. A larger degree of inhomogeneity for Ga-rich CIGS persists over a wide temperature range, which may contribute to the low observed efficiency of Ga-rich CIGS solar cells

    Fractional release factors of long-lived halogenated organic compounds in the tropical stratosphere

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    Fractional release factors (FRFs) of organic trace gases are time-independent quantities that influence the calculation of Global Warming Potentials and Ozone Depletion Potentials. We present the first set of vertically resolved FRFs for 15 long-lived halocarbons in the tropical stratosphere up to 34 km altitude. They were calculated from measurements on air samples collected on board balloons and a high altitude aircraft. We compare the derived dependencies of FRFs on the mean stratospheric transit times (the so-called mean ages of air) with similarly derived FRFs originating from measurements at higher latitudes and find significant differences. Moreover a comparison with averaged FRFs currently used by the World Meteorological Organisation revealed the limitations of these measures due to their observed vertical and latitudinal variability. The presented data set could be used to improve future ozone level and climate projections

    Photosynthesis Is Widely Distributed among Proteobacteria as Demonstrated by the Phylogeny of PufLM Reaction Center Proteins

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    Two different photosystems for performing bacteriochlorophyll-mediated photosynthetic energy conversion are employed in different bacterial phyla. Those bacteria employing a photosystem II type of photosynthetic apparatus include the phototrophic purple bacteria (Proteobacteria), Gemmatimonas and Chloroflexus with their photosynthetic relatives. The proteins of the photosynthetic reaction center PufL and PufM are essential components and are common to all bacteria with a type-II photosynthetic apparatus, including the anaerobic as well as the aerobic phototrophic Proteobacteria. Therefore, PufL and PufM proteins and their genes are perfect tools to evaluate the phylogeny of the photosynthetic apparatus and to study the diversity of the bacteria employing this photosystem in nature. Almost complete pufLM gene sequences and the derived protein sequences from 152 type strains and 45 additional strains of phototrophic Proteobacteria employing photosystem II were compared. The results give interesting and comprehensive insights into the phylogeny of the photosynthetic apparatus and clearly define Chromatiales, Rhodobacterales, Sphingomonadales as major groups distinct from other Alphaproteobacteria, from Betaproteobacteria and from Caulobacterales (Brevundimonas subvibrioides). A special relationship exists between the PufLM sequences of those bacteria employing bacteriochlorophyll b instead of bacteriochlorophyll a. A clear phylogenetic association of aerobic phototrophic purple bacteria to anaerobic purple bacteria according to their PufLM sequences is demonstrated indicating multiple evolutionary lines from anaerobic to aerobic phototrophic purple bacteria. The impact of pufLM gene sequences for studies on the environmental diversity of phototrophic bacteria is discussed and the possibility of their identification on the species level in environmental samples is pointed out. © 2018 Imhoff, Rahn, Künzel and Neulinger

    A Hardware Perspective on the ChaCha Ciphers: Scalable Chacha8/12/20 Implementations Ranging from 476 Slices to Bitrates of 175 Gbit/s

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    AES (Advanced Encryption Standard) accelerators are commonly used in high-throughput applications, but they have notable resource requirements. We investigate replacing the AES cipher with ChaCha ciphers and propose the first ChaCha FPGA implementations optimized for data throughput. In consequence, we compare implementations of three different system architectures and analyze which aspects dominate the performance of those.Our experimental results indicate that a bandwidth of 175 Gbit/s can be reached with as little as 2982 slices, whereas comparable state of the art AES accelerators require 10 times as many slices. Taking advantage of the flexibility inherent in the ChaCha cipher, we also demonstrate how our implementation scales to even higher throughputs or lower resource usage (down to 476 slices), benefiting applications which previously could not employ cryptography because of resource limitations

    Value of self-performed joint counts in rheumatoid arthritis patients near remission

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    INTRODUCTION: To determine the validity and reliability of patients' self-performed joint counts compared to joint counts by professional assessors in rheumatoid arthritis (RA) patients in different disease activity states. METHODS: In patients with established RA we determined the inter-rater reliability of joint counts performed by an independent evaluator and the patient using intraclass correlation (ICC), and agreement on activity in individual joints by kappa statistics. We also performed longitudinal analyses to assess consistency of assessments over time. Finally, we investigated the concordance of joint counts of different assessors in patients with different levels of disease activity. RESULTS: The reliability of patient self-performed joint counts was high when compared to independent objective assessment (ICC; 95%confidence interval (CI)) for the assessment of swelling (0.32; 0.15 to 0.46) and tenderness (0.75; 0.66 to 0.81), with higher agreement for larger joints (kappa: 0.57 and 0.45, respectively) compared to smaller joints (metacarpo-phalangeal joint (MCPs): 0.31 and 0.45; and proximal interphalangeal joint (PIPs): 0.22 and 0.47, for swelling and tenderness, respectively). Patients in remission according to the Simplified Disease Activity Index (SDAI ≤ 3.3) showed better concordance of the joint counts (swollen joint count (SJC) ties 25/37, tender joint count (TJC) ties 26/37) compared to moderate/high disease activity states (SDAI > 11; MDA/HDA: SJC ties 9/72, TJC ties 21/72). Positive and negative predictive values regarding the presence of SDAI remission were reasonably good (0.86 and 0.95, respectively). A separate training session for patients did not improve the reliability of joint assessment. The results were consistent in the longitudinal analyses. CONCLUSIONS: Self-performed joint counts are particularly useful for monitoring in patients having attained remission, as these patients seem able to detect state of remission
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