4,424 research outputs found

    Density of States in Landau Level Tails of GaAs-AlxGa1-xAs Heterostructures

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    From an analysis of the thermally activated resistivity as a function of the magnetic field in the quantum Hall regime we deduced the position of the Fermi energy in the mobility gap as a function of the filling factor and therefore the density of states. The measured density of states is best described by a Gaussian like profile superimposed on a constant background

    The Impact of Photobleaching on Microarray Analysis

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    DNA-Microarrays have become a potent technology for high-throughput analysis of genetic regulation. However, the wide dynamic range of signal intensities of fluorophore-based microarrays exceeds the dynamic range of a single array scan by far, thus limiting the key benefit of microarray technology: parallelization. The implementation of multi-scan techniques represents a promising approach to overcome these limitations. These techniques are, in turn, limited by the fluorophores' susceptibility to photobleaching when exposed to the scanner's laser light. In this paper the photobleaching characteristics of cyanine-3 and cyanine-5 as part of solid state DNA microarrays are studied. The effects of initial fluorophore intensity as well as laser scanner dependent variables such as the photomultiplier tube's voltage on bleaching and imaging are investigated. The resulting data is used to develop a model capable of simulating the expected degree of signal intensity reduction caused by photobleaching for each fluorophore individually, allowing for the removal of photobleaching-induced, systematic bias in multi-scan procedures. Single-scan applications also benefit as they rely on pre-scans to determine the optimal scanner settings. These findings constitute a step towards standardization of microarray experiments and analysis and may help to increase the lab-to-lab comparability of microarray experiment results

    Myocardial ischemia after orthotopic liver transplantation

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    A hypercoagulable state exists after orthotopic liver transplantation. This hematologic abnormality may predispose patients to coronary thrombosis and unstable angina. The incidence of post-operative myocardial ischemia in such patients is unknown. Suitable electrocardiograms and clinical events of consecutive patients undergoing orthotopic liver transplantation (n = 45) and major intraabdominal surgery (n = 28) during a 3-month period at a major university teaching hospital and transplant center were examined retrospectively. Clinical myocardial ischemia or ischemic electrocardiographic changes, or both, occurred in 6 transplant patients compared with no patient in the nontransplant or comparison group. In 4 of the 6 patients with dramatic electrocardiographic changes and ischemic events, coronary arteriography failed to demonstrate significant obstructive disease. It is concluded that severe myocardial ischemia may occur in patients after orthotopic liver transplantation in the absence of significant coronary disease. A hypercoagulable state may predispose to coronary thrombosis in this setting, providing insight (and a future model for study) into the development of unstable angina. © 1994

    The Diversity Factor: How Cultural Diversity Impacts Innovations in Germany

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    The 2018 Reinhard Mohn Prize on “Living Diversity – Shaping Society” is meant to bring new momentum and perspectives to how Germany lives diversity and shapes society. The present study “The Diversity Factor – How Cultural Diversity Impacts Innovations in Germany” examines the question of whether and how cultural diversity affects the innovative power of both companies and society. There is much to suggest that a culturally diverse workforce – e.g. people with different experiences, mindsets and interpretive contexts – fosters creativity and innovation. The current publication is based on evaluations of empirical studies that examine the correlation between cultural diversity and innovation. This analysis of the literature was carried out using a narrow definition of cultural diversity, one that includes, in particular, the dimensions of “ethnicity,” “religion/world view” and “nationality.” Innovation was measured in each study based on the number of patents, patent citations or companies’ self-assessments of their product and process innovations or overall factor productivity. The results of this research were then considered more deeply in interviews and conversations with business experts, public administrators and civil society leaders

    The 13^{13}Carbon footprint of B[e] supergiants

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    We report on the first detection of 13^{13}C enhancement in two B[e] supergiants in the Large Magellanic Cloud. Stellar evolution models predict the surface abundance in 13^{13}C to strongly increase during main-sequence and post-main sequence evolution of massive stars. However, direct identification of chemically processed material on the surface of B[e] supergiants is hampered by their dense, disk-forming winds, hiding the stars. Recent theoretical computations predict the detectability of enhanced 13^{13}C via the molecular emission in 13^{13}CO arising in the circumstellar disks of B[e] supergiants. To test this potential method and to unambiguously identify a post-main sequence B[e]SG by its 13^{13}CO emission, we have obtained high-quality KK-band spectra of two known B[e] supergiants in the Large Magellanic Cloud, using the Very Large Telescope's Spectrograph for INtegral Field Observation in the Near-Infrared (VLT/SINFONI). Both stars clearly show the 13^{13}CO band emission, whose strength implies a strong enhancement of 13^{13}C, in agreement with theoretical predictions. This first ever direct confirmation of the evolved nature of B[e] supergiants thus paves the way to the first identification of a Galactic B[e] supergiant.Comment: 5 pages, 4 figures, accepted for publication in MNRAS Letter

    Effects of ceftiofur treatment on the susceptibility of commensal porcine E.coli – comparison between treated and untreated animals housed in the same stable

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    Background Healthy farm animals have been found to act as a reservoir of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli). Therefore, the objective of the study was to determine the input of antimicrobial active ceftiofur metabolites in the stable via faeces and urine after intramuscular administration of the drug to pigs and the elucidation of the Escherichia coli ESBL resistance pattern of treated and untreated pigs housed in the same barn during therapy. Methods For determination of the minimal inhibitory concentration (MIC) the method of microdilutionaccording to the recommended procedure of the Clinical and Laboratory Standards Institute was used. Inaddition to that, a qualitative determination was performed by agar dilution. Unsusceptible E. coli speciesselected via agar dilution with cefotaxime were confirmed by MALDI-TOF and ESBL encoding genes wereidentified by PCR. The amounts of ceftiofur measured as desfuroylceftiofur (DFC) in the different probes (plasma, urine, faeces and dust) were analysed by UPLC-MS/MS. Results In a first experiment two groups of pigs (6 animals per group) were housed in the same barn in two separated boxes. One group (group B) were treated with ceftiofur according to the licence (3 mg/kg administered intramuscularly (i.m.) on three consecutive days, day 1–3). During a second treatment period (day 29–31) an increased rate of ESBL resistant E. coli was detectable in these treated pigs and in the air of the stable. Moreover, the second group of animals (group A) formerly untreated but housed for the whole period in the same stable as the treated animals revealed increased resistance rates during their first treatment (day 45–47) with ceftiofur. In order to investigate the environmental input of ceftiofur during therapy and to simulate oral uptake of ceftiofur residues from the air of the stable a second set of experiments were performed. Pigs (6 animals) were treated with an interval of 2 weeks for 3 days with different doses of ceftiofur (3 mg/kg, 1 mg/kg and 0.3 mg/kg i.m.) as well as with 3 mg/kg per os) and the renal and biliary excretion of ceftiofur as its active metabolite were measured in comparison to the plasma levels. In addition to that, probes of the sedimentation dust and the air of the stable were analysed for drug residues. Conclusion The present study shows that treatment of several animals in a stable with ceftiofur influences the resistance pattern of intestinal Escherichia coli of the treated as well as untreated animals housed in the same stable. During therapy with the drug which was administered by injection according to the licence we detected nameable amounts of ceftiofur and its active metabolites in the dust and air of the stable

    CompanyKG: A Large-Scale Heterogeneous Graph for Company Similarity Quantification

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    In the investment industry, it is often essential to carry out fine-grained company similarity quantification for a range of purposes, including market mapping, competitor analysis, and mergers and acquisitions. We propose and publish a knowledge graph, named CompanyKG, to represent and learn diverse company features and relations. Specifically, 1.17 million companies are represented as nodes enriched with company description embeddings; and 15 different inter-company relations result in 51.06 million weighted edges. To enable a comprehensive assessment of methods for company similarity quantification, we have devised and compiled three evaluation tasks with annotated test sets: similarity prediction, competitor retrieval and similarity ranking. We present extensive benchmarking results for 11 reproducible predictive methods categorized into three groups: node-only, edge-only, and node+edge. To the best of our knowledge, CompanyKG is the first large-scale heterogeneous graph dataset originating from a real-world investment platform, tailored for quantifying inter-company similarity.Comment: Paper (13 pages, 5 figures and 2 tables) + Appendix (18 pages, 4 figures and 5 tables

    A Scalable and Adaptive System to Infer the Industry Sectors of Companies: Prompt + Model Tuning of Generative Language Models

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    The Private Equity (PE) firms operate investment funds by acquiring and managing companies to achieve a high return upon selling. Many PE funds are thematic, meaning investment professionals aim to identify trends by covering as many industry sectors as possible, and picking promising companies within these sectors. So, inferring sectors for companies is critical to the success of thematic PE funds. In this work, we standardize the sector framework and discuss the typical challenges; we then introduce our sector inference system addressing these challenges. Specifically, our system is built on a medium-sized generative language model, finetuned with a prompt + model tuning procedure. The deployed model demonstrates a superior performance than the common baselines. The system has been serving many PE professionals for over a year, showing great scalability to data volume and adaptability to any change in sector framework and/or annotation.Comment: Accepted by FinNLP (Financial Technology and Natural Language Processing) @ IJCAI2023 as long paper (8 pages and 8 figures
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