566 research outputs found

    Profiling of OCR'ed Historical Texts Revisited

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    In the absence of ground truth it is not possible to automatically determine the exact spectrum and occurrences of OCR errors in an OCR'ed text. Yet, for interactive postcorrection of OCR'ed historical printings it is extremely useful to have a statistical profile available that provides an estimate of error classes with associated frequencies, and that points to conjectured errors and suspicious tokens. The method introduced in Reffle (2013) computes such a profile, combining lexica, pattern sets and advanced matching techniques in a specialized Expectation Maximization (EM) procedure. Here we improve this method in three respects: First, the method in Reffle (2013) is not adaptive: user feedback obtained by actual postcorrection steps cannot be used to compute refined profiles. We introduce a variant of the method that is open for adaptivity, taking correction steps of the user into account. This leads to higher precision with respect to recognition of erroneous OCR tokens. Second, during postcorrection often new historical patterns are found. We show that adding new historical patterns to the linguistic background resources leads to a second kind of improvement, enabling even higher precision by telling historical spellings apart from OCR errors. Third, the method in Reffle (2013) does not make any active use of tokens that cannot be interpreted in the underlying channel model. We show that adding these uninterpretable tokens to the set of conjectured errors leads to a significant improvement of the recall for error detection, at the same time improving precision

    Towards a quantum time mirror for non-relativistic wave packets

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    We propose a method – a quantum time mirror (QTM) – for simulating a partial time-reversal of the free-space motion of a nonrelativistic quantum wave packet. The method is based on a short-time spatially-homogeneous perturbation to the wave packet dynamics, achieved by adding a nonlinear time-dependent term to the underlying Schroedinger equation. Numerical calculations, supporting our analytical considerations, demonstrate the effectiveness of the proposed QTM for generating a time-reversed echo image of initially localized matter-wave packets in one and two spatial dimensions. We also discuss possible experimental realizations of the proposed QTM

    In vitro approaches to assess the hazard of nanomaterials

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    The rapid development of engineered nanomaterials demands for a fast and reliable assessment of their health hazard potential. A plethora of experimental approaches have been developed and are widely employed in conventional toxicological approaches. However, the specific properties of nanomaterials such as smaller size but larger surface area, and high catalytic reactivity and distinctive optical properties compared to their respective bulk entities, often disable a straightforward use of established in vitro approaches. Herein, we provide an overview of the current state-of the art nanomaterial hazard assessment strategies using in vitro approaches. This perspective has been developed based on a thorough review of over 200 studies employing such methods to assess the biological response upon exposure to a diverse array of nanomaterials. The majority of the studies under review has been, but not limited to, engaged in the European 7th Framework Programme for Research and Technological Development and published in the last five years. Based on the most widely used methods and/or the most relevant biological endpoints, we have provided some general recommendations on the use of the selected approaches which would the most closely mimic realistic exposure scenarios as well as enabling to yield fast, reliable and reproducible data on the nanomaterial-cell response in vitro. In addition, the applicability of the approaches to translate in vitro outcomes to leverage those of in vivo studies has been proposed. It is finally suggested that an improved comprehension of the approaches with its limitations used for nanomaterials' hazard assessment in vitro will improve the interpretation of the existing nanotoxicological data as well as underline the basic principles in understanding interactions of engineered nanomaterials at a cellular level; this all is imperative for their safe-by- design strategies, and should also enable subsequent regulatory approvals

    Amantadine Inhibits SARS-CoV-2 In Vitro

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    Since the SARS-CoV-2 pandemic started in late 2019, the search for protective vaccines and for drug treatments has become mandatory to fight the global health emergency. Travel restrictions,social distancing, and face masks are suitable counter measures, but may not bring the pandemic under control because people will inadvertently or at a certain degree of restriction severity or duration become incompliant with the regulations. Even if vaccines are approved, the need for antiviral agents against SARS-CoV-2 will persist. However, unequivocal evidence for efficacy againstSARS-CoV-2 has not been demonstrated for any of the repurposed antiviral drugs so far. Amantadinewas approved as an antiviral drug against influenza A, and antiviral activity against SARS-CoV-2has been reasoned by analogy but without data. We tested the efficacy of amantadine in vitro in Vero E6 cells infected with SARS-CoV-2. Indeed, amantadine inhibited SARS-CoV-2 replication in two separate experiments with IC50 concentrations between 83 and 119μM. Although these IC50 concentrations are above therapeutic amantadine levels after systemic administration, topical admin-istration by inhalation or intranasal instillation may result in sufficient amantadine concentration in the airway epithelium without high systemic exposure. However, further studies in other models are needed to prove this hypothesis.Peer Reviewe

    Fluorine adsorption as well as fluorine and oxygen coadsorption on In-rich InSb(111) surface

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    The oxygen and fluorine adsorption and their coadsorption on the InSb(111)-(1×1) surface have been studied by the projector augmented-wave method within density functional theory. The indium top site was found to be the most energetically favorable for fluorine adsorption, whereas oxygen prefers to be bonded to the bridge site between two In atoms. It is shown that the oxygen-induced surface states are completely or partly removed from the band gap by fluorine coadsorption if it forms bonds with the indium atoms involved in an interaction with oxygen. An increase of fluorine concentration and its coadsorption bring about appreciable structural changes in the near-surface layers due to the penetration of both oxygen and fluorine atoms into the substrate

    Who says what to whom? Alignments and arguments in EU policy-making

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    In the EU multilevel polity, domestic interest groups seek to shape EU legislation by accessing both national and EU institutions. Previous studies indicated that institutional and issue contexts, as well as organizational characteristics shape their strategies of interest representation. However, we know much less about how alignments and arguments impact on their participation in EU and national policy consultations. Addressing this gap, we investigate the lobbying strategies of almost 2,900 national interest organizations from five member states (Germany, the Netherlands, Slovenia, Sweden, and the United Kingdom) on 20 EU directive proposals bringing also a new empirical scope to the study of multilevel interest representation. The findings indicate that alignments and arguments shape the participation of domestic interest groups in consultations on EU policies. We infer from our study that some general predictions of interest group behaviour are overstretched and outline four variations of interest representation routines

    Naturschutzleistungen des Ökologischen Landbaus: Wiederansiedlung seltener und gefährdeter Ackerwildpflanzen naturräumlicher Herkünfte auf Ökobetrieben

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    Die Intensivierung der Landwirtschaft hat zum Rückgang vieler Ackerwildpflanzen geführt. Der Ökologische Landbau bietet günstige Voraussetzungen für ihren Schutz. Wie entsprechende Populationen etabliert werden können, untersuchte ein Verbundprojekt der Bayerischen Landesanstalt für Landwirtschaft, der Technischen Universität München und der Universität Kassel. Die AG Freising untersuchte drei seltene winterannuelle Arten (Consolida regalis, Legousia speculumveneris, Lithospermum arvense) in mehrfaktoriellen Feldversuchen, in Praxisaus-saaten auf Bio-Betrieben sowie in Gewächshausexperimenten. Messgrößen waren Individuendichte, Samenproduktion und Bodensamenvorrat der Zielarten, zudem wurde der Ertrag der Feldfrüchte bestimmt. Frühe Herbstsaaten und geringe Konkurrenz durch Kulturen brachten beste Erfolge. Zur erfolgreichen Ansiedlung der Ackerwildkräuter wird eine Aussaat in Blanksaat oder in reduziert gesäten Winterungen, wie Dinkel oder Roggen, bis spätestens Mitte Oktober empfohlen. Klee-Gras und Sommerungen wie Erbsen ermöglichten kaum bzw. kein Auflaufen der Zielarten, die jedoch teils im Bodensamenvorrat überdauern. Die AG Witzenhausen untersuchte die Wiederansiedlung von Ackerwildkräutern auf Praxis-betrieben. Dazu wurden artenreiche Spenderflächen identifiziert und autochthones Saatgut gefährdeter Arten entnommen. Samenmischungen wurden in Blühfenster und den benachbarten Getreidebestand ausgebracht. Zudem wurde die Übertragung von Oberboden arten-reicher Flächen getestet. Im Anlagejahr konnte sich bei beiden Verfahren ein Teil der eingebrachten Arten reproduzieren. Dies gelang bei Konkurrenz mit Getreide tendenziell schlechter. In den Folgejahren konnten bei Anbau von Getreide wiederum einige Arten nachgewiesen werden; die meisten Samen gelangten bei Bodenbearbeitung in tiefere Bodenschichten und reicherten die Samenbank an. Praxisempfehlungen zur Wiederansiedlung von Ackerwildkräutern auf ökologisch bewirtschafteten Äckern wurden als Broschüre veröffentlicht

    Detailed Annotations of Chest X-Rays via CT Projection for Report Understanding

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    In clinical radiology reports, doctors capture important information about the patient's health status. They convey their observations from raw medical imaging data about the inner structures of a patient. As such, formulating reports requires medical experts to possess wide-ranging knowledge about anatomical regions with their normal, healthy appearance as well as the ability to recognize abnormalities. This explicit grasp on both the patient's anatomy and their appearance is missing in current medical image-processing systems as annotations are especially difficult to gather. This renders the models to be narrow experts e.g. for identifying specific diseases. In this work, we recover this missing link by adding human anatomy into the mix and enable the association of content in medical reports to their occurrence in associated imagery (medical phrase grounding). To exploit anatomical structures in this scenario, we present a sophisticated automatic pipeline to gather and integrate human bodily structures from computed tomography datasets, which we incorporate in our PAXRay: A Projected dataset for the segmentation of Anatomical structures in X-Ray data. Our evaluation shows that methods that take advantage of anatomical information benefit heavily in visually grounding radiologists' findings, as our anatomical segmentations allow for up to absolute 50% better grounding results on the OpenI dataset as compared to commonly used region proposals. The PAXRay dataset is available at https://constantinseibold.github.io/paxray/.Comment: 33rd British Machine Vision Conference (BMVC 2022
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