The causal effect of restrictive bank lending on employment growth: A matching approach

Does restrictive bank lending cause lower employment growth at the firm-level or does it reflect firm characteristics that drive the deterioration of employment figures? Applying propensity score matching, we estimate the treatment effect of restrictive bank lending on employment growth. Combining balance sheet information and survey data on a firm's current and expected future business situation, we rule out the impact of firm heterogeneity. We find that credit constraints have a significant negative effect on employment growth. Restricted firms also apply for short-time work more often, but this effect is small and not significant in all estimations

Event-Based Modelling in Question Answering

In der natürlichen Sprachverarbeitung haben Frage-Antwort-Systeme in der letzten Dekade stark an Bedeutung gewonnen. Vor allem durch robuste Werkzeuge wie statistische Syntax-Parser und Eigennamenerkenner ist es möglich geworden, linguistisch strukturierte Informationen aus unannotierten Textkorpora zu gewinnen. Zusätzlich werden durch die Text REtrieval Conference (TREC) jährlich Maßstäbe für allgemeine domänen-unabhängige Frage-Antwort-Szenarien definiert. In der Regel funktionieren Frage-Antwort-Systeme nur gut, wenn sie robuste Verfahren für die unterschiedlichen Fragetypen, die in einer Fragemenge vorkommen, implementieren. Ein charakteristischer Fragetyp sind die sogenannten Ereignisfragen. Obwohl Ereignisse schon seit Mitte des vorigen Jahrhunderts in der theoretischen Linguistik, vor allem in der Satzsemantik, Gegenstand intensive Forschung sind, so blieben sie bislang im Bezug auf Frage-Antwort-Systeme weitgehend unerforscht. Deshalb widmet sich diese Diplomarbeit diesem Problem. Ziel dieser Arbeit ist zum Einen eine Charakterisierung von Ereignisstruktur in Frage-Antwort Systemen, die unter Berücksichtigung der theoretischen Linguistik sowie einer Analyse der TREC 2005 Fragemenge entstehen soll. Zum Anderen soll ein Ereignis-basiertes Antwort-Extraktionsverfahren entworfen und implementiert werden, das sich auf den Ergebnissen dieser Analyse stützt. Informationen von diversen linguistischen Ebenen sollen daten-getrieben in einem uniformen Modell integriert werden. Spezielle linguistische Ressourcen, wie z.B. WordNet und Subkategorisierungslexika werden dabei eine zentrale Rolle einnehmen. Ferner soll eine Ereignisstruktur vorgestellt werden, die das Abpassen von Ereignissen unabhängig davon, ob sie von Vollverben oder Nominalisierungen evoziert werden, erlaubt. Mit der Implementierung eines Ereignis-basierten Antwort-Extraktionsmoduls soll letztendlich auch die Frage beantwortet werden, ob eine explizite Ereignismodellierung die Performanz eines Frage-Antwort-Systems verbessern kann

Inflammation and Corrosion in Total Hip Prostheses: The Generation and Interaction of Reactive Oxygen Species with CoCrMo Metallic Biomaterial Surfaces

There are many molecules, species and mechanisms that contribute to the overall wear and degradation of biometallic alloys like cobalt-chromium-molybdenum (CoCrMo). Following implantation, orthopaedic alloys are subject to an encompassing inflammatory response that will either lead to foreign body giant cell formation and attachment to the surface or the fibrous tissue encapsulation, forming an inflamed periprosthetic joint. In addition to the inflammatory response, tribocorrosion-based processes of alloy-on-alloy or alloy-on-polymer couples release polymeric wear debris, oxides, hydroxides, and metal ions in response to excessive wear, loading and corrosion. It is hypothesized that these processes, biological and triboelectrochemical, are linked together in a feedback-loop, and there is reason to believe that there exists a common catalyst, reactive oxygen species (ROS), that accelerates the cycle. This dissertation explains how ROS are generated in physiological conditions and how they affect electrochemical properties, under what circumstances ROS are consumed intracellularly, how different cell types respond to ROS-rich conditions, and how ROS interact with solution components native to synovial fluid, with a decisive effort and focus on defining their presence and role in the inflamed joint space. By fluorescently labeling individual ROS like hydroxyl radicals (OH·) and hydrogen peroxide (H2O2), we were able to correlate ROS concentrations against time of applied voltage (-1V vs. Ref) as well as against applied voltage for 2 hours. It was found that there exist thresholds for both the production and consumption of ROS, and there is a voltage range for which ROS are produced in measurable quantities. Under similar electrochemical conditions, different cell types (pre-osteoblast-like MC3T3-E1, monocyte macrophage-like U937) were cultured and exposed to an influx of ROS through cathodic excursions. It was found that cells possess a unique ‘electrochemical zone of viability’ per phenotype with reduced glutathione (GSH) activity, a ROS scavenger molecule produced within inflammatory cells, hypothesized to be the oxidative stress suppressor in the U937 cells. This hypothesis was later confirmed when exposing macrophages (RAW 264.7) to simulated synovial fluid, where it was found that ROS (H2O2) had a significant (p \u3c 0.05) effect on intracellular GSH activity (fluorescent intensity). In addition to influencing cell behavior and response, ROS production and exposure was found to alter electrochemical properties of CoCrMo surfaces. Using nearfield electrochemical impedance spectroscopy (NEIS), CoCrMo retrievals and CoCrMo surfaces damaged by electrocautery and ROS-rich solutions were shown to have significantly (p \u3c 0.05) decreased corrosion resistance (RP) with increased constant phase element capacitance (CPE Q) and open circuit potentials (OCPs), indicating that ROS are major contributors in corrosion susceptibility. By interpreting these observations and results, we were able to demonstrate that ROS are influential in several aspects of the inflammatory reaction to metallic biomaterials. The development of new diagnostics and predictive models centered around ROS can lead to safer practices involving orthopaedic alloys and further support our understanding of an inflamed joint space

A material characterization of two-solution bone cement containing ethylene glycol-dimethacrylate as a crosslinker

Bone cements are primarily used for fixation of implants as well as dampening of mechanical loads between the implant and neighboring bone. Two-solution bone cements offer a variety of advantages over commercial powder-liquid compositions due to a reduction in porosity, which in turn leads to improved mechanical properties. The effectiveness of the material is limited by its mechanical properties due to a large mismatch in moduli and strength between the cement, bone, and implant. Two-solution bone cements modified with ethylene glycol-dimethacrylate (EG-DMA) as a crosslinker have been developed as an attempt to further improve the mechanical and thermal properties of the material. The crosslinker replaces a volumetric portion of the methyl methacrylate (MMA) monomer and the resulting mechanical, thermal and viscous properties were compared to a formulation free of EG-DMA. The result of this study shows that EG-DMA can increase the mechanical properties and fractional monomer conversion without significantly (p\u3c0.05) affecting the thermal characteristics, including maximum polymerization temperature and setting time. The maximum flexural strength and bending modulus increase with increasing EG-DMA concentrations up to 10 vol% EG-DMA, and then decrease following a second order polynomial fit. The critical stress intensity factor increases up to 5 vol% and then decreases with increasing EG-DMA content, and the yield strength increases up to 15 vol% EG-DMA. These results indicate that up to a certain concentration, EG-DMA vol% has more of an effect on a specific mechanical property than decreasing the MMA concentration. All EG-DMA compositions had a higher viscosity than the control at all measurable shear rates due to a higher polymer to MMA ratio. These formulations demonstrated an increase in ductility and the fractured samples displayed different surface morphologies than the control samples. Sample sets containing EG-DMA did not fracture at the upper strain limit (10%) during flexural tests, except 10 and 15 vol% EG-DMA. The fractured EG-DMA samples exhibited evidence of large amounts of plastic strain before failure, indicated by micro-troughs and ridge formation. Samples containing 20 vol% EG-DMA had the highest fractional monomer conversion and lowest residual monomer concentration. This was attributed to the high reactivity of EG-DMA molecules in the presence of an initiator. These formulations provide insight into the effect of substituting a crosslinker for MMA monomer in a two-solution injection system and layout the ideal concentrations of EG-DMA for superior mechanical or fractional monomer conversion properties

IGGSA Shared Tasks on German Sentiment Analysis (GESTALT)

We present the German Sentiment Analysis Shared Task (GESTALT) which consists of two main tasks: Source, Subjective Expression and Target Extraction from Political Speeches (STEPS) and Subjective Phrase and Aspect Extraction from Product Reviews (StAR). Both tasks focused on fine-grained sentiment analysis, extracting aspects and targets with their associated subjective expressions in the German language. STEPS focused on political discussions from a corpus of speeches in the Swiss parliament. StAR fostered the analysis of product reviews as they are available from the website Amazon.de. Each shared task led to one participating submission, providing baselines for future editions of this task and highlighting specific challenges. The shared task homepage can be found at https://sites.google.com/site/iggsasharedtask/

Convolution Kernels for Subjectivity Detection

Proceedings of the 18th Nordic Conference of Computational Linguistics NODALIDA 2011. Editors: Bolette Sandford Pedersen, Gunta Nešpore and Inguna Skadiņa. NEALT Proceedings Series, Vol. 11 (2011), 254-261. © 2011 The editors and contributors. Published by Northern European Association for Language Technology (NEALT) http://omilia.uio.no/nealt . Electronically published at Tartu University Library (Estonia) http://hdl.handle.net/10062/16955

Predictive Features in Semi-Supervised Learning for Polarity Classification and the Role of Adjectives

Proceedings of the 17th Nordic Conference of Computational Linguistics NODALIDA 2009. Editors: Kristiina Jokinen and Eckhard Bick. NEALT Proceedings Series, Vol. 4 (2009), 198-205. © 2009 The editors and contributors. Published by Northern European Association for Language Technology (NEALT) http://omilia.uio.no/nealt . Electronically published at Tartu University Library (Estonia) http://hdl.handle.net/10062/9206

Opinion Holder and Target Extraction on Opinion Compounds – A Linguistic Approach

We present an approach to the new task of opinion holder and target extraction on opinion compounds. Opinion compounds (e.g. user rating or victim support) are noun compounds whose head is an opinion noun. We do not only examine features known to be effective for noun compound analysis, such as paraphrases and semantic classes of heads and modifiers, but also propose novel features tailored to this new task. Among them, we examine paraphrases that jointly consider holders and targets, a verb detour in which noun heads are replaced by related verbs, a global head constraint allowing inferencing between different compounds, and the categorization of the sentiment view that the head conveys

Opinion Holder and Target Extraction for Verb-based Opinion Predicates – The Problem is Not Solved

We offer a critical review of the current state of opinion role extraction involving opinion verbs. We argue that neither the currently available lexical resources nor the manually annotated text corpora are sufficient to appropriately study this task. We introduce a new corpus focusing on opinion roles of opinion verbs from the Subjectivity Lexicon and show potential benefits of this corpus. We also demonstrate that state-of-the-art classifiers perform rather poorly on this new dataset compared to the standard dataset for the task showing that there still remains significant research to be done

Overview of the IGGSA 2016 Shared Task on Source and Target Extraction from Political Speeches

We present the second iteration of IGGSA’s Shared Task on Sentiment Analysis for German. It resumes the STEPS task of IGGSA’s 2014 evaluation campaign: Source, Subjective Expression and Target Extraction from Political Speeches. As before, the task is focused on fine-grained sentiment analysis, extracting sources and targets with their associated subjective expressions from a corpus of speeches given in the Swiss parliament. The second iteration exhibits some differences, however; mainly the use of an adjudicated gold standard and the availability of training data. The shared task had 2 participants submitting 7 runs for the full task and 3 runs for each of the subtasks. We evaluate the results and compare them to the baselines provided by the previous iteration. The shared task homepage can be found at http://iggsasharedtask2016.github.io/