446 research outputs found

    Parsing early and late modern English corpora

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    We describe, evaluate, and improve the automatic annotation of diachronic corpora at the levels of word-class, lemma, chunks, and dependency syntax. As corpora we use the ARCHER corpus (texts from 1600 to 2000) and the ZEN corpus (texts from 1660 to 1800). Performance on Modern English is considerably lower than on Present Day English (PDE). We present several methods that improve performance. First we use the spelling normalization tool VARD to map spelling variants to their PDE equivalent, which improves tagging. We investigate the tagging changes that are due to the normalization and observe improvements, deterioration, and missing mappings. We then implement an optimized version, using VARD rules and preprocessing steps to improve normalization. We evaluate the improvement on parsing performance, comparing original text, standard VARD, and our optimized version. Over 90% of the normalization changes lead to improved parsing, and 17.3% of all 422 manually annotated sentences get a net improved parse. As a next step, we adapt the parser's grammar, add a semantic expectation model and a model for prepositional phrases (PP)-attachment interaction to the parser. These extensions improve parser performance, marginally on PDE, more considerably on earlier texts—2—5% on PP-attachment relations (e.g. from 63.6 to 68.4% and from 70 to 72.9% on 17th century texts). Finally, we briefly outline linguistic applications and give two examples: gerundials and auxiliary verbs in the ZEN corpus, showing that despite high noise levels linguistic signals clearly emerge, opening new possibilities for large-scale research of gradient phenomena in language chang

    Natural variability in hard bottom communities and possible drivers assessed by a time-series study in the SW Baltic Sea: know the noise to detect the change

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    In order to detect shifts in community structure and function associated with global change, the natural background fluctuation in these traits must be known. In a 6 yr study we characterized the composition of young benthic communities at 7 sites along the 300 km coast of the Kiel and Lübeck bights in the German Baltic Sea and we quantified their interannual variability of taxonomic and functional composition. Along the salinity gradient from NW to SE, the relative abundance of primary producers decreased while that of heterotrophs increased. Along the same gradient, annual productivity tended to increase. Taxonomic and functional richness were higher in Kiel Bight as compared to Lübeck Bight. With increasing species richness functional group richness showed saturation indicating an increasing functional redundancy in species rich communities. While taxonomic fluctuations between years were substantial, functionality of the communities seem preserved in most cases. Environmental conditions potentially driving these fluctuations are winter temperatures and current regimes. We tentatively define a confidence range of natural variability in taxonomic and functional composition a departure from which might help identifying an ongoing regime shift driven by global change. In addition, we propose to use RELATE, a statistical procedure in the PRIMER (Plymouth Routines in Multivariate Ecological Research) package to distinguish directional shifts in time ("signal") from natural temporal fluctuations ("noise"

    Low cost pressure sensors for impact detection in composite structures

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    AbstractA new technology of flexible pressure sensors is developed using conducting polymers as electroactive materials on plastic substrates. The sensor measures quantitative pressure and the use of an appropriate synthesis strategy in the electroactive material tuning an adequate electrical conductivity and film morphology allows working pressure ranges to be taylor-made designed. Using low cost materials, high surface sensors are easily fabricated. The present work describes the integration of this innovative, low cost and flexible technology on composite structures opening interesting potential opportunities for impact detection and measurements on these types of components

    Endothelial Tissue-Type Plasminogen Activator Release in Coronary Heart Disease Transient Reduction in Endothelial Fibrinolytic Reserve in Patients With Unstable Angina Pectoris or Acute Myocardial Infarction

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    AbstractObjectives. We sought to examine whether the disturbed fibrinolytic system in patients with an acute coronary syndrome is associated with a reduced endothelial fibrinolytic capacity.Background. Intracoronary thrombus formation is a frequent finding in acute coronary syndromes. Systemic alterations of coagulation and fibrinolysis are known to occur, but possible disturbances of endothelial fibrinolytic function have not been investigated.Methods. We compared 42 patients with an acute coronary syndrome (acute myocardial infarction in 11 and unstable angina pectoris in 31) with 25 patients with stable angina. Venous blood was sampled serially for determination of markers of the fibrinolytic system and of hypercoagulability from admission to day 10. An occlusion test to determine the maximal endothelial tissue-type plasminogen activator (t-PA) release was also performed.Results. Both on day 0 and day 10, patients with an acute coronary syndrome had a marked elevation of t-PA mass concentration (mean value ± SEM 14.4 ± 1.6 [day 0], 18.9 ± 2.5 ng/ml [day 10]) and of plasminogen activator inhibitor (PAI) (9.4 ± 2.2 [day 0], 11.3 ± 2.6 AU/liter [day 10], p < 0.05 vs. patients with stable angina). There was also a hypercoagulative state with elevated thrombin activity and increased D-dimers (p < 0.05 vs. patients with stable angina). Maximal endothelial t-PA release was initially reduced (p < 0.05 vs. patients with stable angina) to 2.3 ± 0.9 ng/ml, but levels recovered during follow-up to 4.4 ± 1.4 ng/ml (vs. 5.7 ± 1.5 ng/ml in patients with stable angina).Conclusions. Despite the known prolonged systemic alteration of fibrinolysis in acute coronary syndromes, endothelial fibrinolytic capacity is reduced only during the acute phase and becomes normalized during follow-up, and thus is linked more to intravascular thrombus formation than to steady state levels of markers of the fibrinolytic system

    Selection of Potent Non-Toxic Inhibitory Sequences from a Randomized HIV-1 Specific Lentiviral Short Hairpin RNA Library

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    RNA interference (RNAi) has been considered as an efficient therapeutic approach against the human immunodeficiency virus type 1 (HIV-1). However, to establish a durable inhibition of HIV-1, multiple effective short hairpin RNAs (shRNAs) need to be stably expressed to prevent the emergence of viral escape variants. In this study, we engineered a randomized lentiviral H1-promoter driven shRNA-library against the viral genome. Potent HIV-1 specific shRNAs were selected by ganciclovir treatment of cell lines stably expressing the cDNA of Herpes Simplex Virus thymidine kinase (HSV-TK) fused to HIV-1 nucleotide sequences. More than 50% of 200 selected shRNAs inhibited an HIV-1 based luciferase reporter assay by more than 70%. Stable expression of some of those shRNAs in an HIV-1 permissive HeLa cell line inhibited infection of wild-type HIV-1 by more than 90%. The combination of a randomized shRNA-library directed against HIV-1 with a live cell selection procedure yielded non-toxic and highly efficient HIV-1 specific inhibitory sequences that could serve as valuable candidates for gene therapy studies

    Long-term records of hard-bottom communities in the southwestern Baltic Sea reveal the decline of a foundation species

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    Highlights • Records of hard-bottom communities show regional differences in community dynamics. • Regionally, signs of regime shift were detected. • Shift can be explained by the decline of the foundation species Mytilus sp. • Modelling process revealed three environmental variables explaining the decline. • Regional differences in larval dispersal could explain contrary Mytilus recoveries. Abstract Ecological processes modulate ecosystem functioning and services. Foundation species are those exerting intense control on such processes as both their existence and loss have profound implications on the structure of ecological communities. For the distinction between random fluctuations and directional regime shifts in community composition, long-term records are of strategic need. In this study we present the monitoring of benthic hard-bottom communities over 11 years along seven stations in the SW Baltic Sea. Regional differences were found between the communities of Kiel and Lübeck bights, with the former area displaying signs of regime shift. The decline and near disappearance of the foundational species Mytilus edulis from settlement panels deployed in Kiel Bight correlated with three environmental variables: sea surface temperature, water current speed and chlorophyll a concentration. Thus, low spring temperatures, in some cases reinforced by local maxima of chlorophyll a, correlated with reduced recruitment of Mytilus. Moreover, regional differences of larval dispersal and population connectivity could explain the rapid recovery after disturbance of the mussel populations in Lübeck Bight in contrast to Kiel Bight. Our findings underscore the relevance of long-term monitoring programmes to detect the interactive impacts of global climatic and regional environmental drivers

    Animation and interactivity facilitate acquisition of pediatric life support skills: a randomized controlled trial using virtual patients versus video instruction

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    Background: Several promising studies suggest a positive impact of interactive and media-enriched e-learning resources such as virtual patients (VP) on skill acquisition in pediatric basic life support (PBLS). This study investigates which immanent VP components account for this effect. Methods: N = 103 medical students in their 5th year were assigned to one of three groups: a video group prepared with self-instructional videos on PBLS (N = 37); an animation-enriched VP group with VP containing interactive questions (N = 35), static and animated media, and a static VP group with VP containing interactive questions and only static media (N = 31). Subsequent PBLS demonstrations were video-documented and scored for adherence to guideline-based algorithm, temporal demands (such as correct pace of rescue breaths and chest compressions), and quality of procedural steps (e.g., correct head positioning), as well as overall competency by two group-blinded, independent pediatricians. Results: Groups did not differ with regard to adherence to correct algorithm (88.7 ± 10.3, 93.3 ± 6.7 and 90.3 ± 10.5, respectively). Self-instruction with animated media – through videos or animation-enriched VP – resulted in a better adherence to temporal demands, as compared with training with static VP (64.5 ± 26.3 and 50.7 ± 25.7, respectively, vs. 23.8 ± 21.0). Procedural quality by the video group was slightly inferior compared with the animation-enriched VP group (79.5 ± 12.3 vs. 82.0 ± 11.9), and distinct inferior in overall ‘competent’ ratings (43.2% vs. 65.7%). The static VP group performed considerably most poorly of all three groups (temporal adherence 73.2 ± 11.9 and 19.4% ‘competent’ ratings). Conclusions: VP can feasibly enhance PBLS skill acquisition. Thoughtful design of animations and interactivity of the VP further improves such skill acquisition, both in quality of performance and in adherence to temporal demands

    Toward Comprehensive Analysis of the Galectin Network in Chicken: Unique Diversity of Galectin-3 and Comparison of its Localization Profile in Organs of Adult Animals to the Other Four Members of this Lectin Family

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    18 pags, 11 figs, 2 tabs. -- Additional Supporting Information may be found in the online version of this articleCharacterization of all members of a gene family established by gene divergence is essential to delineate distinct or overlapping expression profiles and functionalities. Their activity as potent modulators of diverse physiological processes directs interest to galectins (endogenous lectins with β-sandwich fold binding β-galactosides and peptide motifs), warranting their study with the long-term aim of a comprehensive analysis. The comparatively low level of complexity of the galectin network in chicken with five members explains the choice of this organism as model. Previously, the three proto-type chicken galectins CG-1A, CG-1B, and CG-2 as well as the tandem-repeat-type CG-8 had been analyzed. Our study fills the remaining gap to determine gene structure, protein characteristics and expression profile of the fifth protein, that is, chimera-type chicken galectin-3 (CG-3). Its gene has a unique potential to generate variants: mRNA production stems from two promoters, alternative splicing of the form from the second transcription start point (tsp) can generate three mRNAs. The protein with functional phosphorylation sites in the N-terminus generated by transcription from the first tsp (tsp1CG-3) is the predominant CG-3 type present in adult tissues. Binding assays with neoglycoproteins and cultured cells disclose marked similarity to properties of human galectin-3. The expression and localization profiles as well as proximal promoter regions have characteristic features distinct from the other four CGs. This information on CG-3 completes the description of the panel of CGs, hereby setting the stage for detailed comparative analysis of the entire CG family, e.g., in embryogenesis. © 2011 Wiley-Liss, Inc.Spanish Ministry of Science and Innovation Grant number: BFU2009-10052; Grant sponsor: CIBER of Respiratory Diseases (CIBERES) (ISCII
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