Is it worth the effort? Assessing the benefits of partial automatic pre-labeling for frame-semantic annotation

Corpora with high-quality linguistic annotations are an essential component in many NLP applications and a valuable resource for linguistic research. For obtaining these annotations, a large amount of manual effort is needed, making the creation of these resources time-consuming and costly. One attempt to speed up the annotation process is to use supervised machine-learning systems to automatically assign (possibly erroneous) labels to the data and ask human annotators to correct them where necessary. However, it is not clear to what extent these automatic pre-annotations are successful in reducing human annotation effort, and what impact they have on the quality of the resulting resource. In this article, we present the results of an experiment in which we assess the usefulness of partial semi-automatic annotation for frame labeling. We investigate the impact of automatic pre-annotation of differing quality on annotation time, consistency and accuracy. While we found no conclusive evidence that it can speed up human annotation, we found that automatic pre-annotation does increase its overall quality.     

The Morphology Control of BaTiO3 Particles Synthesized in Water and a Water/Ethanol Solvent

The experimental conditions for the growth of shape‐controlled BaTiO₃ particles in NaOH and Ba(NO₃)₂ aqueous and water/ethanol solutions using various TiO₂‐containing precursors were studied at 80°C–100°C. The different chemistries and physical characteristics of the precursors resulted in different BaTiO₃ formation rates and morphologies_. Nanocrystalline anatase led to irregularly shaped BaTiO₃ particles, whereas star‐like, single‐crystalline BaTiO₃ particles grew from aerogel TiO₂ and sodium titanate (NT) belts in alkaline aqueous solutions. With the addition of ethanol, the star‐like BaTiO₃ particles changed to square‐like, the size of which decreased with an increase in the ethanol content. The electron microscopy observations supported a dissolution–precipitation mechanism as the primary reaction mechanism for the formation of BaTiO₃ nanocrystals, which further aggregated into single‐crystalline star‐ or square‐like particles by oriented attachment. The modification in the water solution with ethanol is believed to influence both the nucleation and aggregation process and consequently influence the particle shape and size.     

Maximum-likelihood principle for determining positions in neutronscintillation detectors

Pulse height division is generally used to determine a position channel for storing detection events in position-sensitive detectors (PSDs). An alternative method based on the maximum likelihood principle is discussed. This principle is modified in order that the storage of events can be done online. Analytic expressions for the spatial resolution are derived and evaluated. Both detection methods are simulated for linear PSDs. Results on uniformity, linearity, stability and spatial resolution are presented. The major specific advantage of the proposed method is an improved uniformity of the response along the entire detector     

Probing the ligand-binding specificity and analyzing the folding state of SPOT-synthesized FBP28 WW domain variants

The WW domains are known as the smallest naturally occurring, monomeric, triple-stranded, antiparallel beta-sheet domains. Hence, we chose the FBP28 WW domain as a model to investigate the stability of the beta-sheet structure at the amino acid level in the context of its function (ligand binding). The structure-function relationship was investigated through a complete substitution analysis of the FBP28 WW domain, with variants synthesized as a cellulose-bound peptide array. The functionality of the FBP28 WW domain variants was examined by probing the peptide array for ligand binding. In addition, selected FBP28 WW domain variants were investigated by CD measurements to determine the stability of the antiparallel beta-sheet structure. We discuss the correlation between structure stability and functionality for the FBP28 WW domain, as well as the effect of ligand-induced structure stabilization.     

Synthesis and X-ray Crystal Structures of New Tetrahedral Arylethynyl Substituted Silanes

The tetrakis(arylethynyl)silanes 1–4 of which 2–4 are new compounds have been synthesized and determined by single crystal structure analysis to show their tetrahedral molecular geometries reflected in slightly disturbed S₄ symmetry in the crystal lattices. The lattice structures are mainly determined by close packing effects while the interactions of π-stacking type or C–H···π contacts are rather secondary. A similar behaviour is found for the crystal structure of the comparative compound 5 with reference to 4 which lacks the ethynylene units. It is demonstrated that the given molecular constructions are distinguished by a high degree of tetrahedral persistency governing the packing structures.     

Short- and long-term effectiveness of an empirically supported treatment for agoraphobia.

This study examined the effectiveness of individual high-density exposure (2–3 weeks, all day) for panic disorder with agoraphobia (PDAG). Participants were 416 unselected patients with a primary diagnosis of PDAG who were treated by 52 therapists in 3 outpatient clinics of the Christoph-Dornier Foundation of Clinical Psychology in Germany. Results 6 weeks after the end of therapy and at the 1-year follow-up showed highly significant reductions in anxiety symptoms, anxious cognition, agoraphobic avoidance, general symptomatology, and depressive symptoms. Results did not differ significantly between the 3 outpatient clinics and are comparable with the average effect sizes reported by meta-analytic studies of controlled efficacy research, using selected patients and specifically trained therapists. Effectiveness was not dependent on duration of disorder, number of treatment sessions, and therapist experience. The study suggests that high-density exposure can be transported from research settings to the mental health field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Composition of peel essential oils from four selected Tunisian Citrus species: Evidence for the genotypic influence

The peel essential oils from four selected Tunisian Citrus species: sweet orange (Citrus sinensis Osbeck), mandarin (Citrus reticulata Blanco); sour orange (Citrus aurantium L.) and pummelo (Citrus grandis Osbeck), cultivated under the same pedoclimatic and cultural conditions have been analysed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). The essential oils content ranged from 1.06% to 4.62% (w/w) in pummelo and mandarin, respectively. The qualitative and quantitative analysis led to the identification of 70 components in all oil samples. The analysed oils consist mainly in monoterpene hydrocarbons (97.59–99.3%), with limonene (92.52–97.3%) and β-pinene (1.37–1.82) being the major constituents. The remaining chemical classes were weakly represented (<1%). Both qualitative and quantitative differences between oil samples have been observed and numerous components have been proposed as marker compounds. Since the influence of different environmental factors has been eliminated, the observed chemical variability between the studied species and cultivars seems likely to results from the genetic variability.     

Continuous dark fermentative hydrogen production by mesophilic microflora: Principles and progress

Continuous, dark fermentative hydrogen production technology using mixed microflora at mesophilic temperatures may be suitable for commercial development. Clostridial-based cultures from natural sources have been widely used, but more information on the need for heat treatment of inocula and conditions leading to germination and sporulation are required. The amount of nutrients given in the literature vary widely. Hydrogen production is reported to proceed without methane production in the reactor in the pH range 4.5–6.7, with hydraulic retention times optimally between a few hours and 3 days depending on substrate. Higher substrate concentrations should be more energy-efficient but there are product inhibition limitations, for example from unionised butyric acid. Inhibition by H₂ can be reduced by stirring, sparging or extraction through membranes. Of the reactor types investigated, while granules have the best performance with soluble substrate, for particulate feedstock biofilm reactors or continuous stirred tank reactors may be most successful. A second stage is required to utilise the fermentation end products which, when cost-effective reactors are developed, may be photofermentation or microbial fuel cell technologies. Anaerobic digestion is a currently-available technology and the two-stage process is reported to give greater conversion efficiency than anaerobic digestion alone.     

In vitro approaches to estimate the effect of food processing on carotenoid bioavailability need thorough understanding of process induced microstructural changes

Carotenoids represent an example of micronutrients for which processing-induced food structure changes (e.g., matrix disruption) strongly influence their bioavailability. The available scientific information on this topic resulting from both in vivo and in vitro studies shows however the complexity of this problem. Although in vitro studies have been shown useful to better understand the relation between processing and carotenoid bioavailability, there is still conflicting information. To expand our current knowledge on this topic in order to allow rational design of food processing solutions resulting in products with maximal carotenoid accessibility and (bio)availability, it is suggested (i) to further evaluate and standardize in vitro models to be used as high throughput screening tools to determine the effect of extrinsic (process-related) and intrinsic (product-related) factors and (ii) to integrate food structure information as a useful approach for understanding and quantifying the bioavailability of carotenoids in foods. However, it will be necessary to validate the information obtained from these in vitro methods thoroughly against human studies (in vivo studies).