Distribution of organic pollutants and natural organic matter in urban storm water sediments as a function of grain size

The sealing of surfaces in urban areas makes storm water management compulsory. Contaminated particles carried from urban surfaces are deposited in infiltration ponds. This gives rise to a highly organic (11% DW) contaminated sedimentary layer (Zn:1.2 mg/g, Cd:15 mg/kg) that could threaten groundwater quality. During infiltration, particle arrangement impacts infiltrating water and sediment exchanges. In this context, understanding particle arrangement and leachable components is essential. This study investigates Organic Matter (OM) not only as a pollutant but also as a substrate and a structuring element. The leachable fraction was collected and grain size fractionation was performed. OM of sediments and isolated fractions were characterized by measuring organic carbon content, isolating aromatic hydrocarbons, saturated hydrocarbons and polar compounds after dichloromethane extraction, and by gas chromatography-mass spectrometry (GC-MS) molecular analyses. The organic compounds observed were petroleum byproducts (steranes and terpanes, unresolved complex mixture (UCM) and polycyclic aromatic hydrocarbons (PAH)), but plant and bacteria biomarkers were also found (phytol and derivatives, sterols). Leachable OM consisted of 6% of sediment OM (associated with particles >0.45 microm). This leachable OM is easily extractable by dichloromethane (96%) and contains fewer macromolecules than other fractions. Isolated grain size fractions showed dissimilarities (total organic carbon from 3.5 mg/g to 88.6 mg/g, extraction rate from 24 to 96%, aromatic hydrocarbon distribution) and similarities (proportions of aromatic and saturated hydrocarbons and polar compounds, molecular distribution of saturated hydrocarbons and polar compounds). The results suggest that organic macromolecules take part in the aggregation of sediments and prevent fine particles (<10 microm) from being leached. On the other hand, leachable particles (20 microm grain size mode) could carry low molecular weight organic molecules. The physical structure of the sediments and the leaching of particles containing contaminants are considerably affected by the presence of OM.     

Enhanced transmission of light through a circularly structured aperture

Using the differential theory of light diffraction by finite cylindrical objects, we study light transmission through a small circular aperture in a metallic screen with concentric corrugation around the nanohole. Poynting vector maps in the region below the screen show that the field enhancement compared with an unstructured aperture is obtained with corrugation lying on the entrance face of the screen. Corrugation on the exit face leads to a more directional radiation close to the normal to the screen. The spectral dependence of the transmission shows a sharp maximum linked with surface plasmon excitation.     

Crossdock truck scheduling with time windows: earliness,tardiness and storage policies

This article proposes to simultaneously plan inbound and outbound truck arrivals and departures in a cross-docking platform, as well as the internal pallet handling. The objective is to minimize both the total number of pallets put in storage and the dissatisfaction of the transportation providers, by creating a truck schedule as close as possible to the wished schedule they communicate in advance. The problem is modeled with an integer program tested on generated instances to assess its performance, especially regarding the computation time. The problem is proven to be np-hard in the strong sense. Since the execution takes too long to be used on a daily basis by platform managers, three heuristics are also proposed and tested. Two are based on integer programs solved sequentially, the third one is a tabu search in which the storage part of the objective function is evaluated by a maximum flow model in a graph. Numerical experiments show in which conditions each heuristic performs best, which can help choosing a solution method when confronted to a real-life problem.     

A French clinical corpus with comprehensive semantic annotations: development of the Medical Entity and Relation LIMSI annOtated Text corpus (MERLOT)

Quality annotated resources are essential for Natural Language Processing. The objective of this work is to present a corpus of clinical narratives in French annotated for linguistic, semantic and structural information, aimed at clinical information extraction. Six annotators contributed to the corpus annotation, using a comprehensive annotation scheme covering 21 entities, 11 attributes and 37 relations. All annotators trained on a small, common portion of the corpus before proceeding independently. An automatic tool was used to produce entity and attribute pre-annotations. About a tenth of the corpus was doubly annotated and annotation differences were resolved in consensus meetings. To ensure annotation consistency throughout the corpus, we devised harmonization tools to automatically identify annotation differences to be addressed to improve the overall corpus quality. The annotation project spanned over 24 months and resulted in a corpus comprising 500 documents (148,476 tokens) annotated with 44,740 entities and 26,478 relations. The average inter-annotator agreement is 0.793 F-measure for entities and 0.789 for relations. The performance of the pre-annotation tool for entities reached 0.814 F-measure when sufficient training data was available. The performance of our entity pre-annotation tool shows the value of the corpus to build and evaluate information extraction methods. In addition, we introduced harmonization methods that further improved the quality of annotations in the corpus.     

Anti-Platelet Effect Induced by Iron Oxide Nanoparticles: Correlation with Conformational Change in Fibrinogen

Iron oxide nanoparticles are developed for various biomedical applications, however, there is limited understanding regarding their effects and toxicity on blood components. The particles traveling in circulation inevitably interact with blood cells and plasma proteins and may interfere with hemostasis. Specifically, this study focuses on the influence of superparamagnetic iron oxide nanoparticles (SPIONs) coated with a biocompatible polymer, polyvinyl alcohol (PVA), on platelet function. Here, engineered SPIONs that are functionalized with various PVA coatings to provide these particles with different surface charges and polymer packing are described. These formulations are assessed for any interference with human platelet functions and coagulation, ex vivo. Positively charged SPIONs induce a significant change in platelet GPIIb-IIIa conformation, indicative of platelet activation at the dose of 500 µg mL⁻¹. Remarkably, engineered PVA(polyvinyl alcohol)-SPIONs all display a robust dose-dependent anti-platelet effect on platelet aggregation, regardless of the PVA charge and molecular weight. After assessing hypotheses involving SPION-induced steric hindrance in platelet–platelet bridging, as well as protein corona involvement in the antiplatelet effect, the study concludes that the presence of PVA-SPIONs induces fibrinogen conformational change, which correlates with the observed dose-dependent anti-platelet effect.     

Age-relevance of person characteristics: Persons' beliefs about developmental change across the lifespan.

The authors investigated normative beliefs about personality development. Young, middle-aged, and older adults indicated the age-relevance of 835 French adjectives by specifying person characteristics as typical for any age decade from 0 to 99 years. With this paradigm, the authors determined age-relevance (How typical is a characteristic for a given age decade?). Most characteristics were ascribed to young adulthood. The pattern differed across the lifespan, however, for positive and negative person characteristics as well as for physical, cognitive, and personal/expressive characteristics. Whereas the total number of ascribed positive characteristics peaked in young adulthood and declined thereafter, the number of ascribed negative person characteristics peaked during adolescence, remained fairly low during middle adulthood, and increased slightly in old age (70+ years). As a consequence, the most positive profile was ascribed to young olds (60 to 69 years), whereas the most negative personality profiles were ascribed to the oldest age groups (70+ years) and to adolescence (10 to 19 years). The negative profiles are primarily due to more negative physical characteristics ascribed to older adults and more negative cognitive characteristics ascribed to adolescence. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Correlation between saltiness perception and shear flow behaviour for viscous solutions

Salt plays a major role in the human diet and food as tastant, flavour enhancer, nutrient, preservative and structuring aid. While intake of salt is part of a healthy diet, the vast majority of people in the developed world consume salt at a level high enough to place them at risk of developing diet induced illnesses. Salt intake is predominantly from processed foods. In this study it has been investigated whether careful choice of the viscosity behaviour of food thickeners, as used in processed foods, is exploitable to enhance saltiness perception and therefore allows reducing the content of salt in processed foods without compromising flavour.     

New insights into the structure of hybrid κ-/μ-carrageenan and its alkaline conversion

Hybrid κ-/μ-carrageenan, water-extracted from Kappaphycus alvarezzi, was incubated with Pseudoalteromonas carrageenovora κ-carrageenase. The five most abundant hybrid κ-/μ-carrageenan oligosaccharides were purified and their structure was determined by NMR and mass spectrometry. Since the enzyme-resistant fraction was small, these five oligosaccharides were representative of the distribution of the μ-carrabiose moieties along the carrageenan chain. Three main distributions of μ-carrabiose were found: -μ-, -μ-μ- and -μ-μ-μ-. Interestingly, the chemical shifts of the anomeric proton and carbon were strongly influenced by the identity of the adjacent carrabiose, which explains the asymmetrical D6S-H1 NMR signal that we observed. Although μ-carrabiose chemical shifts are usually attributed to blocks of μ-carrabiose as expected in ideal μ-carrageenan, we demonstrate that they are in fact due to μ-carrabiose units positioned between κ-carrabiose units. Using NMR and chromatography to monitor the alkaline conversion of μ- to κ-carrabiose, we found that the μ-carrabiose distribution (-μ-, -μ-μ-, -μ-μ-μ-) did not influence the conversion rate.     

Coagulation of Concentrated Suspensions of Ultrafine Alumina Powders by pH Shift

Highly concentrated suspensions of ultrafine alumina powders are prepared using 2-phosphonobutane-1,2,4-tricarboxylic acid as dispersant. The coagulation of these suspensions is carried out at around 278 K by adding a blend of acetic anhydride plus ethylene glycol. Coagulation takes place through a pH shift because of a time-delayed hydration of the acetic anhydride. The coagulation kinetics are studied by viscosity measurements with respect to the temperature and composition of the coagulant blend. Finally, the method is used to produce complex 3D parts of large dimensions for bio-applications by direct coagulation casting and the fired bodies are characterized.