695 research outputs found
Parameterization of dust emissions in the global atmospheric chemistry-climate model EMAC: impact of nudging and soil properties
Abstract. Airborne desert dust influences radiative transfer, atmospheric chemistry and dynamics, as well as nutrient transport and deposition. It directly and indirectly affects climate on regional and global scales. Two versions of a parameterization scheme to compute desert dust emissions are incorporated into the atmospheric chemistry general circulation model EMAC (ECHAM5/MESSy2.41 Atmospheric Chemistry). One uses a globally uniform soil particle size distribution, whereas the other explicitly accounts for different soil textures worldwide. We have tested these two versions and investigated the sensitivity to input parameters, using remote sensing data from the Aerosol Robotic Network (AERONET) and dust concentrations and deposition measurements from the AeroCom dust benchmark database (and others). The two versions are shown to produce similar atmospheric dust loads in the N-African region, while they deviate in the Asian, Middle Eastern and S-American regions. The dust outflow from Africa over the Atlantic Ocean is accurately simulated by both schemes, in magnitude, location and seasonality. Approximately 70% of the modelled annual deposition data and 70–75% of the modelled monthly aerosol optical depth (AOD) in the Atlantic Ocean stations lay in the range 0.5 to 2 times the observations for all simulations. The two versions have similar performance, even though the total annual source differs by ~50%, which underscores the importance of transport and deposition processes (being the same for both versions). Even though the explicit soil particle size distribution is considered more realistic, the simpler scheme appears to perform better in several locations. This paper discusses the differences between the two versions of the dust emission scheme, focusing on their limitations and strengths in describing the global dust cycle and suggests possible future improvements
Are Sensory-Motor Relationships Encoded ad hoc or by Default?: An ERP Study
Published: 03 May 2019In this event-related potentials study we tested whether sensory-motor relations
between concrete words are encoded by default or only under explicit ad hoc
instructions. In Exp. 1, participants were explicitly asked to encode sensory-motor
relations (e.g., “do the following objects fit in a pencil-cup?”), while other possible
semantic relations remained implicit. In Exp. 2, using the same materials other group of
participants were explicitly asked to encode semantic relations (e.g., “are the following
objects related to a pencil-cup?”), and the possible sensory-motor relations remained
implicit. The N400 component was sensitive to semantic relations (e.g., “desk” related to
“pencil-cup”) both under implicit (Exp. 1) and explicit instructions (Exp. 2). By contrast,
most sensory-motor relations (e.g., “pea” fitting in “pencil-cup”) were encoded ad hoc
under explicit instructions (Exp. 1). Interestingly some sensory-motor relations were also
encoded implicitly, but only when they corresponded to “functional” actions associated
with high-related objects (e.g., “eraser” fitting in “pencil-cup”) and occurring at a late
time window (500–650 ms; Exp. 2), suggesting that this type of sensory-motor relations
were encoding by default.This research was supported by the Spanish MINECO (Grant Nos. PSI2015-66277-R to MdV and PSI2016-79624-P to HB) and the European Regional Development Funds
The value of usage scenarios for thesaurus alignment in cultural heritage context
Thesaurus alignment is important for efficient access to heterogeneous Cultural Heritage data. Current ontology alignment techniques provide solutions, but with limited value in practice, because the requirements from usage scenarios are rarely taken in account. In this paper, we start from particular requirements for book re-indexing and investigate possible ways of developing, deploying and evaluating thesaurus alignment techniques in this context. We then compare different aspects of this scenario with others from a more general perspective
The species-specific regenerative effects of notochordal cell-conditioned medium on chondrocyte-like cells derived from degenerated human intervertebral discs
During intervertebral disc (IVD) maturation, the main cell type shifts from notochordal cells (NCs) to chondrocytelike cells (CLCs). NCs secrete factors with regenerative potential, making them an interesting focus for regenerative treatments. During initial development, these strategies preferably employ non-human donors due to easy availability of their NC-rich nucleus pulposus (NP) tissue. To increase the success of translating these strategies for clinical application, this study aimed to delineate whether NC-secreted factors of different species have a regenerative effect on human CLCs. Human, canine and porcine NC-rich NP tissue and NC-conditioned medium (NCCM) were analysed biochemically and histologically. Human CLC micro-aggregates from degenerated IVDs were cultured in human, canine or porcine NCCM. Collagen, glycosaminoglycan (GAG) and DNA content was determined and histology was performed. Canine and porcine NPs were richer in NCs than human NPs. Human NPs contained the highest collagen content, whereas the DNA and GAG content of canine NPs was significantly higher than that of human or porcine NPs. NCCM from all species significantly increased the DNA and GAG content of the human CLC micro-aggregates. Porcine and canine NCCM were significantly more potent than human NCCM in inducing GAG deposition, whereas only human NCCM induced collagen type II production. Secreted factors from human, canine and porcine NC-rich NPs exerted regenerative effects on human CLCs, indicating a cross-species effect. Bioactive compound(s) are present in NCCM of different species that may reverse human IVD degeneration, supporting further research into strategies based on NC-technology employing canine or porcine models for their translation into humans.</p
Interobserver and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography
BACKGROUND: Data regarding the inter- and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography are missing in the current literature. This study assessed the inter- and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography (CBCT). MATERIAL AND METHODS: In 107 patients, 130 salivary glands (65 parotid and 65 submandibular) with clinical signs of obstruction were assessed by four independent observers; 2 residents OMFS and 2 experienced OMFS. The observers analyzed the CBCT images and determined the absence or presence of one or more salivary stones in the affected gland. This procedure was repeated after three months. RESULTS: Interobserver agreements showed kappa values of 0.84 for the parotid gland, and 0.93 for the submandibular gland. Intraobserver agreements for the whole group reported kappa values between 0.83 - 0.95. There was no significant difference between residents and experienced OMFS. CONCLUSIONS: Due to the good inter- and intraobserver agreement, CBCT appears to be a reproducible imaging modality for detecting salivary stones in patients with signs and symptoms of obstructed parotid and submandibular glands. Key words:Salivary gland calculi, cone-beam computed tomography, observer variation
Faecal volatile organic compounds analysis using field asymmetric ion mobility spectrometry : non-invasive diagnostics in paediatric inflammatory bowel disease
Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), remains challenging to diagnose. Diagnostic work up carries a high burden, especially in paediatric patients, due to invasive endoscopic procedures. IBD is associated with alterations in intestinal microbiota composition. Faecal volatile organic compounds (VOCs) reflect gut microbiota composition. Aim of this study was to assess the diagnostic accuracy of faecal VOC profiling as non-invasive diagnostic biomarker for paediatric IBD
- …