Spatial characterization of catchment dispersion mechanisms in an urban context

Previous studies have examined in-depth the dispersion mechanisms in natural catchments. In contrast, these dispersion mechanisms have been studied little in urban catchments, where artificial transport elements and morphological arrangements are expected to modify travel times and mobilize excess rainfall from spatially distributed impervious sites. This has the ability to modify the variance of the catchment's travel times and hence the total dispersion. This work quantifies the dispersion mechanisms in an urban catchment using the theory of transport by travel times as represented by the Urban Morpho-climatic Instantaneous Unit Hydrograph (U-McIUH) model. The U-McIUH computes travel times based on kinematic wave theory and accounts explicitly for the path heterogeneities and altered connectivity patterns characteristic of an urban drainage network. The analysis is illustrated using the Aubiniere urban catchment in France as a case study. We found that kinematic dispersion is dominant for small rainfall intensities, whereas geomorphologic dispersion becomes more dominant for larger intensities. The total dispersion scales with the drainage area in a power law fashion. The kinematic dispersion is dominant across spatial scales up to a threshold of approximately 2-3 km(2), after which the geomorphologic dispersion becomes more dominant. Overall, overland flow is responsible for most of the dispersion in the catchment, while conduits tend to counteract the increase of the geomorphologic dispersion with a negative kinematic dispersion. Further study with other catchments is needed to asses if the latter is a general feature of urban drainage networks. (C) 2014 Elsevier Ltd. All rights reserved

π‑Conjugated Heterotriangulene Macrocycles by Solution and Surface-supported Synthesis toward Honeycomb Networks

A comparative analysis between a solution and a surface-mediated synthesis of heterotriangulene macrocycles is reported. The results show a preferential formation of the π-conjugated macrocycles on surface due to two-dimensional confinement. The macrocycle prepared on a several hundred milligram scale by solution chemistry was characterized by single-crystal X-ray analysis and was furthermore extended toward next generation honeycomb species. Investigation of the photophysical and electronic properties together with the good thermal stability revealed the potential of <b>MC6</b> as hole-transport material for organic electronics

π‑Conjugated Heterotriangulene Macrocycles by Solution and Surface-supported Synthesis toward Honeycomb Networks

A comparative analysis between a solution and a surface-mediated synthesis of heterotriangulene macrocycles is reported. The results show a preferential formation of the π-conjugated macrocycles on surface due to two-dimensional confinement. The macrocycle prepared on a several hundred milligram scale by solution chemistry was characterized by single-crystal X-ray analysis and was furthermore extended toward next generation honeycomb species. Investigation of the photophysical and electronic properties together with the good thermal stability revealed the potential of <b>MC6</b> as hole-transport material for organic electronics

A single nucleotide polymorphism in the gene for GPR183 increases its surface expression on blood lymphocytes of patients with inflammatory bowel disease.

The single nucleotide polymorphism rs9557195 within the gene Epstein-Barr virus-induced G protein-coupled receptor 2 (EBI2) has been associated with increased risk for inflammatory bowel diseases (IBD). EBI2 mediates migration of intestinal immune cells and promotes colitis in animal models. Here we study EBI2 surface expression of immune cells and associations of rs9557195 with EBI2 expression and IBD disease course. We recruited 27 IBD patients (15 with ulcerative colitis (UC), 12 with Crohn's disease (CD)), and 8 healthy volunteers (HV). EBI2 expression was measured by fluorescence activated cell sorting in subtypes of peripheral blood mononuclear cells. We further analyzed IBD disease course in 2301 patients (1335 with CD and 966 with UC) of the Swiss IBD cohort study (SIBDCS). We found increased EBI2 expression in lymphocytes expressing chemokine receptors CCR6 or CCR9, implicated in IBD and on Th17 memory T cells. The EBI2 ligand 7α,25-dihydroxycholesterol and the CCR6 ligand CCL20 stimulated migration of memory T cells in an additive manner. Further, IBD patients with the CC allele of rs9557195 had higher EBI2 surface expression compared to individuals with the TT allele. SIBDC patients carrying the rs9557195-CC allele had higher psoriasis rates compared to individuals with the TT allele. We demonstrate increased EBI2 surface expression on T cells with a potential role in gut inflammation. A SNP of the EBI2 locus was associated with EBI2 surface expression and psoriasis rates in IBD patients. Our data suggest a pro-inflammatory role of EBI2 in IBD

A single nucleotide polymorphism in the gene for GPR183 increases its surface expression on blood lymphocytes of patients with inflammatory bowel disease

Background and purpose: Single nucleotide polymorphism rs9557195 within the gene of the G protein-coupled receptor Epstein-Barr virus-induced gene 2 (EBI2/GPR183) has been associated with increased risk for inflammatory bowel diseases (IBD). GPR183 mediates the migration of intestinal immune cells and promotes colitis in animal models. Here, we study GPR183 surface expression of immune cells and associations of rs9557195 with GPR183 expression and IBD disease course. Experimental approach: We recruited 27 IBD patients (15 with ulcerative colitis [UC] and 12 with Crohn's disease [CD]) and eight healthy volunteers (HV). GPR183 expression was measured by FACS in subtypes of peripheral blood mononuclear cells. We analysed IBD disease course in 2301 patients (1335 with CD and 966 with UC) of the Swiss IBD cohort study. Key results: We found increased GPR183 expression in lymphocytes expressing chemokine receptors CCR6 or CCR9, implicated in IBD and on Th17 memory T cells. The GPR183 ligand 7α,25-dihydroxycholesterol and the CCR6 ligand CCL20 stimulated migration of memory T cells in an additive manner. Further, IBD patients with the CC allele of rs9557195 had higher GPR183 surface expression compared to individuals with the TT allele. Swiss IBD cohort study patients carrying the rs9557195-CC allele had higher psoriasis rates compared to individuals with the TT allele. Conclusion and implications: We demonstrate increased GPR183 surface expression on T cells with a potential role in gut inflammation. An SNP of the GPR183 locus was associated with GPR183 surface expression and psoriasis rates in IBD patients. Our data suggest a pro-inflammatory role of GPR183 in IBD. Linked articles: This article is part of a themed issue on Oxysterols, Lifelong Health and Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.16/issuetoc. Keywords: FACS; GPR183/EBI2; IBD; SNP; UBAC2; psoriasis

Plant Core Environmental Stress Response Genes Are Systemically Coordinated during Abiotic Stresses

Hahn A, Kilian J, Mohrholz A, et al. Plant Core Environmental Stress Response Genes Are Systemically Coordinated during Abiotic Stresses. International journal of molecular sciences. 2013;14(4):7617-7641.Studying plant stress responses is an important issue in a world threatened by global warming. Unfortunately, comparative analyses are hampered by varying experimental setups. In contrast, the AtGenExpress abiotic stress experiment displays intercomparability. Importantly, six of the nine stresses (wounding, genotoxic, oxidative, UV-B light, osmotic and salt) can be examined for their capacity to generate systemic signals between the shoot and root, which might be essential to regain homeostasis in Arabidopsis thaliana. We classified the systemic responses into two groups: genes that are regulated in the non-treated tissue only are defined as type I responsive and, accordingly, genes that react in both tissues are termed type II responsive. Analysis of type I and II systemic responses suggest distinct functionalities, but also significant overlap between different stresses. Comparison with salicylic acid (SA) and methyl-jasmonate (MeJA) responsive genes implies that MeJA is involved in the systemic stress response. Certain genes are predominantly responding in only one of the categories, e.g., WRKY genes respond mainly non-systemically. Instead, genes of the plant core environmental stress response (PCESR), e.g., ZAT10, ZAT12, ERD9 or MES9, are part of different response types. Moreover, several PCESR genes switch between the categories in a stress-specific manner