554 research outputs found

    Interactive Problem Structuring with ICZM Stakeholders

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    Integrated Coastal Zone Management (ICZM) is struggling with a lack of science-management integration. Many computer systems, usually known as “decision support systems”, have been developed with the intention to make scientific knowledge about complex systems more accessible for coastal managers. These tools, allowing a multi-disciplinary approach with multi-criteria analyses, are designed for well-defined, structured problems. However, in practice stakeholder consensus on the problem structure is usually lacking. Aim of this paper is to explore the practical opportunities for the new so-called Quasta approach to structure complex problems in a group setting. This approach is based on a combination of Cognitive Mapping and Qualitative Probabilistic Networks. It comprehends a new type of computer system which is quite simple and flexible as well. The tool is tested in two workshops in which various coastal management issues were discussed. Evaluations of these workshops show that (1) this system helps stakeholders to make them aware of causal relationships, (2) it is useful for a qualitative exploration of scenarios, (3) it identifies the quantitative knowledge gaps of the problem being discussed and (4) the threshold for non technicians to use this tool is quite low.Integrated Coastal Zone Management, Problem Structuring, Stakeholder Participation, Cognitive Mapping, Interactive Policy Making

    The Dutch moral foundations stimulus database:A validation of standardized vignettes and images

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    Moral judgments are shaped by socialization and cultural heritage. Understanding how moral considerations vary across the globe requires the systematic development of moral stimuli for use in different cultures and languages. Focusing on Dutch populations, we adapted and validated two recent instruments for examining moral judgments: 1) the Moral Foundations Vignettes (MFVs) and 2) the Socio-Moral Image Database (SMID). We translated all 120 MFVs from English into Dutch and selected 120 images from SMID that primarily display moral, immoral, or neutral content. 586 crowd-workers from the Netherlands provided over 38,460 individual judgments for both stimuli sets on moral and affective dimensions. For both instruments, we find that moral judgments and relationships between the moral foundations and political orientation are similar to those reported in the US, Australia, and Brazil. We provide the validated MFV and SMID images, along with associated rating data here: https://osf.io/9gnza

    Patches in a side-by-side configuration: a description of the flow and deposition fields

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    In the last few decades, a lot of research attention has been paid to flow-vegetation interactions. Starting with the description of the flow field around uniform macrophyte stands, research has evolved more recently to the description of flow fields around individual, distinct patches. However, in the field, vegetation patches almost never occur in isolation. As such, patches will influence each other during their development and interacting, complex flow fields can be expected. In this study, two emergent patches of the same diameter (D = 22 cm) and a solid volume fraction of 10% were placed in a side-by-side configuration in a lab flume. The patches were built as an array of wooden cylinders, and the distance between the patches (gap width Delta) was varied between Delta = 0 and 14 cm. Flow measurements were performed by a 3D Vectrino Velocimeter (Nortek AS) at mid-depth of the flow. Deposition experiments of suspended solids were performed for selected gap widths. Directly behind each patch, the wake evolved in a manner identical to that of a single, isolated patch. On the centerline between the patches, the maximum velocity U-max was found to be independent of the gap width Delta. However, the length over which this maximum velocity persists, the potential core L-j, increased linearly as the gap width increased. After the merging of the wakes, the centerline velocity reaches a minimum value U-min. The minimum centerline velocity decreased in magnitude as the gap width decreased. The velocity pattern within the wake is reflected in the deposition patterns. An erosion zone occurs on the centerline between the patches, where the velocity is elevated. Deposition occurs in the low velocity zones directly behind each patch and also downstream of the patches, along the centerline between the patches at the point of local velocity minimum. This downstream deposition zone, a result of the interaction of neighbouring patch wakes, may facilitate the establishment of new vegetation, which may eventually inhibit flow between the upstream patches and facilitate patch merger

    High-salinity growth conditions promote tat-independent secretion of tat substrates in Bacillus subtilis

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    The Gram-positive bacterium Bacillus subtilis contains two Tat translocases, which can facilitate transport of folded proteins across the plasma membrane. Previous research has shown that Tat-dependent protein secretion in B. subtilis is a highly selective process and that heterologous proteins, such as the green fluorescent protein (GFP), are poor Tat substrates in this organism. Nevertheless, when expressed in Escherichia coli, both B. subtilis Tat translocases facilitated exclusively Tat-dependent export of folded GFP when the twin-arginine (RR) signal peptides of the E. coli AmiA, DmsA, or MdoD proteins were attached. Therefore, the present studies were aimed at determining whether the same RR signal peptide-GFP precursors would also be exported Tat dependently in B. subtilis. In addition, we investigated the secretion of GFP fused to the full-length YwbN protein, a strict Tat substrate in B. subtilis. Several investigated GFP fusion proteins were indeed secreted in B. subtilis, but this secretion was shown to be completely Tat independent. At high-salinity growth conditions, the Tat-independent secretion of GFP as directed by the RR signal peptides from the E. coli AmiA, DmsA, or MdoD proteins was significantly enhanced, and this effect was strongest in strains lacking the TatAy-TatCy translocase. This implies that high environmental salinity has a negative influence on the avoidance of Tat-independent secretion of AmiA-GFP, DmsA-GFP, and MdoD-GFP. We conclude that as-yet-unidentified control mechanisms reject the investigated GFP fusion proteins for translocation by the B. subtilis Tat machinery and, at the same time, set limits to their Tat-independent secretion, presumably via the Sec pathway

    A study on soil loss rate assessment of vegetation mat measures

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    The hydraulic stability of the high-water revetment with and without vegetation mat was tested in both laboratory-scale hydraulic experiments, as well as prototype-scale experiments. Experimental cases cover a wide range of cross-sectional average velocity (0.2-2.0 m/s), different slopes of the embankment, and two different types of soils. For each experimental condition, measurements of velocity field and scouring profile on the embankment were repeated for the cases with and without vegetation mat, respectively, to assess the efficiency of the vegetation mat in protecting the embankment. A dramatic reduction in soil loss rate was observed in the cases with the vegetation mat installed. The experimental results were recast in terms of Froude number and the soil loss rate appears to be proportional to the square of Froude number. Also a functional relationship between the soil loss rate and the cross-sectional average velocity was also deduced so that it could guide actual design practices of such high-water revetments. To the authors' best knowledge, the current study is the first to attempt to provide a practical design guideline. (C) 2016 International Association for Hydro-environment Engineering and Research, Asia Pacific Division. Published by Elsevier B.V. All rights reserved.OAIID:RECH_ACHV_DSTSH_NO:T201636125RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A080988CITE_RATE:1.429FILENAME:pub11_Han_etal_2016JHER.pdfDEPT_NM:걎섀환êČœêł”í•™ë¶€EMAIL:[email protected]_YN:YFILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/d2364169-3df0-4c7a-b814-21a91426dbc8/linkY

    Generation of bacteriophage-insensitive mutants of Streptococcus thermophilus using an antisense RNA CRISPR-Cas silencing approach

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    Predation of starter lactic acid bacteria such as Streptococcus thermophilus by bacteriophages is a persistent and costly problem in the dairy industry. CRISPR-mediated Bacteriophage Insensitive Mutants (BIMs), while straightforward to generate and verify, can quickly be overcome by mutant phages. The aim of this study was to develop a tool allowing the generation of derivatives of commercial S. thermophilus strains which are resistant to phage attack through a non-CRISPR-mediated mechanism, with the objective of generating BIMs exhibiting stable resistance against a range of isolated lytic S. thermophilus phages. To achieve this, standard BIM generation was complemented by the use of the wild-type (WT) strain which had been transformed with an antisense mRNA-generating plasmid (targeting a crucial CRISPR-associated [cas] gene], in order to facilitate the generation of non-CRISPR-mediated BIMs. Phage sensitivity assays suggest that non-CRISPR-mediated BIMs exhibit some advantages compared to CRISPR-mediated BIMs derived from the same strain.Importance: The outlined approach reveals the presence of a powerful host-imposed barrier for phage infection in S. thermophilus. Considering the detrimental economic consequences of phage infection in the dairy processing environment, the developed methodology has widespread applications, particularly where other methods may not be practical or effective in obtaining robust, phage-tolerant S. thermophilus starter strains
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