394 research outputs found

    Stilling basin optimization for a combined inlet-outlet sluice in the framework of the Sigmaplan

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    Within the framework of the so-called Actualised Sigmaplan, i.e. the masterplan to create a sustainable Schelde estuary, flood control areas (FCA) are setup in well-chosen polders along the tidal part of the river Scheldeand its tributaries. In some of these FCAs a semi-diurnal, controlled reduced tide (CRT) is introduced, by means of simple inlet and outlet sluices. Nowadays, it is preferred to combine in- let and outlet sluices in one single structure, in which the inlet culverts are situated on top of the outlet culverts. At inflow, energy is dissipated by means of a vertical drop and a stilling basin. In this paper, results are presented of a physical model study (scale 1:8) aiming at the optimization of the inlet configuration, i.e. the stilling basin, starting from the desktop design of the in- and outlet construction for FCACRT Bergenmeersen

    On hawser force criteria for navigation lock design: Case study of maritime locks in port of Antwerp

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    The first part of this paper offers a general reflection upon the issue of mooring line forces and ship behaviour during filling/emptying of (maritime) navigation locks. The philosophy behind the so-called hawser force criterion and the classical approach to deal with it in design studies, is described first. Secondly, some innovations in the definition, verification and validation of the design criteria are highlighted. In the second part of this paper, a case study is presented focusing on two maritime locks in the Port of Antwerp (Belgium): the Zandvliet lock (L x W = 500m x 57m) and the Berendrecht lock (L x W = 500m x 68m). To illustrate and comment upon the hawser force issues, results of scale modelling, in situ measurements and numerical modelling are discussed, in comparison to published hawser force criteria

    Four problems regarding representable functors

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    Let RR, SS be two rings, CC an RR-coring and RCM{}_{R}^C{\mathcal M} the category of left CC-comodules. The category Rep (RCM,SM){\bf Rep}\, ( {}_{R}^C{\mathcal M}, {}_{S}{\mathcal M} ) of all representable functors RCM→SM{}_{R}^C{\mathcal M} \to {}_{S}{\mathcal M} is shown to be equivalent to the opposite of the category RCMS{}_{R}^C{\mathcal M}_S. For UU an (S,R)(S,R)-bimodule we give necessary and sufficient conditions for the induction functor U⊗R−:RCM→SMU\otimes_R - : {}_{R}^C\mathcal{M} \to {}_{S}\mathcal{M} to be: a representable functor, an equivalence of categories, a separable or a Frobenius functor. The latter results generalize and unify the classical theorems of Morita for categories of modules over rings and the more recent theorems obtained by Brezinski, Caenepeel et al. for categories of comodules over corings.Comment: 16 pages, the second versio

    Gene regulation knowledge commons: community action takes care of DNA binding transcription factors

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    A large gap remains between the amount of knowledge in scientific literature and the fraction that gets curated into standardized databases, despite many curation initiatives. Yet the availability of comprehensive knowledge in databases is crucial for exploiting existing background knowledge, both for designing follow-up experiments and for interpreting new experimental data. Structured resources also underpin the computational integration and modeling of regulatory pathways, which further aids our understanding of regulatory dynamics. We argue how cooperation between the scientific community and professional curators can increase the capacity of capturing precise knowledge from literature. We demonstrate this with a project in which we mobilize biological domain experts who curate large amounts of DNA binding transcription factors, and show that they, although new to the field of curation, can make valuable contributions by harvesting reported knowledge from scientific papers. Such community curation can enhance the scientific epistemic process.Database URL: http://www.tfcheckpoint.org

    World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guideline for diagnosing anthelmintic resistance using the faecal egg count reduction test in ruminants, horses and swine

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    The faecal egg count reduction test (FECRT) remains the method of choice for establishing the efficacy of anthelmintic compounds in the field, including the diagnosis of anthelmintic resistance. We present a guideline for improving the standardization and performance of the FECRT that has four sections. In the first section, we address the major issues relevant to experimental design, choice of faecal egg count (FEC) method, statistical analysis, and interpretation of the FECRT results. In the second section, we make a series of general recommendations that are applicable across all animals addressed in this guideline. In the third section, we provide separate guidance details for cattle, small ruminants (sheep and goats), horses and pigs to address the issues that are specific to the different animal types. Finally, we provide overviews of the specific details required to conduct an FECRT for each of the different host species. To address the issues of statistical power vs. practicality, we also provide two separate options for each animal species; (i) a version designed to detect small changes in efficacy that is intended for use in scientific studies, and (ii) a less resource-intensive version intended for routine use by veterinarians and livestock owners to detect larger changes in efficacy. Compared to the previous FECRT recommendations, four important differences are noted. First, it is now generally recommended to perform the FECRT based on pre- and post-treatment FEC of the same animals (paired study design), rather than on post-treatment FEC of both treated and untreated (control) animals (unpaired study design). Second, instead of requiring a minimum mean FEC (expressed in eggs per gram (EPG)) of the group to be tested, the new requirement is for a minimum total number of eggs to be counted under the microscope (cumulative number of eggs counted before the application of a conversion factor). Third, we provide flexibility in the required size of the treatment group by presenting three separate options that depend on the (expected) number of eggs counted. Finally, these guidelines address all major livestock species, and the thresholds for defining reduced efficacy are adapted and aligned to host species, anthelmintic drug and parasite species. In conclusion, these new guidelines provide improved methodology and standardization of the FECRT for all major livestock species
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