426 research outputs found
Monitoring gastrointestinal nematode and liver fluke infections in Belgium by bulk tank milk ELISA: are we making progress in parasite control?
Parasitic infections with gastrointestinal (GI) nematodes and liver fluke (Fasciola hepatica) are common causes of reduced productivity in ruminants. In this paper, the results of a voluntary monitoring campaign on helminth infections in Belgian dairy herds are summarized and discussed. From 2009 until 2011, a bulk tank milk sample was collected in autumn and analyzed by antibody-detecting bulk tank milk ELISA's to assess the level of exposure to GI nematodes and liver fluke. The number of farms participating in the survey increased over the years, from 1216 in 2009 to 1731 in 2011. The proportion of herds with high exposure to GI nematodes varied significantly between the three years, from 67% in 2009 over 70% in 2010 to 63% in 2011. The proportion of herds with high exposure to F. hepatica remained stable around 30%. Important regional variations were observed with levels of exposure to GI nematodes increasing from the north to the south of the country, whereas the distribution of F. hepatica was concentrated in the province of West-Flanders, the southern part of East-Flanders, Hainaut and the northern part of Luxembourg. It can be concluded that, when compared with surveys conducted in surrounding countries, the levels of helminth exposure in Belgium can be considered high, especially for GI nematodes. If the aim is to decrease levels of exposure in the future, this will likely require control methods based on altered timings of treatment and changes in pasture management
Opportunities and challenges for modelling epidemiological and evolutionary dynamics in a multihost, multiparasite system: Zoonotic hybrid schistosomiasis in West Africa
Multihost multiparasite systems are evolutionarily and ecologically dynamic, which presents substantial trans‐disciplinary challenges for elucidating their epidemiology and designing appropriate control. Evidence for hybridizations and introgressions between parasite species is gathering, in part in line with improvements in molecular diagnostics and genome sequencing. One major system where this is becoming apparent is within the Genus Schistosoma, where schistosomiasis represents a disease of considerable medical and veterinary importance, the greatest burden of which occurs in sub‐Saharan Africa. Interspecific hybridizations and introgressions bring an increased level of complexity over and above that already inherent within multihost, multiparasite systems, also representing an additional source of genetic variation that can drive evolution. This has the potential for profound implications for the control of parasitic diseases, including, but not exclusive to, widening host range, increased transmission potential and altered responses to drug therapy. Here, we present the challenging case example of haematobium group Schistosoma spp. hybrids in West Africa, a system involving multiple interacting parasites and multiple definitive hosts, in a region where zoonotic reservoirs of schistosomiasis were not previously considered to be of importance. We consider how existing mathematical model frameworks for schistosome transmission could be expanded and adapted to zoonotic hybrid systems, exploring how such model frameworks can utilize molecular and epidemiological data, as well as the complexities and challenges this presents. We also highlight the opportunities and value such mathematical models could bring to this and a range of similar multihost, multi and cross‐hybridizing parasites systems in our changing world
Stilling basin optimization for a combined inlet-outlet sluice in the framework of the Sigmaplan
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
Polyparasitism with Schistosoma haematobium and soil-transmitted helmith infections among school children in Loum, Cameroon (vol 8, pg 975, 2003)
Design and Implementation of an Open Source Indexing Solution for a Large Set of Radiological Reports and Images
This paper hopes to share the insights we experienced during designing, building, and running an indexing solution for a large set of radiological reports and images in a production environment for more than 3 years. Several technical challenges were encountered and solved in the course of this project. One hundred four million words in 1.8 million radiological reports from 1989 to the present were indexed and became instantaneously searchable in a user-friendly fashion; the median query duration is only 31 ms. Currently, our highly tuned index holds 332,088 unique words in four languages. The indexing system is feature-rich and language-independent and allows for making complex queries. For research and training purposes it certainly is a valuable and convenient addition to our radiology informatics toolbox. Extended use of open-source technology dramatically reduced both implementation time and cost. All software we developed related to the indexing project has been made available to the open-source community covered by an unrestricted Berkeley Software Distribution-style license
On hawser force criteria for navigation lock design: Case study of maritime locks in port of Antwerp
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
WAAVP guideline for the evaluation of drug efficacy against non-coccidial gastro-intestinal protozoa in livestock and companion animals
Four problems regarding representable functors
Let , be two rings, an -coring and the
category of left -comodules. The category of all representable functors is shown to be equivalent to the opposite of the
category . For an -bimodule we give
necessary and sufficient conditions for the induction functor 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
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