A conceptual river model to support real-time flood control (Demer River, Belgium)

River engineeringFlow management and contro

Identification of uncertainty sources in distributed hydrological modelling: Case study of the Grote Nete catchment in Belgium

The quest for good practice in modelling merits thorough and sustained attention since good practice increases the credibility and impact of the information, and insight that modelling seeks to generate. This paper presents the findings of an evaluation whose goal was to understand the uncertainty in applying a distributed hydrological model to the Grote Nete catchment in Flanders, Belgium. Uncertainties were selected for investigation depending on how significantly they affected the model’s decision variables. A Fault Tree was used to determine various combinations of inputs, mathematical code, and human error failures that could result in a specified risk. A combination of forward and backward approaches was used in developing the Fault Tree. Eleven events were identified as contributing to the top event. A total of 7 gates were used to describe the Fault Tree. A critical path analysis was carried out for the events and established their rank or order of significance. Three measures of importance were applied, namely the F-Vesely, the Birnbaum, and the B-Proschan importance measures. Model development of distributed models involves considerable uncertainty. Many of these dependencies arise naturally and their correct evaluation is crucial to the accurate analysis of the modelling system reliability.Keywords: distributed hydrological models, Grote Nete, MIKE SHE, uncertaint

Voorkomen van gastrale helicobacters in speeksel en feces van honden en katten

Gastric Helicobacter species are present in the stomach of more than 50% of dogs and cats. These bacteria have also been associated with severe gastric pathologies in humans. The route of transmission between pets and from pets to humans remains unclear, but it has been suggested that direct contact might play a role. In order to determine whether transfer might occur through contact with saliva and feces, the presence of Helicobacter DNA was determined in oral swabs and feces of dogs and cats. In this study, 155 saliva samples and141 fecal samples were collected from 106 dogs and 58 cats. From 22 dogs, a gastric biopsy sample was also collected, aiming to investigate whether the same Helicobacter species found in saliva and/or feces could also be detected in the stomach of these animals. All samples were screened for the presence of DNA from gastric Helicobacter species associated with dogs and cats, using species-specific qPCRs and amplicon sequencing. In 43% of the dogs and 41% of the cats, one or more positive samples were found. Helicobacter DNA was detected in 29 % of the saliva samples, 37 % of the fecal samples and 41% of the gastric biopsies. Several dogs and cats were infected with more than one Helicobacter species. No clear correlation between the presence of a Helicobacter species in the stomach of dogs and the detection of this species in their saliva and/or feces was shown. Moreover, the present study did not allow to determine whether the detected Helicobacter DNA originated from viable Helicobacter bacteria, highlighting the need of additional studies in order to determine the importance of saliva and feces in transfer of these gastric Helicobacter species between animals and from animals to humans