Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

    Records 1 - 20 / 159

    • help
    • print

      Print search results

    • export

      Export search results

    Check title to add to marked list
    Microsphere-based multiplex technology for the simultaneous detection of food allergens
    Smits, N.G.E. ; Hoof, R.A. van; Peters, J. ; Koops, A.J. ; Bovee, T.F.H. ; Ginkel, L.A. van - \ 2019
    EU analytical performance criteria: time for a revision!
    Ginkel, Leen van - \ 2019
    Fostering oral presentation competence in higher education
    Ginkel, Stan van - \ 2019
    Wageningen University. Promotor(en): M. Mulder, co-promotor(en): H.J.A. Biemans; J.T.M. Gulikers. - Wageningen : Wageningen University - ISBN 9789463439633 - 172
    cum laude

    Presenting is considered as a core competence of the higher educated professional. However, it remains questionable how effective learning environments fostering presentation competence should be constructed. This thesis focuses on formulating evidence-based educational design principles. Further, research questions explore effective feedback processes within the context of realistic presentation skills courses. These studies verifies the potential impact of feedback sources, such as teachers, peers and the self, on developing students’ oral presentation competence. Besides studying the quality of differing feedback sources, Virtual Reality is studied as an alternative feedback mode encouraging students’ cognition, skills and attitudes towards presenting. The constructed VR-tool, based on the principles of this thesis, is already implemented in secondary education, higher education and the corporate sector.

    Fostering oral presentation competence through a virtual reality-based task for delivering feedback
    Ginkel, Stan van; Gulikers, Judith ; Biemans, Harm ; Noroozi, Omid ; Roozen, Mila ; Bos, Tom ; Tilborg, Richard van; Halteren, Melanie van; Mulder, Martin - \ 2019
    Computers and Education 134 (2019). - ISSN 0360-1315 - p. 78 - 97.
    Formative assessment - Higher education - Oral presentation competence - Virtual reality

    While previous studies have stressed the importance of feedback delivered by experts, it is unclear whether students’ oral presentation competence can be fostered through innovative technology for delivering feedback. This experimental study examined the effectiveness of a virtual reality-based task, in which first-year undergraduate students practiced their presentation in a virtual environment and received feedback produced by the system, on their presentation competence components (i.e. cognition, behaviour and attitudes towards presenting). The effects were compared with a control condition, which was a face-to-face presentation task with expert feedback. The students’ performance was measured using pre- and post-test multiple-choice tests, validated rubrics, and self-evaluation instruments. Results revealed significant improvements from pre-test to post-test in all three presentation competence components, without a difference between the conditions. Furthermore, the self-evaluation tests showed that students who presented in virtual reality were appreciative of the detailed and analytical feedback they received. Because of sample size limitations, the effects found could not be generalised. Therefore, future research on a larger sample is needed to examine population effects. Follow-up studies should focus on the extent to which virtual reality-based tasks can encourage self-regulation skills for the effective and efficient integration of these tasks in presentation courses.

    Food and feed safety : Cases and approaches to identify the responsible toxins and toxicants
    Gerssen, Arjen ; Bovee, Toine H.F. ; Ginkel, Leendert A. van; Iersel, Marlou L.P.S. van; Hoogenboom, Ron L.A.P. - \ 2019
    Food Control 98 (2019). - ISSN 0956-7135 - p. 9 - 18.
    Effect directed analysis - Feed and food safety - Identification strategy - In-vitro bioassays - Intoxications

    There are food and feed safety monitoring programs to protect consumers. These programs however, are strongly focused on known and regulated substances. New or unexpected substances that might be of risk for consumers will thus escape routine controls. These risks are therefore mainly discovered by human or animal intoxications. All kind of analytical chemical methods, in-vitro bioassays, tracking, and chain analysis are then used to reveal the substance(s) responsible for the intoxication. Only in a few occasions (new) risks were revealed in time by analytical chemical methods or cell based in-vitro bioassays. This paper describes some relevant food and feed safety cases and how the causative substances were identified. This overview strongly indicates that more intense monitoring, including the use of cell based effect bioassays, can reduce the number of intoxications. Moreover, registration and follow-up actions should be arranged in a better way, for example by sharing information within the scientific communities or by establishing a national contact point. In addition, a strategy based on broad screening and bioassay directed identification with liquid chromatography high resolution mass spectrometry is proposed to prevent intoxications and identify toxin and toxicants relevant for food and feed safety.

    Comprehensive two-dimensional LC QTOF MS for residue analysis of sulfonamides, beta-agonists and steroids
    Blokland, M.H. ; Zoontjes, P.W. ; Ginkel, L.A. van; Schans, M.G.M. van de; Sterk, S.S. ; Bovee, T.F.H. - \ 2018
    True untargeted workflow for identification of antimicrobial compounds in animal feed using bioassay-directed screening in combination with liquid chromatography-high resolution mass spectrometry
    Wegh, R.S. ; Berendsen, B.J.A. ; Driessen-van Lankveld, W.D.M. ; Pikkemaat, M.G. ; Zuidema, T. ; Ginkel, L.A. van - \ 2018
    National Reference Laboratories RIKILT : annual report 2017
    Leeuwen, S.P.J. van; Mol, J.G.J. ; Lee, M.K. van der; Gerssen, A. ; Lasaroms, J.J.P. ; Sterk, S.S. ; Raamsdonk, L. aan; Jong, J. de; Scholtens, I.M.J. ; Alewijn, A. ; Silletti, E. ; Ginkel, L. van; Noordam, M.Y. ; Meijer, N. - \ 2018
    Wageningen : RIKILT Wageningen University & Research (RIKILT-report 2018.009) - 51
    Students’ online argumentative peer feedback, essay writing, and content learning : does gender matter?
    Noroozi, Omid ; Hatami, Javad ; Bayat, Arash ; Ginkel, Stan van; Biemans, Harm J.A. ; Mulder, Martin - \ 2018
    Interactive Learning Environments (2018). - ISSN 1049-4820 - 16 p.
    Argumentative essay - gender - learning - online peer feedback - writing

    Whilst the importance of online peer feedback and writing argumentative essays for students in higher education is unquestionable, there is a need for further research into whether and the extent to which female and male students differ with regard to their argumentative feedback, essay writing, and content learning in online settings. The current study used a pre-test, post-test design to explore the extent to which female and male students differ regarding their argumentative feedback quality, essay writing and content learning in an online environment. Participants were 201 BSc biotechnology students who wrote an argumentative essay, engaged in argumentative peer feedback with learning partners in the form of triads and finally revised their original argumentative essay. The findings revealed differences between females and males in terms of the quality of their argumentative feedback. Female students provided higher-quality argumentative feedback than male students. Although all students improved their argumentative essay quality and also knowledge content from pre-test to post-test, these improvements were not significantly different between females and males. Explanations for these findings and recommendations are provided.

    INNOVA Ezine 1 – Nijmegen, the EU Green Capital 2018 and Room for the River Waal
    Timmermans, W. ; Jong, F. de; Ginkel, M. van; Martinez, G. ; Bruijn, D. de; Harsema, H. - \ 2018
    Wageningen : Blauwdruk
    The Dutch city of Nijmegen is becoming well-known because of its planning approach that combines large scale climate adaptation measures with a strong emphasis on spatial quality. Nijmegen is situated along the Waal river, one of Europe’s largest transport and ecological corridors. More than 250M euro has been spent on a new bypass of the Waal, called the Mirror Waal, one of the major urban examples of the Dutch Room for the River project. This e-zine shows the Mirror Waal project. From awareness of upcoming flooding risks, via complex planning and design efforts into the final result, including innovative ecological engineering, new sport activities and spontaneous festivals. The e-zine is presented by the INNOVA project. It is the first e-zine out of ten. INNOVA is a research project aiming to facilitate the use of climate data and projections, scientifically known as climate services, in adaptation efforts by urban governments. The project focuses on three European cities, and a small island state. These are: Kiel Bay in Germany, Nijmegen in The Netherlands, Valencia in Spain, and finally, the French West-Indies Islands of Guadeloupe & Martinique.
    Multiclass screening in urine by comprehensive two-dimensional liquid chromatography time of flight mass spectrometry for residues of sulphonamides, beta-agonists and steroids
    Blokland, M.H. ; Zoontjes, P.W. ; Ginkel, L.A. van; Schans, M.G.M. van de; Sterk, S.S. ; Bovee, T.F.H. - \ 2018
    Food Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment 35 (2018)9. - ISSN 1944-0049 - p. 1703 - 1715.
    Antibiotics - comprehensive 2D-LC - growth promoters - LC x LC - mass spectrometry - residues

    Nowadays routine residue monitoring involves the analysis of many compounds from different classes, mainly in urine. In the past two decades, developments heavily focused on the use of mass spectrometers (MS) and faster and more sensitive MS detectors have reached the market. However, chromatographic separation (CS) was rather ignored and the cognate developments in CS were not in line. As a result, residue analysis did not improve to the extent anticipated. CS by LC x LC is a promising technique and will enable a further increase in the range of compounds and compound classes that can be detected in a single run. In the present study, a self-built LC x LC system, using a 10 port valve, was connected to a single quadrupole MS with electrospray interface. Standards containing a mixture of sulphonamides, β-agonists and (steroid) hormones, 53 compounds, in total, were analysed. Results demonstrated that these compounds were well separated and could be detected at low levels in urine, i.e. limit of detection (LOD) from 1 µg L−1 for most β-agonists to 10 µg L−1 for some sulphonamides and most hormones. To enhance the sensitivity, optimisation was performed on an advanced commercial LC x LC system connected to a full scan accurate MS. This ultimately resulted in a fast high throughput untargeted method, including a simple sample clean-up in a 96-well format, for the analysis of urine samples.

    Revision of the National Residue Control Plan - application on the red meat supply chain
    Asselt, E.D. van; Noordam, M.Y. ; Pikkemaat, M.G. ; Ginkel, L.A. van; Sterk, S.S. - \ 2018
    Wageningen : RIKILT Wageningen University & Research (RIKILT report 2018.003) - 61
    A Fast Quantitative Multi-analyte Method for Growth Promoters in Bovine Meat Using Bead-Disruption, 96-well SPE Clean-up and Narrow-Bore UHPLC-MS/MS Analysis
    Tricht, Frederike van; Essers, Martien ; Groot, Maria ; Sterk, Saskia ; Blokland, Marco ; Ginkel, Leen van - \ 2018
    Food Analytical Methods 11 (2018)8. - ISSN 1936-9751 - p. 2206 - 2217.
    96-wells SPE - Bead-disruption - Bovine meat - Growth promoters - Multi-analyte analysis - UHPLC-MS/MS
    A new method for detecting low levels of growth promoters in bovine meat was developed with the following goal: easy, fast and sensitive analysis of a wide range of compounds, with reduced consumption of chemicals and disposables. Several classes of growth promoters were included, i.e. resorcylic acid lactones (RALs) and steroids, the latter including corticosteroids and gestagens. For sample treatment, 0.5 g of homogenised bovine meat was simultaneously disrupted and extracted in a bead-ruptor machine. The organic extraction solvent was further processed by solid-phase extraction (SPE) clean-up using 96-Well Oasis® HLB Plates. Six SPE washing steps were applied to remove matrix compounds after which the growth promoters were eluted and analysed using UHPLC-MS/MS. To achieve lower detection levels and to reduce LC-solvent consumption, a narrow-bore column with an internal diameter of 1 mm was used, instead of the conventional 2.1 mm. During analysis, the mass spectrometer was operated in negative and positive ionisation mode (ion switching). The newly developed method was validated according to the Commission Decision 2002/657. The results demonstrate that the method meets the criteria as established in this Commission Decision. The precision of the method for exogenous steroids varies between 85 and 115%, the CCα for the compounds ranges from 0.1–0.9 μg kg−1 and the expanded measurement uncertainty was lower than 36%. Compared to our current in-house methods with analysis times of 2 days for a maximum of 24 samples, the new method offers improved sample throughput (96 samples in less than 24 h) and lower detection limits.
    Single-molecule protein sequencing through fingerprinting: computational assessment
    Yao, Y. ; Docter, M.W. ; Ginkel, H.G.T.M. van; Ridder, D. de; Joo, C. - \ 2018
    Delft University of Technology
    computational biophysics - proteomics - single-molecule biophysics
    Proteins are vital in all biological systems as they constitute the main structural and functional components of cells. Recent advances in mass spectrometry have brought the promise of complete proteomics by helping draft the human proteome. Yet, this commonly used protein sequencing technique has fundamental limitations in sensitivity. Here we propose a method for single-molecule (SM) protein sequencing. A major challenge lies in the fact that proteins are composed of 20 different amino acids, which demands 20 molecular reporters. We computationally demonstrate that it suffices to measure only two types of amino acids to identify proteins and suggest an experimental scheme using SM fluorescence. When achieved, this highly sensitive approach will result in a paradigm shift in proteomics, with major impact in the biological and medical sciences.
    Applicability of an innovative steroid-profiling method to determine synthetic growth promoter abuse in cattle
    Blokland, M.H. ; Tricht, E.F. van; Ginkel, L.A. van; Sterk, S.S. - \ 2017
    Journal of Steroid Biochemistry and Molecular Biology 174 (2017). - ISSN 0960-0760 - p. 265 - 275.
    A robust LC–MS/MS method was developed to quantify a large number of phase I and phase II steroids in urine. The decision limit is for most compounds lower than 1 ng ml−1 with a measurement uncertainty smaller than 30%. The method is fully validated and was applied to assess the influence of administered synthetic steroids and beta-agonists on the steroidogenesis. From three animal experiments, clenbuterol, diethylstilbestrol and stanozolol, the steroid profiles in urine of bovine animals were compared before and after treatment. It was demonstrated that the steroid profiles were altered due to these treatments. A predictive multivariate model was built to identify deviations from normal population steroid profiles. The abuse of synthetic steroids can be detected in urine samples from bovine animals using this model. The samples from the animal experiments were randomly analysed using this method and predictive model. It was shown that these samples were predicted correctly in the exogenous steroids group.
    Non-targeted workflow for identification of antimicrobial compounds in animal feed using bioassay-directed screening in combination with liquid chromatography-high resolution mass spectrometry
    Wegh, Robin S. ; Berendsen, Bjorn J.A. ; Driessen-Van Lankveld, Wilma D.M. ; Pikkemaat, Mariël G. ; Zuidema, Tina ; Ginkel, Leen A. Van - \ 2017
    Food Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment 34 (2017)11. - ISSN 1944-0049 - p. 1935 - 1947.
    animal feed - antibiotics - Antimicrobials - bioassay - LC-MS
    A non-targeted workflow is reported for the isolation and identification of antimicrobial active compounds using bioassay-directed screening and LC coupled to high-resolution MS. Suspect samples are extracted using a generic protocol and fractionated using two different LC conditions (A and B). The behaviour of the bioactive compound under these different conditions yields information about the physicochemical properties of the compound and introduces variations in co-eluting compounds in the fractions, which is essential for peak picking and identification. The fractions containing the active compound(s) obtained with conditions A and B are selected using a microbiological effect-based bioassay. The selected bioactive fractions from A and B are analysed using LC combined with high-resolution MS. Selection of relevant signals is automatically carried out by selecting all signals present in both bioactive fractions A and B, yielding tremendous data reduction. The method was assessed using two spiked feed samples and subsequently applied to two feed samples containing an unidentified compound showing microbial growth inhibition. In all cases, the identity of the compound causing microbiological inhibition was successfully confirmed.
    National Reference Laboratories RIKILT Wageningen University & Research : annual report 2016
    Leeuwen, S.P.J. van; Mol, J.G.J. ; Lee, M.K. van der; Gerssen, A. ; Lasaroms, J.J.P. ; Sterk, S.S. ; Raamsdonk, L.W.D. van; Jong, J. de; Scholtens-Toma, I.M.J. ; Alewijn, M. ; Weesepoel, Y.J.A. ; Ginkel, L.A. van; Meijer, Nathan ; Noordam, M.Y. - \ 2017
    Wageningen : RIKILT Wageningen University & Research (RIKILT Report 2017.007) - 49
    reference standards - laboratories - food legislation - europe - annual reports - food safety - food quality - feeding standards - referentienormen - laboratoria - voedingsmiddelenwetgeving - europa - jaarverslagen - voedselveiligheid - voedselkwaliteit - voedingsnormen
    National Reference Laboratories (NRLs) are part of the system responsible for the control and enforcement of EU food and feed law. RIKILT Wageningen University & Research has been designated as the NRL for twelve subjects. The tasks of a NRL depend on its research field. This report gives an overview of the activities performed by all of RIKILT's NRLs in 2016.
    Evaluation of a loop-mediated isothermal amplification (LAMP) method for rapid on-site detection of horse meat
    Aartse, Aafke ; Scholtens-Toma, Ingrid ; A, Hans J.G. van der; Boersma-Greve, Monique M. ; Prins, Theo W. ; Ginkel, Leen A. van; Kok, Esther J. ; Bovee, Toine F.H. - \ 2017
    Food Control 81 (2017). - ISSN 0956-7135 - p. 9 - 15.
    Horse meat - Loop-mediated isothermal amplification (LAMP) - On-site detection - qPCR - Rapid method

    Detection of horse DNA by loop-mediated isothermal amplification (LAMP) seems one of the most promising methods to meet the criteria of fast, robust, cost efficient, specific, and sensitive on-site detection. In the present study an assessment of the specificity and sensitivity of the LAMP horse screening assay was made and outcomes were compared with the EURL-AP (European Union Reference laboratory for Animal Proteins in feeding stuffs) qPCR method. The specificity was tested with DNA samples from seven other species. The sensitivity of the LAMP assay was subsequently challenged with different percentages of horse DNA in cattle DNA and different percentages of horse meat in cattle meat. Both qPCR and LAMP were able to reliably detect horse DNA or meat below 0.1%, but LAMP was able to do so in less than 30 min. The DNA of other species did not result in a response in the LAMP horse assay. These features show that the LAMP method is fast, specific, and sensitive. Next, 69 processed meat samples were screened for the presence of horse DNA. The results showed that the LAMP horse assay, combined with a simple and fast on-site DNA extraction method, results in similar outcomes as the EURL-AP qPCR method and is thus a promising screening assay to be used outside the laboratory. Only samples that are screened on-site as suspect in the LAMP horse assay, need to be brought to the laboratory for confirmation with the more laborious EURL-AP qPCR reference method.

    Assessing oral presentation performance : Designing a rubric and testing its validity with an expert group
    Ginkel, Stan van; Laurentzen, Ramona ; Mulder, Martin ; Mononen, Asko ; Kyttä, Janika ; Kortelainen, Mika J. - \ 2017
    Journal of Applied Research in Higher Education 9 (2017)3. - ISSN 2050-7003 - p. 474 - 486.
    Assessment - Feedback - Higher education - Oral presentation competence - Rubrics

    Purpose: The purpose of this paper is to design a rubric instrument for assessing oral presentation performance in higher education and to test its validity with an expert group. Design/methodology/approach: This study, using mixed methods, focusses on: designing a rubric by identifying assessment instruments in previous presentation research and implementing essential design characteristics in a preliminary developed rubric; and testing the validity of the constructed instrument with an expert group of higher educational professionals (n=38). Findings: The result of this study is a validated rubric instrument consisting of 11 presentation criteria, their related levels in performance, and a five-point scoring scale. These adopted criteria correspond to the widely accepted main criteria for presentations, in both literature and educational practice, regarding aspects as content of the presentation, structure of the presentation, interaction with the audience and presentation delivery. Practical implications: Implications for the use of the rubric instrument in educational practice refer to the extent to which the identified criteria should be adapted to the requirements of presenting in a certain domain and whether the amount and complexity of the information in the rubric, as criteria, levels and scales, can be used in an adequate manner within formative assessment processes. Originality/value: This instrument offers the opportunity to formatively assess students’ oral presentation performance, since rubrics explicate criteria and expectations. Furthermore, such an instrument also facilitates feedback and self-assessment processes. Finally, the rubric, resulting from this study, could be used in future quasi-experimental studies to measure students’ development in presentation performance in a pre-and post-test situation.

    Read-across of ready biodegradability based on the substrate specificity of N-alkyl polypropylene polyamine-degrading microorganisms
    Geerts, R. ; Ginkel, C.G. van; Plugge, C.M. - \ 2017
    SAR and QSAR in Environmental Research 28 (2017)4. - ISSN 1062-936X - p. 311 - 323.
    bioavailability - N-alkyl polypropylene polyamine - read-across - ready biodegradability - substrate specificity
    The biodegradation of N-alkyl polypropylene polyamines (NAPPs) was studied using pure and mixed cultures to enable read-across of ready biodegradability test results. Two Pseudomonas spp. were isolated from activated sludge with N-oleyl alkyl propylene diamine and N-coco alkyl dipropylene triamine, respectively. Both strains utilized all NAPPs tested as the sole source of carbon, nitrogen and energy for growth. Mineralization of NAPPs was independent of the alkyl chain length and the size of the polyamine moiety. NAPPs degraded in closed bottle tests (CBTs) using both river water and activated sludge. However, ready biodegradability of NAPPs with alkyl chain lengths of 16–18 carbon atoms and polyamine moieties with three and four nitrogen atoms could not be demonstrated. Biodegradation in the CBT was hampered by their limited bioavailability, making assessment of the true ready biodegradability of these highly adsorptive surfactants impossible. All NAPPs are therefore classified as readily biodegradable through read-across. Read-across is justified by the broad substrate specificity of NAPP-degrading microorganisms, their omnipresence and the mineralization of NAPPs.
    Check title to add to marked list
    << previous | next >>

    Show 20 50 100 records per page

    Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.