Staff Publications

Staff Publications

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    '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.

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    Antimicrobial use and farmers' attitude toward mastitis treatment on dairy farms with automatic or conventional milking systems
    Deng, Z. ; Lam, T.J.G.M. ; Hogeveen, H. ; Spaninks, M. ; Heij, N. ; Postema, M. ; Werven, T. van; Koop, G. - \ 2020
    Journal of Dairy Science 103 (2020)8. - ISSN 0022-0302 - p. 7302 - 7314.
    antimicrobial usage - attitude - automatic milking system - udder health

    Mastitis is one of the major causes for antimicrobial use on dairy cattle farms. On farms with an automatic milking system (AMS), diagnostics differ from those with a conventional milking system (CMS), with potentially a different attitude toward mastitis treatment. This may result in differences in antimicrobial usage (AMU) between these 2 types of farms. The aims of this study were (1) to compare AMU between AMS and CMS farms, (2) to identify variables associated with AMU in both types of herds, and (3) to describe the distribution of mastitis-causing pathogens and their antimicrobial resistance patterns. Data on AMU was collected for 42 AMS and 254 CMS farms in the Netherlands and was expressed as animal-defined daily dose (ADDD). The ADDD variables were total usage (ADDDTOTAL), intramammary usage during lactation (ADDDIMM), usage for dry cow therapy (ADDDDCT), and usage by injection (ADDDINJ). Eighteen AMS farms and 24 CMS farms participated in a survey on factors potentially related to AMU. These farmers collected 5 quarter milk samples from quarters with clinical mastitis or high somatic cell count, which were subjected to bacteriological culture and antimicrobial susceptibility testing. In addition, routinely collected udder health data of these farms were used in the analysis. Nonlinear principal component analysis (NLPCA) was used to explore associations between AMU, udder health, and questionnaire variables. The ADDDTOTAL and ADDDDCT were comparable between AMS and CMS farms, whereas ADDDIMM tended to be lower and ADDDINJ higher on AMS farms than on CMS farms. The NLPCA yielded 3 principal components (PC) that explained 48% of the variation in all these variables. The AMS farms were not distinguished from CMS farms in the principal component space. The 3 PC represented different aspects of udder health, ADDDTOTAL, and treatment strategy. Differences in treatment strategy were unrelated to total antimicrobial usage or overall udder health. The distribution of mastitis-causing pathogens and their antimicrobial resistance were comparable between AMS and CMS farms. In conclusion, our study shows that AMU on AMS farms was similar to that of CMS farms, but AMS farmers tend to apply more injectable and fewer intramammary treatments during lactation than CMS farmers. Across both farm types, farmers' attitudes toward udder health in general and toward mastitis treatment are associated with AMU.

    H7N9 influenza split vaccine with SWE oil-in-water adjuvant greatly enhances cross-reactive humoral immunity and protection against severe pneumonia in ferrets
    Jonge, Jørgen de; Dijken, Harry van; Heij, Femke de; Spijkers, Sanne ; Mouthaan, Justin ; Jong, Rineke de; Roholl, Paul ; Adami, Eduardo Alfredo ; Akamatsu, Milena Apetito ; Ho, Paulo Lee ; Brunner, Livia ; Collin, Nicolas ; Friede, Martin ; Ferreira, José A. ; Luytjes, Willem - \ 2020
    Vaccines 5 (2020)1. - ISSN 2076-393X

    Until universal influenza vaccines become available, pandemic preparedness should include developing classical vaccines against potential pandemic influenza subtypes. We here show that addition of SWE adjuvant, a squalene-in-water emulsion, to H7N9 split influenza vaccine clearly enhanced functional antibody responses in ferrets. These were cross-reactive against H7N9 strains from different lineages and newly emerged H7N9 variants. Both vaccine formulations protected in almost all cases against severe pneumonia induced by intratracheal infection of ferrets with H7N9 influenza; however, the SWE adjuvant enhanced protection against virus replication and disease. Correlation analysis and curve fitting showed that both VN- and NI-titers were better predictors for protection than HI-titers. Moreover, we show that novel algorithms can assist in better interpretation of large data sets generated in preclinical studies. Cluster analysis showed that the adjuvanted vaccine results in robust immunity and protection, whereas the response to the non-adjuvanted vaccine is heterogeneous, such that the protection balance may be more easily tipped toward severe disease. Finally, cluster analysis indicated that the dose-sparing capacity of the adjuvant is at least a factor six, which greatly increases vaccine availability in a pandemic situation.

    Exploring the floristic diversity of tropical Africa
    Sosef, Marc S.M. ; Dauby, Gilles ; Blach-Overgaard, Anne ; Burgt, Xander van der; Catarino, Luís ; Damen, Theo ; Deblauwe, Vincent ; Dessein, Steven ; Dransfield, John ; Droissart, Vincent ; Duarte, Maria Cristina ; Engledow, Henry ; Fadeur, Geoffrey ; Figueira, Rui ; Gereau, Roy E. ; Hardy, Olivier J. ; Harris, David J. ; Heij, Janneke de; Janssens, Steven ; Klomberg, Yannick ; Ley, Alexandra C. ; Mackinder, Barbara A. ; Meerts, Pierre ; Poel, Jeike L. van de; Sonké, Bonaventure ; Stévart, Tariq ; Stoffelen, Piet ; Svenning, Jens Christian ; Sepulchre, Pierre ; Zaiss, Rainer ; Wieringa, Jan J. ; Couvreur, Thomas L.P. - \ 2017
    BMC Biology 15 (2017)1. - ISSN 1741-7007
    Botanical exploration - Digitization - Floristic patterns - Herbarium specimens - Plant growth form - Species richness - Tropical forests
    Background: Understanding the patterns of biodiversity distribution and what influences them is a fundamental pre-requisite for effective conservation and sustainable utilisation of biodiversity. Such knowledge is increasingly urgent as biodiversity responds to the ongoing effects of global climate change. Nowhere is this more acute than in species-rich tropical Africa, where so little is known about plant diversity and its distribution. In this paper, we use RAINBIO - one of the largest mega-databases of tropical African vascular plant species distributions ever compiled - to address questions about plant and growth form diversity across tropical Africa. Results: The filtered RAINBIO dataset contains 609,776 georeferenced records representing 22,577 species. Growth form data are recorded for 97% of all species. Records are well distributed, but heterogeneous across the continent. Overall, tropical Africa remains poorly sampled. When using sampling units (SU) of 0.5°, just 21 reach appropriate collection density and sampling completeness, and the average number of records per species per SU is only 1.84. Species richness (observed and estimated) and endemism figures per country are provided. Benin, Cameroon, Gabon, Ivory Coast and Liberia appear as the botanically best-explored countries, but none are optimally explored. Forests in the region contain 15,387 vascular plant species, of which 3013 are trees, representing 5-7% of the estimated world's tropical tree flora. The central African forests have the highest endemism rate across Africa, with approximately 30% of species being endemic. Conclusions: The botanical exploration of tropical Africa is far from complete, underlining the need for intensified inventories and digitization. We propose priority target areas for future sampling efforts, mainly focused on Tanzania, Atlantic Central Africa and West Africa. The observed number of tree species for African forests is smaller than those estimated from global tree data, suggesting that a significant number of species are yet to be discovered. Our data provide a solid basis for a more sustainable management and improved conservation of tropical Africa's unique flora, and is important for achieving Objective 1 of the Global Strategy for Plant Conservation 2011-2020. In turn, RAINBIO provides a solid basis for a more sustainable management and improved conservation of tropical Africa's unique flora.
    RAINBIO : A mega-database of tropical African vascular plants distributions
    Dauby, Gilles ; Zaiss, Rainer ; Blach-Overgaard, Anne ; Catarino, Luís ; Damen, T.H.J. ; Deblauwe, Vincent ; Dessein, Steven ; Dransfield, John ; Droissart, Vincent ; Duarte, Maria Cristina ; Engledow, Henry ; Fadeur, Geoffrey ; Figueira, Rui ; Gereau, Roy E. ; Hardy, Olivier J. ; Harris, David J. ; Heij, Janneke De; Janssens, Steven ; Klomberg, Yannick ; Ley, Alexandra C. ; Mackinder, Barbara A. ; Meerts, Pierre ; Poel, Jeike van de; Sonké, Bonaventure ; Sosef, M.S.M. ; Stévart, Tariq ; Stoffelen, Piet ; Svenning, Jens Christian ; Sepulchre, Pierre ; Burgt, Xander Van Der; Wieringa, J.J. ; Couvreur, T.L.P. - \ 2016
    CESAB
    Herbarium specimens - tropical forests - georeferencing - taxonomic backbone - habit - digitization - native species - cultivated species - biodiversity assessment
    The tropical vegetation of Africa is characterized by high levels of species diversity but is undergoing important shifts in response to ongoing climate change and increasing anthropogenic pressures. Although our knowledge of plant species distribution patterns in the African tropics has been improving over the years, it remains limited. Here we present RAINBIO, a unique comprehensive mega-database of georeferenced records for vascular plants in continental tropical Africa. The geographic focus of the database is the region south of the Sahel and north of Southern Africa, and the majority of data originate from tropical forest regions. RAINBIO is a compilation of 13 datasets either publicly available or personal ones. Numerous in depth data quality checks, automatic and manual via several African flora experts, were undertaken for georeferencing, standardization of taxonomic names and identification and merging of duplicated records. The resulting RAINBIO data allows exploration and extraction of distribution data for 25,356 native tropical African vascular plant species, which represents ca. 89% of all known plant species in the area of interest. Habit information is also provided for 91% of these species.
    RAINBIO : A mega-database of tropical African vascular plants distributions
    Dauby, Gilles ; Zaiss, Rainer ; Blach-Overgaard, Anne ; Catarino, Luís ; Damen, Theo ; Deblauwe, Vincent ; Dessein, Steven ; Dransfield, John ; Droissart, Vincent ; Duarte, Maria Cristina ; Engledow, Henry ; Fadeur, Geoffrey ; Figueira, Rui ; Gereau, Roy E. ; Hardy, Olivier J. ; Harris, David J. ; Heij, Janneke de; Janssens, Steven ; Klomberg, Yannick ; Ley, Alexandra C. ; Mackinder, Barbara A. ; Meerts, Pierre ; Poel, Jeike L. van de; Sonké, Bonaventure ; Sosef, Marc S.M. ; Stévart, Tariq ; Stoffelen, Piet ; Svenning, Jens Christian ; Sepulchre, Pierre ; Burgt, Xander van der; Wieringa, Jan J. ; Couvreur, Thomas L.P. - \ 2016
    Phytokeys 74 (2016). - ISSN 1314-2011 - p. 1 - 18.
    Biodiversity assessment - Cultivated species - Digitization - Georeferencing - Habit - Herbarium specimens - Native species - Taxonomic backbone - Tropical forests

    The tropical vegetation of Africa is characterized by high levels of species diversity but is undergoing important shifts in response to ongoing climate change and increasing anthropogenic pressures. Although our knowledge of plant species distribution patterns in the African tropics has been improving over the years, it remains limited. Here we present RAINBIO, a unique comprehensive mega-database of georeferenced records for vascular plants in continental tropical Africa. The geographic focus of the database is the region south of the Sahel and north of Southern Africa, and the majority of data originate from tropical forest regions. RAINBIO is a compilation of 13 datasets either publicly available or personal ones. Numerous in depth data quality checks, automatic and manual via several African flora experts, were undertaken for georeferencing, standardization of taxonomic names and identification and merging of duplicated records. The resulting RAINBIO data allows exploration and extraction of distribution data for 25,356 native tropical African vascular plant species, which represents ca. 89% of all known plant species in the area of interest. Habit information is also provided for 91% of these species.

    Voedselzekerheid : LABB sessies, debat ABB
    Meijerink, G.W. - \ 2013
    YouTube
    voedselzekerheid - voedselvoorziening - voedselconsumptie - innovaties - voedselproductie - food security - food supply - food consumption - innovations - food production
    In deze derde aflevering van DebatLABB gaan drie deskundige sprekers in debat over het onderwerp 'voedselzekerheid'. Is er genoeg te eten voor iedereen op aarde, en hoe verandert dat als de wereldbevolking groeit naar van 7 naar 9 miljard mensen? De experts Gerdien Meijerink (LEI Wageningen UR), Wouter de Heij (TOP b.v.) en Marijke Vos (GroenLinks) gaan vanuit hun eigen perspectief met elkaar in gesprek. Conclusie? Voedselzekerheid is nu nog ver weg, maar er zijn genoeg ontwikkelingen gaande om dat in de toekomst wel te kunnen garanderen, zoals het terugdringen van onze verspilling of het opzoeken van innovatieve landbouwmethoden. Dit is alles is te zien in het gevarieerde programma. Jan Douwe Kroeske leidt het gesprek, en de VARA onderzoeksjournalist Daan van Alkemade bezoekt innovaties in de wereld van het voedsel. DebatLABB is onderdeel van LABBsessies en een initiatief van Double 2 en Ziggo.
    Patient ignorance is the main reason for treatment delay in primary rhegmatogenous retinal detachment in The Netherlands
    Goezinne, F. ; Heij, E.C. La; Berendschot, T. ; Tahzib, N.G. ; Koetsier, L.S. ; Hoevenaars, J. ; Liem, A.T.A. ; Kijlstra, A. ; Webers, C.A.B. ; Hendrikse, F. - \ 2009
    Eye 23 (2009)6. - ISSN 0950-222X - p. 1393 - 1399.
    posterior vitreous detachment - visual recovery - symptoms - surgery
    Aims Treatment delay of progressive vision-threatening conditions should be minimal. In this study, the treatment delay of patients with a rhegmatogenous retinal detachment (RRD) undergoing retinal detachment surgery was quantified, and causes for this delay were evaluated. Materials and methods Consecutive patients (n = 205) presenting with a primary RRD between June 2006 and June 2007 at the tertiary referral center (TRC) were interviewed. Five categories of delay were discerned in the following: 'patient delay,' 'general practitioner's delay,' 'referring ophthalmologist's delay,' 'delay at the TRC' and 'delay before surgery at the TRC'. In addition, overall delay was calculated. Results In total, 186 eyes were included in the analysis. Median overall delay between the patients' first symptoms and RRD surgery was 10 days. Almost 60% of this overall delay time was due to patient delay and the delay of the general practitioner. More than 50% of patients had a delay owing to unawareness of the symptoms. The median patient delay was significantly lower in patients with a vitreous hemorrhage and in patients with a history of a RRD in the fellow eye. Conclusions The major reason for patient delay with a RDD was the patients' unawareness and unfamiliarity with the symptoms of a retinal detachment. Eye (2009) 23, 1393-1399; doi:10.1038/eye.2008.272; published online 12 September 2008;
    Innovatief teeltsysteem Alstroemeria : onderzoek naar het lange termijn effect van teelt op substraat
    Labrie, C.W. ; Heij, G. - \ 2008
    Bleiswijk : Wageningen UR Glastuinbouw (Rapport / Wageningen UR Glastuinbouw 198) - 26
    alstroemeria - cultuur zonder grond - teeltsystemen - innovaties - bodemtemperatuur - plantdichtheid - alstroemeria - soilless culture - cropping systems - innovations - soil temperature - plant density
    Alstroemeria wordt gebruikelijk in de grond geteeld. Alternatieve teeltsystemen zouden de rentabiliteit kunnen verhogen door middel van een hogere ruimtebenutting en hogere productie door een beter controleerbaar bodemklimaat. Doel van dit onderzoek was het bepalen van het effect van de teelt in bakken, op de meerjarige productie van verschillende Alstroemeria cultivars in de praktijk. Deze substraatproef is voor een aantal cultivars uitgevoerd bij twee plantdichtheden. De productiegegevens laten zien dat een substraatvolume van 11 liter op kokos na drie jaar niet beperkend is voor de groei. Een bodemtemperatuur per etmaal van 16°C kon worden gehandhaafd doordat hogere temperaturen overdag, werden gecompenseerd door lagere temperaturen ¿s nachts. Een dubbele plantdichtheid gaf niet dubbel zoveel productie, maar wel een meerproductie van 36% bij Virginia. Bij Tiësto was dit verband minder duidelijk. Gedurende de looptijd van de proef bleek het zonder apart gereguleerd druppelsysteem moeilijk om de watergift en EC in de proef optimaal te sturen. Hierdoor is potentiële meerproductie van substraat ten opzichte van grondteelt blijven liggen. Dit onderzoek toont aan dat substraatteelt in Alstroemeria zeker potentie heeft. Ten opzichte van de grondteelt behoeven vochtgehalte en bemesting wel extra aandacht. Met meer kennis over optimale water- en voedingsgift op substraat voor verschillende cultivars, is zeker productieverhoging van Alstroemeria op substraat te verwachten
    Cyclic GMP in the pig vitreous and retina after experimental retinal detachment
    Diederen, R. ; Heij, E.C. La; Lemmens, M.A.M. ; Kijlstra, A. ; Vente, J. De; Hendrikse, F. - \ 2008
    Molecular Vision 14 (2008). - ISSN 1090-0535 - p. 255 - 261.
    soluble guanylate-cyclase - pigment epithelial-cells - oxygen supplementation - subretinal fluid - cgmp - localization - particulate - surgery - pathways - neurons
    Purpose: Earlier studies have revealed a decreased level of cGMP in vitreous fluid obtained from patients with a retinal detachment. To further investigate this phenomenon, we developed an experimental retinal detachment model in pigs. Methods: Experimental unilateral retinal detachments were induced in pig eyes by subretinal injection of 0.25% sodium hyaluronate. Fourteen days later the vitreous and retinas were analyzed for cGMP expression. Following enucleation, the retinas were incubated in the presence of a nonselective phosphodiesterase inhibitor (IBMX), and the particulate guanylyl cyclase stimulator atrial natriuretic peptide (ANP) or the soluble guanylyl cyclase stimulator sodium nitroprusside (SNP). cGMP was visualized in retinal wholemounts by immunochemistry combined with a computer based stereology system. cGMP levels in vitreous were determined by ELISA. Results: The mean vitreous cGMP level in pig eyes with a retinal detachment (1.45 pmol/ml) was significantly lower compared to the mean level of cGMP in healthy pig eyes (4.61 pmol/ml; p= 0.028 was considered significant). In the inner retina, ANP as well as SNP induced cGMP immunoreactivity in both detached and healthy retinas. After incubation with ANP, cGMP could also be detected in the outer nuclear layer of the detached retina, whereas this was not the case in the normal retina. Conclusions: Experimental retinal detachment in the pig eye leads to a decrease of cGMP levels in vitreous similar to that observed in clinical studies. This model may be helpful to analyze the mechanisms involved in cGMP dynamics following retinal detachment.
    Hergroei Aster en Asterini : Deel I: Teeltinnovatie Asterini : Deel II: Productie en hergroei van Aster cultivars
    Heij, G. ; Labrie, C.W. - \ 2008
    Bleiswijk : Wageningen UR Glastuinbouw (Nota / Wageningen UR, Glastuinbouw 542) - 36
    cultuurmethoden - asterales - aster - cultivars - innovaties - hergroei - productie - opbrengsten - kwaliteit - plantenontwikkeling - teeltsystemen - glastuinbouw - cultural methods - asterales - aster - cultivars - innovations - regrowth - production - yields - quality - plant development - cropping systems - greenhouse horticulture
    Het onderzoek naar 'hergroei Aster en Asterini' bestaat uit twee delen. Deel 1 betreft 'Teeltinnovatie Asterini'. Teelt van Asterini, een nieuwe variant in het sortiment van aster, biedt wellicht nieuwe kansen voor de Asterteelt in Nederland. In dit project is een alternatief teeltsysteem voor de teelt van Asterini getoetst. In plaats van hart-tak teelt is de teeltwijze aangehouden waarbij in de loop van het seizoen de uitlopers meerdere malen geoogst worden. Deel 2 betreft 'Productie en hergroei van Aster cultivars'. Om de kosten van plantmateriaal in de asterteelt te verlagen, is een onderzoek gedaan naar de mogelijkheden van de teeltwijze met hergroei van asters ten opzichte van de hart-tak teelt. Met deze teeltwijze zijn meerdere oogsten van een plant mogelijk. Van 25 astercultivars is de mate van ontwikkeling van nieuwe uitlopers onderzocht.
    Invloed van het geconditioneerd bewaren van knollen op de teeltduur van Freesia
    Heij, G. ; Mourik, N.M. van; Labrie, C.W. - \ 2008
    Wageningen : Wageningen UR Glastuinbouw (Nota / Wageningen UR Glastuinbouw 525) - 32
    freesia - bloementeelt - koudeopslag - cultuurmethoden - teeltsystemen - voorbehandeling - gewaskwaliteit - agrarische bedrijfsplanning - freesia - floriculture - cold storage - cultural methods - cropping systems - pretreatment - crop quality - farm planning
    Teeltduurverkorting en een betere kasruimtebenutting in de teelt van Freesia is wenselijk. Indien grondkoeling in de kas niet meer noodzakelijk zou zijn, zou dit een mobiel systeem vereenvoudigen. Hiervoor is in dit onder¬zoek het aantal weken droge 14 oC voorbehandeling gevarieerd en vervolgens het aantal weken geplante 13 oC voor¬behan¬deling. Beiden in een geconditioneerde ruimte. Hierna zijn de planten met dan wel zonder grondkoeling in de kas geplaatst in de zomerperiode. Uit dit onderzoek blijkt dat al na een voorbehandeling van vier weken de grondkoeling in de kas geen effect meer heeft op teeltduur, knopontwikkeling of kwaliteit. De voorbehandelingen zorgen voor een verkorting van de teeltduur tot soms 34 dagen, maar dit gaat ten koste van takgewicht, lengte en kwaliteit. Ook konden geen haken worden geoogst. Waarschijnlijk moet de oorzaak van dit kwaliteitsverlies gezocht worden in de hoge temperatuur in de periode kort na het in de kas zetten van de jonge planten.
    Onderzoek daglengte in de teelt van Freesia
    Heij, G. ; Mourik, N.M. van; Leeuwen, A.G.J. van; Labrie, C.W. - \ 2008
    Wageningen : Wageningen UR Glastuinbouw (Rapport / Wageningen UR, Glastuinbouw 171) - 24
    freesia - bloementeelt - cultivars - rassen (planten) - plantdichtheid - fotoperiode - teelt onder bescherming - groeifactoren - rassenproeven - glastuinbouw - freesia - floriculture - cultivars - varieties - plant density - photoperiod - protected cultivation - growth factors - variety trials - greenhouse horticulture
    Onderzocht is de invloed van de teeltstrategie op freesia met als doel de najaarskwaliteit en daarnaast de productie en teeltduur te verbeteren. Proeffactoren zijn daglengte, plantdichtheid en wel of geen voorbehandeling. Gebruikte cultivars zijn Summer Beach, Ambassador, Dukaat en Gold River
    Op koude ochtenden kan scherm langer dicht
    Buwalda, F. ; Kempkes, F.L.K. ; Pronk, A.A. ; Dieleman, J.A. ; Janse, J. ; Heij, G. - \ 2008
    Gewasnieuws tomaat 11 (2008)2. - p. 3 - 3.
    Knoponderzoek Lisianthus : knoponderzoek ten behoeve van de sturing van de oogst van Lisianthus
    Labrie, C.W. ; Kersten, M. ; Heij, G. - \ 2008
    Wageningen : Wageningen UR, Glastuinbouw (PPO 3242000147) - 27
    eustoma - eustoma grandiflorum - snijbloemen - knoppen - plantenanatomie - opbrengstregeling - teelt onder bescherming - eustoma - eustoma grandiflorum - cut flowers - buds - plant anatomy - yield regulation - protected cultivation
    Device for pasteurizing a mass of foodstuff
    Heij, W.B.C. de; Schuten, H.J. ; Esveld, D.C. ; Vollebregt, H.M. ; Sonder, H.L. - \ 2007
    Octrooinummer: WO2007108680, gepubliceerd: 2007-09-27.
    A device (1) for pasteurizing a mass of foodstuff comprises: a feed; at least one first tube (5), connecting to the feed, of an electrically and magnetically inert material suitable for contact with food; two plate-like electrodes (6,7) which are situated on either side of the first tube and which are connected to an RF power generator (8), whereby the mass present in the first tube is heated dielectrically in this first tube; a first jacket (10) filled with a heatable first liquid and extending around the first tube; and heating means which connect to the first tube and in which the hot mass is held at practically constant temperature; at the end of which heating means the hot mass is discharged for further processing, such as cooling, portioning and packaging.
    Balance of vascular endothelial growth factor and pigment epithelial growth factor prior to development of proliferative vitreoretinopathy
    Dieudonne, S.C. ; Heij, E.C. La; Diederen, R.M.H. ; Kessels, A.G.H. ; Liem, A.T.A. ; Kijlstra, A. ; Hendrikse, F. - \ 2007
    Ophthalmic Research: journal for research in experimental and clinical ophthalmology 39 (2007)3. - ISSN 0030-3747 - p. 148 - 154.
    rhegmatogenous retinal-detachment - subretinal fluid - diabetic-retinopathy - epiretinal membranes - vitreous levels - binding-site - pedf - neovascularization - angiogenesis - expression
    Background: Pigment epithelium-derived factor (PEDF) and vascular endothelial growth factor (VEGF) are imbalanced in eyes with proliferative diabetic retinopathy or proliferative vitreoretinopathy (PVR). It is not known whether such an imbalance is already present in early PVR stages. We therefore analyzed VEGF and PEDF concentrations in subretinal fluids prior to PVR development. Methods: A large number (n = 137) of subretinal fluid samples were obtained at the time of scleral buckling surgery for rhegmatogenous retinal detachment (RRD). Thirty patients developed PVR within 6 months after surgery. One hundred and seven patients undergoing the same surgery but without complications served as controls. Furthermore, vitreous from 16 patients with macular hole or pucker (MHP) served as reference for baseline intraocular concentrations. PEDF and VEGF concentrations were measured by commercial ELISAs. Results: PEDF levels were substantially higher (9.6 µg/ml) compared to MHP vitreous (0.3 µg/ml, p <0.001). VEGF levels were also higher (RRD: 0.07 ng/ml; MHP: 0.01 ng/ml, p <0.05). Subretinal concentrations were not significantly different between PVR and control RRD patients. Conclusions: Although both VEGF and PEDF are increased at first surgery for RRD, they do not predict PVR development later on. The high PEDF concentrations and its known antiangiogenic activity suggest a protective role against neovascularization
    Summary for Policymakers
    Barker, T. ; Bashmakov, I. ; Bernstein, L. ; Bogner, J. ; Bosch, P. ; Dave, R. ; Davidson, O. ; Fisher, B. ; Grubb, M. ; Gupta, S. ; Halsnaes, K. ; Heij, B.J. ; Kahn Ribeiro, S. ; Kobayashi, S. ; Levine, M. ; Martino, D. ; Masera Cerutti, O. ; Metz, B. ; Meyer, L. ; Nabuurs, G.J. ; Najam, A. ; Nakicenovic, N. ; Rogner, H.H. ; Roy, J. ; Sathaye, J. ; Schock, R. ; Shukla, P. ; Sims, R. ; Smith, P. ; Swart, R. ; Tirpak, D. ; Urge-Vorsatz, D. ; Dadi, Z. - \ 2007
    In: Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change / Metz, B., Davidson, O.R., Bosch, P.R., Dave, R., Meyer, L.A., Cambridge (UK) and New York (USA) : Cambridge University Press (Climate Change 2007 ) - ISBN 9780521880114 - p. 1 - 24.
    Sortimentsvergelijking Freesia: Resultaten herfstteelt 2006
    Heij, G. ; Steenbergen, P. ; Kersten, M. - \ 2007
    Bleiswijk : Wageningen UR Glastuinbouw (Rapporten WUR Glastuinbouw ) - 53
    freesia - cultivars - rassen (planten) - rassen (taxonomisch) - rassenproeven - nederland - freesia - cultivars - varieties - races - variety trials - netherlands
    De veredeling van Freesia zorgt voor een geleidelijke vernieuwing van het sortiment. Om zo spoedig mogelijk de teeltmogelijkheden van een nieuwe cultivar te weten, is een gebruikswaarde-onderzoek opgezet in samenwerking met WUR Glastuinbouw. Hierbij is de groei en bloei beoordeeld van 18 nieuwe cultivars en zes vergelijkingscultivars van de herfstteelt van 2006. Voor tien van deze cultivars vormt deze proef de herhaling, omdat zij ook zijn beoordeeld in de herfstteelt 2005. Van deze tien cultivars heeft het comité van de freesiakeuring van het VKC geconcludeerd dat de oranje/rode, dubbele Manderin van veredelaar Royal van Zanten een verbetering vormt op het bestaande assortiment. De A553 van Royal van Zanten kreeg de kwalificatie aanvulling binnen het sortiment geel enkel in de herfstteelt. De JJ 506-1, Paloma Beach, Daytona Beach, Blue Mountain, JJ 1120-7, KK 834-1, 95-128 en Soleil vormen geen aanvulling op het bestaande sortiment. Van de andere cultivars, die dit jaar voor het eerst zijn beoordeeld, kunnen op dit moment nog geen conclusies worden getrokken omdat de herhaling nog niet heeft plaatsgevonden. Resultaten van twee seizoenen geven een betrouwbaarder resultaat vanwege het mogelijke effect van de weersomstandigheden per seizoen.
    Teeltinnovatie Asterini
    Heij, G. - \ 2007
    Bleiswijk : Wageningen UR Glastuinbouw (Rapporten WUR Glastuinbouw ) - 15
    asteraceae - cultivars - rassen (planten) - cultuurmethoden - hergroei - teeltsystemen - teelt onder bescherming - nederland - glastuinbouw - asteraceae - cultivars - varieties - cultural methods - regrowth - cropping systems - protected cultivation - netherlands - greenhouse horticulture
    Middelentoets uitval Lisianthus
    Wurff, A.A.M. van der; Hamelink, R. ; Leeuwen, A.G.J. van; Paternotte, S.J. ; Heij, G. - \ 2007
    gewasbescherming - snijbloemen - teelt onder bescherming - voetrot - myrothecium roridum - schimmelbestrijding - glastuinbouw - plant protection - cut flowers - protected cultivation - foot rot - myrothecium roridum - fungus control - greenhouse horticulture
    Getoetste middelen tegen voetrot en vlekkenziekte bij Lisianthus
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