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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Identification of metabolites involved in heat stress response in different tomato genotypes
Paupière, Marine J. - \ 2017
Wageningen University. Promotor(en): Richard Visser, co-promotor(en): Arnaud Bovy; Yury Tikunov. - Wageningen : Wageningen University - ISBN 9789463431842 - 168
solanum lycopersicum - tomatoes - genotypes - heat stress - heat tolerance - pollen - metabolomes - metabolites - metabolomics - tomaten - genotypen - warmtestress - hittetolerantie - stuifmeel - metabolomen - metabolieten - metabolomica

Tomato production is threatened by climate change. High temperatures lead to a decrease of fruit set which correlates with a decrease of pollen fertility. The low viability of tomato pollen under heat stress was previously shown to be associated with alterations in specific metabolites. In this thesis, we used untargeted metabolomics approaches to broaden the identification of metabolites affected by heat stress. We assessed the suitability of pollen isolation methods for metabolomics analysis and considered the pitfalls for our further analysis. We explored the developmental metabolomes of pollen and anthers of different tomato genotypes under control and high temperature conditions and identified that microsporogenesis is a critical developmental stage for the production of mature and fertile pollen grain under heat stress. Several metabolites were putatively associated with tolerance to high temperature such as specific flavonoids, polyamines and alkaloids. These metabolites can be further used as markers in breeding programs to develop new genotypes tolerant to high temperatures.

Biologische bestrijding trips snijbloemen een stap dichterbij : Roofmijten bijvoeren met stuifmeel helpt bij totaalaanpak trips
Messelink, Gerben ; Leman, Ada - \ 2016
predatory mites - plant protection - biological control - cut flowers - greenhouse horticulture - pollen - pest control - integrated pest management
Milieufactoren en beschikbaarheid nectar en stuifmeel in graslanden
Ozinga, W.A. ; Geerts, R.H.E.M. ; Hennekens, S.M. ; Schaminee, J.H.J. - \ 2016
Landschap : tijdschrift voor landschapsecologie en milieukunde 33 (2016)1. - ISSN 0169-6300 - p. 45 - 47.
functionele biodiversiteit - graslanden - milieufactoren - nectar - stuifmeel - ecosysteemdiensten - bloemen - plantengemeenschappen - functional biodiversity - grasslands - environmental factors - pollen - ecosystem services - flowers - plant communities
Plantengemeenschappen spelen bij veel ecosysteemfuncties en -diensten een cruciale rol. De bijdrage van plantensoorten hangt af van functionele eigenschappen als het aanbod van nectar en stuifmeel in bloemen. Lokale plantengemeenschappen verschillen sterk in het spectrum aan eigenschappen van de soorten en inzicht in deze variatie kan helpen bij duurzaam beheer en gebruik van deze functionele diversiteit. Stilgestaan wordt bij factoren die de variatie in het aanbod van nectar en stuifmeel in graslanden beïnvloeden.
Biologische bestrijding van Echinothrips americanus
Messelink, G.J. ; Gasemzadeh, Somayyeh ; Ada, Leman ; Leman, A. - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw - 1 p.
greenhouse horticulture - plant protection - gerbera - sweet peppers - biological control - predator augmentation - thrips - predatory mites - greenhouse experiments - pollen - glastuinbouw - gewasbescherming - paprika's - biologische bestrijding - plaagbestrijding met predatoren - roofmijten - kasproeven - stuifmeel
Poster van het PlantgezondheidEvent 2016. Het doel van dit onderzoek was te bepalen welke roofmijten het meest geschikt zijn voor de bestrijding van Echinothrips en wat de invloed van stuifmeel op deze bestrijding is. In het laboratorium is nauwkeurig bekeken welke stadia vatbaar zijn voor roofmijten en hoeveel individuen van welk stadium per dag worden gegeten. Dit is getest voor de roofmijten Amblyseius swirskii, Amblydromalus limonicus, Euseius ovalis en Euseius gallicus. Vervolgens zijn kasproeven uitgevoerd op paprika en gerbera om de bestrijding en invloed van stuifmeel te beoordelen.
Bestrijding Echinothrips americanus met roofmijten en roofwantsen : groeiend probleem in sierteelt onder glas
Messelink, G.J. ; Leman, A. ; Gasemzadeh, Somayyeh - \ 2016
Onder Glas 13 (2016)2. - p. 24 - 25.
tuinbouw - glastuinbouw - plantenplagen - sierteelt - rosaceae - capsicum - groenten - snijbloemen - gerbera - gewasbescherming - landbouwkundig onderzoek - thrips - frankliniella occidentalis - roofmijten - reduviidae - stuifmeel - plagenbestrijding - horticulture - greenhouse horticulture - plant pests - ornamental horticulture - vegetables - cut flowers - plant protection - agricultural research - predatory mites - pollen - pest control
Dat trips een enorm probleem is in de sierteelt onder glas is geen nieuws meer. In de meeste gevallen gaat het dan om de Californische trips, een soort met een sterke voorkeur voor bloemen. De laatste jaren duikt er steeds vaker een andere polyfage trips op, de Echinothrips americanus. Deze typische bladbewonende trips kan in sierteeltgewassen zoals gerbera en roos behoorlijk schade geven als er niet tijdig wordt ingegrepen. In onderzoek is nog eens nauwkeurig gekeken naar de bestrijding met een aantal soorten roofmijten en roofwantsen.
De foeragerende honingbij
Steen, J.J.M. van der - \ 2015
Bijenhouden 9 (2015)6. - ISSN 1877-9786 - p. 7 - 9.
bijenhouderij - foerageren - honingbijen - apis - drachtplanten - bloeiende planten - nectar - stuifmeel - bestuivers (dieren) - beekeeping - foraging - honey bees - pollen plants - flowering plants - pollen - pollinators
Dit artikel is een compilatie van het Wageningen-UR PRI rapport 606 ’Factoren die het foerageergedrag van honingbijen bepalen (deel I)’. In dit rapport wordt het haalgedrag van de honingbij beschreven: hoe wordt het bepaald en wat wordt verzameld en hoe. Daarnaast is in het rapport een drachtplantenlijst opgenomen (deel II). Hoe bijen drachten bezoeken is interessant voor de bijenhouder en van wezenlijk belang voor het inzetten van honingbijen voor bestuiving en voor het interpreteren van uitkomsten in studies waarin bijenvolken gebruikt worden voor het aantonen van plantenziekten en milieuverontreinigingen.
Allergieradar Website
Vliet, A.J.H. van; Weger, L.A. de; Bron, W.A. - \ 2015
Wageningen : Wageningen University, Leids Universitair Medisch Centrum en triptic
allergieën - allergische reacties - acute overgevoeligheid - stuifmeel - monitoring - allergies - allergic reactions - immediate hypersensitivity - pollen
De AllergieRadar geeft een actueel en landelijk overzicht van de mate waarin hooikoortspatiënten klachten aan neus, ogen en longen ervaren. Deelnemers geven bij voorkeur minimaal een keer per dag op een schaal van 1 tot 10 de klachtenintensiteit door. Alle registraties worden na het doorgeven direct verwerkt tot een kaart van Nederland. Hoe meer mensen meedoen hoe gedetailleerder de AllergieRadar kan worden weergeve. Tevens informatie over hooikoorts veroorzakende pollen
Delivery of crop pollination services is an insufficient argument for wild pollinator conservation
Kleijn, D. ; Winfree, R. ; Bartomeus, D. ; Carvalheiro, L.G. ; Bommarco, R. ; Scheper, J. ; Tscharntke, T. ; Verhulst, J. ; Potts, S.G. - \ 2015
Nature Communications 6 (2015). - ISSN 2041-1723 - 8 p.
ecosystem services - native bees - biodiversity conservation - european countries - plant diversity - fruit-set - abundance - productivity - decline - pollen
There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments.
Meeste wilde bestuivers buiten boot bij focus op economisch nut
Kleijn, D. - \ 2015
Nature Today (2015)18 juni.
insecten - bestuivers (dieren) - apidae - wilde bijenvolken - bestuiving - biodiversiteit - ecosystemen - stuifmeel - rassen (dieren) - bedreigde soorten - wetenschappelijk onderzoek - soortendiversiteit - insects - pollinators - wild honey bee colonies - pollination - biodiversity - ecosystems - pollen - breeds - endangered species - scientific research - species diversity
Insecten leveren een bijdrage aan ecosysteemdiensten vanwege de bestuiving van allerlei gewassen. Maar uit nieuw onderzoek, gepubliceerd in Nature Communications, blijkt dat dat slechts geldt voor een kleine groep algemene soorten. Zeldzame soorten dragen nauwelijks bij aan bestuiving. In het internationale debat over biodiversiteitsbehoud kan de huidige focus op ecosysteemdiensten als argument voor soortbescherming voor zeldzame soorten dus slecht uitpakken.
Supplemental food that supports both predator and pest: A risk for biological control?
Leman, A. ; Messelink, G.J. - \ 2015
Experimental and Applied Acarology 65 (2015)4. - ISSN 0168-8162 - p. 511 - 524.
neoseiulus-cucumeris acari - mite amblyseius-swirskii - western flower thrips - orius-laevigatus - apparent competition - factitious foods - life-history - prey - phytoseiidae - pollen
Supplemental food sources to support natural enemies in crops are increasingly being tested and used. This is particularly interesting for generalist predators that can reproduce on these food sources. However, a potential risk for pest control could occur when herbivores also benefit from supplemental food sources. In order to optimize biological control, it may be important to select food sources that support predator populations more than herbivore populations. In this study we evaluated the nutritional quality of four types of supplemental food for the generalist predatory mites Amblyseius swirskii Athias-Henriot and Amblydromalus (Typhlodromalus) limonicus (Garman and McGregor), both important thrips predators, and for the herbivore western flower thrips Frankliniella occidentalis Pergande, by assessing oviposition rates. These tests showed that application of corn pollen, cattail pollen or sterilized eggs of Ephestia kuehniella Zeller to chrysanthemum leaves resulted in three times higher oviposition rates of thrips compared to leaves without additional food. None of the tested food sources promoted predatory mites or western flower thrips exclusively. Decapsulated cysts of Artemia franciscana Kellogg were not suitable, whereas cattail pollen was very suitable for both predatory mites and western flower thrips. In addition, we found that the rate of thrips predation by A. swirskii can be reduced by 50 %, when pollen is present. Nevertheless, application of pollen or Ephestia eggs to a chrysanthemum crop still strongly enhanced the biological control of thrips with A. swirskii, both at low and high release densities of predatory mites through the strong numerical response of the predators. Despite these positive results, application in a crop should be approached with caution, as the results may strongly depend on the initial predator–prey ratio, the nutritional quality of the supplemental food source, the species of predatory mites, the distribution of the food in the crop and the type of crop.
Stuifmeel museumbijen levert het bewijs
Kleis, R. ; Scheper, J.A. - \ 2014
Resource: weekblad voor Wageningen UR 9 (2014)8. - ISSN 1874-3625 - p. 9 - 9.
apidae - wilde bijenvolken - rassen (dieren) - stuifmeel - drachtplanten - landbouwkundig onderzoek - veldgewassen - voederpeulvruchten - beplantingen - voedseltekorten - wild honey bee colonies - breeds - pollen - pollen plants - agricultural research - field crops - fodder legumes - plantations - food shortages
Voedseltekort oorzaak afname aantal wilde bijen. Vooral grote bijen zijn de dupe van gebreken in menu.
Spatiotemporal monitoring of allergic rhinitis symptoms in the Netherlands using citizen science
Weger, L.A. de; Hiemstra, P.S. ; Buysch, E. op den; Vliet, A.J.H. van - \ 2014
Allergy 69 (2014)8. - ISSN 0105-4538 - p. 1085 - 1091.
pollen - europe - diseases - impact
Background Airborne pollen is a major symptom trigger in allergic rhinitis patients, but the impact of pollen differs among patients and regions and is influenced by environmental factors. To study these complex relationships, there is a need for data on the severity of symptoms in space and time. ‘Citizen science’ is increasingly recognized as an effective tool to monitor changes in our environment. The aim of this study was to investigate the feasibility of a citizen science-based survey to monitor spatiotemporal variation in allergic rhinitis symptoms. Methods Participants were recruited through the Web site Allergieradar.nl. After registering by completing an extensive questionnaire, they entered (preferably daily) their symptoms of eyes, nose, and lungs on a scale from 1 to 10, as well as their geographic location. Results The registration questionnaire revealed that the majority of the participants (77%) had physician-diagnosed hay fever and 65% of the participants had been tested positively for their allergy. This study shows that the symptom scores of the participants are related to (i) pollen concentrations in the air, (ii) the self-reported sensitivity profile, and (iii) the sales of prescription antihistamines in the Netherlands. Conclusion Our data indicate that the collection of allergic rhinitis symptom data by ‘citizen science’ is feasible and has an added value in studies on the impact of pollen.
Microspore embryogenesis: reprogramming cell fate from pollen to embryo development
Hui Li, - \ 2014
Wageningen University. Promotor(en): Gerco Angenent, co-promotor(en): Kim Boutilier. - Wageningen : Wageningen University - ISBN 9789462570702 - 224
stuifmeel - embryogenese - embryonale ontwikkeling - biologische ontwikkeling - plantenontwikkeling - in vitro kweek - plantenembryo's - brassica napus - pollen - embryogenesis - embryonic development - biological development - plant development - in vitro culture - plant embryos

Microspore embryogenesis is an expression of plant cell totipotency that leads to the production of haploid embryos. Besides being a widely exploited plant breeding tool, microspore embryogenesis is also a fascinating system that can be used to obtain a deeper mechanistic understanding of plant totipotency. This thesis aims to provide more insight into the process of microspore embryogenesis, from the formation of embryogenic cells to the outgrowth of differentiated embryos.

In Chapter 1 background information is provided on the various aspects of Brassica napus microspore culture and plant development that intersect with the topics that are studied in this thesis. Emphasis is placed on the basic requirements and limitations for successful microspore embryo culture, as well as on the roles of the plant hormone auxin and epigenetic regulation in the development of plant embryos, during both zygotic and in vitro embryo development.

Chapter 2 reviews the recent advances that have been made in understanding the developmental and molecular changes that take place during microspore embryogenesis in model systems. The commonly reported cellular changes associated with the establishment of embryo cell fate are summarized and evaluated. The subsequent differentiation of the embryo is also discussed, specifically, what is known about the establishment of polarity, with emphasis on the importance of exine rupture as a positional clue, and the processes that influence meristem maintenance during culture. Finally, the studies on the molecular changes during microspore embryo induction are put into context of male gametophytic development. Overall, the current perspective on microspore embryo initiation presents a landscape in which several routes can lead to the same final destination.

Stress treatments are widely applied to induce embryogenic growth in microspore culture. Chapter 3 explores the role of histone acetylation status in stress-induced microspore embryogenesis in Brassica napus. Inhibition of histone deactylases (HDACs) using the HDAC inhibitor trichostatin A (TSA), phenocopies the heat stress treatment that is normally used to induce embryogenic cell proliferation in B. napus microspore culture. Arabidopsis is recalcitrant for haploid embryogenesis, yet treatment with TSA also induced embryogenic cell divisions in this model species. Our observations suggest that the totipotency of the male gametophyte is kept in check by an HDAC-dependent mechanism and that the stress treatments used to induce haploid embryo development in culture impinge on this HDAC-dependent pathway. The repression of HDACs or HDAC-mediated pathways by stress and the accompanying changes in histone acetylation status could provide a single, common regulation point for the induction of haploid embryogenesis.

Chapter 4 builds on the knowledge developed in Chapter 3 on the role of HDAC proteins in plant totipotency. A wide variety of chemically distinct HDAC inhibitors was evaluated and additional inhibitors that enhance embryogenic cell induction and/or embryo yield were identified. One surprising observation was made during the course of this study: the initial donor microspore/pollen stage affects the quality of the embryo that is formed. In control cultures, embryos from progressively older stages of donor microspores/pollen became progressively compromised in their basal (axis region) region, characterized by a shift from normal embryos with apical (cotyledons) and basal (root) polarity to abnormal embryos with a reduced basal pole and ball-shaped embryos. These abnormal phenotypes could be partially complemented by treatment with HDAC inhibitors, which promoted growth of the basal region of the embryo. Progressive enhancement of embryo basal identity was accompanied by enhanced and broadened expression of the DR5 auxin response reporter. The embryo phenotypes observed in control and HDAC inhibitor treated microspore cultures are similar to the phenotypes induced by altered expression of the Arabidopsis TOPLESS (TPL)/HDAC19/BODENLOS (BDL) repressor complex, which acts to restrict expression of the AUXIN RESPONSE FACTOR ARF5/MONOPTEROS (MP) to the basal region of the embryo during zygotic embryo development.

To understand why most embryogenic callus failed to develop further, we examined the transcriptome of globular-shaped embryos that have started to histodifferentiate and compared it with embryogenic callus. The transcriptome analysis showed that the expression of many genes that regulate (auxin-related) embryo patterning were downregulated in embryogenic callus compared to globular stage embryos. This result may simply reflect the lack of patterning in these embryos or might indicate a role of auxin-signalling in embryogenic callus formation.

Chapter 5 examines how embryo identity and patterning is established in two B. napus microspore embryo pathways, a zygotic-like pathway, characterized by suspensor and then embryo proper formation, and a pathway characterized by initially unorganized structures that lack a suspensor. We specifically asked the question: how can embryo patterning be established in the absence of an initial asymmetric division and in the absence of a suspensor, two key events in zygotic embryo development. Analysis of embryo fate (GRP) and auxin (PIN1, PIN7 and DR5) markers showed that embryo fate was established prior to cell division, and independent of subsequent division pattern. The suspensorless embryo program was marked by a transient auxin maximum, followed by establishment of the apical and basal poles at the globular stage, coincident with release of the embryo from the pollen exine. Unlike zygotic embryo development, polar auxin transport (PAT) was not required for embryo initiation or polarity establishment in this system. Suspensor embryos developed in a similar fashion as zygotic embryos, PAT was required for specification of the embryo proper from the suspensor. Haploid embryogenesis therefore follows at least two programs, a PAT-dependent program that requires embryo proper specification from the suspensor, and an alternative PAT-independent program marked by an initial auxin maximum.

In the final chapter, Chapter 6, the work presented in this thesis is put in context of the broader plant development field. The epigenetic regulation of developmental transitions that respond to stress and during pollen development are highlighted. A model is provided that histone acetylation levels mediated by HAT and HDAC regulate pollen fate.

Development and validation of a rapid multiplex ELISA for pyrrolizidine alkaloids and their N-oxides in honey and feed
Oplatowska, M. ; Elliott, C.T. ; Huet, A.C. ; McCarthy, M. ; Mulder, P.P.J. ; Holst, C. von; Delahaut, P. ; Egmond, H.P. van; Campbell, K. - \ 2014
Analytical and Bioanalytical Chemistry 406 (2014)3. - ISSN 1618-2642 - p. 757 - 770.
linked-immunosorbent-assay - dietary-supplements - enzyme-immunoassay - mass-spectrometry - plants - food - toxicity - invitro - pollen - system
Pyrrolizidine alkaloids (PAs) are a group of plant secondary metabolites with carcinogenic and hepatotoxic properties. When PA-producing plants contaminate crops, toxins can be transferred through the food chain and cause illness in humans and animals, most notably hepatic veno-occlusive disease. Honey has been identified as a direct risk of human exposure. The European Food Safety Authority has recently identified four groups of PAs that are of particular importance for food and feed: senecionine-type, lycopsamine-type, heliotrine-type and monocrotaline-type. Liquid or gas chromatography methods are currently used to detect PAs but there are no rapid screening assays available commercially. Therefore, the aim of this study was to develop a rapid multiplex ELISA test for the representatives of three groups of alkaloids (senecionine, lycopsamine and heliotrine types) that would be used as a risk-management tool for the screening of these toxic compounds in food and feed. The method was validated for honey and feed matrices and was demonstrated to have a detection capability less than 25 µg/kg for jacobine, lycopsamine, heliotrine and senecionine. The zinc reduction step introduced to the extraction procedure allows for the additional detection of the presence of N-oxides of PAs. This first multiplex immunoassay for PA detection with N-oxide reduction can be used for the simultaneous screening of 21 samples for >12 PA analytes. Honey samples (n¿=¿146) from various origins were analysed for PA determination. Six samples were determined to contain measurable PAs >25 µg/kg by ELISA which correlated to >10 µg/kg by LC-MS/MS.
Characterization of polarity development through 2- and 3-D imaging during the initial phase of microspore embryogenesis in Brassica napus L.
Dubas, E. ; Custers, J. ; Kieft, H. ; Wedzony, M. ; Lammeren, A.A.M. van - \ 2014
Protoplasma 251 (2014)1. - ISSN 0033-183X - p. 103 - 113.
nuclear-dna synthesis - cv topas - extracellular-matrix - sporophytic development - cultured microspores - actin-filament - heat-shock - in-vitro - induction - pollen
Isolated microspores of B. napus in culture change their developmental pathway from gametophytic to sporophytic and form embryo-like structures (ELS) upon prolonged heat shock treatment (5 days at 32 °C). ELS express polarity during the initial days of endosporic development. In this study, we focussed on the analysis of polarity development of ELS without suspensor. Fluorescence microscopy and 3-D confocal laser scanning microscopy (CLSM) without tissue interfering enabled us to get a good insight in the distribution of nuclei, mitochondria and endoplasmic reticulum(ER), the architecture of microtubular (MT) cytoskeleton and the places of 5-bromo- 2'-deoxy-uridine (BrdU) incorporation in successive stages of microspore embryogenesis. Scanning electron microscopy (SEM) analysis revealed, for the first time, the appearance of a fibrillar extracellular matrix-like structure (ECM-like structure) in androgenic embryos without suspensor. Two types of endosporic development were distinguished based upon the initial location of the microspore nucleus. The polarity of dividing and growing cells was recognized by the differential distributions of organelles, by the organization of the MT cytoskeleton and by the visualization of DNA synthesis in the cell cycle. The directional location of nuclei, ER, mitochondria and starch grains in relation to theMTs configurations were early polarity indicators. Both exine rupture and ECMlike structure on the outer surfaces of ELS are supposed to stabilize ELS's morphological polarity. As the role of cell polarity during early endosporic microspore embryogenesis in apical–basal cell fate determination remains unclear, microspore culture system provides a powerful in vitro tool for studying the developmental processes that take place during the earliest stages of plant embryogenesis.
Allergieradar Website
Vliet, A.J.H. van; Weger, L.A. de; Buijs, E. Op den - \ 2013
Wageningen : Wageningen University, Leids Universitair Medisch Centrum en triptic
allergieën - allergische reacties - acute overgevoeligheid - stuifmeel - monitoring - allergies - allergic reactions - immediate hypersensitivity - pollen
De AllergieRadar geeft een actueel en landelijk overzicht van de mate waarin hooikoortspatiënten klachten aan neus, ogen en longen ervaren. Deelnemers geven bij voorkeur minimaal een keer per dag op een schaal van 1 tot 10 de klachtenintensiteit door. Alle registraties worden na het doorgeven direct verwerkt tot een kaart van Nederland. Hoe meer mensen meedoen hoe gedetailleerder de AllergieRadar kan worden weergeve. Tevens informatie over hooikoorts veroorzakende pollen
Allergieradar App (Android)
Vliet, A.J.H. van; Weger, L.A. de; Buijs, E. - \ 2013
Eindhoven : triptic, Wageningen University, Leids Universitair Medisch Centrum
gezondheid - allergieën - stuifmeel - software-ontwikkeling - health - allergies - pollen - software engineering
De Allergieradar App ontwikkeld door het Leids Universitair Medisch Centrum (LUMC), Wageningen University en triptic geeft: 1. Het hele jaar een actueel overzicht van de hooikoortsintensiteit in heel Nederland en in vijf regio’s. 2. De mogelijkheid om het verloop van uw eigen hooikoortsklachten te registreren. Hiervoor moet u zich eerst registreren op www.allergieradar.nl. De App bepaalt uw locatie op basis van uw positie ten opzichte van de zendmasten. Indien de GPS aan staat wordt van die optie gebruik gemaakt. U kunt ook op Allergieradar.nl uw vaste locaties aanmaken en deze in de App selecteren. De klachtenscores dienen voor wetenschappelijk onderzoek. Daarmee kan de hooikoortsverwachting en informatievoorziening naar hooikoortspatiënten verbeterd worden.
Standard methods for maintaining adult Apis mellifera in cages under in vitro laboratory conditions
Williams, G.R. ; Alaux, C. ; Costa, C. ; Csaki, C. ; Steen, J.J.M. van der - \ 2013
Journal of Apicultural Research 52 (2013)1. - ISSN 0021-8839
honey-bee workers - division-of-labor - nosema-ceranae microsporidia - proboscis extension response - juvenile-hormone - carbon-dioxide - paenibacillus-larvae - gamma-irradiation - pollen - colony
Adult honey bees are maintained in vitro in laboratory cages for a variety of purposes. For example, researchers may wish to perform experiments on honey bees caged individually or in groups to study aspects of parasitology, toxicology, or physiology under highly controlled conditions, or they may cage whole frames to obtain freshly emerged workers of known age cohorts. Regardless of purpose, researchers must manage a number of variables, ranging from selection of study subjects (e.g. honey bee subspecies) to experimental environment (e.g. temperature and relative humidity). Although decisions made by researchers may not necessarily jeopardize the scientific rigour of an experiment, they may profoundly affect results, and may make comparisons with similar, but independent, studies difficult. Focusing primarily on workers, we provide recommendations for maintaining adults under in vitro laboratory conditions, whilst acknowledging gaps in our understanding that require further attention. We specifically describe how to properly obtain honey bees, and how to choose appropriate cages, incubator conditions, and food to obtain biologically relevant and comparable experimental results. Additionally, we provide broad recommendations for experimental design and statistical analyses of data that arises from experiments using caged honey bees. The ultimate goal of this, and of all COLOSS BEEBOOK papers, is not to stifle science with restrictions, but rather to provide researchers with the appropriate tools to generate comparable data that will build upon our current understanding of honey bees
Effecten van Varroa en stuifmeelaanvoer op bijenvolken
Dooremalen, Coby van - \ 2013
apidae - honey bees - causes of death - animal diseases - varroa - pollen - pollinators - animal physiology - animal health
Beheersing dopluis in Ilex verticillata : dopluis bestrijden maar bijen sparen
Elberse, I.A.M. ; Linden, A. van der - \ 2013
Lisse : Praktijkonderzoek Plant en Omgeving BBF - 43
houtachtige planten als sierplanten - ilex verticillata - parthenolecanium corni - plantenplagen - timing - bestrijdingsmethoden - bloeidatum - apidae - honingbijen - stuifmeel - alternatieve methoden - landbouwkundig onderzoek - organismen ingezet bij biologische bestrijding - ornamental woody plants - plant pests - control methods - flowering date - honey bees - pollen - alternative methods - agricultural research - biological control agents
De laatste jaren vormt dopluis (Parthenolecanium corni) een geducht probleem voor de kwekers van de snijheester Ilex verticillata. Het gewas wordt geteeld voor de snij van takken met rode bessen. Het algemene bestrijdingsadvies voor dopluis is om een bespuiting uit te voeren op het moment dat de jonge dopluizen uitzwermen onder de dop van de moeder vandaan. Ze zijn dan het kwetsbaarst, omdat ze dan nog geen beschermende dop hebben. Bij Ilex valt dit moment echter samen met de bloeiperiode. Op dat moment worden bijen ingezet voor de bestuiving, nodig voor een goede beszetting. Veel middelen zijn schadelijk voor bestuivers en kunnen dus niet worden gebruikt. Het gevolg is dat dopluis onvoldoende bestreden wordt. Een bijkomend probleem is dat in deze periode van het jaar het middel moeilijk op de juiste plaats komt door het dichte gewas. De volgende oplossingsrichtingen werden verkend: ander bestrijdingstijdstip, bij-vriendelijker middelen, benutten natuurlijke vijanden en gemakkelijk verwijderen doppen tijdens afbroei van het blad.
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