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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    Interventiestudie Gezonde Schoolpleinen : Het effect op leerlingen van het herinrichten van schoolplein tot gezond schoolplein
    Vries, S. de; Langers, F. ; Goossen, C.M. ; Rijn, S.E.M. van; Vlasblom, E. ; Sterkenburg, R.P. ; Pierik, F.H. - \ 2017
    Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2830) - 113
    kinderen - scholen - basisscholen - gebiedsontwikkeling - campus - gezondheid van kinderen - speelterreinen - spel - kwaliteit van het leven - sociaal welzijn - welzijn - vragenlijsten - beweging - concentreren - concentratie - children - schools - elementary schools - area development - campus - child health - playgrounds - play - quality of life - social welfare - well-being - questionnaires - movement - concentrating - concentration
    Factsheet Groene re-integratiepraktijken voor mensen met psychische problemen
    Hassink, J. ; Vaandrager, L. ; Jansen, Joke - \ 2017
    Wageningen University & Research - 7
    burgers - participatie - sociaal welzijn - gezondheid - herstellen - beplantingen - natuur - beweging - citizens - participation - social welfare - health - reconditioning - plantations - nature - movement
    Gemeenten zijn per 1 januari 2015 verantwoordelijk voor uitvoering van de Jeugdwet, Wmo en de Participatiewet. De invoering van de Participatiewet leidt tot de toestroom van een nieuwe doelgroep waaronder veel mensen met psychische problemen die behoefte hebben aan langdurige ondersteuning.
    De decentralisaties vormen een grote uitdaging voor gemeenten. Niet alleen komen er nieuwe taken op gemeenten af, maar er wordt ook flink bezuinigd. Gemeenten moeten dus meer doen met minder geld. Maar er zijn ook kansen.
    Voor het eerst krijgt één partij, de gemeente, zeggenschap over praktisch het hele sociale domein. De decentralisaties maken dwarsverbanden tussen de Wmo/Awbz, de jeugdzorg en het domein van werk en inkomen mogelijk. Werkplekken waar mensen vanuit de participatiewet, WMO en jeugdzorg terecht kunnen hebben daarom de aandacht van gemeenten.
    Deze factsheet gaat over de mogelijkheden die het groen biedt voor re-integratie van mensen met psychische problemen. Interessante voorbeelden van re-integratie initiatieven zijn stadslandbouwbedrijven, landschapsonderhoud,
    zorgboerderijen, groenonderhoud en groene wijkinitiatieven.
    De factsheet is gebaseerd op literatuuronderzoek, interviews en groepsgesprekken met initiatiefnemers, mensen met psychische problemen die werken in het groen (deelnemers) en betrokken beleidsmedewerkers van verschillende groene re-integratie initiatieven. In deze factsheet komen de volgende thema’s aan bod:
    • Welke vormen van groene re-integratie bestaan er in Nederland?
    • Wat is de mogelijke theoretische onderbouwing en wat zijn de werkzame elementen van groene re-integratie?
    • Wat zijn de randvoorwaarden van groene re-integratie? En wat is er nodig om deze vorm van re-integratie verder in
    te bedden en op te schalen?
    Blijven Bewegen na de BeweegKuur : De rol van groen in de woonomgeving
    Vries, S. de; Langers, F. ; Meis, Jessie ; Berendsen, B. ; Kremers, Stef - \ 2016
    Wageningen : Alterra, Wageningen-UR (Alterra-rapport 2701) - 25
    voeding en gezondheid - lichamelijke activiteit - levensstijl - openbaar groen - herstellen - gezondheid - voeding - beweging - welzijn - nutrition and health - physical activity - lifestyle - public green areas - reconditioning - health - nutrition - movement - well-being
    De BeweegKuur is een leefstijlinterventie die beoogt blijvend gezonder voedings- en beweeggedrag te
    realiseren. Qua beweging is het de bedoeling dat de deelnemers op het eind van de BeweegKuur
    uitstromen naar het reguliere beweegaanbod in hun leefomgeving. In deze studie is gekeken of groen
    in de woonomgeving een rol speelt bij het volhouden van het beweegniveau tot een jaar na afloop van
    de BeweegKuur. Specifiek is gekeken naar a) de rol van groen bij de keuze voor uitstroomactiviteit en
    b) die van uitstroomactiviteit op de kans op uitval. Daarnaast is, min of meer los van de activiteit,
    gekeken naar c) het volhouden van de mate van lichamelijke activiteit in termen van beweegminuten,
    zoals die op het eind van de BeweegKuur bestond.
    Groen voor gezondheid: wat hebben gezondheidsprofessionals nodig? : Achtergronddocument
    Hermans, C.M.L. ; Lemmens, L. ; Postma, A. - \ 2015
    Wageningen : Alterra, Wageningen-UR (Alterra-rapport 2665) - 49
    natuur - openbaar groen - gezondheid - volksgezondheid - omgevingspsychologie - perceptie - welzijn - stress - lichamelijke activiteit - beweging - nature - public green areas - health - public health - environmental psychology - perception - well-being - stress - physical activity - movement
    Natuur werkt positief op gezondheid en welbevinden van mensen. De werkingsmechanismen achter deze positieve relatie zijn bekend: stress vermindert, lichamelijke activiteit neemt toe, de sociale cohesie in de buurt verbetert. Toch wordt natuur nauwelijks ingezet door professionals uit de eerste lijn of publieke gezondheid. Wat belemmert hen en wat zijn de oplossingen?
    Groen en gebruik ADHD-medicatie door kinderen : de relatie tussen de hoeveelheid groen in de woonomgeving en de prevalentie van AD(H)D-medicatiegebruik bij 5- tot 12-jarigen
    Vries, S. de; Verheij, R. ; Smeets, H. - \ 2015
    Wageningen : Alterra, Wageningen-UR (Alterra 2672) - 23
    kinderen - gezondheid van kinderen - aandachtstekort hyperactiviteitstoornis - natuur - omgevingspsychologie - milieu - lichamelijke activiteit - welzijn - gezondheid - beweging - children - child health - attention deficit hyperactivity disorder - nature - environmental psychology - environment - physical activity - well-being - health - movement
    In deze studie is gekeken naar de relatie tussen de hoeveelheid groen in de woonomgeving en het gebruik van ADHD-medicatie door kinderen. De gegevens over het medicijngebruik zijn afkomstig uit de Achmea Health Database. Uit deze database zijn kinderen die in 2011 tussen de 5 en 12 jaar waren, geselecteerd, ongeacht of ze ADHD-medicatie gebruikten of niet. Hieraan zijn middels de 6-positie postcode van het woonadres gegevens over het groen in de woonomgeving (250 m en 500 m) gekoppeld alsmede enkele buurtkenmerken. Van de 274.698 kinderen in de database waren voor 248.270 kinderen alle gegevens beschikbaar. De uitval werd voornamelijk veroorzaakt door tussentijdse verhuizingen. Middels multilevel logistische regressieanalyse is de relatie tussen de hoeveelheid groen in de woonomgeving en het al dan niet gebruiken van een ADHD-medicijn geanalyseerd.
    Quantifying and simulating movement of the predator carabid beetle Pterostichus melanarius in arable land
    Allema, A.B. - \ 2014
    Wageningen University. Promotor(en): Joop van Lenteren, co-promotor(en): Walter Rossing; Wopke van der Werf. - Wageningen : Wageningen University - ISBN 9789461739100 - 133
    bouwland - insectenplagen - natuurlijke vijanden - roofinsecten - predatoren - pterostichus melanarius - verspreiding - beweging - diergedrag - kwantitatieve analyse - motiliteit - modelleren - methodologie - arable land - insect pests - natural enemies - predatory insects - predators - pterostichus melanarius - dispersal - movement - animal behaviour - quantitative analysis - motility - modeling - methodology

    Keywords: landscape entomology, movement ecology, quantifying movement, population spread, habitat heterogeneity, motility, edge-behaviour, diffusion model, model selection, inverse modelling, Pterostichus melanarius, Carabidae, entomophagous arthropod

    Biological control provided by entomophagous arthropods is an ecosystem service with the potential to reduce pesticide use in agriculture. The distribution of entomophagous arthropods and the associated ecosystem service over crop fields is affected by their dispersal capacity and landscape heterogeneity. Current knowledge on entomophagous arthropod distribution and movement patterns, in particular for soil dwelling predators, is insufficient to provide advice on how a production landscape should be re-arranged to maximally benefit from biological pest control. Movement has mainly been measured in single habitats rather than in habitat mosaics and as a consequence little information is available on behaviour at habitat interfaces, i.e. the border between two habitats.

    This study contributes to insight into movement patterns of the entomophagous arthropod Pterostichus melanarius (Illiger) in an agricultural landscape as a knowledge basis for redesign of landscapes for natural pest control. Movement patterns were studied with video equipment in experimental arenas of 5 m2 and with mark-recapture at much larger scales in the field. Interpretation of the results was supported by diffusion models that accounted for habitat specific motility µ (L2 T−1), a measure for diffusion of a population in space and time, and preference behaviour at habitat interfaces.

    Movement of carabids has mostly been quantified as movement rate, which cannot be used for scaling-up. Available information on movement rate of carabids was made available for scaling-up by calculating motility from published data and looking for patterns through meta-analysis of data from thirteen studies, including 55 records on twelve species. Beetles had on average a three times higher motility in arable land than in forest/hedgerow habitat. The meta-analysis did not identify consistent differences in motility at the individual species level, and a grouping of species according to gender or size did not demonstrate a significant gender or size effect.

    A methodology to directly estimate motility from data using inverse modelling was evaluated on data of a mass mark-recapture field experiment in a single field of winter triticale (x Triticosecale Wittmack.). Inverse modelling yielded the same result as motility calculated from squared displacement distances. In the first case, motility was calculated as an average over motility of individuals, in the second case motility was estimated from a population density distribution fitted to the recapture data. The similarity in motility between these two very different approaches strengthens the confidence in motility as a suitable concept for quantifying dispersal rate of carabid beetles, and in inverse modelling as a method to retrieve movement parameters from observed patterns.

    The effect of habitat heterogeneity on movement behaviour was studied for P. melanarius across adjacent fields of oilseed radish (Raphanus sativus) and rye (Secale cereale) in a mark-recapture experiment. The field study was complemented by observations on movement behaviour in the experimental arena. Motility was neither significantly different between the crop species in the field nor in the arena. Overall movement in the field was significantly affected by behaviour at the interface between the crops. Beetles moved more frequently from rye to oilseed radish than in the opposite direction. The arena data indicated greater frequency of habitat entry into oilseed radish as compared to rye. Analysis of video tracking data from the arena resulted in estimates of motility that, when scaled up were close to those obtained in the field. Thus, the studies at the smaller and larger scales gave qualitatively and quantitatively similar results.

    The effect of habitat heterogeneity on within-season dispersal behaviour was further explored in an agricultural landscape mosaic comprising perennial strips and different crop species with distinct tillage management. Semi-natural grass margins were functionally different from the crop habitats. Motility was lower in margins than in crop habitats, and at the crop-margin interface more beetles moved towards the crop than to the margin. Margins thus effectively acted as barriers for dispersal. In the crop habitats motility differed between fields but no consistent relations were found with crop type, food availability or tillage. Based on the motility in crop habitats P. melanarius was predicted to disperse over a distance of about 100 – 160 m during a growing season in a landscape without semi-natural elements. Given this range little redistribution of beetles is expected between fields within a growing season, even more when fields are surrounded by grass margins or hedgerows, meaning that the success of biological control by this species is more dependent on field management affecting local population dynamics than on habitat heterogeneity.

    This thesis has resulted in a methodological approach to quantify dispersal behaviour of ground-dwelling insects from mark-recapture data in heterogeneous environments using inverse modelling. The combination of models and data proved to be powerful for studying movement and contributes to the development of predictive dynamic models for population spread of entomophagous arthropods. These models for population spread may be used as part of multi-objective assessment of alternative landscape configurations to find spatial arrangements of land use that maximize the ecosystem service of biological control as part of a wider set of landscape functions.

    Tegen de stroom in (interview met Arjan Palstra)
    Ramaker, R. ; Palstra, A.P. - \ 2013
    Resource: weekblad voor Wageningen UR 8 (2013)8. - ISSN 1874-3625 - p. 14 - 15.
    kweekvis - aquacultuur - zwemmen - beweging - viskwekerijen - visvijvers - dierlijke productie - vissen - diergedrag - diergezondheid - farmed fish - aquaculture - swimming - movement - fish farms - fish ponds - animal production - fishes - animal behaviour - animal health
    Vet, gestrest en ongezond. Veel kweekvissen zijn hopeloos uit vorm. Dat is niet alleen slecht voor de vis, maar ook voor de kweker. De oplossing is simpel: vis moet zwemmen.
    Sensor helpt gezondheidsproblemen op te sporen
    Reenen, C.G. van - \ 2012
    V-focus 9 (2012)5a. - ISSN 1574-1575 - p. 44 - 45.
    melkveehouderij - diergezondheid - beweging - tellers - sensors - registreren - dierenwelzijn - dierlijke productie - melkvee - dairy farming - animal health - movement - counters - sensors - recording - animal welfare - animal production - dairy cattle
    Twee jaar lang hebben de koeien op het proefbedrijf ‘Dairy Campus’ van Wageningen UR in Leeuwarden met een Icetag om hun achterpoten gelopen: een sensor die de activiteit van de koe meet. De onderzoekers wilden weten of ze met deze sensoren het gedrag en de gezondheid van de koeien automatisch konden monitoren. Dat blijkt heel redelijk te lukken.
    Het nut van zwemactiviteit voor het kweken van een fittere vis : vis moet zwemmen!
    Palstra, A.P. - \ 2012
    Aquacultuur 27 (2012)3. - ISSN 1382-2764 - p. 7 - 11.
    kweekvis - visteelt - aquacultuur - beweging - zwemmen - farmed fish - fish culture - aquaculture - movement - swimming
    De aquacultuur is gebaat bij een fittere vis die geen misvormingen vertoont, die niet snel ziek wordt, die goed groeit en die een kwaliteitsproduct oplevert.
    Exploring pedestrian movement patterns
    Orellana, D.A. - \ 2012
    Wageningen University. Promotor(en): Arnold Bregt, co-promotor(en): M. Wachowicz; Arend Ligtenberg. - S.l. : s.n. - ISBN 9789461732712 - 140
    beweging - mobiliteit - lopen - geografische informatiesystemen - globale plaatsbepalingssystemen - natuurgebieden - recreatiegebieden - ruimtelijke analyse - patronen - patroonherkenning - natuurtoerisme - openluchtrecreatie - movement - mobility - walking - geographical information systems - global positioning systems - natural areas - amenity and recreation areas - spatial analysis - patterns - pattern recognition - nature tourism - outdoor recreation
    The main objective of this thesis is to develop an approach for exploring, analysing and interpreting movement patterns of pedestrians interacting with the environment. This objective is broken down in sub-objectives related to four research questions. A case study of the movement of visitors in a natural area is used to develop and demonstrate the approach. To achieve the objectives, four research questions were formulated: • How can movement patterns evidencing the stopping behaviour of pedestrians be detected? • What is the validity of the detected movement patterns for describing stopping behaviour of pedestrians? • How can movement patterns be applied to study the movement behaviour of visitors in natural areas? • How can movement patterns be formalized to represent the interactions between pedestrians and between pedestrians and their environment?
    The biomechanical interaction between horse and rider
    Cocq, P. de - \ 2012
    Wageningen University. Promotor(en): Johan van Leeuwen, co-promotor(en): Mees Muller; P.R. van Weeren. - S.l. : s.n. - ISBN 9789461731166 - 206
    paarden - biomechanica - equus - paardrijden - beweging - sporten met dieren - africhten van dieren - horses - biomechanics - equus - horse riding - movement - animal sports - training of animals

    The forces exerted by a rider on a horse have a direct influence on the mechanical load experienced by the horse and consequently on its motion pattern. The aim of this thesis is to explore the biomechanical interaction between rider, saddle and horse in order to get insight in the loading of the horse and to identify potential opportunities to reduce load-related injuries. The influence of man on the horse is mediated trough tack, which functions as an interface between the horse and the human being(s) using it. The tack is often connected to both horse and rider and is therefore well-positioned to incorporate measuring devices that can record the forces between horse and rider.

    So-called saddle-pressure measuring devices have been used to evaluate saddle-fit and could also be a useful tool to study the interaction between horse and rider. However, not much was known thus far about the validity, reliability and usability of these devices for this purpose. Therefore, the first studies in this thesis focussed on this topic. The FSA system was only reliable in highly standardised circumstances. The Pliance system provided reliable and repeatable results and can be used indeed to study the interaction between horse and rider. In this thesis it was used to evaluate the effect of rider position on the force distribution beneath the saddle and to study the signals given by the rider to the horse performing lateral movements in dressage.

    One of the important physical properties of the rider that influences the horse is the rider’s weight. The effect of tack and weight on the movements of the horse was therefore studied. The introduction of a mass with considerable weight on the horse’s back induced an overall extension that might contribute to back injuries.

    During trot, the rider can either rise from the saddle during every stride (rising trot), or remain seated (sitting trot). The back movement during rising trot showed characteristics of both sitting trot and the unloaded condition, with a higher degree of extension during the sitting phase and less extension in the standing phase. In the standing phase peak force on the stirrups is higher, but the overall vertical peak force on the back of the horse is less. This supports the general assumption that rising trot is less demanding for the horse than sitting trot.

    Three spring-(damper-)mass models were constructed to evaluate the biomechanical requirements the rider has to comply with during sitting trot, when using the modern riding technique adopted by jockeys during racing, and in rising trot. The models demonstrate which combinations of rider mass, spring stiffness and damping coefficient will result in these riding modes. Optimization to minimize the peak force of the rider and to minimize the work of the horse resulted in an “extreme” modern jockey technique, which is not adopted by actual riders. The incorporation of an active spring system for the leg of the rider, was needed to simulate the rising trot.

    The general discussion argues that the simultaneous use of a variety of approaches is required to further our understanding of the interaction between horse and rider. A combination of experimental research, which makes use of cutting-edge techniques to measure kinematics of horse and rider, forces acting between horse and rider and between horse and environment, and muscle activation patterns of both horse and rider, with mathematical modelling is the way forward. This combined approach could answer questions concerning the external and internal biomechanical loading of horse and rider of several horse riding and training techniques. Techniques that minimize risk of injury of both horse and rider could possibly be identified, reducing welfare problems of the equine athlete.

    Why elephant roam
    Ngene, S.M. - \ 2010
    University of Twente. Promotor(en): Andrew Skidmore; Herbert Prins; H.A.M.J. van Gils. - Enschede : University of Twente Faculty of Geo-Information and Earth Observation ITC - ISBN 9789061642909 - 195
    loxodonta africana - geografische informatiesystemen - remote sensing - zoögeografie - geografische verdeling - beweging - menselijke activiteit - seizoenen - diergedrag - kenya - menselijke invloed - loxodonta africana - geographical information systems - remote sensing - zoogeography - geographical distribution - movement - human activity - seasons - animal behaviour - kenya - human impact
    The expansion of human activities due to the increase in human population outside protected areas is reducing the range of elephant. This range reduction occurs when elephant habitats are cleared for more farms and settlements. This causes fragmentation of the elephant range, which changes the elephant’ distribution, movement patterns, intensity of occupancy, and speed of movement. The objectives of this study were to use GIS and remote sensing to identify the factors that influence the distribution, intensity of occupancy, and speed of movement of Marsabit elephant; to map and describe their wet and dry season range, intensity of occupancy, and speed of movement, as well as seasonal altitudinal movement in the fragmented mosaic of forest and savanna; to research the cost of humans sharing the environment with the elephant in areas adjacent to Marsabit Protected Area.
    Cortical mechanisms underlying low-level motion processing in the visual system of human and non-human primates
    Bours, R.J.E. - \ 2010
    Wageningen University. Promotor(en): Johan van Leeuwen; R.J.A. Wezel, co-promotor(en): Martin Lankheet. - [S.l.] : S.n. - ISBN 9789085857945 - 158
    ogen - beweging - mens - primaten - hersenen - neurobiologie - neurowetenschap - geest - kenvermogen - eyes - movement - man - primates - mind - neurobiology - neuroscience - cognition
    Leven om te eten : Surinaamse en Antilliaanse vrouwen over eten, bewegen en overgewicht
    Wijk-Jansen, E.E.C. van; Jager, L.C. ; Kroon, S.M.A. van der - \ 2010
    Den Haag : LEI Wageningen UR (Rapport / LEI : Onderzoeksveld Consumenten & gedrag ) - ISBN 9789086154067 - 68
    voedingsgewoonten - overgewicht - beweging - etnische groepen - suriname - nederlandse antillen - vrouwen - gezondheidsbevordering - voeding en gezondheid - feeding habits - overweight - movement - ethnic groups - suriname - netherlands antilles - women - health promotion - nutrition and health
    In dit onderzoek is op basis van literatuurstudie en kwalitatief onderzoek meer inzicht verkregen in verklaringen voor het meer vóórkomen van overgewicht en obesitas bij vrouwen met een Surinaamse en Antilliaanse afkomst. Op basis van deze inzichten wordt een aantal aanbevelingen afgeleid voor overheidscommunicatie over overgewicht en obesitas richting vrouwen met deze afkomst.
    Jeugd, overgewicht en groen : nadere beschouwing en analyse van de mogelijke bijdrage van groen in de woonomgeving aan de preventie van overgewicht bij schoolkinderen
    Vries, S. de; Winsum-Westra, M. van; Vreke, J. ; Langers, F. - \ 2008
    Wageningen : Alterra (Alterra-rapport 1744) - 91
    jeugd - overgewicht - volksgezondheid - kinderen - speelterreinen - recreatiegebieden - stedelijke gebieden - nederland - openbaar groen - natuur - gezondheid - welzijn - lichamelijke activiteit - beweging - youth - overweight - public health - children - playgrounds - amenity and recreation areas - urban areas - netherlands - public green areas - nature - health - well-being - physical activity - movement
    Een in eerder onderzoek gevonden relatie tussen de aanwezigheid van groen en de prevalentie van overgewicht onder schoolkinderen is theoretisch uitgediept. Dit heeft geleid tot een conceptueel model waarin het (zelfstandig) buitenspelen van kinderen een belangrijke schakel vormt. Dat maakt op haar beurt de fysiekruimtelijke (en andere) condities voor deze activiteit van belang. Middels een secundaire analyse van data verzameld door de GGD Regio IJssel-Vecht zijn een aantal uit het model voortvloeiende hypothesen onderzocht. Er werd inderdaad een relatie tussen de hoeveelheid nabij groen en buitenspeeltijd gevonden, maar deze was niet erg sterk. Kanttekening is dat de beschikbare groenindicator niet optimaal was afgestemd op de activiteit. Buitenspeeltijd bleek vervolgens alleen voor jongens (negatief) gerelateerd aan overgewicht. Opvallend was verder de duidelijke relatie tussen buitenspeeltijd en de (door ouders gerapporteerde) gezondheid van het kind, ook na correctie voor overgewicht. Buiten spelen lijkt daarmee meer dan alleen bewegen
    De fysiologie van bewegen : door beweging en aanraking blijven planten korter
    Kierkels, T. ; Heuvelink, E. - \ 2008
    Onder Glas 5 (2008)5. - p. 38 - 39.
    kassen - teelt onder bescherming - sierplanten - beweging - oscillatie - celwanden - verwringing - cultivars - remming - glastuinbouw - groenten - potplanten - greenhouses - protected cultivation - ornamental plants - movement - oscillation - cell walls - distortion - cultivars - inhibition - greenhouse horticulture - vegetables - pot plants
    Door het bewegen of aanraken van planten vervormt de celwand. Dat zet een aantal reacties in werking waardoor uiteindelijk nieuwe cellen korter blijven met dikkere celwanden. Al met al kan trillen, aanraken en borstelen wel perspectief hebben als alternatief voor chemische remming, maar het vergt heel veel uitproberen omdat met de huidige kennis niet te voorspellen valt welk soort of cultivar effectief te remmen valt
    Environmental activism in urban China: the role of personal networks
    Xie Lei, - \ 2007
    Wageningen University. Promotor(en): Arthur Mol. - [S.l.] : S.n. - ISBN 9789085046813 - 246
    stadsomgeving - china - beweging - netwerken (activiteit) - sociale activiteiten - milieubeleid - politieke bewegingen - urban environment - china - movement - networking - social activities - environmental policy - political movements
    The study examines the characteristics of the Chinese environmental movement by looking into the roles played by leaders, activists and their individual networks in environmental NGOs. Looking into individual networks is a vital starting point to examine the dynamics of the Chinese environmental movement, its emergence, growth, and future development. Network analysis will pinpoint the relationships among social actors, while simultaneously identifying the dynamics of the environmental movement by examining the key features of individual networks. With the participation of ENGOs representing the emergence of Chinese civil society, the relationship between the government and civil society will be assessed. In addition, the study will also look into the degree of autonomy of Chinese civil society. Using connections is a characteristic of traditional Chinese society, it is also found as strategies adopted by environmental NGOs. This study will investigate whether the use of individual networks will be a long-term characteristic of Chinese society, or whether it only represents the feature of ENGOs in their early stage. Individual networks can function in three aspects, first they are crucial in institutionalizing Chinese ENGOs in the current policy. Second, individual networks play an important role in the formation of collective identity. And third they facilitate the formation of collective actions, which can be recognized as the formation of the social movement as a whole. Case study methodology will be used to examine how individual networks influence and function in the environmental movement in three urban areas in China.
    Moving to eat : animal foraging movements in a heterogeneous environment
    Hengeveld, G.M. - \ 2007
    Wageningen University. Promotor(en): Herbert Prins, co-promotor(en): Frank van Langevelde. - [S.l.] : S.n. - ISBN 9789085047186 - 112
    foerageren - heterogeniteit - voedingsgedrag - ruimtelijke variatie - voedselopname - beweging - dieren - zoekgedrag - foraging - heterogeneity - feeding behaviour - spatial variation - food intake - movement - animals - searching behaviour
    Animals moving from one place to another transport seeds, parasites, genes and grazing pressure. Insight in the spatial linkage between ecological processes can be gained from understanding the driving forces behind animal movement patterns. From this understanding predictions can be made about which patterns are most likely to be encountered. This thesis addresses the role of foraging in animal movement. Central is the study of the searching efficiency and diffusion of Lévy random searches, both through computer simulations and experiments with goats and ring doves. These computer simulations show that the interactions with targets are crucial in optimising Lévy random searches. Additionally, predictions are made about which foraging decisions animals should make in order to optimise their intake of several nutrients. Finally it is shown how different movement patterns can be incorporated in mean-field approaches of ecology.
    Mechanisms underlying Cowpea mosaic virus systemic infection
    Santos Silva, M. - \ 2004
    Wageningen University. Promotor(en): R.W. Goldbach, co-promotor(en): Jan van Lent; Joan Wellink. - Wageningen : S.n. - ISBN 9789085040385 - 118
    koebonenmozaïekvirus - manteleiwitten - vigna unguiculata - beweging - plantenvirussen - ziekteresistentie - cowpea mosaic virus - coat proteins - vigna unguiculata - movement - plant viruses - disease resistance
    Systemic virus infection of plants involves; intracellularreplication, cell-to-cell movement within the inoculated leaf, and subsequently, long-distance spread to other plant parts via the vasculature (vascular movement).Cell-to-cell movement occurs through the plasmodesma (PD), which are regulated channels in the cell wall connecting adjacent cells. These PD are modified by plant viral movement proteins (MPs) to allow passage of a viral RNA-MP complex as happens with Tobacco mosaic virus (TMV),or virions as happens with Cowpea mosaic virus (CPMV). With the latter virus, virions move through tubules built-up from the MP (tubule-guided cell-to-cell movement). For vascular movement, viruses must enter (loading), translocate through, and exit (unloading) from the phloem. Phloem (un)loading occurs through specialized PD, named the pore-plasmodesma-unit (PPU), connecting the companion cell (CC) and sieve element (SE). The PPU allows passage of much larger molecules than mesophyll PD do. Because of the peculiarities inherent to phloem tissue (e.g. PPU), mechanisms of cell-to-cell movement are usually distinct from those of vascular movement (reviewed in Chapter 1) for the same virus. For instance, TMV requires the viral coat protein (CP) for transport of virions through PPU, but the CP is dispensable for cell-to-cell movement. The success of plant virus infection is also the consequence of an antagonistic balance between viral infection and plant host defence mechanisms that specifically target viral replication (e.g. RNA silencing), or movement (e.g. systemic acquired resistance). In this research thesis CPMV was used as a model for investigations on the mechanisms of systemic infection of plants. Since CPMV replication and cell-to-cell movement are well-investigated, the thesis research was concentrated on vascular movement of CPMV and on barriers imposed by different plant species against systemic infection by this virus.To examine the characteristics of vascular movement in Vigna unguiculata (cowpea), GFP-expressing CPMV (CPMV-GFP) was mechanically inoculated to primary leaves and infection was followed over time (Chapter 2). CPMV-GFP was loaded into both major and minor veins of the primary leaves and unloaded exclusively from major veins, preferentially class III, in the secondary leaves similar to the route of photo-assimilates via phloem. Using electron microscopy, virus infection was observed in all vascular cell types of the loading and unloading sites, with the exception of CC and SE. Furthermore, tubules transporting virions were never found in the PD connecting; phloem parenchyma cells (PPC) and CC, or CC and SE (i.e. PPU). Since in cowpea the SE is symplasmically connected only to the CC, these observations suggest that, unlike cell-to-cell movement, CPMV vascular movement is not tubule-guided.Mutational analysis by reverse genetics is the most common approach to the study of viral factors necessary for vascular movement. CPMV requires its MP and both coat proteins (CPs) for tubule-guided cell-to-cell movement, deletion of any of these genes results in impeded local spread and this restriction severely hampers application of reverse genetics on CPMV for this purpose. In Chapter 3, an attempt was made to circumvent this problem by providing the CPs intrans by agroinfiltration in N. benthamiana to complement cell-to-cell movement of a CPMV mutant devoid of CPs (CPMV-DCP). The aim was to observe whether the mutant would exit from vascular tissue in the absence of CPs in the upper leaves. Whiletrans complementation of CPMV-DCP cell-to-cell movement was demonstrated in planta , the extent of spread was not sufficient to allow CPMV-DCP phloem loading, thus the phloem unloading of the mutant within the upper leaves could not be analysed. Immunoblot analysis of vascular sap from infected cowpea plants showed the presence solely of viral CPs. Furthermore, virions were found in the vasculature of CPMV-immune cowpea scions grafted on CPMV-inoculated susceptible rootstocks (Chapter 3). These results indicate that CPMV circulates in the vasculature in form of mature virions. However, it could not be unequivocally determined whether virions were located in the phloem or in the xylem. As systemic spread by xylem has been reported for beetle transmissible viruses like CPMV, beetle transmission was mimicked by gross-wound inoculation (Chapter 3). However, in this case, as with mechanical inoculation using an abrasive, CPMV spread systemically via the phloem, i.e. directed to sink-leaves solely like the flow of photo-assimilates. This confirms that phloem is the prevailing route for CPMV vascular movement.The potential role of RNA silencing during establishment of infection by CPMV was studied in Chapter 4. Using GFP-expressing CPMV constructs and N. benthamiana as host, the number of infection foci was recorded in the absence or presence of different viral suppressors of RNA silencing, i.e. potyviral HC-Pro, tospoviral NSs and cucumoviral 2b. Upon inoculation with CPMV in vitro transcripts, HC-Pro and NSs, but not 2b, significantly increased the number of CPMV primary infection foci. These results indicate that RNA silencing already has an impact on the establishment of infection even at an early stage. Interestingly, the stimulating effect of suppressors was not observed upon inoculation with virions. This effect may be explained by the recent finding (Lomonossoff, personal communication) that the small (S) CP acts as a suppressor of RNA silencing. To assess the effect of RNA silencing on viral local spread, GFP-expressing CPMV constructs impaired in local spread were tested in the presence or absence of HC-Pro or NSs. Neither of these proteins affected the progress of infection, indicating that RNA silencing does not play a major role in this stage. In Chapter 5, N. tabacum , a semi-permissive host of CPMV, was used to further unravel the viral systemic infection process. CPMV does not infect N. tabacum systemically despite extensive local spread in inoculated leaves. It is shown that neither incubation temperature nor RNA silencing-, salicylic acid- or ethylene-mediated resistance mechanisms are the limiting factor for CPMV systemic infection. Although CPMV-infected N. tabacum plants are normally asymptomatic, symptoms (i.e. necrotic lesions) in the inoculated leaves were observed at low (15 °C) temperature, but not systemic movement. Grafting experiments indicate that CPMV is not capable of phloem loading in N. tabacum , a finding that makes this plant species an interesting system for investigations of the host factors involved in CPMV vascular movement.Finally, in Chapter 6 possible mechanisms of vascular movement of CPMV are presented based on the results obtained in this thesis. Moreover, the various virus-host interactions, which contribute to the success or failure of systemic infection, are put into perspective.
    Invloed van spoorbreedte op spuitboombewegingen
    Michielsen, J.G.P. ; Zande, J.C. van de - \ 2003
    Wageningen : IMAG (Nota / Instituut voor Milieu- en Agritechniek (IMAG) P 2003-24) - 29
    landbouwtechniek - spuitapparaten - veldspuiten - zelfrijdende machines - beweging - yaw - drift - spuitbomen - akkerbouw - stabiliteit - agricultural engineering - sprayers - field sprayers - self propelled machines - movement - yaw - drift - spray booms - arable farming - stability
    In 2002 is een onderzoek uitgevoerd naar het effect van de spoorbreedte van een zelfrijdende veldspuit op spuitboombewegingen.
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