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Deelgebied 1, de eerste fase van Oosterwold (aan de westkant van de A27) is volop in ontwikkeling. Het is tijd om vooruit te kijken naar de doorontwikkeling van Oosterwold: de tweede fase in deelgebied 2. Hier ligt een uitdagende opgave: het gaat om een enorm gebied dat geen ‘tabula rasa’ is maar wel een van de meest uitgestrekte open poldergebieden van Nederland betreft. De belofte van het plan Oosterwold van MVRDV is groots: wat is er nodig om deze belofte daadwerkelijk te verzilveren? Dit rapport bestaat uit twee delen: de analyse (van Oosterwold fase 1 plus een gebiedsanalyse gericht op deelgebied 2) en een schetsboek met daarin voorstellen voor oplossingen op verschillende schaalniveaus voor deelgebied 2.

Colorectal cancer stem cells (CSCs) express Lgr5 and display extensive stem cell-like multipotency and self-renewal and are thought to seed metastatic disease. Here, we used a mouse model of colorectal cancer (CRC) and human tumor xenografts to investigate the cell of origin of metastases. We found that most disseminated CRC cells in circulation were Lgr5- and formed distant metastases in which Lgr5+ CSCs appeared. This pl

Competition for freshwater resources, and legal restrictions on discharge of agrochemicals (plant protection products and fertilisers) increase pressure on agricultural practice to improve water-use-efficiency of crop production globally. Zero-discharge greenhouse crop production can be an effective solution to both problems. Preliminary results of experiments with cucumber and sweet pepper on stone wool substrate in two greenhouse compartments showed that productivity did not differ in zero-discharge growing compared to standard growing strategies. In this paper we present the final evaluation of the sweet pepper trial (December 2014-November 2015). In the reference compartment a total amount of 465 m3 ha-1 year-1 (169.3 kg N) was discharged. In the zero-discharge compartment there was no discharge during cropping. The nutrient composition of irrigation and drain water was analysed weekly (compared to two-weekly in reference) and nutrient stock composition was changed accordingly. Drain water was filtered with a flatbed filter (no rinsing water) and upon changes in fertigation, the new fertigation solution was first distributed throughout the entire irrigation system by a circulation pump, before application. An irrigation strategy was developed for the end of the cropping season, aiming to drain substrate slabs and to empty drain tanks as much as possible and reduce the amount of remaining nutrients in the slabs, without compromising productivity. Water-use-efficiency of the zero-liquid discharge strategy could be optimised by steering towards more generative crop growth.

To apply to the Dutch generic obligation to purify discharge water, each horticultural company needs to treat it’s discharge water with a technology that removes 95% of plant protection products. This report shows the process that growers need to go through to make a good choice for a purification technology: mapping of water flows, decrease the amount of discharge water, determine the strategy to apply to the generic obligation and make a choice for a purification technology. For a cucumber production company and a company that combines vegetable plant propagation and growth of potted plants this process is followed. A design for a purification system is developed and built for a semi-practice scale cucumber and sweet pepper production system. In the semi-practice scale and the cucumber production company, an ozone installation (Agrozone) is chosen, either to disinfect drain water and eventually purify discharge water. At the propagation company, an Opticlear Diamond (WaterIQ) is chosen to disinfect the drain water and eventually purify discharge water. For both installations the purification efficacy is measured. In the second part of the project the practical format for the generic obligation for discharge water purification is elaborated., Om te kunnen voldoen aan de generieke zuiveringsplicht, moet ieder glastuinbouwbedrijf zijn lozingswater behandelen met een techniek die ten minste 95% van de gewasbeschermingsmiddelen uit het water verwijdert. In dit rapport is het proces weergegeven dat telers moeten doorlopen om een goede keuze te kunnen maken voor een zuiveringstechniek: waterstromen in kaart brengen, hoeveelheid lozingswater verlagen, strategie bepalen om te voldoen aan de zuiveringsplicht en een keuze maken voor een bepaald type zuiveringstechniek. Voor een komkommerbedrijf en een gecombineerd bedrijf met opkweek groenteplanten en op- en afkweek van potplanten is dit proces doorlopen. Voor een semi-praktijk situatie is een ontwerp gemaakt van een systeem om het lozingswater op een efficiënte manier te zuiveren. In de semi-praktijksituatie en bij het komkommerbedrijf is gekozen voor een installatie op basis van ozon (Agrozone), zowel om drainwater te ontsmetten als lozingswater te zuiveren. Bij de plantenkwekerij is gekozen voor een Opticlear Diamond (WaterIQ), ook om drainwater te ontsmetten en indien nodig lozingswater te zuiveren. Voor beide installaties is in (semi)praktijksituatie het zuiveringsrendement gemeten. In het tweede deel van het project is de uitvoeringsvorm van de zuiveringsplicht uitgewerkt

The area of strawberries cultivated in glasshouses is currently expanding. Glasshouse strawberries can guarantee a secure supply and a high fruit quality level, but several aspects of this production system may conflict with today’s societal demands for sustainability, such as the avoidance of the use of pesticides, prevention of residuals on fruits, lowering the energy demand and avoiding negative effects on environmental water quality.

Contains fulltext : 171484.pdf (Publisher’s version ) (Open Access), AIMS/HYPOTHESIS: Dynamic processes in pancreatic tissue are difficult to study. We aimed to develop an intravital imaging method to longitudinally examine engraftment, vascularisation, expansion and differentiation in mature islets or embryonic pancreases transplanted under the kidney capsule. METHODS: Isolated pancreatic islets from adult mice and murine embryonic day (E)12.5 pancreases containing fluorescent biomarkers were transplanted under the kidney capsule of immunodeficient recipient mice. Human islet cells were dispersed, transduced with a lentivirus expressing a fluorescent label and reaggregated before transplantation. Graft-containing kidneys were positioned subcutaneously and an imaging window was fitted into the skin on top of the kidney. Intravital imaging using multiphoton microscopy was performed for up to 2 weeks. Volumes of fluorescently labelled cells were determined as a measure of development and survival. RESULTS: Transplanted islets and embryonic pancreases showed good engraftment and remained viable. Engraftment and vascularisation could be longitudinally examined in murine and human islet cells. Murine islet beta cell volume was unchanged over time. Transplanted embryonic pancreases increased to up to 6.1 times of their original volume and beta cell volume increased 90 times during 2 weeks. CONCLUSIONS/INTERPRETATION: This method allows for repeated intravital imaging of grafts containing various sources of pancreatic tissue transplanted under the kidney capsule. Using fluorescent markers, dynamic information concerning engraftment or differentiation can be visualised and measured.

Het is noodzakelijk zuiveringstechnieken op een objectieve manier te toetsen op effectiviteit in de verwijdering van gewasbeschermingsmiddelen uit glastuinbouw lozingswater met water dat representatief is voor de glastuinbouw. Hiervoor is het in dit document beschreven ‘Standaard Water’ ontwikkeld. Dit water wordt gebruikt om op een gestandaardiseerde en reproduceerbare manier technologieën te beoordelen en heeft daarom een vastgestelde samenstelling. Het water dient als standaard voor lozingswater uit zowel substraat- als grondgebonden teelten en bevat nutriënten en sporenelementen, organische en minerale vervuiling en gewasbeschermingsmiddelen.

Het onderzoeksprogramma PPS Glastuinbouw Waterproof heeft als doel oplossingen te ontwikkelen om de emissies van nutriënten en gewasbeschermingsmiddelen via water terug te brengen tot nagenoeg nul in 2027. Om de emissies van gewasbeschermingsmiddelen terug te dringen zijn er in principe vier wegen die bewandeld kunnen worden. In dit artikel wordt hier verder op ingegaan.

Taxanes, such as docetaxel, are microtubule-targeting chemotherapeutics that have been successfully used in the treatment of cancer. Based on data obtained from cell cultures, it is believed that taxanes induce tumor cell death by specifically perturbing mitotic progression. Here, we report on data that suggest that this generally accepted view may be too simplified. We describe a high-resolution intravital imaging method to simultaneously visualize mitotic progression and the onset of apoptosis. To directly compare in vitro and in vivo data, we have visualized the effect of docetaxel on mitotic progression in mouse and human colorectal tumor cell lines both in vitro and in isogenic tumors in mice. We show that docetaxel-induced apoptosis in vitro occurs via mitotic cell death, whereas the vast majority of tumor cells in their natural environment die independent of mitotic defects. This demonstrates that docetaxel exerts its anti-tumor effects in vivo through means other than mitotic perturbation. The differences between in vitro and in vivo mechanisms of action of chemotherapeutics may explain the limited response to many of the anti-mitotic agents that are currently validated in clinical trials. Our data illustrate the requirement and power of our intravital imaging technique to study and validate the mode of action of chemotherapeutic agents in vivo, which will be essential to understand and improve their clinical efficacy., Taxanes, such as docetaxel, are microtubule-targeting chemotherapeutics that have been successfully used in the treatment of cancer. Based on data obtained from cell cultures, it is believed that taxanes induce tumor cell death by specifically perturbing mitotic progression. Here, we report on data that suggest that this generally accepted view may be too simplified. We describe a high-resolution intravital imaging method to simultaneously visualize mitotic progression and the onset of apoptosis. To directly compare in vitro and in vivo data, we have visualized the effect of docetaxel on mitotic progression in mouse and human colorectal tumor cell lines both in vitro and in isogenic tumors in mice. We show that docetaxel-induced apoptosis in vitro occurs via mitotic cell death, whereas the vast majority of tumor cells in their natural environment die independent of mitotic defects. This demonstrates that docetaxel exerts its anti-tumor effects in vivo through means other than mitotic perturbation. The differences between in vitro and in vivo mechanisms of action of chemotherapeutics may explain the limited response to many of the anti-mitotic agents that are currently validated in clinical trials. Our data illustrate the requirement and power of our intravital imaging technique to study and validate the mode of action of chemotherapeutic agents in vivo, which will be essential to understand and improve their clinical efficacy.

Cell dynamics in subcutaneous and breast tumors can be studied through conventional imaging windows with intravital microscopy. By contrast, visualization of the formation of metastasis has been hampered by the lack of long-term imaging windows for metastasis-prone organs, such as the liver. We developed an abdominal imaging window (AIW) to visualize distinct biological processes in the spleen, kidney, small intestine, pancreas, and liver. The AIW can be used to visualize processes for up to 1 month, as we demonstrate with islet cell transplantation. Furthermore, we have used the AIW to image the single steps of metastasis formation in the liver over the course of 14 days. We observed that single extravasated tumor cells proliferated to form "pre-micrometastases," in which cells lacked contact with neighboring tumor cells and were active and motile within the confined region of the growing clone. The clones then condensed into micrometastases where cell migration was strongly diminished but proliferation continued. Moreover, the metastatic load was reduced by suppressing tumor cell migration in the pre-micrometastases. We suggest that tumor cell migration within pre-micrometastases is a contributing step that can be targeted therapeutically during liver metastasis formation., Cell dynamics in subcutaneous and breast tumors can be studied through conventional imaging windows with intravital microscopy. By contrast, visualization of the formation of metastasis has been hampered by the lack of long-term imaging windows for metastasis-prone organs, such as the liver. We developed an abdominal imaging window (AIW) to visualize distinct biological processes in the spleen, kidney, small intestine, pancreas, and liver. The AIW can be used to visualize processes for up to 1 month, as we demonstrate with islet cell transplantation. Furthermore, we have used the AIW to image the single steps of metastasis formation in the liver over the course of 14 days. We observed that single extravasated tumor cells proliferated to form "pre-micrometastases," in which cells lacked contact with neighboring tumor cells and were active and motile within the confined region of the growing clone. The clones then condensed into micrometastases where cell migration was strongly diminished but proliferation continued. Moreover, the metastatic load was reduced by suppressing tumor cell migration in the pre-micrometastases. We suggest that tumor cell migration within pre-micrometastases is a contributing step that can be targeted therapeutically during liver metastasis formation.

The epithelial-mesenchymal transition plays an important role in several developmental processes, tissue repair, but is also associated with fibrosis and cancer. During tumorigenic progression, EMT pathways are used by cancer cells to gain a migratory and invasive phenotype, enabling these cells to metastasize. This increased migratory potential relies on major changes in, for example, cell adhesion molecule (CAM) expression and cytoskeletal reorganization. In this thesis, I discuss the most important transcription factors during EMT, the effects these genes exert at the cellular level, and how these transcription factor aid carcinogenic progression during the different steps of metastasis. Studying the changing cell states during EMT and the responsible signaling pathways during these processes will enhance our understanding of the metastatic cascade and lead to better targeted therapies.

Metastasis, the process by which cells spread from the primary tumor to a distant site to form secondary tumors, is still not fully understood. Although histological techniques have provided important information, they give only a static image and thus compromise interpretation of this dynamic process. New advances in intravital microscopy (IVM), such as two-photon microscopy, imaging chambers, and multicolor and fluorescent resonance energy transfer imaging, have recently been used to visualize the behavior of single metastasizing cells at subcellular resolution over several days, yielding new and unexpected insights into this process. For example, IVM studies showed that tumor cells can switch between multiple invasion strategies in response to various densities of extracellular matrix. Moreover, other IVM studies showed that tumor cell migration and blood entry take place not only at the invasive front, but also within the tumor mass at tumor-associated vessels that lack an intact basement membrane. In this Commentary, we will give an overview of the recent advances in high-resolution IVM techniques and discuss some of the latest insights in the metastasis field obtained with IVM., Metastasis, the process by which cells spread from the primary tumor to a distant site to form secondary tumors, is still not fully understood. Although histological techniques have provided important information, they give only a static image and thus compromise interpretation of this dynamic process. New advances in intravital microscopy (IVM), such as two-photon microscopy, imaging chambers, and multicolor and fluorescent resonance energy transfer imaging, have recently been used to visualize the behavior of single metastasizing cells at subcellular resolution over several days, yielding new and unexpected insights into this process. For example, IVM studies showed that tumor cells can switch between multiple invasion strategies in response to various densities of extracellular matrix. Moreover, other IVM studies showed that tumor cell migration and blood entry take place not only at the invasive front, but also within the tumor mass at tumor-associated vessels that lack an intact basement membrane. In this Commentary, we will give an overview of the recent advances in high-resolution IVM techniques and discuss some of the latest insights in the metastasis field obtained with IVM.

High-resolution intravital imaging (IVM) has proven to be a powerful technique to visualise dynamic processes that are important for tumour progression, such as the interplay between tumour cells and cellular components of the tumour microenvironment. The development of IVM tools, including imaging windows and photo-marking of individual cells, has led to the visualisation of dynamic processes and tracking of individual cells over a time span of days. In order to visualise these dynamic processes, several strategies have been described to develop fluorescent IVM tumour models. Genetic tools to engineer fluorescent tumour cell lines have advanced the applications of cell line-based tumour models to study, for example, changes in behaviour or transcriptional and differentiation state of individual cells in a tumour. In order to study tumour progression, fluorescent genetic mouse models have been engineered that better recapitulate human tumours. These technically challenging tumour models are key in visualising dynamic processes during cancer progression and in the translational aspects of IVM experiments., High-resolution intravital imaging (IVM) has proven to be a powerful technique to visualise dynamic processes that are important for tumour progression, such as the interplay between tumour cells and cellular components of the tumour microenvironment. The development of IVM tools, including imaging windows and photo-marking of individual cells, has led to the visualisation of dynamic processes and tracking of individual cells over a time span of days. In order to visualise these dynamic processes, several strategies have been described to develop fluorescent IVM tumour models. Genetic tools to engineer fluorescent tumour cell lines have advanced the applications of cell line-based tumour models to study, for example, changes in behaviour or transcriptional and differentiation state of individual cells in a tumour. In order to study tumour progression, fluorescent genetic mouse models have been engineered that better recapitulate human tumours. These technically challenging tumour models are key in visualising dynamic processes during cancer progression and in the translational aspects of IVM experiments.

Onderzoek naar nieuwe mogelijkheden voor een gesloten waterkringloop op substraatbedrijven.

Powerpointpresentatie over een project behorend bij het project "de kas als kans", in dit geval de emissieloze kas als kans waarbij geld verdiend kan worden aan water onder andere door het water goed te recirculeren.

Doel van het op deze poster beschreven onderzoek was om inzicht te krijgen in hoe spuitmiddel in drainwater terecht komt, in welke hoeveelheden en hoe is dit te beperken of te voorkomen.

Poster over hoe telers emissie van gewasbeschermingsmiddelen kunnen voorkomen.

Informatieposter waarin oorzaken van spui worden aangegeven en tips worden gegeven om de hoeveelheid spui te verminderen

Informatieposter over emissie van gewasbeschermingsmiddelen. Deze emissie loopt hoofdzakelijk via waterstromen van kassystemen

Powerpoint presentatie van de adviesbijeenkomst van telen met toekomst op 10 december 2009

Powerpoint presentatie van de Themabijeenkomst Potanthurium 2009 waarbij de aandacht gericht was op de emissie van gewasbeschermingsmiddelen en nutriënten

Onderzoek naar effectieve roofmijten in de chrysantenteelt bij de bestrijding van Californische trips

Californische trips(Frankliniella occidentalis) is een belangrijke plaag in de glastuinbouw. In 2000 is een overkoepelend tripsproject gestart, waarin onderzoek van PPO Glastuinbouw en praktijkproeven van DLV Gewasbescherming op elkaar werden afgestemd. Dit resulteerde in onderzoek door PPO aan effectiviteit van bodemroofmijten en gedragsbeinvloedende stoffen. Uit de experimenten gedaan in het bodemroofmijtenonderzoek op de gewassen Impatiens, Petunia, Kalanchoe, Potchrysant, Saintpaulia en Yucca blijkt de bijdrage van bodemroofmijten aan de bestrijding van californische trips minimaal te zijn. De resultaten uit het onderzoek met gedragsbeïnvloedende stoffen laten zien dat er zeker mogelijkheden zijn om met behulp van ´natuurlijke stoffen´ (GNO´s) de tripsbestrijding te verbeteren. Enkele experimentele gedragsbeïnvloedende stoffen werden getest

In veel kasteelten is bladluis een belangrijke plaag. In dit rapport wordt een beschrijving gegeven van onderzoek naar gewasbeschermingsmiddelen van natuurlijke oorsprong (GNO´s), die het gedrag van luizen kunnen beïnvloeden, met als doel deze middelen in te kunnen zetten voor een betere plaagbeheersing. Formulering en dosering van de gebruikte NGO´s en experimentele middelen bleken een groot effect te hebben op het resultaat

In het project 'Telen met toekomst' werken telers met adviseurs, onderzoekers en voorlichters aan geïntegreerde gewasbescherming. Ze doen onder meer ervaring op met natuurlijke vijanden. Het project is er op gericht om de kennis op dat terrein zoveel mogelijk onder telers te versrpeiden. Daarom zijn vijf groepen van elk zeven ondernemers bij komkommer, tomaat, roos, chrysant en potplanten in het leven geroepen

Presentatie over duurzame gewasbescherming voor chrysantenkwekers

Het voorkómen van ziekten en plagen gecombineerd met regelmatige en goede gewaswaarnemingen, is de basis van de geïntegreerde bestrijding in de rozenteelt. Door te investeren in preventie en scouten krijgt de geïntegreerde bestrijding een kans

Heeft de chrysantenteelt ook wat aan de nieuwe roofmijten? De laatste stand van zaken uit het onderzoek

Een korte dompelbehandeling in water van 20°C geeft een goede spintbestrijding van de stek, vergelijkbaar met die van de chemische middelen. Dit resultaat wordt niet of onvoldoende verbeterd door het toevoegen van zepen, spiritus en andere GNO’s aan het dompelwater, of door langere dompeltijden. Er is geen enkele behandeling die zorgt voor 100% doding van spint, inclusief eitjes, behalve Zipper + Spiritus (30 min., 43 °C), maar deze behandeling gaf onacceptabele schade aan de stek. De spintbestrijding is positief beïnvloed door de aanwezigheid van spintroofmijten en spintgalmuglarven in de stektent. Als deze rovers en eventueel andere natuurlijke vijanden in de stektent in voldoende hoge aantallen worden uitgezet zijn zij vermoedelijk een goede aanvulling op dompelbehandelingen om de overgebleven spint (eitje) op te ruimen. De stek ondervindt gauw schade als gevolg van dompelen in sommige middelen; ook kunnen met scherpere middelen de dompeltijden van belang zijn voor de schade. Er is geen schade geconstateerd als gevolg van de warmwater behandelingen.