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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    Scaling sustainable nutrition for all (SN4A) in Zambia : Report community mapping
    Hove, Hermine ten; Bakker, Sanne - \ 2020
    Wageningen : Wageningen Centre for Development Innovation (Report / Wageningen Centre for Development Innovation WCDI-20-110) - 59
    This report present the finding of community mapping exercise conducted in February 2020 in Zambia. The community mapping was done in six communities in the three new Scaling Sustainable Nutrition for All (SSN4A) districts: Lunte (rural), Mporokoso (rural, peri-urban) and Mungwi (rural, peri-urban, urban), with the goal to get familiar with the context and day-to-day realities of the targeted communities, find out about the resources in place (e.g. access to water, markets, agricultural plots), their condition and use by the community; find out which social structures and differences exist in the community, and to develop a common understanding about main issues opportunities, and challenges the community faces.
    Congener patterns of polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls as a useful aid to source identification during a contamination incident in the food chain
    Hoogenboom, Ron L.A.P. ; Malisch, Rainer ; Leeuwen, Stefan P.J. van; Vanderperren, Huig ; Hove, Helge ; Fernandes, Alwyn ; Schächtele, Alexander ; Rose, Martin - \ 2020
    Science of the Total Environment 746 (2020). - ISSN 0048-9697
    Chlorophenols - Congener patterns - Dioxins - Drying - Incidents - PCBs

    Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) are still considered among the most important groups of contaminants in the food chain. Self-control by food producers and official control by authorities are important activities that allow contaminant sources to be traced and promote further reduction in food and feed levels. Strict but feasible maximum levels were set by the EU Commission for food and feed to support this strategy, as well as action levels and thresholds. When products exceed these levels, it is important to trace the source of contamination and take measures to remove it. Congener patterns of PCDD/Fs and PCBs differ between sources and are important tools for source identification. Therefore, patterns associated with different sources and incidents relating to various feed matrices and certain agricultural chemicals were collated from published scientific papers, with additional ones available from some laboratories. The collection was evaluated for completeness by presentations at workshops and conferences. Primary sources appear to derive from 5 categories, i) by-products from production of organochlorine chemicals (e.g. PCBs, chlorophenols, chlorinated pesticides, polyvinyl chloride (PVC)), ii) the result of combustion of certain materials and accidental fires, iii) the use of inorganic chlorine, iv) recycling/production of certain minerals, and v) certain naturally occurring clays (ball clay, kaolinite). A decision tree was developed to assist in the identification of the source.

    Disparities in cancer-related healthcare among people with intellectual disabilities:A population-based cohort study with health insurance claims data
    Cuypers, Maarten ; Tobi, Hilde ; Huijsmans, Cornelis A.A. ; Gerwen, Lieke van; Hove, Michiel ten; Weel, Chris van; Kiemeney, Lambertus A.L.M. ; Naaldenberg, Jenneken ; Leusink, Geraline L. - \ 2020
    Cancer Medicine (2020). - ISSN 2045-7634
    early detection of cancer - healthcare disparities - hospital - intellectual disability - neoplasms - oncology service

    Background: Concerns have been raised about the accessibility and quality of cancer-related care for people with intellectual disabilities (ID). However, there is limited insight into cancer incidence and the utilization of cancer care at the ID population level to inform targeted cancer control strategies. Therefore, we aimed to examine differences in the utilization of cancer-related care between people with and without ID, identified through diagnostic codes on health insurance claims. Methods: In a population-based cohort study, Dutch individuals of all ages who received residential care through the Chronic Care Act due to an ID (n = 65 183) and an age and sex-matched sample of persons without ID (1:2 ratio), who were cancer-free at enrollment in 2013 were followed through 2015. Incidence rates (IRs) of newly started cancer care and IR ratios (IRRs) with 95% CIs were used to compare groups. Separate analyses were performed per cancer type. Results: Individuals with ID received less cancer-related care than individuals without (IRR = 0.64, 95% CI 0.62-0.66). Differences increased with age and were larger for females than for males. Utilization of care for cancers within the national screening program (female breast, cervical, and colon cancer) was lower for people with ID compared to people without ID. Conclusion: Cancer may be underdiagnosed and/or undertreated in people with ID, or cancer is truly less prevalent in this population. In particular, the differences detected between males and females with ID, and the potential underutilization of national screening programs, require urgent follow-up investigations.

    Evidence on effects of plant pests on IPPC strategic objectives and monitoring and evaluation mechanisms by the SPS community : Report based on literature review and interviews with SPS organisations
    Kusters, Cecile ; Hove, Hermine ten - \ 2020
    Wageningen : Wageningen Centre for Development Innovation (Report WCDI 20-108) - ISBN 9789463954051 - 44
    This report is commissioned by the International Plant Protection Commission (IPPC) and is the result of a literature review on the effects of plant pests on the IP strategic objectives, as well as interviews and document review on the monitoring and evaluation (M&E) mechanisms of the SPS community. The review shows that there is evidence that the prevention of pests contributes to IPPC’s strategic objectives: enhancing global food security and sustainable agriculture productivity; protecting the environment; and facilitating safe trade, development, and economic growth. However, the context is very important and requires context specific interventions. In particular low-income countries struggle to reduce plant pests and need support in this to help them to also contribute to these overarching objectives. The review also shows that the different SPS organisations have different mechanisms in place for monitoring and evaluation, and these are generally not embedded in a formal monitoring and evaluation system. There is need for more attention to monitoring and evaluation in support of adaptive management of the SPS organisations, that work in often complex environments.
    Conference Report: Monitoring and Evaluation for Inclusive and Sustainable Food Systems 3-4 April 2019, the Netherlands
    Kusters, Cecile ; Hove, Hermine ten; Bosch, Diane ; Herens, Marion ; Wigboldus, Seerp - \ 2019
    Wageningen : Wageningen Centre for Development Innovation (Report / WCDI 19-066) - 43
    Exploring the views of learners and parents on the effects of school feeding : Action research in the TIDE School Milk Programme, South West Uganda
    Hove, Hermine ten; Roefs, Marlene ; Herens, Marion ; Kizito, Frederick ; Katungye, Vincent ; Mugabi, Faith ; Wasswa, Cosma ; Mugizi, Dan - \ 2019
    Wageningen : Wageningen Centre for Development Innovation (Wageningen Centre for Development Innovation report 19-078) - 35
    This report presents the results of the second phase of the action research on the SNV TIDE School Milk Programme (SMP). The study explores the views of learners and their parents on three aspects ofschool feeding that were identified in the first phase. These areas are 1) Relation between school and home feeding, 2) (Rise of) inequality among learners and 3) Sharing food in school. Focus group interviews were held with parents and learners in three schools, split into groups based on the level of participation in the programme.
    Review of the draft CDC Food & Agriculture Impact Framework : Report for the Food and Agriculture Division of the CDC Group
    Kusters, C.S.L. ; Blomne Sopov, M. ; Wattel, C.J. ; Hove, Hermine ten - \ 2019
    Wageningen : Wageningen Centre for Development Innovation (WCDI-19-071 ) - 81 p.
    A SOSEKI-based coordinate system interprets global polarity cues in Arabidopsis
    Yoshida, Saiko ; Schuren, Alja van der; Dop, Maritza van; Galen, Luc van; Saiga, Shunsuke ; Adibi, Milad ; Möller, Barbara ; Hove, Colette A. ten; Marhavy, Peter ; Smith, Richard ; Friml, Jiri ; Weijers, Dolf - \ 2019
    Nature Plants 5 (2019)2. - ISSN 2055-026X - p. 160 - 166.

    Multicellular development requires coordinated cell polarization relative to body axes, and translation to oriented cell division 1–3 . In plants, it is unknown how cell polarities are connected to organismal axes and translated to division. Here, we identify Arabidopsis SOSEKI proteins that integrate apical–basal and radial organismal axes to localize to polar cell edges. Localization does not depend on tissue context, requires cell wall integrity and is defined by a transferrable, protein-specific motif. A Domain of Unknown Function in SOSEKI proteins resembles the DIX oligomerization domain in the animal Dishevelled polarity regulator. The DIX-like domain self-interacts and is required for edge localization and for influencing division orientation, together with a second domain that defines the polar membrane domain. Our work shows that SOSEKI proteins locally interpret global polarity cues and can influence cell division orientation. Furthermore, this work reveals that, despite fundamental differences, cell polarity mechanisms in plants and animals converge on a similar protein domain.

    Creating effective case studies : a practical guide to making inclusive agribusiness experiences accessible and inspiring
    Guijt, Joost ; Reuver, Roger ; Hove, Hermine ten; Brouwer, Jan ; Sopov, Monika ; Salverda, Irene - \ 2018
    Wageningen : Wageningen Centre for Development Studies - 30
    Shining light on gold nanoparticles
    Schijven, L.M.I. ; Wang, J. ; Hove, J.B. ten; Velders, A.H. - \ 2018
    Manipulating and monitoring nanoparticles in micellar thin film superstructures
    Hove, Jan Bart ten; Leeuwen, Fijs W.B. van; Velders, Aldrik H. - \ 2018
    Nature Communications 9 (2018)1. - ISSN 2041-1723

    Understanding the dynamics of discrete self-assembled structures under influence of external triggers is of interest to harvest the potential of nano- and mesoscale materials. In particular, controlling the hierarchical organization of (macro)molecular and nanoparticle building blocks in monolayer superstructures is of paramount importance for tuning properties and characteristics. Here we show how the electron beam in cryo-transmission electron microscopy can be exploited to induce and follow local migration of building blocks and global migration of micellar aggregates inside micrometer-sized superstructures. We employ stroboscopic exposure to heat up and convert the vitrified superstructure into a liquid-like thin film under cryogenic conditions, resulting in controlled evaporation of water that finally leads to rupture of the micelle-containing superstructure. Micelle-embedded nanoparticles prove a powerful tool to study the complex hierarchically built-up superstructures, and to visualize both global movement of individual dendrimicelles and local migration of nanoparticles inside the micellar core during the exposure series.

    Size-controlled and water-soluble gold nanoparticles using UV-induced ligand exchange and phase transfer
    Hove, Jan Bart ten; Schijven, Laura M.I. ; Wang, Junyou ; Velders, Aldrik H. - \ 2018
    Chemical Communications 54 (2018)95. - ISSN 1359-7345 - p. 13355 - 13358.

    Oleylamine-capped gold nanoparticles (AuNPs) with sizes ranging from 5 to 13 nm and narrow size distributions (<10%) are synthesized by using a seeded growth approach. Water-solubility is achieved by using a UV-induced ligand exchange approach, resulting in transfer from the organic to an aqueous phase.

    Cyclodextrin-based complex coacervate core micelles with tuneable supramolecular host–guest, metal-to-ligand and charge interactions
    Facciotti, Camilla ; Saggiomo, Vittorio ; Bunschoten, Anton ; Fokkink, Remco ; Hove, Jan Bart Ten ; Wang, Junyou ; Velders, Aldrik H. - \ 2018
    Soft Matter 14 (2018)47. - ISSN 1744-683X - p. 9542 - 9549.
    Micelles have been recognized as versatile platforms for different biomedical applications, from bioimaging to drug delivery. Complex coacervate core micelles present great advantages compared to traditional micelles, however controlling the number of charges per core-unit and the stability is still a challenge. We here present cyclodextrin-based complex coacervate core micelles where the charge per core-unit can be straightforwardly tuned by cyclodextrin host–guest interactions. By varying the ratio between two adamantane guest molecules, 1-adamantanecarboxylic acid and 1,3-adamantanediacetic acid, the charge of the monomeric core-units can be finely tuned from 6− to 9−. By adding an adamantane bislinker, monomeric core-units can be combined together in dimeric and polymeric structures, increasing the micelles’ stability. The orthogonal supramolecular host–guest and coordination-chemistry allows for well-controlled cyclodextrin-based complex coacervate core micelles that offer a versatile platform for designing future, e.g., responsive systems.
    Clever and cool : generating design guidelines for climate-responsive urban green infrastructure
    Klemm, Wiebke - \ 2018
    Wageningen University. Promotor(en): A. van den Brink, co-promotor(en): S. Lenzholzer; L.W.A. van Hove. - Wageningen : Wageningen University - ISBN 9789463433051 - 289

    Urban heat problems due to global climate change and urbanization may pose a serious risk to thermal comfort related public health in cities. Urban green infrastructure (UGI), such as parks, gardens and street trees, has the ability to alleviate urban heat and improve residents’ thermal comfort during warm summer days. Research in the field of urban micrometeorology delivers insights into the impacts of UGI on objective thermal conditions. Yet, this knowledge lacks insights into impacts of UGI on people’s subjective thermo-spatial perception and does not match the demand of spatially explicit information by urban designers. Consequently, urban designers lack guidance in the design of climate-responsive UGI in outdoor urban spaces.

    The development of a spatially explicit evidence of subjective and objective impacts of UGI on thermal comfort, and based on that evidence the subsequent development of useful design guidelines for climate-responsive UGI, were the objectives of this thesis. The research approach consisted of two phases: The ‘Research for Design’ approach, a combination of qualitative (surveys, observations) and quantitative (micrometeorological measurements) research methods, delivered scientific evidence needed to inform climate-responsive urban design. A set of multiscale case studies was conducted during warm summer periods in the moderate climate of the Netherlands. In a subsequent participatory ‘Research through Designing’ approach the novel scientific evidence was translated into preliminary design guidelines, and applied in practical design settings with landscape architects. Observations, plan analysis and questionnaires provided insights into the usefulness of the guidelines for end-users and directed the refinement into revised design guidelines for climate-responsive UGI.

    ‘Clever and cool’ urban green can be achieved by implementing the design guidelines for climate-responsive UGI. Findings of the first phase demonstrate that UGI enhances residents’ subjective thermal perception and improves thermal conditions in urban environments. This phase provides spatially-explicit evidence of UGI relevant for design. It furthermore shows the importance of residents’ physical adaptation in the context of thermal perception. The second phase delivered evidence-based, generally applicable design guidelines for climate-responsive UGI that are accompanied by visual representations. Additionally operational principles to support site-specific implementation of the guidelines at the respective scales. The practical design settings furthermore showed that urban designers need a basic understanding of microclimate processes and skills to conduct microclimate analysis to appropriately implement the guidelines. Concluding, this thesis argues for climate-responsive UGI that is ‘clever and cool’: UGI that is designed resource efficiently, is based on site-specific microclimate analysis, and considers spatial conditions as well as the behavioural demands of urban dwellers. Through combining perspectives and knowledge of microclimate science and design practice this thesis provides evidence-based solutions that are considered useful by end-users. As such the design guidelines for climate-responsive UGI, as presented in this thesis, can enhance urban design practice for more thermally comfortable and liveable cities now and in the future.

    Income intervention quick scan: agro-corridors : Farmer Income Lab Intervention Quick Scan
    Hove, Hermine ten - \ 2018
    Wageningen : Wageningen Centre for Development Innovation (Report / WCDI 18-024) - 18
    This quick scan, commissioned by the Farmer Income Lab, is part of a wider research effort looking at, “What are the most effective actions that lead buyers can take to enable smallholder farmers in global supply chains to meaningfully increase their incomes?”. The quick scan provides an overview of the publicly available evidence on the impact of agro-corridors have had on raising farmer income. Such subsidies have had little positive effect on farmer income, are not notably beneficial for women nor is this effect long-term. They have been applied at large scale. This quick scan is part of a series of 16, contributing to a synthesis report “What Works to Raise Farmer’s Income: a Landscape Review"
    Income intervention quick scan: savings-led group models : Farmer Income Lab Intervention Quick Scan
    Hove, Hermine ten - \ 2018
    Wageningen : Wageningen Centre for Development Innovation (Report / WCDI 18-037) - 18
    This quick scan, commissioned by the Farmer Income Lab, is part of a wider research effort looking at, “What are the most effective actions that lead buyers can take to enable smallholder farmers in global supply chains to meaningfully increase their incomes?”. The quick scan provides an overview of the publicly available evidence on the impact of savings-led group models have had on raising farmer income. Such subsidies have had little positive effect on farmer income, are not notably beneficial for women nor is this effect long-term. They have been applied at large scale. This quick scan is part of a series of 16, contributing to a synthesis report “What Works to Raise Farmer’s Income: a Landscape Review”.
    Nanoparticles reveal Extreme Size-Sorting and Morphologies in Complex Coacervate Superstructures
    Hove, Jan Bart ten; Oosterom, Matthias N. van; Leeuwen, Fijs W.B. van; Velders, Aldrik H. - \ 2018
    Scientific Reports 8 (2018)1. - ISSN 2045-2322

    We here provide detailed insight in self-assembled complex coacervate systems exploiting gold nanoparticles for cryoTEM contrast. Nanoparticle-containing dendrimicelles are formed from fifth-generation dendrimer-encapsulated nanoparticles (DENs) and dendrimer-stabilized nanoparticles (DSNs). The complex coacervate structures self-organize in biconcave thin water layers into size-sorted monolayer superstructures. The embedded nanoparticles are a straightforward tool to visualize dendrimicelles and determine the aggregation number and polydispersity. The superstructure shows extreme size-sorting patterns which, contrary to related systems with higher generation dendrimers, consists not only of dendrimicelles but also much bigger complex coacervate nanoassemblies, such as vesicles.

    Conference report: Communicating Evidence for Sustainable Development : 4-5 April 2018, the Netherlands
    Kusters, Cecile ; Hove, Hermine ten; Brouwers, Jan ; Mostert, Riti Hermán - \ 2018
    Wageningen : Wageningen Centre for Development Innovation (Wageningen Centre for Development Innovation report WCDI-18-012) - 36
    This report presents the key highlights and contributions from the conference ‘Communicating Evidence for Sustainable Development’. This conference was held on 4-5 April 2018 in Wageningen, the Netherlands and was the eleventh annual ‘M&E on the Cutting Edge’ conference. This event was organised by Wageningen Centre for Development Innovation (WCDI). This conference aimed to seek clarity in the role that communication can play in generating and using evidence for sustainable development
    Onderzoekers helpen bij tellen van vissen in het Noordzeekanaal
    Leuverink, Cecile - \ 2018
    Mesoscale organization of nanoparticle assemblies: looking into superstructures and aggregates
    Hove, Jan Bart ten - \ 2018
    Wageningen University. Promotor(en): A.H. Velders, co-promotor(en): F.W.B. van Leeuwen. - Wageningen : Wageningen University - ISBN 9789463438391 - 181

    For this thesis, the goal was to investigate:

    1) the self-assembly of amine-terminated dendrimers into well-defined dendrimicelles

    2) the use of the micelle embedded nanoparticles as ‘spy’ particles

    3) the effect of a templating matrix on the self-organization of these dendrimicelles into mesoscale superstructures.

    Throughout the thesis, it is shown that well-defined, 50 nm-sized dendrimicelles can be obtained from PAMAM dendrimer generations five through nine. By combining cryoTEM and light scattering experiments, the self-assembly behavior of the dendrimicelles is studied in unique detail. The dendrimicelle-embedded nanoparticles serve a dualistic purpose; not only do they provide additional contrast in the cryoTEM micrographs, they also allow for the direct determination of the micelle aggregation numbers by simply counting the number of nanoparticles.

    Combining food-based dietary recommendations using Optifood with zinc-fortified water potentially improves nutrient adequacy among 4- to 6-year-old children in Kisumu West district, Kenya
    Kujinga, Prosper ; Borgonjen-van den Berg, Karin J. ; Superchi, Cecilia ; Hove, Hermine J. ten; Onyango, Elizabeth Opiyo ; Andang'o, Pauline ; Galetti, Valeria ; Zimmerman, Michael B. ; Moretti, Diego ; Brouwer, Inge D. - \ 2018
    Maternal and Child Nutrition 14 (2018)2. - ISSN 1740-8695
    children - diets - Optifood - water - zinc
    Children in developing countries often face multiple micronutrient deficiencies. Introduction of zinc-fortified water can increase zinc intake, but additional recommendations are required to address overall diet nutrient adequacy. We developed and tested food-based recommendations (FBRs) that included zinc-fortified water for children aged between 4 and 6 years from rural Kenya to achieve the best possible nutrient adequacy. Dietary intakes of 60 children aged 4–6 years, from Kisumu West district, Kenya, were assessed using a quantitative multipass 24-hr recall. Linear programming model parameters were derived, including a list of foods consumed, median serving sizes, and distribution of frequency of consumption. By using the Optifood linear programming tool, we developed FBRs for diets including zinc-fortified water. FBRs with nutrient levels achieving ≥70% recommended nutrient intake (RNI) of the World Health Organization/Food and Agriculture Organization of the United Nations RNI for most of the 12 considered nutrients were selected as the final recommendations for the children. With no FBRs and no zinc-fortified water, percent RNI coverage range was between 40% and 76% for zinc, improving to 66–101% after introduction of zinc-fortified water. The final set of FBRs achieved nutrient adequacy for all nutrients except for vitamin A (25% RNI) and folate (68% RNI). Introduction of zinc-fortified water combined with FBRs will likely improve the nutrient adequacy of diets consumed by children in Kenya but needs to be complemented with alternative interventions to ensure dietary adequacy.
    Linking slow dynamics and microscopic connectivity in dense suspensions of charged colloids
    Higler, Ruben ; Krausser, Johannes ; Gucht, Jasper Van Der; Zaccone, Alessio ; Sprakel, Joris - \ 2018
    Soft Matter 14 (2018)5. - ISSN 1744-683X - p. 780 - 788.
    The quest to unravel the nature of the glass transition, where the viscosity of a liquid increases by many orders of magnitude, while its static structure remains largely unaffected, remains unresolved. While various structural and dynamical precursors to vitrification have been identified, a predictive and quantitative description of how subtle changes at the microscopic scale give rise to the steep growth in macroscopic viscosity is missing. It was recently proposed that the presence of long-lived bonded structures within the liquid may provide the long-sought connection between local structure and global dynamics. Here we directly observe and quantify the connectivity dynamics in liquids of charged colloids en route to vitrification using three-dimensional confocal microscopy. We determine the dynamic structure from the real-space van Hove correlation function and from the particle trajectories, providing upper and lower bounds on connectivity dynamics. Based on these data, we extend Dyre's model for the glass transition to account for particle-level structural dynamics; this results in a microscopic expression for the slowing down of relaxations in the liquid that is in quantitative agreement with our experiments. These results indicate how vitrification may be understood as a dynamical connectivity transition with features that are strongly reminiscent of rigidity percolation scenarios.
    Carbon dioxide fluxes in the city centre of Arnhem, A middle-sized Dutch city
    Kleingeld, Eva ; Hove, Bert van; Elbers, Jan ; Jacobs, Cor - \ 2018
    Urban Climate 24 (2018). - ISSN 2212-0955 - p. 994 - 1010.
    Carbon dioxide - Eddy-covariance - Flux variability - Long-term flux measurements - Source partitioning, emission inventory - Urban

    This paper reports on the temporal variability of carbon dioxide fluxes in the city centre of Arnhem, a middle-sized Dutch city. The fluxes were continuously measured during four years (2012-2016) using the eddy-covariance method. Additionally, continuous meteorological measurements were carried out. We also analysed data from 30-minute traffic counts performed during those years. Results indicate that the city centre of Arnhem is a strong emission source of CO2 compared to many other cities. The measured annual CO2 flux equals about 8.0kgCm-2 yr-1. Heterogeneity within the footprint of the EC tower appeared to have no or only a small influence on the estimated annual and seasonal carbon fluxes. Sector analysis shows that CO2 fluxes are consistently higher in sectors with the highest built-up surface fraction. However, no statistically significant relationship could be determined. Traffic and space-heating related burning of natural gas are the main emission sources. Weekly and diurnal variations in CO2 flux are clearly correlated with traffic intensity, whereas seasonal variation can largely be explained by space heating demand. Partitioning of the total flux into a heating-related and traffic-related flux revealed that space heating accounts for up to 60% to the total flux during winter. Traffic intensity remains more or less constant throughout the year. In summer, when space heating is absent, CO2 emission is almost entirely related to traffic intensity. However, our estimations suggest that human respiration could have a non-negligible share in this. The contribution of the small fraction of urban green in the city centre is probably minimal. The annual emissions for the city centre estimated from our EC measurements are 20-25% lower than those reported for the whole city by the official emission inventory. Climate projections for the Netherlands suggest that in 2050 Heating Degree Days would be reduced by 27% resulting into a 32% reduction of the heating-related emission flux, without a change in fossil fuel use.

    Dendrimer-encapsulated nanoparticle-core micelles as a modular strategy for particle-in-a-box-in-a-box nanostructures
    Hove, J.B. ten; Wang, J. ; Leeuwen, F.W.B. van; Velders, A.H. - \ 2017
    Nanoscale 9 (2017)47. - ISSN 2040-3364 - p. 18619 - 18623.

    The hierarchically controlled synthesis and characterization of self-assembling macromolecules and particles are key to explore and exploit new nanomaterials. Here we present a versatile strategy for constructing particle-in-a-box-in-a-box systems by assembling dendrimer-encapsulated gold nanoparticles (DENs) into dendrimicelles. This is realized by combining positively charged PAMAM dendrimers with a negative-neutral block copolymer. The number of particles per dendrimicelle can be controlled by mixing DENs with empty PAMAM dendrimers. The dendrimicelles are stable in solution for months and provide improved resistance for the nanoparticles against degradation. The dendrimicelle strategy provides a flexible platform with a plethora of options for variation in the type of nanoparticles, dendrimers and block copolymers used, and hence is tunable for applications ranging from nanomedicine to catalysis.

    Size-Sorting and Pattern Formation of Nanoparticle-Loaded Micellar Superstructures in Biconcave Thin Films
    Hove, Jan Bart ten; Wang, Junyou ; Oosterom, Matthias N. van; Leeuwen, Fijs W.B. Van; Velders, Aldrik H. - \ 2017
    ACS Nano 11 (2017)11. - ISSN 1936-0851 - p. 11225 - 11231.
    Biconcave thin water layers represent a template to induce organization of supramolecular structures into ordered monolayers. Here we show how micelles form extensive micrometer-sized pseudo-2D superstructures that reveal size-sorting and geometric pattern formation, as shown by cryo-transmission electron microscopy (cryoTEM). Electron-rich gold particles inside the micelles facilitate direct visualization and determination of size, composition, and ordering of the micellar assemblies over multiple length scales. Some of the patterns observed show intriguing geometric patterns for superstructures, including Fibonacci-like, double-spiral domains that also appear in, for example, sunflower seed head patterns.
    Tropische vis in Nederlandse zee
    Couperus, A.S. - \ 2017
    All-Aqueous Synthesis of Silica-Encapsulated Quantum Dots with Functional Shells
    Feng, Huanhuan ; Hove, Jan Bart ten; Zheng, Tingting ; Velders, Aldrik H. ; Sprakel, Joris - \ 2017
    European Journal of Inorganic Chemistry 44 (2017). - ISSN 1434-1948 - p. 5152 - 5157.
    Encapsulation - Luminescence - Materials science - Quantum dots - Surface functionalization

    We present a simple yet versatile method for encapsulating water-dispersed quantum dots (QDs) in a silica shell. As our approach, does not require ligand exchange, the colloidal stability of the quantum dots is maintained throughout the process, which results in monodisperse core-shell particles of individual quantum dots with a well-defined silica shell whose thickness can be accurately controlled. While other methods often result in a reduction of luminescence, our approach can retain all or even increases the quantum efficiency of the semiconductor dots. We also show how amine-functional groups can be expressed at the surface of the silica shell, while retaining QD photoluminescence properties, allowing further surface functionalization. Finally, we demonstrate the versatility of this strategy by including dopants into the silica shells to tailor the spectral response of the core-shell particles by energy transfer.

    Auxin response cell-autonomously controls ground tissue initiation in the early Arabidopsis embryo
    Moller, Barbara ; Hove, Colette A. ten; Xiang, Daoquan ; Williams, Nerys ; López, Lorena González ; Yoshida, Saiko ; Smit, Margo ; Datla, Raju ; Weijers, Dolf - \ 2017
    Proceedings of the National Academy of Sciences of the United States of America 114 (2017)12. - ISSN 0027-8424 - p. E2533 - E2539.
    Auxin. - Embryogenesis - Ground tissue - Pattern formation - Plant development

    Plant organs are typically organized into three main tissue layers. The middle ground tissue layer comprises the majority of the plant body and serves a wide range of functions, including photosynthesis, selective nutrient uptake and storage, and gravity sensing. Ground tissue patterning and maintenance in Arabidopsis are controlled by a well-established gene network revolving around the key regulator SHORT-ROOT (SHR). In contrast, it is completely unknown how ground tissue identity is first specified from totipotent precursor cells in the embryo. The plant signaling molecule auxin, acting through AUXIN RESPONSE FACTOR (ARF) transcription factors, is critical for embryo patterning. The auxin effector ARF5/MONOPTEROS (MP) acts both cell-autonomously and noncell-autonomously to control embryonic vascular tissue formation and root initiation, respectively. Here we show that auxin response and ARF activity cell-autonomously control the asymmetric division of the first ground tissue cells. By identifying embryonic target genes, we show that MP transcriptionally initiates the ground tissue lineage and acts upstream of the regulatory network that controls ground tissue patterning and maintenance. Strikingly, whereas the SHR network depends on MP, this MP function is, at least in part, SHR independent. Our study therefore identifies auxin response as a regulator of ground tissue specification in the embryonic root, and reveals that ground tissue initiation and maintenance use different regulators and mechanisms. Moreover, our data provide a framework for the simultaneous formation of multiple cell types by the same transcriptional regulator.

    Towards guidelines for designing parks of the future
    Klemm, Wiebke ; Hove, Bert van; Lenzholzer, Sanda ; Kramer, Henk - \ 2017
    Urban Forestry and Urban Greening 21 (2017). - ISSN 1618-8667 - p. 134 - 145.
    Climate change adaptation - Climate-responsive design - Evidence-based landscape architecture - Heat wave - Public park - Thermal comfort
    This study investigated human behaviour in parks in order to develop spatially explicit design guidelines considering future climate conditions in moderate climates. Fieldwork was carried out in two parks (in Utrecht and Wageningen, the Netherlands) during summer and tropical days (Ta max > 25 °C and > 30 °C, respectively), the latter representing future climate conditions. Behavioural responses (park attendance, spatio-temporal user patterns) and thermal perception of resting park visitors were studied through unobtrusive observations (N = 11337) and surveys (N = 317). Outcomes were related to air temperature (Ta) of meteorological reference stations and spatial data on the vegetation structures of the parks. Observational data show that daily park attendance decreased with rising Ta max. Survey results indicate that resting park visitors perceived a high level of thermal comfort during all investigated days. Park visitors chose resting locations predominantly based on solar exposure conditions (sun, half shade, shade). Those solar exposure preferences were significantly related to Ta: with increased Ta the number of park visitors in the shade increased and decreased in the sun (p < 0.001) with a tipping point of 26 °C. These results indicate that parks in moderate climates may guarantee a high level of thermal comfort, even on tropical days, if a variety of solar exposure conditions is guaranteed. A ratio of 40% sun, 20% half shade and 40% shade in parks was derived from spatio-temporal user patterns, which appear to accommodate preferences of resting park visitors under summer and tropical thermal conditions and on various daytimes. These results and a spatial typology of tree configurations for microclimatic variety provide direction for designing future parks: they need to offer a wide range of sun-exposed, half shaded and shaded places to accommodate for different user needs and future climate conditions.
    Carbon accounting using flux measurements
    Elbers, J.A. ; Kleingeld, Eva ; Jacobs, Cor ; Hove, L.W.A. van; Moors, E.J. - \ 2016
    Transcriptional Analysis of serk1 and serk3 coreceptor mutants
    Esse, Wilma van; Hove, Colette A. ten; Guzzonato, Francesco ; Esse, Peter van; Boekschoten, Mark ; Ridder, Lars ; Vervoort, Jacques ; Vries, Sacco C. de - \ 2016
    Plant Physiology 172 (2016)4. - ISSN 0032-0889 - p. 2516 - 2529.

    Somatic embryogenesis receptor kinases (SERKs) are ligand-binding coreceptors that are able to combine with different ligandperceiving receptors such as BRASSINOSTEROID INSENSITIVE1 (BRI1) and FLAGELLIN-SENSITIVE2. Phenotypical analysis of serk single mutants is not straightforward because multiple pathways can be affected, while redundancy is observed for a single phenotype. For example, serk1serk3 double mutant roots are insensitive toward brassinosteroids but have a phenotype different from bri1 mutant roots. To decipher these effects, 4-d-old Arabidopsis (Arabidopsis thaliana) roots were studied using microarray analysis. A total of 698 genes, involved in multiple biological processes, were found to be differentially regulated in serk1-3serk3-2 double mutants. About half of these are related to brassinosteroid signaling. The remainder appear to be unlinked to brassinosteroids and related to primary and secondary metabolism. In addition, methionine-derived glucosinolate biosynthesis genes are up-regulated, which was verified by metabolite profiling. The results also show that the gene expression pattern in serk3-2 mutant roots is similar to that of the serk1-3serk3-2 double mutant roots. This confirms the existence of partial redundancy between SERK3 and SERK1 as well as the promoting or repressive activity of a single coreceptor in multiple simultaneously active pathways.

    Voorbij verbergen of vieren
    Hoogsteyns, M. ; Horst, H.M. van der - \ 2016
    In: Disability Studies in de Lage Landen / van Hove, Geert, Cardol, Mieke, Schippers, Alice, De Schauwer, Elisabeth, Apeldoorn/Antwerpen : Garant Uitgevers - ISBN 9789044134025 - p. 111 - 129.
    Molecular characterization of arabidopsis GAL4/UAS enhancer trap lines identifies novel cell-type-specific promoters
    Radoeva, Tatyana ; Hove, C.A. ten; Saiga, Shunsuke ; Weijers, Dolf - \ 2016
    Plant Physiology 171 (2016)2. - ISSN 0032-0889 - p. 1169 - 1181.
    Cell-type-specific gene expression is essential to distinguish between the numerous cell types of multicellular organism. Therefore, cell-type-specific gene expression is tightly regulated and for most genes RNA transcription is the central point of control. Thus, transcriptional reporters are broadly used markers for cell identity. In Arabidopsis (Arabidopsis thaliana), a recognized standard for cell identities is a collection of GAL4/UAS enhancer trap lines. Yet, while greatly used, very few of them have been molecularly characterized. Here, we have selected a set of 21 frequently used GAL4/UAS enhancer trap lines for detailed characterization of expression pattern and genomic insertion position. We studied their embryonic and postembryonic expression domains and grouped them into three groups (early embryo development, late embryo development, and embryonic root apical meristem lines) based on their dominant expression. We show that some of the analyzed lines are expressed in a domain often broader than the one that is reported. Additionally, we present an overview of the location of the T-DNA inserts of all lines, with one exception. Finally, we demonstrate how the obtained information can be used for generating novel cell-type-specific marker lines and for genotyping enhancer trap lines. The knowledge could therefore support the extensive use of these valuable lines.
    Assembling quantum dots via critical Casimir forces
    Marino, Emanuele ; Kodger, T.E. ; Hove, Jan Bart ten; Velders, A.H. ; Schall, Peter - \ 2016
    Solar Energy Materials and Solar Cells 158 (2016). - ISSN 0927-0248 - p. 154 - 159.
    Assembly - Casimir force - Nanocrystals - Nanomanipulation - Quantum dots

    Programmed assembly of colloidal inorganic nanocrystal superstructures is crucial for the realization of future artificial solids as well as present optoelectronic applications. Here, we present a new way to assemble quantum dots reversibly using binary solvents. By tuning the temperature and composition of the binary solvent mixture, we achieve reversible aggregation of nanocrystals in solution induced by critical Casimir forces. We study the temperature-sensitive quantum-dot assembly with dynamic light scattering. We show that careful screening of the electrostatic repulsion by adding salt provides a further parameter to tune the reversible assembly.

    Bultrug steeds vaker gespot
    Leopold, Mardik - \ 2015
    MMP-2/9-specific activatable lifetime imaging agent
    Rood, Marcus T.M. ; Raspe, Marcel ; Hove, Jan Bart ten; Jalink, Kees ; Velders, A.H. ; Leeuwen, F.W.B. van - \ 2015
    Sensors 15 (2015)5. - ISSN 1424-8220 - p. 11076 - 11091.
    Enzymatic activation - Fluorescence - FRET - Iridium - Lifetime imaging - Luminescence - MMP

    Optical (molecular) imaging can benefit from a combination of the high signal-to-background ratio of activatable fluorescence imaging with the high specificity of luminescence lifetime imaging. To allow for this combination, both imaging techniques were integrated in a single imaging agent, a so-called activatable lifetime imaging agent. Important in the design of this imaging agent is the use of two luminophores that are tethered by a specific peptide with a hairpin-motive that ensured close proximity of the two while also having a specific amino acid sequence available for enzymatic cleavage by tumor-related MMP-2/9. Ir(ppy)3 and Cy5 were used because in close proximity the emission intensities of both luminophores were quenched and the influence of Cy5 shortens the Ir(ppy)3 luminescence lifetime from 98 ns to 30 ns. Upon cleavage in vitro, both effects are undone, yielding an increase in Ir(ppy)3 and Cy5 luminescence and a restoration of Ir(ppy)3 luminescence lifetime to 94 ns. As a reference for the luminescence activation, a similar imaging agent with the more common Cy3-Cy5 fluorophore pair was used. Our findings underline that the combination of enzymatic signal activation with lifetime imaging is possible and that it provides a promising method in the design of future disease specific imaging agents.

    Hoeveel water verdampt de stad?
    Jacobs, C.M.J. ; Elbers, J.A. ; Moors, E.J. ; Hove, L.W.A. van - \ 2015
    Water Matters : Kenniskatern voor Waterprofessionals - Dutch edition (2015)oktober. - p. 34 - 37.
    evaporatie - waterbeheer - stedelijke gebieden - stedelijke samenleving - waterbehoefte - klimaatverandering - zoet water - evaporation - water management - urban areas - urban society - water requirements - climatic change - fresh water
    Hoeveel water verliest een stad door verdamping? Wat betekent dat? En is dat proces van verdamping te beïnvloeden? Onderzoek van Alterra Wageningen UR levert inzichten op die voor de steden steeds belangrijker zullen worden.
    Tripple-I method empowers professional vocational education students in mobilizing their assets
    Dierx, J. ; Detaille, S. ; Boonekamp, G. ; Peters, V. ; Cuperus, J. ; Hove, P. van; Vaandrager, L. - \ 2015
    In: 8th European Public Health Conference, Health in Europe - from global to local policies, Methods and practices. - - p. 57 - 57.
    Temperature controlled sequential gelation in composite microgel suspensions
    Appel, J. ; Lange, N. de; Kooij, H.M. van der; Laar, T.X. van de; Hove, J.B. ten; Kodger, T.E. ; Sprakel, J.H.B. - \ 2015
    Particle and Particle Systems Characterization 32 (2015)7. - ISSN 0934-0866 - p. 764 - 770.
    attractive particles - liquid - gels
    Depending on the volume fraction and interparticle interactions, colloidal suspensions can exhibit a variety of physical states, ranging from fluids, crystals, and glasses to gels. For microgel particles made of thermoresponsive polymers, both parameters can be tuned using environmental parameters such as temperature and ionic strength, making them excellent systems to experimentally study state transitions in colloidal suspensions. Using a simple two-step synthesis it is shown that the properties of composite microgels, with a fluorescent latex core and a responsive microgel shell, can be finely tuned. With this system the transitions between glass, liquid, and gel states for suspensions composed of a single species are explored. Finally, a suspension of two species of microgels is demonstrated, with different transition temperatures, gels in a sequential manner. Upon increasing temperature a distinct core–sheath structure is formed with a primary gel composed of the species with lowest transition temperature, which acts as a scaffold for the aggregation of the second species.
    Building a plant: cell fate specification in the early Arabidopsis embryo
    Hove, C.A. ten; Lu, Kuan-Ju ; Weijers, D. - \ 2015
    Development 142 (2015). - ISSN 0950-1991 - p. 420 - 430.
    homeodomain-leucine-zipper - apical-basal axis - layer-specific gene - box protein tir1 - transcription factor - vascular development - early embryogenesis - pattern-formation - shoot meristem - f-box
    Embryogenesis is the beginning of plant development, yet the cell fate decisions and patterning steps that occur during this time are reiterated during development to build the post-embryonic architecture. In Arabidopsis, embryogenesis follows a simple and predictable pattern, making it an ideal model with which to understand how cellular and tissue developmental processes are controlled. Here, we review the early stages of Arabidopsis embryogenesis, focusing on the globular stage, during which time stem cells are first specified and all major tissues obtain their identities. We discuss four different aspects of development: the formation of outer versus inner layers; the specification of vascular and ground tissues; the determination of shoot and root domains; and the establishment of the first stem cells.
    Innovative observations and analysis of human thermal comfort in Amsterdam
    Heusinkveld, B.G. ; Steeneveld, G.J. ; Ronda, R.J. ; Attema, J. ; Holtslag, A.A.M. - \ 2015
    The Netherlands has a mild mid-latitude climate. Meteorological records for The Netherlands show that the number of hot summer days has increased, and future climate change projections predict the same trend. Heat stress is the major cause of weatherrelated urban human mortality. The urban heat island effect is significant for the Netherlands (summertime nocturnal UHI 95% >7 K) (Steeneveld et al., 2011, Heusinkveld et al., 2014) as more than 80% of the Dutch population live in cities and are thus subject to such added stress. For human thermal comfort during heat waves, shading is more important than wind according to Mayer and Höppe, 1987. However, for the Netherlands wind may also be relevant due to the proximity of the sea and large lake bodies. Here, measurements and analysis results are presented using an innovative mobile measurement system and a dense urban weather station network. The mobile measurements were used to assess the spatial variability of human thermal comfort (Heusinkveld, et al., 2010 & 2014). A key feature of the mobile measurement system is the direct measurement of mean radiant temperature and wind speed. To do so, a special cargo bicycle was equipped with 6 pyranometers, 6 pyrgeometers, 2D wind speed/direction, temperature, humidity, bicycle speed and GPS sensors. Mobile measurements can provide great spatial detail from a large set of sensors. However temporal resolution is limited and therefore a dense urban weather station network of temperature/humidity and wind speed was set up. Within a city the lower average wind speed increases the radiation induced temperature error of a thermometer screen. To minimize such errors, all air temperature/humidity sensors used on the mobile and urban weather stations were equipped with aspirated thermometer screens. References: Heusinkveld BG, LWA van Hove, CMJ Jacobs, GJ Steeneveld, JA Elbers, EJ Moors, AAM Holtslag (2010) Use of a mobile platform for assessing urban heat stress in Rotterdam, Proceedings of the 7th Conference on Biometeorology. Instituts der Albert-Ludwigs- Universität Freiburg 20 (2010). - ISSN 1435-618X - p. 433–438. Freiburg: 2010. Heusinkveld, B.G. , Steeneveld, G.J. , Hove, L.W.A. van , Jacobs, C.M.J. , Holtslag, A.A.M., 2014: Spatial variability of the Rotterdam urban heat island as influenced by urban land use. Journal of Geophysical Research - Atmospheres 119, 677 - 692. Mayer H, Hoppe P (1987) Thermal comfort of man in different urban environments, Theor Appl Clim 38: 43-49. Steeneveld, G.J., S. Koopmans, B.G. Heusinkveld, L.W.A. van Hove, and A.A.M. Holtslag, 2011: Quantifying urban heat island effects and human comfort for cities of variable size and urban morphology in The Netherlands., J. Geophys. Res., 116, D20129, doi:10.1029/2011JD015988.
    Street greenery and its physical and psychological impact on outdoor thermal comfort
    Klemm, W. ; Heusinkveld, B.G. ; Lenzholzer, S. ; Hove, B. van - \ 2015
    Landscape and Urban Planning 138 (2015). - ISSN 0169-2046 - p. 87 - 98.
    urban-environment - climate-change - human health - vegetation - spaces - infrastructure - design - model - landscapes - trees
    This study focuses on the benefits of street greenery for creating thermally comfortable streetscapes in moderate climates. It reports on investigations on the impact of street greenery on outdoor thermal comfort from a physical and psychological perspective. For this purpose, we examined nine streets with comparable geometric configurations, but varying amount of street greenery (street trees, front gardens) in the city of Utrecht, the Netherlands. Mobile micrometeorological measurements including air temperature (Ta), solar and thermal radiation were performed, enabling the calculation of mean radiant temperature (Tmrt). Additionally, semi-structured interviews with pedestrians about their momentary and long-term perceived thermal comfort and their esthetical appreciation of the green street design were conducted. Measurements showed a clear impact (p = 0.0001) of street greenery on thermal comfort through tree shading: 10% tree crown cover within a street canyon lowered street averaged Tmrt about 1 K. In contrast, our results did not show an influence of street greenery on street averaged Ta. Interview results indicated that momentary perceived thermal comfort tended to be related to the amount of street greenery. However, the results were not statistically significant. Related to long-term perceived thermal comfort respondents were hardly consciously aware of influences by street greenery. Yet, people significantly (p <0.001) valued the presence of street greenery in esthetic terms. In conclusion, street greenery forms a convenient adaptive strategy to create thermally comfortable and attractive living environments. Our results clearly indicate that both physical and psychological aspects of thermal comfort have to be considered in urban design processes.
    Early-season crop colonization by parasitoids is associated with native vegetation, but is spatially and temporally erratic
    Bianchi, F.J.J.A. ; Walters, B.J. ; Hove, A.L.T. ; Cunningham, S.A. ; Werf, W. van der; Douma, J.C. ; Schellhorn, N.A. - \ 2015
    Agriculture, Ecosystems and Environment 207 (2015). - ISSN 0167-8809 - p. 10 - 16.
    terebrans hymenoptera-ichneumonidae - managing ecosystem services - biological-control - bemisia-tabaci - pest-control - agricultural landscapes - habitats - biodiversity - populations - arthropods
    Semi-natural habitats in agricultural landscapes may support parasitoid populations that provide biocontrol services by suppressing populations of crop pests, but little is known about the spatial pattern and variability of these services at different levels of scale. Here we investigate the rarely studied phenomenon of early-season crop colonization by parasitoids and the relationship with the surrounding landscape. We assessed parasitism of whiteflies by placing whitefly infested cotton seedlings in remnant vegetation, arable land 25–125 m from remnant vegetation, and arable land further than 400 m from remnant vegetation. Twelve to twenty sentinel plants were exposed in a 25 × 25 m grid pattern in plots in each habitat. The experiment was conducted at 18 locations across two landscapes and repeated three times in a 2-week period in 2007 and 2008. Parasitism was observed during the first three days after the introduction of the whitefly infested seedlings and was in all cases caused by Encarsia spp. The mean number of parasitized whitefly per plant was 0.106 ± 0.025 and was highest on cotton plants placed in remnant vegetation, declining with increasing distance from remnant vegetation. A regression model with land use and meteorological variables received more statistical support from the data than models with only landscape and time period as factors. Parasitism levels were influenced by the proportion of remnant vegetation, grassland, as well as wind, temperature, dew point temperature and year. Early-season colonization of whitefly infested seedlings by parasitoids was erratic and characterized by large spatial (inter-plant and inter-plot) and temporal variation. Our study confirms that remnant vegetation function as reservoirs for parasitoids and that parasitoids can penetrate arable fields beyond 125 m within 3 days. However, variation in the occurrence of parasitism makes it difficult to predict parasitoid colonization at a specific place and time. Therefore, field-based scouting for pests and parasitoids is necessary, even in landscapes with a high biocontrol potential.
    A plant U-box protein, PUB4, regulates asymmetric cell division and cell proliferation in the root meristem
    Kinoshita, A. ; Hove, C.A. ten; Tabata, R. ; Yamada, M. ; Shimizu, N. ; Ishida, T. ; Yamaguchi, K. ; Shigenobu, S. ; Takebayashi, Y. ; Luchies, J. ; Kobayashi, M. ; Kurata, T. ; Wada, T. ; Seo, M. ; Hasebe, M. ; Blilou, I. ; Fukuda, H. ; Scheres, B. ; Heidstra, R. ; Kamiya, Y. ; Sawa, S. - \ 2015
    Development 142 (2015). - ISSN 0950-1991 - p. 444 - 453.
    receptor-like kinase - arabidopsis shoot meristem - of-function phenotypes - cle peptides - gene-expression - repeat protein - differentiation - thaliana - organization - growth
    The root meristem (RM) is a fundamental structure that is responsible for postembryonic root growth. The RM contains the quiescent center (QC), stem cells and frequently dividing meristematic cells, in which the timing and the frequency of cell division are tightly regulated. In Arabidopsis thaliana, several gain-of-function analyses have demonstrated that peptide ligands of the CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION-RELATED (CLE) family are important for maintaining RM size. Here, we demonstrate that a plant U-box E3 ubiquitin ligase, PUB4, is a novel downstream component of CLV3/CLE signaling in the RM. Mutations in PUB4 reduced the inhibitory effect of exogenous CLV3/CLE peptide on root cell proliferation and columella stem cell maintenance. Moreover, pub4 mutants grown without exogenous CLV3/CLE peptide exhibited characteristic phenotypes in the RM, such as enhanced root growth, increased number of cortex/endodermis stem cells and decreased number of columella layers. Our phenotypic and gene expression analyses indicated that PUB4 promotes expression of a cell cycle regulatory gene, CYCD6;1, and regulates formative periclinal asymmetric cell divisions in endodermis and cortex/endodermis initial daughters. These data suggest that PUB4 functions as a global regulator of cell proliferation and the timing of asymmetric cell division that are important for final root architecture.
    Overview of challenges and achievements in the Climate Adaptation of Cities and in the Climate Proof Cities program
    Albers, R.A.W. ; Bosch, P.R. ; Blocken, B. ; Dobbelsteen, A.A.J.F. van den; Hove, B. van; Split, T.J.M. ; Ven, F. van de; Hooff, T. van; Rovers, V. - \ 2015
    Building and Environment 83 (2015). - ISSN 0360-1323 - p. 1 - 10.
    klimaatverandering - klimaatadaptatie - stedelijke gebieden - temperatuur - governance - onderzoeksprojecten - nederland - climatic change - climate adaptation - urban areas - temperature - governance - research projects - netherlands - urban heat-island - building performance simulation - cfd simulation - environment - ventilation - future - generation - benefits
    Despite all international, national and local initiatives to mitigate climate change, a certain degree of climate change is unavoidable. Urban environments in particular seem vulnerable to the consequences of climate change. How can cities, which are dynamic systems where most people live and work, prepare for such changes in climate? In the Netherlands, the Climate Proof Cities (CPC) research program (2010-2014) was established, aimed at: “strengthening the adaptive capacity and reducing the vulnerability of the urban system against climate change and to develop strategies and policy instruments for adapting our cities and buildings”. The program has contributed to the knowledge on assessing vulnerability of cities, on adaptation options and their effectiveness, and on governance of adaptation. Important features are the role of green infrastructures in combination with available water, improved building designs and collaboration between urban planners and water managers. Nonetheless, in spite of this effort and many other national and international efforts, research in these fields is still in its infancy, and much remains to be done. The broad scope of the CPC research program incited the establishment of this Special Issue. In addition, also papers from other researchers have been added to this Special Issue, in an attempt to provide a valuable – albeit inexhaustive – view on the challenges and achievements in adaptation of cities to climate change.
    Temporal and spatial variability of urban heat island and thermal comfort within the Rotterdam agglomeration
    Hove, B. van; Jacobs, C.M.J. ; Heusinkveld, B.G. ; Elbers, J.A. ; Driel, B.L. van; Holtslag, A.A.M. - \ 2015
    Building and Environment 83 (2015). - ISSN 0360-1323 - p. 91 - 103.
    klimaatverandering - temperatuur - perceptie - stedelijke gebieden - ruimtelijke variatie - variatie in de tijd - rotterdam - climatic change - temperature - perception - urban areas - spatial variation - temporal variation - rotterdam - air-temperature - street geometry - canyon geometry - climate zones - land-use - environment - areas - radiation - impact - fluxes
    This paper reports on temporal and spatial variability of local climate and outdoor human thermal comfort within the Rotterdam agglomeration. We analyse three years of meteorological observations (2010–2012) from a monitoring network. Focus is on the atmospheric urban heat island (UHI); the difference in air temperature between urban areas and rural surroundings. In addition, we calculate the Physiologically Equivalent Temperature (PET) which is a measure of thermal comfort. Subsequently, we determine the dependency of intra-urban variability in local climate and PET on urban land-use and geometric characteristics. During a large part of the year, UHI-intensities in densely built areas can be considerable, under calm and clear (cloudless) weather conditions. The highest maximum UHI-values are found in summer, with 95-percentile values ranging from 4.3 K to more than 8 K, depending on the location. In winter, UHI-intensities are generally lower. Intra-urban variability in maximum UHI-intensity is considerable, indicating that local features have an important influence. It is found to be significantly related to building, impervious and green surface fractions, respectively, as well as to mean building height. In summer, urban areas show a larger number of discomfort hours (PET > 23 °C) compared to the reference rural area. Our results indicate that this is mainly related to the much lower wind velocities in urban areas. Also intra-urban variability in thermal comfort during daytime appears to be mainly related to differences in wind velocity. After sunset, the UHI effect plays a more prominent role and hence thermal comfort is more related with urban characteristics.
    Assessment of evaporative water loss from Dutch cities
    Jacobs, C.M.J. ; Elbers, J.A. ; Brolsma, R. ; Hartogensis, O.K. ; Moors, E.J. ; Rodríguez-CarreteroMárquez, M.T. ; Hove, B. van - \ 2015
    Building and Environment 83 (2015). - ISSN 0360-1323 - p. 27 - 38.
    klimaatverandering - temperatuur - stedelijke gebieden - evaporatie - waterbudget - rotterdam - veluwe - climatic change - temperature - urban areas - evaporation - water budget - rotterdam - veluwe - urban heat-island - energy-balance - large-aperture - evapotranspiration - exchange - surface - scintillometers - requirements - environments - manchester
    Reliable estimates of evaporative water loss are required to assess the urban water budget in support of division of water resources among various needs, including heat mitigation measures in cities relying on evaporative cooling. We report on urban evaporative water loss from Arnhem and Rotterdam in the Netherlands, using eddy covariance, scintillometer and sapflow observations. Evaporation is assessed at daily to seasonal and annual timescale. For the summer half-year (April–September), observations from Arnhem and Rotterdam are consistent regarding magnitude and variability of evaporation that typically varies between 0.5 and 1.0 mm of evaporation per day. The mean daily evaporative cooling rate was 20–25 Wm-2, 11–14% of the average incoming solar radiation. Evaporation by trees related to sapflow was found to be a small term on the water budget at the city or neighbourhood scale. However, locally the contribution may be significant, given observed maxima of daily sap flows up to 170 l per tree. In Arnhem, evaporation is strongly linked with precipitation, possibly owing to building style. During the summer season, 60% of the precipitation evaporated again. In Rotterdam, the link between evaporation and precipitation is much weaker. An analysis of meteorological observations shows that estimation of urban evaporation from routine weather data using the concept of reference evaporation would be a particularly challenging task. City-scale evaporation may not scale with reference evaporation and the urban fabric results in strong microweather variability. Observations like the ones presented here can be used to evaluate and improve methods for routine urban evaporation estimates.
    Psychological and physical impact of urban green spaces on outdoor thermal comfort during summertime in The Netherlands
    Klemm, W. ; Heusinkveld, B.G. ; Lenzholzer, S. ; Jacobs, M.H. ; Hove, B. van - \ 2015
    Building and Environment 83 (2015). - ISSN 0360-1323 - p. 120 - 128.
    public-health - vegetation - environment - temperature - behavior - climate - cities - island - park
    Green infrastructure can improve thermal comfort in outdoor urban spaces in moderate climates. The impact of green spaces on thermal comfort is often exclusively investigated through meteorological variables and human-biometeorological indices. Yet, studies on perceived thermal comfort are scarce. As thermal comfort is a property of human perception of the thermal environment, this knowledge is crucial for understanding the relationship between green spaces and thermal comfort. We investigated inhabitants' long-term perception of thermal comfort on warm summer days in three Dutch cities by means of questionnaires. Additionally, we examined the daytime cooling effect of green spaces in Utrecht, in order to find physical evidence to verify thermal comfort perception. To this end we used bicycles equipped with micrometeorological sensors. We compared thermal conditions of 13 parks with thermal conditions in the city centre and in the open grassland outside the city. And we analysed dependences between thermal conditions and spatial variables of parks (size, tree canopy, upwind vegetation cover). Our results demonstrate that green infrastructure improves generally perceived thermal comfort. People evaluated green urban spaces as the most thermally comfortable spaces which was in line with the physical thermal investigations. Physiological equivalent temperature (PET) in parks on average was 1.9 K lower than in the city centre and 5 K lower than in the surrounding grasslands during the hottest period of the day. Thermal variance between parks was significantly influenced by tree canopy cover (mean radiant temperature p = 0.00005) and upwind vegetation cover (air temperature p = 0.013), not significantly for park size
    Denktank voor investeerders op zee (interview met Floris Groenendijk en Tammo Bult)
    Hove, P. van; Groenendijk, F.C. ; Bult, T.P. - \ 2014
    Zeehavens Amsterdam (2014)4. - ISSN 1569-7304 - p. 40 - 40.
    Fertilizer use should not be a fourth principle to define conservation. Response to the opinion paper of Vanlauwe et al. (2014)
    Sommer, R. ; Thierfelder, C. ; Tittonell, P.A. ; Hove, L. ; Mureithi, J. ; Mkomwa, S. - \ 2014
    Field Crops Research 169 (2014). - ISSN 0378-4290 - p. 145 - 148.
    zea-mays l. - soil quality - residue management - southern africa - ecological intensification - water relations - systems - maize - tillage - yield
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