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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Comparison of smoking-related DNA methylation between newborns from prenatal exposure and adults from personal smoking
Sikdar, Sinjini ; Joehanes, Roby ; Joubert, Bonnie R. ; Xu, Cheng Jian ; Vives-Usano, Marta ; Rezwan, Faisal I. ; Felix, Janine F. ; Ward, James M. ; Guan, Weihua ; Richmond, Rebecca C. ; Brody, Jennifer A. ; Küpers, Leanne K. ; Baïz, Nour ; Håberg, Siri E. ; Smith, Jennifer A. ; Reese, Sarah E. ; Aslibekyan, Stella ; Hoyo, Cathrine ; Dhingra, Radhika ; Markunas, Christina A. ; Xu, Tao ; Reynolds, Lindsay M. ; Just, Allan C. ; Mandaviya, Pooja R. ; Ghantous, Akram ; Bennett, Brian D. ; Wang, Tianyuan ; Consortium, The Bios ; Bakulski, Kelly M. ; Melen, Erik ; Zhao, Shanshan ; Jin, Jianping ; Herceg, Zdenko ; Meurs, Joyce Van; Taylor, Jack A. ; Baccarelli, Andrea A. ; Murphy, Susan K. ; Liu, Yongmei ; Munthe-Kaas, Monica Cheng ; Deary, Ian J. ; Nystad, Wenche ; Waldenberger, Melanie ; Annesi-Maesano, Isabella ; Conneely, Karen ; Jaddoe, Vincent W.V. ; Arnett, Donna ; Snieder, Harold ; Kardia, Sharon L.R. ; Relton, Caroline L. ; Ong, Ken K. ; Ewart, Susan ; Moreno-Macias, Hortensia ; Romieu, Isabelle ; Sotoodehnia, Nona ; Fornage, Myriam ; Motsinger-Reif, Alison ; Koppelman, Gerard H. ; Bustamante, Mariona ; Levy, Daniel ; London, Stephanie J. - \ 2019
Epigenomics 11 (2019)13. - ISSN 1750-1911 - p. 1487 - 1500.
cigarette smoking - epigenetics - infant - maternal exposure - methylation

Aim: Cigarette smoking influences DNA methylation genome wide, in newborns from pregnancy exposure and in adults from personal smoking. Whether a unique methylation signature exists for in utero exposure in newborns is unknown. Materials & methods: We separately meta-analyzed newborn blood DNA methylation (assessed using Illumina450k Beadchip), in relation to sustained maternal smoking during pregnancy (9 cohorts, 5648 newborns, 897 exposed) and adult blood methylation and personal smoking (16 cohorts, 15907 participants, 2433 current smokers). Results & conclusion: Comparing meta-analyses, we identified numerous signatures specific to newborns along with many shared between newborns and adults. Unique smoking-associated genes in newborns were enriched in xenobiotic metabolism pathways. Our findings may provide insights into specific health impacts of prenatal exposure on offspring.

Nutrition and food security impacts of quality seeds of biofortified orange-fleshed sweetpotato: Quasi-experimental evidence from Tanzania
Shikuku, Kelvin Mashisia ; Okello, Julius Juma ; Wambugu, Stella ; Sindi, Kirimi ; Low, J.W. ; McEwan, Margaret - \ 2019
World Development 124 (2019). - ISSN 0305-750X
Biofortified sweetpotato - Nutrition and food security impacts - Orange-fleshed sweetpotato - Quasi-field experiment - Tanzania - Virus-free

This study examined the nutrition and food security impacts of a project that was designed to improve availability of disease-free planting materials of biofortified orange-fleshed sweetpotato (OFSP) in rural Tanzania. Difference-in-difference and matching techniques were employed to estimate causal effects using panel data. Participation in the project increased agronomic and nutritional knowledge of households, raised uptake rate for OFSP varieties, and improved food security status. Effects on nutrition are, however, weak. These results suggest that timely access to quality seeds accompanied by a transfer of skills is important to reduce barriers to adoption of biofortified crops with resulting positive effects on the welfare of rural households. Adequate promotion of both agronomic and nutrition aspects of the technologies may enhance nutrition effects.

Down scaling of climate change scenarii to river basin level : A transdisciplinary methodology applied to Evrotas river basin, Greece
Ker Rault, Philippe A. ; Koundouri, Phoebe ; Akinsete, Ebun ; Ludwig, Ralf ; Huber-Garcia, Verena ; Tsani, Stella ; Acuna, Vicenc ; Kalogianni, Eleni ; Luttik, Joke ; Kok, Kasper ; Skoulikidis, Nikolaos ; Froebrick, Jochen - \ 2019
Science of the Total Environment 660 (2019). - ISSN 0048-9697 - p. 1623 - 1632.
Climate-change - Ecosystem-services - Land-use - Transdisciplinary - Water management

The Mediterranean region is anticipated to be (or, already is) one of the hot spots for climate change, where freshwater ecosystems are under threat from the effects of multiple stressors. Climate change is impacting natural resources and on the functioning of Ecosystem Services. The challenges about modelling climate change impact on water cycle in general and specifically on socio-economic dynamics of the society leads to an exponential amount of results that restrain interpretation and added value of forecasting at local level. One of the main challenges when dealing with climate change projections is the quantification of uncertainties. Modellers might have limited information or understanding from local river catchment management practices and from other disciplines with relevant insights on socio-economic and environmental complex relationship between biosphere and human based activities. Current General Circulation Models cannot fulfil the requirements of high spatial detail required for water management policy. This article reports an innovative transdisciplinary methodology to down scale Climate Change scenarii to river basin level with a special focus on the development of climate change narrative under SSP5-RCP8.5 combination called Myopic scenario and SSP1-RCP4.5 combination called Sustainable scenario. Local Stakeholder participative workshop in the Evrotas river basin provide perception of expected changes on water demand under to two developed scenario narratives.

Low-dose addition of silver nanoparticles stresses marine plankton communities
Tsiola, Anastasia ; Toncelli, Claudio ; Fodelianakis, Stilianos ; Michoud, Grégoire ; Bucheli, Thomas D. ; Gavriilidou, Asimenia ; Kagiorgi, Margarita ; Kalantzi, Ioanna ; Knauer, Katja ; Kotoulas, Georgios ; Mylona, Kyriaki ; Papadopoulou, Eleftheria ; Psarra, Stella ; Santi, Ioulia ; Tsapakis, Manolis ; Daffonchio, Daniele ; Pergantis, Spiros A. ; Pitta, Paraskevi - \ 2018
Environmental Science: Nano covers the benefits... 5 (2018)8. - ISSN 2051-8153 - p. 1965 - 1980.

The release of silver nanoparticles (AgNPs) is expected to rise in the near future, with possible negative effects on aquatic life and enhancement of microbial resistance against AgNPs. However, a realistic evaluation of the toxicity of AgNPs to the marine ecosystem is currently missing. Therefore, we designed a mesocosm experiment to assess the impact of AgNP exposure on natural microbial plankton community dynamics in a coastal marine site at environmentally relevant concentrations. We monitored changes in the composition of the planktonic community, from viruses to protists. Further, we analyzed the concentration and properties of AgNPs for the total time of exposure. We found that the addition of AgNPs even at a low dose affected the plankton communities. Specifically, the growth of Synechococcus was inhibited and bacterial community composition significantly changed. Additionally, the amount of a lysogeny-related gene increased and viral auxiliary metabolic genes that are involved in cyanobacterial photosynthesis decreased, revealing a damaged photosynthetic potential after AgNP exposure. Microbial plankton was significantly affected due to both increased dissolved silver ions and decreased AgNP size. Our results highlight that the release of AgNPs alters the functioning of the marine food web by hampering important viral and bacterial processes.

Hoe goor is eten met de vijf-secondenregel van de grond oppakken?
Hazeleger, Wilma - \ 2018
A Summary of Research Activities from the AgMIP Potato Crop Modeling Intercomparison Pilot
Fleisher, D.H. ; Condori, B. ; Quiroz, R. ; Alva, A. ; Asseng, S. ; Barreda, Carolina ; Berghuijs, H.N.C. ; Bindi, M. ; Boote, K.J. ; Craigon, J. ; Fangmeier, A. ; Ferrise, Roberto ; Franke, A.C. ; Gayler, S. ; Govindakrishnan, P.M. ; Harahagazwe, Dieudonne ; Hoogenboom, G. ; Kremer, P. ; Kroes, J. ; Naresh Kumar, S. ; Merante, Paolo ; Nendel, C. ; Olesen, J.E. ; Parker, P.S. ; Pleijel, H. ; Raes, Dirk ; Raymundo, Rubi ; Reidsma, P. ; Ruana, A. ; Silva, J.V. ; Stella, T. ; Stockle, Claudio ; Supit, I. ; Evert, F.K. van; Vandermeiren, K. ; Vanuytrecht, Eline ; Vorne, V. ; Wolf, J. ; Woli, Prem - \ 2018
Activity-1 of the potato crop model intercomparison pilot was recently completed and focused on quantifying multi-model uncertainty to climate responses when using common data sets from low-and high-input management sites. Median model ensemble response outperformed any single model in terms of replicatingobserved yield across all sites. Uncertainty among models averaged 15% higher for low-versus high-input sites, with larger differences observed for evapotranspiration (ET), nitrogen uptake, and water use efficiency as compared to dry matter. A minimum of five partial, or three full, calibrated models was required for an ensemble approach to keep variability below that of common field variation. Model variation was not influenced by carbon dioxide (C), but increased as much as 41 and 23% for yield and ET respectively as temperature (T) or rainfall (W) moved away from historical levels. Increases in T accounted for the highest amount of uncertainty, suggesting that methods and parameters for T sensitivity represent a considerable unknown among models. Activity-2 research is on-going and tests the capability of multiple models to mimic effects of elevated C concentration on potato yields measured at eight different locations in Europe. A subset from observed OTC and FACE data was used to initially calibrate the models. This research will also evaluate the stability of the models’ calibration with respect to changes in geographic location, as the same variety was used in all locations. This presentation will summarize the Activity-1 results and discuss the current status of Activity-2 investigations.
Dynamic changes between two LHCX-related energy quenching sites control diatom photoacclimation
Taddei, Lucilla ; Chukhutsina, Volha U. ; Lepetit, Bernard ; Stella, Giulio R. ; Bassi, Roberto ; Amerongen, Herbert van; Bouly, Jean P. ; Jaubert, Marianne ; Finazzi, Giovanni ; Falciatore, Angela - \ 2018
Plant Physiology 177 (2018)3. - ISSN 0032-0889 - p. 953 - 965.

Marine diatoms are prominent phytoplankton organisms that perform photosynthesis in extremely variable environments. Diatoms possess a strong ability to dissipate excess absorbed energy as heat via nonphotochemical quenching (NPQ). This process relies on changes in carotenoid pigment composition (xanthophyll cycle) and on specific members of the light-harvesting complex family specialized in photoprotection (LHCXs), which potentially act as NPQ effectors. However, the link between light stress, NPQ, and the existence of different LHCX isoforms is not understood in these organisms. Using picosecond fluorescence analysis, we observed two types of NPQ in the pennate diatom Phaeodactylum tricornutum that were dependent on light conditions. Short exposure of low-light-acclimated cells to high light triggers the onset of energy quenching close to the core of photosystem II, while prolonged light stress activates NPQ in the antenna. Biochemical analysis indicated a link between the changes in the NPQ site/mechanism and the induction of different LHCX isoforms, which accumulate either in the antenna complexes or in the core complex. By comparing the responses of wild-type cells and transgenic lines with a reduced expression of the major LHCX isoform, LHCX1, we conclude that core complex-associated NPQ is more effective in photoprotection than is the antenna complex. Overall, our data clarify the complex molecular scenario of light responses in diatoms and provide a rationale for the existence of a degenerate family of LHCX proteins in these algae.

An integrated approach for increasing breeding efficiency in apple and peach in Europe
Laurens, Francois ; Aranzana, Maria José ; Arus, Pere ; Bassi, Daniele ; Bink, Marco ; Bonany, Joan ; Caprera, Andrea ; Corelli-Grappadelli, Luca ; Costes, Evelyne ; Durel, Charles Eric ; Mauroux, Jehan Baptiste ; Muranty, Hélène ; Nazzicari, Nelson ; Pascal, Thierry ; Patocchi, Andrea ; Peil, Andreas ; Quilot-Turion, Bénédicte ; Rossini, Laura ; Stella, Alessandra ; Troggio, Michela ; Velasco, Riccardo ; De Weg, Eric Van - \ 2018
Horticulture Research 5 (2018)1. - ISSN 2052-7276
Despite the availability of whole genome sequences of apple and peach, there has been a considerable gap between genomics and breeding. To bridge the gap, the European Union funded the FruitBreedomics project (March 2011 to August 2015) involving 28 research institutes and private companies. Three complementary approaches were pursued: (i) tool and software development, (ii) deciphering genetic control of main horticultural traits taking into account allelic diversity and (iii) developing plant materials, tools and methodologies for breeders. Decisive breakthroughs were made including the making available of ready-to-go DNA diagnostic tests for Marker Assisted Breeding, development of new, dense SNP arrays in apple and peach, new phenotypic methods for some complex traits, software for gene/QTL discovery on breeding germplasm via Pedigree Based Analysis (PBA). This resulted in the discovery of highly predictive molecular markers for traits of horticultural interest via PBA and via Genome Wide Association Studies (GWAS) on several European genebank collections. FruitBreedomics also developed pre-breeding plant materials in which multiple sources of resistance were pyramided and software that can support breeders in their selection activities. Through FruitBreedomics, significant progresses were made in the field of apple and peach breeding, genetics, genomics and bioinformatics of which advantage will be made by breeders, germplasm curators and scientists. A major part of the data collected during the project has been stored in the FruitBreedomics database and has been made available to the public. This review covers the scientific discoveries made in this major endeavour, and perspective in the apple and peach breeding and genomics in Europe and beyond.
Genome-wide association study in 79,366 European-ancestry individuals informs the genetic architecture of 25-hydroxyvitamin D levels
Jiang, Xia ; O'Reilly, Paul F. ; Aschard, Hugues ; Hsu, Yi Hsiang ; Richards, J.B. ; Dupuis, Josée ; Ingelsson, Erik ; Karasik, David ; Pilz, Stefan ; Berry, Diane ; Kestenbaum, Bryan ; Zheng, Jusheng ; Luan, Jianan ; Sofianopoulou, Eleni ; Streeten, Elizabeth A. ; Albanes, Demetrius ; Lutsey, Pamela L. ; Yao, Lu ; Tang, Weihong ; Econs, Michael J. ; Wallaschofski, Henri ; Völzke, Henry ; Zhou, Ang ; Power, Chris ; McCarthy, Mark I. ; Michos, Erin D. ; Boerwinkle, Eric ; Weinstein, Stephanie J. ; Freedman, Neal D. ; Huang, Wen Yi ; Schoor, Natasja M. van; Velde, Nathalie van der; Groot, Lisette C.P.G.M. de; Enneman, Anke ; Cupples, L.A. ; Booth, Sarah L. ; Vasan, Ramachandran S. ; Liu, Ching Ti ; Zhou, Yanhua ; Ripatti, Samuli ; Ohlsson, Claes ; Vandenput, Liesbeth ; Lorentzon, Mattias ; Eriksson, Johan G. ; Shea, M.K. ; Houston, Denise K. ; Kritchevsky, Stephen B. ; Liu, Yongmei ; Lohman, Kurt K. ; Ferrucci, Luigi ; Peacock, Munro ; Gieger, Christian ; Beekman, Marian ; Slagboom, Eline ; Deelen, Joris ; Deelen, Joris ; Heemst, Diana van; Kleber, Marcus E. ; März, Winfried ; Boer, Ian H. De; Wood, Alexis C. ; Rotter, Jerome I. ; Rich, Stephen S. ; Robinson-Cohen, Cassianne ; Heijer, Martin Den; Jarvelin, Marjo Riitta ; Jarvelin, Marjo Riitta ; Cavadino, Alana ; Cavadino, Alana ; Joshi, Peter K. ; Wilson, James F. ; Hayward, Caroline ; Lind, Lars ; Michaëlsson, Karl ; Trompet, Stella ; Zillikens, M.C. ; Uitterlinden, Andre G. ; Rivadeneira, Fernando - \ 2018
Nature Communications 9 (2018)1. - ISSN 2041-1723
Vitamin D is a steroid hormone precursor that is associated with a range of human traits and diseases. Previous GWAS of serum 25-hydroxyvitamin D concentrations have identified four genome-wide significant loci (GC, NADSYN1/DHCR7, CYP2R1, CYP24A1). In this study, we expand the previous SUNLIGHT Consortium GWAS discovery sample size from 16,125 to 79,366 (all European descent). This larger GWAS yields two additional loci harboring genome-wide significant variants (P = 4.7×10 -9 at rs8018720 in SEC23A, and P = 1.9×10 -14 at rs10745742 in AMDHD1). The overall estimate of heritability of 25-hydroxyvitamin D serum concentrations attributable to GWAS common SNPs is 7.5%, with statistically significant loci explaining 38% of this total. Further investigation identifies signal enrichment in immune and hematopoietic tissues, and clustering with autoimmune diseases in cell-type-specific analysis. Larger studies are required to identify additional common SNPs, and to explore the role of rare or structural variants and gene-gene interactions in the heritability of circulating 25-hydroxyvitamin D levels.
Genome-enabled predictions for fruit weight and quality from repeated records in European peach progenies
Biscarini, Filippo ; Nazzicari, Nelson ; Bink, Marco ; Arús, Pere ; Aranzana, Maria José ; Verde, Ignazio ; Micali, Sabrina ; Pascal, Thierry ; Quilot-Turion, Benedicte ; Lambert, Patrick ; Silva Linge, Cassia da; Pacheco, Igor ; Bassi, Daniele ; Stella, Alessandra ; Rossini, Laura - \ 2017
BMC Genomics 18 (2017)1. - ISSN 1471-2164
Fruit weight - Genome-enabled predictions - Genotype imputation - Peach (Prunus persica) - Repeatability model - Sugar content - Titratable acidity

Background: Highly polygenic traits such as fruit weight, sugar content and acidity strongly influence the agroeconomic value of peach varieties. Genomic Selection (GS) can accelerate peach yield and quality gain if predictions show higher levels of accuracy compared to phenotypic selection. The available IPSC 9K SNP array V1 allows standardized and highly reliable genotyping, preparing the ground for GS in peach. Results: A repeatability model (multiple records per individual plant) for genome-enabled predictions in eleven European peach populations is presented. The analysis included 1147 individuals derived from both commercial and non-commercial peach or peach-related accessions. Considered traits were average fruit weight (FW), sugar content (SC) and titratable acidity (TA). Plants were genotyped with the 9K IPSC array, grown in three countries (France, Italy, Spain) and phenotyped for 3-5 years. An analysis of imputation accuracy of missing genotypic data was conducted using the software Beagle, showing that two of the eleven populations were highly sensitive to increasing levels of missing data. The regression model produced, for each trait and each population, estimates of heritability (FW:0.35, SC:0.48, TA:0.53, on average) and repeatability (FW:0.56, SC:0.63, TA:0.62, on average). Predictive ability was estimated in a five-fold cross validation scheme within population as the correlation of true and predicted phenotypes. Results differed by populations and traits, but predictive abilities were in general high (FW:0.60, SC:0.72, TA:0.65, on average). Conclusions: This study assessed the feasibility of Genomic Selection in peach for highly polygenic traits linked to yield and fruit quality. The accuracy of imputing missing genotypes was as high as 96%, and the genomic predictive ability was on average 0.65, but could be as high as 0.84 for fruit weight or 0.83 for titratable acidity. The estimated repeatability may prove very useful in the management of the typical long cycles involved in peach productions. All together, these results are very promising for the application of genomic selection to peach breeding programmes.

Socio-enonomic Analysis of a Selected Multi-use Offshore Site in the North Sea
Söderqvist, Tore ; Bas, Bilge ; Bel, Mark de; Boon, Arjen ; Elginoz, Nilay ; Garcao, Rita ; Giannakis, Elias ; Giannouli, Amerissa ; Koundouri, Phoebe ; Moussoulides, Aris ; Norrman, Jenny ; Rosén, Lars ; Schouten, Jan-Joost ; Stuiver, Marian ; Tsani, Stella ; Xepapedeas, Petros - \ 2017
In: The Ocean of Tomorrow / Koundouri, Phoebe, Cham, Switzerland : Springer - ISBN 9783319557700 - p. 43 - 67.
A 600 MW offshore wind farm is under construction in the Netherlands Exclusive Economic Zone at a site called Gemini situated 55 km north of the Wadden Sea island of Schiermonnikoog and 85 km from the nearest Dutch port of Eemshaven. This chapter investigates the option of introducing a multi-use design for the Gemini site by adding mussel cultivation (48 kt wet weight per year) and seaweed cultivation (480 kt wet weight per year) to the wind farm. An institutional analysis indicates a political will in the Netherlands to support the development of adding uses to offshore wind farms, but a number of implementation obstacles are also identified. Those obstacles include an absence of licences for multi-use production and legal restrictions against third-party access to wind farms. There is therefore a need for a regulatory framework for multi-use and trust-building among actors involved in multi-use installations. A financial and economic assessment, and a cost-benefit analysis also taking into account monetized changes in CO2 emissions, indicate that adding mussel cultivation to the wind farm is likely to be both financially and socio-economically viable. Including a seaweed cultivation function is probably not financially and socio-economically viable under current technical and economic conditions. Knowledge gaps and uncertainties in these assessments with respect to, for example, missing site-specific data and non-monetized externalities suggest further research, also including pilot cultivations of mussels and seaweed in planned single-use or multi-use installations.
Weed turns rice plant into slave
Kabiri, Stella - \ 2017

At a first glance, Rhamphicarpa fistulosa might look innocent, but it turns rice plants into slaves. PhD candidate Stella Kabiri investigated the effects of this parasitic weed that damages the African rice production at an ever-increasing rate.

Introduction of the MERMAID Project
Koundouri, Phoebe ; Airoldi, Laura ; Boon, Arjen ; Giannouli, Amerissa ; Levantis, Eleftherios ; Moussoulides, Aris ; Stuiver, M. ; Tsani, Stella - \ 2017
In: The Ocean of Tomorrow / Koundouri, Phoebe, Cham, Switzerland : Springer (Environment & Policy ) - ISBN 9783319557700 - p. 1 - 8.
This chapter provides an introduction to the MERMAID project. MERMAID focused on developing concepts for offshore platforms which can be used for multiple purposes, such as energy and aquaculture production. These concepts were developed with input from experts as well as societal stakeholders. MERMAID consortium comprised of 28 partner institutes, including Universities, Research institutes, Industries and Small and Medium Enterprises from several EU countries. Consortium members brought a range of expertise in hydraulics, wind engineering, aquaculture, renewable energy, marine environment, project management, as well as socioeconomics and governance. Within the scope of MERMAID it has been developed and applied an Integrated Socio-Economic Assessment of the sustainability of Multi-Use Offshore Platforms, using the results from the natural and engineering sciences as inputs, boundaries and constraints to the analysis.
Methodology for Integrated Socio-economic Assessment of Multi-use Offshore Platforms
Koundouri, Phoebe ; Dávila, Osiel G. ; Stithou, Mavra ; Babalos, Vasilis ; Xepapadeas, Anastasios ; Anastasiou, Ioannis ; Antypas, Antonis ; Kourogenis, Nikolaos ; Mousoulides, Aris ; Mousoulides, Marianna ; Zanuttigh, Barbara ; Zagonari, Fabio ; Lange, Manfred A. ; Jimenez, Carlos ; Rosén, Lars ; Lindhe, Andreas ; Norrman, Jenny ; Söderqvist, Tore ; Troianos, Dimitris ; Frentzos, Athanasios ; Krontira, Yukiko ; Diaz Simal, Pedro ; Guanche, Raul ; Bel, Mark de; He, Wei ; Kabdasali, Sedat ; Elginoz, Nilay ; Bagci, Taylan ; Bas, Bilge ; Cantu, Matteo ; Masotti, Matteo ; Suffredini, Roberto ; Stuiver, M. ; Giannakis, Elias ; Tsani, Stella - \ 2017
In: The Ocean of Tomorrow / Koundouri, Phoebe, Cham, Switzerland : Springer (Environment & Policy 56) - ISBN 9783319557700 - p. 11 - 26.
This chapter presents the methodology employed for the Integrated Socio-Economic Assessment (MISEA) of different designs of Multi-Use Offshore Platforms (MUOPs). The methodology allows for the identification, the valuation and the assessment of the potential impacts and their magnitude. The analysis considers a number of feasible designs of MUOP investments, and the likely responses of those impacted by the investment project. The approach provides decision-makers with a valuable tool to assess whether a MUOP project increases the overall social welfare and hence should be undertaken. This is performed under alternative specifications regarding platform design, the discount rate and the stream of net benefits, if a Cost-Benefit Analysis (CBA) is to be followed or a sensitivity analysis of selected criteria in a Multi-Criteria Decision Analysis (MCDA) framework. The methodology can support the implementation of policies aiming at achieving a good environmental status of the EU’s marine waters and the protection of the resource base upon which marine-related economic and social activities depend.
Ecology and biology of Rhamphicarpa fistulosa, a new parasitic weed of Rain-fed Rice (Oryza sativa) in sub-Saharan Africa
Kabiri, Stella - \ 2017
Wageningen University. Promotor(en): N.P.R. Anten, co-promotor(en): L. Bastiaans; J. Rodenburg. - Wageningen : Wageningen University - ISBN 9789463436052 - 130
oryza sativa - parasitic weeds - crop ecology - orobanchaceae - weed control - africa south of sahara - oryza sativa - parasitaire onkruiden - gewasecologie - orobanchaceae - onkruidbestrijding - afrika ten zuiden van de sahara

Rice is an important staple food crop in Africa. The increasing scarcity of agricultural land has driven rice growers to expand into marginal areas that have natural infestations of Rhamphicarpa fitulosa. In return, R. fistulosa has increasingly become a serious problem to rice production in sub-Saharan Africa. To date, the understanding of the ecology and biology of the species and its dependence and effects on a host, is rather limited. The discrepancy between the emergence of this weed problem and the virtual absence of knowledge on the weed species motivated the study presented in this thesis.

In a field survey in Tanzania, Striga asiatica was observed in higher lying and drier fields, while R. fistulosa was observed in the lower lying wetter fields. Experiments confirmed that S. asiatica is favoured by free-draining soils and R. fistulosa by water-logged soils. These results imply that changes in climate, specifically moisture regimes, will be crucial for the future prevalence of both parasitic weed species. In a second investigation, I found that daylight and completely saturated soil conditions were prerequisites for germination, demonstrating that R. fistulosa is a typical species of environments with fluctuating water levels. Neither root exudates collected from rice host plants, nor the synthetic germination stimulant GR24, triggered germination of R. fistulosa seeds. Host plant presence resulted in a 3.7 times higher seed production rate and a 15% larger average seed size. The absence of a host recognition mechanism at the germination stage suggests that either the regulation of germination through light and soil moisture is near optimal, or that for this parasitic plant species an opportunistic germination strategy is superior. In a third study, I observed that infection by R. fistulosa led to significant reductions in leaf photosynthetic rate, stomatal conductance, the quantum efficiency of PSII (ΦPSII) and chlorophyll content of rice. In addition, there was a 19-32% negative deviation of the linear relationship between quantum yield of CO2 assimilation (ΦCO2) and quantum efficiency of PSII (ΦPSII) of infected plants in comparison to un-infected plants. This indicated a parasite induced influence on the photochemical process of the host. Furthermore, there was a considerable time lag between the parasite’s gains in growth and the reduction of host photosynthesis. The reduction in host growth, coincided with suppression of host photosynthesis. This indicates that R. fistulosa affects host growth by first extracting assimilates and making considerable gains in growth, before it affects the host photosynthesis. In the final investigation, I examined how the interaction between host plant and parasite influenced growth and (re)production of R. fistulosa and rice. Infection by R. fistulosa increased root:shoot ratio and decreased plant height, leaf area and tiller number of rice. Reductions in light interception of the host were followed by reductions in light use efficiency, causing 22-71% losses in host plant biomass and 78-100% losses in host kernel production. Parasitism eventually caused a complete standstill of host plant growth, while the parasite managed to gradually increase its share of the total host plant-parasite biomass up to 50-82%. This implies that ultimately the host plant was producing solely for the sake of the parasite.

In a final chapter, I discuss the implications of my findings for the future expansion of this parasitic weed, specifically in light of climate change. I also discuss how the divergent ecology and biology of R. fistulosa is likely to influence the effectiveness of measures that are currently applied to manage Striga spp. I argue that more than the current attention needs to be paid to R. fistulosa, specifically for the problems it causes to the rice sector in sub-Saharan Africa.

Guidelines for experimental practice in organic greenhouse horticulture
Koller, Martin ; Rayns, Francis ; Cubison, Stella ; Schmutz, U. ; Messelink, G.J. ; Voogt, W. - \ 2016
[Netherlands] : BioGreenhouse - ISBN 9789462575349 - 154
greenhouse horticulture - organic farming - guidelines - protected cultivation - greenhouse crops - cultural methods - greenhouse vegetables - trials - glastuinbouw - biologische landbouw - richtlijnen (guidelines) - teelt onder bescherming - kasgewassen - cultuurmethoden - glasgroenten - proeven
The aim of this handbook of experimental guidelines is to help conduct experiments for organic horticulture in greenhouses throughout Europe. It considers vegetables, fruit and ornamental production. Using standardised research procedures for experiments will aid a comparison of results and dissemination of knowledge. The editors have tried to incorporate as many climatic zones, countries and crops as possible in order to represent a wide area of Europe although some smaller crops or certain specific climates could not be included.
The interplay between diverse oil body extracts and exogenous biopolymers or surfactants
Nikiforidis, Costas ; Donsouzi, Stella ; Kiosseoglou, Vasilios - \ 2016
Food Research International 83 (2016). - ISSN 0963-9969 - p. 14 - 24.
Caseinate - Hazelnut - Natural emulsion - Oil bodies - Physical stability - Sesame - Soybean - Tween - Xanthan

Hazelnuts, sesame seeds and soybeans were selected as three diverse sources of oil bodies. Application of aqueous extraction and centrifugation steps resulted in concentrated oil body creams that were studied for their physical stability after dilution to a series of 5.0 wt.% oil-in-water emulsions incorporating sodium caseinate (1.0 wt.%), Tween 80 (1.0 wt.%) or xanthan gum (0.1 wt.%). In terms of aggregation/coalescence and creaming, the stability of the oil body based emulsions was ruled to a large extent by the initial natural oil droplet size and the presence of co-extracted exogenous proteins and secondarily by the added biopolymers and the surfactant. More specifically, soybean oil bodies exhibited the highest physical stability, even though incorporation of Tween 80 into all three oil body emulsions improved the stability against aggregation/coalescence, while xanthan gum was an effective stabilizer against creaming.

O3 and NOx Exchange
Loubet, B. ; Castell, J.F. ; Laville, P. ; Personne, E. ; Tuzet, A. ; Ammann, C. ; Emberson, L. ; Ganzeveld, L. ; Kowalski, A.S. ; Merbold, L. ; Stella, P. ; Tuovinen, J.P. - \ 2015
In: Review and Integration of Biosphere-Atmosphere Modelling of Reactive Trace Gases and Volatile Aerosols / Massad, Raia-Silva, Loubet, Benjamin, Springer Netherlands - ISBN 9789401772846 - p. 163 - 167.

This discussion was based on the background document “Review on modelling atmosphere-biosphere exchange of Ozone and Nitrogen oxides”, which reviews the processes contributing to biosphere-atmosphere exchange of O3 and NOx, including stomatal and non-stomatal exchange of O3 and NO, NO2. Non-stomatal exchange, including soil and chemical reactions in the canopy airspace is discussed, with a focus on how these processes are influenced by turbulent transport in the canopy. Existing models are reviewed, from big-leaf and two layer resistance to multi-layer models. Based on this background document, the discussion in the working group was organized to discuss the current gaps in modelling O3-NO-NO2 exchange and the ideal model that should be developed.

WOFOST developer's response to article by Stella et al., Environmental Modelling & Software 59 (2014): 44-58
Wit, A. de; Boogaard, H. ; Kralingen, D. ; Rötter, R. ; Supit, I. ; Wolf, J. ; Ittersum, M. - \ 2015
Environmental Modelling & Software 73 (2015). - ISSN 1364-8152 - p. 57 - 59.
Modelling the future of Boswellia papyrifera population and its frankincense production
Lemenih, M. ; Arts, B.J.M. ; Wiersum, K.F. ; Bongers, F. - \ 2014
Journal of Arid Environments 105 (2014). - ISSN 0140-1963 - p. 33 - 40.
economic-systems - metema district - dry forest - tree size - land-use - ethiopia - stella - cover
Sustainable production of the aromatic forest product frankincense is at stake due to rapid decline in its resource base. This affects livelihoods of thousands of citizens and several global industries. A system dynamic model approach is used to predict the future population of Boswellia papyrifera trees and its frankincense yield for three decades (2010e2040) in Metema and Abergelle districts in northern Ethiopia. Data from studies on the ecology, distribution, rate of deforestation and participatory future scenario development were put together and analysed using a model platform developed with STELLA. Four alternative scenarios namely Business As Usual (BAU); Low Intervention Scenario (LS), High Intervention Scenario (HS) and Stabilization Scenario (SS) were used. The model predicts 3%, 8% and 37% of the current stem population to exist in 2040 under BAU, LS, HS scenarios, respectively in Metema. Similarly, 11%, 13% and 46% stem density is predicted under BAU, LS and HS, respectively for Abergelle. Test of model sensitivity shows adult mortality is the most serious problem facing the resource. Immediate management intervention should focus on reducing adult tree mortality followed by reducing deforestation. Medium and long term interventions need to focus on how to improve recruitment and afforestation/reforestation of the species.
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