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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The acclimation of leaf photosynthesis of wheat and rice to seasonal temperature changes in T-FACE environments
Cai, Chuang ; Li, Gang ; Di, Lijun ; Ding, Yunjie ; Fu, Lin ; Guo, Xuanhe ; Struik, Paul C. ; Pan, Genxing ; Li, Haozheng ; Chen, Weiping ; Luo, Weihong ; Yin, Xinyou - \ 2019
Global Change Biology (2019). - ISSN 1354-1013
climate change - free-air CO enrichment - growth temperature - leaf nitrogen content - Oryza sativa L. - photosynthesis model - stomatal conductance - Triticum aestivum L.

Crops show considerable capacity to adjust their photosynthetic characteristics to seasonal changes in temperature. However, how photosynthesis acclimates to changes in seasonal temperature under future climate conditions has not been revealed. We measured leaf photosynthesis (An) of wheat (Triticum aestivum L.) and rice (Oryza sativa L.) grown under four combinations of two levels of CO2 (ambient and enriched up to 500 µmol/mol) and two levels of canopy temperature (ambient and increased by 1.5–2.0°C) in temperature by free-air CO2 enrichment (T-FACE) systems. Parameters of a biochemical C3-photosynthesis model and of a stomatal conductance (gs) model were estimated for the four conditions and for several crop stages. Some biochemical parameters related to electron transport and most gs parameters showed acclimation to seasonal growth temperature in both crops. The acclimation response did not differ much between wheat and rice, nor among the four treatments of the T-FACE systems, when the difference in the seasonal growth temperature was accounted for. The relationships between biochemical parameters and leaf nitrogen content were consistent across leaf ranks, developmental stages, and treatment conditions. The acclimation had a strong impact on gs model parameters: when parameter values of a particular stage were used, the model failed to correctly estimate gs values of other stages. Further analysis using the coupled gs–biochemical photosynthesis model showed that ignoring the acclimation effect did not result in critical errors in estimating leaf photosynthesis under future climate, as long as parameter values were measured or derived from data obtained before flowering.

Machine learning to realize phosphate equilibrium at field level in dairy farming
Mollenhorst, H. ; Haan, M.H.A. De; Oenema, J. ; Hoving-Bolink, A.H. ; Veerkamp, R.F. ; Kamphuis, C. - \ 2019
In: Precision Livestock Farming 2019. - Teagasc (Precision Livestock Farming 2019 - Papers Presented at the 9th European Conference on Precision Livestock Farming, ECPLF 2019 ) - ISBN 9781841706542 - p. 41 - 44.
Boosting - Crop yield - Machine learning - Manure - Phosphorus - Regression tree

An important factor in circular agriculture is efficient application of animal manure. Therefore, input and output of nutrients, like phosphorus (P), need to be balanced. Currently, manure application is regulated with rather fixed P application norms as a generic translation of P yields of grassland and maize. Predicting P yields based on field specific, historical data could be an important step to better balance P input and output. This study's objective was to predict P yields based on field and weather data, using machine learning. The dataset contained 640 records of yearly crop yields per field between 1993-2016 with information on P input and output, irrigation, and soil status at field level as well as local weather data. Generalized boosted regression (GBR) was used to predict P yields for the last five years based on information from all previous years. Model performance was evaluated per year as well as together by plotting observed versus predicted values of all five years in one plot. This final plot was compared to a plot with the currently used generic application norms. Model performance per year showed that GBR could predict the trend from low to high rather well (correlations of ~0.8). Results of the five years together showed that GBR performance was better than the generic application norms (correlation 0.68 vs 0.59; RMSE 7.3 vs 8.2). In conclusion, GBR contributed to defining more flexible P application norms with the aim to realize a phosphate equilibrium.

The role of nitrogen fixation in African smallholder agriculture
Giller, K.E. ; Kanampiu, Fred ; Hungria, Mariangela ; Vanlauwe, Bernard - \ 2019
Agriculture, Ecosystems and Environment 285 (2019). - ISSN 0167-8809
African smallholders face a conundrum! They spend their whole life surrounded by air which is 79% nitrogen gas and yet their crops are yellow and starved of nitrogen. The biological fixation of nitrogen by legumes offers a pathway for smallholders to access this infinite source of nitrogen. Yet current input of nitrogen fixation in African smallholder systems is very limited – often much less than 10 kg N ha−1 when calculated across the whole farm.

Legumes are a key component of pathways to the Sustainable Intensification of agriculture: they provide food, fodder other products such as fuelwood and stakes and improve soil fertility (Vanlauwe et al., 2014). Further, legumes offer the opportunity to diversify monotonous diets, as protein and micronutrient dense food and to diversify cropping systems often built on monocultures of cereals or root and tuber crops. In Africa, rates of nitrogen fixation by grain legumes as high as 250 kg N ha−1 have been measured in experimental fields, demonstrating their huge potential. Lastly, the sale of legume grains contributes substantially to household income in major legume production areas.

Against a backdrop of a rapidly growing population and decreasing farm size, a large pan-African collaborative project was initiated in 2009. The project entitled: Putting nitrogen fixation to work for smallholder farmers in Africa: N2Africa works across a wide range of agroecological conditions across 11 countries of sub-Saharan Africa. N2Africa is conceived as a “development-to-research” project in which grain legume technologies emerging from research are disseminated and tested at scale with many thousands of farmers (Giller et al., 2013). Through a structured and targeted approach N2Africa seeks to understand where, when, why and for whom approaches to the intensification and diversification of farming using different grain legume technologies work best. A key concept is the socio-ecological niche – recognizing the rich diversity of agroecologies, societies and cultures to enable the matching of technologies to farming systems, farms and fields (Ojiem et al., 2006).

This Special Issue brings together a series of papers based on recent research on N2-fixation by grain legumes and its wider benefits across sub-Saharan Africa. The final chapter (Vanlauwe et al., 2014) reflects on the contributions and highlights issues requiring the attention of research in future.
Quantifying Localized Macromolecular Dynamics within Hydrated Cellulose Fibril Aggregates
Chen, Pan ; Terenzi, Camilla ; Furó, István ; Berglund, Lars A. ; Wohlert, Jakob - \ 2019
Macromolecules (2019). - ISSN 0024-9297 - p. 7278 - 7288.

Molecular dynamics (MD) simulations of 13C NMR longitudinal relaxation (T1) distributions were recently established as a powerful tool for characterizing moisture adsorption in natural amorphous polymers. Here, such computational-experimental synergy is demonstrated in a system with intrinsically high structural heterogeneity, namely crystalline cellulose nanofibrils (CNFs) in highly hydrated aggregated state. In such a system, structure-function properties on the nanoscale remain largely uncovered by experimental means alone. In this work, broadly polydispersed experimental 13C NMR T1 distributions could be successfully reproduced in simulations and, for the first time, were decomposed into contributions from distinct molecular sources within the aggregated CNFs, namely, (i) the core and (ii) the less-accessible and accessible surface regions of the CNFs. Furthermore, within the surface groups structurally different sites such as (iii) residues with different hydroxymethyl orientations and (iv) center and origin chains could be discerned based on their distinct molecular dynamics. The MD simulations unravel a direct correlation between dynamical and structural heterogeneity at an atomistic-level resolution that cannot be accessed by NMR experiments. The proposed approach holds the potential to enable quantitative interpretation of NMR data from a range of multicomponent high-performance nanocomposites with significantly heterogeneous macromolecular structure.

Coordination as Management Response to the Spread of a Global Plant Disease: A Case Study in a Major Philippine Banana Production Area
Montiflor, Marilou O. ; Vellema, Sietze ; Digal, Larry N. - \ 2019
Frontiers in Plant Science 10 (2019). - ISSN 1664-462X
cross-sector partnerships - Foc TR4 - fusarium wilt - plant disease management - Southeast Asia

An integrative management approach to the spread and emergence of global plant diseases, such as the soil-borne fungus Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4), entails a combination of technical measures and the responsiveness and awareness of area-specific constellations supporting conditions conducive to interactions and coordination among organizations and actors with different resources and diverse interests. Responses to banana diseases are mostly studied through technical and epidemiological lenses and reflect a bias to the export industry. Some authors, however, indicate that cross-sector collaboration is crucial in responding to a disease outbreak. Earlier studies on the outbreak of diseases and natural disasters suggest that shared cognition and effective partnerships increased the success rate of response. Hence, it is important not to focus exclusively on the impacts of a pathogen at farm or field level and to shift attention to how tasks and knowledge are coordinated and shared. This paper aims to detect whether and how the emergence of Foc TR4 is a driver of coordination. The case study focuses on the interactions between a variety of banana producers and among a range of public and private actors in southern Philippines. The analysis identifies distinct forms of coordination emerging in the context of three organizational fields responding to Foc TR4, which underlie shared capacity to handle and understand the spread of a global plant disease. The research is based on qualitative key informant interviews and document analysis and on observations of instructive events in 2014–2017. Analysis of the composition and actions developed in three organizational fields leads to distinguishing three theory-driven forms of coordination: rule-based, cognition-based, and skill-based. The combination of these three forms constitutes the possibility of a collaborative community, which conditions the implementation of an integrative management approach to mitigate Foc TR4.

Malaria mosquito likes humans and apes
Bakker, Julian - \ 2019

Most mosquitoes in areas with both humans and chimpanzees are attracted by the odour of both, according to research by PhD candidate Julian Bakker and WUR alumnus Niels Verhulst. This means those mosquitoes could play a role in the transmission of malaria from apes to humans

Associations between antimicrobial use and the faecal resistome on broiler farms from nine European countries
Luiken, Roosmarijn E.C. ; Gompel, Liese Van; Munk, Patrick ; Sarrazin, Steven ; Joosten, Philip ; Dorado-García, Alejandro ; Borup Hansen, Rasmus ; Knudsen, Berith E. ; Bossers, Alex ; Wagenaar, Jaap A. ; Aarestrup, Frank M. ; Dewulf, Jeroen ; Mevius, Dik J. ; Heederik, Dick J.J. ; Smit, Lidwien A.M. ; Schmitt, Heike - \ 2019
Journal of Antimicrobial Chemotherapy 74 (2019)9. - ISSN 0305-7453 - p. 2596 - 2604.

OBJECTIVES: To determine associations between farm- and flock-level antimicrobial usage (AMU), farm biosecurity status and the abundance of faecal antimicrobial resistance genes (ARGs) on broiler farms. METHODS: In the cross-sectional pan-European EFFORT study, conventional broiler farms were visited and faeces, AMU information and biosecurity records were collected. The resistomes of pooled faecal samples were determined by metagenomic analysis for 176 farms. A meta-analysis approach was used to relate total and class-specific ARGs (expressed as fragments per kb reference per million bacterial fragments, FPKM) to AMU (treatment incidence per DDD, TIDDDvet) per country and subsequently across all countries. In a similar way, the association between biosecurity status (Biocheck.UGent) and the resistome was explored. RESULTS: Sixty-six (38%) flocks did not report group treatments but showed a similar resistome composition and roughly similar ARG levels to antimicrobial-treated flocks. Nevertheless, we found significant positive associations between β-lactam, tetracycline, macrolide and lincosamide, trimethoprim and aminoglycoside antimicrobial flock treatments and ARG clusters conferring resistance to the same class. Similar associations were found with purchased products. In gene-level analysis for β-lactams and macrolides, lincosamides and streptogramins, a significant positive association was found with the most abundant gene clusters blaTEM and erm(B). Little evidence was found for associations with biosecurity. CONCLUSIONS: The faecal microbiome in European broilers contains a high diversity of ARGs, even in the absence of current antimicrobial selection pressure. Despite this, the relative abundance of genes and the composition of the resistome is positively related to AMU in European broiler farms for several antimicrobial classes.

Is comfort food actually comforting for emotional eaters? A (moderated) mediation analysis
Strien, Tatjana van; Gibson, E.L. ; Baños, Rosa ; Cebolla, Ausiàs ; Winkens, Laura H.H. - \ 2019
Physiology and Behavior 211 (2019). - ISSN 0031-9384
Eating satisfaction - Food, mood, emotional eating - Tastiness

An important but unreplicated earlier finding on comfort eating was that the association between food intake and immediate mood improvement appeared to be mediated by the palatability of the food, and that this effect was more pronounced for high than for low emotional eaters [26]. This has not yet been formally tested using mediation and moderated mediation analysis. We conducted these analyses using data from two experiments on non-obese female students (n = 29 and n = 74). Mood and eating satisfaction in Study 1, and mood, tastiness and emotional eating in Study 2 were all self-reported. In Study 1, using a sad mood induction procedure, emotional eaters ate more food, and when mood was assessed immediately after food intake, ‘eating satisfaction’ acted as mediator between food intake and mood improvement (decrease in sadness or increase in happiness). In Study 2, where we measured the difference in actual food intake after a control or a stress task (modified Trier Social Stress Test), and assessed mood during the food intake after stress, we found significant moderated mediation. As expected, there was a significant positive mediation effect of tastiness between food intake and mood improvement in the high emotional eaters, but also a significant negative mediation effect of tastiness between food intake and mood improvement in the low emotional eaters. This suggests that tastiness promotes ‘comfort’ from food in female emotional eaters, but conflicts in non-emotional eaters with a tendency to eat less when stressed. In conclusion, palatable food may indeed provide comfort specifically for high emotional eaters during eating.

Species- and size-related differences in dopamine-like immunoreactive clusters in the brain of Nasonia vitripennis and N. giraulti
Groothuis, Jitte ; Heuvel, Krista van den; Smid, Hans M. - \ 2019
Cell and Tissue Research (2019). - ISSN 0302-766X - 13 p.
Brain - Confocal laser scanning microscopy - Dopamine - Insect - Parasitic wasp

An extreme reduction in body size has been shown to negatively impact the memory retention level of the parasitic wasp Nasonia vitripennis. In addition, N. vitripennis and Nasonia giraulti, closely related parasitic wasps, differ markedly in the number of conditioning trials required to form long-term memory. These differences in memory dynamics may be associated with differences in the dopaminergic neurons in the Nasonia brains. Here, we used dopamine immunoreactivity to identify and count the number of cell bodies in dopaminergic clusters of normal- and small-sized N. vitripennis and normal-sized N. giraulti. We counted in total a maximum of approximately 160 dopaminergic neurons per brain. These neurons were present in 9 identifiable clusters (D1a, D1b, D2, D3, D4a, D4b, D5, D6 and D7). Our analysis revealed that N. giraulti had fewer cells in the D2 and D4a clusters but more in D4b, compared with normal-sized N. vitripennis. In addition, we found fewer cells in the D5 and D7 cluster of small-sized N. vitripennis compared to normal-sized N. vitripennis. A comparison of our findings with the literature on dopaminergic clusters in the fruit fly Drosophila melanogaster and the honey bee Apis mellifera indicates that clusters D2, D3 and D5 may play a role in memory formation in Nasonia wasps. The results from both the species comparison and the size comparison are therefore of high interest and importance for our understanding of the complex intricacies that underlie the memory dynamics of insects.

D4.7 A pan-European simulation of selected interventions
Masotti, Matteo ; Stewart, Gavin ; Close, Andrew ; Setti, Marco ; Vittuari, Matteo ; Bos-Brouwers, H.E.J. ; Aramyan, L.H. ; Logatcheva, K. ; Herpen, H.W.I. van - \ 2019
Wageningen : REFRESH - ISBN 9789463950985 - 63
Author Correction: Diversity-dependent temporal divergence of ecosystem functioning in experimental ecosystems
Guerrero-Ramírez, Nathaly R. ; Craven, Dylan ; Reich, Peter B. ; Ewel, John J. ; Isbell, Forest ; Koricheva, Julia ; Parrotta, John A. ; Auge, Harald ; Erickson, Heather E. ; Forrester, David I. ; Hector, Andy ; Joshi, Jasmin ; Montagnini, Florencia ; Palmborg, Cecilia ; Piotto, Daniel ; Potvin, Catherine ; Roscher, Christiane ; Ruijven, Jasper van; Tilman, David ; Wilsey, Brian ; Eisenhauer, Nico - \ 2019
Nature Ecology & Evolution 3 (2019). - ISSN 2397-334X - p. 1365 - 1365.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Tropical deforestation drivers and associated carbon emission factors derived from remote sensing data
Sy, Veronique De; Herold, Martin ; Achard, Frederic ; Avitabile, Valerio ; Baccini, Alessandro ; Carter, Sarah ; Clevers, Jan G.P.W. ; Lindquist, Erik ; Pereira, Maria ; Verchot, Louis - \ 2019
Environmental Research Letters 14 (2019)9. - ISSN 1748-9318 - 29 p.
Reducing emissions from deforestation and forest degradation, and enhancing carbon stocks (REDD+) is a crucial component of global climate change mitigation. Remote sensing can provide continuous and spatially explicit above-ground biomass (AGB) estimates, which can be valuable for the quantification of carbon stocks and emission factors (EFs). Unfortunately, there is little information on the fate of the land following tropical deforestation and of the associated carbon stock. This study quantified post-deforestation land use across the tropics for the period 1990 – 2000. This dataset was then combined with a pan-tropical AGB map at 30 m resolution to refine EFs from forest conversion by matching deforestation areas with their carbon stock before and after clearing and to assess spatial dynamics of EFs by follow-up land use. In Latin America, pasture was the most common follow-up land use (72%), with large-scale cropland (11%) a distant second. In Africa deforestation was often followed by small-scale cropping (61%) with a smaller role for pasture (15%). In Asia, small-scale cropland was the dominant agricultural follow-up land use (35%), closely followed by tree crops (28%). Deforestation often occurred in forests with lower than average carbon stocks. EFs showed high spatial variation within eco-zones and countries. While our EFs are only representative for the studied time period, our results show that EFs are mainly determined by the initial forest carbon stock. The estimates of the fraction of carbon lost were less dependent on initial forest biomass, which offers opportunities for REDD+ countries to use these fractions in combination with recent good quality national forest biomass maps or inventory data to quantify emissions from specific forest conversions. Our study highlights that the co-location of data on forest loss, biomass and fate of the land provides more insight into the spatial dynamics of land-use change and can help in attributing carbon emissions to human activities.

D4.6 - Pan-European scenarios of food waste levels
Masotti, Matteo ; Stewart, Gavin ; Close, Andrew ; Setti, Marco ; Vittuari, Matteo ; Bos-Brouwers, H.E.J. ; Aramyan, L.H. ; Logatcheva, K. ; Herpen, H.W.I. van - \ 2019
Place of publication not identified : REFRESH - ISBN 9789463950893 - 93
Dietary choices and environmental impact in four European countries
Mertens, Elly ; Kuijsten, Anneleen ; Zanten, Hannah H.E. van; Kaptijn, Gerdine ; Dofková, Marcela ; Mistura, Lorenza ; Addezio, L. D'; Turrini, Aida ; Dubuisson, Carine ; Havard, Sabrina ; Trolle, E. ; Geleijnse, Johanna M. ; Veer, Pieter van 't - \ 2019
Journal of Cleaner Production 237 (2019). - ISSN 0959-6526
Dietary quality - Energy intake - Greenhouse gas emission - Land use - Sustainability

Effective food policies in Europe require insight into the environmental impact of consumers’ diet to contribute to global nutrition security in an environmentally sustainable way. The present study therefore aimed to assess the environmental impact associated with dietary intake across four European countries, and to explain sources of variations in environmental impact by energy intake, demographics and diet composition. Individual-level dietary intake data were obtained from nationally-representative dietary surveys, by using two non-consecutive days of a 24-h recall or a diet record, from Denmark (DK, n = 1710), Czech Republic (CZ, n = 1666), Italy (IT, n = 2184), and France (FR, n = 2246). Dietary intake data were linked to a newly developed pan-European environmental sustainability indicator database that contains greenhouse gas emissions (GHGE) and land use (LU) values for ∼900 foods. To explain the variation in environmental impact of diets, multilevel regression models with random intercept and random slopes were fitted according to two levels: adults (level 1, n = 7806) and country (level 2, n = 4). In the models, diet-related GHGE or LU was the dependent variable, and the parameter of interest, i.e. either total energy intake or demographics or food groups, the exploratory variables. A 200-kcal higher total energy intake was associated with a 9% and a 10% higher daily GHGE and LU. Expressed per 2000 kcal, mean GHGE ranged from 4.4 (CZ) to 6.3 kgCO2eq/2000 kcal (FR), and LU ranged from 5.7 (CZ) to 8.0 m2*year/2000 kcal (FR). Dietary choices explained most of the variation between countries. A 5 energy percent (50 g/2000 kcal) higher meat intake was associated with a 10% and a 14% higher GHGE and LU density, with ruminant meat being the main contributor to environmental footprints. In conclusion, intake of energy, total meat and the proportion of ruminant meat explained most of the variation in GHGE and LU of European diets. Contributions of food groups to environmental footprints however varied between countries, suggesting that cultural preferences play an important role in environmental footprints of consumers. In particular, Findings from the present study will be relevant for national-specific food policy measures towards a more environmentally-friendly diet.

Joint Assimilation of Leaf Area Index and Soil Moisture from Sentinel-1 and Sentinel-2 Data into the WOFOST Model for Winter Wheat Yield Estimation
Pan, Haizhu ; Chen, Zhongxin ; Wit, Allard de; Ren, Jianqiang - \ 2019
Sensors 19 (2019)14. - ISSN 1424-8220
data assimilation - EnKF - LAI - Sentinel-1 and Sentinel-2 - SM - winter wheat yield - WOFOST

It is well known that timely crop growth monitoring and accurate crop yield estimation at a fine scale is of vital importance for agricultural monitoring and crop management. Crop growth models have been widely used for crop growth process description and yield prediction. In particular, the accurate simulation of important state variables, such as leaf area index (LAI) and root zone soil moisture (SM), is of great importance for yield estimation. Data assimilation is a useful tool that combines a crop model and external observations (often derived from remote sensing data) to improve the simulated crop state variables and consequently model outputs like crop total biomass, water use and grain yield. In spite of its effectiveness, applying data assimilation for monitoring crop growth at the regional scale in China remains challenging, due to the lack of high spatiotemporal resolution satellite data that can match the small field sizes which are typical for agriculture in China. With the accessibility of freely available images acquired by Sentinel satellites, it becomes possible to acquire data at high spatiotemporal resolution (10-30 m, 5-6 days), which offers attractive opportunities to characterize crop growth. In this study, we assimilated remotely sensed LAI and SM into the Word Food Studies (WOFOST) model to estimate winter wheat yield using an ensemble Kalman filter (EnKF) algorithm. The LAI was calculated from Sentinel-2 using a lookup table method, and the SM was calculated from Sentinel-1 and Sentinel-2 based on a change detection approach. Through validation with field data, the inverse error was 10% and 35% for LAI and SM, respectively. The open-loop wheat yield estimation, independent assimilations of LAI and SM, and a joint assimilation of LAI + SM were tested and validated using field measurement observation in the city of Hengshui, China, during the 2016-2017 winter wheat growing season. The results indicated that the accuracy of wheat yield simulated by WOFOST was significantly improved after joint assimilation at the field scale. Compared to the open-loop estimation, the yield root mean square error (RMSE) with field observations was decreased by 69 kg/ha for the LAI assimilation, 39 kg/ha for the SM assimilation and 167 kg/ha for the joint LAI + SM assimilation. Yield coefficients of determination (R2) of 0.41, 0.65, 0.50, and 0.76 and mean relative errors (MRE) of 4.87%, 4.32%, 4.45% and 3.17% were obtained for open-loop, LAI assimilation alone, SM assimilation alone and joint LAI + SM assimilation, respectively. The results suggest that LAI was the first-choice variable for crop data assimilation over SM, and when both LAI and SM satellite data are available, the joint data assimilation has a better performance because LAI and SM have interacting effects. Hence, joint assimilation of LAI and SM from Sentinel-1 and Sentinel-2 at a 20 m resolution into the WOFOST provides a robust method to improve crop yield estimations. However, there is still bias between the key soil moisture in the root zone and the Sentinel-1 C band retrieved SM, especially when the vegetation cover is high. By active and passive microwave data fusion, it may be possible to offer a higher accuracy SM for crop yield prediction.

A Medicago truncatula SWEET transporter implicated in arbuscule maintenance during arbuscular mycorrhizal symbiosis
An, Jianyong ; Zeng, Tian ; Ji, Chuanya ; Graaf, Sanne de; Zheng, Zijun ; Xiao, Ting Ting ; Deng, Xiuxin ; Xiao, Shunyuan ; Bisseling, Ton ; Limpens, Erik ; Pan, Zhiyong - \ 2019
New Phytologist 224 (2019)1. - ISSN 0028-646X - p. 396 - 408.
arbuscular mycorrhiza (AM) - glucose - Medicago truncatula - sugar export - SWEET - symbiosis

Plants form a mutualistic symbiosis with arbuscular mycorrhizal (AM) fungi, which facilitates the acquisition of scarce minerals from the soil. In return, the host plants provide sugars and lipids to its fungal partner. However, the mechanism by which the AM fungi obtain sugars from the plant has remained elusive. In this study we investigated the role of potential SWEET family sugar exporters in AM symbiosis in Medicago truncatula. We show that M. truncatula SWEET1b transporter is strongly upregulated in arbuscule-containing cells compared to roots and localizes to the peri-arbuscular membrane, across which nutrient exchange takes place. Heterologous expression of MtSWEET1b in a yeast hexose transport mutant showed that it mainly transports glucose. Overexpression of MtSWEET1b in M. truncatula roots promoted the growth of intraradical mycelium during AM symbiosis. Surprisingly, two independent Mtsweet1b mutants, which are predicted to produce truncated protein variants impaired in glucose transport, exhibited no significant defects in AM symbiosis. However, arbuscule-specific overexpression of MtSWEET1bY57A/G58D, which are considered to act in a dominant-negative manner, resulted in enhanced collapse of arbuscules. Taken together, our results reveal a (redundant) role for MtSWEET1b in the transport of glucose across the peri-arbuscular membrane to maintain arbuscules for a healthy mutually beneficial symbiosis.

Arsenic in Argentina : Technologies for arsenic removal from groundwater sources, investment costs and waste management practices
Litter, Marta I. ; Ingallinella, Ana M. ; Olmos, Valentina ; Savio, Marianela ; Difeo, Gonzalo ; Botto, Lía ; Torres, Elsa Mónica Farfán ; Taylor, Sergio ; Frangie, Sofía ; Herkovits, Jorge ; Schalamuk, Isidoro ; González, María José ; Berardozzi, Eliana ; García Einschlag, Fernando S. ; Bhattacharya, Prosun ; Ahmad, Arslan - \ 2019
Science of the Total Environment 690 (2019). - ISSN 0048-9697 - p. 778 - 789.
Argentina - Arsenic - Drinking water - Mitigation - Removal technologies

An overview about the presence of arsenic (As) in groundwaters of Argentina, made by a transdisciplinary group of experts is presented. In this second part, the conventional and emerging technologies for As removal, management of wastes, and the initial investment costs of the proposed technologies, with emphasis on developments of local groups are described. Successful examples of real application of conventional and emerging technologies for As removal in waters for human consumption, for medium, small and rural and periurban communities are reported. In the country, the two most applied technologies for arsenic removal at a real scale are reverse osmosis and coagulation-adsorption-filtration processes using iron or aluminum salts or polyelectrolytes as coagulants. A decision tree to evaluate the possible technologies to be applied, based on the population size, the quality of the water and its intended use, is presented, including preliminary and indicative investment costs. Finally, a section discussing the treatment and final disposal of the liquid, semiliquid and solid wastes, generated by the application of the most used technologies, is included. Conclusions and recommendations, especially for isolated rural and periurban regions, have been added.

The Lemon Car Game Across Cultures: Evidence of Relational Rationality
Hofstede, G.J. ; Jonker, Catholijn ; Verwaart, T. ; Yorke-Smith, Neil - \ 2019
Group Decision and Negotiation 28 (2019)5. - ISSN 0926-2644 - p. 849 - 877.
Negotiation - Culture - Experimental studies - Power distance - Long-term orientation - Lemon car
In cross-cultural business negotiation, culture is known to influence negotiation processes. As a lens to study this effect we deployed the Lemon Car Game, an online negotiation game developed for this purpose (Hofstede et al. in: Proceedings of 39th international simulation and gaming association conference (ISAGA). Technologia, Kaunas, pp 39–46, 2009a; Hofstede et al. in: David, Sichman (eds) Multi-agent-based simulation IX, international workshop, MABS 2008, revised selected papers, LNAI 5269. Springer, Berlin, pp 1–16, 2009b). In this article we report the results from the game, obtained from over 800 players from more than 70 countries. We employ several complementary analyses in a mixed-methods approach.Our findings show that to make sense of the players’ actions during negotiation, economic rationality falls short. A pan-cultural individual-level analysis of actions and stated intentions also fails to yield a coherent picture. Within countries, however, actions and intentions do cohere, as shown by an ecological country-level factor analysis, from which three factors emerge for the sellers at country level: trustworthiness, opportunism, and fairness. We conclude from these findings that, in this game, players are driven by what we call relational rationality: they are rational from the perspective of the social world in which they live, with interpersonal relationships weighing heavily. Relational rationality changes players’ perspective of economic rationality, and thus their observed behaviour in negotiation. Based on this evidence, we extrapolate that relational rationality significantly influences negotiation processes in all cultures.
Automated Testing of Simulation Software in the Aviation Industry : An Experience Report
Garousi, Vahid ; Tasli, Seckin ; Sertel, Onur ; Tokgoz, Mustafa ; Herkiloglu, Kadir ; Arkin, Hikmet Ferda Ergunes ; Bilir, Osman - \ 2019
IEEE Software 36 (2019)4. - ISSN 0740-7459 - p. 63 - 75.
automated testing - aviation industry - simulation software - test automation

An industry-academia collaboration developed a test automation framework for aviation simulation software. The technology has been successfully deployed in several test teams.

The economic impact of drying off cows with a dry-off facilitator (cabergoline) compared with 2 methods of gradual cessation of lactation for European dairy farms
Steeneveld, W. ; Prado-Taranilla, A. De; Krogh, K. ; Hogeveen, H. - \ 2019
Journal of Dairy Science 102 (2019)8. - ISSN 0022-0302 - p. 7483 - 7493.
cabergoline - dairy cow - drying off - economics - intramammary infection

An abrupt method to dry off cows has disadvantages and is considered inappropriate for current dairy cows due to welfare issues and risks for intramammary infections (IMI). A gradual cessation of lactation (by feeding or milking frequency reduction) has been the generally recommended method for drying off cows to prevent these adverse effects. However, a new alternative to the gradual approach is to abruptly stop milking at the same time as using cabergoline (CAB), a prolactin inhibitor. The aim of the study was to compare the net costs of 3 different methods of drying off cows [gradual reduction in feed (gradual-feeding), gradual reduction in milking frequency (gradual-milking), and abrupt cessation of milking with CAB (abrupt-CAB)]. A stochastic Monte Carlo simulation model, at cow level, was developed to calculate the net costs of applying these methods. All inputs for the model were based on literature information, authors' expertise, and expert knowledge. The net costs were determined by only including costs and benefits, which varied between the 3 methods. The model simulated a cow from 7 d before the day of drying off until the end of the next lactation. The likelihood of whether a cow was leaking milk early in the dry period was determined. Subsequently, it was determined whether or not the cow will get an IMI during the dry period, where the probability of getting an IMI was higher for cows leaking milk than for cows not leaking milk. If the IMI was not cured during the dry period, the cow had an IMI at calving. Also, milk production and feed requirements were modeled, and labor for applying the drying off method was included. For all methods, the net costs were calculated as the sum of costs for feed during the gradual feed reduction period, costs for applying the gradual-milking method, and the IMI costs during the dry period and lactation, minus the milk revenues during the transition from lactation to the dry period. Under default conditions, the average net cost of abrupt-CAB was €49.6/cow. The data showed that 90% of the net costs ranged from −€13.7 to €307.8/cow. The average net costs for gradual-feed and gradual-milking were €99.1 and €71.5/cow, respectively. In conclusion, abrupt-CAB saved €49.5 and €21.9/cow on average compared with gradual-feeding and gradual-milking, respectively. This difference was mainly due to more milk returns and lower labor and IMI costs during lactation.

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