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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Modeling nutrients in Lake Dianchi (China) and its watershed
Li, Xiaolin ; Janssen, Annette B.G. ; Klein, Jeroen J.M. de; Kroeze, Carolien ; Strokal, Maryna ; Ma, Lin ; Zheng, Yi - \ 2019
Agricultural Water Management 212 (2019). - ISSN 0378-3774 - p. 48 - 59.
Critical loading - MARINA nutrient model - Mining - PCLake ecosystem model - River export of nutrients

Lake Dianchi suffered from severe eutrophication for decades. Past efforts to reduce the eutrophication were not very effective. The objective of this study is to improve our understanding of nitrogen (N) and phosphorus (P) loadings and to analyze to what extent they exceed critical nutrient loadings of Lake Dianchi. To this end, we applied the nutrient MARINA model and the ecosystem model PCLake. Results show that river export of dissolved N and P was high in 2012. About 6 209 ton of total dissolved N (TDN) was exported to the lake (i.e. 23.6 kg ha−1), of which more than two-thirds in the form of dissolved inorganic N. For total dissolved P, this export was about 413 ton (i.e. 1.6 kg ha−1), of which 75% dissolved inorganic P. Urban sewage is a major source of nutrients in rivers in the northern sub-basins. In southern sub-basins, agriculture is an important source of both N and P, while P mining and processing is a major source of dissolved inorganic P. Nutrient inputs to the lake are particularly high from urbanization sub-basins draining into the northern part of the lake (Caohai). Critical nutrient loadings for the northern part of the lake (Caohai) are 0.34 mg P m−2d−1 (3.06 mg N m−2d−1) and for the southern part (Waihai) 0.38 mg P m−2d−1 (3.42 mg N m−2d−1). Actual loadings exceed the critical nutrient loadings by 82 times and 17 times of Caohai and Waihai, respectively. Our study illustrates how linking MARINA with PCLake helped to quantify the causes of lake eutrophication and to identify critical loadings for N and P in the lake. Our study can assist local authorities to formulate management options to reduce nutrient pollution in Lake Dianchi in the future.

Causal relationship in the interaction between land cover change and underlying surface climate in the grassland ecosystems in China
Li, Zhouyuan ; Wang, Zezhong ; Liu, Xuehua ; Fath, Brian D. ; Liu, Xiaofei ; Xu, Yanjie ; Hutjes, Ronald ; Kroeze, Carolien - \ 2019
Science of the Total Environment 647 (2019). - ISSN 0048-9697 - p. 1080 - 1087.
Cause-effect - Correlation analysis - Eco-climatology - Grassland - Land-climate - Remote sensing

Land-climate interactions are driven by causal relations that are difficult to ascertain given the complexity and high dimensionality of the systems. Many methods of statistical and mechanistic models exist to identify and quantify the causality in such highly-interacting systems. Recent advances in remote sensing development allowed people to investigate the land-climate interaction with spatially and temporally continuous data. In this study, we present a new approach to measure how climatic factors interact with each other under land cover change. The quantification method is based on the correlation analysis of the different order derivatives, with the canonical mathematical definitions developed from the theories of system dynamics and practices of the macroscopic observations. We examined the causal relationship between the interacting variables on both spatial and temporal dimensions based on macroscopic observations of land cover change and surface climatic factors through a comparative study in the different grassland ecosystems of China. The results suggested that the interaction of land-climate could be used to explain the temporal lag effect in the comparison of the three grassland ecosystems. Significant spatial correlations between the vegetation and the climatic factors confirmed feedback mechanisms described in the theories of eco-climatology, while the uncertain temporal synchronicity reflects the causality among the key indicators. This has been rarely addressed before. Our research show that spatial correlations and the temporal synchronicity among key indicators of the land surface and climatic factors can be explained by a novel method of causality quantification using derivative analysis.

Irrigation reduces the negative effect of global warming on winter wheat yield and greenhouse gas intensity
Li, Jiazhen ; Dong, Wenxu ; Oenema, Oene ; Chen, Tuo ; Hu, Chunsheng ; Yuan, Haijing ; Zhao, Liying - \ 2019
Science of the Total Environment 646 (2019). - ISSN 0048-9697 - p. 290 - 299.
Global warming potential - Greenhouse gas intensity - Greenhouse gases - Irrigation - Warming - Wheat yield

Global warming may exacerbate drought, decrease crop yield and affect greenhouse gas (GHG) emissions in semi-arid regions. However, the interactive effects of increases in temperature and water availability on winter wheat yield and GHG emissions in semi-arid climates are not well-understood. Here, we report on a two-year field experiment that examined the effects of a mean soil temperature increase of ~2 °C (at 5 cm depth) with and without additional irrigation on wheat yield and GHG emissions. Infrared heaters were placed above the crop canopy at a height of 1.8 m to simulate warming. Fluxes of CH4, CO2 and N2O were measured using closed static chamber technique once per week during the wheat growing seasons. Warming decreased wheat yield by 28% in the relatively dry year of 2015, while supplemental irrigation nullified the warming effect completely. Warming did not alter the wheat yield significantly in the relatively wet year of 2016, but supplemental irrigation with no warming decreased the wheat yield by 25%. Warming increased CO2 emissions by 28% and CH4 uptake by 24% and tended to decrease N2O emissions. Supplemental irrigation increased N2O emissions but had little effect on CO2 emissions and CH4 uptake. Evidently, warming and supplemental irrigation had interactive effects on wheat yield, GHG emissions and GHG emissions intensity. Precision irrigation appears to be a means of simultaneously increasing wheat yield and reducing GHG emissions under warming conditions in semi-arid areas.

Quality of terrestrial data derived from UAV photogrammetry : A case study of Hetao irrigation district in northern China
Zhang, Hongming ; Yang, Jiang Tao ; Baartman, Jantiene E.M. ; Li, Shu Qin ; Jin, Bei ; Han, Wen Ting ; Yang, Xiaomei ; Gai, Lingtong ; Ritsema, Coen J. ; Geissen, Violette - \ 2018
International Journal of Agricultural and Biological Engineering 11 (2018)3. - ISSN 1934-6344 - p. 171 - 177.
Accuracy evaluation - DEM - GIS - Irrigation area - Photogrammetry - UAVs

Most crops in northern China are irrigated, but the topography affects the water use, soil erosion, runoff and yields. Technologies for collecting high-resolution topographic data are essential for adequately assessing these effects. Ground surveys and techniques of light detection and ranging have good accuracy, but data acquisition can be time-consuming and expensive for large catchments. Recent rapid technological development has provided new, flexible, high-resolution methods for collecting topographic data, such as photogrammetry using unmanned aerial vehicles (UAVs). The accuracy of UAV photogrammetry for generating high-resolution Digital Elevation Model (DEM) and for determining the width of irrigation channels, however, has not been assessed. A fixed-wing UAV was used for collecting high-resolution (0.15 m) topographic data for the Hetao irrigation district, the third largest irrigation district in China. 112 ground checkpoints (GCPs) were surveyed by using a real-time kinematic global positioning system to evaluate the accuracy of the DEMs and channel widths. A comparison of manually measured channel widths with the widths derived from the DEMs indicated that the DEM-derived widths had vertical and horizontal root mean square errors of 13.0 and 7.9 cm, respectively. UAV photogrammetric data can thus be used for land surveying, digital mapping, calculating channel capacity, monitoring crops, and predicting yields, with the advantages of economy, speed and ease.

The red bayberry genome and genetic basis of sex determination
Jia, Hui Min ; Jia, Hui Juan ; Cai, Qing Le ; Wang, Yan ; Zhao, Hai Bo ; Yang, Wei Fei ; Wang, Guo Yun ; Li, Ying Hui ; Zhan, Dong Liang ; Shen, Yu Tong ; Niu, Qing Feng ; Chang, Le ; Qiu, Jie ; Zhao, Lan ; Xie, Han Bing ; Fu, Wan Yi ; Jin, Jing ; Li, Xiong Wei ; Jiao, Yun ; Zhou, Chao Chao ; Tu, Ting ; Chai, Chun Yan ; Gao, Jin Long ; Fan, Long Jiang ; Weg, Eric van de; Wang, Jun Yi ; Gao, Zhong Shan - \ 2018
Plant Biotechnology Journal (2018). - ISSN 1467-7644
genome - Morella rubra - sex-determining region - sex-linked marker

Morella rubra, red bayberry, is an economically important fruit tree in south China. Here, we assembled the first high-quality genome for both a female and a male individual of red bayberry. The genome size was 313-Mb, and 90% sequences were assembled into eight pseudo chromosome molecules, with 32 493 predicted genes. By whole-genome comparison between the female and male and association analysis with sequences of bulked and individual DNA samples from female and male, a 59-Kb region determining female was identified and located on distal end of pseudochromosome 8, which contains abundant transposable element and seven putative genes, four of them are related to sex floral development. This 59-Kb female-specific region was likely to be derived from duplication and rearrangement of paralogous genes and retained non-recombinant in the female-specific region. Sex-specific molecular markers developed from candidate genes co-segregated with sex in a genetically diverse female and male germplasm. We propose sex determination follow the ZW model of female heterogamety. The genome sequence of red bayberry provides a valuable resource for plant sex chromosome evolution and also provides important insights for molecular biology, genetics and modern breeding in Myricaceae family.

Forest Landscape Hydrology in a ‘New Normal’ Era of Climate and Land Use Change
Jones, Julia A. ; Wei, Xiaohua ; Noordwijk, M. van; Creed, Irena F. ; Gush, Mark ; Ellison, David ; Blanco, Juan A. ; Bishop, Kevin ; McNulty, Steven ; BarguésTobella, Aida ; Archer, E. ; Bruijnzeel, L.A. ; Duinker, P. ; Foster, David ; Gebrekirstos, Aster ; Giles-Hansen, Krysta ; Hacket-Pain, Andrew ; Harper, Richard J. ; Ilstedt, Ulrik ; Li, Qiang ; Liao, Yingchun ; Malmer, Anders ; Mwangi, Hosea ; Orland, Chloé ; Steenberg, James ; Wang, Yi ; Worthy, Fiona ; Xu, Jianchu ; Zhang, Mingfang - \ 2018
In: Forest and Water on a Changing Planet: Vulnerability, Adaptation and Governance Opportunities / Creed, Irena F., van Noordwijk, Meine, International Union of Forest Research Organizations (IUFRO) (IUFRO World Series ) - ISBN 9783902762955 - p. 81 - 99.
Green and Black Tea Phenolics : Bioavailability, Transformation by Colonic Microbiota, and Modulation of Colonic Microbiota
Liu, Zhibin ; Bruins, Marieke Elisabeth ; Ni, Li ; Vincken, Jean Paul - \ 2018
Journal of Agricultural and Food Chemistry 66 (2018)32. - ISSN 0021-8561 - p. 8469 - 8477.
bioavailability - black tea phenolics - green tea catechins - gut microbiota - health benefits - microbial metabolism

Monomeric green tea catechin (GTC) and oligomeric, oxidized black tea phenolic (BTP) have shown promising health benefits, although GTC has been more extensively studied than BTP. We review the current knowledge on bioavailability, colonic transformation, and gut microbiota modulatory effects of GTC and BTP. As a result of their similar poor bioavailability in the small intestine and potentially similar metabolites upon colonic fermentation, it seems as if GTC and BTP have similar health effects, although it cannot be excluded that they have different gut microbiota modulatory effects and that BTP gives a poorer yield of bioactive phenolic metabolites upon colonic fermentation than GTC.

Development and analysis of the Soil Water Infiltration Global database
Rahmati, Mehdi ; Weihermüller, Lutz ; Vanderborght, Jan ; Pachepsky, Yakov A. ; Mao, Lili ; Sadeghi, Seyed Hamidreza ; Moosavi, Niloofar ; Kheirfam, Hossein ; Montzka, Carsten ; Looy, Kris Van; Toth, Brigitta ; Hazbavi, Zeinab ; Yamani, Wafa Al; Albalasmeh, Ammar A. ; Alghzawi, M.Z. ; Angulo-Jaramillo, Rafael ; Antonino, Antônio Celso Dantas ; Arampatzis, George ; Armindo, Robson André ; Asadi, Hossein ; Bamutaze, Yazidhi ; Batlle-Aguilar, Jordi ; Béchet, Béatrice ; Becker, Fabian ; Blöschl, Günter ; Bohne, Klaus ; Braud, Isabelle ; Castellano, Clara ; Cerdà, Artemi ; Chalhoub, Maha ; Cichota, Rogerio ; Císlerová, Milena ; Clothier, Brent ; Coquet, Yves ; Cornelis, Wim ; Corradini, Corrado ; Coutinho, Artur Paiva ; Oliveira, Muriel Bastista De; Macedo, José Ronaldo De; Durães, Matheus Fonseca ; Emami, Hojat ; Eskandari, Iraj ; Farajnia, Asghar ; Flammini, Alessia ; Fodor, Nándor ; Gharaibeh, Mamoun ; Ghavimipanah, Mohamad Hossein ; Ghezzehei, Teamrat A. ; Giertz, Simone ; Hatzigiannakis, Evangelos G. ; Horn, Rainer ; Jiménez, Juan José ; Jacques, Diederik ; Keesstra, Saskia Deborah ; Kelishadi, Hamid ; Kiani-Harchegani, Mahboobeh ; Kouselou, Mehdi ; Jha, Madan Kumar ; Lassabatere, Laurent ; Li, Xiaoyan ; Liebig, Mark A. ; Lichner, Lubomír ; López, María Victoria ; Machiwal, Deepesh ; Mallants, Dirk ; Mallmann, Micael Stolben ; Oliveira Marques, Jean Dalmo De; Marshall, Miles R. ; Mertens, Jan ; Meunier, Félicien ; Mohammadi, Mohammad Hossein ; Mohanty, Binayak P. ; Pulido-Moncada, Mansonia ; Montenegro, Suzana ; Morbidelli, Renato ; Moret-Fernández, David ; Moosavi, Ali Akbar ; Mosaddeghi, Mohammad Reza ; Mousavi, Seyed Bahman ; Mozaffari, Hasan ; Nabiollahi, Kamal ; Neyshabouri, Mohammad Reza ; Ottoni, Marta Vasconcelos ; Ottoni Filho, Theophilo Benedicto ; Pahlavan-Rad, Mohammad Reza ; Panagopoulos, Andreas ; Peth, Stephan ; Peyneau, Pierre Emmanuel ; Picciafuoco, Tommaso ; Poesen, Jean ; Pulido, Manuel ; Reinert, Dalvan José ; Reinsch, Sabine ; Rezaei, Meisam ; Roberts, Francis Parry ; Robinson, David ; Rodrigo-Comino, Jesüs ; Rotunno Filho, Otto Corrêa ; Saito, Tadaomi ; Suganuma, Hideki ; Saltalippi, Carla ; Sándor, Renáta ; Schütt, Brigitta ; Seeger, Manuel ; Sepehrnia, Nasrollah ; Sharifi Moghaddam, Ehsan ; Shukla, Manoj ; Shutaro, Shiraki ; Sorando, Ricardo ; Stanley, Ajayi Asishana ; Strauss, Peter ; Su, Zhongbo ; Taghizadeh-Mehrjardi, Ruhollah ; Taguas, Encarnación ; Teixeira, Wenceslau Geraldes ; Vaezi, Ali Reza ; Vafakhah, Mehdi ; Vogel, Tomas ; Vogeler, Iris ; Votrubova, Jana ; Werner, Steffen ; Winarski, Thierry ; Yilmaz, Deniz ; Young, Michael H. ; Zacharias, Steffen ; Zeng, Yijian ; Zhao, Ying ; Zhao, Hong ; Vereecken, Harry - \ 2018
Earth System Science Data 10 (2018)3. - ISSN 1866-3508 - p. 1237 - 1263.

In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements (∼76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76ĝ€% of the experimental sites with agricultural land use as the dominant type (∼40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in ∗.xlsx and ∗.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it.

Significant enhancement of micropollutant photocatalytic degradation using a TiO2 nanotube array photoanode based photocatalytic fuel cell
Ye, Yin ; Bruning, Harry ; Li, Xiaolu ; Yntema, Doekle ; Rijnaarts, Huub H.M. - \ 2018
Chemical Engineering Journal 354 (2018). - ISSN 1385-8947 - p. 553 - 562.
MCPA - Photocatalysis - Photocatalytic fuel cell - Scavengers - TiO nanotube arrays

This study evaluated the application of a membrane-free photocatalytic fuel cell composed of a TiO2 nanotube array photoanode and a Cu cathode, i.e. TNA-Cu PFC system, for micropollutant removal from water. Significantly enhanced removal of a commonly present aqueous micropollutant 4-chloro-2-methylphenoxyacetic acid (MCPA) was obtained in this TNA-Cu PFC system: the TNA-Cu PFC system achieved better MCPA degradation compared to the conventional photocatalytic method using the same catalyst. In the TNA-Cu PFC system, the MCPA degradation was largely promoted under acidic conditions, indicating this as an important operational condition. The enhancement of MCPA degradation in the TNA-Cu PFC system involved better e/h+ separation and generation of other oxidants: in conventional photocatalytic process, hydroxyl radicals in liquid phase contributed to 93.7% MCPA degradation while only 2.4% MCPA degradation was mediated by other oxidants like [rad]O2 , H2O2, [rad]HO2; for MCPA degradation in the TNA-Cu PFC system, the contribution of hydroxyl radicals in the liquid phase decreased to 83.6%, while contribution of other oxidants like [rad]O2 , H2O2, [rad]HO2 increased to 15.3%. This change in MCPA degradation mechanisms was confirmed via degradation intermediates analysis by LC-MS/MS. The study on the effect of electrolyte concentration suggests that when operated under acidic conditions, addition of electrolyte is not required. The TNA-Cu PFC system was shown to work well in the presence of up to 15 mg/L natural organic matter (originating from two large rivers), high amounts of common inorganic ions, and even in WWTP effluent. The TNA-Cu PFC system also exhibited relatively good stability after several cycles of repeated use. The obtained results demonstrated that this is an adequate system for micropollutant removal from water at various places in the water cycle, i.e. as polisher of WWTP effluents before discharge or for cleaning intake water before producing drinking water.

Sensitive MS method for the detection of palytoxins in shellfish using li+ cationization
Klijnstra, M.D. ; Gerssen, A. - \ 2018
- 1 p.
The importance of surface reflectance anisotropy for cloud and NO2 retrievals from GOME-2 and OMI
Lorente, Alba ; Boersma, K.F. ; Stammes, Piet ; Tilstra, L.G. ; Richter, Andreas ; Yu, Huan ; Kharbouche, Said ; Muller, Jan Peter - \ 2018
Atmospheric Measurement Techniques 11 (2018)7. - ISSN 1867-1381 - p. 4509 - 4529.

The angular distribution of the light reflected by the Earth's surface influences top-of-atmosphere (TOA) reflectance values. This surface reflectance anisotropy has implications for UV/Vis satellite retrievals of albedo, clouds, and trace gases such as nitrogen dioxide (NO2). These retrievals routinely assume the surface to reflect light isotropically. Here we show that cloud fractions retrieved from GOME-2A and OMI with the FRESCO and OMCLDO2 algorithms have an east-west bias of 10% to 50 %, which are highest over vegetation and forested areas, and that this bias originates from the assumption of isotropic surface reflection. To interpret the across-track bias with the DAK radiative transfer model, we implement the bidirectional reflectance distribution function (BRDF) from the Ross-Li semi-empirical model. Testing our implementation against state-of-the-art RTMs LIDORT and SCIATRAN, we find that simulated TOA reflectance generally agrees to within 1 %. We replace the assumption of isotropic surface reflection in the equations used to retrieve cloud fractions over forested scenes with scattering kernels and corresponding BRDF parameters from a daily high-resolution database derived from 16 years' worth of MODIS measurements. By doing this, the east-west bias in the simulated cloud fractions largely vanishes. We conclude that across-track biases in cloud fractions can be explained by cloud algorithms that do not adequately account for the effects of surface reflectance anisotropy. The implications for NO2 air mass factor (AMF) calculations are substantial. Under moderately polluted NO2 and backwardscattering conditions, clear-sky AMFs are up to 20% higher and cloud radiance fractions up to 40% lower if surface anisotropic reflection is accounted for. The combined effect of these changes is that NO2 total AMFs increase by up to 30% for backward-scattering geometries (and decrease by up to 35% for forward-scattering geometries), which is stronger than the effect of either contribution alone. In an unpolluted troposphere, surface BRDF effects on cloud fraction counteract (and largely cancel) the effect on the clearsky AMF. Our results emphasise that surface reflectance anisotropy needs to be taken into account in a coherent manner for more realistic and accurate retrievals of clouds and NO2 from UV/Vis satellite sensors. These improvements will be beneficial for current sensors, in particular for the recently launched TROPOMI instrument with a high spatial resolution.

Spring migration patterns, habitat use, and stopover site protection status for two declining waterfowl species wintering in China as revealed by satellite tracking
Si, Yali ; Xu, Yanjie ; Xu, Fei ; Li, Xueyan ; Zhang, Wenyuan ; Wielstra, Ben ; Wei, Jie ; Liu, Guanhua ; Luo, Hao ; Takekawa, John ; Balachandran, Sivananintha ; Zhang, Tao ; Boer, Willem F. de; Prins, Herbert H.T. ; Gong, Peng - \ 2018
Ecology and Evolution 8 (2018)12. - ISSN 2045-7758 - p. 6280 - 6289.
Anser albifrons - Anser serrirostris - habitat selection - protected area - stopover site

East Asian migratory waterfowl have greatly declined since the 1950s, especially the populations that winter in China. Conservation is severely hampered by the lack of primary information about migration patterns and stopover sites. This study utilizes satellite tracking techniques and advanced spatial analyses to investigate spring migration of the greater white-fronted goose (Anser albifrons) and tundra bean goose (Anser serrirostris) wintering along the Yangtze River Floodplain. Based on 24 tracks obtained from 21 individuals during the spring of 2015 and 2016, we found that the Northeast China Plain is far-out the most intensively used stopover site during migration, with geese staying for over 1 month. This region has also been intensely developed for agriculture, suggesting a causal link to the decline in East Asian waterfowl wintering in China. The protection of waterbodies used as roosting area, especially those surrounded by intensive foraging land, is critical for waterfowl survival. Over 90% of the core area used during spring migration is not protected. We suggest that future ground surveys should target these areas to confirm their relevance for migratory waterfowl at the population level, and core roosting area at critical spring-staging sites should be integrated in the network of protected areas along the flyway. Moreover, the potential bird–human conflict in core stopover area needs to be further studied. Our study illustrates how satellite tracking combined with spatial analyses can provide crucial insights necessary to improve the conservation of declining Migratory species.

Oviposition preference of three lepidopteran species is not affected by previous aphid infestation in wild cabbage
Li, Yehua ; Meijer, Davy ; Dicke, Marcel ; Gols, Rieta - \ 2018
Entomologia Experimentalis et Applicata 166 (2018)5. - ISSN 0013-8703 - p. 402 - 411.
Brassica oleracea - Brevicoryne brassicae - host plant selection - insect herbivores - JA-SA crosstalk - Mamestra brassicae - Pieris brassicae - plant induction - Plutella xylostella - preference–performance hypothesis

Several studies have shown that pre-infestation with aphids can improve plant quality for herbivorous caterpillars. This effect is often explained by the negative crosstalk between specific plant defence, signal-transduction pathways induced by aphids and caterpillars, respectively. However, in these studies caterpillars are introduced on the plants by the researcher, whereas in nature, the adult mother often chooses the food plants for her offspring. According to the preference–performance hypothesis adult females should choose oviposition sites that result in optimal performance and survival of their offspring. In this study, we investigated whether three lepidopteran species–Pieris brassicae (L.) (Pieridae), Plutella xylostella L. (Plutellidae) and Mamestra brassicae L. (Noctuidae)–prefer aphid-infested over clean plants. Adult females of the three species was given the choice between wild cabbage (Brassica oleracea L., Brassicaceae) plants infested with aphids, Brevicoryne brassicae (L.) (Hemiptera: Aphididae) for 3, 7, or 14 days vs. non-infested clean plants. Pieris brassicae females was also given the choice between plants dually infested with B. brassicae aphids and P. xylostella caterpillars when the order of infestation was varied. For oviposition, adult females of all three species did not discriminate between aphid-infested and clean plants, irrespective of the duration of aphid infestation. Also, P. brassicae females did not discriminate between sets of dually infested plants, irrespective of the order of infestation. Several mechanisms are discussed that could explain this lack of preference.

Quantitative and Orthogonal Formation and Reactivity of SuFEx Platforms
Gahtory, Digvijay ; Sen, Rickdeb ; Pujari, Sidharam ; Li, Suhua ; Zheng, Qinheng ; Moses, John E. ; Sharpless, K.B. ; Zuilhof, Han - \ 2018
Chemistry-A European Journal 24 (2018)41. - ISSN 0947-6539 - p. 10550 - 10556.
click chemistry - fluorine - sulfur - surface chemistry - surface modification

The constraints of minute reactant amounts and the impossibility to remove any undesired surface-bound products during monolayer functionalization of a surface necessitate the selection of efficient, modular and orthogonal reactions that lead to quantitative conversions. Herein, we explore the character of sulfur–fluoride exchange (SuFEx) reactions on a surface, and explore the applicability for quantitative and orthogonal surface functionalization. To this end, we demonstrate the use of ethenesulfonyl fluoride (ESF) as an efficient SuFEx linker for creating “SuFEx-able” monolayer surfaces, enabling three distinct approaches to utilize SuFEx chemistry on a surface. The first approach relies on a di-SuFEx loading allowing dual functionalization with a nucleophile, while the two latter approaches focus on dual (CuAAC–SuFEx/SPOCQ–SuFEx) click platforms. The resultant strategies allow facile attachment of two different substrates sequentially on the same platform. Along the way we also demonstrate the Michael addition of ethenesulfonyl fluoride to be a quantitative surface-bound reaction, indicating significant promise in materials science for this reaction.

Tissue Metabolic Changes Drive Cytokine Responses to Mycobacterium tuberculosis
Lachmandas, Ekta ; Rios-Miguel, Ana B. ; Koeken, Valerie A.C.M. ; Pasch, Eva van der; Kumar, Vinod ; Matzaraki, Vasiliki ; Li, Yang ; Oosting, Marije ; Joosten, Leo A.B. ; Notebaart, Richard A. ; Noursadeghi, Mahdad ; Netea, Mihai G. ; Crevel, Reinout van; Pollara, Gabriele - \ 2018
The Journal of Infectious Diseases 218 (2018)1. - ISSN 0022-1899 - p. 165 - 170.
cytokines - functional genomics - human challenge model - immune response - immunometabolism - metabolism - microarrays - transcriptomics - tuberculosis

Cellular metabolism can influence host immune responses to Mycobacterium tuberculosis. Using a systems biology approach, differential expression of 292 metabolic genes involved in glycolysis, glutathione, pyrimidine, and inositol phosphate pathways was evident at the site of a human tuberculin skin test challenge in patients with active tuberculosis infection. For 28 metabolic genes, we identified single nucleotide polymorphisms that were trans-acting for in vitro cytokine responses to M. tuberculosis stimulation, including glutathione and pyrimidine metabolism genes that alter production of Th1 and Th17 cytokines. Our findings identify novel therapeutic targets in host metabolism that may shape protective immunity to tuberculosis.

Influence of humic acid on transport, deposition and activity of lysozyme in quartz sand
Li, Yan ; Koopal, Luuk K. ; Xiong, Juan ; Wang, Mingxia ; Yang, Chenfeng ; Tan, Wenfeng - \ 2018
Environmental Pollution 242 (2018). - ISSN 0269-7491 - p. 298 - 306.
Deposition - Enzyme activity - Humic acid - Lysozyme - Protein - Transport

Increasing humic acid concentration reduced the mobility of proteins with opposite charges, and the increased activity of effluent proteins could bring potential environmental hazards.

Gene expression polymorphism underpins evasion of host immunity in an asexual lineage of the Irish potato famine pathogen
Pais, Marina ; Yoshida, Kentaro ; Giannakopoulou, Artemis ; Pel, Mathieu A. ; Cano, Liliana M. ; Oliva, Ricardo F. ; Witek, Kamil ; Lindqvist-Kreuze, Hannele ; Vleeshouwers, Vivianne G.A.A. ; Kamoun, Sophien - \ 2018
BMC Evolutionary Biology 18 (2018)1. - ISSN 1471-2148
Asexual reproduction - Clonal lineage - Copy number variation - Emergent pathogen - Evolution - Expression polymorphism - Immunity - Loss of heterozygosity - Phenotypic plasticity - Phytophthora infestans - Structural variation

Background: Outbreaks caused by asexual lineages of fungal and oomycete pathogens are a continuing threat to crops, wild animals and natural ecosystems (Fisher MC, Henk DA, Briggs CJ, Brownstein JS, Madoff LC, McCraw SL, Gurr SJ, Nature 484:186-194, 2012; Kupferschmidt K, Science 337:636-638, 2012). However, the mechanisms underlying genome evolution and phenotypic plasticity in asexual eukaryotic microbes remain poorly understood (Seidl MF, Thomma BP, BioEssays 36:335-345, 2014). Ever since the 19th century Irish famine, the oomycete Phytophthora infestans has caused recurrent outbreaks on potato and tomato crops that have been primarily caused by the successive rise and migration of pandemic asexual lineages (Goodwin SB, Cohen BA, Fry WE, Proc Natl Acad Sci USA 91:11591-11595, 1994; Yoshida K, Burbano HA, Krause J, Thines M, Weigel D, Kamoun S, PLoS Pathog 10:e1004028, 2014; Yoshida K, Schuenemann VJ, Cano LM, Pais M, Mishra B, Sharma R, Lanz C, Martin FN, Kamoun S, Krause J, et al. eLife 2:e00731, 2013; Cooke DEL, Cano LM, Raffaele S, Bain RA, Cooke LR, Etherington GJ, Deahl KL, Farrer RA, Gilroy EM, Goss EM, et al. PLoS Pathog 8:e1002940, 2012). However, the dynamics of genome evolution within these clonal lineages have not been determined. The objective of this study was to use a comparative genomics and transcriptomics approach to determine the molecular mechanisms that underpin phenotypic variation within a clonal lineage of P. infestans. Results: Here, we reveal patterns of genomic and gene expression variation within a P. infestans asexual lineage by comparing strains belonging to the South American EC-1 clone that has dominated Andean populations since the 1990s (Yoshida K, Burbano HA, Krause J, Thines M, Weigel D, Kamoun S, PLoS Pathog 10e1004028, 2014; Yoshida K, Schuenemann VJ, Cano LM, Pais M, Mishra B, Sharma R, Lanz C, Martin FN, Kamoun S, Krause J, et al. eLife 2:e00731, 2013; Delgado RA, Monteros-Altamirano AR, Li Y, Visser RGF, van der Lee TAJ, Vosman B, Plant Pathol 62:1081-1088, 2013; Forbes GA, Escobar XC, Ayala CC, Revelo J, Ordonez ME, Fry BA, Doucett K, Fry WE, Phytopathology 87:375-380, 1997; Oyarzun PJ, Pozo A, Ordonez ME, Doucett K, Forbes GA, Phytopathology 88:265-271, 1998). We detected numerous examples of structural variation, nucleotide polymorphisms and loss of heterozygosity within the EC-1 clone. Remarkably, 17 genes are not expressed in one of the two EC-1 isolates despite apparent absence of sequence polymorphisms. Among these, silencing of an effector gene was associated with evasion of disease resistance conferred by a potato immune receptor. Conclusions: Our findings highlight the molecular changes underpinning the exceptional genetic and phenotypic plasticity associated with host adaptation in a pandemic clonal lineage of a eukaryotic plant pathogen. We observed that the asexual P. infestans lineage EC-1 can exhibit phenotypic plasticity in the absence of apparent genetic mutations resulting in virulence on a potato carrying the Rpi-vnt1.1 gene. Such variant alleles may be epialleles that arose through epigenetic changes in the underlying genes.

Effects of different solid carbon sources on water quality, biofloc quality and gut microbiota of Nile tilapia (Oreochromis niloticus) larvae
Li, Jiawei ; Liu, Gang ; Li, Changwei ; Deng, Yale ; Tadda, Musa Abubakar ; Lan, Lihua ; Zhu, Songming ; Liu, Dezhao - \ 2018
Aquaculture 495 (2018). - ISSN 0044-8486 - p. 919 - 931.
Biofloc technology - Gut microbiota - Solid carbon source - Water quality

External carbon source is needed for biofloc system to maintain an optimal C/N ratio for the growth of bacteria biomass. In this study, three solid-phase biodegradable compounds, including Longan powder (LP), polyhydroxybutyrate-hydroxyvalerate/LP (PHBVL) and Poly(butylene succinate)/LP (PBSL), were utilized to feed biofloc-based aquaculture systems in triplicates for nine Nile tilapia (Oreochromis niloticus) larvae culture tanks. LP was applied in the in-situ biofloc system as a “control group” (3 tanks), while PHBVL and PBSL were used in the ex-situ biofloc systems (6 tanks). During the 120-days experiment, the C/N ratio was maintained at 24.87 ± 5.66, 22.93 ± 3.20 and 23.12 ± 3.54 for the LP, PHBVL and PBSL groups, respectively. There were no significant differences (P >.05) of the averaged total ammonia nitrogen (TAN) concentration among the LP, PHBVL and PBSL groups (1.10 ± 1.18, 0.67 ± 0.38 and 1.18 ± 1.40 mg L−1). Significant differences of the averaged NO2 -N concentrations (0.26 ± 0.38, 0.01 ± 0.01 and 0.08 ± 0.12 mg L−1) were detected among the LP, PHBVL and PBSL groups (P <.05). The accumulation of NO3 -N in LP group (>40 mg L−1 on day 120) was significantly higher than that of PHBVL and PBSL groups (about 2–3 mg L−1 on day 120) (P <.05). To characterize the quality of biofloc, the median diameters (D50) and essential amino acids index (EAAI) were measured for three treatments. The D50 (124.7 ± 4.24, 131.6 ± 2.83 and 175.5 ± 9.19 μm) and EAAI (0.969 ± 0.011, 1.007 ± 0.014 and 0.995 ± 0.012) showed that the high quality bioflocs in the LP, PHBVL and PBSL groups could meet the requirement for feeding the aquatic animals. In addition, high throughput sequencing test showed that solid carbon source not only had a significant effect on the microbial community in bioflocs, but also on the composition of fish gut microbiota. Bacillus was the dominating genus discovered in all treatments (48.34% in LP, 49.24% in PHBVL and 50.47% in PBSL) by 16S rRNA sequencing. Overall, blending LP with biodegradable polymers as carbon source showed significantly higher removal efficiency of nitrate and nitrite nitrogen, and higher biofloc quality than using LP as the only carbon source. How exactly various solid carbon sources influence fish growth performance and health need further study.

Feather pecking genotype and phenotype affect behavioural responses of laying hens
Eijk, Jerine A.J. van der; Lammers, Aart ; Li, Peiyun ; Kjaer, Joergen B. ; Rodenburg, T.B. - \ 2018
Applied Animal Behaviour Science 205 (2018). - ISSN 0168-1591 - p. 141 - 150.
Activity - Coping style - Fearfulness - Feather pecking - Genotype - Phenotype

Feather pecking (FP) is a major welfare and economic issue in the egg production industry. Behavioural characteristics, such as fearfulness, have been related to FP. However, it is unknown how divergent selection on FP affects fearfulness in comparison to no selection on FP. Therefore, we compared responses of birds selected on low (LFP) and high feather pecking (HFP) with birds from an unselected control line (CON) to several behavioural tests (i.e. novel object (NO), novel environment (NE), open field (OF) and tonic immobility (TI)) at young and adult ages. Furthermore, the relation between actual FP behaviour (i.e. FP phenotypes) and fearfulness is not well understood. Therefore, we compared responses of birds with differing FP phenotypes. Feather pecking phenotypes of individual birds were identified via FP observations at several ages. The number of severe feather pecks given and received was used to categorize birds as feather peckers, feather pecker-victims, victims or neutrals. Here we show that HFP birds repeatedly had more active responses (i.e. they approached a NO sooner, vocalized sooner and more, showed more flight attempts and had shorter TI durations), which could indicate lower fearfulness, compared to CON and LFP birds at both young and adult ages. Within the HFP line, feather peckers had more active responses (i.e. they tended to show more flight attempts compared to victims and tended to walk more compared to neutrals), suggesting lower fearfulness, compared to victims and neutrals. Thus, in this study high FP seems to be related to low fearfulness, which is opposite to what previously has been found in other experimental and commercial lines. This stresses the need for further research into the genetic and phenotypic correlations between FP and fearfulness in various populations of chickens, especially in commercial lines. Findings from experimental lines should be used with caution when developing control and/or prevention methods that are to be applied in commercial settings. Furthermore, activity and/or coping style might overrule fearfulness within the HFP line, as HFP birds and feather peckers within the HFP line had more active responses. This might indicate a complex interplay between fearfulness, activity and coping style that could play a role in the development of FP.

Testing for complementarity in phosphorus resource use by mixtures of crop species
Li, Chunjie ; Kuijper, T.W.M. ; Werf, Wopke van der; Zhang, Junling ; Li, Haigang ; Zhang, Fusuo ; Hoffland, Ellis - \ 2018
Plant and Soil (2018). - ISSN 0032-079X - 15 p.
Competition - Complementarity - Intercrop - Phosphorus - Resource partitioning

Aims: The phosphorus (P) resource partitioning hypothesis assumes that dissimilarity in P acquisition traits among plant species leads to enhanced P uptake by crop combinations compared with their sole crops. We developed and implemented a test for this hypothesis. Methods: Two pot experiments were conducted with quartz sands. In Experiment 1, the ability of the crop species to acquire P from sparingly soluble sources (Ca phosphate (CaP), phytate (PhyP) and P-coated Fe (hydr)oxide (FeP)) was tested. In accordance with the species performances in Experiment 1, combinations of millet/chickpea and cabbage/faba bean (which have dissimilar P acquisition traits) and wheat/maize (which have similar traits) were selected for Experiment 2. The biomass production and P uptake were compared between the sole crops and species combinations as well as between the single and mixed P sources. Results: A dissimilarity in P acquisition traits enhanced P uptake by millet/chickpea on CaP/PhyP (as expected) but not by cabbage/faba bean on FeP/PhyP. Despite their similar P acquisition traits, we found enhanced P uptake by wheat/maize on CaP/PhyP. Conclusions: Because of complicating factors such as unstable P acquisition traits and competitive inequality between species, the conditions under which the P resource partitioning hypothesis can be tested are limited. This challenge complicates designing for complementarity in soil P pools by intercrops.

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