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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    Soil Microbial Communities on the anode and 2-m distance of Tubular Plant Microbial Fuel Cell in a Paddy Field in West Kalimantan, Indonesia
    Sudirjo, Emilius ; Jager, Pim de; Buisman, Cees ; Strik, David - \ 2020
    Wageningen University
    PRJEB34787 - ERP117748 - metagenome - Plant Microbial Fuel Cell - Soil Microbial Communities - Paddy Field
    Soil samples were collected (on 30 June 2018) from 6 different locations for microbial community analysis from a paddy field in West Kalimantan, Indonesia (0.919215N, 109.468182E; elevation 100m above sea level). Sample A: Soil that attached on the anode from mid of Plant-MFC 1Sample B: soil that attached on the anode from end of the plant-MFC 1Sample C: Soil that attached on the anode from mid of Plant-MFC 2Sample D: soil that attached on the anode from end of the plant-MFC 2Sample E: soil from 2 m distance at northen side of plant-MFC 1 & 2Sample F: soil from 2 m distance at southern side of plant-MFC 1 & 2Samples were grouped into 3: Group I (Samples A and C) was soil that attached on the anode from mid plant-MFC; Group II (samples B and D) was soil that attached on the anode from end of the plant-MFC; and Group III (samples E and F) was from soil with 2 m distance from plant-MFC 1 and 2. After collection, samples were kept in a 30ml-tube container and keep in 40C fridge. The next day samples were transported for 48hours with a cool-ice box for DNA extraction to Genetika Lab, Jakarta (PT. Genetika Science Indonesia), a partner company from 1st BASE Axil Scientific Pte Ltd, Singapore. Sequencing steps were performed by 1st BASEas following: the universal primers that targeted the V3V4 regions were used for amplification. The quantity and quality of the PCR product that targeted the V3V4 regions were measured using Tapestation 4200, picogreen and nanodrop. All the samples passed the QC measurement and proceed straight for a library preparation. The libraries were prepared using Illumina 16s metagenomics library prep kit and their quality and quantity were determine using Agilent Tapestation 4200, Picogreen and qPCR. These libraries were then pooled according to the protocol recommended by the Illumina and proceed straight to sequencing using MiSeq platform at 2x301PE format by 1st BASE Axil Scientific Pte Ltd, Singapore.
    Effects of eggshell temperature pattern during incubation on tibia characteristics of broiler chickens at slaughter age
    Güz, B.C. ; Molenaar, R. ; Jong, I.C. de; Kemp, B. ; Krimpen, M. van; Brand, H. van den - \ 2020
    Poultry Science 99 (2020)6. - ISSN 0032-5791 - p. 3020 - 3029.
    broiler chickens - eggshell temperature - incubation - leg health - tibia

    This study was designed to determine effects of eggshell temperature (EST) pattern in week 2 and week 3 of incubation on tibia development of broiler chickens at slaughter age. A total of 468 Ross 308 eggs were incubated at an EST of 37.8°C from incubation day (E) 0 to E7. Thereafter, a 2 × 2 factorial arrangement with 2 EST (37.8°C and 38.9°C) from E8 to E14 and 2 EST (36.7°C and 37.8°C) from E15 till hatch was applied. After hatching, chickens were reared until slaughter age with the 4 EST treatments and 8 replicates per treatment. At day 41 and 42, one male chicken per replicate per day was selected, and hock burn and food pad dermatitis were scored. Rotated tibia, tibia dyschondroplasia, epiphyseal plate abnormalities, bacterial chondronecrosis with osteomyelitis, and epiphysiolysis were assessed. Tibia weight, length, thickness, head thickness, and robusticity index were determined. X-ray analyses (osseous volume, pore volume, total volume, volume fraction, mineral content, and mineral density) and a 3-point bending test (ultimate strength, yield strength, stiffness, energy to fracture, and elastic modulus) were performed. A high EST (38.9°C) in week 2 of incubation, followed by a normal EST (37.8°C) in week 3 resulted in higher mineral content (P = 0.001), mineral density (P = 0.002), ultimate strength (P = 0.04), yield strength (P = 0.03), and stiffness (P = 0.05) compared with the other 3 EST groups (week 2 × week 3 interaction). A high EST (38.9°C) in week 2 of incubation, regardless of the EST in week 3, resulted in a higher tibia weight (P < 0.001), thickness (P = 0.05), osseous volume (P < 0.001), and total volume (P < 0.001) than a normal EST (37.8°C). It can be concluded that 1.1°C higher EST than normal in week 2 of incubation appears to stimulate tibia morphological, biophysical, and mechanical characteristics of broiler chickens at slaughter age. Additionally, a 1.1°C lower EST in week 3 of incubation appears to have negative effects on tibia characteristics, particularly in interaction with the EST in week 2 of incubation.

    Forecasted freezing level height from the numerical weather prediction model HARMONIE-AROME
    Overeem, Aart ; Vries, Hylke de - \ 2020
    Wageningen University & Research
    air temperature - atmosphere - forecast - freezing level height - HARMONIE-AROME - numerical weather prediction
    Dataset of forecasted freezing level height from the numerical weather prediction model HARMONIE-AROME cycle 38, as of 3 April 2018 cycle 40. HARMONIE-AROME is a non-hydrostatic regional numerical weather prediction model used operationally at the Royal Netherlands Meteorological Institute (KNMI) and various other European weather centers. At KNMI, the HARMONIE-AROME model operates at 2.5 times 2.5 km horizontal resolution and 65 vertical levels, and 48-hour long forecasts are initiated every three hours. A subset of the full output was archived on model-levels for a 300 times 300 cell domain covering part of the full 800 times 800 cell simulation domain. For each cell and simulation output time-step, the freezing level height was determined by scanning from the top of the atmosphere downwards to the first level for which the temperature reached 273.15K. The subset covers the Netherlands and surroundings, coinciding with the coverage of the two KNMI ground-based weather radars. This dataset has been employed for a study on rainfall-induced attenuation correction for two dual-pol C-band radars in the Netherlands, for which a paper is in preparation. For this, HARMONIE data which would have been available in real-time for coupling with real-time 5-min radar data were obtained, resulting in the selection of the forecasts with +2, +3, +4 or +5 h lead time, being available every 3 h (32 files per day). The HARMONIE data allow for distinguishing between rain and other types of precipitation. This dataset may also be useful for other (radar) applications.
    Machine Learning Crash Course : Classification
    Dijk, A.D.J. van - \ 2020
    Wageningen : Wageningen University & Research
    This one-day course includes various aspects of machine learning. Examples are decision trees, linear regression, neural networks, Brix prediction and casus regression.

    You will find the following information:
    1) A reader where you will find the content of the course
    2) Several presentations
    3) Several use cases
    4) Links to video recordings
    Unfortunately some parts of the lecture are missing in the recordings.
    Machine Learning for Beginners : Crash Course Machine Learning
    Kootstra, G.W. ; Dijk, A.D.J. van; Rapado Rincon, David ; Durairaj, J. - \ 2020
    Wageningen : Wageningen University & Research
    This one-day course includes various aspects of machine learning. Examples are decision trees, linear regression, neural networks, Brix prediction and casus regression.

    You will find the following information:
    1) A reader where you will find the content of the course
    2) Several presentations
    3) Several use cases
    4) Links to video recordings
    Unfortunately some parts of the lecture are missing in the recordings.
    Ghost Introgression: Spooky Gene Flow in the Distant Past
    Ottenburghs, Jente - \ 2020
    Bioessays 42 (2020)6. - ISSN 0265-9247
    adaptation - demographic modelling - hybridization - macroevolution - phylogenetic networks - reproductive isolation - speciation

    Evolution is a continuous trial and error process in which most lineages go extinct without leaving fossil remains. Many of these lineages would be closely related and occasionally hybridized with lineages that gave rise to extant species. Hence, it is likely that one can find genetic signatures of these ancient introgression events in present-day genomes, so-called ghost introgression. The increasing availability of high-quality genome assemblies for non-model organisms and the development of more sophisticated methods for detecting introgression will undoubtedly reveal more cases of ghost introgression, indicating that the Tree of Life is even more reticulated than assumed. The presence of ghost introgression has important consequences for the study of numerous evolutionary processes, including adaptation, speciation, and macroevolutionary patterns. In addition, detailed studies of introgressed regions could provide insights into the morphology of the extinct lineage, providing an unexpected link between genomics and the fossil record. Hence, new methods that take into account ghost introgression will need to be developed.

    Low sanitary conditions increase energy expenditure for maintenance and decrease incremental protein efficiency in growing pigs
    Meer, Y. Van Der; Jansman, A.J.M. ; Gerrits, W.J.J. - \ 2020
    Animal (2020). - ISSN 1751-7311
    amino acids - energy metabolism - fasting heat - health status - protein metabolism

    Requirements for energy and particular amino acids (AAs) are known to be influenced by the extent of immune system stimulation. Most studies on this topic use models for immune system stimulation mimicking clinical conditions. Extrapolation to conditions of chronic, low-grade immune system stimulation is difficult. We aimed to quantify differences in maintenance energy requirements and efficiency of energy and protein used for growth (incremental energy and protein efficiency) of pigs kept under low (LSC) or high sanitary conditions (HSC) that were fed either a basal diet or a diet with supplemented AA. Twenty-four groups of six 10-week-old female pigs were kept under either LSC or HSC conditions for 2 weeks and fed a diet supplemented or not with 20% extra methionine, threonine and tryptophan. In week 1, feed was available ad libitum. In week 2, feed supply was restricted to 70% of the realized feed intake (kJ/(kg BW)0.6 per day) in week 1. After week 2, fasting heat production (FHP) was measured. Energy balances and incremental energy and protein efficiencies were measured and analyzed using a GLM. Low sanitary condition increased FHP of pigs by 55 kJ/(kg BW)0.6 per day, regardless of diet. Low sanitary condition did not alter the response of faecal energy output to incremental gross energy (GE) intake, but it reduced the incremental response of metabolizable energy intake (12% units), heat production (6% units) and energy retained as protein (6% units) to GE intake, leaving energy retained as fat unaltered. Incremental protein efficiency was reduced in LSC pigs by 20% units. Incremental efficiencies for energy and protein were not affected by dietary AA supplementation. Chronic, low-grade immune stimulation by LSC treatment increases FHP in pigs. Under such conditions, the incremental efficiency of nitrogen utilization for body protein deposition is reduced, but the incremental efficiency of absorbed energy for energy or fat deposition is unaffected.

    A suppressor of axillary meristem maturation promotes longevity in flowering plants
    Karami, Omid ; Rahimi, Arezoo ; Khan, Majid ; Bemer, Marian ; Hazarika, Rashmi R. ; Mak, Patrick ; Compier, Monique ; Noort, Vera van; Offringa, Remko - \ 2020
    Nature Plants 6 (2020)4. - ISSN 2055-026X - p. 368 - 376.

    Post-embryonic development and longevity of flowering plants are, for a large part, determined by the activity and maturation state of stem cell niches formed in the axils of leaves, the so-called axillary meristems (AMs)1,2. The genes that are associated with AM maturation and underlie the differences between monocarpic (reproduce once and die) annual and the longer-lived polycarpic (reproduce more than once) perennial plants are still largely unknown. Here we identify a new role for the ArabidopsisAT-HOOK MOTIF NUCLEAR LOCALIZED 15 (AHL15) gene as a suppressor of AM maturation. Loss of AHL15 function accelerates AM maturation, whereas ectopic expression of AHL15 suppresses AM maturation and promotes longevity in monocarpic Arabidopsis and tobacco. Accordingly, in Arabidopsis grown under longevity-promoting short-day conditions, or in polycarpic Arabidopsis lyrata, expression of AHL15 is upregulated in AMs. Together, our results indicate that AHL15 and other AHL clade-A genes play an important role, directly downstream of flowering genes (SOC1, FUL) and upstream of the flowering-promoting hormone gibberellic acid, in suppressing AM maturation and extending the plant’s lifespan.

    Impact of fodder management on dairy farm performance in Kenya
    Ndambi, Asaah ; Sinoya, Kevin ; Sakwa, Boniface ; Lee, Jan van der - \ 2020
    Wageningen : Wageningen Livestock Research (Wageningen Livestock Research report 1250) - 31
    This study assesses the impact of adoption of fodder conservation and feed rationing interventions on economic performance and nitrogen use efficiency (NUE) of dairy farms in central Kenya. A comparison was done between groups of farms in these intervention categories and with control farms that had no interventions. The results show that fodder conservation increased daily milk yield by 3 litres per lactating cow, while feed rationing in addition to fodder conservation gave an additional 3 litres milk per lactating cow per day in comparison to fodder conservation alone. We recommend farmers to adopt fodder conservation measures in combination with ration formulation in order to increase their profitability. Ration formulation advisory programs should include follow up visits to enable farm managers better understand formulation concepts, and potentially benefit from the effects of manure utilisation and soil mining for better estimates of NUE.
    Arabidopsis in the wild—the effect of seasons on seed performance
    Souza Vidigal, Deborah de; He, Hanzi ; Hilhorst, Henk W.M. ; Willems, Leo A.J. ; Bentsink, Leónie - \ 2020
    Plants 9 (2020)5. - ISSN 2223-7747
    Arabidopsis - Environmental effects - Field conditions - Seed dormancy - Seed longevity

    Climate changes play a central role in the adaptive life histories of organisms all over the world. In higher plants, these changes may impact seed performance, both during seed development and after dispersal. To examine the plasticity of seed performance as a response to environmental fluctuations, eight genotypes known to be affected in seed dormancy and longevity were grown in the field in all seasons of two years. Soil and air temperature, day length, precipitation, and sun hours per day were monitored. We show that seed performance depends on the season. Seeds produced by plants grown in the summer, when the days began to shorten and the temperature started to decrease, were smaller with deeper dormancy and lower seed longevity compared to the other seasons when seeds were matured at higher temperature over longer days. The performance of seeds developed in the different seasons was compared to seeds produced in controlled conditions. This revealed that plants grown in a controlled environment produced larger seeds with lower dormancy than those grown in the field. All together the results show that the effect of the environment largely overrules the genetic effects, and especially, differences in seed dormancy caused by the different seasons were larger than the differences between the genotypes.

    A Smartphone App Combining Global Positioning System Data and Ecological Momentary Assessment to Track Individual Food Environment Exposure, Food Purchases, and Food Consumption: Protocol for the Observational FoodTrack Study
    Poelman, Maartje ; Lenthe, Frank ; Schneider, Simon ; Kamphuis, Karlijn - \ 2020
    JMIR Research Protocols 9 (2020)1. - ISSN 1929-0748
    Background: Our understanding of how food choices are affected by exposure to the food environment is limited, and there are important gaps in the literature. Recently developed smartphone-based technologies, including global positioning systems and ecological momentary assessment, enable these gaps to be filled.

    Objective: We present the FoodTrack study design and methods, as well as participants’ compliance with the study protocol and their experiences with the app. We propose future analyses of the data to examine individual food environmental exposure taking into account the accessible food environment and individual time constraints; to assess people’s food choices in relation to food environmental exposure; and to examine the moderating role of individual and contextual determinants of food purchases and consumption.

    Methods: We conducted a 7-day observational study among adults (25-45 years of age) living in urban areas in the Netherlands. Participants completed a baseline questionnaire, used an app (incorporating global positioning system tracking and ecological momentary assessment) for 7 days, and then completed a closing survey. The app automatically collected global positioning system tracking data, and participants uploaded information on all food purchases over the 7-day period into the app. Participants also answered questions on contextual or individual purchase-related determinants directly after each purchase. During the final 3 days of the study, the participants also uploaded data on fruit, vegetable, and snack consumption and answered similar ecological momentary assessment questions after each intake.

    Results: In total, 140 participants completed the study. More than half of the participants said they liked the app (81/140, 57.9%) and found it easy to use (75/140, 53.6%). Of the 140 participants, 126 (90.0%) said that they had collected data on all or almost all purchases and intakes during the 7-day period. Most found the additional ecological momentary assessment questions “easy to answer” (113/140, 80.7%) with “no effort” (99/140, 70.7%). Of 106 participants who explored their trips in the app, 20 (18.8%) had trouble with their smartphone’s global positioning system tracking function. Therefore, we will not be able to include all participants in some of the proposed analyses, as we lack these data. We are analyzing data from the first study aim and we expect to publish the results in the spring of 2020.

    Conclusions: Participants perceived the FoodTrack app as a user-friendly tool. The app is particularly useful for observational studies that aim to gain insight into daily food environment exposure and food choices. Further analyses of the FoodTrack study data will provide novel insights into individual food environmental exposure, evidence on the individual food environment-diet interaction, and insights into the underlying individual and contextual mechanisms of food purchases and consumption.
    Multiple Environmental Variables Affect Germination and Mortality of an Annual Salt Marsh Pioneer: Salicornia procumbens
    Regteren, M. Van; Meesters, E.H. ; Baptist, M.J. ; Groot, A.V. De; Bouma, T.J. ; Elschot, K. - \ 2020
    Estuaries and coasts (2020). - ISSN 1559-2723 - 13 p.
    Salt marsh - Annual - sediment dynamics - intertidal flat - Inundation regime - seedling recruitment
    Salt marshes, providing numerous ecosystem services, are degrading worldwide. To effectively aid conservation and restoration efforts, increased knowledge on marsh expansion processes and the initial establishment of pioneer vegetation is essential. In this study, we disentangle environmental drivers that affect the lifecycle of the annual pioneer Salicornia procumbens at the salt marsh edge. We studied the effect of various environmental variables on the start of germination, germination success and mortality before seed-set in a field experiment in the DutchWadden Sea atWesthoek. Our results indicate that temperature and sedimentation inhibited the initiation of germination. Once germination occurred, higher precipitation rates increased germination success. In contrast,
    sedimentation rates above 0.5 mm day−1 halved germination success through burial of freshly sprouted seedlings. Unexpectedly, natural germination was low, indicating that seed availability may have been limited, despite a seed source nearby. Frequent inundation, extended periods without inundation (through desiccation of the soil) and a highly dynamic bed level increased mortality before
    seed-set. Consequently, bed-level dynamics (erosion, sedimentation and bed-level variation) impact seed production dually (decrease germination and increase mortality) and thus potentially reproduction success. A high seed reproduction is crucial for annuals, such as S. procumbens, to re-establish the following year. Next to advancing our general knowledge of natural salt marsh expansion, results in this study can also be used to assess the potential of a given site for saltmarsh stimulation or restoration. Seed availability and local bedlevel dynamics are key in the successful establishment of a salt marsh pioneer: Salicornia procumbens.
    Strategy to minimise nitrogen load to finish a zero discharge cultivation
    Leyh, R. ; Os, E.A. Van; Blok, C. ; Ruijven, J.P.M. Van; Kaarsemaker, R. - \ 2020
    Acta Horticulturae 1273 (2020). - ISSN 0567-7572 - p. 137 - 144.
    Emissions - Phosphate - Water use efficiency

    The Dutch authorities established a plan for the reduction of water emissions from the greenhouse sector to become zero by 2027, to enforce the European Union Water Framework Directive. At the end of the cultivation period, a considerable amount of nitrate and phosphate is still present in solution in substrate slabs and in the irrigation system. The left over nutrient solution is generally discharged into the sewage system or surface water. The end of cultivation strategy was developed to use the plant uptake to reduce this nitrate and phosphate in the last 5 weeks of the cultivation period. This reduction should be realised without affecting the production or quality of the last fruits to be harvested. The strategy consisted of a gradual decrease over the last five weeks of the cultivation of nitrate, phosphate and water quantity supplied to the plant. Chloride was used to replace nitrate in the supply water. The anion-shift allowed maintaining a sufficient quantity of cations in the root environment to meet the plant's needs and to avoid production loss. A progressive shift from nitrate-nitrogen to ammonium-nitrogen was realised. The nitrogen-shift acidified the substrate slabs to release precipitated phosphate. A double irrigation cycle at the start of the day was implemented during the strategy to anticipate nutrient accumulation in the root environment. In 2016, the strategy was applied to a sweet-pepper cultivation. The water volume in the substrate slabs was reduced from 6 to 3.5 L m-2. Nitrate quantity was reduced from 109 to 55 mmol m-2. Phosphate quantity was reduced from 0.5 to 0.2 mmol m-2. In 2017, the strategy was applied to a cucumber cultivation. The average water volume was reduced from 8 to 5.3 L m-2. Average nitrate quantity was reduced from 113 to 45 mmol m-2 and average phosphate quantity from 4.5 to 1.65 mmol m-2,.

    Dietary fibre may mitigate sarcopenia risk: Findings from the NU-AGE cohort of older european adults
    Montiel-Rojas, Diego ; Nilsson, Andreas ; Santoro, Aurelia ; Franceschi, Claudio ; Bazzocchi, Alberto ; Battista, Giuseppe ; Groot, Lisette C.P.G.M. de; Feskens, Edith J.M. ; Berendsen, Agnes ; Pietruszka, Barbara ; Januszko, Olga ; Fairweather-Tait, Susan ; Jennings, Amy ; Nicoletti, Claudio ; Kadi, Fawzi - \ 2020
    Nutrients 12 (2020)4. - ISSN 2072-6643
    C-reactive protein - Exercise - Metabolic syndrome - Muscle mass - Protein intake - Systemic inflammation

    Sarcopenia is characterised by a progressive loss of skeletal muscle mass and physical function as well as related metabolic disturbances. While fibre-rich diets can influence metabolic health outcomes, the impact on skeletal muscle mass and function is yet to be determined, and the moderating effects by physical activity (PA) need to be considered. The aim of the present study was to examine links between fibre intake, skeletal muscle mass and physical function in a cohort of older adults from the NU-AGE study. In 981 older adults (71 ± 4 years, 58% female), physical function was assessed using the short-physical performance battery test and handgrip strength. Skeletal muscle mass index (SMI) was derived using dual-energy X-ray absorptiometry (DXA). Dietary fibre intake (FI) was assessed by 7-day food record and PA was objectively determined by accelerometery. General linear models accounting for covariates including PA level, protein intake and metabolic syndrome (MetS) were used. Women above the median FI had significantly higher SMI compared to those below, which remained in fully adjusted models (24.7 ± 0.2% vs. 24.2 ± 0.1%, p = 0.011, η2p = 0.012). In men, the same association was only evident in those without MetS (above median FI: 32.4 ± 0.3% vs. below median FI: 31.3 ± 0.3%, p = 0.005, η2p = 0.035). There was no significant impact of FI on physical function outcomes. The findings from this study suggest a beneficial impact of FI on skeletal muscle mass in older adults. Importantly, this impact is independent of adherence to guidelines for protein intake and PA, which further strengthens the potential role of dietary fibre in preventing sarcopenia. Further experimental work is warranted in order to elucidate the mechanisms underpinning the action of dietary fibre on the regulation of muscle mass.

    Effect of nitrogen, phosphorus and pH on biological wood oxidation at 42 °C
    Fan, Shiyang ; Sun, Yue ; Heijne, Annemiek ter; Chen, Wei Shan ; Buisman, Cees J.N. - \ 2020
    Science of the Total Environment 726 (2020). - ISSN 0048-9697
    Biological wood oxidation - Fungi - Nitrogen - pH - Phosphorus - Wood waste

    Biological wood oxidation (BWO) is proposed as a cleaner alternative to wood combustion for heat production and wood waste management. Currently, BWO is not extensively studied and little is known about it. Nevertheless, given the composition of wood residues, which is dominated by carbon, nutrient availability may become a limiting factor during BWO. Our objective was to study the nutrition requirements for sustaining the BWO. For this purpose, three different factors including nitrogen addition, phosphorus addition and pH, were studied. Oxygen consumption and mass loss were monitored and used to evaluate the impact of nutrition on BWO and to calculate the theoretical heat production. The result showed that nitrogen addition at a relatively low level (2.5-10 mg/g) enhanced the cumulative oxygen consumption by 60–124% and mass loss by 28–95%, when compared with the BWO without nitrogen addition. The highest nitrogen addition examined in this research (20 mg/g), on the other hand, did not enhance BWO. Different phosphorus addition (0.5–5 mg/g) and pH (4–6) had little impacts on BWO. The highest theoretical heat production rate (0.63 W/kg dry wood biomass) was achieved using 2.5 mg/g nitrogen addition with a 95-day incubation. This suggests that nitrogen addition is required and able to sustain BWO. Besides, the cumulative oxygen consumption showed a good linear relationship with mass loss. This study provides the first indication on the effective quantify of nitrogen addition for enhancing BWO, which contributes to the selection of nutrient source for BWO in future studies.

    Environmental risk assessment of pesticides currently applied in Ghana
    Onwona-Kwakye, Michael ; Hogarh, Jonathan N. ; Brink, Paul J. Van den - \ 2020
    Chemosphere 254 (2020). - ISSN 0045-6535
    Environment - Ghana - Models - Pesticide - Risk assessment

    Registration of pesticides for use in Ghana is based on prospective environmental risk assessment (ERA) to assess the risks of future pesticide use on the environment. The present study evaluated whether pesticides currently used by Ghanaian farmers may harm the aquatic and terrestrial environment under day-to-day farm practice by performing a 1st tier ERA for terrestrial and aquatic environment and a 2nd tier ERA for the aquatic environment using existing scenarios and models. Results of the 1st tier risk assessment indicated that in the investigated regions in south Ghana, many pesticides might pose an acute risk to aquatic ecosystems adjacent to the treated fields while lambda cyhalothrin, chlorpyrifos, cypermethrin, dimethoate, mancozeb, carbendazim, sulphur, maneb and copper hydroxide may pose the highest chronic risks. Butachlor, dimethoate and carbendazim may pose acute risks to the terrestrial soil ecosystem, while glyphosate, chlorpyrifos, imidacloprid, dimethoate, mancozeb, carbendazim, maneb, copper hydroxide and cuprous oxide may pose the highest chronic risks. Many insecticides and some fungicides may pose acute risks to bees and terrestrial non-target arthropods. The 2nd tier acute aquatic risk assessment showed that most risks were substantiated using species sensitivity distribution (SSD). Actual pesticide use was a factor of 1.3–13 times higher than the recommended label instructions, indicating a general practice of overdosing. The case study shows that the PRIMET model in combination with the SSD concept may offer pesticide registration authorities in Ghana a means to assess environmental risks associated with pesticide usage in a user-friendly and cost-effective manner.

    Hepatotoxicity of the pesticides imazalil, thiacloprid and clothianidin – Individual and mixture effects in a 28-day study in female Wistar rats
    Alarcan, Jimmy ; Waizenegger, Julia ; Lourdes Marzo Solano, Marize de; Lichtenstein, Dajana ; Luckert, Claudia ; Peijnenburg, Ad ; Stoopen, Geert ; Sharma, Raju Prasad ; Kumar, Vikas ; Marx-Stoelting, Philip ; Lampen, Alfonso ; Braeuning, Albert - \ 2020
    Food and Chemical Toxicology 140 (2020). - ISSN 0278-6915
    EuroMix - Liver hypertrophy - Mixture effects - Pesticides

    Humans are exposed to pesticide residues through various food products. As these residues can occur in mixtures, there is a need to investigate possible mixture effects on human health. Recent exposure studies revealed the preponderance of imazalil, thiacloprid, and clothianidin in food diets. In this study, we assessed their toxicity alone and in binary mixtures in a 28-day gavage study in female Wistar rats. Five dose levels (up to 350 mg/kg bw/day) ranging from a typical toxicological reference value to a clear effect dose were applied. Data show that the liver was a target organ of all pesticides and their mixtures. Increases in liver weight were observed and histopathological examination revealed centrilobular hepatocellular hypertrophy and cytoplasm degeneration for all treatment conditions. No accumulation of hepatic triglycerides was reported. Tissue residue analysis showed altered pesticide residues in the liver and the kidney when being in mixture as compared to the levels of pesticide residues for the single compound treatment, indicating possible toxicokinetic interactions. Overall, all mixtures appeared to follow the additivity concept, even though quantitative analysis was limited for some endpoints due to the semi-quantitative nature of the data, raising no specific concern for the risk assessment of the examined pesticides.

    UAV-based Multispectral & Thermal dataset for exploring the diurnal variability, radiometric & geometric accuracy for precision agriculture
    Kallimani, Christina ; Heidarian Dehkordi, Ramin ; Evert, Frits van; Kooistra, Lammert ; Rijk, Bert - \ 2020
    Wageningen University & Research
    multispectral - thermal infrared - diurnal variability - unmanned aerial vehicles (UAV) - precision agriculture - wheat - potato - barley
    To explore the diurnal variations, radiometric and geometric accuracy of UAV-based data for precision agriculture, a comprehensive dataset was created in a one-day field campaign (21 June 2017). The multi-sensor data set covers wheat, barley & potato experimental fields, located in Wageningen University and Research (WUR) farm maintained by Unifarm. UAV-based images were collected with several sensors over the experimental area, starting from 7:25am and ending at 20:00pm local solar time. The dataset consists of images collected by 9 flights with senseFly MSP4C, 9 with Parrot Sequoia, 2 with Slant Range P3, 5 with DJI Zenmuse X3 NIR, 4 with the senseFly Thermo-map and 1 with the RGB Sony WX-220. Additionally, validation measurements at radiometric calibration plates and plant sample locations were taken with a Cropscan handheld spectrometer and a tec5 Handyspec spectrometer. The dataset consists of the validation measurements, the raw images and the processed orthomosaics (both with and without geometric correction).
    UAV-based Multispectral & Thermal dataset for exploring the diurnal variability, radiometric & geometric accuracy for precision agriculture
    Kallimani, Christina ; Heidarian, Ramin ; Evert, Frits K. van; Rijk, Bert ; Kooistra, Lammert - \ 2020
    ODjAR : open data journal for agricultural research 6 (2020). - ISSN 2352-6378 - p. 1 - 7.
    To explore the diurnal variations, radiometric and geometric accuracy of UAV-based data for precision agriculture, a comprehensive dataset was created in a one-day field campaign (21 June 2017). The multi-sensor data set covers wheat, barley & potato experimental fields, located in Wageningen University and Research (WUR) farm maintained by Unifarm. UAV-based images were collected with several sensors over the experimental area, starting from 7:25am and ending at 20:00pm local solar time. The dataset consists of images collected by 9 flights with senseFly MSP4C, 9 with Parrot Sequoia, 2 with Slant Range P3, 5 with DJI Zenmuse X3 NIR, 4 with the senseFly Thermo-map and 1 with the RGB Sony WX-220. Additionally, validation measurements at radiometric calibration plates and plant sample locations were taken with a Cropscan handheld spectrometer and a tec5 Handyspec spectrometer. The dataset consists of the validation measurements, the raw images and the processed orthomosaics (both with and without geometric correction).
    Prevalent root-derived phenolics drive shifts in microbial community composition and prime decomposition in forest soil
    Zwetsloot, Marie ; Munoz Ucros, Juana ; Wickings, Kyle ; Wilhelm, Roland C. ; Sparks, Jed ; Buckley, Daniel H. ; Bauerle, Taryn L. - \ 2020
    Soil Biology and Biochemistry 145 (2020). - ISSN 0038-0717
    Phenolic compounds perform various functions in soil ranging from microbial substrate to toxin and form the basis of several plant-mediated processes. The aim of this study was to investigate how phenolics commonly exuded by tree roots influence soil organic matter (SOM) decomposition and interact with other labile forms of carbon (C) abundant in root exudates. Therefore, we performed a 38-day incubation experiment and assessed whether phenolic compounds (benzoic acid, caffeic acid and catechin) facilitated or inhibited SOM decomposition in a glucose-amended forest soil. Changes in decomposition, substrate use, fungal and bacterial community composition, and microbial abundance and activity were measured over time using 13C-stable-isotope tracing, DNA-based molecular methods and enzyme assays. Our findings showed that phenolics inhibited microbial activity and abundance to varying degrees. Yet, benzoic acid was the only compound producing a substantial priming effect leading to a 21% increase in SOM decomposition, which was amplified in glucose-amended soils. This stimulation in microbial activity was associated with an increase in β-1,4-glucosidase activity and the bacterial genera Paraburkholderia and Caballeronia of the Burkholderiaceae family. Phenolics drove microbial community shifts in glucose-amended soils with negligible interactive effects. In conclusion, phenolic priming of SOM decomposition is associated with microbial community shifts and amplified in the presence of glucose. This evidence emphasizes the need for considering phenolics and interactions among root exudates as priming mechanisms in the rhizosphere and other soil environments where aromatics and phenolic compounds are abundant.
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