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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    Towards the analysis of animal fibre: evaluation of extraction and centrifugation procedures
    Hooghe, S. D'; Cuyper, Annelies De; Vanhauteghem, Donna ; Cools, An ; Bosch, G. ; Hendriks, W.H. ; Janssens, Geert P.J. - \ 2019
    In: Proceedings of the 44th Animal Nutrition Research Forum. - - p. 30 - 31.
    NU checkt: Bomen zorgen voor verkoeling, maar niet allemaal evenveel
    Lenzholzer, Sanda - \ 2019

    Interview with about the hypothesis that one tree cools as much as ten air conditioners

    Neuro-cognitive effects of acute tyrosine administration on reactive and proactive response inhibition in healthy older adults
    Bloemendaal, Mirjam ; Froböse, Monja Isabel ; Wegman, Joost ; Zandbelt, Bram Bastiaan ; Rest, Ondine van de; Cools, Roshan ; Aarts, Esther - \ 2018
    eNeuro 5 (2018)2. - ISSN 2373-2822
    Dopamine - Functional MRI - Healthy aging - Response inhibition

    The aging brain is characterized by altered dopamine signaling. The amino acid tyrosine, a catecholamine precursor, is known to improve cognitive performance in young adults, especially during high environmental demands. Tyrosine administration might also affect catecholamine transmission in the aging brain, thereby improving cognitive functioning. In healthy older adults, impairments have been demonstrated in two forms of response inhibition: reactive inhibition (outright stopping) and proactive inhibition (anticipatory response slowing) under high information load. However, no study has directly compared the effects of a catecholamine precursor on reactive and load-dependent proactive inhibition. In this study we explored the effects of tyrosine on reactive and proactive response inhibition and signal in dopaminergically innervated fronto-striatal regions. Depending on age, tyrosine might lead to beneficial or detrimental neurocognitive effects. We aimed to address these hypotheses in 24 healthy older human adults (aged 61-72 years) using fMRI in a double blind, counterbalanced, placebo-controlled, within-subject design. Across the group, tyrosine did not alter reactive or proactive inhibition behaviorally but did increase fronto-parietal proactive inhibition-related activation. When taking age into account, tyrosine affected proactive inhibition both behaviorally and neurally. Specifically, increasing age was associated with a greater detrimental effect of tyrosine compared with placebo on proactive slowing. Moreover, with increasing age, tyrosine decreased fronto-striatal and parietal proactive signal, which correlated positively with tyrosine’s effects on proactive slowing. Concluding, tyrosine negatively affected proactive response slowing and associated fronto-striatal activation in an age-dependent manner, highlighting the importance of catecholamines, perhaps particularly dopamine, for proactive response inhibition in older adults.

    Identifying barriers and levers of biodiversity mainstreaming in four cases of transnational governance of land and water
    Karlsson-Vinkhuyzen, S.I.S.E. ; Boelee, E. ; Cools, J. ; Hoof, L.J.W. van; Hospes, O. ; Kok, M. ; Peerlings, J.H.M. ; Tatenhove, J.P.M. van; Termeer, C.J.A.M. ; Visseren-Hamakers, I.J. - \ 2018
    Environmental Science & Policy 85 (2018). - ISSN 1462-9011 - p. 132 - 140.
    Biodiversity - Mainstreaming - Integration - Values-based leadership - Governance - Certification - Economic sectors - Fisheries - Palm Oil - FDI - Land - Mangroves
    Mainstreaming biodiversity into the governance of economic sectors such as agriculture, forestry and fisheries is required to reverse biodiversity loss and achieve globally adopted conservation targets. Governments have recognized
    this but little progress has been made. This paper addresses the following research question: What are the barriers and levers for mainstreaming biodiversity into economic sectors that exert high pressure on biodiversity?
    This question is approached through applying an analytical framework developed from literature on mainstreaming and Environmental Policy Integration as well as governance theory and practice to four cases in
    agriculture, agro-forestry and fisheries covering multi-level and transnational governance contexts. Decisionmaking and governance in these cases look quite different compared to the kind of public policy machinery of governmental bureaucracies that much EPI literature has focused on. Our analysis demonstrates mainstreaming efforts in some of our cases at the degree of harmonization and even coordination among key actors. It further identifies a number of ‘additional’ barriers and levers that from an Environmental Policy Integration perspective would be considered as external factors out of reach for mainstreaming efforts. The results are pertinent for the evaluation of EPI performance because the governance perspective expands the borders of who can initiate, enable and sustain mainstreaming, what scope of regulatory norms they can use and the potentially useful resources for the process.
    Greater mindful eating practice is associated with better reversal learning
    Janssen, Lieneke K. ; Duif, Iris ; Loon, Ilke Van; Vries, Jeanne H.M. De; Speckens, Anne E.M. ; Cools, Roshan ; Aarts, Esther - \ 2018
    Scientific Reports 8 (2018)1. - ISSN 2045-2322

    Mindfulness-based interventions are thought to reduce compulsive behavior such as overeating by promoting behavioral flexibility. Here the main aim was to provide support for mindfulness-mediated improvements in reversal learning, a direct measure of behavioral flexibility. We investigated whether an 8-week mindful eating intervention improved outcome-based reversal learning relative to an educational cooking (i.e., active control) intervention in a non-clinical population. Sixty-five healthy participants with a wide BMI range (19-35 kg/m2), who were motivated to change their eating habits, performed a deterministic reversal learning task that enabled the investigation of reward- and punishment-based reversal learning at baseline and following the intervention. No group differences in reversal learning were observed. However, time invested in the mindful eating, but not the educational cooking intervention correlated positively with changes in reversal learning, in a manner independent of outcome valence. These findings suggest that greater amount of mindfulness practice can lead to increased behavioral flexibility, which, in turn, might help overcome compulsive eating in clinical populations.

    Top-down expectation effects of food labels on motivation
    Wegman, Joost ; Loon, Ilke van; Smeets, Paul A.M. ; Cools, Roshan ; Aarts, Esther - \ 2018
    NeuroImage 173 (2018). - ISSN 1053-8119 - p. 13 - 24.
    Beliefs - fMRI - Food labeling - Implicit bias - Insula - Motivation
    Labels on food packages inform our beliefs, shaping our expectations of food properties, such as its expected taste and healthiness. These beliefs can influence the processing of caloric rewards beyond objective sensory properties and have the potential to impact decision making. However, no studies, within or beyond the food domain, have assessed how written information, such as food labels, affect implicit motivation to obtain rewards, even though choices in daily life might be strongly driven by implicit motivational biases. We investigated how written information affects implicit motivation to obtain caloric rewards in healthy young adults. We used food labels (high- and low-calorie), associated with an identical fruit-flavored sugar-sweetened beverage, to study motivation for caloric rewards during fMRI. In a joystick task, hungry participants (N = 31) were instructed to make fast approach or avoid movements to earn the cued beverages. Behaviorally, we found a general approach bias, which was stronger for the beverage that was most preferred during a subsequent choice test, i.e., the one labeled as low-calorie. This behavioral effect was accompanied by increased BOLD signal in the sensorimotor cortex during the response phase of the task for the preferred, low-calorie beverage compared with the non-preferred, high-calorie beverage. During the anticipation phase, the non-preferred, high-calorie beverage label elicited stronger fMRI signal in the right ventral anterior insula, a region associated with aversion and taste intensity, than the preferred, low-calorie label. Together, these data suggest that high-calorie labeling can increase avoidance of beverages and reduce neural activity in brain regions associated with motor control. In conclusion, we show effects of food labeling on fMRI responses during anticipation and subsequent motivated action and on behavior, in the absence of objective taste differences, demonstrating the influence of written information on implicit biases. These findings contribute to our understanding of implicit biases in real-life eating behavior.
    Are carnivore digestive separation mechanisms revealed on structure-rich diets?: Faecal inconsistency in dogs (Canis familiaris) fed day old chicks
    Cuyper, Annelies De; Clauss, M. ; Hesta, Myriam ; Cools, An ; Bosch, G. ; Hendriks, W.H. ; Janssens, Geert P.J. - \ 2018
    PLoS ONE 13 (2018)2. - ISSN 1932-6203 - 20 p.
    Pronounced variations in faecal consistency have been described anecdotally for some carnivore species fed a structure-rich diet. Typically two faecal consistencies are distinguished, namely hard and firm versus liquid and viscous faeces. It is possible that a separation mechanism is operating in the carnivore digestive tract, as in many herbivore species. Six beagle dogs were fed two experimental diets in a cross-over design of 7 days. Test diets consisted of chunked day old chicks differing only in particle size (fine = 7.8 mm vs coarse = 13 mm) in order to vary dietary structure. Digestive retention time was measured using titanium oxide (TiO2) as marker. The total faecal output was scored for consistency and faecal fermentation profiles were evaluated through faecal short-chain fatty acid (SCFA) and ammonia (NH3) analyses. A total of 181 faecal samples were collected. Dietary particle size did not affect faecal consistency, fermentative end products nor mean retention time (MRT). However, a faecal consistency dichotomy was observed with firm faeces (score 2–2.5) and soft faeces (score 4–4.5) being the most frequently occurring consistencies in an almost alternating pattern in every single dog. Firm and soft faeces differed distinctively in fermentative profiles. Although the structure difference between diets did not affect the faecal dichotomy, feeding whole prey provoked the occurrence of the latter which raises suspicion of a digestive separation mechanism in the canine digestive tract. Further faecal characterisation is however required in order to unravel the underlying mechanism.
    Humusica 1, article 5: Terrestrial humus systems and forms — Keys of classification of humus systems and forms
    Zanella, Augusto ; Ponge, Jean François ; Jabiol, Bernard ; Sartori, Giacomo ; Kolb, Ekart ; Bayon, Renée Claire Le; Gobat, Jean Michel ; Aubert, Michaël ; Waal, Rein de; Delft, Bas van; Vacca, Andrea ; Serra, Gianluca ; Chersich, Silvia ; Andreetta, Anna ; Kõlli, Raimo ; Brun, Jean Jacques ; Cools, Nathalie ; Englisch, Michael ; Hager, Herbert ; Katzensteiner, Klaus ; Brêthes, Alain ; Nicola, Cristina De; Testi, Anna ; Bernier, Nicolas ; Graefe, Ulfert ; Wolf, Ugo ; Juilleret, Jérôme ; Garlato, Andrea ; Obber, Silvia ; Galvan, Paola ; Zampedri, Roberto ; Frizzera, Lorenzo ; Tomasi, Mauro ; Banas, Damien ; Bureau, Fabrice ; Tatti, Dylan ; Salmon, Sandrine ; Menardi, Roberto ; Fontanella, Fausto ; Carraro, Vinicio ; Pizzeghello, Diego ; Concheri, Giuseppe ; Squartini, Andrea ; Cattaneo, Dina ; Scattolin, Linda ; Nardi, Serenella ; Nicolini, Gianni ; Viola, Franco - \ 2018
    Applied Soil Ecology 122 (2018). - ISSN 0929-1393 - p. 75 - 86.
    Humus - Humus classification - Humus forms - Humus systems - Humusica - Terrestrial humus forms
    This article is an as simple as possible key of classification of terrestrial (aerobic, not submersed) topsoils (organic and organic-mineral series of soil horizons). Based on the introduction exposed in Humusica 1, article 1, and using vocabulary and definitions listed in article 4, a classification is proposed for better understanding the biological functioning of the soil, partially disclosing the process of litter digestion. Five types of terrestrial topsoils, called terrestrial humus systems, are described and illustrated with the help of photographs. Within each humus system, 3–4 humus forms are also revealed, corresponding to similar series of soil horizons generated in a relatively homogeneous environment whose range of ecological factors is not so large to overstep and cause the genesis of another different humus system. The article ends with a figure that shows the relationship between Tangel and Amphi humus systems, and a dichotomous key of classification that one can easily print and bring in the field for practicing humus classification.
    Towards standards for human fecal sample processing in metagenomic studies
    Costea, Paul I. ; Zeller, Georg ; Sunagawa, Shinichi ; Pelletier, Eric ; Alberti, Adriana ; Levenez, Florence ; Tramontano, Melanie ; Driessen, Marja ; Hercog, Rajna ; Jung, Ferris Elias ; Kultima, Jens Roat ; Hayward, Matthew R. ; Coelho, Luis Pedro ; Allen-Vercoe, Emma ; Bertrand, Laurie ; Blaut, Michael ; Brown, Jillian R.M. ; Carton, Thomas ; Cools-Portier, Stéphanie ; Daigneault, Michelle ; Derrien, Muriel ; Druesne, Anne ; Vos, Willem M. De; Finlay, B.B. ; Flint, Harry J. ; Guarner, Francisco ; Hattori, Masahira ; Heilig, Hans ; Luna, Ruth Ann ; Hylckama Vlieg, Johan Van; Junick, Jana ; Klymiuk, Ingeborg ; Langella, Philippe ; Chatelier, Emmanuelle Le; Mai, Volker ; Manichanh, Chaysavanh ; Martin, Jennifer C. ; Mery, Clémentine ; Morita, Hidetoshi ; O'Toole, Paul W. ; Orvain, Céline ; Patil, Kiran Raosaheb ; Penders, John ; Persson, Søren ; Pons, Nicolas ; Popova, Milena ; Salonen, Anne ; Saulnier, Delphine ; Scott, Karen P. ; Singh, Bhagirath ; Slezak, Kathleen ; Veiga, Patrick ; Versalovic, James ; Zhao, Liping ; Zoetendal, Erwin G. ; Ehrlich, S.D. ; Dore, Joel ; Bork, Peer - \ 2017
    Nature Biotechnology 35 (2017)11. - ISSN 1087-0156 - p. 1069 - 1076.
    Technical variation in metagenomic analysis must be minimized to confidently assess the contributions of microbiota to human health. Here we tested 21 representative DNA extraction protocols on the same fecal samples and quantified differences in observed microbial community composition. We compared them with differences due to library preparation and sample storage, which we contrasted with observed biological variation within the same specimen or within an individual over time. We found that DNA extraction had the largest effect on the outcome of metagenomic analysis. To rank DNA extraction protocols, we considered resulting DNA quantity and quality, and we ascertained biases in estimates of community diversity and the ratio between Gram-positive and Gram-negative bacteria. We recommend a standardized DNA extraction method for human fecal samples, for which transferability across labs was established and which was further benchmarked using a mock community of known composition. Its adoption will improve comparability of human gut microbiome studies and facilitate meta-analyses.
    Humusica 1, article 4 : Terrestrial humus systems and forms-Specific terms and diagnostic horizons
    Zanella, Augusto ; Ponge, Jean François ; Jabiol, Bernard ; Sartori, Giacomo ; Kolb, Eckart ; Gobat, Jean Michel ; Bayon, Renée Claire Le ; Aubert, Michael ; Waal, Rein de; Delft, Bas van; Vacca, Andrea ; Serra, Gianluca ; Chersich, Silvia ; Andreetta, Anna ; Cools, Nathalie ; Englisch, Michael ; Hager, Herbert ; Katzensteiner, Klaus ; Brethes, Alain ; Nicola, Cristina De ; Testi, Anna ; Bernier, Nicolas ; Graefe, Ulfert ; Juilleret, Jérôme ; Banas, Damien ; Garlato, Adriano ; Obber, Silvia ; Galvan, Paola ; Zampedri, Roberto ; Frizzera, Lorenzo ; Tomasi, Mauro ; Menardi, Roberto ; Fontanella, Fausto ; Filoso, Carmen ; Dibona, Raffaella ; Bolzonella, Cristian ; Pizzeghello, Diego ; Carletti, Paolo ; Langhor, Roger ; Cattaneo, Dina ; Nardi, Serenella ; Nicolini, Gianni ; Viola, Franco - \ 2017
    Applied Soil Ecology 122 (2017)1. - ISSN 0929-1393 - p. 56 - 74.
    Humic component - Humipedon - Humus - Humus classification - Humus diagnostic horizon - Humusica - Recognizable remains - Terrestrial humus - Zoogenically transformed material
    Knowledge of a little number of specific terms is necessary to investigate and describe humipedons. This "new vocabulary" allows individuating and circumscribing particular diagnostic horizons, which are the fundamental bricks of the humipedon. Few "components" defined by specific terms characterize a specific "humipedon horizon"; few "humipedon horizons" compose a given "humus form" and some similar "humus forms" are grouped in a functional "humus system". In this article, specific terms and humus horizons are listed and explained one by one. Field difficulties are illustrated and resolved. The aim of the article is to present in a manner as simple as possible how to distinguish in the field the soil structures allowing a morpho-functional classification of terrestrial (aerated, not submerged) humipedons.
    Loss of lateral prefrontal cortex control in food-directed attention and goal-directed food choice in obesity
    Janssen, Lieneke K. ; Duif, Iris ; Loon, Ilke van; Wegman, Joost ; Vries, Jeanne H.M. de; Cools, Roshan ; Aarts, Esther - \ 2017
    NeuroImage 146 (2017). - ISSN 1053-8119 - p. 148 - 156.
    Attention - Choice - Cognitive control - fMRI - Obesity

    Loss of lateral prefrontal cortex (lPFC)-mediated attentional control may explain the automatic tendency to eat in the face of food. Here, we investigate the neurocognitive mechanism underlying attentional bias to food words and its association with obesity using a food Stroop task. We tested 76 healthy human subjects with a wide body mass index (BMI) range (19–35 kg/m2) using fMRI. As a measure of obesity we calculated individual obesity scores based on BMI, waist circumference and waist-to-hip ratio using principal component analyses. To investigate the automatic tendency to overeat directly, the same subjects performed a separate behavioral outcome devaluation task measuring the degree of goal-directed versus automatic food choices. We observed that increased obesity scores were associated with diminished lPFC responses during food attentional bias. This was accompanied by decreased goal-directed control of food choices following outcome devaluation. Together these findings suggest that deficient control of both food-directed attention and choice may contribute to obesity, particularly given our obesogenic environment with food cues everywhere, and the choice to ignore or indulge despite satiety.

    Why CO2 cools the middle atmosphere - a consolidating model perspective
    Goessling, Helge F. ; Bathiany, Sebastian - \ 2016
    Earth System dynamics 7 (2016)3. - ISSN 2190-4979 - p. 697 - 715.

    Complex models of the atmosphere show that increased carbon dioxide (CO2) concentrations, while warming the surface and troposphere, lead to lower temperatures in the stratosphere and mesosphere. This cooling, which is often referred to as "stratospheric cooling", is evident also in observations and considered to be one of the fingerprints of anthropogenic global warming. Although the responsible mechanisms have been identified, they have mostly been discussed heuristically, incompletely, or in combination with other effects such as ozone depletion, leaving the subject prone to misconceptions. Here we use a one-dimensional window-grey radiation model of the atmosphere to illustrate the physical essence of the mechanisms by which CO2 cools the stratosphere and mesosphere: (i) the blocking effect, associated with a cooling due to the fact that CO2 absorbs radiation at wavelengths where the atmosphere is already relatively opaque, and (ii) the indirect solar effect, associated with a cooling in places where an additional (solar) heating term is present (which on Earth is particularly the case in the upper parts of the ozone layer). By contrast, in the grey model without solar heating within the atmosphere, the cooling aloft is only a transient blocking phenomenon that is completely compensated as the surface attains its warmer equilibrium. Moreover, we quantify the relative contribution of these effects by simulating the response to an abrupt increase in CO2 (and chlorofluorocarbon) concentrations with an atmospheric general circulation model. We find that the two permanent effects contribute roughly equally to the CO2-induced cooling, with the indirect solar effect dominating around the stratopause and the blocking effect dominating otherwise.

    Contrasting neural effects of aging on proactive and reactive response inhibition
    Bloemendaal, Mirjam ; Zandbelt, Bram ; Wegman, Joost ; Rest, O. van de; Cools, Roshan ; Aarts, Esther - \ 2016
    Neurobiology of aging 46 (2016). - ISSN 0197-4580 - p. 96 - 106.
    Functional MRI - Healthy aging - Proactive response inhibition - Reactive response inhibition

    Two distinct forms of response inhibition may underlie observed deficits in response inhibition in aging. We assessed whether age-related neurocognitive impairments in response inhibition reflect deficient reactive inhibition (outright stopping) or also deficient proactive inhibition (anticipatory response slowing), which might be particularly evident with high information load. We used functional magnetic resonance imaging in young (n = 25, age range 18–32) and older adults (n = 23, 61–74) with a stop-signal task. Relative to young adults, older adults exhibited impaired reactive inhibition (i.e., longer stop-signal reaction time) and increased blood oxygen level-dependent (BOLD) signal for successful versus unsuccessful inhibition in the left frontal cortex and cerebellum. Furthermore, older adults also exhibited impaired proactive slowing, but only as a function of information load. This load-dependent behavioral deficit was accompanied by a failure to increase blood oxygen level-dependent (BOLD) signal under high information load in lateral frontal cortex, presupplementary motor area and striatum. Our findings suggest that inhibitory deficits in older adults are caused both by reduced stopping abilities and by diminished preparation capacity during information overload.

    Plant water-stress parameterization determines the strength of land-atmosphere coupling
    Combe, M. ; Vila-Guerau de Arellano, J. ; Ouwersloot, H.G. ; Peters, W. - \ 2016
    Agricultural and Forest Meteorology 217 (2016). - ISSN 0168-1923 - p. 61 - 73.
    Atmospheric boundary layer - CO - Drought - Heat wave - Land-atmosphere interactions - Water stress

    Land-surface models used in studies of the atmosphere and vegetation during droughts usually include an underlying parameterization that describes the response of plants to water stress. Here, we show that different formulations of this parameterization can lead to significant differences in the coupling strength (i.e. the magnitude of the carbon and water exchange) between the land surface and the atmospheric boundary layer (ABL). We use a numerical model that couples the daytime surface fluxes typical for low vegetation to the dynamics of a convective ABL, to systematically investigate a range of plant water-stress responses. We find that under dry soil conditions, changing from a sensitive to an insensitive vegetation response to water stress has the same impact on the land-atmosphere (L-A) coupling as a strong increase in soil moisture content. The insensitive vegetation allows stomata to remain open for transpiration (+150Wm-2 compared to the sensitive one), which cools the atmosphere (-3.5K) and limits the ABL growth (-500m). During the progressive development of a dry spell, the insensitive response will first dampen atmospheric heating because the vegetation continues to transpire a maximum of 4.6mmday-1 while soil moisture is available. In contrast, the more sensitive vegetation response reduces its transpiration by more than 1mmday-1 to prevent soil moisture depletion. But when soil moisture comes close to wilting point, the insensitive vegetation will suddenly close its stomata causing a switch to a L-A coupling regime dominated by sensible heat exchange. We find that in both cases, progressive soil moisture depletion contributes to further atmospheric warming up to 6K, reduced photosynthesis up to 89%, and CO2 enrichment up to 30ppm, but the full impact is strongly delayed for the insensitive vegetation. Then, when we analyze the impact of a deviation of the modeled large-scale boundary conditions (e.g. subsidence, cloud cover, free-troposphere lapse rates, etc.) from their true state during a drought, we find that the two coupled systems (with a sensitive or insensitive vegetation) respond much differently to the generated atmospheric warming, this due to the difference in the basic surface coupling regime (coupled vs. uncoupled). This is of importance for the simulation of heat waves and meteorological droughts, as well as carbon-climate projections, as we show the predictive skill of coupled models is tied to the underlying vegetation response to water stress.

    The Arabidopsis SIAMESE-RELATED cyclin-dependent Kinase Inhibitors SMR5 and SMR7 Regulate the DNA damage checkpoint in response to reactive oxygen species
    Yi, Dalong ; Kamei, Claire Lessa Alvim ; Cools, Toon ; Vanderauwera, Sandy ; Takahashi, Naoki ; Okushima, Yoko ; Eekhout, Thomas ; Yoshiyama, Kaoru Okamoto ; Larkin, John ; Daele, Hilde Van den; Conklin, Phillip ; Britt, Anne ; Umeda, Masaaki ; Veylder, Lieven De - \ 2014
    The Plant Cell 26 (2014)1. - ISSN 1040-4651 - p. 296 - 309.

    Whereas our knowledge about the diverse pathways aiding DNA repair upon genome damage is steadily increasing, little is known about the molecular players that adjust the plant cell cycle in response to DNA stress. By a meta-analysis of DNA stress microarray data sets, three family members of the SIAMESE/SIAMESE-RELATED (SIM/SMR) class of cyclin-dependent kinase inhibitors were discovered that react strongly to genotoxicity. Transcriptional reporter constructs corroborated specific and strong activation of the three SIM/SMR genes in the meristems upon DNA stress, whereas overexpression analysis confirmed their cell cycle inhibitory potential. In agreement with being checkpoint regulators, SMR5 and SMR7 knockout plants displayed an impaired checkpoint in leaf cells upon treatment with the replication inhibitory drug hydroxyurea (HU). Surprisingly, HU-induced SMR5/SMR7 expression depends on ATAXIA TELANGIECTASIA MUTATED (ATM) and SUPPRESSOR OF GAMMA RESPONSE1, rather than on the anticipated replication stress-activated ATM AND RAD3-RELATED kinase. This apparent discrepancy was explained by demonstrating that, in addition to its effect on replication, HU triggers the formation of reactive oxygen species (ROS). ROS-dependent transcriptional activation of the SMR genes was confirmed by different ROS-inducing conditions, including high-light treatment. We conclude that the identified SMR genes are part of a signaling cascade that induces a cell cycle checkpoint in response to ROS-induced DNA damage.

    Mainstreaming biodiversity where it matters most
    Karlsson-Vinkhuyzen, S.I.S.E. ; Boelee, E. ; Cools, J. ; Visseren-Hamakers, I.J. ; Hoof, L.J.W. van; Hospes, O. ; Kok, M. ; Peerlings, J.H.M. ; Podvin, K.J. ; Tatenhove, J.P.M. van; Termeer, C.J.A.M. - \ 2014
    Wageningen & Bilthoven : Wageningen University & PBL Netherlands Environmental Assessment Agency - ISBN 9789462573840 - 180
    biodiversiteit - bosbouw - visserij - palmoliën - mangroves - wereld - biodiversity - forestry - fisheries - palm oils - mangroves - world
    This report presents the result of applying the framework in five cases in or on the cross roads between agriculture, forestry and fisheries where considerable pressure on biodiversity is exerted. The cases were selected based on several criteria with the aim that they together cover as broad span as possible of: Relevance for biodiversity (from having very clear impacts to much more uncertain impacts) Governance levels (including both local, national, global levels) Governance context (type of actors, type of norms etc.) Regions (continents and eco‐climatic zones)
    High frequency ground temperature fluctuation in a Convective Boundary Layer
    Garai, A. ; Kleissl, J. ; Lothon, M. ; Lohou, F. ; Pardyjak, E. ; Saïd, F. ; Cuxart, J. ; Steeneveld, G.J. ; Yaguë, C. ; Derrien, S. ; Alexander, D. ; Villagrasa, D.M. - \ 2012
    In: 20th Symposium on Boundary Layers and Turbulence/18th Conference on Air-Sea Interaction, American Meteorological Society (9-13 July 2012, Boston, MA). - Boston : American Meteorological Society - p. 14B.3 - 14B.3.
    To study influence of the turbulent structures in the convective boundary layer (CBL) on the ground temperature, during the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) observational campaign, high frequency ground temperature was recorded through infra-red imagery from 13 June - 8 July, 2011. The 2-D ground temperature characteristics were then studied and compared to surface layer turbulence data for clear days. The ground temperature standard deviation follows the power-law exponent similar to surface layer similarity theory. The high correlation region between the air and the ground temperatures is aligned with the wind direction; the spanwise spread of the correlation region depends on the wind direction variability. The upwind part of the high correlation region is comparable with the flux footprint function by Hsieh et al. (2000). Conditional averaging shows that when a cold air parcel descends through the atmospheric surface layer (ASL) during a sweep event, the ground cools down. As the air parcel remains near the ground, it warms up and the heat transport from the ground to the air decreases. Thus the ground warms up during this period. After attaining a certain buoyancy the warm air parcel ascends, creating an ejection event. During the initial period of ejection, the ground temperature peaks, and subsequently the ground starts to cool down as the ground heat flux starts to decrease. Animation of ground temperature fluctuations reveals that the imprints of these ejection and sweep events move along with the wind. The estimated speed of these coherent structures is of the same order as the wind speed at 8 m above ground level or higher. With increasing stability of the CBL, the mean size of these structures increases and they become streakier.
    Dietary supplementation with dimethylglycine affects broiler performance and plasma metabolites depending on dose and dietary fatty acid profile
    Kalmar, I.D. ; Cools, A. ; Verstegen, M.W.A. ; Huyghebaert, G. ; Buyse, J. ; Roose, P. ; Janssens, G.P.J. - \ 2011
    Journal of Animal Physiology and Animal Nutrition 95 (2011)2. - ISSN 0931-2439 - p. 146 - 153.
    vitamin-e - fish-oil - resistance - hypertension
    The effect of dietary supplementation with N,N-dimethylglycine sodium salt (Na-DMG) was evaluated in a feeding trial with 1500 1-day-old broiler chicks (Cobb 500). DMG was supplemented at 0, 0.1, 0.2, 0.5 or 1 g Na-DMG/kg feed to a ration with either animal fat (chicken fat) or vegetal fat (soy oil) as main fat source. In the vegetal fat diets, production value was significantly linearly improved by supplementation with DMG up to 11%. Irrespective of dietary fat source, abdominal fat percentage was significantly linearly reduced up to 24% and meat yield tended to increase linearly with DMG level up to 4%. In the vegetal fat groups, DMG significantly lowered abdominal fat pad by up to 38% and tended to increase meat yield up to 6% at the highest dose. Fasted non-esterified fatty acid level significantly decreased with increasing DMG level up to 36% and thiobarbituric acid reactive species (TBARS) decreased with a statistical trend up to 46% at the highest dose. In vegetal fat diets, addition of DMG resulted in significant lower TBARS level by 56% at the highest dose. Finally, a significant quadratic effect on ascites heart index was present in the vegetal fat diets, with a minimal value at 0.5 g Na-DMG/kg. In conclusion, dietary supplementation with DMG may improve technical and slaughter performance, and may reduce oxidative stress and pulmonary hypertension, but the degree of effects is modulated by fatty acid profile of the diet. Herewith, effects are more pronounced in a diet rich in polyunsaturated fatty acids compared with a diet rich in saturated and monounsaturated fatty acids.
    Finished Genome of the Fungal Wheat Pathogen Mycosphaerella graminicola Reveals Dispensome Structure, Chromosome Plasticity, and Stealth Pathogenesis
    Goodwin, S.B. ; M'Barek, S. Ben; Dhillon, B. ; Wittenberg, A.H.J. ; Crane, C.F. ; Hane, J.K. ; Foster, A.J. ; Lee, T.A.J. van der; Grimwood, J. ; Aerts, A. ; Antoniw, J. ; Bailey, A. ; Bluhm, B. ; Bowler, J. ; Bristow, J. ; Burgt, A. van der; Canto-Canché, B. ; Churchill, A.C.L. ; Conde-Ferràez, L. ; Cools, H.J. ; Coutinho, P.M. ; Csukai, M. ; Dehal, P. ; Wit, P.J.G.M. de; Donzelli, B. ; Geest, H.C. van de; Ham, R.C.H.J. van; Hammond-Kosack, K.E. ; Henrissat, B. ; Kilian, A. ; Kobayashi, A.K. ; Koopmann, E. ; Kourmpetis, Y. ; Kuzniar, A. ; Lindquist, E. ; Lombard, V. ; Maliepaard, C.A. ; Martins, N. ; Mehrabi, A. ; Nap, J.P.H. ; Ponomarenko, A. ; Rudd, J.J. ; Salamov, A. ; Schmutz, J. ; Schouten, H.J. ; Shapiro, H. ; Stergiopoulos, I. ; Torriani, S.F.F. ; Tu, H. ; Vries, R.P. de; Waalwijk, C. ; Ware, S.B. ; Wiebenga, A. ; Zwiers, L.H. ; Oliver, R.P. ; Grigoriev, I.V. ; Kema, G.H.J. - \ 2011
    Plos Genetics 7 (2011)6. - ISSN 1553-7404 - 17 p.
    magnaporthe-grisea - b-chromosomes - gene - host - organization - annotation - resistance - neurospora - expression - symbiosis
    The plant-pathogenic fungus Mycosphaerella graminicola (asexual stage: Septoria tritici) causes septoria tritici blotch, a disease that greatly reduces the yield and quality of wheat. This disease is economically important in most wheat-growing areas worldwide and threatens global food production. Control of the disease has been hampered by a limited understanding of the genetic and biochemical bases of pathogenicity, including mechanisms of infection and of resistance in the host. Unlike most other plant pathogens, M. graminicola has a long latent period during which it evades host defenses. Although this type of stealth pathogenicity occurs commonly in Mycosphaerella and other Dothideomycetes, the largest class of plant-pathogenic fungi, its genetic basis is not known. To address this problem, the genome of M. graminicola was sequenced completely. The finished genome contains 21 chromosomes, eight of which could be lost with no visible effect on the fungus and thus are dispensable. This eight-chromosome dispensome is dynamic in field and progeny isolates, is different from the core genome in gene and repeat content, and appears to have originated by ancient horizontal transfer from an unknown donor. Synteny plots of the M. graminicola chromosomes versus those of the only other sequenced Dothideomycete, Stagonospora nodorum, revealed conservation of gene content but not order or orientation, suggesting a high rate of intra-chromosomal rearrangement in one or both species. This observed “mesosynteny” is very different from synteny seen between other organisms. A surprising feature of the M. graminicola genome compared to other sequenced plant pathogens was that it contained very few genes for enzymes that break down plant cell walls, which was more similar to endophytes than to pathogens. The stealth pathogenesis of M. graminicola probably involves degradation of proteins rather than carbohydrates to evade host defenses during the biotrophic stage of infection and may have evolved from endophytic ancestors. Author Summary The plant-pathogenic fungus Mycosphaerella graminicola causes septoria tritici blotch, one of the most economically important diseases of wheat worldwide and a potential threat to global food production. Unlike most other plant pathogens, M. graminicola has a long latent period during which it seems able to evade host defenses, and its genome appears to be unstable with many chromosomes that can change size or be lost during sexual reproduction. To understand its unusual mechanism of pathogenicity and high genomic plasticity, the genome of M. graminicola was sequenced more completely than that of any other filamentous fungus. The finished sequence contains 21 chromosomes, eight of which were different from those in the core genome and appear to have originated by ancient horizontal transfer from an unknown donor. The dispensable chromosomes collectively comprise the dispensome and showed extreme plasticity during sexual reproduction. A surprising feature of the M. graminicola genome was a low number of genes for enzymes that break down plant cell walls; this may represent an evolutionary response to evade detection by plant defense mechanisms. The stealth pathogenicity of M. graminicola may involve degradation of proteins rather than carbohydrates and could have evolved from an endophytic ancestor.
    A dynamic framework for managing horizontal cooperation in logistics
    Verstrepen, S. ; Cools, M. ; Cruijssen, F.C.A.M. ; Dullaert, W. - \ 2009
    International Journal of Logistics Systems and Management (IJLSM) 5 (2009)3/4. - ISSN 1742-7967 - p. 228 - 248.
    This paper first explores the motives and drivers that Logistic Service Providers (LSPs) may feel to start up horizontal cooperation. Secondly, a classification supporting LSPs in their search for a suitable collaboration structure is developed based on distinguishing cooperation characteristics encountered in practice. The third contribution consists of a description of the typical life cycle of a partnership and how it can be managed over time. Partnerships are presented as a means for LSPs to cope with increasingly difficult market conditions. In addition, they offer positive side effects for society and the environment
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