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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    Lerende evaluatie van het Natuurpact 2020 : Gezamenlijk de puzzel leggen voor natuur, economie en maatschappij: tweede rapportage
    Folkert, Rob ; Bouwma, Irene ; Kuindersma, Wiebren ; Hoek, Dirk-Jan van der; Gerritsen, Alwin ; Kunseler, Eva ; Buijs, Arjen ; Broekhoven, Saskia van; Knegt, Bart de; Aalbers, Carmen ; Kamphorst, Dana ; Doren, Didi van; Klaassen, Pim ; Wit-de Vries, Esther de; Roelofsen, Hans ; Agricola, Herman ; Os, Jaap van; Frissel, Joep ; Donders, Josine ; Verwoerd, Lisa ; Giesen, Paul ; Sanders, Marlies ; Goossen, Martin ; Nuesink, Nienke ; Arnouts, Rikke ; Boer, Tineke de; Dam, Rosalie van - \ 2020
    Den Haag : PBL Planbureau voor de Leefomgeving (PBL-publicatie 3852) - 183
    Natuurrapportage Zeeland 2019
    Boddeke, Paul ; Boudewijn, Theo ; Helsdingen, Arda van; Lensink, Rob ; Röell, Ineke ; Roelofsen, Hans ; Sanders, Marlies ; Schütt, Jeroen ; Wamelink, Wieger ; Zee, Friso van der; Soomers, Hester - \ 2019
    Middelburg : Provincie Zeeland - 153
    Borging MNP, data en indicatoren bestaand natuurbeleid (Borging MNP) 2019 : Tussenrapportage WOT-04-011-037.12
    Henkens, R.J.H.G. ; Roelofsen, H.D. ; Knegt, B. de; Wamelink, G.W.W. ; Jochem, R. ; Meeuwsen, H.A.M. ; Greft-van Rossum, J.G.M. van der - \ 2019
    The use of metabolic profiling to identify insulin resistance in veal calves
    Pantophlet, Andre J. ; Roelofsen, H. ; Vries, Marcel P. de; Gerrits, Walter J.J. ; Borne, Joost J.G.C. Van Den; Vonk, R.J. - \ 2017
    PLoS ONE 12 (2017)6. - ISSN 1932-6203 - 12 p.

    Heavy veal calves (4–6 months old) are at risk of developing insulin resistance and disturbed glucose homeostasis. Prolonged insulin resistance could lead to metabolic disorders and impaired growth performance. Recently, we discovered that heavy Holstein-Friesian calves raised on a high-lactose or high-fat diet did not differ in insulin sensitivity, that insulin sensitivity was low and 50% of the calves could be considered insulin resistant. Understanding the patho-physiological mechanisms underlying insulin resistance and discovering biomarkers for early diagnosis would be useful for developing prevention strategies. Therefore, we explored plasma metabolic profiling techniques to build models and discover potential biomarkers and pathways that can distinguish between insulin resistant and moderately insulin sensitive veal calves. The calves (n = 14) were classified as insulin resistant (IR) or moderately insulin sensitive (MIS) based on results from a euglycemic-hyperinsulinemic clamp, using a cut-off value (M/I-value <4.4) to identify insulin resistance. Metabolic profiles of fasting plasma samples were analyzed using reversed phase (RP) and hydrophilic interaction (HILIC) liquid chromatography–mass spectrometry (LC-MS). Orthogonal partial least square discriminant analysis was performed to compare metabolic profiles. Insulin sensitivity was on average 2.3x higher (P <0.001) in MIS than IR group. For both RP-LC-MS and HILIC-LC-MS satisfactory models were build (R2Y >90% and Q2Y >66%), which allowed discrimination between MIS and IR calves. A total of 7 and 20 metabolic features (for RP-LC-MS and HILIC-LC-MS respectively) were most responsible for group separation. Of these, 7 metabolites could putatively be identified that differed (P <0.05) between groups (potential biomarkers). Pathway analysis indicated disturbances in glycerophospholipid and sphingolipid metabolism, the glycine, serine and threonine metabolism, and primary bile acid biosynthesis. These results demonstrate that plasma metabolic profiling can be used to identify insulin resistance in veal calves and can lead to underlying mechanisms.

    Lactose in milk replacer can partly be replaced by glucose, fructose, or glycerol without affecting insulin sensitivity in veal calves
    Pantophlet, A.J. ; Gilbert, M.S. ; Borne, J.J.G.C. van den; Gerrits, W.J.J. ; Roelofsen, H. ; Priebe, M.G. ; Vonk, R.J. - \ 2016
    Journal of Dairy Science 99 (2016)4. - ISSN 0022-0302 - p. 3072 - 3080.
    Fructose - Glucose homeostasis - Glycerol - Insulin sensitivity - Veal calves

    Calf milk replacer (MR) contains 40 to 50% lactose. Lactose strongly fluctuates in price and alternatives are desired. Also, problems with glucose homeostasis and insulin sensitivity (i.e., high incidence of hyperglycemia and hyperinsulinemia) have been described for heavy veal calves (body weight >100 kg). Replacement of lactose by other dietary substrates can be economically attractive, and may also positively (or negatively) affect the risk of developing problems with glucose metabolism. An experiment was designed to study the effects of replacing one third of the dietary lactose by glucose, fructose, or glycerol on glucose homeostasis and insulin sensitivity in veal calves. Forty male Holstein-Friesian (body weight = 114 ± 2.4 kg; age = 97 ± 1.4 d) calves were fed an MR containing 462 g of lactose/kg (CON), or an MR in which 150 g of lactose/kg of MR was replaced by glucose (GLU), fructose (FRU), or glycerol (GLY). During the first 10 d of the trial, all calves received CON. The CON group remained on this diet and the other groups received their experimental diets for a period of 8 wk. Measurements were conducted during the first (baseline) and last week of the trial. A frequently sampled intravenous glucose tolerance test was performed to assess insulin sensitivity and 24 h of urine was collected to measure glucose excretion. During the last week of the trial, a bolus of 1.5 g of [U-13C] substrates was added to their respective meals and plasma glucose, insulin, and 13C-glucose responses were measured. Insulin sensitivity was low at the start of the trial and remained low [1.2 ± 0.1 and 1.0 ± 0.1 (mU/L)-1 × min-1], and no treatment effect was noted. Glucose excretion was low at the start of the trial (3.4 ± 1.0 g/d), but increased (P <0.01) in CON and GLU calves (26.9 ± 3.9 and 43.0 ± 10.6 g/d) but not in FRU and GLY calves. Postprandial glucose was higher in GLU, lower in FRU, and similar in GLY compared with CON calves. Postprandial insulin was lower in FRU and GLY and similar in GLU compared with CON calves. Postprandial 13C-glucose increased substantially in FRU and GLY calves, indicating that calves are able to partially convert these substrates to glucose. We concluded that replacing one third of lactose in MR by glucose, fructose, or glycerol in MR differentially influences postprandial glucose homeostasis but does not affect insulin sensitivity in veal calves.

    Doing femininity and respectability: social networks and social capital among female members of Dutch student organisations
    Peters, K.B.M. ; Roelofsen, M. - \ 2015
    Leisure Studies 36 (2015)3. - ISSN 0261-4367 - p. 341 - 356.
    This research explores the complexities that underlie the formation of women’s social networks at traditional social student organisations in the Netherlands, advancing theory on the intersectionality of gender and class in leisure space. Building on Pierre Bourdieu’s theory of social capital it investigates if these social networks are segregated, and to what extent their divisions depend on previously acquired economic, cultural and symbolic capital. It analyses the hierarchical structures and ‘ranking’ of women’s year clubs within student organisations, and examines how the enactment and achievement of femininity determines women’s ability to move through social space. Finally, it investigates the use of social capital for women’s career progression. Semi-structured interviews were held with 20 women who were current or former members of one of the most traditional Dutch student organisations, the corps. Their accounts were used to gather information about the meaning women gave to their membership, and shed light on the role of previously acquired capital in the formation of clubs. Our findings show that women’s previously acquired social capital allowed them easier access to corps’ space and advanced their ability to navigate it. The establishment and ranking of year clubs and their members demonstrate the power dynamics that operate within the corps and the way class underlines network formation. Femininity was deemed one of the important markers of respectability and the enactment and achievement of ‘proper’ femininity determined women’s recognition and position in corps space. Despite the hierarchies of placement in the corps, most women profit from the social capital they acquired during membership, and can use it in selective ways for career progression and acquisitions.
    An evaluation of remote sensing derived soil pH and average spring groundwater table for ecological assessments
    Roelofsen, H.D. ; Bodegom, P.M. van; Kooistra, L. ; Amerongen, L. van; Witte, J.M. - \ 2015
    International Journal of applied Earth Observation and Geoinformation 43 (2015)sp.issue. - ISSN 0303-2434 - p. 149 - 159.
    Ecological assessments such as species distribution modelling and benchmarking site quality towards regulations often rely on full spatial coverage information of site factors such as soil acidity, moisture regime or nutrient availability. To determine if remote sensing (RS) is a viable alternative to traditional data sources of site factor estimates, we analysed the accuracy (using ground truth validation measurements) of traditional and RS sources of pH and mean spring groundwater level (MSL, in m) estimates. Traditional sources were a soil map and hydrological model. RS estimates were obtained using vegetation indicator values (IVs) from a Dutch national system as an intermediate between site factors and spectral response. IVs relate to those site factors that dictate vegetation occurrence, whilst also providing a robust link to canopy spectra. For pH, the soil map and the RS estimate were nearly as accurate. For MSL, the RS estimates were much closer to the observed groundwater levels than the hydrological model, but the error margin of the estimates still exceeded the tolerance range of moisture sensitive vegetation. The relatively high accuracy of the RS estimates was made possible by the availability of local calibration points and large environmental gradients in the study site. In addition, the error composition of the RS estimates could be analysed step-by-step, whereas the traditional sources had to be accepted ‘as-is’. Also considering that RS offers high spatial and temporal resolution at low costs, RS offered advantages over traditional sources. This will likely hold true for any other situation where prerequisites of accurate RS estimates have been met.
    Maintaining the CSR-identity of Sustainable Entrepreneurial Firms: The role of corporate governance in periods of business growth
    Roelofsen, M. ; Blok, V. ; Wubben, E.F.M. - \ 2015
    In: Corporate Social Responsibility and Governance: theory and practice / Idowu, S.O., Frederiksen, S.C., Mermod, A.Y., Nielsen, M.E.W., Dordrecht : Springer - ISBN 9783319109091 - p. 63 - 88.
    This chapter focuses on the maintenance of the CSR-identity of sustainable entrepreneurial firms (SEFs) during periods of business growth. Our aim is to explore to what extent corporate governance mechanisms can be seen as effective mechanisms to maintain the CSR-identity of growing SEFs. To this end, a comprehensive literature review is conducted to obtain conceptual insights, which are subsequently empirically illustrated by a multiple case study of SEFs (N = 7). We conclude that the following barriers to business growth might have an impact on the CSR-identity of SEFs: overtrading/uncontrolled growth, control and delegation, decentralization and formation, indirect expression of identity. Furthermore, we conclude that the following mechanisms of corporate governance might prevent or compensate for the dilution of the CSR-identity of SEFs in periods of business growth: strategy, human resource management, organizational culture, formal monitoring, coordination, media involvement and social monitoring. Finally, we provide recommendations for practitioners, based on our results.
    Predicting leaf traits of herbaceous species from their spectral characteristics
    Roelofsen, H.D. ; Bodegom, P.M. van; Kooistra, L. ; Witte, J.P.M. - \ 2014
    Ecology and Evolution 4 (2014)6. - ISSN 2045-7758 - p. 706 - 719.
    optical-properties - conifer needles - plant traits - squares regression - tropical forests - canopy structure - carbon gain - wide-range - nitrogen - reflectance
    Trait predictions from leaf spectral properties are mainly applied to tree species, while herbaceous systems received little attention in this topic. Whether similar trait–spectrum relations can be derived for herbaceous plants that differ strongly in growing strategy and environmental constraints is therefore unknown. We used partial least squares regression to relate key traits to leaf spectra (reflectance, transmittance, and absorbance) for 35 herbaceous species, sampled from a wide range of environmental conditions. Specific Leaf Area and nutrient-related traits (N and P content) were poorly predicted from any spectrum, although N prediction improved when expressed on a per area basis (mg/m2 leaf surface) instead of mass basis (mg/g dry matter). Leaf dry matter content was moderately to good correlated with spectra. We explain our results by the range of environmental constraints encountered by herbaceous species; both N and P limitations as well as a range of light and water availabilities occurred. This weakened the relation between the measured response traits and the leaf constituents that are truly responsible for leaf spectral behavior. Indeed, N predictions improve considering solely upper or under canopy species. Therefore, trait predictions in herbaceous systems should focus on traits relating to dry matter content and the true, underlying drivers of spectral properties.
    Mapping a priori defined plant associations using remotely sensed vegetation characteristics
    Roelofsen, H.D. ; Kooistra, L. ; Bodegom, P.M. van; Verrelst, J. ; Krol, J. ; Witte, J.M.P. - \ 2014
    Remote Sensing of Environment 140 (2014). - ISSN 0034-4257 - p. 639 - 651.
    ellenberg indicator values - continuous floristic gradients - hyperspectral imagery - imaging spectroscopy - endmember selection - tropical forests - aviris data - classification - regression - moisture
    Incorporation of a priori defined plant associations into remote sensing products is a major challenge that has only recently been confronted by the remote sensing community. We present an approach to map the spatial distribution of such associations by using plant indicator values (IVs) for salinity, moisture and nutrients as an intermediate between spectral reflectance and association occurrences. For a 12 km2 study site in the Netherlands, the relations between observed IVs at local vegetation plots and visible and near-infrared (VNIR) and short-wave infrared (SWIR) airborne reflectance data were modelled using Gaussian Process Regression (GPR) (R2 0.73, 0.64 and 0.76 for salinity, moisture and nutrients, respectively). These relations were applied to map IVs for the complete study site. Association occurrence probabilities were modelled as function of IVs using a large database of vegetation plots with known association and IVs. Using the mapped IVs, we calculated occurrence probabilities of 19 associations for each pixel, resulting in both a crisp association map with the most likely occurring association per pixel, as well as occurrence probability maps per association. Association occurrence predictions were assessed by a local vegetation expert, which revealed that the occurrences of associations situated at frequently predicted indicator value combinations were over predicted. This seems primarily due to biases in the GPR predicted IVs, resulting in associations with envelopes located in extreme ends of IVs being scarcely predicted. Although the results of this particular study were not fully satisfactory, the method potentially offers several advantages compared to current vegetation classification techniques, like site-independent calibration of association probabilities, site-independent selection of associations and the provision of IV maps and occurrence probabilities per association. If the prediction of IVs can be improved, this method may thus provide a viable roadmap to bring a priori defined plant associations into the domain of remote sensing.
    Short-chain fatty acids stimulate angiopoietin-like 4 synthesis in human colonocytes by selective PPARγ modulation
    Alex, Sheril ; Lange, Katja ; Amolo, Tom ; Grinstead, Jeffrey S. ; Szalowska, Ewa ; Koppen, Arjen ; Mudde, Karin ; Haenen, Danielle ; Al-Lahham, S. ; Roelofsen, Han ; Houtman, René ; Burg, Bart van den; Bonvin, Alexandre M. ; Kalkhoven, Eric ; Muller, Michael ; Hooiveld, Guido ; Kersten, Sander - \ 2013
    Wageningen University
    Homo sapiens - GSE40706 - PRJNA174693 - Homo sapiens - GSE40706
    Angiopoietin-like protein 4 (ANGPTL4, also referred to as Fiaf) has been proposed as a circulating mediator between the gut microbiota and fat storage in adipose tissue. Very little is known about the mechanisms of regulation of ANGPTL4 in the colon. Here we show that transcription and subsequent secretion of ANGPTL4 in human T84 and HT-29 colonocytes is highly induced by physiological concentrations of products of bacterial fermentation, the short-chain fatty acids. Short-chain fatty acids induce ANGPTL4 by activating the nuclear receptor PPARγ, as shown by microarray, transactivation assays, coactivator peptide recruitment assay, and use of PPARγ antagonist. At concentrations required for PPARγ activation and ANGPTL4 induction in colonocytes, SCFA do not stimulate PPARγ in mouse 3T3-L1 and human SGBS adipocytes, suggesting that SCFA act as selective PPARγ modulators (SPPARM), which is supported by coactivator peptide recruitment assay and structural modelling. It can be concluded that 1) SCFA potently stimulate ANGPTL4 synthesis in human colonocytes, and 2) SCFA transactivate and bind to PPARγ by serving as selective PPAR modulators. Our data point to activation of PPARγ as a novel mechanism of gene regulation by SCFA in the colon.
    Plant trait estimation from hyperspectral imagery in a heterogeneous grassland environment
    Roelofsen, H.D. ; Bodegom, P.M. van; Kooistra, L. ; Witte, J.P.M. - \ 2013
    Trait estimation in herbaceous plant assemblages from in situ canopy spectra
    Roelofsen, H.D. ; Bodegom, P.M. van; Kooistra, L. ; Witte, J.M. - \ 2013
    Remote Sensing 5 (2013)12. - ISSN 2072-4292 - p. 6323 - 6345.
    least-squares regression - hyperspectral data - economics spectrum - vegetation indexes - indicator values - nitrogen-content - national-park - chlorophyll - reflectance - model
    Estimating plant traits in herbaceous plant assemblages from spectral reflectance data requires aggregation of small scale trait variations to a canopy mean value that is ecologically meaningful and corresponds to the trait content that affects the canopy spectral signal. We investigated estimation capacities of plant traits in a herbaceous setting and how different trait-aggregation methods influence estimation accuracies. Canopy reflectance of 40 herbaceous plant assemblages was measured in situ and biomass was analysed for N, P and C concentration, chlorophyll, lignin, phenol, tannin and specific water concentration, expressed on a mass basis (mg·g-1). Using Specific Leaf Area (SLA) and Leaf Area Index (LAI), traits were aggregated to two additional expressions: mass per leaf surface (mg·m-2) and mass per canopy surface (mg·m-2). All traits were related to reflectance using partial least squares regression. Accuracy of trait estimation varied between traits but was mainly influenced by the trait expression. Chlorophyll and traits expressed on canopy surface were least accurately estimated. Results are attributed to damping or enhancement of the trait signal upon conversion from mass based trait values to leaf and canopy surface expressions. A priori determination of the most appropriate trait expression is viable by considering plant growing strategies
    Hoe met remote sensing via de vegetatie bodem en water kunnen worden gekarteerd
    Roelofsen, H.D. ; Amerongen, J. van; Kooistra, L. ; Runhaar, J. ; Witte, J.P. - \ 2013
    Stromingen : vakblad voor hydrologen 19 (2013)2. - ISSN 1382-6069 - p. 107 - 120.
    remote sensing - ecohydrologie - vegetatietypen - evapotranspiratie - grondwaterstand - monitoring - remote sensing - ecohydrology - vegetation types - evapotranspiration - groundwater level - monitoring
    Remote sensing is de verzamelterm voor diverse vormen van aardobservatie. Zoals observaties van het aardoppervlak door satellieten (spaceborne remote sensing). Observaties vanuit vliegtuigen (airborne remote sensing) zijn eveneens mogelijk. De vraag wat remote sensing kan betekenen voor hydrologische toepassingen stond centraal tijdens de NHV voorjaarsbijeenkomst, in mei 2012. Daar betoogden wij dat diverse hydrologische grootheden afgeleid kunnen worden van remote sensing beelden. Dit artikel is een verdere uitwerking van dit betoog. We willen met deze bijdrage aantonen dat de natuurlijke vegetatie een nuttige vertaalsleutel kan vormen tussen remote sensing observaties enerzijds en eigenschappen van de ondergrond anderzijds.
    Short chain fatty acids stimulate Angiopoietin-like 4 synthesis in human colon adenocarcinoma cells by activating PPARy
    Alex, S. ; Lange, K. ; Amolo, T. ; Grinstead, J.S. ; Haakonsson, A.K. ; Szalowska, E. ; Koppen, A. ; Mudde, C.M. ; Haenen, D. ; Al-Lahham, S. ; Roelofsen, H. ; Houtman, R. ; Burg, B. van der; Mandrup, S. ; Bonvin, A.M.J.J. ; Kalkhoven, E. ; Muller, M.R. ; Hooiveld, G.J.E.J. ; Kersten, A.H. - \ 2013
    Molecular and Cellular Biology 33 (2013)7. - ISSN 0270-7306 - p. 1303 - 1316.
    inflammatory-bowel-disease - ppar-gamma - transcriptional activity - lipoprotein-lipase - skeletal-muscle - gut microbiota - target gene - expression - protein-4 - butyrate
    Angiopoietin-like protein 4 (ANGPTL4/FIAF) has been proposed as a circulating mediator between the gut microbiota and fat storage. Here, we show that transcription and secretion of ANGPTL4 in human T84 and HT29 colon adenocarcinoma cells is highly induced by physiological concentrations of short-chain fatty acids (SCFA). SCFA induce ANGPTL4 by activating the nuclear receptor peroxisome proliferator activated receptor ¿ (PPAR¿), as demonstrated using PPAR¿ antagonist, PPAR¿ knockdown, and transactivation assays, which show activation of PPAR¿ but not PPARa and PPARd by SCFA. At concentrations required for PPAR¿ activation and ANGPTL4 induction in colon adenocarcinoma cells, SCFA do not stimulate PPAR¿ in mouse 3T3-L1 and human SGBS adipocytes, suggesting that SCFA act as selective PPAR¿ modulators (SPPARM), which is supported by coactivator peptide recruitment assay and structural modeling. Consistent with the notion that fermentation leads to PPAR activation in vivo, feeding mice a diet rich in inulin induced PPAR target genes and pathways in the colon. We conclude that (i) SCFA potently stimulate ANGPTL4 synthesis in human colon adenocarcinoma cells and (ii) SCFA transactivate and bind to PPAR¿. Our data point to activation of PPARs as a novel mechanism of gene regulation by SCFA in the colon, in addition to other mechanisms of action of SCFA.
    Remote sensing allows mapping plant traits and a-priori defined vegetation types
    Roelofsen, H. ; Verrelst, J. ; Bodegom, P.M. van; Kooistra, L. ; Witte, J.P.M. - \ 2012
    In: Proceedings of the 2nd Terrabites Symposium 2012, 06-08 February, Frascati, Italy. - - p. 78 - 79.
    Nonlegume Parasponia andersonii deploys a broad rhizobium host range strategy resulting in largely variable symbiotic effectiveness
    Camp, R.H.M. op den; Polone, E. ; Fedorova, E. ; Roelofsen, W. ; Squartini, A. ; Camp, H.J.M. op den; Bisseling, T. ; Geurts, R. - \ 2012
    Molecular Plant-Microbe Interactions 25 (2012)7. - ISSN 0894-0282 - p. 954 - 963.
    tolerant legume nodulation - medicago-truncatula - tropici ciat899 - strain ngr234 - nod factors - leucaena-leucocephala - nitrogen-fixation - lotus-japonicus - root-nodules - genes
    The non-legume genus Parasponia has evolved the rhizobium symbiosis independent from legumes and has done so only recently. We aim to study the promiscuity of such newly evolved symbiotic engagement and determine the symbiotic effectiveness of infecting rhizobium species. It was found that Parasponia andersonii can be nodulated by a broad range of rhizobia belonging to four different genera, and therefore, we conclude that this non-legume is highly promiscuous for rhizobial engagement. A possible drawback of this high promiscuity is that low-efficient strains can infect nodules as well. The strains identified displayed a range in nitrogen-fixation effectiveness, including a very inefficient rhizobium species, Rhizobium tropici WUR1. Because this species is able to make effective nodules on two different legume species, it suggests that the ineffectiveness of P. andersonii nodules is the result of the incompatibility between both partners. In P andersonii nodules, rhizobia of this strain become embedded in a dense matrix but remain vital. This suggests that sanctions or genetic control against underperforming microsymbionts may not be effective in Parasponia spp. Therefore, we argue that the Parasponia-rhizobium symbiosis is a delicate balance between mutual benefits and parasitic colonization.
    Comparative analysis of the human hepatic and adipose tissue transcriptomes during LPS-induced inflammation leads to the identification of differential biological pathways and candidate biomarkers
    Szalowska, E. ; Dijkstra, M. ; Elferink, M.G.L. ; Weening, D. ; Vries, M. de; Bruinenberg, M. ; Hoek, A. ; Roelofsen, H. ; Groothuis, G.M.M. ; Vonk, R.J. - \ 2011
    BMC Medical Genomics 4 (2011). - ISSN 1755-8794
    amino-acid-metabolism - long pentraxin ptx3 - fatty liver-disease - insulin-resistance - gene-expression - t-cells - obesity - mechanisms - endotoxemia - cytokine
    Background: Insulin resistance (IR) is accompanied by chronic low grade systemic inflammation, obesity, and deregulation of total body energy homeostasis. We induced inflammation in adipose and liver tissues in vitro in order to mimic inflammation in vivo with the aim to identify tissue-specific processes implicated in IR and to find biomarkers indicative for tissue-specific IR. Methods: Human adipose and liver tissues were cultured in the absence or presence of LPS and DNA Microarray Technology was applied for their transcriptome analysis. Gene Ontology (GO), gene functional analysis, and prediction of genes encoding for secretome were performed using publicly available bioinformatics tools (DAVID, STRING, SecretomeP). The transcriptome data were validated by proteomics analysis of the inflamed adipose tissue secretome. Results: LPS treatment significantly affected 667 and 483 genes in adipose and liver tissues respectively. The GO analysis revealed that during inflammation adipose tissue, compared to liver tissue, had more significantly upregulated genes, GO terms, and functional clusters related to inflammation and angiogenesis. The secretome prediction led to identification of 399 and 236 genes in adipose and liver tissue respectively. The secretomes of both tissues shared 66 genes and the remaining genes were the differential candidate biomarkers indicative for inflamed adipose or liver tissue. The transcriptome data of the inflamed adipose tissue secretome showed excellent correlation with the proteomics data. Conclusions: The higher number of altered proinflammatory genes, GO processes, and genes encoding for secretome during inflammation in adipose tissue compared to liver tissue, suggests that adipose tissue is the major organ contributing to the development of systemic inflammation observed in IR. The identified tissue-specific functional clusters and biomarkers might be used in a strategy for the development of tissue-targeted treatment of insulin resistance in patients.
    Assessment of the biomass and nitrogen status of natural grasslands using hyperspectral remote sensing
    Kooistra, L. ; Roelofsen, H. ; Wamelink, G.W.W. ; Witte, J.P.M. ; Clevers, J.G.P.W. - \ 2010
    In: Proceedings of the Hyperspectral 2010 Workshop (SP-683), Frascati, Italy, 17-19 March 2010. - Frascati, Italy : ESA - p. 6 - 6.
    Zwavel regenvast maar met verlies van effectiviteit
    Jong, P.F. de; Heijne, B. ; Roelofsen, W. - \ 2004
    De Fruitteelt 94 (2004)24. - ISSN 0016-2302 - p. 10 - 11.
    gewasbescherming - zwavel - dosering - fruitteelt - appels - plantenziekteverwekkende schimmels - biologische landbouw - plant protection - sulfur - dosage - fruit growing - apples - plant pathogenic fungi - organic farming
    Zwavel is in de biologische teelt het meest gebruikte middel tegen appelschurft. Twee zwavelsoorten, Thiovit en Thiopaq, zijn door PPO getest op effectiviteit tegen schurft. Daaruit bleek dat na meer regen de effectiviteit afnam en meer schurftaantasting voorkwam. Echter de hoeveelheid zwavel op het blad vermindert niet extreem
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