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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State updating of root zone soil moisture estimates of an unsaturated zone metamodel for operational water resources management
Pezij, Michiel ; Augustijn, Denie C.M. ; Hendriks, Dimmie M.D. ; Weerts, Albrecht H. ; Hummel, Stef ; Velde, Rogier van der; Hulscher, Suzanne J.M.H. - \ 2019
Journal of Hydrology 4 (2019). - ISSN 0022-1694
Data assimilation - Ensemble Kalman filter - Hydrological modelling - Metamodelling - Remote sensing - SMAP - Soil moisture

Combining metamodels with data assimilation schemes allows the incorporation of up-to-date information in metamodels, offering new opportunities for operational water resources management. We developed a data assimilation scheme for the unsaturated zone metamodel MetaSWAP using OpenDA, which is an open source data assimilation framework. A twin experiment showed the feasibility of applying an Ensemble Kalman filter as a data assimilation method for updating metamodels. Furthermore, we assessed the accuracy of root zone soil moisture model estimates when assimilating the regional SMAP L3 Enhanced surface soil moisture product. The model accuracy is assessed using in situ soil moisture measurements collected at 12 locations in the Twente region, the Netherlands. Although the accuracy of the model estimates does not improve in terms of correlation coefficient, the accuracy does improve in terms of Root Mean Square Error and bias. Therefore, the assimilation of surface soil moisture observations has value for updating root zone soil moisture model estimates. In addition, the accuracy of the model estimates improves on both regional and local spatial scales. The increasing availability of remotely sensed soil moisture data will lead to new possibilities for integrating metamodelling and data assimilation in operational water resources management. However, we expect that significant investments in computational capacities are necessary for effective implementation in decision-making.

Modulation of sensory perception of cheese attributes intensity and texture liking via ortho- and retro-nasal odors
Han, Pengfei ; Fark, Therese ; Wijk, Rene A. de; Roudnitzky, Natacha ; Iannilli, Emilia ; Seo, Han Seok ; Hummel, Thomas - \ 2019
Food Quality and Preference 73 (2019). - ISSN 0950-3293 - p. 1 - 7.
Cheese - Congruency - Cross-modal sensory enhancement - Orthonasal - Retronasal - Texture

Cross-modal sensory integration plays a key role in food flavor perception and acceptance during consumption. The current study investigated the effect of a butter odor, delivered at various stages of the oral processing cycle, on modulating the sensory properties of cheese. Twenty healthy volunteers (aged between 25 and 29 years, 12 women) were measured for their detection thresholds for the butter odor. In the sensory evaluation sessions, participants chewed and swallowed three types of cheese (low-fat, 20% fat content, LF; a medium-fat, 30% fat content, MF; high-fat, 40% fat content, HF, served in 16 × 16 × 12 mm3 cubes) while the butter odor was presented ortho- and retronasally in two concentrations at various points of the oral processing cycle. After swallowing, participants rated on a visual analogue scale for the intensities of cheese creaminess, butter note, overall flavor, and the pleasantness for cheese texture. Enhancement of added butter odor on perceived sensory attributes differed as a function of the delivery routes and timings. Creaminess intensity increased significantly when butter odor presented retro-nasally at the start of chewing. Butter note was enhanced when the retro-nasal odor was added during chewing. The texture pleasantness was increased with ortho-nasal odor presentation. In addition, for the creaminess intensity and texture liking enhancement, the observed effects were more pronounced with butter odor presentation at the lower concentration. Taken together, these findings suggested the importance of temporal congruency for cross-modal sensory enhancement in food flavor perception. The findings help to better understand flavor perception during oral processing of solid food and add value for future development of foods with nutritional benefits.

Reduction in nutritional quality and growing area suitability of common bean under climate change induced drought stress in Africa
Hummel, Marijke ; Hallahan, Brendan F. ; Brychkova, Galina ; Ramirez-Villegas, Julian ; Guwela, Veronica ; Chataika, Bartholomew ; Curley, Edna ; McKeown, Peter C. ; Morrison, Liam ; Talsma, Elise F. ; Beebe, Steve ; Jarvis, Andy ; Chirwa, Rowland ; Spillane, Charles - \ 2018
Scientific Reports 8 (2018)1. - ISSN 2045-2322 - 11 p.

Climate change impacts on food security will involve negative impacts on crop yields, and potentially on the nutritional quality of staple crops. Common bean is the most important grain legume staple crop for human diets and nutrition worldwide. We demonstrate by crop modeling that the majority of current common bean growing areas in southeastern Africa will become unsuitable for bean cultivation by the year 2050. We further demonstrate reductions in yields of available common bean varieties in a field trial that is a climate analogue site for future predicted drought conditions. Little is known regarding the impact of climate change induced abiotic stresses on the nutritional quality of common beans. Our analysis of nutritional and antinutritional compounds reveals that iron levels in common bean grains are reduced under future climate-scenario relevant drought stress conditions. In contrast, the levels of protein, zinc, lead and phytic acid increase in the beans under such drought stress conditions. This indicates that under climate-change induced drought scenarios, future bean servings by 2050 will likely have lower nutritional quality, posing challenges for ongoing climate-proofing of bean production for yields, nutritional quality, human health, and food security.

Sensory and cultural acceptability tradeoffs with nutritional content of biofortified orangefleshed sweetpotato varieties among households with children in Malawi
Hummel, Marijke ; Talsma, Elise F. ; Honing, Ati van der; Gama, Arthur Chibwana ; Vugt, Daniel van; Brouwer, Inge D. ; Spillane, Charles - \ 2018
PLoS ONE 13 (2018)10. - ISSN 1932-6203 - 19 p.

Background Biofortified orange-fleshed sweetpotato (OFSP) varieties are being promoted to reduce vitamin A deficiencies due to their higher beta-carotene content. For OFSP varieties to have impact they need to be accepted and consumed at scale amongst populations suffering from vitamin A deficiencies. Objective We investigated the sensory and cultural acceptability of OFSP varieties amongst households with children aged between 2-5 years old in two areas in Central and Southern Malawi using an integrated model of the Theory of Planned Behavior (TPB) and the Health Belief Model (HBM). Methods Sensory acceptability was measured using a triangle, preference and acceptance test using three OFSP varieties and one control variety, among 270 adults and 60 children. Based on a food ethnographic study, a questionnaire on cultural acceptability was developed and administered to 302 caretakers. Data were analyzed by calculating Spearman's correlations between constructs and multiple linear regression modeling. Results The sensory evaluation indicates that all three OFSP varieties are accepted (scores > 3 on 5-point scale), but there is a preference for the control variety over the three OFSP varieties. Almost all caretakers are intending to frequently prepare OFSP for their child in future (97%). Based on regression analysis, the constructs 'subjective norms' (β = 0.25, p = 0.00) reflecting social pressure, and 'attitudes toward behavior' (β = 0.14 p = 0.01), reflecting the feelings towards serving their child OFSP, were the best predictors for caretakers' behavior to prepare OFSP for their child. Conclusions Our study shows that both sensory and cultural attributes can influence acceptability of varieties and consumption amongst households with children. Considering these attributes can improve the impact of biofortified crops in future programming, by reducing Vitamin A deficiencies through the intake of these nutrient-rich crops.

Marine and coastal ecosystem services on the science-policy-practice nexus : Challenges and opportunities from 11 European case studies
Drakou, Evangelia G. ; Kermagoret, Charlène ; Liquete, Camino ; Ruiz-Frau, Ana ; Burkhard, Kremena ; Lillebø, Ana I. ; Oudenhoven, Alexander P.E. van; Ballé-Béganton, Johanna ; Rodrigues, João Garcia ; Nieminen, Emmi ; Oinonen, Soile ; Ziemba, Alex ; Gissi, Elena ; Depellegrin, Daniel ; Veidemane, Kristina ; Ruskule, Anda ; Delangue, Justine ; Böhnke-Henrichs, Anne ; Boon, Arjen ; Wenning, Richard ; Martino, Simone ; Hasler, Berit ; Termansen, Mette ; Rockel, Mark ; Hummel, Herman ; Serafy, Ghada El; Peev, Plamen - \ 2017
International Journal of Biodiversity Science, Ecosystem Services & Management 13 (2017)3. - ISSN 2151-3732 - p. 51 - 67.
Bottom-up approach - Data gaps - Ocean literacy - Pan-European approach - Policy relevance - Uncertainty
We compared and contrasted 11 European case studies to identify challenges and opportunities toward the operationalization of marine and coastal ecosystem service (MCES) assessments in Europe. This work is the output of a panel convened by the Marine Working Group of the Ecosystem Services Partnership in September 2016. The MCES assessments were used to (1) address multiple policy objectives simultaneously, (2) interpret EU-wide policies to smaller scales and (3) inform local decision-making. Most of the studies did inform decision makers, but only in a few cases, the outputs were applied or informed decision-making. Significant limitations among the 11 assessments were the absence of shared understanding of the ES concept, data and knowledge gaps, difficulties in accounting for marine social-ecological systems complexity and partial stakeholder involvement. The findings of the expert panel call for continuous involvement of MCES ‘end users’, integrated knowledge on marine social-ecological systems, defining thresholds to MCES use and raising awareness to the general public. Such improvements at the intersection of science, policy and practice are essential starting points toward building a stronger science foundation supporting management of European marine ecosystems.
Habituation and adaptation to odors in humans
Pellegrino, R. ; Sinding, C. ; Wijk, R.A. de; Hummel, T. - \ 2017
Physiology and Behavior 177 (2017). - ISSN 0031-9384 - p. 13 - 19.
Adaptation - Desensitization - Human - Neuroscience - Olfaction - Smell

Habituation, or decreased behavioral response, to odors is created by repeated exposure and several detailed characteristics, whereas adaptation relates to the neural processes that constitute this decrease in a behavioral response. As with all senses, the olfactory system continually encounters an enormous variety of odorants which is why mechanisms must exist to segment them and respond to changes. Although most olfactory habitation studies have focused on animal models, this non-systematic review provides an overview of olfactory habituation and adaptation in humans, and techniques that have been used to measure them. Thus far, psychophysics in combination with modern techniques of neural measurement indicate that habituation to odors, or decrease of intensity, is relatively fast with adaptation occurring more quickly at higher cerebral processes than peripheral adaptation. Similarly, it has been demonstrated that many of the characteristics of habitation apply to human olfaction; yet, evidence for some characteristics such as potentiation of habituation or habituation of dishabituation need more support. Additionally, standard experimental designs should be used to minimize variance across studies, and more research is needed to define peripheral-cerebral feedback loops involved in decreased responsiveness to environmental stimuli.

SNV's modes of ordering : Organizing tourism as development practice
Hummel, John ; Duim, Rene van der - \ 2016
Tourism Management 57 (2016). - ISSN 0261-5177 - p. 312 - 322.
Actor-network theory - Aidnography - Development - Modes of ordering - SNV Netherlands Development Organisation

This article adopts an aidnographic approach to examine how internal organizational modes of ordering have influenced tourism development practices of SNV Netherlands Development Organisation (SNV). Our research revealed six modes of ordering: administration, project management, enterprising, development brokering, development visioning and result management. In each period the organization was involved with tourism a particular mix of modes of ordering prevailed. This mix influenced how SNV evolved from an organization implementing own-managed tourism projects, to facilitating capacity building in multi-stakeholder approaches to finally developing complex inclusive destination development projects. We conclude that SNV only could remain relevant because of these multi-discursive modes of ordering.

Time-course of trigeminal versus olfactory stimulation : Evidence from chemosensory evoked potentials
Flohr, E.L.R. ; Boesveldt, Sanne ; Haehner, Antje ; Iannilli, Emilia ; Sinding, Charlotte ; Hummel, Thomas - \ 2015
International Journal of Psychophysiology 95 (2015)3. - ISSN 0167-8760 - p. 388 - 394.
Chemosensory event-related potentials - Habituation - Olfaction - Trigeminal stimulation

Habituation of responses to chemosensory signals has been explored in many ways. Strong habituation and adaptation processes can be observed at the various levels of processing. For example, with repeated exposure, amplitudes of chemosensory event-related potentials (ERP) decrease over time. However, long-term habituation has not been investigated so far and investigations of differences in habituation between trigeminal and olfactory ERPs are very rare. The present study investigated habituation over a period of approximately 80. min for two olfactory and one trigeminal stimulus, respectively. Habituation was examined analyzing the N1 and P2 amplitudes and latencies of chemosensory ERPs and intensity ratings. It was shown that amplitudes of both components - and intensity ratings - decreased from the first to the last block. Concerning ERP latencies no effects of habituation were seen. Amplitudes of trigeminal ERPs diminished faster than amplitudes of olfactory ERPs, indicating that the habituation of trigeminal ERPs is stronger than habituation of olfactory ERPs. Amplitudes of trigeminal ERPs were generally higher than amplitudes of olfactory ERPs, as it has been shown in various studies before. The results reflect relatively selective central changes in response to chemosensory stimuli over time.

Fuzzy temporal logic, flexible methods for interaction analysis
IJsselmuiden, Joris - \ 2015
Journal of Ambient Intelligence and Smart Environments 7 (2015)3. - ISSN 1876-1364 - p. 391 - 392.
fuzzy metric temporal logic - group behavior - Interaction analysis - situation graph trees

On July 17 2014 in Karlsruhe Germany, Joris IJsselmuiden successfully defended his PhD thesis entitled "Interaction analysis in smart work environments through fuzzy temporal logic" [1]. The examination committee consisted of Rainer Stiefelhagen, Jürgen Beyerer, Michael Beigl, Dorothea Wagner, Oliver Hummel, and Peter H. Schmitt (Fig. 1). The main publications associated with this PhD thesis are [2-9].

The rise and fall of tourism for poverty reduction within SNV Netherlands Development Organisation
Hummel, J.A. - \ 2015
Wageningen University. Promotor(en): Rene van der Duim, co-promotor(en): Jaap Lengkeek. - Wageningen : Wageningen University - ISBN 9789462574939 - 206
toerisme - ontwikkeling van toerisme - ontwikkelingsstudies - tourism - tourism development - development studies

Although development organizations have been involved in tourism for poverty reduction for more than 30 years, their role remains contested. In my study, I examined the rise and fall of tourism within SNV Netherlands Development Organisation in the period 1993–2013. Here, I show how and why tourism as a development tool was introduced within SNV, how it was conceptualized and implemented as development practice, how the organization’s internal ‘ways of working’ influenced this implementation and why SNV recently phased out tourism.

Only a few researches have studied tourism development practices in development organizations. To study on these development practices, I used notions that are of importance at the intersection of tourism studies, development studies and organization studies. As such, this thesis contributes to ‘aidnography’, an ethnographic approach to study institutions, organizations and people involved in international development. Aidnography often includes notions of the actor-oriented and actor-network theory approaches.

Based on my research I conclude that tourism emerged as a tool for poverty reduction in SNV when development paradigms changed to an alternative/sustainable development paradigm in the 1990s, providing possibilities for tourism to be introduced as an element of integrated rural development. A few enterprising SNV directors started tourism initiatives.

The development discourses of SNV and the Netherlands Ministry of Foreign Affairs have always been closely related, reflecting and influencing international development debates. Around the turn of the millennium, SNV changed its main development concepts, emphasizing capacity development. In the second half of the 2000s, partnerships for development became more important. Tourism in SNV was enabled by and followed these paradigm shifts.

In line with these shifts, SNV changed its tourism development approaches and tools. In this thesis I discerned six phases. In the first years tourism was an element in sustainable rural development projects, especially in relation to local participatory planning. A few years later, the tourism practice focused more on capacity development, using multi-stakeholder approaches. Finally, in the years before phasing out, private sector engagement and support, and value chain analysis and development, became dominant approaches.

The way tourism was organized and implemented in the organization, was strongly related to the way SNV changed its internal organization over the years. Combinations of six organizational modes of ordering created possibilities for organizational change, which kept SNV relevant as a development organization and consequently influenced the tourism development practice.

The way SNV measured its results changed in every phase, and consequently its definition of development success changed in every phase. SNV needed periods of conceptual and material stability to get its result frameworks in place. Within SNV, and in development aid in general, ideas about what needed to be measured changed; changes occurred in the way development results had to be measured and documented, by whom and when. Therefore, impact was not measured thoroughly in the various phases.

In early 2011, tourism as a development sector was rather suddenly phased out by SNV. The organization concluded that tourism had not demonstrated its development impact convincingly and had limited donor funding potential, and that not enough expertise was available within SNV in comparison to other development sectors. It also seemed that tourism as a development sector in SNV did not have a strong internal or external lobby. Due to announced budget cuts for the end of 2010 by a new coalition government in the Netherlands, SNV decided to immediately focus only on its most prominent development sectors, namely agriculture, water and sanitation, and renewable energy. Tourism and other development sectors were phased out.

However, tourism as a development sector remains relevant wherever poverty persists in existing or potential tourism destinations. It is a growing sector in several developing countries. Tourism can propel innovative local development and provides opportunities for ethnic minority groups and remoter communities. An inclusive destination development approach is proposed, combining an enabling policy environment with strategic marketing and product development, capacity development, local enterprise development, and impact measurement on the ground. To support these multi-stakeholder development processes, a facilitating organization is often required to act as a catalyst.

If no local organizations are readily available to take the facilitating role, development organizations can support tourism for poverty reduction through three interrelated roles: facilitating, linking and networking; capacity development of local organizations and in local contexts; and knowledge development, innovating and sharing;. It is suggested that development organizations focus on innovative solutions and on time and space for experimenting and situated learning from the start of new development initiatives, and use tourism for poverty reduction to pull local social and economic development, demanding more dynamic pathways for inclusive and sustainable growth at the local level.

As tourism for poverty reduction is a composite and complex cross-cutting development sector, development impacts are difficult to measure and demonstrate. To improve impact assessments, the focus might need to be broadened beyond employment and income to include the multiple impacts (based on direct, indirect and dynamic effects) of tourism for poverty reduction in destinations. The focus could be on multi-stakeholder capacity development situations, with more emphasis on local learning. There seems a need for more case studies and impact narratives in tourism for development. Continued analysis and comparison of case studies will enhance situated learning and increase understanding of tourism in development and poverty reduction.

Proteomic LC-MS analysis of Arabidopsis cytosolic ribosomes: Identification of ribosomal protein paralogs and re-annotation of the ribosomal protein genes
Hummel, M. ; Dobrenel, T. ; Cordewener, J.H.G. ; Davanture, M. ; Meyer, C. ; Smeekens, J.C.M. ; Bailey-Serres, J. ; America, A.H.P. ; Hanson, J. - \ 2015
Journal of Proteomics 128 (2015). - ISSN 1874-3919 - p. 436 - 449.
Arabidopsis thaliana cytosolic ribosomes are large complexes containing eighty-one distinct ribosomal proteins (r-proteins), four ribosomal RNAs (rRNA) and a plethora of associated (non-ribosomal) proteins. In plants, r-proteins of cytosolic ribosomes are each encoded by two to seven different expressed and similar genes, forming an r-protein family. Distinctions in the r-protein coding sequences of gene family members are a source of variation between ribosomes. We performed proteomic investigation of actively translating cytosolic ribosomes purified using both immunopurification and a classical sucrose cushion centrifugation-based protocol from plants of different developmental stages. Both 1D and 2D LC-MSE with data-independent acquisition as well as conventional data-dependent MS/MS procedures were applied. This approach provided detailed identification of 165 r-protein paralogs with high coverage based on proteotypic peptides. The detected r-proteins were the products of the majority (68%) of the 242 cytosolic r-proteins genes encoded by the genome. A total of 70 distinct r-proteins were identified. Based on these results and information from DNA microarray and ribosome footprint profiling studies a re-annotation of Arabidopsis r-proteins and genes is proposed. This compendium of the cytosolic r-protein proteome will serve as a template for future investigations on the dynamic structure and function of plant ribosomes.
Comparison of PCBs and PAHs levels in European coastal waters using mussels from the Mytilus edulis complex as biomonitors
Olenycz, M. ; Sokolowski, A. ; Niewinska, A. ; Wolowicz, M. ; Namiesnik, J. ; Hummel, H. ; Jansen, J.M. - \ 2015
Oceanologia = Oceanology 57 (2015). - ISSN 0078-3234 - p. 196 - 211.
polycyclic-aromatic-hydrocarbons - polychlorinated biphenyl congeners - chromatography mass-spectrometry - toxic equivalency factors - baltic sea - blue mussels - seasonal-variations - gas-chromatography - organic pollutants - marine-environment
Mussels from the Mytilus edulis complex were used as biomonitors for two groups of organic pollutants: polychlorinated biphenyls (PCBs, congeners: 28, 52, 101, 118, 138, 153 and 180) and polycyclic aromatic hydrocarbons (PAHs, naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenz(a,h)anthracene, benzo(g,h,i)perylene) at 17 sampling sites to assess their relative bioavailabilities in coastal waters around Europe. Because of the temporal differences in PCBs and PAHs concentrations, data were adjusted using Seasonal Variation Coefficients (SVC) before making large-scale spatial comparisons. The highest concentrations of PCBs were found near estuaries of large rivers flowing through urban areas and industrial regions. Elevated bioavailabilities of PAHs occurred in the vicinity of large harbors, urban areas, and regions affected by petroleum pollution as well as in some remote locations, which indicated long-range atmospheric deposition.
Oral texture influences the neural processing of ortho- and retronasal odors in humans
Iannilli, E. ; Bult, J.H.F. ; Roudnitzky, N. ; Gerber, J. ; Wijk, R.A. de; Hummel, T. - \ 2014
Brain Research 1587 (2014). - ISSN 0006-8993 - p. 77 - 87.
taste interactions - human brain - sensory integration - olfactory function - fat preference - auditory cues - perception - stimulation - representation - responses
Eating implies mutual interactions between different senses. In the present work we aimed at studying relations between food texture and food odor, using both psychophysical and imaging techniques. Eighteen right-handed healthy human subjects participated to both behavioral and fMRI sessions. Fresh, sweetened milk and a more thickened version were delivered orally; in addition, a buttery-cream aroma was presented ortho- or retronasally. Stimuli were applied using a gustometer and or an air-dilution olfactometer, both computer-controlled. In each session subjects rated separately odor-, taste- and thickness intensities of the stimuli. The behavioral data show that odors, presented through either retro- or orthonasal path, induce a significant flavor enhancement with respect to the no-odor condition. Brain functional data indicated a significant enhancement of the activation of olfactory eloquent areas in favor of ortho-nasal odor presentation while activations of mechanosensory areas were favored by the retro-nasal odor route. As effect of oral stimuli we found a significant correlation between the texture intensity rating vs. the BOLD signal in the supplementary motor area, known to drive subconsciously primed movement, putatively associated in this case with the tongue movement required with the handling of the stimulus. Moreover, we found inhibition of the signal in different sensory specific areas as an effect of the mutual interaction between stimulus qualities. In conclusion, ortho- and retronasal odors differentially affect the neural processing of the texture of oral stimuli.
Evolution of tourism approaches for poverty reduction impact in SNV Asia: Cases from Lao PDR, Bhutan and Vietnam
Hummel, J.A. ; Gujadhur, T. ; Ritsma, N. - \ 2013
Asia Pacific Journal of Tourism Research 18 (2013)4. - ISSN 1094-1665 - p. 369 - 384.
Development agencies are facing a growing demand to demonstrate larger impacts on poverty, which has resulted in a questioning of tourism as an effective intervention strategy. Tourism has been employed as an agent of economic development, job creation, and environmental and cultural conservation. However, critics have cited a dearth of evidence of tourism's contribution to poverty reduction. SNV Asia responded to this impetus in the last decade. The article provides a review of approaches to reach more development impact. Cases from Lao PDR, Bhutan and Vietnam show how SNV's way of working changed. It demonstrates how SNV involved the private sector, and how the organization adjusted its impact measurement systems. However, assessing development impact remained challenging. SNV decided to focus on select sectors that showed most development impact, and phases out from tourism. The article proposes not to move away, but find pragmatic approaches to increase tourism benefits for communities.
Dynamic protein composition of Arabidopsis thaliana cytosolic ribosomes in response to sucrose feeding as revealed by label free MSE proteomics
Hummel, M. ; Cordewener, J.H.G.C. ; Groot, J.C.M. de; Smeekens, S. ; America, A.H.P. ; Hanson, J. - \ 2012
Proteomics 12 (2012)7. - ISSN 1615-9853 - p. 1024 - 1038.
messenger-rna translation - mass-spectrometric analysis - data-independent analysis - leaf adaxial identity - gene-expression - extraribosomal functions - 80s ribosome - eukaryotic ribosome - oxygen deprivation - subunit
Cytosolic ribosomes are among the largest multisubunit cellular complexes. Arabidopsis thaliana ribosomes consist of 79 different ribosomal proteins (r-proteins) that each are encoded by two to six (paralogous) genes. It is unknown whether the paralogs are incorporated into the ribosome and whether the relative incorporation of r-protein paralogs varies in response to environmental cues. Immunopurified ribosomes were isolated from A. thaliana rosette leaves fed with sucrose. Trypsin digested samples were analyzed by qTOF-LC-MS using both MSE and classical MS/MS. Peptide features obtained by using these two methods were identified using MASCOT and Proteinlynx Global Server searching the theoretical sequences of A. thaliana proteins. The A. thaliana genome encodes 237 r-proteins and 69% of these were identified with proteotypic peptides for most of the identified proteins. These r-proteins were identified with average protein sequence coverage of 32% observed by MSE. Interestingly, the analysis shows that the abundance of r-protein paralogs in the ribosome changes in response to sucrose feeding. This is particularly evident for paralogous RPS3aA, RPS5A, RPL8B, and RACK1 proteins. These results show that protein synthesis in the A. thaliana cytosol involves a heterogeneous ribosomal population. The implications of these findings in the regulation of translation are discussed.
Tourism and development at work: 15 years of tourism and poverty reduction within the SNV Netherlands Development Organisation
Hummel, J.A. ; Duim, V.R. van der - \ 2012
Journal of Sustainable Tourism 20 (2012)3. - ISSN 0966-9582 - p. 319 - 338.
Over the last 20 years, international development agencies like SNV Netherlands Development Organisation have hesitantly become involved in tourism. This paper explains the complex and rarely researched political and technical issues behind the working practices, drivers and beliefs of an aid agency seeking to alleviate poverty via tourism development. Based on insiders’ commentaries and documentary sources, it presents five phases of the conceptual and material ordering of tourism within SNV. The phases took SNV from opposition to tourism work, through Community-Based Tourism (CBT), expansion, links to Millennium Development Goals, working in partnership with the private sector and an overall increasing need to deliver defined short term results – to closure. It explains how and why tourism became an important part of development work and how changing policy discourses and practices of international and national organisations influence the way tourism is practised as part of development work. It shows that SNV itself stimulated strong international debates about tourism and development. It concludes that relations between tourism and development remain highly contested and require the continual production of “success”. SNV is now gradually closing its poverty reduction through tourism work. The paper reflects on lessons that might be learned from the SNV story
Short and mid-long term effects of cockle-dredging on non-target macrobenthic species: a before-after-control-impact experiment on a tidal mudflat in the Oosterschelde (The Netherlands)
Wijnhoven, S. ; Escaravage, V. ; Herman, P.M.J. ; Smaal, A.C. ; Hummel, H. - \ 2011
Marine Ecology 32 (2011). - ISSN 0173-9565 - p. 117 - 129.
wadden sea - zoobenthic community - physical disturbance - benthic communities - estuary - fauna - recruitment - predation - nutrients - habitats
To study the possible environmental impact of hydraulic cockle-dredging on macrobenthic communities and the environment, a fishing experiment was executed on a tidal mudflat in the Oosterschelde (SW Netherlands) according to a BACI (before-after-control-impact) design. Following the characterization of the initial situation, a part of the mudflat was commercially fished, after which dredged and undredged areas were compared on the basis of macrofauna descriptors and sediment constitution approximately 2 months (short term) and 1 year (mid-long term) after fishing. Whereas a clear reduction of the larger Cerastoderma edule cockles (>23 mm) in the fished areas was found, no effect of dredging on total macrofauna densities or median grain size was observed. No negative effect of fishing on total macrofauna biomass was found; in contrast, an increase of the biomass of the non-target species almost compensated for the loss in weight due to the extraction of the larger cockles. No significant effect of dredging on species diversity, richness or evenness was found in the short or mid-long term, these descriptors tending to have increased rather than decreased in the dredged plots after 1 year. The selective fishing for larger cockles reduced the average cockle size, but 1 year after fishing the average size had returned to the initial values in the dredged area. However, compared to the control area, the average size might still be reduced, as the size of the cockles in the control area also increased during the year. Local environmental conditions, with their specific macrobenthic communities, seem to be crucial for the type of effects and the impact of dredging. It is therefore of eminent importance to follow a research design with pre-defined environmental conditions, rather than a comparison of different areas that are open or closed to fisheries. The present study based on a BACI approach indicates that mechanical cockle fisheries had no overall negative impact in our study area.
Gustatory and olfactory dysfunction in older adults: a national probability study
Boesveldt, S. ; Lindau, S.T. ; McClintock, M.K. ; Hummel, T. ; Lundstrom, J.N. - \ 2011
Rhinology 49 (2011)3. - ISSN 0300-0729 - p. 324 - 330.
odor identification - depressive symptoms - anorexia-nervosa - smell perception - united-states - taste - prevalence - disease - population - impairment
BACKGROUND: Olfactory and gustatory functions have not been well characterized in older adults in the US. Consequently, their relationships to sociodemographic characteristics, as well as physical and mental health, were studied in a large national probability sample using brief validated tests of chemosensory function. METHODS: A five-odour identification test and taste-impregnated strips of filter paper (sweet, sour, bitter, and salty) assessed the ability to identify chemosensory stimuli. RESULTS: Severe gustatory dysfunction was more prevalent than severe olfactory dysfunction. Age, education and sex were independently associated with performance on both the olfactory and gustatory identification tasks. Higher scores were associated with female sex, higher level of education, and lower age. Odour identification scores exhibited a positive, albeit weak, correlation with BMI, and food-related odours were better identified than non-food odours. In addition, odour identification performance was also negatively associated with depressive symptoms. CONCLUSIONS: These data demonstrate a high prevalence of severe gustatory and, to a somewhat lesser extent, olfactory dysfunction in a population-based sample and demonstrate that even brief tests are capable of detecting correlations between both chemical senses and relevant health measures outside a clinical setting.
Investigation of interactions between texture and ortho- and retronasal olfactory stimuli using psychophysical and electrophysiological approaches
Roudnitzky, N. ; Bult, J.H.F. ; Wijk, R.A. de; Reden, J. ; Schuster, B. ; Hummel, T. - \ 2011
Behavioural Brain Research 216 (2011)1. - ISSN 0166-4328 - p. 109 - 115.
flavor perception - response alternatives - odor identification - swallowing process - release - mouth - taste - discrimination - integration - potentials
Flavor is a result of the complex combination of olfactory, gustatory and trigeminal sensations perceived during oral processing of foods, including thermal, painful, tactile and/or kinesthetic effects. Aim of this study was to better understand interactions between synchronous tactile (texture) and olfactory (odor) sensations, using a psychophysical and an electrophysiological approach. Texture stimuli were aliquots of lean milk and thickened lean milk. A butter aroma was presented either orthonasally or retronasally after oral processing and before swallowing the oral stimulus or in the absence of an oral stimulus. Eighteen subjects (11 women, 7 men, mean age 24 years), naïve to the expected effects, rated both odor and texture intensity of each stimulus. Event-related potentials (ERP) were obtained from five recording positions. For the psychophysical data, the presence of an oral stimulus increased odor intensity, irrespective of odor presentation route. For the electrophysiological data, both early and late chemosensory ERPs were affected by odor conditions, texture conditions, and their respective interaction. In conclusion: (1) perceptual interactions occurred between food texture and odor, with cross-modal interactions being found for both orthonasal and retronasal odor administration, and (2) these interactions between texture and odor occur at both primary-sensory and cognitive evaluative levels of stimulus processing. The temporal dimension plays then a critical role in the investigation of odor–texture interactions.
From OpenMI 1.4 to 2.0
Gijsbers, P. ; Hummel, S. ; Vanechek, S. ; Groos, J. ; Harper, A. ; Knapen, M. ; Gregersen, J. ; Schade, P. ; Antonello, A. ; Donchyts, G. - \ 2010
In: Modelling for Environment's Sake. - - p. 1081 - 1088.
Integrated modelling - Linking - Model interoperability - Open Modelling Interface
The Open Modelling Interface (OpenMI) was launched end of 2005 with the aim to become a global standard for linking models and tools in the environmental domain with focus on water. Over the past few years, the user and development community has grown substantially and various well known models have become compliant. Some of the uses did not adopt the OpenMI.Standard interfaces completely, but used a slight deviation to achieve their goal in a similar style. Improvements would be necessary to become a true global interface standard instead of a style for developing new model codes. Starting in 2007, a core group of six institutes has worked on an upgrade of the OpenMI towards version 2.0. A long list of deficiencies was composed, having a few use cases as general guidance for improvement. The proposed redesign, based on similar leading concepts and a similar data model, required however a non-backward compatible upgrade of the interface standard to remove the weak points from the first version. This decision allowed the OpenMI to become more suitable for a larger range of applications, from non-time dependent Geographical Information Systems (GIS) towards e.g. master-slave controlled modelling frameworks. The OpenMI 2.0 standard has been open for review early 2010. Once completed and processed, the release of OpenMI 2.0, in both C# and Java is expected late 2010. This paper will discuss the reasons for change in more detail and highlights how the proposed solution meets the needs in a better way.
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