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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    The landscape setting of bog bodies: Interdisciplinary research into the site location of Yde Girl, The Netherlands
    Beek, R. van; Candel, J.H.J. ; Quik, C. ; Bos, J.A.A. ; Gouw-Bouman, M.T.I.J. ; Makaske, A. ; Maas, G.J. - \ 2019
    Holocene 29 (2019)7. - ISSN 0959-6836 - p. 1206 - 1222.
    Past studies of archaeological bog finds, such as bog bodies, wooden trackways and a wide variety of other materials, are characterized by a strong focus on material culture. Their original environmental and cultural context has received far less attention. This paper centres on the original landscape setting of bog bodies. Interdisciplinary reconstructions of the physical and cultural landscape at the time of deposition can lead to significant new and more detailed insights into the context and meaning of this remarkable phenomenon. We aim to show the value of such interdisciplinary research by reconstructing the original physical and cultural landscape setting of the most iconic bog body of The Netherlands: Yde Girl. This approximately 16-year-old girl was killed about 2000 years ago and deposited in a bog south of the modern-day village of Yde (province of Drenthe). Our interdisciplinary research team used a combination of research methods from physical geography, geomorphology, palynology and archaeology to analyse both the site itself and its wider environment. This kind of integrated, detailed landscape research on bog bodies has hardly been done yet. We expect that our research design, methodology and results may also be applied in future research of other bog bodies. Furthermore, they may inspire research on other types of archaeological find categories from peatlands.
    Holocene drift-sand activity in the Netherlands
    Pierik, Harm J. ; Lanen, Rowin J. van; Gouw-Bouman, Marjolein T.I.J. ; Groenewoudt, Bert J. ; Wallinga, J. ; Hoek, Wim Z. - \ 2018
    Utrecht University
    drift sand activity - stuifzandvoorkomen
    This dataset contains a new national overview of the occurrence of drift sand activity in the Netherlands from ca. 5000 BC to AD 1700. The dataset has been compiled from overview studies, field studies and new data.
    Controls on late-Holocene drift-sand dynamics : The dominant role of human pressure in the Netherlands
    Pierik, Harm J. ; Lanen, Rowin J. van; Gouw-Bouman, Marjolein T.I.J. ; Groenewoudt, Bert J. ; Wallinga, Jakob ; Hoek, Wim Z. - \ 2018
    Holocene 28 (2018)9. - ISSN 0959-6836 - p. 1361 - 1381.
    chronology - climate - drift-sand activity - Holocene - human impact - vegetation development

    Holocene drift-sand activity in the northwest European sand belt is commonly directly linked to population pressure (agricultural activity) or to climate change (e.g. storminess). In the Pleistocene sand areas of the Netherlands, small-scale Holocene drift-sand activity began in the Mesolithic, whereas large-scale sand drifting started during the Middle Ages. This last phase not only coincides with the intensification of farming and demographic pressure but also is commonly associated with a colder climate and enhanced storminess. This raises the question to what extent drift-sand activity can be attributed to either human activities or natural forcing factors. In this study, we compare the spatial and temporal patterns of drift-sand occurrence for the four characteristic Pleistocene sand regions in the Netherlands for the period between 1000 BC and AD 1700. To this end, we compiled a new supra-regional overview of drift-sand activity based on age estimates (14C, optically stimulated luminescence (OSL), archaeological and historical ages). The occurrence of sand drifting was then compared in time and space with historical-route networks, relative vegetation openness and climate. Results indicate a constant but low drift-sand activity between 1000 BC and AD 1000, interrupted by a remarkable decrease in activity around the BC/AD transition. It is evident that human pressure on the landscape was most influential on initiating sand drifting: this is supported by more frequent occurrences close to routes and the uninterrupted increase of drift-sand activity from AD 900 onwards, a period of high population density and large-scale deforestation. Once triggered by human activities, this drift-sand development was probably further intensified several centuries later during the cold and stormier ‘Little Ice Age’ (LIA; AD 1570–1850).

    Virtuele varkens als proefkonijn in gedragsonderzoek
    Boumans, Iris - \ 2017

    Virtuele varkens kunnen een bijdrage leveren aan de huidige varkenshouderij om zowel economisch rendabel te produceren als het dierenwelzijn te bevorderen. Dat blijkt uit het promotieonderzoek van Iris Bouman. Zij promoveerde begin september aan de Wageningen Universiteit.

    Nijkerk en Wageningen samen gezond : Monitor JOGG Scholenproject
    Bouman, Mariëtte ; Vaandrager, L. - \ 2016
    Wageningen : Wageningen University & Research - 110
    Nijkerk en Wageningen geven als Jongeren Op Gezond Gewicht (JOGG) gemeenten een impuls aan het stimuleren van een gezonde leefstijl en het tegengaan van overgewicht onder kinderen en jongeren. Begin 2015 hebben zij door de provincie Gelderland een subsidie toegekend gekregen voor een gezamenlijk deelproject op scholen: ‘Nijkerk en Wageningen Samen Gezond’. Binnen dit scholenproject zijn in beide gemeenten op scholen gezonde leefstijlactiviteiten georganiseerd. Beide gemeenten hebben binnen het project hun eigen benadering met ieder hun specifieke kansrijke elementen en moeilijkheden, welke in kaart moeten worden gebracht. Voor het monitoren en evalueren van het scholenproject Nijkerk en Wageningen Samen Gezond is de leerstoelgroep Gezondheid en Maatschappij van de Wageningen Universiteit gevraagd een plan te ontwikkelen en uit te voeren.

    Dit onderzoek duidt erop dat de aanpak van het scholenproject niet los kan worden gezien van de bredere JOGG aanpak in de gemeenten. Als het gaat om een gezonde leefstijl, kunnen specifiek op het gebied van gezond voedingsgedrag onder leerlingen en ouders nog stappen worden gezet. Dit onderzoek laat zien dat scholen en leerlingen het positief ontvangen wanneer een organisatie van buitenaf zoals een buurtsportcoachteam uiteenlopende gezonde leefstijlactiviteiten aanbiedt. Buurtsportcoaches kunnen expertise en nieuwe invalshoeken de klas binnen brengen. De inbedding van een gezonde leefstijl in het schoolbeleid en het betrekken van ouders zijn aandachtspunten voor het borgen van de blijvende aandacht voor gezond opgroeien.
    The complete picture: combining palynological, cultural and landscape data to reconstruct palaeovegetation patterns
    Beek, Roy van; Gouw-Bouman, M.T.I.J. ; Bos, J.A.A. ; Pierik, H.J. - \ 2016
    A taxonomy-based approach to shed light on the babel of mathematical models for rice simulation
    Confalonieri, Roberto ; Bregaglio, Simone ; Adam, Myriam ; Ruget, Françoise ; Li, Tao ; Hasegawa, Toshihiro ; Yin, Xinyou ; Zhu, Yan ; Boote, Kenneth ; Buis, Samuel ; Fumoto, Tamon ; Gaydon, Donald ; Lafarge, Tanguy ; Marcaida, Manuel ; Nakagawa, Hiroshi ; Ruane, Alex C. ; Singh, Balwinder ; Singh, Upendra ; Tang, Liang ; Tao, Fulu ; Fugice, Job ; Yoshida, Hiroe ; Zhang, Zhao ; Wilson, Lloyd T. ; Baker, Jeff ; Yang, Yubin ; Masutomi, Yuji ; Wallach, Daniel ; Acutis, Marco ; Bouman, Bas - \ 2016
    Environmental Modelling & Software 85 (2016). - ISSN 1364-8152 - p. 332 - 341.
    Model classification - Model ensemble - Model parameterisation - Model structure - Rice - Uncertainty

    For most biophysical domains, differences in model structures are seldom quantified. Here, we used a taxonomy-based approach to characterise thirteen rice models. Classification keys and binary attributes for each key were identified, and models were categorised into five clusters using a binary similarity measure and the unweighted pair-group method with arithmetic mean. Principal component analysis was performed on model outputs at four sites. Results indicated that (i) differences in structure often resulted in similar predictions and (ii) similar structures can lead to large differences in model outputs. User subjectivity during calibration may have hidden expected relationships between model structure and behaviour. This explanation, if confirmed, highlights the need for shared protocols to reduce the degrees of freedom during calibration, and to limit, in turn, the risk that user subjectivity influences model performance.

    Particle morphology development during spray drying studied by a sessile droplet drying approach
    Both, E.M. ; Bouman, J. ; Venema, P. ; Boom, R.M. ; Schutyser, M.A.I. - \ 2016
    Hole and vacuole formation during drying of sessile whey protein droplets
    Bouman, Jacob ; Venema, Paul ; Vries, Renko J. de; Linden, Erik van der; Schutyser, Maarten A.I. - \ 2016
    Food Research International 84 (2016). - ISSN 0963-9969 - p. 128 - 135.
    Droplet drying - Dynamics - Morphology - Process conditions - Protein solution

    Morphological development from droplet to particle during drying has strong influence on powder structure and functionality. We study the evolving morphological properties of whey protein droplets during single sessile droplet drying experiments as a well-defined model for spray drying. Sessile drying droplets were visualised with a camera and subjected to varying drying conditions such as temperature, initial protein concentration, presence of airflow and droplet rotation. The final particles were imaged by SEM and X-ray tomography. Under all conditions used, the droplets initially shrink steadily while at a specific point a hole nucleates. Subsequently, a vacuole develops until a rigid hollow particle is obtained. The location of the hole was found strongly dependent on the presence and the direction of the applied air flow. We hypothesise that in the early drying stage a skin forms, which becomes more rigid when the hole nucleates. The hole forms at the position where the local modulus of the skin layer is minimal and/or at the point below the skin where the local pressure is minimal, and that after the hole has nucleated, the vacuole develops mainly by evaporation of water through the hole.

    Controlled Release from Zein Matrices : Interplay of Drug Hydrophobicity and pH
    Bouman, Jacob ; Belton, Peter ; Venema, Paul ; Linden, Erik Van Der; Vries, Renko De; Qi, Sheng - \ 2016
    Pharmaceutical Research 33 (2016)3. - ISSN 0724-8741 - p. 673 - 685.
    controlled release - diffusion mechanism - dissolution kinetics modelling - extrusion-injection moulding - Zein

    Purpose: In earlier studies, the corn protein zein is found to be suitable as a sustained release agent, yet the range of drugs for which zein has been studied remains small. Here, zein is used as a sole excipient for drugs differing in hydrophobicity and isoelectric point: indomethacin, paracetamol and ranitidine. Methods: Caplets were prepared by hot-melt extrusion (HME) and injection moulding (IM). Each of the three model drugs were tested on two drug loadings in various dissolution media. The physical state of the drug, microstructure and hydration behaviour were investigated to build up understanding for the release behaviour from a zein based matrix for drug delivery. Results: Drug crystallinity of the caplets increases with drug hydrophobicity. For ranitidine and indomethacin, swelling rates, swelling capacity and release rates were pH dependent as a consequence of the presence of charged groups on the drug molecules. Both hydration rates and release rates could be approached by existing models. Conclusion: The drug state and pH dependant electrostatic interactions are hypothesised to influence release kinetics. Both factors can potentially be used to influence release kinetics release, thereby broadening the horizon for zein as a tuneable release agent.

    Voorbij de ziek(t)e: belangrijke naasten over het samen leven met diabetes - uitdagingen voor de zorgverlening
    Bouman, Mariëtte ; Engels, J. - \ 2015
    Creating Drug Solubilization Compartments via Phase Separation in Multicomponent Buccal Patches Prepared by Direct Hot Melt Extrusion-Injection Molding
    Alhijjaj, Muqdad ; Bouman, Jacob ; Wellner, Nikolaus ; Belton, Peter ; Qi, Sheng - \ 2015
    Molecular Pharmaceutics 12 (2015)12. - ISSN 1543-8384 - p. 4349 - 4362.
    buccal - hot melt extrusion - injection molding - solid dispersions - X-ray micro-CT

    Creating in situ phase separation in solid dispersion based formulations to allow enhanced functionality of the dosage form, such as improving dissolution of poorly soluble model drug as well as being mucoadhesive, can significantly maximize the in vitro and in vivo performance of the dosage form. This formulation strategy can benefit a wide range of solid dosage forms for oral and alternative routes of delivery. This study using buccal patches as an example created separated phases in situ of the buccal patches by selecting the excipients with different miscibility with each other and the model drug. The quaternary dispersion based buccal patches containing PEG, PEO, Tween 80, and felodipine were prepared by direct hot melt extrusion-injection molding (HME-IM). The partial miscibility between Tween 80 and semicrystalline PEG-PEO led to the phase separation after extrusion. The Tween phases acted as drug solubilization compartments, and the PEG-PEO phase had the primary function of providing mucoadhesion and carrier controlled dissolution. As felodipine was preferably solubilized in the amorphous regions of PEG-PEO, the high crystallinity of PEG-PEO resulted in an overall low drug solubilizing capacity. Tween 80 was added to improve the solubilization capacity of the system as the model drug showed good solubility in Tween. Increasing the drug loading led to the supersaturation of drug in Tween compartments and crystalline drug dispersed in PEG-PEO phases. The spatial distribution of these phase-separated compartments was mapped using X-ray micro-CT, which revealed that the domain size and heterogeneity of the phase separation increased with increasing the drug loading. The outcome of this study provides new insights into the applicability of in situ formed phase separation as a formulation strategy for the delivery of poorly soluble drugs and demonstrated the basic principle of excipient selection for such technology.

    Effects of a single glucocorticoid injection on propylene glycol-treated cows with clinical ketosis
    Drift, S.G.A. van der; Houweling, M. ; Bouman, Marina ; Koets, A.P. ; Tielens, A.G.M. ; Nielen, M. ; Jorritsma, R. - \ 2015
    The Veterinary Journal 204 (2015)2. - ISSN 1090-0233 - p. 144 - 149.
    This study investigated the metabolic effects of glucocorticoids when administered to propylene glycol-treated cows with clinical ketosis. Clinical ketosis was defined by depressed feed intake and milk production, and a maximal score for acetoacetate in urine. All cows received 250 mL oral propylene glycol twice daily for 3 days and were randomly assigned to a single intramuscular injection with sterile isotonic saline solution (n = 14) or dexamethasone-21-isonicotinate (n = 17). Metabolic blood variables were monitored for 6 days and adipose tissue variables for 3 days. β-Hydroxybutyrate (BHBA) concentrations in blood decreased in all cows during treatment, but were lower in glucocorticoid-treated cows. Cows treated with glucocorticoids had higher plasma glucose and insulin concentrations, whereas concentrations of non-esterified fatty acids, 3-methylhistidine and growth hormone were unaffected. mRNA expression of hormone-sensitive lipase, BHBA receptor and peroxisome proliferator-activated receptor type γ in adipose tissue was not affected. This shows that lipolytic effects do not appear to be important in ketotic cows when glucocorticoids are combined with PG. Plasma 3-methyl histidine concentrations were similar in both groups, suggesting that glucocorticoids did not increase muscle breakdown and that the greater rise in plasma glucose in glucocorticoid-treated cows may not be due to increased supply of glucogenic amino acids from muscle.
    Drying and hydration of proteins at high concentration
    Bouman, J. - \ 2015
    Wageningen University. Promotor(en): Erik van der Linden, co-promotor(en): Renko de Vries. - Wageningen : Wageningen University - ISBN 9789462575509 - 161
    eiwit - wei-eiwit - zeïne - drogen - droogmethoden - geneesmiddeltoedieningssystemen - hydratatie - hydrofobiciteit - ph - vacuolen - protein - whey protein - zein - drying - drying methods - drug delivery systems - hydration - hydrophobicity - ph - vacuoles

    Proteins are the building blocks of life and serve a wide range of essential functions in organisms. Many metabolic reactions in organisms are catalysed by enzymes, DNA is replicated by proteins and in cells proteins often facilitate active transport of e.g. glucose or ions. Proteins also serve an essential functionality in foods, pharmaceutics, bioplastics and even clothing. Recently, the use of proteins towards higher concentrations is of interest for food, pharmaceutical and medical applications. Nevertheless, the preparation of products with desired product properties can be challenging, when approaching higher protein concentrations. Therefore, in this thesis we investigate proteins at higher concentrations, especially focussing on their drying and hydration behaviour.

    In part one of the thesis, the focus is on the dynamics of drying of proteins towards higher concentrations. Dense proteins systems have been scarcely studied compared to proteins at lower concentrations. We address drying behaviour where we focus on the use of whey protein isolate as a model system. In part two of the thesis we focus on the hydration properties of the corn protein zein, where we apply it as a drug excipient. In this part we also investigate the influence of hydration on the release behaviour of drugs into the hydration media.

    The drying part (part one) contains two studies. The first study is more fundamental in nature, focussing on the drying of a protein coating. In previous studies mainly the macroscopic properties of protein coatings after drying are investigated, leaving the drying dynamics virtually unexplored. Here we investigate the drying behaviour of the model protein β-lactoglobulin on multiple length scales with an unique combination of in-line techniques. On the microscopic length scale we use dynamic vapour sorption and magnetic resonance imaging while on a smaller length scales, we apply diffusing wave spectroscopy and IR-spectroscopy to monitor the drying process. For all used techniques, the changes in the measured physical properties of the coating as a function of water weight fraction Xw from Xw = 0.8 down to Xw = 0.2 are gradual. However, using dynamic vapour sorption and IR-spectroscopy we measure a sharp change below water weight fractions of Xw = 0.2. We hypothesise that changes in the molecular interactions caused by dehydration of the protein results in a change in the drying kinetics of the film.

    In the second study of part one, protein drying is approached on a more applied level, where we study the drying of a spherical droplet. We use single droplet drying as a methods that can model the spray drying process in a simplified and well-controlled way. Sessile droplets are subjected to varying drying conditions such as temperature, initial protein concentration, presence of airflow and droplet rotation. During these experiments the morphological development is monitored by a camera. After drying, scanning electron microscopy and X-ray tomography are used to examine the particles that are formed after complete drying. Irrespective of the conditions used, we observe an initial droplet shrinkage, followed by the nucleation of a hole in the droplet skin, which is followed by the formation of a vacuole. The drying conditions used, strongly influenced the location of the hole and the locking point prior to hole formation. We hypothesise that the location of the hole is caused by local inhomogeneities in protein concentration causing a the nucleation of the hole where the local skin modulus is lowest. Also the locking point of the droplet is found to be due to a inhomogeneity over the whole droplet caused by rapid evaporation. These results can be of importance to understand powder structure and functionality as obtained in spray drying.

    In the hydration part (part 2), we investigate the potential of zein as a sole excipient in macroscale caplets obtained by hot melt extrusion (HME) and injection moulding (IM). Zein is good candidate as a sustained release agent, because it is insoluble in two studies. In the first study zein matrices were loaded with the drug paracetamol. Physical mixtures of zein, water and crystalline paracetamol are extruded and injection moulded into caplets. Characterisation of these caplets is performed using differential scanning calorimetry, IR- spectroscopy, scanning electron microscopy and powder X-ray diffraction. The hydration and drug release kinetics from the caplet slices is measured. We find that the drug release kinetics is broadly independent of the dissolution medium and drug loading. The release kinetics is diffusion limited and could be well described by a 2D diffusion model. The results demonstrate that the drug release rate from zein caplet slices can be tuned by its dimensions.

    In the second study, a wider range of drugs differing in hydrophobicity is studied. Next to paracetamol, we have used two other model drugs: the hydrophobic indomethacin and the more hydrophilic ranitidine. The zein matrix is capable to stabilize the different dugs in a non-crystalline state, which is promising especially for increasing the bioavailability of poorly water-soluble drugs. Overall crystallinity of the drugs in the caplets increases with its degree of hydrophobicity. For the poorly soluble indomethacin, dissolution rates at low pH were higher from caplet slices, compared to the dissolution rates of indomethacin crystals by themselves. In addition, we found that the electrostatic interactions between zein and drugs can also be used to influence the release kinetics.

    Various aspects were found to be of importance both for drying and hydration of concentrated protein systems. The homogeneity during both processes deserves attention as its manipulation can strongly influence final properties if the system. Also the plasticising effect of water on dense proteins is often found essential, when understanding the dynamics of both drying and hydration processes. Finally protein hydrophobicity and its manipulation can provide a window of opportunities in many applications which are involve by drying or hydration.

    A statistical analysis of three ensembles of crop model responses to temperature and CO2 concentration
    Makowski, D. ; Asseng, S. ; Ewert, F. ; Bassu, S. ; Durand, J.L. ; Li, G. ; Martre, P. ; Adam, M.Y.O. ; Aggarwal, P.K. ; Angulo, C. ; Baron, C. ; Basso, B. ; Bertuzzi, P. ; Biernath, C. ; Boogaard, H.L. ; Boote, K.J. ; Bouman, B. ; Bregaglio, S. ; Brisson, N. ; Buis, S. ; Cammarano, D. ; Challinor, A.J. ; Confalonieri, R. ; Conijn, J.G. ; Corbeels, M. ; Deryng, D. ; Sanctis, G. De; Doltra, J. ; Fumoto, T. ; Gayler, S. ; Gaydon, D. ; Goldberg, R. ; Grant, R.F. ; Grassini, P. ; Hatfield, J.L. ; Hasegawa, T. ; Heng, L. ; Hoek, S.B. ; Hooker, J. ; Hunt, L.A. ; Ingwersen, J. ; Izaurralde, C. ; Jongschaap, R.E.E. ; Jones, J.W. ; Kemanian, R.A. ; Kersebaum, K.C. ; Kim, S.H. ; Lizaso, J. ; Marcaida III, M. ; Müller, C. ; Nakagawa, H. ; Naresh Kumar, S. ; Nendel, C. ; O'Leary, G.J. ; Olesen, J.E. ; Oriol, P. ; Osborne, T.M. ; Palosuo, T. ; Pravia, M.V. ; Priesack, E. ; Ripoche, D. ; Rosenzweig, C. ; Ruane, A.C. ; Ruget, F. ; Sau, F. ; Semenov, M.A. ; Shcherbak, I. ; Singh, B. ; Soo, A.K. ; Steduto, P. ; Stöckle, C.O. ; Stratonovitch, P. ; Streck, T. ; Supit, I. ; Tang, L. ; Tao, F. ; Teixeira, E. ; Thorburn, P. ; Timlin, D. ; Travasso, M. ; Rötter, R.P. ; Waha, K. ; Wallach, D. ; White, J.W. ; Wilkens, P. ; Williams, J.R. ; Wolf, J. ; Ying, X. ; Yoshida, H. ; Zhang, Z. ; Zhu, Y. - \ 2015
    Agricultural and Forest Meteorology 214-215 (2015). - ISSN 0168-1923 - p. 483 - 493.
    Ensembles of process-based crop models are increasingly used to simulate crop growth for scenarios of temperature and/or precipitation changes corresponding to different projections of atmospheric CO2 concentrations. This approach generates large datasets with thousands of simulated crop yield data. Such datasets potentially provide new information but it is difficult to summarize them in a useful way due to their structural complexities. An associated issue is that it is not straightforward to compare crops and to interpolate the results to alternative climate scenarios not initially included in the simulation protocols. Here we demonstrate that statistical models based on random-coefficient regressions are able to emulate ensembles of process-based crop models. An important advantage of the proposed statistical models is that they can interpolate between temperature levels and between CO2 concentration levels, and can thus be used to calculate temperature and [CO2] thresholds leading to yield loss or yield gain, without re-running the original complex crop models. Our approach is illustrated with three yield datasets simulated by 19 maize models, 26 wheat models, and 13 rice models. Several statistical models are fitted to these datasets, and are then used to analyze the variability of the yield response to [CO2] and temperature. Based on our results, we show that, for wheat, a [CO2] increase is likely to outweigh the negative effect of a temperature increase of +2°C in the considered sites. Compared to wheat, required levels of [CO2] increase are much higher for maize, and intermediate for rice. For all crops, uncertainties in simulating climate change impacts increase more with temperature than with elevated [CO2].
    The development of direct extrusion-injected moulded zein matrices as novel oral controlled drug delivery systems
    Bouman, J. ; Belton, P. ; Venema, P. ; Linden, E. van der; Vries, R.J. de; Qi, Sheng - \ 2015
    Pharmaceutical Research 32 (2015)8. - ISSN 0724-8741 - p. 2775 - 2786.
    solid-state - diffusion - protein - acetaminophen - paracetamol - release - history - ftir
    Purpose To evaluate the potential of zein as a sole excipient for controlled release formulations prepared by hot melt extrusion. Methods Physical mixtures of zein, water and crystalline paracetamol were hot melt extruded (HME) at 80 degrees C and injection moulded (IM) into caplet forms. HME-IM Caplets were characterised using differential scanning calorimetry, ATR-FTIR spectroscopy, scanning electron microscopy and powder X-ray diffraction. Hydration and drug release kinetics of the caplets were investigated and fitted to a diffusion model. Results For the formulations with lower drug loadings, the drug was found to be in the non-crystalline state, while for the ones with higher drug loadings paracetamol is mostly crystalline. Release was found to be largely independent of drug loading but strongly dependent upon device dimensions, and predominately governed by a Fickian diffusion mechanism, while the hydration kinetics shows the features of Case II diffusion. Conclusions In this study a prototype controlled release caplet formulation using zein as the sole excipient was successfully prepared using direct HME-IM processing. The results demonstrated the unique advantage of the hot melt extruded zein formulations on the tuneability of drug release rate by alternating the device dimensions.
    Uncertainties in predicting rice yield by current crop models under a wide range of climatic conditions
    Li, T. ; Hasegawa, T. ; Yin, X. ; Zhu, Y. ; Boote, K. ; Adam, M. ; Bregaglio, S. ; Buis, S. ; Confalonieri, R. ; Fumoto, T. ; Gaydon, D. ; Marcaida III, M. ; Nakagawa, H. ; Oriol, P. ; Ruane, A.C. ; Ruget, F. ; Singh, B. ; Singh, U. ; Tang, L. ; Yoshida, H. ; Zhang, Z. ; Bouman, B. - \ 2015
    Global Change Biology 21 (2015)3. - ISSN 1354-1013 - p. 1328 - 1341.
    air co2 enrichment - high-temperature stress - elevated co2 - spikelet fertility - night temperature - carbon-dioxide - growth - sterility - face - productivity
    Predicting rice (Oryza sativa) productivity under future climates is important for global food security. Ecophysiological crop models in combination with climate model outputs are commonly used in yield prediction, but uncertainties associated with crop models remain largely unquantified. We evaluated 13 rice models against multi-year experimental yield data at four sites with diverse climatic conditions in Asia and examined whether different modeling approaches on major physiological processes attribute to the uncertainties of prediction to field measured yields and to the uncertainties of sensitivity to changes in temperature and CO2 concentration [CO2]. We also examined whether a use of an ensemble of crop models can reduce the uncertainties. Individual models did not consistently reproduce both experimental and regional yields well, and uncertainty was larger at the warmest and coolest sites. The variation in yield projections was larger among crop models than variation resulting from 16 global climate model-based scenarios. However, the mean of predictions of all crop models reproduced experimental data, with an uncertainty of less than 10% of measured yields. Using an ensemble of eight models calibrated only for phenology or five models calibrated in detail resulted in the uncertainty equivalent to that of the measured yield in well-controlled agronomic field experiments. Sensitivity analysis indicates the necessity to improve the accuracy in predicting both biomass and harvest index in response to increasing [CO2] and temperature.
    Coating formation during drying of ß-lactoglobulin: Gradual and sudden changes
    Bouman, J. ; Vries, R.J. de; Venema, P. ; Belton, P. ; Baukh, V. ; Huinink, H. ; Linden, E. van der - \ 2015
    Biomacromolecules 16 (2015)1. - ISSN 1525-7797 - p. 76 - 86.
    diffusing-wave spectroscopy - concentrated colloidal suspensions - water-vapor sorption - mechanical-properties - film formation - protein films - wheat gluten - hydration - dynamics - solids
    The drying dynamics of protein coatings is of importance for many applications. The main focus of research so far was to investigate macroscopic properties of protein coatings, leaving drying dynamics virtually unexplored. A unique combination of techniques is used to monitor drying of a coating containing the protein ß-lactoglobulin. The techniques used cover both macroscopic and microscopic aspects of the drying process. For all water fractions amenable to diffusing wave spectroscopy analysis (xw > 0.2 w/w), the tracer particles diffuse in the coating as in a Newtonian viscous medium. Magnetic resonance imaging shows both protein and water are distributed homogeneously over the coating during drying, up to water fractions above 0.2 w/w. When drying continues to lower water fractions, sudden transitions in drying behavior are observed by both dynamic vapor sorption and IR spectroscopy, which we suggest are due to changes in molecular interactions caused by dehydration of the protein backbone.
    Dispatch from the field: Ecology of ground-webbuilding spiders with description of a new species (Araneae, Symphytognathidae)
    Miller, Jeremy A. ; Schilthuizen, Menno ; Burmester, Jennie Lilliendahl ; Graaf, Lot van der; Merckx, Vincent ; Jocqué, Merlijn ; Kessler, Paul Joseph Antonius ; Fayle, Tom Maurice ; Breeschoten, Thijmen ; Broeren, Regi ; Bouman, Roderick ; Chua, Wan Ji ; Feijen, Frida ; Fermont, Tanita ; Groen, Kevin ; Groen, Marvin ; Kil, Nicolaas Johannes Cornelis ; Laat, Henrica Allegonda de; Moerland, Michelangelo Sergio ; Moncoquet, Carole ; Panjang, Elisa ; Philip, Amelia Joyce ; Roca-Eriksen, Rebecca ; Rooduijn, Bastiaan ; Santen, Marit van; Swakman, Violet ; Evans, Meaghan N. ; Evans, Luke J. ; Love, Kieran ; Joscelyne, Sarah H. ; Tober, Anya Victoria ; Wilson, Hannah F. ; Ambu, Laurentius N. ; Goossens, Benoit - \ 2014
    Biodiversity Data Journal 2 (2014)1. - ISSN 1314-2828
    Borneo - Crassignatha - Disturbance - Inundation - Oil palm plantation - Riparian forest - Riverine forest - Tropical field course

    Crassignatha danaugirangensis sp. n. (Araneae: Symphytognathidae) was discovered during a tropical ecology field course held at the Danau Girang Field Centre in Sabah, Malaysia. A taxonomic description and accompanying ecological study were completed as course activities. To assess the ecology of this species, which belongs to the ground-webbuilding spider community, three habitat types were surveyed: riparian forest, recently inundated riverine forest, and oil palm plantation. Crassignatha danaugirangensis sp. n. is the most abundant ground-web-building spider species in riparian forest; it is rare or absent from the recently inundated forest and was not found in a nearby oil palm plantation. The availability of this taxonomic description may help facilitate the accumulation of data about this species and the role of inundated riverine forest in shaping invertebrate communities.

    The drying of a single whey protein droplet: vacuole and hole formation
    Bouman, J. ; Venema, P. ; Vries, R.J. de; Linden, E. van der; Schutyser, M.A.I. - \ 2014
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