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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    Data from: Crop pests and predators exhibit inconsistent responses to surrounding landscape composition
    Karp, Daniel S. ; Chaplin-Kramer, Rebecca ; Meehan, Timothy D. ; Martin, Emily A. ; DeClerck, Fabrice ; Grab, Heather ; Gratton, Claudio ; Hunt, Lauren ; Larsen, Ashley E. ; Martínez-Salinas, Alejandra ; Bianchi, F.J.J.A. ; Werf, W. van der - \ 2018
    University of California
    agroecology - biological control - natural enemies - pest control - pest - ecosystem services - landscape
    The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.
    Crop pests and predators exhibit inconsistent responses to surrounding landscape composition
    Karp, Daniel S. ; Chaplin-Kramer, Rebecca ; Meehan, Timothy D. ; Martin, Emily A. ; Declerck, Fabrice ; Grab, Heather ; Gratton, Claudio ; Hunt, Lauren ; Larsen, Ashley E. ; Martínez-Salinas, Alejandra ; O’Rourke, Megan E. ; Rusch, Adrien ; Poveda, Katja ; Jonsson, Mattias ; Rosenheim, Jay A. ; Schellhorn, Nancy A. ; Tscharntke, Teja ; Wratten, Stephen D. ; Zhang, Wei ; Iverson, Aaron L. ; Adler, Lynn S. ; Albrecht, Matthias ; Alignier, Audrey ; Angelella, Gina M. ; Zubair Anjum, Muhammad ; Avelino, Jacques ; Batáry, Péter ; Baveco, Johannes M. ; Bianchi, Felix J.J.A. ; Birkhofer, Klaus ; Bohnenblust, Eric W. ; Bommarco, Riccardo ; Brewer, Michael J. ; Caballero-López, Berta ; Carrière, Yves ; Carvalheiro, Luísa G. ; Cayuela, Luis ; Centrella, Mary ; Ćetković, Aleksandar ; Henri, Dominic Charles ; Chabert, Ariane ; Costamagna, Alejandro C. ; La Mora, Aldo De; Kraker, Joop De; Desneux, Nicolas ; Diehl, Eva ; Diekötter, Tim ; Dormann, Carsten F. ; Eckberg, James O. ; Entling, Martin H. ; Fiedler, Daniela ; Franck, Pierre ; Veen, F.J.F. van; Frank, Thomas ; Gagic, Vesna ; Garratt, Michael P.D. ; Getachew, Awraris ; Gonthier, David J. ; Goodell, Peter B. ; Graziosi, Ignazio ; Groves, Russell L. ; Gurr, Geoff M. ; Hajian-Forooshani, Zachary ; Heimpel, George E. ; Herrmann, John D. ; Huseth, Anders S. ; Inclán, Diego J. ; Ingrao, Adam J. ; Iv, Phirun ; Jacot, Katja ; Johnson, Gregg A. ; Jones, Laura ; Kaiser, Marina ; Kaser, Joe M. ; Keasar, Tamar ; Kim, Tania N. ; Kishinevsky, Miriam ; Landis, Douglas A. ; Lavandero, Blas ; Lavigne, Claire ; Ralec, Anne Le; Lemessa, Debissa ; Letourneau, Deborah K. ; Liere, Heidi ; Lu, Yanhui ; Lubin, Yael ; Luttermoser, Tim ; Maas, Bea ; Mace, Kevi ; Madeira, Filipe ; Mader, Viktoria ; Cortesero, Anne Marie ; Marini, Lorenzo ; Martinez, Eliana ; Martinson, Holly M. ; Menozzi, Philippe ; Mitchell, Matthew G.E. ; Miyashita, Tadashi ; Molina, Gonzalo A.R. ; Molina-Montenegro, Marco A. ; O’Neal, Matthew E. ; Opatovsky, Itai ; Ortiz-Martinez, Sebaastian ; Nash, Michael ; Östman, Örjan ; Ouin, Annie ; Pak, Damie ; Paredes, Daniel ; Parsa, Soroush ; Parry, Hazel ; Perez-Alvarez, Ricardo ; Perović, David J. ; Peterson, Julie A. ; Petit, Sandrine ; Philpott, Stacy M. ; Plantegenest, Manuel ; Plećaš, Milan ; Pluess, Therese ; Pons, Xavier ; Potts, Simon G. ; Pywell, Richard F. ; Ragsdale, David W. ; Rand, Tatyana A. ; Raymond, Lucie ; Ricci, Benoît ; Sargent, Chris ; Sarthou, Jean-Pierre ; Saulais, Julia ; Schäckermann, Jessica ; Schmidt, Nick P. ; Schneider, Gudrun ; Schüepp, Christof ; Sivakoff, Frances S. ; Smith, Henrik G. ; Stack Whitney, Kaitlin ; Stutz, Sonja ; Szendrei, Zsofia ; Takada, Mayura B. ; Taki, Hisatomo ; Tamburini, Giovanni ; Thomson, Linda J. ; Tricault, Yann ; Tsafack, Noelline ; Tschumi, Matthias ; Valantin-Morison, Muriel ; Trinh, Mai Van; Werf, Wopke Van Der; Vierling, Kerri T. ; Werling, Ben P. ; Wickens, Jennifer B. ; Wickens, Victoria J. ; Woodcock, Ben A. ; Wyckhuys, Kris ; Xiao, Haijun ; Yasuda, Mika ; Yoshioka, Akira - \ 2018
    Proceedings of the National Academy of Sciences of the United States of America 115 (2018)33. - ISSN 0027-8424 - p. E7863 - E7870.
    IPM
    The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.
    Maximizing farm-level uptake and diffusion of biological control innovations in today’s digital era
    Wyckhuys, Kris A.G. ; Bentley, Jeff W. ; Lie, Rico ; Nghiem, Le Thi Phuong ; Fredrix, Marjon - \ 2018
    BioControl 63 (2018)1. - ISSN 1386-6141 - p. 133 - 148.
    Conservation biological control - Crop protection - Ecological intensification - Information diffusion - IPM - Rural sociology - Socio-ecological systems
    When anthropologists interviewed Honduran and Nepali smallholders in the mid-1990s, they were told that “Insects are a terrible mistake in God’s creation” and “There’s nothing that kills them, except for insecticides”. Even growers who maintained a close bond with nature were either entirely unaware of natural pest control, or expressed doubt about the actual value of these services on their farm. Farmers’ knowledge, beliefs and attitudes towards pests and natural enemies are of paramount importance to the practice of biological control, but are all too often disregarded. In this study, we conduct a retrospective analysis of the extent to which social science facets have been incorporated into biological control research over the past 25 years. Next, we critically examine various biological control forms, concepts and technologies using a ‘diffusion of innovations’ framework, and identify elements that hamper their diffusion and farm-level uptake. Lastly, we introduce effective observation-based learning strategies, such as farmer field schools to promote biological control, and list how those participatory approaches can be further enriched with information and communication technologies (ICT). Although biological control scientists have made substantial technological progress and generate nearly 1000 papers annually, only a fraction (1.4%) of those address social science or technology transfer aspects. To ease obstacles to enhanced farmer learning about biological control, we describe ways to communicate biological control concepts and technologies for four divergent agricultural knowledge systems (as identified within a matrix built around ‘cultural importance’ and ‘ease of observation’). Furthermore, we describe how biological control innovations suffer a number of notable shortcomings that hamper their farm-level adoption and subsequent diffusion, and point at ways to remediate those by tactical communication campaigns or customized, (ICT-based) adult education programs. Amongst others, we outline how video, smart phones, or tablets can be used to convey key ecological concepts and biocontrol technologies, and facilitate social learning. In today’s digital era, cross-disciplinary science and deliberate multi-stakeholder engagement will provide biocontrol advocates the necessary means to bolster farmer adoption rates, counter-act surging insecticide use, and restore public trust in one of nature’s prime services.
    The development of biodiversity conservation measures in China's hydro projects : A review
    Bai, Ruiqiao ; Liu, Xuehua ; Liu, Xiaofei ; Liu, Lanmei ; Wang, Jianping ; Liao, Sihui ; Zhu, Annah ; Li, Zhouyan - \ 2017
    Environment International 108 (2017). - ISSN 0160-4120 - p. 285 - 298.
    Biodiversity conservation - China - Hydropower - Policy - Research

    The hydropower capacity of China ranks first in the world and accounts for approximately 20% of the total energy production in the country. While hydropower has substantially contributed to meeting China's renewable energy targets and providing clean energy to rural areas, the development of hydropower in China has been met with significant controversy. Ecologically, hydro projects alter the landscape, with potential impacts to the country's aquatic biodiversity. Over the past four decades in China, various mainstream opinions and misunderstandings have been presented concerning how to alleviate the negative impacts of hydro projects on aquatic ecosystems. This article reviews research concerning potential mitigation measures to enhance aquatic biodiversity conservation in hydro projects in China. Based on the academic attention such research has attracted, three technical measures for aquatic biodiversity conservation are considered: (1) fish passages, (2) restocking efforts and (3) river and lake renovations. This article provides a historical comparison of these three practices in China to demonstrate the advantages and disadvantages of each method. The article also reviews the relevant legislation, regulations and technical guidelines concerning China's hydro projects dating back to 1979. The dynamics in research, publications, and patents concerning these three mitigation measures are summarized to demonstrate their technological developments in the context of legislative and policy advances. Data were gathered through the China Knowledge Resource Integrated Database and the State Intellectual Property Office of the People's Republic of China. Based on the analysis provided, the article recommends an expansion of China's environmental certification system for hydro projects, more robust regional legislation to bolster the national framework, the cooperation between upstream and downstream conservation mechanisms, and better monitoring to determine the efficacy of mitigation measures.

    Toward a Sustainable Future Earth : Challenges for a Research Agenda
    Lahsen, Myanna - \ 2016
    Science, technology and human values 41 (2016)5. - ISSN 0162-2439 - p. 876 - 898.
    Belmont Forum - climate change - environmental research - Future Earth - global environmental change - International Council for Science - science policy - social transformation - sustainability - sustainability science

    Future Earth is an evolving international research program and platform for engagement aiming to support transitions toward sustainability. This article discusses processes that led to Future Earth, highlighting its intellectual emergence. I describe how Future Earth has increased space for contributions from the social sciences and humanities despite powerful, long-standing preferences for bio-geophysical research in global environmental research communities. I argue that such preferences nevertheless are deeply embedded in scientific institutions that continue to shape environmental science agendas and, as such, constitute a formidable obstacle that needs to be recognized and countered to bolster efforts at effective societal transformation in the face of sustainability challenges. The analysis draws on two decades of observant participation in environmental research communities in the United States, Europe, Brazil, and elsewhere, including participation in the visioning process that led to Future Earth.

    Data from: Origins of food crops connect countries worldwide
    Khoury, C.K. ; Achicanoy, Harold A. ; Bjorkman, Anne D. ; Navarro-Racines, Carlos ; Guarino, Luigi ; Flores-Palacios, Ximena ; Engels, Johannes M.M. ; Wiersema, John H. ; Dempewolf, Hannes ; Sotelo, Steven ; Ramírez-Villegas, Julian ; Castañeda-Álvarez, Nora P. ; Fowler, Cary ; Jarvis, Andy ; Rieseberg, Loren H. ; Struik, P.C. - \ 2016
    Wageningen University & Research
    food security - crop diversity - crop origins - plant genetic resources - crop domestication - crop improvement
    Research into the origins of food plants has led to the recognition that specific geographical regions around the world have been of particular importance to the development of agricultural crops. Yet the relative contributions of these different regions in the context of current food systems have not been quantified. Here we determine the origins (‘primary regions of diversity’) of the crops comprising the food supplies and agricultural production of countries worldwide. We estimate the degree to which countries use crops from regions of diversity other than their own (‘foreign crops’), and quantify changes in this usage over the past 50 years. Countries are highly interconnected with regard to primary regions of diversity of the crops they cultivate and/or consume. Foreign crops are extensively used in food supplies (68.7% of national food supplies as a global mean are derived from foreign crops) and production systems (69.3% of crops grown are foreign). Foreign crop usage has increased significantly over the past 50 years, including in countries with high indigenous crop diversity. The results provide a novel perspective on the ongoing globalization of food systems worldwide, and bolster evidence for the importance of international collaboration on genetic resource conservation and exchange.
    Origins of food crops connect countries worldwide
    Khoury, Colin K. ; Achicanoy, Harold A. ; Bjorkman, Anne D. ; Navarro-Racines, Carlos ; Guarino, Luigi ; Flores-Palacios, Ximena ; Engels, Johannes M.M. ; Wiersema, John H. ; Dempewolf, Hannes ; Sotelo, Steven ; Ramírez-Villegas, Julian ; Castañeda-Álvarez, Nora P. ; Fowler, Cary ; Jarvis, Andy ; Rieseberg, Loren H. ; Struik, Paul C. - \ 2016
    Proceedings of the Royal Society. B: Biological Sciences 283 (2016)1832. - ISSN 0962-8452 - 9 p.
    Crop diversity - Crop domestication - Crop improvement - Crop origins - Food security - Plant genetic resources

    Research into the origins of food plants has led to the recognition that specific geographical regions around the world have been of particular importance to the development of agricultural crops. Yet the relative contributions of these different regions in the context of current food systems have not been quantified. Here we determine the origins ('primary regions of diversity') of the crops comprising the food supplies and agricultural production of countries worldwide. We estimate the degree to which countries use crops from regions of diversity other than their own ('foreign crops'), and quantify changes in this usage over the past 50 years. Countries are highly interconnected with regard to primary regions of diversity of the crops they cultivate and/or consume. Foreign crops are extensively used in food supplies (68.7% of national food supplies as a global mean are derived from foreign crops) and production systems (69.3% of crops grown are foreign). Foreign crop usage has increased significantly over the past 50 years, including in countries with high indigenous crop diversity. The results provide a novel perspective on the ongoing globalization of food systems worldwide, and bolster evidence for the importance of international collaboration on genetic resource conservation and exchange.

    Een dubbele kijk op co-creatie
    Bakker, H.C.M. de; Dagevos, H. - \ 2016
    Bestuurskunde 25 (2016)1. - ISSN 0927-3387 - p. 90 - 99.
    This essay review discusses three publications on co-creation: ‘We, the government’ by Davied van Berlo (2012), ‘Co-creation of innovation’ by Corry Ehlen (2015), and ‘New Business Models’ by Jan Jonker et al. (2014). The theme of this essay is the specific character of co-creation compared to other buzzwords (e.g. participation, co-production, social responsibility) that can be heard in the search for a new balance between the state and civil society. We suggest that the distinctive character of co-creation lies in the active engagement of parties who work together to co-create. Co-creation means raising the bar of collaboration and dialogue. Openness, trust, equality and reciprocity are emphasised as essential elements in the process. It is literally about collectively creating multiple values in which there should be plenty of room for creativity and sharing ideas. Following on the publications of Ehlen and Jonker a dual vision on co-creation arises. In general terms, the potential of co-creation depends on the know-how, commitment and values of the actors involved (microscopic perspective) and on the social capital in the wider environment that they can draw upon to bolster the co-creation process (macroscopic perspective).
    Future agriculture with minimized phosphorus losses to waters : Research needs and direction
    Sharpley, Andrew N. ; Bergström, Lars ; Aronsson, Helena ; Bechmann, Marianne ; Bolster, Carl H. ; Börling, Katarina ; Djodjic, Faruk ; Jarvie, Helen P. ; Schoumans, Oscar F. ; Stamm, Christian ; Tonderski, Karin S. ; Ulén, Barbro ; Uusitalo, Risto ; Withers, Paul J.A. - \ 2015
    Ambio 44 (2015)Supplement 2. - ISSN 0044-7447 - p. 163 - 179.
    Implementation - Manure - Mitigation measures - Monitoring - P management - Transport pathways
    The series of papers in this issue of AMBIO represent technical presentations made at the 7th International Phosphorus Workshop (IPW7), held in September, 2013 in Uppsala, Sweden. At that meeting, the 150 delegates were involved in round table discussions on major, predetermined themes facing the management of agricultural phosphorus (P) for optimum production goals with minimal water quality impairment. The six themes were (1) P management in a changing world; (2) transport pathways of P from soil to water; (3) monitoring, modeling, and communication; (4) importance of manure and agricultural production systems for P management; (5) identification of appropriate mitigation measures for reduction of P loss; and (6) implementation of mitigation strategies to reduce P loss. This paper details the major challenges and research needs that were identified for each theme and identifies a future roadmap for catchment management that cost-effectively minimizes P loss from agricultural activities.
    Tracking the mutual shaping of the technical and social dimensions of solar-powered mosquito trapping systems (SMoTS) for malaria control on Rusinga Island, western Kenya
    Oria, P.A. ; Hiscox, A.F. ; Alaii, J. ; Ayugi, M. ; Mukabana, W.R. ; Takken, W. ; Leeuwis, C. - \ 2014
    Parasites & Vectors 7 (2014). - ISSN 1756-3305
    infectious-disease control - oral rehydration therapy - public-health - community - policy
    Background There has been increasing effort in recent years to incorporate user needs in technology design and re-design. This project employed a bottom-up approach that engaged end users from the outset. Bottom-up approaches have the potential to bolster novel interventions and move them towards adaptive and evidence-based strategies. The present study concerns an innovative use of solar-powered mosquito trapping systems (SMoTS) to control malaria in western Kenya. Our paper highlights the co-dependence of research associated with the development of the SMoTS technology on one hand and research for enhancing the sustainable uptake of that very same intervention within the community on the other. Methods During the pre-intervention year, we examined the design, re-design and piloting of a novel technology to generate lessons for malaria elimination on Rusinga Island. Initial ideas about many technological necessities were evaluated and re-designed following feedback from various sources, including technical and social research as well as broader interactions with the social environment. We documented the interlocking of the multiple processes and activities that took place through process observation and document reviews. We analysed the data within the conceptual framework of system innovation by identifying mutual shaping between technical and social factors. Results Our findings illustrate how various project stakeholders including project staff, collaborators, donor, and community members simultaneously pursued interdependent technological transformations and social interests. In the ongoing process, we observed how partial outcomes in the technological domain influenced social events at a later phase and vice versa. Conclusions Looking at malaria intervention projects employing novel technologies as niches that may evolve towards system innovation, helps to reveal interrelations between the various technical and social aspects. Revealing these interrelations requires a different role for research and different perspective on innovation where innovation is more than the technical aspects. This approach therefore requires that research is designed in a way that enables obtaining feedback from both aspects. Keywords: Malaria; Co-evolution; Socio-technical; System innovation; Solar; Mosquito trap; Feedback; Community; Kenya
    Kokosvezelplaten als duurzaam bouwmateriaal
    Dam, J.E.G. van - \ 2010
    bouwmaterialen - bouwplaten - kokosvezel - eigenschappen - economische haalbaarheid - biobased economy - biomaterialen - productieprocessen - building materials - wallboard - coir - properties - economic viability - biobased economy - biomaterials - production processes
    Het is mogelijk plaatmateriaal te produceren dat voor 100% bestaat uit kokosvezels afkomstig van de bolster van de kokosnoot. Het plaatmateriaal heeft uitstekende sterkte eigenschappen. Voor het aantonen van de technische- en economische haalbaarheid is op de Filippijnen een vezelplaatproductie unit op pilot schaal gebouwd. De mogelijkheden voor opschaling en industriële productie worden momenteel door verschillende kokosproducerende landen onderzocht waaronder India, Indonesië, Filippijnen, Suriname en Mozambique.
    The current capacity for training in public health nutrition in West Africa
    Pepping, F. - \ 2010
    Global Public Health 5 (2010)S1. - ISSN 1744-1692 - p. S20 - S41.
    This article is based on a paper prepared for the Workshop on Establishing a Regional Institute for Public Health Nutrition Research and Training in West Africa, convened in Dakar, Senegal, 26-28 March, 2009. Information was gathered mainly prior to this workshop; several responses, however, came in after the workshop and these have been included in the current paper. In completion of the article use was made of the views and opinions as expressed during this workshop. Objectives were to provide background information on academic programmes (undergraduate and graduate) and research institutions with a focus on human nutrition in West Africa, to describe the importance of foreign nutrition training programmes for West African students and to detail existing nutrition training activities currently in the region. Data were obtained from a survey of 15 UNICEF country offices in the West African region, previously published reports, United Nations University/International Union of Nutrition Sciences capacity development activities 1996-2009, personal communications and websites of relevant African institutions. Results indicate that West African nutrition academic programmes and research institutes do not adequately meet the demand for nutritionists and technical services in the region. Exceptions seem to be Bnin, Ghana and Nigeria. Diploma courses and other short courses have been an important means of attracting people from a variety of disciplines to nutrition. A well-equipped regional institute could directly and indirectly bolster nutrition capacity in the region. To meet the regional nutrition research and training needs in West Africa, it is not necessary to make a choice between creating a new regional institution vs. expanding existing national institutions. Based on solid capacity development principles, both options need action
    `And then I'm really like . . .': `preliminary' self-quotations in adolescent talk
    Lamerichs, J.M.W.J. ; Molder, H.F.M. te - \ 2009
    Discourse Studies 11 (2009)4. - ISSN 1461-4456 - p. 401 - 419.
    extreme case formulations - reported speech - conversation
    This article explores the discursive uses of a self-quotation in adolescent talk. The self-quotation uses the quotative marker be + like to convey or project bold statements as part of a larger narrative. We will demonstrate how the preface leading up to the self-quotation is designed as hard to counter, and instructs the hearer how to understand what comes next. The self-quotation, on the other hand, constitutes the assessment as a `mere characterization' that provides the speaker with a number of opportunities for testing the proposed view. Speakers are thus able to bolster potentially controversial views against refutation while also giving them a preliminary status. These features make for an interesting conversational resource that enables speakers and recipients to engage in a collaborative process of putting potentially bold statements to the test. Key Words: adolescent talk ¿ direct reported speech ¿ discursive psychology ¿ self-quotations
    Ambergris fragrance compounds from labdanolic acid and larixol
    Bolster, M.G. - \ 2002
    Wageningen University. Promotor(en): Æ. de Groot; B.J.M. Jansen. - S.l. : S.n. - ISBN 9789058086662 - 214
    diterpenen - welriekendheid - aromatische verbindingen - biosynthese - chemische eigenschappen - oxidatie - biologische eigenschappen - diterpenes - fragrance - aromatic compounds - biosynthesis - chemical properties - oxidation - biological properties

    Since ancient times, ambergris has been one of the most highly valued perfumery materials. Ambergris is a metabolic product of the spermwhale ( Physeter macrocephalus L.), which accumulates as concretions in the gut. (-)-AmbroxÒ, the commercially most important constituent of natural ambergris, is recognized as the prototype of all ambergris odorants. For this reason, various synthetic routes to (-)-AmbroxÒand its racemate have been developed, preferrably starting from cheap, abundantly available natural labdanes. Sclareol is nowadays the industrially used starting material for the preparation of (-)-AmbroxÒ. Labdanolic acid and larixol are both easily and abundantly available from labdanum gum of Cistus ladaniferus L. ("Rock-rose") and turpentine of the Larix decidua , respectively, but have found little use as starting material in syntheses of Ambergris odour compounds. In this thesis new chemistry in that field is described.

    From the acetate of labdanolic acid short procedures are developed for the synthesis of AmbroxÒ. Also a standard method has been developed for the oxidation of the side chain of several labdanes. Generally good to high yields of single products can be obtained using anhydrous potassium permanganate in the presence of a phase-transfer catalyst. In this way larixol can be converted into suitable synthons for the synthesis of several Ambrox-like compounds. 6a-hydroxy Ambrox can be considered to be a key intermediate in such syntheses and conversions of larixol into this intermediate are described. From 6a-hydroxy Ambrox a number of simple Ambrox derivatives have been synthesized. By heating with acid a mixture was formed consisting ofD5- andD6-Ambroxene, which both are pleasant smelling.D5-Ambroxene was produced in a more selective way by elimination of methanesulfonic acid from the corresponding mesylate of 6a-hydroxy Ambrox. A selective synthesis ofD6-Ambroxene proved to be more difficult and laborious. Several approaches were investigated, and ultimately the one via ringclosure of an allylic alcohol proved to give good results. It turned out that this new approach could not be extended to the selective synthesis of six-membered cyclic ethers, e.g.D6-Ambra oxides. In the latter case, elimination of the 6b-hydroxyl group to the correspondingD6,8-dienes was observed as the major reaction.

    The synthesis of ambra oxide related compounds starting from (+)-larixol. Part 3
    Bolster, M.G. ; Jansen, B.J.M. ; Groot, A. de - \ 2002
    Tetrahedron 58 (2002). - ISSN 0040-4020 - p. 5275 - 5285.
    Ambergris fragrance compounds from larixol and labdanolic acid
    Bolster, M.G. ; Jansen, B.J.M. ; Groot, A. de - \ 2001
    In: EuroConference Book Of Abstracts : XIX Conference On Isoprenoids, Gdansk-Jurata, Poland, 8-14 September, 2001 - p. 71 - 71.
    The synthesis of Ambrox -like compounds starting from (+)-larixol. Part 2
    Bolster, M.G. ; Lagnel, B.M.F. ; Jansen, B.J.M. ; Morin, C. ; Groot, Æ. de - \ 2001
    Tetrahedron 57 (2001). - ISSN 0040-4020 - p. 8369 - 8379.
    The synthesis of (-)-ambrox starting from labdanolic acid
    Bolster, M.G. ; Jansen, B.J.M. ; Groot, Æ. de - \ 2001
    Tetrahedron 57 (2001). - ISSN 0040-4020 - p. 5657 - 5662.
    The synthesis of Ambrox-like compounds starting from (+)-larixol
    Bolster, M.G. ; Jansen, B.J.M. ; Groot, Æ. de - \ 2001
    Tetrahedron 57 (2001). - ISSN 0040-4020 - p. 5663 - 5679.
    Labdanes as starting material in organic synthesis
    Bolster, M.G. ; Jansen, B.J.M. ; Groot, C.P.G.M. de - \ 2000
    In: IUPAC Book of Abstracts : 13th International Conference On Organic Synthesis, Warsaw, Poland, July 1-5, 2000 - p. 132 - 132.
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