Metabolic modeling to understand and redesign microbial systems
Heck, Ruben G.A. van - \ 2017
Wageningen University. Promotor(en): V.A.P. Martins dos Santos, co-promotor(en): M. Suárez Diez. - Wageningen : Wageningen University - ISBN 9789463434553 - 239
micro-organismen - modelleren - kooldioxide - biotechnologie - algen - metabolisme - pseudomonas - microorganisms - modeling - carbon dioxide - biotechnology - algae - metabolism - pseudomonas
The goals of this thesis are to increase the understanding of microbial metabolism and to functionally (re-)design microbial systems using Genome- Scale Metabolic models (GSMs). GSMs are species-specific knowledge repositories that can be used to predict metabolic activities for wildtype and genetically modified organisms. Chapter 1 describes the assumptions associated with GSMs, the GSM generation process, common GSM analysis methods, and GSM-driven strain design methods. Thereby, chapter 1 provides a background for all other chapters. In this work, there is a focus on the metabolically versatile bacterium Pseudomonas putida (chapters 2,3,4,5,6), but also other model microbes and biotechnologically or societally relevant microbes are considered (chapters 3,4,6,7,8).
GSMs are reflections of the genome annotation of the corresponding organism. For P. putida, the genome annotation that GSMs have been built on is more than ten years old. In chapter 2, this genome annotation was updated both on a structural and functional level using state-of-the-art annotation tools. A crucial part of the functional annotation relied on the most comprehensive P. putida GSM to date. This GSM was used to identify knowledge gaps in P. putida metabolism by determining the inconsistencies between its growth predictions and experimental measurements. Inconsistencies were found for 120 compounds that could be degraded by P. putida in vitro but not in silico. These compounds formed the basis for a targeted manual annotation process. Ultimately, suitable degradation pathways were identified for 86/120 as part of the functional reannotation of the P. putida genome.
For P. putida there are 3 independently generated GSMs, which is not uncommon for model organisms. These GSMs differ in generation procedure and represent different and complementary subsets of the knowledge on the metabolism of the organism. However, the differing generation procedures also makes it extremely cumbersome to compare their contents, let alone to combine them into a single consensus GSM. Chapter 3 addresses this issue through the introduction of a computational tool for COnsensus Metabolic Model GENeration (COMMGEN). COMMGEN automatically identifies inconsistencies between independently generated GSMs and semi-automatically resolves them. Thereby, it greatly facilitates a detailed comparison of independently generated GSMs as well as the construction of consensus GSMs that more comprehensively describe the knowledge on the modeled organism.
GSMs can predict whether or not the corresponding organism and derived mutants can grow in a large variety of different growth conditions. In comparison, experimental data is extremely limited. For example, BIOLOG data describes growth phenotypes for one strain in a few hundred different media, and genome-wide gene essentially data is typically limited to a single growth medium. In chapter 4 GSMs of multiple Pseudomonas species were used to predict growth phenotypes for all possible single-gene-deletion mutants in all possible minimal growth media to determine conditionally and unconditionally essential genes. This simulated data was integrated with genomic data on 432 sequenced Pseudomonas species, which revealed a clear link between the essentiality of a gene function and the persistence of the gene within the Pseudomonas genus.
Chapters 5 and 6 describe the use of GSMs to (re-)design microbial systems. P. putida is, despite its acknowledged versatile metabolism, an obligate aerobe. As the oxygen-requirement limits the potential applications of P. putida, there have been several experimental attempts to enable it to grow anaerobically, which have so far not succeeded. Chapter 5 describes an in silico effort to determine why P. putida cannot grow anaerobically using a combination of GSM analyses and comparative genomics. These analyses resulted in a shortlist of several essential and oxygen-dependent processes in P. putida. The identification of these processes has enabled the design of P. putida strains that can grow anaerobically based on the current understanding of P. putida metabolism as represented in GSMs.
Efficient microbial CO2 fixation is a requirement for the biobased community, but the natural CO2 fixation pathways are rather inefficient, while the synthetic CO2 fixation pathways have been designed without considering the metabolic context of a target organism. Chapter 6 introduces a computational tool, CO2FIX, that designs species-specific CO2 fixation pathways based on GSMs and biochemical reaction databases. The designed pathways are evaluated for their ATP efficiency, thermodynamic feasibility, and kinetic rates. CO2FIX is applied to eight different organisms, which has led to the identification of both species-specific and general CO2 fixation pathways that have promising features while requiring surprisingly few non-native reactions. Three of these pathways are described in detail.
In all previous chapters GSMs of relatively well-understood microbes have been used to gain further insight into their metabolism and to functionally (re-)design them. For complex microbial systems, such as algae (chapter 7) and gut microbial communities (chapter 8), GSMs are similarly useful, but substantially more difficult to create and analyze. Algae are widely considered as potential centerpieces of a biobased economy. Chapter 7 reviews the current challenges in algal genome annotation, modeling and synthetic biology. The gut microbiota is an incredibly complex microbial system that is crucial to our well-being. Chapter 8 reviews the ongoing developments in the modeling of both single gut microbes and gut microbial communities, and discusses how these developments will enable the move from studying correlation to causation, and ultimately the rational steering of gut microbial activity.
Chapter 9 discusses how the previous chapters contribute to the research goals of this thesis. In addition, it provides an extensive discussion on current GSM practices, the issues associated therewith, and how these issues can be tackled. In particular, the discussion focuses on issues related to: (i) The inability to distinguish between biological difference and GSM generation artifacts when using multiple GSMs, (ii) The lack of continuous GSM updates, (iii) The mismatch between what GSM predictions and experimental data represent, (iv) The need for standardization in GSM evaluation, and (v) The lack of experimental validation of GSM-driven strain design for metabolic engineering.
Kennisagenda biomimicry 2015-2018
Vogelzang, T.A. ; Vader, J. ; Michels, R. - \ 2016
Den Haag : Wageningen Economic Research - 23
biobased economy - ontwerp - innovaties - biomimicry - duurzame ontwikkeling - productontwikkeling - biotechnologie - kennismanagement - gebiedsontwikkeling - organisatieontwikkeling - biobased economy - design - innovations - biomimicry - sustainable development - product development - biotechnology - knowledge management - area development - organizational development
Biomimicry , de ontwerpfilosofie die de natuur als inspiratiebron ziet voor innovaties, kan grote ecologische en economische voordelen opleveren voor onze samenleving wanneer het bre ed wordt ingezet ten behoeve van maatschappelijke en wetenschappelijke vraagstukken. Het biedt ook veel toepassingsmogelijkheden voor een groot aantal sectoren , zoals bouw, industrie en landbouw . Om aan een kennisinfrastructuur voor biomimicry te kunn en werken, is het van belang om te weten welke kennis diverse partijen in ons land in huis hebben, welke ze willen delen en welke kennislacunes er zijn. Deze kennisagenda is met dat doel opgesteld. De kennisagenda agendeert een aantal vraagstukken voor de komende periode waaraan betrokken stakeholders in onderlinge samenwerking gericht kunnen werken om de toepassing van biomimicry in ons land de komende jaren op een hog er plan te brengen. Deze kennisagenda geeft daarmee richting aan biomimicry -innovaties die de komende jaren (wellicht) met voorrang opgepakt worden.
Starch meets biotechnology : in planta modification of starch composition and functionalities
Xu, Xuan - \ 2016
Wageningen University. Promotor(en): Richard Visser, co-promotor(en): Luisa Trindade. - Wageningen : Wageningen University - ISBN 9789462579200 - 169
starch - potato starch - potatoes - solanum tuberosum - plant biotechnology - biotechnology - genetic engineering - transgenic plants - modified starches - phosphate - arabidopsis thaliana - plant breeding - zetmeel - aardappelzetmeel - aardappelen - solanum tuberosum - plantenbiotechnologie - biotechnologie - genetische modificatie - transgene planten - gemodificeerd zetmeel - fosfaat - arabidopsis thaliana - plantenveredeling
Storage starch is an energy reservoir for plants and the major source of calories in the human diet. Starch is used in a broad range of industrial applications, as a cheap, abundant, renewable and biodegradable biopolymer. However, starch needs to be modified before it can fulfill the required properties for specific industrial applications. Genetic modification of starch, as a green technology with environmental and economic advantages, has attracted increasingly attention. Many achievements obtained from earlier studies have demonstrated the feasibility and potential of using this approach to produce starches with novel properties (Chapter 2).
The main objective of this research was to produce novel starches with enhanced functionalities through genetic modification, while gaining a better understanding of storage starch biosynthesis. A focus on potato was warranted as it represents a superior model system for storage starch biosynthesis studies and for the production of starches with novel properties. To this end, a number of enzymes from various sources have been expressed in potato tubers to modify starch phosphate content and polysaccharide structure, since these two characteristics have long been recognized as key features in starch properties.
To modify starch phosphate content and explore starch (de)phosphorylation, a human phosphatase enzyme named laforin, and modifications of it, were introduced into potato (Chapter 3). Interestingly, modified starches exhibited a significantly higher phosphate content rather than the expected lower phosphate content. Transcriptome analysis showed that the increase in phosphate content was a result of upregulation of starch phosphorylating genes, which revealed a compensatory response to the loss of phosphate content in potato starch. Furthermore, the increase of phosphate content in potato starch was reached to a threshold level. This was in line with the observations in the modified starches from overexpressed- Glucan water dikinase (GWD1) transgenic plants (Chapter 4). Furthermore, overexpression of two starch dikinases from Arabidopsis thaliana, glucan water dikinase 2 and 3 (AtGWD2 and AtGWD3), did not result in a significant increase in phosphate content of potato starch (Chapter 5). Taken together, these results indicated that phosphate content of potato starch is under strict control.
Morphological analysis of starch granules containing different levels of phosphate content confirmed the indispensible role of phosphate content in the normal formation of starch granules, since cracked granules were observed in the starches containing low phosphate content, while irregular bumpy shaped granules were observed in the tubers from plants containing high phosphate content. Interestingly, further analyses on the expression level of genes involved in starch metabolism and sugar-starch conversion suggested that starch phosphorylation might affect starch synthesis by controlling the carbon flux into starch while simultaneously modulating starch-synthesizing genes. Further studies are needed to confirm this finding (Chapter 4).
To produce starches with novel structures, an (engineered) 4, 6-α-glucanotransferase (GTFB) from Lactobacillus reuteri 121 was introduced into potato tubers (Chapter 6). The resulting starches showed severe changes in granule morphology, but not in starch fine structure. Transcriptome analysis revealed the existence of a self-repair mechanism to restore the regular packing of double helices in starch granules, which possibly resulted in the removal of novel glucose chains potentially introduced by the (engineered) GTFB.
This research successfully generated starches with various functionalities, including altered gelatinization characteristics (Chapter 3 and 4), improved freeze-thaw stability (Chapter 4) and higher digestibility (Chapter 6). The exploitation of relationships between starch characteristics and starch properties revealed that starch properties represent the outcome of the combined effect of many factors and are highly dependent on the genetic background in which the modification has been performed.
In conclusion, the research described in this thesis demonstrates the great potential of genetic modification in producing starches with novel properties. Meanwhile, these results revealed the presence of complex and exquisite molecular regulation mechanisms for starch biosynthesis in potato. In future research, these regulations need to be taken into account for the relational design of starch in planta. Certainly, a better understanding of the process of starch metabolism in storage organs would be a great step forward towards tailoring starch in an economically important crop such as potato.
Next-generation salmonid alphavirus vaccine development
Hikke, M.C. - \ 2016
Wageningen University. Promotor(en): Just Vlak, co-promotor(en): Gorben Pijlman. - Wageningen : Wageningen University - ISBN 9789462577404 - 159
alphavirus - atlantic salmon - rainbow trout - vaccine development - immunity - virology - fish culture - aquaculture - biotechnology - alfavirus - europese zalm - regenboogforel - vaccinontwikkeling - immuniteit - virologie - visteelt - aquacultuur - biotechnologie
Aquaculture is essential to meet the current and future demands for seafood to feed the world population. Atlantic salmon and rainbow trout are two of the most cultured aquaculture species. A pathogen that threatens these species is salmonid alphavirus (SAV). A current inactivated virus vaccine against SAV provides cross-protection against all SAV subtypes in salmonids and reduces mortality amongst infected fish. However, protection is not 100% and due to virus growth at low temperature, the vaccine production process is time consuming. In addition, the vaccine needs to be injected into the fish, which is a cumbersome process. The work described in this thesis aimed to increase the general knowledge of SAV and to assess current vaccine technologies, and to use this knowledge in designing next-generation vaccines for salmonid aquaculture.
An alternative cell line to support SAV proliferation was identified, however, the virus production time could not yet outcompete the current SAV production system. Making use of the baculovirus insect cell expression system, multiple enveloped virus-like particle (eVLP), and core-like particle (CLP) prototype vaccines were produced in insect cells at high temperature. An in vivo vaccination study showed, however, that these vaccines could not readily protect Atlantic salmon against SAV. The low temperature-dependent replication of SAV was attributed to the glycoprotein E2, and it was found that E2 only correctly travelled to the cell surface at low temperature, and in the presence of glycoprotein E1. The biological impact of this finding was confirmed in the development and in vivo testing of a DNA-launched replicon vaccine. The effective DNA-launched replicon vaccine was extended by delivery of the capsid protein in trans. It was hypothesized that viral replicon particles (VRP) were formed in vivo, which would cause an additional single round of infection and might further elevate the immune response in comparison to the replicon vaccine. A second animal trial indicated that the inclusion of capsid did not yet improve vaccine efficacy. This trial however did show that a DNA vaccine transiently expressing the SAV structural proteins provided superior protection over both replicon vaccines (with and without capsid).
In this thesis, some virus characteristics, such as the cause of temperature-dependency of SAV replication, of an unique aquatic virus were further explored. The production and in vivo testing of multiple next-generation vaccines defined the prerequisites for induction of a potent immune response in Atlantic salmon. A prototype DNA-launched replicon vaccine has shown potential for further development. The research described in this thesis contributes to the development of next-generation vaccines in the challenging area of fish vaccinology.
Composting trial with BioFoam® products in a full scale commercial composting facility : final report, April 2015
Zee, M. van der - \ 2015
Wageningen : Wageningen UR - Food & Biobased Research (Wageningen UR Food & Biobased Research report 1561) - ISBN 9789462575141 - 31
biobased economy - biobased materials - biomass - organic wastes - degradation - composts - composting - biotechnology - technology - plastic foam - biobased economy - materialen uit biologische grondstoffen - biomassa - organisch afval - degradatie - compost - compostering - biotechnologie - technologie - schuimplastic
The main objective of the trial was to be able to judge whether BioFoam® material degrades at sufficient rate to be composted together with regular source separated municipal solid biowaste in a full scale industrial composting facility.
Bacterial battery chargers
Versluis, K. ; Heijne, A. ter - \ 2015
stedelijk afvalwater - afvalwaterbehandeling - elektriciteit - elektronen - bacteriën - bio-energie - biobased economy - biotechnologie - waterzuivering - municipal wastewater - waste water treatment - electricity - electrons - bacteria - bioenergy - biotechnology - water treatment
Annemiek ter Heijne investigates a new method to produce electricity from waste water. She uses bacteria as battery chargers.
Prof. Justus Wesseler over overheidsingrijpen bij nieuwe biotechnologische ontwikkelingen
Wesseler, J.H.H. - \ 2014
genetische modificatie - transgene planten - transgene organismen - biotechnologie - schade - rijst - india - economische aspecten - genetic engineering - transgenic plants - transgenic organisms - biotechnology - damage - rice - economic aspects
Overheidsregels rond biotechnologie en genetisch gemodificeerde gewassen leiden vaak tot substantieel hoge investeringskosten. Die hebben weer een lager niveau van productontwikkeling tot gevolg en een concentratie in de industrie, een herschikking van onderzoeksprioriteiten en een verschuiving van onderzoek en ontwikkeling naar landen met minder stringente regelgeving. Die trend leidde zelfs tot schade aan duurzame ontwikkeling uit oogpunt van milieu en volksgezondheid.
|Genenfluisteren : kunst en kunde
Tramper, J. ; Mossink, L. - \ 2014
Wageningen : Johanes Tramper - ISBN 9789082203103 - 139
biotechnologie - voedselbiotechnologie - wetenschap - wetenschapsfilosofie - biotechnology - food biotechnology - science - philosophy of science
On the traces of Hephaestus : skills, technology and social participation
Nicolosi, G. - \ 2014
Wageningen University. Promotor(en): Han Wiskerke; Guido Ruivenkamp. - Wageningen University : Wageningen - ISBN 9789462570672 - 173
technologie - technische vooruitgang - samenleving - sociologie - filosofie - participatie - vaardigheden - biotechnologie - technology - technical progress - society - sociology - philosophy - participation - skills - biotechnology
In the general understanding, and also in scientific practice, technology and society are viewed as two distinct entities. Related to this view is the assumption that technology and human experience are quite different and unconnected and also the idea that modernity has uprooted, de-contextualized and disembodied technical rationality. Taking a contrary approach, this study represents a theoretical exploration aimed at showing that in the domain of technological development, there are significant margins for maneuver in which to recuperate and valorize human and social action. As a work of theoretical sociology or social epistemology, this thesis approaches its subject from the theoretical background of the philosophy and sociology of technique. The historical and conventional assumptions of this theoretical background, it is argued, have been and continue to be characterized by a hegemonically defined essentialist paradigm. This paradigm has been fiercely counteracted by two opposed approaches, critical theory and pragmatism. The present work combines these approaches, usually considered mutually incompatible, for the development of a new theoretical gaze or perspective. The aim has been to engage in a theoretical research oriented to a new philosophy of praxis in order to instigate a critical and constructivist approach to technology. The main result expected of this work is the provision of a problematized and multifaceted semantic map leading to a multidimensional conceptual re-integration of skilled experience in human technical action.
|Lotz B (2013) “Genetische modificatie geen wondermiddel”. Interview in serie Zomercollege.
Versprille, H. ; Lotz, L.A.P. - \ 2013
Boerderij 98 (2013)47. - ISSN 0006-5617 - p. 12 - 14.
genetische modificatie - cisgenese - maatschappelijk draagvlak - biotechnologie - aardappelen - gewasbescherming - plantenveredeling - genetic engineering - cisgenesis - public support - biotechnology - potatoes - plant protection - plant breeding
Bert Lotz houdt zich bij Plant Research International (onderdeel Wageningen UR) onder meer bezig met biologische bestrijding en genetische modificatie. Hij mist respect voor de wetenschap in het debat over 'gentech'. "We staan pas aan de vooravond van talloze toepassingen." Een interview.
|Control of Pig Reproduction IX
Rodriguez-Martinez, H. ; Soede, N.M. ; Flowers, W.L. - \ 2013
Leicestershire, United Kingdom : Context Products Ltd (Society of Reproduction and Fertility volume 68) - ISBN 9781899043484 - 345
varkens - geslachtelijke voortplanting - gameten - embryo's - kunstmatige inseminatie - embryotransplantatie - zwangerschap - partus - pasgeborenen - biggen - overleving - biotechnologie - metabolomica - eiwitexpressieanalyse - kunstmatige selectie - pigs - sexual reproduction - gametes - embryos - artificial insemination - embryo transfer - pregnancy - parturition - neonates - piglets - survival - biotechnology - metabolomics - proteomics - artificial selection
A physiologically based kinetic model for bacterial sulfide oxidation
Klok, J.B.M. ; Graaff, C.M. de; Bosch, P.L.F. van den; Boelee, N.C. ; Keesman, K.J. ; Janssen, A.J.H. - \ 2013
Water Research 47 (2013)2. - ISSN 0043-1354 - p. 483 - 492.
afvalwaterbehandeling - biotechnologie - zwavelwaterstof - oxidatie - ontzwaveling - alkalibacillus haloalkaliphilus - microbiële fysiologie - afvalwaterbehandelingsinstallaties - waste water treatment - biotechnology - hydrogen sulfide - oxidation - desulfurization - alkalibacillus haloalkaliphilus - microbial physiology - waste water treatment plants - sulfur-oxidizing bacteria - biologically produced sulfur - dissolved sodium sulfide - parameter-estimation - hydrogen-sulfide - soda lakes - bioreactors - thiosulfate - mechanisms - pathways
In the biotechnological process for hydrogen sulfide removal from gas streams, a variety of oxidation products can be formed. Under natron-alkaline conditions, sulfide is oxidized by haloalkaliphilic sulfide oxidizing bacteria via flavocytochrome c oxidoreductase. From previous studies, it was concluded that the oxidation-reduction state of cytochrome c is a direct measure for the bacterial end-product formation. Given this physiological feature, incorporation of the oxidation state of cytochrome c in a mathematical model for the bacterial oxidation kinetics will yield a physiologically based model structure. This paper presents a physiologically based model, describing the dynamic formation of the various end-products in the biodesulfurization process. It consists of three elements: 1) Michaelis–Menten kinetics combined with 2) a cytochrome c driven mechanism describing 3) the rate determining enzymes of the respiratory system of haloalkaliphilic sulfide oxidizing bacteria. The proposed model is successfully validated against independent data obtained from biological respiration tests and bench scale gas-lift reactor experiments. The results demonstrate that the model is a powerful tool to describe product formation for haloalkaliphilic biomass under dynamic conditions. The model predicts a maximum S0 formation of about 98 mol%. A future challenge is the optimization of this bioprocess by improving the dissolved oxygen control strategy and reactor design.
On design-oriented research and digital learning materials in higher education
Hartog, R.J.M. - \ 2012
Wageningen University. Promotor(en): Adrie Beulens; Hans Tramper. - S.l. : s.n. - ISBN 9789461735089 - 246
informatietechnologie - computerondersteund onderwijs - onderwijzen - hoger onderwijs - voedselwetenschappen - biotechnologie - information technology - computer assisted instruction - teaching - higher education - food sciences - biotechnology
The context of the research described in this thesis is formed by a number of research projects that were aimed at the design, development, implementation, use and evaluation of innovative digital learning materials. Most of these projects were carried out mainly within Wageningen University. In this thesis, these projects are collectively referred to as 'WU Projects'. During this research it became clear that available literature provided insufficient support with respect to a number of issues. Examples are 'How to phrase research questions?', 'What output to expect?', 'What type of evaluation is relevant?' and 'What methods should be used?'. In fact, in parallel with the WU projects, the body of literature on methodology for design related research approaches in several disciplines was growing considerably. This thesis aims to contribute to this methodological discussion. In addition, this thesis presents a view on the characteristics and possibilities of digital learning materials in higher education.
In Chapters 2,3 and 4, a methodological framework for design, development, implementation, use and evaluation of innovative digital learning materials in higher education is defined and elaborated. Research that fits this framework is called design-oriented research (DOR). The framework is the result of a systems-oriented theoretical discussion of literature from a range of knowledge domains such as learning and instruction, knowledge and information systems research and engineering design. The concepts and terminology are illustrated with examples from publications that resulted from various WU projects. In addition, part of the framework is captured in a glossary of terms. The glossary aims to provide a coherent and ‘workable’ set of terms and corresponding definitions or descriptions. For many terms, this implies a compromise between natural language preferences of members of different disciplines.
In Chapter 4, a classification of outputs that are potentially valuable is presented. An important implication of the view presented in this chapter, is that the actual design goal can be output, rather than input of a DOR project. This is in agreement with the view of instructional design and design of digital learning resources as processes of constraint exploration and constraint satisfaction. In Chapter 5 and Chapter 6 the most important strategic decisions in DOR projects that aim to deliver digital learning materials in higher education are discussed. In Chapter 5, a classification of design goals with their relation to various knowledge domains is presented. In Chapter 6, a classification of large-scale use scenarios with their relation to design requirements is given. Finally, Chapter 7 describes requirements and opportunities for evaluation in design-oriented research in education and reflects on evaluation in a number of WU projects. This leads to a number of suggestions for improvement with respect to evaluation in DOR.
Plantenveredeling : een creatief vak, gestoeld op wetenschap, technologie en regelgeving
Jacobsen, E. - \ 2012
Wageningen : Wageningen University - ISBN 9789461733238 - 24
plantenveredeling - selectiemethoden - geschiedenis - biotechnologie - wetgeving - Nederland - plant breeding - selection methods - history - biotechnology - legislation - Netherlands
Adaptive e-learning for biotechnology : (how) does it work?
Seters, J.R. van - \ 2011
Wageningen University. Promotor(en): Hans Tramper; M.A. Goedhart, co-promotor(en): M.A. Ossevoort. - [S.l.] : S.n. - ISBN 9789461730886 - 156
computerondersteund onderwijs - probleemgestuurd onderwijs - geprogrammeerd leren - biotechnologie - computer assisted instruction - problem-based learning - programmed learning - biotechnology
By for example the Bachelor-Master system, the composition of student groups at universities changed in recent years. The knowledge of students may be more divergent. This makes the teaching of these groups more difficult, since the updating of individual students is very time consuming for the teacher. Digital materials can then support teachers. Adaptive digital learning materials adapt the level of the offered material and exercises to suit the individual student. In this study we examined existing teaching materials for effectiveness and looked at how students use and appreciate it. Also, we introduced a pedagogical structure to develop adaptive digital learning materials in a systematic way. The developed material proves to be effective, if properly designed and tested. Students’ use of the material is indeed very diverse regarding the time they devote to the material and the way they approach the exercises. For example, some students find it more pleasant to first deepen the theory, while others want to learn from their mistakes. Students appreciate the material, but make high demands on the provided automated feedback. Adaptive digital materials can therefore be a good way to teach heterogeneous student groups, provided the material is carefully designed and tested.
|Microcanon : wat je beslist moet weten over microbiologie
Smit, H. ; Doorn, J. van; Oost, J. van der; Reijnders, W. ; Willemsen, P.T.J. - \ 2011
Diemen : Veen Magazines (Wetenschappelijke Bibliotheek van Natuurwetenschap&Techniek 109) - ISBN 9789085713272 - 246
microbiologie - bacteriën - virussen - biotechnologie - bacterieziekten - microbiology - bacteria - viruses - biotechnology - bacterial diseases
Micro-organismen zijn onmisbaar voor het leven op aarde. De organismen zijn zo klein dat we ze niet zien, maar ze zijn des te belangrijk. Deze kleine organismen kunnen een positieve of negatieve invloed hebben. Soms klein, soms groot. De Microcanon geeft daarvan een goed beeld in zo'n zestig voorbeelden. Een team van auteurs beschrijft op begrijpelijke wijze de belangrijkste feiten uit de microbiologie. De micro-organismen zijn niet alleen onmisbaar bij grote geologische processen zoals de koolstof- en stikstofkringloop, maar ook in het dagelijks leven en natuurlijk ook binnen de land- en tuinbouw. Het kennen van deze organismen en hun processen is van groot belang
Modern biotechnology Panacea or new Pandora's box?
Tramper, J. ; Yang Zhu, Yang - \ 2011
The Netherlands : Wageningen Academic Publishers - ISBN 9789086861699 - 284
biotechnologie - voedselbiotechnologie - genetische modificatie - plantenbiotechnologie - biotechnology - food biotechnology - genetic engineering - plant biotechnology
According to Greek mythology Pandora was sent down to earth upon the orders of Zeus. She was given a mysterious box which she was not allowed to open. However, Pandora was very curious and when she arrived on earth she couldn?t help taking a peek inside the box. She saw that it was filled with gifts and calamities and to her astonishment they all escaped and spread throughout humanity, with all the dire consequences thereof. Only hope was left at the bottom. Figuratively speaking, Pandora's box today represents a source of much suffering. Is modern biotechnology just such a Pandora's box, as the anti-biotechnology lobby would have us believe? Or can we selectively release the gifts and turn this new Pandora's box into a Panacea? Modern biotechnology makes use of the recombinant DNA technology to genetically modify microorganisms, plants and animals in order to make them more suitable for all kinds of applications, such as cultivating food crops, baking bread, making wine, antibiotics and hormones, xenotransplantation, and gene- and stem cell therapy. The book also particularly addresses the controversial aspects of these applications.
|Cisgenese: modern veredelen met traditioneel resultaat
Schouten, H.J. - \ 2010
De Boomkwekerij 22 (2010)17. - ISSN 0923-2443 - p. 14 - 16.
fruitteelt - fruitgewassen - appels - malus - rassen (planten) - genetische modificatie - biotechnologie - plantenveredelingsmethoden - cisgenese - fruit growing - fruit crops - apples - varieties - genetic engineering - biotechnology - plant breeding methods - cisgenesis
Traditionele veredeling is bij fruitbomen enorm tijdrovend. Veredeling met behulp van genetische modificatie kan het proces erg versnellen, maar dit stuit in Europa op veel maatschappelijke weerstand. Appelveredelaar Henk Schouten van PRI denkt met cisgenese alleen de voordelen van genetische modificatie te introduceren in de traditionele appelveredeling.
Biotechnologie in de plantveredeling sector: Een historisch overzicht van technologische ontwikkelingen en maatschappelijk debat
Bakker, T. ; Minten, S.L.J.N. - \ 2010
Den Haag : LEI, onderdeel van Wageningen UR - 23
plantenveredeling - plantenveredelingsmethoden - biotechnologie - multinationale corporaties - genetische modificatie - innovaties - plant breeding - plant breeding methods - biotechnology - multinational corporations - genetic engineering - innovations
Naar aanleiding van het 30 jarig bestaan van TTI groene genetica is vanuit LNV de vraag ontstaan naar de geschiedenis van de plantenveredelingsector. Er is achterhaald hoe de bedrijfsstrategieën tot stand zijn gekomen in een dynamisch tijdperk gekenmerkt door de opkomst van vele nieuwe technologieën. Het is een leuke zoektocht geworden in de geschiedenis van de veredelingssector. Biotechnologie heeft veel losgemaakt in de afgelopen 30 jaar
Behavioural change as a key to sustainable agriculture
Lauwere, C.C. de; Pierick, E. ten; Beekman, V. ; Asseldonk, M.A.P.M. van - \ 2010
In: Global food security: ethical and legal challenges, EurSafe 2010, 16-18 September 2010. - Bilbao : Wageningen Academic Publishers - ISBN 9789086861545 - p. 91 - 96.
voedselzekerheid - recht - klimaatverandering - duurzaamheid (sustainability) - landbouwbeleid - wereld - aquacultuur - biotechnologie - octrooien - volksgezondheid - voeding - etiketteren - bescherming van de consument - ethiek - dierenwelzijn - beleid inzake voedsel - sociale ethiek - Nederland - food security - law - climatic change - sustainability - agricultural policy - world - aquaculture - biotechnology - patents - public health - nutrition - labelling - consumer protection - ethics - animal welfare - food policy - social ethics - Netherlands
Food security will exist when all people, at all times, have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life (as stated in the Rome Declaration in 1996). Given the dimension of the current global food crisis, food security means adopting effective and specific actions at individual, household, national, regional and global levels. Food security invites us to reflect upon ethical principles like human equity, justice between current and future generations, respect for human dignity and sustainable food production. We strive to maintain our basic ethical convictions and engage in societal debates about other important values. While we do this, we may have to change our ways of life and learn to create new priorities in the face of global responsibility. Science and technology are key tools to reach the Millennium Goals, providing both society and decision makers alike with relevant information and new options within an ethical framework. The contributions found in this publication bring together the perspectives of a diverse group of authors. Coming from the academic world, the public sector and non-governmental organisations (NGOs), they provide the latest views on 'Global food security: ethical and legal challenges'.