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    Baron op klompen : mr. B.W.A.E. baron Sloet tot Oldhuis (1807-1884) aan de hefboom tot welvaart
    Coster, W. - \ 2008
    Wageningen University. Promotor(en): Pim Kooij. - [S.l.] : S.n. - ISBN 9789085049500 - 416
    biografieën - politiek - economie - onderwijs - kennis - communicatie - handel - landbouw - plattelandseconomie - kolonialisme - nederland - geschiedenis - plattelandsontwikkeling - oost-nederland - biographies - politics - economics - education - knowledge - communication - trade - agriculture - rural economy - colonialism - netherlands - history - rural development - east netherlands
    During the nineteenth century many changes took place in The Netherlands, which in various ways have determined the structures we are living in today. Not only did the unification of the ‘archipelago of regions and communities’ from the period of The Republic make progress in the field of politics, (social-)economy and demography, but also in the field of language and culture, (town- and country-)planning and the structure of the landscape. Simultaneously the nation state of The Netherlands -which developed after a strongly directive French-Batavian intermezzo- remained a colourful mosaic of fixed or changing structures, materials and nuances. The origin, direction and pace of the various, sometimes co-existing phases in this process were, to a large extent, determined by people who stepped forward with their ideas, ideals and initiatives. These people had to deal with counter forces: from other persons, both individually and collectively, or from the physical environment which confronted them with sometimes unexpected difficulties and possibilities. It was – although opinions differ in this respect – above all a process of the work of man.
    One of those who played an important role in the changing process of the nineteenth century was the lawyer Bartholomeus Willem Anne Elisa baron Sloet tot Oldhuis (1807-1884). ‘Sloet’, as he was usually called, was born in the village of Voorst in Gelderland, but most of his life he lived in and worked for the province of Overijssel. He held many offices, including those of mayor, judge, council member, provincial councillor and school inspector. In 1841 he was the originator of the ‘Overijsselsche Vereeniging tot Ontwikkeling van Provinciale Welvaart (‘Overijssel Society for the development of Provincial Prosperity’), in short ‘Welvaart’, and also of the subsequent ‘Landhuishoudkundige Congressen’ (‘Agronomic Congresses’) in 1846. Between 1840 and 1860 he was one of the leading men in the national political arena. In 1840 and again in 1848 he was a member of the Double Chamber for the amendment of the Constitution and he resided in the Second Chamber (Commons) between 1848 and 1860. Sloet was known to be a critical and headstrong liberal, who stood up for the interests of the countryside, especially those of the provinces of Overijssel and Gelderland, without becoming a narrow minded regionalist. He fought with and against Thorbecke, supported Van Hoëvell in debates on the policy regarding the Dutch East Indies and was one of the most ferocious opponents of Groen van Prinsterer. For decades the ‘Tijdschrift voor staathuishoudkunde en statistiek’ (Journal for political economy and statistics), which was founded by him in 1841, was considered to be the essential liberal mouthpiece. Both in word and in action Sloet was a pioneer who devoted himself to the emancipation and development of agriculture and the countryside, the construction of roads and waterways, and to the spreading of knowledge and skills. His views on the relationship with the colonies in the East and the West were sensational. Meanwhile he published widely both as a poet and a folklorist. Many of his initiatives succeeded, others failed, but his goal remained to stand at ‘the lever to prosperity’.
    His strongly felt presence, his wilful character, his versatility and his vigour make Sloet a splendid guide through his time. Not only because of what he achieved but also because of his disappointments and failures and the opposition he was confronted with. The fact that he came from the eastern part of the country, together with his regional orientation and the availability of relevant sources makes it possible to select specific regional fragments against the scenery of the nineteenth century.
    The present research concerning Sloet tot Oldhuis fits perfectly into the biographical tradition which over the past decade has also found its way into the field of agrarian history. By choosing themes from the life and work of a renowned figure in his time Baron op klompen (‘Baron in clogs’) seeks to show the important role Sloet has played during a large part of the nineteenth century in the political, economical and rural arena, more specifically in agriculture, planning and (political) culture; those aspects which were decisive in the development of the nation state of the Netherlands. The emphasis will be on the period between, roughly, 1840 and 1870.
    The title ‘Baron op klompen’ also refers to the fact that Sloet -being a nobleman who did not out of ‘noblesse oblige’ feel obliged to defend the rights of his class- became an advocate for the backward rural regions and the peasantry. A new element in the present research is the fact that the results of the explorations of the ‘curriculum’ of chapter 2 are elaborated in subsequent chapters and in the interaction between them. That is why this new type of biography may be called a ‘concentric biography’.
    The essence of this research is to show how a representative from the eastern part of the Netherlands, who may be assumed to have had much influence on the development of the modern nation, manifested himself. Here the term ‘modernization’ is used as ‘a complex of simultaneously occurring developments which strengthen each other into a certain direction’. These developments are elaborated in four themes representing important aspects in Sloet’s social life: knowledge and skill, infrastructure, the countryside with its agriculture, and the colonies. Again and again the question is raised how his personality and intellectual background affected his actions. Each of these chapters raises a specific research question. A recurring question is what contribution Sloet has made to the development of the political culture by his public actions in the local, regional and national arenas.
    In a way this research is a counterpart to the NWO-research of modernization and democratization in the Dutch countryside which is being conducted by the Rural History Group of Wageningen University, under the guidance of dr A.J. Schuurman. It therefore also poses the question which government bodies, organizations, newspapers and periodicals were responsible for stimulating the process of modernization and the development of the countryside. In this case the question is aimed specifically at the role Sloet played in this process. In other words – see the conclusion of chapter 1 - whether figures like him, who did not belong to the ‘titans’ in national politics, could ‘move the lever of prosperity’.
    After the introductory chapter 1, ‘Aan de hefboom tot welvaart’ (‘At the lever of prosperity’), chapter 2, ‘Achtergronden’ (‘Backgrounds’) describes Sloet’s personal life. It deals with his curriculum vitae cum annexis, characterises him as a person and shows which tools he was given and which he gained during his life. It inquires after his ambitions and after his economic, social and cultural capital. In line with the concentric method, specific answers to these questions will be given in each of the subsequent chapters. This chapter pays special attention to Sloet as mayor of Hengelo (Overijssel) between 1832 and 1838, because it would prove to be the breeding ground for Sloet’s ambitions and activities afterwards in national politics. What he tried to achieve in Hengelo at a local level he would later attempt at a national level. Finally this chapter pays explicit attention to his literary work, which in the other chapters is mainly used to illustrate.

    Chapter 3, ‘Twee maal een onzichtbare hand’ (‘Twice an invisible hand’), elaborates on Sloet’s intellectual baggage. His thoughts appear to have been guided by two invisible hands: that of religion and that of economy, while Classic Antiquity also took up a prominent part of this baggage.
    In his religious life Sloet was guided by ‘physico-theology’, a school of thought which originated during the age of Enlightenment and was based on the idea that the forces of nature refer to a Creator. Other physico-theological writers, such as J.F. Martinet (1729-1795) wanted to convince their readers of the existence of God and his lasting care for his Creation on the strength of the available knowledge of natural phenomena. They wanted to point out that Nature is organized in such a systematic and functional way that a Nature without God simply cannot exist. What is more they summoned everybody to get to know and admire the magnitude of the Creator by means of the investigation of Nature. This way of thinking is based on both rational proof of God’s existence and the visible manifestation of God’s power, wisdom and goodness in the cosmic order of things. In accordance with the empirical spirit of the times this last aspect was emphasised most in the eighteenth century. Although a man of the nineteenth century, empiricism fitted Sloet like a glove.
    According to Sloet morality was closely connected with religion in defining morals, norms, values and (therefore) citizenship. From morality to political economy was another small step as far as Sloet and many of his contemporaries were concerned. Within this context statistics and rural economy were also important and Sloet was certainly intensively engaged in these matters. The pillars of his world view and thoughts on people’s happiness -in the sense of material and non-material prosperity- were therefore a mixture of classic, Christian and profane materials. Chapter 3 explores the composition of this mixture.
    As Hans Boschloo quite rightly states in his work De productiemaatschappij, in 1848 Sloet was ‘just like almost every other ‘laisser faire’ economist probably a Thorbeckian’. However, over the years he found himself more and more estranged from the liberal mainstream. In his eyes liberalism brought too much state interference, which was harmful to regional autonomy and resulted in unnecessary bureaucracy, his two largest frights. Because where could personal interests be served better than in one’s own immediate surroundings? And why should civil servants in The Hague interfere with the life of a farmer in Overijssel? Sloet considered freedom and centralisation to be opposites. This does not mean, that he was against any form of state interference, except where it concerned the care for the poor or the non-productive citizens. In that case he adhered to the principle: ‘he who does not work shall not eat’, although he would not say so outright. For Sloet – who was after all a lawyer – the form of government was less important than the general Christian state family in which everybody knew his place and lived by the same unwritten rules and principles, while fulfilling a task in order to provide for his or her livelihood.
    The next four chapters show how Sloet operated, being guided by this way of thinking.

    Chapter 4, ‘ ‘Kennis is de ware tooverij’ ’ (‘ ‘Knowledge is the true magic’ ’), pursues the value Sloet attached to organizations which furthered mutual contacts, research, information and education, public governance and well functioning media as necessary links to knowledge and information. Or, to put it in modern terms: networks, education and research, public relations and communication. His contribution to the political culture is also dealt with explicitly, while in the following chapters this contribution is further illustrated with practical examples. The question is what his approach was, who he involved and what the results were of his efforts, even though the answer to this last question will be saved for chapters 5, 6 and 7.
    According to folklorist Tjaard de Haan, the fact that Sloet, in his ‘Ode aan de IJssel’ (‘Ode to the IJssel’) rhymes ‘stichting’ (edification/foundation) with ‘volksverlichting (‘enlightenment of the masses’), is typical for his active attitude toward life. He was one of the gentlemen who had woken, or wanted to wake, the countryside. His great strength was his zest for work, which was fed by his belief in the possibility of shaping or at least improving society and in the power of science. ‘Knowledge is the true magic’ was his motto as written down in 1865. At the same time it meant a confirmation of his belief in the divine nature which would allow itself to be uncovered by science. Nevertheless these discoveries needed to be translated to all layers of society if they were to benefit general prosperity.

    Chapter 5, ‘ ‘Wegen te water en te land’ ’ (‘ ‘Roads in the water and on land’ ’), deals with the development of infrastructure, both locally and internationally, i.e. roads, waterways and railroads in the Netherlands and across the borders. How Sloet dealt with his ideas in these areas is examined here. What were his goals? Who were his allies and who his opponents in the borderland between public and private interests? What effects did his efforts achieve? Especially his activities in Overijssel, notably his desire to change its capital into a genuine seaport are emphasised here. Special attention is paid to his conspicuous efforts to make improvements on ‘the waterway between Zwolle and the sea’, the route via the ‘Zwarte Water’ and the ‘Zwolse Diep’. For this case caused political and personal polarization and shows a great deal of Sloet’s character and his political style. Besides, the perils around this ever so important part of Overijssel’s infrastructure led to a novelty in Dutch politics: the first full Parliamentary Inquiry in 1856.
    At a time when Sloet exerted all his influence for the realization of the waterway from Zwolle to the sea and for the first railroads to and in Overijssel, shortly before the middle of the nineteenth century, he also pointed out the importance of ‘the footpaths of the nation’: the indispensable and undeniable winding paths in the countryside which were literally threatened to be buried by modern times. On the one hand he valued them because of their arcadian character, on the other also and the more so because of their economic value. The moral of the story being that modernization was useful and necessary but one should take care not to reject the good with the bad because old things also had their rights and served their purpose and should not be so easily dismissed. Sloet compared infrastructure to a blood circulation system in which each little vein served its purpose both for the entire body and for an individual body part. Without roads, however small they might be, there could be no trade and without trade there was no progress. This was the lesson he had learnt from Martinet and Adam Smith.
    One victory was booked in 1860: just before he left the Second Chamber a Railway Act with national validity was passed, which also served the provinces, even though practice would show once again the West taking control over the initiative and the National Railways. Private initiative resulted in the completion of the ‘Zuiderzeelijn’ in 1864, a project in which Sloet had put a lot of effort, as far back as in the 1840s. At least his ideas and initiatives had contributed to the development of a coherent network of transport and communication lines, one of the necessary requirements for environmental integration.

    Chapter 6, ‘Landbouw, landhuishoudkunde en landleven’ (‘Agriculture, rural economy and rural life’), deals with the role the agricultural sector played within and for Dutch national economy and how aspects such as knowledge, know-how and communication influenced this role according to Sloet. The chapter starts with a short description of agriculture in Overijssel in the nineteenth century.
    The first question in this context is how Sloet valued the situation of agriculture in The Netherlands and its developments, especially in the province of Overijssel. Secondly, which arguments does he pose for the different views there are on this issue? A third question is what Sloet has contributed to the development of agriculture, both nationally and in Overijssel? Finally, can he be considered a representative of a certain group or did he occupy a special position within Dutch agriculture?
    Sloet saw the agricultural sector as full of potential, some of which was also realised. Although this filled him with satisfaction and delight, it was no reason to sit back complacently, because new situations and developments also created new opportunities which needed to be utilized. The overall goal remained to explore and exploit the treasures of nature which became available through agriculture and, of course, otherwise. Farmers had a specific and important role in this process. For the eastern part of the Netherlands with its specific agrarian characteristics Sloet thought the best option was to develop the small family business. In a way and avant la lettre this manner of thinking fits within the later theory of Ester Boserup who speaks of ‘the relation between population growth in a certain ecological system and the changes in agriculture, more specifically the intensification of farming, which are a result of this growth’. Sloet considered ecology and economy to go hand in hand and according to him developments in the agricultural production process were determined by natural circumstances. But it was up to man to recognize these circumstances and to make use of them and improve them. Only then could the population grow. The necessary employment could amply be found in the countryside. Sloet considered investing on a small scale, such as providing seeds and simple sausage recipes better than introducing large farming equipment which would mostly benefit the big farmers. Modernization of agriculture should therefore aim at the small peasant family business. Rather than for mechanization Sloet opted for the use of human labour as a means to increase productivity.
    Where the second question - of the different views on production development in agriculture- is concerned, Sloet simply does not provide us with the necessary statistics, despite his efforts. He did recognize, however, the rapid growth in population, the resulting pressure on the soil, the necessary intensification in agriculture and the just as necessary improvements of the infrastructure with, of course, the opportunities which these developments created. Van Zanden’s thesis, that up to about 1870 the influence of ‘institutions’, organizations and institutes on actual farming had been small, needs to be questioned. The existing agricultural societies before 1870 certainly made their contributions, especially Sloet’s Agronomic Congresses and, where Overijssel is concerned, ‘Welvaart’. Sloet was living proof that ‘people do make a difference’.
    This also forms the beginning of the answer to the third research question, namely which contribution Sloet has made to Dutch agriculture, and especially that of Overijssel. By using his countless connections in politics, the Agronomic Congresses, among men of science and farmers, with his knowledge of national and international literature on the subject and last but not least on the basis of his own observation, he was the seemingly tireless stimulator behind small but indispensable little pulls at the lever of prosperity. To his great dismay and despite his efforts of many years he did not succeed in causing the tithes, a tax which he considered to be harmful to the development of agriculture, to be abolished.
    The answer to the question as to what extent Sloet has taken up a position of his own in Dutch agriculture is closely connected with his descent and the region he grew up in. His childhood in Gelderland gave him direction and shaped him – as it had done his father and mother before him – into a tool of progress in the countryside and it made him an exponent of rural life. Not because he desired to play the role of ‘gentleman’, but for the love of his surroundings and the people with whom he felt connected. With his ‘physico-theological’ way of thinking as a liberal politician, economist, governor, man of letters and as a folklorist he is indissolubly connected with the agriculture and the countryside of The Netherlands and especially the countryside of the eastern part of The Netherlands or the ‘Saxon’ countryside, as he called it.
    All together this creates a colourful and original person. In a sense Sloet was born in the wrong environment. He was different; he was a baron in clogs. However, if he had been a farmer in clogs he would not have been able to achieve the things he did by being the man he was.

    Chapter 7, ‘Provincies overzee’ (‘Provinces overseas’), describes the way Sloet, together with baron Van Hoëvell, the militant ex-clergyman in the East Indies, initiated the discussion on colonial policy and launched ideas to emancipate the colonies in the East and the West and to make them more profitable. His actions are mainly highlighted by his role in the Second Chamber. Especially his interpellations on several issues and on a few particular items: a colonization project in Surinam, his proposal to sell land on Java, the ‘Cultuurstelsel’ (cultivation system) and the Government Regulation for the Dutch East Indies which came into force in 1854. Moreover his attitude towards the Dutch Trading Company (Nederlandsche Handel-Maatschappij, in short ‘NHM’) and the issue of slavery, which he strongly condemned, are discussed here. The results of his actions should be regarded in the light of the question what his contribution has been towards the development of the political culture after 1848.
    Where the issue of the ‘colonies’ was concerned, Sloet brought about a change of culture. He endured storms without being able to harvest but he opened up possibilities for others, especially with regard to the East. Several interpretations with regard to the abolishment of the ‘Cultuurstelsel’ were congruent with his ideas on the topic. Firstly, as a classic liberal, he fought against forced labour and the monopoly of the colonial government, and especially the NHM. The amendments and changes which were attributed to criticism of left-wing liberals were mostly due to Sloet’s work. Already in 1849 Sloet started discussions in the Second Chamber on various matters, thereby uncovering abuses which were unheard of at that time. What is more, in doing so he specifically drew attention to the interests of the native people.
    Secondly, he did not mind reforms made by civil servants in, as Fasseur states, removing or softening the aggravating burdens of the ‘Cultuurstelsel’ (Cultivation system). On the contrary, by making these changes (which could only be realised in a government system based on transparency) the ‘Cultuurstelsel’ could – according to Sloet - actually coexist with a system based on free labour and Western entrepreneurship. Finally, the interpretation that in the Dutch Indies there was a growing group of entrepreneurs with sufficient knowledge and capital to change the ‘Cultuurstelsel’ into a system based on free labour and Western enterprise, was very much in line with Sloet’s ideas. However, he also wanted to make it possible for new initiatives from the Netherlands and from the Western world in general to exploit the potential riches of the Dutch East Indies (including the Outer Provinces). If he thought fit Sloet looked not only across the regional, but also across the national borders. For him the general interest took precedence over the private interest.
    In his perception of the colonies Sloet agreed with the French economist and colonial propagandist Paul Leroy-Beaulieu (1843-1916) who spoke of ‘colonisation moderne’ as exploitation based on free production and private capital. ‘Such colonization does not recognize a difference between colonials and the colonized, exploiters and the exploited, but is beneficial to both’. Proper colonial policy should not impoverish or deprive the indigenous people but should enrich them, and with that the colonial government. This was exactly the doctrine he had expounded in his ‘Grondtrekken van de Staathuishoudkunde’ (Characteristic Features of Political Economy) and this was congruent with the principles he attributed to christianity. According to him the colonies were also guided by the two invisible hands of political economy and of Christendom.
    Most important however, was the fact that Sloet by his heavy criticism provided politics and political culture with a new form and substance in a time when colonial benefits had culminated.

    The main research question in this study was posed in chapter 1, questioning whether individuals who were not considered to be among the ‘titans’ of nineteenth century politics could bring about any movement in the lever of prosperity. Focussing on Sloet’s person this was mostly about the development of the countryside in the eastern part of the Netherlands, Overijssel specifically, and about the Dutch colonies. There was also the question how much he has contributed to the political culture of his time.
    The first conclusion in the final chapter 8, ‘Eén gezin, vastgesnoerd door broedermin’ (‘One family, tied together by brotherly love’), is that Sloet’s life and aspiration were permanently aimed at his ultimate goal: progress. This did not necessarily mean choosing new methods and techniques or enormous expansions. His perception of modernization was that of the definition as mentioned in chapter 1: ‘a complex of simultaneously occurring developments which strengthen each other into a certain direction’. The object of this direction was ahead of him, but where necessary and if there were things to be learned, he was not afraid of looking back either. In the same way his perspectives would change in his geographical orientation. The basic elements for the desired development he found first and foremost in his immediate surroundings. Most examples would come from his own sphere of work in the eastern part of the Netherlands, but they only served to provide substance for a model for Overijssel or Gelderland, The Netherlands, the Dutch colonies or for the world. On the other hand he was also in the habit of using the knowledge he acquired from his connections or through literature to the benefit of his immediate environment. Nevertheless he would always keep the natural situation in mind and would take care not to damage any other regions wherever these might be. As Martinet’s Katechismus der Natur (‘Nature’s Catechism’) had taught the young Sloet: that was not in accordance with God’s intentions.
    In 1862, two years after he had been obliged to leave the Second Chamber -thereby practically ending his role in national politics- Sloet was both satisfied and dissatisfied. In his case this was inevitable. Of course, much had been achieved. He had had his share in the new and constantly changing world. He had been responsible for waking up the countryside of Overijssel not only by introducing new farming methods and new strains and crops but also by providing knowledge and insights and means to express them. He had contributed to the construction of roads, railways and canals. He had stirred the political debates with his critical, though sometimes rather thoughtless contributions. As a Multatuli avant la lettre he had spoken for the people of the Dutch East Indies. In his poetry he had focussed on the beauty and intrinsic value of nature. He had explored limits and most of all he had shown how far human effort could reach. Therefore he was all about progress, but he would not think twice about stopping a vehicle that was out of control either.
    Sloet supported the late eighteenth century ideal of freedom, which revolved around the freedom of the citizen and which limited the powers of the state to the passing and upholding of laws necessary for a society to function. He even went one step further and would have preferred to reduce those laws as well, convinced as he was that they were not necessary, for in his eyes mankind was ‘one family, tied together by brotherly love’. In the end we can only come to the conclusion that Sloet may not have been a ‘titan’, but he certainly has set ‘the lever to prosperity’ going. He has explored and shifted boundaries and he has served as a model for the creed: ‘People do make a difference’.

    Spectral Sensitization of TiO2 Substrates by Monolayers of Porphyrin Heterodimers
    Koehorst, R.B.M. ; Boschloo, G.K. ; Savenije, T.J. ; Goossens, A. ; Schaafsma, T.J. - \ 2000
    The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical 104 (2000)10. - ISSN 1520-6106 - p. 2371 - 2377.
    Photoelectrochemical cells have been constructed by depositing monolayers of oriented covalently linked zinc/free base porphyrin heterodimers onto ~30 nm nonporous layers of TiO2 on ITO, deposited by metal-organic chemical vapor deposition (MO-CVD), and onto ~100 nm porous, nanostructured TiO2 layers, spin-coated from a suspension of P25 (Degussa) on ITO. Fluorescence quenching of the dyes on both types of TiO2 substrates is compared with that of dilute solutions of the dyes and with that of dye-coated, porous ZrO2 (Degussa) substrates. By functionalizing one of the porphyrin dimer components with carboxylic substituents, which bind to the TiO2 or ZrO2 substrate surface, either the zinc porphyrin (ZnP) or the free base porphyrin (H2P) component of the dimer can be made to be in direct contact with the substrate. These dimer-substrate arrangements are denoted ZnP-H2P- -TiO2 (dimer 1) and H2P-ZnP- -TiO2 (dimer 2), respectively, where "- -" denotes binding of the carboxyl-substituted porphyrin in the heterodimer to the substrate surface. In solution as well as deposited on ZrO2, in contact with the solvent without a redox couple, both types of dimers show efficient internal ZnP to H2P energy transfer. Deposited on TiO2, in the presence of the solvent, monolayers of both types of dimers show less efficient energy transfer than the dimers on ZrO2. For a ZnP-H2P- -TiO2 electrochemical cell the photocurrent action spectrum reproduces the absorption spectrum, i.e., contains contributions of both the ZnP and H2P moieties. By contrast, for H2P-ZnP- -TiO2 cells mainly the ZnP dimer component contributes to the photocurrent, demonstrating that in H2P-ZnP- -TiO2 cells electron transfer from the ZnP into the TiO2 substrate is faster than energy transfer to the adjacent free base porphyrin. The photocurrent action spectrum of the ZnP-H2P- -TiO2 cell also demonstrates that energy transfer in monolayers of this dimer results in sensitization of the semiconductor substrate, since the spectral response of a cell is enhanced with respect to that of a cell with a monolayer of a monomeric sensitizer. These results are relevant for the construction of a solar cell containing a supramolecular, light-collecting antenna
    Photogeneration and transport of charge carriers in a porphyrin p/n heterojunction.
    Savenije, T.J. ; Moons, E. ; Boschloo, G.G.K. ; Goossens, A. ; Schaafsma, T.J. - \ 1997
    Physical Review. B : Condensed Matter and Materials Physics 55 (1997)15. - ISSN 1098-0121 - p. 9685 - 9692.
    Photo-generation and transport of charge carriers in a porphyrin P/N-heterojunction.
    Savenije, T.J. ; Schaafsma, T.J. ; Moons, E. ; Boschloo, G.K. ; Goossens, A. - \ 1996
    In: Proc. 3rd European Conf. on Molecular Electronics. Leuven, Belgium - p. 248 - 251.
    Sensitization of thin TiO2 films with porphyrin monolayers.
    Boschloo, G.K. ; Koehorst, R.B.M. ; Goossens, A. ; Schoonman, J. ; Schaafsma, T.J. - \ 1996
    In: Proc. 3rd European Conf. on Molecular Electronics. Leuven, Belgium - p. 55 - 58.
    Organic solar cells using porphyrin assemblies on semiconductor substrates.
    Schaafsma, T.J. ; Wienke, J.A. ; Koehorst, R.B.M. ; Sudhölter, E.J.R. ; Kroon, J.M. ; Boschloo, G.K. ; Goossens, A. ; Schoonman, J. ; Schropp, R.E.I. ; Maree, T. - \ 1994
    In: Abstract 10th Int. Conf. Photochemical conversion and storage of solar energy. Interlaken, Switzerland - p. 555 - 556.
    Genetic analysis of Aspergillus niger mutants defective in benzoate-4-hydroxylase functions.
    Boschloo, J.G. ; Moonen, E. ; Gorcom, R.F.M. van; Hermes, H.F.M. ; Bos, C.J. - \ 1991
    Current Genetics 19 (1991). - ISSN 0172-8083 - p. 261 - 264.
    The influence of the preparation temperature of colloidal ruthenium dioxide on the photosensitized reduction of H+ ions.
    Kleijn, J.M. ; Boschloo, G.K. - \ 1991
    Journal of Electroanalytical Chemistry 300 (1991). - ISSN 1572-6657 - p. 595 - 606.
    Development of biocatalysts with mono-oxygenase activity: isolation, characterisation and expression of the Aspergillus niger bphA gene, a member of a new gene family of the cytochrome P450 superfamily.
    Gorcom, R.F.M. van; Boschloo, J.G. ; Tweel, W.J.J. van den; Hondel, C.A.M.J.J. van den - \ 1990
    In: Proc. 3rd Neth. Biotechn. Congr., H. Breteler et al. (eds). Amsterdam (1990) 104
    Development of biocatalysts with monooxygenase activity: isolation of and complementation with Aspergillus niger mutants defective in the conversion of benzoate in parahydroxybenzoate.
    Boschloo, J.G. ; Gorcom, R.F.M. van; Tweel, W.J.J. van den; Bos, C.J. - \ 1990
    In: Proc. 3rd Neth. Biotechn. Congr., H. Breteler et al. (eds). Amsterdam (1990) 96
    Development of biocatalysts with mono-oxygenase activity: isolation of, and complementation tests with Aspergillus niger mutants defective in the conversion of benzoate in para-hydroxybenzoate.
    Boschloo, J.G. ; Gorcom, R.F.M. van; Tweel, W.J.J. van den; Bos, C.J. - \ 1990
    In: Proc. 5th Eur. Congr. Biotechnology, Munksgaaard, Copenhagen (1990) 297. / Christiansen, C., Munck, L., Villadsen, J.,
    Transformation of Mycobacterium aurum by electroporation: the use of glycine, lysozyme and isonicotinic acid hydrazide in enhancing transformation efficiency.
    Hermans, J. ; Boschloo, J.G. ; Bont, J.A.M. de - \ 1990
    FEMS Microbiology Letters 72 (1990). - ISSN 0378-1097 - p. 221 - 224.
    Biocatalysts with mono-oxygenase activity: Isolation and characterisation of the A. niger BPHA gene, a member of a new gene family of the cytochrome P450 superfamily.
    Gorcom, R.F. van; Boschloo, J.G. ; Tweel, W.J. van den; Hondel, C.A.M.J.J. van den - \ 1990
    In: Abstract 6th Int. Symp. Genet. Industr. Microorg. GIM90, Strasbourg - p. 121 - 121.
    Isolation, characterization and expression of the Aspergillus niger bphA gene, a member of the cytochrome P450 gene family.
    Gorcom, R.F.M. van; Boschloo, J.G. ; Tweel, W.J. van den; Hondel, C.A.M.J.J. van den - \ 1990
    In: Abstract 8th Soc. Gen. Meeting Molecular biology of fungi, Nottingham, UK
    Isolation and molecular characterisation of the benzoate-p-hydroxylase gene (bphA) of Aspergillus niger: a member of a new gene family of the cytochrome P450 superfamily.
    Gorcom, R.F.M. van; Boschloo, J.G. ; Kuyvenhoven, A. ; Lange, J. ; Vark, A.J. van; Bos, C.J. ; Balken, J.A.M. van; Pouwels, P.H. ; Hondel, C.A.M.J.J. van den - \ 1990
    Molecular and General Genetics 223 (1990). - ISSN 0026-8925 - p. 192 - 197.
    Genetic analysis of benzoate metabolism in Aspergillus niger.
    Boschloo, J.G. ; Paffen, A. ; Koot, T. ; Tweel, W.J.J. van den; Gorcom, R.F.M. van; Cordewener, J.H.G. ; Bos, C.J. - \ 1990
    Applied Microbiology and Biotechnology 34 (1990). - ISSN 0175-7598 - p. 225 - 228.
    Development of biocatalysts with mono-oxygenase activity: isolation, characterization and expression of the Aspergillus niger bphA gene.
    Gorcom, R.F.M. van; Boschloo, J.G. ; Hondel, C.A.M.J.J. van den - \ 1989
    In: Book of Abstracts EMBO-Alko Workshop Molecular biology of filamentous fungi, Espoo, Finland - p. 36 - 36.
    Construction of strains for transformation in Aspergillus niger.
    Bos, C.J. ; Boschloo, J.G. ; Debets, A.J.M. ; Swart, K. - \ 1989
    In: Book of Abstracts EMBO-Alko Workshop Molecular biology of filamentous fungi, Espoo, Finland - p. 25 - 25.
    Strain construction and genetic analysis in Aspergillus niger.
    Bos, C.J. ; Boschloo, J.G. ; Debets, A.J.M. ; Swart, K. - \ 1989
    In: Book of Abstracts 15th Fungal genetics Conf., Asilomar, USA - p. 30 - 30.
    Strain construction and genetic analysis in Aspergillus niger.
    Bos, C.J. ; Boschloo, J.G. ; Debets, A.J.M. ; Swart, K. - \ 1989
    Fungal Genetics Newsletter 36 (1989). - ISSN 0895-1942 - p. 17 - 17.
    Localization of genes involved in alkene degradation in Mycobacterium aurum.
    Hermans, J. ; Huijberts, G.N.M. ; Boschloo, J.G. ; Bont, J.A.M. de - \ 1988
    In: Proc. 2nd Neth. Biotechnology Congr., Amsterdam / Breteler, H., van Lelyveld, P.H., Luyben, K.Ch.A.M., - p. 147 - 148.
    A transformation procedure for Mycobacterium aurum.
    Hermans, J. ; Boschloo, J.G. ; Bont, J.A.M. de - \ 1988
    In: Proc. 2nd Neth. Biotechnology Congr., Amsterdam / Breteler, H., van Lelyveld, P.H., Luyben, K.Ch.A.M., - p. 149 - 149.
    Hydroxylering van benzoaat door A. niger.
    Boschloo, J.G. ; Bos, C.J. - \ 1988
    Unknown Publisher
    Pathway and characteristics of enzymes of benzoate degradation in Aspergillus niger.
    Cordewener, J.H.G. ; Busink, R. ; Boschloo, J.G. ; Bos, C.J. ; Visser, J. - \ 1988
    In: Abstract 4th Meeting Int. Workshop Microbial physiology and the manufacturing industry. Hajduszoboszlo, Hungary (1988)
    Development of biocatalysts with mono-oxygenase activity: isolation and characterization of the Aspergillus niger bph gene.
    Gorcom, R.F.M. van; Boschloo, J.G. ; Hondel, C.A.M.J.J. van den - \ 1988
    In: Proc. 2nd Neth. Biotechnology Congr. / Breteler, H., van Lelyveld, P.H., Luyben, K.Ch.A.M., - p. 179 - 179.
    Verslag van het onderzoek naar de hydroxylering van benzoaat door Aspergillus niger.
    Bos, C.J. ; Boschloo, J.G. ; Cordewener, J.H.G. ; Visser, J. - \ 1987
    Unknown Publisher
    Verslag van het onderzoek naar de hydroxylering van benzoaat door Aspergillus niger.
    Bos, C.J. ; Boschloo, J.G. ; Cordewener, J.H.G. ; Visser, J. - \ 1987
    Unknown Publisher
    Hydroxylering van benzoaat door A. niger.
    Bos, C.J. ; Boschloo, J.G. ; Cordewener, J.H.G. ; Visser, J. - \ 1987
    Unknown Publisher
    Development of biocatalysts with mono-oxygenase activity: Pathway and characterization of enzymes with benzoate degradation in Aspergillus niger.
    Cordewener, J.H.G. ; Busink, R. ; Boschloo, J.G. ; Visser, J. ; Bos, C.J. - \ 1987
    In: Proc. 4th Eur. Congr. Biotechnology, O.M. Neijssel, R.R. van der Meer, K.Ch.A.M. Luyben (eds.). Elsevier Vol. 3 (1987) 366. Ook: Abstr. 19th Lunteren Lectures
    Development of biocatalysts with mono-oxygenase activity: Isolation of the benzoate-para-hydroxylase gene of Aspergillus niger.
    Boschloo, J.G. ; Gorcom, R.F.M. van; Bos, C.J. ; Pouwels, P.H. ; Hondel, C.A.M.J.J. van den - \ 1987
    In: Proc. 4th Eur. Congr. Biotechnology, O.M. Neijssel, R.R. van der Meer, K.Ch.A.M. Luyben (eds.). Elsevier Vol. 1 (1987) 414. Ook: Abstr. 19th Lunteren Lectures
    Mutagenicity with a duplication strain of Aspergillus nidulans heterozygous for a sorbose resistance marker.
    Boschloo, J.G. ; Bos, C.J. - \ 1986
    In: Abstr. 5th Int. Symp. Genetics Industrial microorganisms, Split, Yugoslavia - p. 124 - 124.
    Development and standardization of a mutagenicity test system using Aspergillus nidulans as test organism
    Boschloo, J.G. - \ 1985
    Landbouwhogeschool Wageningen. Promotor(en): J.H. van der Veen. - Wageningen : Boschloo - 115
    aspergillus - biologische technieken - uitrusting - experimenten - methodologie - mutagenese - aspergillus - biological techniques - equipment - experiments - methodology - mutagenesis

    The suitability of Aspergillusnidulans as a test organism for mutagenicity testing has been investigated. Several test systems have been tried. Those systems were preferred in which the mutants or recombinants could be selected without the need of adding a compound to the medium which itself is genetically active.

    Four incubation methods have been compared. The plate incorporation assay (method 1) is the easiest method for testing chemical compounds, but it is often difficult to obtain reliable quantitative data. Moreover, complications may arise when the compound is toxic or causes a selective advantage of the mutants. In the liquid suspension test (method 2) the conditions can be controlled more accurately, so this method is more suitable for obtaining reliable quantitative data. For testing germinating conidia, the suspension test (method 3) turned out to be less suitable, since some conidia germinated directly from the start causing - in spite of the presence of 0.2% agar - big clumps of conidia at the end of the incubation period. Germinating conidia (and growing mycelium) can better be tested with the media mediated assay (method 4). However, an extra control experiment must be performed in order to discriminate between a real mutagenic activity and a selective advantage.

    Strain 110, which carries the methGl allele, proved to be very suitable for measuring the point mutation frequency when methionine independent suppressor mutants are scored. The instability of a duplication strain can be also used as an indication for the genetic activity of a chemical compound. The construction of a duplication strain heterozygous for the recessive sorA2 allele (strain 007) reduced the number of plates needed for the scoring of segregants. The exact process by which the sectors arise is not known. Some crossing-over products are scored as deletion products when no special attention is
    paid to the morphology of the segregants.
    For determining the crossing-over and non-disjunction frequencies scoring of mitotic segregation is the easiest way, at least when it is not intended to distinguish the inducing processes. If such a distinction is required, it is easier to select the recombinants. Strain D4 can be used to select recombinants homozygous for the suAladE20 allele, and the crossing-over and non-disjunction products can be directly distinguished by their conidial colour. In practice, complications arose since the conidial colour was faint and the leaky growth of the test strain led to a concentration effect. Selection of sorbose resistant recombinants was even less suitable, and a combinated selection of sorbose resistant and adenine prototroph recombinants proved unfeasible. Selection of pimaricin resistant recombinants of strain D7 was much easier and therefore preferably used in this study. However, since pimaricin itself is known to induce non-disjunctions this system has only been used in combination with the media mediated assay to minimize the risk of complications.

    The system for measuring the frequency of recessive lethals developed by Morpurgo et al. (1978) has also been investigated, but the background in the control was relatively high. This was most likely caused by incomplete haploidization on FPA medium. Changing the medium did hardly improve the results. This implies that one can only measure larger effects on the frequency of recessive lethals.
    Several chemicals, mostly with known mutagenic properties have been tested by means of the proposed test systems. These confirmed the suitability of the test systems.
    Thus, in addition to other mutagenicity tests like the Ames test with bacteria, the fungus Aspergillusnidulans offers good opportunities to asses the genetic activity of chemical compounds on eucaryotic organisms.

    D-galactose requiring mutants in Aspergillus nidulans lacking phosphoglucomutase
    Boschloo, J.G. ; Roberts, C.F. - \ 1979
    FEBS Letters 104 (1979). - ISSN 0014-5793 - p. 17 - 20.
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