Title Promoter Affiliations Abstract "Big, small or no data at all: resisting a 'smartness' that is 'all over the place' through art" "Karin Hannes" "Centre for Sociological Research" "Big,small or no data at all: resisting a smartness that is all over the place." "Downstream targets of the metabolic stress sensor SnRK1 - One kinase to rule them all" "Filip Rolland" "Molecular Biotechnology of Plants and Micro-organisms" "The evolutionarily conserved SnRK1 (SNF1-related kinase 1) protein kinase (the ortholog of yeast SNF1 and mammalian AMPK) is a major metabolic sensor, allowing acclimatization and energy homeostasis upon changes in energy availability, thereby ensuring plant survival. SnRK1 is activated by low energy stress and repressed by high photosynthetic sugar levels, with the allosteric inhibitor trehalose-6-P acting as a proxy for sucrose supply. To maintain energy homeostasis during energy-depleting stress conditions, SnRK1 not only induces catabolic processes (recovering C and energy from alternative sources), but also suppresses nonessential energy-consuming anabolic processes to redirect the C and energy fluxes to processes vital for plant survival. In this work, we explored plant growth and anthocyanin biosynthesis as energy-intensive processes directly repressed by SnRK1 activity in Arabidopsis thaliana. As a case study of redirection of resources to increased (a)biotic stress tolerance, we identified Plasmodiophora brassicae(clubroot disease) resistance in transgenic lines with increased SnRK1 activity and programmed cell death as a positively regulated target process in the plant’s immune response.Phenotyping of transgenic Arabidopsis lines with altered SnRK1 activity suggests a role for SnRK1 in growth rate control via repression of cell division activity and turgor-driven cell expansion. Cellular assays with transient overexpression of the cell cycle regulatory machinery in leaf mesophyll protoplasts identified different direct SnRK1 targets involved in the G1/S and G2/M phase transitions, consistent with a novel and perhaps counterintuitive role for SnRK1 as positive regulator of endoreduplication.Analysis of mutant and transgenic Arabidopsis lines and cellular assays with transient overexpression in leaf mesophyll protoplasts also confirmed SnRK1 as a negative regulator of anthocyanin biosynthesis and identified MYB75transcription factorexpression and MYB75/bHLH/TTG1 (MBW) transcription factorcomplex association and stability as its direct targets. Both the transcriptional and post-translational regulation appear to be mediated by TCP-type transcription factors. Consistently, we also identified these plant-specific transcription factors as part of the SnRK1 signaling network using a forward genetics approach with a tps1mutant suppressor screen based on the restoration of sucrose-induced anthocyanin accumulation and root growth.Finally, we assessed whether modification of SnRK1 activity is a viable strategy to broadly and more sustainably increase biotic stress tolerance using Plasmodiophora brassicae infection, causing clubroot disease in crucifer species (Brassicaceae). Preliminary qualitative phenotyping indeed showed an increased tolerance of Arabidopsis plants upon overexpression of the SnRK1 catalytic subunit, SnRK1α1, without a significant effect on seed yield and total seed fatty acid content, economically important traits for closely related oleaginous Brassica crops such as rapeseed.Resistance to clubroot infection in some cases coincides with the onset of a hypersensitive response and several reports point to SnRK1 as a positive regulator of the associated programmed cell death. Using cellular assays, we identified the LSD1/bZIP10 pathway as a likely direct positively regulated target of SnRK1, possibly stimulating cell death upon pathogen recognition or pathogen-dependent energy depletion.In conclusion, the results obtained in this work contribute to our understanding of the processes targeted by the metabolic stress sensor SnRK1 upon carbon and energy depletion. Detailed elucidation of the downstream signaling network will enable more directed selection and precision breeding of crops with increased yields and enhanced performance in stressful and increasingly unpredictable environments." "Long-term neurocognitive outcome of critically ill children after hospital discharge." "Adrian Covaci" "Laboratory Experimental Medicine and Pediatrics (LEMP), Toxicological Centre" "This project represents a formal research agreement between UA and on the other hand the client. UA provides the client research results mentioned in the title of the project under the conditions as stipulated in this contract." "FuPLATex - Functionalization of PLA fibers and textiles" "Raf Van Olmen" "R&D Functional Thermoplastic Textiles" "in te vullen" "Novel insights in the HPA-axis during critical illness" "Greet Van den Berghe" "Laboratory of Intensive Care Medicine" "Critical illness is defined as any condition that requires support of failing vital organ functions, without which death would rapidly ensue. As such, it represents an extreme example of physical stress, where stress comprises the normal physical response of the human body that ariseswhen confronted with a threat. In healthy individuals, experiencing stress causes an immediate activation of the hypothalamic-pituitary-adrenalaxis, which induces secretion of the hypothalamic corticotropin-releasing hormone, followed by the release of adrenocorticotropic hormone (ACTH) from the anterior pituitary gland. ACTH causes production of cortisol from cholesterol in the adrenal gland. Cortisol itself exerts feedback inhibition at the pituitary and the hypothalamic level, as such regulating its own release. Under normal conditions, these hormones are secreted in a pulsatile manner according to a fixed daily rhythm. Whenever stressoccurs, activation of the hypothalamic-pituitary-adrenal axis causes anadditional episodic release of cortisol.Critical illness is therefore hallmarked by the presence of high circulating cortisol levels, proportionate to the severity of illness. This was traditionally attributed to activation of the hypothalamic-pituitary-adrenal axis and increased ACTH-driven cortisol production. However, ACTH levels were observed to be low, suggesting that non-ACTH dependent regulators of cortisol production are important during critical illness. Cortisol production has even never been quantified during critical illness. Furthermore, it is assumed that activation of the hypothalamic-pituitary-adrenal axis can sometimesbe insufficient to cope with severe illness. In the presence of high plasma cortisol, this condition has been labeled relative adrenal insufficiency. However, the underlying mechanisms remain unknown. Also, it remains controversial whether treating such patients with corticosteroids is required, as interventional studies provided conflicting results. The main objective of this doctoral thesis was to explore the regulation of cortisol secretion and metabolism during critical illness in order to gain more insight in the pathophysiology of adrenal insufficiency. The general hypothesis of this doctoral thesis postulated that during critical illness reduced cortisol breakdown, rather than continuously stimulated cortisol secretion, contributes to maintain the elevated plasmacortisol concentrations. Negative feedback inhibition, exerted by high circulating cortisol levels would then explain low ACTH levels. When ACTH deprivation sustains, adrenal integrity and function could be negatively affected, predominantly in the prolonged phase of critical illness.In a first part, we investigated in critically ill patients and matched healthy control subjects daily ACTH and cortisol levels in plasma during the first week of illness; plasma cortisol clearance and production during infusion of cortisol isotopes as tracers; plasma clearance of 100 mg of synthetic cortisol and the urinary cortisol metabolites and enzymeexpression at tissue level to assess the major cortisol-metabolizing enzymes. This showed that while circulating cortisol levels were consistently higher in patients than in controls, ACTH levels were decreased during critical illness. Cortisol production was less than doubled in patients. Furthermore, critically ill patients showed a more than 50% reductionin cortisol clearance during tracer infusion and after the administration of exogenous cortisol. All these factors accounted for the 4-fold increased plasma cortisol levels in patients, as compared with controls. Reduced cortisol metabolism was explained by reduced inactivation of cortisol in the liver and kidney of patients.In the first study, only single sample ACTH and cortisol concentrations were reported. Since both ACTH and cortisol are secreted in pulses, this precludes analysis of theirsecretory dynamics and their relation during critical illness. In a second study, we therefore analyzed the dynamics of ACTH and cortisol secretion in critically ill patients and matched healthy control subjects, via nocturnal time series of repeated blood samples.  We documented that hypercortisolemia during critical illness coincided with suppressed pulsatile ACTH and cortisol secretion, whereas the cortisol secretory response to a given plasma ACTH concentration was unaltered. These findings speak against the classical dogma of an activated hypothalamic-pituitary-adrenal axis in critical illness and instead suggest feedback-inhibition on ACTH exerted by circulating cortisol. Considering the important function of ACTH in ensuring adrenal structure and function, theobserved low ACTH levels could negatively affect the adrenal glands, possibly predominantly in patients who stayed in the ICU for a prolonged time. In the third part of this thesis, we therefore investigated post-mortem adrenal glands from patients who died in the intensive care unit compared to adrenal glands from sudden out-of-hospital deaths as controls.Adrenal glands from patients who stayed long in the intensive care unitwere clearly more distorted in structure. Furthermore, the amount of stored cholesterol droplets was reduced in the adrenal glands from these patients. We also showed that the genes responsible for cholesterol uptake and synthesis as well as crucial genes for the production of cortisol were downregulated only in prolonged critically ill patients. Since cortisol cannot be stored in the adrenal gland and its production is dependent on rapid synthesis from cholesterol, these alterations limit cortisolproduction. Given that all the observed alterations are regulated by ACTH, one could speculate that the observed low ACTH levels might play a role and, when ACTH deprivation sustains, may help to explain the increased incidence of adrenal failure in the prolonged phase of critical illness.In conclusion, reduced cortisol metabolism contributes to high cortisol levels during critical illness. Consequently, these high cortisollevels could suppress pulsatile ACTH secretion by negative feedback inhibition, causing acutely a reduced pulsatile cortisol secretion. Maintaining cortisol by not breaking it down seems a highly energy efficient way. However, the concurrent low ACTH levels could explain the observed disruption in structure and function of the adrenal gland in the prolongedphase of critical illness. These novel insights help to understand adrenal failure during critical illness and may have important implications for its diagnosis and treatment. " "Study of the role of the pituitary in prolonged critical illness" "Greet Van den Berghe" "Laboratory of Intensive Care Medicine" "The critically ill condition is characterized by biphasic alterations in all hypothalamus driven hormone axes which disrupt normal homeostasis and lead to metabolic and immunological changes. In the first hours to days after severe physical stress, the pituitary is actively secreting its hormones into the circulation while anabolic target hormone levels in the periphery are reduced. The chronic phase of critical illness is characterized by a markedly reduced pulsatile secretion pattern of pituitaryhormones, which is now related to the low circulating levels of peripheral anabolic target hormones. The neuro-endocrine impairment in prolonged critical illness co-occurs with the ongoing hypercatabolism which contributes to the wasting of critically ill patients. Based on previous observations, we hypothesize that the biphasic stress response in the ICUis caused by perturbations at the level of the hypothalamus instead of a disturbed pituitary hormone secretion. An impaired hypothalamic function could also explain the observed hypercatabolism, since the equilibrium between energy intake and energy expenditure is regulated by a homeostatic circuit in the hypothalamus. We will thoroughly investigate the changes in hypothalamic control and morphological changes in the pituitary during acute and chronic critical illness using our animal model of illness and test different therapeutic strategies to elucidate the mechanisms of neuro-endocrine dysfunction and hypercatabolism in critical illness." "Transport infrastructure and regional development in China during the Maoist era" "Valeria Zanier" "Chinese Studies, Leuven" "1. IntroductionThis project aims to investigate the link between transport infrastructure and regional economic development in China during the Mao era. Economists argue that public investments have a positive impact on economic growth for a number of reasons. As we will elaborate in what follows, the Chinese story contains many unique and intriguing elements which complicate this statement. A thorough investigation of the topic will allow us to better understand present day’s China in terms of infrastructure and variations in economic development. Furthermore, it will provide guidelines for countries which are presently on the path of development.This PhD project will touch upon several academic fields, among which development economics and Chinese history. In this section we first explore the link between transportation and economic development, after which we turn to the Chinese case.2. The relation between transport infrastructure and economic growth2.1. Transportation and economic growthThe PhD project is mainly interested in the effects of transport investments on economic development. Since Aschauer’s pioneering study in 1989, the link between public investment and economic growth has become a popular research topic. Aschauer suggested that infrastructure investments had a significant positive effect on economic production. Theoretically, one can make a strong case why transport infrastructure would have a positive impact on economic growth. First, factor mobility is considered requisite for economic development, industrialisation and growth (Banerjee et al., 2012; Wu Wenjie, 2017, p. 141). Second, a proper transport network reduces both travel time and transportation costs, which increases efficiency. Third, improved accessibility of (remote) regions enlarges the market size. On the one hand, this stimulates local production and development. On the other hand, it improves competition between firms, which threatens the existence of monopolies and pushes companies to explore more efficient production methods. Fourth, free movement of people improves the efficiency of the labour market. Finally, a reliable and dense transport system attracts national and foreign investments (OECD, 2002; Sloboda & Haliemun, 2010; Qu Xiaojuan, 2012; Hong Junjie et al., 2011).However, although most scholars agree that public investment in transport has a positive impact on economic growth, empirical research finds mixed evidence of the magnitude of this impact. Some authors point out to the fact that transport infrastructure is indeed a necessary, but not a sufficient condition for economic growth (Blum & Dudley, 2002, p. 56; Wei Zou, 2008). Furthermore, scholars vary in their understanding of the causal direction of this relationship. While a bunch of literature supports the idea that infrastructure promotes economic development (e.g. Barro, 1990; Bleaney et al., 2001), others find that transport infrastructure is mainly a result rather than a cause of economic growth. The latter is in line with Wagner’s law, which prescribes that higher incomes will lead to higher public investments (e.g. Wagner, 1958; Verma & Arora, 2010). All in all, empirical results vary greatly depending on which direct and indirect effects are accounted for in the econometric model, and on which place and time are being investigated. More research on the relation between transport infrastructure and economic growth is required, as this will bring important insights for both economists and policy-makers (Montolio & Solé-Ollé, 2007).2.2. Transportation in developing countriesThe past thirty years, the majority of research has been focusing on investments and growth in developed countries. Much less attention has been devoted to developing countries. Transport infrastructure will most probably have another impact on economic growth in less-developed countries than it does in high-developed nations. The Industrial Revolution in the Western world was strongly supported by the existence of trains and railways for the transport of primary resources to the industrial centres. At the start of industrialisation, a transport network is of great importance to make specialisation, agglomeration effects and scale effects possible (Njoh, 2000). Unfortunately, there is a dearth of empirical literature on the impact of transport infrastructure in developing countries. However, recently some scholars are starting to investigate this topic. O’Fallon (2003) finds that the impact of transport infrastructure on the economy is higher in developing countries than in first world countries. Njoh’s results describe a significant positive relationship between infrastructure and development in Sub-Sahara Africa. Mapuru & Mazumder (2017), on the other hand, comes to the conclusion that regional development in India is more or less in line with Wagner’s law.Disparities in regional economic development has drawn a lot of scientific attention during the past sixty years. Kuznets (1955) was the first to introduce the ‘inverted-U-hypothesis’, which suggests that in the early stages of economic development, income inequality within the country first rises, before it falls again in a later phase. In the following decades, there have been studies confirming this hypothesis (e.g. Lindert & Williamson, 1985), while others have been challenging it (e.g. Alesina & Rodrik, 1994). Until today, theories and empirical results are mixed (e.g. Forbes, 2000; Barro, 2000). Related to this, Williamson (1965) perceived that in developing countries all over the world, there tend to be one (or a few) regions within a country developing earlier and faster than others – causing inequality to increase. This is a peculiar phenomenon, as one would expect knowledge and technology to spread easily within national borders. Williamson considers the absence of a proper transport and communication network as a possible explanation.3. Transport infrastructure and regional development in Mao’s ChinaThe above makes clear that many questions regarding the impact of transport infrastructure in developing countries remain to be solved. This is especially the case for China in the 20th century, certain unique characteristics of this period make the link between infrastructure and regional development even more complex. However, we start with a concise overview of the socio-economic situation in China during the communist period.3.1. China during the Mao eraMost scholars agree to date the Mao era from 1949 (the year in which the People’s Republic of China was founded) until 1978 (the start of the economic Reform and Opening). This period in Chinese history was characterised by the implementation of a planned economy and an authoritarian party-state, while the ideas of Chairman Mao Zedong were presented as the national ideology. Both historians and economists tend to emphasize the shortcomings of the socialist economy, which resulted in a distortion of incentives, low productivity and low economic growth, notwithstanding the two ‘disasters’ of the Great Leap Forward and the Great Cultural Revolution. However, much less highlighted is the fact that much progress was made in terms of human development. Both literacy and schooling levels improved, and life expectancy rose rapidly. By 1978, the Gini-coefficient in China was 0.30, one of the lowest in the world (Naughton, 2007, p. 218). Gini thereafter rose rapidly during the period of economic reforms, to 0.47 in 2017 (CEIC National Bureau of Statistics, 2018). While some scholars consider the thirty years of Maoism as a black page in Chinese history (e.g. Deng & Shen, 2018), others tend to highlight the rather positive social outcomes (e.g. Bramall, 2009). This is to show that nothing is black or white: although communism had many flaws, this should not cause us to overlook possible positive aspects.3.2. The link between transportation and economic development in a planned economyThe Chinese territories cover a vast area with distinctive geographical structures. While the east coast is flat and easily accessible, with a high population density, the west is characterised by deserts and mountains, which makes it a lot more difficult to access. In 1949, China’s road and railway network was rather primitive, although there had been some efforts to expand the transport network during the Republican Era. The first five-year plan was mainly concerned with rebuilding infrastructure after the war. Furthermore, the railway network was expanded inland with aid of the Soviet Union, with the eye on industrialisation (Mom, 2018). In the following years, the construction of roads and railroads took place in the North- and Southwest. On the one hand for the goal of supporting heavy industry there, on the other hand as a means for ‘territorial integration’. Within a socialist context, all citizens and minorities should be united as one, therefore, a proper transport and communication network would make the spread of central policy measures easier (Comtois, 1990; Wu Wenjie, 2017, p. 3). When the relation with the USSR deteriorated in the 1960s, much investment flew to transport infrastructure in the Western ‘thirdtier’regions, in order to make them easily accessible – and thus defensible against foreign powers. During the Cultural Revolution (1966-1976), transportation was severely disturbed. In summary, by the end of the Mao era, the transport network had considerably expanded since 1949, but the density of roads remained to be much higher in the East than in the Western regions. This brief overview shows that investment decisions did not only stem from economic considerations, on the contrary the government was very concerned with social unification and defence. Regarding regional economic development, one would expect of a planned economy that all investment decisions were made on a national level by party policy-makers. However, reality proved to be different. Although there was indeed an overarching central policy, much independence was granted to the local governments, especially since the 1960s. As a result of this self-sufficiency, cities and localities executed different plans and therefore followed uneven developmental paths (Wu Wenjie, 2017; Démurger, 2001). There exists a dearth of literature on this topic, local party archives should be investigated to attain a more thorough understanding of this phenomenon.While several scholars have focused on regional economic development in China and its link with transport infrastructure since the Reform and Opening, it is surprising that there are no studies concerned with the impact and planning of transport during the communist era. Only Wu Wenjie (2017) touches upon this topic, but mainly focuses on general planning policies. Researchers concerned with the period after 1978 came to mixed results, but the overall conclusion seems to point to a positive impact of transport infrastructure on economic development. Wei Zou et al. (2008) suggest a unidirectional positive relationship between transport investment in poor regions and economic growth. Banerjee et al. (2012) find that proximity to transport networks has a moderate positive effect on household incomes. Both Wei Zou et al. and Banerjee et al. explain their results in terms of improved factor mobility. Démurger concludes that differences in geographic location and transport and telecommunication networks have a significant impact onthe variation in economic growth between provinces. Yu et al. (2011) find a bidirectional relationship between transport infrastructure and economic growth in the affluent eastern regions for the period 1978-2008. However, for the low-income regions in the centre and the west and on a national scale, the results point to a unidirectional relation in which economic growth induces investments in transport infrastructure. This is in line with Mohmand et al.’s (2016) conclusions for Pakistan." "Ecology, systematics and evolutionary biology of frog blood parasites in northern KwaZulu-Natal" "Nico Smit, Luc Brendonck" "Ecology, Evolution and Biodiversity Conservation" "Blood parasites have been recorded in a variety of vertebrate and invertebrate hosts, inhabiting both aquatic and terrestrial environments. Until this study, only a few blood parasite surveys had been carried out on frogs in sub-Saharan Africa. Thus information on the diversity of these parasites remained limited. To increase our knowledge of frog blood parasites, a large multi-approach study on the diversity, evolutionary biology, and ecology of frog blood parasites was undertaken. The majority of the fieldwork took place in northern KwaZulu-Natal (KZN), South Africa, focussing specifically on the area adjacent to the Phongolo River and its associated floodplain. However, samples also included those collected from frogs in the southern regions of the Kruger National Park, South Africa, and from frogs in Belgium. The latter was fortuitous, as Europe is the type locality for many frog blood parasite species and genera. These samples provided essential data for phylogenetic comparisons between the African and European species. Presently this is the largest multi-species, generic and family amphibian blood parasite survey to be completed, including a total of 643 anurans of 38 species, 20 genera and 13 families. The study was divided into three main components for the collection, analysis and reporting of data. The first component was to determine the frog blood parasite diversity, the second to determine phylogenetic relationships in conjunction with the former component, and lastly the ecological and host-vector-parasite relationships. Blood samples were drawn from the femoral artery of each frog and thin blood smears prepared for screening and morphometrics; the remaining blood fixed in 70% molecular grade EtOH for later molecular analysis. Giemsa stained blood smears were screened microscopically for the presence of any blood inhabiting organisms. Positive infections were then further analysed according to the aims of the respective chapters. Analyses included both morphological and molecular aspects. Morphology was used for the description and identification of species, and molecular analyses were used to assist with the morphology-based descriptions, as well as to allow for phylogenetic relationship comparisons of the blood parasites with one another.In the present study, three new species of Hepatozoon were described from hyperoliid frogs (Afrixalus fornasini, Hyperolius argus, and Hyperolius marmoratus), namely Hepatozoon involucrum Netherlands, Cook & Smit, 2018; Hepatozoon tenuis Netherlands, Cook & Smit, 2018; and Hepatozoon thori Netherlands, Cook & Smit, 2018. Phylogenetic relationships show that species of Hepatozoon isolated from African frogs form as a monophyletic group, separate from the species of Hepatozoon isolated from European and North American frogs. Two species of Dactylosoma Labbé, 1894, were found parasitising three species of frogs namely, Ptychadena anchietae and Sclerophrys gutturalis from South Africa, as well as Pelophylax lessonae from Belgium. Based on morphometrics and molecular findings a new dactylosomatid, Dactylosoma sp. 1, is described form Pty. anchietae and Scl. gutturalis. The species of Dactylosoma isolated from Pel. lessonae conforms morphologically with Dactylosoma splendens Labbé 1894, thus placing in question the validity of D. splendens synonymy with D. ranarum (Kruse, 1890). Phylogenetic analysis shows species of anuran Dactylosoma as a monophyletic group, separate from the other haemogregarine groups. Five species of frogs from South Africa and two from Belgium were found parasitised with haemococcidia. Based on morphological, morphometric and molecular findings Lankesterella minima (Chaussat 1850) is redescribed from Pelophylax kl. esculentus (Linnaeus, 1758) and Pel. lessonae (Camerano, 1882) from Belgium. Additionally, two new species of Lankesterella were described, namely Lankesterella sp. 1 in Pel. lessonae from Belgium, and Lankesterella sp. 2 in Afr. delicates and Afr. fornasini from South Africa. Furthermore, a new genus of haemococcidia, with a new species combination, is described from Phr. mababiensis, Pty. anchietae, and Pyx. edulis from South Africa; as well as a new species, haemococcidia sp. 2, described from Afr. fornasini from South Africa. This is the first study to provide molecular data for species of haemococcidia from African and European anurans.A new species of amphibian filarial nematode (Onchocercidae: Waltonellinae) was described from the toads Scl. gutturalis and Scl. garmani. The life history of this nematode was elucidated from its natural mosquito vectors Uranotaenia (Pseudoficalbia) mashonaensis and Uranotaenia (Pfc.) montana. All stages of development were characterised using morphological and molecular methods. This study is the first to elucidate the life history of an amphibian filarial nematode from southern Africa, and provide data on its phylogenetic placement within the Onchocercidae. In addition to the taxonomic and phylogenetic perspective of this study, this study also aimed at exploring the potential of frog blood parasites as indicators of environmental health. For this, blood parasites infecting grass frogs (Ptychadena Boulenger, 1917) from the Phongolo River system in South Africa were used as a case study. In general, findings indicate that frogs from more impacted sites harboured more blood parasites than from less-impacted sites.In summary, this study explored the efficacy of a large multi-species, multi-approach survey on the diversity of frog blood parasites from northern KwaZulu-Natal, South Africa. Based on the results several new species of frog blood parasites from different taxa were discovered and described, greatly contributing to knowledge and species records on the overall diversity of frog blood parasites from South Africa. Furthermore, this study provides the first molecular data for species of Dactylosoma and Lankesterella for frogs from Africa, as well as the first molecular data for a filarial nematode for frogs from South Africa. The phylogenetic relationships of species of Hepatozoon, Dactylosoma, Lankesterella, and the filarial nematode were also characterised based on comparisons to other available molecular data. From an ecological perspective, blood parasites from this study adhere to several criteria of what is considered a good indicator and thus demonstrate potential as indicators for healthy ecosystems and intact food webs. The results of this study establish a foundation for future research into the blood parasite biodiversity in northern KZN, an area that this study has highlighted as not only rich in anuran diversity, but also rich in anuran blood parasite diversity. Furthermore, this study provides a baseline for future taxonomic and ecological studies on these parasite groups, not only in South Africa but globally as well." "Local and systemic immune interactions in malignant gliomas" "Steven De Vleeschouwer" "Research Group Experimental Neurosurgery and Neuroanatomy, Inborn Errors of Immunity" "Glioblastoma (GBM), the most frequent primary intrinsic brain tumor, is without any doubt one of the most devastating diseases known to mankind. GBM are currently being treated with neurosurgical resection followed by radio- and chemotherapy. However, despite this treatment, prognosis for these patients is grim with a median survival of only 15 months and less than 20% 3-year survival rates. Already at diagnosis, GBM cells are infiltrating beyond the visible tumor margins, making complete resection impossible. A therapy-resistant subpopulation of these remaining cells eventually leads to tumor recurrence.In the past 2 decades, immunotherapy has gained interest as a possible fourth treatment strategy. Immunotherapy is theoretically appealing, firstly because tumor-infiltrating cytotoxic immune cells could target all invasive cancer cells without damaging surrounding normal tissue. Secondly, when immunological memory develops, responses can be long-lasting without the need of persistent administration of therapy. For GBM, these concepts have been shown in preclinical animal models with several vaccination strategies. However, until now no randomized immunotherapy trials have been able to shown survival benefit in humans.In this research project we aimed to get more insight in the complex interactions between the immune system and GBM, in particular the differences in immune profiles between the local tumor micro-environment and the systemic / peripheral compartment. We hypothesize that better understanding on how the immune system interacts with a developing GBM is essential to develop effective immunotherapy, or at least to understand why successful preclinical therapies don’t work in the clinical setting. For this research we used tumor tissue and blood samples from glioma patients, as well as the orthotopic murine GL261 malignant glioma model in which malignant brain tumors are induced by stereotactic injection of GL261 cells.In the first part of the research (Chapter 3 – Research paper 1), we focused on the immune checkpoint molecule PD-1 as a contemporary paradigm target for current immunotherapy in several cancers. PD-1 is a surface protein present on activated T-lymphocytes that, after binding with its ligand PD-L1, leads to a negative feedback signal. This pathway is being used by many cancers to suppress infiltrating lymphocytes, and blockade of PD-1 has been shown to reactivate anti-tumor T cells and prolong survival in advanced melanomas and other cancers. Using flow cytometry, we show a strong upregulation of PD-1 on tumor-infiltrating CD4+, CD8+ and regulatory T cells. This upregulation was not restricted to GBM, but also present in lower grade 2 and 3 gliomas. Moreover, we showed that PD-1 expression on circulating T-lymphocytes is not different between patients and healthy volunteers. In the GL261 model we found a similar upregulation on brain-infiltrating T cells, and markedly prolonged survival with a CD8+ driven T cell response after treatment with a PD-1 blocking antibody. This research provides further evidence for trials with PD-1 blocking strategies to treat GBM.In the second part of the research (Chapter 4 – Research paper 2), we wondered whether local and systemic immune profiles in human GBM could be related to specific biological subgroups of GBM. We studied a large cohort of patients with histologically proven GBM, which were treated with standard therapy and experimental immunotherapy. Tumor samples were subclassified according to DNA methylation profiles into 4 subgroups and a rest group with unclassifiable tumors. With immunohistochemistry, we quantified tumor-infiltrating CD3+ T cells and found these to be significantly more numerous in tumors belonging to the mesenchymal subgroup. On the other hand, IDH tumors had the lowest CD3+ T cell infiltration. This T cell infiltration contrasted with overall survival, which was significantly longer in IDH tumors than mesenchymal tumors. In a multivariate analysis, DNA methylation-based stratification of these tumors remained an independent variable for survival. We also characterized CD68+ myeloid cell infiltration, but found this not to be related to any methylation subgroups or survival. With flow cytometry, we also assessed T cell populations in the blood before and after radiochemotherapy in these patients. We found an overall reduction in lymphocyte count after radiochemotherapy, but relative increase in CD8+ T and CD8+ PD-1+ T cells in all subgroups except IDH tumors. Together, these finding support the hypothesis that histologically identical GBM can be classified into relevant biological subgroups, related to survival and T cell infiltration. Subclassification seems useful in trials as it is plausible that the efficacy of new therapies could be restricted to one or several subgroups.In the final part of the research (Chapter 5 – Research paper 3), we investigated the effects of subcutaneous implantations of living syngeneic GL261 cells in the murine GL261 malignant glioma model. We see living tumor cell vaccination as the theoretical most basic type of vaccination strategy, able to provide us with more insight in differences of immunity based on specific tumor location and timing of vaccination. The interest in heterotopic living tumor cell implantations originates from the rarity of extracranial metastasis of GBM, despite its local aggressiveness and frequent systemic dissemination of individual tumor cells. We found that subcutaneously implanted GL261 cells are rejected in > 80% of mice, while intracerebral implantations induce lethal tumors in all mice. Furthermore, 79% of mice that rejected subcutaneous tumors were protected against subsequent intracranial tumor implantation (prophylactic model). Immunologically, the brains of prophylactically vaccinated mice were noticed to have an early CD3+ CD8+ T cell influx and decreased regulatory T cells compared to control mice. Interestingly, unlike in control mice, an initial high PD-1 expression in prophylactically vaccinated mice decreased towards basal PD-1 expression 4 weeks after intracerebral tumor implantation. Despite the high protection rate in the prophylactic model, subcutaneous GL261 implantations did not induce any survival benefit in mice with established cerebral tumors, nor did they induce subcutaneous tumors. These findings confirm that the capability of the immune system to control and reject tumor cells depends on the implantation site, and that location-based prophylactic vaccination is possible with living unmodified tumor cells. However, in the presence of an established brain tumor, peripheral living tumor cell implantation isn’t capable anymore to induce a clinically beneficial immunity, nor does it seem to induce palpable tumors. As there seem to be different immunological answers to subcutaneous GL261 implantations in the prophylactic and established tumor models, the local subcutaneous microenvironment after GL261 implantation in these different models is currently further investigated with pathology and immunohistochemistry." "Model Platinum Catalysts" "Johan Martens" "Department of Materials Engineering, Center for Surface Chemistry and Catalysis: Characterisation and Application Team" "Platinum is used by many industries because of its exceptional catalytic activity, electrochemical properties and corrosion resistance. It is widely used as a catalyst in the chemical production, in fuel cell and electrolyser electrodes and in sensors for analytical and medical applications. Catalysts are key to face grand technological challenges in the fields of energy and environmental protection and to ensure a sustainable supply of chemicals and materials.Catalysts are shaped in many ways. Due to the high cost of platinum, most efforts are directed towards maximizing the exposed surface area in order to increase the utilization of the platinum itself and thus to reduce the Pt loadings. This is conventionally achieved through reducing the size of the Pt particles to the nanoscale by dispersing them on porous high surface area supports. For some specific applications, and especially electrocatalysis and molecular sensing, unsupported nanostructured platinum architectures, combining high exposed surface area with electric conductivity, are needed.Understanding kinetic data by relating it with structural and compositional properties is essential for rational design of new catalysts. Gaining scientific insight when using industrial catalysts is very difficult because of the complexity and heterogeneous nature of such materials. They often contain a combination of phases that can vary in bulk and surface structure, particle size, shape, chemical composition, defects, impurities, promotors and interactions among the different phases. Usually supports themselves are also irregular with a heterogeneous surface. Characterization is inherently challenging for these catalysts and the active site is ill-defined. This complexity has been the driving force for many researchers to use model catalysts. Many model studies have been previously reported using single crystals or Pt particles on planar supports. Yet, examples of well-characterized 3D Pt model catalysts were only scarcely reported.The primary focus of this thesis was on the synthesis and characterization of generic 3D model platinum catalysts that can be used in kinetic investigations of many types of reactions under practically relevant reaction conditions. Compared to planar model catalysts, the structural complexity of such 3D model catalyst systems is more closely related to the industrial catalysts.A first model system was prepared by using a monodisperse, spherical alumina support to reduce the complexity. Spherical alumina particles with a particle size of about 1 µm were synthesized by a chemical precipitation method. Using 2D and 3D electron microscopy and 27Al solid-state NMR, the core-shell structure of the particles was fully characterized. The spherical alumina particles were then decorated with uniform Pt nanoparticles (~1 nm) using the strong electrostatic adsorption method. To establish its relevance as a model catalyst, the Pt alumina catalyst was combined with erionite zeolite having comparable morphology to generate a bifunctional catalyst. The suitability of such a physical mixture with a well-characterized Pt model catalyst was demonstrated in the hydroisomerization-hydrocracking of n-decane.The potential of atomic layer deposition (ALD) of platinum for creation of model catalysts was investigated. ALD could even be used to introduce acid sites next to platinum performing bifunctional catalysis with zeolites. Plasma-enhanced ALD of Ga2O3 (Ga-ALD) was performed on COK-14, an all-silica zeolite that lacks acid sites. After ALD, metal sites were introduced via Pt incipient wetness impregnation. Using electron microscopy, Pt nanoparticles were found to be preferentially located on the edges of the COK-14 plates. The optimum proximity between the Ga acid and Pt metal sites resulted in high activity and selectivity surpassing other large pore zeolites. To understand the potential of ALD for introducing metal sites in a zeolite, Pt-ALD was performed on ZSM-5 zeolite, which resulted in finely dispersed Pt nanoparticles of 1-2 nm. The hydroisomerization experiments confirmed Pt-ALD to be an adequate method for introducing metal sites on aluminosilicate zeolites. This work demonstrates how ALD-tailored materials can help in understanding the relationship between structure and performance.The final model system was a continuous unsupported platinum catalyst with an open and porous structure. The structure was prepared using the hard templating concept, consisting of filling the pores of a mesoporous template followed by removal of the template. Pt-ALD was chosen for depositing Pt in the pores and Zeotile-4 was selected as the template. By using Pt-ALD, the replica structure could be created over micrometer distances. Such larger structures are valuable in electrode and sensor applications. The structure was studied in detail with electron microscopy and tomography. The applicability was demonstrated in the electrocatalytic hydrogen evolution reaction (HER). Furthermore, the suitability of the structure for use in biomedical sensors was demonstrated."