Search

The pervasive phenomenon of adaptivity in face-to-face interaction is described inconsistently, using numerous concepts (e.g. alignment/attunement/complementarity/imitation/reciprocity/scaffolding/synchrony), impeding the streamlining of adaptivity research. We explored 33 adaptivity concepts and various adaptivity theories from different fields. We developed a theory-based conceptual framework consisting of two key dimensions. Relatedness refers to how people’s actions should relate to each other to be considered adaptive and is described in terms of sameness (e.g. both friendly), oppositeness (e.g. dominant/submissive), or specified attentiveness (dissimilar acts). Responsivity refers to the timing of people’s actions (sequential/simultaneous). The framework helps to understand what key elements adaptivity consists of. The framework can help transcending the concept and discipline level and examining and synthesizing research pertaining to adaptivity with similar dimensional characteristics.

Hot-humid environmental conditions have a negative impact on exercise performance and increase the risk of exertional heat illness. To attenuate the adverse effects of heat stress, athletes can adopt heat mitigation strategies such as heat acclimation and cooling. In this thesis, we assessed individual responsiveness to exercise under heat stress and heat mitigation strategies. First, we focused on heat-induced performance decrements in able-bodied and para-athletes. In Chapter 2, we observed that, for both able-bodied and para-athletes, performance was substantially impaired in hot-humid compared to temperate conditions. We did, however, observe considerable inter-individual variability, suggesting that some athletes need to invest more in heat mitigation strategies (i.e., cooling and heat acclimation) than others. Second, we focused on heat acclimation in recreational athletes. In Chapter 3, we demonstrated that the magnitude of adaptations following humid heat acclimation varied across individuals. We found that individuals with a relatively large body mass showed large sweat rate adaptations, whereas individuals with a relatively small body mass showed large heart rate adaptations. In Chapter 4, we observed that humid heat acclimation did not negatively affect salivary immunoglobulin-A (i.e., an important biomarker of the mucosal immune system), self-reported respiratory illness symptoms, and self-reported wellness parameters. Third, we focused on heat mitigation strategies in para-athletes. Para-athletes with a spinal cord injury perform upper-body exercise, and therefore lower-body cooling may be convenient. However, in Chapter 5, we observed that for these athletes, lower-body cooling was less effective in lowering heat strain compared to upper-body cooling. In Chapter 6, we observed that many para-athletes at the Tokyo 2020 Paralympic Games used heat acclimation and cooling strategies, which may have contributed to the low incidence of exertional heat illness. Altogether, the observations in this thesis indicate that heat mitigation needs and responsiveness vary across athletes, emphasizing that a one-size-fits-all heat mitigation approach may be suboptimal. Practitioners are encouraged to measure (thermo)physiological responses of individual athletes in the lab and/or field to determine their personal heat mitigation needs and responsiveness. Future studies should aim to further elucidate what factors influence the individual responsiveness to exercise under heat stress, cooling, and heat acclimation.

Hot-humid environmental conditions have a negative impact on exercise performance and increase the risk of exertional heat illness. To attenuate the adverse effects of heat stress, athletes can adopt heat mitigation strategies such as heat acclimation and cooling. In this thesis, we assessed individual responsiveness to exercise under heat stress and heat mitigation strategies. First, we focused on heat-induced performance decrements in able-bodied and para-athletes. In Chapter 2, we observed that, for both able-bodied and para-athletes, performance was substantially impaired in hot-humid compared to temperate conditions. We did, however, observe considerable inter-individual variability, suggesting that some athletes need to invest more in heat mitigation strategies (i.e., cooling and heat acclimation) than others. Second, we focused on heat acclimation in recreational athletes. In Chapter 3, we demonstrated that the magnitude of adaptations following humid heat acclimation varied across individuals. We found that individuals with a relatively large body mass showed large sweat rate adaptations, whereas individuals with a relatively small body mass showed large heart rate adaptations. In Chapter 4, we observed that humid heat acclimation did not negatively affect salivary immunoglobulin-A (i.e., an important biomarker of the mucosal immune system), self-reported respiratory illness symptoms, and self-reported wellness parameters. Third, we focused on heat mitigation strategies in para-athletes. Para-athletes with a spinal cord injury perform upper-body exercise, and therefore lower-body cooling may be convenient. However, in Chapter 5, we observed that for these athletes, lower-body cooling was less effective in lowering heat strain compared to upper-body cooling. In Chapter 6, we observed that many para-athletes at the Tokyo 2020 Paralympic Games used heat acclimation and cooling strategies, which may have contributed to the low incidence of exertional heat illness. Altogether, the observations in this thesis indicate that heat mitigation needs and responsiveness vary across athletes, emphasizing that a one-size-fits-all heat mitigation approach may be suboptimal. Practitioners are encouraged to measure (thermo)physiological responses of individual athletes in the lab and/or field to determine their personal heat mitigation needs and responsiveness. Future studies should aim to further elucidate what factors influence the individual responsiveness to exercise under heat stress, cooling, and heat acclimation.

Tipping points are an emerging concept in climate change research and communication. However, previous research has strongly focussed on tipping points in biophysical systems, which left the potential for climate change induced socio-economic tipping points (SETPs) mostly unexplored. The objective of this thesis is to identify and assesses SETPs in order to support decision making on climate policy. A SETP is defined as “a climate change induced, abrupt change of a socio-economic system, into a new, fundamentally different state”. SETPs are characterised by: (1) stable states at two sides of a threshold; (2) a non-linear change mechanism, and (3) rapid change while passing the threshold. Examples are: the collapse of winter sports tourism, farmland abandonment, and sea-level rise-induced migration. The clearest examples of SETPs are likely to be found on small scale homogeneous systems, that can exhibit a system-wide uniform response to a climate driver. When modelling SETPs, there is an extra layer of complexity compared to biophysical tipping points, because of the complex dynamic character of the socio-economic system and the fact that humans proactively and autonomously alter the system to anticipate biophysical change. This thesis presents a stepwise approach for identification and assessment of SETPs, which in seven steps guides the researcher through key study design choices. The first application is urban water security. The essence of urban water security lies in an adequate response to partly inevitable system pressures, with well-functioning infrastructure that prevents adverse impacts such as flood damage. At the same time, in cities under pressure, like Amsterdam and Rotterdam, flood pressures may always propagate along the cause-effect chain via an unexpected mechanism. For example, a flood or near-miss experience could lead to the SETP of an abrupt house price collapse. Stepwise SETP-assessment shows that house price collapses could happen under conditions of high-end sea level rise, reactive flood risk management, and slow measure implementation. A new policy insight is that this SETP may be avoided by managing risk perceptions; when all buyers and sellers on the housing market are aware of gradual changes in flood risk, large fluctuations in risk perceptions and related house price booms and busts may be prevented. The second application field is the road transport infrastructure of thirty European countries. The SETP investigated is an abrupt large-scale malfunctioning of the road network from a river flood event. National-scale SETPs are most likely in small mountainous countries like Slovenia, Macedonia and Albania, where the 5% least favourable small-scale flood events may already disrupt some 30-40% of the preferred routes between major economic regions. Targeted flood proofing of a few critical weak spots by road operators could be a relatively easy, yet very effective, way to enhance the network robustness. Many countries have certain regions that could abruptly become poorly accessible during river floods. Such regional-scale tipping points seem to be much more likely and policy relevant than large national-scale disruptions. The third application is winter sports tourism. For six ski resorts in the Swiss Alps, the SETP of an abrupt bankruptcy is investigated. Bankruptcy might follow when in consecutive years, the number of days with good snow conditions falls below a critical threshold. The effectiveness of incremental and more transformative adaptation, resp. artificial snowmaking and year-round business model diversification, is explicitly modelled. The resulting policy insight is that beyond 2050, low-altitude resorts cannot avoid SETPs with artificial snow making alone, and can only survive with economic diversification towards year-round, less snow-dependent activities. Higher-altitude resorts must be aware that ski lift and real estate investments come with a long-term commitment to artificial snow making to avoid SETPs.

Tipping points are an emerging concept in climate change research and communication. However, previous research has strongly focussed on tipping points in biophysical systems, which left the potential for climate change induced socio-economic tipping points (SETPs) mostly unexplored. The objective of this thesis is to identify and assesses SETPs in order to support decision making on climate policy. A SETP is defined as “a climate change induced, abrupt change of a socio-economic system, into a new, fundamentally different state”. SETPs are characterised by: (1) stable states at two sides of a threshold; (2) a non-linear change mechanism, and (3) rapid change while passing the threshold. Examples are: the collapse of winter sports tourism, farmland abandonment, and sea-level rise-induced migration. The clearest examples of SETPs are likely to be found on small scale homogeneous systems, that can exhibit a system-wide uniform response to a climate driver. When modelling SETPs, there is an extra layer of complexity compared to biophysical tipping points, because of the complex dynamic character of the socio-economic system and the fact that humans proactively and autonomously alter the system to anticipate biophysical change. This thesis presents a stepwise approach for identification and assessment of SETPs, which in seven steps guides the researcher through key study design choices. The first application is urban water security. The essence of urban water security lies in an adequate response to partly inevitable system pressures, with well-functioning infrastructure that prevents adverse impacts such as flood damage. At the same time, in cities under pressure, like Amsterdam and Rotterdam, flood pressures may always propagate along the cause-effect chain via an unexpected mechanism. For example, a flood or near-miss experience could lead to the SETP of an abrupt house price collapse. Stepwise SETP-assessment shows that house price collapses could happen under conditions of high-end sea level rise, reactive flood risk management, and slow measure implementation. A new policy insight is that this SETP may be avoided by managing risk perceptions; when all buyers and sellers on the housing market are aware of gradual changes in flood risk, large fluctuations in risk perceptions and related house price booms and busts may be prevented. The second application field is the road transport infrastructure of thirty European countries. The SETP investigated is an abrupt large-scale malfunctioning of the road network from a river flood event. National-scale SETPs are most likely in small mountainous countries like Slovenia, Macedonia and Albania, where the 5% least favourable small-scale flood events may already disrupt some 30-40% of the preferred routes between major economic regions. Targeted flood proofing of a few critical weak spots by road operators could be a relatively easy, yet very effective, way to enhance the network robustness. Many countries have certain regions that could abruptly become poorly accessible during river floods. Such regional-scale tipping points seem to be much more likely and policy relevant than large national-scale disruptions. The third application is winter sports tourism. For six ski resorts in the Swiss Alps, the SETP of an abrupt bankruptcy is investigated. Bankruptcy might follow when in consecutive years, the number of days with good snow conditions falls below a critical threshold. The effectiveness of incremental and more transformative adaptation, resp. artificial snowmaking and year-round business model diversification, is explicitly modelled. The resulting policy insight is that beyond 2050, low-altitude resorts cannot avoid SETPs with artificial snow making alone, and can only survive with economic diversification towards year-round, less snow-dependent activities. Higher-altitude resorts must be aware that ski lift and real estate investments come with a long-term commitment to artificial snow making to avoid SETPs.

In our daily lives, we have to process information about all kinds of quantities such as the set size of a group of items (i.e., numerosity), time and size, among others. We have previously reported specialized neurons in our brain which respond selectively to or ‘prefer’ a specific number of items such as one, two or three. These neurons are organized topographically which means that these neurons are laid out in a shape that allows those most closely related to communicate and interact over the shortest possible distance in the brain. The general research goal of this thesis was to examine the properties of numerosity-tuned neural populations, and numerosity perception as part of a generalized quantity system by investigating the possibility of shared, tuned mechanisms between numerosity and time, and other quantities and sensory modalities. We first examined whether and how the selective response or preference of these numerosity selective neurons can change based on recent sensory experience. We used the method of adaptation and ultra-high-field 7 Tesla fMRI, where participants were repeatedly shown a low or high numerosity so to adapt the numerosity-selective neural populations. Sensory adaptation, makes the appearance of subsequently presented stimuli appear more different from the adapting stimulus than they actually are. This method is a powerful tool which allows us to make inferences about the existence of specialized neurons in the brain which respond selectively to the adapting stimuli. We show the dynamic nature of numerosity selective neural populations, where neural numerosity selectivity was altered systematically in all numerosity selective brain areas. Based on findings showing brain regions which process more than one type of quantity, such as numerosity and time, we proceeded to use cross-adaptation to numerosity and time to study whether neural populations selective for numerosity or time interact. We found an unbalanced interaction between numerosity and time where adaptation to time affected numerosity perception but not the other way around. After finding this interaction between neurons selective for processing numerosity and time, further experiments showed that the neural populations underlying the effect of adaptation to time on numerosity perception are partially distinct from those underlying the effect of the time of adaptation on numerosity perception. Collectively, these results highlight that there are partially overlapping neural mechanisms which are dedicated for processing both numerosity and time. We propose that neurons which are selective or are ‘tuned’ to different quantities such as number, time or size are fundamental to understanding quantity perception. We illustrate how the properties of quantity-tuned neurons can underlie various perceptual phenomena. We further show that quantity-tuned neurons are organized in distinct but overlapping neural networks. We suggest that this overlap in tuning provides the neural basis for perceptual interactions between different quantities.

In our daily lives, we have to process information about all kinds of quantities such as the set size of a group of items (i.e., numerosity), time and size, among others. We have previously reported specialized neurons in our brain which respond selectively to or ‘prefer’ a specific number of items such as one, two or three. These neurons are organized topographically which means that these neurons are laid out in a shape that allows those most closely related to communicate and interact over the shortest possible distance in the brain. The general research goal of this thesis was to examine the properties of numerosity-tuned neural populations, and numerosity perception as part of a generalized quantity system by investigating the possibility of shared, tuned mechanisms between numerosity and time, and other quantities and sensory modalities. We first examined whether and how the selective response or preference of these numerosity selective neurons can change based on recent sensory experience. We used the method of adaptation and ultra-high-field 7 Tesla fMRI, where participants were repeatedly shown a low or high numerosity so to adapt the numerosity-selective neural populations. Sensory adaptation, makes the appearance of subsequently presented stimuli appear more different from the adapting stimulus than they actually are. This method is a powerful tool which allows us to make inferences about the existence of specialized neurons in the brain which respond selectively to the adapting stimuli. We show the dynamic nature of numerosity selective neural populations, where neural numerosity selectivity was altered systematically in all numerosity selective brain areas. Based on findings showing brain regions which process more than one type of quantity, such as numerosity and time, we proceeded to use cross-adaptation to numerosity and time to study whether neural populations selective for numerosity or time interact. We found an unbalanced interaction between numerosity and time where adaptation to time affected numerosity perception but not the other way around. After finding this interaction between neurons selective for processing numerosity and time, further experiments showed that the neural populations underlying the effect of adaptation to time on numerosity perception are partially distinct from those underlying the effect of the time of adaptation on numerosity perception. Collectively, these results highlight that there are partially overlapping neural mechanisms which are dedicated for processing both numerosity and time. We propose that neurons which are selective or are ‘tuned’ to different quantities such as number, time or size are fundamental to understanding quantity perception. We illustrate how the properties of quantity-tuned neurons can underlie various perceptual phenomena. We further show that quantity-tuned neurons are organized in distinct but overlapping neural networks. We suggest that this overlap in tuning provides the neural basis for perceptual interactions between different quantities.

In our daily lives, we have to process information about all kinds of quantities such as the set size of a group of items (i.e., numerosity), time and size, among others. We have previously reported specialized neurons in our brain which respond selectively to or ‘prefer’ a specific number of items such as one, two or three. These neurons are organized topographically which means that these neurons are laid out in a shape that allows those most closely related to communicate and interact over the shortest possible distance in the brain. The general research goal of this thesis was to examine the properties of numerosity-tuned neural populations, and numerosity perception as part of a generalized quantity system by investigating the possibility of shared, tuned mechanisms between numerosity and time, and other quantities and sensory modalities. We first examined whether and how the selective response or preference of these numerosity selective neurons can change based on recent sensory experience. We used the method of adaptation and ultra-high-field 7 Tesla fMRI, where participants were repeatedly shown a low or high numerosity so to adapt the numerosity-selective neural populations. Sensory adaptation, makes the appearance of subsequently presented stimuli appear more different from the adapting stimulus than they actually are. This method is a powerful tool which allows us to make inferences about the existence of specialized neurons in the brain which respond selectively to the adapting stimuli. We show the dynamic nature of numerosity selective neural populations, where neural numerosity selectivity was altered systematically in all numerosity selective brain areas. Based on findings showing brain regions which process more than one type of quantity, such as numerosity and time, we proceeded to use cross-adaptation to numerosity and time to study whether neural populations selective for numerosity or time interact. We found an unbalanced interaction between numerosity and time where adaptation to time affected numerosity perception but not the other way around. After finding this interaction between neurons selective for processing numerosity and time, further experiments showed that the neural populations underlying the effect of adaptation to time on numerosity perception are partially distinct from those underlying the effect of the time of adaptation on numerosity perception. Collectively, these results highlight that there are partially overlapping neural mechanisms which are dedicated for processing both numerosity and time. We propose that neurons which are selective or are ‘tuned’ to different quantities such as number, time or size are fundamental to understanding quantity perception. We illustrate how the properties of quantity-tuned neurons can underlie various perceptual phenomena. We further show that quantity-tuned neurons are organized in distinct but overlapping neural networks. We suggest that this overlap in tuning provides the neural basis for perceptual interactions between different quantities.

Coastal floods are one of the deadliest and costliest of natural hazards, triggering or contributing to economic disruption, displacement, (mental) health implications, environmental disasters, poverty traps, and geomorphic change. In the coming century, coastal communities are projected to face increases in coastal flood risk. To prevent this increase in coastal flood risk, or even reduce risk below today’s levels, adaptation strategies are necessary. To make informed decisions on what measures to take, it is important to better understand the effectiveness of such coastal flood risk adaptation strategies, preferably beyond just monetary terms. Therefore, the overall aim of this thesis is to disentangle drivers of coastal flood risk and assess costs and benefits of adaptation strategies. By doing so, the thesis improves upon conventional flood risk assessments by taking steps into the direction of integrated and holistic assessments that include Nature-based Solutions and valuing of adaptation beyond monetary terms. This thesis uses artificial intelligence in the form of deep learning to construct a model to predict storm surges (which may lead to coastal flooding) at the global scale. Next to this, a risk model has been constructed to assess the effectiveness of adaptation strategies (based on structural measures, Nature-based Solutions, or a combination which is called “hybrid” measures). We assess risk by using projections of sea-level rise, socioeconomic change, subsidence, foreshore vegetation and restoration potential. Next to this we use vulnerability data, like poverty dynamics, to assess effectiveness of adaptation measures beyond monetary values. The results show that EAD increases by a factor of 150 between 2010 and 2080, if no adaptation were to take place, and that 15 countries account for approximately 90% of this increase. Moreover, sea-level rise contributed the most to the increase in coastal flood risk, but socioeconomic change and subsidence also play an important role at the regional scale. Furthermore, the results show that implementing Nature-based Solution, like conservation and restoration of foreshore vegetation, can contribute a large share to reduce flood risk and will next to structural measures, likes dikes and levees, increase the feasibility of adaptation strategies for two-thirds (68%) of the regions assessed. Moreover, we show that restoration of mangroves contribute to the safeguarding of communities by providing coastal flood protection benefits. Therefore, implementing adaptation in low- and middle-income countries could contribute to the resilience of people in poverty, poverty alleviation and help tackle poverty traps. Overall, the results of this thesis contribute to international initiatives such as the Sendai Framework for Disaster Risk Reduction and can be used to inform policy makers and development agencies on risks from global to regional level. In order to bridge the gap between academia and the risk management community, we integrated the results into the Aqueduct Global Floods webtool (www.wri.org/floods). This webtool allows any user to examine current and future risk, as well as the benefits of strucutral flood protection at the sub-national scale. Implementing adaptation measures, such as mangrove restoration, in LMICs could contribute to the resilience of people in poverty, decrease the risk of displacement and migration, and tackle poverty traps. The loss of these ecosystems disproportionally affects vulnerable groups and communities that live close to the coast and often heavily depend on natural resources. The results can help policymakers to assess the threat of coastal flooding and design sustainable adaptation measures considering poverty dynamics.

Literary historians have often noted the ‘conventional’ nature of the 14th-century Middle Dutch verse romance or ridderroman. While the corpus has long been depreciated as derivative, a mixture of older romance motifs amplified into sometimes grotesque proportions: ‘epic in decay’, this view has slowly been reconsidered. The complicated intertextuality of 14th-century ridderromans is now more understood as part of a literary game of recognition and surprise between creators and recipients. However, little comparative research has been done into the exact nature of such reworking strategies and the ‘game of romance’ in a larger 14th-century corpus. This research projects asks how adaptation as a compositional process is positioned with regards to the poetics of the 14th-century ridderroman. This will be done through an intra-textual analysis of the poetical markers and through a thorough review of the material, performance and socio-cultural contexts of the corpus texts. As such, it also reconceptualizes the corpus of 14th-century ridderromans in terms of 14th-century material production and reception, rather than purely textual composition.

Toediening van lage doses nitriet veroorzaakte bij ratten hypertrofie van de zona glomerulosa van de bijnieren. Het mechanisme achter het ontstaan van deze hypertrofie was onduidelijk. Er is gesuggereerd dat deze hypertrofie het gevolg was van het bloeddrukverlagend effect van nitriet en de daarmee gepaarde activatie van het renine-angiotensine systeem. Daarom werd het effect van gelijktijdige blootstelling gedurende 4 weken aan nitriet en een remmer van het angiotensine converting enzym (ramipril, 1 mg/kg lichaamsgewicht/dag) op de morfologie van de bijnier onderzocht. Bloeddruk en hartslag werden continu geregistreerd. De plasma renine activiteit (PRA) en de concentraties van angiotensine I (AI) en aldosteron in plasma werden bepaald vlak voor en twee weken na begin van de blootstelling aan nitriet en ramipril. Blootstelling van de ratten aan ramipril veroorzaakte een permanente daling van de bloeddruk en ophoping van AI. Blootstelling aan nitriet leidde tot herhaalde, kortdurende perioden van licht verlaagde bloeddruk en een kleine stijging van de concentraties PRA en AI in plasma. Gelijktijdige blootstelling aan ramipril en nitriet leidde tot de hoogste AI concentratie hetgeen suggereerde dat het effekt van beide stoffen additief was. De aldosteron-concentratiebepaling liet geen statistisch significante verschillen tussen de groepen zien. De resultaten van de histopathologische beoordeling van de bijnieren en van de morfometrie lieten duidelijk zien dat ramipril de hypertrofie onder invloed van nitriet van de zona glomerulosa van de bijnieren onderdrukte. Deze hypertrofie was dus niet het gevolg van een direkt effect van nitriet op de bijnieren maar werd gemedieerd door het renine-angiotensine systeem dat was geactiveerd door de bloeddrukdaling als gevolg van nitriet. De hypertrofie - onder invloed van nitriet - van de zona glomerulosa van de bijnieren kan worden beschouwd als een normale fysiologische aanpassing aan herhaalde perioden van lichte bloeddrukdaling

Anthropogenic and climate-related stressors challenge the health of nearly every part of the global oceans. They affect the capacity of oceans to regulate global weather and climate, as well as ocean productivity and food services, and result in the loss or degradation of marine habitats and biodiversity. Moreover, they have a negative impact on maritime economic sectors and on the social welfare of dependent coastal populations. In order to overcome the deficiencies of traditional single-sector management, in the recent decades several scientific approaches emerged, based on the view of marine systems as Complex Adaptive Systems (CAS), i.e. systems where components interact in non-linear, path dependent ways, with lock-in and feedback loop mechanisms, and unpredictable effects also across scales. These approaches have been introduced into the texts of several international agreements related to marine CAS, and related management practices, with contrasting results in relation to effectiveness and integration of governance. This thesis evaluates for the first time the current international and European legal frameworks from the perspective of marine CAS. To accomplish this objective, four research objectives are formulated: (1) Develop a framework for marine CAS assessment and management; (2) Evaluate the entire European Union (EU) legal framework against the framework developed; (3) Evaluate the international legal framework for the assessment and management of the global oceans against the framework developed; and (4) Evaluate the implementation of the EU and global legal frameworks into practice. Chapter 2 develops a framework for marine CAS, based on the combination of two promising theoretical approaches: Adaptive Management (AM) and Transition Management (TM). The framework is based on the idea that AM and TM have the potential to overcome each other’s limitations, which are related to the insufficient attention to micro-level socio-economic components, and to the limited incorporation of environmental aspects into socio-technical assessments, respectively. More into detail, the proposed framework is articulated into three components. First, the two sets of marine social-ecological systems and connected socio-technical systems (e.g. fisheries, maritime transportation, coastal tourism and energy) must be clearly identified, and the complex interactions and influences between socio-economic patterns of production and consumption, and ecological components must be assessed. Second, the achievement of ecological resilience of a marine social-ecological system should be performed in coordination with transitions of unsustainable connected socio-technical systems. This implies that sustainability should be evaluated in relation to the pressures socio-technical systems generate on the ecological resilience of connected social-ecological systems, and related impacts. Third, the implementation of the two approaches should be articulated into iterative, learning- and science-based policy cycles, with mechanisms to foster coordination between the policy cycles of social-ecological and socio-technical systems. The benefits of this framework are threefold. First, the assessment of the two sets of social-ecological and socio-technical systems, taken together, allows to overcome current AM limitations and include micro-level socio-economic components into the assessment of ecological resilience. Second, by linking AM managers with established transition arenas, it is possible to overcome TM limitations and streamline the consideration of ecological aspects into the TM process. Third, by linking AM and TM policy cycles, it is possible to reduce the current legal and policy fragmentation. Chapters 3 and 4 apply the framework proposed in Chapter 2 to evaluate the EU and global legal frameworks for the assessment and management of marine CAS. Chapter 3 presents the first comprehensive review ever realised of the entire EU legal framework, composed of more than 12,000 EU legal acts, from the perspective of marine CAS assessment and management. It concludes that the EU legislation does not provide a fully coherent framework for the assessment and management of EU marine CAS. Although the Marine Strategy Framework Directive (MSFD; 2008/56/EC) is a major step towards this purpose, the present research highlights three major limitations: (1) the limited capacity of the MSFD to support the coordination between Member States sharing the same marine region or sub-region; (2) the insufficient characterisation of marine ecological resilience, in particular in relation to socio-economic elements, ecosystem services, human benefits and cross-scale interactions; and (3) the limited capacity of the MSFD to tackle the fragmentation of the EU legal framework and integrate ecological resilience into the objectives of sector-based laws and policies. Chapter 4 reviews 500 multilateral agreements, evaluated for the first time from the perspective of marine CAS. It shows that there is no international agreement aiming at the ecological resilience of the global oceans social-ecological system. Instead, the international legal framework is fragmented along two dimensions. On the one side, global agreements focus on specific objectives for determined socio-economic activities, ecological features or anthropogenic pressures. On the other side, regional agreements are in place for 18 ocean regions of the world, with a varying level of inclusion of elements of marine CAS assessment and management. The need is highlighted for a reformed global ocean governance framework, which should be based on a bio-geographical approach to the ecological resilience of the global oceans, and build on iteration, learning, and science-based advice to policy and management. Chapter 5 evaluates the implementation of the EU and global legal frameworks into the practice of assessment and management of a case-study area, the Adriatic Sea. It shows the importance of the MSFD as the first policy trying to deliver a CAS approach to marine assessment and management. However, the case-study investigation confirms the three limitations of the MSFD, laying in: 1) an insufficient geographical approach, where implementation is driven at national level and the requirement of cross-border cooperation is weak; 2) the vagueness of legal requirements, and the limited capacity to include socio-economic aspects into the required assessment; and 3) an insufficient capacity to coordinate with other laws, policies and programmes at various levels of governance. Based on the identified limitations, suggestions are advanced on how to strengthen the implementation of the MSFD, both at Adriatic and EU level. These suggestions are further advanced in Chapter 6, which includes detailed proposals on how to foster integrated large-scale marine monitoring in the EU, in order to contribute to the implementation of the MSFD in an efficient and effective way, also in relation to costs. Chapter 7 synthesizes the major findings of this thesis and evaluates the capacity of the framework to deliver a CAS approach to marine systems. It concludes that AM and TM, although holding different visions on sustainability and referring to different principles, have the potential to be put in synergy at the practical level. Further scientific research and management practices should focus on the need for AM and TM to overcome the relative isolation and foster synergies across sector-based management, in order to integrate environmental considerations into economic sectors. Suggestions are advanced to improve legal frameworks and policy practices at the global and EU level. They focus on the need: (i) to fill the gaps in the geographical scope of legal texts and to foster international cooperation at the right social-ecological scale; (ii) to increase guidance in translating complex scientific requirements into clear management objectives, and improve related data collection and sharing; and (iii) to reduce current legal and policy fragmentation through targeted, ecological resilience-based marine environmental impact assessments and maritime spatial planning. Lines for further scientific research are suggested, focusing on: (i) improving the evidence-base through additional case-studies; (ii) analysing legal frameworks and governance regimes in place for other marine social-ecological systems, like e.g. the United States of America, Canada, Australia and China; (iii) improving existing tools, or creating new ones for marine ecological resilience assessment; and (iv) developing innovative instruments and mechanisms to strengthen global oceans governance.

This thesis examines the three-way interaction between yeast-like symbionts, an insect herbivore [Nilaparvata lugens (Stål)] and its rice (Oryza sativa L.) host, during adaptation of the herbivore to resistant rice varieties. A long-term selection study (20 generations of continuous rearing, ca. 24 months) was conducted with N. lugens populations on four rice varieties (IR22, a susceptible variety and IR65482, IR62, and PTB33, three resistant varieties). Planthopper performance and the abundance of yeast-like symbionts (YLS) were monitored throughout the selection process. N. lugens populations adapted to the resistant varieties as noted by increasing body size and increased egglaying. Xylem feeding was observed as a possible behavioural adaptation of N. lugens: planthoppers on resistant plants had relatively high levels of xylem feeding compared with planthoppers on susceptible plants. Planthoppers selected on resistant varieties, had clear differences in YLS densities that were not related to fitness on the varieties and, therefore, did not support a YLS density-mediated adaptation hypothesis. Furthermore, this study examined whether YLS density affected the capacity of planthoppers to switch between hosts on which they have been selected for several generations (natal plant) to new varieties (exposed plants) under normal YLS densities (symbiotic) and after reduction of YLS densities by heat treatment (aposymbiotic). The results suggested that YLS do not mediate host plant switching in planthoppers as removal of symbionts influenced body weight but not the relative capacity of nymphs to feed on different plants. This study also tested if virulence is acquired by shared feeding sites with virulent and avirulent planthoppers. In the study, planthoppers with varying levels of virulence affected the host plants differently: The most virulent hoppers appeared to suppress rice defences to a greater extent than non-virulent planthoppers. Planthoppers attained highest weights on those plants on which virulent planthoppers had previously fed which suggests that feeding by the virulent planthoppers facilitated subsequent planthopper feeding on the same plant. Our preliminary results indicate that feeding by mixed virulent-avirulent populations could potentially accelerate adaptation by N. lugens to resistant rice varieties. The capacity of virulent and avirulent planthoppers to feed on a range of 24 resistant rice varieties was examined using a series of bioassays. Planthoppers were observed to feed and lay eggs on all the varieties tested, many of which have never been widely deployed in the field. Furthermore, planthoppers selected on resistant varieties often had increased fitness on other resistant varieties, even when these possess different resistance genes. However, there was no strong evidence that once planthoppers have adapted to a resistant variety, they will exhibit fitness costs on other varieties with dissimilar genes. The mechanisms underlying insect virulence are complex and further research on planthopper adaptation is necessary to help conserve genetic resources and prolong the durability of available resistant varieties.

Southern Africa is characterized by natural climate variability onto which human-induced climate change is being superimposed. Rural communities that depend heavily on rain-fed agriculture for their livelihood are particularly vulnerable to the effects of climate-related change. This report takes stock of existing perceptions of- and responses to climate change among smallholder farmers in the region, in the hope of contributing to a better understanding of the complexities of local knowledge- and adaptation systems.

SummaryAquatic photosynthetic organisms unavoidably experience light fluctuations that vary in amplitude, duration and origin, compromising their photosynthetic efficiency. Weather conditions and underwater flow cause continuous changes in irradiance to which the organisms have to adapt. Many light-adaptation strategies of photosynthetic organisms, such as light acclimation, photoprotection and state transitions are still not well understood. In this thesis, time-resolved fluorescence spectroscopy is used to obtain insight into the response of diatoms and cyanobacteria, both aquatic photosynthetic organisms, to changing light conditions.In chapter 2, photoacclimation (long-term acclimation to irradiance conditions) of the diatom Cyclotella meneghiniana is discussed. It is shown that the diatom cells fine-tune the amount of absorbed light energy by modifying their antenna size: cells grown in high light intensity have smaller antennas than those grown in low light. At the same time, the increase of growth light intensity leads to a decrease of the relative amount of photosystem I (PSI) as compared to PSII. Such a strategy might be beneficial for diatoms, since they are known to have an electron transfer cycle around PS II to release excess electrons produced in high light intensities. Besides discussing photoacclimation, we give a detailed description the fluorescence kinetics in C. meneghiniana. It is concluded that the diatom antenna, represented by light-harvesting fucoxanthin chlorophyll proteins (FCPs), transfer their excitation energy predominantly to PSII. FCPs associated with PSII are slightly richer in red-absorbing fucoxanthin than the FCPs associated with PSI, suggesting that PSII antennas (partly) constitute the antenna form FCPb (i.e. oligomeric antenna complexes).In chapter 3 the process of non-photochemical quenching (NPQ, thermal dissipation of excess absorbed light energy) of chlorophyll a fluorescence was studied in the same diatom species. Diatoms can rapidly switch on/off NPQ to respond to fast light-intensity changes in moving waters. They are capable to induce higher NPQ values than plants or other photosynthetic organisms. The reason for such high NPQ values, however, is not clear. We performed picosecond fluorescence measurements at 77K on cells locked in three different states: Besides using conventional unquenched and quenched states of the cells (in the absence and presence of the total NPQ component, respectively), we also performed measurements on the dark-adapted state directly following NPQ. In this state, diatoxantin (Dtx, a carotenoid related to NPQ), accumulated during the NPQ period and Dtx-related NPQ persists, while ΔpH-related NPQ has relaxed. In this way we revealed the following sequence of events during full development of NPQ. First, the pH gradient across the thylakoid membrane induces quenching of FCP trimers (FCPa complexes), while they are still part of PSII. This is followed by (partial) detachment of FCPa from PSII after which quenching persists. The pH gradient also causes the formation of Dtx, which leads to further quenching of isolated PSII cores and some aggregated FCPa. To summarize, quenching of PSII -both cores and complexes- and FCPa substantially contribute to NPQ in diatoms. The FCPb antenna form on the other hand does not contribute to the NPQ process.Certain aquatic photosynthetic organisms, such as cyanobacteria and green algae, can also cope with changing light conditions by dynamically varying the relative antenna size of PSI and of PSII. Consequently, a redistribution of light energy between the PSs is achieved. This phenomenon is called “state transitions”. It is known to be driven via a change in the redox status of electron carriers between PSII and PSI. In cyanobacteria, this redox change can be achieved via dark-light transitions. However, the cascade of microscopic events that lead to subsequent energy redistribution in cyanobacteria is still not completely clear. In chapter 4, a study on dark-light transitions using the cyanobacterium Synechocystis sp. PCC 6803 as a model organism is described. It is demonstrated that during dark to light transitions, there is mainly detachment of phycobilisomes (PBSs) (cyanobacterial antennas) from PSI, generally not followed by their attachment to PSII: only 15 % of the PBSs that detach from PSI actually move to PSII, while the major part remains detached from both PSs. We conclude that PSI-PSII-PBS megacomplexes, which were recently isolated using chemical cross-linking, are not involved in dark/light state transitions, suggesting that, if present, they are only transiently formed in cyanobacteria. To summarize, the findings presented in chapter 4 suggest that in cyanobacteria, unlike in green algae or higher plants, the main role of state transitions is to change the absorption cross-section of PSI, rather than that of PSII.In chapter 5, a study of the role of flv4-2 operon-encoded proteins in Synechocystis is described. Three genes are found in the operon: Flv4, Sll0218, and Flv2. Only recently flv4-2 operon-encoded proteins were found to constitute an additional photoprotective mechanism in a number of cyanobacteria by safeguarding PSII activity via an alternative electron chain. Its contribution becomes vital for the cells in high light and in air-level CO2, when the photosynthetic electron transport chain is over-reduced. It is demonstrated that deletion of the operon induces 20% PBS detachment. The reduced PSII dimer to monomer ratio, as a result of the absence of the small Sll0218 protein, favors a relative decrease of the PSII dimer content of about 20%, showing a direct correlation between PSII dimer destabilization and PBS detachment from reaction centers. On the other hand, the suggested binding of the Flv2/Flv4 heterodimer closely to the quinone B (QB) pocket in PSII increases the QB redox potential, thereby promoting forward electron transfer and increasing the charge separation rates in PSII. This activity of the Flv2/Flv4 heterodimer in combination with its earlier reported role as an electron acceptor in alternative electron chain provides more oxidized state of the PQ pool in high light and in air-level CO2.

Short Summary Cynthia McDougall--PhD Dissertation Knowledge, Technology, &Innovation Chairgroup (WASS) Adaptive collaborative governance of Nepal’s community forests: Shifting power, strengthening livelihoods Community-based natural resource governance has taken root around the globe. And, yet, as demonstrated by community forestry in Nepal, such programmes have generally not yet lived up to their goals and expectations. After decades of implementation, community forestry in Nepal faces several key challenges. Central to these challenges are: the need to increase equity in community forest user group decision making and benefit sharing; and, to increase the livelihood benefits from community forestry overall. The research project on which this study is based sought to address these challenges at the community forest user group scale. The research objective was to contribute empirically-based insights regarding if and how adaptive collaborative governance of community forests in Nepal can constructively influence engagement, livelihoods, social capital and conflict—especially in regard to women and the poor. Further, the research aimed to elucidate the underlying issue of power in community-based natural resource governance. In particular, it sought to contribute deeper, theoretically-based understanding of the persistence of power imbalances in community forestry, and of the potential of adaptive collaborative governance to shift such imbalances.

SummaryAquatic photosynthetic organisms unavoidably experience light fluctuations that vary in amplitude, duration and origin, compromising their photosynthetic efficiency. Weather conditions and underwater flow cause continuous changes in irradiance to which the organisms have to adapt. Many light-adaptation strategies of photosynthetic organisms, such as light acclimation, photoprotection and state transitions are still not well understood. In this thesis, time-resolved fluorescence spectroscopy is used to obtain insight into the response of diatoms and cyanobacteria, both aquatic photosynthetic organisms, to changing light conditions.In chapter 2, photoacclimation (long-term acclimation to irradiance conditions) of the diatom Cyclotella meneghiniana is discussed. It is shown that the diatom cells fine-tune the amount of absorbed light energy by modifying their antenna size: cells grown in high light intensity have smaller antennas than those grown in low light. At the same time, the increase of growth light intensity leads to a decrease of the relative amount of photosystem I (PSI) as compared to PSII. Such a strategy might be beneficial for diatoms, since they are known to have an electron transfer cycle around PS II to release excess electrons produced in high light intensities. Besides discussing photoacclimation, we give a detailed description the fluorescence kinetics in C. meneghiniana. It is concluded that the diatom antenna, represented by light-harvesting fucoxanthin chlorophyll proteins (FCPs), transfer their excitation energy predominantly to PSII. FCPs associated with PSII are slightly richer in red-absorbing fucoxanthin than the FCPs associated with PSI, suggesting that PSII antennas (partly) constitute the antenna form FCPb (i.e. oligomeric antenna complexes).In chapter 3 the process of non-photochemical quenching (NPQ, thermal dissipation of excess absorbed light energy) of chlorophyll a fluorescence was studied in the same diatom species. Diatoms can rapidly switch on/off NPQ to respond to fast light-intensity changes in moving waters. They are capable to induce higher NPQ values than plants or other photosynthetic organisms. The reason for such high NPQ values, however, is not clear. We performed picosecond fluorescence measurements at 77K on cells locked in three different states: Besides using conventional unquenched and quenched states of the cells (in the absence and presence of the total NPQ component, respectively), we also performed measurements on the dark-adapted state directly following NPQ. In this state, diatoxantin (Dtx, a carotenoid related to NPQ), accumulated during the NPQ period and Dtx-related NPQ persists, while ΔpH-related NPQ has relaxed. In this way we revealed the following sequence of events during full development of NPQ. First, the pH gradient across the thylakoid membrane induces quenching of FCP trimers (FCPa complexes), while they are still part of PSII. This is followed by (partial) detachment of FCPa from PSII after which quenching persists. The pH gradient also causes the formation of Dtx, which leads to further quenching of isolated PSII cores and some aggregated FCPa. To summarize, quenching of PSII -both cores and complexes- and FCPa substantially contribute to NPQ in diatoms. The FCPb antenna form on the other hand does not contribute to the NPQ process.Certain aquatic photosynthetic organisms, such as cyanobacteria and green algae, can also cope with changing light conditions by dynamically varying the relative antenna size of PSI and of PSII. Consequently, a redistribution of light energy between the PSs is achieved. This phenomenon is called “state transitions”. It is known to be driven via a change in the redox status of electron carriers between PSII and PSI. In cyanobacteria, this redox change can be achieved via dark-light transitions. However, the cascade of microscopic events that lead to subsequent energy redistribution in cyanobacteria is still not completely clear. In chapter 4, a study on dark-light transitions using the cyanobacterium Synechocystis sp. PCC 6803 as a model organism is described. It is demonstrated that during dark to light transitions, there is mainly detachment of phycobilisomes (PBSs) (cyanobacterial antennas) from PSI, generally not followed by their attachment to PSII: only 15 % of the PBSs that detach from PSI actually move to PSII, while the major part remains detached from both PSs. We conclude that PSI-PSII-PBS megacomplexes, which were recently isolated using chemical cross-linking, are not involved in dark/light state transitions, suggesting that, if present, they are only transiently formed in cyanobacteria. To summarize, the findings presented in chapter 4 suggest that in cyanobacteria, unlike in green algae or higher plants, the main role of state transitions is to change the absorption cross-section of PSI, rather than that of PSII.In chapter 5, a study of the role of flv4-2 operon-encoded proteins in Synechocystis is described. Three genes are found in the operon: Flv4, Sll0218, and Flv2. Only recently flv4-2 operon-encoded proteins were found to constitute an additional photoprotective mechanism in a number of cyanobacteria by safeguarding PSII activity via an alternative electron chain. Its contribution becomes vital for the cells in high light and in air-level CO2, when the photosynthetic electron transport chain is over-reduced. It is demonstrated that deletion of the operon induces 20% PBS detachment. The reduced PSII dimer to monomer ratio, as a result of the absence of the small Sll0218 protein, favors a relative decrease of the PSII dimer content of about 20%, showing a direct correlation between PSII dimer destabilization and PBS detachment from reaction centers. On the other hand, the suggested binding of the Flv2/Flv4 heterodimer closely to the quinone B (QB) pocket in PSII increases the QB redox potential, thereby promoting forward electron transfer and increasing the charge separation rates in PSII. This activity of the Flv2/Flv4 heterodimer in combination with its earlier reported role as an electron acceptor in alternative electron chain provides more oxidized state of the PQ pool in high light and in air-level CO2.

Southern Africa is characterized by natural climate variability onto which human-induced climate change is being superimposed. Rural communities that depend heavily on rain-fed agriculture for their livelihood are particularly vulnerable to the effects of climate-related change. This report takes stock of existing perceptions of- and responses to climate change among smallholder farmers in the region, in the hope of contributing to a better understanding of the complexities of local knowledge- and adaptation systems.

This thesis examines the three-way interaction between yeast-like symbionts, an insect herbivore [Nilaparvata lugens (Stål)] and its rice (Oryza sativa L.) host, during adaptation of the herbivore to resistant rice varieties. A long-term selection study (20 generations of continuous rearing, ca. 24 months) was conducted with N. lugens populations on four rice varieties (IR22, a susceptible variety and IR65482, IR62, and PTB33, three resistant varieties). Planthopper performance and the abundance of yeast-like symbionts (YLS) were monitored throughout the selection process. N. lugens populations adapted to the resistant varieties as noted by increasing body size and increased egglaying. Xylem feeding was observed as a possible behavioural adaptation of N. lugens: planthoppers on resistant plants had relatively high levels of xylem feeding compared with planthoppers on susceptible plants. Planthoppers selected on resistant varieties, had clear differences in YLS densities that were not related to fitness on the varieties and, therefore, did not support a YLS density-mediated adaptation hypothesis. Furthermore, this study examined whether YLS density affected the capacity of planthoppers to switch between hosts on which they have been selected for several generations (natal plant) to new varieties (exposed plants) under normal YLS densities (symbiotic) and after reduction of YLS densities by heat treatment (aposymbiotic). The results suggested that YLS do not mediate host plant switching in planthoppers as removal of symbionts influenced body weight but not the relative capacity of nymphs to feed on different plants. This study also tested if virulence is acquired by shared feeding sites with virulent and avirulent planthoppers. In the study, planthoppers with varying levels of virulence affected the host plants differently: The most virulent hoppers appeared to suppress rice defences to a greater extent than non-virulent planthoppers. Planthoppers attained highest weights on those plants on which virulent planthoppers had previously fed which suggests that feeding by the virulent planthoppers facilitated subsequent planthopper feeding on the same plant. Our preliminary results indicate that feeding by mixed virulent-avirulent populations could potentially accelerate adaptation by N. lugens to resistant rice varieties. The capacity of virulent and avirulent planthoppers to feed on a range of 24 resistant rice varieties was examined using a series of bioassays. Planthoppers were observed to feed and lay eggs on all the varieties tested, many of which have never been widely deployed in the field. Furthermore, planthoppers selected on resistant varieties often had increased fitness on other resistant varieties, even when these possess different resistance genes. However, there was no strong evidence that once planthoppers have adapted to a resistant variety, they will exhibit fitness costs on other varieties with dissimilar genes. The mechanisms underlying insect virulence are complex and further research on planthopper adaptation is necessary to help conserve genetic resources and prolong the durability of available resistant varieties.

Short Summary Cynthia McDougall--PhD Dissertation Knowledge, Technology, &Innovation Chairgroup (WASS) Adaptive collaborative governance of Nepal’s community forests: Shifting power, strengthening livelihoods Community-based natural resource governance has taken root around the globe. And, yet, as demonstrated by community forestry in Nepal, such programmes have generally not yet lived up to their goals and expectations. After decades of implementation, community forestry in Nepal faces several key challenges. Central to these challenges are: the need to increase equity in community forest user group decision making and benefit sharing; and, to increase the livelihood benefits from community forestry overall. The research project on which this study is based sought to address these challenges at the community forest user group scale. The research objective was to contribute empirically-based insights regarding if and how adaptive collaborative governance of community forests in Nepal can constructively influence engagement, livelihoods, social capital and conflict—especially in regard to women and the poor. Further, the research aimed to elucidate the underlying issue of power in community-based natural resource governance. In particular, it sought to contribute deeper, theoretically-based understanding of the persistence of power imbalances in community forestry, and of the potential of adaptive collaborative governance to shift such imbalances.

Governing Congo Basin Forests in a Changing Climate: Actors, Discourses and Institutions for Adaptation and Mitigation OA Somorin Abstract The thesis deals with the central question of the governance processes of making tropical forests deliver climate change adaptation and mitigation outcomes of sustainable livelihoods, biodiversity conservation and enhanced carbon stocks. Using the case of the Congo Basin forests, it analyzes the nexus between forest and climate change, particularly on the governance processes of using the forests to respond to climate change. The thesis questions the dominant frames and discourses shaping the policymaking processes of adaptation and mitigation strategies in the Congo Basin. The research is informed by past (and still current) debates among different actors on the forms of institutional and policy frameworks required for policy making on adaptation and mitigation in the Congo, given the region’s context of weak human and governance capacities. Drawing from the theoretical perspective of discursive institutionalism which takes into account the institutional context in which discourses emerge and the way in which they are institutionalized in social practices. Conceptually, the thesis employs the analytical elements of discursive institutionalism: discourses, actors and institutions in terms of their consequences for governance process analysis. The focus is to understand the types of actors involved along with their capacity and competence to contribute to the policy processes; the overarching global to local discourses on the issues; and the institutional structures considered relevant for adaptation and mitigation in the Congo Basin. Despite the framing of adaptation as a priority for the Congo Basin region due to the high vulnerability (and low adaptive capacity) of the population to climate risks, the thesis finds more significant policy attention is rather given to mitigation. The dominance of the mitigation discourses is largely due to elements of financial resources, knowledge and influence employed by their actor coalitions to advance the policymaking process. While mitigation policy debates among state and non-state actors on institutional and governance frameworks exist at the national level, adaptation strategies including sustaining food security, income generation and livelihood diversification, are already in practice at the local levels. Ultimately, policy actors’ interest to match the multiple opportunities that mitigation offers with the priorities of adaptation underlines the deliberate actions towards fostering synergy. The thesis concludes that the future of the Congo Basin forests under a changing climate lies in how the actors are able to develop policy frameworks and governance arrangements to foster mitigative adaptation and adaptive mitigation.

Governing Congo Basin Forests in a Changing Climate: Actors, Discourses and Institutions for Adaptation and Mitigation OA Somorin Abstract The thesis deals with the central question of the governance processes of making tropical forests deliver climate change adaptation and mitigation outcomes of sustainable livelihoods, biodiversity conservation and enhanced carbon stocks. Using the case of the Congo Basin forests, it analyzes the nexus between forest and climate change, particularly on the governance processes of using the forests to respond to climate change. The thesis questions the dominant frames and discourses shaping the policymaking processes of adaptation and mitigation strategies in the Congo Basin. The research is informed by past (and still current) debates among different actors on the forms of institutional and policy frameworks required for policy making on adaptation and mitigation in the Congo, given the region’s context of weak human and governance capacities. Drawing from the theoretical perspective of discursive institutionalism which takes into account the institutional context in which discourses emerge and the way in which they are institutionalized in social practices. Conceptually, the thesis employs the analytical elements of discursive institutionalism: discourses, actors and institutions in terms of their consequences for governance process analysis. The focus is to understand the types of actors involved along with their capacity and competence to contribute to the policy processes; the overarching global to local discourses on the issues; and the institutional structures considered relevant for adaptation and mitigation in the Congo Basin. Despite the framing of adaptation as a priority for the Congo Basin region due to the high vulnerability (and low adaptive capacity) of the population to climate risks, the thesis finds more significant policy attention is rather given to mitigation. The dominance of the mitigation discourses is largely due to elements of financial resources, knowledge and influence employed by their actor coalitions to advance the policymaking process. While mitigation policy debates among state and non-state actors on institutional and governance frameworks exist at the national level, adaptation strategies including sustaining food security, income generation and livelihood diversification, are already in practice at the local levels. Ultimately, policy actors’ interest to match the multiple opportunities that mitigation offers with the priorities of adaptation underlines the deliberate actions towards fostering synergy. The thesis concludes that the future of the Congo Basin forests under a changing climate lies in how the actors are able to develop policy frameworks and governance arrangements to foster mitigative adaptation and adaptive mitigation.

Water stress assessment of natural vegetation plays a key role in water management of desert ecosystems. It allows scientists and managers to relate water extraction rates to changes in vegetation water condition, and consequently to define safe water extraction rates for maintaining a healthy ecosystem. Previous research has shown that optical remote sensing constitutes a powerful tool for assessing vegetation water stress due to its capability of quantitatively estimating important parameters of vegetation such as leaf area index (LAI), green canopy fraction (GCF), and canopy water content (CWC). However, the estimation of these parameters using remote sensing can be challenging in the case of desert vegetation. Desert plants have to cope with high solar irradiation and limited water. In order to maintain an adequate water balance and to avoid photoinhibition, desert plants have evolved different adaptations. A common one is heliotropism or ‘solar tracking’, an ability of many desert species to move their leaves to avoid facing direct high solar irradiation levels during the day and season. This adaptation (paraheliotropism) can have an important effect on the canopy spectral reflectance measured by satellites as well as on vegetation indices such as the normalized difference vegetation index (NDVI). In this thesis, I propose a remote sensing based approach to assess water stress of desert vegetation, exemplified in the case of the Tamarugo (Prosopis tamarugo Phil) tree in the Atacama Desert (Northern Chile), a ‘solar tracker’ species, which is threatened by groundwater overexploitation. In the first chapter of this thesis (general introduction), I explained the motivation of the PhD project and elaborated four research questions, which are later discussed in chapters 2, 3, 4, and 5. The thesis concluded with chapter 6, where I provide a synthesis of the main results, general conclusions and a final reflection and outlook. In the second chapter, I studied the effects of water stress on Tamarugo plants under laboratory conditions and modelled the light-canopy interaction using the Soil-Leaf-Canopy radiative transfer model. I described for the first time pulvinar movement of Tamarugo and quantified its effects on canopy spectral reflectance with and without stress. I showed that different spectral indices have potential to assess water stress of Tamarugo by means of LAI and CWC. In the third chapter, I measured the effects of pulvinar movements on canopy reflectance for Tamarugos under field conditions and used high spatial resolution images to assess water stress at the tree level. I developed an automated process to first identify single trees and delineate their crowns, and secondly, to estimate LAI and GCF using spectral vegetation indices. These indices (NDVI and chlorophyll red-edge index) were negatively correlated to diurnal values of solar irradiation as a consequence of leaf pulvinar movements. For this reason, higher values of both vegetation indices are expected to occur in the morning and in winter (low solar radiation) than at midday or summer. In the fourth chapter I studied the effects of diurnal pulvinar movements on NDVI time series from the MODIS-Terra satellite (acquired in the morning) and the MODIS-Aqua satellite (acquired at midday) for the period 2003-2012 and the seasonal effects of pulvinar movements on NDVI time series of Landsat images for the period 1998-2012 for Tamarugo areas with and without water stress. NDVI values measured by MODIS-Terra (morning) were higher than the NDVI values measured by MODIS-Aqua (afternoon) and the difference between the two, the ΔNDVImo-mi, showed good potential as water stress indicator. In a similar way, I observed a strong seasonal effect on the Landsat NDVI signal, attributed to pulvinar movements, and the difference between winter and summer, the ΔNDVIW-S, also showed good potential for detecting and quantifying water stress. The ΔNDVImo-mi, the ΔNDVIW-S and the NDVI itself measured systematically in winter time (NDVIW) were negatively correlated with in situ groundwater depth measurements. In chapter five I used a dense NDVI time series of Landsat images for the period 1989-2013, combined with high spatial resolution satellite imagery and hydrogeological records, to provide a quantitative assessment of the water status of Tamarugo vegetation after 50 years of increasing groundwater extraction. The results showed that the NDVIW and ΔNDVIW-S of the Tamarugo vegetation declined 19% and 51%, respectively, as groundwater depleted (3 meters on average) for the period 1989-2013. Both variables were negatively correlated to groundwater depth both temporally and spatially. About 730.000 Tamarugo trees remained in the study area by 2011, from which 5.2% showed a GCF

Keywords: Climate change; Increased climate variability; Vulnerability; Smallholder farmers; Adaptation Climate change and increased climate variability are currently seen as the major constraints to the already stressed smallholder farming livelihood system in southern Africa. The main objectives of this study were first to understand the nature and sources of vulnerability of smallholder farmers to climate variability and change, and second to use this knowledge to evaluate possible farm-level management options that can enhance the adaptive capacity of smallholder farmers in the face of increased climate variability and long-term change in climate. The study was conducted in Makoni and Hwedza districts in eastern Zimbabwe. Local famers’ and expert empirical knowledge were combined using research tools that mainly included detailed field observations and surveys, systems analysis and field experimentation, and simulation modelling (the Agricultural Production Systems Simulator (APSIM)). To understand the nature and sources of vulnerability, long term climate data were analysed and farmers were interviewed individually and in groups. On-farm experimentation and simulation modelling were conducted to evaluate the impacts and interactions of adaptation options namely maize cultivar choice, staggered planting dates, and variable fertilizer rates, on maize yield under both short-term climate variability and long-term climate change. Another on-farm experiment was conducted to assess whether small grains (finger millet and sorghum) perform as well as maize under variable soil and rainfall conditions. The long-term rainfall and temperature analyses closely supports farmers’ perceptions that the total annual rainfall has so far not changed, but variability in the rainfall distribution within seasons has increased. The number of rain days has decreased, and the frequency of dry spells within season increased. The mean daily minimum temperature increased by 0.2°C per decade in Makoni, and by 0.5°C per decade in Hwedza, over the period from 1962 to 2000. The surface air temperature is further projected to increase significantly in Makoni and Hwedza, by 2100. The impacts of rising temperatures and increased rainfall variability among smallholder households were highly differentiated because different households depend on varied farming livelihood sub-systems, which were exposed uniquely to aspects of climatic risk. For example, livestock production was sensitive to drought due to lack of feed, affecting resource-endowed farmers, who often own relatively large herds of cattle. Crop production was more sensitive to increased rainfall variability, affecting especially farmers with intermediate resource endowment. Availability of wild fruits and social safety nets were affected directly and indirectly by extreme temperatures and increased rainfall variability, impacting the livelihoods of poorer farmers. Farmers have also access to different biophysical and socioeconomic resources such as fertilizer and farm labour inputs, and as a result they respond variedly to impacts of a changing climate. Thus, alongside climate variability and change, farmers also faced biophysical and socioeconomic challenges, and these challenges had strong interactions with adaptation options to climate change. Experimentation in this studydemonstrated that the maize cultivars currently on the market in Zimbabwe, and in many parts of southern Africa, exhibit narrow differences in maturity time such that they do not respond differently to prolonged dry spells. The yield performance for all three cultivars is projected to be similar in future change in climates, consistent with results from the experiments.In the current cropping system farmers can select any cultivar available on the market without a yield penalty. However, with climate change none of the available cultivars will be able to compensate for the decline in yield. Greater maize grain yields were obtained with both the early (25 October – 20 November) and normal (21 November – 15 December) plantings, with no significant differences between these planting windows(e.g. on average 5 t ha-1 in Makoni, and 3 t ha-1 in Hwedza for the high fertilization rate).Contrary to previous research findings, there is a reasonably wide planting window in which good yields can be obtained if the rains start on time, but if the start of the rains is delayed until after the beginning of December planting should be done as soon as possible. Regardless of the amount of fertilizer applied, yields were reduced strongly when planting was substantially delayed by four weeks after the start of the rainy season. Maize yielded more than finger millet and sorghum even when rainfall was poor in the 2010/2011 season. For example, maize yielded 2.4 t ha-1 compared with 1.6 t ha-1 for finger millet and 0.4 t ha-1 for sorghum in the 2010/2011 rainfall season in Makoni. Finger millet and sorghum failed to emerge unless fertilizer was applied. Application of manure alone failed to address this challenge of poor emergence until fertilizer was added. Sorghum suffered critical yield losses due to bird damage. The better performance of maize over finger millet and sorghum suggested that the recommendation to substitute small grains for maize as a viable adaptation option to a changing climate, will neither be the best option for robust adaptation nor attractive for farmers in southern Africa. Alternatively spreading crops across the farm and in time can be a viable strategy to spread climatic risk as well as improve human nutrition. Poor soil fertility constrained yield more strongly than rainfall and late planting, as demonstrated by the large yield gap (> 1.2 t ha-1) between the unfertilized and fertilized cultivars even in the poor rainfall season (2010/2011). Fertilization increased yield significantly under both the baseline and future climates particularly when planting before mid-December.The maize response to mineral nitrogen is, however, projected to decline as climate changes, although effects only become substantial towards the end of the 21st Century. Soil fertility management is therefore likely to be a major entry point for increasing the adaptive capacity of smallholder farmers to climate change and increased climate variability. However, management of factors related to both nutrient resource access and farmers decisions to enhance resource use efficiencies are critical if agriculture is to be used as robust adaptation options to climate change by smallholder in Southern Africa.

Water stress assessment of natural vegetation plays a key role in water management of desert ecosystems. It allows scientists and managers to relate water extraction rates to changes in vegetation water condition, and consequently to define safe water extraction rates for maintaining a healthy ecosystem. Previous research has shown that optical remote sensing constitutes a powerful tool for assessing vegetation water stress due to its capability of quantitatively estimating important parameters of vegetation such as leaf area index (LAI), green canopy fraction (GCF), and canopy water content (CWC). However, the estimation of these parameters using remote sensing can be challenging in the case of desert vegetation. Desert plants have to cope with high solar irradiation and limited water. In order to maintain an adequate water balance and to avoid photoinhibition, desert plants have evolved different adaptations. A common one is heliotropism or ‘solar tracking’, an ability of many desert species to move their leaves to avoid facing direct high solar irradiation levels during the day and season. This adaptation (paraheliotropism) can have an important effect on the canopy spectral reflectance measured by satellites as well as on vegetation indices such as the normalized difference vegetation index (NDVI). In this thesis, I propose a remote sensing based approach to assess water stress of desert vegetation, exemplified in the case of the Tamarugo (Prosopis tamarugo Phil) tree in the Atacama Desert (Northern Chile), a ‘solar tracker’ species, which is threatened by groundwater overexploitation. In the first chapter of this thesis (general introduction), I explained the motivation of the PhD project and elaborated four research questions, which are later discussed in chapters 2, 3, 4, and 5. The thesis concluded with chapter 6, where I provide a synthesis of the main results, general conclusions and a final reflection and outlook. In the second chapter, I studied the effects of water stress on Tamarugo plants under laboratory conditions and modelled the light-canopy interaction using the Soil-Leaf-Canopy radiative transfer model. I described for the first time pulvinar movement of Tamarugo and quantified its effects on canopy spectral reflectance with and without stress. I showed that different spectral indices have potential to assess water stress of Tamarugo by means of LAI and CWC. In the third chapter, I measured the effects of pulvinar movements on canopy reflectance for Tamarugos under field conditions and used high spatial resolution images to assess water stress at the tree level. I developed an automated process to first identify single trees and delineate their crowns, and secondly, to estimate LAI and GCF using spectral vegetation indices. These indices (NDVI and chlorophyll red-edge index) were negatively correlated to diurnal values of solar irradiation as a consequence of leaf pulvinar movements. For this reason, higher values of both vegetation indices are expected to occur in the morning and in winter (low solar radiation) than at midday or summer. In the fourth chapter I studied the effects of diurnal pulvinar movements on NDVI time series from the MODIS-Terra satellite (acquired in the morning) and the MODIS-Aqua satellite (acquired at midday) for the period 2003-2012 and the seasonal effects of pulvinar movements on NDVI time series of Landsat images for the period 1998-2012 for Tamarugo areas with and without water stress. NDVI values measured by MODIS-Terra (morning) were higher than the NDVI values measured by MODIS-Aqua (afternoon) and the difference between the two, the ΔNDVImo-mi, showed good potential as water stress indicator. In a similar way, I observed a strong seasonal effect on the Landsat NDVI signal, attributed to pulvinar movements, and the difference between winter and summer, the ΔNDVIW-S, also showed good potential for detecting and quantifying water stress. The ΔNDVImo-mi, the ΔNDVIW-S and the NDVI itself measured systematically in winter time (NDVIW) were negatively correlated with in situ groundwater depth measurements. In chapter five I used a dense NDVI time series of Landsat images for the period 1989-2013, combined with high spatial resolution satellite imagery and hydrogeological records, to provide a quantitative assessment of the water status of Tamarugo vegetation after 50 years of increasing groundwater extraction. The results showed that the NDVIW and ΔNDVIW-S of the Tamarugo vegetation declined 19% and 51%, respectively, as groundwater depleted (3 meters on average) for the period 1989-2013. Both variables were negatively correlated to groundwater depth both temporally and spatially. About 730.000 Tamarugo trees remained in the study area by 2011, from which 5.2% showed a GCF

Lactobacillus plantarumis one of the most versatile lactic acid bacteria that can successfully inhabit a variety of environmental niches. It is a common inhabitant of the human and animal gastrointestinal (GI) tract and it is used as starter culture in various fermentation processes for different food raw-materials, including milk, fruits, vegetables, and meat. Moreover, L. plantarum is marketed as a health-promoting culture, i.e. a probiotic. In these different environments and processes the bacteria encounter stress conditions, such as heat, cold, acid, salt, and oxygen stress. Since starter cultures and probiotics require metabolic activity to contribute to the taste and texture of the fermented products, and/or viability to exert their in situ beneficial effect on the consumer, it is important to understand and improve the gene-regulatory adaptation that sustains their function and viability under these challenging conditions. Nowadays, genomic approaches are available that enable the global, genome-wide analysis of stress responses in lactic acid bacteria. The work presented in this thesis employs such tools and also developed some novel strategies to understand stress responses in L. plantarum. During wine fermentation, L. plantarum is exposed to ethanol and global transcriptome profiling demonstrated the gene expression adaptation of this microorganism upon short and long term exposure to sublethal levels of this solvent. The results suggested that the ethanol induced activation of the CtsR-related stress regulon contributes to its adaptation to ethanol exposure which also provides cross-protection against heat stress. Transcriptome analyses under different growth conditions of gene deletion derivatives of the L. plantarum WCFS1 strain that lack the genes encoding the stress response regulators ctsR and/or hrcA, enabled the refinement of the gene regulation repertoire that is controlled by these central regulators of stress responses in this species. Notably, the deletion of both stress-regulators, elicited transcriptome changes that affected a large variety of additional gene-functions in a temperature-dependent manner, which prominently included genes related to cell-envelope remodelling. Culturing of L. plantarum WCFS1 under different fermentation conditions led to large differences in GI-tract survival and robustness, which was addressed using a simple in vitro survival assay. Enhanced GI-tract survival and robustness could be associated with low salt and low pH conditions during the fermentations. The transcriptomes obtained for each of the fermentation conditions employed, were correlated with the observed GI-tract survival rates, enabling the identification of candidate genes involved in the robustness phenotype, including a transcription regulator involved in capsular polysaccharide remodelling (Lp_1669), a penicillin-binding protein (Pbp2A) involved in peptidoglycan biosynthesis, and a Na+/H+ antiporter (NapA3). A role of these candidate genes in actual survival in the GI-tract assay could be confirmed by mutation analysis, further confirming their contribution to GI-tract stress robustness in L. plantarum. This thesis also describes the use of a novel, next-generation sequencing-based method, for the assessment of the in vivo GI-tract persistence of different L. plantarum strains that were administered to healthy human volunteers in specifically designed strain-mixtures. A remarkable consistency of the strain-specific in vivo persistence curves was observed when comparing data obtained from different volunteers. Moreover, a striking congruency was observed between the strain-specific in vivo persistence curves and the predicted GI-tract survival based on the simple in vitro assay. Finally, evolutionary adaptation of L. plantarum WCFS1 to the murine GI-tract was studied by extended exposure of the strain to the mice digestive tract through consecutive rounds of (re)feeding of the longest persisting bacterial colonies. Re-sequencing of the genomes of more persistent derivatives of the original strain, and the evaluation of the genomic modifications identified, implied that genes encoding cell envelope-associated functions and energy metabolism play an important role in the determination of GI-tract persistence in L. plantarum. The results described in this thesis strive to obtain an improved understanding of the gene-regulatory adaptations of L. plantarum that allow its survival under stress conditions, including those associated with residence in the gastrointestinal tract of animals and humans, with the intention to exploit such understanding to rationally improve the robustness of these bacteria.

Lactobacillus plantarumis one of the most versatile lactic acid bacteria that can successfully inhabit a variety of environmental niches. It is a common inhabitant of the human and animal gastrointestinal (GI) tract and it is used as starter culture in various fermentation processes for different food raw-materials, including milk, fruits, vegetables, and meat. Moreover, L. plantarum is marketed as a health-promoting culture, i.e. a probiotic. In these different environments and processes the bacteria encounter stress conditions, such as heat, cold, acid, salt, and oxygen stress. Since starter cultures and probiotics require metabolic activity to contribute to the taste and texture of the fermented products, and/or viability to exert their in situ beneficial effect on the consumer, it is important to understand and improve the gene-regulatory adaptation that sustains their function and viability under these challenging conditions. Nowadays, genomic approaches are available that enable the global, genome-wide analysis of stress responses in lactic acid bacteria. The work presented in this thesis employs such tools and also developed some novel strategies to understand stress responses in L. plantarum. During wine fermentation, L. plantarum is exposed to ethanol and global transcriptome profiling demonstrated the gene expression adaptation of this microorganism upon short and long term exposure to sublethal levels of this solvent. The results suggested that the ethanol induced activation of the CtsR-related stress regulon contributes to its adaptation to ethanol exposure which also provides cross-protection against heat stress. Transcriptome analyses under different growth conditions of gene deletion derivatives of the L. plantarum WCFS1 strain that lack the genes encoding the stress response regulators ctsR and/or hrcA, enabled the refinement of the gene regulation repertoire that is controlled by these central regulators of stress responses in this species. Notably, the deletion of both stress-regulators, elicited transcriptome changes that affected a large variety of additional gene-functions in a temperature-dependent manner, which prominently included genes related to cell-envelope remodelling. Culturing of L. plantarum WCFS1 under different fermentation conditions led to large differences in GI-tract survival and robustness, which was addressed using a simple in vitro survival assay. Enhanced GI-tract survival and robustness could be associated with low salt and low pH conditions during the fermentations. The transcriptomes obtained for each of the fermentation conditions employed, were correlated with the observed GI-tract survival rates, enabling the identification of candidate genes involved in the robustness phenotype, including a transcription regulator involved in capsular polysaccharide remodelling (Lp_1669), a penicillin-binding protein (Pbp2A) involved in peptidoglycan biosynthesis, and a Na+/H+ antiporter (NapA3). A role of these candidate genes in actual survival in the GI-tract assay could be confirmed by mutation analysis, further confirming their contribution to GI-tract stress robustness in L. plantarum. This thesis also describes the use of a novel, next-generation sequencing-based method, for the assessment of the in vivo GI-tract persistence of different L. plantarum strains that were administered to healthy human volunteers in specifically designed strain-mixtures. A remarkable consistency of the strain-specific in vivo persistence curves was observed when comparing data obtained from different volunteers. Moreover, a striking congruency was observed between the strain-specific in vivo persistence curves and the predicted GI-tract survival based on the simple in vitro assay. Finally, evolutionary adaptation of L. plantarum WCFS1 to the murine GI-tract was studied by extended exposure of the strain to the mice digestive tract through consecutive rounds of (re)feeding of the longest persisting bacterial colonies. Re-sequencing of the genomes of more persistent derivatives of the original strain, and the evaluation of the genomic modifications identified, implied that genes encoding cell envelope-associated functions and energy metabolism play an important role in the determination of GI-tract persistence in L. plantarum. The results described in this thesis strive to obtain an improved understanding of the gene-regulatory adaptations of L. plantarum that allow its survival under stress conditions, including those associated with residence in the gastrointestinal tract of animals and humans, with the intention to exploit such understanding to rationally improve the robustness of these bacteria.

niet beschikbaar

verkrijgbaar bij/available at: WAB-secretariaat, Postbus 1, 3720 BA Bilthoven, Ottelien Steenis; nopsecr@rivm.nl

niet beschikbaar

verkrijgbaar bij/available at: WAB-secretariaat, Postbus 1, 3720 BA Bilthoven, Ottelien Steenis; nopsecr@rivm.nl

This thesis describes the adaptation of smallholders to market changes shaped by neoliberal policy reforms in the Mexican maize sector. Contrary to expectations about smallholder responses to a liberalised maize market, in the study area maize still is the main source of income. Farmers did not leave the maize sector to produce more profitable crops neither did they exit agriculture. Special attention is given to the role of social capital in shaping households’ adaptation behaviour. By analysing the role of trust in adaptation processes, this study enhances our understanding of the importance of the social and historical context in contemporary livelihood decisions. It demonstrates that new forms of social capital are difficult to sustain if they do not link up with existing, local forms of social capital. Data collection in the field took place between March 2007 and May 2010. The research was conducted in Morelos, Veracruz, Mexico.

In reactie op klimaatverandering verschuift van veel soorten het areaal, maar het is duidelijk dat dit voor lang niet alle soorten snel genoeg gaat. Habitatfragmentatie zal in het algemeen de noodzakelijke areaalverschuivingen vertragen. Er is geopperd dat de combinatie van areaalverschuivingen en de lokale aanpassing van soorten aan de veranderende omstandigheden hun overleving positief zal beïnvloeden

The main goal of my research was to analyze how the desire to affect and be affected by foreign signs relates to the commoditization of food products offered in Mexican restaurants in Amsterdam, Madrid and San Francisco. I conceive restaurants as foodscapes. Iargue that actors’ attachments to passionate networks enable their enactment. Foodscapes areintersemiotic translations of landscapes. In these translations, the commoditization of food has been based on its relationships with idealized entities from the Mexican and U.S. landscapes, giving rise to Tex‐Mex, Cal‐Mex, Mex‐Mex, Regional‐Mex and “Real”‐ Mex restaurants. The resulting foodscapes have the power to seduce consumers either by fixing their beliefs for certain foods or contaminating new passions. My approach is an innovative way to analyze the differentiation of markets in an economy that bases its reproduction in the contamination of desires and passions.

In reactie op klimaatverandering verschuift van veel soorten het areaal, maar het is duidelijk dat dit voor lang niet alle soorten snel genoeg gaat. Habitatfragmentatie zal in het algemeen de noodzakelijke areaalverschuivingen vertragen. Er is geopperd dat de combinatie van areaalverschuivingen en de lokale aanpassing van soorten aan de veranderende omstandigheden hun overleving positief zal beïnvloeden

This thesis describes the adaptation of smallholders to market changes shaped by neoliberal policy reforms in the Mexican maize sector. Contrary to expectations about smallholder responses to a liberalised maize market, in the study area maize still is the main source of income. Farmers did not leave the maize sector to produce more profitable crops neither did they exit agriculture. Special attention is given to the role of social capital in shaping households’ adaptation behaviour. By analysing the role of trust in adaptation processes, this study enhances our understanding of the importance of the social and historical context in contemporary livelihood decisions. It demonstrates that new forms of social capital are difficult to sustain if they do not link up with existing, local forms of social capital. Data collection in the field took place between March 2007 and May 2010. The research was conducted in Morelos, Veracruz, Mexico.

The main goal of my research was to analyze how the desire to affect and be affected by foreign signs relates to the commoditization of food products offered in Mexican restaurants in Amsterdam, Madrid and San Francisco. I conceive restaurants as foodscapes. Iargue that actors’ attachments to passionate networks enable their enactment. Foodscapes areintersemiotic translations of landscapes. In these translations, the commoditization of food has been based on its relationships with idealized entities from the Mexican and U.S. landscapes, giving rise to Tex‐Mex, Cal‐Mex, Mex‐Mex, Regional‐Mex and “Real”‐ Mex restaurants. The resulting foodscapes have the power to seduce consumers either by fixing their beliefs for certain foods or contaminating new passions. My approach is an innovative way to analyze the differentiation of markets in an economy that bases its reproduction in the contamination of desires and passions.

Higher water levels and more space for water will fundamentally change the way our coastal lowlands are being managed. Appropriate conservation, adaptation and mitigation actions need to take place in the context of sustainable development. In the Netherlands, adaptation measures focus on the water management system as well as the spatial planning. The selection of adaptation measures, mainly depends the type of land use. For the three major types of land types, i.e. the low-lying peatlands in the western part of the country, the higher sandy soil areas in the east and southeast and the marine clay areas in the reclaimed polder areas, adaptation measures, for both agriculture and nature, adaption strategies are discussed.

Higher water levels and more space for water will fundamentally change the way our coastal lowlands are being managed. Appropriate conservation, adaptation and mitigation actions need to take place in the context of sustainable development. In the Netherlands, adaptation measures focus on the water management system as well as the spatial planning. The selection of adaptation measures, mainly depends the type of land use. For the three major types of land types, i.e. the low-lying peatlands in the western part of the country, the higher sandy soil areas in the east and southeast and the marine clay areas in the reclaimed polder areas, adaptation measures, for both agriculture and nature, adaption strategies are discussed.

Developing countries are extremely vulnerable to climate change, due to their strong economic dependency on rain-fed agriculture. Land-use policies can offer a less vulnerable future by design and application of relevant mitigation and/or adaptation strategies. Effectiveness of such strategies depends on local conditions. Therefore, hotspot regions are defined, where specific issues related to agriculture will be assessed. Mitigation strategies in East Africa in general and Ethiopia in particular include reforestation, while adaptation covers aspects such as crop diversification and water use efficiency. An analytical framework is developed in which a science-policy interface is the main focus. On one hand policy-makers and stakeholders can be involved in such a framework for policy design, while scientists on the other hand deliver data and modeling tools. The model chain in the framework is integrated by an evaluation step where policy options are compared for efficiency on several development targets. The framework will be tested in 2010 in hotspot regions in East Africa.

Developing countries are extremely vulnerable to climate change, due to their strong economic dependency on rain-fed agriculture. Land-use policies can offer a less vulnerable future by design and application of relevant mitigation and/or adaptation strategies. Effectiveness of such strategies depends on local conditions. Therefore, hotspot regions are defined, where specific issues related to agriculture will be assessed. Mitigation strategies in East Africa in general and Ethiopia in particular include reforestation, while adaptation covers aspects such as crop diversification and water use efficiency. An analytical framework is developed in which a science-policy interface is the main focus. On one hand policy-makers and stakeholders can be involved in such a framework for policy design, while scientists on the other hand deliver data and modeling tools. The model chain in the framework is integrated by an evaluation step where policy options are compared for efficiency on several development targets. The framework will be tested in 2010 in hotspot regions in East Africa.

The microbial stability and safety of minimally processed foods is controlled by a deliberate combination of preservation hurdles. However, this preservation strategy is challenged by the ability of spoilage bacteria and food-borne pathogens to adapt to stressing environments providing cell robustness. Bacillus cereus is a toxin-producing, spore-forming bacterium, and is able to survive minimal processing conditions. A quantitative approach was followed to gain insight in B. cereus’ stress adaptive behavior at population, individual cell and molecular level. B. cereus’ ability to adapt to salt stress and gain robustness towards subsequent heat challenge-stress exposure was quantified in detail using primary kinetics models. The adaptive salt stress response was influenced by the adaptation-stress concentration, the growth phase of the cells, strain diversity and the culturing temperature during adaptation-stress treatment. The nonlinear nature of the heat inactivation kinetics suggested heterogeneity within the population with respect to stress adaptive behavior. The direct-imaging-based Anopore technology was used to quantitatively describe the population heterogeneity of B. cereus upon mild and severe salt stress treatments and during low temperature growth. Fluorescent labeling of cells provided insights in the origin of stress-induced population heterogeneity. Then, to elucidate adaptive salt stress responses at molecular level, the genome-wide transcriptome profiles of mildly and severely salt-stressed cells were compared. Various transcriptome responses could be correlated to phenotypic features of salt stress-adapted cells. Comparison of the transcriptome profiles of salt stress-adapted cells to those that were exposed to mild heat, acid and oxidative stress, directed to potential cellular biomarkers for stress adaptation. The selected candidate-biomarkers  the transcriptional regulator B (activating general stress responses), catalases (removing reactive oxygen species), and chaperones and proteases (maintaining protein quality)  were measured upon adaptation-stress treatment at transcript, protein and/or activity level, and their induction was correlated to adaptation-stress induced robustness towards challenge-stress. Various candidate-biomarkers were suitable to predict the robustness level of adaptation-stress pretreated cells towards challenge-stress, and are therefore potential predictive cellular indicators for adaptation-stress induced robustness. The predictive potential of transcripts differed from that of proteins and activity level, underlining the significance to evaluate predictive potential of candidate-biomarkers at different functional cell levels. This quantitative understanding of B. cereus’ stress adaptive behavior provides mechanistic insights and opens up avenues to come to a mechanism-based approach for designing mild preservation strategies.

Exploited resources might genetically evolve as a consequence of ex¬ploitation by adapting their life history to the imposed mortality re¬gime. Although evolution favors traits for survival and reproduction of the fittest, human-induced evolution might have negative consequences for the exploiter. In general, a shift towards lower growth rate, earlier maturation and increased reproductive investment might be expected from increased (unselective) mortality and these changes might lead to generally smaller exploited individuals. Hence, the evolution might ne¬gatively affect the productivity of the resource and thus the sustainable exploitation and furthermore, genetic changes might be slow to reverse. If selection forces are high, evolution might occur fast and be observa¬ble within a few decades. Fisheries provide a large scale experiment for fisheries-induced evolution (FIE) since fishing mortality rates, typically being size-selective, exceed natural mortality rates by a multiple and data samples are available for decadal time scales. This thesis aims to assess the potential importance of FIE for sustainable exploitation by empirical evidence as well as evolutionary modeling, illustrated for the North Sea flatfish plaice and sole.In empirical studies the problem of inferring on genetic changes from phenotypic observations lies in the disentangling of the phenotypic plasticity caused by environmental variations from the potential gene¬tic change. This is at least partly achieved by constructing norms of reaction that account for this environmental variation. The probabi¬listic maturation reaction norm for instance disentangles phenotypic plasticity in maturation caused by variation in growth. Because growth, maturation and reproductive investment are correlated due to tradeoffs on the individual level, a method was developed that fits an energy al¬location model to individual growth trajectories, obtained by the back-calculation of otoliths. This method provides size-specific estimates of the mechanistic individual life history tradeoffs and of the selection differentials imposed by the fishery. Because the correlation of esti¬mated life-history traits is captured, temporal changes could (for the first time) be analyzed conditionally on the correlation and on potenti¬al environmental effectors, thus disentangling not only environmental variability but also effects from changes in another trait. The results suggest that maturation shifted to occur earlier, surplus energy and reproductive investment increased partly due to environmental factors, but that all changes also bear a genetic component, indicative for FIE.Species-specific individual-based eco-genetic models were developed to explore the evolutionary causes of reverse sexual size dimorphism in the case of flatfish. The hypothesis that males are smaller than fe¬males because of an energy loss through behavioural reproductive in¬vestments has to be rejected in this evolutionary perspective, since a higher demand on reproductive investment is compensated by increased energy acquisition. In contrast, the results show that males are smaller because increasing reproductive investment pays off less in males than in females. The finding can likely be generalized to many cases where mating opportunities are limited in space and time. Since eco-genetic models include the inheritance of traits with frequency-dependent se¬lection, they are therefore a powerful tool to study FIE and the model is therefore fitted to the estimated evolution of plaice and the evolu¬tionary impact of different management scenarios is assessed. The so called maximum sustainable yield MSY and the corresponding maximal fishing mortality FMSY evolve along with the population life history and occur both at lower levels after a while. The currently estimated refe¬rence points are thus not sustainable but slipping targets. By a dome-shaped exploitation pattern being protective for larger fish the evolu¬tionary trends could be reversed and with it the negative evolutionary impact. However, the evolutionary impact trades off against the short term loss in yield: by protecting the large fish the evolutionary impact is minimized but the instantaneous yield is decreased too – the optimal strategy for a given time horizon is somewhere in between. In summary, the thesis provides evidence that FIE should be taken into account for sustainable management.

The microbial stability and safety of minimally processed foods is controlled by a deliberate combination of preservation hurdles. However, this preservation strategy is challenged by the ability of spoilage bacteria and food-borne pathogens to adapt to stressing environments providing cell robustness. Bacillus cereus is a toxin-producing, spore-forming bacterium, and is able to survive minimal processing conditions. A quantitative approach was followed to gain insight in B. cereus’ stress adaptive behavior at population, individual cell and molecular level. B. cereus’ ability to adapt to salt stress and gain robustness towards subsequent heat challenge-stress exposure was quantified in detail using primary kinetics models. The adaptive salt stress response was influenced by the adaptation-stress concentration, the growth phase of the cells, strain diversity and the culturing temperature during adaptation-stress treatment. The nonlinear nature of the heat inactivation kinetics suggested heterogeneity within the population with respect to stress adaptive behavior. The direct-imaging-based Anopore technology was used to quantitatively describe the population heterogeneity of B. cereus upon mild and severe salt stress treatments and during low temperature growth. Fluorescent labeling of cells provided insights in the origin of stress-induced population heterogeneity. Then, to elucidate adaptive salt stress responses at molecular level, the genome-wide transcriptome profiles of mildly and severely salt-stressed cells were compared. Various transcriptome responses could be correlated to phenotypic features of salt stress-adapted cells. Comparison of the transcriptome profiles of salt stress-adapted cells to those that were exposed to mild heat, acid and oxidative stress, directed to potential cellular biomarkers for stress adaptation. The selected candidate-biomarkers  the transcriptional regulator B (activating general stress responses), catalases (removing reactive oxygen species), and chaperones and proteases (maintaining protein quality)  were measured upon adaptation-stress treatment at transcript, protein and/or activity level, and their induction was correlated to adaptation-stress induced robustness towards challenge-stress. Various candidate-biomarkers were suitable to predict the robustness level of adaptation-stress pretreated cells towards challenge-stress, and are therefore potential predictive cellular indicators for adaptation-stress induced robustness. The predictive potential of transcripts differed from that of proteins and activity level, underlining the significance to evaluate predictive potential of candidate-biomarkers at different functional cell levels. This quantitative understanding of B. cereus’ stress adaptive behavior provides mechanistic insights and opens up avenues to come to a mechanism-based approach for designing mild preservation strategies.

Exploited resources might genetically evolve as a consequence of ex¬ploitation by adapting their life history to the imposed mortality re¬gime. Although evolution favors traits for survival and reproduction of the fittest, human-induced evolution might have negative consequences for the exploiter. In general, a shift towards lower growth rate, earlier maturation and increased reproductive investment might be expected from increased (unselective) mortality and these changes might lead to generally smaller exploited individuals. Hence, the evolution might ne¬gatively affect the productivity of the resource and thus the sustainable exploitation and furthermore, genetic changes might be slow to reverse. If selection forces are high, evolution might occur fast and be observa¬ble within a few decades. Fisheries provide a large scale experiment for fisheries-induced evolution (FIE) since fishing mortality rates, typically being size-selective, exceed natural mortality rates by a multiple and data samples are available for decadal time scales. This thesis aims to assess the potential importance of FIE for sustainable exploitation by empirical evidence as well as evolutionary modeling, illustrated for the North Sea flatfish plaice and sole.In empirical studies the problem of inferring on genetic changes from phenotypic observations lies in the disentangling of the phenotypic plasticity caused by environmental variations from the potential gene¬tic change. This is at least partly achieved by constructing norms of reaction that account for this environmental variation. The probabi¬listic maturation reaction norm for instance disentangles phenotypic plasticity in maturation caused by variation in growth. Because growth, maturation and reproductive investment are correlated due to tradeoffs on the individual level, a method was developed that fits an energy al¬location model to individual growth trajectories, obtained by the back-calculation of otoliths. This method provides size-specific estimates of the mechanistic individual life history tradeoffs and of the selection differentials imposed by the fishery. Because the correlation of esti¬mated life-history traits is captured, temporal changes could (for the first time) be analyzed conditionally on the correlation and on potenti¬al environmental effectors, thus disentangling not only environmental variability but also effects from changes in another trait. The results suggest that maturation shifted to occur earlier, surplus energy and reproductive investment increased partly due to environmental factors, but that all changes also bear a genetic component, indicative for FIE.Species-specific individual-based eco-genetic models were developed to explore the evolutionary causes of reverse sexual size dimorphism in the case of flatfish. The hypothesis that males are smaller than fe¬males because of an energy loss through behavioural reproductive in¬vestments has to be rejected in this evolutionary perspective, since a higher demand on reproductive investment is compensated by increased energy acquisition. In contrast, the results show that males are smaller because increasing reproductive investment pays off less in males than in females. The finding can likely be generalized to many cases where mating opportunities are limited in space and time. Since eco-genetic models include the inheritance of traits with frequency-dependent se¬lection, they are therefore a powerful tool to study FIE and the model is therefore fitted to the estimated evolution of plaice and the evolu¬tionary impact of different management scenarios is assessed. The so called maximum sustainable yield MSY and the corresponding maximal fishing mortality FMSY evolve along with the population life history and occur both at lower levels after a while. The currently estimated refe¬rence points are thus not sustainable but slipping targets. By a dome-shaped exploitation pattern being protective for larger fish the evolu¬tionary trends could be reversed and with it the negative evolutionary impact. However, the evolutionary impact trades off against the short term loss in yield: by protecting the large fish the evolutionary impact is minimized but the instantaneous yield is decreased too – the optimal strategy for a given time horizon is somewhere in between. In summary, the thesis provides evidence that FIE should be taken into account for sustainable management.