Sociology of Development group research projects
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Terra Preta do Indio: Recovering the past, regaining the future of Amazonian Dark Earths
- Highly fertile, anthropogenic soils in the Amazon (Terra Preta; Amazonian Dark Earth) challenge conventional theories on environmental limitation in the Amazonian basin. These improved soils (and their co-evolved crops) offer a major inspiration for (re-)creating soils for sustainable agriculture and climate change mitigation through carbon sequestration. -
Comparative analysis of plant genomes using advanced fluorescent in-situ hybridization (FISH)
- During speciation, chromosome segments may change position on chromosomes through translocations and inversions. Such structural rearrangements can be visualized using microscopy and advanced fluorescent in-situ hybridization (FISH). We use this approach to investigate structural rearrangements between different species.
In recent years, many genome sequences became available for (crop-) plants. It is possible to use these genome sequences to design sets of fluorescent probes (oligos) that can be used to visualize specific regions on plant chromosomes. This technique is known as oligo-FISH. Such probe-sets can be used to investigate visualize and identify structural variation between the genomes of related species. -
Ecology and evolution of plasmid-mediated antimicrobial resistance (pAMR) transfer in the chicken microbiome
- Plasmid-mediated antimicrobial resistance (pAMR) presents a major challenge to both human and animal health. Extended spectrum beta-lactamase (ESBL)-producing bacteria with resistance to a range of beta-lactam antibiotics are highly prevalent among farm animals, and the same plasmids and resistance genes can be found in human bacterial isolates. The prevalence of pAMR is affected by selection pressures on host bacteria, compensatory adaptation of the host and plasmid and plasmid conjugation rates. Despite this, we know little about the ecological and evolutionary processes influencing the invasion and maintenance of pAMR within the microbiome of a (group of ) individual animals. These processes can be better understood using controlled experiments in the laboratory of conjugation rates and pAMR invasion in the absence and presence of synthetic microbial communities. -
Climate and diversification effects on population structures and host selection behaviour of natural enemies
- Olive fruit fly (OFF) is a major threat of olive trees causing high yield losses. Up to date, the control of this pest is mainly done by spraying synthetic pesticides. However, the OFF has developed resistance to pesticides limiting the effectiveness of this method. Long-term exposure to pesticides negatively affects humans’ health, the environment, and the quality of the olive products. Hence, an environmentally sound way of controlling this pest is of great importance. Therefore, to be able to develop an appropriate pest management it is essential to investigate the interactions between OFF and their parasitoids in different spatial and temporal scales and thus to understand how spatial heterogeneity and abiotic factors affect the ecological function of insect organisms in a given habitat. Knowledge on foraging behavior of OFF parasitoids and chemical cues involved in therein as well as on population structure and genetic diversity of the OFF and their parasitoids is essential to develop more adequate OFF control strategies and thus to minimize the negative impact of pesticides on the biodiversity in agro-ecosystems as well as on humans’ health.
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Conflict and cooperation among Termitomyces fungi cultivated by termites
- Termites in Africa and Asia cultivate fungi of the genus Termitomyces. The fungus is actively farmed by the termites in a monoculture well protected in the termite nest. Theory predicts that long-term cultivation of fungal monocultures, may open the door to less productive mutants, which would ultimately lead to a tragedy of the commons and a potential collapse of the mutualistic symbiosis. Nevertheless, the mutualism between termites and fungi has persisted for milions of years and a single colony can live for multiple decades. In this project I address the following questions:
1. The ecological stability of monoculture. Is the fungus garden of one termite mound indeed a monoculture, not only in space but also over time?
2. Selection of a suboptimal fungal strain in the initial stage. The initial fungal garden will sometimes be a mixed culture.
3. The genetic stability of Termitomyces monocultures.
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Addressing Health Inequalities in Vulnerable Urban Neighbourhoods by Social Community Enterprises
- The overarching goal is to measure the impacts of the intervention social community enterprises on the health of residents with low socioeconomic status. This project is based on the assets model of health: residents and communities are supported to identify and mobilize assets for their own health and well-being. Six social community enterprises have been selected as case studies in socially vulnerable neighbourhoods of the city of Arnhem. Their aim is to create, in co-creation with residents, added value for community members by deploying a mixture of social, economic and environmental activities. Core of the approach is that residents participate, make choices by themselves, improve their local community and by doing so improve their health. Concrete activities are creation of informal meeting places, creation of social enterprises, training of working skills, taking care of the physical environment and initiating support networks. -
iFlow
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Genetics and evolution of toxin production by Aspergillus flavus
- Mycotoxin contamination in maize and other important crops like groundnuts is a major problem in Zambia, throughout Africa and beyond. Maize is often infested by mixed communities of fungi and unfortunately some of these fungi produce so-called mycotoxins. Our main objective therefore is to reduce mycotoxin contamination of maize through effective use of biological agents that promote replacement of producer by non-toxin producer strains.
Central is the conceptual framework of niche exclusion that can occur in mixed communities of multiple species. In natural systems species co-exist and evolve as complex communities which is determined by the niche environment and the biological properties of each species. We will use theoretical models that use the ecological relationships between individuals and species to formulate predictions for the dynamics of mixed fungal maize-infesting communities. -
Amazonian Historical Ecology
- This project evaluates how past and current human management activities may influence useful species distribution and dominance in Amazonian forests. -
Traditional fermented foods to promote food and nutrition security in Africa