Masquerades form an important part of indigenous African religions, and headpieces of masks are found all over the world as an iconic African art form. Contrary to expectation, however, the... Show moreMasquerades form an important part of indigenous African religions, and headpieces of masks are found all over the world as an iconic African art form. Contrary to expectation, however, the geographical distribution of masking is very restricted, occurring only in three areas of the continent, mainly situated in the forested zones. I explain this peculiar distribution by tracing the ecological and historical parameters of the societies that harbor mask rituals. The main ecological factors are the absence of cattle and the type of horticulture, while a crucial historical element is the long history of slave raiding and trading to which the continent has been subjected. These factors have led to societies in which both gender and local power arrangements show a marked indeterminacy, operating as internal arenas between men and women, and between different groups of men. Crucial in the explanation of masquerades is the fact that masking is completely absent from societies that practice cattle husbandry with the Bos indicus species (zebu). Since sleeping sickness prohibits cattle husbandry, wherever the tsetse fly thrives, masks appear. Show less
This thesis pioneers diatom molecular identification and quantification through genome-scale methods, with four key aims: (i) reviewing DNA/RNA sequencing methods in aquatic biomonitoring to... Show moreThis thesis pioneers diatom molecular identification and quantification through genome-scale methods, with four key aims: (i) reviewing DNA/RNA sequencing methods in aquatic biomonitoring to highlight their strengths and limitations; (ii) unraveling the evolutionary history of Nitzschia palea and investigating species delimitation within the species complex; (iii) identifying silica genes in N. palea for insights into ecology and evolution; and (iv) assessing a genome-scale quantification method for diatom biomonitoring to improve accuracy and scalability in estimating abundances. The review (Chapter 2) emphasizes disparities between molecular and morphology-based approaches and introduces the challenges in accurately estimating species abundances. Chapter 3 explores N. palea's evolutionary history using transcriptome data and reveals reticulate evolutionary patterns resulting in a putative hybrid between populations with different morphological characteristics. Chapter 4 pinpoints silica genes in N. palea and reveals variations among different populations that may lead to differences in silica metabolism. Chapter 5 introduces a genome-scale quantification approach that provides a promising alternative for molecular diatom biomonitoring due to its improved taxonomic resolution and quantification accuracy. In summary, this thesis underscores that genome-scale methods' have a critical role in diatom identification and quantification, and in advancing our understanding of microalgal taxonomy, ecology, and evolution. Show less
An Arduino-based data-logger for meteorological data including: air pressure/altitude, gas, humidity, temperature, wind direction, wind speed. Data is collected with a specified interval, starting... Show moreAn Arduino-based data-logger for meteorological data including: air pressure/altitude, gas, humidity, temperature, wind direction, wind speed. Data is collected with a specified interval, starting from the moment the device is powered and saving the measurements to a csv file on a SD card. Show less
Gaudzinski-Windheuser, S.; Kindler, L.; MacDonald, K.; Roebroeks, W. 2023
Straight-tusked elephants (Palaeoloxodon antiquus) were the largest terrestrial mammals of the Pleistocene, present in Eurasian landscapes between 800,000 and 100,000 years ago. The occasional co... Show moreStraight-tusked elephants (Palaeoloxodon antiquus) were the largest terrestrial mammals of the Pleistocene, present in Eurasian landscapes between 800,000 and 100,000 years ago. The occasional co-occurrence of their skeletal remains with stone tools has generated rich speculation about the nature of interactions between these elephants and Pleistocene humans: Did hominins scavenge on elephants that died a natural death or maybe even hunt some individuals? Our archaeozoological study of the largest P. antiquus assemblage known, excavated from 125,000-year-old lake deposits in Germany, shows that hunting of elephants weighing up to 13 metric tons was part of the cultural repertoire of Last Interglacial Neanderthals there, over >2000 years, many dozens of generations. The intensity and nutritional yields of these well-documented butchering activities, combined with previously reported data from this Neumark-Nord site complex, suggest that Neanderthals were less mobile and operated within social units substantially larger than commonly envisaged. Show less
Biodiversity enables ecosystems to thrive through the synergy of functional differences among organisms. While human well-being strongly depends on biodiversity-driven ecosystem services, human... Show moreBiodiversity enables ecosystems to thrive through the synergy of functional differences among organisms. While human well-being strongly depends on biodiversity-driven ecosystem services, human actions are also at the root of current unprecedented biodiversity declines. Comprehensive methods to assess the dynamics and state of biodiversity are therefore increasingly urgent. This thesis studies the overlooked capabilities of current satellite observations to conduct large-scale monitoring of plant functional diversity, with a focus on the European Space Agency’s flagship Sentinel-2 satellite. Specifically, it addresses the use of spectral diversity metrics, radiative transfer model inversion, the need for adequate in-situ validation, and the role of spatial scale in our perception and estimation of satellite-derived plant functional diversity patterns. Show less
Studying change in the course of human history, in different places, through the lens of a diverse set of core themes, World History for International Studies offers readers a set of windows into... Show moreStudying change in the course of human history, in different places, through the lens of a diverse set of core themes, World History for International Studies offers readers a set of windows into different debates historians have been conducting. Key themes, such as communication, trade, order, slavery, religion, war, identity, modernity, norms and ecology, are linked to specific world regions, which tell a story about how local ideas and individual contacts developed, started to overlap and became globally understood and used by ever larger groups of people. These themes are brought to life by a diverse set of key primary sources, such as a book, a letter, a medal, a temple and an epic, to showcase how historians have used sources to tell these stories and conduct debates. The book provides an introductory resource into the study of history and includes detailed suggestions for further study. Show less
This dissertation studies the changes in the rural economy and society of south-eastern Panjab during the eighteenth and nineteenth centuries. This region was an ecological and political frontier,... Show moreThis dissertation studies the changes in the rural economy and society of south-eastern Panjab during the eighteenth and nineteenth centuries. This region was an ecological and political frontier, where nomadic-pastoral and agrarian ways of life overlapped, and effective power lay in the hands of different husbanding communities, which were each represented by warlords from established clans. This research seeks to understand the impact of colonization upon south-eastern Panjab, where the British East India Company first acquired a foothold in 1803. The Company faced two main challenges. First, the large number of princes, chiefs, and warlords whose domains dotted the region, and whose authority posed a challenge to that of the British. Second, the itinerant ways of local agro-pastoral populations, which made them difficult to monitor and tax. How did the state’s attempts to counter these challenges impact local populations? In particular, how did it affect the households of the husbandman, the warlord and the preceptor, the three key figures in rural society? It is these questions that this thesis seeks to answer. It suggests that while the region was impoverished by colonization, the household-based rural order survived into the twentieth century. Show less
We consider situations where repeated invasion attempts occur from a source population into a receptor population over extended periods of time. The receptor population contains two locations that... Show moreWe consider situations where repeated invasion attempts occur from a source population into a receptor population over extended periods of time. The receptor population contains two locations that provide different expected off- spring numbers to invaders. There is demographic stochasticity in offspring numbers. In addition, temporal variation causes local invader fitnesses to vary. We show that effects of environmental autocorrelation on establishment success depend on spatial covariance of the receptor subpopulations. In situ- ations with a low spatial covariance this effect is positive, whereas high spatial covariance and/or high migration probabilities between the subpopulations causes the effect to be negative. This result reconciles seemingly contradictory results from the literature concerning effects of temporal variation on popu- lation dynamics with demographic stochasticity. We study an example in the context of genetic introgression, where invasions of cultivar plant genes occur through pollen flow from a source population into wild-type receptor populations, but our results have implications in a wider range of contexts, such as the spread of exotic species, metapopulation dynamics and epidemics. Show less
Lubbers, M.; Hovius, S.A.; Chai, R.R.; Byng, J.W.; Schilthuizen, M. 2020
Metallyticus is a genus of rare mantids, occurring mostly in SouthEast Asia. Five species have been described. However, their ecology and behaviour remain virtually unknown. In this study, we... Show moreMetallyticus is a genus of rare mantids, occurring mostly in SouthEast Asia. Five species have been described. However, their ecology and behaviour remain virtually unknown. In this study, we describe a small population of Metallyticus splendidus Westwood, 1889 on a dead dipterocarp tree standing in disturbed tropical rainforest around Danau Girang Field Centre, Sabah, Malaysia. At dawn, in the afternoon and at night, four individuals, two adults and two nymphs, were monitored. Our findings confirm earlier behavioural observations: they hold their bodies flat when running. We did not observe any lurking behaviour: the mantids were walking fast across the tree stem and in tree holes. M. splendidus was found at dawn, in the afternoon, and at night only on this single dead tree in a plot of 50 X 50 m. This suggests that M. splendidus is day and night-active and that its habitat is restricted to dead standing trees. We failed to find other individuals on other dead as well as living trees. Our findings show that the habitat of M. splendidus could be restricted to large dead trees, giving novel insights into the ecology of Metallyticidae. Show less
This dissertation together with the artworks documented in it is the result of an investigation across multiple media over a seven-year period of the cultural, artistic and spiritual legacy of... Show moreThis dissertation together with the artworks documented in it is the result of an investigation across multiple media over a seven-year period of the cultural, artistic and spiritual legacy of the late nineteenth- and early twentieth-century Lebensreform (Life Reform) movement. In the course of this research I situate this movement with its origins in Europe and its promotion of a back-to-nature lifestyle (health foods, sexual emancipation, rational dress/nudism, pantheism/syncretic New Age religions) in a long line of radical reform projects, that lead back to the Reformation and the Anabaptist rebellions in sixteenth-century Germany, the Netherlands and Switzerland. At the same time, I link the passage to America of Lebensreform beliefs and practices to the rise of the hippy counter-culture in California and the global spread in the decades since the nineteen-sixties of today’s ecological, organic food and naturopathy/Wellness movements. In both the dissertation and the series of artworks discussed within it I set out to unravel and confront the complicated legacy of Theosophy and Anthroposophy, the holistic systems of belief that formed the spiritual backbone of the Lebensreform phenomenon. In the process I probe the question of how it came to be, that an occult world view based on a synthesis of world religions could appeal equally to purist avant-garde proponents of abstraction such as Kandinsky and Mondriaan and to figurative painters and illustrators such as Fidus (Hugo Höppener) and Fritz Mackensen, whose work promoted an idealized ‘Aryan’ aesthetic in line with German National Socialist ideology. As such the present work forms part of the larger reappraisal currently under way among artists and scholars of the history of utopian counter-cultural thinking and alternative life-style experimentation in the West. Following in the footsteps of historians such as Peter Staudenmaier, Janet Biehl, and Susan A. Manning, I argue that this reappraisal forces us to acknowledge the anti-rational esoteric roots of Modernism along with the progressive strands in Modernist thinking and practice, that tend to be foregrounded in most historical accounts. However my interest in this project as an artist is not conventionally historical or academic but rather personal and performative. And the way the arguments are made, for the most part through installations, drawings, sculptural objects, video works, artist statements and performances, bears little relation to the orderly modes of presentation and detached forms of analysis that mark traditional academic discourse. Instead, the project unfolded over time as a prolonged archaeological dig into two intersecting strata, the muddy history of the Lebensreform movement and my own formation as someone born into an anthroposophical/Reform Church household in Leiden. The tension between Progress (social engineering/the collaborative ideal) and ℞egression (back to nature/childhood/basics) dictates the rhythm of the dig. The excavation metaphor gets literalized as I move closer to home, and in many of the artworks (Dutch) mud and compacted soil become the primary material: both the medium in which the inquiries are conducted and the consumable message/medicine dispensed at the door in pill-form to the departing exhibition visitor. Show less
Mollusca form an important animal phylum that first appeared in the Cambrian, and today is,after Arthropoda, the second largest animal phylum, with more than 100,000 extant species(Bieler, 1992,... Show moreMollusca form an important animal phylum that first appeared in the Cambrian, and today is,after Arthropoda, the second largest animal phylum, with more than 100,000 extant species(Bieler, 1992, Brusca and Brusca, 2003), with the class Gastropoda accounting for 80% of the extant species in the Mollusca. Despite its species-richness, a generalised gastropod shell architecture is maintained because of conserved developmental processes. All of the shelled gastropods grow by adding, in a unidirectional accretionary way, shell material with the mantle edge organ, usually at different deposition rates around the existing aperture. This shell ontogeny, or to be more specific aperture ontogeny, gives the general spiral form for the shells. However, spiral forms can vary when there are changes in any one of the aspects in the aperture ontogeny profiles, namely, the rate and direction of shell deposition around the aperture, size and shape of the aperture (i.e. mantle edge), and the total length of the shell ontogeny processes. The interplays between these developmental parameters have generated a great diversity in shell form, for which taxonomists and evolutionary biologist are now trying to accurately characterise and to understand with regard to its evolution.This thesis reveals several hitherto unknown aspects of Plectostoma shell forms,in terms of the developmental homology, the aperture ontogeny profile, anti-predation functionality, and evolutionary pattern in shell characters and ontogenetic morphospace evolution. In fact, these are the issues that have been targeted by biologists for centuries in order to improve the way shell shape is characterised and to improve understanding of shell form evolution. Show less
Africa is often called ‘the fire continent’ based on the high frequency and large extent of burning. Over 200 million hectares of land are regularly burned, mostly savanna areas. In this thesis the... Show moreAfrica is often called ‘the fire continent’ based on the high frequency and large extent of burning. Over 200 million hectares of land are regularly burned, mostly savanna areas. In this thesis the ecological effects of fire on savanna herbivores in Bénoué National Park in North Cameroon are described. Analyses of grass quality show that unburned grass swards are of insufficient quality to sustain grazing herbivores during the dry season. Post-fire regrowth, however, is of much better quality, as it contains higher nutrient levels and higher digestibility. As a result, herbivores strongly prefer to graze on burned swards. This is more than just a simple food preference: most grazers probably would not survive the dry season on unburned swards. Because of this, fire proves to be a major factor governing diversity patterns of herbivores, both at the local scale (the park) and at larger scales (West Africa as a whole). In this thesis it is argued that the species richness of grazing herbivores throughout West Africa is primarily governed by fire, rather than by moisture or soil fertility. Without fire it would thus be impossible to maintain current diversity levels of herbivores in the Guinea savanna zone of West Africa. Show less
What does it mean to be human in a world of technology? What could be the role of religion in responding to the ecological crisis? Should we be concerned about the modification of food, and even of... Show moreWhat does it mean to be human in a world of technology? What could be the role of religion in responding to the ecological crisis? Should we be concerned about the modification of food, and even of ourselves? Who do we trust to make decisions regarding our common future? What do we use our technology for? These are not questions for experts only. How can the wider public be involved? Do experts and the general public trust each other sufficiently? Or is the public ignorant, in the eyes of the scientists? And are too many engineers narrow minded, according to the general public? The contributors to this timely and necessary volume address expertise, trust and engagement, as we consider our technological condition , religious resources for the ecological crisis , biotechnology , and matters of trust between scientists and the general public. With contributions from leading scholars in the field, including James Miller from Queen's University, Canada and Tony Watling from the University College, London, this book will captivate a range of readers interested in the spirtitual dimension of of our culture and society Show less
Bacteria belonging to the genus Collimonas consist of soil bacteria that can grow at expense of living fungal hyphae i.e. they are mycophagous. This PhD studies deals with the ecology of... Show moreBacteria belonging to the genus Collimonas consist of soil bacteria that can grow at expense of living fungal hyphae i.e. they are mycophagous. This PhD studies deals with the ecology of mycophagous bacteria in soil using collimonads as model organisms. Collimonads were found to be widely distributed in different types of soils albeit at low densities. Highest numbers were present in fungal-rich grassland soils and lowest numbers in fungal-poor arable soils. Yet, no significant positive correlation between numbers of collimonads and fungal biomass densities was obtained when all soils were included in the analysis. Actual growth of indigenous collimonads in soils upon invasion by fungal hyphae was demonstrated using a newly, developed Collimonas-specific qPCR assay. The fungal-induced increase in numbers of collimonads was moderate and did not result in an increased turn-over of fungal biomass. In contrast to the effects on fungal-biomass turn-over, effects of presence of collimonads on soil fungal community composition were strong. This implies that collimonads can change the competitive relationships between soil fungal species. Hence, our conclusion is that a small component of the soil microbial community can have a huge impact on this community. Show less
