<p>The face of the Earth is constantly renewed by continental rifts that open and allow ridges to spread oceanic floor. Both types of these linear extensional structures are morphologically and structurally segmented. This thesis aims to provide insights into the interaction of such segments as they propagate and mature. It is based on the results of analogue models of evolving rifts and ridges together with field studies of populations of dilational normal faults in the active rift zone of Iceland. Linkage of initially separate segments along rifts and ridges leads to formation of through-going systems operating on a planetary scale. It is argued here that the processes of segment initiation and growth are effectively scale-independent and essentially the same in wide and narrow modes of extension and for shear and dilational failure. Three distinct types of segment coalescence are recognized; these involve tip-to-tip, one tip-to-sidewall and two tips-to-sidewalls segment linkage. The overall structural pattern, particularly the width of the extending domain and the range of displacements and orientations of smaller-scale internal extensional structures, is influenced by both the geometry of extension and the mechanical properties of the extending material. Types of segment linkage appear to be largely independent of localization of dilation or intensity of magmatic accretion. Instead they are controlled mainly by the relative distribution and orientation of interacting segments. A few orders of segmentation along global rift-ridge systems and arrays of dilational normal faults indicate that linear continuous structures accumulate extension in successive increments during which the segments change their geometries in semi-continuous interaction and coalescence.</p>

<p><font face="Times New Roman" size="3"><font face="Times New Roman" size="3"> <p align="left">The Social Capital approach to development is based on the premise that both cognitive and structural aspects of a given society determine the level of development performance. It is argued that norms of trust and reciprocity, networks, and mutual aid govern interaction among people, hold them together, facilitate opportunities to manage common property and pursue common goals, and ultimately contribute to development by facilitating their cooperation and collective action. In this thesis I explore the relationship between social capital and development by analysing the performance of household wellbeing in a given community. Two dominant views on social capital and the outcomes of development performance are currently in prominence in the development discourse. This debate centres on whether social capital is a sufficient cause on its own or whether it needs intermediary actors. The social capital theory argues that the development performance of a particular community can be explained directly by the prevailing level of social capital, and that the underlying levels of trust, social norms and networks are sufficient to explain development. On the other hand, the school of thought that supports the need for intermediary actors argues that social capital is unable to influence development performance at higher levels. If a larger impact and a more precise outcome are expected, intermediary actors who facilitate interest formation, aggregation and representation are necessary. Without them, social capital remains largely inactive and dormant. In exploring the possible link between the two variables, this thesis supports the second premises, introducing the notion of intermediary actors that might activate the stock of social capital and its performance on household wellbeing. The need to explore the relationship between the two variables demanded empirical research. The research was conducted in the rural villages of Oromia regional State of Ethiopia. Based on the empirical evidence, the relationship between the stock of social capital and performance in household wellbeing is generally positive. A large stock of social capital is generally accompanied by a higher level of performance in household wellbeing. However, I argue that social capital is only truly social when activated by an intermediary development actor. Failing this, though it contributes significantly to village solidarity and unity, social capital remains inactive and dormant. Therefore, the general conclusion of this thesis is that social capital matters, but its utilisation by intermediary agencies matters more.</p> </font></font></p>

<p><font face="Times New Roman" size="3"><font face="Times New Roman" size="3"> <p align="left">The Social Capital approach to development is based on the premise that both cognitive and structural aspects of a given society determine the level of development performance. It is argued that norms of trust and reciprocity, networks, and mutual aid govern interaction among people, hold them together, facilitate opportunities to manage common property and pursue common goals, and ultimately contribute to development by facilitating their cooperation and collective action. In this thesis I explore the relationship between social capital and development by analysing the performance of household wellbeing in a given community. Two dominant views on social capital and the outcomes of development performance are currently in prominence in the development discourse. This debate centres on whether social capital is a sufficient cause on its own or whether it needs intermediary actors.</p> </font></font></p>

The face of the Earth is constantly renewed by continental rifts that open and allow ridges to spread oceanic floor. Both types of these linear extensional structures are morphologically and structurally segmented. This thesis aims to provide insights into the interaction of such segments as they propagate and mature. It is based on the results of analogue models of evolving rifts and ridges together with field studies of populations of dilational normal faults in the active rift zone of Iceland. Linkage of initially separate segments along rifts and ridges leads to formation of through-going systems operating on a planetary scale. It is argued here that the processes of segment initiation and growth are effectively scale-independent and essentially the same in wide and narrow modes of extension and for shear and dilational failure. Three distinct types of segment coalescence are recognized; these involve tip-to-tip, one tip-to-sidewall and two tips-to-sidewalls segment linkage. The overall structural pattern, particularly the width of the extending domain and the range of displacements and orientations of smaller-scale internal extensional structures, is influenced by both the geometry of extension and the mechanical properties of the extending material. Types of segment linkage appear to be largely independent of localization of dilation or intensity of magmatic accretion. Instead they are controlled mainly by the relative distribution and orientation of interacting segments. A few orders of segmentation along global rift-ridge systems and arrays of dilational normal faults indicate that linear continuous structures accumulate extension in successive increments during which the segments change their geometries in semi-continuous interaction and coalescence.

Rift Valley Fever virus (RVFV) causes an infection with severe impact on animal and human health. The disease is endemic throughout almost the entire African continent and large regions of the Arabian Peninsula. During epidemics, high mortality is observed in animals, especially among cattle, goats, and sheep. In humans, the symptoms vary from a benign influenza-like disease to a life-threatening hemorrhagic fever. Due to the devastating effect on communities in endemic regions and the possibility of further spread of this virus, there is an imperative need to improve and develop control measurements against this emerging disease. Therefore, this thesis focuses on diagnostics and vaccines against RVFV. RVFV infection kinetics was studied in a mouse model system by detection and quantification of viral genomes, using a developed quantitative real-time PCR (QRT-PCR) method. This novel QRT-PCR method proved to be reliable and serves as a supplement to standard diagnostics, direct virus isolation and serological methods. High levels of viral RNA were found in blood and liver samples from experimentally infected mice during the first days post infection. Thereafter the levels declined rapidly and dropped below detection limit approximately seven days post infection. The QRT-PCR technique was also used in a study aimed to improve diagnosis of RVFV from field samples collected on filter strips. Today, the available RVFV vaccines are only approved for animal use and these vaccines have several shortcomings. Since RVFV is a highly pathogenic organism requiring bio-safety level 3 laboratories, two different none-replicating vaccine approaches have been applied and evaluated using a mouse model. A DNA based vaccine, administered via gene-gun, and the use of virus-like particles (VLP), by the intra-peritoneal route. RVFV specific and neutralising antibodies were raised with both vaccine approaches. However, VLP vaccination against Rift valley Fever proved to be more promising as a future vaccine, since higher titres of neutralising antibodies and improved survival rate were found upon a lethal RVFV challenge in mice. In conclusion, a sensitive and specific method for quantifying RVFV infection and a promising vaccine candidate against RVFV were developed.

A detailed study was made of the composition and distribution of modern and fossil animal and plant traces around saline, alkaline lakes in tectonically active, closed lake-basins. Modern and Pleistocene traces that were examined in lake basins of the Kenya Rift Valley (Lakes Bogoria, Magadi, and Nasikie Engida) were compared directly with fossil traces from the Eocene Lake Gosiute in the Green River Formation of Wyoming, U.S.A., which had a similar hydrochemistry. Analysis of lithofacies and the stratigraphic packaging of the sediments hosting biogenic structures was undertaken so that their vertical and lateral distribution could be used to interpret lake histories and to help to develop depositional models of enigmatic sedimentary successions. A focus was given to the application of the results for paleoecology and stratigraphy, and a model for predicting the position of different trace associations in vertical successions and in different parts of saline, alkaline lake basins has been developed. Evidence from the Kenyan lakes and Eocene Lake Gosiute shows that (1) sedimentary environments are diverse in underfilled basins, and frequent lake-level fluctuations strongly impact the distribution of sedimentary environments suitable for the production and preservation of biogenic structures; (2) the distribution of biogenic structures in underfilled basins is related to the geomorphological and structural setting, tectonic activity, catchment lithology, the basin margin or basin centre location, climate, and salinity and alkalinity, together with other finer-scale environmental and biological controls; (3) because saline environments are restrictive, sites of relatively dilute inflow (springs, rivers and deltas, ephemeral streams) provide oasis-like habitats for animals and plants, and contribute to the increased diversity and laterally variable distribution of saline-lake trace assemblages; and (4) the vertical distribution of trace fossils in a stratigraphic succession reflects changing environments through time; important stratigraphic surfaces, usually formed during periods of lake-level fall, can be recognized from the overprinting patterns of traces produced under different conditions.

A detailed study was made of the composition and distribution of modern and fossil animal and plant traces around saline, alkaline lakes in tectonically active, closed lake-basins. Modern and Pleistocene traces that were examined in lake basins of the Kenya Rift Valley (Lakes Bogoria, Magadi, and Nasikie Engida) were compared directly with fossil traces from the Eocene Lake Gosiute in the Green River Formation of Wyoming, U.S.A., which had a similar hydrochemistry. Analysis of lithofacies and the stratigraphic packaging of the sediments hosting biogenic structures was undertaken so that their vertical and lateral distribution could be used to interpret lake histories and to help to develop depositional models of enigmatic sedimentary successions. A focus was given to the application of the results for paleoecology and stratigraphy, and a model for predicting the position of different trace associations in vertical successions and in different parts of saline, alkaline lake basins has been developed. Evidence from the Kenyan lakes and Eocene Lake Gosiute shows that (1) sedimentary environments are diverse in underfilled basins, and frequent lake-level fluctuations strongly impact the distribution of sedimentary environments suitable for the production and preservation of biogenic structures; (2) the distribution of biogenic structures in underfilled basins is related to the geomorphological and structural setting, tectonic activity, catchment lithology, the basin margin or basin centre location, climate, and salinity and alkalinity, together with other finer-scale environmental and biological controls; (3) because saline environments are restrictive, sites of relatively dilute inflow (springs, rivers and deltas, ephemeral streams) provide oasis-like habitats for animals and plants, and contribute to the increased diversity and laterally variable distribution of saline-lake trace assemblages; and (4) the vertical distribution of trace fossils in a stratigraphic succession reflects changing environments through time; important stratigraphic surfaces, usually formed during periods of lake-level fall, can be recognized from the overprinting patterns of traces produced under different conditions.

Rift Valley Fever Virus is a plebovirus that causes epidemics and epizootics in sub-Saharan African countries but has expanded to Egypt and the Arabian Peninsula. The laboratory rat (Rattus norvegicus) is susceptible to RVFV and has been shown to manifest the characteristic responses of humans and livestock. The rat has frequently been used as a model to study RVFV pathogenesis. Several strains have been infected and some found to be resistant to hepatic disease while others were not. This resistance was found to be associated with a dominant gene inherited in Mendelian fashion. The congenic rat strain WF.LEW and several substrains of the parental strains were used to try and locate the resistance gene. Microsatellites and single nucleotide polymorphisms were used to characterize the genomes of various rat substrains in an attempt to map the gene. Breeding and viral challenge experiments were used to further characterize the strains and assign a location to the resistance gene. The LEW/SsNHsd rats showed approximately 37% genomic difference as compared with LEW/MolTac rats, and 8% difference as compared with LEW/Crl rats. WF/NHsd rats demonstrated a difference of approximately 8% as compared with WF/CrCrl rats. Genotyping of the congenic WF.LEW revealed Lewis markers on RNO3 and RNO9. Subsequent backcross experiments and viral challenge experiments assigned the resistance gene to the distal end of RNO3.

Over the course of the last several decades, an increase in the level of concern surrounding the various health and environmental consequences of current, popular waste disposal methods, including landfilling and incineration, have resulted in an increase in municipal recycling efforts. These efforts take place primarily at the residential and commercial levels, while the availability of recycling in public spaces like sidewalks, transit stops, parks and other areas is not something that is often encountered in cities around the United States. This thesis studies the implications and opportunities for public space recycling through the action research process during which I conducted case study research of existing public space recycling programs in Portland, Oregon, and New York, New York, alongside the planning and implementation of a pilot program for transit stop recycling in Austin, Texas. The aim of this thesis is to examine and establish various goals and common strategies for the implementation of public space recycling programs and ultimately make a case for this arguably invaluable, yet often overlooked, recycling initiative. Working under the theoretical framework of the urban metabolism and Karl Marx’s theory of the metabolic rift, the reimagining of waste disposal practices to include widespread materials recycling is one avenue for the restructuring of the relationship between the city and the natural environment. The expansion of recycling practices into public spaces forwards the overall mission to make recycling an integral part of daily life. If implemented properly, the widespread implementation of recycling programs like public space recycling could begin to heal the fragmented urban metabolism and ensure the longevity of the ever-evolving urban and natural environments. The conclusions of this research revolve around the importance of context for public space (and other) recycling practices. This research shows that for public space recycling to succeed as a strategy for the mainstreaming of recycling practices and the reparation of the metabolic rift, the unique characteristics of each individual public space must be taken into consideration upon the implementation of a public space recycling program. / text

<p><font face="Times New Roman" size="3"><font face="Times New Roman" size="3"> <p align="left">The Social Capital approach to development is based on the premise that both cognitive and structural aspects of a given society determine the level of development performance. It is argued that norms of trust and reciprocity, networks, and mutual aid govern interaction among people, hold them together, facilitate opportunities to manage common property and pursue common goals, and ultimately contribute to development by facilitating their cooperation and collective action. In this thesis I explore the relationship between social capital and development by analysing the performance of household wellbeing in a given community. Two dominant views on social capital and the outcomes of development performance are currently in prominence in the development discourse. This debate centres on whether social capital is a sufficient cause on its own or whether it needs intermediary actors.</p> </font></font></p>