6,703 research outputs found

    Embodying entrepreneurship: everyday practices, processes and routines in a technology incubator

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    The growing interest in the processes and practices of entrepreneurship has been dominated by a consideration of temporality. Through a thirty-six-month ethnography of a technology incubator, this thesis contributes to extant understanding by exploring the effect of space. The first paper explores how class structures from the surrounding city have appropriated entrepreneurship within the incubator. The second paper adopts a more explicitly spatial analysis to reveal how the use of space influences a common understanding of entrepreneurship. The final paper looks more closely at the entrepreneurs within the incubator and how they use visual symbols to develop their identity. Taken together, the three papers reject the notion of entrepreneurship as a primarily economic endeavour as articulated through commonly understood language and propose entrepreneuring as an enigmatic attractor that is accessed through the ambiguity of the non-verbal to develop the ‘new’. The thesis therefore contributes to the understanding of entrepreneurship and proposes a distinct role for the non-verbal in that understanding

    'Exarcheia doesn't exist': Authenticity, Resistance and Archival Politics in Athens

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    My thesis investigates the ways people, materialities and urban spaces interact to form affective ecologies and produce historicity. It focuses on the neighbourhood of Exarcheia, Athens’ contested political topography par excellence, known for its production of radical politics of discontent and resistance to state oppression and eoliberal capitalism. Embracing Exarcheia’s controversial status within Greek vernacular, media and state discourses, this thesis aims to unpick the neighbourhoods’ socio-spatial assemblage imbued with affect and formed through the numerous (mis)understandings and (mis)interpretations rooted in its turbulent political history. Drawing on theory on urban spaces, affect, hauntology and archival politics, I argue for Exarcheia as an unwavering archival space composed of affective chronotopes – (in)tangible loci that defy space and temporality. I posit that the interwoven narratives and materialities emerging in my fieldwork are persistently – and perhaps obsessively – reiterating themselves and remaining imprinted on the neighbourhood’s landscape as an incessant reminder of violent histories that the state often seeks to erase and forget. Through this analysis, I contribute to understandings of place as a primary ethnographic ‘object’ and the ways in which place forms complex interactions and relationships with social actors, shapes their subjectivities, retains and bestows their memories and senses of historicity

    Radionuclide and heavy metal sorption on to functionalised magnetic nanoparticles for environmental remediation

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    The presence of radionuclides and heavy metal ions in aqueous waste streams from industrial processes, especially in the nuclear waste industry, are a major concern. Many other processes are inherent producers of hazardous aqueous waste streams that require treatment for further disposal. These wastes quite often contain many contaminants, from harmful to very toxic. Contact with the environment, through groundwater or rivers, with such contaminants needs to be avoided. The ability to selectively sequester and remove contaminants from aqueous wastes with high loading capacities is of paramount importance to achieve full removal of the contaminants produced in many industries. The recent development of phosphate functionalised superparamagnetic magnetite ((PO)x-Fe3O4) nanoparticles have been shown to have ultra-high loading capacities and a high degree of selectivity towards uranium (U(VI)). The ability to manipulate these NPs with an external magnetic field gives these nanomaterials an advantage over many other conventional technologies in the field. These low-cost, non-toxic, and easily prepared magnetic NPs are highly biocompatible and have already been widely applied in the biotechnology and biomedical industries. The addition of specific functionalities allows for the fine tuning of the selectivity towards certain elements, therefore allowing full control over the selective removal of a wide range of contaminants. This study addresses the optimisation of the NPs manufacturing process that allows for the use of these NPs in a wider range of environments. Many of these waste streams are extreme environments, where they can be highly acidic or highly basic conditions. Therefore the feasibility of coating the Fe3O4 with silica (SiO2) was addressed, to provide an acid resistant layer and substrate for further functionalisation. Both the silica coating, and the applied surface functionality, were found to be stable against dissolution or chemical changes under acidic conditions from pH 1-4. Once acid resistance was established, the ability to extract a wide range of contaminant ions was also investigated. Sorption experiments with a wide range of contaminant ions were conducted to determine the selectivity and loading capacities of both (PO)x-Fe3O4 and (PO)x-SiO2@Fe3O4 NPs, at acidic (pH 3), neutral (pH 7), and basic (pH 11) conditions. Providing a basis for the manufacture of a state-of-the-art, novel extraction tool for both heavy metals and radionuclides. Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES), Transmission Electron Microscopy (TEM), and Scanning Transmission Electron Microscopy - Energy Dispersive X-Ray (STEM-EDX) were used to achieve full characterisation of the NP complexes and supernatants to determine the successful extraction and presence of the contaminant metal ions used in this study. Determining the uptake kinetics, loading capacities for Cs(I), K(I), Na(I), Ca(II), Cd(II), Co(II), Cu(II), Mg(II), Mn(II), Mo(II), Ni(II), Pb(II), Sr(II), Al(III), Ce(III), Cr(III), Eu(III), Fe(III) and La(III) on to (PO)x-Fe3O4 and (PO)x-SiO2@Fe3O4 NPs. Implications of the use of these NPs in the extraction of radionuclides and heavy metals have been discussed in each case along with the potential for developing a broad-spectrum adsorbent. In conclusion, this PhD has shown the potential of these novel as-synthesised phosphate functionalised NP complexes to be utilised for heavy metal and radionuclide extraction, of a range of contaminants, from aqueous solutions, in acidic, neutral, and basic conditions. The production of these cost-effective and selective nanomaterials which exhibit rapid kinetics has the potential to be an important asset to the water treatment industry. Overall, these NP-complexes have been effective in fully removing a wide range of heavy metal contaminants and, therefore, have shown great promise to become a broad-spectrum adsorbent tool, which ultimately will aid in the clean-up of many new and legacy waste environments.Open Acces

    Identification of Hindbrain Neural Substrates for Motor Initiation in the hatchling Xenopus laevis Tadpole

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    Animal survival profoundly depends on the ability to detect stimuli in the environment, process them and respond accordingly. In this respect, motor responses to a sensory stimulation evolved into a variety of coordinated movements, which involve the control of brain centres over spinal locomotor circuits. The hatchling Xenopus tadpole, even in its embryonic stage, is able to detect external sensory information and to swim away if the stimulus is considered noxious. To do so, the tadpole relies on well-known ascending sensory pathway, which carries the sensory information to the brain. When the stimulus is strong enough, descending interneurons are activated, leading to the excitation of spinal CPG neurons, which causes the undulatory movement of swimming. However, the activation of descending interneurons that marks the initiation of motor response appears after a long delay from the sensory stimulation. Furthermore, the long-latency response is variable in time, as observed in the slow-summating excitation measured in descending interneurons. These two features, i.e. long-latency and variability, cannot be explained by the firing time and pattern of the ascending sensory pathway of the Xenopus tadpole. Therefore, a novel neuronal population has been proposed to lie in the hindbrain of the tadpole, and being able to 'hold' the sensory information, thus accounting for the long and variable delay of swim initiation. In this work, the role of the hindbrain in the maintenance of the long and variable response to trunk skin stimulation is investigated in the Xenopustadpole at developmental stage 37/38. A multifaceted approach has been used to unravel the neuronal mechanisms underlying the delayed motor response, including behavioural experiments, electrophysiology analysis of fictive swimming, hindbrain extracellular recordings and imaging experiments. Two novel neuronal populations have been identified in the tadpole's hindbrain, which exhibit activation patterns compatible with the role of delaying the excitation of the spinal locomotor circuit. Future work on cellular properties and synaptic connections of these newly discovered populations might shed light on the mechanism of descending control active at embryonic stage. Identifying supraspinal neuronal populations in an embryonic organism could aid in understanding mechanisms of descending motor control in more complex vertebrates

    Fast forward: technography of the social integration of connected and automated vehicles into UK society

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    The emerging connected and automated vehicles (CAV) have caught much research attention in the past few years. However, a techno-centric bias in the CAV research domain implies the lack of in-depth qualitative studies. To fill the gap, this Ph.D. project bridges the fields of Social Anthropology with STS by adopting technography, an ethnography of technology, to enable a thick description of the CAV technology’s social integration into UK society. By critically drawing a holistic view of the ongoing process of the CAV social deployment, it aims to (1) unfold CAV’s potential problems and dynamic contributions to everyday life through the lens of sociotechnical imaginaries, and (2) reveal and analyse the institutional practice on its social rollout. Based on pilot research and one-year-long fieldwork in London and Edinburgh, the thesis investigated a wide range of important socio-political aspects where fundamental topics such as trust, human-and-machine relationship, social safety, political transparency, and equity in transport systems were explicated. Different from the planners’ top-down CAV imaginaries that focused on its contribution to functional safety, environment, and the economy, the public’s bottom-up imaginaries highlighted issues that were related to their travelling experiences, such as inequity of transport service distribution and sexual harassment during commutes. These findings inspired thinking and rethinking on what constitutes the success of technology’s social deployment from multiple perspectives. In particular, it critically pointed out that safety means not only technological feasibility but also social safety that refers to a safe commuting environments. Such finding in my thesis thus suggests that CAV technology is not a one-size-fits-all solution to problems in our transport system and calls for research effort to the broader socio-political and ethical areas of this technology. through an investigation of the institutional practice, it identified four major institutional forces, including technicians, industry stakeholders, researchers, and policymakers who have been working on these aspects with different approaches and priorities. Apart from acknowledging their efforts in building safety cases, pushing forward the CAV legislation, and engaging the public in trials, it critically explained challenges such as technical uncertainty and political tension in developing and implementing a legal framework. Hence, the project contributes to an understanding of a close encounter between the CAV technology and its imaginaries, in which, technical and socio-political problems and potentials fabricate the richness in its social deployment. It also explicates the importance of embracing multiple perspectives and calls for continuous research in this field

    Adaptive task selection using threshold-based techniques in dynamic sensor networks

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    Sensor nodes, like many social insect species, exist in harsh environments in large groups, yet possess very limited amount of resources. Lasting for as long as possible, and fulfilling the network purposes are the ultimate goals of sensor networks. However, these goals are inherently contradictory. Nature can be a great source of inspiration for mankind to find methods to achieve both extended survival, and effective operation. This work aims at applying the threshold-based action selection mechanisms inspired from insect societies to perform action selection within sensor nodes. The effect of this micro-model on the macro-behaviour of the network is studied in terms of durability and task performance quality. Generally, this is an example of using bio-inspiration to achieve adaptivity in sensor networks

    Knowledge Transfer for and through the Replication of Organisational Routines in Franchise Systems

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    Routines are dispositions to behave according to established sets of rules that are also repositories of the organisational memory about “how things get done”. Franchise systems are organisational forms which expand through the replication of routines by new units owned by franchisees. Drawing on insights from the literatures on organisational learning, organisational evolution (under generalised Darwinism), and cognitive psychology, this thesis identifies the building blocks for a conceptual explanation of routine replication in franchise systems. It then proposes an original case study of Yázigi, a large Brazilian franchise system of language schools, which is used to develop a novel process model that captures how knowledge is transferred for and through the replication of routines within an expanding franchise system. Four principal lessons are derived. First, when direct knowledge transfer is not available, artefacts, most notably template representations of routines, are essential. Second, intermediaries, as agents of routine compilation who direct participants to template representations, are crucial to the process of routine replication. Third, just as routines are analogues of habits, routine compilation seems to reproduce habit compilation. Finally, existing learning-related habits of thought may work in favour of or against the adoption of new habits in the replication process. This thesis outlines the prescriptive implications of these lessons for franchise practitioners and details opportunities for future research

    Motion patterns of subviral particles: Digital tracking, image data processing and analysis

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    At the Institute of Virology, Philipps-University, Marburg, Germany, currently research on the understanding of the transport mechanisms of Ebola- and Marburgvirus nucleocapsids is carried out. This research demands a profound knowledge about the various motion characteristics of the nucleocapids. The analysis of large amounts of samples by conventional manual evaluation is a laborious task and does not always lead to reproducible and comparable results. In a cooperation between the Institute of Virology, Marburg, and the Institute for Biomedical Engineering, University of Applied Sciences, Giessen, Germany, algorithms are developed and programmed that enable an automatic tracking of subviral particles in fluorescence microscopic image sequences. The algorithms form an interface between the biologic and the algorithmic domain. Furthermore, methods to automatically parameterize and classify subviral particle motions are created. Geometric and mathematical approaches, like curvature-, fractal dimension- and mean squared displacement-determination are applied. Statistical methods are used to compare the measured subviral particle motion parameters between different biological samples. In this thesis, the biological, mathematical and algorithmic basics are described and the state of the art methods of other research groups are presented and compared. The algorithms to track, parameterize, classify and statistically analyze subviral particle tracks are presented in the Methods section. All methods are evaluated with simulated data and/or compared to data validated by a virologist. The methods are applied to a set of real fluorescence microscopic image sequences of Marburgvirus infected live-cells. The Results chapter shows that subviral particle motion can be successfully analyzed using the presented tracking and analysis methods. Furthermore, differences between the subviral particle motions in the analyzed groups could be detected. However, further optimization with manually evaluated data can improve the results. The methods developed in this project enhance the knowledge about nucleocapsid transport and may be valuable for the development of effective antiviral agents to cure Ebola- and Marburgvirus diseases. The thesis concludes with a chapter Discussion and Conclusions
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