VictorJuiz/thesis huggingface dataset:
Bonded-particle Modeling of Thermally Induced Damage in Rock
Keywords: coupled modeling
thermo-mechanical simulation
bonded-particle modeling
damage
brittle rock

The objective of the research presented in this thesis is to validate the parallel-bonded modeling method in the context of coupled thermo-mechanical simulations. The simulation results were compared with analytical and experimental data, in the attempt to assess the usability of this particular modeling method. Previous studies of numerical approaches that related to the thermal fracturing of hard rock had used continuum-based models with constitutive relations. The simulations in the thesis were conducted using Particle Flow Code (PFC) which was chosen for the research because of its several benefits. The code has unique features such as spontaneous damage development without imposed conditions, and emergent properties such as material heterogeneity, and dynamic behavior giving possibility to monitor synthetic seismic events. The basic code has been available since 1995 and research using the code has produced hundreds of publications. The thermal option for the code is a recent addition and lacked verification, validation and applications. The thesis is the answer for that. In the course of the research work new particle clustering and grouping routines were developed and tested. Three modeling studies were conducted varying from laboratory to field scales. The 2D modeling study of the heated cylinder experiment yielded similar results both in fracture-behavioral and acoustic emission (AE) magnitude ranges when compared with the laboratory data. The 3D cubic numerical specimens, created with breakable particle clusters, were heated, and the induced damage was observed by P wave velocity measurements. The results showed trends comparable to the laboratory data: P wave velocity decreases with rising temperatures of up to 250°C and cluster-boundary cracking occurs, comparable to grain-boundary cracking in the heated rock samples. The large 2D tunnel models captured the phenomena observed in-situ displaying the difference in the damage to the roof and floor regions, respectively. This damage was due to the filling material confinement of about 100 kPa on the tunnel floor. In general, the results of the thermo-mechanical simulations were in accordance with the experimental data. The modeled temperature evolutions during the heating and cooling periods were also in accordance with the experimental and analytical data.
Science, Egypt, and Escapism in Lucan
Keywords: Lucan
Science
Egypt
Escapism
Seneca
Naturales Quaestiones
Pompey
Caesar
Cato
Manilius
Astronomy
Ethnography
Utopia
Nile

This dissertation seeks to demonstrate Lucan's profound engagement and conflict with two ancient intellectual and literary traditions that can both be regarded as escapist, that is, as promising or postulating a sanctuary (whether physical or spiritual) from the world's troubles, and that were both active in Lucan's own day: utopian writing about science, exemplified in Latin by Lucan's uncle Seneca the Younger, as well as by the astronomical poet Manilius, and utopian Egyptology, as reflected in a wide variety of texts ranging from Herodotus, through Diodorus Siculus, to Lucan's contemporary, the Alexandrian polymath Chaeremon. To this end, I have examined two closely related sequences in the De Bello Civili that have received little attention from scholars of Lucan, namely Pompey's journey to Egypt in Book Eight and Caesar's Egyptian sojourn in Book Ten, during which Lucan's two main characters are each shown attempting to take refuge from the poem's ubiquitous violence through the double avenue of travel to Egypt (to which the defeated Pompey flees, and where his pursuer Caesar hopes to leave the civil war behind) and the practice of natural science (with Pompey's astronomical inquiry and Caesar's investigation of the Nile). In this context, I have also considered Cato's Libyan adventures, from the intervening Book Nine. Both Pompey and Caesar discover that escape through either method is impossible, for the fabled Egyptian Shangri-La is now embroiled in the political, social, and economic crisis of the outside world, while not only the natural universe but even the very act of inquiry into nature are alike contaminated by the ethos of civil war. The virtuous Cato, on the other hand, does not even make the attempt, maintaining a single-minded focus on his civic duties. By revealing such escape to be both immoral (through Cato's example) and impossible (through the examples of Pompey and Caesar), Lucan signals his decisive rejection of the escapist predilections of many of his contemporaries (including his uncle Seneca and his own father Annaeus Mela), who tried to distance themselves from the vicissitudes of political life under the later Julio-Claudians through retirement into a state of philosophical otium.
Progressive Enlightenment: The Origins of the Gaslight Industry 1780–1820
Keywords: gaslight
Industrial Revolution
Boulton and Watt
William Murdock
Philippe Lebon
Frederick Winsor
Gas Light and Coke Company
technological networks
pneumatic chemistry

Gaslight, an Industrial Revolution technology, developed in the period 1780–1820. The foundations for the technology are partly found in the pneumatic chemistry of the eighteenth century, both in terms of the knowledge of gases and their properties, and the instruments used to manipulate them, such as the gasometer, making gaslight one of the earliest instances of a technology heavily based on science. Although many people experimented with lighting with gases in the late eighteenth century, the move to a commercial technology began with Philippe Lebon and William Murdock who had a clear commercial purpose in mind. The technology in its early phases was found everywhere in Europe, but it was at Boulton & Watt in Birmingham that it was ﬁrst successfully applied. As Boulton & Watt developed the technology they identiﬁed many and solved some of the problems associated with scaling up the technology. They were not, however, very interested in gaslight and only sporadically gave attention to it, before effectively abandoning it around 1812. They nevertheless had an important role to play in its development not only because if their technical work, but also because they demonstrated the technology’s viability to the broad public, and by giving people experience in gas engineering. The technology's ﬁnal form as a network utility was partly as a result of a battle fought between Boulton & Watt and Frederick Winsor's Gas Light and Coke Company in London during 1807–1810. Boutlon & Watt did not want a large limited-liability corporation as a competitor, and the contest in Parliament between the two groups resulted in a negotiated compromise where the Gas Light and Coke Company gave up all rights to manufacture apparatus, and focused exclusively on gas provision, effectively making it a utility. The years from 1812–1820 saw the technology mature into a large network which included not only technical development, such as the pressure balancing with valves and regulators, but also political and social elements, such as the control of user expectations through education and usage enforcement through inspectors. By 1820, the technology was sufﬁciently developed to be transferred to the Continent.
Auditory Sensitivity and Defence Strategy in Insects
Keywords: General Biology

Predation pressure is a powerful agent of natural selection and is responsible for the evolution of various antipredator defence strategies in animals. Sensory thresholds for predator detection could play an important role in the evolution of defence strategies. I tested the hypothesis that the ability of animals to detect predators is correlated with defence strategy, with the prediction that animals with poor predator detection abilities rely more on preventative (primary) defence strategies than animals with low predator detection thresholds. Bats and their insect prey were used as a simple study system for these experiments due to the reliance on a single modality (hearing) for both predator and prey detection. Many insects have ears tuned to the ultrasonic echolocation calls of bats and can use this predator cue to initiate evasive action, but variation in auditory thresholds exists among species. In moths, a group in which the only known function of hearing is predator detection, a clear relationship was found between auditory thresholds for predatory ultrasound and a risky behaviour, nocturnal flight time. A more complicated situation exists when the sensory system serves more than one purpose, as with the ears of orthopteran insects used for both predator detection and mate localization. Some gleaning bats use calling song as a cue to locate these insects as prey, and both primary (reduced calling) and secondary (song cessation in response to ultrasound) defences have been identified in orthopterans. The auditory interneurons considered the “bat-detectors” in katydids and crickets most likely have context dependent functions in several groups, as a predator-detector in flight and mate-detector on the ground. The relationship between reliance on primary over secondary defence and auditory sensitivity in these insects appears to be influenced by the nature of the calling song of the species and their mating strategy.
The Role of Interleukin-6 Signalling Molecules in Murine Models of Photoreceptor Degeneration
Keywords: Genetics
Neuroscience

We previously reported that in inherited photoreceptor degenerations (IPDs), the mutant photoreceptors (PRs) are at a constant risk of death (Pacione, Szego et al, 2003). Using microarrays to identify genes that may mediate the constant risk, I identified 145 differentially expressed transcripts in the Rds+/- mouse model of IPD at a time when 90% of the PRs were alive. A major finding was the up-regulation, quantified by qPCR, of four components of a putative IL-6 cytokine signaling pathway: Oncostatin M (Osm) (2-fold increased), Oncostatin M receptor (Osmr)(2.6-fold increased), Stat-3 (2.3-fold increased), C/EBP delta(3.2-fold increased). Similarly, I found increases in the cognate proteins Osmr (3-fold), Stat-3 (2.6-fold), and the phosphorylated, transcriptionally active form of Stat-3, pStat-3 (5.8-fold)(all p<0.01). Other Il-6 cytokine signaling molecules were largely unchanged, but the mRNA of leukemia inhibitory factor (Lif), was increased (3.0-fold). Comparable increases of most transcripts were also present in the Rd1-/- and mutant rhodopsin P347S transgenic (P347S) IPD models. The increases in cytokine signaling molecules occurred predominantly in Müller glia, although C/EBP delta transcript was increased in PRs. Because exogenous IL-6 cytokine treatment slows PR death in IPDs, I asked whether the endogenous increases in IL-6 pathway proteins in IPD retinas were a survival response, and generated IPD models with Osmr, Lif or C/EBP delta loss-of-function (LOF) mutations. Osmr LOF decreased PR survival in the retinas of Rds+/-;Osmr-/- mice, which had 12.5% fewer PRs than those of Rds+/-;Osmr+/+ mice (n=9, p<0.05) at 4 month of age, and Tg-RHO(P347S);Osmr-/- mice had 13.5% fewer PRs (n=6, p<0.01) at 31 days of age. Unexpectedly, Osmr LOF had no effect on pStat3 levels in Rds+/-;Osmr-/- retinas, indicating that retinal Stat3 activation may be predominantly regulated by other molecules. In contrast to the Osmr LOF, Lif or C/EBP delta LOF unexpectedly increased mutant PR survival. Rd1-/-;Lif -/- mice at 13 days had 14% more PRs than Rd1-/-;Lif+/+ mice (n=6, p<0.003) and a 1.7 fold decrease in pStat-3 (n=4, p<.05). Similarly, 8 month-old Rds+/-; C/EBP delta-/- mice had 18% more PRs than Rds+/-; C/EBP delta+/+ mice (n=5, p<0.005). These findings suggest that in mutant PRs: 1) up-regulation of the Osmr receptor is protective; 2) the presence of Lif or C/EBP delta is pathogenic, and therefore 3) Osmr, Lif and C/EBP delta act either in different pathways or different cells, to account for the differing effects of their LOF on PR cell death; and 4) the partial effects of Osmr, Lif and C/EBP delta LOF indicate that other genes also mediate the constant risk of death of mutant PRs in IPDs.
The Creative Advantage of Diverse City-regions: Local Context and Social Networks
Keywords: Economic Geography
Creativity
City-Regions
Canada

Local diversity is often credited with being a driver of creative economic activity. Comparative research on this topic is often however highly structural in nature and does little to address questions of agency. This work seeks to link the traditional regional science approach to questions of potential advantages of local diversity with a more bottom-up view of the creative process. From a theoretical perspective this involves incorporating the social psychology literature on the creative process as well as concepts from social network analysis with more aggregated spatial notions of creativity and diversity. More specifically, it addresses how different knowledge is connected through social interaction and how this fuels the creation of new ideas and ultimately creative economic activity. A number of empirical innovations are made in order to test these theoretical constructs beginning with an agent-model/simulation which illuminates how social networks form and evolve over space and time. These artificial networks suggest how agents embedded in diverse local contexts have a creative advantage by possessing greater access to a variety of knowledge. Subsequent statistical analysis of large secondary datasets seeks to provide external validity to the agent-model. The first demonstrates a strong relationship between local diversity and the concentration of creative economic activities across 140 Canadian city-regions. A key implication of this finding is that local diversity is more closely associated with certain types of economic activity, rather than overall economic performance. The second statistical analysis uses the Canadian General Social Survey to compare the social network characteristics of individuals. This analysis shows that people engaged in creative industries and occupations tend to have larger, more dynamic, and more diverse sets of social relations than any other category of worker. The dissertation concludes with a model that suggests policy interventions should focus on developing local environments that provide the necessary conditions in which creative activity can thrive, rather than attempting to intervene directly in the creative process itself.
Characterization of the Role of Neuralized in Delta Endocytosis and Notch Signalling
Keywords: Notch
Neuralized
phosphoinositides
ubiquitin ligase
Drosophila
signalling
NHR domains
CG3894

Development requires the acquisition of different cell fates. A major conserved pathway required for cell fate determination is the Notch signalling pathway. Neuralized is a key regulator of the Notch pathway and is essential for embryonic development in Drosophila melanogaster. I have been studying the role of Neuralized during Drosophila development, focusing on the regulation of this protein. Neuralized is an E3 ubiquitin ligase that targets Notch ligands for ubiquitination and endocytosis in the signal sending cell. This endocytic event is required for signal transduction, and cells lacking Neuralized fail to signal through Notch. I have identified a conserved interaction between Neuralized and phosphoinositides that is essential for the ability of Neuralized to promote ligand endocytosis and Notch signalling. Interactions between Neuralized and phosphoinositides are not required for ligand ubiquitination, identifying a role for Neuralized in downstream aspects of ligand trafficking. I have also determined that Neuralized is dynamically regulated through a combination of tissue specific expression, subcellular trafficking, protein interactions and posttranslational modification. Neuralized contains two related protein domains of unknown function called Neuralized homology repeats (NHR). To gain insight into the function of the NHR domain, I characterized another NHR containing protein, CG3894. CG3894 is required for development and preliminary data indicate that NHR domains dimerize, suggesting a possible interaction between Neuralized and CG3894. The study of Neuralized in Drosophila has contributed to our understanding of this essential protein both at a developmental and cellular level, and has provided a means through which to ask questions about regulation of Notch signalling in a relatively simple context. Given the importance of Notch signalling to development, and contributions that aberrations in signalling make to cancer and diseases of the nervous system, expanding our understanding of the regulation of Notch signalling is essential to understanding how this important pathway functions.
Characterization of the Role of Foxh1 in TGFbeta-Mediated Transcription and Development
Keywords: Molecular Biology

The Transforming Growth Factor beta (TGFb) superfamily of ligands are highly versatile, functioning throughout development and in adult organisms as diverse as worms and humans to regulate a myriad of biological activities. TGFb family members signal through their cognate serine/threonine kinase receptors to mediate the phosphorylation and activation of receptor-regulated Smads (R-Smads), that then complex with the common Smad (co-Smad/Smad4) to transduce TGFb signals from the membrane into the nucleus. This thesis recounts the first identification of a mammalian Smad-interacting transcription factor, Foxh1. Investigation of the Smad/Foxh1 DNA-binding complex, which mediates TGFb-dependent regulation of transcription from a Gsc enhancer, determined that both Smad and Foxh1 binding sites are required. These studies also defined the first known biological difference between the highly related R-Smads, Smad2 and Smad3. Specifically, it was shown that while both can similarly participate in Smad/Foxh1 DNA-binding complexes, Smad2 activates and Smad3 represses Foxh1-mediated TGFb-dependent transcription. A detailed analysis of the Gsc enhancer element subsequently defined the sequence req irements for a functional Smad/Foxh1 enhancer (SFE). This information was utilized to direct in silico, genome wide searches for genes harbouring evolutionarily conserved SFEs, which successfully expanded the repertoire of Smad/Foxh1 targets. Analysis of these targets revealed novel roles for Smad/Foxh1 signalling in forebrain development and retinoic acid production. Finally, the importance of Foxh1 to heart development was examined. The interaction between Foxh1 and the heart specific factor Nkx2-5 was characterized with respect to TGFb-dependent regulation of Mef2c expression via a compound Foxh/Nkx2-5 enhancer (FNE). Genome-wide searches for similar FNEs identified many potential Foxh1/Nkx2-5 targets, further analysis of which will provide greater insights into how Foxh1 functions in heart development. In summary, the work presented herein expands our understanding of the role of TGFb in development through the identification and characterization of Foxh1 and its genomic targets downstream of TGFb signalling.
Autonomic Contributions in Compensatory Balance Control
Keywords: standing posture
autonomic nervous system

This thesis examined Autonomic Nervous System activity evoked by postural instability. Autonomic reactions were assessed using measures of electrodermal activity at the surface of the skin. Perturbation-evoked electrodermal responses (EDRs) were consistently observed in conjunction with both upper and lower limb postural reactions. These autonomic responses were sensitive to perturbation amplitude, as well as experimental manipulations which did not influence the perturbation itself but which affected response execution. In particular, stimulus predictability and movement challenge modulated EDRs, although purely cognitive manipulations did not significantly affect autonomic responses. Probes examining the potential role of such autonomic potentials in compensatory balance control revealed that EDRs evoked during compensatory postural reactions were larger and more consistent than potentials evoked by purely motor or sensory stimuli, suggesting that evoked autonomic activity plays a role in compensatory behavior. While the specific role of autonomic contributions in compensatory balance control require further study, speculative models for autonomic contributions propose either feedback-based pathways for detection of instability to initiate the postural reaction, and/ or an adaptive role to higher centers important for establishing sensorimotor gain in future conditions. This thesis presents new evidence regarding basic neural mechanisms engaged in the recognition and response to postural instability, and future work may extend these findings in clinical populations with high fall incidence and offer clues as to alternative causes for falls and fall prevention.
Global Village, Global Marketplace, Global War on Terror: Metaphorical Reinscription and Global Internet Governance
Keywords: Globalization
Metaphors
Global Governance
International Relations
Internet
Internet Engineering Task Force
Internet Corporation for Assigned Names and Numbers
Internet Service Providers
Global Village
Global Marketplace
Global War on Terror
neoliberalism
cyberterrorism
anti-terrorism
surveillance
censorship
domain names
Rorty
Foucault

My thesis examines how metaphors of globalization shape the global governance of the Internet. I consider how, in a short span of time, discussions of the Internet’s globalizing potential have gone from the optimism of the global village to the penchant of the global marketplace to the anxiety of the global war on terror. Building upon Rorty’s theory of metaphors and Foucault’s notion of productive power, I investigate how the shifts in these prevailing metaphors have produced and legitimated different frameworks of global governance. In considering how these patterns of governance have been shaped in the context of a familiar example of globalization, I demonstrate that globalization has an important discursive dimension that works as a constitutive force – not only in Internet governance, but in global governance more generally. By illuminating globalization’s discursive dimensions, this thesis makes an original theoretical contribution to the study of globalization and global governance. It demonstrates that globalization is more than a set of empirical flows: equally important, globalization exists as a set of discourses that reconstitute political legitimacy in more ‘global’ terms. This recasts the conventional understanding of global governance: rather than a response to the challenges posed by the empirical transcendence of territorial borders or the visible proliferation of non-state actors, the aims, institutions and policies of global governance are shaped and enabled by discourses of globalization, and evolve as these discourses change. In short, this thesis provides further insight into globalization’s transformations of state-based political order. It links these transformations to the discursive processes by which systems of global governance are produced and legitimated as sites of power and authority.