VictorJuiz/thesis huggingface dataset:
'Borders...Are No Longer at the Border': High-skilled Labour Migration, Discourses of Skill and Contemporary Canadian Nationalism
Keywords: discourse analysis
high skilled labour migration
knowledge economy
national membership
settler nationalism
skill deficit

This dissertation explores the constitutive relationship between immigration and nationalism as manifest in the high skilled labour market of post-liberalization (post 1960s) Canada. I show that as skilled immigration became crucial for Canadian national prosperity, a simultaneous rise in discourses of skill deficit rendered actively recruited immigrants as deficient worker subjects. Unfolding in the decades following liberalization, persistent discourses of deficit - refracted through a systemic privileging of Canadian/Western skills and training (understood as both tangible credentials and intangible soft/cultural skills) - constructed the figure of the immigrant as a prototypically skill-deficient subject struggling to integrate into the Canadian labour market, and by extension, to the larger Canadian society. Scholarship on labour market integration has frequently seen the issue as an example of policy level and administrative disjuncture. In contrast, I argue that skilled immigrants’ marginalization in the labour market of the very nation that recruited them as vital for national prosperity creates a gap between immigrants’ juridical and substantive membership. It is systematic and socio-politically productive. I conduct a critical discourse analysis of post-liberalization skilled immigration policies and related texts (government commissioned reports, press releases, ministerial speeches, and policy backgrounders) and show how the nation state continues to be an exclusive space where immigrants’ welcome is contingent and conditional on their ability to approximate an amorphous and contested Canadianness. I argue that it is through the mobilization of deficit discourses that the post-liberalization state negotiated its increasing reliance on immigrant labour with the historically racially conceptualized criteria for national membership. In the post- liberalization global hierarchy of nation states, the dynamics of welcome (as labour) and expulsion (from membership) allowed Canada to open up the national space to the raceless meritocracy of the best and the brightest, while continuing to re-align it along racial lines. This dissertation makes three key interventions: 1) it repositions the high skilled labour market – typically considered unfettered by practices of racialized nationalism - as a key site for its exercise in post-liberalization era, 2) it argues that training/learning discourses in this context are better seen as nationalist discourses subsumed within the discriminatory notion of Canadian experience, and finally, 3) it proposes a dialogue between scholarships on Canadian nationalism and immigrants’ labour market integration as the conceptual disconnect between these is analytically costly for our understanding of post-liberalization Canadian nationalism.
The Modern Moon: Studies of recent lunar chronology and links to future sample-return missions
Keywords: cratering
moon
regolith formation
remote sensing

The Moon acts as a time capsule for events in our region of the Solar System. The combination of returned lunar samples, lunar meteorites, orbital and lander data have allowed a fundamental understanding of the formation and history of the Moon and the inner Solar System. With the lack of returned samples from other planetary bodies, the lunar bombardment rate is used as the basis of modeled crater production functions for other planetary bodies. Thus, having a more constrained lunar chronology is critical in providing more precise surface ages, as well as anchoring the bombardment rate in our region of the Solar System. The first chapter of my thesis focuses on refining the recent lunar chronology by using the rockiness of craters’ ejecta as a proxy for their age. Using this method, I have dated all craters with diameters 10 km, younger than roughly one billion years. This new dataset suggests that the lunar bombardment rate has increased by a factor of ~2.6 in the past ~290 million years. In comparing the lunar craters with terrestrial ones, it is evident that both impact rates follow the same trend. Thus, the dearth of large terrestrial craters between ~290-650 Myr is most likely an implication of an implied lower past impact flux, rather than preservation bias. Additionally, I use high-resolution images from the Lunar Reconnaissance Orbiter to compare rock populations resulting from impact craters of similar sizes and ages across different terrains and compare their evolution over time. As craters age, they become less rocky and my results show that rocks of all sizes in their ejecta diminish in number at the same rate, regardless of their location on the Moon. These results further imply that regolith thickness variations do not strongly affect impact production of rocks for craters 10 km in diameter. Lastly, through a study for exploration of the lunar south polar region, this thesis provides information for future sample collection locations on the Moon in order to obtain a more precise lunar chronology, which could then be extended to other planetary bodies in the Solar System.
Enhancement of peripheral nerve regeneration with controlled local release of Tacrolimus (FK506)
Keywords: Biomaterial
FK506
Drug delivery
Nerve injury
Nerve regeneration
Rat model
Regenerative medicine

Despite substantial improvements in microsurgical techniques, patients with peripheral nerve injuries rarely recover fully. FK506, an FDA approved immunosuppressant, improves functional recovery and reinnervation following peripheral nerve injury in animal models. However, systemically delivered FK506 causes undesirable global immunosuppression. We have therefore engineered a biodegradable local delivery system for FK506 using fibrin gel as a drug reservoir that can be placed at a site of nerve injury. We used our FK506 delivery system to enhance nerve regeneration in clinically applicable models of nerve injuries. We further investigated the mechanism of action by which local FK506 promoted peripheral nerve regeneration. In the first aim of this study, the drug delivery system was engineered to provide sustained and controlled release of bioactive FK506. Moreover, the optimal local FK506 dose delivered to the peripheral nerve tissue was investigated in a three-dimensional organotypic system. In the second aim, we demonstrated the efficacy of local FK506 release from the delivery system on enhancing axon regeneration and functional recovery in clinically applicable models of nerve injury in rats. We documented the biodistribution of FK506 within the nervous system in vivo following the drug release from the delivery system implanted at the site of nerve repair. In the third aim, the neuroregenerative mechanism of action for the local FK506 administration was investigated both in vitro and in vivo. The analysis of FK506 binding proteins (FKBP)s’ localization within the peripheral nerve in vivo suggested Schwann cells containing FKBP52 at the site of nerve injury and repair can be a cellular target for the locally applied FK506. FKBP52 was further confirmed to be a molecular target for the FK506 mediated neuroregeneration effect in vitro. In the studies presented in this thesis, we demonstrated the local application of FK506 using our engineered drug delivery system resulted in superior axon regeneration while preventing the toxicity of systemic FK506 that has prevented clinicians from using FK506 routinely for treating peripheral nerve injuries. The findings in this study provide compelling evidence that the tested FK506 delivery system can provide a new and effective clinical solution for treatment of peripheral nerve injury.
A Novel Antibody Detection Technique Using the Agglutination of Surface Displaying Yeasts
Keywords: agglutination
antibody
Chagas
dengue
diagnostic
yeast

Blood screening for disease in the developing world remains an enormous challenge despite significant advances in modern biotechnology. Simple, affordable, and easily deployed tools for antibody detection in blood and other fluids are still desperately needed. A simple yeast-based agglutination assay that requires no electricity, no sophisticated equipment, and minimal training is described here, using established methods for displaying stable fusion proteins on the surface of S cerevisiae. Strains displaying peptides with known binding regions for generic human immunoglobulin G antibodies, and for specific human antibodies against T. cruzi (the causative agent for Chagas’ disease) and dengue virus were created and grown. The cells displaying disease epitopes were mixed with the samples positive for the disease antibodies, and have been shown to capture the specific antibodies to their surfaces. After washing, the coated cells were mixed with cells displaying the Z domain derived from S. aureus, which binds to the Fc region of the captured antibodies, linking the cell types together. The links formed between the cell types cause the cells to agglutinate, resulting in positive and negative signals that are easily distinguishable to the naked eye. Factors affecting the agglutination, including ionic strength, cell mass, the geometry of the well, and proper growth conditions were studied to produce a working protocol for the assay. The key strengths of the assay: simplicity, stability, modularity, low cost, low technical requirement, and broad familiarity with similar tests, give it promising potential to be a new alternative to current industry methods.
Chaucer's French Sources — Literary and Codicological Play and the Author's Persona
Keywords: Authorship
Chaucer
Fourteenth-century French poetry
Manuscripts
Narrative persona

This dissertation studies the ways that Chaucer and his French contemporaries, Guillaume de Machaut, Jean Froissart, Oton de Graunson, and Eustache Deschamps, craft poetic authority. They do so in relation to the books that convey their writing and literary reputations to their audiences. Chaucer, translating the work of these French poets, reacts to the constructions of authority he finds in medieval sources, in manuscripts, and in a scribal culture in which the transmission of texts can be unpredictable. I argue that Chaucer adapts Machaut's pseudo-autobiographical narrative voice in his own poetry. He responds to a contrast evident in manuscript culture between the single-author codex — for example, surviving books of Froissart's poetry, Paris, BNF f.fr. 830 and 831 — and the ubiquitous miscellany, a contrast that seems to operate along gendered and poetic as well as codicological lines. Chaucer adapts the poetic form of Graunson's "Cinq Ballades" to ensure that his "Complaint of Venus" circulates as a single piece, unlike some copies of his source text. Finally, I argue that Deschamps invites Chaucer to participate in a cross-Channel exchange of invective, one that is part of a bookish and literary tradition. The main argument of my dissertation is that Chaucer puts ideas about books into play in his poetry. He imagines manuscripts as forms for literature and as forms for authority, like the way the disordered aesthetic of the Canterbury Tales creates — ironically — a work of literature resembling a single-author manuscript: a collection of works by one author that circulates intact. Chaucer's investigation of bookish forms is playful, but it also has high poetic stakes: for Chaucer, as for his French contemporaries, play locates the poet in an authoritative literary tradition and secures his future renown.
Identification and characterization of a pathological TDP-43 variant in amyotrophic lateral sclerosis and frontotemporal lobar degeneration
Keywords: Amyotrophic lateral sclerosis
Frontotemporal dementia
Frontotemporal lobar degeneration
Mitochondria-associated ER membrane
Neurodegeneration
Transgenic mouse model

TAR DNA-binding protein 43 (TDP-43) proteinopathy is a key pathological feature of a majority of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) cases. One key feature of pathological TDP-43 is the presence of lower molecular weight (MW) C-terminal species of 25 and 35 kDa, the origins of which were unclear. In investigating the mechanism(s) which generate such species, we identified an abnormal TDP-43 splice variant, TDP-43 r.[106_196del], that was upregulated in ALS. TDP-43 r.[106_196del] contains a 91 base pair splicing deletion in exon 2, leading to translation from a downstream methionine and the production of a N-terminally truncated protein of 35 kDa. This protein isoform, herein referred to as TDP-35, resembles the pathological 35 kDa C-terminal species seen in disease. Expression of TDP-35 in cultured cells and primary motor neurons showed that TDP-35 has reduced solubility, cytoplasmic distribution, increased tendency to form aggregates, and the capacity to induce motor neuron death. Generation of a neo-epitope TDP-35 antibody immunolabeled the pathological 35 kDa TDP-43 species in ALS and FTLD tissues as well as pathological inclusions in ALS spinal cords, providing evidence that the 35 kDa TDP-43 species in ALS and FTLD can be generated by aberrant alternative splicing leading to the use of a downstream start codon, Met85. Expressing TDP-35 in transgenic mice led to the development of regionally selective neuropathology that included downregulation of endogenous mouse TDP-43, age-dependent neurodegeneration, and associated neuroinflammation. Furthermore, TDP-35 transgenic mice developed age-dependent non-spatial memory deficits and were impaired in emotional processing, but retained an intact spatial memory, all of which closely resemble the selective cognitive deficits observed in clinical frontotemporal dementia (FTD). To elucidate the underlying disease mechanism, our interactome study that identified TDP-35-interacting proteins pinpointed the mitochondria-associated ER membrane (MAM) as an affected cellular pathway in TDP-35-mediated pathogenicity. More specifically, TDP-35, but not endogenous TDP-43, redistributes to the MAM and this was associated with an increased mitochondrial-ER association and abnormal morphologies of the ER and mitochondria. In summary, the work encompassed by this thesis has uncovered a novel and exciting cellular mechanism underlying TDP-43-mediated pathogenesis in ALS and FTLD.
Improving the Thermal Performance and Durability of Historic Masonry Buildings
Keywords: durability
energy efficiency
historic buildings
masonry

Historic buildings are less energy efficient than modern structures due to the nature of their construction. Although envelope improvements can reduce operating energy, such retrofits can potentially accelerate the deterioration of the historic facade. Consequently, the challenge is to improve the energy performance while maintaining a durable facade. This research proposes a retrofit approach for historic buildings that addresses both energy consumption and durability of the masonry facade. To improve energy performance, an 1879 historic solid masonry home was retrofitted using an innovative Nested Thermal Envelope Design (NTED). An envelope controlling heat, moisture and air movement was constructed around Core and Perimeter zones that were independently operated. Conditioning the entire house provided 36% space heating energy savings below the Ontario Building Code 2012, while turning off the heat to the Perimeter areas increased savings to 68%. To address durability concerns arising from insulating the masonry walls, the use of a vented airspace installed between the masonry and the thermal insulation was explored. The vented airspace at the first field trial increased the drying potential of the historic masonry during the winter when the brick was most vulnerable to freeze-thaw damage. An estimated 1.1 kg/m2/a was removed at South and East walls. The second field trial showed drying between 4.3 kg/m2/a and 5.7 kg/m2/a at the South and 0.08 kg/m2/a wetting at the North. In situ moisture content levels of the brick varied between 10% - 15% while laboratory testing of similar brick revealed a saturated moisture content of 29%. Both field trials showed that the vented airspace drying potential was influenced by facade orientation and solar radiation levels. An alternative way of constructing the airspace was then tested in the laboratory to explore the use of air permeable insulation in lieu of a clear airspace. Walls constructed with rock wool insulation and vent holes, but with no clear airspace, removed between 52% - 90% of moisture, depending on the insulation density and vent hole area. Walls featuring a clear airspace removed between 59% - 95% of moisture. These laboratory tests showed that enough air was able to move through the air permeable insulation thereby improving the drying potential of the walls.
Novel Single Cell Methods to Identify the Genetic Composition at a Single Nuclear Structure
Keywords: microscopy
nanodissection
optical dissection
single cell
single molecule pcr

Reported here are two novel techniques that allow for the identification of DNA obtained from a nanoscale region of a single cell nucleus based on either direct DNA dissection with high-precision nano-tools operated inside a scanning electron microscope, or the ligation of oligo probes to subnuclear sites of double stranded breaks induced by 2-photon irradiation. It is demonstrated that these techniques afford the ability to identify loci occupying a shared site at a single nuclear substructure, and are thus uniquely suited for identifying specific sets of loci that converge non-randomly at a shared nuclear body (NB; the "gene hub" model of nuclear organization). The techniques are applied towards determining DNA in the vicinity of single PML nuclear bodies and yield novel loci that show significant frequency of association with PML bodies in a population of cells. As the "gene hub" model may be a general feature of nuclear organization, these techniques, applied to other NBs, may reveal specific sets of convergent loci that reflect novel gene co-regulatory relationships.
The Cloning and Characterization of MADD-4, A Novel Guidance Cue in C. elegans
Keywords: ADAMTSL
C. elegans
DCC
EVA-1
MADD-4
Netrin

Directed cell migration is fundamental to the development of all multicellular organisms including humans. To investigate the molecular underpinnings of directed cell migration, our lab primarily exploits plasma membrane extensions called muscle arms, from the body wall muscles in the tiny nematode Caenorhabditis elegans. Through genetic screens for genes required for muscle arm extension, we found that the UNC-40/DCC netrin guidance receptor directs muscle arm extension to the midlines. Surprisingly, neither the UNC-6/netrin cue (the canonical ligand for UNC-40) nor other well-characterized guidance cues such as the slits, ephrins and semaphorins were found to be the primary cue for muscle arm extension. This suggested that muscle arms were likely responding to a novel guidance cue. In this thesis, I describe the cloning and characterization of MADD-4, a novel secreted cue that diffuses and attracts muscle arms and sensory axons along the dorsoventral axis in C. elegans. MADD-4 is a member of the non-enzymatic ADAMTSL family of proteins and is well conserved among animals. Very little is known about the biological role of any of MADD-4's orthologs. Together with Kevin Chan, I found that MADD-4's guidance function is dependent on an EVA-1-UNC-40 co-receptor complex. We found that MADD-4 interacts with both EVA-1 and UNC-40. Similarly, we found that EVA-1 and UNC-40 likely physically interact and this interaction is critical for the MADD-4 response. Furthermore, we found that the binding of EVA-1 to UNC-40 increases UNC-40's sensitivity to MADD-4. This enhanced sensitivity becomes especially meaningful within a field of other ligands capable of binding UNC-40 like UNC-6. In the absence of UNC-6, UNC-40's responsiveness to MADD-4 becomes less dependent on EVA-1. Hence, by regulating UNC-40's sensitivity to MADD-4, EVA-1 may increase the precision by which UNC-40-directed processes can reach MADD-4-expressing target cells. Collectively, the work discussed in this thesis recounts the first description of a novel guidance cue and its mechanism of action. Furthermore, since the biological role of any ADAMTSL family member outside of MADD-4 is largely unknown, it is very likely that my work on MADD-4 will broaden our understanding of the biological role of the ADAMTSL family of proteins.
Formulation Design for Surfactant-coated Iron Nanoparticle Suspensions
Keywords: formulation
interaction
nanoparticles
surfactant
suspension

This work describes the design of surfactant formulations used to coat iron oxide nanoparticles and nanoparticles of zero-valent iron (NZVI) with the purpose of imparting colloidal stability and target delivery properties while maintaining the reactivity of NZVI. Iron oxide nanoparticles, although useful as an adsorbent for arsenic and other contaminants, were also used as a non-reactive homologue for the oxide shell structure of partially oxidized NZVI. NZVI can act as reducing agents to transform contaminants such as dense non-aqueous phase liquid (DNAPL) into hydrocarbons and chlorides. Desirable NZVI properties for DNAPL remediation include colloidal stability, mobility in porous media, preferential affinity for contaminant zones (target delivery characteristics), and sustained reactivity with the chlorinated contaminants (for NZVI).
Nonlinear Intermittent Field Dynamics in the Early Universe
Keywords: Bubble Collisions
Cosmology
Inflation
Phase Transitions
Preheating
Topological Defects

We explore nonequilibrium dynamics of inhomogeneous nonlinearly interacting scalar fields in several cosmological settings. In particular, we explore the effects of (initially small) asymmetric fluctuations around field configurations with a high degree of spatial symmetry. These symmetric configurations include planar domain wall and SO(2,1) vacuum bubble collisions, and oscillations of a homogeneous scalar field condensate after inflation. In the last of these, it is well known that linear fluctuations may experience a variety of dynamical instabilities --- a process known as preheating. By extending methods from the Floquet theory of ODEs to PDEs, we demonstrate that linear fluctuations around the planar wall and vacuum bubble collisions also experience exponential growth. This effect has been ignored in the existing literature. We use sophisticated numerical lattice techniques to study the full (3+1)-dimensional dynamics of the collisions. Once the fluctuations begin to interact nonlinearly, the original spacetime symmetries of the collision are badly broken. In each model we study, this symmetry breaking occurs through an inhomogeneous annihilation of the walls. As a result of this annihilation, a collection of oscillons is produced in the collision region. In our study of preheating, we focus on entropy generation as the field transitions from a homogeneous, coherent state to an inhomogeneous, incoherent state. We introduce a coarse-graining procedure based on maximizing the (differential) Shannon entropy subject to a collection of observational constraints. Using lattice simulations, we find a sharp spike in the entropy production rate around the onset of strong nonlinearities amongst the fluctuations. Based on an analogy with a hydrodynamic shock as randomization front, we dub this sudden increase in entropy as the ``shock-in-time''. In each of the systems considered, the new dynamics we discover suggest potential observational signatures. Perhaps the most interesting new signatures are the production of gravitational waves from individual vacuum bubble collisions and the production of nonGaussian density perturbations during preheating. A novel aspect of these signatures is that they are spatially (or temporally) intermittent. Although this thesis focusses on the underlying dynamics responsible for these signatures, it suggests interesting future work developing the necessary methods to observationally constrain them.